Objective To investigate the effects of N-acetylcysteine （NAC） on the intestinal barrier in rats with severe acute pancreatitis （SAP） and its possible mechanism. Methods Eighty Wistar rats were randomly （random number method） divided into normal control group （CON group， n=8）， sham operation group （SO group， n=24）， SAP group （n=24）， and NAC group （n=24）， then the rats of latter 3 groups were sub-divided into 6， 12， and 24 hours group， each time point group enrolled 8 rats， respectively. Rats of CON group didn’t receive any treatment. SAP rat models were established by injecting 5.0% sodium taurocholate into the biliary-pancreatic duct for SAP group and NAC group， while rats of SO group were injected normal saline instead of sodium taurocholate. The rats of NAC group were given an intraperitoneal injection of NAC at 1 hour before operation， and the rats of SO group and SAP group were given an intraperitoneal injection of normal saline instead at the same time. Rats of CON group were sacrificed to get ileum （about 5cm） and blood from right ventricular （5mL） for further test， and rats of the other 3 groups were sacrificed at 6， 12， and 24hours after operation. Then the levels of amylase （AMY）， C-reactive protein （CRP）， endotoxin， D-lactic acid， and diamine oxidase （DAO） in plasma， the levels of superoxide dismutase （T-SOD）， myeloperoxidase （MPO）， and malondialdehyde （MDA） in ileum tissues were tested. Apoptosis of mucosal cells in ileum tissues was determined by terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling （TUNEL）. Pathological changes in ileum tissues were observed and scored. Expression levels of bax and bcl-2mRNA in ileum tissues were determined by real-timefluorescence quantitative PCR （real-time PCR）， and related proteins were tested by Western blot method， respectively. Results Compared with SAP group at the same time point， the levels of CRP in NAC group were lower at all the 3 time points （P＜0.05） and AMY were lower at 12 and 24 hours （P＜0.05）， levels of DAO， endotoxin， and D-lactic acid were lower at 12 and 24 hours （P＜0.05）， but level of DAO was higher than SAP group at 6 hours （P＜0.05）. Compared with SAP group at the same time point， the levels of MPO and MDA in ileum tissues were lower in NAC group at all the 3 time points （P＜0.05）， but levels of T-SOD increased significantly at 12 and 24 hours （P＜0.05）. Compared with SAP group at the same time point， the apoptosis indexes were lower in NAC group at all the 3 time points （P＜0.01）， and pathologic scores of ileum tissues were lower at 12 and 24 hours （P＜0.05）. The pathological changes under a light microscope were observed better in NAC group than that of SAP group at each time point. Moreover， compared with SAP group at the same time point， the expression levels of bax mRNA and protein were lower in NAC group at all the 3 time points （P＜0.05）， while higher in bcl-2 mRNA and protein （P＜0.05）. Conclusions NAC can protect the function of small intestinal barrier， and can alleviate SAP-induced injury of the intestinal mucosa. In addition to antioxidant effects， the underlying mechanisms also may include the anti-apoptotic effects.
Objective To retrospectively analyze the clinical characteristics of heat stroke (HS) and HS-acute kidney injury (AKI), analyze the risk factors leading to death in patients, and provide new ideas for the prevention and treatment of HS. Methods Patients with HS who visited 13 hospitals in Sichuan subtropical monsoon climate and HS high-incidence areas between July 2019 and September 2023 were retrospectively selected. According to whether in-hospital death or AKI occurred, the patients were divided into survival group and death group, AKI group and non-AKI group. According to serum creatinine level, patients in the AKI group were divided into AKI stage 1 group, AKI stage 2 group and AKI stage 3 group. The main clinical manifestations and important clinical data of the patients were analyzed, and the risk factors affecting the death of patients were analyzed by multivariate logistic regression. Results A total of 195 patients with HS and 115 patients with HS-AKI were included. The results of multivariate logistic regression analysis showed that AKI, abnormal coagulation function, nervous system injury, neutrophil/lymphocyte ratio, and D-dimer were independent risk factors for death (P＜0.05). The results of clinical characteristics analysis of HS-AKI showed that the mortality rate of patients with AKI stage 2 and AKI stage 3 was higher (P＜0.05). Conclusions AKI, abnormal coagulation function, nervous system injury, neutrophil/lymphocyte ratio, and D-dimer are independent risk factors for death in HS. Therefore, active treatment of patients with HS combined with AKI, abnormal coagulation function, and nervous system injury in the future will help reduce the risk of death in patients.