fibrin and Hyperplasia

Fibrin-associated large B-cell lymphoma is a rare microscopic-sized tumor, typically representing an unexpected finding at sites rich in chronic fibrin deposition. It is associated with Epstein-Barr virus, and has been reported to occur in a wide variety of anatomic sites and clinical scenarios. We report a case arising in a thyroid hyperplastic nodule, only the second case reported in this location. Notably, this is only the fourth case of fibrin-associated large B-cell lymphoma that is not associated with Epstein-Barr virus. We provide a literature review on the clinico-pathological characteristics and outcome of this newly characterized indolent lymphoma type, which has only recently been separated out from the pathologically similar but highly aggressive large B-cell lymphoma associated with chronic inflammation.

Topics: Epstein-Barr Virus Infections; Fibrin; Herpesvirus 4, Human; Humans; Hyperplasia; Lymphoma, Large B-Cell, Diffuse; Thyroid Nodule

Mesothelial/monocytic incidental cardiac excrescence (MICE) is a rare entity which is an amalgam of mesothelial cells, histiocytes, and fibrin, often found occasionally during cardiac valve replacement. We report a case in a 25-year-old Chinese female with serous mitral stenosis and patent foramen ovale. Routine and immunohistochemical stains and ultrastructure examination revealed the vegetation was predominantly composed of histocytes with scattered mesothelial cells. In fact nodular histiocytic/mesothelial hyperplasia (NHMH) is a similar lesion to MICE. MICE and NHMH could be unified, and NHMH may be a better choice.

Topics: Adult; Biomarkers; Epithelium; Female; Fibrin; Foramen Ovale, Patent; Heart Valve Prosthesis Implantation; Humans; Hyperplasia; Immunohistochemistry; Microscopy, Electron; Mitral Valve; Mitral Valve Stenosis; Monocytes; Terminology as Topic

Topics: Animals; Antigens; Arteriosclerosis; Binding Sites, Antibody; Blood Platelets; Disease Models, Animal; Endothelium; Fibrin; Humans; Hyperplasia; Microscopy, Electron, Scanning; Muscle, Smooth; Thrombosis

Forensic investigations generally contain extensive morphological examinations to accurately diagnose the cause of death. Thus, the appearance of a new disease often creates emerging challenges in morphological examinations due to the lack of available data from autopsy- or biopsy-based research. Since late December 2019, an outbreak of a novel seventh coronavirus disease has been reported in China caused by "severe acute respiratory syndrome coronavirus 2" (SARS-CoV-2). On March 11, 2020, the new clinical condition COVID-19 (Corona-Virus-Disease-19) was declared a pandemic by the World Health Organization (WHO). Patients with COVID-19 mainly have a mild disease course, but severe disease onset might result in death due to proceeded lung injury with massive alveolar damage and progressive respiratory failure. However, the detailed mechanisms that cause organ injury still remain unclear. We investigated the morphological findings of a COVID-19 patient who died during self-isolation. Pathologic examination revealed massive bilateral alveolar damage, indicating early-phase "acute respiratory distress syndrome" (ARDS). This case emphasizes the possibility of a rapid severe disease onset in previously mild clinical condition and highlights the necessity of a complete autopsy to gain a better understanding of the pathophysiological changes in SARS-CoV-2 infections.

Topics: Alveolar Epithelial Cells; Autopsy; Betacoronavirus; Coronavirus Infections; Cough; COVID-19; Diabetes Mellitus, Type 2; Fever; Fibrin; Fibrosis; Humans; Hyperplasia; Hypertension; Lung; Lymphocytes; Macrophages; Male; Megakaryocytes; Metaplasia; Middle Aged; Neutrophils; Pandemics; Pneumonia, Viral; Quarantine; SARS-CoV-2; Tachycardia; Thrombosis

A 75-year-old man presented to a French hospital with a 4-day fever after returning from a coronavirus disease-19 (COVID-19) cluster region. A reverse-transcription polymerase chain reaction test was positive for severe acute respiratory syndrome coronavirus-2 (SARS CoV-2) using a nasopharyngeal swab sample. After he returned home and a telephone follow-up, he was found deceased 9 days after first showing symptoms. Whole-body, non-enhanced, post-mortem computed tomography (PMCT) and a forensic autopsy were performed approximately 48 h after death, with sanitary precautions. The PMCT showed bilateral and diffuse crazy-paving lung opacities, with bilateral pleural effusions. Post-mortem virology studies detected the presence of SARS-CoV-2 (B.1 lineage) in the nasopharynx, plasma, lung biopsies, pleural effusion and faeces confirming the persistence of viral ribonucleic acid 48 h after death. Microscopic examination showed that severe lung damage was responsible for his death. The main abnormality was diffuse alveolar damage, associated with different stages of inflammation and fibrosis. This case is one of the first to describe complete post-mortem data for a COVID-19 death and highlights the ability of PMCT to detect severe involvement of the lungs before autopsy in an apparently natural death. The present pathology results are concordant with previously reported findings and reinforce the disease pathogenesis hypothesis of combined viral replication with an inappropriate immune response.

