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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The current consensus definition of septic shock requires hypotension after adequate fluid challenge or vasopressor requirement. Some patients with septic shock present with hypotension and hyperlactatemia greater than 2 mmol/L (tissue dysoxic shock), whereas others have hypotension alone with normal lactate (vasoplegic shock). ⋯ In this analysis of patients with septic shock, we found a significant difference in in-hospital mortality between patients with vasoplegic versus tissue dysoxic septic shock. These findings suggest a need to consider these differences when designing future studies of septic shock therapies.
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Severe trauma is characterized by a pronounced immunologic response with both proinflammatory and anti-inflammatory characteristics. The clinical course of trauma patients is often complicated by late-onset (>5 days) sepsis. However, the underlying mechanisms remain poorly defined. Here we studied the kinetics of systemic activation of neutrophils and monocytes following injury in trauma patients in the context of development of sepsis. ⋯ Phenotyping blood PMNs enables identification of the kinetics and magnitude of the initial systemic inflammatory response after injury. The decreased functionality of PMNs and monocytes reaches its minimum before the development of sepsis and could be an important contributing factor. This could support the early identification of patients at risk.
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It is well established that CD4CD25 regulatory T cells (Tregs) downregulate inflammatory immune responses and help to maintain immune homeostasis. Recent reports have shown that ligation of germline encoded pattern recognition receptors such as Toll-like receptors can stimulate Tregs and therefore implicate Tregs in the pathophysiology of sepsis and other inflammatory diseases. In this report, we show that injection of lipopolysaccharide (LPS) leads to expansion of CD4CD25FoxP3 Tregs, suggesting that these cells may play an important role in immune regulation in LPS-induced acute inflammation. ⋯ Unlike LPS, depletion of Tregs followed by concanavalin A (Con A) challenge does not result in mortality, suggesting that Treg depletion does not globally influence all models of acute inflammation. We authenticate our findings by showing that depletion of Tregs leads to mortality in a nonlethal Escherichia coli challenge accompanied by elevated serum levels of proinflammatory cytokines. Collectively, our results indicate that in addition to regulation of LPS-induced acute inflammation, Tregs help to improve bacterial clearance and promote survival in an acute model of bacterial infection.
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We examined the effects of hypertonic saline (HS) on inflammatory, metabolic variables, and bacterial translocation (BT) in rats submitted to intestinal obstruction and ischemia (IO). Male Wistar rats were submitted to IO and treated, 2 h thereafter, with lactated Ringer's (LR) (4 mL/kg per 5 min, i.v.) or HS (7.5% NaCl, 4 mL/kg per 5 min, i.v.). Twenty-four hours after IO, rats were also submitted to enterectomy/enteroanastomosis to resection of necrotized small bowel. ⋯ Local intestinal damage was attenuated, and renal and hepatic function preserved by treatment with HS followed by enterectomy. Survival rate increased to 86% up to 15 days. Data presented suggest that HS solution followed by enterectomy reduces mesenteric microcirculatory dysfunctions and BT, attenuating local and remote damage in a model of strangulated small bowel obstruction.
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The aim of this present study was to examine changes in RhoA protein levels and the role in RhoA in lymphatic contractility and reactivity after hemorrhagic shock. Levels of RhoA and phospho-RhoA in lymphatic tissue isolated from hemorrhagic shock rats were measured, and the contractility and reactivity to substance P of lymphatics isolated from control rats and rats subjected to shock 0.5 and 2 h were determined with an isolated lymphatic perfusion system at a transmural pressure of 3 cmH2O. At the same time, lymphatics isolated from rats subjected to shock 0.5 and 2 h were incubated with agonists and antagonists of RhoA/Rho kinase signaling. ⋯ The RhoA agonist U-46619 increased the contractility and reactivity of 2-h-shocked lymphatics, whereas Y-27632 suppressed the effect of U-46619. Okadaic acid, an inhibitor of myosin light-chain phosphatase, had no effect on the contractility of 2-h-shocked lymphatics, but improved lymphatic reactivity. These results suggest that RhoA is involved in the modulation of lymphatic pump function during hemorrhagic shock and that its effects may be mediated by Rho kinase and MLCP.