ObjectiveTo evaluate the detection specificity for clinical samples and the detection capability for standard substances of five commercially available multiplex polymerase chain reaction (PCR) nucleic acid detection kits (hereinafter referred to as the kits) for respiratory pathogens, and to provide a reference for selecting appropriate detection kits for multi-pathogen nucleic acid testing of respiratory infections. MethodsA total of 60 respiratory pathogen-positive clinical samples with known redults were selected and tested using the five kits (labeled as A, B, C, D, and E). The detection rates and Kappa coefficients were calculated to evaluate the consistency between the results from these kits and those from single-pathogen PCR kits. According to the limit of detection (LOD) provided by the kits, standard substances of respiratory pathogens (including 12 types such as influenza virus, Mycoplasma pneumoniae, and Bordetella pertussis) were diluted to four concentrations (250, 500, 1 000, and 2 000 copies·mL⁻¹). All five kits were used for detection to evaluate their respective detection capabilities. ResultsCompared with the results from single-pathogen PCR kits, the five tested kits demonstrated good consistency (all Kappa >0.80). Among them, Kit A had the highest detection rate (100.00%), followed by Kits C and E (98.33%), and then Kits B and D (95.00%). All five kits showed a relatively low false negative rate (FNR) for samples with a cycle threshold (Ct) value ≤35 (≤2.38%). However, for samples with Ct values>35, the FNR increased accordingly(average FNR=6.67%, P=0.029). Kit C exhibited the highest detection sensitivity for the tested standard substances (average LOD: 458.33 copies·mL⁻¹), followed by Kit D, then Kits A/E, and finally Kit B. ConclusionThe five multiplex PCR kits showed good consistency with single-pathogen detection results, but each had its own performance emphasis. Kit A, with the highest detection rate and high throughput, is suitable for targeted viral screening. Kit B, covering the broadest pathogen spectrum (including fungi/bacteria), is suitable for comprehensive respiratory pathogen screening. Kits C, D and E, are applicable for rapid detection. It is important to note that the detection efficacy of all kits decreases for low viral load samples with Ct values >35. In practical application, selection should be based on specific screening objectives, throughput requirements, and sample types.

ObjectiveTo sort out the pre-ethical review status of drug clinical trials in a tertiary A hospital， summarize practical experience， and provide references for pre-ethical review. MethodA retrospective analysis was conducted on the ethical review of pre-ethical projects in a tertiary A hospital from 2018 to 2023. ResultsFrom 2018 to 2023， a total of 285 pre-ethical projects were reviewed in this tertiary hospital， including 79 projects where it served as the leading unit. Among these， 279 clinical trials ultimately received approval of the ethical review committee， while 6 projects were not approved due to sponsors’ refusal to modify study protocols. In terms of trial phases， phase III clinical trials constituted the largest proportion， and the oncology center was the department with the highest number of projects. In 2023， the average time for pre-ethical review projects from submission to approval was 43 calendar days， 3 days longer than for other project types. In 2023， this hospital reviewed 75 pre-ethical review projects， including 58 where it served as a participating unit. Among these， 42 projects received approval later than the leading unit， while 9 projects were approved earlier than the leading unit’s ethical approval date. Among the pre-ethical review projects applied in 2023， 70 projects obtained drug clinical trial notifications from the National Medical Products Administration， while 5 projects had unknown notification status due to the lack of ethical approval or discontinuation. Of the projects receiving approval notifications， 16 were annotated with matters requiring enhanced attention during clinical trials， and 7 necessitated protocol improvements. ConclusionThis tertiary A hospital has implemented multiple measures to optimize the management of pre-ethical review. This ethical review model does not compromise the quality of ethical review and contributes to accelerating the initiation of clinical trials. Notably， it is crucial to construct a patient-centered drug development system. Clinical trials guided by this concept align with ethical values， laying the foundation for the smooth conduct of clinical trials， assisting in the drug development process， and safeguarding patients’ medication needs.