Topics: Aged; Alveolar Epithelial Cells; Autopsy; Betacoronavirus; Coronavirus Infections; COVID-19; Fibrin; Humans; Hyperplasia; Lung; Male; Pandemics; Pleural Effusion; Pneumonia, Viral; Pulmonary Alveoli; SARS-CoV-2; Tomography, X-Ray Computed

Oral lichen planus (OLP) exhibits variations in severity and response to corticosteroid therapy. This study aims to assess the histopathological features of OLP at the time of diagnosis and their relationship in response to corticosteroid therapy.In this retrospective study, OLP patients were selected if a histopathological report was available. Data were collected regarding patients' demographics and medical history. Clinical and histological data were also obtained. The outcomes were histopathological findings, clinical form of OLP, number of exacerbations per year, and the response to corticosteroid therapy.In this study, 100 OLP patients were enrolled. Basal layer hydropic degeneration and band-like subepithelial lymphocytes infiltrate were observed in all patients. Plasma cells, identified in 62% of OLP patients, were significantly associated with fewer disease exacerbations and better response to corticosteroid treatment.Identifying histopathological features that may affect the clinical course would be clinically helpful in tailoring patient management.

Topics: Adult; Aged; Aged, 80 and over; Connective Tissue; Disease Progression; Dose-Response Relationship, Drug; Epithelium; Female; Fibrin; Glucocorticoids; Humans; Hyperplasia; Lichen Planus, Oral; Male; Middle Aged; Plasma Cells; Retrospective Studies; T-Lymphocytes

Platelets are increasingly recognized for their contributions to tumor metastasis. Here, we show that the phosphoinositide signaling modulated by phosphatidylinositol transfer protein type α (PITPα), a protein which shuttles phosphatidylinositol between organelles, is essential for platelet-mediated tumor metastasis. PITPα-deficient platelets have reduced intracellular pools of phosphoinositides and an 80% reduction in IP

Topics: Animals; Anticoagulants; Blood Platelets; Fibrin; Gene Deletion; Hemostasis; Hyperplasia; Immunity, Mucosal; Inositol 1,4,5-Trisphosphate; Integrases; Lung Neoplasms; Lymphoid Tissue; Male; Melanoma, Experimental; Mice; Mice, Inbred C57BL; Phospholipid Transfer Proteins; Platelet Aggregation; Signal Transduction; Thrombin; Thrombosis

Topics: Adult; Allografts; Biopsy; Cryptogenic Organizing Pneumonia; Female; Fibrin; Humans; Hyperplasia; Idiopathic Interstitial Pneumonias; Lung; Lung Transplantation; Male; Middle Aged; Retrospective Studies; Terminology as Topic; Tomography, X-Ray Computed; Treatment Outcome; Young Adult

Coagulation cascade activation and fibrin deposits have been implicated or observed in diverse forms of liver damage. Given that fibrin amplifies pathological inflammation in several diseases through the integrin receptor αMβ2, we tested the hypothesis that disruption of the fibrin(ogen)-αMβ2 interaction in Fibγ(390-396A) mice would reduce hepatic inflammation and fibrosis in an experimental setting of chemical liver injury. Contrary to our hypothesis, α-naphthylisothiocyanate (ANIT)-induced liver fibrosis increased in Fibγ(390-396A) mice, whereas inflammatory cytokine expression and hepatic necrosis were similar to ANIT-challenged wild-type (WT) mice. Increased fibrosis in Fibγ(390-396A) mice appeared to be independent of coagulation factor 13 (FXIII) transglutaminase, as ANIT challenge in FXIII-deficient mice resulted in a distinct pathological phenotype characterized by increased hepatic necrosis. Rather, bile duct proliferation underpinned the increased fibrosis in ANIT-exposed Fibγ(390-396A) mice. The mechanism of fibrin-mediated fibrosis was linked to interferon (IFN)γ induction of inducible nitric oxide synthase (iNOS), a gene linked to bile duct hyperplasia and liver fibrosis. Expression of iNOS messenger RNA was significantly increased in livers of ANIT-exposed Fibγ(390-396A) mice. Fibrin(ogen)-αMβ2 interaction inhibited iNOS induction in macrophages stimulated with IFNγ in vitro and ANIT-challenged IFNγ-deficient mice had reduced iNOS induction, bile duct hyperplasia, and liver fibrosis. Further, ANIT-induced iNOS expression, liver fibrosis, and bile duct hyperplasia were significantly reduced in WT mice administered leukadherin-1, a small molecule that allosterically enhances αMβ2-dependent cell adhesion to fibrin. These studies characterize a novel mechanism whereby the fibrin(ogen)-integrin-αMβ2 interaction reduces biliary fibrosis and suggests a novel putative therapeutic target for this difficult-to-treat fibrotic disease.

Topics: 1-Naphthylisothiocyanate; Animals; Benzoates; Bile Ducts; Cell Adhesion; Female; Fibrin; Humans; Hyperplasia; Inflammation; Interferon-gamma; Liver Cirrhosis, Biliary; Macrophage-1 Antigen; Male; Mice; Mice, Knockout; Necrosis; Thiohydantoins

Although it is known that in-stent restenosis (ISR) patterns appear homogeneous or nonhomogeneous by optical coherence tomography (OCT), interpretations of the ISR inflammatory response, of the OCT image, and its pathological implications are unclear. The aim of this study was to use OCT to characterize ISR and its inflammatory index in patients after coronary stenting.. OCT was performed at follow-up in 100 angiographic ISR lesions. ISR lesions were divided into two groups: (a) homogeneous (n=48) and (b) nonhomogeneous (n=52) image groups. We assessed the ISR images produced by OCT for tissue heterogeneity and neo-intimal hyperplasia using the normalized standard deviation of OCT signal-intensity (OCT-NSD) observed in neo-intimal hyperplasia tissue. In some patients with a nonhomogeneous OCT image, we collected pathological tissue.. The prevalence of drug-eluting stents was 48% in the nonhomogeneous group and 29% in the homogeneous group (P=0.05). The OCT-NSD value in the nonhomogeneous group (0.223±0.019) was significantly higher than that in the homogeneous group (0.203±0.025; P<0.0001). Pathological tissue showed fibrin thrombi with infiltrating macrophage in 12 cases of nonhomogeneous ISR. The area under the receiver operating characteristic curve for the prediction of a nonhomogeneous image was 0.73 for OCT-NSD (95% confidence interval: 0.62-0.83: P<0.0001). The odds ratio for the prediction of a nonhomogeneous image was 3.47 (95% confidence interval: 1.18-10.2: P=0.02) for smoking by logistic regression analysis.. Nonhomogeneous ISR visualized by OCT showed a high OCT-NSD value, which was a useful predictor for nonhomogeneous images. Moreover, the nonhomogeneous ISR image visualized by OCT may show chronic inflammation and fibrin thrombi.

