1.Influencing factors for condom use among men who have sex with men
LIU Jing ; ZHU Han ; YIN Jue ; XIA Manman ; LU Yi ; DAI Qing ; GU Chengjie ; LUO Zhen
Journal of Preventive Medicine 2026;38(2):115-118
Objective:
To investigate the status of condom use and its influencing factors among men who have sex with men (MSM), so as to provide a basis for improving condom utilization rates and AIDS prevention and control in this population.
Methods:
From May to October 2024, a snowball sampling method was employed to recruit MSM in Songjiang District, Shanghai Municipality. Self-administered questionnaires were used to collect data on demographic characteristics, AIDS-related knowledge, sexual behaviors, pre-exposure prophylaxis (PrEP) and post-exposure prophylaxis (PEP), and condom use in the past six months. Multivariable logistic regression model was used to analyze the influencing factors for consistent condom use.
Results:
A total of 921 MSM were surveyed, with a median age of 29.00 (interquartile range, 9.00) years. Among them, 697 (75.68%) were aware of AIDS-related knowledge, 826 (89.69%) expressed willingness to use PrEP, and 835 (90.66%) were willing to use PEP. Additionally, 787 (85.45%) MSM reported their age at first homosexual intercourse as ≥18 years, while 519 (56.35%) reported consistent condom use in the past six months. Multivariable logistic regression analysis revealed that MSM who were aware of AIDS-related knowledge (OR=0.582, 95% CI: 0.423-0.801), willing to use PrEP (OR =0.611, 95% CI: 0.385-0.969), and whose age at first homosexual intercourse was <18 years (OR=0.480, 95% CI: 0.330-0.700) were less likely to consistent use condoms.
Conclusion
The proportion of consistent condom use among the MSM remains relatively low, which is primarily associated with AIDS-related knowledge, willingness to use PrEP, and the age at first homosexual intercourse.
2.Specific extraction and analysis of synthesized proteins from mesenchymal stem cells transplanted into the ischemic heart
Wan-Er LU ; Ying DAI ; Mu-Han TANG ; Kang WEI ; Shu-Jia CHEN ; Huai HUANG ; Jing LIN ; Hao-Rong PENG ; Li-Xuan ZHOU ; Dun-Zheng HAN
Medical Journal of Chinese People's Liberation Army 2025;50(8):991-998
Objective To specifically extract and analyze nascent proteins synthesized by bone marrow mesenchymal stem cells(BMSCs)after transplantation into ischemic hearts using a technique employing mutant methionyl-tRNA synthetase(MetRSL247G)for nascent protein labeling,in order to explore the potential mechanisms of action in BMSCs post-transplantation.Methods Point mutation at position 274 of the MetRS gene in BMSCs was induced via lentiviral infection to enable azidonorleucine(ANL)-mediated labeling of nascent proteins in BMSCs.The labeling efficiency was verified by means of fluorescent non-canonical amino-acid tagging(FUNCAT).Thirty healthy female C57BL/6J mice(8-10 weeks old)were divided into control and experimental groups,with 15 mice in each group.The acute myocardial infarction model was constructed by ligating the left anterior descending coronary artery in experimental group,while control mice underwent only thoracotomy without coronary ligation.After modeling,both groups received intramyocardial injections of MetRSL247G-modified BMSCs(MetRSL247G-BMSCs)at 3 different sites in the peri-infarct ischemic region.Mice were intraperitoneally injected with ANL every 6 hours for 4 times on postoperative days 0,2,and 6(n=5 for each time point)respectively,euthanized 24 h after the last injection,and cardiac tissues were isolated.The newly synthesized and labeled proteins produced by BMSCs after transplantation into the myocardium of experimental and control groups were collected,using an enrichment technique for ANL-tagged proteins and liquid chromatography-tandem mass spectrometry(LC-MS)analysis.Gene ontology(GO)analysis,Kyoto Encyclopedia of Genes and Genomes(KEGG)pathway analysis,protein-protein interaction(PPI)analysis,and heatmap visualization analysis were performed to identify differentially expressed proteins at the 3 time points and screen key pathways and genes.Results Under fluorescence microscopy,the MetRSL247G lentivirus-infected BMSCs were observed to be labelled with mCherry signals,confirming the