struvite and calcium-phosphate--dibasic--anhydrous

An 88-year-old woman was hospitalized with the chief complaints of lower abdominal pain, miction pain and pollakisuria. Radiographs showed a giant bladder stone shadow, 12.0 x 9.0 cm in size. Cystolithotomy was performed under the diagnosis of bladder stone. The extirpated stone weighed 510 g, and measured 10.0 x 7.5 x 6.0 cm in size. The stone had four compartments of stratified lamellae composed of calcium phosphate and magnesium ammonium phosphate. The postoperative course was uneventful and the bilateral hydronephrosis improved markedly on DIP.

Topics: Aged; Aged, 80 and over; Calcium Phosphates; Female; Humans; Magnesium Compounds; Phosphates; Struvite; Treatment Outcome; Urinary Bladder 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

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

Topics: Calcium Phosphates; Catheters, Indwelling; Crystallization; Equipment Contamination; Equipment Design; Humans; Magnesium; Magnesium Compounds; Phosphates; Struvite; Urinary Catheterization

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

Blockages caused by inorganic precipitates are a major problem of urine-collecting systems. The trigger of precipitation is the hydrolysis of urea by bacterial urease. While the maximum amount of precipitates, i.e. the precipitation potential, can be estimated with equilibrium calculations, little is known about the dynamics of ureolysis and precipitation. To gain insight in these processes, we performed batch experiments with precipitated solids and stored urine from a urine-collecting system and later simulated the results with a computer model. We found that urease-active bacteria mainly grow in the pipes and are flushed into the collection tank. Both, bacteria and free urease, hydrolyse urea. Only few days are necessary for complete urea depletion in the collection tank. Two experiments with precipitated solids from the pipes showed that precipitation sets in soon after ureolysis has started. At the end of the experiments, 11% and 24% of urea was hydrolysed while the mass concentration of newly formed precipitates already corresponded to 87% and 97% of the precipitation potential, respectively. We could simulate ureolysis and precipitation with a computer model based on the surface dislocation approach. The simulations showed that struvite and octacalcium phosphate (OCP) are the precipitating minerals. While struvite precipitates already at low supersaturation, OCP precipitation starts not until a high level of supersaturation is reached. Since measurements and computer simulations show that hydroxyapatite (HAP) is the final calcium phosphate mineral in urine solutions, OCP is only a precursor phase which slowly transforms into HAP.

Topics: Bacteria; Calcium Phosphates; Chemical Precipitation; Hydrolysis; Magnesium Compounds; Models, Theoretical; Phosphates; Struvite; Urea; Urease; Waste Disposal, Fluid; Water Purification

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 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

Comprehensive metabolic evaluation has become an important aspect of the management of recurrent nephrolithiasis, yet the role of stone analysis is often neglected or perhaps underestimated. The purpose of this study was to determine the role of stone analysis in medical decision making in patients with recurrent nephrolithiasis.. We evaluated 100 consecutive stone-forming patients who had undergone compositional stone analysis as well as comprehensive metabolic evaluation at our institution. An analysis of stone composition in relation to metabolic disturbances was performed. Patients were stratified into two groups: calcium and non-calcium stone formers.. Patients having non-calcium stones were found to have a metabolic analysis reflecting specific metabolic disorders. Alternatively, patients with calcium stones were heterogeneous with regard to metabolic disorders, but there was a significant likelihood of renal tubular acidosis in those patients with calcium phosphate calculi. On the basis of these results, a simplified metabolic evaluation and nonselective medical therapy based on stone composition was formulated to facilitate assessment, management, and monitoring of stone disease.. Compositional stone analysis should be an integral part of the metabolic evaluation of patients with nephrolithiasis. Moreover, stone analysis alone may provide guidance for therapeutic treatment and obviate a formal metabolic evaluation.