Topics: Aged; Area Under Curve; Biomarkers; Biopsy; Chi-Square Distribution; Coronary Angiography; Coronary Restenosis; Coronary Thrombosis; Coronary Vessels; Drug-Eluting Stents; Female; Fibrin; Humans; Hyperplasia; Immunohistochemistry; Inflammation; Logistic Models; Male; Middle Aged; Multivariate Analysis; Neointima; Observer Variation; Odds Ratio; Percutaneous Coronary Intervention; Predictive Value of Tests; Prosthesis Design; Reproducibility of Results; Risk Factors; ROC Curve; Smoking; Tomography, Optical Coherence; Treatment Outcome

Polymer-free drug-eluting stents (DES) may overcome the shortcomings of polymer-based DES. The aim of this study was to examine the effect of the polymer-free TiO2 film-coated stent with abciximab or alpha lipoic acid in a porcine coronary overstretch restenosis model.. Pigs were randomized into four groups in which the coronary arteries (24 pigs, 48 coronaries in each group) had TiO2 film-coated stent with abciximab (TCA, n = 12), TiO2 film-coated stent with alpha lipoic acid (TCALA, n = 12), biolimus A9-eluting stents with biodegradable polymer (BES, n = 12), and TiO2 film-coated stent (TCstent, n = 12). Histopathologic analysis was performed at 28 days after stenting.. There was no significant difference in the injury score and internal elastic lamina (IEL) among the four groups. There were significant differences in the lumen area, neointima area, percent area stenosis, fibrin score, and inflammation score among the four groups [2.7 ± 1.0mm(2), 2.6 ± 0.94 mm(2), 48.9 ± 16.25%, 1.0 (range 0.0-3.0), 1.0 (range 0.0-2.0) in TCA stent group vs. 2.7 ± 1.24 mm(2), 2.9 ± 0.83 mm(2), 53.5 ± 17.19%, 1.0 (range 0.0-2.0), 1.0 (range 0.0-2.0) in TCALA stent group vs. 2.7 ± 1.30 mm(2), 2.6 ± 1.06 mm(2), 50.1 ± 23.20%, 2.0 (range 1.0-3.0), 2.0 (range 1.0-3.0) in BES group vs. 1.7 ± 0.63 mm(2), 3.3 ± 0.58 mm(2), 60.2 ± 10.12%, 0.5 (range 0.0-2.0), 1.0 (range 0.0-2.0) in TC stent group, respectively].. TCA and TCALA are more effective to reduce neointimal hyperplasia compared to TC. Moreover, fibrin and inflammation scores are significantly lower in TCA and TCALA than BES in porcine coronary restenosis model.

Topics: Abciximab; Animals; Antibodies, Monoclonal; Coronary Restenosis; Disease Models, Animal; Drug-Eluting Stents; Fibrin; Hyperplasia; Immunoglobulin Fab Fragments; Inflammation; Male; Neointima; Percutaneous Coronary Intervention; Polymers; Swine; Thioctic Acid; Time Factors; Titanium; Treatment Outcome

Peri-strut low-intensity area (PLI) is a common imaging finding during the evaluation of in-stent neointima using optical coherence tomography (OCT). We aimed to determine the biological significance of PLI by comparing in-vivo OCT images with the corresponding histological sections obtained from the familial hypercholesterolemic swine model of coronary stenosis.. A total of 26 coronary vessels of nine familial hypercholesterolemic swine were injured with 30% balloon overstretch and then immediately followed by everolimus eluting or bare metal stent placement at 20% overstretch. At 30 days, all stented vessels were subjected to in-vivo OCT analysis and were harvested for histological evaluation. For OCT analysis, stent cross-sections (three per stent) were categorized into presence (PLI+) or absence (PLI-) of PLI. In histology, inflammation and fibrin deposition were scored semiquantitatively from 0 (none) to 3 (severe).. PLI was found in 64.9% of stent sections. Peri-strut inflammation was more frequently observed in OCT sections PLI (+) compared with PLI (-) (56.0 vs. 7.4%, P=0.01). In contrast, peri-strut fibrin deposits was similar in both groups (PLI+=58.0% vs. PLI-=59.3%, P=0.94). Histological neointimal thickness was significantly higher in PLI (+) sections (mean±SE: 0.68±0.06 vs. 0.34±0.02 mm; P<0.01), yielding a higher percent area stenosis compared with PLI (-) (mean±SE: 59.0±4.4 vs. 34.1±2.2%, P<0.01). The PLI diagnostic sensitivity and specificity for inflammation were 80 and 76.1%, respectively (>56% PLI, area under the curve=0.86, P<0.01), whereas for fibrin deposition, the sensitivity and specificity were 42.2 and 76.1%, respectively (area under the curve=0.56, P=NS). Area under the receiver operating characteristic curve was significantly higher for identifying inflammation than fibrin (0.86 vs. 0.56, P<0.01). The severity of PLI correlated with the neointimal thickness when assessed by OCT (R=0.79, P<0.001).. The presence of PLI in OCT correlates with neointimal thickness and appears to have a diagnostic value in the recognition of peri-strut inflammation, therefore possibly serving as a surrogate for in-vivo assessment of stent efficacy.