successful construction of the MetRSL247G-BMSCs cell line.Green fluorescent signals were detected only in nascent proteins in culture medium containing both MetRSL247G-BMSCs and ANL,validating the sensitivity and specificity of the labeling method.GO analysis revealed that differentially expressed proteins were primarily involved in basic cellular biological processes such as extracellular exosome formation,extracellular matrix organization,and focal adhesion.KEGG and PPI analyses indicated that the differential proteins were mainly involved in complement and coagulation cascade pathway,actin cytoskeleton regulation pathway,and apoptosis pathway.Heatmap analysis showed significantly upregulated expression of anti-apoptosis and cell adhesion-related factors in experimental group on day 1(P<0.05),upregulated anti-apoptotic factors,pro-apoptotic factors,and cell adhesion-related factors on day 3(P<0.05),and upregulated anti-apoptotic factors,cell differentiation-related factors,and cell adhesion-related factors on day 7(P<0.05)compared with control group.Expression of apoptosis-inducing factor 1 was significantly downregulated on days 1 and 7(P<0.05).On day 3,most differentially expressed proteins,including anti-apoptosis factors(Protein S100-A11,Clusterin,Gelsolin),pro-apoptosis factor(Cathepsin B),cell differentiation-related factor(Transgelin-2),and cell adhesion-related factors(Cofilin-1,Periostin,Fibronectin)were significantly upregulated(P<0.05).Conclusions The MetRSL247G mutation enables BMSCs to incorporate ANL and synthesize labeled proteins,confirming the feasibility of this nascent protein labeling technique.Nascent proteins of BMSCs in ischemic myocardium primarily contribute to extracellular exosome secretion and extracellular matrix organization.BMSCs may adapt to and respond to ischemic and hypoxic environments by influencing complement and coagulation cascades,activating inflammatory factors,regulating actin cytoskeleton structure,and modulating apoptosis,thereby maintaining the survival of BMSCs.
3.Comparative analysis of the therapeutic effects of transcranial magnetic stimulation targeting the primary motor cotice of handand the lower limb or sciatic nerve on motor dysfunction after a spinal cord injury
Xin ZHANG ; Yixing LU ; Xinyu LIU ; Tao HAN ; Xiangbo WU ; Chunqiu DAI ; Hua YUAN ; Xiaolong SUN
Chinese Journal of Physical Medicine and Rehabilitation 2025;47(8):710-714
Objective:To compare the effect of repeated transcranial magnetic stimulation (rTMS) targeting the M1 hand area, the M1 lower limb area, or the sciatic nerve on the motor functioning and ability in the activities of daily living of persons after a spinal cord injury (SCI).Methods:This was a retrospective analysis of data describing 86 hospitalized SCI patients. They were divided into four groups based on where the rTMS was applied: an M1 hand area group ( n=22), an M1 lower limb area group ( n=20), a sciatic nerve group ( n=24), and a control group ( n=20) who never received rTMS. In addition to conventional medication and rehabilitation training, the M1 hand area group, the M1 lower limb area group and the sciatic nerve group received 10Hz rTMS over the named area for 4 weeks. Before and after the treatment, the Spinal Cord Independence Measure (SCIM) total scores, SCIM indoor activity (SCIM12) sub-scores, Modified Barthel Index (MBI) scores, and lower extremity motor (LEMS) scores were compared among the four groups. Results:After the treatment, the average SCIM, SCIM12, MBI, and LEMS scores had improved significantly in all four groups. The average SCIM [10.00(4.00, 24.75] and MBI scores [12.00(6.75, 31.50)] of the M1 hand area group were then significantly better than the control group′s averages [3.50(0.00, 9.50) and 7.50(1.25, 17.75)]. There was also significantly greater improvement in the average LEMS score of the M1 hand area group [2.00(0.00, 10.00)] compared with both the sciatic nerve group [0.00(0.00, 2.00)] and the control group [0.00(0.00, 1.75)].Conclusions:High-frequency rTMS stimulation of the M1 hand area significantly promotes the recovery of lower limb motor function and self-care ability after an SCI. It is more effective than stimulating the M1 lower limb area or the sciatic nerve.
