BACKGROUND:Alzheimer's disease has been associated with sarcopenia,but a causal relationship has not been established.Exploring the causal relationship between the two most common disability-burdening diseases in the aging population-Alzheimer's disease and sarcopenia-and their potential mediating factors holds certain implications for further alleviating the healthcare costs and socioeconomic burden for older adults in China.OBJECTIVE:To explore the potential causal relationship between Alzheimer's disease and sarcopenia in the general population using a Mendelian randomization study and to explore the role of body mass index in this context.METHODS:Two-sample Mendelian randomization analysis based on published genome-wide association studies(GWAS)were used to infer causality,and univariate Mendelian randomization and mediation analyses were used in the study design.Through the Integrative Epidemiology Unit(IEU)database,ieu-b-2 was selected as the Alzheimer's disease dataset(sample size:63 926),ieu-b-4816 as the body mass index dataset(99 998),ebi-a-GCST90000027 as the appendicular lean mass dataset(244 730),ukb-b-7478 as the left hand grip strength dataset(461 026),ukb-b-10215 as the right hand grip strength dataset(461 089)and ukb-b-4711 as the walking pace dataset(459 915).Inverse-variance weighting was used as the primary analysis method,and the results were validated by pleiotropy and heterogeneity analysis.The Steiger Directionality Test was performed to validate the reasonableness of the causal direction.RESULTS AND CONCLUSION:(1)The Mendelian randomization analyses provided evidence that Alzheimer's disease predicted the risk of appendicular lean mass[odds ratio(OR)=1.009;95％confidence interval(Cl),1.001-1.017;P=0.023),and walking pace(OR=1.010;95％Cl,1.003-1.017;P=0.008).No correlation with hand grip strength was observed.(2)Alzheimer's disease was negatively correlated with body mass index(OR=0.893;95％Cl,0.811-0.984;P=0.022);body mass index was positively correlated with appendicular lean mass(OR=1.084;95％Cl,1.031-1.141;P=0.002)and negatively correlated with walking pace(OR=0.975;95％Cl,0.969-0.980;P＜0.001).(3)Mediation analyses showed that the causal relationship between Alzheimer's disease and appendicular lean mass and walking pace was partially mediated by body mass index,with the proportion of mediations being 50.25％and 32.11％,respectively.(4)The results of this study suggest that based on large-scale population studies,genetic prediction of Alzheimer's disease is a potential risk factor for sarcopenia,in which body mass index plays an important mediating role.This suggests that in clinical practice,attention should be paid to the muscle condition of patients with Alzheimer's disease,and weight management should be implemented,as maintaining a body mass index within the normal high range may have a preventive effect on the occurrence of sarcopenia in patients with Alzheimer's disease.However,further research is needed to verify the applicability of this conclusion to other ethnic groups.This study utilized an international public database for analysis,providing a reference for research on the correlation between Alzheimer's disease and sarcopenia in the Chinese population.It also highlights the significant mediating role of body mass index,offering insights for further prevention and treatment of sarcopenia among Chinese individuals.