Topics: Animals; Coronary Artery Disease; Coronary Restenosis; Coronary Vessels; Disease Models, Animal; Drug-Eluting Stents; Fibrin; Graft Occlusion, Vascular; Hyperlipoproteinemia Type II; Hyperplasia; Inflammation; Male; Neointima; Stents; Swine; Tomography, Optical Coherence

Cardiovascular disease is a global scourge to society, with novel therapeutic approaches required in order to alleviate the suffering caused by sustained cardiac damage. MicroRNAs (miRNAs) are being touted as one such approach in the fight against heart disease, acting as possible post-transcriptional molecular triggers responsible for invoking cardiac regeneration. To further ones understanding of miRNAs and cardiac regeneration, it is prudent to learn from organisms that can intrinsically regenerate their hearts following injury. Using the red-spotted newt, an adult chordate capable of cardiac regeneration, we decided to delve deeper into the role miRNAs play during this process. RNA isolated from regenerating newt heart samples, was used in a microarray screen, to identify significantly expressed candidate miRNAs during newt cardiac regeneration. We performed quantitative qPCR analysis on several conserved miRNAs and found one in particular, miR-128, to be significantly elevated when cardiac hyperplasia is at its peak following injury. In-situ hybridisation techniques revealed a localised expression pattern for miR-128 in the cardiomyocytes and non-cardiomyocytes in close proximity to the regeneration zone and in vivo knockdown studies revealed a regulatory role for miR-128 in proliferating non-cardiomyocyte populations and extracellular matrix deposition. Finally, 3'UTR reporter assays revealed Islet1 as a biological target for miR-128, which was confirmed further through in vivo Islet1 transcriptional and translational expression analysis in regenerating newt hearts. From these studies we conclude that miR-128 regulates both cardiac hyperplasia and Islet1 expression during newt heart regeneration and that this information could be translated into future mammalian cardiac studies.

Topics: Animals; Base Sequence; Down-Regulation; Extracellular Matrix; Fibrin; Gene Expression Regulation; Hyperplasia; LIM-Homeodomain Proteins; MicroRNAs; Molecular Sequence Data; Myocardium; Myocytes, Cardiac; Regeneration; RNA Transport; Salamandridae; Transcription Factors; Transcription, Genetic

To evaluate the effect of a polymer-free Biolimus A9-eluting stent [BioFreedom (BF)], compared with that of a biodegradable polymer-based Biolimus A9-eluting stent [BioMatrix Flex (BMF)] and a bare metal stent (BMS) in balloon denuded and radiated hypercholesterolemic rabbit iliac arteries.. Rabbits were fed with 1% cholesterol diet (n = 14) for 14 days, both iliac arteries were balloon denuded and radiated, and then rabbits were switched to 0.15% cholesterol diet. After 4 weeks, BF (n = 8), BMF (n = 8), and BMS (n = 8) were deployed in denuded and radiated areas. Four weeks later animals were euthanized, arterial segments were processed for morphometry.. The neointimal area in vessels implanted with BF stents was significantly less than that seen in vessels implanted with BMS (0.90 mm(2) ± 0.14 vs. 1.29 mm(2) ± 0.23, P <0.01). Percent fibrin and fibrin score were higher with BMF stents compared to BMS (P <0.03 and <0.04) and giant cell number was significantly higher with both BMF and BF stents (P < 0.01 for both). Percent endothelialization was significantly higher and % uncovered struts were lower with BMS compared to either BMF or BF stents (P < 0.05 for both).. This study demonstrates that compared to BMS, BF stents significantly decreased neointimal hyperplasia.

Topics: Absorbable Implants; Angioplasty, Balloon; Animals; Atherosclerosis; Cardiovascular Agents; Constriction, Pathologic; Disease Models, Animal; Drug-Eluting Stents; Fibrin; Hypercholesterolemia; Hyperplasia; Iliac Artery; Inflammation; Male; Metals; Neointima; Plaque, Atherosclerotic; Polymers; Prosthesis Design; Rabbits; Sirolimus; Stents; Time Factors

Chronic cholestatic liver injury induced by cholestasis in rodents is associated with hepatic fibrin deposition, and we found evidence of fibrin deposition in livers of patients with cholestasis. Key components of the fibrinolytic pathway modulate cholestatic liver injury by regulating activation of hepatocyte growth factor. However, the exact role of hepatic fibrin deposition in chronic cholestasis is not known. We tested the hypothesis that fibrinogen (Fbg) deficiency worsens liver injury induced by cholestasis. Fbg-deficient mice (Fbgα(-/-) mice) and heterozygous control mice (Fbgα(+/-) mice) were fed either the control diet or a diet containing 0.025% α-naphthylisothiocyanate (ANIT), which selectively injures bile duct epithelial cells in the liver, for 2 weeks. Hepatic fibrin and collagen deposits were evident in livers of heterozygous control mice fed the ANIT diet. Complete Fbg deficiency was associated with elevated serum bile acids, periportal necrosis, and increased serum alanine aminotransferase activity in mice fed the ANIT diet. Fbg deficiency was associated with enhanced hepatic expression of the transcription factor early growth response-1 (Egr-1) and enhanced induction of genes encoding the Egr-1-regulated proinflammatory chemokines monocyte chemotactic protein-1, KC growth-regulated protein, and macrophage inflammatory protein-2. Interestingly, peribiliary collagen deposition was not evident near necrotic areas in Fbg-deficient mice. The results suggest that in this model of chronic cholestasis, fibrin constrains the release of bile constituents from injured intrahepatic bile ducts, thereby limiting the progression of hepatic inflammation and hepatocellular injury.

