BACKGROUND:Exosomes derived from mesenchymal stem cells play pivotal roles in cell communication and epigenetic regulation due to their low immunogenicity and targeted delivery effects,and have been clinically applied in the treatment of various diseases.OBJECTIVE:To review the isolation,purification,identification methods,and application progress of mesenchymal stem cell-derived exosomes,and to facilitate the development of large-scale preparation techniques and clinical translation of mesenchymal stem cell-derived exosomes.METHODS:The Chinese search terms"exosome,mesenchymal stem cells,isolation,purification,characterization,clinical application"and the English search terms"exosome,extracellular vesicles,mesenchymal stem cells,isolation,characterization,application"were used to search the literature published before September 2024 in CNKI,PubMed,and Web of Science databases.Articles with poor relevance to the topic,outdated,or duplicated content were excluded,and finally,109 articles were included for review.RESULTS AND CONCLUSION:(1)This paper reviews recent methods for isolating and purifying exosomes,comparing the characteristics of ultracentrifugation,ultrafiltration,size-exclusion chromatography,polymer precipitation,immunoaffinity,microfluidic methods,and other novel approaches based on their underlying principles.(2)Methods for identifying exosomes can be categorized into physical and biochemical analyses,characterizing exosomes based on their shape,size,and characteristic proteins.(3)Mesenchymal stem cell-derived exosomes have broad applications in multiple fields such as medical aesthetics,wound repair,and cancer treatment,due to their immune-regulatory properties and ability to cross biological barriers.(4)The clinical translation of exosomes faces challenges due to their complex structure,lack of universal isolation techniques,and poor stability,making it difficult to achieve in a short period of time.

Skeletal muscle atrophy refers to a pathological condition characterized by muscle fiber atrophy as well as decreased muscle mass and muscle strength induced by various predisposing factors. It falls under the category of “flaccidity syndrome” in traditional Chinese medicine， and its pathogenesis is mainly associated with disturbed protein homeostasis， mitochondrial dysfunction and oxidative stress injury. Active ingredients of traditional Chinese medicine exerts synergistic regulatory effects via multiple pathways， thus possessing unique advantages in the clinical prevention and treatment of skeletal muscle atrophy. This paper reviews the mechanisms by which active ingredients of traditional Chinese medicine alleviate skeletal muscle atrophy. Existing studies have demonstrated that such active ingredients can ameliorate skeletal muscle atrophy through multiple approaches： regulating protein metabolic balance （geniposide， matrine， schisandrin A， etc.） and oxidative stress （astragaloside Ⅳ， Gastrodia elata polysaccharide， Angelica sinensis polysaccharide， etc.）， improving mitochondrial function （parthenolide， berberine， curcumin， etc.）， facilitating myogenesis and myogenic differentiation （cucurbitacin Ⅱb， saikosaponin A， saikosaponin D， etc.）， suppressing inflammatory response （ursolic acid， triptolide， emodin， etc.）， ameliorating insulin resistance （akebiasaponin D， etc.）. In the future， active ingredients of traditional Chinese medicine are expected to achieve breakthroughs in clinical treatment for skeletal muscle atrophy， providing novel ideas and strategies for the prevention and treatment of degenerative disorders.

BACKGROUND:Exosomes derived from mesenchymal stem cells play pivotal roles in cell communication and epigenetic regulation due to their low immunogenicity and targeted delivery effects,and have been clinically applied in the treatment of various diseases.OBJECTIVE:To review the isolation,purification,identification methods,and application progress of mesenchymal stem cell-derived exosomes,and to facilitate the development of large-scale preparation techniques and clinical translation of mesenchymal stem cell-derived exosomes.METHODS:The Chinese search terms"exosome,mesenchymal stem cells,isolation,purification,characterization,clinical application"and the English search terms"exosome,extracellular vesicles,mesenchymal stem cells,isolation,characterization,application"were used to search the literature published before September 2024 in CNKI,PubMed,and Web of Science databases.Articles with poor relevance to the topic,outdated,or duplicated content were excluded,and finally,109 articles were included for review.RESULTS AND CONCLUSION:(1)This paper reviews recent methods for isolating and purifying exosomes,comparing the characteristics of ultracentrifugation,ultrafiltration,size-exclusion chromatography,polymer precipitation,immunoaffinity,microfluidic methods,and other novel approaches based on their underlying principles.(2)Methods for identifying exosomes can be categorized into physical and biochemical analyses,characterizing exosomes based on their shape,size,and characteristic proteins.(3)Mesenchymal stem cell-derived exosomes have broad applications in multiple fields such as medical aesthetics,wound repair,and cancer treatment,due to their immune-regulatory properties and ability to cross biological barriers.(4)The clinical translation of exosomes faces challenges due to their complex structure,lack of universal isolation techniques,and poor stability,making it difficult to achieve in a short period of time.

