Mitochondrial aldehyde dehydrogenase 2 alleviates septic liver injury by inhibiting ferroptosis in mouse model / 中华危重病急救医学

OBJECTIVE@#To observe the ferroptosis triggered by in different pathways during cecal ligation and puncture (CLP)-induced liver injury in septic mice, and to investigate whether mitochondrial aldehyde dehydrogenase 2 (ALDH2) can alleviate sepsis-induced liver injury by inhibiting ferroptosis.@*METHODS@#Sixty 8-week-old male C57BL/6J mice were randomly divided into sham operation group (Sham group), CLP group, ferroptosis inhibitor ferrostain-1 (Fer-1) group, ALDH2-specific agonist Alda-1 group, iron chelator deferasirox Fe3+ chelate (DXZ) group and dimethyl sulfoxide (DMSO) group, with 10 mice in each group. The septic liver injury was induced by CLP in mice model. In the Sham group, only laparotomy was performed without ligation and puncture of the cecum. 10 mL/kg 5% DMSO, 5 mg/kg Fer-1, 50 mg/kg DXZ and 10 mg/kg Alda-1 were injected intraperitoneally 1 hour before CLP in the DMSO, Fer-1, DXZ and Alda-1 groups respectively. At 24 hours after operation, eyeball blood and liver tissue were collected from anesthetized mice. The hepatic structure and inflammatory infiltration were observed by hematoxylin-eosin (HE) staining. The levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST) in serum, the levels of hepatic malondialdehyde (MDA), superoxide dismutase (SOD) and reactive oxygen species (ROS) were detected. Western blotting was used to detect the protein expressions of ALDH2, ferroptosis-related proteins glutathione peroxidase 4 (GPX4), ferroptosis suppressor protein 1 (FSP1) and transferrin receptor 1 (TFR1) in liver tissue.@*RESULTS@#Compared with Sham group, the mice in CLP group showed varying degrees of congestion, disorganized hepatocyte arrangement, inflammatory cell infiltration at 24 hours after operation. Compared with the CLP group, the mice in the Fer-1 group, DXZ group and Alda-1 group liver morphology, liver injury and inflammatory cell infiltration was improved. Compared with Sham group, the serum levels of ALT and AST, the contents of MDA and ROS, and the expression of TFR1 protein in CLP group were significantly increased, while the activity of SOD and the expressions of ALDH2, GPX4 and FSP1 protein in CLP group were significantly decreased. Compared with CLP group, serum ALT and AST levels in Fer-1, DXZ and Alda-1 groups were significantly decreased [ALT (U/L): 45.76±10.81, 37.30±2.98, 36.40±12.75 vs. 73.06±12.20, AST (U/L): 61.57±2.69, 52.41±6.92, 56.05±8.29 vs. 81.59±5.46, all P < 0.05], and the contents of MDA, ROS and TFR1 protein expression in liver tissue were significantly decreased [MDA (μmol/L): 0.60±0.10, 0.57±0.18, 0.83±0.39 vs. 1.61±0.30, ROS (fluorescence intensity): 270.34±9.64, 276.02±62.33, 262.05±18.55 vs. 455.38±36.07, TFR1/GAPDH: 0.90±0.04, 1.01±0.09, 0.55±0.08 vs. 1.18±0.06, all P < 0.05], and the SOD activity and ALDH2, GPX4 and FSP1 protein expressions in liver tissue were significantly increased [SOD (kU/g): 88.77±8.20, 88.37±4.47, 93.43±7.24 vs. 50.27±3.57, ALDH2/GAPDH: 1.10±0.15, 1.02±0.07, 1.14±0.07 vs. 0.70±0.04, GPX4/GAPDH: 1.02±0.12, 0.99±0.08, 1.05±0.19 vs. 0.71±0.10, FSP1/GAPDH: 1.06±0.24, 1.02±0.08, 0.93±0.09 vs. 0.66±0.03, all P < 0.05]. There was no significant difference in the parameters between DMSO group and CLP group.@*CONCLUSIONS@#Both GPX4 and FSP1 mediated ferroptosis are involved in liver injury in septic mice. Activation of ALDH2 and inhibition of ferroptosis can alleviatehepatic injury. ALDH2 may play a protective role by regulating FSP1 and GPX4 mediated ferroptosis.