4.The value of thrombin generation and activated protein C resistance in thrombotic risk assessment for patients with lupus anticoagulant
Guiting ZHANG ; Aili JUERAITI ; Yu LIU ; Guanqun XU ; Han SHEN ; Jing DAI ; Xuefeng WANG ; Yeling LU
Chinese Journal of Laboratory Medicine 2025;48(8):979-984
Objective:To analyze the levels of thrombin generation and activated protein C resistance (APC-R) in lupus anticoagulant (LA)-positive patients, and to assess their effectiveness in predicting thrombotic risk in these patients.Methods:Retrospective case-control study. A total of 185 patients with positve LA [91 males, 94 females; age (47.59±19.14) years] in Ruijin Hospital of Shanghai Jiaotong University School of Medicine from November 1st, 2024 to March 31st, 2025 were included. Patients were stratified into thrombotic ( n=91) and non-thrombotic groups ( n=94) based on clinical diagnosis and imaging evidence of thrombosis. The basic characteristics and routine laboratory coagulation levels of LA-positive patients were analyzed. Post-test plasma samples were collected from 43 cases with positive or strongly positive LA, categorized into thrombotic ( n=23) and non-thrombotic ( n=20) groups. Additionally, plasma was collected from 80 healthy controls [40 males and 40 females, age (38.37±15.74) years]. Using simple random sampling method, plasma samples from 10 selected males and 10 selected females were mixed to make 1 group of healthy control, thus accordingly resulted in a total of 4 healthy control groups. Thrombin generation assays (TGA) were then employed to measure prothrombin generation and activated protein C resistance (APC-R) levels in the healthy control, non-thrombotic, and thrombotic groups. One-way analysis of variance was utilized to compare thrombin generation and APC-R levels across these groups. Results:Among the routine laboratory coagulation indexes, the median levels of activated partial thromboplastin time (APTT), fibrin degradation product (FDP) and protein C (PC) in thrombotic group were 30.9 (28.8, 35.5) s, 2.5 (1.3, 2.8) mg/L, and 107.0 (93.0, 127.0)%, respectively, which were significantly higher compared with the non-thrombosis group (all P<0.05). However, between the thrombotic and non-thrombotic group, no statistically significant differences were observed for the levels of prothrombin time (PT), thrombin time (TT), fibrinogen (Fg), or D-dimer (D-D) ( P>0.05). The TGA results showed that the total thrombin generation, the maximal thrombin generation and APC-R levels of patients in the thrombotic group were (1 118.72±387.34) nmol/L·min, (106.01±59.00) nmol/L and (0.33±0.22), respectively, which were significantly higher compared with those in the non-thrombotic group (all P<0.05). Conclusion:Significantly increased thrombin generation and enhanced APC-R were present in the LA-positive patients with thrombosis, indicating the important values of thrombin generation and APC-R in assessing thrombosis risk among this population.
5.National bloodstream infection bacterial resistance surveillance report 2023: Gram-positive bacteria
Chaoqun YING ; Jinru JI ; Zhiying LIU ; Qing YANG ; Haishen KONG ; Jiangqin SONG ; Hui DING ; Yanyan LI ; Yuanyuan DAI ; Haifeng MAO ; Pengpeng TIAN ; Lu WANG ; Yongyun LIU ; Yizheng ZHOU ; Jiliang WANG ; Yan JIN ; Donghong HUANG ; Hongyun XU ; Peng ZHANG ; Xinhua QIANG ; Hong HE ; Lin ZHENG ; Junmin CAO ; Zhou LIU ; Ying HUANG ; Yan GENG ; Haiquan KANG ; Dan LIU ; Guolin LIAO ; Lixia ZHANG ; Fenghong CHEN ; Yanhong LI ; Baohua ZHANG ; Haixin DONG ; Xiaoyan LI ; Donghua LIU ; Qiuying ZHANG ; Xuefei HU ; Liang GUO ; Sijin MAN ; Dijing SONG ; Rong XU ; Youdong YIN ; Kunpeng LIANG ; Aiyun LI ; Zhuo LI ; Hongxia HU ; Guoping LU ; Jinhua LIANG ; Qiang LIU ; Yinqiao DONG ; Jilu SHEN ; Shuyan HU ; Liang LUAN ; Jian LI ; Ling MENG ; Dengyan QIAO ; Xiusan XIA ; Bo QUAN ; Dahong WANG ; Chunhua HAN ; Xiaoping YAN ; Fei LI ; Shifu WANG ; Ping SHEN ; Yunbo CHEN ; Yonghong XIAO
Chinese Journal of Clinical Infectious Diseases 2025;18(2):118-132
