OBJECTIVE To investigate the effects of metformin （Met） on liver injury in non-alcoholic steatohepatitis （NASH） rats by regulating the PI3K/AKT/PDGF signaling pathway. METHODS NASH model was constructed by feeding rats with a high- glucose and high-fat diet， and assigned into Model group， Met low-dose group （Met-L group， 100 mg/kg）， Met medium-dose group （Met-M group， 200 mg/kg）， Met high-dose group （Met-H group， 400 mg/kg）， and high dose of Met+PI3K activator group （Met-H+740 Y-P group， 400 mg/kg Met+50 mg/kg 740 Y-P）， with 12 rats in each group. Another 12 rats were regarded as the Control group. Each group of rats was orally administered/injected with the corresponding medication once a day for 6 consecutive weeks. The changes in body weight and liver index of rats were recorded and analyzed. The pathological damage [evaluation of non-alcoholic fatty liver disease activity score （NAS）]， lipid deposition （calculation of the proportion of oil red O-positive staining area）， and fibrosis （calculation of collagen deposition score） were observed in liver tissue of rats. The levels of inflammatory factors [interleukin-6 （IL-6） and tumor necrosis factor-α （TNF-α）] in serum and liver tissue， the levels of serum lipid metabolism indicators [total cholesterol （TC）， triglyceride （TG）， and low-density lipoprotein cholesterol （LDL-C）] and liver function indicators [aspartate aminotransferase （AST） and alanine Δ 基金项目 武汉市知识创新专项项目（No.2022020801010588）； aminotransferase （ALT）] were measured. The expression levels of PI3K/AKT/PDGF signaling pathway-related proteins and Caspase-3 in liver tissue of rats were determined. RESULTS Compared with the Control group， body weight， liver index， the levels of serum lipid metabolism indicators and liver function indicators， the levels of IL-6 and TNF-α in serum and liver tissue， the NAS， the proportion of oil red O-positive staining area， the collagen deposition fraction， and the levels of phosphorylated PI3K and AKT proteins， as well as the expression levels of PDGF and Caspase-3 proteins in liver tissue， were all significantly increased （P＜0.05）. The liver tissue showed severe pathological damage， characterized by an abundance of lipid droplets and pronounced collagen deposition. After the intervention with Met， the aforementioned quantitative indicators and pathological changes in rats were significantly improved in a dose- dependent manner （P＜0.05）. 740 Y-P could reverse the improvement effects of high dose of Met on the above indexes of rats （P＜ 0.05）. CONCLUSIONS Met can improve liver damage， and alleviate inflammatory reactions and liver fibrosis of NASH rats， the mechanism of which may be associated with inhibiting PI3K/AKT/PDGF signaling pathway.

In recent years, the deep integration of artificial intelligence (AI) into medical education has created new opportunities for teaching Biochemistry and Molecular Biology, while also offering innovative solutions to the pedagogical challenges associated with protein structure and function. Focusing on the case of anaplastic lymphoma kinase (ALK) gene mutations in non-small-cell lung cancer (NSCLC), this study integrates AI into case-based learning (CBL) to develop an AI-CBL hybrid teaching model. This model features an intelligent case-generation system that dynamically constructs ALK mutation scenarios using real-world clinical data, closely linking molecular biology concepts with clinical applications. It incorporates AI-powered protein structure prediction tools to accurately visualize the three-dimensional structures of both wild-type and mutant ALK proteins, dynamically simulating functional abnormalities resulting from conformational changes. Additionally, a virtual simulation platform replicates the ALK gene detection workflow, bridging theoretical knowledge with practical skills. As a result, a multidimensional teaching system is established—driven by clinical cases and integrating molecular structural analysis with experimental validation. Teaching outcomes indicate that the three-dimensional visualization, dynamic interactivity, and intelligent analytical capabilities provided by AI significantly enhance students’ understanding of molecular mechanisms, classroom engagement, and capacity for innovative research. This model establishes a coherent training pathway linking “fundamental theory-scientific research thinking-clinical practice”, offering an effective approach to addressing teaching challenges and advancing the intelligent transformation of medical education.

