Intrahepatic B cell clonal expansions and extrahepatic manifestations of chronic HCV infection

B cell repertoire in three biological compartments (liver, bone marrow and peripheral blood) of 30 unselected patients chronically infected with HCV has been characterized. Restriction of humoral immune response defined by enrichment of B cell clonal expansions occurred in the liver of 15 patients (50%), in the bone marrow and peripheral blood of 2 (6.7%) and 8 (26.7%) patients, respectively. An in situ hybridization technique was developed for the detection of dominant B cell clones in patients with monoclonal expansions. It was shown that morphologically distinct B cell expansion contributes to the formation of intraportal follicle-like structures. Sequence analyses of CDRH3 gene segments revealed a wide range of variations. Clones derived from the same founder were demonstrated simultaneously in the three compartments explored. The occurrence of B cell clonal expansions profoundly influenced the clinical expression of HCV infection, since it was associated with extrahepatic manifestations. In sharp contrast, no extrahepatic signs or disease occurred in patients without evidence of intrahepatic B cell clonalities. These findings emphasize the profound B cell function derangement in at least half of HCV-infected patients. Thus, the restriction of V gene usage has a direct impact on the clinical spectrum of HCV infection

Influência da densidade populacional nas relações entre matéria orgânica carbonácea, nitrogênio e fósforo em rios urbanos situados em áreas com baixa cobertura sanitária Influence of the urban density in the relationship among carbonic organic matter, nitrogen and phosphorous in small rivers with low sanitation coverage

O objetivo principal deste trabalho é a análise da variação da relação entre a matéria orgânica carbonácea (representada pelas Demandas Biológica e Bioquímica de Oxigênio), Nitrogênio Total Kjeldhal e Fósforo Total nas águas de pequenos rios urbanos cujas áreas de drenagem apresentem baixa cobertura sanitária. Para isso, foram selecionadas 4 bacias hidrográficas urbanas com ocupação residencial, densidade populacional entre 0 e 100 hab/ha e similaridade de condições naturais e de ocupação humana. Os resultados mostraram alterações importantes nas relações entre os conteúdos de matéria orgânica carbonácea, Nitrogênio e Fósforo indicando que, a partir de uma condição natural não urbanizada, mesmo pequenas densidades populacionais são capazes de alterar significativamente a qualidade das águas.<br>The purpose of this study is to evaluate the relationship among the carbonic organic matter (measured as Chemical and Biological Oxygen Demand), Total Kjeldhal Nitrogen and Total Phosphorous in small urban rivers with low sanitation coverage in its hydrographic basins. Four basins with similar natural condition and residential occupation but variable urban densities between 0 and 100 inhabitants per hectare were selected. The results show important changes in the carbonic organic matter, Nitrogen and Phosphorous relationships indicating that, compared with a natural condition, even low urban densities can significantly change de water quality