Shock : molecular, cellular, and systemic pathobiological aspects and therapeutic approaches : the official journal the Shock Society, the European Shock Society, the Brazilian Shock Society, the International Federation of Shock Societies
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Nitric oxide (NO) prevents the myocardial apoptosis and dysfunction resulting from cardioplegia-induced cardiac arrest (CCA) under cardiopulmonary bypass (CPB). Inasmuch as CCA-induced myocardial dysfunction is associated with acute ischemia/reperfusion (I/R) and inflammatory response, which activates nuclear factor kappaB (NF-kappaB) translocation, we assessed the hypothesis that the detrimental effects of CCA under CPB result from NO imbalance inducing NF-kappaB activation. New Zealand white rabbits (10 in each group, each 2.5-3.5 kg) received total CPB. ⋯ The inflammatory and apoptotic responses of cardiomyocytes could be lessened by restoring NO concentration via modulation of the (1) nuclear translocation of NF-kappaB, (2) inducible NO synthase mRNA expression, (3) cytochrome c production, and (4) occurrence of apoptosis. Cardioplegia-induced cardiac arrest under CPB can decrease endogenous NO production, which can be restored with exogenous NO supplementation. Exogenous NO can ameliorate the myocardial inflammatory response by inhibition of NF-kappaB translocation, inflammatory gene expression, inducible NO synthase expression, and cytochrome c production.
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In recent investigations, high-mobility group box 1 (HMGB1) has been recognized to be an important factor in the development of sepsis. On the other hand, a serine protease inhibitor, nafamostat mesilate (NM) inhibits the enzyme activities of various protease and coagulation factors. We examined whether NM could inhibit HMGB1 in a rat sepsis model and thus could potentially be useful for treating sepsis. ⋯ Regarding the cell signal in each cell, we observed the inhibition of the phosphorylation of IkappaB. We thus concluded that it is possible to prevent the occurrence of pulmonary disorders in an endotoxic shock model by administering NM, however, this also inhibits the cell signal in a cell, mainly by the phosphorylation of IkappaB, thereby inhibiting the HMGB1 levels. Our findings thus suggest that the administration of NM may therefore potentially improve the condition of patients who have septic shock.
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Sepsis is one of the most important risk factors in acute respiratory distress syndrome (ARDS). beta-Glucan is a potent reticuloendothelial modulating agent, the immunobiological activity of which is mediated in part by an increase in the number and function of macrophages. In this study, we investigated the putative protective role of beta-glucan against sepsis-induced lung injury. Sepsis was induced by cecal ligation and puncture (CLP) in Wistar rats. ⋯ In contrast, beta-1,3-D-glucanase caused a significantly increased MPO and ICAM-1 levels in the lung. These data reveal that beta-glucan treatment improved the course of CLP-induced peritonitis and attenuated the lung injury. Administration of beta-glucanase inhibited the beta-glucan activity and resulted in enhanced lung injury.
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Studies have indicated that there is a development of generalized immune dysfunction after septic insult. However, the mechanisms responsible for these changes remain unclear. Recently, accumulating evidence shows that several lymphocyte subpopulations such as NKT-, CD4(+)-Th2-T-, CD8(+)-T-, gammadelta-T-, and CD4+ CD25+ T regulatory cells are capable of actively contributing to the induction of septic immune suppression. ⋯ Similarly, in vitro proliferation studies showed that proliferation index increased in CD4+ CD25+ cells from septic C57BL/6J and IL6 -/- mice, but it remained the same in IL-10 -/- mice. Surprisingly, depletion of CD25+ cells before inducing sepsis did not alter septic mortality. Together, these findings suggest that although CD4+ CD25+ T regulatory cells induced by IL-10 seem to contribute to aspects of sepsis-induced lymphoid immune suppression, the oblation of CD25+ cells does not provide a survival advantage or disadvantage.
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Although comprehension of postburn pathophysiology has grown in recent years, we are still unable to accurately identify burn patients who are at an increased risk of infectious complications and death. This unexplained variation is likely influenced by heritable factors; the genetic predisposition for death from infection has been estimated as greater than that for cardiovascular disease or cancer. Identify genetic variants associated with increased mortality after burn injury. ⋯ None of the other single nucleotide polymorphisms examined were significantly associated with mortality. These data provide strong evidence that a CD14 promoter allele that is known to impart lower baseline and induced CD14 transcription also affects mortality risk after burn injury. A potential (although untested) mechanism for our observation is that reduced signaling through CD14/toll-like receptor 4 in response to challenge by gram-negative bacteria after burns results in a blunted innate immune response and subsequent increased likelihood for systemic infection and death.