struvite and Urinary-Calculi

The prevalence of urolithiasis is steadily increasing worldwide in both genders. Diet and lifestyle, such as the rising prevalence of obesity and other metabolic syndrome traits, are considered key factors in this trend. Gender differences as a result of interventional therapy for urolithiasis have not been observed. However, iatrogenic injury to the male urethra is considered the most common reason for urethral strictures after endourologic (stone) therapy. In contrast, sepsis, as the major cause of urinary stone-related mortality, is more frequently reported in women after ureterorenoscopy and percutaneous nephrolithotomy. There are also differences in the frequency of various types of stones between men and women. Calcium oxalate and uric acid stones are more commonly observed in men, while carbonate apatite and struvite are diagnosed more often in women. Urinary stone analysis is therefore paramount for successful recurrence prevention. Diagnosis is based on the assignment of patients to the low-risk or high-risk group. The medical nutrition and pharmacological measures for the therapy of the respective type of stone are based on the risk factors in 24 h urine samples. A personalized approach that accounts for gender differences could further improve treatment, and recurrence prevention decisions for urinary stones.. Die Prävalenz der Urolithiasis nimmt weltweit bei beiden Geschlechtern stetig zu. Ernährung und Lebensstil, wie die zunehmende Prävalenz der Adipositas und weitere Komponenten des metabolischen Syndroms, gelten als Schlüsselfaktoren für diese Entwicklung. Geschlechtsspezifische Unterschiede als Ergebnis der interventionellen Therapie der Urolithiasis wurden bisher nicht beobachtet. Iatrogene Verletzungen der männlichen Harnröhre gelten jedoch als häufigster Grund für Harnröhrenstrikturen nach endourologischer (Stein)therapie. Dagegen wird eine Sepsis, als Hauptursache der harnsteinbedingten Mortalität, nach Ureterorenoskopie und perkutaner Nephrolithotomie häufiger bei Frauen konstatiert. Zudem bestehen Unterschiede in der Häufigkeit verschiedener Steinarten zwischen Männern und Frauen. Kalziumoxalat- und Harnsäuresteine werden häufiger bei Männern beobachtet, während Karbonatapatit und Struvit bevorzugt bei Frauen diagnostiziert werden. Die Harnsteinanalyse ist daher die wichtigste Voraussetzung für eine erfolgreiche Rezidivprävention. Die Diagnostik richtet sich nach der Zuordnung der Patienten zur Niedrig- oder Hochrisikogruppe. Die ernährungsmedizinischen und pharmakologischen Maßnahmen zur Therapie der jeweiligen Steinart orientieren sich dabei an den Risikofaktoren im 24-h-Harn. Ein personalisierter Ansatz, der geschlechtsspezifische Unterschiede berücksichtigt, könnte Therapie und Entscheidungen zur Rezidivprävention von Harnsteinen weiter verbessern.

Topics: Calcium Oxalate; Female; Humans; Male; Struvite; Uric Acid; Urinary Calculi; Urolithiasis

Struvite is one of the most common urinary/kidney stones, composed of magnesium ammonium phosphate (MgNHPO. This review summarizes various reports on the factors responsible for inducing struvite stones in the kidney and gives a detailed account of studies on inhibition of growth of struvite crystals.. The presence of urea-splitting bacteria such as Proteus mirabilis and alkaline pH plays a crucial role in struvite formation. In vitro inhibition of struvite stones by various chemical agents were examined mainly in artificial urine whereas inhibition by herbal extracts was studied in vitro by gel diffusion technique. Herbal extracts of curcumin, Boerhaavia diffusa Linn, Rotula aquatica and many other plants, as well as some chemicals like pyrophosphate, acetohydroxamic acid, disodium EDTA and trisodium citrate, were reported to successfully inhibit struvite formation.. The present review recapitulates various factors affecting the growth of struvite urinary stones and the inhibitory role of certain chemicals and herbal extracts. Most of the tested plants are edible hence can be easily consumed without any adverse effects whereas the side effects of chemicals are unknown due to lack of toxicity studies. Thus, the use of herbal extracts might serve as an alternate and safe therapy for prevention of struvite stones.

Topics: Animals; Crystallization; Humans; Kidney; Plant Preparations; Struvite; Urinary Calculi; Urinary Tract Infections; Urolithiasis

Infectious urinary stones make a serious medical problem concerning up to 20% of population. Additionally, recurrence after treatment reaches 50%. The formation of infectious urinary stones is connected with urinary tract infection with various bacteria. These are mainly the bacteria from Proteus species which have been isolated in 70% of bacteriainduced urinary stone cases. These microorganisms produce urease - a bacterial enzyme which plays a principal role in the crystallization process and is one of the main virulence parameters of these bacteria. The most common solid components of infectious urinary stones are the crystals of struvite and amorphous carbonate apatite. The formation of this kind of stones involves two main processes. The first one is the nucleation process of solid phases and the second is the aggregation of the precipitated phases, both crystalline and amorphous. In recent years, both these processes have been deeply investigated. In particular, different active compounds have been reported as potentially novel therapeutic agents to prevent or inhibit the formation of infectious urinary stones. In addition, there is rich scientific evidence regarding the chemical mechanisms of inhibitory effect of these active compounds. In recent years, specific interior and exterior structure of struvite and its porous nature have also been reported. In this article, we summarize and discuss recent development in this field of research. The paper concludes with future goals and challenges.

Topics: Animals; Apatites; Bacterial Infections; Humans; Struvite; Urinary Calculi

The incidence of urolithiasis has increased in both the developed and the developing countries during the past decades. Economically, the increase of urolithiasis contributes to the rise of the healthcare burden everywhere. Moreover, this increase has been associated with a change in the epidemiology of urolithiasis in terms of age and sex distribution, and also the location and type of calculi.. We searched the MEDLINE for relevant literature dating back to 1980. This review compared the trends in epidemiological factors affecting urolithiasis in the developed and the developing countries during the past decades.. People in the developing countries are more likely to contract kidney calculi at a younger age than in the developed countries. Although calculus disease is still more prevalent in men than in women, the latter are increasingly affected in both worlds. Uric acid calculi are more prevalent in the developing than in industrialized countries. There is a progressive increase in the frequency of calcium oxalate and calcium phosphate calculi in the developing countries where these used to be less frequent.. The incidence and prevalence of urinary calculi is increasing globally. Many factors including aging of the population, changes in diet, global warming, and employment of more accurate diagnostic tools seem to be involved in this increase. An increasing affluence and adaptation of Western diet habits in many developing countries seem likely to contribute to the changes.

Topics: Age Distribution; Calcium Oxalate; Calcium Phosphates; Developed Countries; Developing Countries; Diet; Female; Global Warming; Humans; Incidence; Male; Risk Factors; Sex Distribution; Struvite; Uric Acid; Urinary Calculi

Urinary composition is the result of the interplay of all metabolic processes, including all metabolites and toxins produced. Any change in urine composition influences urinary supersaturation, the major thermodynamic driving force of crystal formation. Urolithiasis is a wide-spread disease with a prevalence rate of 4% to 10%. Formation risk of calcium-oxalate, by far the most common mineral in uroliths, is quantified by the Bonn-Risk-Index (BRI). The BRI measures induced crystal growth within native urine and shows superior diagnostic sensitivity and specificity compared to other urolithiasis risk indices. The concept of BRI quick test presented in this work allowes even untrained persons to easily determine the urolithiasis risk. Many diseases lack a simple, easily accessible and cost effective diagnostic approach to monitor their course and treatment success. Since BRI takes into account every constituent of native urine, it can be used to monitor a wide range of metabolic diseases.

Topics: Adult; Calcium Oxalate; Cross-Sectional Studies; Crystallization; Female; Humans; Magnesium Compounds; Microscopy, Electron, Scanning; Phosphates; Predictive Value of Tests; Recurrence; Risk Assessment; Risk Factors; Struvite; Urinalysis; Urinary Calculi

The classic "infection stone" struvite is formed as a result of metabolic activity of urease-positive bacteria from alkaline urine with pH-values above 7.5. Due to improved infection diagnostics and antibiotic therapy, the occurrence of infection-related urinary stones in the western industrialized world decreases, despite the generally increasing prevalence rates of urolithiasis in these societies. Struvite is often associated with other mineral phases. These accessory mineral phases could indicate other, non-infection-related causes of urinary stone formation. Thus, mineral analysis is always recommended. Struvite stones as well as struvite encrustations on urinary tract implants are characterized by rapid growth. The rapid growth-related embedding of urease-positive bacteria in the crystalline material makes the urinary stone a persistent source of recurrent urinary tract infections. According to the German Society of Urology guidelines on urolithiasis, a patient with the diagnosis "infection stone" should be assigned to the "high-risk" patient group. Complete stone and debris removal, as well as a special metaphylaxis strategy are required to initiate successful stone therapy.

Topics: Acid-Base Equilibrium; Bacterial Infections; Drug Resistance, Microbial; Humans; Magnesium Compounds; Phosphates; Recurrence; Risk Factors; Struvite; Urease; Urinary Calculi; Urinary Tract Infections

This article discusses the composition, formation, and treatment of canine compound uroliths and the importance of recognizing the unique causal factors that may be present in each individual patient. After first giving a detailed analysis of what compound uroliths are and how they form, the authors give examples and data from canine uroliths submitted between 1981 and 2007. Finally, the article discusses the importance of this data when formulating management strategies for individual patients to either dissolve existing stones or minimize urolith recurrence.

Topics: Animals; Breeding; Calcium Oxalate; Dog Diseases; Dogs; Female; Magnesium Compounds; Male; Phosphates; Secondary Prevention; Struvite; Uric Acid; Urinary Calculi

Urolithiasis is a general term referring to the causes and effects of stones anywhere in the urinary tract. Urolithiasis should not be viewed conceptually as a single disease with a single cause, but rather as a sequela of multiple interacting underlying abnormalities. Thus, the syndrome of urolithiasis may be defined as the occurrence of familial, congenital, or acquired pathophysiologic factors that, in combination, progressively increase the risk of precipitation of excretory metabolites in urine to form stones (ie, uroliths). The following epidemiologic discussion is based on quantitative analysis of 350,803 canine uroliths, 94,778 feline uroliths, and 6310 feline urethral plugs submitted to the Minnesota Urolith Center from 1981 to 2007.

Topics: Animal Feed; Animal Nutritional Physiological Phenomena; Animals; Breeding; Calcium Oxalate; Cat Diseases; Cats; Dog Diseases; Dogs; Female; Magnesium Compounds; Male; Minnesota; Phosphates; Risk Factors; Struvite; Urinary Calculi; Urolithiasis

Urolithiasis is a relevant clinical problem in everyday practice with a subsequent burden for the health system. Urolithiasis is classically explained as the derangement in the process of biomineralization involving the equilibrium between promoters and inhibitors of crystallization: a deficit of one or several inhibitors or an excess of one or several promoters plays a pivotal role in the stone formation. The revolutionary introduction of the molecular biology in medicine has given a new insight in urolithiasis too. Genetic factors have also been postulated to play an important role. A review of the current knowledge on urolithiasis based upon a molecular and genetic approach is reported.

Topics: Animals; Apoptosis; Biological Transport, Active; Calcium; Crystallization; Cysteine; Humans; Magnesium Compounds; Phosphates; Struvite; Uric Acid; Urinary Calculi

Childhood urolithiasis remains endemic in certain parts of the world, namely, Turkey and the Far East. The prevalence of nephrolithiasis in North American children varies widely among geographic regions and accounts for 1 per 1000 to 1 per 7600 pediatric hospital admissions. Stones occur in children of all ages. The clinical manifestations of stone disease are often more subtle in children when compared with the dramatic adult presentation. This article discusses the evaluation and medical management of pediatric stone disease.

Topics: Calcium; Child; Cystinuria; Humans; Hyperoxaluria, Primary; Magnesium Compounds; Phosphates; Struvite; Uric Acid; Urinary Bladder Calculi; Urinary Calculi

Topics: Calcium; Child; Child, Preschool; Cystine; Female; Hematuria; Humans; Kidney Calculi; Magnesium Compounds; Male; Metabolic Diseases; Oxalates; Phosphates; Struvite; Uric Acid; Urinalysis; Urinary Calculi; Urinary Tract Infections

Irrigant chemolysis was developed to collaborate with open surgery, removing the residual fragments. With the worldwide diffusion of the procedures performed by the endourologist in the early 1980s and the present availability of ESWL, however, direct irrigation of stones has a reduced field of influence even as an adjunctive measure. Urologists have applied economic analysis to their clinical practices, and the findings related to irrigant chemolysis made this technique an unusual procedure. The cost to the providers of medical care, the burden on the patient in terms of suffering and loss of productivity, and the amount of time required to liberate the patient even partially from the stones make irrigant chemolysis an inauspicious scenario. In this era of cost containment and decreasing length of stay, it is increasingly difficult to justify hospital admissions for this form of therapy. Being simultaneously more expensive and less effective than the existing alternatives, local chemolysis should be discarded, except for special situations, such as patients at high risk for any surgical procedure. Oral chemolysis preserves reduced indications, for example as an adjuvant to an endourologic operation or ESWL in special situations. As long as urinary stones continue to afflict humans, chemolysis is likely to retain a limited but important role in their management.

Topics: Calcium Oxalate; Cystine; Humans; Magnesium Compounds; Phosphates; Struvite; Therapeutic Irrigation; Uric Acid; Urinary Calculi

Topics: Apatites; Calcium Compounds; Calcium Oxalate; Calcium Phosphates; History, 18th Century; History, 19th Century; History, 20th Century; Humans; Magnesium Compounds; Minerals; Names; Phosphates; Struvite; Urinary Calculi

Of the hundreds of minerals that are found in the earth, most canine uroliths are comprised of only six types: (1) magnesium ammonium phosphate, (2) calcium oxalate, (3) calcium phosphates, (4) ammonium urate and other salts or uric acid, (5) cystine, or (6) silica. Each type has characteristics that allow its identification. During the past two decades, the prevalence of calcium oxalate canine uroliths has dramatically increased, while struvite has decreased. The most effective treatment and prevention protocols are based on knowledge of the primary mineral type comprising the urolith.

Topics: Age Distribution; Animals; Calcium Oxalate; Calcium Phosphates; Cystine; Dog Diseases; Dogs; Magnesium Compounds; Phosphates; Prevalence; Silicon Dioxide; Struvite; Uric Acid; Urinary Calculi

Two types of canine struvite uroliths have been recognized: infection-induced struvite is the most common type; sterile struvite is uncommonly recognized. Infection-induced struvite is most commonly associated with urease-producing staphylococcal UTI. For dogs that qualify, medical dissolution is an effective method of treatment. Medical dissolution protocols encompass: (1) eradication or control of UTI; (2) use of calculolytic diets; and (3) administration of urease inhibitors to patients with persistent UTI caused by urease-producing microbes.

Topics: Animals; Dog Diseases; Dogs; Magnesium Compounds; Phosphates; Struvite; Urinary Calculi

Struvite calculi have afflicted man for thousands of years. Despite recent advances in surgical technology to treat these disabling stones, high recurrence rates and inability to remove all stone fragments remain significant problems. Previous non-surgical alternatives have been disappointing because of low success rates, increased side effects or poor tolerability. New research in this area continues to provide insight into origins of lithogenesis and non-invasive therapy for calculi caused by infection.

Topics: Bacteria; Humans; Hydrogen-Ion Concentration; Magnesium Compounds; Phosphates; Struvite; Urease; Urinary Calculi

The most important phosphates involved in urinary stone disease are carbonate apatite, brushite, and struvite. Overall, phosphate stones account for 12-20% of all stones, with a downward trend for struvite and an increase in carbonate apatite being observed in the last decade. The physicochemical basis for the formation of phosphate calculi is supersaturation. Once the solubility product has been exceeded, a metastable process of supersaturation begins, with slow crystalline growth. If a critical limit of supersaturation is exceeded, large-scale spontaneous precipitation of crystals occurs in a second stage. No urinary tract infection is involved in brushite stone formation. Although infection is not a prerequisite for the formation of carbonate apatite stones, infective conditions favor carbonate apatite formation. Struvite is the characteristic infection calculus, formed as a result of urinary tract infection with urease-producing bacteria. During the first episode of urinary stone disease a definitive diagnosis of the type of stone involved is very difficult without analysis of the latter by infrared spectroscopy or X-ray diffraction. In recurrent disease, appropriate treatment can be initiated on the basis of the previous stone analysis in the majority of cases. The best means of preventing recurrent disease involving any type of phosphate stone is definitive calculus removal by shock-wave lithotripsy, percutaneous stone removal, or open surgery (especially in children). Chemolysis via acidification of the urine with Suby G solution or hemicidrin supported by oral acidification, achieved by the metabolism of L-methionine, and antibiotic therapy (especially for infectious stones) are important adjuvant modalities of therapy. After therapy of phosphate stones, metaphylaxis involving controlled urinary acidification with L-methionine supports the treatment of infection and, at a pH value of less than 6.2 and urine dilution to 2.5 l/24 h, prevents the crystallization of struvite, brushite, and carbonate apatite.

Topics: Acids; Apatites; Calcium Phosphates; Crystallization; Humans; Magnesium Compounds; Phosphates; Struvite; Urinary Calculi

The cause of urinary stone disease can now be detected in approximately 80% of patients. Effective treatment can substantially reduce the recurrence of urinary calculi. Proper therapy depends on a thorough understanding of the physiology of calcium, oxalate, uric acid, cystine, and struvite formation and the medication developed for prevention. This article reviews the physiologic basis of urinary stone management in a straightforward, understandable fashion.

Topics: Acetazolamide; Calcium; Carbonic Anhydrase Inhibitors; Citrates; Cystinuria; Humans; Hyperoxaluria; Magnesium Compounds; Phosphates; Struvite; Urease; Uric Acid; Urinary Calculi

A variety of different types of uroliths occur in cats, of which calcium oxalate and magnesium ammonium phosphate are the most common. Treatment and prevention are most likely to be successful if associated risk factors are identified and eliminated or controlled.

Topics: Animals; Calcium Oxalate; Calcium Phosphates; Cat Diseases; Cats; Cystine; Magnesium Compounds; Phosphates; Risk Factors; Struvite; Uric Acid; Urinary Calculi

Feline urethral plugs commonly are composed of large quantities of matrix mixed with minerals (especially struvite). However, some urethral plugs are composed primarily of matrix, some consist of sloughed tissue, blood, and/or inflammatory reactants, and a few are composed primarily of aggregates of crystalline minerals. The formation of matrix-crystalline urethral plugs may be analogous to the preparation of fruit jello.

Topics: Animals; Calcium Oxalate; Calcium Phosphates; Cat Diseases; Cats; Magnesium Compounds; Male; Minerals; Phosphates; Purines; Struvite; Urethral Obstruction; Urinary Calculi

Companion animal diets may be related to prevention, pathogenesis and/or treatment of diseases of the lower urinary tract. For example, urolithiasis can be either diet induced or nutrient sensitive. One of the most interesting developments in veterinary urolithiasis research has been the recent change in the composition of stones recovered from cats. In 1984, 88% of stones analyzed by quantitative methods were > 70% struvite, whereas < 1% were calcium oxalate. In 1992, the percentage of struvite had dropped to 62, whereas the percentage of calcium oxalate had increased to 24. Another recent development in lower urinary tract disease of cats is the recognition that urolithiasis appears to be a minor cause of the signs of frequency, urgency and hematuria for which patients are presented. This suggests that diet may no longer be involved, or be involved in previously unrecognized ways, in many current cases of this disease. Some of these feline patients may have a disease similar to interstitial cystitis, a disease of humans that appears to be of neuroepithelial origin. Our laboratory has been studying this possibility recently, and many similarities between the two diseases have been found.

Topics: Animal Feed; Animals; Calcium Oxalate; Cat Diseases; Cats; Cystitis; Female; Humans; Magnesium Compounds; Male; Phosphates; Struvite; Urinary Calculi; Urologic Diseases

Glycosaminoglycans (GAGs) are suspended in urine and are present on tissue surfaces in the urinary tract. Consequently, they have the potential to influence any pathological disorder in this environment, including urinary tract infections by Proteus mirabilis and struvite (NH4MgPO4.6H2(0)) urolithiasis. Although GAGs, suspended in urine, may inhibit the formation of other types of calculus minerals, no such effect has been reported in struvite calculi. Nevertheless, GAGs are a major component of the organic matrix of all types of urinary calculi. In contrast, there is evidence that the GAG layer on the bladder surface may act as a defence mechanism against infection by inhibiting bacterial adhesion. More studies are needed to elucidate fully the role of GAGs in urinary infections and struvite urolithiasis.

Topics: Glycosaminoglycans; Humans; Magnesium Compounds; Phosphates; Proteus Infections; Proteus mirabilis; Struvite; Urinary Calculi; Urinary Tract Infections

Topics: Female; Humans; Magnesium; Magnesium Compounds; Male; Phosphates; Struvite; Urinary Calculi

The relatively simple scheme described here should become part of the urologist's stone evaluation plan. It allows for the rapid identification of the metabolic disorders and the prompt implementation of appropriate therapy. With a stone remission rate of 70 to 90 per cent and a reduction in the stone formation rate of 88 to 100 per cent, an overwhelming incentive exists to master this evaluation scheme.

Topics: Calcium; Cystine; Humans; Magnesium; Magnesium Compounds; Metabolic Diseases; Phosphates; Struvite; Uric Acid; Urinary Calculi

Urine must be oversaturated with magnesium ammonium phosphate for struvite uroliths to form. Oversaturation of urine with magnesium ammonium phosphate may be associated with several factors, including urinary tract infections with urease-producing microbes, alkaline urine, diet, and genetic predisposition. Of the urease-producing microbes, staphylococci are most struvitogenic in dogs. The precise mechanisms resulting in formation of sterile struvite uroliths in dogs have not been determined.

Topics: Animals; Dog Diseases; Dogs; Magnesium; Magnesium Compounds; Phosphates; Struvite; Urinary Calculi

Topics: Enterobacteriaceae; Enterobacteriaceae Infections; Humans; Magnesium; Magnesium Compounds; Phosphates; Struvite; Urease; Urinary Calculi; Urinary Tract Infections

A previous study of urinary stones by a combined electron microscopy demonstrated the potential of scanning electron microscopy and X-ray analysis as an analytic tool for urinary stones. Electron diffraction was chosen for the final confirmation of crystals in the study. Although electron diffraction is highly accurate for this purpose, it is desirable to establish the sensitivity of X-ray analysis for the identification of stone components relative to the more commonly used methods. Eighty six consecutive urinary stones were analyzed by X-ray analysis and the findings were compared with those of X-ray diffraction, infrared spectrometry and chemical analysis. The results indicate that X-ray analysis exceeds X-ray diffraction and infrared spectroscopy in its sensitivity for the identification of stone components several fold. This was largely due to the inability of the latter methods to detect apatite in more than half of the apatite containing stones. The findings in X-ray analysis had the best correlation with chemical analysis, which was applied mainly to the detection of apatite. X-ray analysis is particularly suited for the detection of rare and minor inorganic components of urinary stones such as silica and gypsum, and is obviously one of the most powerful tools for the analysis of urinary stones. Further application of X-ray analysis to urinary stone is likely to discern rare inorganic components of urinary stones overlooked by other methods.

Topics: Calcium Oxalate; Calcium Phosphates; Calcium Sulfate; Cystine; Electron Probe Microanalysis; Humans; Magnesium; Magnesium Compounds; Microscopy, Electron, Scanning; Phosphates; Silicon Dioxide; Spectrum Analysis; Struvite; Uric Acid; Urinary Calculi; X-Ray Diffraction

Topics: Calcinosis; Calcium; Cystine; Humans; Magnesium; Magnesium Compounds; Phosphates; Radiography; Struvite; Uric Acid; Urinary Calculi

Urinary stone disease is a common affliction in our society and may affect 1 to 5 per cent of the population. The physician involved in caring for the stone-forming patient must have a thorough understanding of the metabolic as well as anatomic abnormalities that may lead to repeat stone formation. The authors review the common metabolic abnormalities frequently seen in the stone-forming patient and present the current medical management of these problems. Ongoing changes in the surgical approach to urinary stones are also discussed.

Topics: Calcium; Crystallization; Cystine; Cystinuria; Humans; Kidney Calculi; Magnesium; Magnesium Compounds; Phosphates; Physical Examination; Struvite; Tomography, X-Ray Computed; Ultrasonography; Uric Acid; Urinary Calculi; Urinary Tract Infections; Urine; Urography

Topics: Animals; Cat Diseases; Cats; Dog Diseases; Dogs; Humans; Magnesium; Magnesium Compounds; Phosphates; Radiography; Struvite; Ureaplasma; Urinary Calculi; Urinary Tract Infections

A diet providing less than 20 mg of magnesium per 100 kcal that maintains urine pH near 6.0 3 to 5 hours after eating, or a diet providing this amount fo magnesium (see Table 2) with 1 gm of ammonium chloride or 1.5 gm of dl-methionine added daily, should be fed for 1 to 3 months to dissolve struvite uroliths (see Fig. 1). The low-magnesium diet should be fed indefinitely to prevent recurrence, because struvite urolithiasis and all of its effects (hematuria, pollakiuria, and/or complete to partial obstruction to urinary excretion) recurs repeatedly in cats that have previously experienced the condition if they are returned to regular cat food. In contrast, if a diet low in magnesium is fed, recurrence is uncommon. For cats that have never been affected, feeding a low-magnesium ration is unnecessary. For all cats, the following measures are recommended: encourage exercise, allow frequent urination, prevent obesity, decrease confinement, keep the litter box clean, and always have palatable water readily available.

Topics: Animal Feed; Animals; Cat Diseases; Cats; Magnesium; Magnesium Compounds; Methionine; Phosphates; Sodium Chloride; Struvite; Urinary Calculi

This case is typical of recurrent urolithiasis managed by repeated surgery. Retrospective assessment of the disorder indicates the need for quantitative analyses of uroliths removed by cystotomy. Compliance of the owners with recommendations to minimize recurrent urolithiasis might have been beneficial. Results of medical therapy designed to induce dissolution of uroliths in this case are representative of preliminary findings of medical dissolution of naturally occurring struvite uroliths in ten other cats. It is of interest that the uroliths dissolved even though no effort was made to induce diuresis. The underlying cause of UTI in this patient may have been damage to the lower urinary tract induced by previous diagnostic and therapeutic procedures and/or sterile struvite uroliths that compromised local host defense mechanisms. Lack of urease production by the uropathogens suggests that they did not play a causative role in formation of uroliths. The need for preventative therapy of recurrent formation of uroliths after their medical dissolution is worthy of further comment. In this patient, specific measures to prevent urolith recurrence were not initiated because it is a part of a prospective clinical study. In the event uroliths recur, medical therapy designed to induce dissolution of uroliths would be repeated. Need for long-term preventative therapy would be dependent on the time interval between recurrent episodes (weeks, months, or years), and the effectiveness of medical therapy for urolith dissolution. Long-term prophylactic therapy would include urine acidifiers and diets low in magnesium.

Topics: Ammonium Chloride; Animals; Anti-Infective Agents; Anti-Inflammatory Agents; Cat Diseases; Cats; Diverticulum; Female; Magnesium; Magnesium Compounds; Male; Methionine; Parasympatholytics; Phosphates; Struvite; Urachus; Urinary Calculi; Urinary Tract Infections

Prednisolone (10 mg PO q24h) or placebo was administered to healthy cats for 2 weeks in a masked, placebo-controlled, crossover-design study, and 24-hour urine samples were collected. When cats received prednisolone, 24-hour urine pH was lower and 24-hour urine excretion of creatinine, magnesium, phosphate, and potassium was higher than when cats received placebo. No significant difference was found in urinary relative supersaturation for calcium oxalate (CaOx) or struvite between treatment groups. Prednisolone administration did not induce diuresis, nor was it associated with increased calcium excretion or urinary saturation for CaOx in these healthy cats. Results of this study, however, should not be extrapolated to cats that form CaOx uroliths associated with idiopathic hypercalcemia.

Topics: Administration, Oral; Animals; Anti-Inflammatory Agents; Calcium Oxalate; Cat Diseases; Cats; Cross-Over Studies; Female; Magnesium Compounds; Phosphates; Prednisolone; Struvite; Treatment Outcome; Urinalysis; Urinary Calculi

Hydrochlorothiazide (1 mg/kg PO q12h) or placebo was administered to healthy cats for 2 weeks in a masked, placebo-controlled, crossover-design study, and 24-hour urine samples were collected. When cats received hydrochlorothiazide, 24-hour urine volume, ammonia, chloride, creatinine, magnesium, oxalic acid, phosphate, potassium, and sodium were significantly higher than when cats received placebo. Hydrochlorothiazide was associated with significantly lower urinary saturation for calcium oxalate, but no difference was found in 24-hour urine calcium and citrate, urinary saturation for struvite, or blood ionized calcium. Hydrochlorothiazide decreased urinary saturation for calcium oxalate and could be useful in managing cats with calcium oxalate uroliths. Results of this study, however, should not be extrapolated to cats that form calcium oxalate uroliths.

Topics: Administration, Oral; Animals; Calcium Oxalate; Cat Diseases; Cats; Cross-Over Studies; Female; Hydrochlorothiazide; Magnesium Compounds; Phosphates; Sodium Chloride Symporter Inhibitors; Struvite; Treatment Outcome; Urinalysis; Urinary Calculi

To evaluate the effects of a high-protein diet versus dietary supplementation with ammonium chloride (NH4Cl) on struvite crystal formation in the urine of clinically normal cats by measuring the urine concentration of hydrochloric acid (HCl)-insoluble sediment, urine pH, struvite activity product (SAP), number of struvite crystals in urine, and urine volume.. 23 healthy adult cats.. Urine was fractionated by centrifugation with subsequent extraction of the sediment with 1 N HCl (study 1). Diets containing either 29% crude protein or 55% crude protein were fed to cats in a crossover trial of 3 weeks/period (study 2). Diets supplemented with either sodium chloride (NaCl) or NH4Cl were fed, by use of a 3 x 3 Latin-square design with 3 wk/period (study 3). In studies 2 and 3, urine samples were collected for the last 7 days of each period.. The HCl-insoluble sediment contained Tamm-Horsfall glycoprotein (THP; study 1). The high-protein diet (study 2) and dietary supplementation with NH4Cl (study 3) resulted in a decrease in urine pH, SAP, and the number of struvite crystals in urine. However, the high-protein diet decreased urine concentrations of HCl-insoluble sediment containing THP (study 2), in contrast to the NH4Cl supplementation that increased urine volume without a significant effect on the urine concentration of the HCl-insoluble sediment (study 3).. Our results indicate that compared with dietary supplementation with NH4Cl, the high-protein diet is preferable as a urine acidifier for the prevention of struvite crystal formation in clinically normal cats.

Topics: Ammonium Chloride; Animal Feed; Animals; Cat Diseases; Cats; Cross-Over Studies; Dietary Proteins; Dietary Supplements; Female; Hydrogen-Ion Concentration; Magnesium Compounds; Male; Phosphates; Struvite; Urinary Calculi

In a prospective, double-blind, placebo-controlled study, the efficacy and safety of acetohydroxamic acid (AHA) in preventing urinary calculogenesis was evaluated in 94 patients with chronic urinary infection. Stone growth occurred in 17% of the AHA group and in 46% of the placebo group (p less than 0.005). Completely reversible side effects consisting predominantly of psychoneurologic and musculo-integumentary symptoms were more prevalent in the AHA group (p less than 0.01). Side effects which were judged 'intolerable' were experienced by 10 (22.2%) of patients in the AHA group and 2 (4.1%) in the placebo group. It is concluded that AHA treatment is effective, relatively safe, and clinically useful in preventing infection-induced urinary calculogenesis.

Topics: Adult; Aged; Bacteriuria; Chronic Disease; Double-Blind Method; Female; Humans; Hydroxamic Acids; Magnesium; Magnesium Compounds; Male; Middle Aged; Palliative Care; Phosphates; Placebos; Prospective Studies; Struvite; Urinary Calculi

 The aim of the study is to explore the relationship between clinical characteristics and urinary calculus in Xinjiang Uyghur children, and to provide clinical basis for the prevention as well as treatment of urinary stone..  In total, 236 urinary tract stone samples were collected from pediatric patients from February 2017 to April 2019, and those samples were analyzed by infrared spectroscopy. Stone compositions were compared with demographic data..  Among the 236 cases, 166 cases were boys (70.34%) and 70 cases were girls (29.66%), with a male-to-female ratio of 2.37:1. A total of 21 kinds of calculi were detected, including 107 cases with six kinds of simple calculi and 129 cases with 15 kinds of mixed calculi. In this study, magnesium ammonium phosphate hexahydrate was only found in boys, and the difference was statistically significant (6.6 vs. 0.0%,.  Uyghur pediatric patients with urolithiasis were young and the majority of stones was mixed, The main components of calculi were ammonium hydrogen urate, calcium oxalate and apatite carbonate, and there are differences in the localization of calculi between genders.

Topics: Ammonium Compounds; Apatites; Calcium Oxalate; Carbonates; Child; Female; Humans; Male; Struvite; Uric Acid; Urinary Calculi; Urolithiasis

Urinary stones comprise both single and mixed compositions. Knowledge of the stone composition helps the urologists choose appropriate medical interventions for patients. The parameters from the spectral computerized tomography (CT) analysis have potential values for identification of the urinary stone compositions.. The present study aims to identify the compositions of urinary stones in vivo using parameters from spectral CT and machine learning, based on multi-label classification modeling.. This retrospective study collected 252 urinary stone samples with single/mixed compositions (including carbapatite [CP], calcium oxalate monohydrate [COM], calcium oxalate dehydrate [COD], uric acid [UA], and struvite [STR]), which were confirmed by ex vivo infrared spectroscopy. Parameters were extracted from an energy spectrum analysis (ESA) of the spectral CT, including the effective atomic number (Z. The multi-label classification fusion framework achieved an overall. The parameters extracted from the ESA on spectral CT can be utilized to characterize single or mixed stone compositions via multi-label classification modeling. The generalization capability of the proposed methodology still requires further verification.

Topics: Calcium Oxalate; Humans; Machine Learning; Retrospective Studies; Struvite; Tomography, X-Ray Computed; Uric Acid; Urinary Calculi

As part of the management of nephrolithiasis, determination of chemical composition of stones is important. Our objective in this study is to assess urologists' accuracy in making visual, intraoperative determinations of stone composition.. We conducted a REDCap survey asking urologists to predict stone composition based on intraoperative images of 10 different pure-composition kidney stones of 7 different types: calcium oxalate monohydrate (COM), calcium oxalate dihydrate (COD), calcium phosphate (CP) apatite, CP brushite, uric acid (UA), struvite (ST) and cystine (CY). To evaluate experience, we examined specific endourologic training, years of experience, and number of ureteroscopy (URS) cases/week. A self-assessment of ability to identify stone composition was also required.. With a response rate of 26% (366 completed surveys out of 1,370 deliveries), the overall accuracy of our cohort was 44%. COM, ST, and COD obtained the most successful identification rates (65.9%, 55.7%, and 52.0%, respectively). The most frequent misidentified stones were CP apatite (10.7%) and CY (14.2%). Predictors of increased overall accuracy included self-perceived ability to determine composition and number of ureteroscopies per week, while years of experience did not show a positive correlation.. Although endoscopic stone recognition can be an important tool for surgeons, it is not reliable enough to be utilized as a single method for stone identification, suggesting that urologists need to refine their ability to successfully recognize specific stone compositions intraoperatively.

Topics: Apatites; Calcium Oxalate; Cystine; Humans; Kidney Calculi; Struvite; Urinary Calculi; Urologists

In this paper, we present the results of research on the physicochemical properties of two selected faces of the struvite crystal, which is the main component of infectious urinary stones. Two main faces, (001) and ([Formula: see text]), ending the c-axis, were selected for the study. These faces are not related by symmetry relations, which means, among other things, that they should have a different atomic structure, which was confirmed experimentally. In addition, the studies show that the tested surfaces have hydrophilic properties, however, the ([Formula: see text]) face is more hydrophilic compared to the (001) face. The physicochemical properties of the crystal as a whole, as well as the physicochemical properties of these faces influence the magnitude of adhesion. The adhesive force in both water and artificial urine is greater for face ([Formula: see text]) compared to face (001). The assessment of the adhesion of Proteus mirabilis bacteria in artificial urine also shows that the adhesion is greater for face ([Formula: see text]) than for face (001). The adhesion of bacteria to the examined faces of the struvite crystal, and in particular the increased adhesion of bacteria to the face ([Formula: see text]), may be the first stage of biofilm formation, which may result in a high rate of recurrence of infectious urinary stones after treatment.

Topics: Bacterial Adhesion; Humans; Struvite; Urinary Calculi; Urolithiasis

To determine the efficacy and safety of a urinary acidifier (d,l-methionine [Methio-Form]) and an antimicrobial agent (amoxicillin-clavulanic acid [Clavamox]) without changing diet for dissolving infection-induced struvite urocystoliths in dogs.. 14 dogs were recruited for this prospective study; 11 completed it and 3 dogs withdrew due to inability of the owners to administer the treatment (n = 2) or refusal of treatment by the dog (1).. All dogs were administered d,l-methionine (approx initial dose of 75 mg/kg, PO, q 12 h) and amoxicillin-clavulanic acid (22 mg/kg, PO, q 12 h) based on urine culture and sensitivity. Urine pH, urinalysis, urine culture, venous blood gas and serum biochemical analysis, and lateral survey abdominal radiographic images were evaluated initially and every 4 weeks until urolith dissolution (success) or lack of change in size and/or shape of urocystoliths on 2 consecutive reevaluation points (failure) occurred.. Uroliths dissolved in 8 of 11 dogs in a median of 2 months (range, 1 to 4 months) with a final effective dosage of d,l-methionine of approximately 100 mg/kg, PO, every 12 hours. In 3 dogs, uroliths failed to dissolve and were removed surgically; they contained variable amounts of calcium oxalate. No adverse events occurred.. Infection-induced struvite urolithiasis is 1 of the 2 most common minerals occurring in canine uroliths. Results of this study supported the use of d,l-methionine and amoxicillin-clavulanic acid without changing diet for dissolution of infection-induced struvite urocystoliths in dogs.

Topics: Amoxicillin-Potassium Clavulanate Combination; Animals; Dog Diseases; Dogs; Magnesium Compounds; Methionine; Phosphates; Pilot Projects; Prospective Studies; Struvite; Urinary Calculi; Urolithiasis

The prevalence and disease burden of urolithiasis has increased substantially worldwide in the last decade, and intraluminal holmium laser lithotripsy has become the primary treatment method. However, inappropriate laser energy settings increase the risk of perioperative complications, largely due to the lack of intraoperative information on the stone composition, which determines the stone melting point. To address this issue, we developed a fiber-based fluorescence spectrometry method that detects and classifies the autofluorescence spectral fingerprints of urinary stones into three categories: calcium oxalate, uric acid, and struvite. By applying the support vector machine (SVM), the prediction accuracy achieved 90.28 % and 96.70% for classifying calcium stones versus non-calcium stones and uric acid versus struvite, respectively. High accuracy and specificity were achieved for a wide range of working distances and angles between the fiber tip and stone surface in an emulated intraoperative ambient. Our work establishes the methodological basis for engineering a clinical device that achieves real-time, in situ classification of urinary stones for optimizing the laser ablation parameters and reducing perioperative complications in lithotripsy.

Topics: Humans; Lithotripsy, Laser; Struvite; Uric Acid; Urinary Calculi; Urolithiasis

Abdominal radiography is an important diagnostic to detect uroliths. Cystine and urate uroliths were historically characterized as nonmineral opaque on survey radiographs. However, recent research and clinical observations indicate that pure urate and cystine uroliths may be detected with digital radiography. The primary purpose of this prospective, in vitro, diagnostic accuracy study was to determine the sensitivity of digital radiography in detecting cystoliths of varying size and composition. Forty canine uroliths of pure composition (10 each of calcium oxalate, struvite, cystine, and urate), acquired from Minnesota Urolith Center and ranging from 1 to 10 mm, were placed in phantoms of three various sizes and radiographed. The radiographs, including three sets of each urolith separately, were evaluated by three blinded radiologists on two separate occasions. Evaluation included presence or absence of urolith, number of uroliths, and maximum diameter of the urolith(s). For all four types of uroliths and all readers, the specificity and PPV were 100% with an associated very high sensitivity (94.4%-98.9%) and NPV (94.8%-98.9%). Calcium oxalate uroliths were the most accurately measured and struvite were the least accurately measured when compared with the gross measurement. Smaller uroliths were more accurately measured than larger uroliths. Uroliths placed in smaller bladder phantoms were more accurately measured than in larger bladder phantoms. Though accurate measurement of uroliths is complicated by and dependent on numerous variables, our results reveal that urate and cystine uroliths are visualized on digital radiography making them a relevant differential diagnosis when seen clinically.