Application value of high-flow nasal cannula oxygen therapy in patients with moderate acute respiratory failure / 中华急诊医学杂志

Objective:To evaluate the effect of high-flow nasal cannula (HFNC) therapy on patients with moderate acute respiratory failure.Methods:This was a randomized controlled trial. The patients with moderate acute respiratory failure in the Intensive Care Unit (ICU) of Changshu Hospital Affiliated to Soochow University from March 2019 to September 2020 were included. Patients with severe asthma or acute exacerbation of chronic respiratory failure, hemodynamic instability, disturbance of consciousness, non-invasive ventilation (NIV) contraindication, urgent need for endotracheal intubation, refusal of intubation, age <18 years and pregnancy were excluded. The patients were randomized to HFNC or NIV. Treatment failure was defined as the need for intubation and invasive ventilation. The vital signs, ROX index, blood gas analysis index, ultrasound parameters and endotracheal intubation rate were recorded at 1, 6, 12, 24 and 48 h after treatment. Kaplan-Meier method was used to draw the survival curve, and multivariate logistic regression was used to analyze the risk factors of treatment failure.Results:A total of 91 patients were included in the study, including 46 patients in the HFNC group and 45 patients in the NIV group. PaO 2/FiO 2 of the two groups were significantly increased after treatment compared with baseline ( P<0.05). The respiratory rate was lower in the NIV group than in the HFNC group at 1 and 24 h ( P<0.05). There were no significant differences in other vital signs, arterial blood gas and ultrasound parameters between the two groups (all P>0.05). The intubation rate was 52.2% in the HFNC group and 48.9% in the NIV group. Kaplan-Meier survival analysis showed that there was no significant difference in intubation rate and mortality between the two groups ( P>0.05). Multivariate logistic regression analysis showed that increased end-diastolic right ventricle/left ventricle ratio ( OR=1.044, 95% CI: 1.012~1.077) and high acute physiology and chronic health evaluationⅡ score ( OR=1.082, 95% CI: 1.006~1.163) at 0 h, lung ultrasound score ( OR=1.353, 95% CI: 1.034~1.772) and end-diastolic RV/LV ratio ( OR=1.097, 95% CI: 1.038~1.159) at 1 h were independent risk factors for non-invasive respiratory strategies failure. Increased diaphragm excursion ( OR=0.341, 95% CI: 0.165~0.704) at 0 h, high PaO 2/FiO 2 ( OR=0.929, 95% CI: 0.884~0.977), increased ROX index ( OR=0.524, 95% CI: 0.332~0.826), and increased diaphragm mobility ( OR=0.119, 95% CI: 0.030~0.476) at 1 h were independent protective factor for successful treatment. Conclusions:HFNC and NIV can improve oxygenation in patients with acute hypoxemic respiratory failure. There is no significant difference in intubation rate and mortality between HFNC and NIV. Ultrasound parameters may be helpful for predicting treatment failure.

The value of acute gastrointestinal injury grading combined with qSOFA score in the diagnosis of sepsis / 中华急诊医学杂志