Objective:To report the nationwide surveillance results of pathogenic profiles and antimicrobial resistance patterns of Gram-positive bloodstream infections in China in 2023.Methods:The clinical isolates of Gram-posttive bacteria from blood cultures were collected in member hospitals of National Bloodstream Infection Bacterial Resistant Investigation Collaborative System(BRICS)during January to December 2023. Antimicrobial susceptibility testing was performed using the dilution method recommended by the Clinical and Laboratory Standards Institute(CLSI). Statistical analyses were conducted using WHONET 5.6 and SPSS 25.0 software.Results:A total of 4 385 Gram-positive bacterial isolates were obtained from 60 participating center. The top five pathogens were Staphylococcus aureus( n=1 544,35.2%),coagulase-negative Staphylococci( n=1 441,32.9%), Enterococcus faecium( n=574,13.1%), Enterococcus faecalis( n=385,8.8%),and α-hemolytic Streptococci( n=187,4.3%). The prevalence of methicillin-resistant Staphylococcus aureus(MRSA)and methicillin-resistant coagulase-negative Staphylococci(MRCNS)was 26.2%(405/1 544)and 69.8%(1 006/1 441),respectively. Notably,all Staphylococci remained susceptible to glycopeptide or daptomycin. Staphylococcus aureus demonstrated excellent susceptibility(>97.0%)to cephalobiol,rifampicin,trimethoprim-sulfamethoxazole,linezolid,minocycline,tigecycline,and eravacycline. No Enterococcus exhibiting resistance to linezolid were detected. Glycopeptide resistance was uncommon but more frequent in Enterococcus faecium(resistance to vancomycin and teicoplanin:both 1.7%)compared to Enterococcus faecalis(both 0.3%). The detection rates of MRSA and MRCNS exhibited significant regional variations across the country( χ2=17.674 and 148.650,respectively,both P<0.001). No vancomycin-resistant Enterococci were detected in central China. Institutional comparison demonstrated higher prevalence of MRSA( χ2=14.111, P<0.001)and MRCNS( χ2=4.828, P=0.028)in provincial hospitals than that in municipal hospitals. Socioeconomic analysis identified elevated detection rates of both MRSA( χ2=18.986, P<0.001)and MRCNS( χ2=4.477, P=0.034)in less developed regions(per capita GDP
6.National bloodstream infection bacterial resistance surveillance report (2023) : Gram-negative bacteria
Jinru JI ; Zhiying LIU ; Chaoqun YING ; Qing YANG ; Haishen KONG ; Jiangqin SONG ; Hui DING ; Yanyan LI ; Yuanyuan DAI ; Haifeng MAO ; Pengpeng TIAN ; Lu WANG ; Yongyun LIU ; Yizheng ZHOU ; Jiliang WANG ; Yan JIN ; Donghong HUANG ; Hongyun XU ; Peng ZHANG ; Xinhua QIANG ; Hong HE ; Lin ZHENG ; Junmin CAO ; Zhou LIU ; Ying HUANG ; Yan GENG ; Haiquan KANG ; Dan LIU ; Guolin LIAO ; Lixia ZHANG ; Fenghong CHEN ; Yanhong LI ; Baohua ZHANG ; Haixin DONG ; Xiaoyan LI ; Donghua LIU ; Qiuying ZHANG ; Xuefei HU ; Liang GUO ; Sijin MAN ; Dijing SONG ; Rong XU ; Youdong YIN ; Kunpeng LIANG ; Aiyun LI ; Zhuo LI ; Hongxia HU ; Guoping LU ; Jinhua LIANG ; Qiang LIU ; Yinqiao DONG ; Jilu SHEN ; Shuyan HU ; Liang LUAN ; Jian LI ; Ling MENG ; Dengyan QIAO ; Xiusan XIA ; Bo QUAN ; Dahong WANG ; Chunhua HAN ; Xiaoping YAN ; Fei LI ; Shifu WANG ; Ping SHEN ; Yunbo CHEN ; Yonghong XIAO
Chinese Journal of Clinical Infectious Diseases 2025;18(1):47-62
Objective:To report the results of bacterial resistant investigation collaborative system(BRICS)on the distribution and antimicrobial resistance profile of clinical Gram-negative bacteria isolates from bloodstream infections in China in 2023,and provide reference for clinical tretment of bloodstream infections and prevention and control of bacterial resistance.Methods:The clinical isolates of Gram-negative bacteria from blood cultures in member hospitals of BRICS were collected during January 2023 to December 2023. 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 were used to analyze the data.Results:During the study period,11 492 strains of Gram-negative bacteria were collected from 60 hospitals,of which 10 098(87.9%)were Enterobacterales and 1 394(12.1%)were non-fermentative bacteria. The top 5 bacterial species were Escherichia coli(50.0%), Klebsiella pneumoniae(26.1%), Pseudomonas aeruginosa(5.1%), Acinetobacter baumannii complex(5.0%)and Enterobacter cloacae complex(4.1%). The ESBL-producing rates in Escherichia coli, Klebsiella pneumoniae and Proteus mirablilis were 46.8%(2 685/5 741),18.3%(549/2 999)and 44.0%(77/175),respectively. The prevalence of carbapenem-resistant Escherichia coli(CREC)and carbapenem-resistant Klebsiella pneumoniae(CRKP)were 1.3%(76/5 741)and 15.0%(450/2 999);32.9%(25/76)and 78.0%(351/450)of CREC and CRKP were sensitive to ceftazidime/avibactam combination,respectively. 