Objective To investigate the distribution characteristics of pathogens causing infections within 90 days after liver transplantation and the influencing factors of infection. Methods Clinical data of 176 recipients who underwent liver transplantation at the Liver Transplant Center of Beijing Friendship Hospital Affiliated to Capital Medical University from September 2021 to August 2024 were retrospectively analyzed. Patients were divided into the infection group (n=124) and the non-infection group (n=52) based on whether they developed infection within 90 days after transplantation. The distribution characteristics of pathogens in infected patients were analyzed. Univariate and multivariate logistic regression analyses were used to explore the influencing factors of infection. Results Among the 176 liver transplant recipients, 124 cases developed 243 episodes of 518 bacterial, fungal, viral or mycoplasma infections within 90 days after transplantation, with an overall infection rate of 70.5% (124/176). The composition of pathogens was mainly Gram-negative bacteria (38.6%, 200/518), followed by Gram-positive bacteria (32.2%, 167/518) and viruses (15.4%, 80/518), and fungi accounted for 13.1% (68/518). Among Gram-negative bacteria, the main pathogen was Klebsiella pneumoniae (6.8%, 35/518), and among Gram-positive bacteria, the main pathogen was Enterococcus faecalis (8.5%, 44/518). Viruses included Epstein-Barr virus (3.7%, 19/518) and cytomegalovirus (3.7%, 19/518), and fungi were mainly Candida albicans (6.8%, 35/518). The most common infection site among the 243 episodes was pulmonary infection (42.0%, 102/243), followed by abdominal infection (22.6%, 55/243) and bloodstream infection (18.1%, 44/243). The infections mainly occurred within 2 weeks after transplantation (60.9%, 148/243). Multivariate logistic regression analysis indicated that preoperative infection within 2 weeks, a high preoperative model for end-stage liver disease (MELD) score, and preoperative sarcopenia were independent risk factors for infection within 90 days after liver transplantation (all odds ratio>1, P<0.05). After multivariate correction, the levels of CD4⁺T cells and CD8⁺T cells within 90 days after surgery were independently associated with the occurrence of infection. Low levels of CD4⁺T cells and CD8⁺T cells might be related to an increased risk of infection. Conclusions The infection rate after liver transplantation is high, and the pathogens are mainly Gram-negative bacteria. The lungs are the most common infection site. Preoperative MELD score, preoperative sarcopenia and preoperative infection within 2 weeks are independent risk factors for infection within 90 days after liver transplantation. Regular monitoring of immune indicators CD4⁺T cells and CD8⁺T cells levels after transplantation is helpful to reduce the occurrence of post-transplantation infection.

Ferroptosis is a form of programmed cell death,which plays a crucial driving role in the onset and progression of diabetic nephropathy(DN).Ferroptosis is closely related to the damage of renal intrinsic cells in patients with diabetes.Chinese materia medica can improve DN by regulating the ferroptosis of renal intrinsic cells,with a good research and application prospect.This article reviewed the key regulatory factors and regulatory pathways of ferroptosis in DN,explained the"imbalance between yin and yang"of ferroptosis in DN based on TCM theories,and combed the research status of targeted inhibition of ferroptosis by active components of Chinese materia medica.The regulation of active components of Chinese materia medica on ferroptosis in DN has the characteristics of multiple targets,multiple links and integrity,which can provide a reference for the mechanism research and drug development of Chinese materia medica in treating DN.

