Objective To explore the construction of heart preservation model of empty beating donor based on extracorporeal membrane oxygenation (ECMO). Methods From January 2022 to August 2023, 20 Guangxi Bama miniature pigs weighing 25-30 kg were selected, half male and half female. Under general anesthesia and heparinization, a midline thoracotomy was performed. The pericardium was cut after freeing the anterior and posterior vena cavae, and a perfusion needle was inserted near the brachiocephalic artery in the ascending aorta, connected to a blood collection bag to collect 500-600 mL of blood. The anterior and posterior vena cavae were ligated, the aorta was blocked and perfused with HTK solution to stop the heart beating. The superior and inferior vena cavae were cut off, the right pulmonary vein was decompressed, the aorta and left and right pulmonary arteries and veins were cut off, and the whole heart was removed. An ECMO device was used to continuously perfuse a cardioprotective solution mainly composed of oxygenated warm blood, maintaining the isolated pig heart beating for 8 hours, monitoring (once/hour) ECMO perfusion parameters, blood gas indicators, perfusate electrolytes, inflammatory factors, myocardial enzymes, myoglobin, and troponin levels. Myocardial tissue was taken for hematoxylin-eosin (HE) staining to observe myocardial cell damage and evaluate the quality of heart preservation. Results Among the 20 isolated beating pig hearts, 17 successfully resumed beating, 3 experienced ventricular fibrillation, resuscitated after intracardiac electrical defibrillation, and all 20 pig hearts successfully beat for 8 hours. There was no statistical difference in ECMO perfusion parameters, blood gas indicators, perfusate electrolytes, and inflammatory factors at each time point (P>0.05). There were statistical increases in myocardial enzymes, myoglobin, and troponin levels (P<0.05). HE staining results suggested that there was no severe myocardial damage. Conclusion ECMO technology can be used for pig heart preservation with good results, and this study provides experimental evidence for improving heart preservation research in clinical heart transplantation.

Randomized controlled trials have long been regarded as the gold standard for evaluating vaccine efficacy. However, conducting randomized controlled trials to assess vaccines in real-world settings is often impractical due to limitations in research resources and ethical considerations. In recent years, the emulated target trial has emerged as a novel methodological framework that applies the design principles of randomized trials to observational studies. By using observational data to emulate the randomization and treatment assignment of a clinical trial, this approach enables the evaluation of vaccine effectiveness in the real world. The application of emulated target trials enhances the quality and applicability of real-world evidence. This article explains the fundamental principles, design elements, advantages, and limitations of using emulated target trials to evaluate vaccine effectiveness, providing methodological guidance for conducting such studies in China.

Objective To investigate the effect and mechanism of actin gamma1(ACTG1)downregulation on apoptosis in gastric cancer cells line HGC-27.Methods Stable ACTG1 knockdown HGC-27 cell line was constructed by CRISPR/Cas9,ACTG1 knockdown was verified by DNA sequencing and Western blot,apoptosis rate was detected by flow cytometry,Western blot detected the expression level of apoptosis-related proteins Bcl2-associated X protein(Bax),B cell lymphoma 2 family protein(Bcl2)and PI3K/AKT signal pathway-related proteins AKT and p-AKT.Results HGC-27 cell lines with stable knockdown of ACTG1 were constructed,and the ACTG1 protein levels were decreased in the sgACTG1-1 and sgACTG1-2 groups compared with the Control group.Compared with the apoptosis rate in the Control group(6.54%±0.67%),cell apoptosis rate in the sgACTG1-1 and sgACTG1-2 groups(10.11%±0.46%,14.67%±0.17%)were significantly increased,the differences were statistically significant(t=-7.58,-20.28,all P<0.01).Compared the Control group,the Bax protein levels in the sgACTG1-1 and sgACTG1-2 groups(0.89±0.02,1.00±0.08 vs 0.71±0.03)were significantly increased(t=-8.14,-5.87),the level of Bcl2 protein(0.49±0.06,0.39±0.06 vs 0.65±0.07)were significantly decreased(t=3.09,5.35),the differences were statistically significant(all P<0.05).Compared with the Control group,the AKT protein levels in the sgACTG1-1 and sgACTG1-2 groups(0.95±0.10,0.43±0.09 vs 1.17±0.06)and the P-AKT protein level(0.38±0.08,0.28±0.12 vs 0.70±0.14)were significantly decreased,the differences were statistically significant(t=3.20,12.13;3.44,3.85,all P<0.05).Conclusion Downregulation of ACTG1 inhibits the expression of PI3K/Akt signaling pathway related proteins AKT,p-AKT and promotes gastric cancer cells line HGC-27 apoptosis.