Topics: 1-Naphthylisothiocyanate; Afibrinogenemia; Aged; Animals; Bile Ducts; Cholestasis; Chronic Disease; Collagen; Diet; Disease Models, Animal; Early Growth Response Protein 1; Feeding Behavior; Female; Fibrin; Fibrinogen; Gene Expression Regulation; Humans; Hyperplasia; Inflammation; Liver; Liver Cirrhosis; Male; Mice; Middle Aged; Neutrophils; Xenobiotics

Topics: Aged; Biopsy; Chronic Disease; Colonic Polyps; Colonoscopy; Colorectal Neoplasms; Diagnosis, Differential; Diarrhea; Fibrin; Granulation Tissue; Humans; Hyperplasia; Inflammatory Bowel Diseases; Intestinal Mucosa; Male

We set out to compare the effectiveness of platelet aggregation therapy in association with the development of in-stent neointimal hyperplasia in porcine coronary arteries.. Thirty-two pigs underwent coronary stenting with bare-metal stents under general anaesthesia. One hundred milligrams of aspirin and loading doses of either 300 mg clopidogrel (group C, n=13) or 2 x 500 mg ticlopidine (group T, n=19) were administered before intervention. During the follow-up, the animals received a daily dose of 100 mg aspirin and 75 mg clopidogrel or 2 x 250 mg ticlopidine, respectively. After 4 weeks, the histopathological and histomorphometric parameters of the explanted stented coronaries were assessed. Levels of circulating cytokines and platelet activation factors were measured. ADP-induced and collagen-induced aggregation was measured immediately before stenting and then every 3rd day. The aggregation profiles were calculated and correlated with the histological parameters.. The fibrin deposition scores and inflammation scores were higher in group T than in group C, with similar injury scores. Endothelialization was complete in both groups. A significantly lower neointimal area (1.08+/-0.36 vs. 1.58+/-0.5, group C vs. T, P=0.026) and percentage of area stenosis (29.8+/-12.1 vs. 44.3+/-16.3, group C vs. T, P=0.032) were observed in group C. The loading dose of clopidogrel significantly reduced the platelet activation parameters before the first angiography as compared with ticlopidone. Clopidogrel treatment resulted in a significantly better aggregation profile relative to ticlopidine (mean ADP-induced aggregation: 28.4+/-9.1 vs. 52.5+/-12.0%, P<0.001). Significant (P<0.05) positive linear correlations were observed between the ADP-induced aggregation profile and the neointimal area (r=0.584), percentage of area stenosis (r=0.666), inflammation (r=0.476) and fibrin deposition (r=0.496).. The effectiveness of dual antiplatelet therapy plays an important role in the inhibition of in-stent neointimal hyperplasia.

Topics: Adenosine Diphosphate; Angioplasty, Balloon, Coronary; Animals; Aspirin; Cell Proliferation; Clopidogrel; Collagen; Coronary Angiography; Coronary Stenosis; Coronary Vessels; Cytokines; Disease Models, Animal; Drug Therapy, Combination; Fibrin; Hyperplasia; Inflammation Mediators; Metals; P-Selectin; Platelet Activating Factor; Platelet Aggregation; Platelet Aggregation Inhibitors; Prosthesis Design; Stents; Swine; Ticlopidine; Time Factors; Tunica Intima

To evaluate the influence of impaired masseter function during growth on the development of temporomandibular synovitis.. Sixteen 3-week-old male Wistar rats were classified into four groups. The first group served as control; and in the second group, jaw opening was forced for 3 hours when the rats were 9 weeks old. In the third and fourth groups, the masseter muscles were bilaterally resected at 3 weeks of age, and the rats in the fourth group were additionally forced to open their jaw at 9 weeks of age. All rats were sacrificed at 9 weeks. Temporomandibular joint (TMJ) tissue samples were processed for histology, and evaluated for cyclooxygenase-2 (COX-2) and inducible nitric oxide synthase (iNOS) expressions by immunohistochemistry to examine the inflammatory changes in the synovial membrane.. The control group showed noninflammatory changes. In the jaw-opening group, vascular dilation and weak COX-2 immunoreactivity were induced by jaw opening in the synovium. In the masseter-resection group, the masseter-resected rats exhibited moderate synovial changes while in the resection with opening group, the masseter-resected rats revealed more significant inflammatory changes including synovial hyperplasia, dilated vasculature, fibrin deposits, and intense immunoreactivity for COX-2 and iNOS, all caused by jaw opening.. These results suggest that masseter activity in the growth period is an important factor in the induction of temporomandibular synovitis.