Objective To gain insights into the biological characteristics of different populations of Culex tritaeniorhynchus within and around the Yellow Sea wetland from the perspective of the occurrence of resistance, we investigated the levels of resistance to deltamethrin and kdr gene mutation in the wetland and its peripheral areas. Methods Specimens were collected from Cx. tritaeniorhynchus populations at two monitoring sites in the Rare Bird National Nature Reserve and Tiaozi Ni Wetland Scenic Area, and also from two populations in Yancheng City and the Liuhe District of Nanjing, and the resistance of these mosquitoes to deltamethrin was determined using the CDC biotest bottle method. For each concentration of deltamethrin assessed, a random subset of exposed specimens was selected for amplification of the kdr gene fragment, followed by Sanger sequencing to identify and analyze resistance-associated mutations. Results The LC50 levels of deltamethrin among mosquitoes from the four populations in Luhe, Yancheng, the Rare Bird National Nature Reserve and the Tiaozi Ni Wetland Scenic Area were 2.048 5, 7.798 2, 3.473 3, and 17.695 5 mg/mL, respectively, with corresponding concentrations of deltamethrin ranging from 0.005 to 5.000,0.050 to 50.000,0.050 to 25.000 and 0.050 to 50.000 mg/mL, respectively. Furthermore, the ranges of the KT50 values were 11.76-107.43, 67.05-216.30,29.77-107.43 and 28.40-329.51 min; the 1-h knockdown rates were 34.58%-99.15%, 9.52%-43.80%, 55.09%-73.01%, and 10.09%-68.07%; and the 24-h mortality rates were 12.15%-67.52%,9.52%-79.56%,13.17%-82.21%, and 11.01%-78.99%, respectively. With respect to kdr gene mutation, we assayed a total of 63,70,59, and 57 mosquitoes for the four populations, for which we detected L1014F mutation frequencies of 14.29%, 35.00%, 20.34%, and 31.58%, respectively, with a majority of these mutations being heterozygous for resistance. In addition, five adult mosquitoes were identified has having synonymous mutations at site 1011[i. e. , AAT(asparagine)mutation to AAC(asparagine)]. Conclusions Our findings revealed the clear resistance of Cx. tritaeniorhynchus to deltamethrin in the Yancheng region of the Yellow Sea wetland, and the resistance phenotype and kdr frequency of Cx. tritaeniorhynchus in the wetland environment were comparable to those of Cx. tritaeniorhynchus in the wetland environment, thereby indicating that the resistance of different populations of Cx. tritaeniorhynchus was homogeneous under the pressure of different insecticide selection within and around the wetland. However, the underlying mechanisms need to be further studied.

Aim To explore the effect of C1q/tumor necrosis factor-related protein 6(CTRP6)on cardio-myocyte pyroptosis in rats with acute myocardial infarc-tion(AMI)inhibited by quercetin(Que)and the un-derlying mechanism.Methods A rat model of AMI was established by ligation of the left anterior descend-ing coronary artery.Firstly,the rats were divided into the sham operation group(Sham),AMI group,low-dose quercetin group(Que-L,25 mg·kg-1),high-dose quercetin group(Que-H,100 mg·kg-1),fosino-pril sodium tablet group(fosinopril,4 mg·kg-1),with 10 rats in each group.Each group was orally ad-ministered with the corresponding drug dose or physio-logical saline once a day for 14 consecutive days.Doppler ultrasonography was used to detect the changes of cardiac function,the pathological changes of rat myo-cardial tissue were observed,and Western blot was used to detect the myocardial tissue pyroptosis-related proteins and CTRP6 expression.The optimal dosage of Que was determined through the screening of the above experimental indicators.Subsequently,the experiment was divided into the Sham,AMI,Que(100 mg·kg-1),Que+si-NC group,Que+si-CTRP6,with 10 rats in each group.After 14 days of intervention,myo-cardial infarction,myocardial injury indicators,pyropto-sis,CTRP6,and PI3K/Akt pathway protein expression were detected.Results Compared with the Sham group,the LVEDV and LVESV significantly increased,the EF and FS significantly decreased(P＜0.05),the myocardial tissue had obvious pathological damage,the degree of fibrosis increased,the myocardial infarction area,LDH,CK-MB,cTnI levels,TUNEL positive cell ratio increased,NLRP3,cleaved caspase-1,GSDMD-N,IL-1 β,IL-18 expression increased,and CTRP6 expres-sion,p-PI3K/PI3K,p-Akt/Akt ratio decreased in the AMI group(P＜0.05).Compared with the AMI group,Que-L and Que-H rats showed reduced cardiac function indicators and pathological damage to myocar-dial tissue,decreased myocardial infarction area,LDH,CK-MB,cTnI levels,decreased TUNEL positivity rate(P＜0.05),decreased expression of pyroptosis related proteins,and increased expression of CTRP6 and PI3K/Akt pathway proteins(P＜0.05),all of which were dose-dependent.Compared with the Que group,the changes in the above indicators in the Que+si-CTRP6 group rats were significantly reversed.Conclu-sions Que can inhibit cardiomyocyte pyroptosis and improve myocardial infarction in AMI rats,and its mechanism is related to up-regulating CTRP6 expres-sion and promoting the activation of PI3 K/Akt signa-ling pathway.

