Objective To explore the impact of meteorological factors on the incidence of scarlet fever in Xicheng District of Beijing, and to provide a scientific basis for formulating targeted prevention and control measures. Methods Daily scarlet fever incidence data and corresponding meteorological data from 2010 to 2019 in Xicheng District of Beijing were collected. Using year, month, and day of the week as time-stratified variables, a conditional logistic regression model with a time-stratified case-crossover design was employed to analyze the impact of different meteorological factors on the number of scarlet fever cases in Xicheng District, while controlling for long-term trends, seasonality and other confounding factors. Results From 2010 to 2019, a total of 3,195 cases of scarlet fever were reported in Xicheng District, with an average annual incidence rate of 24.17/100 000. The overall trend showed fluctuating decline, during which three incidence peaks occurred, with the highest incidence rate observed in 2011. No severe or fatal cases were reported. The incidence of scarlet fever exhibited a distinct seasonal bimodal distribution, primarily concentrated between April to June and November to January of the following year. The conditional logistic regression results showed that the average relative humidity and average temperature were positively correlated with scarlet fever cases (β=0.0203, β=0.0613, P＜0.001), while the average vapor pressure was negatively correlated with scarlet fever cases (β=-0.1468, P＜0.001). Increases average relative humidity and average temperature were risk factors for scarlet fever incidence (OR=1.0205，95%CI=1.0150 -1.0261；OR=1.0632，95%CI=1.0379 -1.0891). For every 1.00% increase in average relative humidity, the number of scarlet fever cases increased by 2.05% (1.50% –2.61%). Similarly, for every 1^。C rise in average temperature, the number of cases increased by 6.32% (3.79% – 8.91%). In contrast, an increase in average vapor pressure had a protective effect against scarlet fever (OR=0.8635,95%CI=0.8392-0.8885). For every 1 hPa increase in average vapor pressure, the number of scarlet fever cases decreased by 13.65% (11.15%–16.08%). Conclusion The average relative humidity, average temperature and average vapor pressure are the primary meteorological factors influencing the incidence of scarlet fever in Xicheng District of Beijing, and can be utilized as indicators for the prevention, control, surveillance and early warning of scarlet fever.

OBJECTIVE To prepare an intelligent responsive liposome-hydrogel nanopreparation co-loaded with gambogic acid （GA）， and characterize its antitumor activity in vitro . METHODS GA-ICG-Lip-gel was prepared by ethanol injection and cold dissolution， incorporating GA and the photosensitizer indocyanine green （ICG）. The appearance and microscopic morphology of GA-ICG-Lip-gel were observed， its encapsulation efficiency and drug loading capacity were measured， and its photothermal conversion performance， photothermal stability， and infrared imaging properties were investigated， along with the determination of its in vitro release profile. Human breast cancer MCF-7 cells were used as objects to investigate the effects of GA-ICG-Lip-gel （or with near-infrared light irradiation） on cell viability， migration ability， and the cellular uptake capacity of GA-ICG-Lip-gel. RESULTS GA-ICG-Lip-gel existed in a solution state at room temperature and transformed into a gel state at 37 ℃. Its microstructure was dense with small pores， and its encapsulation efficiency and drug loading were （96.07±0.86） % and （6.28±1.16） %， respectively. After exposure to near-infrared light， the temperature of GA-ICG-Lip-gel rose above 42 ℃， with no significant attenuation observed in the heating curve. The heating efficiency was dependent on both the irradiation time and drug concentration. Compared to media without gelatinase， the cumulative release rate of GA-ICG-Lip-gel increased in media containing gelatinase. In vitro studies showed that GA-ICG-Lip-gel could be efficiently taken up by MCF-7 cells； GA-ICG-Lip-gel significantly inhibited the viability and migration ability of MCF-7 cells （ P ＜0.05）， and this inhibitory effect was further enhanced under near-infrared light irradiation. CONCLUSIONS This study successfully prepares GA-ICG-Lip-gel， which exhibits favorable photothermal conversion properties and temperature/enzyme dual-responsive drug release characteristics， and demonstrates significant inhibitory effects on the proliferation and migration of breast cancer cells.