AIM To observe the effects of Hugan Tablets on high-fat diet induced non-alcoholic fatty liver disease(NAFLD)in a mouse model,and the autophagy,pyroptosis and the PI3K/Akt/mTOR signaling pathway as well.METHODS The C57BL/6 mice were randomly divided into the normal group,the model group,the Hugan Tablets group(0.7 g/kg)and the Yishanfu group(0.23 g/kg),with 10 mice in each group.The NAFLD mouse model was established by 16 weeks feeding of high-fat diet.From the 13th week,the mice started their corresponding dosing of the drug by gavage followed by killing of the mice at the end of 16th week and collection of their serum and liver tissue samples.The mice had their serum ALT,AST,TG,TC,LDL levels,liver TG,TC,NEFA,MDA levels and activities of SOD and GSH-Px detected;their serum levels of IL-1β,IL-6 and TNF-αdetected by ELISA;their hepatic pathological changes observed using HE staining and oil red O staining;and their hepatic protein expressions of ACC,CPT1A,FAS,p-PI3K,p-Akt,p-mTOR,P62,LC3,NLRP3,GSDMD and Caspase1 detected by Western blot.RESULTS Compared with the model group,the Hugan Tablets group displayed decreased body weight and hepatosmatic index level(P＜0.01);decreased levels of serum ALT,AST,TG,TC,LDL,IL-6,IL-1β and TNF-α(P＜0.05,P＜0.01);increased hepatic levels of TG,TC,NEFA and MDA(P＜0.05);decreased activities of SOD and GSH-Px(P＜0.05);improved pathological changes of hepatic lipid deposition and hepatocytic ballooning and decreased NAS score and oil red O staining area(P＜0.01);decreased hepatic protein expressions of ACC1,FAS,NLRP3,Caspase1,GSDMD,P62,p-PI3K,p-Akt and p-mTOR(P＜0.05,P＜0.01);and increased protein expressions of CPT1A and LC3(P＜0.01).CONCLUSION Hugan Tablets can effectively prevent and control the development of high-fat diet induced NAFLD in mice,and the mechanism may be associated with the promotion of autophagy in hepatocytes and the inhibition of pyroptosis via the inhibition of PI3K/Akt/mTOR signaling pathway.

OBJECTIVE To investigate the clinical distribution and dynamic change of drug resistance of K.pneu-moniae and carbapenem-resistant Klebsiella pneumoniae(CRKP)isolated from a three-A hospital of Suzhou so as to provide scientific bases for prevention and control of hospital-associated infections and reasonable application of antibiotics.METHODS The K.pneumoniae and CRKP strains that were isolated from the submitted specimens were collected from the patients who treated in the Affiliated Suzhou Hospital of Nanjing Medical University from 2019 to 2023.The clinical characteristics of the patients with infection and the trend of drug resistance were statis-tically analyzed.RESULTS Totally 5631 strains of K.pneumoniae were isolated,1205(21.40％)of which were CRKP,and the isolation rate of CRKP showed an upward trend in the five years(x2=236.352,P＜0.001).Among the K.pneumoniae isolates,51.59％were isolated from sputum,13.51％from urine;19.43％were isolated from intensive care unit(ICU),7.64％from emergency department,and 7.19％from respiratory department.There were significant differences in gender,age and season between the patients detected with CRKP and the patients detected with non-CRKP(P＜0.05).The drug resistance rates of the K.pneumoniae strains to cephalosporins,quinolones and carbapenems con-tinuously increased from 2019 to 2023(P＜0.001),the drug resistance rate to imipenem increased from 11.69％to 34.24％,meropenem from 10.92％to 34.24％.CONCLUSIONS The K.pneumoniae isolates show severe drug re-sistance from 2019 to 2023,and the isolation rate of CRKP strains rises increasingly.It is necessary for the hospi-tal to focus on the continuous monitoring of key populations and departments and optimize the management of an-tibiotics and infection control strategies so as to provide guidance for reasonable clinical use of antibiotics,effective control of transmission of drug-resistant strains and cope with the increasingly severe drug resistance.