Objective To investigate the protective effect of dexmedetomidine(Dex)pretreatment on myocardial ischemia-reperfusion mice and the effect of Nod-like receptor protein 3(NLRP3)inflammatory signaling pathway.Methods C57BL/6J mice were randomly divided into sham group(only threading without ligation),model group(recovery after ligation of left anterior descending coronary artery),positive group(modeling after intraperitoneal injection of 1 mg·kg-1 trimetazidine),Dex group(modeling after intraperitoneal injection of 20 μg·kg-1 dexmedetomidine),MCC950 group(modeling after intraperitoneal injection of 10 mg·kg-1 NLRP3 inhibitor MCC950),12 mice in each group.Cardiac function indexes were detected at 24 h after reperfusion,the expression level of related proteins in myocardial tissue was detected by Western blot,enzyme-linked immunosorbent assay(ELISA)was used to detect the expression level of serum factor,myocardial antioxidant index was detected by kit method,and apoptosis was detected by Tunel method.Results The NLRP3 protein expression levels of sham group,model group,positive group,Dex group and MCC950 group were 0.31±0.05,1.06±0.07,0.52±0.05,0.65±0.07 and 0.39±0.04,respectively;the expression levels of apoptosis-associated granuloid protein(ASC)were 0.27±0.08,0.88±0.09,0.46±0.05,0.59±0.07 and 0.34±0.04,respectively;CK-MB levels were(25.64±2.94),(102.08±7.04),(49.61±7.70),(60.86±5.24)and(63.24±5.38)U·L-1,respectively;IL-6 levels were(104.78±10.73),(231.54±15.56),(158.20±16.54),(165.10±14.77)and(141.17±14.08)pg·mL-1,respectively;Tunel positive cell rates were(4.34±0.16)％,(25.98±1.58)％,(8.74±0.93)％,(11.06±1.07)％and(9.19±0.88)％,respectively.Sham group were compared with model group;Dex group and MCC950 group were compared with model group,the above indexes were statistically significant(all P＜0.05).Conclusion Dexmedetomidine preconditioning may prevent ischemia-reperfusion myocardial injury by inhibiting NLRP3/ASC/caspase-1 inflammatory pathway,inflammatory response and myocardial cell apoptosis.

20-hydroxyeicosatetraenoic acid(20-HETE)and epoxyeicosatrienoic acids(EETs)are products of enzyme metabolism of arachidonic acid(AA)by cytochrome P450(CYP).20-HETE is mainly produced by CYP4A,CYP4F metabolism of AA,which has a certain toxic effect on the cardiovascular and cerebrovascular system.EETS is mainly produced by CYP2J,CYP2C metabolizes AA,which has a certain protective effect on the cardiovascular and cerebrovascular system.This article reviews the effects and mechanisms of drugs related to AA-CYP-HETE/EETs metabolic pathway on cardiovascular diseases such as myocardial hypertrophy,hypertension,heart failure,and myocardial infarction,in order to provide a reference for the clinical use of cardiovascular diseases and provide ideas and directions for the basic research and development of cardiovascular disease treatment drugs.

Objective To study the pharmacokinetic characteristics of etoricoxib tablets in healthy Chinese subjects and to evaluate the bioequivalence and safety of the test and reference formulations.Methods In a randomised,single-dose,two-period,two-sequence crossover trial,28 healthy subjects were enrolled under the fasting and fed conditions,respectively,who received a single oral dose of 60 mg of etoricoxib tablets in the test or reference formulation.The concentration of etoricoxib in plasma was detected by LC-MS/MS,and the main pharmacokinetic parameters were calculated to evaluate bioequivalence and using WinNonlin 8.2 software.Results The main pharmacokinetic parameters of the test and reference preparations were as follows:The fasting condition Cmax of etoricoxib were(1 176.96±287.95)and(1 164.93±189.65)ng·mL-1;AUC0-t were(18 651.95±6 100.27)and(19 241.39±6 107.48)ng·h·mL-1;and AUC0-∞ were(19 939.15±7 553.27)and(20 536.31±7 223.40)ng·h·mL-1.The fed condition Cmax of etoricoxib were(913.50±184.72)and(878.59±164.35)ng·mL-1;and AUC0-t were(19 085.22±5 155.01)and(18 669.54±4 508.21)ng·h·mL-1;AUC0-∞ were(20 103.77±5 567.02)and(19 528.05±4 989.74)ng·h·mL-1.The 90％confidence intervals for the geometric mean ratios of the main pharmacokinetic parameters in the fasting and fed conditions fell between 80.00％and 125.00％.The incidence of adverse events in the fasting and fed conditions were 28.57％and 21.43％,respectively.Conclusion Two kinds of etoricoxib tablets are bioequivalent,and have similar safety in healthy Chinese subjects.

