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 purpose of this study was to evaluate the prognostic significance of classification of patients with septic shock into different critical illness-related corticosteroid insufficiency subgroups. A retrospective observational study was conducted in patients with septic shock who underwent a short corticotropin stimulation test within 72 h of the onset of shock. Patients were classified into normal adrenal function (NOM), low basal cortisol (LBC) (basal cortisol, <10 μg/dL), or low Δ cortisol (LDC) (basal cortisol, ≥10 μg/dL; cortisol, <9 μg/dL) groups. ⋯ The 28-day mortalities of the NOM, LBC, and LDC groups were 40.5%, 38.5%, and 63.2%, respectively (P = 0.007). Classification into the LDC group significantly increased the odds of 28-day mortality (odds ratio, 2.717; 95% confidence interval, 1.452-5.082; P = 0.002) and remained an independent risk factor for mortality even after controlling for all the other potential risk factors identified (odds ratio, 3.638; 95% confidence interval, 1.418-9.028; P = 0.006). Classification into the LDC group is an independent risk factor for mortality in hydrocortisone-treated septic shock patients.
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Endotoxin, an outer membrane component of gram-negative bacteria, plays an important role in the pathogenesis of septic shock. Endotoxin adsorption therapy by polymyxin B-immobilized fiber column hemoperfusion (PMX) has been used for the treatment of septic shock patients in Japan since 1994. The covalent binding of polymyxin B onto the surface of the polystyrene-based carrier fiber in PMX inactivates the endotoxin in the blood without exerting toxicity. ⋯ These beneficial effects may be attributable to the direct adsorption of endotoxin, monocytes, activated neutrophils, and anandamide, as well as indirect decrease in inflammatory cytokines and other mediators. Polymyxin B-immobilized fiber column hemoperfusion treatment has additional effects on reducing endothelial damage, proapoptotic activity, and immunosuppression. Further studies will be needed to confirm the efficacy and mechanism of PMX treatment in septic shock.
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The contribution of the adaptive and innate immune systems to the pathogenesis and outcome of sepsis remains a fundamental yet controversial question. Here, we use mice lacking the recombination activating gene 1 (Rag-1) to study the role of T and B cells in sepsis after cecal ligation and puncture (CLP). Spleens of Rag-1 mice were atrophic and completely devoid of CD3 T cells and CD19 B cells. ⋯ Levels for most mediators were unaffected by the absence of T and B lymphocytes. Only the concentrations of IL-6 and IL-17 were found to be significantly lower in Rag-1 mice compared with wild-type mice. In conclusion, the absence of T and B cells in the CLP model used does not appear to affect the acute outcome of severe sepsis.
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Glucocorticoids serve as important therapeutic agents in diseases of inflammation, but clinical use, especially in advanced septic shock, remains controversial because of the unpredictable response. Prior studies correlate human glucocorticoid receptor (hGR) isoforms with a decreased response to steroid therapy. Further analysis of additional hGR isoforms may improve the understanding of the steroid response. ⋯ Transactivation studies revealed a SNP within the ligand-binding domain exerted the greatest influence over hyperactivity. In evaluating the response to hydrocortisone, hGR NCBI and hGR NS-1 displayed an increased dose-dependent response, but hGR NS-1 had a response more than twice hGR NCBI. Characterization of the novel hyperactive hGR NS-1 provides insight into a possible mechanism underlying the unpredictable response to steroid treatment.
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We investigated the effect of the angiotensin-converting enzyme (ACE) inhibitor captopril in a clinically relevant ovine model of smoke and burn injury, with special reference to oxidative stress and activation of poly(ADP-ribose) polymerase, in the lung and in circulating leukocytes. Female, adult sheep (28-40 kg) were divided into three groups. After tracheostomy and under deep anesthesia, both vehicle-control-treated (n = 5) and captopril-treated (20 mg/kg per day, i.v., starting 0.5 h before the injury) (n = 5) groups were subjected to 2 × 20%, third-degree burn injury and were insufflated with 48 breaths of cotton smoke. ⋯ Our results suggest that the ACE inhibitor captopril exerts beneficial effects on the pulmonary function in burn/smoke injury. The effects of the ACE inhibitor may be related to the prevention of reactive oxygen species-induced poly(ADP-ribose)polymerase overactivation. Angiotensin-converting enzyme inhibition may also exert additional beneficial effects by inhibiting the expression of the profibrotic mediator transforming growth factor β.