Topics: Abdomen; Animals; Calcium Oxalate; Cystine; Dog Diseases; Dogs; Prospective Studies; Radiographic Image Enhancement; Struvite; Uric Acid; Urinary Calculi

With limited information available, the association among urinary tract infections, urease-producing bacteria and the presence of magnesium ammonium phosphate (MAP) urolithiasis in canines in Thailand requires more study.. This study aimed to investigate the association between demographic characteristics of canines and the presence of MAP urolithiasis in canines, and to evaluate antimicrobial susceptibility patterns of bacteria isolated from canine uroliths.. A total of 56 canines admitted for treatment with surgical removal of uroliths were recruited. Demographic characteristics and clinical chemistry data were recorded. Bacteria isolated from the removed uroliths were identified. Chemical compositions of the uroliths were analyzed by Fourier transform infrared spectrometer. Potential risk factors were determined with univariable and multivariable logistic regression analyses.. Of 56 canine urolithiasis, bacteria were isolated from uroliths of 38 canines (27 MAP and 11 non-MAP) but not from uroliths of 18 canines (5 MAP and 13 non-MAP). The most common bacteria found in nidus of MAP uroliths was. Our results indicate that

Topics: Animals; Anti-Infective Agents; Bacteria; Bacterial Infections; Dog Diseases; Dogs; Drug Resistance, Bacterial; Female; Phosphates; Risk Factors; Struvite; Urease; Urinary Calculi; Urolithiasis

Urolithiasis is the most common cause of urinary tract disease in small ruminants and has significant economic and production impacts worldwide. Urolithiasis is multifactorial in origin and generally begins with the formation of cystoliths followed by urethral obstruction. The condition is most common in males. Clinical signs are variable depending on the severity of the obstruction. Uroliths can be calcium, struvite, or silicate based; however, struvite and amorphous magnesium calcium phosphate are the most common urolith types observed in small ruminants. Although urethral process (vermiform appendage) amputation is widely considered the first line of treatment, reobstruction is common within the first 36 hours. Surgical interventions such as temporary tube cystostomy, perineal urethrostomy (PU), modified proximal perineal urethrostomy, vesico-preputial anastomosis (VPA), and urinary bladder marsupialization (BM) are reported to carry an improved prognosis for long-term survival. PU carries a lower proportion of long-term success (> 12-month survival time) when compared with VPA and BM. Stoma stricture and urine scald are the most commonly observed surgical complications. Currently, the literature provides minimal direction for clinician decision-making in managing these cases while accounting for patient history, client financial ability, composition of calculi, and potential treatment complications. Small ruminant urinary obstructions are challenging and complicated conditions to treat, due to their multifactorial etiology, ruminant urogenital anatomy, and the variety of imperfect treatment options available. The purpose of this article this article is to provide veterinary practitioners with decision trees to guide management and treatment of urolithiasis in small ruminants.

Topics: Animals; Decision Trees; Goat Diseases; Goats; Male; Ruminants; Struvite; Urethral Obstruction; Urinary Bladder Calculi; Urinary Calculi; Urolithiasis

To assess the potential of automated machine-learning methods for recognizing urinary stones in endoscopy.. Surface and section images of 123 urinary calculi (109 ex vivo and 14 in vivo stones) were acquired using ureteroscopes. The stones were more than 85% 'pure'. Six classes of urolithiasis were represented: Groups I (calcium oxalate monohydrate, whewellite), II (calcium oxalate dihydrate, weddellite), III (uric acid), IV (brushite and struvite stones), and V (cystine). The automated stone recognition methods that were developed for this study followed two types of approach: shallow classification methods and deep-learning-based methods. Their sensitivity, specificity and positive predictive value (PPV) were evaluated by simultaneously using stone surface and section images to classify them into one of the main morphological groups (subgroups were not considered in this study).. Using shallow methods (based on texture and colour criteria), relatively high sensitivity, specificity and PPV for the six classes were attained: 91%, 90% and 89%, respectively, for whewellite; 99%, 98% and 99% for weddellite; 88%, 89% and 88% for uric acid; 91%, 89% and 90% for struvite; 99%, 99% and 99% for cystine; and 94%, 98% and 99% for brushite. Using deep-learning methods, the sensitivity, specificity and PPV for each of the classes were as follows: 99%, 98% and 97% for whewellite; 98%, 98% and 98% for weddellite; 97%, 98% and 98% for uric acid; 97%, 97% and 96% for struvite; 99%, 99% and 99% for cystine; and 94%, 97% and 98% for brushite.. Endoscopic stone recognition is challenging, and few urologists have sufficient expertise to achieve a diagnosis performance comparable to morpho-constitutional analysis. This work is a proof of concept that artificial intelligence could be a solution, with promising results achieved for pure stones. Further studies on a larger panel of stones (pure and mixed) are needed to further develop these methods.

Topics: Artificial Intelligence; Cystine; Humans; Struvite; Uric Acid; Urinary Calculi

This study was aimed to assess the distribution and frequency of uroliths in cats as well as to evaluate gender-, age-, and breed-specific differences.. 3629 uroliths from cats in Germany were analyzed by infrared-spectroscopy during the period 2016-2020. The majority (3300) of the uroliths originated from purebred cats of 22 breeds.. Uroliths were prevalent in the order of male neutered (45.3 %), female spayed (35.3 %), male intact (7.4 %), and female intact cats (6.3 %). Median age of the cats with uroliths was 7 years, although it varied slightly depending on types of the urolith. The most frequent uroliths were calcium oxalate (59.5 %), followed by struvite (33.7 %), ammonium urate (2 %), calcium phosphate (1.7 %), cystine (0.7 %) and xanthine (0.4 %). Males (59.4 %) and females (59.2 %) showed nearly identical prevalence of calcium oxalates, whereas it significantly diverged in castrated (60.2 %) versus intact animals (54.4 %; p = 0.01). With regard to struvites, male cats (32.6 %) were less prone than females (35.4 %; p = 0.08) while intact cats (38.2 %) significantly outnumbered the castrated cohorts (33.1 %; p = 0.02). The prevalence for calcium oxalate uroliths increased by 6.6 % during the study period, contrasting a decrease of 5.5 % for struvites. Some breeds (> 10 individuals) showed significantly higher propensities than others for urolith formation. Calcium oxalates were significantly more frequent in British shorthair cats (85.2 %), Ragdoll (75 %), Scottish fold (74.1 %) and Persians (72.4 %). Struvites were prevailing in Norwegian forest cats (48.5 %), British longhair (41.7 %), European shorthair (41.7 %) and Siberian forest cats (36.8 %). Siamese cats had the significantly highest percentage of cystine uroliths (16 %).. The occurrence of urine calculi in cats from Germany was found to be most frequent for calcium oxalate and struvite types. We also found breed-, age-, gender- specific differences in addition to variations depending on the neutering status of the animals.. Ziel der Studie war, die Verteilung und Häufigkeit unterschiedlicher Harnsteine von Katzen aus Deutschland zu erfassen sowie geschlechts-, alters-, und rassespezifische Unterschiede zu evaluieren.. Im Zeitraum 2016–2020 wurden mittels Infrarotspektroskopie 3629 Harnsteinproben von Katzen aus Deutschland analysiert. 3330 Harnsteine stammten von Rassekatzen, die 22 Rassen zugeordnet werden konnten.. Die Harnsteine entfielen auf männlich kastrierte (45,3 %), weiblich kastrierte (35,3 %), männlich intakte (7,4 %) und weiblich intakte (6,3 %) Tiere. Das mediane Alter (Jahre) der Tiere war 7, variierte aber zwischen den unterschiedlichen Steinarten. Die häufigsten Steinarten waren: Kalziumoxalate (59,5 %), Struvite (33,7 %), Ammoniumurate (2 %), Kalziumphosphate (1,7 %), Cystine (0,7 %) und Xanthine (0,4 %). Männliche (59,4 %) und weibliche (59,2 %) Tiere hatten nahezu identische prozentuale Anteile an Kalziumoxalaten, während der Anteil bei Kastraten mit 60,2 % signifikant höher war als bei intakten Tieren (54,4 %; p = 0,01). Bei Struvitsteinen war der Anteil männlicher (32,6 %) geringer als der weiblicher Tiere (35,4 %; p = 0,08) und der Anteil der intakten Tiere (38,2 %) übertraf den der kastrierten Tiere signifikant (33,1 %; p = 0,02). Die Prävalenz der Kalziumoxalatsteine stieg im Untersuchungszeitraum um 6,6 %, während die der Struvitsteine 5,5 % abnahm. Einige Rassen (> 10 Individuen) zeigten eine signifikant gehäufte Neigung zur Bildung bestimmter Steinarten. Kalziumoxalate fanden sich signifikant häufiger bei Britisch Kurzhaar (85,2 %), Ragdoll (75 %), Scottish Fold (74,1 %) und Perserkatzen (72,4 %). Struvitsteine waren die dominierende Steinart bei Norwegischer Waldkatze (48,5 %), Britisch Langhaar (41,7 %), Europäisch Kurzhaar (41,7 %) und Sibirischer Waldkatze (36,8 %). Siamkatzen hatten den signifikant höchsten prozentualen Anteil an Cystinsteinen (16 %) SCHLUSSFOLGERUNG UND KLINISCHE RELEVANZ: Kalziumoxalate und Struvitsteine sind bei Katzen aus Deutschland die häufigsten Steinarten. Rasse-, alters-, geschlechts- und kastrationsspezifische Unterschiede wurden festgestellt.

Topics: Age Factors; Animals; Calcium; Calcium Oxalate; Cat Diseases; Cats; Cystine; Female; Germany; Magnesium Compounds; Male; Phosphates; Struvite; Urinary Calculi

Topics: Calcium; Calcium Oxalate; Cystine; Humans; Kidney Calculi; Struvite; Uric Acid; Urinary Calculi

Stone composition can provide valuable information for the diagnosis, treatment and recurrence prevention of urolithiasis. The aim of this study was to evaluate the distribution of urinary stone components and the impact of different crystal forms according to gender and age of patients in Germany.. A total of 45,783 urinary stones submitted from 32,512 men and 13,271 women between January 2007 and December 2020 were analyzed by infrared spectroscopy. Only the first calculus obtained per patient was included in the analysis.. The most common main stone component was calcium oxalate (CaOx) (71.4%), followed by carbonate apatite (CA) (10.2%) and uric acid (UA) (8.3%). Struvite (2.1%), brushite (1.3%), protein (0.5%) and cystine (0.4%) stones were only rarely diagnosed. CaOx (75%) and UA stones (81%) were more frequently obtained from men than women (p < 0.001). Weddellite (COD) and uric acid dihydrate (UAD) were more common in younger ages than whewellite (COM) and anhydrous uric acid (UAA), respectively, in both men and women. The ratios of COM-to-COD and UAA-to-UAD calculi were approximately 4:1 and 8:1, respectively. The peak of stone occurrence was between the ages of 40 and 59 years.. Stone composition is strongly associated with gender and age. The peak incidence of calculi in both women and men was in the most active phase of their working life. The distinction between different crystal forms could provide clues to the activity and mechanisms of lithogenesis. Further research is needed in understanding the causative factors and the process of stone formation.

Topics: Adult; Calcium Oxalate; Female; Humans; Incidence; Male; Middle Aged; Struvite; Uric Acid; Urinary Calculi

This study aimed to predict the composition of urolithiasis using deep learning from urinary stone images.. We classified 1,332 stones into 31 classes according to the stone composition. The top 4 classes with a frequency of 110 or more (class 1: calcium oxalate monohydrate [COM] 100%, class 2: COM 80%+struvite 20%, class 3: COM 60%+calcium oxalate dihydrate [COD] 40%, class 4: uric acid 100%) were selected. With the 965 stone images of the top 4 classes, we used the seven convolutional neural networks (CNN) to classify urinary stones and compared their classification performances.. Among the seven models, Xception_Ir0.001 showed the highest accuracy, precision, and recall and was selected as the CNN model to predict the stone composition. The sensitivity and specificity for the 4 classes by Xception_Ir0.001 were as follows: class 1 (94.24%, 91.73%), class 2 (85.42%, 96.14%), class 3 (86.86%, 99.59%), and class 4 (94.96%, 98.82%). The sensitivity and specificity of the individual components of the stones were as follows. COM (98.82%, 94.96%), COD (86.86%, 99.64%), struvite (85.42%, 95.59%), and uric acid (94.96%, 98.82%). The area under the curves for class 1, 2, 3, and 4 were 0.98, 0.97, 1.00, and 1.00, respectively.. This study showed the feasibility of deep learning for the diagnostic ability to assess urinary stone composition from images. It can be an alternative tool for conventional stone analysis and provide decision support to urologists, improving the effectiveness of diagnosis and treatment.

Topics: Calcium Oxalate; Deep Learning; Humans; Struvite; Uric Acid; Urinary Calculi; Urolithiasis

Persistent uroliths after a cystotomy in dogs are a common cause of surgical failure.. This study examined the following: the success rate of retrograde urohydropropulsion in male dogs using non-enhanced computed tomography (CT), whether the CT mean beam attenuation values in Hounsfield Units (mHU) measured. All dogs and cats that presented with lower urinary tract uroliths and had a non-enhanced CT preceding surgery were included. In male dogs, CT was performed after retrograde urohydropropulsion to detect the remaining urethral calculi. The percentage and location of persistent calculi were recorded. The images were reconstructed using three kernels, from smooth to ultrasharp, and the calculi mHU were measured.. Sixty-five patients were included in the study. The success rate of retrograde urohydropropulsion in the 45 male dogs was 55.6% and 86.7% at the first and second attempts, respectively. The predominant components of the calculi were cystine (20), struvite (15), calcium oxalate (8), and urate (7). The convolution kernel influenced the mHU values (p < 0.05). The difference in mHU regarding the calculus composition was better assessed using the smoother kernel. A mHU greater than 1,000 HU was predictive of calcium oxalate calculi.. Non-enhanced CT is useful for controlling the success of retrograde urohydropropulsion. The mHU could allow a prediction of the calculus composition, particularly for calcium oxalate, which may help determine the therapeutic strategy.

Topics: Animals; Calcium Oxalate; Calculi; Cat Diseases; Cats; Cystine; Dog Diseases; Dogs; Male; Struvite; Tomography, X-Ray Computed; Uric Acid; Urinary Calculi

In lithogenesis, for a stone to form it is necessary that the urine is supersaturated with respect to the salt that will constitute the future stone. The objective was to analyze the urinary saturations of Calcium Oxalate (CaOxa), brushite (calcium phosphate), struvite (ammonium-magnesium phosphate) and uric acid (UA) in children with and without lithiasis. Correlate them with the different parameters involved in the lithiasic process. And compare saturations in children with or without overweight.. We examined 108 healthy children and 53 patients diagnosed with lithiasis. In 24-h urine, the different biochemical parameters involved in lithiasis and the saturation levels of CaOxa, brushite, struvite and UA.. We studied 108 healthy children with a mean age of 9.5 ± 3.9 years. Renal lithiasis was diagnosed in 53 patients with an average age of 10.5 ± 5.8 years. Children with lithiasis had higher saturation values of CaOxa (4.86 ± 2.71 vs. 3.15 ± 1.99,. The mean values of calcium oxalate and brushite saturations were higher in children with lithiasis. Uric acid saturation was elevated in overweight children. Finally, urinary pH greatly influenced uric acid saturation.

Topics: Adolescent; Ammonium Compounds; Calcium Oxalate; Calcium Phosphates; Child; Child, Preschool; Humans; Kidney Calculi; Overweight; Struvite; Uric Acid; Urinary Calculi

This article summarizes urinary stone submissions from foxes in human care to the Minnesota Urolith Center over 40 years. A previous report documented the analysis of uroliths from foxes that were submitted between 1981 and 2007.

Topics: Animals; Calcium Oxalate; Calcium Phosphates; Calculi; Cystine; Dog Diseases; Dogs; Humans; Magnesium Compounds; Male; Minnesota; Phosphates; Struvite; Urinary Calculi; Urolithiasis

To study urinary stone composition patterns in different populations around the world.. Data were collected by reviewing charts of 1204 adult patients of 10 countries with renal or ureteral stones (> 18 years) in whom a stone analysis was done and available. Any method of stone analysis was accepted, but the methodology had to be registered.. In total, we observed 710 (59%) patients with calcium oxalate, 31 (1%) with calcium phosphate, 161 (13%) with mixed calcium oxalate/calcium phosphate, 15 (1%) with carbapatite, 110 (9%) with uric acid, 7 (< 1%) with urate (ammonium or sodium), 100 (9%) with mixed with uric acid/ calcium oxalate, 56 (5%) with struvite and 14 (1%) with cystine stones. Calciumcontaining stones were the most common in all countries ranging from 43 to 91%. Oxalate stones were more common than phosphate or mixed phosphate/oxalate stones in most countries except Egypt and India. The rate of uric acid containing stones ranged from 4 to 34%, being higher in Egypt, India, Pakistan, Iraq, Poland and Bulgaria. Struvite stones occurred in less than 5% in all countries except India (23%) and Pakistan (16%). Cystine stones occurred in 1% of cases.. The frequency of different types of urinary stones varies from country to country. Calcium-containing stones are prevalent in all countries. The frequency of uric acid containing stones seems to depend mainly on climatic factors, being higher in countries with desert or tropical climates. Dietary patterns can also lead to an increase in the frequency of uric acid containing stones in association with high obesity rates. Struvite stones are decreasing in most countries due to improved health conditions.

Topics: Adult; Calcium Oxalate; Humans; Kidney Calculi; Struvite; Ureteral Calculi; Urinary Calculi

the aim of the determination of the diagnostic information content of the qualitative analysis method - urinary calculus for use in medical practice in the study of the chemical structure of urolite. Materials, methods: Determination of the chemical composition of uroliths in the collection of urinary stones (n=2960), presented in "a Database of patients with urolithiasis who live in the territory of the Republic of Belarus" (2006-2019), made the developed method of qualitative analysisbased on the combined conduct of optical macroscopy of the sample, qualitative chemical reactions and chemical reactions of reprecipitation with subsequent microscopy of the crystals formed.. The developed method allowed identifying the following clinically most significant mineral components of urinary stones: vevellite (42.4%), weddellite (28.1%), Apatite (19.6%), carbonate Apatite (5.1%), struvite (13.2%), uric acid (17.6%), ammonium urate (0.4%), cystine (0.7%). The obtained data were consistent with the results of studying the elemental composition of urinary stones (n=24) by atomic emission spectrometry with inductively coupled plasma. The calcium level was highest in calcium stones (25.56% C oxalate and 19.73% C phosphate) with a minimum content (0.012%) in urate stones. The amount of magnesium prevailed in the group with magnesium-ammonium-phosphate stones (2.51%) at extremely low concentrations in urate samples (7.810-4%). The percentage of phosphorus was maximum (13.47%) in the group of uroliths, represented by phosphate salts of calcium and magnesium (with values of 0.67% - calcium oxalate and 0.013% urate). Identification of trace elements Al, Ba, Cu, Fe, Zn, Sr revealed a fluctuation in their content in the range from 0.037 to 546.3 ppm.. Considering the practical availability of implementation, low financial costs and sufficient information, the method of qualitative rapid analysis of urinary stone, based on a combined optical macroscopy of the sample, qualitative chemical reactions and chemical reactions of reindeposition with subsequent microscopy of the formed crystals, can be recommended for wide use in medical institutions of any regional level in the diagnosis of chemical types of uroliths in patients with ICD.

Topics: Humans; Phosphates; Struvite; Uric Acid; Urinary Calculi; Urolithiasis

To assess the largest stone composition data available and to present the variations in the stone composition according to gender and different climatic environments in Turkey.. Data for a total of 24 768 urinary stone patients from the Turkish Mineral Research and Exploration Institute were evaluated. X-ray diffraction crystallography was used for analysis and the Köppen-Trewartha classification was used to assess the climatic features of the cities. After the assessment, the cities were divided into two groups-those with a continental climate (Dc) were defined as inland areas and the others (Non-Dc) were defined as coastal areas.. The male-to-female ratio was 2.2:1. Amongst the patients, 53.7% had pure stones, while 46.3% had mixed-type stones. The most common type of stone was calcium oxalate in both pure and mixed stone groups. Given the climate patterns, the stone ratio between regions with a Dc climate and a Non-Dc climate was approximately 2:3. Cystine and uric acid stones were observed more frequently in inland regions, while calcium oxalate, whewellite, and struvite stones were observed more frequently in coastal areas (P = .005, P < .001, P < .001, P = .002, P = .002, respectively). Calcium oxalate stones were found at a higher rate in men, while cysteine, struvite, and calcium phosphate stones were more common in women (P < .001, P = .003, P < .001, P < .001, respectively).. This study provides the most comprehensive data on the stone disease in Turkey. Considering the distribution of stone disease in Turkey, the frequency of analysed stones had parallels with the temperature averages and climate features, presenting crescent-like distribution.

Topics: Female; Humans; Male; Phosphates; Struvite; Turkey; Uric Acid; Urinary Calculi

There is an apparent reciprocal relationship between magnesium ammonium phosphate (MAP, struvite) and calcium oxalate (CaOx) urolithiasis incidence rate in cats. The number of struvite uroliths submitted for analysis over the past 35 years has been decreasing, with an increase in CaOx urolith submissions. Commercial diets aimed to dissolve struvite uroliths are typically acidified, and it has been suggested that dietary acidification increases urinary calcium excretion and the risk of CaOx crystallization. The objective of this study was to assess the effect of urine acidification on the relative supersaturation (RSS) of CaOx in cats, as a representation of crystallization risk. Four diets were extruded to contain identical nutrient contents, but with gradual acidification (0, 0.6, 1.3 and 1.9% sodium bisulphate substituted sodium chloride in diets A, B, C and D respectively). Thirteen adult cats were fed each diet sequentially for a minimum of 10 days. Average urine pH was 6.4, 6.2, 6.0 and 5.9 on diets A, B, C and D respectively (p < 0.0001). Struvite RSS decreased on diets inducing more acidic urine pH (p < 0.0001). Urinary calcium excretion and concentration increased with diets inducing lower urine pH (p < 0.0001), but oxalate excretion and concentration decreased (p < 0.001). CaOx RSS was not different between diets (p = 0.63). These results suggest that a lower diet base excess and resulting urine pH to support struvite dissolution do not increase the risk for CaOx crystallization in the range of urine pH representative of most commercial feline diets. Long-term studies are needed to confirm this.

Topics: Animals; Calcium; Calcium Oxalate; Cat Diseases; Cats; Diet; Hydrogen-Ion Concentration; Struvite; Urinary Calculi

Analysis of large datasets of uroliths is necessary to illustrate the prevalence and risk factors of urolithiasis. Furthermore, it may help to improve treatment and prevention of urolithiasis. In this study, 7866 uroliths (44.5% feline and 55.5% canine) from veterinary practitioners in the Netherlands between 2014 and 2020 were analysed. Between 2014 and 2020 the distribution over the different types of uroliths remained similar over time. Female cats, obese cats, Domestic Shorthair cats, female dogs, and large breed dogs had an increased risk for struvite. Neutered cats, all cat breeds except Domestic Shorthair, neutered dogs, male dogs, intact male dogs, and small breed dogs had an increased risk for calcium oxalate urolithiasis. Cystine and urate were found predominantly in male dogs. Dalmatians were at highest risk for urate urolithiasis. The findings of this study in the Netherlands were similar to findings in previous studies from different countries. However, urate urolithiasis in the English Cocker Spaniel and cystine urolithiasis in the Yorkshire Terrier were new associations. Body condition score, information about recurrence of urolithiasis, medical history, and diet history should be included in submission sheets in the future to explore other possible associations.

Topics: Animals; Calcium Oxalate; Cat Diseases; Cats; Dog Diseases; Dogs; Female; Magnesium Compounds; Male; Netherlands; Phosphates; Risk Factors; Struvite; Uric Acid; Urinary Calculi; Urolithiasis

Adhesion molecules play an important role in urinary calculus formation. The expressions of adhesion molecules in renal tubular has been reported in some animals. However, the role of adhesion molecules in the process of sheep urinary calculus formation is still unclear. The magnesium ammonium phosphate (MAP) is the main component of sheep urinary calculus. In this paper, the sheep renal tubular epithelial cells (RTECs) were isolated and treated with MAP, the expressions of osteopontin (OPN), intercellular adhesion molecule-1 (ICAM-1), vascular cell adhesion molecule-1 (VCAM-1) and apoptosis-related indicators caspase-3, Bcl-2 and Bax in RTECs were observed, the viability of RTECs was detected by Cell Counting Kit-8 (CCK-8). The levels of superoxide dismutase (SOD) and malondialdehyde (MDA), and the expressions of inflammatory factors Interleukin-6 (IL-6), Interleukin-1 (IL-1), Interleukin-17 (IL-17) and tumor necrosis factor-α (TNF-α) were measured by enzyme-linked immunosorbent (ELISA). The histopathological observation of kidney in urolithiasis sheep was made. The results showed that MAP could reduce the viability and SOD activity, enhance the activity of MDA significantly and promote the expressions of IL-1, IL-6, IL-17 and TNF-α of RTECs. By western blot and qPCR methods, the expressions of ICAM-1, VCAM-1 and OPN increased in 48 h. In addition, the expression of caspase-3 increased significantly and the ratio of Bcl-2/Bax reduced with exposure to MAP. The renal tissue structure was seriously damaged, the RTECs in urolithiasis sheep were degenerative and necrotic.

Topics: Animals; Apoptosis; Cell Adhesion Molecules; Cell Survival; Cells, Cultured; Cytokines; Epithelial Cells; Intercellular Adhesion Molecule-1; Kidney; Osteopontin; Oxidative Stress; Sheep, Domestic; Struvite; Urinary Calculi; Vascular Cell Adhesion Molecule-1

To evaluate the characteristics of urinary stone composition in a Korean population using a large database of stone composition.. From January 1, 2014, to June 30, 2019, a total of 33,078 urinary stone composition data were analyzed. Stone composition was classified into four main groups: calcium oxalate (CaOx), struvite, uric acid (UA), and calcium phosphate (CaP). We examined the relationship between stone composition and sex, age, geographic region, calendar month, and season.. The CaOx group (46.41%) was the largest, followed by the struvite group (29.66%), UA group (19.61%), and CaP group (4.32%). The CaOx group tended to decrease with age, but the UA group increased with age. Also, the CaOx group had the highest percentage in summer and the lowest in spring (p<0.001). The struvite and CaP groups had higher percentages of females than males (struvite: 36.6% vs. 25.7%, p<0.001; CaP: 6.2% vs. 3.3%, p<0.001). Conversely, the UA stones were more common in males than in females (24.5% vs. 11.0%, p<0.001). The UA group had the lowest percentage in the capital region (p<0.001). The total male-to-female ratio decreased over time from 1.95:1 in 2014 to 1.67:1 in 2018 (p<0.001).. There were differences for each stone composition in the percentages according to sex, age, geographic region, month, and season. Identifying these differences based on the stone composition is vital for the treatment and prevention of urinary stones.

Topics: Adolescent; Adult; Age Factors; Aged; Aged, 80 and over; Calcium Oxalate; Calcium Phosphates; Child; Child, Preschool; Databases, Factual; Female; Geography; Humans; Infant; Infant, Newborn; Male; Middle Aged; Republic of Korea; Seasons; Sex Factors; Struvite; Uric Acid; Urinary Calculi; Urolithiasis; Young Adult

This paper presents the differential diagnosis of a calcified mass found in the pelvic cavity of an adult male dating to the 10th century AD.. Skeletal remains of an adult male exhumed from the cemetery associated with the early medieval church of Riner (Solsonès, Catalonia).. The structure and composition of the mass were examined by x-ray imaging, microscopic stereoscopy and Fourier transform infrared spectrometry analysis.. The examination reveals a light brown kidney-shaped calcification with well-defined margins, irregular hypodense zones, and several thin concentric layers. The obtained spectra showed a mixture of carbonate apatite (with a high level of carbonation) and calcite in all the sections studied.. The calcification most likely corresponds to a urinary calculus of infectious origin.. Given the insights that urinary calculi can provide towards understanding consequences of infection and environmental conditions, this case will be of interest to other researchers wishing to initiate comparative analyses.. The discussion of the etiology of the stone is limited by the lack of preservation of certain elements such as struvite.

Topics: Adult; Cemeteries; Humans; Male; Spain; Struvite; Urinary Calculi

INTRODUCTION The objective of this study is to explore the association between urinary stone composition and surgical recurrence.. Patients who underwent kidney stone surgeries (between 2009-2017), were followed for > 1 year, and had ≥ 1 stone composition analyses were included in our analysis. Surgical stone recurrence (repeat surgery) was defined as the second surgery on the same kidney unit. Recurrence-free survival analysis was used.. A total number of 1051 patients were included (52.7% men, average age 59.1 +/- 15.1 years). Over 4.7 +/- 2.5 years follow up, 26.7% of patients required repeat surgery. Patients' stone compositions were calcium oxalate (66.0%), uric acid (12.2%), struvite (10.0%), brushite (5.7%), apatite (5.1%) and cystine (1.0%). Results suggested that patients with cystine stones had the highest surgical recurrence risk; brushite had the second-highest surgical recurrence risk. Struvite, uric acid, and apatite stones were at higher risk compared with calcium oxalate stones (lowest risk in our cohort). When pre and postoperative stone size was controlled, patients with a history of uric acid, brushite, and cystine stones were at higher surgical risk. After controlling clinical and demographic factors, only brushite and cystine stones were associated with higher surgical recurrence.. Patients with cystine stones had the highest surgical recurrence risk; brushite stones had the second highest surgical recurrence risk. Struvite, uric acid, and apatite stones were at higher risk compared with calcium oxalate stones. When pre and postoperative stone size, clinical and demographic factors were controlled, only those with brushite or cystine stones were at significantly higher risk of surgical recurrence.

Topics: Adult; Aged; Calcium Oxalate; Female; Humans; Kidney Calculi; Male; Middle Aged; Struvite; Uric Acid; Urinary Calculi

To predict the main component of pure and mixed kidney stones using dual-energy computed tomography and machine learning.. 200 kidney stones with a known composition as determined by infrared spectroscopy were examined using a non-anthropomorphic phantom on a spectral detector computed tomography scanner. Stones were of either pure (monocrystalline, n = 116) or compound (dicrystalline, n = 84) composition. Image acquisition was repeated twice using both, normal and low-dose protocols, respectively (ND/LD). Conventional images and low and high keV virtual monoenergetic images were reconstructed. Stones were semi-automatically segmented. A shallow neural network was trained using data from ND1 acquisition split into training (70%), testing (15%) and validation-datasets (15%). Performance for ND2 and both LD acquisitions was tested. Accuracy on a per-voxel and a per-stone basis was calculated.. Main components were: Whewellite (n = 80), weddellite (n = 21), Ca-phosphate (n = 39), cysteine (n = 20), struvite (n = 13), uric acid (n = 18) and xanthine stones (n = 9). Stone size ranged from 3 to 18 mm. Overall accuracy for predicting the main component on a per-voxel basis attained by ND testing dataset was 91.1%. On independently tested acquisitions, accuracy was 87.1-90.4%.. Even in compound stones, the main component can be reliably determined using dual energy CT and machine learning, irrespective of dose protocol.. • Spectral Detector Dual Energy CT and Machine Learning allow for an accurate prediction of stone composition. • Ex-vivo study demonstrates the dose independent assessment of pure and compound stones. • Lowest accuracy is reported for compound stones with struvite as main component.

Topics: Algorithms; Calcium Oxalate; Calcium Phosphates; Cysteine; Humans; Kidney Calculi; Machine Learning; Neural Networks, Computer; Phantoms, Imaging; Struvite; Tomography Scanners, X-Ray Computed; Tomography, X-Ray Computed; Uric Acid; Urinary Calculi; Xanthine

There has not been a study that analyzed the composition of urinary stones from patients in the eastern Shandong region of China. Thus, we explored the composition of urinary stones in the eastern Shandong region of China and discuss the clinical significance of the findings.. A total of 3684 urinary calculi from the eastern Shandong region were collected in our study. Compositions of the stones were analyzed using an Automatic Infrared Spectrum Analysis System (type LIIR-20). The results were verified through manual analysis of the spectrograms, which was accompanied by polarizing microscopy and chemical analysis if necessary.. Among the 3684 specimens, there were 1767 single-component stones and 1917 mixed-component stones. According to the main components of the stones, the stones were divided into the following types: calcium oxalate monohydrate stones (1779, 48.3%), anhydrous uric acid stones (1105, 30.0%), carbonate apatite stones (590, 16.0%), ammonium magnesium phosphate hexahydrate stones (143, 3.9%), calcium oxalate dihydrate stones (36, 1.0%), and cystine stones (31, 0.8%).. There was a relatively high rate of uric acid stones in patients from the eastern Shandong region of China.

Topics: Calcium Oxalate; China; Humans; Struvite; Urinalysis; Urinary Calculi

Previous studies have shown that split-bolus protocols in virtual non-contrast (VNC) reconstructions of dual-energy computed tomography (DE-CT) significantly decrease radiation dose in patients with urinary stone disease. To evaluate the impact on kidney stone detection rate of stone composition, size, tube voltage, and iodine concentration for VNC reconstructions of DE-CT.. In this prospective study, 16 kidney stones of different sizes (1.2-4.5 mm) and compositions (struvite, cystine, whewellite, brushite) were placed within a kidney phantom. Seventy-two scans with nine different iodine contrast agents/saline solutions with increasing attenuation (0-1400 HU) and different kilovoltage settings (70 kV/150 kV; 80 kV/150 kV; 90 kV/150 kV; 100 kV/150 kV) were performed. Two experienced radiologists independently rated the images for the presence and absence of stones. Multivariate classification tree analysis and descriptive statistics were used to evaluate the diagnostic performance.. Classification tree analysis revealed a higher detection rate of renal calculi > 2 mm in size compared with that of renal calculi < 2 mm (84.7%; 12.7%; p < 0.001). For stones with a diameter > 2 mm, the best results were found at 70 kV/Sn 150 kV and 80 kV/Sn 150 kV in scans with contrast media attenuation of 600 HU or less, with sensitivity of 99.6% and 96.0%, respectively. A higher luminal attenuation (> 600 HU) resulted in a significantly decreased detection rate (91.8%, 0-600 HU; 70.7%, 900-1400 HU; p < 0.001). In our study setup, the detection rates were best for cystine stones.. Scan protocols in DE-CT with lower tube current and lower contrast medium attenuation show excellent results in VNC for stones larger than 2 mm but have limitations for small stones.. • The detection rate of virtual non-contrast reconstructions is highly dependent on the surrounding contrast medium attenuation at the renal pelvis and should be kept as low as possible, as at an attenuation higher than 600 HU the VNC reconstructions are susceptible to masking ureteral stones. • Protocols with lower tube voltages (70 kV/Sn 150 kV and 80 kV/Sn 150 kV) improve the detection rate of kidney stones in VNC reconstructions. • The visibility of renal stones in virtual non-contrast of dual-energy CT is highly associated with the size, and results in a significantly lower detection rate in stones below 2 mm.

Topics: Calcium Oxalate; Calcium Phosphates; Contrast Media; Cystine; Humans; Image Processing, Computer-Assisted; Iodine; Kidney Calculi; Phantoms, Imaging; Prospective Studies; Radiation Dosage; Struvite; Tomography, X-Ray Computed; Urinary Calculi

A 52-year-old man with flank pain on the right side presented to the emergency room. A computer tomography of the abdomen showed a right ureterolithiasis with 3.5 mm stone in the proximal ureter with consecutive grade 2 hydronephrosis. After standard treatment of the right ureterolithiasis, there was a relapse on the left side and throughout the entire upper and lower urinary tract with struvite stones due to a persistent infection with Proteus mirabilis.. Auf der Notfallstation präsentiert sich ein 52-jähriger Patient mit Flankenschmerzen rechtsseitig. Eine Computertomographie des Abdomens zeigte eine Ureterolithiasis rechts bei 3,5-mm-Konkrement im proximalen Ureter mit konsekutiver Hydronephrose Grad II. Nach standardmäßiger Behandlung der Ureterolithiasis rechts kam es zu einem Rezidiv auf der linken Seite und im Verlauf des ganzen oberen und unteren Harntrakts mit Struvitsteinen bei einem persistierenden Infekt mit Proteus mirabilis.

Topics: Humans; Male; Middle Aged; Proteus mirabilis; Struvite; Urinary Calculi; Urinary Tract Infections

An increase of the frequency of uric acid urinary stones compared to calcium-containing ones has been recently described. This study was aimed at assessing the frequency of different types of urinary stones in the population of northern Italy in the period 2016-18 compared to 2001-2003.. Analyses by infrared spectroscopy of 1007 stones endoscopically removed at two institutions in the area of Milan (Northern Italy) were retrospectively considered. Stones were classified as calcium oxalate monohydrate (COM) and dihydrate (COD), mixed uric acid/calcium oxalate (UC); uric acid (UA), struvite (ST); apatite (CAP); mixed calcium oxalate / apatite (CAPOX); others. The patients were divided into two groups: 2001-2003 and 2016-2018. The average temperature values of the region over the two time periods were obtained by the national statistical institute.. The average age of the 2001-2003 group (45.8+/- 15.4 years) was significantly lower than the average age of the 2016-18 group (57.9+/- 14.8) (0.000). M / F ratio was similar in the two groups: 119 / 69 (1,0.58) in 2001-2003 and 527 / 292 (1,0.55) in 2016-18 (p = 0.862). COM stones tended to more frequent in 2016-18 group than in 2001-03. COD stones were significantly more frequent in 2001-03 than in 2016-18. ST stone frequency was increased from 2001 to 03 to 2016-18. No increase of uric acid containing stones was observed in 2016-18. Results were confirmed after adjustment by age. Averages annual regional temperatures increased from 14 °C to 15.4 °C during the two observation periods.. No increase of UA stones was observed, probably due to the limited impact of the global warming in our temperate climate.

Topics: Adult; Age Distribution; Aged; Calcium Oxalate; Climate; Climate Change; Female; Humans; Italy; Male; Middle Aged; Struvite; Uric Acid; Urinary Calculi

Poorly crystalline and amorphous precipitate (PCaAP) is one of the components of the so-called infectious urinary stones, which are the result of the activity of urease-producing microorganisms, mainly from the Proteus species, in particular Proteus mirabilis. The main component of this kind of stones is crystalline struvite (MgNH

Topics: Apatites; Durapatite; Humans; Lipopolysaccharides; Proteus mirabilis; Struvite; Urinary Calculi; Urinary Tract Infections; Urine; Urolithiasis

The aim of the study was to identify any dietary, signalment, geographic and clinical factors associated with hematuric struvite crystalluria (HSC) in a population of cats that visit general care veterinary hospitals in the USA.. In total, 4032 cats that had a first-time diagnosis of HSC and 8064 control cats with no history of hematuria or crystalluria were identified from medical records of all cats examined between 2007 and 2011 at 790 US veterinary hospitals. Extracted variables included age, sex, neuter status, breed, diet, urinalysis results and history of cystitis. Potential associations between these variables and HSC were estimated.. Controlling for other factors, young cats fed a dry diet had an increased likelihood of HSC relative to young cats fed a non-dry diet. However, as age increased, the likelihood of HSC declined for cats fed a dry diet and increased for cats fed a non-dry diet. Moreover, the odds of HSC were significantly greater when cats were unneutered (vs neutered; odds ratio [OR] 45.52) or had a thin (vs heavy) body condition (OR 23.81), diagnosis of cystitis (OR 2.84), urine protein concentration >30 mg/dl (OR 4.72), alkaline (vs neutral) urine pH (OR 3.34), pyuria (OR 23.67) or bacteriuria (OR 2.24).. The present study provides estimates of the strengths of association between HSC and certain signalment and clinical characteristics of cats. This information could help clinicians to perform a more directed screening for struvite crystalluria in certain cat populations. Follow-up studies that build on the findings of this study could explore the clinical importance of HSC in cats.

Topics: Animal Feed; Animals; Cat Diseases; Cats; Cystitis; Diet; Female; Male; Struvite; Urinary Calculi

Incidence of pediatric urolithiasis is decreasing in most developing countries where endemic bladder stones are less prevalent than in the past years. In parallel, stone composition has changed. Only few data are available in North Africa, except for Tunisia. We report stone composition in the Moroccan pediatric population.. Composition of 432 stones from children (302 boys, 130 girls) was determined by infrared spectroscopy. The samples were collected during the period 1999-2016. Stone morphology, which is an important aspect for etiology was determined by examination of each stone under a stereomicroscope. Stone composition was compared to patients' age and gender.. The global male-to-female ratio was 2.32. Regarding stone composition, calcium oxalate was the main component in 51.6% of the stones, followed by struvite (18.1%), ammonium urate (9.5%) and carbapatite (9%). Significant differences were found between males and females: calcium oxalate accounted for 72.3% of stones in girls and 42.7% in boys (P<10. This is the largest series of pediatric stones in Morocco studied by infrared analysis and morphological examination.. 3.

Topics: Adolescent; Age Factors; Apatites; Calcium Oxalate; Child; Child, Preschool; Female; Humans; Incidence; Infant; Male; Morocco; Sex Factors; Spectrophotometry, Infrared; Struvite; Urinary Calculi; Urolithiasis

The present study aimed to investigate the chemical composition of urinary calculi in people living in the northern border area of Saudi Arabia and to formulate suggestions for prevention of renal stones. Urinary stones were obtained from patients attending the Urology Departments of Prince Abdul Aziz Bin Musaad Hospital and Central Hospital, Arar, Saudi Arabia. Stones were analyzed using kit for semi-quantitative colorimetric determination of carbonate, calcium, magnesium, ammonium, oxalate, phosphate, uric acid and cysteine; manufactured by LTA s.r.l. Milano 15/F, 20060 Bussero (Milano), Italy. From a total of 55 urinary stones, 49 (89%) were retrieved from males, while 6 (11%) from females. Ages of patients ranged from 15 to 75 years with the mean of 50.22}14.46 and majority of patients were between 31-50 years (69.08%). Most of the patients were overweight (70.91 %) in both the genders. Calcium oxalate stones were 60%, uric acid 18.18% and calcium phosphate 10.90%, while other forms of stones were scarce. It is concluded that upper urinary tract stones were predominant, comprising mostly of calcium oxalate and urate, which could be prevented by control of obesity; moderate intake of meat, dairy products, fruit vegetables (with minimal oxalates); and plenty of fluids.