Topics: Acidosis, Renal Tubular; Calcium; Calcium Phosphates; Cystine; Female; Humans; Kidney Calculi; Magnesium Compounds; Male; Metabolic Diseases; Phosphates; Struvite; Uric Acid

In this paper, the clinical and metabolic patterns of nephrolithiasis in different ages of adulthood are studied.. Eight-hundred patients observed at the Mauriziano Hospital between 1990 and 1995, were classified into 3 groups, on the basis of age at the onset of disease: A: 20 through 39 years; B: 40 through 59; C: 60 years and over.. Calcium-oxalate stones had a lower recurrence in C (19.1%) and B (31.5%) than in A (41.7%). Pure uric acid stones recurred in 18.9% of C, 16.7% of B and 4.3% of A. The prevalence of hypercalciuria was higher in A (50.3%) than in B (35.9%) and C (36%); so did hypocitraturia. Hyperuricuria was lower in A (5%, p < 0.05) than in B (9.4%) and C (10%). Low urine pH (< 5.5) was 13% in A, 21.3% in B, 38% in C. Prevalence of hyperoxaluria was about 14% in all groups. The whole prevalence of secondary forms of stone disease was 13% in A, 12% in B and 30% in C. Differences among groups were mainly due to prevalence of urological abnormalities and urinary tract infection. In patients without metabolic disturbances. urological abnormalities or urinary tract infections altogether, were 4.6% in A; 5.2% in B; 33% in C. Urological approach removed 8% of stones in A, 5.6% in B and 10.2% in C.. Higher morbidity in younger patients could be due to a lower prevalence of easier-passing uric acid stones. The higher occurrence of urological disturbances and struvite stones in the elderly could explain the higher morbidity in this group.

Topics: Adult; Age of Onset; Aged; Calcium; Calcium Oxalate; Calcium Phosphates; Citric Acid; Comorbidity; Female; Humans; Hydrogen-Ion Concentration; Kidney Calculi; Kidney Function Tests; Magnesium Compounds; Male; Middle Aged; Oxalic Acid; Phosphates; Prevalence; Pyelonephritis; Recurrence; Retrospective Studies; Struvite; Uric Acid; Urinary Tract; Urinary Tract Infections

The successful fragmentation of kidney stones by means of extracorporeal shock wave lithotripsy partly depends on stone composition. In case of incomplete or coarse fragmentation, multiple urological procedures following ESWL may be necessary for removal of obstructive fragments. It is difficult to be sure that a given stone will be successfully destroyed. X-ray examinations before treatment are useful to classify calculi as calcium stones or not. Nevertheless, such investigations are often not sufficient to identify the main crystalline phases which form the stone and that can make it either resistant or friable to ESWL.. The aim of this study was to compare crystalluria and stone composition in patients with kidney calculi.. Seventy-five untreated patients (54 males, 21 females) were included. Their first morning urine was collected three days before surgical removal of the stone. Urine samples were kept at 4 degrees C during 48 hours before examination.. Crystalluria occurred in 97.3% of urine specimens. Weddellite was the most frequent crystalline species found in urine (66.2%), followed by carbapatite (33.1%) and whewellite (23.1%). When compared to stone composition, crystalluria was mainly made of weddellite in urines from 68% of patients with weddellite-rich calculi. Stones from patients presenting with whewellite crystals in urine were mainly composed of whewellite in 88.9% of cases. Struvite stones were associated with struvite and carbapatite crystalluria in 85.7% of cases.. Crystalluria studies could be of clinical interest to predict the main crystalline phase of calcium-containing stones in order to define the best procedures for stone removal.

