fibrin and Calcinosis

Central venous catheters (CVC) are used in many clinical settings for a variety of indications. We performed a systematic literature review concerning case reports of retained calcified fibrin sheaths after dialysis CVC removal. The aim of our study was to systematize the knowledge regarding clinical management of this phenomenon, placing special emphasis on diagnostic radiological features in different imaging modalities, including chest radiography, echocardiography, computed tomography, and magnetic resonance imaging. We discuss the most common risk factors associated with this CVC complication. In our review, we found eight cases of hemodialysis patients. The most common risk factors associated with calcified fibrin sheath formation in the analyzed cases were pro-thrombotic and pro-calcification factors related to patient comorbidities, and prolonged catheter dwell time. Differentiating between a calcified fibrin sheath (present in about 6% of patients with long-term indwelling CVC as diagnosed by computed tomography) and a retained catheter tip can be challenging. The initial diagnosis based on imaging methods was incorrect in most of the analyzed cases. This suggests that some cases of retained fibrin sheaths may remain undetected or misinterpreted. This is important in patients with known pro-thrombotic and pro-calcification risk factors and prolonged catheter dwell time. Therefore, implementation of preventive strategies, familiarity with radiological findings of this phenomenon, comparison with previous imaging studies, and an overall comprehensive assessment with clinical data is imperative.

Topics: Calcinosis; Catheterization, Central Venous; Catheters, Indwelling; Central Venous Catheters; Fibrin; Humans; Renal Dialysis; Thrombosis

Topics: Animals; Aorta; Arteriosclerosis; Blood Platelets; Calcinosis; Child; Cholesterol; Collateral Circulation; Coronary Disease; Coronary Vessels; Erythrocytes; Female; Fibrin; Fibroblasts; Glycosaminoglycans; Hemorrhage; Histocytochemistry; Humans; Lipids; Macrophages; Male; Middle Aged; Muscle, Smooth; Necrosis; Rabbits; Rupture; Thrombosis

Efficient cell seeding and subsequent support from a substrate ensure optimal cell growth and neotissue development during tissue engineering, including heart valve tissue engineering. Fibrin gel as a cell carrier may provide high cell seeding efficiency and adhesion property, improved cellular interaction, and structural support to enhance cellular growth in trilayer polycaprolactone (PCL) substrates that mimic the structure of native heart valve leaflets. This cell carrier gel coupled with a trilayer PCL substrate may enable the production of native-like cell-cultured leaflet constructs suitable for heart valve tissue engineering. In this study, we seeded valvular interstitial cells onto trilayer PCL substrates with fibrin gel as a cell carrier and cultured them for 1 month in vitro to determine if this gel can improve cell proliferation and production of extracellular matrix within the trilayer cell-cultured constructs. We observed that the fibrin gel enhanced cellular proliferation, their vimentin expression, and collagen and glycosaminoglycan production, leading to improved structure and mechanical properties of the developing PCL cell-cultured constructs. Fibrin gel as a cell carrier significantly improved the orientations of the cells and their produced tissue materials within trilayer PCL substrates that mimic the structure of native heart valve leaflets and, thus, may be highly beneficial for developing functional tissue-engineered leaflet constructs.

Topics: Aortic Valve; Aortic Valve Stenosis; Calcinosis; Cells, Cultured; Fibrin; Humans; Tissue Engineering; Tissue Scaffolds

Cardiovascular imaging is evolving in response to systemwide trends toward molecular characterization and personalized therapies. The development of new radiotracers for PET and SPECT imaging is central to addressing the numerous unmet diagnostic needs that relate to these changes. In this 2-part review, we discuss select radiotracers that may help address key unmet clinical diagnostic needs in cardiovascular medicine. Part 1 examined key technical considerations pertaining to cardiovascular radiotracer development and reviewed emerging radiotracers for perfusion and neuronal imaging. Part 2 covers radiotracers for imaging cardiovascular inflammation, thrombosis, fibrosis, calcification, and amyloidosis. These radiotracers have the potential to address several unmet needs related to the risk stratification of atheroma, detection of thrombi, and the diagnosis, characterization, and risk stratification of cardiomyopathies. In the first section, we discuss radiotracers targeting various aspects of inflammatory responses in pathologies such as myocardial infarction, myocarditis, sarcoidosis, atherosclerosis, and vasculitis. In a subsequent section, we discuss radiotracers for the detection of systemic and device-related thrombi, such as those targeting fibrin (e.g.,