Objective To compare the bioavailability and bioequivalence of pivastatin calcium dispersive tablets in healthy Chinese subjects.Methods A single dose of pitavastatin calcium(2 mg)was orally administered to the test preparation or reference preparation under fasting and postprandial conditions,respectively.The plasma concentrations of pitavastatin calcium were measured at different time points before and after administration by high performance liquid chromatography-tandem mass spectrometry(HPLC-MS/MS).The bioequivalence of the two formulations was evaluated.Results Subjects received pitavastatin calcium test preparation and reference preparation in fasting condition,the Cmax were(47.79±23.99)and(46.03±21.82)ng·L-1;AUC0_,were(96.56±42.64)and(97.96±35.40)ng·h·L-1;AUC0_∞ were(102.09±43.01)and(103.46±35.62)ng·h·L-1,respectively.The 90％confidence intervals of the geometric mean ratios of Cmax,AUC0_t and AUC0-∞ of pitavastin-calcium test formulation and reference formulation were 96.28％-111.16％,94.46％-101.19％and 94.77％-101.31％,respectively.Subjects received pitavastatin calcium test preparation and reference preparation in fasting condition,the Cmax were(27.32±10.68)and(28.58±11.39)ng·L-1;AUC0_t were(82.76±27.58)and(84.06±29.12)ng·h·L-1;AUC0_∞ were(87.88±26.93)and(89.29±29.18)ng·h·L-1,respectively.The 90％confidence intervals of the geometric mean ratios of Cmax,AUC0_t and AUC0_∞ of the test formulation and the reference formulation of pitavastatin calcium were 87.39％-102.10％,94.62％-101.34％and 94.88％-101.47％,respectively.All of them were within the bioequivalence range of 80.00％to 125.00％.Conclusion Two pivastatin calcium dispersion tablets were bioequivalent and safe in healthy Chinese adult subjects.

Objective Viral encephalitis is an infectious disease severely affecting human health.It is caused by a wide variety of viral pathogens,including herpes viruses,flaviviruses,enteroviruses,and other viruses.The laboratory diagnosis of viral encephalitis is a worldwide challenge.Recently,high-throughput sequencing technology has provided new tools for diagnosing central nervous system infections.Thus,In this study,we established a multipathogen detection platform for viral encephalitis based on amplicon sequencing. Methods We designed nine pairs of specific polymerase chain reaction(PCR)primers for the 12 viruses by reviewing the relevant literature.The detection ability of the primers was verified by software simulation and the detection of known positive samples.Amplicon sequencing was used to validate the samples,and consistency was compared with Sanger sequencing. Results The results showed that the target sequences of various pathogens were obtained at a coverage depth level greater than 20×,and the sequence lengths were consistent with the sizes of the predicted amplicons.The sequences were verified using the National Center for Biotechnology Information BLAST,and all results were consistent with the results of Sanger sequencing. Conclusion Amplicon-based high-throughput sequencing technology is feasible as a supplementary method for the pathogenic detection of viral encephalitis.It is also a useful tool for the high-volume screening of clinical samples.

Objective:To report the results of national surveillance on the distribution and antimicrobial resistance profile of clinical Gram-negative bacteria isolates from bloodstream infections in China in 2022.Methods:The clinical isolates of Gram-negative bacteria from blood cultures in member hospitals of national bloodstream infection Bacterial Resistant Investigation Collaborative System（BRICS）were collected during January 2022 to December 2022. Antibiotic susceptibility tests were conducted by agar dilution or broth dilution methods recommended by Clinical and Laboratory Standards Institute（CLSI）. WHONET 5.6 and SPSS 25.0 software were used to analyze the data.Results:During the study period，9 035 strains of Gram-negative bacteria were collected from 51 hospitals，of which 7 895（87.4%）were Enterobacteriaceae and 1 140（12.6%）were non-fermenting bacteria. The top 5 bacterial species were Escherichia coli（ n=4 510，49.9%）， Klebsiella pneumoniae（ n=2 340，25.9%）， Pseudomonas aeruginosa（ n=534，5.9%）， Acinetobacter baumannii complex（ n=405，4.5%）and Enterobacter cloacae（ n=327，3.6%）. The ESBLs-producing rates in Escherichia coli， Klebsiella pneumoniae and Proteus spp. were 47.1%（2 095/4 452），21.0%（427/2 033）and 41.1%（58/141），respectively. The prevalence of carbapenem-resistant Escherichia coli（CREC）and carbapenem-resistant Klebsiella pneumoniae（CRKP）were 1.3%（58/4 510）and 13.1%（307/2 340）；62.1%（36/58）and 9.8%（30/307）of CREC and CRKP were resistant to ceftazidime/avibactam combination，respectively. The prevalence of carbapenem-resistant Acinetobacter baumannii（CRAB）complex was 59.5%（241/405），while less than 5% of Acinetobacter baumannii complex was resistant to tigecycline and polymyxin B. The prevalence of carbapenem-resistant Pseudomonas aeruginosa（CRPA）was 18.4%（98/534）. There were differences in the composition ratio of Gram-negative bacteria in bloodstream infections and the prevalence of main Gram-negative bacteria resistance among different regions，with statistically significant differences in the prevalence of CRKP and CRPA（ χ2=20.489 and 20.252， P<0.001）. The prevalence of CREC，CRKP，CRPA，CRAB，ESBLs-producing Escherichia coli and Klebsiella pneumoniae were higher in provinicial hospitals than those in municipal hospitals（ χ2=11.953，81.183，10.404，5.915，12.415 and 6.459， P<0.01 or <0.05），while the prevalence of CRPA was higher in economically developed regions（per capita GDP ≥ 92 059 Yuan）than that in economically less-developed regions（per capita GDP <92 059 Yuan）（ χ2=6.240， P=0.012）. Conclusions:The proportion of Gram-negative bacteria in bloodstream infections shows an increasing trend，and Escherichia coli is ranked in the top，while the trend of CRKP decreases continuously with time. Decreasing trends are noted in ESBLs-producing Escherichia coli and Klebsiella pneumoniae. Low prevalence of carbapenem resistance in Escherichia coli and high prevalence in CRAB complex have been observed. The composition ratio and antibacterial spectrum of bloodstream infections in different regions of China are slightly different，and the proportion of main drug resistant bacteria in provincial hospitals is higher than those in municipal hospitals.

