Mycobacterial laminin-binding histone-like protein mediates collagen-dependent cytoadherence

When grown in the presence of exogenous collagen I, Mycobacterium bovis BCG was shown to form clumps. Scanning electron microscopy examination of these clumps revealed the presence of collagen fibres cross-linking the bacilli. Since collagen is a major constituent of the eukaryotic extracellular matrices, we assayed BCG cytoadherence in the presence of exogenous collagen I. Collagen increased the interaction of the bacilli with A549 type II pneumocytes or U937 macrophages, suggesting that BCG is able to recruit collagen to facilitate its attachment to host cells. Using an affinity chromatography approach, we have isolated a BCG collagen-binding protein corresponding to the previously described mycobacterial laminin-binding histone-like protein (LBP/Hlp), a highly conserved protein associated with the mycobacterial cell wall. Moreover, Mycobacterium leprae LBP/Hlp, a well-characterized adhesin, was also able to bind collagen I. Finally, using recombinant fragments of M. leprae LBP/Hlp, we mapped the collagen-binding activity within the C-terminal domain of the adhesin. Since this protein was already shown to be involved in the recognition of laminin and heparan sulphate-containing proteoglycans, the present observations reinforce the adhesive activities of LBP/Hlp, which can be therefore considered as a multifaceted mycobacterial adhesin, playing an important role in both leprosy and tuberculosis pathogenesis.

Effect of ascorbic acid on stimulatory status of activated mouse peritoneal phagocytes.

Mouse peritoneal macrophages (MPM) when elicited by the antioxidant ascorbic acid have been found to be significantly stimulatory, exhibiting marked alteration at the cellular and enzyme levels. Alterations recorded were as follows--cellular yield per mouse, their protein content, lysosomal acid hydrolase levels and capability to phagocyte, all were significantly enhanced. The new stimulant was observed to produce no synergistic action on MPM when thioglycollate, BCG or endotoxin along with the same stimulated the latter. Levels of antioxidants like ascorbic acid and glutathione were found to be enhanced in elicited macrophages whereas superoxide dismutase levels varied when the three above stimulators were administered. However, the ascorbic acid elicited cells showed an increase in glutathione levels and a decrease in SOD levels but no change in total intracellular ascorbic acid levels. Further, though ascorbic acid interaction enhanced the phagocytic capability of MPM as compared to resident cells, no significant boosting of phagocytic process could be observed when each of three stimulators coupled with ascorbic acid was used for macrophage elicitation.

Manejo del carcinoma superficial de vejiga; BCG intravesical: la nueva alternativa / BCG in the management or superficial blader neoplasms: the new alternative

La BCG intravesical representa una nueva forma de terapia intravesical para el tratamiento del cáncer superficial de vejiga reportado en un rango que va de 10 (por ciento) a 20 (por ciento). La rata de recurrencia es comparable al 40 (por ciento) de la thiotepa y 60 (por ciento) de fulguración sólo. Presenta un 59 (por ciento) a 83 (por ciento) de incidencia de regresión del tumor residual, lo cual es comparable con el 30 a 50 (por ciento) de la thiotepa y una incidencia de un 60 a 80 (por ciento) de regresión del carcinoma in situ, el cual es comparable con el 55 (por ciento) de la thiotepa y el 8 (por ciento) de la fulguración. Hay muchos protocolos en la aplicación de la terapia, uno de los más aceptados es Pasteur BCG 120 MG. en 50 cc de Salina administrado semanalmente por seis semanas, empezando 1 ó 2 semanas después de la resección, una dósis de BCG equivale en costo a 30 MG de thiotepa el agente quimioterapéutico más barato. La terapia es seguida de cistoscopía, biopsias y citología, cada 3 meses por 2 años. El estado de la prueba cutánea con PPD, la radiografía de torax y la química sanguínea, deben ser monitorizados antes y después de la terapia. La conversión de la prueba cutánea es positiva en el transcurso de la terapia y la aparición de granulomas en la vejiga se considera un efecto terapéutico beneficioso. Los efectos secundarios de la BCG son síntomas irritativos leves que no tienen trascendencia. Todavía no hay nada conclusivo en la relación sobre la cepa óptima y la ruta de administración. No se conoce a largo plazo el efecto antitumoral y efecto secundario de la BCG en la vejiga. Para finalizar, la terapia con BCG es sin duda alguna la mejor opción para el paciente con cáncer superficial de vejiga, pero todavía hay mucho que aprender para mejorar la eficacia óptima de este tratamiento