This study was aimed at preliminarily investigating the genetic and antimicrobial resistance characteristics of Salmonella Alachua isolates through whole-genome analyses.Five Salmonella Alachua isolates from various sources(both hu-man and non-human)were collected and identified.Phenotype and serotype verification,antimicrobial susceptibility testing,and whole-genome sequencing were performed.Virulence genes,antimicrobial resistance genes,and plasmid replicons were predicted according to globally available Salmonella Alachua genomic data.A phylogenetic tree was constructed to explore the genetic background.The first report of Salmonella Alachua in China emerged in Shanghai in 2015,and patients presented pri-marily with diarrhea.The isolates have been found predominantly in the eastern and southern coastal regions.Among the five i-solates analyzed,four belonged to sequence type(ST)2061,and one belonged to ST1298.All isolates were susceptible to most commonly used clinical antibiotics.Whole-genome analyses revealed that two ST2061 strains carried the blaKPC-2 gene,and one ST1298 strain carried the fosA7 gene.Phylogenetic analysis of global Salmonella Alachua populations indicated that the ST2061 clone belonged to the C1 clade,which was closely related to strains from the UK,whereas the ST1298 clone was found in the C4 clade,a globally disseminated fosA 7-positive lineage.This study provides initial insights into the genetic and antimi-crobial resistance characteristics of Salmonella Alachua in China,highlighting the presence of strains carrying blaKPC-2 and fo-sA7 genes.These findings may provide a reference for future large-scale molecular epidemiological surveillance and source-trac-ing efforts,and they underscore the importance of enhanced resistance monitoring for Salmonella Alachua.

This study was aimed at understanding the prevalence and drug resistance status of Salmonella of waterfowl ori-gin in the Guangdong region in the past decade,to guide prevention and control efforts.The drug-sensitive paper slide method was used to conduct drug susceptibility testing on 314 waterfowl-originating Salmonella strains isolated from 238 waterfowl farms in the Guangdong region from 2013 to 2023.The isolated Salmonella strains were most resistant to penicillin,amoxicil-lin,cefradine,and cefazolin in the β-lactam group;sulphadoxine dimethylpyrimidine in the sulphonamide group;and tetracy-cline in the tetracycline group.The resistance rates ranged from 73.57％to 89.49％.The highest sensitivity was observed to amikacin,gentamicin,and kanamycin in the aminoglycoside group,and norfloxacin in the quinolone group,with susceptibility rates all exceeding 50％.The 280 strains of Salmonella showed multi-drug resistance to six classes of antimicrobial drugs and high resistance(as much as 60.83％)to five drug classes.Correlation analysis revealed the highest correlations for florfenicol with gentamicin,and for amoxicillin with penicillin(r=0.650 for both),followed by gentamicin with kanamycin(r=0.620).Salmonella resistance in waterfowl in Guangdong Province was generally severe and showed a complex pattern of drug resist-ance.Detection of waterfowl pathogens should be strengthened to prevent the spread of drug-resistant bacteria and support ra-tional use of antibiotics.This work provides a reference for Salmonella prevention and control in waterfowl farms.