Topics: Amyloidosis; Calcinosis; Fibrin; Fibrosis; Humans; Inflammation; Positron-Emission Tomography; Thrombosis

Calcified amorphous tumor (CAT) of the heart is a rare non-neoplastic intracardiac mass, a calcium deposition surrounded by amorphous fibrous tissue, and possibly causes cerebral embolism. Even rarer is CAT associated with infection, and no CAT with antecedent infection has been reported to our knowledge. In addition, although some CAT in patients on hemodialysis has been reported to grow rapidly, no case has been reported on CAT that grew and diminished rapidly in a short period of time. Here, we report the case of an 82-year-old Japanese woman with normal renal function who developed multiple cerebral infarctions due to CAT that grew rapidly, associated with inflammation from an antecedent infection, and diminished rapidly by detachment of fibrin on the mass surface and antithrombotic drugs.. The patient developed fever after dental treatment and found musical hallucination on the left ear worsened in degree and frequency. In a nearby clinic, she was treated with antibiotics, and her body temperature turned to normal in approximately 1 month. She presented to our hospital for workup on the worsened musical hallucination. Magnetic resonance imaging (MRI) showed multiple cerebral infarctions, and transthoracic echocardiography (TTE) revealed an immobile hyperechoic mass with an acoustic shadow arising from a posterior cusp of the mitral valve. CAT was suspected and treated with apixaban and aspirin. Follow-up MRI and TTE showed newly developed multiple cerebral infarctions and rapidly diminished CAT. Cardiac surgery was performed to resect the CAT. The pathological findings showed calcifications surrounded by amorphous fibrous tissue including fibrin, indicating CAT. The patient's symptoms improved and no cerebral infarctions recurred in 4 months follow-up.. Inflammation from an antecedent infection can cause CAT to grow rapidly. Fibrous tissue including fibrin may attach to the surface of CAT, resulting in multiple cerebral infarctions. Fibrous tissue may detach and disappear by antithrombotic drugs, leading to a rapid diminishment of CAT in size.

Topics: Anti-Bacterial Agents; Aspirin; Calcinosis; Calcium; Cerebral Infarction; Female; Fibrin; Fibrinolytic Agents; Hallucinations; Heart Neoplasms; Humans; Inflammation; Neoplasm Recurrence, Local

The histological findings in the heart in cases of fatal sepsis can show myocytolysis, interstitial fibrosis, necrotic contraction band, mononuclear infiltrates, and interstitial edema, which can be used in post mortem diagnosis of sepsis. Septic myocardial calcification is a very rare condition, and only a few cases have been reported in the literature. In general, the pathogenesis of the myocardial calcification has not been well clarified, but two pathogenic mechanisms have been universally recognized: metastatic or dystrophic. We present a rare case of sepsis-related myocardial calcification. Here we report a case involving a 72-year-old white male who was admitted to a hospital for a polytrauma caused by a motorbike accident. On the 110th day of hospitalization, the patient was diagnosed with a septic process and a subsequent transesophageal echocardiogram revealed the presence of a calcification on the right atrial wall. According to the medical history of the patient there were no systemic factors predisposing to calcium crystals deposition in tissues. Patient died due to multi-organ failure in the course of multimicrobial septic shock during the 149th day. The autopsy revealed both the presence of a greenish-brown formation and a greater consistency of the right atrial wall. The histological investigation of the right atrium wall showed a wide calcification area localized at subendocardial level, which contained fibrin deposition and was surrounded by fibrotic tissue.

