OBJECTIVE To observe the effects of endogenous metabolite mesaconate combined with Sodium lactate Ringer’s injection （LR） on prolonging the golden treatment time window and its resuscitation efficacy in rats with hemorrhagic shock under high-altitude conditions. METHODS Rats were divided into the shock group， LR group， and 5， 20， 50 mg/kg mesaconate+LR groups， with 20 rats in each group， to investigate the effect of additional use of mesaconate on the golden treatment time window. After establishing a model of uncontrolled hemorrhagic shock under high-altitude conditions in all groups by housing in a hypobaric hypoxia chamber combined with splenic artery transection， rats in the shock group received no resuscitation， while rats in the LR group and mesaconate+LR groups underwent low-pressure resuscitation with LR or mesaconate combined with LR. Blood pressure control， fluid infusion volume， blood loss rate and survival status were observed in each group. Rats were further divided into the normal group， shock group and mesaconate （50 mg/kg）+LR group， with 10 or 20 rats in each group， to evaluate the resuscitation effects after extending the golden treatment time window by additionally using mesaconate. Except for the normal group， the other groups underwent the same procedure to establish an uncontrolled hemorrhagic shock model under high-altitude conditions. Rats in the shock group received no resuscitation. In the mesaconate+LR group， after 3 h of low-pressure resuscitation， bleeding control was performed by ligation of the spleen artery， and the infusion volume and blood loss rate were recorded； subsequently， the rats received LR resuscitation with twice the volume of blood loss. Then， blood gas indicators of the mesaconate+LR group were measured at different time points. Survival rates， indicators related to sublingual microcirculatory perfusion， liver and kidney blood flow， indicators related to the function of vital organs， and lung and brain water content were observed in all groups. RESULTS LR infusion alone could effectively maintain mean arterial pressure （MAP） within 50-60 mmHg for approximately 1 h. The administration of mesaconate combined with LR during hypotensive resuscitation could maintain MAP within 50-60 mmHg for over 3 h， with significantly reduced fluid infusion volume and blood loss rate in 50 mg/kg mesaconate+LR group， compared to the LR group （ P ＜0.05）. In the LR group， rats maintained low pressure for up to 1 hour with a survival rate of 52.94%， and no rats survived beyond 2 h. In the 5， 20 and 50 mg/kg mesaconate+LR groups， rats maintained low pressure for up to 1 h with a survival rate exceeding 80%； in the 20 and 50 mg/kg mesaconate+LR groups， rats maintained low pressure for up to 3 h with a survival rate exceeding 70%. After complete resuscitation with mesaconate combined with LR， the 72 h survival rate of rats was 43.75%， and significant improvements in blood gas parameters were observed compared to the end of the shock phase （ P ＜0.05）. Compared to the shock group， the mesaconate+LR group showed significant recovery in sublingual microcirculatory indicators， and liver/kidney blood flow after complete resuscitation （ P ＜0.05）， with significant reductions in heart， liver and kidney function-related indicators and lung water content （ P ＜0.05）. CONCLUSIONS Mesaconate combined with LR significantly extends the golden treatment time window for hemorrhagic shock in rats under high-altitude conditions， improves blood gas parameters， sublingual microcirculatory perfusion， and liver/kidney blood flow， mitigates vital organ impairment and pulmonary edema， and increases the survival rate of shocked rats.

Objective:To Analysis of the current status of occupational hazard factors of 1, 2-dichloroethane (1, 2-DCE) in workplaces of enterprises in a certain district of Chongqing City, to provide a basis for its prevention and control.Methods:In January 2024, the monitoring data from the 2023 key occupational disease survey in the district were collected and organized. Qualitative analysis was conducted on the organic solvents used by enterprises in their production processes, and the detection results of 1, 2-DCE were statistically analyzed.Results:A total of 88 organic solvent samples were collected, with a qualitative detection rate of 21.6% (19/88) for 1, 2-DCE. A total of 30 enterprises using organic solvents were surveyed and tested, with an enterprise detection rate of 36.7% (11/30) for 1, 2-DCE. The workplace exceedance rate for 1, 2-DCE was 37.0% (34/92), and the post exceedance rate was 15.4% (4/26) .Conclusion:The degree of occupational exposure hazard related to 1, 2-DCE remains severe. It is necessary to strengthen the management of organic solvents used by enterprises and implement effective measures to prevent acute and chronic poisoning caused by 1, 2-DCE.