Objective To investigate the predictive value of preoperative combined detection of neutrophil-to-lymphocyte ratio (NLR) and prothrombin time-international normalized ratio to albumin ratio (PTAR) for early abdominal infection after liver transplantation. Methods Clinical data of 287 recipients who underwent liver transplantation at the Liver Transplant Center of Beijing Friendship Hospital, Affiliated to Capital Medical University, from January 2020 to April 2024 were retrospectively analyzed. The patients were divided into infection group (n=60) and non-infection group (n=227) based on whether abdominal infection occurred within 30 days after surgery. The distribution characteristics of pathogens and infection time in infected patients were analyzed. Spearman correlation analysis was used to assess the correlation between NLR, PTAR, Child-Pugh score and preoperative model for end-stage liver disease (MELD) score. Univariate and multivariate logistic regression analyses were performed to identify risk factors for abdominal infection. Receiver operating characteristic (ROC) curves were plotted for NLR, PTAR, and the combined prediction model to evaluate their predictive efficacy for abdominal infection after liver transplantation. Based on the cutoff value of the combined model, recipients were divided into low-risk and high-risk groups, and Kaplan-Meier analysis was used to compare the cumulative incidence of abdominal infection within 30 days after surgery between the two groups. Results Among the 287 recipients who underwent liver transplantation, 60 developed bacterial or fungal abdominal infections postoperatively. A total of 86 strains were isolated from infected patients, with Gram-negative bacteria accounting for 58%, Gram-positive bacteria for 36%, and fungi for 5%. Preoperative NLR and PTAR were positively correlated with Child-Pugh and MELD scores (all 1 > r > 0, P < 0.05). Logistic regression analysis showed that preoperative NLR, preoperative PTAR, postoperative ICU stay duration and postoperative biliary leakage were risk factors for abdominal infection within 30 days after surgery. The area under the curve (AUC) for NLR, PTAR, Child-Pugh score and MELD score were 0.771, 0.735, 0.650 and 0.741, respectively. The AUC for the combined NLR and PTAR prediction model was 0.824 (95% confidence interval: 0.763-0.885, P < 0.001), with a cutoff value of 0.168. Kaplan-Meier analysis showed that the cumulative incidence of abdominal infection within 30 days after surgery was lower in the low-risk group than in the high-risk group, with statistically significant difference (P < 0.001). Conclusions Preoperative NLR and PTAR are independent risk factors for abdominal infection within 30 days after liver transplantation. The combined prediction model of NLR and PTAR may effectively identify high-risk recipients for early abdominal infection after liver transplantation, providing basis for early intervention.

AIM:This study aims to investigate whether vitamin E succinate(VES)induces autophagy in hu-man gastric cancer cells through the promotion of mitochondria-associated endoplasmic reticulum membranes(MAMs).METHODS:Human gastric cancer cell lines MKN28 and MKN45 were cultured in vitro.Cell viability was assessed us-ing the CCK8 assay,and two cell growth curves were plotted to determine the treatment concentration of VES.Control groups,VES dose groups(MKN28:5,10,20,and 40 mg/L;MKN45:10,20,40,and 80 mg/L),an autophagy-posi-tive control group(rapamycin,RAPA,100 nmol/L),and a MAMs-positive control group(oligomycin A,10 mg/L)were set up.Cells were harvested after 24 h of treatment for subsequent experiments.The formation of autophagosomes and MAMs was observed using transmission electron microscopy.The expression levels of autophagy-related proteins,includ-ing beclin-1,LC3-II/LC3-I,and p62,were detected by Western blot.MAMs labeled with split green fluorescent protein(GFP)were visualized by fluorescence microscopy.The expression of mitofusin 2(MFN2),a key molecule of MAMs,was also detected by Western blot.To inhibit MFN2 specifically,the cells were treated with mitochondrial fusion inhibitor 8(MFI8)and simultaneously transfected with an MFN2 plasmid to achieve MFN2 overexpression(OE-MFN2).The cells were divided into control group,MFI8(20 μmol/L)group,VES groups(20 mg/L for MKN28 cells and 40 mg/L for MKN45 cells),VES+MFI8 group,OE-MFN2+MFI8 group and OE-MFN2+VES+MFI8 group.The MAMs were visualized by fluorescence microscopy,and the expression changes of MFN2,beclin-1 and LC3-II/I were detected by Western blot.RESULTS:The results of the CCK8 assay showed that VES significantly inhibited the viability of both human gastric can-cer cell lines(P<0.05).After VES treatment,the formation of typical autophagosomes and MAMs was observed in both cell lines by transmission electron microscopy.Fluorescence microscopy showed a significant increase in GFP signals of MAMs.Western blot analysis showed that with increasing doses of VES,the expression levels of MFN2,beclin-1,and LC3-II/I were significantly up-regulated,while that of p62 was significantly down-regulated(P<0.05).Compared with VES group,the cells pretreated with MFI8 followed by VES exposure showed markedly reduced GFP signals of MAMs and much lower protein levels of MFN2,beclin-1 and LC3-II/LC3-I(P<0.05).Transfection with an MFN2 overexpression plasmid rescued MFN2 expression.Compared with VES+MFI8 group,the cells in OE-MFN2+VES+MFI8 group had much higher protein expression levels of MFN2,beclin-1 and LC3-II/LC3-I(P<0.05).CONCLUSION:The VES may partici-pates in the regulation of autophagy in human gastric cancer cells by promoting the formation of MAMs.