Objective:To develop a prediction model of acute gastrointestinal injury (AGI) grading combined with qSOFA score for the diagnosis of sepsis, and evaluate its value.Methods:This was a prospective observational study. The patients with infection or suspected infection in the General Ward of Changshu Hospital Affiliated to Soochow University from September 2018 to September 2019 were included. Patients younger than 18 years, pregnant, abandoned treatment and died within 3 days after admission were excluded. Clinical characteristics, laboratory test results and AGI grading from 48 h before the infection to 24 h after the onset of infection were recorded. The patients were divided into the sepsis and non-sepsis groups according to whether they were diagnosed with sepsis. The patients were allocated randomly to a modeling cohort and a validation cohort with a ratio of 7:3. Univariate and multivariate logistic regression analyses were used to analyze the relevant risk factors for sepsis in the modeling cohort. Three types of diagnostic models were constructed in the modeling cohort: model A (qSOFA model), model B (the combined model of AGI grading and qSOFA score), and model C (the combined model of clinical parameters). The clinical usefulness of the diagnostic models was assessed by receiver operating characteristic curve (ROC), calibration curve and decision curve analysis (DCA) in the validation cohort. The nomograms were developed based on these models.Results:A total of 2 553 patients were enrolled in the study, 1 789 patients in the modeling cohort and 764 patients in the validation cohort. and 326 were diagnosed with sepsis. There was no statistical difference in the basic conditions of patients in the two groups. Univariate analysis showed that age, gender, the source of infection, temperature, heart rate, polypnea, changes in consciousness, severe edema, hyperglycemia, white blood cell, C-reactive protein and procalcitonin, hypotension, hypoxemia, acute oliguria, coagulation disorders, hyperlacticemia, capillary filling damage or piebaldskin, AGI grading and qSOFA score were significantly correlated with sepsis (all P<0.01). Multivariate logistic regression analysis showed that age ( OR=1.027, P<0.01), source of infection ( OR=2.809, P=0.03), hypotension ( OR=35.449, P<0.01), hypoxemia ( OR=57.018, P<0.01), and AGI grading ( OR=19.313, P<0.01) were significantly associated with sepsis. ROC analysis showed that the area under the curve (AUC) of model A, B and C were 0.784, 0.944 and 0.971 in the modeling cohort, and 0.832, 0.975 and 0.980 in the validation cohort, respectively. The sensitivities were 63.9%, 89.5% and 97.5% in the modeling cohort, and 72.7%, 90.9% and 96.6% in the validation cohort; and the specificities were 90.8%, 90.3% and 88.1% in the modeling cohort, and 92.2%, 94.5% and 92.8% in the validation cohort, respectively. AUC of model B and C were significantly higher than that of model A ( P<0.01). Model A in the validation cohort was poorly calibrated, with low accuracy and high risk of missed sepsis diagnosis ( P=0.044). The net benefits of model B and C were better than that of model A. Conclusions:AGI grading combined with qSOFA score has a high predictive value and accuracy in the diagnosis of sepsis.

Investigation on compliance with sepsis bundle and outcomes in patients with septic shock in Changshu area / 中华急诊医学杂志