Topics: Adult; Calcium Oxalate; Calcium Phosphates; Crystallization; Female; Humans; Kidney Calculi; Magnesium Compounds; Male; Microscopy, Polarization; Middle Aged; Phosphates; Spectrophotometry, Infrared; Struvite; Uric Acid

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

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

Several reports in the 1970s suggested that etidronate disodium might be clinically useful to prevent calcium stones, but the use of etidronate in the urolithiasis field was discontinued due to adverse effects of this drug on skeletal turnover and mineralization. Because the drug might affect not only crystallization, but also crystal-tubular interactions, we investigated the minimum dose of etidronate necessary to effectively prevent stone recurrence without adverse side effects.. We examined the effect of etidronate on the crystallization of calcium oxalate, calcium phosphate and magnesium ammonium phosphate using synthetic urine and measured by an aggregometer. We also studied its effect on the adhesion of calcium oxalate monohydrate crystals to Madin-Darby canine kidney (MDCK) cells in vitro.. Etidronate affected the crystallization+ of not only calcium phosphate and calcium oxalate, but also magnesium ammonium phosphate in synthetic urine. The inhibitory activities on these crystallizations were detected at extremely low drug concentrations. Etidronate also had a strong inhibitory activity against the adhesion of calcium oxalate crystals to MDCK cells.. Although further studies are necessary regarding the effects of etidronate on crystallization and crystal adhesion both in vivo and in vitro, and the appropriate schedule of dosing to prevent side effects, it is possible that etidronate may be useful in the treatment of urinary stones.

Topics: Animals; Calcium Oxalate; Calcium Phosphates; Cell Adhesion; Cell Line; Crystallization; Dogs; Etidronic Acid; Kidney; Magnesium Compounds; Phosphates; Struvite; Urine

This study was designed to assess the effect of i.v. treatment with aminophylline (AMPH) on the risk of calcium phosphate and struvite stone formation. We administered AMPH in doses of 4 mg/kg body weight in 15-min i.v. infusions to 60 infants with clinical symptoms of obstructive bronchitis with dyspnoea. During 3 hours after infusion we observed a significant increase in urine saturation with brushite, octocalcium phosphate and struvite. This rise in urine saturation may increase the risk of kidney stone formation.

Topics: Aminophylline; Bronchitis; Bronchodilator Agents; Calcium Phosphates; Dyspnea; Humans; Hydrogen-Ion Concentration; Infant; Infusions, Intravenous; Kidney Calculi; Magnesium Compounds; Male; Phosphates; Risk Factors; Struvite

An aggregometer technique was used to study urease-induced crystallizations in synthetic urine and human urine from healthy subjects and patients with chronic spinal cord injuries. The two different phases of crystallization, calcium phosphate and magnesium ammonium phosphate, were easily evaluated with a single assay using this technique. The crystallization of calcium phosphate and magnesium ammonium phosphate varied markedly among the different urine specimens after incubation with urease. The turbidity curves from human urine were divided into four patterns. We assumed that the variations in the patterns of the turbidity curves appeared to be mainly due to differences in the composition of the urine and in the original pH, and that the calcium and magnesium concentrations were very important in the urinary constituents.

Topics: Calcium Phosphates; Crystallization; Female; Humans; Hydrogen-Ion Concentration; Magnesium Compounds; Male; Phosphates; Spinal Cord Injuries; Struvite; Urease

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

Phosphates precipitating from artificial urine in the pH range 6-8 were identified using X-ray diffraction, chemical analysis and scanning electron microscopy. The influence of magnesium and citrate on phases precipitating from urine was established. From urine containing a normal quantity of magnesium (around 70 ppm), brushite accompanied by hydroxyapatite (HAP) precipitated at pH < or = 7.0 and struvite with HAP at pH > 7.0. HAP was formed exclusively from magnesium deficient urine at pH 7.0. Newberyite, octacalcium phosphate and whitlockite were not identified. The chemical and phase composition and inner fine structure of 14 phosphate calculi were studied. Three types of stones were distinguished based on their magnesium content: (i) stones rich in magnesium composed of struvite, hydroxyapatite and abundant organic matter, (ii) stones with low magnesium content constituted by calcium deficient hydroxyapatite, up to 5% of struvite, considerable amount of organic matter and occasionally brushite, and (iii) calculi without magnesium consisting of brushite, hydroxyapatite and little organic matter. Conditions prevaling during stone-formation assessed for each type of stone were confirmed by corresponding urinary biochemical data and corroborate the in vitro studies of phosphates precipitation.