Topics: Aged; Calcinosis; Fatal Outcome; Fibrin; Fibrosis; Heart Atria; Humans; Male; Multiple Organ Failure; Sepsis; Shock, Septic

We present a case of cardiac calcified amorphous tumor, a rare intracardiac non-neoplastic tumor, in a hemodialysis patient. A 72-year-old woman with no history of thromboembolic, malignant, or inflammatory disease presented with dyspnea. Echocardiography revealed a highly echoic, slightly mobile mass with an acoustic shadow originating from the mitral subvalvular apparatus, extending to the left ventricular outflow tract. She underwent surgical resection of the mass through the aortic valve, which was easily excised from the papillary muscle and chordae tendineae. Histopathologic examination revealed nodular calcium deposits on a background of amorphous degenerated fibrin material, consistent with calcified amorphous tumor.

Topics: Aged; Biomarkers, Tumor; Biopsy; Calcinosis; Cardiac Surgical Procedures; Echocardiography, Transesophageal; Female; Fibrin; Heart Neoplasms; Humans; Renal Dialysis; Tomography, X-Ray Computed; Treatment Outcome

Topics: Calcinosis; Catheter-Related Infections; Catheters, Indwelling; Diagnosis, Differential; Fibrin; Humans; Jugular Veins; Male; Middle Aged; Radiography; Vascular Diseases

A role of coagulation in the pathogenesis of aortic stenosis (AS) is unknown. The aim of this study was to investigate the fibrin (Fn) presence and its determinants in calcified stenotic aortic valve leaflets. Twenty-one patients with dominant AS and 17 well-matched patients with dominant aortic insufficiency (AI) undergoing aortic valve replacement were studied. Immunofluorescence analysis was performed on decalcified leaflets using antibodies against human Fn and tissue factor (TF). Fn-positive (41.4%) and TF-positive (25.3%) areas were increased in AS valves compared with AI valves (7.9% and 5.9%, respectively, both p<0.001). Patients with AS had elevated plasma D-dimer (236.4 ± 28 ng/ml, p=0.002) and prothrombin fragment 1+2 (F1.2) (261.7 ± 27.1 pM, p=0.005) compared to AI subjects (142.8 ± 10 ng/ml and 131.2 ± 1.3 pM, respectively). In AS patients Fn-positive areas correlated with TF-positive areas (r=0.68, p=0.0005), D-dimer (r=0.45, p=0.018), F1.2 (r=0.64, p=0.002), the time required for plasma fibrin clot formation (r=0.44, p=0.015) and maximum absorbance of fibrin clots (r=-0.38, p<0.0001), but not with clot permeability or lysis time. Thickness of Fn layer within AS valves was associated with maximum transvalvular gradient (r =0.41, p=0.048). Patients with maximal gradient above 75 mmHg (n=11) showed significant associations between Fn-positive area and both maximal (r =0.63) and mean (r =0.67) transvalvular gradients. Large fibrin amounts, mostly co-localised with TF, are present within the valve leaflets of patients with advanced AS. In vivo thrombin generation and fibrin clot formation are associated with the extent of Fn presence within leaflets, which might contribute to the AS progression.

Topics: Aged; Aortic Valve; Aortic Valve Insufficiency; Aortic Valve Stenosis; Biomarkers; Blood Coagulation; Calcinosis; Chi-Square Distribution; Female; Fibrin; Fibrin Fibrinogen Degradation Products; Fluorescent Antibody Technique; Humans; Male; Middle Aged; Peptide Fragments; Poland; Prothrombin; Severity of Illness Index; Thrombin; Thromboplastin; Ultrasonography

Nanomaterials have been used to create new consumer products as well as applications for life sciences and biotechnology. The aim of this study was to evaluate the tissue response to implanted polyethylene tubes filled with fibrin sponge embedded with silver nanoparticles dispersion.. Thirty rats received individually 4 polyethylene tubes filled with sponge embedded in 47 ppm, 23 ppm silver nanoparticles dispersion, 2.5% sodium hypochlorite, or with no embedding as control. The observation periods were 7, 15, 30, 60, and 90 days. After each period of time, 6 animals were killed, and the tubes and surrounding tissue were removed, fixed, and prepared to be analyzed in light microscope with glycol methacrylate embedding, 3-μm serial cutting, and hematoxylin-eosin stain. Qualitative and quantitative evaluations of the reactions were performed.. Both materials caused moderate reactions at 7 days. The response was similar to the control on the 15th day with 23 ppm silver nanoparticles dispersion and 2.5% sodium hypochlorite and on the 30th day with 47 ppm silver nanoparticles dispersion.. It was possible to conclude that silver nanoparticles dispersion was biocompatible especially in a lower concentration.