ObjectiveTo investigate the trends in the disease burden of falls among Chinese children and adolescents from 1990 to 2021, and to inform the development of targeted prevention and control strategies. MethodsData on age-standardized incidence rate, age-standardized mortality rate and age-standardized disability-adjusted life years (DALYs) rate for falls among Chinese children and adolescents under 20 years of age from 1990 to 2021 were systematically extracted from the Global Burden of Disease Study (GBD) 2021 database. The annual percent change (APC) and average annual percent change (AAPC) were calculated to evaluate temporal trends in fall-related disease burden across different age groups and sexes. ResultsFrom 1990 to 2021, the age-standardized incidence rate of falls among Chinese children and adolescents showed a non-linear fluctuation (AAPC=0.08%, P=0.040), while both the age-standardized mortality rate and age-standardized DALYs rate declined (AAPC=-3.66% and -3.09%, both P<0.001). The crude incidence rate decreased in the <5 years old and 5 ‒ <10 years old groups (AAPC=-1.38% and -0.29%, both P<0.001), but increased annually in the 10 ‒ <15 years old and 15 ‒ <20 years old groups (AAPC=0.27% and 0.81%, both P<0.001). The crude mortality rate and crude DALYs rate declined across all four age groups, with the most significant reduction observed in the <5 years old group (AAPC=-5.21%, 95%CI:-5.55%‒ -5.00%; AAPC=-4.98%, 95%CI: -5.20%‒ -4.79%, both P<0.001). For both males and females, the age-standardized incidence rate of falls showed a V-shaped trend (initial decline followed by a subsequent rise). In contrast, the age-standardized mortality rate and age-standardized DALY rate declined in both sexes, with an AAPC of -3.40% and -2.94% for males, and -4.50% and -3.49% for females, respectively (all P<0.001). ConclusionThe overall disease burden of falls among Chinese children and adolescents has been substantially improved; however, the incidence burden remains considerable. Future prevention efforts should be tailored to age- and sex-specific characteristics, with the family as the fundamental care unit in conjunction with high-quality nursing extension services, to establish a closed-loop management model encompassing “early identification, immediate intervention, and continuous follow-up.”

Abstract Drowning is a global public health issue characterized by sudden occurrence, insidious presentation, and poor health prognosis, which poses higher requirements for the time sensitivity, judgment accuracy, and response reliability of drowning prevention and control technologies. Among drowning prevention and control strategies, passive strategies can achieve injury prevention and control purposes through safely designed products, making them more effective than active strategies. This paper reviewed literature, books, and patent webpages related to drowning prevention and control technologies from January 2015 to August 2025. Based on the basic characteristics of drowning, this paper summarized innovative technologies for passive strategies including physical drowning hazard environments, drowning person identification, and rescue, analyzed and compared their technical principles, applicable scenarios, advantages and disadvantages, so as to provide the evidence for promoting interdisciplinary research and practical application of drowning prevention and control technologies.

