The Journal of surgical research
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Effects of lisofylline (1-(5-R-hydroxyhexyl)-3,7-dimethylxanthine), a functional inhibitor of phosphatidic acid (PA) generation derived from de novo synthesis, on neutrophil function were examined in a porcine sepsis model. Hanford minipigs (18-25 kg) were randomly separated into six groups of six animals each: (1) saline control group; (2) sepsis control group, infused with Pseudomonas aeruginosa (1 x 10(6) colony-forming units/kg/min) for 2 h; (3) lisofylline control group, given a 25 mg/kg bolus of lisofylline 30 min prior to time zero, followed by a continuous infusion of 10 mg/kg/h throughout the study; (4) lisofylline pretreatment sepsis group, given lisofylline 30 min prior to sepsis, (5) lisofylline 1-h post-treatment sepsis group, and (6) lisofylline 2-h post-treatment sepsis group. All animals were studied for 6 h. ⋯ Sepsis caused neutropenia, pretreatment produced neutrophilia, and 1-h post-treatment caused the neutropenia to recover to control levels. Interestingly, toward the end of the 6-h period, the neutrophil count was higher in the lisofylline control group than in the saline control groups. Thus, the inhibition of PA generation from de novo synthesis during sepsis not only can selectively downregulate some neutrophil functions but can also reverse neutropenia.
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Activated neutrophils play an important role in reperfusion injury following hepatic ischemia. Neutrophil elastase is a powerful proteolytic enzyme. We investigated the possibility that ONO-5046. ⋯ Histologically, widely spread hepatocyte necrosis was found in dogs in the nontreatment group that died prematurely. Neutrophil infiltration of the sinusoids was less evident in the ONO group than in the nontreatment group. Neutrophil elastase inhibitor may prevent injuries of both endothelial and parenchymal cells in extended hepatectomy with vascular occlusion.
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Burn injury delays allograft rejection and impairs the host defense against infection. These functions are mediated via the cytotoxic T-lymphocyte (CTL) response. The CTL response is divided into antigen recognition/processing and effector phases. Presensitization allows selective analysis of changes, induced by burn injury, in the effector limb of the CTL response in relation to time and burn size. ⋯ Burn injury impairs the effector limb of the CTL response as a function of burn size in the immediate postburn period. CTL activity returns to baseline within 7-10 days postburn and has a rebound increase by Day 14. Early CTL suppression, after burn injury, may be due to a decrease in the T-helper subpopulation. The late increase in cytotoxicity may be secondary to an increase in the effector CTL population in the late postburn period. Burn injury causes a T-helper-2 phenotype as demonstrated by depressed IL-2 and IFN-gamma production and increased IL-5 production.
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To identify vascular beds where endogenous adenosine plays a significant role as a mediator of resting perfusion alterations associated with sepsis, we tested the hypothesis that adenosine receptor blockade would cause differential regional increases in vascular resistance during intraperitoneal (ip) sepsis in the rat. ⋯ These data suggest that adenosine receptor-mediated actions during sepsis affect vascular beds selectively and indicate a significant role for adenosine in resting perfusion redistribution in sepsis.
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Endothelial cells (EC) are important for regulating the hemostatic balance of prothrombotic and antithrombotic activities. Proinflammatory cytokines such as tumor necrosis factor-alpha (TNFalpha) play an important role in the regulation of EC and also regulate the production of plasminogen activator inhibitor type 1 (PAI-1), which is an EC-producing factor with the inhibitory activity of fibrinolysis, and the expression of intercellular adhesion molecule-1 (ICAM-1), which is an adhesion molecule that plays an important role in inflammation. Protease inhibitors such as gabexate mesilate (GM) and ulinastatin (UTI) have been shown to improve the microcirculatory environment and reduce tissue damage, but the mechanism for this has yet to be fully elucidated. We investigated the effect of GM or UTI on EC regarding PAI-1 synthesis and ICAM-1 expression. ⋯ These data suggest that GM may thus provide a beneficial effect which improves the microcirculatory environment and prevents tissue damage by inhibiting the activation of the vascular EC themselves.