Topics: Calcium Phosphates; Chemical Precipitation; Crystallization; Kidney Calculi; Magnesium Compounds; Phosphates; Struvite

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

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

To examine the effectiveness of bladder washouts in reducing catheter encrustation.. A model of the catheterized bladder was developed and used to produce catheter encrustation in vitro. The effects of bladder wash-outs with Suby G, mandelic acid 1% or saline 0.9% were compared with control catheters that did not receive wash-outs, by measuring the area of patent catheter lumen and the changes in urinary calcium and magnesium concentrations after wash-outs.. Encrustation was reduced significantly, compared with the controls, in catheters washed out with the acidic reagents, Suby G and mandelic acid. Saline wash-outs did not reduce encrustation.. The model of the catheterized bladder provided a reliable technique with which to examine the effects of bladder wash-out on catheter encrustation under controlled conditions. The results indicate that bladder wash-outs with Suby G or mandelic acid may be beneficial for patients who suffer from recurrent catheter encrustation and blockage.

Topics: Calcium; Calcium Phosphates; Humans; Hydrogen-Ion Concentration; Magnesium; Magnesium Compounds; Models, Structural; Phosphates; Struvite; Therapeutic Irrigation; Urinary Bladder; Urinary Catheterization

In vitro studies have demonstrated that trace elements have inhibitory as well as stimulatory effects on the crystallization of urinary stones. Little is known about the activities of rare-earth elements (REEs) in the human body. Although their physiological role is unclear, an effect on calcium transport mechanisms is discussed. In the present study, ten kidney stones (six oxalate and four phosphate stones) were analyzed by neutron-activation analysis for their REE patterns. Urinary stones are capable of concentrating these elements, and some fractionation into light and heavy REEs appears to take place during deposition. Significantly elevated concentrations of heavy REEs such as europium, terbium, and lutetium were detected in phosphate stones as compared with oxalate stones (P < 0.005).

Topics: Calcium Oxalate; Calcium Phosphates; Europium; Humans; Kidney Calculi; Lutetium; Magnesium Compounds; Metals, Rare Earth; Neutron Activation Analysis; Phosphates; Struvite; Terbium

Most staghorn calculi are infection stones composed of struvite and/or carbonate apatite. Sometimes, cystine, uric acid, whewellite and brushite stones also assume a staghorn configuration when located in the kidney. It is very important in stone crushing to know the composition and architecture of the stones. Struvite stones show a concentric laminal structure and are fragile because of wide interstices of crystals and rich organic matrix. These stones usually contain many bacterial colonies in the interstices of crystals and bacteria break out of the stones when they are crushed. Therefore, perioperative administration of antibiotics is necessary for prevention of bacteremia and sepsis. Whewellite stones and uric acid stones have a smooth surface and reveal compact radial and laminal structure especially in the peripheral layer. They are very hard and are refractory to crushing, and the fragments are large. Cystine stones show a compact radial monomineral texture and are very hard. The fragments made by crushing are large. Therefore, combination therapy of stone crushing and irrigation of alkali solution may be useful for treatment of cystine stones as well as uric acid stones. Calcium phosphate stones, hydroxyapatite or brushite stones, are rare and are formed in hyperparathyroidism, Cushing syndrome and renal tubular acidosis. Hydroxyapatite stones are rich in matrix and fragile. Brushite stones reveal radiate structure and are hard. There is no general method of treatment for staghorn calculi but we should select the most reasonable method including open surgery for each case taking into consideration the stone composition, predisposing factors and possibility of stone residue and recurrence.

Topics: Apatites; Calcium Phosphates; Cystine; Humans; Kidney Calculi; Lithotripsy; Magnesium Compounds; Phosphates; Struvite; Uric Acid

Out of 500 Iranian sheep examined, six revealed the presence of lithiasis in their kidneys. Nephroliths in three animals were composed of ammonium magnesium phosphates and in the others of calcium carbonates and calcium phosphates. Interestingly sodium and ammonium urate crystals were present in the kidneys of three animals.