BACKGROUND:Alzheimer's disease has been associated with sarcopenia,but a causal relationship has not been established.Exploring the causal relationship between the two most common disability-burdening diseases in the aging population-Alzheimer's disease and sarcopenia-and their potential mediating factors holds certain implications for further alleviating the healthcare costs and socioeconomic burden for older adults in China.OBJECTIVE:To explore the potential causal relationship between Alzheimer's disease and sarcopenia in the general population using a Mendelian randomization study and to explore the role of body mass index in this context.METHODS:Two-sample Mendelian randomization analysis based on published genome-wide association studies(GWAS)were used to infer causality,and univariate Mendelian randomization and mediation analyses were used in the study design.Through the Integrative Epidemiology Unit(IEU)database,ieu-b-2 was selected as the Alzheimer's disease dataset(sample size:63 926),ieu-b-4816 as the body mass index dataset(99 998),ebi-a-GCST90000027 as the appendicular lean mass dataset(244 730),ukb-b-7478 as the left hand grip strength dataset(461 026),ukb-b-10215 as the right hand grip strength dataset(461 089)and ukb-b-4711 as the walking pace dataset(459 915).Inverse-variance weighting was used as the primary analysis method,and the results were validated by pleiotropy and heterogeneity analysis.The Steiger Directionality Test was performed to validate the reasonableness of the causal direction.RESULTS AND CONCLUSION:(1)The Mendelian randomization analyses provided evidence that Alzheimer's disease predicted the risk of appendicular lean mass[odds ratio(OR)=1.009;95％confidence interval(Cl),1.001-1.017;P=0.023),and walking pace(OR=1.010;95％Cl,1.003-1.017;P=0.008).No correlation with hand grip strength was observed.(2)Alzheimer's disease was negatively correlated with body mass index(OR=0.893;95％Cl,0.811-0.984;P=0.022);body mass index was positively correlated with appendicular lean mass(OR=1.084;95％Cl,1.031-1.141;P=0.002)and negatively correlated with walking pace(OR=0.975;95％Cl,0.969-0.980;P＜0.001).(3)Mediation analyses showed that the causal relationship between Alzheimer's disease and appendicular lean mass and walking pace was partially mediated by body mass index,with the proportion of mediations being 50.25％and 32.11％,respectively.(4)The results of this study suggest that based on large-scale population studies,genetic prediction of Alzheimer's disease is a potential risk factor for sarcopenia,in which body mass index plays an important mediating role.This suggests that in clinical practice,attention should be paid to the muscle condition of patients with Alzheimer's disease,and weight management should be implemented,as maintaining a body mass index within the normal high range may have a preventive effect on the occurrence of sarcopenia in patients with Alzheimer's disease.However,further research is needed to verify the applicability of this conclusion to other ethnic groups.This study utilized an international public database for analysis,providing a reference for research on the correlation between Alzheimer's disease and sarcopenia in the Chinese population.It also highlights the significant mediating role of body mass index,offering insights for further prevention and treatment of sarcopenia among Chinese individuals.

Objective:To prepare the resiquimod-loaded lipid microbubbles R848-MBs, evaluate their enhanced ultrasound imaging and high intensity focused ultrasound (HIFU) ablation effects, and explore their ability to improve tumor immune microenvironment synergize with HIFU.Methods:R848-MBs were prepared by the thin film hydration-mechanical shock method; The basic characteristics and safety of R848-MBs were detected, the HIFU controlled-release characteristics were verified in vitro and the drug metabolism and biological distribution were investigated in vivo. The ability of enhancing ultrasound imaging was observed in vitro and in vivo. To investigate the enhanced HIFU ablation effect of R848-MBs, six EMT6 tumor-bearing mice were randomly divided into HIFU group and R848-MBs+ HIFU group, three mice in each group, the changes in contrast average sound intensity before and after ablation in mouse tumor areas and the change of ultrasound image gray value in tumor area were evaluated, the tumor were resected to observe the coagulative necresis by TTC staining and HE staining. Forty-five tumor-bearing mice were randomly divided into control group, Free R848 group, HIFU group, Blank-MBs+ HIFU group and R848-MBs+ HIFU group, nine mice in each group. On the third day after treatment, 3 mice in each group were randomly selected and killed, to evaluate the ability of R848-MBs to improve tumor immune microenvironment synergize with HIFU. The expression level of CRT on the surface of tumor cells were detected by immunofluorescence staining, the proportion of mature DC in lymph nodes, spleen, and CD8 + T cells in spleen were detected by flow cytometry. The treatment effectiveness of each group( n=6) were evaluated by measuring tumor volume, observing and drawing survival curves. Results:The R848-MBs lipid microbubbles with good safety were successfully prepared, with a concentration of 2.58×10 9/ml, as spherical bubbles under optical microscope and laser confocal microscopy, in a particle size of (1.72±0.11)μm, at a surface potential of (-10.16±0.73)mV. The cumulative drug release was up to 83.44% after HIFU (90 W, 3 s) in vitro. The concentration of R848 in plasma decreased rapidly, and the drug concentration in tumor tissue of the R848-MBs+ HIFU group was higher than that of the R848 group 24 hours after treatment ( P<0.01). The ultrasound imaging of R848-MBs was significantly enhanced in contrast mode in vitro and in vivo; R848-MBs can significantly enhance the HIFU ablation effect, the contrast average sound intensity change in the tumor area before and after ablation in the R848MBs+ HIFU group was greater than that in the R848 group ( P<0.05), and the immediate ultrasound grayscale value change in the HIFU+ R848-MBs group was 46.34±3.21, which was significantly greater than that in the HIFU group (10.67±1.53), with statistical significance ( P<0.000 1). Coagulation necrosis was observed in tumor HE staining and TTC staining. The results of treatment efficacy in vivo showed that R848-MBs+ HIFU group had the strongest therapeutic effect, and R848-MBs combined with HIFU treatment could significantly prolong the survival period of mice compared with intravenous injection of free R848 ( P<0.01). Immunofluorescence staining and flow cytometry results showed an increase in the expression level of CRT on the surface of tumor tissue in the R848-MBs combined with HIFU group, and the percentage of mature DC in tumor draining lymph nodes (58.53±1.04)% were significantly higher than those in the HIFU group (37.56±2.13)% ( P<0.001), and the percentage of mature DC in the spleen (70.65±1.91)% were significantly higher than those in the HIFU group (36.46±3.89)% ( P<0.001), the percentage of CD8 + T cells in the spleen (27.46±3.04)% was significantly higher than that in the HIFU group (18.69±0.29)% ( P<0.01). Conclusions:The HIFU controlled-release lipid microbubbles R848-MBs can not only enhance the efficiency of HIFU ablation, but also improve the tumor immune microenvironment.