94.7%(72/76)and 90.2%(406/450)of CREC and CRKP were sensitive to aztreonam/avibactam combination. Furthermore,57.9%(44/76)and 79.1%(356/450)were sensitive to imipenem/relebactam combination. The prevalence of carbapenem-resistant Acinetobacter baumannii(CRAB)complex was 64.6%(370/573),while more than 80.0% of CRAB complex was sensitive to tigecycline,eravacycline and polymyxin B. The prevalence of carbapenem-resistant Pseudomonas aeruginosa(CRPA)was 17.0%(99/581). There were differences in the composition ratio of Gram-negative bacteria in bloodstream infections and the prevalence of important Gram-negative bacteria resistance among different regions in China,with statistically significant differences in the prevalence of CREC,CRKP,CRPA and CRAB complex( χ2=10.6,28.6,10.8 and 19.3, P<0.05). The prevalence of ESBL-producing Escherichia coli, CREC,CRAB complex and CRKP were higher in provincial hospitals than those in municipal hospitals( χ2=12.5,9.8,12.7 and 57.8,all P<0.01). Conclusions:Gram-negative bacteria are the main pathogens causing bloodstream infections in China,and Escherichia coli is ranked in the top,while the trend of Klebsiella pneumoniae increases continuously with time. CRKP infection shows a slow upward trend,CREC infecton maintains a low prevalence level,and CRAB complex infection continues to exhibit a high prevalence rate. The composition and resistance patterns of pathogens causing bloodstream infections vary to some extent across different regions and levels of hospitals in China.
7.Identification of Taste Critical Quality Attribute and Formulation Optimization of Qingre Jiedu Oral Liquid Based on the Combination of Electronic Tongue and Real Human Senses
Xingyue HUAN ; Zhisheng WU ; Ying LU ; Haiyang LI ; Shuoshuo XU ; Han HE ; Qiatong XIE ; Nan LI ; Jun JIA ; Lu YAO ; Run ZHANG ; Jiafu CHEN ; Xingxing DAI
World Science and Technology-Modernization of Traditional Chinese Medicine 2025;27(11):3213-3223
Objective To identify the taste critical quality attribute and design and optimize the flavor-correcting formulation of the traditional Chinese medicine oral preparation Qingre Jiedu Oral Liquid,in order to improve its taste and enhance patient medication adherence.Methods The taste assignment method was employed to identify the taste critical quality attribute of Qingre Jiedu Oral Liquid.Based on human sensory evaluation and the standardized Euclidean distance in electronic tongue analysis,suitable types of corrigent were determined.Subsequently,under constraints such as maximum allowable dosage,solubility,and sweetness,the optimal taste formulation for the sugar-free intermediate of Qingre Jiedu Oral Liquid was determined using Box-Behnken experimental design combined with electronic tongue and human sensory evaluation results.The study was reviewed and approved by the Ethics Committee of Beijing University of Chinese Medicine(Ethics Approval Number 2020BZYLL0609).Results The quantitative score for bitter taste of Qingre Jiedu Oral Liquid accounted for 30.36%,confirming bitterness as the taste critical quality attribute requiring attention.The optimal taste formulation for the sugar-free intermediate of Qingre Jiedu Oral Liquid was determined to be 120 mg·mL?1 erythritol,12 mg·mL?1 acesulfame potassium,and 2.4 mg·mL?1 stevioside.This formulation achieved an 11.75-point improvement in sensory evaluation scores compared to the original commercially available oral liquid.Conclusion This study successfully improved the taste of Qingre Jiedu Oral Liquid and established a comprehensive strategy for flavor-correcting formulation optimization,including a method for identifying taste critical quality attribute.This strategy provides a referential paradigm for palatability enhancement of similar traditional Chinese medicine oral preparations,laying a crucial technical foundation for elevating the clinical value of Chinese herbal medicines and promoting the high-quality development of traditional Chinese medicine(TCM).