Objective To explore the protective effect of L-carnitine on myocardial systolic dysfunction in sepsis and its underlying mechanism.Methods A mouse sepsis model was established by cecal ligation and puncture(CLP).Ten-week-old male SPF-grade C57BL/6 mice(body weight 20～30 g)were randomly divided into 5 groups via random number table:Sham group,Sepsis group,L-carnitine group,L-carnitine+Etomoxir(Eto)group,and Eto group.Echocardiography assessed cardiac function,ELISA measured serum creatine kinase isoenzyme MB(CK-MB)levels,and 72-hour survival rates were recorded to evaluate L-carnitine's effects on cardiac function.Cardiomyocytes were isolated,and a cell microtensiometer was used to detect cardiomyocyte contractile function and calcium transients.Myocardial tissues were collected from each group,and ELISA was used to determine the contents of triglyceride(TG),free fatty acid(FFA),and adenosine triphosphate(ATP).An in vitro sepsis model was constructed by stimulating HL-1 cardiomyocytes with lipopolysaccharide(LPS)for 12 hours,which was divided into 5 groups:control(CTRL)group,LPS group,L-carnitine group,L-carnitine+Eto group,and Eto group.ELISA was used to detect the contents of TG,FFA,and ATP as well as the activity of carnitine palmitoyltransferase 1A(CPT1A)in cardiomyocytes.A cellular energy metabolism analysis system was employed to measure fatty acid oxidation capacity,and Western blot was used to detect the protein expression of CPT1A in cardiomyocytes.BODIPY-FL-C16(green fluorescently labeled palmitic acid)was utilized to detect the distribution of fatty acids in the cytoplasm and mitochondria via immunofluorescence technology,thereby observing the ability of cells to transport fatty acids into mitochondria.Results Compared with the Sham group,cardiac function was significantly impaired in the Sepsis group,as evidenced by decreased ejection fraction and mean arterial pressure(P<0.05),along with elevated levels of the cardiac injury marker CK-MB(P<0.05).Treatment with L-carnitine significantly improved myocardial function,restored blood pressure in septic mice,and increased their survival rate from 12.50%to 81.25%(P<0.05).Compared with the Sham group,the contractile function and calcium transients of acutely isolated single cardiomyocytes were significantly reduced in the Sepsis group(P<0.05),while L-carnitine treatment remarkably restored the contractile function and calcium release capacity of septic cardiomyocytes(P<0.05).Both in vivo and in vitro experiments showed that TG and FFA levels were significantly increased(P<0.05),and ATP levels was significantly decreased(P<0.05)in the Sepsis and LPS groups—effects significantly reversed by L-carnitine treatment.Compared with the CTRL group,the basal oxidation rate and maximum oxidation capacity of fatty acids in cardiomyocytes of the LPS group were significantly reduced(P<0.05),and L-carnitine treatment notably improved these indicators.Compared with the CTRL group,the expression and activity of CPT1A in cardiomyocytes of the LPS group were significantly decreased(P<0.05),while L-carnitine treatment significantly increased the expression and activity of CPT1A(P<0.05).In LPS group cardiomyocytes,green fluorescently labeled palmitic acid primarily formed numerous granular/clumpy aggregates in the cytoplasm with minimal mitochondrial colocalization.In the L-carnitine group,the green fluorescent granules in the cytoplasm of cardiomyocytes were smaller,and colocalization with mitochondria was increased.However,the L-carnitine+Eto group exhibited similar phenomena to the LPS group.In addition,both in vivo and in vitro experiments demonstrated that treatment with the CPT1A inhibitor Eto reversed the effect of L-carnitine.Compared with the L-carnitine group,the ATP content in the L-carnitine+Eto group was significantly decreased(P<0.05),while the FFA content was significantly increased(P<0.05).Conclusion L-carnitine facilitates fatty acid entry into mitochondria for β-oxidation via a CPT1A-dependent mechanism,thereby ameliorating fatty acid oxidation dysfunction in septic cardiomyocytes and improving myocardial contractile function.

