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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To investigate changes in protein expression by proteomic analysis in the sera of patients with sepsis and to identify new biomarkers of sepsis. A total of 45 consecutive patients with severe sepsis or septic shock (sepsis group), 22 healthy volunteers, and 23 patients undergoing off-pump coronary artery bypass grafting (control group). Serum samples from eight patients of each group underwent proteomic analysis involving removal of 12 major proteins and subsequent reversed-phase high-performance liquid chromatography fractionation and one-dimensional electrophoresis. ⋯ A positive correlation between sYKL-40 and blood IL-6 level on ICU admission was noted in the sepsis group (r = 0.465, P < 0.01). YKL-40 identified by proteomic analysis is considered as a biomarker of sepsis. However, further investigation is needed to clarify its roles and clinical usefulness as a biomarker.
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The purpose of the present study was to test the hypothesis that endogenous NO negatively affects translation in skeletal muscle cells after exposure to a combination of endotoxin (LPS) and interferon-gamma (IFN-gamma). Individually, LPS and IFN-gamma did not alter protein synthesis, but in combination, they inhibited protein synthesis by 80% in C2C12 myotubes. The combination of LPS and IFN-gamma dramatically downregulated the autophosphorylation of the mammalian target of rapamycin and its substrates S6K1 and 4EBP-1. ⋯ LPS/IFN-gamma downregulated the phosphorylation of multiple Akt substrates, including the proline-rich Akt substrate 40, while enhancing the phosphorylation of raptor on a 5'-AMP-activated kinase (AMPK)-regulated site. The negative effects of LPS/IFN-gamma were blunted by the AMPK inhibitor compound C. The data suggest that, in combination, LPS and IFN-gamma induce a prolonged expression of NOS2 and excessive production of NO that reciprocally alter Akt and AMPK activity and consequently downregulate translation via reduced mammalian target of rapamycin signaling.
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Hypotensive resuscitation prolongs survival of patients with severe bleeding until they can undergo hemorrhage control. However, its value is limited by continuing ischemic injury. Purified poloxamer 188 (P188), a copolymer with rheological and cytoprotective activities, was known to reduce mortality of hemorrhagic shock when used as an adjunct to full resuscitation with fresh whole blood and crystalloid. ⋯ Additional studies demonstrated that P188 increased survival from 0% to 75% in 50% volume-controlled hemorrhage (P < 0.001). Finally, P188 did not increase bleeding in uncontrolled hemorrhage produced by 75% tail amputation. Because P188 prolongs survival, decreases fluid requirements, and reduces tissue damage, it deserves further consideration as an adjunct to hypotensive resuscitation.
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Liver dysfunction affects a variety of metabolic pathways in the critically ill, but mechanisms remain poorly understood. We prospectively assessed markers of hepatic injury and function in sepsis and I/R injury in vivo and molecular mechanisms in human liver tissue ex vivo. Markers of hepatocellular injury, synthesis, and excretion, including plasma disappearance rate of indocyanine green (ICG), were measured in 48 patients with severe sepsis. ⋯ In conclusion, standard liver tests lack the required sensitivity to assess hepatic injury and function in the critically ill. Dye excretion better reflects excretory and/or microvascular dysfunction but still underestimates impaired canalicular transport. The observed differential susceptibility of the polar surfaces of human hepatocytes has potential implications for monitoring liver function and drug-induced liver injury.
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The vasoconstrictive and proinflammatory peptide endothelin 1 (ET-1) is highly involved in the pathogenesis of sepsis and associated lung injury. Systemic administration of ET-receptor antagonists has been beneficial in experimental pulmonary hypertension. We wanted to study the effects of inhaled tezosentan, a dual endothelin-receptor antagonist on endotoxin-induced pulmonary hypertension, deterioration of gas exchange, and edema formation. ⋯ Despite similar effects on pulmonary hypertension systemic treatment resulted in significantly higher plasma levels of ET-1 (twofold) and tezosentan (10- to 100-fold). Inhalation of the dual ET-receptor antagonist tezosentan was feasible and efficiently counteracted endotoxin-induced pulmonary hypertension. These effects were obtained with only minor systemic uptake of tezosentan and without affecting circulating levels of plasma ET-1 as compared with intravenous administration.