Topics: Animals; Calcinosis; Connective Tissue; Drug Carriers; Fibrin; Male; Nanoparticles; Necrosis; Neutrophil Infiltration; Rats; Rats, Wistar; Root Canal Irrigants; Silver; Sodium Hypochlorite

Glutaraldehyde-preserved bioprosthetic heart valves are non-viable and have a limited durability because of calcification, tissue wear, and inflammation, especially in children. Decellularized porcine heart valves, when treated with deoxycholic acid (DOA), have exhibited complete recellularization and an absence of calcification when implanted into the pulmonary position in juvenile sheep. The study aim was to determine the degree of recellularization and calcification in DOA-treated heart valve prostheses in the mitral position in juvenile pigs.. A mitral heart valve prosthesis was implanted into each of 17 pigs, and subsequently explanted and fixed in formaldehyde after between five and 26 weeks. A gross pathologic assessment, high-resolution X-ray imaging and histological examination were then performed on each valve.. Eight pigs survived the observational period. Five valves had only a slight fibrin deposition and calcification foci within the fibrin deposits. Three valves had severe thrombotic material deposits with disseminated calcification and valve stenosis, and one valve had infective endocarditis. A myofibroblast-like cell ingrowth was observed at different locations of the valve housing in all explanted heart valves, but ingrowth in the basal part of the cusp matrix was limited. In four valve prostheses, endothelial cells covered up to 10% of the cusp surface after six months. Inflammatory cells were observed in large numbers in those valves showing endocarditis and severe thrombosis, but in only limited numbers in the other valves.. All valves showed the deposition of fibrin and platelet material, in three cases to a severe degree. A limited ingrowth of both endothelial and myofibroblast-like cells was observed in five valves in which calcification was limited to a few commissural foci. The non-endothelialized surface of the decellularized valves makes them very susceptible to platelet and fibrin deposition; however, slow revitalization seems possible.

Topics: Animals; Bioprosthesis; Calcinosis; Deoxycholic Acid; Equipment Failure Analysis; Fibrin; Heart Valve Prosthesis; Mitral Valve; Models, Animal; Swine; Time Factors

The lack of therapies that inhibit valvular calcification and the conflicting outcomes of clinical studies regarding the impact of 3-hydroxy-3-methylglutaryl-coenzyme A (HMG-CoA) reductase inhibitors on valve disease highlight the need for controlled investigations to characterize the interactions between HMG-CoA reductase inhibitors and valve tissue. Thus, we applied multiple in vitro disease stimuli to valvular interstitial cell (VIC) cultures and examined the impact of simvastatin treatment on VIC function.. VICs were cultured on 3 different substrates that supported various levels of nodule formation. Transforming growth factor (TGF)-beta1 was also applied as a disease stimulus to VICs on 2-D surfaces or encapsulated in 3-D collagen gels and combined with different temporal applications of simvastatin. Simvastatin inhibited calcific nodule formation in a dose-dependent manner on all materials, although the level of statin efficacy was highly substrate-dependent. Simvastatin treatment significantly altered nodule morphology, resulting in dramatic nodule dissipation over time, also in a substrate-dependent manner. These effects were mimicked in 3-D cultures, wherein simvastatin reversed TGF-beta1-induced contraction. Decreases in nodule formation were not achieved via the HMG-CoA reductase pathway, but were correlated with decreases in ROCK activity.. These studies represent a significant contribution to understanding how simvastatin may impact heart valve calcification.