Objective:To Analysis of the current status of occupational hazard factors of 1, 2-dichloroethane (1, 2-DCE) in workplaces of enterprises in a certain district of Chongqing City, to provide a basis for its prevention and control.Methods:In January 2024, the monitoring data from the 2023 key occupational disease survey in the district were collected and organized. Qualitative analysis was conducted on the organic solvents used by enterprises in their production processes, and the detection results of 1, 2-DCE were statistically analyzed.Results:A total of 88 organic solvent samples were collected, with a qualitative detection rate of 21.6% (19/88) for 1, 2-DCE. A total of 30 enterprises using organic solvents were surveyed and tested, with an enterprise detection rate of 36.7% (11/30) for 1, 2-DCE. The workplace exceedance rate for 1, 2-DCE was 37.0% (34/92), and the post exceedance rate was 15.4% (4/26) .Conclusion:The degree of occupational exposure hazard related to 1, 2-DCE remains severe. It is necessary to strengthen the management of organic solvents used by enterprises and implement effective measures to prevent acute and chronic poisoning caused by 1, 2-DCE.

Objective To observe the improved effect of propofol on vascular hyporeactivity in septic rats and its underlying mechanism.Methods A total of 96 SD rats(12 weeks old,both genders,weighing 200～220 g)were randomly divided into sham group(n=16),sepsis group(n=16,cecal ligation and puncture),propofol group(n=16),propofol+ROCK inhibitor Y-27632 group(n=16),propofol+PKCαinhibitor GO6976 group(n=16),propofol+IP3 inhibitor 2-APB group(n=8)and propofol+gap junction inhibitor metoclopramide sodium(Movens)group(n=8).In vitro vascular ring reactivity and vascular calcium sensitivity were measured to observe the improved effects of propofol on vascular hyporeactivity in septic rats and its relationships with RhoA/ROCK,PKCα,IP3 and cell gap junction.Results Determination of in vitro vascular ring and calcium sensitivity showed that the contractile reactivity to norepinephrine(NE)and to calcium sensitivity were significantly decreased in the arterial rings isolated from the septic rats compared with those from the sham group,with the dose-response curve shifting to the right,and most significant decrease by 51.42％in the superior mesenteric artery(SMA,P＜0.05).Propofol treatment significantly improved the hyporeactivity and calcium sensitivity of the vessels isolated from the septic rats,especially those of the femoral artery with a recovery rate of 89.57％(P＜0.05).In comparison with the propofol group,the dose-response curves of the propofol+Y-27632 group and the propofol+GO6976 group were shifting to right,indicating that Y-27632 and GO6976 could significantly inhibit the amelioration of propofol on calcium sensitivity of SMA in severely septic rats with an inhibitory rate of 146.95％and 88.63％(P＜0.05),respectively.Isolated vascular reactivity measurement demonstrated that Y-27632 and Movens treatment significantly antagonized the ameliorated role of propofol on hyporeactivity of blood vessels from the septic rats with an inhibitory rate of 40.79％and 169.90％(P＜0.05),separately,while no such effect was observed in the propofol+GO6976 and propofol+2-APB groups.Conclusion Propofol treatment can significantly improve vascular hyporeactivity of septic rats,which may attribute to the increase of vascular calcium sensitivity through RhoA/ROCK pathway.