Aim To explore the effect of C1q/tumor necrosis factor-related protein 6(CTRP6)on cardio-myocyte pyroptosis in rats with acute myocardial infarc-tion(AMI)inhibited by quercetin(Que)and the un-derlying mechanism.Methods A rat model of AMI was established by ligation of the left anterior descend-ing coronary artery.Firstly,the rats were divided into the sham operation group(Sham),AMI group,low-dose quercetin group(Que-L,25 mg·kg-1),high-dose quercetin group(Que-H,100 mg·kg-1),fosino-pril sodium tablet group(fosinopril,4 mg·kg-1),with 10 rats in each group.Each group was orally ad-ministered with the corresponding drug dose or physio-logical saline once a day for 14 consecutive days.Doppler ultrasonography was used to detect the changes of cardiac function,the pathological changes of rat myo-cardial tissue were observed,and Western blot was used to detect the myocardial tissue pyroptosis-related proteins and CTRP6 expression.The optimal dosage of Que was determined through the screening of the above experimental indicators.Subsequently,the experiment was divided into the Sham,AMI,Que(100 mg·kg-1),Que+si-NC group,Que+si-CTRP6,with 10 rats in each group.After 14 days of intervention,myo-cardial infarction,myocardial injury indicators,pyropto-sis,CTRP6,and PI3K/Akt pathway protein expression were detected.Results Compared with the Sham group,the LVEDV and LVESV significantly increased,the EF and FS significantly decreased(P＜0.05),the myocardial tissue had obvious pathological damage,the degree of fibrosis increased,the myocardial infarction area,LDH,CK-MB,cTnI levels,TUNEL positive cell ratio increased,NLRP3,cleaved caspase-1,GSDMD-N,IL-1 β,IL-18 expression increased,and CTRP6 expres-sion,p-PI3K/PI3K,p-Akt/Akt ratio decreased in the AMI group(P＜0.05).Compared with the AMI group,Que-L and Que-H rats showed reduced cardiac function indicators and pathological damage to myocar-dial tissue,decreased myocardial infarction area,LDH,CK-MB,cTnI levels,decreased TUNEL positivity rate(P＜0.05),decreased expression of pyroptosis related proteins,and increased expression of CTRP6 and PI3K/Akt pathway proteins(P＜0.05),all of which were dose-dependent.Compared with the Que group,the changes in the above indicators in the Que+si-CTRP6 group rats were significantly reversed.Conclu-sions Que can inhibit cardiomyocyte pyroptosis and improve myocardial infarction in AMI rats,and its mechanism is related to up-regulating CTRP6 expres-sion and promoting the activation of PI3 K/Akt signa-ling pathway.

This study was aimed at understanding the prevalence and drug resistance status of Salmonella of waterfowl ori-gin in the Guangdong region in the past decade,to guide prevention and control efforts.The drug-sensitive paper slide method was used to conduct drug susceptibility testing on 314 waterfowl-originating Salmonella strains isolated from 238 waterfowl farms in the Guangdong region from 2013 to 2023.The isolated Salmonella strains were most resistant to penicillin,amoxicil-lin,cefradine,and cefazolin in the β-lactam group;sulphadoxine dimethylpyrimidine in the sulphonamide group;and tetracy-cline in the tetracycline group.The resistance rates ranged from 73.57％to 89.49％.The highest sensitivity was observed to amikacin,gentamicin,and kanamycin in the aminoglycoside group,and norfloxacin in the quinolone group,with susceptibility rates all exceeding 50％.The 280 strains of Salmonella showed multi-drug resistance to six classes of antimicrobial drugs and high resistance(as much as 60.83％)to five drug classes.Correlation analysis revealed the highest correlations for florfenicol with gentamicin,and for amoxicillin with penicillin(r=0.650 for both),followed by gentamicin with kanamycin(r=0.620).Salmonella resistance in waterfowl in Guangdong Province was generally severe and showed a complex pattern of drug resist-ance.Detection of waterfowl pathogens should be strengthened to prevent the spread of drug-resistant bacteria and support ra-tional use of antibiotics.This work provides a reference for Salmonella prevention and control in waterfowl farms.