Topics: Adolescent; Adult; Aged; Calcium Carbonate; Calcium Oxalate; Calcium Phosphates; Female; Humans; Male; Middle Aged; Phosphates; Prospective Studies; Saudi Arabia; Struvite; Uric Acid; Urinary Calculi; Urolithiasis; Young Adult

Pathological biomineralization in the urinary system leads to urolithiasis. Formation of kidney stones involves a series of events during which they undergo morphological and mineralogical changes. We investigated the mineralization of biogenic struvite (in vitro) and examined the transformation of distinct interior and exterior structure of struvite. In vitro crystallization of struvite was performed in the presence of two bacteria that were originally isolated from the kidney stone patients. Morphological evaluation was carried out using SR-μCT as well as FESEM, XRD and FT-IR. Characteristic internal 3-D morphology and porosity of the stones were studied. For comparison, patient derived struvite stones were used. From the results obtained, we report that the presence of bacteria enhances the crystallization process of struvite in vitro. A series of time-resolved experiments revealed that struvite crystals experienced a significant morphologic evolution from pin pointed structure to X-shaped and tabular morphologies. These X-shaped and unusual tabular habits of struvite resembled biogenic morphologies of struvite. SR-μCT showed similarities between the patient derived and the in vitro derived struvite crystals. In conclusion, these experiments revealed that the bacteria play a major role in the specific morphogenesis of struvite and can able to control the nucleation, modulate crystalline phases, and shape of the growing crystal.

Topics: Bacterial Proteins; Calcinosis; Crystallization; Enterobacter cloacae; Humans; Imaging, Three-Dimensional; In Vitro Techniques; Porosity; Pseudomonas aeruginosa; Struvite; Urease; Urinary Calculi; Urine; X-Ray Microtomography

Urolithiasis affects primarily the urinary tract and complications as debilitating as renal failure may develop. Determining the chemical composition of uroliths can aid management and prevention of recurrence in patients.. To determine the chemical composition and anatomical distribution of uroliths in Nigeria.. This descriptive cross-sectional study was conducted between March 2014 and February 2016, in a tertiary hospital in Nigeria. We reviewed the outcomes of uroliths of adult patients sent to our laboratory for chemical analyses. Samples were analyzed using simple qualitative tests.. 52 adult patients were included with a mean age (SD) of 46.6 (12.6) years. Males (76.9%) were more affected than females (23.1%). For both sexes, highest occurrence of stones was in bladder (85.7%). Calcium-containing stones had the highest occurrence (85.2%) and predominated in the renal, ureter and urethra, followed by struvite stones (59.5%). In the bladder, struvite stones were predominant (85.8%), with calcium-containing stones accounting for 71.4%.. This study showed that struvite and calcium phosphate-containing stones constitute majority of uroliths in our setting with low occurrence of calcium oxalate stones. This indicates that urinary tract infection most likely plays a substantial role in the formation of uroliths in Nigerians. Modern methods of stone analysis is advocated to further define management options.

Topics: Adult; Aged; Calcium Phosphates; Cross-Sectional Studies; Female; Humans; Magnesium Compounds; Male; Middle Aged; Nigeria; Struvite; Tertiary Care Centers; Urinary Calculi; Urinary Tract Infections; Urolithiasis

It is a fact that recurrence of urinary stones is a common medical problem. One of the key factors used in determining the risk of urinary stone-formation is the urine relative saturation in the major constituents of lithiasis. Nomograms were developed in the 1970's to estimate the relative saturation of urine. We present here easy-to-use mathematical equations derived from these nomograms. These equations can be integrated directly in the LIS of any laboratories, and can be used as a tool in the treatment and prevention of recurrent stone-formation.

Topics: Algorithms; Ammonia; Calcium; Calcium Oxalate; Calcium Phosphates; Cysteine; Cystine; Hospitals, Urban; Humans; Hydrogen-Ion Concentration; Kidney Calculi; Magnesium; Models, Biological; Oxalic Acid; Phosphates; Quebec; Recurrence; Remission Induction; Risk Factors; Struvite; Uric Acid; Urinary Calculi

To explore underlying mechanism of urinary stones formation, the composition and microstructure of urinary stones were analyzed systematically with a large sample study from China.. A total of 2437 urinary stones were obtained from the urology department at our Hospital. The composition of the stones was analyzed by Fourier transform infrared spectroscopy (FTIR). Meanwhile, the microstructure and element distribution were observed with scanning electron microscopy combined with element distribution analysis (SEM-EDAX).. Urinary stones were classified into eight types, that were consisted of calcium oxalate stones (1301/2437, 53.39%), calcium phosphate stones (131/2437, 5.38%), anhydrous uric acid stones (434/2437, 17.81%), magnesium ammonium phosphate stones (12/2437, 0.49%), sodium urate stones (5/2437, 0.21%), brushite stones (4/2437, 0.16%), cystine stones (3/2437, 0.12%) and mixed stones (547/2437, 22.45%, ten subtypes were included). Under SEM, they displayed distinct microstructures: plank-like, brick-like, polyhedron or paliform crystals for calcium oxalate stones, similar sized echin-sphere or rough bulbiform or tree bark-like crystals for calcium phosphate stones, rotten-wood-like or petrous crystals for anhydrous uric acid stones, globular or gallet-like crystals for magnesium ammonium phosphate stones, sawdust-like crystals for sodium urate stones, broken-wood-like crystals for brushite stones, stacking hexagonal cystine crystals for cystine stones, and two or more of the above crystals for mixed stones. Meanwhile, they also presented distinct elemental composition and distribution by EDAX.. Urinary stones can be classified into eight types, and exhibit a diversity of microstructure and elemental compositions in China. The formation process of different types of urinary stones may be diverse.

Topics: Calcium Oxalate; Calcium Phosphates; China; Cystine; Humans; Microscopy, Electron, Scanning; Spectroscopy, Fourier Transform Infrared; Struvite; Uric Acid; Urinary Calculi

Many studies have been performed on adult patients to reveal the relationship between Hounsfield unit (HU) value and composition of stone, but none have focused on childhood.. We aimed to predict stone composition by HU properties in pre-intervention non-contrast computed tomography (NCCT) in children. This could help to orient patients towards more successful interventions.. Data of 94 children, whose pre-intervention NCCT and post-interventional stone analysis were available were included. Stones were grouped into three groups: calcium oxalate (CaOx), cystine, and struvite. Besides spot urine PH value, core HU, periphery HU, and Hounsfield density (HUD) values were measured and groups were compared statistically.. The mean age of patients was 7 ± 4 (2-17) years and the female/male ratio was 51/43. The mean stone size was 11.7 ± 5 (4-24) mm. There were 50, 38, and 6 patients in the CaOx, cystine, and struvite groups, respectively. The median values for core HU, periphery HU, and mean HU in the CaOx group were significantly higher than the corresponding median values in the cystine and struvite groups. Significant median HUD difference was seen only between the CaOx and cystine groups. No difference was seen between the cystine and struvite groups in terms of HU parameters. To distinguish these groups, mean spot urine PH values were compared and were found to be higher in the struvite group than the cystine group (Table).. The retrospective nature and small number of patients in some groups are limitations of this study, which also does not include all stone compositions. Our cystine stone rate was higher than childhood stone composition distribution in the literature. This is because our center is a reference center in a region with high recurrence rates of cystine stones. In fact, high numbers of cystine stones helped us to compare them with calcium stones more accurately and became an advantage for this study.. NCCT at diagnosis can provide some information for determination of stone composition. While CaOx stones can be discriminated from cystine and struvite stones using HU parameters, a simple spot urine pH assessment must be added to distinguish cystine stones from struvite stones.

Topics: Adolescent; Calcium Oxalate; Child; Child, Preschool; Clinical Decision-Making; Cohort Studies; Contrast Media; Cysteine; Female; Humans; Male; Preoperative Care; Retrospective Studies; ROC Curve; Sensitivity and Specificity; Statistics, Nonparametric; Struvite; Tomography, X-Ray Computed; Uric Acid; Urinary Calculi

Topics: Humans; Phosphates; Struvite; Urinary Calculi

OBJECTIVE To determine whether dual-energy CT (DECT) could accurately differentiate the composition of common canine uroliths in a phantom model. SAMPLE 30 canine uroliths with pure compositions. PROCEDURES Each urolith was composed of ≥ 70% struvite (n = 10), urate (8), cystine (5), calcium oxalate (4), or brushite (3) as determined by standard laboratory methods performed at the Canadian Veterinary Urolith Centre. Uroliths were suspended in an agar phantom, and DECT was performed at low (80 kV) and high (140 kV) energies. The ability of low- and high-energy CT numbers, DECT number, and DECT ratio to distinguish uroliths on the basis of composition was assessed with multivariate ANOVA. RESULTS No single DECT measure differentiated all urolith types. The DECT ratio differentiated urate uroliths from all other types of uroliths. The DECT and low-energy CT numbers were able to differentiate between 8 and 7 pairs of urolith types, respectively. CONCLUSIONS AND CLINICAL RELEVANCE Results indicated that DECT was unable to differentiate common types of canine uroliths in an in vitro model; therefore, it is unlikely to be clinically useful for determining urolith composition in vivo. Given that the primary reasons for determining urolith composition in vivo are to predict response to shock wave lithotripsy and develop a treatment plan, future research should focus on the correlation between DECT measurements and urolith fragility rather than urolith composition.

Topics: Animals; Calcium Oxalate; Calcium Phosphates; Canada; Dog Diseases; Dogs; Struvite; Tomography, X-Ray Computed; Uric Acid; Urinary Calculi

The Objective of this study is to analyze the difference in renal stone composition between Uyghur and Han children with urolithiasis in China and possible reasons. From May 2011 to September 2013, we analyzed the stone compositions of 274 Chinese children with urolithiasis, including 151 Uyghur children from Xinjiang Province and 123 Han children from Guangdong Province. All the stone components were determined by Infrared spectroscopy and the main components were recorded. We also evaluated the data, including age, gender and geographic region of the patients. The mean age of Uyghur children was less than Han children (5.3 ± 4.2 vs 8.6 ± 5.7 years, p < 0.001). Calcium oxalate (CaOx) was the main stone composition in both Uyghur (35.1 %) and Han (64.2 %) children, but was more common in Han children (p < 0.0001). Cystine stone was also more abundant in Han children (8.9 % vs 0.7 %, p = 0.001). While, both uric acid (20.5 % vs 3.3 %, p < 0.0001) and magnesium ammonium phosphate (16.6 % vs 2.5 %, p < 0.0001) stones were more common in Uyghur. Interestingly, the significant differences in stone composition between the two groups were only observed in males. When the pediatric patients were further divided into three age groups which were 0-5, 6-12 and >12, the prevalence of calcium oxalate stones increased with age in both groups and was higher in Han children at each age level. The compositions of urinary stones were significantly different between Uyghur and Han children with urolithiasis, factors such as diet habit, life style, genetic diversity, environmental and medical conditions may all contribute to the variances.

Topics: Adolescent; Age Factors; Calcium Oxalate; Child; Child, Preschool; China; Cystine; Cystinuria; Female; Humans; Infant; Male; Prevalence; Retrospective Studies; Sex Factors; Spectrophotometry, Infrared; Struvite; Uric Acid; Urinary Calculi

The incidence and prevalence of urinary stone are increasing throughout the world. Compared to the past, recent demographics of patient with urolithiasis compositions are strikingly different. Furthermore, recent clinical studies implied that seasonal cyclicity might influence the distribution of stone composition.. We sought to determine the trends in pathogenesis of urolithiasis based on urinary stone analyses. Between 2002 and 2014, a total of 2,383 eligible urinary stone samples from different patients were collected in our center. Infrared spectroscopy was used for urinary calculi analysis. A logistic regression analysis was used to investigate the relationship between urinary calculi composition and calendar month (season), gender, and age in north China during the past 13 years.. Calcium-containing calculi were the most frequent with an overall incidence of 84.1%. Calcium phosphate (CaP) or magnesium ammonium phosphate (MAP) stones were more frequent in females, while monohydrate calcium oxalate (COM), dihydrate calcium oxalate (COD), or uric acid (UA) stones were more common in males. Older individuals were associated with an increased risk of UA stones and a decreased risk of COD, CaP, or cystine stones. Additionally, from 2002 to 2014, the frequency of COD and MAP stone increased, whereas the trend of CaP, UA and cystine stones decreased. However, calendar month (season) was not significantly associated with differences in composition.. This study provides the present distribution of urolithiasis compositions in China. From 2002 to 2014, age and gender were significantly associated with stone composition, whereas calendar month was not.

Topics: Adolescent; Adult; Age Distribution; Age Factors; Aged; Aged, 80 and over; Calcium Oxalate; Calcium Phosphates; Child; Child, Preschool; China; Female; Humans; Infant; Infant, Newborn; Longitudinal Studies; Male; Middle Aged; Multivariate Analysis; Regression Analysis; Seasons; Sex Factors; Struvite; Urinary Calculi; Young Adult

To better understand the basis of urinary calculi formation, we studied the composition, microstructure, and element analysis of different types of urinary calculi. Sixty people with urinary stones in Shanxi province were selected randomly. The composition of urinary stones was analyzed using Fourier transform infrared spectroscopy. The microstructure of material components was observed by a scanning electron microscopy and the elemental distribution and composition were analyzed by an X-ray energy spectrometer. Furthermore, general information, BMI, history of medicine, chronic medical history, family history, and recurrence rates were collected. Female-to-male ratio was 1:2.5; median age was 43.2 years old. Of the patients, 13.3% were found definite family history and 46.6% of patients for recurrence history. It was found that mixed stones account for the largest proportion (65%), followed by calcium oxalate monohydrate calculi (26.67%). In mixed stones, the mixture of calcium oxalate monohydrate and hydroxyapatite had the largest proportion, accounting for 71.79%. Stones showed different microcosmic characteristics and element distribution. Stones varied widely in distribution, infrared spectrum, microstructure, and element composition, which provided an important basis for urinary calculi research regarding urinary stone formation.

Topics: Adult; Apatites; Calcium Oxalate; Cystine; Female; Humans; Male; Microscopy, Electron, Scanning; Middle Aged; Spectrometry, X-Ray Emission; Spectroscopy, Fourier Transform Infrared; Struvite; Uric Acid; Urinary Calculi

Stone analysis is not always available, and recent studies reveal interlaboratory reporting differences, suggesting inaccurate reports. We sought to determine whether appropriate medical therapy could be made without stone analysis when imaging, history, and laboratory data were available.. One hundred stone formers (SFs) were categorized as calcium oxalate, calcium phosphate, uric acid, or struvite based on a single analysis. Age, gender, body mass index, comorbidities, serum chemistries, 24-hour urine, and imaging information were incorporated into a "Megaprofile." Radiographic details about patients' stones were recorded. Attenuation: Size ratios were calculated to predict stone composition. Stone composition data were then withheld and three urologists (S.L.B., S.S., and S.Y.N.) evaluated each Megaprofile, making nutritional and pharmacologic recommendations. Next, a repeat evaluation ensued with stone analyses. Recommendations were compared with the gold standard being those made using stone composition data.. Without stone analysis, the panel recommended targeted nutrition therapy in 91% of cases, which remained unchanged once composition was revealed. Medication was prescribed in 68% of cases. Overall, therapy based on the Megaprofile without stone composition data was appropriate 93% of the time. In 7% of cases, therapy was changed after stone composition was revealed. In 21% of patients with recurrent urinary tract infections (UTIs), knowledge of stone composition altered therapy.. Medical, laboratory, and radiographic data provide sufficient information to direct both nutritional and pharmacologic therapy in most SFs (93%), but those with recurrent UTIs may derive more benefit from stone analysis prior to directed medical therapy.

Topics: Adult; Aged; Allopurinol; Anti-Bacterial Agents; Body Mass Index; Calcium Oxalate; Calcium Phosphates; Cohort Studies; Diet Therapy; Diuretics; Enzyme Inhibitors; Female; Humans; Magnesium Compounds; Male; Middle Aged; Phosphates; Potassium Citrate; Struvite; Thiazides; Time Factors; Uric Acid; Urinary Calculi; Urology

Nephrolithiasis is a common disease caused by the multifactorial components such as geographical location, bacterial infection, low urine volume, and low intake of water. This disease induces severe metabolic abnormalities in the human body. As the prevalence of this disease was high in Dharmapuri district located in Tamil Nadu, urinary stones removed from the patients pertaining to this district were collected and to identify the toxic elements present in the stones. The presence of functional groups and phases of the stones were analyzed using X-ray diffraction (XRD), Fourier transform Raman spectroscopy and Fourier transform infrared spectroscopy (FT-IR). The majority of stones were found to be calcium oxalate monohydrate (COM) and mixed stones having minor existence of struvite and uric acid. Hexagonal shaped COM crystals, needle shaped uric acid crystals and layered arrangement of struvite crystals in the core region were revealed by Scanning Electron Microscopy (SEM). Thermo Gravimetric Analysis (TGA) was used to determine the thermal stability and the hardness of the stone which was measured using Vickers hardness (HV). The presence of toxic elements in stones such as zirconium and mercury was identified using Energy Dispersive X-ray Spectroscopy (EDS). The EDS analysis showed higher concentration of zirconium in the core region compared to the periphery. The percentage of zirconium was relatively high compared to other toxic elements in the stones. The Vickers hardness results indicated that high HV values in the core region than the periphery and this might be due to the presence of zirconium.

Topics: Calcium Oxalate; Hardness; Humans; India; Magnesium Compounds; Phosphates; Spectroscopy, Fourier Transform Infrared; Spectrum Analysis, Raman; Struvite; Uric Acid; Urinary Calculi; X-Ray Diffraction; Zirconium

In the present study, FT-IR, XRD, TGA-DTA spectral methods have been used to investigate the chemical compositions of urinary calculi. Multi-components of urinary calculi such as calcium oxalate, hydroxyl apatite, struvite and uric acid have been studied. The chemical compounds are identified by FT-IR spectroscopic technique. The mineral identification was confirmed by powder X-ray diffraction patterns as compared with JCPDS reported values. Thermal analysis techniques are considered the best techniques for the characterization and detection of endothermic and exothermic behaviors of the urinary stones. The percentages of each hydrate (COM and COD) are present together, in the presences of MAPH or UA. Finally, the present study suggests that the Urolithiasis is significant health problem in children, and is very common in some parts of the world, especially in India. So that present study is so useful and helpful to the scientific community for identification of latest human health problems and their remedies using spectroscopic techniques.

Topics: Calcium Oxalate; Child; Differential Thermal Analysis; Humans; India; Magnesium Compounds; Phosphates; Spectroscopy, Fourier Transform Infrared; Struvite; Thermogravimetry; Uric Acid; Urinary Calculi; X-Ray Diffraction

Recent studies have found that certain urinary proteins can efficiently inhibit stone formation. These discoveries are significant for developing effective therapies for stone disease, but the inhibition mechanism of crystallization remains elusive. In the present study, polyaspartic acid (PASP) was employed as a model peptide to investigate the effect of urinary proteins on the crystallization and morphological evolution of struvite. The results demonstrate that selective adsorption/binding of PASP onto the {010} and {101} faces of struvite crystals results in arrowhead-shaped morphology, which further evolves into X-shaped and unusual tabular structures with time. Noticeably, these morphologies are reminiscent of biogenic struvite morphology. Concentration-dependent experiments show that PASP can inhibit struvite growth and the inhibitory capacity increases with increasing PASP concentration, whereas aspartic acid monomers do not show a significant effect. Considering that PASP is a structural and functional analogue of the subdomains of aspartic acid-rich proteins, our results reveal that aspartic acid-rich proteins play a key role in regulating biogenic struvite morphology, and aspartic acid residues contribute to the inhibitory capacity of urinary proteins. The potential implications of PASP for developing therapeutic agents for urinary stone disease is also discussed.

Topics: Biomimetics; Crystallization; Humans; Magnesium Compounds; Microscopy, Electron, Scanning; Minerals; Molecular Weight; Peptides; Phosphates; Spectroscopy, Fourier Transform Infrared; Struvite; Urinary Calculi; X-Ray Diffraction

Information on composition of uroliths collected between 2003 and 2009 from dogs in Switzerland and epidemiologic data of affected dogs are summarised in this paper. Of 490 stones analysed 44% were composed of calcium oxalate, 330% of struvite, 80% of silica, 7% of urate, 3% of cystine, 3% were mixed stones and 1% each were calcium phosphate and xanthine stones. Compared to other dogs, Norwich Terriers, Norfolk Terriers, Miniature Schnauzers, Miniature Pinscher and Yorkshire Terriers had a significantly increased risk to suffer from calcium oxalate stones, Dalmatians and Continental Bulldogs from urate stones and English Bulldogs from cystine stones. No breed had an increased risk of struvite or silica stones. Stones composed of silica were more prevalent in Switzerland compared to other countries and were more common in the eastern part than in the western part of Switzerland. This study shows that there are differences in occurrence and prevalence of uroliths between Switzerland and surveys of other countries.

Topics: Animals; Breeding; Calcium Oxalate; Calcium Phosphates; Cystine; Dog Diseases; Dogs; Female; Magnesium Compounds; Male; Phosphates; Prevalence; Risk Factors; Silicon Dioxide; Struvite; Switzerland; Uric Acid; Urinary Calculi; Urolithiasis; Xanthine

To describe a cohort of bilateral stone formers with significantly different compositions between renal units.. Patients treated for bilateral nephrolithiasis over a 4-year period (2007-2010) were identified. Stones were categorized by dominant (≥50%) mineralogical component. Patients with significant compositional differences between renal units (discordant stone formers) were compared to patients with a similar stone type in each kidney.. Fifteen of the 59 bilateral stone formers (25.4%) were discordant stone formers with significant differences in stone composition between renal units. Forty-four of the 59 patients (74.6%) had the same stone composition on each side. Thirty percent of discordant stones had calcium phosphate as the dominant stone component. Discordant stone formers were younger, had better renal function, and tended to have a larger stone burden (p < 0.05).. A significant minority of bilateral stone formers form a different type of stone in each kidney. Local or micro-environmental etiologies may explain this phenomenon and may also account for failure of preventive therapy in some patients.

Topics: Age Factors; Body Mass Index; Calcium Oxalate; Calcium Phosphates; Cellular Microenvironment; Cohort Studies; Female; Glomerular Filtration Rate; Humans; Kidney; Magnesium Compounds; Male; Middle Aged; Phosphates; Retrospective Studies; Sex Factors; Struvite; Ureteroscopy; Urinary Calculi

Proteus mirabilis cause urinary tract infections which are recurrent and can lead to formation of urinary calculi. Both bacterial and the host factors are involved in the development of urolithiasis. To determine the impact of glycosaminoglycans (GAGs) in the formation of P. mirabilis-induced urinary stones, we investigated the in vitro crystallization, aggregation and adhesion of crystals in the presence of GAGs naturally appearing in urine. Crystallization experiments were performed in synthetic urine infected with P. mirabilis in the presence of: hyaluronic acid (HA), heparan sulfate (HS), chondroitin sulfate A, B and C (ChSA, ChSB, ChSC). The intensity of crystallization and aggregation were established by counting particles and phase-contrast microscopy. To analyze the adhesion of crystals, we used normal urothelium and (45)Ca isotope-labeled crystals. In the presence of ChSC, both the size of the crystals formed and their number were higher compared with the control. GAGs increased crystals adhesion to the cells, but only for ChSA this effect was significant. Chondroitin sulfates, which accelerate the first stages of infection-induced stones formation, may play an important role in the pathogenesis of infectious urolithiasis.

Topics: Adhesiveness; Apatites; Cell Line; Chondroitin Sulfates; Crystallization; Dermatan Sulfate; Glycosaminoglycans; Heparitin Sulfate; Host-Pathogen Interactions; Humans; Hyaluronic Acid; Magnesium Compounds; Microscopy, Phase-Contrast; Models, Biological; Phosphates; Proteus Infections; Proteus mirabilis; Struvite; Urinary Calculi; Urinary Tract Infections; Urothelium; Virulence

We reported a retrospective review of the urinary stone compositions in 12,846 patients. Data on urinary stone compositions analyzed between January 2003 and December 2012 in our center were collected. Infrared spectroscopy was used for stone analysis. Predominant stone component was recorded. Patients were divided into four age groups: 0-18, 19-40, 41-60, and 61-92, and five categories by components. In order to determine the change of stone characteristics with respect to time, data were also divided into two periods, 2003-2007 and 2008-2012. A total of 12,846 stones were included in this study. The age of the patients ranged from 1 to 92 years with 7,736 males and 5,110 females. Stone made of single component was rare, 2.61%. Calcium oxalate stone was the most common component at 82.56%. Calcium oxalate and uric acid stones were more common in male than in female. The incidence of calcium phosphate stones and uric acid stones had increased during the past 5 years, while calcium oxalate stones decreased. We found the highest incidence of stone disease in the 41-60 years old group and the lowest in the 1-18 years old for both genders. Calcium oxalate was the dominant component in every group but was more prevalent in 19-40 years group. The percentage of magnesium ammonium phosphate stone and uric acid stone increased with age.

Topics: Adolescent; Adult; Aged; Aged, 80 and over; Calcium Oxalate; Calcium Phosphates; Child; Child, Preschool; China; Female; Humans; Infant; Magnesium Compounds; Male; Middle Aged; Phosphates; Retrospective Studies; Spectrophotometry, Infrared; Struvite; Uric Acid; Urinary Calculi; Young Adult

To compare the accuracy between conventional computed tomography (CT) and dual-energy CT (DECT) in predicting stone composition in a blinded, prospective fashion.. A total of 32 renal stones with known composition were scanned in vitro, first using standard CT techniques at 120 kilovolt peak (kV[p]) and then using fast-switched kilovolt DECT at 80 and 140 kilovolt peak (kV[p]). For the DECT scan, a spectral curve was created demonstrating the change of Hounsfield units (HU) across the kiloelectron volt spectrum. The composition of each stone was estimated by comparing each sample curve with curves of known materials. To attempt stone determination using single-energy CT, the HU of each stone was compared with ranges reported in previous studies. The accuracy of each method was compared.. Included were 27 stones large enough to allow analysis. Single-energy measurements accurately identified 14 of 27 stones of all composition (52%), whereas the DECT spectral curves correctly identified 20 (74%). When analyzed by stone type, single-energy vs DECT correctly identified 12 vs 12 of the 12 uric acid stones, 2 vs 3 of the 6 struvite stones, 0 vs 3 of the 5 cystine stones, and 0 vs 2 of the 4 calcium oxalate stones, respectively. When simply attempting to differentiate uric acid vs nonuric acid stones, single-energy CT could accurately differentiate only 6 of 15 stones as nonuric acid (40%) compared with 14 of 15 stones (93%) for DECT.. DECT appears to be superior to conventional CT in differentiating stone composition and is particularly accurate in differentiating nonuric acid from uric acid stones.

Topics: Absorptiometry, Photon; Calcium Oxalate; Cystine; Humans; Magnesium Compounds; Phosphates; Sampling Studies; Sensitivity and Specificity; Single-Blind Method; Struvite; Tomography, X-Ray Computed; Uric Acid; Urinary Calculi

Results of the structural analysis of urinary sediments by means of infrared spectral microscopy are presented. The results are in good agreement with the results of standard optical microscopy in the case of single-component and crystalline urinary sediments. It is found that for noncrystalline or multicomponent sediments, the suggested spectroscopic method is superior to optical microscopy. The chemical structure of sediments of any molecular origin can be elucidated by this spectroscopic method. The method is sensitive enough to identify solid particles of drugs present in urine. Sulfamethoxazole and traces of other medicines are revealed in this study among the other sediments. We also show that a rather good correlation exists between the type of urinary sediments and the renal stones removed from the same patient. Spectroscopic studies of urinary stones and corresponding sediments from 76 patients suffering from renal stone disease reveal that in 73% of cases such correlation exists. This finding is a strong argument for the use of infrared spectral microscopy to prevent kidney stone disease because stones can be found in an early stage of formation by using the nonintrusive spectroscopic investigation of urinary sediments. Some medical recommendations concerning the overdosing of certain pharmaceuticals can also be derived from the spectroscopic studies of urinary sediments.

Topics: Calcium Oxalate; Calcium Phosphates; Durapatite; Humans; Kidney Calculi; Magnesium Compounds; Microscopy; Optical Phenomena; Phosphates; Spectroscopy, Fourier Transform Infrared; Struvite; Uric Acid; Urinary Calculi

To evaluate the feasibility of determining the chemical composition of urinary stones using computed tomography (CT) spectral imaging (SI) MATERIALS AND METHODS: Two hundred and ten urinary stones were scanned in vitro using the SI mode and conventional polychromatic imaging (CPI; 120 kVp) mode. The radiodensity at 50 keV and 120 kVp, the mean calcium density (CD), and the water density (WD) were measured using the 50 keV images, 120 kVp images, calcium-based images, and water-based images, respectively. These parameters and the calcium-water ratio (CWR) were compared between different types of stones. CWR was defined as: CWR = ‌calcium density/water density‌.. According to the results determined by infrared spectroscopy, 116 pure urinary stones were divided into five groups: uric acid (UA, n = 16), struvite (STR, n = 23), cystine (CYS, n = 10), calcium phosphate (CaP, n = 29), and calcium oxalate (COX, n = 38). CD, CWR, and the radiodensity of stones at 50 keV CT imaging of each group were as follows: UA (-3.55 ± 10.85 mg/ml, 0.03 ± 0.05, 510.08 ± 157.29 HU); STR (224.99 ± 64.28 mg/ml, 0.19 ± 0.07, 1058.58 ± 260.13 HU); CYS (139.67 ± 34.66 mg/ml, 0.13 ± 0.03, 725.75 ± 142.35 HU); CaP (619.39 ± 26.13 mg/ml, 0.69 ± 0.11, 2617.46 ± 186.22 HU); COX (518.61 ± 95.5 mg/ml, 0.58 ± 0.1, 2247.47 ± 379.51 HU). The differences in the CD, CRW, and radiodensity of stones at 50 keV CT imaging among the groups were statistically significant by binary comparison (p < 0.05). There were no significant differences in the radiodensity of stones at 120 keV CT imaging between UA and CYS (p = 0.267), CaP and COX (p = 0.065), and in the WD between STR and CYS (p = 0.108).. SI provides a novel method to better characterize pure urinary stones using the mean CD, CWR, and the radiodensity of stones at 50 keV CT imaging.

Topics: Animals; Calcium Oxalate; Calcium Phosphates; Cystine; Feasibility Studies; Humans; Magnesium Compounds; Phosphates; Spectrophotometry, Infrared; Struvite; Sus scrofa; Tomography, Spiral Computed; Uric Acid; Urinary Calculi

We propose a simple and inexpensive in vitro crystallization assay of measuring turbidity by spectrophotometry in synthetic urine. We validated our method by investigating the effect of potassium (K) citrate on the crystallization of calcium oxalate monohydrate (CaOx), calcium phosphate, and magnesium ammonium phosphate using synthetic urine.. The crystallization of CaOx was studied using turbidimetric measurements of solution produced by mixing calcium chloride and sodium oxalate at 37 °C, pH 5.7. The turbidity of the crystal suspension was measured immediately with double-beam spectrophotometer as the absorbance of light at 660 nm wavelength. The rates of crystal formation and aggregation were obtained by measuring optical density (OD) over 30 min. The obtained results were compared to CaOx crystal concentration with and without citrate assessed by optical microscopy.. The sensitivity of spectrophotometry in measuring turbidity was confirmed by the linear correlation between the crystal concentration and OD readings at 660 nm seen on the standard curve. Under similar experimental conditions, the results were comparable to the ones obtained by optical microscopy. The OD readings over 30 min revealed an instant decrease in the number of crystals, with maximum aggregation noted at 18 min. Addition of K-citrate at 1.25 mg/ml led to initial less crystal formation (OD = 0.236 nm vs. OD = 0.527 nm), with a maximum aggregation reached at 18 min. Overall, citrate addition decreased nucleation with a small change in the aggregation (OD = 0.316 vs. OD = 0.359).. Spectrophotometric measurement of urinary turbidity is feasible and sensitive in assessing the potential clinical usefulness of different medications in inhibiting crystallization in urine.

Topics: Calcium Oxalate; Calcium Phosphates; Crystallization; Feasibility Studies; Humans; In Vitro Techniques; Magnesium Compounds; Nephelometry and Turbidimetry; Phosphates; Potassium Citrate; Reproducibility of Results; Sampling Studies; Sensitivity and Specificity; Spectrophotometry; Struvite; Urinary Calculi; Urine

In the present study the human urinary stones were observed in their different chemical compositions of calcium oxalate monohydrate, calcium oxalate dihydrate, calcium phosphate, struvite (magnesium ammonium phosphate), uric acid, cystine, oxammite (ammonium oxalate monohydrate), natroxalate (sodium oxalate), glushinkite (magnesium oxalate dihydrate) and moolooite (copper oxalate) were analyzed using Fourier Transform-Raman (FT-Raman) spectroscopy. For the quantitative analysis, various human urinary stone samples are used for ratios calculation of binary mixtures compositions such as COM/COD, HAP/COD, HAP/COD, Uric acid/COM, uric acid/COD and uric acid/HAP. The calibration curve is used for further analysis of binary mixture of human urinary stones. For the binary mixture calculation the various intensities bands at 1462 cm(-1) (I(COM)), 1473 cm(-1) (I(COD)), 961 cm(-1) (I(HAP)) and 1282 cm(-1) (I(UA)) were used.

Topics: Calcium Phosphates; Copper; Cystine; Fourier Analysis; Humans; Magnesium Compounds; Oxalic Acid; Phosphates; Spectrum Analysis, Raman; Struvite; Uric Acid; Urinary Calculi

Epidemiological surveys are important tools to identify emerging trends in disease. The Minnesota Urolith Centre has been tracking the occurrence of uroliths for over 30 years. To evaluate global changes in the frequencies of canine uroliths, submissions to the Minnesota Urolith Centre in 1999 and 2000 (n = 39,965) were compared with submissions in 2009 and 2010 (n = 99,598). The proportion of calcium oxalate uroliths rose on every continent except in Europe. Seventy-five per cent of dogs with calcium oxalate uroliths were between 5 and 11 years old. The proportion of struvite uroliths decreased on every continent except in Australia-Oceania. Seventy-seven per cent of all struvite formers were between two and eight years old. The proportion of purine uroliths has declined slightly. Worldwide, uroliths composed of cystine, calcium phosphate, calcium phosphate carbonate and silica remain uncommon. Epidemiological studies of urolithiasis are essential for constructing effective experimental designs and selecting appropriate cases and controls to conduct clinical trials with meaningful results.

Topics: Age Factors; Animals; Calcium Oxalate; Dog Diseases; Dogs; Female; Magnesium Compounds; Male; Phosphates; Sentinel Surveillance; Species Specificity; Struvite; Urinary Calculi; Urolithiasis

In the present work, we carried out density functional calculations of struvite--the main component of the so-called infectious urinary stones--to study its structural and elastic properties. Using a local density approximation and a generalised gradient approximation, we calculated the equilibrium structural parameters and elastic constants C(ijkl). At present, there is no experimental data for these elastic constants C (ijkl) for comparison. Besides the elastic constants, we also present the calculated macroscopic mechanical parameters, namely the bulk modulus (K), the shear modulus (G) and Young's modulus (E). The values of these moduli are found to be in good agreement with available experimental data. Our results imply that the mechanical stability of struvite is limited by the shear modulus, G. The study also explores the energy-band structure to understand the obtained values of the elastic constants.

Topics: Biomechanical Phenomena; Computer Simulation; Crystallization; Elastic Modulus; Humans; Magnesium Compounds; Microscopy, Electron, Scanning; Microscopy, Phase-Contrast; Models, Biological; Molecular Structure; Phosphates; Struvite; Urinary Calculi

Struvite in kidney stones is an important marker for infection. In kidney stone samples, struvite is known to be prone to chemical breakdown, but no data exist on the stability of samples stored in dry form. The objective of this study was to examine stability of struvite under increasingly poor conditions of storage.. Samples of struvite kidney stones were broken to obtain 38 pieces averaging 67 mg in weight, and these were randomized into four storage conditions: Airtight containers stored in the dark, open containers in the dark, open containers in ambient light, and open containers at elevated temperature (40°C). Pieces were left for 6 months, and then analyzed for changes using micro CT and Fourier transform infrared spectroscopy (FT-IR).. Initial samples proved to be struvite, indicating no transformation in the large specimens that had been stored in airtight containers in the dark for more than 6 years before this study. Pieces of struvite taken from these large specimens appeared unchanged by micro CT and FT-IR after being stored in closed containers for 6 months, but 8 of 9 pieces in open containers showed the presence of newberyite in surface layers, as did 10 of 10 pieces in open containers out in ambient light. All pieces stored at 40°C showed transformation of struvite, with 60% of the pieces showing the presence of amorphous phosphates, indicating complete breakdown of struvite in the surface layers of the pieces.. We conclude that struvite in dry kidney stone samples is stable when the specimens are stored in airtight containers at room temperature, even after several years.

Topics: Humans; Infections; Magnesium Compounds; Phosphates; Spectroscopy, Fourier Transform Infrared; Struvite; Tomography, X-Ray Computed; Urinary Calculi

Evaluation of urinary stones analysed between 1981 and 2008 in cats and comparison with data submitted, such as breed, age, sex and body weight.. Over the given years 5173 feline uroliths from cats in Germany and some neighbouring countries were analysed. From the forms submitted the following data was obtained for most cats: breed, age, sex, body weight, obesity status and location of the urinary stone(s). All uroliths were analysed by infrared spectroscopy. Uroliths containing at least 70% of a single mineral were classified as being of that type.. The cats with urolithiasis belonged to 25 different breeds. The most common breed was the European shorthair (64.3%) followed by Persian (15.2%), British shorthair (3.9%), Chartreux (1.7%), Maine Coon (1.5%) and Siamese (1.1%). Most animals were neutered or castrated (81.8%). Tom cats were significantly more frequently affected than female cats. The mean age (7 years) was virtually identical between both sexes, but varied between different stone types. Cats with struvite stones were significantly younger than cats with calcium oxalate stones (6.6 versus 7.6 years). Most urinary stones were retrieved from the bladder and/or urethra (93%). Over the entire time period (1981-2008) struvite (51.2%) and calcium oxalate (38.7%) stones were the two most common urolith types. Percent calcium oxalate stones increased significantly over time and were seen more often in 2008 than struvite stones (48.6% versus 43.4%). Amongst other urinary stones, ammonium urate (1.7%), carbonate apatite (1.7%), cystine (0.5%) and xanthine (0.3%) uroliths were analysed.. While struvite and calcium oxalate stones are presently found at approximately equal frequency in cats, various different urinary stones types can also occur in this species. Epidemiological knowledge of urinary stones is crucial as a basis for adequate therapy and prevention.

Topics: Age Factors; Animals; Breeding; Calcium Oxalate; Cat Diseases; Cats; Europe; Female; Germany; Magnesium Compounds; Male; Phosphates; Sex Factors; Spectrophotometry, Infrared; Struvite; Urinary Calculi

Studies that evaluate the effect of age on stone composition are scarce. The aim of this study was to highlight the changes in epidemiological characteristics (stone composition and location) of urolithiasis according to patients' age.. We studied 1,301 urolithiasis patients with age ranging from 6 months to 92 yr (781 males and 520 females). Stone analysis was performed using a stereomicroscope and infrared spectroscopy to determine the morphological type and molecular composition of each stone.. The annual average incidence of new stone formation was 31.7 per 100,000 persons. In 71.8% of cases, calculi were located in the upper urinary tract. Compared to other age groups, children and old men were more affected by bladder stones. Calcium oxalate monohydrate was the most frequent stone component, even though its frequency decreased with age (59.5% in young adults and 43.7% in the elderly, P<0.05) in favor of an increase in uric acid stones (11.5% in young adults and 36.4% in the elderly, P<0.05). Struvite stones were rare (3.8%) and more frequent in children than in adults.. The analysis of these data showed that urinary stones in Tunisian patients are tending to evolve in the same direction as the stones in patients from industrialized countries.

Topics: Adolescent; Adult; Age Factors; Aged; Aged, 80 and over; Calcium Oxalate; Child; Child, Preschool; Female; Humans; Infant; Kidney Calculi; Magnesium Compounds; Male; Middle Aged; Phosphates; Retrospective Studies; Spectrophotometry, Infrared; Struvite; Tunisia; Uric Acid; Urinary Bladder Calculi; Urinary Calculi; Young Adult

To identify breed-associated risk factors for urolithiasis in dogs from the UK.. Records of all canine uroliths submitted to Hills Pet Nutrition UK for analysis at the University of Minnesota Urolith Centre over 10 years (1997 to 2006) were reviewed. The results, along with the request forms completed by the submitting veterinarian, were analysed. The most commonly affected breeds, age and gender of the dogs were identified for each of the most common types of uroliths (struvite, calcium oxalate, urate, cystine and mixed). Pearson's chi-squared tests were performed to assess whether certain breeds of dogs were over-represented relative to a reference population (from an insurance database).. The records of 14,008 urolith submissions were analysed. The relative frequency of struvite remained stable over time, whereas calcium oxalate decreased over the study period. Breeds found to be significantly over-represented for calcium oxalate uroliths included the Chihuahua, miniature poodle and Yorkshire terrier. Staffordshire bull terriers and English bulldogs were at increased risk for cystine uroliths.. Associations between breed, gender, age and urolith formation were similar to those reported elsewhere. However, temporal trends and novel breed predispositions were identified.

