Navegando por Palavras-chave "basement membrane"
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- ItemSomente MetadadadosCleavage of human fibronectin and other basement membrane-associated proteins by a Cryptococcus neoformans serine proteinase(Elsevier B.V., 2003-02-01) Rodrigues, M. L.; Reis, FCG dos; Puccia, R.; Travassos, L. R.; Alviano, C. S.; Universidade Federal do Rio de Janeiro (UFRJ); Universidade Federal de São Paulo (UNIFESP)The interaction between the fungal pathogen Cryptococcus neoformans and human fibronectin (HFN) was examined in this study. Polypeptides from cryptococcal whole homogenates and cell wall with molecular masses of 25 and 35 kDa, respectively reacted with HFN. the relevance of the occurrence of these proteins in intact cells was uncertain, since yeast cells from different strains and serotypes of C neoformans did not significantly adhere to soluble or solid-phased HFN. in contrast, an exocellular proteolytic activity that cleaves HFN was suggested. Degradation of HFN by culture supernatant fluids was demonstrated by Western blotting using a monoclonal anti-HFN antibody. Several fragments of lower molecular weights were observed which reacted with the antibody. Proteolysis was mediated by a serine protease activity, since HFN cleavage was completely inhibited by phenylmethylsulfonyl fluoride (PMSF), aprotinin, and N-tosyl-L-phenylalanyl chloromethylketone (TPCK), but not by inhibitors of metalo, cysteine, or aspartyl proteases. Similar results were obtained when the fluorogenic peptide carbobenzoxy-phenylalanyl-arginyl-7-amido-4-methylcoumarin (CBZ-Phe-Arg-NHmet-C) was used as substrate. the cryptococcal supernatant also cleaved laminin and type IV collagen, as demonstrated by polyacrylamide gel electrophoresis with co-polymerized proteins. the hydrolysis of these proteins was mediated by a single cryptococcal protease with a molecular mass of 75 kDa. the cleavage of key host components of the basement membrane and extracellular matrix by C. neoformans may be a relevant factor in the process of fungal invasion. (C) 2003 Elsevier B.V. All rights reserved.
- ItemRestritoDermatose por IgA linear induzida pela gestação(Soc Brasileira Dermatologia, 2008-01-01) Kanagusuko, Telma; Aoki, Valeria; Tebcherani, Antonio Jose [UNIFESP]; Galli Sanchez, Ana Paula; Complexo Hosp Padre Bento Guarulhos; Universidade de São Paulo (USP); Universidade Federal de São Paulo (UNIFESP)Linear IgA disease is a rare autoimmune subepidermal bullous disorder characterized by linear IgA deposits at the epidermal basement membrane zone. According to the literature, in patients who have linear IgA disease and become pregnant, the disease tends to improve. We report a case of linear IgA disease induced by pregnancy, successfully treated with dapsone and prednisone with no adverse effects observed in the patient and her newborns.
- ItemAcesso aberto (Open Access)Diferenciação histopatológica e imunoistoquímica das alterações epiteliais no nódulo vocal em relação aos pólipos e ao edema de laringe(ABORL-CCF Associação Brasileira de Otorrinolaringologia e Cirurgia Cérvico-Facial, 2004-08-01) Neves, Beatrice M. J. [UNIFESP]; G. Neto, João; Pontes, Paulo [UNIFESP]; Universidade Federal de São Paulo (UNIFESP); Universidade de São Paulo (USP)AIM: To evaluate by histological and immunohistochemical methods the epithelial lesions in vocal nodule and correlate with polyp, laryngeal edema and vocal folds without macroscopic lesions. STUDY DESIGN: Chart review. MATERIAL AND METHOD: In a retrospective analysis of medical records, twenty-six patients, who underwent microsurgical excision of laryngeal inflammatory lesions (nodules, polyps and laryngeal edema), were identified. Vocal folds without macroscopic lesions were obtained from autopsy. To evaluate epithelial lesions, specimens were stained with H&E, PAS, and with antibodies against laminin and collagen type IV. These specimens were analyzed by light microscopy. RESULTS: Lesions diagnosed as nodules showed more collagen type IV and laminin deposition when compared to polyps (p=0,034 and p=0,036, respectively) and to vocal folds without macroscopic lesions (p=0,019 and p=0,021, respectively). Nodules showed basement membranes thicker than polyps on PAS stain (p=0,102). Laryngeal edema could not be differentiated from nodules, polyps or vocal folds without macroscopic lesions by PAS, laminin or collagen type IV stain (p>0,10). CONCLUSION: By histological and immunohistochemical techniques to evaluate epithelium of laryngeal inflammatory lesions we conclude that vocal fold nodule differentiate from polyps on the three techniques used to stain basement membrane (PAS, laminin, collagen IV) and from vocal folds without macroscopic lesions on two techniques used (laminin, collagen IV). Laryngeal edema cannot be differentiated from the others laryngeal lesions, neither from vocal folds without macroscopic lesions, when the techniques before described are used.
- ItemSomente MetadadadosExocellular proteolytic activity of Paracoccidioides brasiliensis: cleavage of components associated with the basement membrane(Blackwell Science Ltd, 1998-10-01) Puccia, R.; Carmona, A. K.; Gesztesi, J. L.; Juliano, L.; Travassos, L. R.; Universidade Federal de São Paulo (UNIFESP)We have previously characterized an exocellular serine-thiol proteinase activity in Paracoccidioides brasiliensis, using as substrates peptides analogous of the internally quenched fluorogenic peptide Abz-MKWLTL-EDDnp. in this communication, detection of maximal proteinase activity in the culture supernatant fluids followed the abrupt increase in the medium pH, owing to the accumulation of ammonia generated by urease activity. Culture supernatant fluids collected at the peak of proteinase activity against Abz-MRKLTL-EDDnp were able to cleave components of the basal membrane of the extracellular matrix (EM), including laminin, fibronectin, collagen type IV and proteoglycans, and the proteolytic activity was selectively inhibited both by PMSF and p-HMB (sodium 7-hydroxymercuribenzoate), which are also specific inhibitors of the serine-thiol proteinase. Human collagen I, bovine fibrinogen, human immunoglobulin G, BSA or P. brasiliensis gp43 were resistant to proteolysis. the kinetics of appearance of the proteinase activity against EM substrates coincided with that of proteolysis of Abz-MKRLTL-EDDnp. Moreover, chromatographic fractions of culture supernatants containing the serine-thiol proteinase at high specific activity were also active against EM substrates. These data suggest the involvement of this enzyme activity in the degradation of the basement membrane, which is the first step for fungal tissue invasion.