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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Heme oxygenase 1 (HO-1) is a cytoprotective enzyme upregulated by various critical illness-related stress stimuli. We investigated the association of HO-1 gene polymorphisms and plasma concentrations with the outcome of critically ill patients in a prospective cohort study of 231 critically ill patients admitted to tertiary care medical and medical-surgical intensive care units. Blood samples were collected on days 1, 2, and 3 to 4 in the intensive care unit. ⋯ The HO-1 plasma concentrations of study patients were significantly higher than the values of healthy controls at all time points (P < 0.001), and the first-day plasma HO-1 levels were independently associated with the Sequential Organ Failure Assessment score (P = 0.001). In conclusion, the HO-1 -413T/GT(L)/+99C haplotype is associated with HO-1 plasma levels and the frequency of multiple-organ dysfunction in critically ill patients. The HO-1 plasma concentrations are significantly increased among critically ill patients and associated with the degree of organ dysfunction.
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We compared the effects of a new compound (TV7130) with those of activated protein C (APC) in a large animal model of septic shock. Thirty-two fasted, anesthetized, invasively monitored, mechanically ventilated female sheep received 1.5 g/kg body weight of feces into the abdomen to induce sepsis. Immediately after feces injection, all animals received a bolus followed by a continuous infusion of saline (n = 8, bolus 1.5 mL for 15 min, infusion 1.5 mL/[kg·h]), low-dose TV7130 (n = 8; 0.4 mg/kg bolus, 0.4 mg/[kg·h] infusion), high-dose TV7130 (n = 8; 0.8 mg/kg bolus, 0.8 mg/[kg·h] infusion), or APC (n = 8; saline bolus, APC infusion of 0.024 mg/[kg·h]). ⋯ Functional capillary density and proportion of perfused vessels, evaluated in the sublingual region using sidestream dark-field videomicroscopy, were significantly higher in the TV7130 and APC groups than in the vehicle group at 16 h. Survival time was significantly longer in the high-dose TV7130 and APC groups than in the other groups (log-rank test, P = 0.0002). TV7130 has similar effects to APC and may be a promising agent for the management of severe sepsis.
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The authors aimed to test the hypothesis that xenon anesthesia limits adverse hypotensive effects of losartan during acute hemorrhage. In six conscious unsedated Beagle dogs, the systemic and pulmonary circulation were monitored invasively, and two subsequent 60-min hypotensive challenges were performed by (a) induction (propofol) and maintenance of anesthesia with isoflurane/remifentanil or xenon/remifentanil and by (b) subsequent hemorrhage (20 mL kg⁻¹ within 5 min) from a central vein. The same amount of blood was retransfused 1 h after hemorrhage. ⋯ Losartan potentiates hypotension induced by isoflurane/remifentanil anesthesia but does not affect the hemodynamic stability during xenon/remifentanil anesthesia. Losartan does not deteriorate the hemodynamic adaptation to hemorrhage of 20 mL kg⁻¹ during xenon/remifentanil and isoflurane/remifentanil anesthesia. Therefore, xenon/remifentanil anesthesia protects against circulatory side effects of losartan pretreatment and thus may afford safer therapeutic use of losartan during acute hemorrhage.
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The authors aimed to clarify the effects of hypercapnic acidosis and its timing on gastric mucosal oxygenation in a canine model of hemorrhage. This was designed as a prospective, controlled, randomized animal study set in a university research laboratory. Five chronically instrumented dogs were used. ⋯ Initial effects of hemorrhage in THE were comparable to CON (DO2 from 11 ± 2 mL·kg⁻¹·min⁻¹ to 8 ± 1 mL·kg⁻¹·min⁻¹; μHbO2 from 56% ± 7% to 43% ± 9%), but after application of hypercapnic acidosis, baseline levels were restored (DO2 10 ± 3 mL·kg⁻¹·min⁻¹; μHbO2 52% ± 14%). Hypercapnic acidosis applied before or after hemorrhage (THE) preserves microvascular mucosal oxygenation. If these experimental findings may be transferred to the clinical setting, deliberate hypercapnic acidosis could serve to augment oxygenation of the splanchnic region in states of compromised circulation, e.g., hemorrhage.
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To investigate the molecular mechanism underlying heme oxygenase-1 (HO-1)-modulated infiltration of neutrophils, the sepsis model of cecal ligation and puncture in Sprague-Dawley rats was used. In vivo induction and suppression of HO-1 were performed by pretreatment with cobalt protoporphyrin IX (CoPP) and zinc protoporphyrin IX, respectively. Tricarbonyldichlororuthenium(II) dimer, [Ru(CO)₃Cl₂]₂ (a carbon monoxide [CO] releaser), and hemoglobin (a CO scavenger) were used to examine the participation of HO-1/CO in the effect of CoPP pretreatment on formylated peptide (fMLP)-induced p38 mitogen-activated protein kinase (MAPK) phosphorylation. ⋯ Moreover, anisomycin diminished the suppressive effects of CoPP pretreatment on fMLP-induced migration, actin polymerization, polarization, and migration speed of neutrophils. These results suggest that HO-1 in neutrophil attenuates its infiltration during sepsis via the inactivation of p38 MAPK. Understanding the mechanism that diminishes neutrophil infiltration by HO-1 may help prevent hepatic failure during sepsis.