Topics: Animals; Aortic Valve; Calcinosis; Cell Culture Techniques; Cells, Cultured; Collagen; Dose-Response Relationship, Drug; Extracellular Matrix; Fibrin; Gels; Heart Valve Diseases; Hydroxymethylglutaryl-CoA Reductase Inhibitors; Laminin; Mevalonic Acid; Polystyrenes; rho-Associated Kinases; Simvastatin; Swine; Time Factors; Transforming Growth Factor beta1

Valvular calcification is an active, cell-mediated process that results in significant morbidity and mortality. In standard culture, valvular interstitial cells (VICs) elicit significant calcification as a result of myofibroblast activation, and this limits their use in characterization studies. The study aim was to identify culturing substrates that would suppress atypical VIC calcification, and to investigate culture substrates representing a more physiological system.. Several culture platforms were selected to compare and contrast the influence of biochemical and mechanical properties on VIC calcification. Substrates investigated included: tissue culture polystyrene (TCPS), TCPS coated with either fibronectin or fibrin, and an elastic poly(ethylene glycol) (PEG) hydrogel, also with fibronectin or fibrin coupled to the surface. Experiments were repeated with profibrotic growth factor transforming growth factor-beta 1 (TGF-beta1). VIC calcification was characterized by calcific nodule formation, alkaline phosphatase activity and calcium accumulation. Gene and protein expression of alpha smooth muscle actin (aSMA) and core binding factor-1 (CBFa-1) were analyzed with qRT-PCR and immunostaining.. Unmodified TCPS substrates had an innate ability to promote the markers of calcification studied. The addition of TGF-beta1 enhanced levels of all osteoblastic markers studied. When TCPS surfaces were modified with fibronectin, all markers for calcification were repressed, but alphaSMA - a marker for myofibroblastic activity was unchanged. Meanwhile, fibrin-modified TCPS surfaces enhanced calcification over unmodified TCPS substrates. On soft PEG hydrogels, all markers for calcification were repressed, regardless of the surface chemistry, while alphaSMA expression remained unaffected.. Collectively, VIC properties are highly linked to the culture microenvironment. Both, the biochemical and mechanical environment of tissue culture has an effect on the spontaneous calcification of VICs, and may also have a profound effect on their molecular properties, as related to an understanding of the disease process in vivo.

Topics: Actins; Animals; Aortic Valve; Biomarkers; Calcinosis; Cells, Cultured; Core Binding Factor Alpha 1 Subunit; Culture Techniques; Fibrin; Fibronectins; Immunohistochemistry; Polyethylene Glycols; Polymerase Chain Reaction; Polystyrenes; Surface-Active Agents; Swine; Transforming Growth Factor beta1

Topics: Calcinosis; Catheterization, Central Venous; Device Removal; Fibrin; Humans; Infant, Newborn; Infant, Premature; Infant, Premature, Diseases; Male

Pseudoxanthoma elasticum (PXE) is a rare genetic disorder clinically characterized by skin, cardiovascular and eye manifestations, mainly due to calcification and fragmentation of elastic fibres. Although infrequent, complications during pregnancy in women affected by PXE have been reported. The aim of the present study was to compare structural features of placentae at term from 14 control and 15 PXE-affected women, in order to better understand if and how abnormal mineral and/or matrix accumulation might affect placental function in PXE. In all cases, pregnancy, fetus growth and delivery were normal. Both gross and light microscopy examination did not reveal dramatic differences between placentae of PXE patients and controls, with regard to weight, dimensions, infarcts, thrombi, inflammatory lesions or vessels. However, necrotic changes and mineralization appeared statistically more pronounced in PXE. By electron microscopy the most remarkable differences between PXE and control placentae were observed in the localization and morphology of mineral precipitates; a significant higher deposition of mineral precipitates was observed associated with the "matrix"-type fibrinoid and among collagen fibrils, especially on the maternal side. Immunocytochemistry revealed the presence of vitronectin and fibronectin associated with the PXE-specific mineralizations and the absence of mineralization on the small and scarce elastic fibres in either controls or in PXE.