Aim To compare the observation results of atomic force microscopy(AFM)and scanning electron microscopy(SEM),and to summarize the main problems and solutions of AFM in observing biological macromolecules,using the observa-tion subjects of protein samples purified by our research group.Methods The protein samples were diluted to 15 nmol·L-1 with PBS,fixed on glass slides,silicon wafers,and mica sheets,dried,and made into solid-phase observation samples.SEM sam-ples were plated with platinum before observation.The surface structures of proteins were observed using AFM and SEM,sample heights were calculated,and differences in results were com-pared.Results Protein samples with positive charges tended to shift to the right during observation due to the repulsion of the AFM probe;mica sheets could effectively eliminate the positive charge of proteins to avoid sample movement;PBS provided a stable environment for protein samples,but the crystallization of PBS salts interfered with probe operation and imaging clarity;SEM samples needed to be plated with platinum before observa-tion and could not achieve the precision of AFM.Conclusions Both AFM and SEM can directly observe protein structures in vitro,with AFM providing higher precision results;when protein sample stability permits,ultrapure water is preferred as the sol-vent carrier,and volatile liquids such as ethanol can also serve as solvent carriers.The application of AFM offers a new approach for pharmacological studies on interactions between biological macromolecules.

AIM:This study aims to investigate the role of dynamin-related protein 1(Drp1)in the A1 type activation of astrocytes and elucidate the underlying mechanism of abnormal astrocyte activation.METHODS:Rat astro-cyte line CTX-TNA2 was divided into control group,astrocyte-conditioned medium(ACM)group,and 5,10 and 25 μmol/L mitochondrial division inhibitor-1(Mdivi-1;a selective inhibitor of Drp1)+ACM group.The cells in ACM group were exposed to ACM containing interleukin-1α(IL-1α),tumor necrosis factor-α(TNF-α)and complement 1q(C1q)for 24 h to induce type A1 activation,while those in Mdivi-1+ACM group were pre-treated with various concentrations of Mdi-vi-1 for 2 h before stimulation with ACM for 24 h.RT-qPCR was used to detect the expression levels of A1 type activation-related indicators IL-1β,TNF-α and IL-10 mRNA in each group.Immunofluorescence was utilized to assess the expres-sion levels of A1 type activation marker molecules C3,inducible nitric oxide synthase(iNOS)and S100 calcium binding protein A10(S100A10).The level of mitochondrial reactive oxygen species(ROS)was measured using MitoSOX Red staining and flow cytometry analysis.The mitochondrial morphology was observed using the MICA full-field imaging analy-sis platform.Lastly,the expression level of mitochondrial fission protein 1(FIS1)and the activation level of Drp1 in each group were evaluated through immunoblotting analysis.RESULTS:The RT-qPCR and immunofluorescence results indi-cated that the ACM group exhibited significantly elevated levels of IL-1β and TNF-α mRNA,and C3 protein expression compared with control group,along with increased iNOS protein expression and reduced IL-10 mRNA and S100A10 pro-tein expression(P＜0.05).Interventions with 10 and 25 μmol/L Mdivi-1 effectively inhibited the rise in IL-1β and TNF-α mRNA,and C3 and iNOS protein expression induced by ACM,while promoting S100A10 expression.MitoSOX Red staining revealed a significant increase in mitochondrial ROS levels in astrocytes stimulated by ACM,which was effectively re-versed by Mdivi-1 intervention.The MICA full-field imaging analysis platform demonstrated that ACM induced the forma-tion of round-shaped mitochondria in astrocytes,while 10 and 25 μmol/L Mdivi-1 interventions facilitated the restoration of their tubular shape.Additionally,Western blot results confirmed that Mdivi-1 intervention effectively reversed the acti-vation of Drp1 and FIS1.CONCLUSION:The Drp1-mediated mitochondrial fission represents one of the intrinsic molecu-lar mechanisms underlying A1 type activation of astrocytes,and Mdivi-1,as a selective inhibitor of Drp1,can effectively inhibit abnormal astrocyte activation.