Hemorrhagic Shock Sensitized the Diaphragm to Ventilator-Induced Dysfunction through the Activation of IL-6/JAK/STAT Signaling-Mediated Autophagy in Rats.

Mechanical ventilation (MV) is a major life support technique for the management of trauma-associated hemorrhagic shock (HS). Ventilator-induced diaphragm dysfunction (VIDD), one of the most common complications of MV, has been well demonstrated in animal and human studies. However, few data are available concerning the effects of MV on diaphragm function in HS victims. In the present study, we found diaphragm muscle atrophy and weakness in HS but not in healthy animals after 4 hours of MV. The inhibition of autophagy resulted in reduced muscle fiber atrophy and improved forces. In addition, we observed diaphragmatic interleukin- (IL-) 6 overexpression and activation of its downstream signaling JAK/STAT in HS animals after MV, and either the neutralization of IL-6 or the inhibition of the JAK/STAT pathway attenuated autophagy, diaphragm atrophy, and weakness. Importantly, treatment with nonselective antioxidant exerted no protective effects against VIDD in HS animals. In addition, in vitro study showed that exogenous IL-6 was able to induce activation of JAK/STAT signaling and to increase autophagy in C2C12 cells. Moreover, the inhibition of JAK/STAT signaling abolished IL-6-induced cell autophagy. Together, our results suggested that HS sensitized the diaphragm to ventilator-induced atrophy and weakness through the activation of IL-6/JAK/STAT signaling-mediated autophagy in rats.

Effect of bed width on the quality of compressions in simulated resuscitation: a randomized crossover manikin study.

OBJECTIVES: To investigate the effects of bed width on the quality of chest compressions during simulated in-hospital resuscitation. METHODS: Each candidate performed two 2-minute cycles of compression-only cardiopulmonary resuscitation on an adult manikin placed on either an emergency stretcher (narrow bed) or a standard hospital bed (wide bed) in random order at 1 day intervals. We conducted subjective assessments of cardiopulmonary resuscitation quality and rescuer fatigue at the end of each session, using surveys. RESULTS: There were no significant differences between narrow and wide bed sessions in either mean depth or the percentage of compressions with adequate depth (P=.56 and .58, respectively). The mean rate of compressions and the percentage of compressions with adequate rate were also similar between sessions (P=.24 and .27, respectively). However, the percentage of correct hand position and complete chest recoil was significantly higher in the narrow bed session than in the wide bed session (P=.02 and .02, respectively). In addition, survey results showed that rescuers felt more comfortable and less exhausted in the narrow bed session compared with the wide bed session (P<.001 and < .001). CONCLUSIONS: When rescuers performed chest compressions on an emergency stretcher, chest compression quality increased, and the fatigue of rescuers decreased compared with a standard hospital bed. Therefore, we propose a narrow bed for critically ill inpatients with high risk of cardiac arrest.

Medical students do not adversely affect the quality of cardiopulmonary resuscitation for ED patients.

OBJECTIVES: To investigate the effect of medical student involvement on the quality of actual cardiopulmonary resuscitation (CPR). METHODS: A digital video-recording system was used to record and analyze CPR procedures for adult patients from March 2011 to September 2012. RESULTS: Twenty-six student-involved and 40 non-student-involved cases were studied. The chest compression rate in the student-involved group was significantly higher than that in the non-student-involved group (P < .001). The proportion of compressions at "above 110 cpm" was higher in the student-involved group (P = .021), whereas the proportion at "90-110 cpm" was lower in the student-involved group (P = .015). The ratio of hands-off time to total manual compression time was significantly lower in the student-involved group than in the non-student-involved group (P = .04). In contrast, the student-involved group delivered a higher ventilation rate compared with the non-student-involved group (P = .02). The observed time delay to first compression and first ventilation were very similar between the groups. There were no significant differences between the groups in either return of spontaneous circulation or time from survival to discharge. CONCLUSION: Student-involved resuscitation teams were able to perform good CPR, with higher compression rates and fewer interruptions. However, the supervision from medical staff is still needed to ensure appropriate chest compression and ventilation rate in student-involved actual CPR in the emergency department.

Protective effects of lipoxin A4 in testis injury following testicular torsion and detorsion in rats.