Objective To compare the epidemic characteristics of seasonal influenza in Xicheng District, Beijing, between 2018-2019 and 2023-2024. Methods The present study was a cross-sectional study. The influenza cases and etiological surveillance data of Xicheng District, Beijing in 2018-2019 and 2023-2024, respectively, were analyzed to study the differences in the incidence rate of influenza cases in different ages, regions, occupations, and etiological detection results during the four years. Results There were significant differences in the incidence rates of influenza (χ²=37 038.65，P＜0.05) and the interval between visits (Z=468.692, P < 0.05) in 2018, 2019, 2023 and 2024. There were statistically significant differences in the incidence rates of influenza among different age groups, streets, and occupations during the four years (Z=75.646, 209.276, 72.132, 361.176, 43.570, all P < 0.05). Compared with 2018-2019, the growth rate of influenza in Xicheng District, Beijing in 2023-2024 was the highest in the 15-24 year-old group, Tianqiao Street, and housework and unemployed people. The difference in the interval between influenza visits among people of different age groups during these 4 years was statistically significant (P < 0.05). The growth rate of the interval between influenza visits in Xicheng District, Beijing in 2023-2024 was the highest in the 15-24 year-old group, while it showed a decrease in the 0-4 year-old group. The etiology in 2018-2019 was mainly H1N1 and H3N2 subtypes, and in 2023-2024 it was mainly H3N2 subtype and influenza B, and the peak values of H1N1, H3N2 subtype and influenza B in 2023-2024 were all higher than those in 2018-2019. Conclusion During the epidemic period, non-medical interventions have changed the transmission mode, seasonal peak and subtype distribution of influenza virus. As the epidemic has eased, the pattern of influenza has gradually rebounded.

BACKGROUND:Previous studies have found that neuronal damage caused by continuous excessive fluoride exposure is related to Ca2+overload,but the mechanism of Ca2+flow conversion between intracellular calcium stores and cell apoptosis damage is still unclear.OBJECTIVE:To investigate the effect of fluoride exposure on Ca2+transport channel proteins and apoptosis levels in the mitochondria-associated endoplasmic reticulum membrane of primary cultured neural cells.METHODS:Primary nerve cells of neonatal SD rats were cultured in vitro and identified by immunofluorescence staining with neuronal nucleus-specific antibody up to day 7.The nerve cells were divided into control group(containing 0 mmol/L sodium fluoride),low fluoride group(containing 0.5 mmol/L sodium fluoride),and high fluoride group(containing 1 mmol/L sodium fluoride).The cell morphological changes were observed by light microscope 24 hours after fluorine exposure.The expression levels of apoptosis-related protein BAX/BCL-2 and calcium transfer-related pathways VDAC1,GRP 75,and IP3R were detected using western blot assay.The expression levels of VDAC1,GRP 75,and IP3R mRNA were detected by RT-PCR.Ca2+levels were detected by Rhood-2AM Ca2+probe.Mitochondrial membrane potential detection kit was used to detect the change in mitochondrial membrane potential.The level of apoptosis was determined by flow cytometry and TUNEL staining.RESULTS AND CONCLUSION:(1)The purity of neurons cultured on day 7 had been determined to be over 90％,with few impurities,good growth status,and tight cell network connections,meeting the requirements of subsequent experiments.(2)Compared with the control group,growth of neural cell clusters in the low-fluoride group and the high-fluoride group increased;the processes were broken;the cell body was rounded,and the connection network between cells was destroyed.Compared with the low-fluoride group,the cell damage changes in the high-fluoride group were more obvious.(3)Compared with the control group,the protein expressions of VDAC1,GRP75,and IP3R were increased in the low-fluoride group and the high-fluoride group(P＜0.05),and the ratio of apoptosis-related protein BAX/BCL-2 was increased(P＜0.05).Compared with the control group,the expression of VDAC1 and GRP75 mRNA in the low-fluoride group was significantly increased(P＜0.05);the expression levels of VDAC1,GRP75,and IP3R mRNA in the high-fluoride group were significantly increased(P＜0.01).(4)The level of cell apoptosis increased significantly after fluoride exposure,and the high-fluoride group was significantly higher than the control and low-fluoride groups(P＜0.01).(5)After fluoride exposure,the concentration of mitochondrial Ca2+in nerve cells increased significantly(P＜0.05),the mitochondrial membrane potential decreased(P＜0.01),and the degree of damage in the high-fluoride group was more obvious(P＜0.05).The results show that fluoride exposure impairs the morphological structure of primary neural cells,resulting in upregulation of Ca2+transfer pathway protein expression between the endoplasmic reticulum and mitochondria,mitochondrial Ca2+overload,mitochondrial damage,and increased levels of apoptosis.