Topics: Abattoirs; Animals; Calcium Carbonate; Calcium Phosphates; Iran; Kidney Calculi; Magnesium Compounds; Phosphates; Sheep; Sheep Diseases; Struvite

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

The composition of 2,755 calculi obtained from the upper urinary tract (1,409 by spontaneous passage and 1,346 by urological procedures) was analyzed using an infrared spectrophotometer, and the spontaneous passage rate was investigated in relation to the composition as well as other variables, such as stone size, and patient age and sex. Mixed stones of calcium oxalate and calcium phosphate were most frequently found, followed by those of calcium oxalate. The mean size (the maximum diameter) was largest in struvite stones and smallest in calcium oxalate ones. The sizes of stones from women were significantly larger than those from men (p < 0.01). As expected, the stone passage rates were inversely related to increasing stone size. The size of 55.6% of the stones passed was < or = 5 mm, and that of 96.6% of the stones < or = 10 mm.

Topics: Adolescent; Adult; Aged; Aged, 80 and over; Calcium Oxalate; Calcium Phosphates; Child; Child, Preschool; Cystine; Female; Humans; Infant; Kidney Calculi; Magnesium; Magnesium Compounds; Male; Middle Aged; Phosphates; Spectrophotometry, Infrared; Struvite; Ureteral Calculi; Uric Acid

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

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 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

At Osaka City University Hospital, we performed extracorporeal shock-wave lithotripsy (ESWL) for 1277 patients in a total of 1788 sessions using Dornier kidney lithotripter Model HM III from July, 1985 to the end of December, 1988. Among the patients with a solitary stone, 911 cases were available for the follow-up study and we have compared the results among these cases in respect to the stone location and size. The results obtained were as follows: the ratio of kidney stone to ureter stone was found to be 2.2:1 in male, and 3.8:1 in female patients. This indicates that ureter stones are more frequently found in male than in female patients. In addition, we compared the size of kidney stones found in the patients including 415 male and 243 female patients. Stones larger than 20 mm were more frequently found in female than in male patients. Moreover, a stone composition study of these patients showed that the contents of both phosphate calcium and magnesium ammonium phosphate were higher in female than in male patients. ESWL performed against stones at pelvis and calyces exhibited the best results. The results obtained with the stones less than 20 mm in diameter were especially favorable with a success rate of 100% for the stones less than 10 mm and 83% for the stones 10-20 mm, in diameter, while the results with the stones larger than 20 mm in diameter were rather poor with a success rate of 31%. ESWL performed against ureter stones showed poor results with a success rate of 63% for the stones smaller than 20 mm in diameter.

Topics: Calcium Phosphates; Evaluation Studies as Topic; Female; Humans; Kidney Calculi; Lithotripsy; Magnesium; Magnesium Compounds; Male; Phosphates; Sex Factors; Struvite; Ureteral Calculi

Previous studies have shown human urine to have an inhibitory action on urease-induced crystallisation. Centrifugation and 0.45 microns filtration of the urine did not reduce this activity. This eliminates larger urine particles as being the cause of the inhibitory activity. Both the retenate and the filtrate after ultrafiltration of urine with a 100.000 mol weight cut-off influenced the urease-induced crystallisation of magnesium ammonium phosphate and calcium phosphate. The results indicate that the inhibitory action is exerted by more than one urinary component.

Topics: Calcium Phosphates; Crystallization; Humans; In Vitro Techniques; Magnesium; Magnesium Compounds; Molecular Weight; Phosphates; Struvite; Ultrafiltration; Urease; Urine

Routine thermogravimetric (TG) analysis of 501 upper urinary calculi from the State of Jammu and Kashmir is described. The technique is simple, rapid and quantitative, and the equipment is easily maintained. The technique was found to be helpful in 95.4% of urinary stones and it is suggested that TG analysis may be employed as a technique of first choice in the routine quantitative analysis of all urinary calculi.