Objective:To analyze the effect of precipitation on road traffic injuries (RTI) in Zhejiang Province.Methods:The RTI surveillance and meteorological data from 2009 to 2022 in Zhejiang Province were collected. Based on the time-stratified case-crossover design, the precipitation of case day and control day was compared, and the distributed lag nonlinear model was applied to analyze the correlation of precipitation and RTI. Stratified analyses were conducted to analyze the effect modification of gender, age, injury location, and temperature. An attributable fraction was used to assess the burden of RTI caused by precipitation.Results:A total of 239 970 RTIs were monitored in Zhejiang Province from 2009 to 2022, averaging 46 daily cases. The distributed lag nonlinear model showed that compared with no rain, the risk of RTI increased first and then decreased with the increase of precipitation. The risk of RTI was the highest when the precipitation was 30.99 mm ( OR=1.08, 95% CI: 1.05-1.11). The adverse effects on RTI mainly occurred on the day of precipitation, and it showed insignificant or protective effects with the extension of lag days. 1.34%(95% CI: 1.31%-1.36%) of RTI could be attributed to precipitation. Stratified analysis showed that gender, age, injury location, and temperature may modify the effect of precipitation on RTI. Precipitation caused a heavier burden on RTI in subgroups aged 18-64, females, and occurring on roads and in low temperatures. Conclusions:Precipitation can increase the risk of RTI. People aged 18-64 or females are the key groups for RTI prevention, and prevention and control efforts of precipitation-related RTI should be increased in road and low-temperature environments.

Objective To evaluate the clinical utility of the f-wave to QRS complex amplitude ratio(f/R ratio)in intracardiac electrogram(IC-ECG)-guided positioning of peripherally inserted central catheter(PICC)tips in patients with atrial fibrillation(AF),providing evidence to enhance clinical practice.Methods This study employed a conve-nience sampling method to enroll eligible AF patients admitted to a tertiary hospital in Suzhou from July 2023 to July 2024.During PICC placement,IC-ECG was utilized to monitor f-wave and QRS complex amplitude variations.Following successful catheterization,the f/R ratio was measured,and chest X-ray was performed to confirm the catheter tip position.The accuracy of PICC tip positioning across different f/R ratio ranges was analyzed,and the incidence of arrhythmias was recorded.A receiver operating characteristic curve was constructed to assess the diag-nostic performance of the f/R ratio in PICC tip localization.Results A total of 68 AF patients were included,with f/R ratios ranging from 20.63％to 91.24％.PICC tip positioning accuracy varied significantly across different f/R ratio ranges(P=0.006).The area under the ROC curve(AUC)for f/R ratio in PICC tip positioning was 0.784(P=0.009),with a maximum Youden index of 0.567,an optimal diagnostic threshold of 40.00％,a sensitivity of 81.7％,a speci-ficity of 75.0％,a positive predictive value of 96.1％,and a negative predictive value of 35.3％.No arrhythmias other than AF occurred during the procedure.Conclusion The f/R ratio provides reliable and safe guidance for PICC tip positioning in AF patients.An f/R ratio ≥40％is associated with higher accuracy in identifying the optimal catheter tip position.

Objective To compare the efficacy and adherence of rivaroxaban versus low-molecular-weight heparin for prophylactic anticoagulation in cancer patients with venous thromboembolism(VTE).Methods A total of 120 intermediate-to-high VTE risk patients with malignant tumors admitted to Depart-ment of Hematology and Oncology,West China Longquan Hospital of Sichuan University between September 2021 and December 2022,were randomly assigned to the rivaroxaban group(n=60)and the low-molecular-weight heparin group(n=60)using the random number table.The rivaroxaban group received oral Rivaroxa-ban,while the low-molecular-weight heparin group received subcutaneous injections of low-molecular-weight heparin sodium for prophylactic anticoagulation.All patients were followed up for 180 days.The primary end-point was medication adherence.The secondary endpoints included the incidence of VTE,bleeding events,and changes in coagulation parameters.Results The rate of good medication adherence was significantly higher in the rivaroxaban group than in the low-molecular-weight heparin group(95.00％vs.88.33％,P＜0.05).However,there were no statistically significant differences in the incidence of VTE or overall bleeding events between the two groups(P＜0.05).Following treatment,parameters including fibrinogen,prothrombin time(PT),and D-dimer levels showed significant improvement from baseline in both groups.Compared to the low-molecular-weight heparin group,the Rivaroxaban group demonstrated significantly higher fibrinogen levels,shorter PT,and lower D-dimer levels(P＜0.05).Stepwise logistic regression analysis identified the post-treatment platelet(PLT)count as a significant factor influencing bleeding events during prophylactic antico-agulation(P＜0.05).Khorana score≥3(high risk)was identified as a risk factor for bleeding events(P＜0.05).The incidence of clinically relevant non-major bleeding(CRNMB)was higher in the rivaroxaban group[11.67％(7/60)]compared to the low-molecular-weight heparin group[8.33％(5/60)],although the differ-ence was not statistically significant(P＜0.05).Kaplan-Meier curve analysis revealed no significant difference in the cumulative incidence of bleeding-free events between the two groups(P＜0.05).Conclusion Oral ri-varoxaban and subcutaneous low-molecular-weight heparin demonstrate comparable efficacy and safety for VTE prevention in cancer patients,but rivaroxaban significantly improves patient's adherence.