Objective By organizing and implementing a laboratory proficiency validation plan for air change rate testing, this study aims to explore proficiency testing approaches in laboratory animal facilities, assess the current status of relevant laboratories regarding standard application and test capabilities, standardize air change rate testing methods, and ensure the accuracy and reliability of test results. Methods From September to November 2023, the National Institutes for Food and Drug Control (NIFDC) organized a laboratory proficiency validation plan for air change rate testing in laboratory animal facilities (Plan Number: NIFDC-PT-417). The proficiency testing was conducted on-site and consisted of two parts: a written test and practical operation. The written test was open-book. True/false questions focused on participants' understanding of specific clauses in relevant standards, while application-based questions assessed their ability to handle data processing in simulated testing scenarios. The practical operation was conducted according to the relevant criteria of the China National Accreditation Service for Conformity Assessment (CNAS). Two laboratory animal rooms were prepared as proficiency testing samples using a sample splitting approach. These rooms underwent uniformity and stability testing according to CNAS requirements and were approved. Participating laboratories were required to conduct three tests on each of the two laboratory animal rooms, complete the testing and calculation of air change rate within the specified timeframe, and submit their test result reports and original records. Results A total of 27 laboratories registered and participated in the proficiency testing. All participating laboratories submitted their results within the designated timeframe, and the outcomes of all tested laboratories were rated as satisfactory. Conclusion This proficiency validation program objectively and scientifically evaluates the air change rate testing capabilities of selected domestic laboratories, effectively promoting the overall improvement of testing capabilities in the industry. It provides technical support for regulatory authorities to standardize testing institutions and offers reliable references for the purchase of testing services. Through this activity, it was identified that some laboratories need to further enhance their calibration of instruments and the utilization of calibration results. Future efforts should focus on refining related standards to improve the accuracy and reliability of testing.

Objective Through organizing a proficiency evaluation activity for animal illuminance testing laboratories,to assess the accuracy of testing data from participating laboratories,and to propose suggestions for testing methods.Methods In September 2024,China National Institute for Food and Drug Control(NIFDC)organised reference laboratories to conduct on-site testing through open registration.A total of 35 laboratories participated,completed on-site testing,and submitted their reports.The samples to be tested were two adjacent guinea pig breeding rooms in the NIFDC laboratory animal facility.In order to reduce the impact of room voltage fluctuations on animal illumination,chip on board(COB)light sources powered by regulated power supply were used,and brightness was adjusted by regulating voltage output.Split-level test sample pairs were used to set animal illuminance in both rooms,and the reference laboratories conducted testing according to Laboratory animals——Environment and housing facilities(GB 14925-2023).Each reference laboratory was assigned a 3-digit random code,conducted 2 tests for each breeding room,and submitted an on-site test report,original records,and illuminance meter verification or calibration certificate.WPS Spreadsheet 12.1 was used to summarize data,Grubbs' test(α=0.01)was used to check the data and remove outliers,and SPSS 26.0 software was used for data processing and graph drawing.The median value from each reference laboratory was used as the specified value,the robust standard deviation was used as the uncertainty,the robust z-score method(both intra-laboratory and inter-laboratory z-scores)was used to evaluate the test results from each laboratory,and the factors affecting results were analyzed from aspects of personnel,equipment,and operational environment.Results Under the detection level of α=0.01,no outliers were identified.The specified values for Room 1 and Room 2 were 17.80 lx and 19.00 Ix,respectively.The results obtained from 34 laboratories were evaluated as"satisfactory",while the results from one laboratory were"unsatisfactory".Through analysis of illuminance meter calibration certificates from various laboratories,it was found that some reference laboratories had insufficient calibration points and coverage,which caused test results to fail to accurately reflect the actual illuminance of the facility.Conclusion The present study reveals that factors such as personnel,equipment,and operation environment have different impacts on animal illuminance measurements.The present study concentrates exclusively on animal illuminance in guinea pig breeding rooms,where the testing environment is relatively dim.Future research should focus on the development of more efficient methods for selecting measurement sites,with the combination of illuminance meters equipped with wireless probes and storage functions to enhance testing efficiency.