Objective:To investigate the rate of compliance with sepsis Bundle and outcomes in patients with septic shock in intensive care units (ICU) in Changshu area.Methods:A multi-center retrospective study was conducted on patients who were diagnosed as septic shock in ICU of three hospitals in Changshu area from January 2014 to October 2017. Patients who were diagnosed as septic shock meeting the 2016 diagnostic criteria were enrolled. The exclusion criteria were paients younger than 18 years, pregnancy, death within 6 h of admission, halfway abandoned treatment, and those who had entered other studies on septic shock intervention. Clinical characteristics, past history, situation on admission, Bundle completion at 1 h, 3 h and 6 h, and prognosis were recorded. Patients were divided into the survival group and death groups according to whether they survived or not. The differences of completion of Bundle indicators between the two groups were compared. The independent risk factors of prognosis were analyzed by Logistic regression analysis, and the survival curve was plotted by Kaplan-Meier method.Results:Totally 207 patients from 3 hospitals were enrolled in this study. The complition rate of 1 h Bundle was 27.1%, of which the completion rate of serum lactate determination was 81.2%, the completion rate of blood culture before antibiotic administration was 72.5%, the completion rate of broad-spectrum antibiotic administration was 48.4%, the completion rate of fluid resuscitation was 74.4%, and the completion rate of vasopressors to maintain MAP≥65 mmHg was 86.0%; the completion rate of 3 h Bundle was 67.6%, of which the completion rate of serum lactate determination was 97.1%, the completion rate of blood culture before antibiotic administration was 84.5%, the completion rate of broad-spectrum antibiotic administration was 97.1%, and the completion rate of fluid resuscitation was 76.8%; the completion rate of 6 h Bundle was 30.4%, of which the completion rate of vasopressors to maintain MAP≥65 mmHg was 98.1%, the completion rate of reassessed volume stasis (at least two indexes) was 48.3%, the completion rate of central venous pressure (CVP) was 42.5%, the completion rate of ScvO 2 was 10.6%, the completion rate of bedside ultrasound was 48.8%, the completion rate of passive leg raising and rehydration therapy was 42.5%, and the completion rate of re-evaluation of lactate was 55.1%. The total Bundle completion rate at 3 h and 6 h was 27.1%. There was no significant difference in the completion of the three hospitals. The mortality of patients with septic shock was 58.9%, length of stay in the ICU was 10 d (5, 23) d, and length of hospital stay was 14 d (6, 26) d. Univariate analysis showed that antibiotic use time, CVP, bedside ultrasound, passive leg raising and rehydration experiments, re-evaluation after elevated lactate, 6 h Bundle completion, total Bundle completion at 3 and 6 h, and APACHE Ⅱ score were associated with the prognosis (all P<0.01). Logistic regression analysis showed that CVP ( OR=23.236, P=0.001), passive leg raising and rehydration experiments ( OR=0.102, P=0.012), re-evaluation after elevated lactate ( OR=0.197, P=0.001) and APACHEⅡ score ( OR=1.103, P<0.01) were risk factors of the prognosis. Kaplan-Meier analysis showed that the 28 d survival rate was significantly higher if 6 h Bundle was completed (Log Rank χ 2=8.944, P=0.003). Conclusions:The compliance with sepsis Bundle is not high in Changshu area, and the compliance is closely related to the prognosis, so it needs to improve compliance with the guidelines.

Activation of aldehyde dehydrogenase 2 alleviates H O -induced injury in cardiomyocytes / 南方医科大学学报

<p><b>OBJECTIVE</b>To investigate the changes of aldehyde dehydrogenase 2 (ALDH2) expression in H O inducedcardiomyocytes oxidative stress injury.</p><p><b>METHODS</b>Cultured H9C2 cardiomyocytes were exposed to H O -inducedoxidative stress and the effects of the ALDH2 agonist Alda-1 and ALDH2 inhibitor Daidzin were tested on the stress level ofthe exposed cells. MTT colorimetric assay was used to assess the cell viability after the treatments. The oxidative stress level inthe myocardial cells was detected using DHE fluorescence staining, and the activity and protein level of ALDH2 were detectedwith spectrophotometry and Western blotting.</p><p><b>RESULTS</b>Compared with normal control cells, Alda-1 treatment did notsignificantly affect the cell viability, oxidative stress level, or ALDH2 activity and protein level. H O exposure significantlylowered the cell activity and ALDH2 activity and protein expression and increased the oxidative stress level; Alda-1 treatmentobvious antagonized the effects of H O . Blocking ALDH2 with Daidzin produced similar effects to H O exposure on theviability, oxidative stress level, and ALDH2 activity and expression in the myocardial cells.</p><p><b>CONCLUSIONS</b>H O exposure lowersthe activity and reduces the protein expression of ALDH2 in cardiomyocyte H9C2 cells, and activation of ALDH2 can alleviateH O -induced oxidative stress in the cells.</p>

A clinical study of hemoperfusion on extravascular lung water and other related factors of patients with septic shock / 中国中西医结合急救杂志