Topics: Animals; Calcium Oxalate; Dog Diseases; Dogs; Female; Magnesium Compounds; Male; Phosphates; Retrospective Studies; Risk Factors; Species Specificity; Struvite; United Kingdom; Urinary Calculi; Urolithiasis

FT-Raman spectroscopy is the most useful tool for the purpose of bio-medical diagnostics. In the present study, FT-Raman spectral method is used to investigate the chemical composition of urinary calculi. Urinary calculi multi-components such as calcium oxalate, hydroxyl apatite, struvite and uric acid are studied. FT-Raman spectrum has been recorded in the range of 3500-400 cm(-1). Chemical compounds are identified by Raman spectroscopic technique. The quantitative estimations of calcium oxalate monohydrate (COM) 1463 cm(-1), calcium oxalate dehydrate (COD) 1478 cm(-1), hydroxyl apatite 959 cm(-1), struvite 575 cm(-1), uric acid 1283 cm(-1) and oxammite (ammonium oxalate monohydrate) 2129 cm(-1) are calculated using particular peaks of FT-Raman spectrum. The quantitative estimation of human urinary stones suitable for the single calibration curve was performed.

Topics: Calcium Oxalate; Durapatite; Humans; Magnesium Compounds; Oxalic Acid; Phosphates; Spectroscopy, Fourier Transform Infrared; Struvite; Uric Acid; Urinary Calculi

The mineral composition of 7819 small animal uroliths in the UK was determined by semi-quantitative X-ray diffraction over a period of 90 months from 2002 to 2010. Canine and feline uroliths constituted 97% of the study population and the mineral phase detected most frequently was struvite (43%), followed by calcium oxalate (41%). Uroliths from crossbreeds, Dalmatians, Yorkshire terriers and Shih Tzus accounted for almost 30% of all canine uroliths, with the highest frequency in Dalmatians, which had a predominance of urate uroliths. The average ages of dogs and cats with uroliths were 7.0 years and 7.4 years, respectively. The ratio of the number of dogs presenting with struvite compared to oxalate phases reached a maximum at 3years of age.

Topics: Age Factors; Animals; Breeding; Calcium Oxalate; Cats; Dogs; Female; Ferrets; Guinea Pigs; Magnesium Compounds; Male; Phosphates; Rabbits; Risk Factors; Species Specificity; Struvite; United Kingdom; Urinary Calculi; Urolithiasis

A series of 5,248 urinary stones was analyzed by Fourier transform infrared spectroscopy between 1999 and 2008. This study evaluated the percentage of each stone type and the association with sex and age in Chinese stone formers presenting with the first stone episode. The overall sex ratio (male:female) was 2.34:1. Results showed that the preponderant type of stone was calcium oxalate, followed by carbapatite, anhydrous uric acid, struvite and cystine. Struvite stones in this study accounted for a relatively low rate compared to that reported by others. Of 5,248 stones, only 38.1% had one component, 42.5% consisted of two components, and 20.4% consisted of three components. Our results also showed the higher percentage of carbapatite stones in females than in males and the increment of anhydrous uric acid stones with age. In addition, the percentage of calcium oxalate stones decreased with increase in the percentage of carbapatite stones over the period.

Topics: Adolescent; Adult; Aged; Aged, 80 and over; Apatites; Asian People; Calcium Oxalate; Child; Child, Preschool; China; Cystine; Female; Humans; Infant; Magnesium Compounds; Male; Middle Aged; Phosphates; Sex Factors; Spectroscopy, Fourier Transform Infrared; Struvite; Uric Acid; Urinary Calculi; Young Adult

The objective of the study was to evaluate epidemiological data derived from 2735 canine uroliths received by Hill's Pet Nutrition from Spain and Portugal between January 2004 and December 2006. The results of quantitative analysis from Minnesota Urolith Center (MUC) were compared with that from other countries and interrelations of mineral composition, age, breed, and gender were determined. The most frequent calculus was calcium oxalate (38.1%) followed by struvite (32.9%). Eighty-three breeds plus crossbreeds (25%) were identified. In all of them, but Dalmatians, calcium oxalate and struvite accounted for 71-78%. The mean age of urolith appearance was 7.6 years. There was a significant difference in the frequency of different uroliths composition among the six most common breeds presenting urolithiasis in Spain and Portugal (Yorkshire terrier, Miniature Schnauzer, Cocker Spaniel, Poodle, Shih Tzu and Dalmatian). This is the first report on xanthine urolithiasis found in Spain. Prevalence of cystine calculi was significantly lower (3.2%) than that reported previously in parts of Spain (26%).

Topics: Age Factors; Animals; Breeding; Calcium Oxalate; Cystine; Dog Diseases; Dogs; Female; Magnesium Compounds; Male; Phosphates; Portugal; Retrospective Studies; Sex Factors; Spain; Struvite; Urinary Calculi; Urolithiasis; Xanthine

By means of X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), nano-particle size analyzer, scanning electron microscopy (SEM) and transmission electron microscopy (TEM), the composition, morphology, particle size and zeta potential of urinary microcrystalline in urine of magnesium ammonium phosphate stone formers were investigated. The components of stones were also analyzed. The results showed that there was a close relationship among stone components, urinary microcrystalline composition and urine pH. A high pH value of 6.5 or more usually appeared in the urine of magnesium ammonium phosphate stone formers. The main component of urine microcrystalline was magnesium ammonium phosphate crystals with different crystal water such as monohydrate or hexahydrate. Magnesium ammonium phosphate crystals are mainly petal-shaped, crosswise shape. These microcrystalline have an uneven particle size distribution, a wider distribution range, and apparent aggregation. There is no significant difference in the zeta potential between the magnesium ammonium phosphate stone formers (mean (-9.83 +/- 0.66) mV) and healthy control subjects (mean (-10.74 +/- 0.25) mV). This study can help predict the occurrence of urolithiasis, and provide inspiration to the prediction of the type of urinary stones.

Topics: Humans; Hydrogen-Ion Concentration; Magnesium Compounds; Microscopy, Electron, Scanning; Microscopy, Electron, Transmission; Phosphates; Spectroscopy, Fourier Transform Infrared; Struvite; Urinary Calculi; X-Ray Diffraction

Formation of urinary stone is a serious and debilitating problem throughout the world. In the present study, the inhibitory effect of aqueous extract of root of Rotula aquatica was investigated against struvite crystals (one of the components of urinary stone) grown in vitro using single diffusion gel growth technique. For setting the gel, sodium metasilicate solution (specific gravity 1.05) and 0.5 M aqueous solution of ammonium dihydrogen phosphate were mixed, so that the pH of the mixture could be set at 7.0. Equal amounts of supernatant solution of magnesium acetate (1.0 M) prepared with 0.0%, 0.5% and 1% concentrations of the extract were gently poured on the set gels. It was observed that the number, dimension, total mass, total volume, growth rate and depth of growth of struvite crystals decreased with the increasing extract concentrations in the supernatant solutions. The enhancement of dissolution rate and fragmentation of struvite crystals suggested potential application of the extract for inhibition of struvite type urinary stone.

Topics: Crystallization; Humans; Magnesium Compounds; Particle Size; Phosphates; Plant Extracts; Plant Roots; Solubility; Struvite; Urinary Calculi

Using thermoluminescence spectrometer, X-ray diffraction and Fourier transform infrared spectroscopy, the chemical compositions of four types of kidney stones were investigated. They are calcium oxalate, uric acid, calcium phosphate and magnesium ammonium phosphate calculi (struvite). Experimental results showed that in the 305 cases of stones, calculi oxalate stones were found to account for 63%, uric acid stones 22%, calcium phosphate stones 8%, struvite 5%, and the stones with other compositions 2%. There were significant differences in the thermoluminescence spectra among the 4 types of urinary stones, which can provide an important basis for the clinic diagnosis of urinary stone types.

Topics: Calcium Oxalate; Calcium Phosphates; Humans; Kidney Calculi; Magnesium Compounds; Phosphates; Spectroscopy, Fourier Transform Infrared; Struvite; Uric Acid; Urinary Calculi; X-Ray Diffraction

This report describes light and scanning electron microscopic appearance of an ovum from the giant kidney worm, Dioctophyme renale found in the nidus and stone layer of a struvite calculus. The stone had been surgically removed from the bladder of a 4-year-old spayed female mixed breed dog from northern Ontario.

Topics: Animals; Dog Diseases; Dogs; Enoplida Infections; Female; Larva; Magnesium Compounds; Phosphates; Struvite; Urinary Calculi; Urine

The chemical composition and ultrastructure of urinary calculi obtained from male Boer goats were studied using qualitative chemical analysis, scanning electron microscopy, X-ray diffraction, X-ray energy dispersive spectrometry and Fourier transform infra-red spectroscopy. The calculi came from 10 naturally-occurring cases of urolithiasis and from seven cases of urolithiasis experimentally-induced by feeding a cottonseed meal-rice straw diet supplemented with magnesium oxide. The results indicated that the major component of urinary calculi collected from naturally-occurring and experimentally-induced cases of urolithiasis was struvite (magnesium ammonium phosphate). The study also identified previously unreported prismatic crystals in the uroliths of goats, similar to struvite but rich in potassium. The characteristic ultrastructure of struvite uroliths is described along with a brief discussion of their formation.

Topics: Animals; Crystallization; Goat Diseases; Goats; Magnesium Compounds; Male; Phosphates; Struvite; Urinary Calculi; Urolithiasis

Diuron, a substituted urea herbicide, is carcinogenic to the urinary bladder of rats at high dietary levels. Its proposed carcinogenic mode of action (MOA) includes urothelial cytotoxicity and necrosis followed by regenerative cell proliferation and sustained urothelial hyperplasia. Cytotoxicity could be induced either by urinary solids or by chemical toxicity by diuron and/or metabolites excreted in the urine. Diuron was not genotoxic in a previous single-cell gel (comet) assay, but possible cross-linking activity remained to be evaluated. The present study explored the MOA of diuron and the effect of urinary acidification on the development of urothelial lesions. Male Wistar rats were fed diuron (2500 ppm, about 130 mg/kg of body weight) either with or without NH(4)Cl 10,000 ppm to acidify the urine. Reversibility of urothelial changes was also examined. The animals were euthanized after 15, 25, or 30 weeks. Diuron-fed rats had urinary amorphous precipitate and magnesium ammonium phosphate crystals similar to control animals. Groups treated with diuron + NH(4)Cl showed decreased urinary pH and reduced amounts of urinary crystals and precipitate. Urothelial necrosis and simple hyperplasia were observed by light microscopy and scanning electron microscopy both in diuron- and in diuron + NH(4)Cl-treated groups. Cytotoxicity and proliferative changes were mostly reversible. A modified comet assay developed in vitro with Chinese hamster ovary cells showed that diuron did not induce DNA cross-links. These data suggest that cytotoxicity with consequent regenerative cell proliferation is the predominant MOA for diuron rat urothelial carcinogenesis, the cytotoxicity being chemically induced and not due to urinary solids.

Topics: Ammonium Chloride; Animals; Body Weight; Carcinogens; Cell Proliferation; CHO Cells; Comet Assay; Cricetinae; Cricetulus; Diuron; DNA Damage; Herbicides; Hydrogen-Ion Concentration; Hyperplasia; Magnesium Compounds; Male; Necrosis; Phosphates; Rats; Rats, Wistar; Regeneration; Struvite; Time Factors; Urinary Bladder; Urinary Bladder Neoplasms; Urinary Calculi; Urothelium

Using the spatial scan statistic with a Bernoulli model, in a comparison of the two most common canine uroliths, calcium oxalate (CaOx) and magnesium ammonium phosphate (struvite) we determined whether there was evidence of spatial and/or temporal clustering of each urolith type based on canine submissions from Ontario to the Canadian Veterinary Urolith Centre (CVUC) between 1998 and 2006. During this period, there were 10,478 canine submissions, excluding cases that were identified as recurrent. We were able to georeference approximately 93% of these incident cases. After adjusting for spatial and temporal distributions of dogs based on the demographic risk factors of age, sex, and breed-type, statistically significant spatial and temporal clusters were present for both CaOx and struvite urolith types. A purely temporal struvite cluster occurred between February 10, 1998 and December 20, 2001, whereas, a purely temporal CaOx cluster occurred between September 2, 2005 and December 21, 2006. Hypotheses to explain the spatial clustering of uroliths include variation in the spatial distribution of water hardness, diet-type, access to veterinary care, and the use of surgical versus medical therapies to treat these uroliths. Based on the cluster locations, water hardness was unlikely to explain the spatial difference between the two cluster types whereas variables related to human population density were more consistent with our findings; the CaOx cluster occurred in the highest population density area of Ontario, and the struvite cluster occurred in the lowest population density area of southern Ontario. The temporal struvite cluster at the beginning and CaOx cluster at the end of the study period reflect a similar trend away from struvite towards CaOx urolithiasis among both canines and humans in the developed countries of North America and Europe.

Topics: Animals; Calcium Oxalate; Cluster Analysis; Dog Diseases; Dogs; Female; Magnesium Compounds; Male; Ontario; Phosphates; Risk Factors; Struvite; Urinary Calculi; Urolithiasis; Water

Crystallographic structure, total energy, electronic structure, and the most important elastic properties of struvite, NH(4)MgPO(4).6H(2)O, the main component of infectious urinary stones, are presented. The calculations were performed using ab initio full-electron calculations within the density functional theory-generalized gradient approximation (DFT-GGA) framework. The obtained crystallographic symmetry and the calculated lattice parameters and also the elastic constants are in good agreement with the experimental data. The elastic properties are essential for establishing an optimal response of urinary stones during shock-wave lithotripsy. The calculated electronic charge distribution confirms the layered structure of the struvite crystals. The polar character of the crystal, well-known from crystal growth experiments, was also confirmed by the magnitude of spontaneous polarization which was obtained from direct determination of the electrical dipole density. The calculated value of spontaneous polarization is equal to -8.8 microC cm(-2). This feature may play a key role in struvite crystallization, electrically binding the charged active impurities and other active species, and consequently determining urinary stone formation. We also present the results of our own experiment of the mineralization of struvite induced to growth by Proteus bacteria which are mainly isolated from infectious urinary stones.

Topics: Algorithms; Crystallization; Crystallography, X-Ray; Elasticity; Electronics; Magnesium Compounds; Phosphates; Quantum Theory; Struvite; Urinary Calculi

The crystallites in urine are related closely with the formation of urolithiasis. In the present paper the composition, morphology and Zeta potential of crystallites of twenty calcium oxalate stone formers were comparatively studied using X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, nanoparticle size analyzer, scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The results showed that calcium oxalate calculi usually coexisted with a little of uric acid, calcium phosphate, and magnesium ammonium phosphate. By contrast, the compositions of urine crystallites of the patients with calcium oxalate calculi were mainly uric acid, phosphate, calcium oxalate and so on. Most of them had sharp angularity with a particle size distribution ranging from tens of nanometers to tens of microns; and obvious aggregation was observed. The negative value of Zeta potential of urine crystallites in the twenty stone formers (average value -5.92 mV) was less than that in the twenty normal subjects (-12.9 mV). However, there was no obvious difference in the urine pH between stone formers (average pH 6.03) and normal subjects (average pH 5.92). The study on the relationship between urine crystallites and urinary calculi components will be helpful for finding out the causes of urolithiasis and providing an important basis for the scientific prevention methods and reasonable treatments in clinic.

Topics: Calcium Oxalate; Calcium Phosphates; Humans; Magnesium Compounds; Microscopy, Electron, Scanning; Microscopy, Electron, Transmission; Nanoparticles; Particle Size; Phosphates; Spectroscopy, Fourier Transform Infrared; Struvite; Uric Acid; Urinary Calculi; Urolithiasis; X-Ray Diffraction

To get complete information about the chemical composition and physicochemical principles underlying the formation of stone there is a need for more precise information. At present there is no single analytical procedure that provides an exact quantitative analysis of urinary calculi. In this present procedure it is assumed that only calcium oxalate monohydrate, hydroxyapatite, or magnesium ammonium phosphate hexahydrate are present in stone, therefore the percent chemical composition of stone is calculated on the basis of molecular weight of an element and related molecular formula of the stone. By analysis of 100 stones the chemical composition observed with Mean +/- SD value for calcium is 25.68 +/- 5.38, for Calcium oxalate hydrate crystal is 32.84 +/- 17.28 which contains oxalic acid 20.35 +/- 10.70, for Apatite crystal is found to be 41.70 +/- 16.56 which contains inorganic phosphate 8.09 +/- 3.08. Total uric acid found in these stones is 27.12 +/- 11.42. Major component are calcium oxalate 32.8% (combined monohydrate and dihydrate), Phosphate 41.7%, Magnesium ammonium phosphate hexahydrate 3.3% and uric acid 27.1%. No pure stone was obtained. Calcium oxalate was present in nearly all stones, and the majority of renal calcium stones contains mixtures of calcium oxalate and calcium phosphates in addition some contains uric acid or magnesium ammonium phosphate. The mixture of calcium oxalate/uric acid/magnesium ammonium phosphate hexa hydrate has never been observed.

Topics: Calcium; Calcium Oxalate; Humans; Kidney Calculi; Magnesium Compounds; Oxalic Acid; Phosphates; Struvite; Uric Acid; Urinary Calculi

Struvite is one of the components of urinary stone. Large number of people is suffering from urinary stones (calculi) problem all over the globe. These stones can grow rapidly forming "staghorn-calculi", which is more painful urological disorder. Therefore, it is of prime importance to study the growth and inhibition of Struvite crystals. This in vitro study has been carried out in the presence of herbal extract of Commiphora wightii by using single diffusion gel growth technique. Sodium metasilicate solution of specific gravity 1.05 and an aqueous solution of ammonium dihydrogen phosphate of 0.5 M concentration were mixed so that the pH value 7.0 could be set. After the gelation, equal amount of supernatant solutions comprising of pure 1.0 M magnesium acetate as well as the mixtures of magnesium acetate and the herbal extract solutions of 0.5 and 1% concentrations of C. wightii were gently poured on the set gels. From the study of growth and inhibition behavior of Struvite crystals, it was found that C. wightii inhibits the growth of the Struvite. This study incorporates multidisciplinary interests and may be used for formulating the strategy for prevention or dissolution of urinary stones.

Topics: Chemical Precipitation; Commiphora; Crystallization; Dose-Response Relationship, Drug; Down-Regulation; In Vitro Techniques; Kidney Calculi; Magnesium Compounds; Particle Size; Phosphates; Plant Extracts; Solubility; Struvite; Urinary Calculi

To analyse three outcomes of stone prevention strategies in one clinic devoted to that activity since 1969, i.e. stone recurrence rates, stone-related procedures and 24-h urinary stone risk factor, to assess whether such treatment can be maintained over long periods.. We selected 2509 patients with at least one laboratory follow-up after initial clinical and laboratory evaluation. We divided them into five time cohorts of 5, 10, 15, 20 and >20 years of follow-up. Rates of new stones and stone-related procedures, and 24-h urinary stone risk factors were compared between the cohorts using analysis of variance and general linear modelling.. Stone rates and rates of stone-related procedures declined in all five cohorts, as did 24-h urinary stone risk indices. We found no diminution of treatment effects for any of these three over time.. Those patients who remained under active care had significant reductions in stone recurrence and rates of stone-related urological procedures for up to >20 years. However, only a small fraction of patients who entered the clinic remained for such long periods. Urine testing substantiates impressive and sustained reductions in supersaturation, the principle driving force for stone formation. Overall, for those patients willing to remain in continuous treatment for periods of up to three decades, medical stone prevention appears to be effective in maintaining low recurrence and procedure rates.

Topics: Adult; Calcium Oxalate; Calcium Phosphates; Cystine; Epidemiologic Methods; Female; Humans; Kidney Calculi; Magnesium Compounds; Male; Middle Aged; Phosphates; Risk Factors; Secondary Prevention; Struvite; Time Factors; Uric Acid; Urinary Calculi

The composition of urinary stones in children depends on socioeconomic conditions, geography and dietary habits. Pediatric urolithiasis remains endemic in developing countries. The aim of this study was to analyze stone composition in an Egyptian patient population.. We analyzed prospectively urinary stones from 100 consecutive children (73 males, 27 females), aged 14 months to 12 years. The stones were located in the upper urinary tract in 78%, lower urinary tract in 19% and both in 3%. Male patients had more lower urinary tract stones. On presentation 67% had flank pain and 37% had hematuria. Stones were treated by open surgery in 69% of patients, shockwave lithotripsy in 20% and endoscopic extraction in 13%.. The components of the upper urinary tract calculi were calcium oxalate (47%), ammonium acid urate (26%) and calcium carbonate (21%), whereas the main components of the lower urinary tract calculi were ammonium acid urate (27.2%), struvite (27.2%) and calcium carbonate (22.7%). Urinary tract infection was involved in the development of one third of the stones. Endemic stones were present in 17% of patients, and stones of metabolic origin in 15%. The etiology of stone formation remained unknown in one third of patients.. The epidemiological profile of urinary stones in Egyptian children can now be considered intermediate between developing countries where dietary deficiencies are the main causes and developed countries where infectious and metabolic calculi are observed.

Topics: Calcium Carbonate; Calcium Oxalate; Calcium Phosphates; Child; Child, Preschool; Egypt; Female; Humans; Infant; Lithotripsy; Magnesium Compounds; Male; Phosphates; Prospective Studies; Sex Distribution; Struvite; Uric Acid; Urinary Calculi; Urinary Tract Infections; Urologic Surgical Procedures

Urethral catheters often become encrusted with crystals of magnesium struvite and calcium phosphate. The encrustation can block the catheter, which can cause urine retention in the bladder and reflux into the kidneys. We develop a mathematical model to investigate crystal deposition on the catheter surface, modelling the bladder as a reservoir of fluid and the urethral catheter as a rigid channel. At a constant rate, fluid containing crystal particles of unit size enters the reservoir, and flows from the reservoir through the channel and out of the system. The crystal particles aggregate, which we model using Becker-Döring coagulation theory, and are advected through the channel, where they continue to aggregate and are deposited on the channel's walls. Inhibitor particles also enter the reservoir, and can bind to the crystals, preventing further aggregation and deposition. The crystal concentrations are spatially homogeneous in the reservoir, whereas the channel concentrations vary spatially as a result of advection, diffusion and deposition. We investigate the effect of inhibitor particles on the amount of deposition. For all parameter values, we find that crystals deposit along the full length of the channel, with maximum deposition close to the channel's entrance.

Topics: Algorithms; Biofilms; Calcium Phosphates; Catheters, Indwelling; Citric Acid; Crystallization; Humans; Hydrogen-Ion Concentration; Magnesium Compounds; Models, Biological; Phosphates; Rheology; Struvite; Urinary Calculi; Urinary Catheterization; Urinary Tract; Urinary Tract Physiological Phenomena; Urine

The aim of this study is to assess the clinical and biological characteristics of renal stone disease among children living in the coastal region of Tunisia. This retrospective multi-center study included 100 children under the age of 16 years, who presented with urinary stones. The patients' charts were reviewed with regard to age at diagnosis, sex, history and physical examination as well as laboratory and radiologic findings. Stone analysis was performed by infrared spectrophotometry. The male/female sex ratio was 1.5 to 1. The clinical presentation of this pathology was dominated by dysuria. Stones were located in the upper urinary tract in 76 cases (76%). A total of 13% of the study subjects had positive urine cultures. Metabolic investigations were performed in all patients and were normal in 80 cases. Whewellite (calcium oxalate) was found in 77 stones (77.0%). Stone section was made of whewellite in 69.0% of cases and ammonium urate in 47.0%. Struvite stones were more frequently seen in the lower urinary tract. Our study suggests that the epidemiological profile of renal stones in Tunisia has changed towards a predominance of calcium oxalate stones and upper tract location. Also, the male predominance of pediatric urolithiasis is becoming less obvious in Tunisia.

Topics: Abdominal Pain; Adolescent; Calcium Oxalate; Child; Child, Preschool; Dysuria; Female; Flank Pain; Humans; Infant; Magnesium Compounds; Male; Phosphates; Physical Examination; Retrospective Studies; Sex Distribution; Spectrophotometry, Infrared; Struvite; Tunisia; Uric Acid; Urinary Calculi; Urinary Tract Infections; Urolithiasis

To determine frequency of and interval until recurrence after initial ammonium urate, calcium oxalate, and struvite uroliths in cats and whether breed, age, or sex was associated with increased risk for urolith recurrence.. Case-control study.. 4,435 cats with recurrent uroliths.. To identify recurrence of uroliths in cats for which uroliths were submitted for analysis at the Minnesota Urolith Center in 1998, the facility's database was searched for urolith resubmissions from the same cats between 1998 and 2003. Risk factors and differences in mean interval until recurrence were assessed.. Of 221 cats with ammonium urate uroliths in 1998, 29 (13.1%) had a first and 9 (4.1%) had a second recurrence. Mean interval until recurrence was 22 and 43 months for the first and second recurrence, respectively. Of 2,393 cats with calcium oxalate uroliths in 1998, 169 (7.1%) had a first, 15 (0.6%) had a second, and 2 (0.1%) had a third recurrence. Mean interval until recurrence was 25, 38, and 48 months for the first, second, and third recurrence, respectively. Of 1,821 cats with struvite uroliths in 1998, 49 (2.7%) had a first and 3 (0.2%) had a second recurrence. Mean interval until recurrence was 29 months for first and 40 months for second recurrences.. These results provided insights into the frequency of urolith recurrence in cats. Because some uroliths associated with recurrent episodes probably were not submitted to our facility, our data likely represented an underestimation of the actual recurrence rate.

Topics: Animals; Calcium Oxalate; Case-Control Studies; Cat Diseases; Cats; Magnesium Compounds; Odds Ratio; Phosphates; Recurrence; Struvite; Uric Acid; Urinary Calculi; Urolithiasis

This study reports on trends in canine and feline urolithiasis in Canada during the past 10 years. Age, sex, breed of animals and mineral composition from 40 637 canine and 11 353 feline bladder uroliths submitted to the Canadian Veterinary Urolith Centre between 1998 and 2008 were recorded. Struvite and calcium oxalate uroliths comprised > 85% of all uroliths submitted. In dogs, the number of struvite submissions has declined and the number of calcium oxalate submissions has increased. Struvite uroliths were most common in female dogs and calcium oxalate uroliths in male dogs. The shih tzu, miniature schnauzer, bichon frisé, lhasa apso, and Yorkshire terrier were the breeds most commonly affected for both struvite and calcium oxalate uroliths. Urate uroliths were most common in male dalmatians. In cats, struvite submissions declined and calcium oxalate submissions remained constant. Struvite and calcium oxalate uroliths were common in domestic, Himalayan, Persian, and Siamese cats. Urate uroliths were over-represented in Egyptian maus.

Topics: Age Factors; Animals; Breeding; Calcium Oxalate; Canada; Cat Diseases; Cats; Dog Diseases; Dogs; Female; Magnesium Compounds; Male; Phosphates; Risk Factors; Species Specificity; Struvite; Urinary Calculi; Urolithiasis

In this work 85337 urinary stones were analysed by X-ray diffraction in regard of their qualitative and quantitative composition. Urological practitioners and hospitals from all areas of the former FRG sent urinary stones to the Institute of Mineralogy in Bonn and to the Urology Department of the St Josef-Hospital in Troisdorf up to December 31st, 1994. The evaluations were carried out with special regard to the frequency of occurrence and to the quantity portions. The frequency of occurrence of one component describes the percentage of the urinary stones which contain this component. The quantity portion describes the average amount of one component in regard to all urinary stones which contain this component as well. The frequency of occurrence of whewellite was 75.77% and of wheddellite 46.41%. 34.25% of all calculi were monomineralic and 55.3% were bimineralic.

Topics: Adolescent; Adult; Age Factors; Aged; Apatites; Calcium Oxalate; Child; Child, Preschool; Cross-Sectional Studies; Crystallography, X-Ray; Female; Germany; Humans; Infant; Magnesium Compounds; Male; Middle Aged; Phosphates; Sex Factors; Struvite; Uric Acid; Urinary Calculi

The Rietveld method is one of the most innovative and most important applications in x-ray diffraction and has now, for the first time, been applied to standard-free precise quantitative crystallographic analysis of urinary stones.. The capability of the Rietveld method was demonstrated by analysis of a synthetic mixture of five typical urinary stones: whewellite, hydroxylapatite, brushite, struvite, and uric acid, with 20 weight % for each pure component.. The quantitative phase analysis (Rietveld method) yielded a mean absolute error of only 1.6% for the weight fractions of the single urinary stone components. The largest error in weight fraction, 2.3%, occurred with hydroxylapatite, caused by the typical insufficient crystallinity.. Crystallographic analysis of complex urinary stones with the aid of x-ray diffraction, in combination with a Rietveld structure refinement, is the method of first choice for qualitative and quantitative phase analysis. With this tool, significant changes in weight fractions for recurrent urinary stones can be precisely detected, with therapeutic consequences.

Topics: Calcium Oxalate; Calcium Phosphates; Crystallography, X-Ray; Durapatite; Humans; Magnesium Compounds; Phosphates; Predictive Value of Tests; Recurrence; Risk Factors; Struvite; Uric Acid; Urinary Calculi

Report the relationship of composition with age and sex of the patients.. A series of 426 urinary stones, 33 from the lower (LUT) and 393 from the upper urinary tract (UUT) of adults, were analyzed for their chemical composition using infrared spectroscopy. The majority of LUT stones were from males (n = 26) and in the age group beyond 60 years (n = 20).. Calcium oxalate (CaOx) and uric acid and urate (UA-UR) were the main constituents in LUT stones of males and UA-UR and magnesium ammonium phosphate (MAP) of females. While UA-UR was distributed in all age group of males, it was only detected in elderly females. In cases of UUT stones, the peak finding for both sexes was for the 50-59-year-olds (age class). The MAP component was found more commonly in UUT stones of females, particularly in the younger age groups. CaOx and calcium phosphate (CaP) were the main components of UUT stones in both sexes (CaP was slightly more common in females) with the highest proportion in the 30-49-year-olds (age class), thereafter they declined and were replaced with UA-UR.. Although the proportion of LUT stones in the present study was small, the present findings agree with previous studies on the role of both age and sex in the etiopathogeny of urinary stones.

Topics: Adult; Age Factors; Aged; Aged, 80 and over; Calcium Oxalate; Female; Humans; Magnesium Compounds; Male; Middle Aged; Phosphates; Pilot Projects; Risk Factors; Sex Factors; Spectrophotometry, Infrared; Struvite; Thailand; Uric Acid; Urinary Calculi; Young Adult

Mechanical properties of renal calculi dictate how a stone interacts and disintegrates by shock wave or intracorporeal lithotripsy techniques. Renal stones of different compositions have large variation in their mechanical strength and susceptibilities to shock waves. Operated urinary stones and artificially developed stones using pharmaceutical methods, composed of phosphates were subjected to tensile, flexural and compressive strength studies using universal testing machine. The infrared spectra confirmed the presence of hydroxyapatite in both the natural stones and struvite with calcium oxalate trihydrate in one stone and struvite with uric acid in the other. The X-ray diffraction analyses confirmed their crystalline nature. It has been observed that the flexural properties depend on the size of the sample even for the samples cut from a single stone. The compressive strengths were almost 25 times larger than the tensile strengths of the respective natural stones as well as the artificial stones prepared.

Topics: Biomechanical Phenomena; Calcium Oxalate; Calcium Phosphates; Durapatite; Humans; Lithotripsy; Magnesium Compounds; Materials Testing; Phosphates; Spectrophotometry, Infrared; Struvite; Tensile Strength; Urinary Calculi; X-Ray Diffraction

The goal of this prospective study was to characterize ureteral stents encrustation in stone formers.. We report the results of a study based on 658 double-J stents (412 men and 246 women) collected from patients with in situ urinary calculi. The mean age was 48.2+/-16.0 years without differences between genders. Ureteral stent encrustation was analysed by infrared spectroscopy. Results are expressed according to the main component.. The mean indwelling time was 73.5+/-73.2 days. The main component in stent encrustations was calcium oxalate (43.8%), essentially the monohydrate form (27.1%), followed by proteins (27.4%), calcium phosphates (16.4% with 8.4% brushite), and uric acid (5.2%). Struvite, detected on 49 stents, was the main component in 2.4% of cases. Significant differences according to gender and age were found: calcium oxalate monohydrate, which represented 24.5% in 20 to 29 years old men class increased to 37.0% in 50 to 59 years class and then decreased in older patients. Calcium oxalate dihydrate increased with age up to 70 years in women while it felt dramatically in man beyond 50 years old. Brushite was more abundant in young men (20.4% in patients aged 20-29 years) and was decreasing beyond this age while it remained in stable proportion for all age classes in women. Increasing prevalence of uric acid encrustations with age was observed, especially in men beyond the age of 70 years. Mineral encrustations increased with the indwelling time, the part of mineral being preponderant after 15 days: 7,3% of the stents had become massively encrusted within 113 days mean period. The comparison between biomaterials showed that silicone stents were significantly less encrusted than polyurethane stents.. Stent encrustation constitutes a serious complication of ureteral stent use in stone formers. Lithogenic factors should be considered for the prevention of stent encrustation in these patients.

Topics: Adolescent; Adult; Age Factors; Aged; Aged, 80 and over; Calcium Oxalate; Calcium Phosphates; Female; Hemostatics; Humans; Magnesium Compounds; Male; Middle Aged; Phosphates; Polyurethanes; Prospective Studies; Proteins; Risk Factors; Sex Factors; Silicones; Spectrophotometry, Infrared; Stents; Struvite; Ureteral Calculi; Uric Acid; Urinary Calculi; Urinary Catheterization

From 1994 to 2004, Hill's Pet Nutrition received 4495 canine (65%) and feline (35%) uroliths from Benelux veterinary practitioners. They were sent to the Minnesota Urolith Center, USA for analysis. In 1994, 110 uroliths were analysed - 85% from dogs - and in 2003, 1067 uroliths were analysed - 59% from dogs. During this period, substantial changes were observed in composition. In 1994, 77% of the cats had uroliths composed of struvite, and 12% had uroliths composed of calcium oxalate. In 2003, feline uroliths were composed of 32% struvite, and 61% calcium oxalate. The same evolution was observed in the dogs. In 1994, 51% of canine uroliths were composed of struvite, and 33% of calcium oxalate. In 2003, 40% had struvite uroliths, and 46% had calcium oxalate uroliths. A significant effect of the size, the breed, and the gender were noticed in the dogs. The mean age of uroliths appearance was 7.3 years in the dogs and 7.2 years in the cats. The findings are similar to those previously published in the USA.

Topics: Animal Feed; Animal Nutritional Physiological Phenomena; Animals; Belgium; Breeding; Calcium Oxalate; Cat Diseases; Cats; Dog Diseases; Dogs; Female; Luxembourg; Magnesium Compounds; Male; Netherlands; Phosphates; Retrospective Studies; Sex Factors; Struvite; Urinary Calculi; Urolithiasis

Topics: Animals; Cystitis; Magnesium Compounds; Male; Phosphates; Radiography; Rats; Rats, Sprague-Dawley; Rodent Diseases; Struvite; Urinary Calculi

To derive hardness factors for crystal phases of urinary tract stones and describe the hardness pattern in a stone population.. In a retrospective study, recordings from patients treated with extracorporeal shock-wave lithotripsy (ESWL) (stone surface area < or = 100 mm2) were used to derive hardness factors. The number of re-treatments, the number of shock waves and the energy index (the voltage in kilovolts multiplied by the number of shock waves) required for a satisfactory stone disintegration were assumed to reflect the hardness. The stone composition in 2100 patients provided the basis for an average hardness pattern. A hardness index was calculated from the fraction of each crystal phase and its hardness factor.. The hardness factors were as follows: calcium oxalate monohydrate, 1.3; calcium oxalate dehydrate, 1.0; hydroxyapatite, 1.1; brushite, 2.2; uric acid/urate, 1.0; cystine, 2.4; carbonate apatite, 1.3; magnesium ammonium phosphate, 1.0; and mixed infection stones, 1.0. The hardness index for 114 stones (surface area 100-200 mm2) corresponded reasonably well to the ESWL treatment efforts. Calcium oxalate monohydrate, calcium oxalate dihydrate and hydroxyapatite were the most frequently encountered crystal phases in all 2100 stones. Only 21% of the stones were composed of only one crystal phase. There were two, three and more than three crystal phases in 26%, 38% and 15% of the stones, respectively. The hardness index calculated for 2100 stones ranged between 0.70 and 2.33, with a mean (SD) of 1.18 (0.15).. The hardness factors and hardness index derived in this study might be useful for describing the stone situation in individual patients and groups of patients and for comparison of various treatment strategies.

Topics: Apatites; Calcium Oxalate; Calcium Phosphates; Cystine; Durapatite; Hardness; Humans; Lithotripsy; Magnesium Compounds; Phosphates; Retrospective Studies; Struvite; Uric Acid; Urinary Calculi; Urinary Tract Infections

The clinical application of chemolysis for struvite stones is limited because of the need for a nephrostomy tube and the potential risk of elevated intrarenal pressures, which may be associated with sepsis and metabolic derangements. We evaluated the utility of a high-flow low-pressure irrigation system, designed to minimize the disadvantages of chemolysis, for struvite-stone dissolution.. An in-vitro urinary-tract model was used to compare a novel dual-lumen ureteral catheter with a standard nephrostomy tube for struvite stone chemolysis. A laboratory-proved large human struvite stone was divided into 3.5-g fragments, which were placed in the model. In the experimental group, Renacidin (citric acid, glucono-Delta-lactone, and magnesium carbonate; Guardian Laboratories, Lake Forest, IL) irrigation was performed through the high-flow low-pressure irrigation system. In the control group, Renacidin solution was infused at 120 mL/hour through a nephrostomy tube. Three stones were tested in each group. Intrarenal pressures, irrigant-flow rates, chemolysis rates at each time interval, overall chemolysis rates, and changes in chemolysis rates over time were compared using ANOVA.. The mean intrarenal pressure with the high-flow low-pressure irrigation system and the nephrostomy tube were 5.3 and 7.5 cm H(2)O, respectively (P < 0.001). The overall chemolysis rates with the high-flow low-pressure irrigation and control systems were 0.12 g/hr and 0.06 g/hr, respectively (P = 0.025). The chemolysis rates in the experimental and control groups did not differ significantly with time (P = 0.75 and 0.21, respectively).. In this in-vitro model, the high-flow low-pressure irrigation system facilitated struvite-stone chemolysis by achieving significantly higher flow rates than a traditional percutaneous system. Additionally, the system yielded lower intrarenal pressures than standard nephrostomy-tube irrigation.

Topics: Catheterization; Citrates; Humans; Magnesium Compounds; Models, Biological; Models, Structural; Phosphates; Struvite; Therapeutic Irrigation; Urinary Calculi

Two-thirds of the organic matrix in urinary stones consists of proteins. Their relationship to calculogenesis remains controversial with regard to their effect as inhibitors or promoters during stone formation. The purpose of the present study was to determine the differences in peptide and protein pattern between the urine of stone formers (n = 23) and control dogs (n = 12), as well as between organic matrix of different urinary stones (struvite n = 11, calcium oxalate n = 8, uric acid n = 4) using surface-enhanced laser desorption/ionization time-of-flight mass spectrometry. Specific differences in protein and peptide profiles were found in the organic matrix of different mineral compositions. Characteristic differences were also found in urinary peptide and protein pattern especially in molecular masses below 20 kDa between affected and healthy dogs. Based on the obtained molecular masses they were in some cases tentatively identified as proteins that are known to be involved in stone formation in humans. The study shows that in dogs, specific-urinary peptides and proteins might be associated with urolithiasis. It indicates the importance to further characterize those proteins for possible diagnostic purposes in prognosis and therapy.

Topics: Animals; Calcium Oxalate; Dietary Proteins; Dog Diseases; Dogs; Female; Magnesium Compounds; Male; Molecular Weight; Phosphates; Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; Struvite; Uric Acid; Urinalysis; Urinary Calculi

Individuals with struvite uroliths are susceptible to recurrent urinary tract infections (UTI), sepsis, and renal disease. Unfortunately, little is known about the host-specific factors that predispose to this disease. In order to develop a rodent model that can address this problem, we inoculated female Fischer 344 (F344), Lewis (LEW), Sprague-Dawley (SD), and Wistar (WIS) rats with a host-adapted strain of Ureaplasma parvum. Animals were necropsied at 2 weeks postinoculation; 100% of F344, 42% of SD, 10% of LEW, and 10% of WIS rats remained infected. Severe bladder lesions and struvite calculi were seen in 64% of F344 rats; in other rat strains, bladder lesions were mild or absent. F344 rats with struvite uroliths had the highest urinary levels of proinflammatory cytokines, such as GRO/KC, interleukin-1alpha (IL-1alpha), and IL-1beta. F344 rats without struvite stones at necropsy had milder bladder lesions and significantly lower urinary levels of proinflammatory cytokines but a more prominent inflammatory response than did other rat strains. Based on our results, struvite stone formation is linked to a robust inflammatory response that does not resolve UTI but instead promotes damage to surrounding tissues.