Objective:To analyze the epidemiological and etiological characteristics of a dengue fever outbreak in Hunan province in 2018.Methods:Real-time PCR assay was performed for the laboratory diagnosis of 8 suspected dengue fever cases. Etiological surveillance was performed in 186 suspected dengue fever cases and fever cases who had close contacts with dengue fever patients. C6/36 cells was used for the virus isolation from acute phase serum. By sequencing the full length of E genes of 15 dengue virus strains, phylogenetic analysis was performed based on the sequences obtained, including reference sequences from the NCBI GenBank database, the serotypes and gene subtypes of the virus were analyzed to trace the possible source of transmission. An emergency monitoring of vector density and a retrospective survey of sero-epidemiology in healthy population were conducted in the epidemic area.Results:In the serum samples of 8 suspected patients, 6 were dengue virus RNA positive, and 4 were NS1 antigen positive. In 186 suspected patients, 96 were dengue virus nucleic acid, NS1 antigen or antibody positive in etiological test. A total of 64 dengue virus strains were isolated. The phylogenetic analysis showed that all the dengue virus strains belonged to type 2, which might be from Guangdong or Zhejiang provinces. The Bretub index was up to 65, indicating an extremely high risk of transmission. The positive rate of the dengue virus IgG antibody was 0.53%(2/377) in retrospective survey of 377 healthy people.Conclusion:The field epidemiologic and the molecular genetics analyses showed the outbreak of dengue fever in Hunan in 2018 was caused by imported cases and dengue virus 2.

Objective To investigate the radiosensitizing effects of artemisinin on CNE human nasopharyngeal carcinoma cells in vitro.Methods CNE human nasopharyngeal carcinoma cell line was used in this study.Cell growth kinetics was determined by MTT assay.Effect of the drug on radiosensitivity of CNE cells was analyzed by clonogenic assay.The change of cell cycle was measured by flow cytometry.Results The inhibition of CNE cells growth by artemisinin was increased with concentrations.Artemisinin (1 μmol/L)could enhance the radiosensitizing effects on CNE cell line,and the sensitizing enhancement ratio(SER)was 1.26.Artemisinin abrogated radiation-induced G2/M arrest of the tested CNE cells.Compared with the radiation alone group,the proportion of G2/M phase cells increased in radiation combined with drug group.Conclusions Artemisinin could reduce radiation-induced G2/M arrest and enhance the cytotoxicity of γ-irradiation on the CNE ceils.

Objective To investigate the radiosensitizing effects of dihydroartemisinin(DHA)on human HeLa cells of cervical cancer irradiated by X rays.Methods Cell growth kinetics was determined using MTF assay.Cell survival was analyzed by elonogenic assay.The change of cell cycle and apeptosis was measured by flow cytometry.Results Dihydroartemisinin inhibited the growth of HeLa cells of human cervical cancer and showed a dose-dependent and time-dependent manner.Dihydroartemisinin(20 μmol/L)showed the radiosensitizing effects on HeLa cells,and the sensitizing enhancement ratio(SER)was 1.47.Dihydroartemisinin abrogated radiation-induced G2 arrest of the tested HeLa cells,the G2 ratio of medicine + radiation group dechned from 73.58% to 48.31%.Dihydroartemisinin enhanced the apoptosis of HeLa cells by X-irradiation,the apoptosis rates of medicine + radiation group significantly increased from 29.46%,48.04%,70.21% to 45.79%,66.36% and 79.58%,respectively for 2,4 and 6 Gy.Conclusions Dihydroartemisinin could increase the radiesensitivity of HeLa cells of human cervical cancer.Abrogation of radiation-induced C2 arrest could be part of the mechanism.