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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Traumatic injury and its sequelae remains a major, unrecognized, public health problem in North America. It is the principle cause of death in patients aged 1-44 and the overall leading cause of life years lost in the United States. Recognizing this the National Heart, Lung and Blood Institute (NHLBI), in conjunction with other federal agencies, organized a conference in June 2000 to discuss the basic and clinical research projects that could lead to improved outcomes following cardiopulmonary or post-injury resuscitation. ⋯ A coordinated trauma research program should aim to replicate the success achieved by such programs; however, a centralized federal "home" for trauma research does not exist. Consequently, the existing limited research support is derived from NIH institutes in addition to other federal and state agencies. This report serves to describe some of the obstacles and to outline various strategies and priorities for basic science, clinical and translational trauma resuscitation research.
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Immune system cytokines induce vascular shock. Tumor necrosis factor-alpha (TNF-alpha), interleukin 1beta (IL-1beta), and bacterial endotoxin (E) circulate in human heatstroke to suggest that E release from a heat-damaged gut may stimulate cytokines that contribute to hypovolemia. However, immune activation by heat-induced tissue necrosis might stimulate cytokine generation in the absence of E. ⋯ IL-1srII expression was unchanged by PPHS and/or E. PPHS in the absence of E did not induce cytokine responses, nor were there elevations in TNF-alpha or IL-1beta mRNA. Thus, some factor normally absent under in vitro conditions, like endotoxin, was required to provoke HWB cytokine expressions and the heat stress and E conditions that characterize heatstroke affected HWB cytokine metabolism to favor a proinflammatory environment.
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Resuscitative interventions that improve mesenteric perfusion without causing instability in systemic arterial pressures may be helpful for improving trauma patient outcomes. Blocking angiotensin II formation with enalaprilat may be such an intervention. Two questions were addressed in this two-part study investigating resuscitation from hemorrhagic shock in dogs: Can systemic arterial pressures be maintained while administering a constant rate infusion of enalaprilat during resuscitation, and can enalaprilat improve cardiovascular status during resuscitation? Animals were hemorrhaged to a mean arterial pressure (MAP) of 40 to 45 mmHg for 30 min and then 30 to 35 mmHg for 30 min. ⋯ Corresponding increases were not observed in controls. We conclude that administration of a constant rate infusion of enalaprilat during resuscitation can be accomplished without causing a hypotensive crisis. Since enalaprilat significantly improved cardiovascular status including mesenteric perfusion even during intentional hypotension, it has potential value for improving the treatment of trauma patients.
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Hemorrhagic shock (HS) elicits an inflammatory response characterized by increased cytokine production and recruitment of PMN which we previously found to be iNOS dependent. In this study we attempted to remove excess induced-NO by administration of the NO scavenger, NOX, with the goal of suppressing proinflammatory signaling and reducing organ damage. Rats subjected to HS (MAP = 40 mmHg for 100 min) followed by resuscitation and examined 24 h later demonstrated histological signs of lung injury including pulmonary edema as well as an 8.6-fold increase in MPO-positive PMN. ⋯ Administration of NOX (30 mg/kg/h beginning at 60 min of shock for total of 4.5 h) resulted in reduced lung injury as measured by a 46% reduction in PMN infiltration, a 20% decrease in wet-to-dry ratio, and improved arterial blood gases. NOX reduced proinflammatory signaling in the lung as demonstrated by a 62% decrease in NF-kappaB binding, 47% reduction in Stat3 binding, a reduction in mRNA expression of 48% for IL-6, 57% for ICAM-1, 67% for IL-1beta, and 64% for TNFalpha, as well as a marked reduction in the intensity of IL-6 protein staining. These data indicate that NOX prevents lung injury in this HS model, possibly through downmodulation of proinflammatory signaling and the shock-induced inflammatory response.
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Sesquiterpene lactones are extracts of common medicinal Asteracae plants used in folk medicine for their anti-inflammatory activity. Recently, in vitro studies have shown that these compounds may interfere with pro-inflammatory gene regulation. This study examines the effects of parthenolide, a sesquiterpene lactone, in experimental myocardial ischemia and reperfusion. ⋯ Administration of parthenolide ameliorated myocardial injury, lowered serum creatine phosphokinase activity, and reduced neutrophil infiltration and the subsequent oxidative damage. These beneficial effects were associated with inhibition of IKK activity, enhanced stability of IkappaBalpha, and inhibition of nuclear translocation of NF-kappaB. The results of this study suggest that parthenolide may be beneficial for the treatment of reperfusion-induced myocardial damage by inhibition of the IKK/NF-kappaB pathway.