Examinando por Autor "Escobar, J."
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Ítem Endocarditis por Lactococcus garvieae en un paciente sometido a hemodialisis crónica. Primer caso reportado en Chile y revisión de la literatura(Sociedad Chilena de Infectología, 2017) Clavero, R.; Escobar, J.; Ramos-Avasola, S.; Merello, L.; Álvarez, F.Los casos reportados de infección por Lactococcus garvieae son escasos y sólo uno asociado a hemodiálisis. Comunicamos el caso de endocarditis infecciosa de curso fatal por L. garvieae en un paciente con una enfermedad renal crónica sometido a hemodiálisis y portador de diverticulosis colónica no complicada. Se realiza una revisión de los casos publicados y se discuten los actuales desafíos diagnósticos y terapéuticos de este patógeno, capaz de producir infecciones graves y potencialmente fatales en pacientes susceptibles. Este sería el segundo caso de infección asociada a hemodiálisis y el primero reportado en Chile.Ítem Lipopolysaccharide inhibits the channel activity of the P2X7 receptor(2011) Leiva-Salcedo, E.; Coddou, C.; Rodríguez, F.; Penna, A.; Lopez, X.; Neira, T.; Fernández, R.; Imarai, M.; Rios, M.; Escobar, J.; Montoya, M.; Huidobro-Toro, J.; Escobar, A.; Acuña-Castillo, C.The purinergic P2X7 receptor (P2X7R) plays an important role during the immune response, participating in several events such as cytokine release, apoptosis, and necrosis. The bacterial endotoxin lipopolysaccharide (LPS) is one of the strongest stimuli of the immune response, and it has been shown that P2X7R activation can modulate LPS-induced responses. Moreover, a C-terminal binding site for LPS has been proposed. In order to evaluate if LPS can directly modulate the activity of the P2X7R, we tested several signaling pathways associated with P2X7R activation in HEK293 cells that do not express the TLR-4 receptor. We found that LPS alone was unable to induce any P2X7R-related activity, suggesting that the P2X7R is not directly activated by the endotoxin. On the other hand, preapplication of LPS inhibited ATP-induced currents, intracellular calcium increase, and ethidium bromide uptake and had no effect on ERK activation in HEK293 cells. In splenocytes-derived T-regulatory cells, in which ATP-induced apoptosis is driven by the P2X7R, LPS inhibited ATP-induced apoptosis. Altogether, these results demonstrate that LPS modulates the activity of the P2X7R and suggest that this effect could be of physiological relevance.