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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Red blood cell distribution width (RDW) is known to be a predictor of severe morbidity and mortality in some chronic diseases such as congestive heart failure. However, to our knowledge, little is known about RDW as a predictor of mortality in patients with Gram-negative bacteremia, a major nosocomial cause of intra-abdominal infections, urinary tract infections, and primary bacteremia. Therefore, we investigated whether RDW is an independent predictor of mortality in patients with Gram-negative bacteremia. ⋯ In addition, the area under the curve of RDW at the onset of bacteremia, the 72-h RDW, and the Sequential Organ Failure Assessment score for 28-day mortality were 0.764 (P = 0.001), 0.802 (P < 0.001), and 0.703 (P = 0.008), respectively. Red blood cell distribution width at the onset of bacteremia was an independent predictor of mortality in patients with Gram-negative bacteremia. Also, 72-h RDW could be a predictor for all-cause mortality in patients with Gram-negative bacteremia.
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Alterations in the activity of vascular K channels are commonly associated with abnormalities in cerebral vascular function after subarachnoid hemorrhage (SAH). Subarachnoid hemorrhage-induced vasospasm remains incompletely understood; nevertheless, activation of K channels may be of benefit in relieving spastic constriction. This study was to examine whether the vasodilators KMUP-1 and pinacidil, a KATP-channel opener, have the ability to prevent SAH-induced vasospasm via the large-conductance Ca-activated K (BKCa) channels in cerebral arteries. ⋯ Subarachnoid hemorrhage-induced deficits in motor function and BKCa-channel inhibition were improved by KMUP-1-treated and pinacidil-treated rats. In addition, SAH appears to modify BKCa-channel calcium sensitivity. KMUP-1 and pinacidil prevent SAH-induced vasospasm at least in part by the restoration of BKCa-channel activities.
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Previous studies have shown that PI3K/GSK-3β/β-catenin signaling pathway plays a vital role in ischemic preconditioning. The present study attempts to evaluate whether PI3K/GSK-3β/β-catenin signaling pathway might be responsible for the cardioprotection in ischemic postconditioning. Male Sprague-Dawley rats underwent 30 min of left anterior descending coronary artery occlusion and 2 h of reperfusion. ⋯ It was found that Post and SB + I/R reduced infarct size (32.3% [SD, 2.8%], 32.7% [SD, 2.1%], vs. 53.4% [SD, 3.2%], respectively, P < 0.05) and apoptotic index of cardiomyocytes (23.2% [SD, 1.8%], 23.8% [SD, 1.8%], vs. 47.3% [SD, 5.8%], respectively, P < 0.05); compared with I/R, wortmannin abolished the cardioprotection of ischemic postconditioning. Post and SB + I/R increased phosphorylated Akt, phosphorylated GSK3β, β-catenin in cytosol and nucleus, and Bcl-2 expression versus I/R. These results indicate that ischemic postconditioning could induce myocardial protection via PI3K/GSK-3β/β-catenin signaling pathway, activation of which results in accumulation of β-catenin and upregulation of its target genes Bcl-2.
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The use of liposome-encapsulated hemoglobin (LHb), which is a cellular Hb, has been demonstrated to be beneficial in the treatment of hypohemoglobinemic shock. As a molecule of appropriate size (220 nm) that can carry oxygen, LHb may ameliorate cardiac dysfunction during lethal hemodilation. The purpose of this study was to determine the efficacy of LHb transfusion in relieving cardiovascular dysfunction in a rat model of lethal progressive hemodilution. ⋯ More than 80% of the rats transfused with either LHb or washed rat red blood cells survived for 8 days. Liposome-encapsulated hemoglobin transfusion suppressed hypoxia-inducible factor 1α expression in the heart, maintained low levels of heart-type fatty acid-binding protein, and attenuated sympathetic nerve activity as reflected by changes in heart rate variability and plasma levels of epinephrine and norepinephrine. The results indicate that LHb attenuates cardiac dysfunction and sympathetic overactivity during lethal hemorrhage.
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The aim of the present study was to investigate the effects of lipopolysaccharide (LPS) on the contractile response induced by electrical field stimulation (EFS) in rat mesenteric segments, as well as the mechanisms involved. Effects of LPS incubation for 2 or 5 h were studied in mesenteric segments from male Wistar rats. Vasomotor responses to EFS, nitric oxide (NO) donor DEA-NO, and noradrenaline (NA) were studied. ⋯ Short-term exposure of rat mesenteric arteries to LPS produced a time-dependent enhanced contractile response to EFS. The early phase (2 h) was associated to a reduction in NO from neuronal NO synthase and an enhanced response to NA. After 5 h of LPS exposure, this enhancement was reduced, because of restoration of the adrenergic component and maintenance of the nitrergic reduction.