Topics: Animals; Antibody Formation; Cytokines; Disease Susceptibility; Female; Magnesium Compounds; Phosphates; Rats; Rats, Inbred Strains; Struvite; Ureaplasma; Ureaplasma Infections; Urinary Calculi; Urinary Tract Infections

The purpose of the present paper was to study the spectrum of stone composition of upper urinary tract calculi by X-ray diffraction crystallography technique, in patients managed at All India Institute of Medical Sciences.. Between 30 April 1998 and 31 March 2003, a total of 1050 urinary calculi (900 renal, 150 ureteric) were analyzed. The stone fragments were collected after extracorporeal shock-wave lithotripsy, or retrieval by endoscopic (percutaneous nephrolithotomy, ureterorenoscopy), laparoscopic and various open surgical procedures. The structural analysis of the stones was done using X-ray diffraction crystallography.. Four types of primary and three secondary X-ray diffraction patterns were obtained. The primary patterns were as follows. Pattern A, well organized crystalline structure; pattern B, moderately organized crystalline structure; pattern C, poorly organized crystalline structure; pattern D, very poorly organized crystalline structure. The three secondary patterns mainly highlighted the mixed variety of stones. These patterns were further analyzed and compared with standard X-ray diffraction (powder) photographs. Of the 1050 stones analyzed, 977 (93.04%) were calcium oxalate stones, out of which 80% were calcium oxalate monohydrate (COM) and 20% were calcium oxalate dihydrate (COD). Fifteen were struvite (1.42%) and 19 were apatite (1.80%). Ten were uric acid stones (0.95%) and the remaining 29 (2.76%) were mixed stones (COM + COD and calcium oxalate + uric acid, calcium oxalate + calcium phosphate, and calcium phosphate + magnesium ammonium phosphate). A total of 89.98% of staghorn stones were made of oxalates (COM/+COD) and only 4.02% were struvite.. Urinary stone disease in the Indian population is different from that in Western countries, with a larger percentage of patients having calcium oxalate stones, predominantly COM. Also, the majority of staghorn stones (89.98%) were made of oxalates.

Topics: Adolescent; Adult; Aged; Apatites; Calcium Oxalate; Child; Child, Preschool; Crystallography, X-Ray; Female; Humans; India; Magnesium Compounds; Male; Middle Aged; Phosphates; Powder Diffraction; Struvite; Uric Acid; Urinary Calculi

For this study, 25 samples of urinary stones were chosen from different provinces in Iraq as representative sampling localities. These samples of urinary stones were collected to represent kidney, urate, and bladder stones. The main objectives of this study are to try to shed some light on the possibilities of tracking down the effective environmental factors that determine the mineralogical and chemical composition of these stones. The stones were examined using several techniques, the most important of which was the use of the X-ray diffraction (XRD) technique to determine the mineralogical composition of these stones. A scanning electron microscopy (SEM) test was conducted to determine the crystallographic forms and structures for the minerals forming these stones. Optical properties of these minerals were studied using a polarizing microscope. All these techniques revealed that the calcium oxalate, represented in Whewellite mineral, is the most dominant type of these stones, in addition to other minerals such as Hydroxy apatite, Struvite, and Uricite. Dittmarite was pointed out for the first time ever in some samples. This mineral has not been determined in any previous study worldwide. Considering the results of mineralogical and chemical examinations of the urinary stones in question, and the statistical information gathered from the Iraqi Health Ministry, statistical analyses were applied. The ratio of male-female cases in this study happened to be 4:1, which was higher than the ratio in the years 1988-1989 and 1993-1994, 2:1; 3:1 respectively. The highest percentage of the cases was in the 15-50 age group, which is considered as the most productive years of human lifetime. This study showed that one of the most significant factors was that the mineralogical variation of urinary stones in some Iraqi provinces was due to geographical differences, which reflect the variation in lithogenic factors and also climatological factors. Other factors may be socioeconomic, genetic, physiological, and pathological, which remain the important factors in forming urinary stones.

Topics: Adolescent; Adult; Aged; Aged, 80 and over; Apatites; Calcium Oxalate; Climate; Female; Humans; Iraq; Magnesium Compounds; Male; Microscopy, Electron, Scanning; Middle Aged; Minerals; Phosphates; Socioeconomic Factors; Struvite; Uric Acid; Urinary Calculi; X-Ray Diffraction

To compare data on the epidemiology of canine urolithiasis in the Czech Republic with that from other countries.. The records from the Centre for Mineralogical Analysis from 1997 to 2002 were reviewed. The data were obtained from mineralogical analysis of 1366 canine uroliths obtained from patients in the Czech Republic. These included 396 females and 629 males.. Sixty-eight breeds plus crossbreeds were identified. Eight breeds plus the crossbreeds accounted for 71.3 per cent of all cases. Males were affected more frequently than females (61.4 per cent versus 38.6 per cent). Struvites significantly predominated in females, while in males calcium oxalates, brushites and cystines were the most common stones. Most of the uroliths (48.9 per cent) were 5 mm or less in dimension. By 2001, struvite was the most frequent (38.5 to 44.1 per cent) urolith, followed by calcium oxalate (26.5 to 32.0 per cent). In 2002, calcium oxalate became the most frequent calculus, followed by struvite, mixed calculi and others.. Comparison of these results with studies by other authors showed that for most of the monitored parameters there was agreement with respect to the proportions of different breeds within the populations of dogs in different geographical areas.

Topics: Age Factors; Animals; Calcium Oxalate; Czech Republic; Dog Diseases; Dogs; Female; Magnesium Compounds; Male; Phosphates; Retrospective Studies; Sex Factors; Struvite; Urinary Calculi

The purpose of this study was to report on the age, sex, breed, and mineral composition of 16 647 canine bladder uroliths submitted to the Canadian Veterinary Urolith Centre between February 1998 and April 2003. Each urolith submission was accompanied by a questionnaire. Of the submissions, approximately 43.8% were struvite and 41.5% oxalate. Struvite uroliths were most common in female dogs. Mixed breed dogs predominated, followed by the shih tzu, bichon frise, miniature schnauzer, Lhasa apso, and Yorkshire terrier. Oxalate uroliths were most common in males and in the miniature schnauzer, bichon frise, Lhasa apso, shih tzu, and Yorkshire terrier. Urate uroliths were most common in male Dalmations. Other urolith types, including cystine, xanthine, silica, and calcium phosphate, were less commonly reported. A review of risk factors for the various uroliths is presented, along with some recommendations for treatment and prevention.

Topics: Animals; Breeding; Calcium Oxalate; Calcium Phosphates; Diet; Dog Diseases; Dogs; Female; Magnesium Compounds; Male; Phosphates; Risk Factors; Sex Factors; Struvite; Surveys and Questionnaires; Uric Acid; Urinary Calculi

On 27 January 2000, a struvite calculus was observed in the vagina during necropsy of a 138-cm-long female bottlenose dolphin (Tursiops truncatus) collected from the Stono River, South Carolina (USA). Vaginal calculi have been reported in other species of cetaceans but not in bottlenose dolphins. Urinary tract infection might have been an underlying cause of the calculus. While urinary tract inflammation was not detected by light microscopic evaluation of sections of the urinary tract, it is conceivable that sufficient time had lapsed following voiding of the calculus through the urethra for urinary tract infection to have resolved. To further define the prevalence and significance of urolithiasis, prosectors of dead stranded marine mammals are encouraged to closely observe their urinary and genital tracts for calculi and to submit them for quantitative analysis.

Topics: Animals; Dolphins; Female; Magnesium Compounds; Phosphates; Struvite; Urinary Calculi; Urinary Tract Infections; Vagina

The aim of this study was to evaluate the efficacy of helical CT using a combination of CT-attenuation values and visual assessment of stone density as well as discriminant linear analysis to predict the chemical composition of urinary calculi. One hundred human urinary calculi were obtained from a stone-analysis laboratory and placed in 20 excised pig kidneys. They were scanned at 80, 120 and 140 kV with 3-mm collimation. Average, highest and lowest CT-attenuation values and CT variability were recorded. The internal calculus structure was assessed using a wide window setting, and visual assessment of stone density was recorded. A stepwise discriminant linear analysis was performed. The following three variables were discriminant: highest CT-attenuation value, visual density, and highest CT-attenuation value/area ratio, all at 80 kV. The probability of correctly classifying stone composition with these three variables was 0.64, ranging from 0.54 for mixed calculi to 0.69 for pure calculi. The probabilities of correctly classifying calculus composition were: 0.91 for calcium oxalate monohydrate and brushite, 0.89 for cystine, 0.85 for uric acid, 0.11 for calcium oxalate dihydrate, 0.10 for hydroxyapatite, and 0.07 for struvite calculi. When the first two ranks of highest probability for the accurate classification of each calculus type were taken into account, 81% of the calculi were correctly classified. Assessment at 80 kV of the highest CT-attenuation value, visual density and the highest CT-attenuation value/area ratio accurately predicts the chemical composition of 64-81% of urinary calculi. When the first two ranks of highest probability for the accurate classification of each calculus type were taken into account, all cystine, calcium oxalate monohydrate and brushite calculi were correctly classified.

Topics: Animals; Calcium Oxalate; Calcium Phosphates; Cystine; Discriminant Analysis; Durapatite; Humans; Magnesium Compounds; Phosphates; Predictive Value of Tests; Struvite; Swine; Tomography, Spiral Computed; Uric Acid; Urinary Calculi; Urography

Massive urolithiasis of the penile urethra was observed in an adult pygmy sperm whale (Kogia breviceps) stranded on Topsail Island, North Carolina, USA. Calculi occupied the urethra from just distal to the sigmoid flexure to the tip of the penis for a length of 43 cm. A urethral diverticulum was present proximal to the calculi. The major portion of the multinodular urolith weighed 208 g and was 16 cm long x 3.7 cm diameter at the widest point. The urolith was composed of 100% struvite (magnesium ammonium phosphate) and on culture yielded Klebsiella oxytoca, a urease-positive bacterium occasionally associated with struvite urolith formation in domestic animals. Reaction to the calculi was characterized histologically by moderate multifocal to coalescing plasmacytic balanitis and penile urethritis. Role of the urethrolithiasis in the whale's stranding is speculative but could have involved pain or metabolic perturbations such as uremia or hyperammonemia.

Topics: Animals; Fatal Outcome; Klebsiella Infections; Klebsiella oxytoca; Magnesium Compounds; Male; Phosphates; Struvite; Urethra; Urinary Calculi; Urinary Tract Infections; Whales

To determine the incidence, mode of presentation, first line of management and composition of non-recurrent urolithiasis in Kuwait.. Consecutive patients admitted between January 1999 and December 2002 with non-recurrent urolithiasis were prospectively analyzed.. The average annual incidence of hospital admission for non-recurrent urolithiasis in Kuwait was 43.44 per 100,000 population, representing men and women (ratio, 9:1) with a median age of 41.91 years. Of the hospital admissions for non-recurrent urolithiasis, 57.2% of cases were acute. Overall, the most predominant symptom was flank pain, while the least common symptom was acute urinary retention. Ureteroscopic stone manipulation was the most common initial treatment modality in the present series, as it was utilized in 43.3% and 37.09% for patients admitted on elective and emergency basis, respectively. Of the calculi available for chemical analysis, 91% contained calcium, 73% contained calcium oxalate, 17% contained mixed calcium and 1% contained calcium phosphate. The composition of the rest of the stones were urate in 7%, struvite in 1% and cystine in 1%.. Urolithiasis is a common disease in the Kuwait region that mainly presents with flank pain. Ureteroscopic calculus removal is the most common modality of treatment. The majority of the calculi seen in Kuwait contained calcium.

Topics: Acute Disease; Adolescent; Adult; Aged; Aged, 80 and over; Calcium; Calcium Oxalate; Cystine; Cystoscopy; Female; Flank Pain; Hospitalization; Humans; Kuwait; Lithotripsy; Magnesium Compounds; Male; Middle Aged; Phosphates; Prospective Studies; Struvite; Ureteroscopy; Uric Acid; Urinary Calculi; Urinary Diversion; Urinary Retention

The objective of our study was to evaluate the color Doppler sonographic effect known as twinkling artifact.. Struvite (ammonium magnesium phosphate) stone fragments, wire mesh, and a flat surface were scanned in a water bath with a sonography scanner using a high-frequency linear array probe fixed in a ring clamp. Pulse repetition frequency, color-write priority, gray-scale gain, and spectral Doppler gain were varied. Color and spectral Doppler modes were used.. Twinkling artifact and spectral broadening were seen most intensely behind struvite stone fragments, and both were seen more strongly behind wire mesh with greater surface roughness than behind wire mesh with less surface roughness or a flat surface. The appearance of the twinkling artifact is highly dependent on machine settings. System noise measured on a flat surface generates a band-limited Doppler shift on spectral displays with a mean frequency shift of 0 Hz and a mean (+/- SD) absolute fluctuation of 86 +/- 10 Hz over a pulse repetition frequency range of 1250-10,000 Hz. Rough surfaces increase the spectral bandwidth.. The appearance of the twinkling artifact is highly dependent on machine settings and is likely generated by a narrow-band, intrinsic machine noise called phase (or clock) jitter. Surface roughness secondarily broadens the noise spectrum. With a strongly reflecting, rough surface such as a renal stone, the high amplitude, broadband signal appears as random motion in color Doppler sonography. Understanding of the twinkling artifact may result in better use of its clinical appearance.

Topics: Artifacts; Humans; Magnesium Compounds; Phantoms, Imaging; Phosphates; Struvite; Ultrasonography, Doppler, Color; Urinary Calculi

Infection stones make up approximately 15% of urinary stone diseases and are thus an important group. These stones are composed of struvite and/or carbonate apatite. The basic precondition for the formation of infection stones is a urease-positive urinary tract infection. Urease is necessary to split urea into ammonia and CO(2). As a result, ammonia ions can form and at the same time alkaline urine develops, both being preconditions for the formation of struvite and carbonate apatite crystals. When these crystals are deposited infection stones form. Pathogenetically, various risk factors play a role: urinary obstruction, neurogenic bladder, dRTA, and MSK. If these infections are not treated and the stones are not removed, the kidney will be damaged. Modern methods are available for stone removal, e.g., ESWL and/or instrumental urinary stone removal. Here, especially less invasive methods are preferable. Any treatment must be adjusted to the patient individually. Patients should be examined frequently for recurrent urinary tract infections and stone recurrences, and new infections must be resolutely treated. Good therapy and prophylaxis are possible with present-day treatment modalities.

Topics: Apatites; Bacteria; Comorbidity; Humans; Hydrogen-Ion Concentration; Magnesium Compounds; Phosphates; Risk Factors; Struvite; Urease; Urinary Calculi; Urinary Tract Infections; Urography

We have extended our previous observation that the percent occurrence of calcium oxalate stones decreased while that of calcium phosphate stones increased with each new stone event.. The National VA Crystal Identification Center has analyzed veteran patient urinary tract stones from VA hospitals throughout the United States since 1983. We reviewed the composition of 33,198 stones with emphasis on the changes in composition. More than 11,786 stones came from 5,088 recurrent stone formers. Stones were analyzed using high resolution x-ray powder diffraction and Fourier transform infrared spectroscopic techniques. When the stones were investigated as a function of time, it was determined that there was greater variability when samples were more than 30 days apart.. The percent occurrence of whewellite, weddelite, apatite, brushite and uric acid in stones increased between 1.0% and 5.9% since our previous study. The percent occurrence of struvite decreased by 2.6%. The percent of calcium oxalate stones decreased while that of calcium phosphate stones increased with each new event. However, the total percent occurrence of all calcium containing stones did not significantly change with recurrent stone events.. Our study suggests a strong trend for the conversion of stone disease from calcium oxalate to calcium phosphate containing stones, which could influence the progression and severity of disease.

Topics: Apatites; Calcium Oxalate; Calcium Phosphates; Humans; Magnesium Compounds; Phosphates; Recurrence; Spectroscopy, Fourier Transform Infrared; Struvite; Uric Acid; Urinary Calculi; X-Ray Diffraction

The human urinary calculi are mainly formed from calcium oxalate, magnesium ammonium phosphate hexahydrate (MAPH) and uric acid (UA) crystals. It is important for the physician and surgeon to distinguish the two types of hydrates of calcium oxalate, mainly mono- (COM, Whewellite) and dihydrate (COD, Weddelite). This is because COM stones are evacuated two times more frequently than COD, which sometimes needs to be extracted surgically.. Thermal analysis techniques, such as Differential Thermal Analysis (DTA) and Thermogravimetry (TG), are considered the best techniques for the characterization of the two hydrates of calcium oxalate. A simultaneous thermal analysis method (TG-DTA) was applied to determine the percentage of each hydrate (COM and COD) when present together, in the presence of MAPH or in the presence of UA.. The results performed on 156 urinary calculi were as follows (according to the major component): 74.36%, 7.05% and 10.26% for calcium oxalate hydrate, UA and MAPH, respectively. The COD/COM ratios were 0.75 and 1.75, when they are present in mixtures with UA and MAPH, respectively.. Fourier transform infrared (FTIR) and X-ray diffraction (XRD) have been used in urinary calculi analysis. Simultaneous thermal analysis TG-DTA would be an alternative method for quantitative determination of the two types of calcium oxalate in urinary stones.

Topics: Calcium Oxalate; Child; Child, Preschool; Differential Thermal Analysis; Humans; Infant; Magnesium Compounds; Mass Spectrometry; Phosphates; Reference Standards; Struvite; Uric Acid; Urinary Calculi

The Twinheads extracorporeal shock wave lithotriptor (THSWL) is composed of 2 identical shock wave generators and reflectors. One reflector is under the table and the other is over the table with a variable angle between the axes of the 2 reflectors. The 2 reflectors share a common second focal point, making it possible to deliver an almost synchronous twin pulse to the targeted stone. We studied the optimal parameters for in vitro stone fragmentation.. Two types of 1 cm artificial stones were used, namely Bon(n)-stones of 3 compositions (75% calcium oxalate monohydrate [COM] plus 25% uric acid, struvite and cystine) and plaster of Paris. The parameters tested were shock wave number (100, 500 and 1,000), shock wave power (8, 11 and 14 kV) and angle between the reflector axes (67, 90 and 105 degrees). After the optimal parameters were determined we studied the disintegrative efficacy of THSWL for 3 types of human urinary calculi, including COM, calcium hydrogen phosphate (brushite) and cystine. Each stone received 1,000 twin shock waves at 14 kV with an angle of 90 degrees between the reflectors. All experiments were done using a rate of 60 twin shock waves per minute. Following lithotripsy stone fragments were processed and sized. The ratio of the weight of fragments greater than 2 mm-to-total weight of all fragments was calculated.. Optimal stone fragmentation results for THSWL were obtained with the maximum number of shock waves (1,000) and full power (14 kV). There was no significant statistical difference in fragment size or the ratio of fragments greater than 2 mm with the use of different angles except for cystine and plaster of Paris calculi, for which the right angle was most effective. At application of the optimal parameters to human stones THSWL produced small fragment size for COM and cystine stones, while brushite stones were not fragmented to the same extent.. The efficacy of synchronous twin pulse technology improves as the number of shock waves and power increase. A 90-degree angle between the shock wave reflectors is advantageous for certain stones (that is cystine and plaster of Paris) but it is not a factor for other stone compositions. THSWL has satisfactory disintegrative efficacy for human stones, especially COM and cysteine calculi.

Topics: Calcium Oxalate; Calcium Phosphates; Calcium Sulfate; Cystine; Humans; In Vitro Techniques; Lithotripsy; Magnesium Compounds; Particle Size; Phosphates; Struvite; Technology Assessment, Biomedical; Uric Acid; Urinary Calculi

Efficacy of ESWL treatment can be evaluated by determining the number and size of urinary stone fragments. However, the available methods for classification of stone fragments are inaccurate. Therefore, a method for semi-automatic determination of fragment size and number after ESWL was developed.. Artificial struvite stones (BON[N]-STONES) were disintegrated with a lithotriptor (Siemens, Lithostar plus) by application of 50 and 200 shock waves at 19 kV. The stone fragments were collected and pre-sorted on cascade sieves. Pictures taken of the fractions were digitalized and the images optimized in edge sharpness, contrast, and colour depth using an image processing software. Finally, the pixel number of each fragment was determined and the real area was calculated. Fragment size and volume were then depicted by frequency of occurrence in a histogram.. Fragments with a diameter ranging from 0.3 - 5 mm could be determined by the system described. About 2,000 - 3,600 fragments were generated in this size range from the artificial struvite stones. With low shock-wave application, a considerable number of fragments larger than 2 mm could be observed. By increasing the impact to 200, more than 90 % of the stone volume was found in fragments smaller than 2 mm (previously 50 %).. The system described enables a qualitative and quantitative description of stone fragmentation after ESWL not achieved thus far.

Topics: Humans; Image Processing, Computer-Assisted; Lithotripsy; Magnesium Compounds; Phosphates; Struvite; Urinary Calculi

The results of 5484 submissions from cats to the Canadian Veterinary Urolith Centre between February 1998 and February 2003 are presented. Of the submissions, 618 were urethral plugs and 4866 were bladder uroliths. The majority of the urethral plugs were from male domestic shorthair and longhair cats. Approximately 50% of the urolith submissions were oxalate, 44% were struvite. Oxalate uroliths were the most common mineral type in males and in Himalayan, Persian, and Siamese cats. Struvite uroliths were the most common mineral type in domestic shorthair and longhair cats. Females outnumbered males by 1.4:1 in struvite urolith submissions. A review of risk factors for urethral plugs and bladder uroliths is presented.

Topics: Age Factors; Animals; Breeding; Calcium Oxalate; Canada; Cat Diseases; Cats; Female; Magnesium Compounds; Male; Phosphates; Risk Factors; Sex Factors; Struvite; Urethral Obstruction; Urinary Calculi

The choice of the most efficient treatment modality for renal calculi could be facilitated by determining the precise chemical stone composition before treatment. We investigated the possibility of using conventional X-ray imaging to determine stone composition and to find a simple method of predicting stone fragility for treatment planning.. The X-ray density of 92 stones with known infrared spectroscopy analyses (calcium oxalate monohydrate, calcium oxalate dihydrate, struvite, and calcium phosphate) was retrospectively investigated by scanning the films with a digital camera. The data analysis was done using a commercially available graphics program to compare the total gray-scale levels of the stones.. There was a significant difference in the mean gray-scale level of calcium phosphate and calcium oxalate stones (P < 0.01). The mean gray-scale difference between calcium oxalate dihydrate and calcium oxalate monohydrate was also significant (p < 0.02). All calcium oxalate, struvite, and calcium phosphate stones were correctly identified. Of the calcium oxalate monohydrate and calcium oxalate dihydrate stones, 98.4% and 66.6%, respectively, were correctly identified.. The method allows a reliable diagnosis of stone composition from radiographs, which can be useful in stone treatment planning.

Topics: Calcium Oxalate; Calcium Phosphates; Female; Humans; Magnesium Compounds; Male; Phosphates; Radiography; Retrospective Studies; Sensitivity and Specificity; Statistics, Nonparametric; Struvite; Urinary Calculi

More than ten per cent of stones are associated with a urinary tract abnormality. To verify whether the malformation influences stone composition, we studied the composition of stones observed in fifteen urological abnormalities.. This study is based on 1,461 stones associated with a clearly defined malformation analysed by infrared spectroscopy plus 402 bladder stones in men with benign prostatic hyperplasia.. In this series of 1,863 abnormalities, 732 (39.3%) involved the kidney, 561 (30.1%) involved the ureter and 570 (30.6%) involved the lower tract. Whewellite stones were predominant in all renal abnormalities with the exception of cysts, which were mainly associated with uric acid. The main differences concerned the second constituent: weddellite in horseshoe kidneys, carbapatite in Cacchi-Ricci disease and caliceal abnormalities. Struvite was uncommon (<10%). Whewellite was the main component in ureteric abnormalities except for megaureter and reflux in which carbapatite was predominant. Struvite was present in 10% to 30% of stones. Vesicourethral abnormalities were accompanied by calcium and magnesium phosphate stones (90% of cases), and struvite was present in 58% to 90% of cases. The exception to this general rule was bladder stones associated with benign prostatic hyperplasia, in which the main component was uric acid.. Significant differences in stone composition were observed as a function of anatomical abnormalities reflecting the fact that some abnormalities add infectious or metabolic risk factors to anatomical factors.

Topics: Female; Humans; Kidney; Kidney Diseases; Magnesium Compounds; Male; Middle Aged; Phosphates; Prostatic Hyperplasia; Struvite; Ureter; Ureteral Diseases; Urinary Calculi; Urinary Tract

To determine hospital proportional morbidity rates (HPMR) for urethral obstructions, urethral plugs or urethroliths, and urethrostomies in cats in veterinary teaching hospitals (VTH) in Canada and the United States between 1980 and 1999.. Epidemiologic study.. 305,672 cats evaluated at VTH.. Yearly HPMR were determined for cats with urethral obstructions, urethral plugs or urethroliths, or urethrostomies from data compiled by the Purdue Veterinary Medical Database. The test for a linear trend in proportions was used.. Urethral obstructions were reported in 4,683 cats. Yearly HPMR for urethral obstructions declined from 19 cases/1,000 feline evaluations in 1980 to 7 cases/1,000 feline evaluations in 1999. Urethral plugs or urethroliths affected 1,460 cats. Yearly HPMR for urethral plugs or urethroliths decreased from 10 cases/1,000 feline evaluations in 1980 to 2 cases/1,000 feline evaluations in 1999. A total of 2,359 urethrostomies were performed. Yearly HPMR for urethrostomies decreased from 13 cases/1,000 feline evaluations in 1980 to 4 cases/1,000 feline evaluations in 1999.. Frequency of feline urethrostomies performed at VTH in Canada and the United States declined during the past 20 years and paralleled a similar decline in frequency of urethral obstructions and urethral plugs or urethroliths. These trends coincide with widespread use of diets to minimize struvite crystalluria in cats, which is important because struvite has consistently been the predominant mineral in feline urethral plugs during this period.

Topics: Animal Feed; Animals; Canada; Cat Diseases; Cats; Epidemiologic Studies; Female; Hospitals, Animal; Magnesium Compounds; Male; Morbidity; Ostomy; Phosphates; Retrospective Studies; Struvite; United States; Urethral Diseases; Urethral Obstruction; Urinary Calculi

This study was performed to look for an improvement of therapeutic strategies with regard to the treatment of infectious urinary stones using artificial stones made of struvite and apatite ('Bon(n) stones') which are comparable to their natural counterparts.. Using an experimental arrangement simulating the physiological conditions in the upper urinary tract, the efficacy of artificial urine (pH 5.7), Suby G solution (pH 3.6), mixtures of artificial urine with Suby G (pH 3.9 and pH 4.1) in dissolving artificial struvite and apatite stones (Bon(n) stones) was investigated. The dissolution of natural infectious urinary stones was also measured. Additionally, investigations on shock-wave lithotripsy (SWL) combined with initial chemolytic treatment of the stones were performed.. The efficacy of Suby G solution in dissolving artificial stones was demonstrated. Direct comparison of chemolysis of natural and artificial stones showed no statistical difference between infectious urinary stones and Bon(n) stones of the same material. The investigations on SWL showed a significant improvement on stone comminution, especially of artificial apatite stones after initial chemolytic treatment with Suby G.. New basics to improve dissolution of infectious urinary stones have been developed by performing standardized in vitro investigations. Local chemolysis with Suby G is an effective tool in the treatment of infectious stone disease. SWL can be improved by varying the physical properties of infectious stones through initial treatment with Suby G solution.

Topics: Apatites; Equipment Design; In Vitro Techniques; Lithotripsy; Magnesium Compounds; Models, Biological; Phosphates; Sensitivity and Specificity; Solvents; Statistics, Nonparametric; Struvite; Urinary Calculi; Urinary Tract Infections

An epidemiologic study of urinary calculi (N = 1843) was conducted in Western France: distribution according to the main chemical compounds, age and sex. Comparison with the results of a study with national recruitment (N = 10,617) and a study with regional recruitment (N = 1774).. The study involved 1843 stones characterized beforehand by morphological analysis associated with infra-red spectrophotometry (FTIR). If analysis of the composition of the stones was carried out on the totality of calculi, studies related to age and sex included only 1583 cases. Comparison of percentages was made using chi 2 test.. The composition in main compounds of calculi was comparable with the results of other studies; minor significant compounds presented great differences, raising the problem of interpretation of the infra-red spectra of the latter. Hence, our work was directed towards the analysis of the major compounds and we showed, like most authors, that monohydrate calcium oxalate is predominant in male (46%) as well as in females (37%). Calculi average sex-ratio was 2.19 but dehydrated calcium oxalate sex-ratio was 4.42, suggesting that this compound is found mainly in men. Conversely, for the majority of phosphate stones, the sex-ratio was lower or equal to one, indicating that they predominate in women. Infectious calculi (particularly struvite calculi) appeared slightly more frequent in our population than in other studies, whereas the number of uric acid calculi was lower. This, however, remains to be confirmed.. The population studied was not significantly different from the national population regarding lithiasis, except perhaps for uric acid and struvite calculi, despite specific regional differences in diet and the role of nutritional factors in lithogenesis.

Topics: Adolescent; Adult; Age Factors; Aged; Calcium Oxalate; Chi-Square Distribution; Child; Child, Preschool; Female; France; Humans; Infant; Infant, Newborn; Magnesium Compounds; Male; Middle Aged; Phosphates; Sex Factors; Spectrophotometry, Infrared; Struvite; Uric Acid; Urinary Calculi

Due to rapid economic development over the past four decades, urinary stone components may have changed in Taiwan. We studied the changes in urinary stone components over time and the possible association with dietary changes during the same period.. From 1956 to 1999, 9,715 urinary calculi were collected at a single institution and analyzed using polarizing microscopy. Dietary information was obtained from an official national report. Linear regression was used to analyze the possible correlation between the change in stone components with daily consumption of animal protein, vegetable protein, and lipid.. Eleven distinct components were identified. Calcium oxalate (Jensen type I stone; found in sterile, acidic urine) was found most frequently (87.3%), and its incidence increased gradually with time. However, the incidence of Jensen type III stone (caused by metabolic abnormality) gradually decreased from 1956 to 1999. The male to female ratio among subjects was 2.3:1, and the modal age was in the forties. Female patients were more likely to suffer from type II stones (found in infected, alkaline urine), whereas type I and III stones were more prevalent in males. Among the dietary components, consumption of animal and vegetable proteins and lipid increased significantly during the same period, and appeared to be coincident with the increased incidence of type I stones during the study period.. Patterns of urinary tract stones in Taiwan have progressively changed in the past four decades and are now similar to those in western populations. The incidence of type I stones has increased during the past four decades, which may reflect the Westernization of dietary habits in Taiwanese during the same period.

Topics: Adult; Aged; Apatites; Calcium Oxalate; Cystine; Dietary Fats; Dietary Proteins; Female; Humans; Magnesium Compounds; Male; Middle Aged; Phosphates; Struvite; Taiwan; Uric Acid; Urinary Calculi

Topics: Animals; Disease Models, Animal; Hydrogen-Ion Concentration; Kidney Pelvis; Magnesium Compounds; Phosphates; Rabbits; Stomach; Struvite; Swine; Urinary Calculi

Feeding dry foods supplemented with urine acidifier (D,L-methionine (Met) or ammonium chloride) decreased urinary pH and struvite activity product in clinically normal cats. As a result, the number of struvite crystals in urine was greatly reduced. Supplementation with 3% Met but not 1% Met caused decrease in the urinary concentration of sediment, which resulted from a reduction in the HCl-soluble fraction. The concentration of HCl-insoluble sediment was not affected by supplementation with the urine acidifier.

Topics: Ammonium Chloride; Animal Feed; Animals; Cat Diseases; Cats; Cross-Over Studies; Dietary Supplements; Female; Hydrogen-Ion Concentration; Magnesium Compounds; Male; Methionine; Phosphates; Struvite; Urinary Calculi

Struvite calculi form in an alkaline environment created by urease producing uropathogens. We developed a viable upper tract urinary acidification model by performing gastric patch pyeloplasty in the rabbit. This model produces urinary acidification sufficient for the treatment and prevention of struvite renal calculi. We evaluated the physiological, metabolic and surgical outcomes.. gastric segment was harvested based on branches of the left gastro-epiploic artery. The flap was folded along the transverse axis and the adjacent edges were closed. The mouth of this reconfigured pouch provided optimal dimensions for anastomosis with the diminutive renal pelvis. Half of the rabbits were treated with internal stenting and H-2 blockade. Urinary pH was assessed by weekly cage collection and direct collection from the cannulated ureters. Urine culture was done, and serum gastrin and electrolytes were assessed at regular intervals. The rabbits were sacrificed at 3 to 26 weeks. Histological examination was routinely performed.. A total of 15 rabbits were available for complete assessment. Sustained urinary acidification was produced in 7 animals (47%) with a mean pH decrease of 2.27. In another 2 rabbits (13%) the urine was initially acidic but subsequently became alkaline due to ureteral obstruction. Electrolytes and gastrin were unchanged in these rabbits and urine culture was positive in 2. Histological testing revealed nonspecific inflammatory changes of the renal pelvis. Anastomotic complications were the most common surgical complication and the most common cause of failed acidification. The cohort treated without stents and H-2 blockade was at significantly greater risk for anastomotic leakage.. Gastric patch pyeloplasty may significantly increase urinary acidity in the rabbit model without altering the serum electrolyte balance or gastrin level. The procedure utilizes common techniques of reconstructive urology and may be possible with laparoscopy. Further study is required to assess the in vivo effect of this procedure for treating and preventing upper tract struvite calculi.

Topics: Animals; Electrolytes; Gastrins; Hydrogen-Ion Concentration; Kidney Pelvis; Magnesium Compounds; Models, Animal; Phosphates; Rabbits; Stomach; Struvite; Surgical Flaps; Urinary Calculi; Urine

Noncontrast computed tomography (NCCT) has emerged as the diagnostic study of choice in the evaluation of acute flank pain. Recent in vitro studies have suggested that NCCT can be used to predict the composition of urinary stones on the basis of differences in radiodensity (measured in Hounsfield units, HUs). We sought to determine whether the analysis of in vivo urinary stones seen on NCCT could predict their composition.. Between March 1997 and August 1999, 100 pure stones from patients seen at the Wilford Hall Medical Center in San Antonio, Texas were submitted for analysis. All had been visualized by NCCT before stone passage or retrieval. A General Electric High-Speed Advantage CT scanner evaluated most of these patients by a "flank pain protocol" (ie, helical technique with breath-holding at 120 kV, 200 mA with 5 mm collimation). Each scan was interpreted by one of two staff radiologists who measured the HUs for each stone. A statistical comparison was made between the stone composition and radiodensity. To allow for subsequently observed increases in radiodensity with increasing stone size regardless of composition, the HU value was divided by each stone's largest transverse diameter in millimeters to give the HU density. A statistical comparison was then made between stone composition and HU density.. No significant difference was noted between the HU values of calcium oxalate and calcium phosphate stones, and thus they were analyzed collectively as "calcium stones." When the HU values of calcium (n = 87), uric acid (n = 7), struvite (n = 4), and cystine (n = 2) stones were compared, the overlap of ranges precluded accurate identification, and the mean HU values were not significantly different from one another. There was less overlap noted when comparing the HU densities of the stones studied, and no noncalcium stone had an HU density greater than 76 HU/mm. Using one-way analysis of variance, significant differences were noted between the mean HU density of calcium (105 +/- 43) and uric acid (50 +/- 24) stones (P = 0.006). A trend toward significance was found between the mean HU density of the calcium and struvite stones (53 +/- 28, P = 0.073). No significant differences were found among the other stones.. HU density compared with the HU value alone better characterized differences in radiodensities among urinary stones; calcium stones can be distinguished from uric acid stones on the basis of this value. However, neither the HU density nor the mean HU value was able to identify urinary stones in vivo.

Topics: Analysis of Variance; Calcium; Cystine; Humans; Magnesium Compounds; Phosphates; Struvite; Tomography, X-Ray Computed; Uric Acid; Urinary Calculi

To identify dietary factors associated with the increase in occurrence of calcium oxalate (CaOx) uroliths and the decrease in occurrence of magnesium ammonium phosphate (MAP) uroliths in cats.. Case-control study.. 173 cats with CaOx uroliths, 290 cats with MAP uroliths, and 827 cats without any urinary tract diseases.. Univariate and multivariate logistic regression were performed.. Cats fed diets low in sodium or potassium or formulated to maximize urine acidity had an increased risk of developing CaOx uroliths but a decreased risk of developing MAP uroliths. Additionally, compared with the lowest contents, diets with the highest moisture or protein contents and with moderate magnesium, phosphorus, or calcium contents were associated with decreased risk of CaOx urolith formation. In contrast, diets with moderate fat or carbohydrate contents were associated with increased risk of CaOx urolith formation. Diets with the highest magnesium, phosphorus, calcium, chloride, or fiber contents and moderate protein content were associated with increased risk of MAP urolith formation. On the other hand, diets with the highest fat content were associated with decreased risk of MAP urolith formation.. Results suggest that diets formulated to contain higher protein, sodium, potassium, moisture, calcium, phosphorus, and magnesium contents and with decreased urine acidifying potential may minimize formation of CaOx uroliths in cats. Diets formulated to contain higher fat content and lower protein and potassium contents and with increased urine acidifying potential may minimize formation of MAP uroliths.

Topics: Animals; Calcium Oxalate; Calcium, Dietary; Case-Control Studies; Cat Diseases; Cats; Diet; Dietary Carbohydrates; Dietary Fats; Dietary Fiber; Dietary Proteins; Female; Hydrogen-Ion Concentration; Logistic Models; Magnesium; Magnesium Compounds; Male; Phosphates; Phosphorus, Dietary; Potassium, Dietary; Sodium, Dietary; Struvite; Surveys and Questionnaires; Urinalysis; Urinary Calculi; Water

The aim of the study was to look for strategies that improve the clinical outcome of struvite stones. An in vitro experimental set up with artificial stones made of struvite (BON(N)-STONES) was chosen to perform standardized and reproducible analyses on various artificial urines with pH-values that may be reached by acidification with oral methionine treatment.. Artificial ball-shaped stones made of struvite (BON(N)-STONES) with a diameter of 0.8 cm were used. The investigations on chemolysis were performed using a dissolution device which simulates the physiological conditions in the upper urinary tract with computer-assisted on line measurement of data. For chemolysis of struvite BON(N)-STONES artificial urines according to Griffith at four different pH-values (pH 5.75, pH 6.0, pH 6.25, pH 6.5) were used. Furthermore natural and struvite BON(N)-STONES were treated with Suby G-solution (pH = 4.0).. Comparing natural and artificial struvite stones after treatment with Suby G there was no significant difference regarding their dissolution rate. The dissolution rate of struvite stones in artificial urine rose with a decreasing pH-value. The diminution of the pH-value from 6.5 to 5.75 lead to an increase of the dissolution rate of more than 35%. This increase in the dissolution rate decreased with falling pH-value.. The acidification of urine accelerated the dissolution rate of struvite stones in vitro. Considering in vivo conditions the intake of 1,500-3,000 mg L-methionine may lead to a sufficient acidification for a good dissolution of struvite stones.

Topics: Humans; In Vitro Techniques; Magnesium Compounds; Methionine; Models, Biological; Phosphates; Struvite; Urinary Calculi; Urine

We studied the relationship of stone frequency and composition to age, sex and stone weight.. A retrospective study was performed of all 15,624 stones submitted for analysis with infrared and wet chemical methods in Newfoundland and Labrador from 1979 to 1998.. There were 1,067 bladder stones of which 216 contained magnesium ammonium phosphate. The remaining 14,557 stones were from the kidney and ureter, and 11,707 were composed only of calcium oxalate and/or phosphate. Of the remaining 2,850 kidney and ureter stones magnesium ammonium phosphate was present in 573, uric acid/urate without magnesium ammonium phosphate in 1,109 and other compounds in 1,168. The 11,707 oxalate phosphate group was subdivided by infrared peak analysis based on oxalate-to-phosphate ratio into phosphate-ratio 1 or less, intermediate-1 to 10 and oxalate-10+. Oxalate comprised 65% of the 11,707 stones compared to 16% for phosphate. Women submitted 52% of phosphate stones compared with 28% of oxalate stones. From the first (1980 to 1983) to the last (1995 to 1998) complete 4-year study periods, there was a relative increase in oxalate and decrease in phosphate stones, associated with increasing age from decades 5 to 6 for oxalate and phosphate stones, except that the age peak for phosphate stones in women remained in decade 3. Median weight of 1, 828 phosphate stones was 43 mg. (mean 234) compared with 25 mg. (mean 98) for 7,634 oxalate stones. Male-to-female ratio was 0.91 for phosphate stones compared with 2.62 for oxalate stones.. Phosphate stones were on average heavier and relatively more common in women, had an earlier age peak frequency in women than oxalate stones and became less frequent during our last 4-year study period. In contrast, oxalate stones were much more common, of lighter weight and became more frequent with time.