PURPOSE: To investigate the protective effects of lipoxin A4 (LXA4) in rat testis injury following testicular torsion/detorsion. METHODS: A rat testicular torsion model has been established as described. Rats were randomly divided into 6 groups: sham group, torsion group, torsion/detorsion (T/D) group, and T/D plus LXA4-pretreated groups (3 subgroups). Rats in LXA4-pretreated groups received LXA4 injection (0.1, 1.0, and 10 µg/kg body weight in LXA4-pretreated subgroups 1-3, resp.) at a single dose 1 h before detorsion. Biochemical analysis, apoptosis assessment, and morphologic evaluation were carried out after orchiectomies. RESULTS: GPx and SOD levels significantly increased and MDA levels significantly reduced in LXA4-pretreated groups compared to T/D group. LXA4 also reverted IL-2 and TNF- α to basal levels and improved the expression of IL-4 and IL-10 in LXA4-pretreated groups. Moreover, the expression of NF- κ B was downregulated in LXA4-pretreated groups. LXA4 treatment also showed an improved testicular morphology and decreased apoptosis in testes. CONCLUSION: Lipoxin A4 protects rats against testes injury after torsion/detorsion via modulation of cytokines, oxidative stress, and NF- κ B activity.

Fluid resuscitation with preventive peritoneal dialysis attenuates crush injury-related acute kidney injury and improves survival outcome.

BACKGROUND: In-hospital renal replacement therapy (RRT) is widely used for the treatments of acute kidney injury (AKI) in crush injury (CI) victims. This study was designed to investigate whether preventive peritoneal dialysis (PPD) is useful for renal protection in CI. METHODS: Animals received hindlimb compressions for 6 h to induce CI. Then, animals were untreated or treated with PPD and/or massive fluid resuscitation (MFR) for 8 h since the onset of compression release. Blood and renal tissue samples were collected at various time points for biological and morphological analysis. RESULTS: PPD attenuated lactic acidosis and reduced serum K+ and myoglobin levels in CI animals. In addition, PPD was effective in removing blood urea nitrogen (BUN) and creatinine, and reduced renal expressions of neutrophil gelatinase-associated lipocalin (NGAL). The combination of PPD and MFR furtherly attenuated AKI with significantly decreased histological scores (p = 0.037) and reduced NGAL expressions (p = 0.0002) as compared with the MFR group. Moreover, MFR + PPD group had a significantly higher survival rate than that in the MFR and the PPD groups (p < 0.05, respectively). CONCLUSION: The use of PPD at the onset of compression release is beneficial for renal protection and survival outcome in a rabbit model of CI.

Thalidomide Inhibits TGF-ß1-induced Epithelial to Mesenchymal Transition in Alveolar Epithelial Cells via Smad-Dependent and Smad-Independent Signaling Pathways.

Recent evidence indicates that the epithelial to mesenchymal transition (EMT) in primary alveolar cells (AECs) plays an important role in idiopathic pulmonary fibrosis (IPF). In vivo models have suggested that thalidomide (THL) has anti-fibrotic effects against pulmonary fibrosis, but the underlying mechanism of this effect is not clear. This study investigated whether THL regulates alveolar EMT and the possible mechanisms underlying this process. CCL-149 cells were treated with TGF-ß1 in the presence of THL at the indicated concentrations. EMT was assessed by changes in cell morphology and in phenotypic markers. Signaling pathways involved in EMT were characterized by western blot analysis. THL inhibited the TGF-ß1 induction of α-SMA, vimentin, MMP-2/-9 and collagen type IV expression and restored the morphological changes in primary alveolar epithelial cells caused by TGF-ß1. TGF-ß1 induction of α-SMA expression was partially dependent on the activation of p38, JNK, ERK, Akt, Smad 2 and Smad3. Moreover, THL inhibited TGF-ß1-induced phosphorylation of p38, JNK, ERK, Akt, GSK3ß, Smad 2 and Smad3 without altering the total expression levels of those proteins. These findings indicate that TGF-ß1-induced EMT in alveolar epithelial cells is inhibited by THL via both Smad-dependent and non-Smad-dependent signaling pathways and suggests therapeutic approaches for targeting this process in pulmonary fibrosis.

Kaempferol pretreatment modulates systemic inflammation and oxidative stress following hemorrhagic shock in mice.