Topics: Calcium Oxalate; Calcium Phosphates; Humans; Kidney Calculi; Magnesium; Magnesium Compounds; Phosphates; Struvite; Thermogravimetry; Ureteral Calculi

During a seven-year period (1975-1981) a total of 1325 patients hospitalized for stone disease were studied as to the occurrence of positive urine cultures. Urinary stones from 535 surgically treated patients were analyzed with infrared spectrophotometry and the relationships between stone composition, level of surgery and bacteriological strains were studied. Positive urinary cultures were found in 34% of the surgically treated patients and in 21% of those not operated upon. Among the surgically treated patients with urinary tract infection (UTI) E. coli was the most frequent microorganism (35%), followed by Proteus (28%). Patients with Proteus infection had the highest frequency of UTI episodes, most of which occurred before hospitalization. There was a higher frequency of magnesium ammonium phosphate (MAP) calculi among patients with Proteus infection than among those with non-Proteus infection, in whom no difference in stone composition was found. Patients infected with E. coli had more phosphate-containing stones (CaP+MAP) than non-infected patients. The highest frequency of oxalate calculi (CaOx+CaOx/CaP) was found among patients without infection. No E. coli infections were seen in male patients with CaP and MAP calculi. MAP stones were most often found in the kidney and oxalate stones in the ureter.

Topics: Calcium Oxalate; Calcium Phosphates; Escherichia coli Infections; Female; Humans; Kidney Calculi; Magnesium; Magnesium Compounds; Male; Middle Aged; Phosphates; Proteus Infections; Spectrophotometry, Infrared; Struvite; Urinary Tract Infections

The greater frequency of renal stones seen on excretory urograms in women, compared with the greater frequency of ureteral stones in men has been termed a sexual paradox. We assessed stone composition and weight, and sex as possible explanatory factors. A total of 4,014 renal and ureteral calculi was analyzed. For the 3,119 calculi in which only calcium oxalate and/or phosphate was detected by infrared and wet chemical analysis, there was a strong relationship between the oxalate-to-phosphate weight ratio and sex (p less than 0.0001). The mean weight for phosphate stones was 330 mg. but for oxalate stones it was 107 mg. Male-to-female ratios were 2.7, 2.2 and 1.8 for stone weight groups of 20 or less, 21 to 100 and more than 100 mg. The male-to-female ratio was 0.87 for the 171 stones containing magnesium ammonium phosphate; the average weight was 508 mg. for men and 1,560 mg. for women. The tendency for phosphate stones to be heavier and relatively more common in women compared to predominantly oxalate stones may partly account for the sexual paradox.

Topics: Calcium Oxalate; Calcium Phosphates; Female; Humans; Kidney Calculi; Magnesium; Magnesium Compounds; Male; Phosphates; Sex Characteristics; Struvite; Ureteral Calculi

Experimental irrigation of 15 infectious renal stones with hemiacidrin resulted in complete dissolution of 11 stones within 5 days. Three of the undissolved stones had a calcium oxalate (CaOx) content of more than 10%. Stones containing calcium phosphate (CaP) and magnesium ammonium phosphate (MAP) and weighing less than 500 mg were most easily dissolved. Twenty-five stones placed in 10 ml of hemiacidrin resulted in complete dissolution of 13 and partial dissolution of 11. Even this experiment showed that the CaOx content was of importance for the outcome of hemiacidrin treatment. After treatment the MAP and CaP fractions had decreased and CaOx increased. In 36 clinical irrigations of residual concrements of known chemical composition, 5 resulted in total stone dissolution and 21 in a reduced stone volume, whereas the result was inconclusive in 3. Seven stones were not affected by the treatment, these stones were usually composed of CaP and CaOx. There was a good correlation between the dissolution test and the clinical response to hemiacidrin treatment. Based on these findings it is suggested that hemiacidrin might be a useful complement to the modern techniques of stone fragmentation such as extracorporeal shock wave lithotripsy and percutaneous surgery, at least for infectious stones with a CaOx content of less than 10%.