Objective To investigate the correlation between peripheral blood syndecan-1(SDC-1)and ma-londialdehyde-modified low-density lipoprotein(MDA-LDL)with arteriosclerosis(AS)in hemodialysis pa-tients and their clinical predictive value.Methods A total of 125 hemodialysis patients admitted to the hospi-tal from January 2022 to June 2024 as the hemodialysis group,and 65 healthy individuals who underwent physical examination during the same period as the control group.According to whether AS occurred,hemodi-alysis patients were divided into AS group(65 cases)and non-AS group(60 cases).The levels of SDC-1 and MDA-LDL in peripheral blood were detected by enzyme-linked immunosorbent assay.The correlation between the levels of SDC-1 and MDA-LDL in peripheral blood of hemodialysis patients and brachial-ankle pulse wave velocity(baPWV)was analyzed by Spearman correlation analysis.Multivariate unconditional Logistic regres-sion was used to determine the relationship between the levels of SDC-1 and MDA-LDL in peripheral blood and AS in hemodialysis patients.The receiver operating characteristic(ROC)curve was used to analyze the pre-dictive efficacy of peripheral blood SDC-1 and MDA-LDL levels for AS in hemodialysis patients.Results Compared with the control group,the levels of SDC-1 and MDA-LDL in the peripheral blood of the hemodialysis group increased(P＜0.05).The levels of SDC-1 and MDA-LDL in the peripheral blood of hemodialysis patients were positively correlated with left baPWV and right baPWV(P＜0.05).High SDC-1 and high MDA-LDL were both independent risk factors for AS in hemodialysis patients(P＜0.05).The area under the curve for the combined prediction of AS in hemodialysis patients by peripheral blood SDC-1 and MDA-LDL levels was 0.858,which was greater than 0.785 and 0.778 predicted separately by peripheral blood SDC-1 and MDA-LDL levels(P＜0.05).Conclusion The increase of SDC-1 and MDA-LDL levels in peripheral blood of hemodialy-sis patients is closely related to AS,and the combination of SDC-1 and MDA-LDL levels in peripheral blood has a higher energy efficiency in predicting AS.

Objective To generate and characterize natural killer cell (NK cell)-conditional Cd226 gene knockout mice using Cre-loxP technology, and to explore the role of CD226 on NK cells in alleviating intestinal inflammation in a murine model of ulcerative colitis (UC). Methods NK cell-conditional Cd226 gene knockout mice were generated by crossing loxP-flanked Cd226 mice with Ncr1-Cre mice via the Cre-loxP system. Polymerase chain reaction (PCR) and agarose gel electrophoresis were used for genotyping. A UC model was established by dextran sulfate sodium (DSS) induction. Flow cytometry was performed to analyze CD226 expression levels on NK cells and the infiltration of related immune cells in colon tissues. Hematoxylin-eosin (HE) staining was performed to assess the degree of colonic inflammation. Results DNA gel electrophoresis and flow cytometry confirmed the successful generation of NK cell-specific Cd226 knockout mice. After conditional knockout of Cd226 in NK cells, inflammation in the UC mouse model was alleviated. Flow cytometry results showed a reduced proportion of NK cells in peripheral blood and the colon lamina propria, while HE staining demonstrated attenuated inflammatory responses. Conclusion Specific knockout of Cd226 in NK cells mitigates intestinal inflammation in UC mice by reducing NK cell numbers and inhibiting their pro-inflammatory functions.
Animals ; Colitis, Ulcerative/pathology* ; Killer Cells, Natural/metabolism* ; Mice, Knockout ; T Lineage-Specific Activation Antigen 1 ; Antigens, Differentiation, T-Lymphocyte/genetics* ; Mice ; Disease Models, Animal ; Mice, Inbred C57BL ; Male