Objective:To investigate the role of vitamin E succinate (VES) in inducing autophagy of human gastric cancer cells by activating calcium redistribution through inositol 1, 4, 5-trisphosphate receptors (IP 3R) pathway. Methods:Human gastric cancer lines MKN28 (moderately differentiated) and MKN45 (poorly differentiated) cells were cultured in vitro in March 2022. Gastric cancer cells were treated with VES at different doses for 24 h, and cell viability was measured by CCK-8 method to determine VES dose for subsequent study. The experiment was set up with solvent control group (0.1% ethanol), VES dose groups, 100 nmol/L rapamycin (RAPA) as autophagy positive control group (RAPA group), 15 μg/ml tunicamycin (TM) was used as the endoplasmic reticulum stress (ERS) positive control group (TM group), 10 μmol/ml 2-aminoethyl diphenylborinate (2-APB group) was used to inhibit IP 3R (2-APB group) and VES+2-APB group. The occurrence of autophagosomes in gastric cancer cells was observed by transmission electron microscopy, and microtubule associated protein 1 light chain 3 (LC3), Beclin1, IP 3R, glucose-regulated protein 75 (Grp75), voltage-dependent anion channel 1 (VDAC1) protein expression was detected by western blotting. Fluo-4 AM was used to label intracellular calcium ions, Rhod-2 AM was used to label mitochondrial calcium ions, and the fluorescence intensity of calcium ions was observed by fluorescence microscope. One-way analysis of variance was used to compare the means among multiple groups, and LSD- t method was used for pairwise comparison. Results:CCK-8 results showed that compared with solvent control group, the proliferation rates of MKN28 cells in 10-100 μg/ml VES group and MKN45 cells in 20-100 μg/ml VES group were significantly decreased ( P<0.05). Subsequent VES dosages were determined according to the growth curve, MKN28 was 5, 10, 20, 40 μg/ml, and MKN45 was 10, 20, 40, 80 μg/ml. The results of transmission electron microscopy and fluorescence showed that autophagosomes were formed in MKN28 cells in 5 and 20 μg/ml VES groups and MKN45 cells in 10 and 40 μg/ml VES groups, and the fluorescence intensity of calcium ions in cytoplasm and mitochondria was significantly higher than that in solvent control group ( P<0.05). Compared with solvent control group, LC3, Beclin1, IP 3R, Grp75 and VDAC1 protein expressions of MKN28 cells in 20 and 40 μg/ml VES groups and MKN45 cells in 40 and 80 μg/ml VES groups were significantly increased ( P<0.05). After inhibiting IP 3R with 2-APB, the expression levels of IP 3R, Grp75 and VDAC1 in two kinds of gastric cancer cells in VES+2-APB group were significantly decreased compared with VES group ( P<0.05). The fluorescence results showed that the fluorescence intensity of cytoplasmic and mitochondrial calcium ions in VES+2-APB groups was significantly lower than that in VES group ( P<0.05). Compared with VES group, LC3 and Beclin1 protein expressions in two kinds of gastric cancer cells in VES+2-APB groups were significantly decreased ( P<0.05) . Conclusion:VES may activate intracellular calcium redistribution through IP 3R-Grp75-VDAC1 calcium channel and induce autophagy in gastric cancer cells.

