RESUMO
Reactive oxygen intermediates induce cell injury in a variety of pathophysiological conditions. Human umbilical cord vein endothelial cell (HUVEC) cultures were exposed to 1 or 200 microM H2O2 for 15 min, and observed after 15 min, or 1, 4, 24, or 120 h. Factor VIII and the cytoskeletal proteins vimentin and tubulin were visualized immunocytochemically. Release of lactate dehydrogenase (indices of cell membrane injury) did not increase after H2O2 exposure; nor was cellular expression of factor VIII affected. 200 microM H2O2 induced cell contraction after 15 min which disappeared after 1 and 4 h, but was evident again after 24 h. Immediately after exposure, the filamentous structure of vimentin and tubulin disappeared, but normalized after 1 h. After 120 h, the cytoskeleton filaments were coarsened and disorganized, and an abundance of multinucleated giant cells were observed. Catalase (150 U/ml) abolished all effects of H2O2. One microM H2O2 did not induce any changes in HUVEC. Thus, the present concentrations of H2O2 did not induce cell necrosis or altered expression of factor VIII. Early, reversible cell contraction and depolymerization of cytoskeletal proteins were observed, followed by a delayed contraction and cell atypia after 200 microM H2O2.
Assuntos
Citoesqueleto/efeitos dos fármacos , Endotélio Vascular/efeitos dos fármacos , Peróxido de Hidrogênio/farmacologia , Espécies Reativas de Oxigênio/metabolismo , Anticorpos Monoclonais , Biopolímeros , Endotélio Vascular/patologia , Fator VIII/imunologia , Humanos , L-Lactato Desidrogenase/metabolismo , Estimulação Química , Tubulina (Proteína)/imunologia , Vimentina/imunologiaRESUMO
The potential modes of transmission for hepatitis C virus (HCV) infections were studied using a multivariate analysis of risk factor exposure among 51 2nd generation anti-HCV and HCV-RNA positive and matched anti-HCV negative blood donors. The following variables were found to be independently associated with anti-HCV and HCV-RNA positivity: intravenous drug use (IVDU) (p < 0.001), blood transfusion (p < 0.01), tattoos (p < 0.001), previous hospitalization (p < 0.05), history of sexually transmitted disease (STD) (p < 0.001) and lack of travels outside of Europe (p < 0.05). Among the 23 HCV-RNA positive donors without a history of IVDU or blood transfusion, an increased frequency of hospitalization (p = 0.017) and history of STD (p = 0.023) were found. Five of 22 sexual partners of the 51 index blood donors were HCV-RNA positive and in one of these couples sexual transmission was suspected. Anti-HCV and HCV-RNA positive donors were more often seropositive for herpes simplex virus type 2 (HSV-2) antibodies than were HCV-negative controls (p = 0.015). Sexual transmission of HCV may occur, but the possible role of HSV-2 requires further investigation.