Topics: Animals; Cyclooxygenase 2; Dilatation, Pathologic; Fibrin; Hyperplasia; Immunohistochemistry; Male; Masseter Muscle; Muscle Weakness; Nitric Oxide Synthase Type II; Range of Motion, Articular; Rats; Rats, Wistar; Stress, Mechanical; Synovial Membrane; Synovitis; Temporomandibular Joint; Temporomandibular Joint Disorders; Vascular Diseases

Although effective coverage of challenging coronary lesions has warranted the use of overlapping drug-eluting stents, the histopathological response to stent overlap is unknown.. The arterial reaction to overlapping Cypher or Taxus drug-eluting stents was examined in rabbits with bare metal stents, BxVelocity or Express, serving as controls. Single iliac artery balloon injury was followed by placement of 2 overlapping 3.0-mm-diameter drug-eluting stents or bare metal stents in 60 animals (mean length of overlap, 9.8+/-3.6 mm). Stented arteries were harvested at 28 and 90 days for histology. Overlapped segments exhibited delayed healing compared with proximal and distal nonoverlapping sites at 28 days. Overlapped segments in Taxus stents induced significantly more luminal heterophils/eosinophils and fibrin deposition than Cypher; peristrut giant cell infiltration, however, was more frequent in the latter. Overlapping bare metal stents also showed mild delayed healing compared with nonoverlapped segments, but not to the same extent as drug-eluting stents. Although neointimal thickness within the overlap was similar in 28- and 90-day Cypher stents, there was a significant increase with Taxus (P=0.03).. Compared with bare metal stents, drug-eluting stents further delay arterial healing and promote inflammation at sites of overlap. Taxus stents induced greater fibrin deposition, medial cell loss, heterophils/eosinophils, and late neointimal hyperplasia. Patients receiving overlapping drug-eluting stents need more frequent follow-up than patients with nonoverlapping stents.

Topics: Animals; Catheterization; Drug Therapy, Combination; Fibrin; Hyperplasia; Iliac Artery; Inflammation; Paclitaxel; Rabbits; Sirolimus; Stents; Treatment Outcome; Tunica Intima; Wound Healing

Electron microscopy was used to examine the histologic effect of trauma on the rat temporomandibular joint synovial membrane.. Trauma to the TMJ in male Wister rats (100-200 g) was introduced through repeated forced condylar hypermobility. Ultrastructural observations were made 5 days and 6 weeks after the trauma.. The early response of the synovial membrane was synovial hyperplasia, type A synovial cell loss, dilation of the r-ER in the type B synovial cells and fibrin deposition on the synovial surfaces. The late response included degeneration of synovial cells with swollen mitochondria and cell projections, and cell fragmentation. Large amount of fibrin deposition on opposing surface layers was also noticed.. The type A cell loss and fibrin deposition followed by the occurrence of fibrinous materials at opposing surface layers of the synovial membrane suggest that traumatic synovitis causes synovial adhesions.

Topics: Animals; Endoplasmic Reticulum, Rough; Fibrillar Collagens; Fibrin; Hyperplasia; Joint Instability; Male; Rats; Rats, Wistar; Synovial Membrane; Synovitis; Temporomandibular Joint; Tissue Adhesions

Gross and microscopic examination was conducted on one hundred placentas. These included twenty five normal controls and seventy five from intrauterine growth retardation (IUGR) pregnancies. Weight of the placentas from IUGR pregnancies were less than those of normal placentas. The incidence of infarction, intervillous fibrin deposition were much higher in IUGR placentas on gross examination. Highly significant increase in the incidence of infarction, intervillous fibrin deposition, stromal fibrosis and syncytial knotting were found in IUGR placentas compared to full term normal placentas on microscopic examination. The incidence of basement membrane thickening and cytotrophoblastic hyperplasis were also higher in IUGR placentas. All the major histologic findings pointed towards reduced blood flow to the placentas resulting in the restriction of blood flow to fetus. The information obtained from their examination can be a useful adjunct in planning and management of future pregnancies.

Topics: Basement Membrane; Case-Control Studies; Female; Fetal Growth Retardation; Fibrin; Humans; Hyperplasia; Infarction; Organ Size; Placenta; Pregnancy; Trophoblasts

Seven patients with mammographic lesions entirely removed at percutaneous core needle biopsy that required wider excision underwent freehand localization of the site of the prior lesion with orthogonal and reproducible mammographic landmarks to guide needle placement. Successful excision was accomplished in all cases, as evidenced by similar histopathologic findings, fibrin bands or collagen, and core needle biopsy tract at microscopy.

Topics: Aged; Biopsy, Needle; Breast; Breast Neoplasms; Carcinoma in Situ; Carcinoma, Ductal, Breast; Collagen; Coloring Agents; Feasibility Studies; Female; Fibrin; Follow-Up Studies; Humans; Hyperplasia; Mammography; Methylene Blue; Middle Aged; Needles; Neoplasm, Residual; Preoperative Care; Radiography, Interventional; Stereotaxic Techniques

We hypothesized that activation of the coagulation cascade is involved in arterial remodeling in response to sequential injury. An active site-inhibited recombinant human factor VIIa (FVIIai) was used to inhibit tissue factor, the primary cofactor in the extrinsic pathway of coagulation, in a sequential balloon injury model of the rabbit abdominal aorta. Single balloon injury produced limited intimal thickening at 3 weeks (intimal area, 0.40+/-0.05 mm2) and no loss in luminal area (12.2+/-0.9 mm2 before injury and 12.1+/-0.9 mm2 at 6 weeks after injury). Sequential balloon injury, 3 weeks after the first balloon denudation, produced a progressive loss of lumen, with 22% and 47% loss of luminal area, respectively, at 3 and 6 weeks. Luminal loss could not be accounted for by intimal growth (at 3 weeks after sequential injury, the intimal area was 0.47+/-0.08 mm2, <4% of the initial luminal area). Sequential injury acutely produced extensive mural and intramural fibrin deposition. Treatment with FVIIai inhibited both the fibrin deposition and the chronic loss of lumen. At 3 weeks after sequential injury, luminal cross-sectional areas were 9.8+/-0.6 mm2 for control rabbits and 14.3+/-1.4 mm2 for FVIIai-treated rabbits. Neither neointimal area nor cell proliferation was reduced by FVIIai treatment. The intimal cell proliferation index 3 days after injury was 7.6+/-1.1% in control rabbits versus 5.8+/-1.1% in treated rabbits (P>0.05). These results indicate that tissue factor is an important mediator of coagulation in repeat injury and implicate the extrinsic coagulation cascade in a blood vessel remodeling response that is independent of neointimal growth but leads to extensive loss of lumen.