Topics: Calcium Oxalate; Calcium Phosphates; Citrates; Female; Humans; In Vitro Techniques; Kidney Calculi; Magnesium; Magnesium Compounds; Male; Nephrostomy, Percutaneous; Pharmaceutic Aids; Phosphates; Struvite; Therapeutic Irrigation

CT examinations were conducted in 47 patients with staghorn calculi in the renal pelvis. Density measurements in the region of the calculus supplied pointers to the structure of the calculus.

Topics: Adult; Calcium Oxalate; Calcium Phosphates; Female; Humans; Kidney Calculi; Kidney Pelvis; Magnesium; Magnesium Compounds; Male; Phosphates; Struvite; Tomography, X-Ray Computed

Urine alkalinization favours the formation of calcium phosphate (CaP) and struvite stones. In this retrospective study we analyze the effect of chronic urinary acidification on phosphatic stone recurrence. Twenty-four patients with CaP-struvite recurrent stones and persistently high urinary pH were divided in two groups: group A, 11 patients who failed to lower the urinary pH below 5.5 during a standard acid load test: group B, 13 patients with preserved acidification power. Ammonium sulfate 2-3 g/day was given for 4.7 and 6.5 years to groups A and B, respectively. A persistent reduction in urinary pH, relative saturation for CaP and stone formation rate was observed in both groups. The treatment did not cause systemic acidosis as long as renal function remained normal. Urinary daily excretion of Ca and P as well as their renal tubular handling did not change with time. Results suggest acidifying agents might be useful in preventing recurrence of CaP-struvite stones even in the presence of a mild acidification defect and encourage undertaking properly controlled prospective trials.

Topics: Adult; Ammonium Sulfate; Calcium Phosphates; Chronic Disease; Drug Evaluation; Female; Humans; Hydrogen-Ion Concentration; Kidney Calculi; Magnesium; Magnesium Compounds; Male; Middle Aged; Phosphates; Recurrence; Retrospective Studies; Struvite; Time Factors

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

A case of soft vesical calculi is reported. A 72-year-old male, visited our clinic complaining of discharge of white muddy substance. KUB film revealed calcification in the vesical region. Urinalysis showed UTI, and culture of urine was positive for Proteus mirabilis. Thereafter, the patient suffered from discharges of similar calculi several times. Two of three infrared spectroscopic charts showed mixture of calcium phosphate and ammonium hydrogen urate and that of the remaining disclosed magnesium ammonium phosphate. An alcian blue-PAS double staining of this calculus revealed the presence of acid and neutral glycosaminoglycans, and bacterial colonies. These calculi were thought to be different from the so called 'matrix calculi'.

Topics: Aged; Calcium Phosphates; Glycosaminoglycans; Humans; Magnesium; Magnesium Compounds; Male; Phosphates; Proteus Infections; Proteus mirabilis; Radiography; Struvite; Uric Acid; Urinary Bladder Calculi; Urinary Tract Infections

The majority of staghorn calculi (branched calculi)--25 per cent bilateral--is mainly composed of calcium phosphates, in about 2/3 with varying fractions of Struvite. Pure Struvite stones are rare. Large fractions of Struvite form a soft concrement. Infection with urea splitting bacteria arises ascending, therefore predominantly in female kidneys, except for the first decennium. Staghorn calculi without Struvite (1/3 of our cases), show extremely large growth and sterile urine. Some Struvite stones have sterile urine or Struvite without urea splitting bacteria. The shape of branched calculi depends on the form of hilus renalis and the aggressiveness of the alkaline urine and the infection. Renal cirrhosis--almost always present--follows bacterial or abacterial obstruction, depending on the degree of vascular obliteration by reactive fibrosis of the intima, with or without pyonephrotic, xanthomatous necrosis, similar to renal tuberculosis. The so-called "large stone kidney" is obstructive, aseptic and lipomatous special form of staghorn calculus and cirrhosis. Stone formation and grade of cirrhosis may be determined by tomography.