Objective To develop and validate a transgenic mouse model enabling specific and inducible optogenetic activation of oligodendrocyte precursor cells(OPCs).Methods A conditional allele for the photosensitive opsin chicken opsin 5(cOpn5)(Rosa26-LSL-cOpn5)was generated using CRISPR/Cas9 technology.These mice were subsequently crossed with NG2-CreERT transgenic mice to produce NG2-CreERT;cOpn5 animals.In this model,tamoxifen administration induces Cre-mediated recombination,leading to specific expression of cOpn5 in NG2-positive OPCs.The specificity and efficiency of cOpn5 expression in OPCs were confirmed by immunofluorescent staining.Functional validation of light-induced OPC activation was performed by using calcium imaging in acute brain slices after stimulation with 470 nm blue light.Results Immunofluorescence analysis confirmed robust and specific expression of cOpn5 within NG2-positive OPCs in the brains of tamoxifen-treated NG2-CreERT;cOpn5 mice.Crucially,calcium imaging of acute brain slices from these mice demonstrated a significant increase in intracellular calcium levels in cOpn5-expressing OPCs upon stimulation with 470 nm blue light,indicating successful optogenetic activation.Conclusion We have successfully generated and validated a novel transgenic mouse model(NG2-CreERT;cOpn5)that permits specific and inducible optogenetic activation of OPCs.This model provides a novel tool for subsequent in vivo studies of the role and regulating mechanisms of OPCs in the central nervous system.

OBJECTIVE To investigate the clinical distribution and dynamic change of drug resistance of K.pneu-moniae and carbapenem-resistant Klebsiella pneumoniae(CRKP)isolated from a three-A hospital of Suzhou so as to provide scientific bases for prevention and control of hospital-associated infections and reasonable application of antibiotics.METHODS The K.pneumoniae and CRKP strains that were isolated from the submitted specimens were collected from the patients who treated in the Affiliated Suzhou Hospital of Nanjing Medical University from 2019 to 2023.The clinical characteristics of the patients with infection and the trend of drug resistance were statis-tically analyzed.RESULTS Totally 5631 strains of K.pneumoniae were isolated,1205(21.40％)of which were CRKP,and the isolation rate of CRKP showed an upward trend in the five years(x2=236.352,P＜0.001).Among the K.pneumoniae isolates,51.59％were isolated from sputum,13.51％from urine;19.43％were isolated from intensive care unit(ICU),7.64％from emergency department,and 7.19％from respiratory department.There were significant differences in gender,age and season between the patients detected with CRKP and the patients detected with non-CRKP(P＜0.05).The drug resistance rates of the K.pneumoniae strains to cephalosporins,quinolones and carbapenems con-tinuously increased from 2019 to 2023(P＜0.001),the drug resistance rate to imipenem increased from 11.69％to 34.24％,meropenem from 10.92％to 34.24％.CONCLUSIONS The K.pneumoniae isolates show severe drug re-sistance from 2019 to 2023,and the isolation rate of CRKP strains rises increasingly.It is necessary for the hospi-tal to focus on the continuous monitoring of key populations and departments and optimize the management of an-tibiotics and infection control strategies so as to provide guidance for reasonable clinical use of antibiotics,effective control of transmission of drug-resistant strains and cope with the increasingly severe drug resistance.