BACKGROUND: Kaempferol has been reported as beneficial for both acute and chronic inflammatory diseases. This study aims to investigate whether kaempferol affects systemic inflammation and oxidative stress in the heart, lung, and liver after hemorrhagic shock in mice. METHODS: Male C57/BL6 mice underwent hemorrhagic shock (mean arterial pressure of 35 mmHg for 90 min) and were arbitrarily divided into Sham, hemorrhagic shock (HS), and Kae groups (n = 10 in each group). Mice in the Kae groups received a kaempferol (10-mg/kg body weight) injection 12 h prior to (Group Kae PT) or 90 min after (Group Kae T) the initiation of hemorrhagic shock. Plasma proinflammatory cytokines (TNF-α and IL-6), organ myeloperoxidase (MPO) and superoxide dismutase (SOD) activities, and organ malondialdehyde (MDA) concentrations and heme oxygenase-1 (HO-1) expression levels were assessed by enzyme-linked immunosorbent assay (ELISA) or western blot assay. RESULTS: Compared with the HS group and the Kae T group, pretreatment with kaempferol significantly decreased proinflammatory cytokines TNF-α (P = 0.012 and 0.015, respectively) and IL-6 (P = 0.023 and 0.014, respectively) following hemorrhagic shock. Kae pretreatment reverted MPO, SOD, and MDA to basal levels in the heart, lung, and liver (Ps < 0.05), while the Kae T group showed no significant differences in these biomarkers compared with the HS group (Ps > 0.05). HO-1 expression was significantly increased in the Kae PT group compared with the other groups (P = 0.011 vs. HS group and P = 0.02 vs. Kae T group). CONCLUSIONS: Pretreatment of hemorrhagic shock mice with kaempferol significantly decreased plasma levels of TNF-α and IL-6; reverted MPO, SOD, and MDA in the heart, lung, and liver; and increased expression of HO-1 in the same organs.

Roles of lipoxin A4 in preventing paracetamol-induced acute hepatic injury in a rabbit model.

The objective of this research is to investigate the potential role of lipoxin A4 in preventing paracetamol (PCM)-induced hepatic injury. One hundred male New Zealand white rabbits were randomly divided into control group, PCM group, N-acetylcysteine (NAC) group, lipoxin A4 (LXA4) group, and LXA4 + NAC group. The rabbits were assigned to receive 300 mg/kg weight PCM in 0.9 % saline or equivalent volume of saline via gastric lavage. LXA4 (1.5 µg/kg) and equivalent volume of 2 % ethanol were separately given to the rabbits in LXA4-treated and PCM groups 24 h after PCM administration. Meanwhile, the rabbits in the NAC-treated groups received a loading dose of 140 mg/kg of N-acetylcysteine. The blood samples and liver tissue were collected for biochemical and histological evaluation 36 h after paracetamol administration. The administration of LXA4 24 h after paracetamol poisoning resulted in significant improvement in hepatic injury as represented by decrease of hepatocellular enzyme release and attenuation of hepatocyte apoptosis and necrosis. In LXA4-treated groups, the expression of TNF-α was significantly lower than those in PCM and NAC groups (p < 0.05). In contrast, the level of IL-10 was significantly higher than PCM and NAC groups (p < 0.05). Moreover, the expressions of NF-κB p65 in PCM and NAC groups were significantly increased compared with those of LXA4-treated groups and control group (respectively, p < 0.05 and p < 0.01). LXA4-treated groups also showed significantly higher survival rates. Lipoxin A4 significantly mitigates paracetamol-induced hepatic injury, in which anti-inflammation effect may play an important role, leading to hepatic apoptosis and necrosis.

Early fluid resuscitation with hypertonic solution in a rat crush injury model.

AIM OF THE STUDY: The aim of the study was to evaluate the effects of bolus infusion of hypertonic hydroxyethyl starches (HHESs) and continuous infusion of hypertonic saline (HTS) in the early resuscitation in crush syndrome. METHODS: A rat model of crush injury was established. Rats were randomly divided into five groups: (1) HHES group, (2) HTS group, (3) volume resuscitation group, (4) normal resuscitation (NR) group, and (5) sham group. Blood samples were collected 6 h after the crush period for biochemical evaluation. Blood pressure was monitored throughout this experiment. Muscles and kidneys were evaluated morphologically 24 h after reperfusion. Twenty rats in each group were taken for survival observation for 72 h. RESULTS: Compared with the NR and HTS groups, the HHES group had significantly increased the survival rate 72 h after release (P < 0.05). In the first 2 h after release, mean arterial blood pressure in the HHES group was significantly higher than in HTS, volume resuscitation, and NR groups (respectively, P < 0.05). Animals that received HHES infusion showed a better acid-base balance and renal function. However, there was no significant difference in survival rate between the HTS and NR groups. Furthermore, animals in the HTS group showed a bad acid-base balance and a higher serum sodium level. CONCLUSIONS: Bolus infusion of HHES combined with normal saline could be an effective therapy for crush syndrome in the early resuscitation period. However, continuous HTS injection was not seemed to be a suitable choice particularly in the absence of monitoring equipment for serum irons or blood gases (institutional protocol no. ZN5R20110016).