Topics: Adult; Calcinosis; Chemical Precipitation; Female; Fibrin; Fibronectins; Gestational Age; Humans; Immunohistochemistry; Microscopy, Electron; Minerals; Necrosis; Organ Size; Placenta; Pregnancy; Pregnancy Complications; Pregnancy Outcome; Pseudoxanthoma Elasticum; Vitronectin

Reduction of biomaterial calcification is an important aim in the basic research of biological heart valves. An in vitro model was used to investigate the influence of serum calcium concentration and surface coverage with cells or basal proteins on calcium uptake of bovine pericardium.. Samples of glutaraldehyde-tanned bovine pericardium, stored in formaldehyde and detoxified with borohydride were incubated for two weeks with cell culture medium containing low (1.0 mmol/l) or physiologic (2.3 mmol Ca/l) calcium concentration. Specimens were either unseeded, completely surface-covered with rat fibrocytes (rf) or fibrin (fi), or incompletely seeded with rabbit cells (re). Quality of surface coverage was assessed by surface scanning electron microscopy and calcium content by atomic absorption spectroscopy.. Serum calcium had a significant influence on calcium uptake (low versus physiological (1.58 +/- 2.45 mg/g versus 8.10 +/- 1.73 mg/g wet wt, p < 0.001). This may explain early calcification of bioimplants in children and patients on dialysis. Surface coverage significantly reduces calcium uptake (fi, 1.20 +/- 0.41 mg/g, rf, 4.20 +/- 1.70 mg/g, p < 0.001) but complete coverage is necessary (re, 6.98 +/- 1.64 mg/g, NS).. In vitro testing of calcium uptake has proven to be a valuable tool for evaluation of biomaterial calcification.

Topics: Animals; Biocompatible Materials; Bioprosthesis; Calcinosis; Calcium; Cardiomyopathies; Cattle; Cells, Cultured; Culture Media; Disease Models, Animal; Fibrin; Heart Valve Prosthesis; Microscopy, Electron; Pericardium; Prosthesis Design; Rabbits; Rats; Reference Values; Spectrometry, Mass, Fast Atom Bombardment; Surface Properties

The stentless xenograft with its favorable hemodynamic performance on the left side of the heart seems an attractive, readily available alternative for the reconstruction of the right ventricular outflow tract in children.. To assess its function in a preclinical animal investigation, we replaced the pulmonary root with a Freestyle stentless aortic xenograft in 18 piglets of 26.6 +/- 3.2 kg weight. The animals were allowed to grow as much as possible and slaughtered when symptoms of heart failure developed or body weight reached more than 160 kg. All valve explants were analyzed by gross examination and photography and, in 4 representative pigs, by histologic examination.. Fourteen animals died prematurely after 2 weeks to 11 months. Twelve xenograft explants showed thick, immobilized, large nodular structures as cuspal remnants causing significant stenosis. At microscopy, large cuspal masses of degenerating collagen and fibrin and various inflammatory cells were frequently found. In the growing pig, most of the xenografts implanted in the pulmonary position showed early degeneration causing severe stenosis.. Use of this valve for right ventricular outflow tract reconstruction in children cannot be recommended.

Topics: Animals; Aortic Valve; Bioprosthesis; Body Weight; Calcinosis; Cardiac Output, Low; Cause of Death; Collagen; Constriction, Pathologic; Disease Models, Animal; Endocarditis; Fibrin; Growth; Heart Valve Prosthesis; Heart Valve Prosthesis Implantation; Prosthesis Design; Prosthesis Failure; Pulmonary Valve; Surface Properties; Swine

The degenerating tissues found in rat periodontal ligaments during tooth movement were examined morphologically, histochemically, and elementally, with decalcified and unfixed, undecalcified frozen sections. There were two types of degenerating tissues found in the compressed periodontal ligaments: One (type A tissue) was stained differently from collagen and the other (type B tissue) showed the same color as collagen. Type A tissue also showed the deposition of fibrin in Martius scalet blue and Weigert stain. The electron micrograph also showed the deposition of fibrin in type A tissue. No collagen fibers with typical bandings were seen in either tissue. The digestion experiment showed that type A tissue was digested by trypsin but not type B, whereas most of type B tissue was digested by collagenase but not type A. The backscattered electron image by scanning electron microscopy of type A tissue of the unfixed undecalcified frozen sections showed the presence of many small pieces. The elemental analysis of the pieces showed high peaks of phosphorous and calcium. These results indicate that collagen degradation, fibrin deposition, and calcification occurred in the degenerating tissues, especially in type A tissue during the experimental tooth movement.