Topics: Adolescent; Adult; Age Factors; Aged; Child; Female; Humans; Kidney Calculi; Magnesium Compounds; Male; Middle Aged; Oxalates; Phosphates; Retrospective Studies; Sex Factors; Struvite; Ureteral Calculi; Urinary Bladder Calculi; Urinary Calculi

To determine whether breed, age, sex, or reproductive status (i.e., neutered versus sexually intact) was associated with the apparent increase in prevalence of calcium oxalate (CaOx) uroliths and the decrease in prevalence of magnesium ammonium phosphate (MAP) uroliths in cats over time.. Case-control study.. Case cats consisted of cats with CaOx (n = 7,895) or MAP (7,334) uroliths evaluated at the Minnesota Urolith Center between 1981 and 1997. Control cats consisted of cats without urinary tract disease admitted to veterinary teaching hospitals in the United States and Canada during the same period (150,482).. Univariate and multivariate logistic regression were performed.. British Shorthair, Exotic Shorthair, Foreign Shorthair, Havana Brown, Himalayan, Persian, Ragdoll, and Scottish Fold cats had an increased risk of developing CaOx uroliths, as did male cats and neutered cats. Chartreux, domestic shorthair, Foreign Shorthair, Himalayan, Oriental Shorthair, and Ragdoll cats had an increased risk of developing MAP uroliths, as did female cats and neutered cats. Cats with CaOx uroliths were significantly older than cats with MAP uroliths.. Results suggest that changes in breed, age, sex, or reproductive status did not contribute to the apparent reciprocal relationship between prevalences of CaOx and MAP uroliths in cats during a 17-year period. However, cats of particular breeds, ages, sex, and reproductive status had an increased risk of developing CaOx and MAP uroliths.

Topics: Age Factors; Animals; Breeding; Calcium Oxalate; Case-Control Studies; Cat Diseases; Cats; Female; Logistic Models; Magnesium Compounds; Male; Odds Ratio; Phosphates; Risk Factors; Sex Factors; Struvite; Time Factors; Urinary Calculi

To determine extent and nature of regional differences in distribution of canine urinary calculi.. 13,552 calculus specimens: 7,056 (52.1%) from females, 6,492 (47.9%) from males, and 4 from dogs of unrecorded sex. Procedure Records were used to compile information from all specimens submitted between July 1981 and December 1995. Results from mixed-breed and various breeds of stone-forming dogs were analyzed. Interrelations of breed, sex, and age of dogs, and anatomic location and mineral composition of specimens were analyzed and compared for 6 US geographic regions.. Struvite-, apatite-, and urate-containing calculi were reported significantly most often from female dogs of the Mountain/Pacific region. Oxalate-, silica-, and brushite-containing calculi were reported significantly most often from male dogs in the New England/mid-Atlantic (NEMA) region. Cystine-containing calculi were reported most frequently from the NEMA and South Central (SC) regions. Dogs from the NEMA region were oldest in average age at diagnosis. Significant regional differences in distribution were found for several breeds. Sex distribution of renal calculi in 11 breeds of dogs (Lhasa Apso, Yorkshire Terrier, Shih Tzu, Basset Hound, Pug, Mastiff, Bichon Frise, Doberman Pinscher, Dalmatian, English Bulldog, and Pekingese) reported to be at high risk of renal lithiasis differed among the 6 geographic regions. Renal and ureteral calculi were reported significantly most often from dogs in the South Atlantic region, and bladder and urethral calculi were reported most often from dogs in the SC region.. Wide regional differences exist in distribution of stone-forming dogs by sex, average age at diagnosis, breed, and minerals contained within and anatomic location of calculi.

Topics: Age Factors; Animals; Apatites; Breeding; Calcium Phosphates; Cystine; Dog Diseases; Dogs; Female; Magnesium Compounds; Male; Odds Ratio; Oxalates; Phosphates; Retrospective Studies; Risk Factors; Sex Factors; Silicon Dioxide; Struvite; United States; Uric Acid; Urinary Calculi

Topics: Animal Nutritional Physiological Phenomena; Animals; Calcium Oxalate; Cat Diseases; Cats; Cystine; Diet; Dog Diseases; Dogs; Magnesium Compounds; Phosphates; Quaternary Ammonium Compounds; Struvite; Uric Acid; Urinary Calculi

We tested the hypotheses that Proteus mirabilis viability of struvite calculi differs after exposure to different lithotripsy modalities and that the photothermal mechanism of holmium:YAG lithotripsy is antibacterial.. Human calculi of known struvite composition (greater than 90% magnesium ammonium phosphate hexohydrate) were incubated with P. mirabilis. Calculi were randomly distributed and fragmented with no lithotripsy (controls), or shock wave, intracorporeal ultrasonic, electrohydraulic, pneumatic, holmium:YAG or pulsed dye laser lithotripsy. After lithotripsy fragments were sonicated and specimens were serially plated for 48 hours at 38C. Bacterial counts and the rate of bacterial sterilization were compared.. Median bacterial counts (colony-forming units per ml.) were 8 x 10(6) in controls and 3 x 10(6) in shock wave, 3 x 10(7) in ultrasonic, 4 x 10(5) in electrohydraulic, 8 x 10(6) in pneumatic, 5 x 10(4) in holmium:YAG and 1 x 10(6) in pulsed dye laser lithotripsy cases (p <0.001). The rate of bacterial sterilization was 50% for holmium:YAG lithotripsy treated stones versus 0% for each of the other cohorts (p <0.01).. P. mirabilis viability varies among lithotrites. The photothermal mechanism of holmium:YAG lithotripsy is antibacterial.

Topics: Humans; Magnesium Compounds; Phosphates; Proteus mirabilis; Struvite; Urinary Calculi

We tested the hypothesis that holmium:YAG laser lithotripsy speed is best maximized by using low pulse energy at high pulse frequency.. To demonstrate that optical fiber damage increases with pulse energy and irradiation, the 365-microm optical fiber irradiated calcium hydrogen phosphate dihydrate (CHPD), calcium oxalate monohydrate (COM), cystine, magnesium ammonium phosphate hexahydrate (MAPH), and uric acid calculi at pulse energies of 0.5 to 2.0 J. Optical energy output was measured with an energy detector after 10 J to 200 J of total energy. To demonstrate that lithotripsy efficiency varies with power, fragmentation was measured at constant power settings at total energies of 200 J and 1 kJ with the 365-microm optical fiber. Fragmentation was measured for the 272-microm optical fiber at pulse energies of 0.5 J to 1.5 J at 10 Hz. To demonstrate that low pulse energy produces smaller fragments than high pulse energy, fragment size was characterized for COM and uric acid calculi after 0.25 kJ of irradiation using the 272-microm to 940-microm optical fibers at 0.5 J to 1.5 J.. Damage to the 365-microm optical fiber was greatest for irradiation of CHPD, followed by MAPH, and COM (P<0.001). There was no significant optical fiber damage after cystine and uric acid lithotripsy. For the 365-microm optical fiber and CHPD, fragmentation after 200 J was greatest for pulse energies < or =1.0 J (P< 0.001). For other compositions, fragmentation was not statistically different among the power settings for constant irradiation. No significant difference was noted in fragmentation for any composition at different pulse energies (1.0 v. 2.0 J) for 1-kJ irradiation. However, for all compositions, the calculated lithotripsy speed was greatest at high power settings (P<0.001). For the 272-microm optical fiber, CHPD fragmentation was greatest for the 1.0-J pulse energy. The mean fragment size and relative quantity of fragments > or =2 mm both increased as pulse energy increased.. Optical fiber degradation varies with stone composition, irradiation, and pulse energy. Holmium:YAG lithotripsy speed is maximized with higher power (either increased pulse energy or higher pulse frequency). Because low pulse energy may be safer and yields smaller fragments than high pulse energy, holmium:YAG lithotripsy speed is best increased by using pulse energies < or =1.0 J at a high repetition rate.

Topics: Calcium Oxalate; Calcium Phosphates; Cysteine; Fiber Optic Technology; Humans; In Vitro Techniques; Lithotripsy, Laser; Magnesium Compounds; Optical Fibers; Phosphates; Reproducibility of Results; Struvite; Uric Acid; Urinary Calculi

Choice of efficacious clinical management of symptomatic renal calculi can be facilitated by ascertaining the precise chemical composition of the calculus. Spiral computerized tomography (CT) is becoming a frequently used radiographic examination to establish the diagnosis and severity of calculus disease. Our objective for this study was to determine the precision of spiral CT in identifying the chemical composition of 6 different types of urinary calculi with region of interest measurements using spiral CT.. A total of 102 chemically pure stones were separated into 6 groups. The stones along with phantoms containing butter (fat) and jello (water) were mounted vertically in the scanner gantry. Then 1 mm. thickness scanning was performed with a high speed scanner at the 2 energy levels of 80 and 120 kV. The determination of the chemical composition was performed using the absolute CT value measured at 120 kV. and the dual kilovolt CT values measured at 80 and 120 kV. Hounsfield unit at 80 kV.-Hounsfield unit at 120 kV.).. The absolute CT value measured at 120 kV. was able to identify precisely the chemical composition of uric acid, struvite and calcium oxalate stones. It was imprecise in differentiating calcium oxalate from brushite stone and struvite from cystine stone. However, dual kilovolt CT value was able to differentiate these latter stones with statistical significance (p < 0.03). Uric acid stones were easily differentiated from all other stones using the absolute CT value.. This study demonstrates that the chemical composition of urinary calculi can be accurately determined by CT scanning in an in vitro setting.

Topics: Calcium Oxalate; Cystine; Humans; Magnesium Compounds; Phantoms, Imaging; Phosphates; Struvite; Tomography, X-Ray Computed; Uric Acid; Urinary Calculi

Holmium:YAG lithotripsy fragments stones through a photothermal mechanism. Uric acid when heated is known to be converted into cyanide. We test the hypothesis that holmium: YAG lithotripsy of uric acid calculi produces cyanide.. Human calculi of known uric acid composition were irradiated with holmium:YAG energy in water. Stones received a total holmium:YAG energy of 0 (control), 0.1, 0.25, 0.5, 0.75, 1.0 or 1.25 kJ. The water in which lithotripsy was performed was analyzed for cyanide concentration. A graph was constructed to relate holmium:YAG energy to cyanide production.. Holmium:YAG lithotripsy of uric acid calculi in vitro produced cyanide consistently. Cyanide production correlated with total holmium:YAG energy (p <0.001).. Holmium:YAG lithotripsy of uric acid calculi risks production of cyanide. This study raises significant safety issues.

Topics: Aluminum Silicates; Analysis of Variance; Calcium Oxalate; Calcium Phosphates; Coloring Agents; Cyanides; Cystine; Holmium; Hot Temperature; Humans; Light; Lithotripsy, Laser; Magnesium Compounds; Phosphates; Radiation Dosage; Regression Analysis; Safety; Struvite; Sulfuric Acids; Uric Acid; Urinary Calculi; Water; Yttrium

Topics: Animals; Dog Diseases; Dogs; Female; Hydrogen-Ion Concentration; Magnesium Compounds; Male; Phosphates; Struvite; Urinary Calculi; Urologic Diseases

To determine the effects of the takushya portion of choreito, a traditional Chinese treatment for urolithiasis, on urine and struvite crystal variables in cats fed diets containing takushya.. 6 male and 6 female adult cats, all considered to be clinically normal on the basis of physical examination findings, results of CBC, serum biochemical analyses, urinalyses, and urine cultures; and freedom from urolithiasis on the basis of urethrocystoscopic (females) or urethrocystographic (males) findings.. Cats were fed a commercial canned diet supplemented with 0.1-mg of takushya/kg of body weight, or with 0.5 mg of choreito/kg. Diets were fed, using a Latin-square design, to 3 groups of 4 cats (2 male, 2 female) each for 2 weeks, followed by blood and 24-hour urine sample collections.. Consumption of takushya, which comprises 20% by weight of choreito, was not associated with adverse effects in cats at the amounts provided during the period of study. Moreover, takushya was responsible for most of the effect of choreito consumption on reduction of urine pH, and approximately half its ability to reduce struvite crystal formation in cat urine.. Alternative treatments for struvite urolithiasis in cats may be feasible.

Topics: Analysis of Variance; Animal Feed; Animals; Cats; Diuretics; Drugs, Chinese Herbal; Female; Food, Fortified; Magnesium Compounds; Male; Phosphates; Struvite; Urinary Calculi

This study was conducted to determine the epidemiological profile of urolithiasis in Kuwaiti patients and the associated metabolic abnormalities favouring stone formation in this patient population. Between 1986 and 1994, a total of 421 Kuwaiti patients were studied in Al-Amiri renal stone laboratory. The mineral composition of stones was determined using a combination of stereoscopic microscopy and infrared spectrophotometry. Mineral metabolic screen (MMS) was available in 306 (72.7%) of those patients. The average annual incidence of new stone formation in Kuwaiti patients was 23.9 per 100,000 population. The incidence was only 6.9 per 100,000 population in those from pediatric age group, 33.4 in adults and 73.6 in the elderly. The frequency of new stone formation was higher among males as compared to females at different age groups. Calcium oxalate (CaO) constituted 72.1% of renal stones encountered in adults as compared to only 52.1% and 40.7% in elderly and pediatric age groups. Eighty four patients had recurrent and/or high stone load. Detailed family history was available in 57 of those 84 patients and was suggestive of strong family aggregation of stone disease in 30 (53%) patients. The proportion of urate stones was 15.4% of all stones formed and constituted a major cause of renal stones in children (24.1%), adults (14.4%) and elderly (12.5%). Cystine stones were found in 10 patients (2.4%). Hyperuricemia was detected in 1/3 of patients from pediatric age group. In adults, 89 (38.4%) of 232 patients had abnormal MMS, of which hyperuricosuria with or without hyperuricemia accounted for 79.8% of those abnormalities. In elderly patients, metabolic disorders were detected in 7 (17.5%) of the 40 patients. In the latter group, all except one, had hyperuricosuria with or without hyperuricemia. Cystinuria, distal renal tubular acidosis (d-RTA) and hyperparathyroidism constituted 6.6% of metabolic abnormalities in the patients studied. Primary abnormalities of upper and lower urinary tract was detected in 6% of adult patients as compared to 47% in children and 30% in the elderly. In conclusion; the incidence rate of new stone former in Kuwait is significantly lower from that reported in Europe and USA. This latter finding and the high familial aggregation of urolithiasis in our area constitute a cogent argument against the role of hot climate in the pathogensis of urolithiasis and are in favour of genetic predisposition. Isolated hyperuricosuria was detec

Topics: Adolescent; Adult; Age Distribution; Aged; Calcium Oxalate; Chi-Square Distribution; Child; Family Health; Female; Humans; Incidence; Kuwait; Magnesium Compounds; Male; Metabolic Diseases; Middle Aged; Minerals; Phosphates; Retrospective Studies; Sex Distribution; Struvite; Uric Acid; Urinary Calculi

We analyzed a series of 61 stones from children aged 3 to 14 years old using Fourier transform infrared spectroscopy. The calculi were collected from urology departments of the University Hospitals of Oran, Sidi-Bel-Abbès and Mostaganem in West Algeria. This series is the first investigation concerning the composition of stones in children based on infrared analysis. Calculi were more frequent in males (75.4%) and mainly localized in the bladder (55.8%). Upper urinary tract calculi were more frequent in children over the age of 10 years, and the sex ratio was about 1. Calcium oxalate monohydrate was present in 70.5% of stones and was the main component in 50.8% of cases both in whole stones and nuclei. In contrast, calcium oxalate dihydrate was the main component in only 9.8% of calculi although it was present in 75.4% of stones. Ammonium urate was detected in 29.5% of stones and was always the main component of nuclei. Uric acid, observed in 31.1% of calculi, was the major constituent in 14.7% of stones and 19.7% of nuclei. Magnesium ammonium phosphate was observed in 24.6% of stones as a consequence of urinary tract infection by urea-splitting bacteria. Our observations emphasized that the anatomical location of stone and their composition were in accordance with those previously reported in other countries.

Topics: Adolescent; Age Factors; Algeria; Calcium Oxalate; Child; Child, Preschool; Female; Humans; Kidney Calculi; Magnesium Compounds; Male; Phosphates; Sex Factors; Spectrum Analysis; Struvite; Ureteral Calculi; Uric Acid; Urinary Bladder Calculi; Urinary Calculi

5706 canine urinary stones were analyzed by means of infrared spectroscopy from 1984-1996. The stones were sent in together with epidemiologic data (breed, age, sex, localisation of the stones, type of stone removal, stone frequency etc.) by more than 800 veterinarians from Germany, the Netherlands, Austria, and Switzerland. Irrespective of stone type, urinary stones were observed in almost all breeds, but small breeds like dachshound, poodle, terrier, schnauzer, and pekingese have a higher tendency to form stones. With 59.5% struvite is the most frequent stone type, followed by cystine with 15.5%. Cystine stones are becoming less frequent during the observation time, whereas the share of calcium oxalate (14.2%) and ammonium urate (6.0%) stones remains unchanged. The latter stone types are found predominantly in specific breeds. The stone formation appears predominantly at the age of 7. Male dogs form stones twice as often as female dogs. 98% of the stones were located in the lower urinary tract. About 90% of the urinary stones required surgical treatment.

Topics: Animals; Calcium Oxalate; Cystine; Dog Diseases; Dogs; Female; Magnesium Compounds; Male; Phosphates; Sex Factors; Struvite; Uric Acid; Urinary Calculi

Ureaplasma urealyticum is a fastidious organism which is not recovered by conventional bacterial cultures techniques, but special cultures are required for its isolation and identification. As it is a urease-producing organism, it is considered a risk factor for the formation of struvite calculi in the urinary tract. A total of 30 patients with urinary infection stones (19 of them with the 1st formation and 11 with recurrent stone formation) were included in the study. Both bladder urine specimen (cystoscopically obtained) and stones removed were subjected to conventional cultures and also to Ureaplasma specific cultures (A7 agar and U9 broth). The results of culture techniques revealed that 86.7% of patients had aerobic organisms (E. coli in 46.7%, Klebsiella in 30%, Proteus in 6.7% and Pseudomonas in 3.3%) and 26.7% showed U. urealyticum in mid stream urine. As regards stone cultures, they revealed aerobic organisms in 76.7%, and U. urealyticum in 20%. Sensitivity tests for U. urealyticum showed that minocycline was the most effective antimicrobial followed by tetracycline and ciprofloxacin. From these data, we conclude that U. urealyticum may be the causative organism for infection stone and should be searched for via its specific cultures, especially in patients with recurrent stones and with the so-called sterile pyuria.

Topics: Adult; Anti-Bacterial Agents; Apatites; Bacterial Typing Techniques; Calcium Oxalate; Causality; Cystoscopy; Drug Therapy, Combination; Egypt; Female; Humans; Hydroxamic Acids; Magnesium Compounds; Male; Microbial Sensitivity Tests; Phosphates; Recurrence; Struvite; Ureaplasma Infections; Ureaplasma urealyticum; Urinalysis; Urinary Calculi; Urinary Tract Infections

to test the hypothesis that breed, sex and age of cats, and anatomic location of uroliths are risk factors for calcium oxalate and magnesium ammonium phosphate urolithiasis.. Retrospective case-control study.. Records of 3,498 feline urolith accessions submitted between September 1982 and September 1992.. Mineral composition of feline uroliths was quantitatively analyzed. Odds ratios and 95% confidence intervals were calculated for breed, sex, age, and urolith location as risk factors for calcium oxalate and magnesium ammonium phosphate urolith formation. The population at risk was defined as all cats for which that type of urolith had been submitted. The control population was all cats for which uroliths had been submitted, excluding cats with the type of urolith being evaluated.. Burmese, Persian, and Himalayan breeds were at higher risk for developing calcium oxalate uroliths, but at reduced risk for developing magnesium ammonium phosphate uroliths. Compared with females, neutered male cats had a higher risk for developing calcium oxalate uroliths, but a reduced risk for developing magnesium ammonium phosphate uroliths. The risk for calcium oxalate urolith formation increased with age. One- to 2-year-old female cats had the highest risk for magnesium ammonium phosphate uroliths. Uroliths removed from the kidneys were more likely to be composed of calcium oxalate than of magnesium ammonium phosphate.. Breed, sex, and age of cats, and anatomic location of uroliths should be considered when evaluating risk of calcium oxalate and magnesium ammonium phosphate urolithiasis in urolith-forming cats.

Topics: Age Factors; Animals; Breeding; Calcium Oxalate; Case-Control Studies; Cat Diseases; Cats; Confidence Intervals; Female; Magnesium Compounds; Male; Odds Ratio; Phosphates; Prevalence; Retrospective Studies; Risk Factors; Sex Factors; Struvite; Urinary Calculi

In regard to identify the compositions of urinary stones, the infrared spectra is a contemporary routine method. However, it is difficult to detect the absorption of carbonate in struvite stone by infrared spectra, because NH4 absorption of magnesium ammonium phosphate overlaps CO3 absorption of carbonate at 1420-1435 cm-1. With the purpose of demonstrating the existence of carbonate in struvite stones, the analysis of these stones by means of Raman spectra has been tried.. Forty urinary stones, the chemical compositions of which were previously determined by infrared spectroscopy, were submitted to Raman spectrum analysis, and subsequently to analysis by x-ray diffraction.. Thirty of 40 urinary stones were found to be composed of struvite and of mixed struvite-calcium oxalate by infrared analysis. Twelve of these stones were shown to have Raman spectra of magnesium ammonium phosphate, and the other stones to have spectra of apatite. By x-ray diffraction magnesium ammonium phosphate crystals were detected in 25 of these struvite stones and hydroxyl-apatite in another 3, and 2 cases were undeterminable. For other components, such as calcium oxalate, uric acid and cystine, the analytical results of infrared spectra coincided with those of Raman spectra and x-ray diffraction. Carbonate was detected in only a part of one struvite stone by Raman spectra.. Above-mentioned results may indicate that carbonate is only a minor component of urinary stones. Therefore, most of 1420-1435 cm-1 bands on the infrared spectra of struvite stones do not indicate CO3 absorption of carbonate, but NH(4) absorption of magnesium ammonium phosphate.

Topics: Calcium Oxalate; Carbonates; Female; Hemostatics; Humans; Kidney Calculi; Magnesium Compounds; Male; Phosphates; Spectrophotometry, Infrared; Spectrum Analysis, Raman; Struvite; Urinary Calculi; X-Ray Diffraction

To elucidate the ultrastructural details of struvite-containing urinary calculi from cats.. Specimens studied were inclusive of the range of textures visible during preliminary analysis by use of a stereoscopic dissecting microscope. Textural types, which were used to infer crystal growth conditions, were differentiated with regard to crystal habit, crystal size, growth orientation, and primary porosity.. Thirty specimens were selected from a collection of approximately 1,600 feline urinary calculi: 20 of these were composed entirely of struvite, and 10 consisted of struvite and calcium phosphate (apatite).. Qualitative and quantitative analyses of specimens included use of plain and polarized light microscopy, x-ray diffractometry, scanning electron microscopy with backscattered electron imagery, x-ray fluorescence scans, and electron probe microanalysis.. Four textural types were recognized among struvite calculi, whereas 2 textural types of struvite-apatite calculi were described.. The presence of minute, well interconnected primary pores in struvite-containing urinary calculi from cats is an important feature, which may promote possible interaction of calculi with changes in urine composition.. Primary porosity, which can facilitate interaction between the calculus and changing urine composition, may explain the efficacy of dietary or medicinal manipulations to promote the dissolution of struvite-containing uroliths from this species.

Topics: Animals; Apatites; Calcium; Cat Diseases; Cats; Electron Probe Microanalysis; Magnesium; Magnesium Compounds; Microscopy, Electron, Scanning; Microscopy, Polarization; Phosphates; Potassium; Spectrometry, X-Ray Emission; Struvite; Urinary Calculi; X-Ray Diffraction

To elucidate the ultrastructural details of struvite-containing urinary calculi from dogs.. 38 specimens were selected from a collection of approximately 13,000 canine urinary calculi: 18 of these were composed entirely of struvite, and 20 consisted of struvite and calcium phosphate (apatite).. Qualitative and quantitative analyses of specimens included use of plain and polarized light microscopy, x-ray diffractometry, scanning electron microscopy with backscattered electron imagery, x-ray fluorescence scans, and electron microprobe analysis.. 4 textural types were recognized among struvite calculi, and 4 textural types of struvite-apatite calculi were described. Evidences of calculus dissolution were described from 4 calculi studied.. The presence of small, well interconnected primary pores in struvite-containing urinary calculi from dogs appears to be a significant factor in determining the possible interaction of calculi with changes in the urine composition. The progress of dissolution from the calculus surface to the calculus interior appears to be largely affected by the primary porosity originally present between crystals forming the calculus framework. Apatite was observed to be more resistant to dissolution than struvite.. The prevalence of fine concentric laminations having low porosity, and the common occurrence of apatite among struvite-containing urinary calculi from dogs may be 2 reasons why the efficacy of dietary and medicinal manipulations in dissolving urinary calculi is greater among cats than it is among dogs.

Topics: Animals; Calcium Phosphates; Cat Diseases; Cats; Dog Diseases; Dogs; Electron Probe Microanalysis; Magnesium Compounds; Microscopy, Electron, Scanning; Phosphates; Polarography; Spectrometry, X-Ray Emission; Struvite; Urinary Calculi; X-Ray Diffraction

The stones removed from 273 patients (220 males, 53 females) with bladder stones and 27 patients with urethral stones (males) were analyzed by infrared spectroscopy. Of these stones 50.0% contained magnesium ammonium phosphate (MAP), 39.9% calcium (oxalate and/or phosphate), 9.4% uric acid (urate), and 0.7% cystine. The disorders associated with bladder stones were prostatic hyperplasia and cancer (47.8%), neurogenic bladder (11.8%), urethral stricture (3.6%) and so on in males, and neurogenic bladder (48.1%), after operation of uterus (29.0%), bladder cancer (5.7%) and so on in females. Urinary infections were complications in 59.3% of patients with MAP stones, 41.2% with urate stones and 20.0% with calcium stones. The most often isolated bacteria from the infected urine were of the Proteus species.

Topics: Adolescent; Adult; Aged; Aged, 80 and over; Bacteriuria; Calcium Oxalate; Calcium Phosphates; Chi-Square Distribution; Child; Child, Preschool; Cystine; Female; Humans; Magnesium Compounds; Male; Middle Aged; Phosphates; Prostatic Hyperplasia; Spectrophotometry, Infrared; Struvite; Urethral Diseases; Uric Acid; Urinary Bladder Calculi; Urinary Bladder, Neurogenic; Urinary Calculi; Urinary Tract Infections; Urologic Diseases

Complete metabolic evaluation was performed in 21 patients with infected renal lithiasis. Patients with pure struvite stones (struvite +/- carbonate apatite) were significantly less likely to have metabolic abnormalities than patients who had struvite +/- carbonate apatite+calcium oxalate (2 of 14 v 7 of 7, P = 0.0003). Urine calcium excretion was markedly higher in the mixed stone group than the pure struvite group (342 +/- 98 mg/24 h v 136 +/- 82 mg/24 h; P < 0.0001). The differing opinions among researchers regarding the likelihood of finding metabolic abnormalities in patients with urolithiasis and infection probably reflect differences in the definitions of the populations studied. If patients with calculi containing only struvite +/- carbonate apatite are evaluated, we believe that few significant metabolic abnormalities will be identified.

Topics: Adolescent; Adult; Aged; Aged, 80 and over; Apatites; Calcium; Calcium Oxalate; Female; Humans; Infections; Magnesium Compounds; Male; Middle Aged; Phosphates; Sex Characteristics; Struvite; Urinary Calculi; Urine

It has been reported that up to half of renal stones and associated urine specimens have been positive on culture, and that up to 50% of such stones contain magnesium ammonium phosphate. In a prospective study using infrared and wet chemical analysis, we found positive cultures in only 7 of 132 renal, 5 of 105 ureteral and 6 of 21 bladder stones obtained surgically and handled with sterility. Of the culture positive calculi only 43% from the kidney, none from the ureter and 50% from the bladder contained detectable magnesium ammonium phosphate. However, magnesium ammonium phosphate was detectable in 20% of renal, 2% of ureteral and 27% of bladder stones with negative cultures. Of the culture positive renal and ureteral calculi 42% were predominantly calcium phosphate and 17% were predominantly calcium oxalate. For culture negative stones 25% and 51% from the kidney, and 15% and 82% from the ureter were composed of predominantly calcium phosphate and calcium oxalate, respectively. Among the culture positive stones, related positive urine cultures were noted in 100% of the renal, 20% of the ureteral and 50% of the bladder cases, compared to 26%, 10% and 27%, respectively, of culture negative calculi. The same organism was found in the stone and urine in only 38% of the cases. The lower frequency of positive urine cultures, of stones with magnesium ammonium phosphate, and especially of culture positive renal and ureteral stones (5%) than in previous reports suggests that stone culture may be of less value than indicated previously, except for bladder calculi and large renal stones, such as the branched type.

Topics: Adult; Aged; Bacteria; Calcium Oxalate; Calcium Phosphates; Female; Humans; Magnesium Compounds; Male; Middle Aged; Phosphates; Prospective Studies; Struvite; Urinary Calculi

Topics: Bone Neoplasms; Calcium Oxalate; Cystine; Hardness; Humans; Kidney Calculi; Kinetics; Magnesium Compounds; Phosphates; Preoperative Care; Radionuclide Imaging; Struvite; Technetium Tc 99m Medronate; Uric Acid; Urinary Calculi

In vitro extracoporeal shock wave lithotripsy (ESWL) on different types of urinary calculi, in combination with microfocus x-ray and microphotography, illustrates the importance of the internal stone structure. Calculi with a rough surface layered structure (calcium oxalate monohydrate) and untextured calculi (cystine) are characterized by a low stone fragility, whereas coarse-grain calculi (calcium oxalate dihydrate, struvite), and calculi with a smooth surface layered structure (uric acid), are very fragile. Shell-like fragmentation in layered calculi, with smooth surface of the crystalline laminations, suggests that the stone matrix influenced the propagation of the shock wave energy inside the stone.

Topics: Calcium Oxalate; Crystallization; Cystine; Humans; Lithotripsy; Magnesium Compounds; Microradiography; Phosphates; Struvite; Uric Acid; Urinary Calculi

Struvite (MgNH4PO4.6H2O) calculi are a common complication of Proteus mirabilis urinary tract infections. Although urease is a major virulence factor in calculus formation, the polysaccharide capsule (CPS) of this organism also enhances struvite crystallization and growth in vitro (L. Clapham, R. J. C. McLean, J. C. Nickel, J. Downey, and J. W. Costerton, J. Crystal Growth 104:475-484, 1990). We obtained purified CPS, of known structure and varying anionic character, from P. mirabilis ATCC 49565 and several other organisms. Artificial urine was added to CPS, and the pH was elevated from 5.8 to 8.5 by the addition of urease or titration with 0.25 M NH4OH to induce struvite crystallization. Crystallization was measured by particle counting (Coulter counter), and the morphology (crystal habit) was examined by phase-contrast microscopy. In the presence of partially anionic P. mirabilis CPS, struvite formation occurred at a lower pH than in the absence of CPS or in the presence of other neutral, partially anionic, or anionic CPS. At pH 7.5 to 8.0, significantly more struvite crystals formed in the presence of P. mirabilis CPS than under other experimental conditions. With the exception of one polymer (curdlan) which did not bind Mg2+, enhancement of struvite formation by CPS polymers was inversely proportional to their Mg2+ binding ability. We speculate that the structure and partial anionic nature of P. mirabilis CPS enable it to enhance struvite formation by weakly concentrating Mg2+ ions during struvite crystal formation. This illustrates a new virulence aspect of bacterial CPS during infection.

Topics: Bacterial Capsules; Carbohydrate Sequence; Crystallization; Humans; Hydrogen-Ion Concentration; In Vitro Techniques; Magnesium Compounds; Metals; Molecular Sequence Data; Phosphates; Polysaccharides, Bacterial; Proteus mirabilis; Species Specificity; Struvite; Urinary Calculi; Urine

In a previous study we showed that the magnesium-calcium ratio of tap water is negatively correlated with the incidence of calcium-containing urinary stones. In this study we examined the relationship between the incidence of struvite stones, water hardness and the regional geological features on the basis of our previous study and an epidemiological study of urolithiasis performed in Japan. The magnesium-calcium ratio of tap water was found to correlate positively with the incidence of struvite stones. The tap water magnesium-calcium ratio was high in regions of basalt and sedimentary rock and was low in granite and limestone areas. The incidence of struvite stones in the regions of basalt and sedimentary rock was higher than that in the granite and limestone areas. Thus, this study suggested that the incidence of struvite stones is related to the magnesium-calcium ratio of tap water and to the regional geology, as is the case for calcium-containing stones.

Topics: Calcium; Epidemiologic Factors; Geological Phenomena; Geology; Humans; Japan; Magnesium; Magnesium Compounds; Phosphates; Struvite; Urinary Calculi; Water Supply

Six healthy adult cats were fed a basal minced beef meat and rice diet with varying amounts or combinations of acidifying and alkalizing additives (ammonium chloride, calcium and sodium carbonate). The base excess in the food (mmol/kg dry matter) was calculated (data on food compounds in g/kg dry matter) as follows: base excess = 49.9*Ca + 82.3*Mg + 43.5*Na + 25.6*K - 64.6*P - 13.4*Met-16.6*Cystine -28.2*Cl. It amounted to between +305 and -1079 mmol/kg dry matter. Urine and blood pH as well as balance of minerals and water were determined in the cats. The mean urine pH ranged between 6.1 and 7.8. There was a highly significant correlation between the base excess in the food and the mean urine pH. The regression line was linear down to a base excess in the diet of about -400 to -500 mmol/kg dry matter and a pH in the urine of 6.2. The postprandial increase of urine pH was suppressed either by large amounts of ammonium chloride (> 780 mmol/kg dry matter) alone or in combination with calcium carbonate, but not in combination with sodium carbonate. The relationship between the decrease of the blood pH and the amount of ammonium chloride added to the diet was more marked than the relationship between blood pH and base excess in the food. In order to avoid health risks by long term application of acidifying diets it is recommended to formulate struvite diets with low base excess in such a way, that they contain as few alkalizing compounds as possible, which must be neutralized by acidifiers.

Topics: Acid-Base Equilibrium; Ammonium Chloride; Animals; Carbonates; Cat Diseases; Cats; Food Additives; Magnesium Compounds; Minerals; Phosphates; Struvite; Urinary Calculi

Fragmentation has become the standard therapy for urinary calculi in the modern era. Stone fragility as well as position and size are important for the determination of a treatment program. To compare the efficacy of stone fragmentation, seven kinds of human urinary calculi with known composition (calcium oxalate monohydrate and dihydrate, dibasic calcium phosphate, uric acid, struvite, calcium phosphate, and cystine) were treated by three fragmentation techniques commonly used, namely extracorporeal shock wave (SWL), electrohydraulic (EHL), and pulsed-dye laser lithotripsy. Uric acid, calcium oxalate dihydrate, and calcium phosphate stones could be destroyed easily by any of these methods. Struvite was soft but sticky and not easy to break into tiny particles. Both dibasic calcium phosphate and calcium oxalate monohydrate stones were resistant to the laser and EHL; SWL is the treatment of choice. For cystine stones, none of the treatments was satisfactory; SWL was the only way to break them into large pieces.

Topics: Calcium Oxalate; Calcium Phosphates; Cystine; Humans; Lithotripsy; Lithotripsy, Laser; Magnesium Compounds; Phosphates; Struvite; Uric Acid; Urinary Calculi

Thirty-six urinary stones were studied by computed tomography and bone densitometry in order to find a correlation between the chemical composition of the stones and the densitometric data. In vitro, the more common cases of lithiasis can be divided into 3 main groups: uric acid, cystine and the calcium salts, e.g. calcium oxalate monohydrate, calcium oxalate dihydrate and calcium phosphate. Struvite stones fall between the second and third groups. Computed tomography and bone densitometry can differentiate between the groups, provided that the value of the "stone mineral or calcium content" is correlated with the true calculated volume of the stone (resulting in the specific stone density) instead of the projection area (resulting in the area density). This is only possible in vitro. The in vivo application of these technologies in the treatment of stones of unknown composition could provide important information, but major restrictive factors pose difficulties. Further clinical studies are necessary, especially to define the role of bone densitometry.

Topics: Absorptiometry, Photon; Calcium Oxalate; Cystine; Humans; In Vitro Techniques; Magnesium Compounds; Phosphates; Struvite; Tomography, X-Ray Computed; Uric Acid; Urinary Calculi; X-Ray Diffraction

In a 2 year carcinogenicity bioassay using B6C3F1 mice, one male mouse developed clinical signs near termination of the study, comprising skin sores around the prepuce, penile prolapse and urine scalding. The predominant finding at necropsy was a markedly distended urinary bladder filled with numerous crystallized particles. Microscopically, there was subacute cystitis with marked hyperplasia of the transitional epithelium. X-ray diffraction analysis of the crystals showed a diffraction pattern characteristic of struvite (ammonium magnesium phosphate). The implications of the spontaneous occurrence of bladder stones in rodents on long-term toxicology studies are discussed.

Topics: Animals; Crystallization; Cystitis; Female; Magnesium; Magnesium Compounds; Male; Mice; Mice, Inbred C3H; Mice, Inbred C57BL; Phosphates; Rodent Diseases; Struvite; Urinary Calculi; X-Ray Diffraction

In order to reduce the relapse of the disease lithiasis, it is very important to have a very good idea about the growth process of the urinary stone. The greatest concern is the recuperation and the profound analysis of the nucleus and the peripheral layers. The preceding morphological study of the stone fragments in combination with the infrared spectrometry is the only manner to know all about the urinary calculus. Many information is lost if only an overall infrared spectrum of the sample is taken.

Topics: Calcium Oxalate; Hemostatics; Humans; Infant; Magnesium; Magnesium Compounds; Male; Middle Aged; Phosphates; Spectrophotometry, Infrared; Struvite; Urinary Calculi

A 3-month-old Thoroughbred colt was presented with signs of colic. Findings from physical examination, abdominal paracentesis, abdominal radiographs and clinical pathology revealed uroperitoneum secondary to a calculus obstructing the urethra and causing subsequent urinary bladder rupture. Analysis of the calculus demonstrated a tissue center with outer concretions composed primarily of struvite.

Topics: Animals; Colic; Horse Diseases; Horses; Magnesium; Magnesium Compounds; Male; Phosphates; Rupture; Struvite; Urethral Obstruction; Urinary Bladder; Urinary Calculi

After feeding various diets we studied the effects of dietary calcium, magnesium and phosphorus on the formation of struvite stones in rats with urinary tract infections, and also studied the effects of the administration of vitamin D3 and aluminium gel on stone formation. A low-magnesium diet decreased urinary magnesium and prevented stone formation, but a medium-calcium diet did not significantly decrease stone weight. A high-calcium diet decreased urinary phosphorus and inhibited stone formation. A high-calcium and high-phosphorus diet decreased urinary excretion of magnesium and inhibited stone formation. Although the administration of vitamin D3 did not inhibit stone formation, aluminium gel decreased the urinary level of phosphorus and prevented stone formation. A marked decrease in urinary magnesium and/or phosphorus may prevent struvite stone formation in rats with urinary tract infections.

Topics: Aluminum; Animals; Calcium, Dietary; Cholecalciferol; Magnesium; Magnesium Compounds; Male; Phosphates; Phosphorus, Dietary; Proteus Infections; Proteus mirabilis; Rats; Rats, Inbred Strains; Struvite; Urinary Calculi; Urinary Tract Infections

Struvite (MgNH4PO4.6H2O) crystals, the major mineral component of infectious urinary calculi, were produced in vitro by growth of a clinical isolate of Proteus mirabilis in artificial urine. P. mirabilis growth and urease-induced struvite production were monitored by phase contrast light microscopy and measurements of urease activity, pH, ammonia concentrations, turbidity, and culture viability. In the absence of pyrophosphate, struvite crystals appeared within 3-5 h due to the urease-induced elevation of pH and initially assumed a planar or 'X-shaped' crystal habit (morphology) characteristic of rapid growth. When pyrophosphate was present, initial precipitation and crystal appearance were significantly impaired and precipitates were largely amorphous. When crystals did appear (usually after 7 or 8 h) they were misshapen or octahedral in shape indicative of very slow growth. X-ray diffraction and Fourier transform infrared spectroscopy (FTIR) identified all crystals as struvite. Trace contaminates of carbonate-apatite (Ca10(PO4)6CO3) or newberyite (MgHPO4.H2O) were produced only in the absence of pyrophosphate. P. mirabilis viability and culture pH elevation were unaffected by the addition of pyrophosphate, whereas urease activity and ammonia concentrations were marginally reduced. Struvite could also be produced chemically by titration of the artificial urine with NH4OH. If pyrophosphate was present during titration, the same inhibitory effect on crystal growth occurred, so it is unlikely that urease inhibition is important. Lowering of pyrophosphate concentration from 13-0.45 mumol/l did not reduce its inhibitory activity so it is unlikely to act by chelating free Mg2+. We propose that pyrophosphate inhibits struvite growth principally through direct interference with the chemical mechanisms involved in crystal nucleation and growth, because of its effectiveness at very low concentrations.

Topics: Ammonia; Crystallization; Crystallography; Diphosphates; Drug Evaluation, Preclinical; Hemostatics; Hydrogen-Ion Concentration; Magnesium; Magnesium Compounds; Phosphates; Proteus mirabilis; Spectrophotometry, Infrared; Struvite; Urinary Calculi; Urine

Topics: Animals; Magnesium; Magnesium Compounds; Male; Mice; Phosphates; Struvite; Urinary Calculi

Six high operative risk patients with urinary retention caused by benign prostatic hyperplasia were managed with an intraprostatic spiral at our hospital. Three of them had severe coronary artery disease, 1 had uremia, 1 had cerebral stroke and 1 had poorly controlled diabetes mellitus. The urinary retention was successfully relieved by the intraprostatic spiral in all patients. No operative mortality or severe complication was encountered. One patient experienced a repeat attack of urinary retention due to proximal migration of the spiral. Four patients complained of urgency, which was relieved by anticholinergic agents. Stone incrustation was found on 2 out of 3 spirals removed (66%), and the stone turned out to be calcium phosphate and struvite by scanning electron microscopy and infrared spectrophotometry. In 1 patient, stone formation was so abundant that it almost obstructed the lumen of the redundant tip of the spiral. From our preliminary results, the intraprostatic spiral seems to be a good alternative to an indwelling catheter for patients awaiting prostatectomy. Nevertheless, the potential complication of stone incrustation should be anticipated and it is suggested to remove the device as soon as possible or to replace it at regular intervals.

