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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Intercellular adhesion molecule 1 (ICAM-1) plays an important role in the transmigration of polymorphonuclear neutrophils (PMN) in sepsis. Moreover, the transmigration rate of leukocytes from the blood via endothelial adhesion molecules into tissues correlates with the severity of multi organ failure. We examined the effect of the deletion of the ICAM-1 gene in polymicrobial sepsis using a cecal ligation and puncture (CLP) sepsis model in mice. ⋯ The DTH reaction was significantly decreased in ICAM-1-/- mice versus WT mice (0.34 vs 0.41 mm; P < 0.05). Our results demonstrate a significant reduction of mortality after septic challenge in ICAM-1-/- mice compared to normal mice. This is associated with a decrease in lymphocyte subpopulations, cytokine levels, and DTH type 4 reaction, possibly reflecting an overall attenuation of the immune system.
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Recently, we demonstrated that mice under lethal sepsis present failure of neutrophil migration (FNM) to infectious focus, which is mediated by nitric oxide. The aims of the present study were to investigate whether FNM is also observed in severe sepsis induced by cecal ligation and puncture in rats and the effects of the prevention of nitric oxide production and of the elimination of the infectious focus through peritoneal lavage or by antimicrobial treatment on FNM and disease outcome. Rats were submitted to several septic stimuli (low, moderate, and severe) by cecal ligation and puncture. ⋯ In contrast, the antimicrobial treatment of severe septic stimulus animals with sulfamethoxazole and trimethoprim significantly improved the survival rate of the severe septic stimulus but did not re-establish neutrophil migration. However, the association of aminoguanidine plus sulfamethoxazole and trimethoprim brought about a significant increase in the survival rate and re-established neutrophil migration to infectious focus; reduced the colony-forming units in the peritoneal cavity, blood, and lung tissues; and caused an improvement in the cardiovascular performance. The results showed, for the first time, that the pharmacological prevention of FNM to the infectious focus associated with the antimicrobial therapy could be a new beneficial strategy for the treatment of sepsis syndrome.
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No pharmacologic agent has shown benefit in treating heatstroke. Previous data indicate that enhanced heat shock protein 70 (HSP-70) expression can improve survival postexperimental heatstroke. Glutamine (GLN) can enhance HSP-70 expression in other injury models. ⋯ These results also indicate that enhanced HSP-70 may have functional significance as GLN-treated animals had decreased gut permeability, plasma endotoxin, and improve survival following lethal hyperthermia. Enhanced expression of HSP-70 may be an important mechanism leading to enhanced survival via GLN. These data indicate that oral GLN may useful in prevention of mortality from heatstroke in at risk populations.
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Several hemoglobin (Hb)-based oxygen carriers are available for use in clinical situations, but their use risks inducing cardiovascular dysfunction as a result of Hb interacting with nitric oxide. Hb vesicles (HbV) are liposome-encapsulated purified human Hb with polyethylene glycol chains at the surface. This study evaluated the effects of HbV on hemodynamics, tissue and systemic oxygenation, and osmotic pressure after fluid resuscitation in an acute hemorrhagic shock model. ⋯ Fluid resuscitation using HbV/rHSA immediately increased MAP and cardiac index but not systemic vascular resistance, maintained a high level of oxygen consumption, and reduced the blood glucose level, which increased after hemorrhage. Fluid resuscitation using HbV/rHSA did not disturb microoxygenation in the brain, kidneys, liver, or muscle; allowed an immediate recovery of tissue oxygenation without decreasing cardiac output or increasing systemic vascular resistance, and increased the oxygen consumption. HbV solution offers the advantages of systemic oxygenation without impairing microcirculation in the treatment of hemorrhagic shock.
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Comparative Study
Dietary arginine enhances adhesion molecule and T helper 2 cytokine expression in mice with gut-derived sepsis.
This study investigated the effects of arginine (Arg) on cellular adhesion molecules and intracellular Th1/Th2 cytokine expressions in mice with polymicrobial sepsis. Myeloperoxidase activity in organs was also analyzed to identify the extent of tissue injury resulting from neutrophil infiltration. Mice were randomly assigned to a normal group (NC), a control group, or an Arg group. ⋯ These findings suggest that pretreatment with an Arg-supplemented diet enhances adhesion molecule and inflammatory cytokine expression during sepsis, which may aggravate the inflammatory reaction and increase neutrophil infiltration into tissues. In addition, Arg supplementation reduced intracellular interferon-gamma and enhanced IL-4 expression. This change may promote the Th2-type response and suppress the cellular immune response in gut-derived sepsis.