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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We have shown previously that bum trauma activates the stress responsive proteins, p38 mitogen-activated protein kinase (MAPK), c-jun NH2-terminal kinase (JNK), and NF-kappaB, and we have shown further that p38 MAPK is an important mediator of cardiomyocyte TNF-alpha secretion and cardiac dysfunction in burn trauma. Since burn trauma causes a rise in circulating catecholamine levels, we hypothesized that this increased sympathetic activity may function as an upstream activator of the p38 MARK pathway in burn trauma. This study determined whether the alpha1-adrenergic receptor ligand phenylephrine could mimic burn trauma activation of p38 MAPK, JNK, and NF-kappaB nuclear translocation; and the effect of the alpha1-adrenergic receptor antagonist prazosin on either phenylephrine or burn-mediated activation of the stress response pathway was examined. ⋯ Burn trauma activated cardiac p38 MAPK/JNK and NF-kappaB, increased TNF-alpha secretion by cardiomyocytes, and impaired cardiac function. Prazosin treatment in burns interrupted the burn-mediated signaling cascade, decreasing TNF-alpha secretion by cardiomyocytes and preventing post-burn cardiac contractile dysfunction. Thus, burn trauma-related sympathetic activity likely activates the stress-responsive cascade, which regulates myocardial TNF-alpha transcription/translation and culminates in cardiac contraction and relaxation defects.
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Recent studies have demonstrated gender differences in the immune response following hemorrhagic shock with an enhanced immune function and lower mortality following subsequent sepsis in females. Early interleukin-10 (IL-10) treatment has been shown to have beneficial effects on the depressed immune function in males, but not in females following shock. However, it remains unclear if the observed gender-related effect of IL-10 treatment results in an advantage following subsequent polymicrobial sepsis. ⋯ Early IL-10 treatment restored depressed proinflammatory immune response in males (TNF-alpha and PGE2), which was associated with an enhanced survival (P < 0.05) following subsequent sepsis as compared with placebo-treated mice (8/20 and 1/20, respectively). In contrast, the immune response and survival in females receiving IL-10 was not significantly changed, although females treated with IL-10 had a trend towards higher mortality (7/15 and 2/15, respectively; P = 0.08). Thus, early IL-10 anti-inflammatory treatment following hemorrhage has potential beneficial effects only in males associated with enhanced survival following subsequent sepsis.
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Comparative Study
Hypertonic saline improves intestinal mucosa barrier function and lung injury after trauma-hemorrhagic shock.
Our objective was to test the hypotheses that small volume hypertonic saline (HTS) resuscitation protects against trauma-hemorrhagic shock (T/HS)-induced intestinal and lung injury better than standard volume resuscitation with Ringer's lactate (RL), and that the degree of lung injury correlates with the degree of gut injury after therapy. Male Sprague-Dawley rats were subjected to laparotomy (trauma) and 90 min of T/HS or sham shock (T/SS), and were then resuscitated with RL or 7.5% NaCl solution at an equivalent sodium load. Intestinal and lung injury was assessed at 3 and 24 h after resuscitation. ⋯ Linear regression analysis revealed direct correlations between the percent of injured villi, increased lung permeability, and pulmonary neutrophil sequestration. Resuscitation with HTS ameliorated T/HS-induced gut and lung injury seen with RL resuscitation. These results, together with the direct correlation found between gut and lung injury, suggest that lung injury after T/HS may be mediated by gut injury.
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Base deficit has been established as a predictor of mortality and endpoint of resuscitation. We hypothesized that in a significant subset of surgical intensive care patients, base deficit is secondary to hyperchloremic acidosis, and that these patients experience lower mortality than those patients whose base deficits are secondary to other causes. Seventy-five consecutive surgical intensive care patients with base deficits greater than 2.0 were prospectively studied. ⋯ It is associated with lower mortality than base deficit secondary to other causes. Moreover, it is frequently induced following resuscitation with lactated Ringer's solution. Failure to properly diagnose this subset of acidotic patients may result in inappropriate clinical interventions due to the erroneous presumption of ongoing tissue hypoxia.
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The purpose of the study was to investigate the course of the zymosan-induced multiple organ dysfunction syndrome (MODS) in the absence of tumor necrosis factor (TNF) in a murine model. Tumor Necrosis Factor-alpha-lymphotoxin-a knockout (TNF/LT-/-) mice (n = 36) and wild-type (TNF/LT+/+) mice (n = 36) received 40 microg of lipopolysaccharide (LPS) intraperitoneally followed by zymosan at a dose of 1 mg/g body weight 6 days later (day 0). Animals were monitored daily for body weight and temperature and clinical symptoms. ⋯ Interestingly, besides mononuclear cells, inflammatory infiltrates in lungs and livers of TNF/LT+/+ but not of TNF-/- mice contained neutrophils. In conclusion, TNF-deficient mice exhibit significantly improved morbidity and mortality during zymosan-induced MODS. However, the absence of TNF does not completely protect against MODS in this murine model.