Topics: Aged; Calcium Oxalate; Crystallization; Humans; Magnesium; Magnesium Compounds; Male; Middle Aged; Phosphates; Prostatic Hyperplasia; Stents; Struvite; Urinary Calculi; Urinary Retention

We measured the mineral content of urinary tract stones by dual photon absorptiometry, which is widely used for the analysis of bone mineral content, and compared the values of the stones by dual photon absorptiometry (DPA values) with the results of an in vitro fracture study as well as those of an in vivo extracorporeal shock wave lithotripsy treatment study. The results of a preliminary experiment showed that the DPA values of 20 urinary tract stones reflected actual stone mineral content. As a result of the in vitro fracture study, the DPA value calculated by volume of a struvite stone, which was the most easily disintegrated, was the lowest (0.53 g/cm3). The DPA values of calcium oxalate monohydrate and apatite stones, which poorly disintegrated, were the highest (0.98, 1.01 g/cm3). The DPA value of calcium oxalate dihydrate, which moderately disintegrated, was 0.86 g/cm3. By the in vivo extracorporeal shock wave lithotripsy treatment study, the total DPA values of stones measured before extracorporeal shock wave lithotripsy treatment in 12 patients were 0.73 +/- 0.34 g in successful cases and 1.92 +/- 0.43 g in unsuccessful cases with a significant difference between the two (p less than 0.05). These results showed that the measurement of stone mineral content by dual photon absorptiometry was useful in predicting the fragility of stones against shock waves before performing extracorporeal shock wave lithotripsy treatment for patients with urinary tract stones.

Topics: Absorptiometry, Photon; Apatites; Calcium Oxalate; Humans; In Vitro Techniques; Lithotripsy; Magnesium; Magnesium Compounds; Phosphates; Radionuclide Imaging; Struvite; Urinary Calculi

The aim of this paper is to evaluate the possible causes of the origin of "infection stones". The main differences between the ordinary biochemical parameters of a group of patients with this type of stones was analyzed and compared with a group of oxalocalcic stone-formers and with a group of healthy subjects. The importance of persistent basic urinary pH values is pointed out as possible origin of "infection stones" in some instances. The main urinary citrate concentration in patients with "infection stones" was significantly lower than in healthy subjects, this being an important factor that favours this kind of stone formation.

Topics: Calcium Oxalate; Creatinine; Diuresis; Humans; Hydrogen-Ion Concentration; Magnesium; Magnesium Compounds; Phosphates; Struvite; Urinary Calculi

Corynebacterium D2, a saprophytic microorganism of skin, causes alkaline encrusted cystitis in patients with a previous bladder injury. In 5 patients that had presented this nosological entity, these gram-positive rods were isolated in urine cultures and calculi. Four patients had undergone urological instrumentation maneuvers and one patient (female) had a history of recurrent cystitis from gram-negative bacteria. Corynebacterium D2 grows slowly and under certain conditions, as those described above, must be considered pathological despite counts of less than 100,000/ufc-cc. It is ureolytic and highly resistant to antibiotics. The synergistic effects of antimicrobials, acetohydroxamic acid and transurethral resection of the lithiasic plaques achieve satisfactory treatment of alkaline encrusted cystitis from Corynebacterium D2.

Topics: Aged; Aged, 80 and over; Bacteriological Techniques; Corynebacterium; Corynebacterium Infections; Cystitis; Female; Humans; Magnesium; Magnesium Compounds; Male; Middle Aged; Phosphates; Struvite; Urea; Urinary Calculi; Urinary Catheterization

Topics: Citrates; Edetic Acid; Humans; Lithotripsy; Magnesium; Magnesium Compounds; Phosphates; Struvite; Urinary Calculi

The composition and structure of 48 canine cystine urinary stones were determined by infrared spectroscopy, scanning electron microscopy and electron dispersive X-ray analysis. The infrared analysis showed that about 45% of the specimens were composed of pure cystine. The remainder also contained calcium oxalate (mono and/or dihydrate), magnesium ammonium phosphate hexadydrate (struvite), calcium hydrogen phosphate dihydrate (brushite) and complex urates (ammonium, ammonium potassium and/or potassium enriched ammonium urate). The infrared study of several samples heated at 620 degrees C and 750 degrees C revealed the presence of apatitic calcium phosphate. This compound was difficult to detect in the spectrum of the original samples due to the small proportion of phosphate contained in the calculi and to band overlapping. The examination of a series of selected samples by means of scanning electron microscopy and energy dispersive X-ray analysis complemented the infrared results.

Topics: Animals; Apatites; Calcium Oxalate; Calcium Phosphates; Cystine; Dog Diseases; Dogs; Electron Probe Microanalysis; Magnesium; Magnesium Compounds; Male; Microscopy, Electron, Scanning; Phosphates; Spectrophotometry, Infrared; Struvite; Uric Acid; Urinary Calculi

Proteus mirabilis biofilm formation, struvite (MgNH4PO4.6H2O) crystal formation and dissolution in an artificial urine mixture were monitored using computer-enhanced microscopy (CEM) and a 1 x 3 mm. glass flow cell. Image analysis showed that P. mirabilis biofilm formation did not occur to any extent at macroenvironment flow rates greater than two mL/h (equivalent to a microenvironment flow rate of less than 5 microns./sec). Essentially, cells attached to glass surfaces, grew slowly and divided. Daughter cells were generally released directly into the medium where they could then presumably colonize other regions. Microcolonies formed by the adhesion of aggregates of cells from the medium, and over time grew into biofilms. Struvite crystallization due to urease activity and pH elevation above neutrality, was preceded by the deposition of organic matter on the glass surface, followed by the appearance of a number of tiny (one to two microns.) crystals. Crystals forming within a biofilm at low dilution rates took on a characteristic twinned or "X-shaped" appearance (crystal habit) indicative of a rapid growth rate. Those forming outside the biofilm took on a more tabular appearance reflecting their slower growth. When the macroenvironment flow rate of artificial urine (initial pH 5.8) in the glass flow cell was increased from two mL/h to four mL/h, struvite crystals not associated with biofilms dissolved within five to 10 min. Crystals entrapped within the P. mirabilis biofilm withstood flow rates up to 200 mL/h presumably due to the maintenance of an alkaline Mg-saturated microenvironment within the biofilm. These observations may suggest a mechanism by which struvite calculi can grow in spite of neutral or acidic urine pH and resist mild acidification therapy.

Topics: Bacterial Adhesion; Crystallization; Image Processing, Computer-Assisted; In Vitro Techniques; Magnesium; Magnesium Compounds; Microscopy, Phase-Contrast; Phosphates; Proteus mirabilis; Solubility; Struvite; Urinary Calculi

To estimate the epidemiology of upper urinary stones in the elderly, a total of 1,957 patients (1,349 men and 608 women) with urolithiasis were studied. The ratio of men to women was approximately 3:1 in middle-aged (between 30 and 59 years), 1:1 in young (29 or younger) and 1:1 in old patients (60 or older). Compared with the age distribution of the entire Japanese population, the incidence of urinary stones was very low in both male and female children, twice as high in middle-aged men, slightly higher in middle-aged women, and equal or slightly lower in the male and female elderly. Stones of calcium oxalate and uric acid occurred more frequently and those of calcium phosphate and struvite less frequently in men than in women. This tendency was especially obvious in the middle-aged. In the old generation, calcium oxalate stones occurred almost equally in men and women. Results of urinary stone analysis were similar among men of the three generations, although the incidence of uric acid stones increased with patient age. In women, however, the incidence of calcium oxalate was higher in the young and old generations, while that of calcium phosphate was higher in the middle-aged.

Topics: Adolescent; Adult; Age Factors; Aged; Calcium Oxalate; Calcium Phosphates; Female; Humans; Japan; Magnesium; Magnesium Compounds; Male; Middle Aged; Phosphates; Sex Factors; Struvite; Uric Acid; Urinary Calculi

We report our initial experience using the pulsed dye laser in 26 patients with urolithiasis. The patients ranged in age from 27 to 82 years; 11 patients were female and 15 were male. Of the 26 patients, 4 stones were in the kidney, 21 were in the ureter, and one was in the bladder. Surgical time ranged from 32 to 130 minutes. All patients were treated under spinal or general anesthesia. The size of ureteral stones ranged from 0.2 to 1.5 cm, and the renal stones 3.0 to 4.0 cm. Chemical analysis of the stones was not available on all patients, but when available, chemical analysis revealed the stones to be calcium monohydrate, calcium dihydrate, or struvite. The use of the Candela miniscope in 11 patients permitted access without ureteral dilation. In 19 patients, ureteral stents were placed. One patient suffered a ureteral perforation. Success was defined as adequate disintegration of the stone for passage of the fragments without the necessity of a secondary procedure. Using this criterion, 22 of 26 patients were successfully treated for an overall success rate of 85%.

Topics: Adult; Aged; Aged, 80 and over; Calcium; Female; Hemostatics; Humans; Laser Therapy; Magnesium; Magnesium Compounds; Male; Middle Aged; Phosphates; Struvite; Urinary Calculi

The crystallization of magnesium ammonium phosphate (MAP) was studied in salt solutions and dialysed urine at similar levels of MAP supersaturation. At pH levels of 7.1 or higher crystallization occurred to the same extent in solutions with and without urinary macromolecules. Whereas crystals in the size range 3.5-5 microns were observed in the salt solution at pH 7.0, this was not so in dialysed urine. When the crystal size distribution was determined after 30 min larger crystals were observed in dialysed urine, indicating a promoting effect by urinary macromolecules on the formation of MAP crystals. A modified AP(MAP) index was formulated based on calculations with the EQUIL 2 programme in order to improve the relationship between this simplified estimate and the ion-activity product of MAP (APMAP). This index had the following form: [formula: see text] for 24-h values of magnesium (Mg), ammonium (NH4), phosphate (P), pH and urine volume (V). The APMAP required for the formation of 2,000 crystals in the size range 3.5-5 microns varied between 226 x 10(-15) and 293 x 10(-15) (mmol/l)2 in dialysed urine. An experimental system was designed based on the measurement of pH during the addition of NH4OH. At the point assumed to correspond to the start of crystallization, AP(MAP) index values between 409 and 903 were recorded. Such a test might provide useful information on the crystallization properties in urine.

Topics: Crystallization; Humans; Hydrogen-Ion Concentration; Macromolecular Substances; Magnesium; Magnesium Compounds; Phosphates; Struvite; Urinary Calculi

To Study how the composition of urine influences urease-induced crystallization, human urine samples were incubated with urease and the subsequent precipitation measured. Beside the pH increase, the urinary content of magnesium and calcium had profound effects on the precipitation of magnesium ammonium phosphate and calcium phosphate, respectively. Urine phosphate, ammonium and osmolarity had no direct effects on the precipitation. Among the urine components with potential inhibitory properties, only albumin was found to be correlated with such an effect. This inhibitory activity was especially influential in urines with high calcium and magnesium levels. These findings suggest that the composition of urine could also influence the formation of stones consisting of magnesium ammonium phosphate and calcium phosphate.

Topics: Calcium Oxalate; Calcium Phosphates; Crystallization; Glycoproteins; Humans; Hydrogen-Ion Concentration; Magnesium; Magnesium Compounds; Phosphates; Struvite; Urease; Urinary Calculi; Urine

The aim of this study was to determine whether extracorporeal shock wave lithotripsy (ESWL) affected the viability of the infecting bacteria within a simulated struvite stone matrix. A strain, Proteus mirabilis 28cii, was prepared in three forms: (1) suspended in saline and urine, (2) artificially encapsulated by suspending in agar beads and (3) artificially encapsulated and mineralised by suspending in agar beads with calcium carbonate crystals. The preparations were placed in capped vials partially immersed in degassed water and held in the focal point of the Siemens Lithostar and given 1,000 shocks. Subsequent viability testing showed that bacteria suspended in urine were greatly affected by shock treatments (55% loss in viability), but incorporation into agar beads negated this effect (even if the cells were exposed to 2000 shocks). Mineralisation of the beads with calcium carbonate crystals caused a decrease in viability of 82% that was significantly different from controls. However, this still left 2.3 X 10(8) viable organisms (82% of 2.8 X 10(8], easily enough to form the focus for further infections. A series of control experiments carried out using an ultrasonic cell sonicator probe gave comparable results to those obtained with ESWL. These results demonstrate the ESWL treatment of infected stones must be accompanied by antimicrobial coverage.

Topics: Humans; In Vitro Techniques; Lithotripsy; Magnesium; Magnesium Compounds; Phosphates; Proteus mirabilis; Struvite; Urinary Calculi

Struvite crystals were produced by Proteus mirabilis growth in artificial urine, in the presence of a number of naturally occurring crystallization inhibitors. The use of phase contrast light microscopy enabled the effects of added chondroitin sulfate A, chondroitin sulfate C, heparin sulfate, or sodium citrate, on struvite crystal growth rates to be rapidly monitored as changes in crystal habit. Struvite crystals formed as a consequence of the urease activity of P. mirabilis under all chemical conditions. In the absence of inhibitor, early crystal development was marked by large quantities of amorphous precipitate, followed immediately by the appearance of rapidly growing X-shaped or planar crystals. Addition of the glycosaminoglycans, chondroitin sulfate A, chondroitin sulfate C, or heparin sulfate to the artificial urine mixture had no effect on the rate of crystal growth or appearance. When sodium citrate was present in elevated concentrations, crystal appearance was generally slowed, and the crystals assumed an octahedral, slow growing appearance. None of the added compounds had any influence on bacterial viability, pH, or urease activity. It is therefore likely that the inhibitory activity displayed by sodium citrate might be related to its ability to complex magnesium or to interfere with the crystal structure during struvite formation. From these experiments it would appear that citrate may be a factor in the natural resistance of whole urine to struvite crystallization.

Topics: Chondroitin Sulfates; Citrates; Citric Acid; Crystallization; Heparin; Humans; In Vitro Techniques; Magnesium; Magnesium Compounds; Microscopy, Phase-Contrast; Phosphates; Proteus mirabilis; Struvite; Urinary Calculi

The chemical constituents of 171 specimens of canine urinary calculi have been analysed by infrared spectroscopy. The analysis revealed that 46 per cent of the total contained struvite as the major component; 26 per cent contained cystine; 16 per cent were found to be composed of whewellite and, or, weddellite; 8 per cent of urates; 3 per cent of calcium phosphate (apatite and, or, brushite) and 1 per cent of silica. A series of selected samples was also studied by scanning electron microscopy and energy dispersive X-ray analysis (EDAX). This examination revealed structures similar to human stones. Potassium and complex urates containing two or more cations were commonly found in many areas of ammonium urate and sodium urate calculi. Moreover, EDAX analysis detected a calcium enriched urate in several zones of urate calculi.

Topics: Age Factors; Animals; Breeding; Calcium Oxalate; Calcium Phosphates; Cystine; Dog Diseases; Dogs; Electron Probe Microanalysis; Female; Magnesium; Magnesium Compounds; Male; Microscopy, Electron, Scanning; Phosphates; Sex Factors; Silicon Dioxide; Spectrophotometry, Atomic; Spectrophotometry, Infrared; Struvite; Uric Acid; Urinary Calculi

Struvite urolithiasis forms as a consequence of a urinary tract infection by urease-producing species of bacteria such as Proteus mirabilis. Ammonia, produced by the enzymatic hydrolysis of urea, elevates urine pH causing a supersaturation and precipitation of Mg++ as struvite (NH4MgPO4). Calcium often precipitates as well, forming the mineral carbonate-apatite (Ca10(PO4)6CO3). We have developed a procedure based on direct observation by light microscopy whereby struvite crystal growth can be quickly monitored in response to chemical changes in urine. As struvite crystals assume a characteristic shape or crystal habit based on their growth rate, the effect of urine chemistry and the action of various crystallization or urease inhibitors on struvite formation can be quickly shown. In addition preliminary effects of alkaline pH, or the presence of toxic compounds on bacteria can also be shown through their loss of motility.

Topics: Crystallization; Humans; In Vitro Techniques; Magnesium; Magnesium Compounds; Microscopy, Phase-Contrast; Phosphates; Proteus Infections; Proteus mirabilis; Struvite; Urinary Calculi; Urinary Tract Infections

Yersinia strains either urease-positive or urease-negative were examined for precipitation of struvite in human urine at 25 and 37 degrees C. All urease-positive strains and 8 out of 10 urease-negative strains showed the ability to produce these crystals. Incubation time required for precipitation was longer for urease-negative strains and quantity of struvite formed was higher in urease-positive ones. Regarding incubation temperature, no significant influence has been observed.

Topics: Humans; In Vitro Techniques; Magnesium; Magnesium Compounds; Phosphates; Struvite; Urease; Urinary Calculi; Yersinia; Yersinia enterocolitica

A single (100 mg/kg) intraperitoneal dose of 2-bromoethanamine hydrobromide induced renal papillary necrosis (RPN) acutely in rodents and caused a transient crystalluria between 4 and 8 h after dosing. These crystals comprised struvite or magnesium ammonium phosphate (MAP) as assessed by shape, solubility, infra-red spectrum and X-ray microprobe analysis. Acid-soluble, bi-refringent crystals were also present within the renal medullary matrix during the same time period as the crystalluria. The presence of the MAP was associated with loss of the anionic renal medullary mucopolysaccharides staining. A total of 5/64 rats with a 2-bromoethanamine-induced renal papillary necrosis and monitored for up to 160 days had bladder calculi that were predominantly MAP. These data suggest that medullary mucopolysaccharide matrix disruption associated with RPN leads to a release of previously bound cations, super-saturation and the nucleation of crystalline MAP. These processes could also be implicated in the formation of MAP bladder calculi.

Topics: Animals; Ethylamines; Kidney Papillary Necrosis; Magnesium; Magnesium Compounds; Male; Phosphates; Rats; Rats, Inbred Strains; Spectrophotometry, Infrared; Struvite; Time Factors; Urinary Bladder Calculi; Urinary Calculi

The efficacy of a diet designed to facilitate dissolution of feline magnesium ammonium phosphate (struvite) uroliths was evaluated in 30 cases of urolithiasis, sterile struvite uroliths dissolved in a mean of 36 days after initiation of dietary treatment. In 5 cases of urolithiasis, struvite urocystoliths associated with urease-negative bacterial urinary tract infection dissolved in a mean of 23 days after initiation of dietary and antimicrobial treatment. In 3 cases of urolithiasis, struvite urocystoliths associated with urease-positive staphylococcal urinary tract infection dissolved in a mean of 79 days after initiation of dietary and antimicrobial treatment. Dissolution of uroliths in cats fed the treatment diet was associated with concomitant remission of dysuria, hematuria, and pyuria, and reduction in urine pH and struvite crystalluria. In one case, a urocystolith composed of 100% ammonium urate, and in another case, a urolith composed of 60% calcium phosphate, 20% calcium oxalate, and 20% magnesium ammonium phosphate did not dissolve.

Topics: Amoxicillin; Amoxicillin-Potassium Clavulanate Combination; Animals; Cat Diseases; Cats; Clavulanic Acids; Drug Therapy, Combination; Female; Follow-Up Studies; Hydrogen-Ion Concentration; Magnesium; Magnesium Compounds; Male; Phosphates; Radiography; Recurrence; Specific Gravity; Struvite; Time Factors; Urinary Calculi; Urinary Tract Infections

A nationwide survey on urolithiasis in Japan between 1965 through 1987 was carried out, succeeding the previous 1955 and 1966 studies, in an effort to evaluate chronological and geographical changes in urolithiasis among the Japanese people who are relatively racially homogenous and living with similar customs and habits, which have changed dramatically from the old Japanese to westernized modes in a very short period after the Second World War. Incidence of calcium-containing urinary stones in the upper urinary tract has been increasing in Japan since the Second World War with increasing westernization of life-style and industrialization, with the annual incidence of urolithiasis steadily increasing from 53.8/100,000 general population in 1965 to 92.5 in 1985. According to the data, 5.4% of the population may be expected to develop a urinary calculus at least once in their life time. Analysis of 69,949 stones obtained during the years from 1978 to 1987 with infrared analysis showed that 79.4% were calcium oxalate and/or calcium phosphate stones, 7.4% were struvite with or without carbonate apatite, 5.2% were uric acid or urate, and 1.0% were cystine. In the era of new treatment modalities such as the endourological surgery and the extracorporeal shock wave lithotripsy, open surgical treatments were replaced with new types of treatment in about 75% of the cases in 1985.

Topics: Calcium; Cystine; Female; Humans; Japan; Life Style; Magnesium; Magnesium Compounds; Male; Phosphates; Struvite; Uric Acid; Urinary Calculi

One hundred fifty specimens of urinary calculi from 150 cats were analyzed by at least 1 of 4 quantitative methods. Struvite (magnesium ammonium phosphate) was the predominant mineral substance encountered, with 104 (69%) of the calculi being composed entirely of struvite and 23 (15%) being composed partially of struvite. Most (93%) of the calculi were located in the urinary bladder. Growth of bacteria was observed in samples from calculi or urine from 30 (41%) of 74 cats. Coagulase-positive staphylococci were isolated from the urine or calculi from 17 cats (45% of bacteria isolated). Ten other bacterial species were isolated. Median and mean ages of the cats were 5.0 and 5.1 years, respectively. Domestic short-hair and domestic longhair breeds predominated. Fifty-seven percent of the calculi came from females, 43% from males. The distribution by gender did not differ significantly (P greater than 0.2) among the 3 groups (domestic shorthair, domestic longhair, and other). However, the distribution of struvite calculi differed significantly (chi 2 = 15.5, P less than 0.001) by age and gender; among cats less than or equal to 2 years of age, males predominated 2:1 over females, and among cats greater than 2 years of age, females predominated by nearly 3:1 over males. When compared with the general population, females greater than 2 years old were significantly (chi 2 = 15.4, P less than 0.001) overrepresented.

Topics: Age Factors; Animals; Apatites; Bacteria; Bacteriuria; Breeding; Calcium Oxalate; Cat Diseases; Cats; Female; Magnesium; Magnesium Compounds; Male; Phosphates; Sex Factors; Struvite; Uric Acid; Urinary Calculi

We have studied retrospectively 68 children who presented with urolithiasis between 1965 and 1986. Male to female ratio was 1.83 to 1 and the mean age was 9.5 years. Fifty four children (79%) had calculi in the upper urinary tract, 9 (13%) had in the lower, and 4 (6%) had calculi both in the upper and lower urinary tract. The most common presenting symptoms were gross hematuria (53%) and abdominal or flank pain (38%). Predisposing factors could be found only in 21 children (31%). Twenty four of the 68 patients (35%) had open surgery and 16 patients (24%) passed their stones spontaneously. Twenty one stones were analyzed by infrared spectroscopy. Infectious stone was more frequent than in adult cases. Among children five years old and younger, infectious stone was the most frequent. Among children over five years old, the number of idiopathic calcium stone has been on the increase with the years.

Topics: Adolescent; Apatites; Calcium Oxalate; Child; Child, Preschool; Female; Humans; Infant; Magnesium; Magnesium Compounds; Male; Phosphates; Struvite; Urinary Calculi; Urinary Tract Infections

Topics: Adult; Calcium Oxalate; Citrates; Cystinuria; Female; Humans; Kidney Transplantation; Magnesium; Magnesium Compounds; Male; Phosphates; Struvite; Transplantation, Homologous; Uric Acid; Urinary Calculi

Topics: Animals; Disease Models, Animal; Female; Humans; Magnesium; Magnesium Compounds; Male; Phosphates; Rats; Struvite; Urinary Calculi; Urinary Tract Infections

The internal-standard method and the powder diffractometer have been applied here to the quantitative determination of urinary stone constituents by x-ray diffraction (XRD). Reference intensity ratios determined for six stone substances were used in the reduction of intensity data. Constituent concentrations calculated for 21 stones were compared with values obtained from an element-sensitive technique. We conclude that XRD analysis alone cannot be regarded as a routine technique for the quantitative characterization of uroliths, but that semiquantitative XRD analysis supplemented by accurate quantitative elemental data is more suitable for the precise determination of true stone composition.

Topics: Calcium Oxalate; Calcium Phosphates; Durapatite; Humans; Hydroxyapatites; Magnesium; Magnesium Compounds; Phosphates; Struvite; Uric Acid; Urinary Calculi; X-Ray Diffraction

The presence of lipids in urinary stones was determined by histochemical and biochemical methods. When crystals of calcium oxalate, made by mixing calcium chloride and potassium oxalate solutions and sections of human calcium oxalate urinary stones, were exposed to osmium vapors, there was no staining of the pure crystals whereas the stone sections were stained. De-paraffinized sections of demineralized calcium oxalate stones showed positive sudanophilia on staining with Sudan black B. Both these experiments indicate the presence of lipids in calcium oxalate stones. Lipids were extracted from uric acid, struvite, and calcium oxalate stones using standard techniques. Phospholipids were separated by one-dimensional thin layer chromatography. All the stones studied contained lipids. In calcium oxalate stones they accounted for 10.15% of the matrix. Calcium oxalate and struvite stones contained more phospholipids than uric acid stones. Cardiolipin, sphingomyelin, phosphatidyl choline, phosphatidyl inositol, phosphatidyl ethanolamine, phosphatidyl serine, and phosphatidyl glycerol were identified in lipid extracts. Demineralization by ethylenediaminetetra-acetate (EDTA) treatment increased lipid output from calcium oxalate stones by 15.5%.

Topics: Calcium Oxalate; Histocytochemistry; Humans; Magnesium; Magnesium Compounds; Microscopy, Electron, Scanning; Phosphates; Phospholipids; Struvite; Uric Acid; Urinary Calculi

The properties of a laser which effect stone fragmentation have been studied. The pulsed dye laser emitting at 504 nm. in one microsecond duration pulses appears to be the optimum out of a wide range of parameters tested. The laser is coupled to a 200 micron core fiber; this complete with its cladding has a total diameter of only 0.25 mm. Most calculi are fragmented by a series of pulses of up to 30 mJ. The system is used by firing bursts of pulses with the fiber actually in contact with the stone. The result is a very controlled fragmentation which is particularly suited to use in the confines of the ureter. This modality of treatment utilises less energy than ultrasound or electrohydraulic probes to fragment a stone and the very fine, flexible fiber represents a considerable miniaturization.

Topics: Calcium Oxalate; Humans; Laser Therapy; Lithotripsy; Lithotripsy, Laser; Magnesium; Magnesium Compounds; Phosphates; Struvite; Time Factors; Urinary Calculi

Topics: Bacteriological Techniques; Bacteriuria; Computers; Drug Interactions; Humans; Hydroxamic Acids; Magnesium; Magnesium Compounds; Netilmicin; Phosphates; Proteus Infections; Proteus mirabilis; Struvite; Urease; Urinary Calculi

Four adult, castrated, male ferrets were studied in two similar trials for effects of food intake on variables hypothesized to promote struvite (ammonium, magnesium, phosphate hexahydrate) crystal formation in urine. Struvite crystalluria occurred in three of the four ferrets. Urine pH (UpH) averaged 6.6 for these ferrets. UpH in the ferret without crystalluria was 6.0. By simple linear regression analysis, no relationship was found between the amount of food ingested and the urinary concentration and excretion of magnesium and phosphorous. However, urine osmolality and excretion of both protein and ammonium were correlated to food intake (P less than .05). Ways in which these effects could promote struvite crystal formation are discussed.

Topics: Animals; Carnivora; Crystallization; Feeding Behavior; Ferrets; Magnesium; Magnesium Compounds; Male; Phosphates; Struvite; Urinary Calculi

Topics: Calcium Oxalate; Elements; Humans; Magnesium; Magnesium Compounds; Neutron Activation Analysis; Phosphates; Struvite; Uric Acid; Urinary Calculi; Xanthine; Xanthines

Struvite uroliths are found more frequently than other types of uroliths in the urinary tracts of dogs. Medical dissolution of struvite uroliths with a Swedish calculolythic diet has been evaluated. The palatability of the diet was good and only two out of a total of 69 dogs in the study could not be maintained on the diet because of diarrhea. In 19 of 33 dogs medically treated, the uroliths were dissolved over a period of one to 6 months (mean time 2.5 months). In the remaining dogs uroliths were surgically removed, and calculolytic diet was postoperatively given. Consumption of the calculolytic diet was in most cases associated with a lowered specific gravity and pH of the urine. A representative case report of medical dissolution of struvite uroliths located in the urinary bladder of a 9 year-old female cocker spaniel with a history of recurrent urolithiasis is described. It is concluded that the Swedish calculolytic diet can be used successfully to dissolve struvite in adults dogs.

Topics: Animals; Dog Diseases; Dogs; Female; Magnesium; Magnesium Compounds; Phosphates; Radiography; Struvite; Urinary Bladder Calculi; Urinary Calculi

Fluoride concentrations in 42 urinary calculi were determined using a microdiffusion procedure in conjunction with a fluoride sensitive electrode. Mean values of 56, 230 and 1112 ng./mg. fluoride were obtained for uric acid, calcium oxalate monohydrate and apatite/struvite stones, respectively. Fluoride concentration was found to be related to calcium oxalate dihydrate levels as well as to apatite content. It is suggested that the former has zeolithic properties which might trap fluoride while formation and growth of the latter appears to be enhanced by elevated urinary fluoride levels.

Topics: Apatites; Calcium Oxalate; Fluorides; Humans; Magnesium; Magnesium Compounds; Phosphates; Struvite; Uric Acid; Urinary Calculi

Extracorporeal shock wave lithotripsy (ESWL) can require more than two thousand acoustic shocks to achieve an adequate degree of renal calculus comminution. A decrease in the number of shocks necessary for effective treatment offers both technical and clinical benefits. The results presented here demonstrate that it is possible in particular cases to increase substantially the degree of comminution produced using a fixed number of acoustic impulses by exposing the stones to solutions of controlled pH and chemical composition during acoustic shock treatment. The largest increase in comminution was observed for magnesium ammonium phosphate hexahydrate/apatite stones exposed to citrate solutions. The smaller particle sizes are shown to result not only from stone dissolution but also from an increase in the ease of stone fracture during acoustic shocking. The degree of comminution of the largest fragment sizes was also found to be slightly increased for calcium oxalate stones by exposure to synthetic urine of elevated pH. These chemical methods of increased stone comminution appear to be directly applicable to particular cases and may have general clinical utility if suitable conditions affecting all stones can be found.

Topics: Calcium Oxalate; Carbonates; Citrates; Citric Acid; Combined Modality Therapy; Drug Evaluation, Preclinical; Humans; Hydrogen-Ion Concentration; In Vitro Techniques; Lithotripsy; Magnesium; Magnesium Compounds; Magnesium Oxide; Phosphates; Solutions; Struvite; Urinary Calculi

Eighteen male cats were fed either a canned complete diet or a commercially available dry pelleted diet or the same dry diet containing 1.6 per cent ammonium chloride. The daily food and water intake of four of these cats was measured. Urine samples were taken at random and the pH and the presence of struvite crystals in their sediment estimated. In some samples in which the pH was less than 7.0, and struvite crystals were absent, the pH was increased to 7.0 and any sediment was examined for struvite. No spontaneous struvite was seen in urine samples (pH 5.8) from cats fed the canned complete diet but when its pH was raised to 7.0, 46 per cent of these samples showed struvite. Cats fed the dry pelleted diet had urine of higher pH (7.55) and 78 per cent of the samples contained struvite crystals. Cats fed this diet supplemented with ammonium chloride had a urine pH of 5.97 and only 9 per cent contained struvite crystals but when the pH was adjusted to 7.0 all the samples showed struvite crystals. Energy intake was similar on all three diets but the intake of dry matter was greater on the dry diets. Liquid water intake was greater on the dry diets but total water intake was greatest on the canned complete diet. The intake of magnesium, calcium and phosphate was greater on the dry diets. It is concluded that urine pH is a more important controller of struvite precipitation than mineral intake.

Topics: Animal Feed; Animals; Cat Diseases; Cats; Diet; Hydrogen-Ion Concentration; Magnesium; Magnesium Compounds; Male; Phosphates; Struvite; Urinary Calculi

In three separate experiments nine male cats were fed either a canned complete diet or a commercially available dry pelleted diet or the same dry diet containing 1.6 per cent ammonium chloride for seven days and then fasted for 20 hours. Then ad libitum feeding was continued and urine samples were taken at four-hour intervals for 12 hours and a final sample 12 hours later. Urine pH and the presence of struvite crystals in urine sediment were evaluated. The food and water intake of four of the nine cats was measured at the time of urine collection. After the fast, urine pH was raised, even after feeding the dry diet supplemented with ammonium chloride. A post prandial rise in urine pH was also seen on all three diets. After feeding the dry diet the postprandial peak pH was 7.97 and struvite occurred spontaneously. Urine pH after feeding the dry diet supplemented with ammonium chloride peaked at 7.75 then fell to 6.1 12 hours after the start of feeding. Struvite occurred spontaneously at all times until the pH reached 6.1 but when the pH of urine was raised to 7.0 the struvite crystallised. Urine pH on the canned complete diet peaked at 6.8 then fell to 5.8; struvite did not occur spontaneously but when urine pH was raised to 7.0 struvite crystallised except at the eighth and 12th hour sampling. These data show that fasting initiates a post prandial rise in urine pH and struvite crystalluria even when a normally effective urinary acidifier is used.(ABSTRACT TRUNCATED AT 250 WORDS)

Topics: Ammonium Chloride; Animal Feed; Animals; Cat Diseases; Cats; Drinking; Eating; Fasting; Hydrogen-Ion Concentration; Magnesium; Magnesium Compounds; Male; Phosphates; Struvite; Urinary Calculi

Topics: Adult; Ammonium Sulfate; Calcium Oxalate; Calcium Phosphates; Female; Humans; Hydrogen-Ion Concentration; Magnesium; Magnesium Compounds; Male; Middle Aged; Phosphates; Recurrence; Retrospective Studies; Struvite; Urinary Calculi

Topics: Enterobacteriaceae Infections; Humans; Hydroxamic Acids; Hydroxyurea; Magnesium; Magnesium Compounds; Phosphates; Pseudomonas Infections; Struvite; Urease; Urinary Calculi; Urinary Tract Infections

Topics: Adult; Ammonia; Bacterial Infections; Citrates; Female; Humans; Hydrogen-Ion Concentration; Hydroxamic Acids; Magnesium; Magnesium Compounds; Male; Middle Aged; Phosphates; Struvite; Urease; Urinary Calculi

In this study, 17 kidney tissue specimens and 29 renal stones were obtained from patients with urolithiasis. Control kidney specimens were dissected from 7 individuals not suffering from urolithiasis. The tissue specimens were fixed with 1% cetylpiridinium chloride (CPC) in 10% formalin (for 24 hours at room temperature). Then the kidney tissue specimens were embedded in paraffin and stained with hematoxylin-eosin for general observation as well as histochemically for demonstration of complex carbohydrates. Also, stone specimens were embedded in epon and thin sections made by the mineral polishing specimen preparation, and stained along with the kidney tissues. For identifying individual acidic and neutral carbohydrates, the enzyme digestion was performed for some tissue sections prior to histochemical staining. The stone-forming kidney tissues, normal kidney tissues and urinary stones (calcium oxalate, mixed, struvite) contained some glycosaminoglycans and neutral glycoproteins, but uric acid stones and cystine stones did not. The results of digestion with enzymes indicated that calcium oxalate stone-forming kidney tissue contains heparitin (heparan) sulfate; mixed stone-forming tissue contains sialic acid, hyaluronic acid, chondroitin sulfate A, B, C and heparitin (heparan) sulfate; struvite stone-forming tissue contains sialic acid, hyaluronic acid, chondroitin sulfate A, C and heparitin (heparan) sulfate; and cystine stone-forming tissue contains sialic acid, chondroitin sulfate A, C and heparitin (heparan) sulfate. The stone organic matrix is classified into the amorphous and stratiform types. The amorphous type matrix contains chondroitin sulfate A, B, C and heparitin (heparan) sulfate, and the stratiform type matrix also contains sialic acid and hyaluronic acid. The stone-forming kidney tissues, normal kidney tissues and stones (calcium oxalate, mixed, struvite) contain an appreciable amount of alpha-D-glucose, alpha-D-mannose and beta-D-galactose, but the uric acid stones and cystine stones do not contain sugar residues. Since the specific glycosaminoglycan composition differed for kidneys of different mineral content and stones of different morphological type, we believe that some glycosaminoglycans in kidneys and amorphous type matrix might play the role of a nucleating agent, and that a stratiform type matrix encourages stone enlargement.

Topics: Adult; Aged; Calcium Oxalate; Cystine; Female; Glycosaminoglycans; Hexoses; Humans; Kidney; Magnesium; Magnesium Compounds; Male; Middle Aged; Phosphates; Struvite; Urinary Calculi

This article contains an analysis of data compiled from 813 specimens of canine uroliths submitted to the Urinary Stone Analysis Laboratory at University of California School of Veterinary Medicine.

Topics: Animals; Apatites; Calcium Phosphates; Cystine; Cystinuria; Dog Diseases; Dogs; Magnesium; Magnesium Compounds; Minerals; Oxalates; Phosphates; Silicon Dioxide; Struvite; Uric Acid; Urinary Calculi

Wet chemical tests have deficiencies when applied to mixtures containing silica, which are common in the uroliths of some domestic animals. Consequently, the applicability of an infrared spectroscopic method was tested on 104 uroliths obtained from cattle, sheep, goats, horses, pigs, dogs, a chicken and a rabbit during diagnostic investigations. The following components were satisfactorily identified: silica, calcium oxalate, calcium carbonate, calcium phosphate, magnesium ammonium phosphate, magnesium phosphate and urates. The infrared characteristics of these compounds and their mixtures are described.

Topics: Animals; Animals, Domestic; Calcium Carbonate; Calcium Oxalate; Calcium Phosphates; Cattle; Chickens; Dogs; Goats; Horses; Magnesium; Magnesium Compounds; Phosphates; Rabbits; Sheep; Silicon Dioxide; Spectrophotometry, Infrared; Struvite; Swine; Uric Acid; Urinary Calculi

Crystalluria results from oversaturation of urine with crystallogenic substance. However, oversaturation may occur as a result of in vitro as well as in vivo events. The microscopic appearance of crystals only represents a tentative identification of their composition because variable conditions associated with their formation, growth, and dissolution may alter their appearance. Definitive identification is dependent on physical methods such as optical crystallography, x-ray diffraction, and electron microscopic analysis.

Topics: Animals; Bilirubin; Calcium Carbonate; Calcium Oxalate; Calcium Phosphates; Cholesterol; Crystallography; Cystinuria; Dog Diseases; Dogs; Hippurates; Leucine; Magnesium; Magnesium Compounds; Minerals; Phosphates; Quaternary Ammonium Compounds; Struvite; Tyrosine; Uric Acid; Urinary Calculi

Distal RTA is characterized by decreased distal renal tubular hydrogen ion secretion, decreased ability to acidify urine, hypercalciuria, hyperphosphaturia, hypocitraturia, and metabolic acidosis. Because of the resulting alterations in urine composition and pH, patients with distal RTA are predisposed to urolithiasis and renal calcification. Diagnosis of distal RTA is important because it is a potentially reversible disorder that, left untreated, may cause nephrocalcinosis, recurrent urolith formation, moderate to severe metabolic acidosis, and renal failure.

Topics: Acidosis, Renal Tubular; Animals; Calcium Phosphates; Dog Diseases; Dogs; Magnesium; Magnesium Compounds; Phosphates; Struvite; Urinary Calculi

Accurate analysis of urinary calculi is essential for greater understanding of urinary stone disease and initiation of effective management and preventive measures. Quantitative and qualitative analysis of uroliths are discussed in this article.

Topics: Animals; Crystallography; Dog Diseases; Dogs; Electron Probe Microanalysis; Magnesium; Magnesium Compounds; Microscopy, Electron, Scanning; Minerals; Phosphates; Spectrophotometry, Infrared; Struvite; Urinary Calculi; X-Ray Diffraction

A study was performed to compare qualitative test results of canine uroliths with quantitative test results. Qualitative test results were in agreement with quantitative test results in only 96 of 223 specimens (43 per cent). Lack of agreement was caused by false-negative qualitative test results (85 of 223), false-positive qualitative test results (15 of 233), and a combination of false-negative and false-positive qualitative test results (27 of 233). This study indicates that the veterinary profession should abandon exclusive use of qualitative chemical test kits for uroliths.

Topics: Animals; Calcium Oxalate; Calcium Phosphates; Cystine; Cystinuria; Dog Diseases; Dogs; Magnesium; Magnesium Compounds; Minerals; Phosphates; Quaternary Ammonium Compounds; Struvite; Uric Acid; Urinary Calculi

Medical therapy is an effective method of canine struvite urolith dissolution. Recommendations include (1) eradication or control of urinary tract infection (if present), (2) use of calculolytic diets, and (3) administration of urease inhibitors to patients with persistent urinary tract infection caused by urease-producing microbes.