Topics: Animals; Azo Compounds; Calcinosis; Calcium; Collagen; Collagenases; Coloring Agents; Decalcification Technique; Electron Probe Microanalysis; Fibrin; Fixatives; Frozen Sections; Histocytochemistry; Male; Microscopy, Electron; Microscopy, Electron, Scanning; Paraffin Embedding; Periodontal Ligament; Phosphorus; Rats; Rats, Wistar; Tooth Movement Techniques; Trypsin; Ultrasonography

The masseter and temporalis muscles were investigated ultrastructurally in 2 patients having fibrodysplasia ossificans progressiva (FOP). Results showed atrophy and necrosis of muscle fibres. Both cases contained cartilage which was calcified in the second case and was associated with degenerating chondrocytes. The blood vessels showed various changes, with haematoma formation and large fibrin deposits. Some of the fibrin deposits seen in the second case were surrounded with cartilage. This suggests that the cartilage probably forms as a reaction to an old haemorrhage. It is possible that the effect of the mutant gene found in FOP is on blood vessels rather than the normal regulatory mechanisms of the inducible osteogenic precursor cells. These degenerating blood vessels often result in haemorrhage and fibrin deposits; the fibrosis, cartilage or bone formation are probably secondary changes. Amianthoid fibres found in the tendon of the temporalis muscles of the second case, together with the other changes of fibrosis and cartilage formation, account for the severe restricted mouth opening suffered by these patients.

Topics: Adolescent; Adult; Arterioles; Calcinosis; Capillaries; Cartilage; Female; Fibrin; Fibrosis; Hematoma; Humans; Male; Masseter Muscle; Muscle Fibers, Skeletal; Muscular Atrophy; Mutation; Myositis Ossificans; Necrosis; Temporal Muscle; Tendons; Venules

Eighty-five patients with retinal emboli, visible ophthalmoscopically, were studied retrospectively. All the patients had presented with transient or permanent visual loss. Follow up from the time of presentation was one year to 12 years with a mean of 4.5 years. Life expectancy in the 58 medically treated patients who presented with cholesterol emboli was significantly reduced (p = 0.028). Stroke was the commonest cause of death and was significantly more frequent than in the general population (p less than 0.001); there was also an increased total incidence of cerebrovascular disease (fatal and non-fatal) compared with the Oxfordshire Stroke Project (p less than 0.001). The mortality from ischaemic heart disease was not significantly increased. We report a series of 85 patients with retinal emboli, 69 of whom had cholesterol emboli (70 fundi), 15 calcific emboli and one platelet-fibrin embolus. The natural history of medically treated patients with cholesterol emboli is compared both with an age and sex matched population and with patients with amaurosis fugax but no visible retinal emboli.

Topics: Adult; Aged; Aged, 80 and over; Blindness; Calcinosis; Cholesterol; Embolism; Female; Fibrin; Humans; Male; Middle Aged; Platelet Aggregation; Prognosis; Retinal Artery; Retinal Diseases; Risk Factors

Polyurethane sponges were soaked in a 5 mg/ml solution of lead acetate, dried, and implanted subcutaneously in rats. Sponges soaked in distilled water were implanted as controls. The reaction to the sponges was studied from 5 h to 140 days after implantation, utilising sponge dry weight gain, rate of ingrowth of granulation tissue, histology and electron microscopy. Five hours after implantation, test sponges showed lead phosphate deposits in the central sponge zone and by one day the deposits stained positively for calcium. Transmission electron microscopy (TEM) showed needle-shaped crystals of hydroxyapatite. Ingrowth of granulation tissue into test sponges was delayed. Breakdown of the sponge matrix was observed in control sponges after 140 days. This model highlighted the physicochemical nature of the calcergic reaction, implicating fluid transudates/exudates in the initial stages.

Topics: Animals; Calcinosis; Cell Aggregation; Connective Tissue; Drug Implants; Fibrin; Granulation Tissue; Lead; Macrophages; Male; Neutrophils; Organometallic Compounds; Rats; Rats, Inbred Lew; Time Factors

The importance of the study of the subcellular structure of cardiac valve bioprostheses by means of scanning and transmission electron microscopy and x-ray microanalysis lies in the data it may provide for morphology, physiology, biochemistry, and pathology, as well as in clinical and surgical application.