Objective To explore the therapeutic effect of combining continuous venovenous hemofiltration (CVVH) with hemoperfusion (HP) on patients with septic shock.Methods A prospective study was conducted. Thirty-two patients with septic shock admitted to Changshu No.1 People's Hospital were enrolled, and they were divided into two groups according to random digits table. The observation group (17 cases) was given HP before CVVH, in the control group (15 cases), only CVVH treatment was carried out, and lasting for 5 days in both groups. The changes of pulse oxygen saturation (SpO2), central venous pressure (CVP), systemic vascular resistance index (SVRI), cardiac index (CI), extra-vascular lung water index (EVLWI) were observed before treatment and 5 days after treatment.Results Compared with those before treatment, the levels of SpO2, CVP, SVRI, CI were obviously elevated, and EVLWI was markedly decreased after treatment in two groups. Compared with those of control group, the degrees of improvement of above indicators in observation group were more prominent [SpO2: 0.966±0.035 vs. 0.939±0.036, CVP (mmHg, 1 mmHg = 0.133 kPa): 8.5±3.2 vs. 8.1±4.2, SVRI (kPa·s·L-1·m-2): 1 497.35±157.08 vs. 1 343.60±144.48, CI (mL·s-1·m-2): 120.36±15.34 vs. 106.69±12.33, EVLWI (mL/kg): 6.84±0.73 vs. 7.65±0.70, allP < 0.05].Conclusion Combing HP with CVVH for treatment of patients with septic shock can improve their prognosis more obviously than using CVVH alone.

Calcium activated potassium channel and protein kinase C participate in the cardiac protection of remote post conditioning

The present study was designed to investigate the roles of Ca[2+] activated K[+] channel [KCa] and protein kinase C [PKC] in the protective mechanisms of remote ischemic post conditioning [RPostC] when rat heart was subjected to ischemia/reperfusion [I/R] injury in vivo. Rat heart was subjected to regional ischemia for 45 min and reperfusion for 180 min in vivo to mimic I/R injury. RPostC was induced by 5 min right femoral artery occlusion followed by 5 min reperfusion for 3 cycles [totally 30 min] after 15 min of cardiac ischemia. Delayed remote ischemic post conditioning [delayed RPostC] was induced after 10 min of cardiac reperfusion. The hemodynamic parameters including mean arterial blood pressure and heart rate [HR] were recorded, and lactate dehydrogenase [LDH] release in plasma and infarct size were determined, and arrhythmia scores were calculated. In contrast to I/R, RPostC reduced infarct size and LDH release during reperfusion, the occurrence of arrhythmia was decreased, but no changes in delayed RPostC. The specific inhibitor of KCa iberiotoxin and PKC inhibitor chelerythrine both attenuated the role of RPostC. The findings indicated that RPostC had a protective effect on myocardial ischemia/reperfusion injury. Opening of KCa and activating of PKC may be involved in the mechanisms of RPostC

Diaphragm dysfunction and expressions of calcium regulatory proteins in diabetic rats / 南方医科大学学报

<p><b>OBJECTIVE</b>To study the changes in diaphragmatic function and gene expressions of calcium regulatory proteins in diabetic rats and explore the mechanism of diaphragm dysfunction in diabetes mellitus.</p><p><b>METHODS</b>SD rats were randomly divided into normal control group and diabetic (induced by intraperitoneal STZ injection) group. After 4 and 8 weeks, the body weight and diaphragm to body weight ratio were measured, and the activities of succinic dehydrogenase (SDH) in the diaphragm and blood glucose were assayed. The diaphragm contractility was assessed and the alterations of diaphragm ultrastructure were observed. RT-PCR was used to detect the changes in sarcoplasmic reticulum Ca(2+)-ATPase (SERCA) and phospholamban (PLB) mRNA expressions in the diaphragm.</p><p><b>RESULTS</b>The diabetic rats showed a significant weight loss with a lowered diaphragm to body weight ratio (P<0.01) and SDH activity (P<0.01). The peak twitch tension and maximum tetanic tension of the diaphragm were significantly lowered and the time to peak contraction and half relaxation time significantly prolonged (P<0.01) in the diabetic rats, which also exhibited a lowered tetanic force in response to stimulus (P<0.01). Transmission electron microscopy revealed obvious ultrastructural changes of the diaphragm in diabetic rats. RT-PCR showed significantly decreased SERCA and increased PLB mRNA expressions in diabetic rat diaphragm (P<0.01), and these changes intensified with time (P<0.01).</p><p><b>CONCLUSION</b>Diabetes can cause impairment of diaphragmatic ultrastructure, mitochondrial injuries, and lowered SDH activity and ATP production. Decreased SERCA and increased PLB mRNA expressions in diabetes result in reduced Ca(2+) uptake by the diaphragm sarcoplasmic reticulum to induce diaphragm dysfunction.</p>