Objective Through organizing a proficiency evaluation activity for animal illuminance testing laboratories,to assess the accuracy of testing data from participating laboratories,and to propose suggestions for testing methods.Methods In September 2024,China National Institute for Food and Drug Control(NIFDC)organised reference laboratories to conduct on-site testing through open registration.A total of 35 laboratories participated,completed on-site testing,and submitted their reports.The samples to be tested were two adjacent guinea pig breeding rooms in the NIFDC laboratory animal facility.In order to reduce the impact of room voltage fluctuations on animal illumination,chip on board(COB)light sources powered by regulated power supply were used,and brightness was adjusted by regulating voltage output.Split-level test sample pairs were used to set animal illuminance in both rooms,and the reference laboratories conducted testing according to Laboratory animals——Environment and housing facilities(GB 14925-2023).Each reference laboratory was assigned a 3-digit random code,conducted 2 tests for each breeding room,and submitted an on-site test report,original records,and illuminance meter verification or calibration certificate.WPS Spreadsheet 12.1 was used to summarize data,Grubbs' test(α=0.01)was used to check the data and remove outliers,and SPSS 26.0 software was used for data processing and graph drawing.The median value from each reference laboratory was used as the specified value,the robust standard deviation was used as the uncertainty,the robust z-score method(both intra-laboratory and inter-laboratory z-scores)was used to evaluate the test results from each laboratory,and the factors affecting results were analyzed from aspects of personnel,equipment,and operational environment.Results Under the detection level of α=0.01,no outliers were identified.The specified values for Room 1 and Room 2 were 17.80 lx and 19.00 Ix,respectively.The results obtained from 34 laboratories were evaluated as"satisfactory",while the results from one laboratory were"unsatisfactory".Through analysis of illuminance meter calibration certificates from various laboratories,it was found that some reference laboratories had insufficient calibration points and coverage,which caused test results to fail to accurately reflect the actual illuminance of the facility.Conclusion The present study reveals that factors such as personnel,equipment,and operation environment have different impacts on animal illuminance measurements.The present study concentrates exclusively on animal illuminance in guinea pig breeding rooms,where the testing environment is relatively dim.Future research should focus on the development of more efficient methods for selecting measurement sites,with the combination of illuminance meters equipped with wireless probes and storage functions to enhance testing efficiency.

AIM:This study aims to investigate whether vitamin E succinate(VES)induces autophagy in hu-man gastric cancer cells through the promotion of mitochondria-associated endoplasmic reticulum membranes(MAMs).METHODS:Human gastric cancer cell lines MKN28 and MKN45 were cultured in vitro.Cell viability was assessed us-ing the CCK8 assay,and two cell growth curves were plotted to determine the treatment concentration of VES.Control groups,VES dose groups(MKN28:5,10,20,and 40 mg/L;MKN45:10,20,40,and 80 mg/L),an autophagy-posi-tive control group(rapamycin,RAPA,100 nmol/L),and a MAMs-positive control group(oligomycin A,10 mg/L)were set up.Cells were harvested after 24 h of treatment for subsequent experiments.The formation of autophagosomes and MAMs was observed using transmission electron microscopy.The expression levels of autophagy-related proteins,includ-ing beclin-1,LC3-II/LC3-I,and p62,were detected by Western blot.MAMs labeled with split green fluorescent protein(GFP)were visualized by fluorescence microscopy.The expression of mitofusin 2(MFN2),a key molecule of MAMs,was also detected by Western blot.To inhibit MFN2 specifically,the cells were treated with mitochondrial fusion inhibitor 8(MFI8)and simultaneously transfected with an MFN2 plasmid to achieve MFN2 overexpression(OE-MFN2).The cells were divided into control group,MFI8(20 μmol/L)group,VES groups(20 mg/L for MKN28 cells and 40 mg/L for MKN45 cells),VES+MFI8 group,OE-MFN2+MFI8 group and OE-MFN2+VES+MFI8 group.The MAMs were visualized by fluorescence microscopy,and the expression changes of MFN2,beclin-1 and LC3-II/I were detected by Western blot.RESULTS:The results of the CCK8 assay showed that VES significantly inhibited the viability of both human gastric can-cer cell lines(P<0.05).After VES treatment,the formation of typical autophagosomes and MAMs was observed in both cell lines by transmission electron microscopy.Fluorescence microscopy showed a significant increase in GFP signals of MAMs.Western blot analysis showed that with increasing doses of VES,the expression levels of MFN2,beclin-1,and LC3-II/I were significantly up-regulated,while that of p62 was significantly down-regulated(P<0.05).Compared with VES group,the cells pretreated with MFI8 followed by VES exposure showed markedly reduced GFP signals of MAMs and much lower protein levels of MFN2,beclin-1 and LC3-II/LC3-I(P<0.05).Transfection with an MFN2 overexpression plasmid rescued MFN2 expression.Compared with VES+MFI8 group,the cells in OE-MFN2+VES+MFI8 group had much higher protein expression levels of MFN2,beclin-1 and LC3-II/LC3-I(P<0.05).CONCLUSION:The VES may partici-pates in the regulation of autophagy in human gastric cancer cells by promoting the formation of MAMs.