8.Impact of Postoperative Reduction Quality on Biomechanics of the Femoral Head Following Internal Fixation of Femoral Neck Fractures
Shixiong ZHANG ; Jianxiong MA ; Bin LU ; Ying WANG ; Aixian TIAN ; Lei SUN ; Zhe HAN ; Jiahui CHEN ; Jing DAI ; Haohao BAI ; Hongzhen JIN ; Jie ZHAO ; Pengfei LI ; Xinlong MA
Journal of Medical Biomechanics 2025;40(5):1144-1149
Objective To investigate the effect of postoperative reduction quality in femoral neck fracture internal fixation on mechanical properties of the femoral head from the perspective of trabecular bone biomechanics.Methods From patients who underwent hip replacement surgery for femoral neck fractures,a total of 26 femoral head slice specimens were obtained.The central axis of the primary compressive trabeculae was defined as the 0° group,with the intersection point of the primary compressive trabeculae and the femoral calcar serving as the center.By rotating the specimens to simulate different reduction angles,the cut femoral head slice specimens were randomly divided into five groups:-10°,-5°,0°,5°,and 10°,representing femoral heads with varying reduction qualities.The specimens were subjected to single compression load tests and fatigue load tests.The load was set from 70 N to 1 400 N,at a frequency of 1 Hz,with 10 000 cycles.Axial stiffness,displacement,and the number of collapse cycles were measured,to compare the biomechanical properties of femoral head specimens under different reduction qualities.Results There were differences in the axial stiffness,displacement,and number of collapse cycles among the femoral head specimens in different groups.Under 800 N load,the axial stiffness of 0° group was significantly greater than that of±10° groups(P<0.05).The axial stiffness of 0° group was also greater than that of the±5° groups,but the differences were not statistically significant(P>0.05).The axial stiffness of±5° groups was greater than that of±10° groups(P<0.05).0° group had a lower displacement than±5° groups and±10° groups.However,the differences in displacement between 0° group and±5° groups were not statistically significant(P>0.05),while the differences between the 0° group and±10° groups were statistically significant(P<0.05).The differences in displacement between±5° groups and±10° groups were also statistically significant(P<0.05).0° group had a significantly higher number of collapse cycles than±10° groups(P<0.05).The number of collapse cycles in 0° group was also higher than that in±5° groups,but the differences were not statistically significant(P>0.05).The number of collapse cycles in±5° groups was significantly higher than that±10° groups(P<0.05).Conclusions The quality of reduction after internal fixation of femoral neck fractures significantly affects the biomechanical properties of the femoral head.This study provides a scientific basis for optimizing treatment and postoperative management,aiming to improve clinical outcomes and patients' quality of life.
