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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Hemorrhagic shock (HS)-induced microvascular hyperpermeability poses a serious challenge in the management of trauma patients. Microvascular hyperpermeability occurs mainly because of the disruption of endothelial cell adherens junctions, where the "intrinsic" apoptotic signaling plays a regulatory role. The purpose of this study was to understand the role of the "extrinsic" apoptotic signaling molecules, particularly Fas-Fas ligand interaction in microvascular endothelial barrier integrity. ⋯ FasFc treatment showed protection against HS serum-induced disruption of the adherens junctions and monolayer hyperpermeability (P < 0.05) in the endothelial cells. Pretreatment with FasFc also decreased HS serum-induced increase in mitochondrial reactive oxygen species formation, restored HS serum-induced drop in mitochondrial transmembrane potential, and reduced HS serum-induced caspase 3 activity in RLMECs. These findings open new avenues for drug development to manage HS-induced microvascular hyperpermeability by targeting the Fas-Fas ligand-mediated pathway.
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Hepatic ischemia-reperfusion (I/R) injury contributes to hepatic dysfunction and failure after liver transplantation, major hepatic resection, trauma, and hypovolemic shock. Therefore, reducing I/R injury is an important goal to improve the outcome of these procedures. Recently, high-mobility group box 1 protein (HMGB1) has been identified as a pathogenic mediator in several inflammatory diseases, including hepatic I/R. ⋯ The results showed that pretreatment with PNU-282987 decreased serum transaminase levels and ameliorated liver injury after hepatic I/R. Moreover, pretreatment with PNU-282987 suppressed NF-κB activation, cytokine production (tumor necrosis factor α, interleukin 1β), and HMGB1 expression in liver after hepatic I/R. These observations suggest that PNU-282987 protects the liver from I/R injury possibly by inhibiting HMGB1 expression, suppressing cytokine production, and preventing NF-κB activation in mice.
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Our objectives were to determine the incidence of critical illness-related corticosteroid insufficiency (CIRCI) in patients with septic shock using a 1 μg corticotropin (ACTH) test and to describe their clinical outcomes. We retrospectively identified 219 consecutive patients with septic shock assessed for CIRCI with a 1 μg ACTH test. Standardized testing involved plasma cortisol measurements at baseline (T0) and at 30 min (T30) and 60 min (T60) after ACTH administration. ⋯ The incidence of CIRCI based on 1 μg ACTH was high in this septic shock cohort. The highest mortality rates were observed in patients with high baseline cortisol and in those who failed to respond appropriately to ACTH. The administration of corticosteroids was not associated with a reduction in mortality.
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We hypothesized that pretreatment with single-dose cyclosporine (CsA) prevents alterations and improves tissue oxygen and mitochondrial cytochrome oxidase redox (CytOx) state in skeletal muscle ischemia and reperfusion-reoxygenation (I/R). Latissimus dorsi muscle was prepared and mobilized in New Zealand white rabbits. Ischemia was induced for 4 h, followed by 2 h of reperfusion. ⋯ Muscle HEP levels (phosphocreatine, adenosine triphosphate) were significantly preserved in the CsA group versus the control group (P < 0.01, P < 0.05). Mitochondrial viability index and wet-to-dry ratio confirmed significantly preserved tissue and lower edema formation in the CsA group. The pretreatment with single-dose CsA prevents alterations and improves tissue oxygenation and mitochondrial oxidation in skeletal muscle I/R.
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The assessment of baroreflex function since the first appearance of endotoxemia is important because the arterial baroreflex should exert a protective role during sepsis. Nevertheless, contrasting results were previously reported. This could be due to the hemodynamic instability characterizing this condition that may per se interfere with reflex cardiovascular adjustments. ⋯ We found that blood pressure levels did not change with the infusion of LPS, whereas inflammatory cytokines increased significantly. The baroreflex sensitivity was significantly reduced 10 min after the beginning of LPS infusion, reached values about half those at baseline within 15 min after the start of infusion, and remained significantly low after the end of infusion. In conclusion, we documented that septic shock inducing LPS infusion is responsible for a very rapid impairment of the baroreflex function, independent from the level of blood pressure.