Objective:To investigate the effects of SINC, a novel secreted protein of Chlamydia psittaci, on the apoptosis of host cells and the regulatory role of mitogen-activated protein kinase/extracellular signal-regulated kinase (MAPK/ERK) signaling pathway in it. Methods:HeLa cells were treated with recombinant SINC. The expression of Bax and Bcl-2 at protein level and the phosphorylation of ERK1/2 were analyzed by Western blot. Hoechst 33258 staining was used to detect the apoptosis of HeLa cells after SINC stimulation. Moreover, HeLa cells were pretreated with MEK1/2 inhibitor U0126 (50 μmol/L), and then stimulated with different concentrations of SINC for different time. Flow cytometry was used to detect the changes in cell apoptosis rates and Western blot was performed to detect the expression of Bax and Bcl-2 at protein level.Results:Treating HeLa cells with 10 μg/ml of SINC for 18 h resulted in down-regulated Bax and up-regulated Bcl-2 at protein level. Besides, the ratio of Bax/Bcl-2 was the lowest and a significant increase in the ratio of phosphorylated ERK1/2 (p-ERK1/2) to ERK1/2 was observed. Hoechst 33258 staining showed that the number of apoptotic bodies decreased significantly after stimulating HeLa cells with 5, 10 and 15 μg/ml of SINC. In the presence of MEK1/2 inhibitor U0126, the expression of Bcl-2 at protein level was down-regulated, while the expression of cleaved PARP was significantly up-regulated. Flow cytometry showed a significantly enhanced apoptosis of HeLa cells.Conclusions:SINC can inhibit the apoptosis of HeLa cells through activating the MAPK/ERK signaling pathway.

Objective To clarify the high-touch surface in oral diagnosis and treatment procedures,provide basis and guidance for cleaning and disinfection.Methods The direct observation method was used to investigate the tou-ch time and frequency of environmental surfaces in 7 outpatient departments of a tertiary stomatology hospitals in Beijing.The average touch frequency,95％confidence interval and cumulative touch rate were calculated.Results In oral diagnosis and treatment procedures,the average touch frequency of the environmental surface was 26.75 times per procedure,with the highest in endodontics(46.25 times per procedure)and the lowest in the oral mucosal specialty(10.19 times per procedure).The high-touch surface consisted of the shadowless lamp handle,manipula-tion panel and handle on dental unit(doctor's side),computer keyboard and mouse,handle and line front end of three way syringe,as well as dental high speed handpiece and line front end,with average touch frequencies of 3.99,3.85,2.65,1.86,and 1.40 times per procedure.The high-touch surface in all stomatology specialties in-cluded the manipulation panel and handle on dental unit(doctor's side),75％of specialties included computer key-board and mouse,and the shadowless lamp handle has the highest touch frequency in 50％of specialties.The ave-rage touch frequency of the environmental surface was highest(113.50 times per procedure)during crown prepara-tion procedure,and the lowest(8.50 times per procedure)during the orthodontic consultations.Conclusion The high-touch surface of different dental specialties and different diagnosis and treatment procedures are different.Me-dical institutions should take corresponding cleaning,disinfection and management measures according to the actual situation of high-touch surface in stomatology departments,so as to effectively improve the quality of environmental cleaning and disinfection.