fibrin and Metaplasia

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

Topics: Cataract Extraction; Cells, Cultured; Dinoprostone; Enzyme-Linked Immunosorbent Assay; Epithelium; Fibrin; Humans; Interleukin-1; Lens Capsule, Crystalline; Lens, Crystalline; Lenses, Intraocular; Metaplasia; Radioimmunoassay

In examination of 732 knee joints through the arthroscope since 1961, various types of debris were observed in 47. The debris was classified into four groups: precipitation of fibrin, degeneration and necrosis of villi, desquamation of articular cartilage, and metaplasia of villi. Diseases of the knee joint and their pathogenesis are discussed in the light of these findings.

Topics: Cartilage, Articular; Endoscopy; Fibrin; Humans; Joint Diseases; Knee Joint; Metaplasia; Necrosis

Administration of 0.5 mg bleomycin to mice twice weekly for 4 weeks induced pulmonary fibrosis. The initial site of injury was the intima of pulmonary arteries and veins where endothelial cells became edematous and were separated from the underlying basement membrane by large blebs. These lesions occurred after 2 weeks and were associated with infiltration of perivascular spaces by lymphocytes and plasma cells. Capillary endothelial blebbing and interstitial edema were observed after 4 weeks, when multifocal necrosis of type 1 alveolar epithelial cells was accompanied by fibrinous exudation into the alveoli. The process of repair was characterized by proliferation and metaplasia of type 2 epithelial cells, fibroblastic organization of alveolar fibrin and fibrosis of the interstitium within 8 to 12 weeks. The consistent induction of changes similar to those of diffuse pulmonary fibrosis or fibrosing alveolitis in man suggests that bleomycin-induced injury may provide a suitable model for the investigation of this ill-defined group of diseases.

Topics: Animals; Bleomycin; Capillaries; Disease Models, Animal; Endothelium; Epithelium; Exudates and Transudates; Fibrin; Fibroblasts; Lung; Lymphocytes; Metaplasia; Mice; Microscopy, Electron; Necrosis; Plasma Cells; Pulmonary Alveoli; Pulmonary Artery; Pulmonary Edema; Pulmonary Fibrosis; Pulmonary Veins