Topics: Animals; Aorta, Abdominal; Blood Coagulation; Catheterization; Cell Division; Factor VII; Female; Fibrin; Humans; Hyperplasia; Microscopy, Electron, Scanning; Rabbits; Thromboplastin; Tunica Intima; Tunica Media

A 23-year-old Italian woman presented with asymptomatic, symmetric, hyperpigmented patches on her face. The dermatosis became exacerbated in summer and closely resembled melasma. The histologic examination and immunofluorescence studies revealed typical features of lichen planus. Actinic lichen planus mimicking melasma is a rare dermatosis occurring mostly in women of oriental origin. The differential diagnosis of further facial melanoses will be discussed.

Topics: Adult; Diagnosis, Differential; Facial Dermatoses; Female; Fibrin; Fluorescent Antibody Technique, Direct; Humans; Hyperpigmentation; Hyperplasia; Immunoglobulin A; Immunoglobulin M; Keratinocytes; Keratosis; Lichen Planus; Lymphocytes; Melanosis

In a porcine coronary model, fibrin film soaked for 3 h in heparin was used as a circumferential coating on a tantalum stent to assess the effect of this naturally occurring biopolymer on arterial healing. The results were compared with those obtained with medical grade polyurethane-coated stainless steel stents.. Thrombus plays an important role in healing after arterial injury and may affect the development of neointimal hyperplasia. Manipulation of the initial thrombus may alter the healing response. To study this, we placed a template of fibrin in a porcine coronary artery restenosis model.. Thirty-four fibrin film stents were delivered in 20 swine. Oversizing was avoided, to prevent deep arterial injury, by placement of optimally sized stents. Initial patency of the stented vessel was confirmed by angiography.. Three fibrin-stented swine died within 48 h; in each, the stent was occluded with a fibrin/red blood cell mass. In two of these three, a portion of the exogenous fibrin had become detached from the stent and partially occluded the lumen. Of the remaining 31 stents, all were patent at elective sacrifice at 28 days. Eighty-four percent had a diameter stenosis < 50%, and the mean (+/- SD) diameter stenosis was 32.3 +/- 13%. There was no evidence of significant foreign-body giant-cell reaction. These results contrasted with the medical grade polyurethane-coated stents placed according to the same protocol without oversizing. Twelve of these stents were placed; six swine died of thrombotic occlusion within the 1st 48 h. At elective sacrifice at 28 days, the remaining polyurethane-coated stents were occluded by marked neointimal hyperplasia.. Fibrin film-coated stents seem promising as a template for modifying the local response to arterial injury and for potentially decreasing restenosis rates.

Topics: Animals; Biocompatible Materials; Coronary Disease; Coronary Vessels; Disease Models, Animal; Equipment Design; Fibrin; Hyperplasia; Materials Testing; Polyurethanes; Recurrence; Stents; Swine; Tunica Intima

Nonoperative therapeutic approaches to chronic venous ulceration, although effective, often require prolonged dressing care and immobilization with leg elevation. Results of skin grafting, perforator ligation, and valve interpositions and reconstructions improve results of ulcer healing but have not uniformly prevented ulcer recurrence. Our hypothesis is that reconstruction of chronic venous ulcers by excision of the diseased tissue bed and replacement with a free flap containing multiple competent microvenous valves and a normal tissue microcirculation will result in long-term cure of these debilitated patients.. Six patients with chronic venous insufficiency and recurrent ulceration (class 3) underwent excision of ulcers and surrounding liposclerotic tissue beds and reconstruction with fasciocutaneous free flaps (two bilateral). Preoperative and postoperative photoplethysmography was used to assess venous refilling times. Duplex scanning was performed to assess deep venous reflux.. There were no flap failures. Photoplethysmographic venous refilling times measured on flaps demonstrated significant immediate and long-term increases from preoperative values (all results +3 by Society of Vascular Surgery outcome grading). Long-term maintenance of tissue integrity is shown by absence of recurrent ulceration and no evidence of recurrent tissue lipodermatosclerosis in all flaps at follow-up (8 months to 7.5 years; mean 24 months). No recurrent lipodermatosclerosis was seen on flap biopsy at 2 and 7 years. Separate cadaveric injection studies, including scanning electron microscopy, revealed numerous microvenous valves directed toward the draining pedicle in the flaps used for reconstruction.. This is the first comprehensive report providing combined laboratory and clinical evaluation, anatomic rationale, and long-term outcome of surgical rehabilitation of patients with chronic venous ulceration who have undergone microsurgical flap reconstruction.

Topics: Adult; Anastomosis, Surgical; Capillaries; Chronic Disease; Female; Fibrin; Humans; Hyperplasia; Male; Microcirculation; Microsurgery; Middle Aged; Photoplethysmography; Popliteal Vein; Scleroderma, Localized; Surgical Flaps; Tibia; Ultrasonography; Varicose Ulcer; Venous Insufficiency; Venules; Wound Healing

Basic fibroblast growth factor (bFGF) can stimulate the proliferation and differentiation of keratinocytes, fibroblasts, and endothelial cells. These cells are involved during the healing of tympanic membrane (TM) perforations. Light and electron microscopy examinations were used to study the histology of TM healing after application of 400 ng of bFGF on the perforation. The progress of healing is accelerated, but the basic healing process is unchanged, i.e., epithelial proliferation first closes the perforation and is then followed by connective tissue growth. There is more connective tissue in the TM receiving bFGF, and extracellular fibers are better oriented. No significant increase of neoangiogenesis was detected in the treated TM. In the nonperforated area of treated TM, an extensive hyperplasia of the submucosal connective tissue is observed. These results demonstrate that bFGF can produce a TM scar containing more connective tissue, which may be of benefit in the prevention of atrophic healed TM.