Objective To investigate the relationship between biological aging and the rate of cognitive decline in middle-aged and elderly populations.Methods Longitudinal tracking data of cognitive function were obtained from the China Health and Retirement Longitudinal Study(CHARLS).We employed the Klemera and Doubal method(KDM)to estimate biological age(BA),and calculate the biological aging index(BAI)and biological aging type(BAT).A multivariate linear regression model was employed to analyze the relationships between baseline BAI,BAT,and cognitive function scores.Based on the baseline analysis,a mixed-effects model was used to examine the longitudinal associations between baseline BAI,BAT,and cognitive function during follow-up.Results A total of 5 897 participants were included in the study.BAI was found to be negatively associated with baseline cognitive function scores,with the partial regression coefficient(β)(95％CI)being-0.185(—0.231,—0.139)(P＜0.001).Compared with the lagged aging group,the premature aging group had lower cognitive function scores(β[95％CI]:—0.741[—0.966,—0.516]).For age and sex,for each additional year of baseline BAI,cognitive function scores declined by an average of 0.012(95％CI:—0.019,—0.005)points per year after adjusting for age and sex,and declined by 0.011(95％CI:—0.018,—0.004)points per year after adjusting for other covariates.Compared with participants with lagged aging,those with premature aging experienced,on average,an additional decline of 0.042(95％CI:—0.075,0.009)points per year in cognitive function scores after adjusting for age and sex alone,and by 0.039(95％CI:—0.072,—0.007)points per year after adjusting for other covariates.Conclusion Biological aging affects the rate of cognitive decline in middle-aged and elderly populations.A higher BAI is associated with a faster decline in cognitive function.Compared with those with lagged aging,individuals with premature aging exhibit a more rapid rate of cognitive decline.

Randomized controlled trials have long been regarded as the gold standard for evaluating vaccine efficacy. However, conducting randomized controlled trials to assess vaccines in real-world settings is often impractical due to limitations in research resources and ethical considerations. In recent years, the emulated target trial has emerged as a novel methodological framework that applies the design principles of randomized trials to observational studies. By using observational data to emulate the randomization and treatment assignment of a clinical trial, this approach enables the evaluation of vaccine effectiveness in the real world. The application of emulated target trials enhances the quality and applicability of real-world evidence. This article explains the fundamental principles, design elements, advantages, and limitations of using emulated target trials to evaluate vaccine effectiveness, providing methodological guidance for conducting such studies in China.

AIM To observe the effects of Hugan Tablets on high-fat diet induced non-alcoholic fatty liver disease(NAFLD)in a mouse model,and the autophagy,pyroptosis and the PI3K/Akt/mTOR signaling pathway as well.METHODS The C57BL/6 mice were randomly divided into the normal group,the model group,the Hugan Tablets group(0.7 g/kg)and the Yishanfu group(0.23 g/kg),with 10 mice in each group.The NAFLD mouse model was established by 16 weeks feeding of high-fat diet.From the 13th week,the mice started their corresponding dosing of the drug by gavage followed by killing of the mice at the end of 16th week and collection of their serum and liver tissue samples.The mice had their serum ALT,AST,TG,TC,LDL levels,liver TG,TC,NEFA,MDA levels and activities of SOD and GSH-Px detected;their serum levels of IL-1β,IL-6 and TNF-αdetected by ELISA;their hepatic pathological changes observed using HE staining and oil red O staining;and their hepatic protein expressions of ACC,CPT1A,FAS,p-PI3K,p-Akt,p-mTOR,P62,LC3,NLRP3,GSDMD and Caspase1 detected by Western blot.RESULTS Compared with the model group,the Hugan Tablets group displayed decreased body weight and hepatosmatic index level(P＜0.01);decreased levels of serum ALT,AST,TG,TC,LDL,IL-6,IL-1β and TNF-α(P＜0.05,P＜0.01);increased hepatic levels of TG,TC,NEFA and MDA(P＜0.05);decreased activities of SOD and GSH-Px(P＜0.05);improved pathological changes of hepatic lipid deposition and hepatocytic ballooning and decreased NAS score and oil red O staining area(P＜0.01);decreased hepatic protein expressions of ACC1,FAS,NLRP3,Caspase1,GSDMD,P62,p-PI3K,p-Akt and p-mTOR(P＜0.05,P＜0.01);and increased protein expressions of CPT1A and LC3(P＜0.01).CONCLUSION Hugan Tablets can effectively prevent and control the development of high-fat diet induced NAFLD in mice,and the mechanism may be associated with the promotion of autophagy in hepatocytes and the inhibition of pyroptosis via the inhibition of PI3K/Akt/mTOR signaling pathway.