Topics: Animals; Dog Diseases; Dogs; Magnesium; Magnesium Compounds; Phosphates; Struvite; Urinary Calculi

From 1953 to 1984 upper urinary tract calculi obtained by operation or spontaneous discharge were analyzed by infrared spectroscopy. A review of the stone compositions for each 4-year interval from 1953 to 1984 showed a decreased incidence of magnesium ammonium phosphate-containing stones from 1961 and later. The incidence of these stones was approximately 20 per cent before 1960 and approximately 10 per cent after 1961, although the percentage increased again after 1973, especially in female patients. The decreased percentage after 1961 coincided with a decrease in the ratio of renal-to-ureteral stones. The development of antibiotics might have had an important role in the variation of stone compositions.

Topics: Adolescent; Adult; Aged; Calcium; Child; Child, Preschool; Cysteine; Female; Humans; Magnesium; Magnesium Compounds; Male; Middle Aged; Phosphates; Struvite; Uric Acid; Urinary Calculi

The urinary tract calculus patients seen at our Department between January, 1974 and December, 1983 were reviewed to determine the trend of urolithiasis. The urinary tract calculus patients accounted for 10.1% of all the outpatients. Recurrent calculus diseases were seen in 16.9% of male patients and in 12.1% of female patients. The frequency of recurrence was very high in the patients in their forties. Upper urinary tract calculi were seen most frequently in the patients in their forties. We could expect spontaneous passage of stone for at least 6 months in the case of a middle-sized stone (less than 6 X 10 mm). The percentage of calcium oxalate-containing stone was 73.2% in male patients and the percentage of phosphate-containing stones was 81.6% in female patients. Hypercalciuric patients were seen in 34.0% of the calculus inpatients. Urinary bacterial culture revealed positive in 33.0% of the calculus inpatients.

Topics: Adolescent; Adult; Calcium Oxalate; Calcium Phosphates; Child; Female; Humans; Magnesium; Magnesium Compounds; Male; Middle Aged; Phosphates; Recurrence; Retrospective Studies; Struvite; Uric Acid; Urinary Calculi; Urine

Topics: Adult; Age Factors; Aged; Calcium Oxalate; Calcium Phosphates; Female; Humans; Magnesium; Magnesium Compounds; Male; Middle Aged; Phosphates; Sex Factors; Spectrophotometry, Infrared; Struvite; Urinary Calculi

Topics: Calcium Oxalate; Cysteine; Humans; Magnesium; Magnesium Compounds; Phosphates; Quaternary Ammonium Compounds; Struvite; Uric Acid; Urinary Calculi

The effect of 3 hydroxamic acid derivatives on urease-induced crystalluria was studied in vitro. Acetohydroxamic acid is more effective than salicylhydroxamic and gentisohydroxamic acids in inhibiting the kinetic of urease enzymatic reaction and in retarding the formation of struvite and apatite. Crystal deposits studied by scanning electron microscope (S.E.M.) and X-ray microanalysis indicated that acetohydroxamic acid favours the formation of large crystals of struvite, and less aggregation is observed. Salicyl and gentiso derivatives favour the formation of brushite together with struvite and apatite.

Topics: Apatites; Calcium; Crystallization; Humans; Hydroxamic Acids; Kinetics; Magnesium; Magnesium Compounds; Microscopy, Electron, Scanning; Phosphates; Phosphorus; Salicylamides; Struvite; Urease; Urinary Calculi

Fragments of urinary stones resulting from extracorporeal shock wave lithotripsy were examined by light and scanning electron microscopy. Calcium oxalate monohydrate and uric acid stone fragments were homogeneous and regular whereas struvite stone fragments were irregular in shape. Examination of the fractured surfaces revealed that the process of stone fragmentation involved fracture and cleavage of the crystals at some places and their separation from each other at others. In stones whose crystals are organised in layers, for instance calcium oxalate monohydrate and uric acid, crystalline layers separated along the concentric laminations. In struvite stones, which are an agglomeration of struvite and calcium phosphate crystals, major fragmentation occurred along the crystalline interfaces.

Topics: Calcium Oxalate; Crystallography; Cysteine; Electron Probe Microanalysis; Humans; Lithotripsy; Magnesium; Magnesium Compounds; Microscopy, Electron, Scanning; Phosphates; Struvite; Uric Acid; Urinary Calculi

Based on the analysis of magnesium (Mg), ammonium (NH4), phosphate (P), urine pH, and urine volume (V), a simplified estimate (AP[MAP] index) of the ion-activity product of magnesium ammonium phosphate (AP MAP) was derived: (Formula: see text). The factor A varies according to the collection period. In 4-hour urine samples more than half of the patients with staghorn calculi had values above 5 in contrast to normal subjects and calcium oxalate stone formers in whom lower values apparently were the rule. The AP(MAP) index might be of value in the evaluation and follow-up of patients with staghorn calculous disease.

Topics: Calcium Oxalate; Chemical Phenomena; Chemistry; Humans; Hydrogen-Ion Concentration; Kidney Calculi; Magnesium; Magnesium Compounds; Phosphates; Struvite; Urinary Calculi

Over the last few years there have been marked advances in both the surgical and medical treatment of urinary stone disease. At present, we have expectations of decreasing the incidence of stone recurrence in a vast majority of patients with medical therapy alone. While there are still many patients who will continue to develop new stones, decreasing their rate of new stone formation will lessen the need for surgical intervention.

Topics: Calcium; Cystinuria; Fluid Therapy; Humans; Kidney Calculi; Magnesium; Magnesium Compounds; Phosphates; Risk; Struvite; Uric Acid; Urinary Calculi

Thirty canine urinary calculi, most of which had been qualitatively classified as struvite calculi, were analyzed by instrumental neutron activation analysis at the University of Missouri Research Reactor. Measurements of sodium, magnesium, aluminum, silicon, phosphorus, chloride, potassium, and calcium were possible, using a dual irradiation procedure. Magnesium was used to calculate the percentage of struvite mineral, Mg(NH4) (PO4) X 6H2O, in the calculi by making use of the stoichiometric relationship of the element magnesium to the mineral. For those calculi containing greater than 80% struvite, the mean elemental concentrations were found to be 0.12% Na, 9.35% Mg, 0.0033% Al, 12.1% P, 0.02% Cl, 0.85% K, and 2.05% Ca. A new method for determination of silicon in urinary calculi also was discussed. Two calculi were found to contain 45.0% and 37.3% silicon, and 1 mixed calculus was composed of 1.4% silicon.

Topics: Animals; Dog Diseases; Dogs; Magnesium; Magnesium Compounds; Neutron Activation Analysis; Phosphates; Struvite; Urinary Calculi

The role of urinary glycosaminoglycans (GAGs) in lithogenesis is a topic of current interest in urologic research. One GAG, chondroitin sulfate, has previously been shown to inhibit calcium oxalate crystal formation. It has long been known that the chemical components of GAGs are present in the matrix of urinary concretions, but it has not been determined whether these components exist in free form or as constituents of GAG. This study was undertaken to determine whether GAGs are present in urinary stone matrices and, if so, to characterize them. Matrices of nine single urinary stones of various compositions and of three stone pools (calcium oxalate, magnesium ammonium phosphate) were isolated by exhaustive dialysis. The techniques of cellulose acetate electrophoresis, Alcian blue staining and enzymatic degradation were used to identify various GAGs. Material that stained Alcain blue was present in eleven of twelve samples. GAG was detected as this material in ten samples. The GAGs identified are heparan sulfate, hyaluronic acid and possibly keratan sulfate. The most prominent urinary GAG, chondroitin sulfate, was notably absent from urinary stone matrix. GAG seems to be incorporated into matrix on a selective basis. This finding may be due to differences in the affinities of different GAG species for the crystals which comprise the calculi. It has been proposed that the inhibitory activity of GAGs lies in their ability to bind to (and therefore block) the growth sites of crystals. It is apparent from this study that certain GAG species are incorporated into the structure of the stone and they may be intimately related to stone development and growth.

Topics: Calcium Oxalate; Calcium Phosphates; Electrophoresis, Cellulose Acetate; Glycosaminoglycans; Heparitin Sulfate; Hexosamines; Humans; Magnesium; Magnesium Compounds; N-Acetylneuraminic Acid; Phosphates; Sialic Acids; Struvite; Uric Acid; Urinary Calculi; Uronic Acids

Of 5 analysis tests of the 3rd International Ring Experiment for the control of the quality of methods of the analysis of urinary calculi 38 findings compiled according to 9 different techniques came in from 12 countries. The average deviation per component concerning all 5 analysis tests is considerably low with 0.10 mol proportions. The average quality measure SQ concerning all participants is approximately 2.00; it deteriorates from the X-ray diffraction method over the IR-technique to the other quantitative methods used. Advantages and disadvantages of the X-ray diffraction and IR-spectroscopic analysis are discussed. A methodically homogeneous and centralized performed analysis of urinary calculi shows advantages in the quality of the analyses.

Topics: Apatites; Calcium Oxalate; Germany, East; Humans; International Cooperation; Magnesium; Magnesium Compounds; Microchemistry; Microscopy, Polarization; Phosphates; Quality Control; Spectrophotometry, Atomic; Spectrophotometry, Infrared; Struvite; Uric Acid; Urinary Calculi; X-Ray Diffraction

With advanced techniques of scanning and transmission electron microscopy we studied the ultrastructural ecology of bacteria associated with struvite calculi on catheter surfaces, and in the bladder, ureter and renal pelvis. These detailed morphological data indicate that the interstices, core and external surface of such struvite aggregates contain large numbers of bacterial cells that grow as microcolonies and thick biofilms within extensive fibrous organic matrices. These bacterial cells and their secreted products (glycocalyx or biofilm matrix) appear to provide initial foci for crystal development and aggregation of crystals to form macroscopic struvite stones. The protective glycocalyx-enclosed microcolonial mode of bacterial growth also may explain the relative resistance to antibiotics observed in bacteria associated with infection stones.

Topics: Bacterial Infections; Crystallization; Glycoproteins; Humans; Magnesium; Magnesium Compounds; Microscopy, Electron; Microscopy, Electron, Scanning; Phosphates; Polysaccharides; Struvite; Urinary Calculi; Urinary Tract Infections

Topics: Calcium Oxalate; Calcium Phosphates; Cystine; Female; Humans; Magnesium; Magnesium Compounds; Male; Methods; Phosphates; Recurrence; Struvite; Uric Acid; Urinary Calculi; Urinary Tract; Urography

Total serum protein levels in 70 patients with urolithiasis were not significantly different from those in 20 control subjects, although certain variations were detected in individual protein patterns. In contrast, total urinary protein was significantly higher in patients with urolithiasis. 4-6 different components, i.e., albumin, alpha 1-acidic glycoprotein, alpha 1-antitrypsin, Gc-globulin, fibrinogen and immunoglobulin G, were found in the matrices of calculi and in urine, suggesting that proteinuria may play a role in the formation of stones in patients with urolithiasis.

Topics: Blood Proteins; Calcium Oxalate; Humans; Magnesium; Magnesium Compounds; Phosphates; Proteins; Proteinuria; Struvite; Uric Acid; Urinary Calculi

Topics: Adolescent; Adult; Aged; Calcium Oxalate; Calcium Phosphates; Child; Female; Humans; Magnesium; Magnesium Compounds; Male; Middle Aged; Phosphates; Struvite; Uric Acid; Urinary Calculi

Severe encrustation and stone formation on indwelling ureteral stents in 2 patients with a lithogenic history are reported. In both cases this complication occurred in the presence of sterile urine and treatment required pyelolithotomy in one and renal pelvic irrigation with urologic G solution in the other. Analyses of these stones revealed struvite and apatite, respectively. Dissolution of encrustations and stones via renal pelvic irrigation is suggested as a viable alternative to surgical intervention for this problem. A review of the literature shows a correlation between chronic stone formers and stent encrustation, rather than from bacteriuria alone. Long-term antibiotic suppression, more frequent followup with abdominal roentgenograms, and shorter periods of internal stenting are suggested for patients with a lithogenic history.

Topics: Adult; Apatites; Catheters, Indwelling; Humans; Magnesium; Magnesium Compounds; Male; Phosphates; Silicones; Struvite; Therapeutic Irrigation; Time Factors; Ureter; Urinary Calculi; Urinary Catheterization

Stone analysis was performed for 216 urinary calculi which were obtained from 205 patients in our hospital from January, 1980 to June, 1984. The results revealed 161 calcium stones, 21 uric acid stones, 19 struvite stones, 2 cystine stones and 13 others. Sixty one of the 205 patients (male 44, female 17) and 19 controls (male 11, female 8) were investigated for 24-hour urine calcium and uric acid. Forty seven of the patients had calcium stones, 7 of the patients had uric acid stones and 7 of the patients had struvite stones. The mean 24-hour urine calcium level was 146.8 +/- 76.5 mg/day for the male controls and 139.1 +/- 69.9 mg/day for the female controls. The mean 24-hour urine uric acid level was 528.1 +/- 132.6 mg/day for the male controls and 362.0 +/- 135.2 mg/day for the female controls. The mean 24-hour urine calcium level for the male calcium-stone group was 214.6 +/- 96.8 mg/day, and it was significantly higher than that for the male controls (p less than 0.05). The 24-hour urine analysis revealed abnormalities in 17 urolithiasis patients (27.9%) including hypercalciuria in 11 patients (18.0%) and hyperuricosuria in 9 patients (14.1%).

Topics: Adolescent; Adult; Aged; Calcium; Cystine; Female; Humans; Magnesium; Magnesium Compounds; Male; Middle Aged; Phosphates; Struvite; Uric Acid; Urinary Calculi

The stones associated with urinary tract infection were cultured using a method to distinguish between surface contamination and bacteria within the stone. Twenty three of 30 stones (77%) were infected mainly by Proteus mirabilis or Pseudomonas aeruginosa and most were composed of struvite and/or apatite. Most oxalate and uric acid stones were sterile; occasionally the stones with positive culture had a non-urea-splitting bacteria and these were thought to have been infected secondarily. Some infected stones were studied by light microscopy scanning election microscopy and transmission electron microscopy. We found many rods in the interstices of crystals of struvite and apatite extensively from the nucleus to peripheral layers. These findings are important in the prevention and treatment of infection stones.

Topics: Adolescent; Adult; Aged; Apatites; Child; Child, Preschool; Female; Humans; Infant; Magnesium; Magnesium Compounds; Male; Middle Aged; Phosphates; Proteus mirabilis; Pseudomonas aeruginosa; Struvite; Urinary Calculi; Urinary Tract Infections

Topics: Adult; Aged; Calcium Oxalate; Calcium Phosphates; Female; Humans; Hydroxyapatites; Magnesium; Magnesium Compounds; Male; Middle Aged; Phosphates; Struvite; Urinary Calculi; X-Ray Diffraction

Topics: Adolescent; Adult; Aged; Calcium; Calcium Phosphates; Child; Cystinuria; Diet; Disease Susceptibility; Female; Humans; Magnesium; Magnesium Compounds; Male; Middle Aged; Oxalates; Phosphates; Risk; Struvite; Uric Acid; Urinary Calculi

Topics: Calcium; Calcium Oxalate; Calcium Phosphates; Humans; Magnesium; Magnesium Compounds; Phosphates; Statistics as Topic; Struvite; Urinary Calculi

Effective treatment and prevention of urolithiasis depends on accurate determination of the chemical nature of the uroliths. A widely used qualitative chemical procedure was compared with quantitative crystallographic analysis of 272 canine uroliths. Agreement between the 2 methods was 78%. Qualitative analysis failed to detect 62% of calcium-containing uroliths and 83% of carbonate apatite uroliths. Qualitative analysis gave false-positive results for urates in 55% of cystine uroliths. Mixed uroliths comprising 6% of the total could not be classified without quantitative analysis. Silicate, cystine, and urate uroliths generally were of pure composition. Crystallographic analysis indicated the following distribution of major types: struvite, 69%; calcium oxalate, 10%; urate, 7%; silicate, 3.5%; cystine, 3.2%; calcium phosphate, 1%; and mixed, 6%. Among dogs with struvite uroliths, 66% had positive results of bacterial culturing from the urinary bladder. Six breeds (Miniature Schnauzer, Welsh Corgi, Lhasa Apso, Yorkshire Terrier, Pekingese, and Pug) had a significantly higher risk for urolithiasis, compared with other breeds. The German Shepherd Dog had a significantly lowered risk, compared with other breeds. Two breeds had significant relationship to a specific type of urolith: Miniature Schnauzer for oxalate, and Dalmatian for urate (P less than 0.001). It was concluded that quantitative analysis, using crystallography, was superior for the detection of calcium oxalate, carbonate apatite, cystine, urate, and mixed uroliths.

Topics: Animals; Bacteriuria; Calcium Oxalate; Calcium Phosphates; Crystallography; Cystine; Dog Diseases; Dogs; Female; Magnesium; Magnesium Compounds; Male; Phosphates; Silicic Acid; Struvite; Uric Acid; Urinary Calculi; Urinary Tract Infections

The composition and structure of nuclei of infection stones were investigated. Twenty seven out of 40 renal stones were found to contain struvite and/or carbonate apatite in the nuclei as well as peripheral layers, and 13 contained calcium oxalate. Some bladder stones also contained different substances in the nuclei. In some infection stones whose architecture was studied in thin section and with scanning electron microscopy, we found large numbers of bacteria in the nuclei composed of struvite and/or apatite. Though we could find no bacteria within the nuclear parts composed of oxalate, we found them in apatite layers outside the nuclei. Urea-splitting bacteria are suggested to participate both in the initial formation of struvite stones and in the diversion of oxalate stones into phosphate stones. Such bacteria may play important roles in stone formation, not only as promotors of crystallization of struvite and apatite but also as a component such as of an organic matrix.

Topics: Calcium Oxalate; Calcium Phosphates; Humans; Magnesium; Magnesium Compounds; Microscopy, Electron; Microscopy, Electron, Scanning; Phosphates; Struvite; Urinary Calculi; Urinary Tract Infections

Topics: Crystallization; Humans; Hydrogen-Ion Concentration; Magnesium; Magnesium Compounds; Models, Chemical; Phosphates; Risk; Spectrophotometry; Struvite; Urinary Calculi

Results from an external quality assessment program of urinary calculi analysis are shown. Some analytical improvements have been observed since a similar investigation two years earlier. Many erroneous results, however, were found. Best agreement was found between laboratories which produced results on an interval scale ("quantitative"). The laboratories in this group used either x-ray diffraction, infrared spectrometry, or wet chemistry. This, however, did not apply to the wet chemistry kit Merckognost 11003, which was used by 24 of the 57 participating laboratories. A study of this kit by our laboratory led to several improvements including better calibration and reduced imprecision. General recommendations of how to present the analytical results to the clinician are given.

Topics: Calcium Oxalate; Calcium Phosphates; Cystine; False Negative Reactions; False Positive Reactions; Humans; Magnesium; Magnesium Compounds; Methods; Phosphates; Quality Control; Reagent Kits, Diagnostic; Spectrophotometry, Infrared; Struvite; Uric Acid; Urinary Calculi; X-Ray Diffraction

Excised urinary calculi were subjected to computed tomographic (CT) scanning in an attempt to determine whether CT attenuation values would allow accurate analysis of stone composition. The mean, maximum, and modal pixel densities of the calculi were recorded and compared; the resulting values reflected considerable heterogeneity in stone density. Although uric acid and cystine calculi could be identified by their discrete ranges on one or more of these criteria, calcium-containing stones of various compositions, including struvite, could not be distinguished reliably. CT analysis of stone density is not likely to be more accurate than standard radiography in characterizing stone composition in vivo.

Topics: Calcium Oxalate; Calcium Phosphates; Cystine; Humans; Magnesium; Magnesium Compounds; Phosphates; Struvite; Tomography, X-Ray Computed; Uric Acid; Urinary Calculi

Topics: Animals; Calcium Oxalate; Calcium Phosphates; Cat Diseases; Cats; Female; Magnesium; Magnesium Compounds; Male; Minerals; Phosphates; Sex Factors; Species Specificity; Struvite; Urethral Diseases; Urinary Calculi

A high incidence (8/892) of urinary tract calculi was encountered during a study involving rats being fed diets supplemented with retinoids. When the incidence was compared to that observed in earlier studies without retinoid supplements and spanning several years (2/2998), the incidence in the current study was significantly higher. Possible causative factors such as age, sex, strain, diet and carcinogen or retinoid treatment have been analyzed without a clear explanation for the increased incidence. The data suggest that retinoid treatment increased the risk of stone formation, but that retinoids were less important than some other unidentified factor(s) that operated during the recent period.

Topics: Animals; Female; Food, Fortified; Magnesium; Magnesium Compounds; Male; Phosphates; Rats; Rats, Inbred F344; Rats, Inbred Lew; Rats, Inbred Strains; Retinoids; Rodent Diseases; Species Specificity; Struvite; Urinary Calculi

Twenty-four cats were fed a dry commercial cat food once daily for 2 weeks and then ad libitum for 2 weeks. Urine pH was measured 4 times daily the last 3 days of each feeding period. Subsequently, the cats were allotted to 2 equal groups and fed ad libitum an experimental, dry ration with or without 1.5% ammonium chloride for 11 months. During this period, urine pH was measured at 1, 3, 6, and 9 weeks, then monthly through 29 weeks, and then every 6 weeks for the duration of the study. When the cats were fed ad libitum, urine pH remained constant throughout the day, regardless of ration. In cats fed once daily, urine pH increased to 7.6 by 2 hours after feeding and remained between 6.6 and 7.6 for 9 hours. Urine pH remained constant throughout the study when cats were fed the experimental ration with or without 1.5% ammonium chloride, but was significantly different (P less than 0.01) between the 2 groups, 5.9 +/- 0.3 (n = 1,035) and 7.0 +/- 0.5 (n = 616), respectively. Ammonium chloride consumption had no effect on food and water consumption or body weight. It was concluded that ammonium chloride was an effective urinary acidifier for a prolonged time, maintained urine pH below 6.6, and did not decrease food intake when given at a concentration of 1.5% of the diet.

Topics: Ammonium Chloride; Animals; Cat Diseases; Cats; Diet; Evaluation Studies as Topic; Hydrogen-Ion Concentration; Magnesium; Magnesium Compounds; Male; Phosphates; Struvite; Urinary Calculi; Urine

Two groups of 12 cats were fed ad libitum an experimental dry expanded ration high in magnesium (0.37%, dry matter basis) and similar to most commercial dry cat foods in all other nutrients. The diet of one of the groups contained 1.5% ammonium chloride, which was added to the diet before processing. Urethral obstruction developed twice in 7 of the 12 cats fed the ration without ammonium chloride. Of the 5 remaining cats in that group, 2 had calculi in the urinary bladder and urethra at necropsy. In contrast, only 2 of the 12 cats fed the ration containing ammonium chloride had urethral blockage once; neither cat had another blockage. Both cats had been catheterized twice as paired controls before urethral obstruction. One of these 2 cats died from a urinary tract infection apparently introduced through the indwelling catheter, and at necropsy there were 2 small calculi in the urethra. At the end of the study, only 1 other cat fed the ammonium chloride diet had a calculus in the urinary bladder at necropsy; this cat had not had a urethral obstruction throughout the study. After each cat had 2 urethral blockages, its diet was changed. Four cats were fed the ration containing ammonium chloride and 3, a dry, commercial ration. Of the 4 cats fed the diet containing ammonium chloride, none developed another urethral obstruction within 6 months, and at necropsy, no calculi were in the urinary bladder or urethra. Two of the 3 cats fed the commercial ration experienced urethral blockage within 3 months. These 2 cats were then fed the diet containing ammonium chloride.(ABSTRACT TRUNCATED AT 250 WORDS)

Topics: Ammonium Chloride; Animal Feed; Animals; Cat Diseases; Cats; Hydrogen-Ion Concentration; Magnesium; Magnesium Compounds; Male; Phosphates; Struvite; Urethral Obstruction; Urinary Calculi; Urine

There are difficult problems in the management of urinary calculi associated with infections. Stones associated with infections are not only infection stones such as struvite stones, but also other kinds of stones such as calcium oxalate. Therefore, from practical view points, bacteriological studies should be carried out on urinary calculi associated with infections as a whole. We investigated 120 cases of urinary calculi associated with infections with special reference to bacteria on the stone surface, within the stone, compositions of the stone and permeation of an antibiotic into the stone. Proteus was isolated most frequently from the urine, followed by E. coli and Pseudomonas. These bacteria were isolated from the stone surface, although the incidence of Proteus mirabilis was higher than that in the urine. Bacteria were isolated in 25 of the 33 specimens of the inside parts and in 12 of the 12 stones of MAP and MAP plus other components. Proteus mirabilis was found in 7 of the 12 stones. Bacteria were isolated from the inside of 9 of the 16 stones of CaP and CaP plus other components and Proteus mirabilis was found in 6 of these 9 cases. Pseudomonas was isolated in 2 out of the 7 stones of CaP plus CaOX and its growth was seen in 5 specimens. The incorporation of an antibiotic, Cefmetazole, into the stone differed greatly with each stone. There were some cases in which the concentration of Cefmetazole in the inside was less than 5% of that in the outside. Stones may function as a sanctuary for organisms and may protect these organisms.

Topics: Adult; Aged; Anti-Bacterial Agents; Bacteria; Calcium Oxalate; Calcium Phosphates; Female; Humans; Magnesium; Magnesium Compounds; Male; Middle Aged; Phosphates; Struvite; Urinary Calculi; Urinary Tract Infections

In our laboratories, more than 1,500 urinary calculi have been analyzed by infrared spectroscopy. These data were statistically analyzed by microcomputer. The most frequent type was calcium oxalate combined with calcium phosphate, followed by pure calcium oxalate and magnesium ammonium phosphate combined with calcium phosphate. In particular, the composition of magnesium ammonium phosphate combined with calcium phosphate increased as compared with that four years earlier. Four years ago, we spent one month to statistically analyze 300 urinary calculi. But in this study, only sixteen days was required to analyze 1,500 urinary calculi by using a microcomputer.

Topics: Adolescent; Adult; Age Factors; Aged; Calcium Oxalate; Calcium Phosphates; Child; Child, Preschool; Computers; Female; Humans; Infant; Magnesium; Magnesium Compounds; Male; Microcomputers; Middle Aged; Phosphates; Sex Factors; Statistics as Topic; Struvite; Urinary Calculi

On the basis of routine clinical and laboratory investigations, one or more probable or possible causes of stone formation were established in 27% of upper urinary tract and 98% of bladder stone patients. In the upper urinary tract, causes were usually found for triple phosphate and pure calcium phosphate stones and rarely for pure calcium oxalate stones. Except for cystine stones and largely for triple phosphate stones there was no definite correlation between the composition of stone and causes. Uric acid and urate stones were often not associated with obvious causes, but their demonstration should lead to further investigations. In a small group of recurrent calcium stone formers examined for hypercalciuria, hyperoxaluria, hyperuricosuria, and renal tubular acidosis, positive findings were noted for 65%, but there was no consistent correlation between these findings and the types of stone. Stone analysis is most useful in so far as it identifies or excludes triple phosphate, cystine, and uric acid/urate stones. This may be done by simple chemical analysis. Certain rare components may, however, be overlooked, as will details of stone structure, unless crystallographic methods are employed.

Topics: Bacterial Infections; Calcium Oxalate; Calcium Phosphates; Cystine; Escherichia coli Infections; Humans; Magnesium; Magnesium Compounds; Phosphates; Struvite; Urinary Bladder Calculi; Urinary Bladder Neck Obstruction; Urinary Calculi

Quantitative analytical findings on upper urinary tract stones from 500 patients are reported and compared to data in the literature. Methods of presentation of quantitative data are discussed. A wide range of findings between recurrent stones in the same patient and between stones from patients with the same cause of stone formation was found. No immediate clinical value of quantitation can be seen, but larger materials and correlation with metabolic investigations in stone formers may reveal correlations of clinical interest. Quantitative observations may identify groups of patients and types of stones not recognised on the basis of qualitative analysis. Examples of this are given for calcium oxalate-calcium phosphate stones and for stones containing brushite. The organic matrix which usually contributes 2-3% of stone mass was not considered, but distinctly visible and separate organic material in 7 stones was quantitated by visual estimate. 32 stones were incomplete, and their quantitation may not be wholly representative. Their exclusion, however, would have led to major bias because most were large and nearly half were triple phosphate stones, both properties being relatively rare. In cases of multiple stones, usually only one was quantitated. Seventy patients provided more than one stone for analysis (Otnes, 1983b), but except when specifically stated only the first stone is considered.

Topics: Calcium Oxalate; Calcium Phosphates; Crystallization; Crystallography; Cystine; Humans; Magnesium; Magnesium Compounds; Phosphates; Recurrence; Struvite; Uric Acid; Urinary Calculi

This report describes the results obtained with a combination of acetohydroxamic acid (AHA) and antibacterial agents in 13 patients with recurrent struvite stones complicated by refractory infections with urease-producing bacteria. Intravenous antibiotic pulses plus oral AHA achieved urine sterilisation in all. Then oral chemotherapy plus AHA was given for a mean period of 10.8 +/- 5.4 months. In four patients, the urine remained sterile, but in all the patients urinary pH remained below 6.4 and urinary NH4+ below 40 mg/dl. Despite the persistence of urea-splitting bacteria, the radiographic data showed an arrest of stone growth during the first year of treatment.

Topics: Anti-Bacterial Agents; Drug Therapy, Combination; Humans; Hydroxamic Acids; Magnesium; Magnesium Compounds; Phosphates; Struvite; Urease; Urinary Calculi; Urinary Tract Infections

Crystalluria was induced in male Sprague-Dawley rats by implanting potassium-oxalate-containing mini-osmotic pumps. Urine of all experimental animals had abundant crystals of calcium oxalate, hydroxypatite, struvite, and calcium phosphate. These crystals were similar in morphology to the crystals found in human crystalluria. Histological examination of kidneys and tissue samples from other organs revealed no abnormality. One group of animals was injected with sodium oxalate in addition to implantation of potassium-oxalate-containing mini-osmotic pumps. Bladder urine from these animals contained calcium oxalate microstones and their kidneys had deposits of calcium oxalate crystals.

Topics: Animals; Calcium Oxalate; Calcium Phosphates; Crystallization; Drug Implants; Hydroxyapatites; Magnesium; Magnesium Compounds; Male; Osmosis; Phosphates; Potassium; Rats; Rats, Inbred Strains; Struvite; Urinary Calculi

Chronic urinary infection is thought to be a major factor in the causation of urinary calculi in paraplegic patients. Acetohydroxamic acid is reported to be effective in some patients for the management of this type of stone disease, but there have been no studies of urinary saturation levels during therapy with this drug. In this study 10 patients received oral acetohydroxamic acid for seven days. Marked lowering of urinary pH and ammonium levels were observed, but decreases in urinary saturation were small. The administration of acetohydroxamic acid resulted in increased urinary excretion of magnesium and phosphate, effects that have not previously been reported.

Topics: Adult; Calcium Phosphates; Humans; Hydrogen-Ion Concentration; Hydroxamic Acids; Magnesium; Magnesium Compounds; Male; Middle Aged; Paraplegia; Phosphates; Struvite; Urinary Calculi; Urinary Tract Infections

During a 5 year period, 500 stones from the upper urinary tract and 100 from the urinary bladder of as many unselected and consecutive patients were obtained in one hospital and analysed crystallographically. 90.4% of the upper urinary tract stones and 65% of the bladder stones belonged to the groups of calcium stones, while 6.6% and 24%, respectively, were triple phosphate stones. The contribution of calcium stones to this material is higher and that of triple phosphate stones lower than in comparable materials. Frequency variations between materials also exist within the groups of calcium stones, and for uric acid, urate and cystine stones. On the basis of published material, it is not possible to say if these differences are renal or reflect variations in the selection of stones and the methods of analysis. Reports on stone materials should include information on these aspects in order to allow meaningful comparison. Distinction between stones from the upper urinary tract and from the bladder is mandatory. The composition pattern reported here is believed to be as representative as is possible to obtain. A major part of stones from the upper urinary tract is, however, lost for analysis following spontaneous passage. Such stones are more often pure calcium oxalate and less often triple phosphate stones than those which are obtained by surgical methods, and the extent to which they are obtained will influence the findings in stone materials.

Topics: Adult; Aged; Calcium Carbonate; Calcium Oxalate; Calcium Phosphates; Crystallography; Cystine; Female; Humans; Kidney Calculi; Magnesium; Magnesium Compounds; Male; Middle Aged; Phosphates; Struvite; Ureteral Calculi; Uric Acid; Urinary Bladder Calculi; Urinary Calculi

Stones removed from 120 adults and 22 children were analysed for chemical composition. Calcium oxalate was the main component of both adult (49%) and childhood (44%) stones. Calcium stones formed the major type in adults and were slightly more common in males, whereas urate/uric acid stones were predominant in children and were more common in girls. In adults, the stones were usually found in the upper urinary tract (UUT) and were mainly of calcium type (72%), while all three types were found in almost equal amounts in the lower urinary tract (LUT). Magnesium ammonium phosphate and urate/uric acid were the stones found mainly in the upper and lower urinary tracts respectively of children.

Topics: Adolescent; Adult; Calcium Oxalate; Calcium Phosphates; Child; Female; Humans; Magnesium; Magnesium Compounds; Male; Phosphates; Struvite; Thailand; Uric Acid; Urinary Calculi

The clinical management of renal calculi would be aided if a direct in vivo determination of stone chemical composition could be made. We investigated the possibility of obtaining this information by a quantitative analysis of the computerized tomography scan images of 80 urinary calculi. Our results show that by using an appropriately calibrated computerized tomography scanner the differentiation of stone chemical composition can be made on the basis of 3 parameters, namely, absolute computerized tomography value at a single x-ray energy, the difference between computerized tomography values measured at 2 different x-ray energies, and computerized tomography value-frequency histograms (pixel patterns) of the stones. Uric acid stones were differentiated from all other stones at a significance level of p less than 0.001. Cystine was differentiated from calcium oxalate and brushite at the same significance level. Using pixel patterns cystine and struvite were separated from each other correctly with 70 per cent accuracy. Struvite stones of low or moderate calcium phosphate content were identified correctly with 80 per cent accuracy. Struvite stones of high calcium phosphate content could not be differentiated from calcium oxalate or brushite. Calcium oxalate and brushite could not be separated. The minimum stone size that allowed chemical identification was established for each stone type. In addition, we demonstrated that all the urinary calculi examined were visible on computerized tomography scan regardless of chemical composition or size.

Topics: Calcium Oxalate; Calcium Phosphates; Cystine; Humans; Magnesium; Magnesium Compounds; Mathematics; Phosphates; Struvite; Tomography, X-Ray Computed; Urinary Calculi

Topics: Calcium; Cystine; Female; Humans; Magnesium; Magnesium Compounds; Male; Phosphates; Radiography; Struvite; Uric Acid; Urinary Calculi

The mineral composition of 150 calculi from the urinary tracts of Miniature Schnauzer dogs was determined by qualitative and quantitative methods. Struvite was the predominant mineral in 92% of the calculi. Other calculi contained predominantly apatite, calcium oxalate, ammonium urate, or silica. Most calculi were from the urinary bladder or urethra, or both. Four were from the renal pelves. Struvite calculi were more frequently encountered in females than males. The mean age of the dogs at the time of detection of calculi was 4.8 years. Qualitative analysis failed to detect some minerals that were identified by quantitative analysis.

Topics: Animals; Apatites; Calcium Oxalate; Dog Diseases; Dogs; Magnesium; Magnesium Compounds; Minerals; Phosphates; Struvite; Urinary Calculi

Struvite (magnesium ammonium phosphate) uroliths are found more frequently in the urinary tracts, of dogs than are other types of uroliths. Infection of the urinary tract with urease-producing bacteria, especially staphylococci, plays an important role in urolith formation. An inherited predisposition to urinary tract infection may be associated with the high rat of occurrence of struvite uroliths in some dogs. Diagnosis of struvite urolithiasis should encompass analysis of the mineral composition of calculi and identification of concomitant urinary tract infection. Since urinary tract infections occur as sequelae to abnormalities in local or systemic host-defense mechanisms, appropriate effort should be directed toward detection of these abnormalities. Therapy of struvite urolithiasis should encompass relief of obstruction to outflow when necessary, elimination of existing calculi, eradication or control of urinary tract infection, and prevention of recurrence. Although surgical removal remains as the preferred method to eliminate struvite uroliths from dogs, nonsurgical methods of urolith dissolution should be considered. Recurrence of struvite uroliths may be prevented by various combinations of antimicrobial therapy, administration of urease inhibitors, acidification of urine, and induction of diuresis.

Topics: Animals; Dog Diseases; Dogs; Magnesium; Magnesium Compounds; Phosphates; Recurrence; Struvite; Urinary Calculi

Topics: Calcium Oxalate; Calcium Phosphates; Centrifugation, Density Gradient; Chemical Fractionation; Chemistry Techniques, Analytical; Humans; Hydroxyapatites; Magnesium; Magnesium Compounds; Phosphates; Struvite; Uric Acid; Urinary Calculi; X-Ray Diffraction

The composition of the stone was determined in 24 paraplegic patients from whom 26 stones were surgically removed. Twenty-five of the 26 stones consisted of 90 per cent magnesium ammonium phosphate and 10 per cent carbonate apatite. The remaining single stone was composed of 90 per cent calcium oxalate and 10 per cent magnesium ammonium phosphate. Renal function improved significantly with the removal of the stones.

Topics: Adult; Aged; Humans; Magnesium; Magnesium Compounds; Male; Middle Aged; Paraplegia; Phosphates; Spinal Cord Injuries; Struvite; Urinary Calculi; Urinary Tract Infections

The results of chemical analyses of 429 urinary calculi are presented and classified according to chemical composition. Some of the general features of the different chemical types of the stones are discussed. Although the general distribution of the chemical types of stones in Lebanon is essentially similar to that reported from other countries, the two striking features of this series are: (1) a relatively lower incidence of infection stones (i.e. stones containing magnesium ammonium phosphate) and (2) a relatively higher incidence of stones containing a mixture of uric acid and calcium oxalate and/or calcium phosphate.

Topics: Calcium Oxalate; Calcium Phosphates; Cystine; Humans; Incidence; Kidney Calculi; Lebanon; Lithotripsy; Magnesium Compounds; Phosphates; Struvite; Uric Acid; Urinary Calculi

Urolithiasis is a rare complication following kidney transplantation. Experience with this complication in 6 of 426 transplantations performed from 1968 to 1979 is reviewed. The clinical symptoms are different from the disease in non-transplant patients. Three major predisposing causes for the development of calculi after kidney transplantation were found in our patients--urodynamic disorders following complications of the ureterovesical anastomosis, persistent bacteriuria and renal tubular acidosis and, less importantly, the presence of hypercalcemia and hypercalciuria as a result of secondary hyperparathyroidism. Crystal-optical and x-ray-diffraction studies contributed to the interpretation of the constituents and texture of the calculi and of the aetiological factors concerned.

Topics: Adolescent; Adult; Apatites; Calcium Oxalate; Carbonates; Female; Humans; Kidney Transplantation; Magnesium; Magnesium Compounds; Male; Phosphates; Postoperative Complications; Quaternary Ammonium Compounds; Struvite; Transplantation, Homologous; Uric Acid; Urinary Calculi

Magnesium ammonium phosphate calculi developed in the urinary bladders and urethras of four of five offspring of Miniature Schnauzer parents with recurrent struvite urolithiasis. Calculi were detected by radiograhy when the dogs were 12 to 15 months old. Males and females were affected. A significant number of urease-producing staphylococci were identified in the urine of three of four dogs before urolith formation, and in one dog after urolith formation. The dogs were evaluated until they were 26 months old. Serum concentrations of calcium, phosphorus, and magnesium were inside usual limits throughout the study. Abnormalities that might predispose to urinary tract infection were not identified by radiography or necropsy studies. In one dog, bladder calculi recurred after surgical removal of multiple cystoliths. In another, urethral obstruction and acute generalized pyelonephritis induced a lethal uremic crisis. Gross and microscopic lesions, detected after necropsy of all dogs with uroliths, were typical of bacterial infection.

Topics: Animals; Coagulase; Dog Diseases; Dogs; Female; Magnesium; Magnesium Compounds; Male; Phosphates; Quaternary Ammonium Compounds; Radiography; Staphylococcal Infections; Staphylococcus aureus; Struvite; Urease; Urinary Bladder Calculi; Urinary Calculi; Urinary Tract Infections

Urease positive staphylococcal urinary tract infection was experimentally induced in 13 dogs. Eight dogs developed cystic and/or urethral struvite calculi in 2 to 8 weeks. No abnormalities in systemic cell mediated immunity were detected in dogs before or after the establishment of the urinary tract infection. Miniature schnauzers whose ancestors had developed stones seemed to be no more susceptible to experimental urinary tract infection and stone formation than miniature schnauzers or beagles whose ancestors did not develop stones.

Topics: Animals; Dog Diseases; Dogs; Female; Kidney Calculi; Magnesium; Magnesium Compounds; Male; Phosphates; Quaternary Ammonium Compounds; Staphylococcal Infections; Struvite; Urethral Diseases; Urinary Bladder Calculi; Urinary Calculi; Urinary Tract Infections

Topics: Ammonium Compounds; Calculi; Humans; Magnesium; Magnesium Compounds; Phosphates; Quaternary Ammonium Compounds; Solubility; Struvite; Urinary Calculi; Urinary Tract

Topics: Apatites; Calcium; Calcium Phosphates; Calculi; Humans; Magnesium; Magnesium Compounds; Phosphates; Struvite; Urinary Calculi; Urinary Tract; Urine