Topics: Bioprosthesis; Calcinosis; Connective Tissue; Electron Probe Microanalysis; Endocardium; Fibrin; Heart Valve Prosthesis; Humans; Microscopy, Electron; Microscopy, Electron, Scanning; Postoperative Complications

Gross anatomic, histologic, and transmission and scanning electron microscopic observations were made of 29 bioprosthetic valves that had been implanted in patients for up to 115 months. On the basis of these morphologic data, no significant evidence of tissue rejection was seen. However, the durability of these valve bioprostheses is still questionable. Our observation primarily emphasize three factors: (1) disruption of the endothelial cell barrier and the lack of significant host endothelialization even 115 months after transplantation; (2) increased permeability that eased diffusion of circulating host plasma proteins into valve tissue, and increased activity of infiltration processes, eg. calcification and lipid accumulation; and (3) biodegradation of the collagen framework. Each of these factors may contribute further to valve dysfunction. Development of an intimal fibrous sheath seems to occur in porcine bioprostheses that have been implanted for the longest periods of time, but the rate of host tissue ingrowth varies.

Topics: Adolescent; Adult; Aged; Aldehydes; Aortic Valve; Bioprosthesis; Calcinosis; Child; Collagen; Connective Tissue; Endocarditis; Endothelium; Evaluation Studies as Topic; Female; Fibrin; Glutaral; Heart Valve Diseases; Heart Valve Prosthesis; Humans; Male; Mediastinitis; Methods; Microscopy, Electron, Scanning; Middle Aged; Mitral Valve

Topics: Abruptio Placentae; Calcinosis; Female; Fibrin; Hemangioma; Humans; Hydatidiform Mole; Infarction; Placenta; Placenta Diseases; Pregnancy; Thrombosis; Ultrasonography; Uterine Neoplasms

Topics: Animals; Assisted Circulation; Calcinosis; Cattle; Diffusion; Fibrin; Fibrinolysis; Heart Ventricles; Heart, Artificial; Permeability; Time Factors; Water

Topics: Animals; Aorta; Calcinosis; Dental Pulp Capping; Dentin; Fibrin; Histological Techniques; Humans; Kidney; Luminescent Measurements; Mesentery; Microscopy, Electron, Scanning; Plants

Topics: Basement Membrane; Calcinosis; Capillaries; Collagen; Endoplasmic Reticulum; Female; Fibrin; Fibroblasts; Gestational Age; Humans; Infarction; Microscopy, Electron; Placenta; Placenta Diseases; Polyribosomes; Pregnancy; Pregnancy, Prolonged; Time Factors; Trophoblasts

Topics: Adolescent; Adult; Animals; Antigens; Aortic Valve; Calcinosis; Collagen; Elastic Tissue; Female; Fibrin; Formaldehyde; Humans; Infections; Male; Microscopy, Electron; Middle Aged; Mitral Valve Insufficiency; Stress, Mechanical; Swine; Thrombosis; Tissue Preservation; Transplantation Immunology; Transplantation, Heterologous

Topics: Adult; Aged; Arteriosclerosis; Autopsy; Blood Platelets; Calcinosis; Cholesterol; Coronary Disease; Coronary Vessels; Embolism; Erythrocytes; Female; Fibrin; Heart Ventricles; Hemorrhage; Humans; Leukocytes; Male; Middle Aged; Myocardial Infarction; Myocardium; Thrombosis; Time Factors

Topics: Aorta, Abdominal; Arteriosclerosis; Calcinosis; Cholesterol; Fibrin; Humans; Lipid Metabolism; Microscopy, Electron, Scanning

Topics: Adult; Aged; Asbestosis; Calcinosis; Diagnosis, Differential; Female; Fibrin; Humans; Male; Mesothelioma; Middle Aged; Pleural Diseases; Pleural Neoplasms; Pneumothorax, Artificial; Radiography; Tissue Adhesions; Tuberculosis, Pulmonary

Topics: Calcification, Physiologic; Calcinosis; Coagulants; Fibrin; Fibrinogen; Hemostatics; Humans; Lipids; Plasma; Thrombin