A research on effects of rhubarb combined with glutamine on repair of gut mucosal barrier injury in rats / 中国中西医结合急救杂志

Objective To investigate the effects of rhubarb combined with glutamine on repair of gut mucosal barrier injury after gastrointestinal surgery in rats. Methods Fifty male healthy Sprague-Dawley(SD)rats were randomly divided into five groups:control(C group),enteral nutrition(EN group),rhubarb with EN(R-EN group), glutamine with EN(G-EN group)and rhubarb combined with glutamine and EN(R-G-EN group)groups(each n=10). The rats of C group received no treatment and were fed normally. Cecectomy and gastrostomy were performed in EN,R-EN,G-EN and R-G-EN groups,and in 24 hours after surgery,they were interfered with the use of amoxicillin 50 mg/d and metronidazole 20 mg twice a day. From the first day after operation,each group was treated with the same prescription of enteral isocaloric and isonitrogenous nutrition for consecutive 7 days. Seven days later, under anaesthesia,laparotomy was performed,and a specimen of 1 cm intestinal segment was taken from the terminal 5 cm long ileum for all the groups;under the light microscope,the morphological examination of intestinal mucosal epithelial tight junctions(including villus height and mucosal thickness)was carried out. For each group,enzyme-linked immunosorbent assay(ELISA)was used to measure the levels of plasma citruline and D-lactate,and the serum concentration of TNF-αwas detected by utilizing double antibody ABC-ELISA. Results The levels of D-lactate and TNF-αin EN,R-EN,G-EN and R-G-EN groups were obviously higher than those in C group(all P0.05). Conclusion The application of rhubarb combined with glutamine can protect gut mucosa,reduce the level of inflammatory reaction and elevate the level of plasma citruline, that is beneficial to the repair of gut mucosal barrier injury and its functional recovery after gastrointestinal surgery in rats.

The effect of hypothermia on the early inflammatory reaction in acute lung injury induced by intestinal ischemia-reperfusion in rabbits / 中华急诊医学杂志

Objective To study the effect of hypothemah on the early inflammatory reaction in acute lung injury induced by intestinal ischemia-repeffusion(IlR)in rabbits.Method Seventy-two healthy rabbits provided by Peking Union Medical Colege Hospital Anhnal center were randomly divided into four groups(n=18 pergroup):(1)normothermia control group (rectal temperature 37-38 C;sham group);(2)normothermia IlR group(rectal temperature 37-38 C);(3)mild hypothermia HR group(rectal temperature 32-35℃);and (4)moderate hypothermia IIR group(rectal temperature 28-31.9C).Acute lung injury was induced by claIllp.ithe superiornteric artery(SMA)for 1 hour and declamping the SMA for 6 hours.Hypothermia WaS induced by surface cooling.Before and 2.4 and 6 hours after IIR,the Olasmlevels o,IL-,IL-6 and IL10 were measured.All rabbits were killed 6 hours after IIR and water content in lung tissue Wttk'assessed.Iaght mieropic examination was performed tbr morphological assessment of the hmg.The data were analyzed by AN()VA.Statistical significance wag dned as a P of<0.05.Results In the IIR groups,the plasma levels ofTHE-a.IL-l,IL-6 and IL-10 and lung water were increased.There Was evidence of acute lung injury from morphologi-cal assessment of the lung.The acute lung injury induced by IIR was improved by hypethennia.Mild hypothermia Was similar to moderate hypothermia for the treatment of acute lung injury induced by IIR.ConclusiotMild hy-pothermia and moderate hypothermia Can significantly improve acute lung injury induced by IIR in rabbits.Mild hypothea had similar efficacy to moderate hypothermia for the treatment of acute lung injury induced by IIR.