Topics: Animals; Basement Membrane; Cell Division; Connective Tissue; Epithelium; Exudates and Transudates; Fibrin; Fibroblast Growth Factor 2; Fibroblasts; Hyperplasia; Hypertrophy; Keratins; Male; Microscopy, Electron; Neutrophils; Rats; Rats, Sprague-Dawley; Tympanic Membrane; Wound Healing

According to the conventional hypothesis and its variants, wound granulation tissue is formed by the proliferation and the migration of two closely cooperating but separated cell systems: the endothelial and the fibroblastic (including pericytes). While the elaborated theory of angiogenesis explains the former, there is not a similar theory concerning the latter. The recently proposed angiogenic hypothesis of repair and fibrosis unifies both cell systems by proposing endothelial origin for fibroblastic cells. It was formed on the basis of hyperplastic capillaries and vascular endothelium derived fibroblastic cells in chronic fibrotic diseases. The recent description of hyperplastic capillary sprouts in experimental fibrin clots confirms the validity of this hypothesis also in healing by primary and secondary intentions.

Topics: Angiogenesis Inducing Agents; Animals; Capillaries; Cell Differentiation; Cicatrix; Endothelium, Vascular; Fibrin; Fibroblasts; Fibrosis; Growth Substances; Humans; Hyperplasia; Neovascularization, Pathologic; Wound Healing

Normal, rigid and fibrotic utero-placental arteries are resistant to the action of circulating vaso-motor substances. In contrast, the persistence and the hyperplasia of smooth muscle fibres result in a reduced flow in the intervillous compartment and a sensitivity of the vessels to vaso-constrictor substances. These lesions, which develop after the twentieth week, provide the necessary conditions for the subsequent development of the characteristic vicious cycles of eclampsia.

Topics: Arteries; Complement C3; Female; Fibrin; Fluorescent Antibody Technique; Humans; Hyperplasia; Immunoglobulin A; Immunoglobulin G; Immunoglobulin M; Maternal-Fetal Exchange; Placenta; Pre-Eclampsia; Pregnancy; Uterus

The plasminogen activator content of the extracts of excise prostate cancers (25 specimens) was determined with an azocasein assay and found to be on the average 1.7 times higher than that of extracts of excised prostate benign hyperplasias (29 specimens). Both groups contained the same average percentage of human urokinase type activator (approximately 45%) as determined by the inhibition of activity when anti-human urokinase antibody was included in the assay system. The two types of activators were partially purified and found to have distinctly different properties. The most striking difference was the large augmentation of activity o the non-urokinase enzyme in fibrinolysis. The implications of an enhanced fibrinolysis relative to azocaseinolysis (or other) is discussed, particularly with respect to its importance in the quantitation and characterization of activators by different investigators. Highly purified urokinase-like activator was found to be similar to commercial urokinase preparation with respect to molecular weight, isoelectric point, inhibition by the antibody, and inhibition by placenta inhibitor.

Topics: Fibrin; Humans; Hyperplasia; Male; Plasminogen Activators; Prostate; Prostatic Hyperplasia; Prostatic Neoplasms; Urokinase-Type Plasminogen Activator

Topics: Animals; Capillaries; Diabetes Mellitus, Experimental; Disseminated Intravascular Coagulation; Fibrin; Hyperglycemia; Hyperlipidemias; Hyperplasia; Insulin; Rabbits; Triglycerides

Topics: Adult; Basement Membrane; Biopsy, Needle; Complement System Proteins; Female; Fibrin; Fluorescent Antibody Technique; Follow-Up Studies; Glomerulonephritis; Histocytochemistry; Humans; Hyperplasia; Immunoglobulin G; Immunosuppression Therapy; Kidney Glomerulus; Male; Microscopy, Electron

Topics: Arteries; Biopsy; Chromatin; Endometrium; Endoplasmic Reticulum; Female; Fibrin; Glycogen; Golgi Apparatus; Humans; Hyperplasia; Microscopy, Electron; Mitochondria; Placenta; Pregnancy; Ribosomes; Trophoblasts

Topics: Acute Kidney Injury; Adolescent; Adult; Aged; Azathioprine; Child; Child, Preschool; Epithelial Cells; Epithelium; Female; Fibrin; Glomerulonephritis; Glucocorticoids; Heparin; Humans; Hyperplasia; Infant; Infant, Newborn; Kidney Glomerulus; Male; Middle Aged; Renal Dialysis

Topics: Arthritis, Juvenile; Child; Child, Preschool; Chronic Disease; Female; Fibrin; Humans; Hydrarthrosis; Hyperplasia; Microscopy, Electron, Scanning; Synovectomy; Synovial Membrane

Topics: Adult; Appetite Depressants; Electrocardiography; Female; Fibrin; Humans; Hyperplasia; Hypertension, Pulmonary; Obesity; Pulmonary Artery; Radiography, Thoracic

Topics: Aneurysm; Female; Fibrin; Heart Defects, Congenital; Histological Techniques; Humans; Hyperplasia; Hypertension, Pulmonary; Infant; Infant, Newborn; Lung; Male; Pulmonary Artery