Topics: Adult; Age Factors; Aged; Calcium Oxalate; Calcium Phosphates; Female; Humans; Kidney; Kidney Calculi; Magnesium; Magnesium Compounds; Male; Middle Aged; Phosphates; Sex Factors; Struvite; Urea

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

Thirty-three patients operated on for renal staghorn calculous disease were studied retrospectively with respect to urine and stone composition, bacteriuria, and abnormalities of the urinary tract. Calcium phosphate was the most common stone constituent, present in 30 of 31 concrements. Twenty-one of these stones also contained magnesium ammonium phosphate, despite the fact that only 10 patients had presented evidence of urinary tract infection during the initial period of the disease. Twenty-four-hour urine composition was normal in only 3 patients. In 59 per cent an increased CaOx risk index was observed suggesting that CaOx risk factors might contribute to the development of staghorn concrements. A metabolic evaluation of staghorn stone formers appears to be of importance for design of the postoperative treatment.

Topics: Adolescent; Adult; Bacteriuria; Calcium Oxalate; Calcium Phosphates; Female; Humans; Kidney Calculi; Magnesium; Magnesium Compounds; Male; Middle Aged; Phosphates; Risk; Struvite; Urologic Diseases

To study whether human urine contains inhibitors against urease-induced crystallization, Jackbean urease and human urine, in amounts small enough (0.5 to 10 per cent) not to influence the ion concentration, buffering capacity or pH, were added to synthetic urine. The ammonia production and alkalinization that followed were independent of the amounts of human urine added. The addition of human urine gave a dose-related decrease in the amount of calcium phosphate and struvite precipitated on glass rods immersed in the synthetic urine, however. Addition of only 0.5 per cent human urine gave a reproducible decrease and when 10 per cent human urine was added to the synthetic urine the precipitation of calcium phosphate was reduced by 50 per cent and that of struvite by 75 per cent. The results thus indicate that human urine contains components with the ability to reduce the urease-induced crystallization.

Topics: Adult; Ammonia; Calcium Phosphates; Chemical Precipitation; Crystallization; Dose-Response Relationship, Drug; Humans; Hydrogen-Ion Concentration; Magnesium; Magnesium Compounds; Phosphates; Struvite; Urease; Urine

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

The urease-induced crystallization of magnesium ammonium phosphate and calcium phosphate was studied at different alkalinization degrees by incubating synthetic urine with increasing Jack Bean urease concentrations. The crystallization was studied as precipitation on glass rods immersed in synthetic urine. The calcium phosphate precipitation on the glass rods occurred when the pH reached 6.8. Magnesium ammonium phosphate precipitation occurred when the pH reached 7.0. The maximal crystallization occurred at a pH between 7.5 and 8.0; at higher pHs the precipitation was considerably lower. The possible mechanisms and clinical implications behind this narrow pH optimum for urease-induced crystallization, which also have important implications for future experimental studies, are discussed.

Topics: Calcium Phosphates; Chemical Precipitation; Crystallization; Hydrogen-Ion Concentration; Magnesium; Magnesium Compounds; Phosphates; Struvite; Urea; Urease; Urine

A case of milk-of-calcium with an exceptional location is reported. The characteristics of milk-of-calcium are presented, with stasis and urinary tract infection being the most important etiologic factors in this case. Structurally the stones are formed by a central core of calcium phosphate surrounded by magnesium-ammonium phosphate (struvite).

Topics: Adult; Calcium Phosphates; Female; Humans; Magnesium; Magnesium Compounds; Phosphates; Struvite; Ureteral Calculi; Ureterocele

Topics: Adolescent; Adult; Aged; Calcium Oxalate; Calcium Phosphates; Child; Female; Humans; Magnesium; Magnesium Compounds; Male; Middle Aged; Phosphates; 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

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