9.Study on Susceptibility and Infection Characteristics of Dengue Virus in Cells Sourced from Different Tissues of Tree Shrews
Xin LIU ; Mengdi QI ; Wenguang WANG ; Yuanyuan HAN ; Meili LU ; Na LI ; Jiejie DAI ; Caixia LU
Laboratory Animal and Comparative Medicine 2025;45(2):229-238
Objective To investigate the susceptibility and infection characteristics of dengue virus(DENV)in cells derived from diverse tissues of tree shrews and to provide a basis for expanding the repertoire of DENV-permissive cell models in this species.Methods DENV was inoculated at a multiplicity of infection(MOI)of 0.02 into tree shrew skin fibroblasts(TSFs),primary tree shrew renal epithelial cells(pTRECs),tree shrew aortic endothelial cells(TAECs),tree shrew aortic smooth muscle cells(TASMCs),tree shrew hepatocytes(THs),tree shrew corneal stromal cells(TCSCs),tree shrew brain microvascular endothelial cells(TBMECs),and tree shrew retinal microvascular endothelial cells(TRMECs).C6/36,Vero,A549,and BHK-21 cells(commonly used for DENV propagation)were used as positive controls.Over 6 days post-infection,cellular cytopathic effects were monitored at 12-hour intervals using an inverted microscope,viral RNA loads in cell lysates were quantified by real-time fluorescent quantitative PCR to generate proliferation curves,and viral titers were determined by plaque assay.Results Seven types of tree shrew cells,except TRMECs,were susceptible to DENV.Prolonged infection induced pronounced cytopathic effects,including cell rounding,detachment,necrosis,and lysis,across all susceptible cells.The viral RNA loads detected in lysates of pTRECs,TBMECs,TASMCs,TAECs and THs,approached those of positive controls(≥4×107 copies/μL).Infectious progeny viruses were produced by these five cell types,with three(TAECs,3.13×105 PFU/mL;THs,2.03×105 PFU/mL;pTRECs,1.58×105 PFU/mL)exhibiting titers comparable to C6/36(3.85×10 5 PFU/mL)and earlier viral harvests.Conclusion DENV exhibits broad susceptibility to tree shrew cells of multiple tissue origins,with proliferation rates surpassing those of conventional cell lines sourced from other species.TAECs,THs,and pTRECs are particularly suitable for large-scale DENV proliferation,suggesting their potential involvement in in vivo infection.
10.Impact of Postoperative Reduction Quality on Biomechanics of the Femoral Head Following Internal Fixation of Femoral Neck Fractures
Shixiong ZHANG ; Jianxiong MA ; Bin LU ; Ying WANG ; Aixian TIAN ; Lei SUN ; Zhe HAN ; Jiahui CHEN ; Jing DAI ; Haohao BAI ; Hongzhen JIN ; Jie ZHAO ; Pengfei LI ; Xinlong MA
Journal of Medical Biomechanics 2025;40(5):1144-1149
Objective To investigate the effect of postoperative reduction quality in femoral neck fracture internal fixation on mechanical properties of the femoral head from the perspective of trabecular bone biomechanics.Methods From patients who underwent hip replacement surgery for femoral neck fractures,a total of 26 femoral head slice specimens were obtained.The central axis of the primary compressive trabeculae was defined as the 0° group,with the intersection point of the primary compressive trabeculae and the femoral calcar serving as the center.By rotating the specimens to simulate different reduction angles,the cut femoral head slice specimens were randomly divided into five groups:-10°,-5°,0°,5°,and 10°,representing femoral heads with varying reduction qualities.The specimens were subjected to single compression load tests and fatigue load tests.The load was set from 70 N to 1 400 N,at a frequency of 1 Hz,with 10 000 cycles.Axial stiffness,displacement,and the number of collapse cycles were measured,to compare the biomechanical properties of femoral head specimens under different reduction qualities.Results There were differences in the axial stiffness,displacement,and number of collapse cycles among the femoral head specimens in different groups.Under 800 N load,the axial stiffness of 0° group was significantly greater than that of±10° groups(P<0.05).The axial stiffness of 0° group was also greater than that of the±5° groups,but the differences were not statistically significant(P>0.05).The axial stiffness of±5° groups was greater than that of±10° groups(P<0.05).0° group had a lower displacement than±5° groups and±10° groups.However,the differences in displacement between 0° group and±5° groups were not statistically significant(P>0.05),while the differences between the 0° group and±10° groups were statistically significant(P<0.05).The differences in displacement between±5° groups and±10° groups were also statistically significant(P<0.05).0° group had a significantly higher number of collapse cycles than±10° groups(P<0.05).The number of collapse cycles in 0° group was also higher than that in±5° groups,but the differences were not statistically significant(P>0.05).The number of collapse cycles in±5° groups was significantly higher than that±10° groups(P<0.05).Conclusions The quality of reduction after internal fixation of femoral neck fractures significantly affects the biomechanical properties of the femoral head.This study provides a scientific basis for optimizing treatment and postoperative management,aiming to improve clinical outcomes and patients' quality of life.


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