BACKGROUND:Macrophage polarization plays a key role in chronic inflammatory joint diseases such as rheumatoid arthritis.Cerium dioxide(CeO2)nanoparticles have a wide range of biomedical applications such as modulating the local inflammatory microenvironment of tissues.OBJECTIVE:To investigate the role of CeO2 nanoparticles on macrophage polarization and inflammatory factor expression,as well as inflammatory modulation in a co-culture system of macrophages and fibroblasts.METHODS:(1)CeO2 nanoparticles were dispersed and observed morphologically by transmission electron microscopy.(2)Human leukemia monocytes(THP-1)were induced to differentiate and establish the M1 macrophage pro-inflammatory cell model of rheumatoid arthritis.The cells were divided into M0 group(undifferentiated macrophages),M1 group(successful macrophage modeling),CeO2 nanoparticle treatment group(M1 group with CeO2 nanoparticle treatment),and dexamethasone control group(M1 group with dexamethasone treatment)and incubated for 48 hours.The effects of CeO2 nanoparticles on the expression of inflammatory factors(endogenous nitric oxide synthase,CD86,CD80)in M1 macrophages and M1 macrophage phenotype(CD80,CD206)were detected by RT-qPCR,western blot assay,and flow cytometry.(3)A co-culture system of macrophages and fibroblasts was established,and CeO2 nanoparticles acted on the upper macrophages.The regulation of CeO2 nanoparticles on the expression of inflammatory factors(interleukin-6,tumor necrosis factor-α,cyclooxygenase-2,and endogenous nitric oxide synthase)of fibroblasts in the co-culture system was observed at the mRNA and protein levels.RESULTS AND CONCLUSION:(1)Transmission electron microscopy showed that the diameter of CeO2 nanoparticles was(19.5±2.0)nm.(2)Compared with the M0 group,the mRNA of endogenous nitric oxide synthase and CD86,and the protein expression of endogenous nitric oxide synthase and CD80 in the M1 group were upregulated.Compared with the M1 group,the mRNA expression of endogenous nitric oxide synthase and CD86,and the protein expression of endogenous nitric oxide synthase and CD80 in the CeO2 nanoparticle treatment group were downregulated.Flow cytometry showed that 20 nm CeO2 nanoparticles downregulated the number of M1 macrophages.(3)Compared with the M1 group,20 nm CeO2 nanoparticles downregulated the mRNA and protein expression of inflammatory factors(tumor necrosis factor α,interleukin 6,cyclooxygenase 2,and endogenous nitric oxide synthase)in the co-culture system HFL1 cells.(4)The results showed that 20 nm CeO2 nanoparticles can alleviate inflammation in the co-culture system by inhibiting the expression of pro-inflammatory factors in M1 macrophages,providing a new idea for the treatment of inflammatory diseases such as rheumatoid arthritis.

BACKGROUND:Previous studies have found that neuronal damage caused by continuous excessive fluoride exposure is related to Ca2+overload,but the mechanism of Ca2+flow conversion between intracellular calcium stores and cell apoptosis damage is still unclear.OBJECTIVE:To investigate the effect of fluoride exposure on Ca2+transport channel proteins and apoptosis levels in the mitochondria-associated endoplasmic reticulum membrane of primary cultured neural cells.METHODS:Primary nerve cells of neonatal SD rats were cultured in vitro and identified by immunofluorescence staining with neuronal nucleus-specific antibody up to day 7.The nerve cells were divided into control group(containing 0 mmol/L sodium fluoride),low fluoride group(containing 0.5 mmol/L sodium fluoride),and high fluoride group(containing 1 mmol/L sodium fluoride).The cell morphological changes were observed by light microscope 24 hours after fluorine exposure.The expression levels of apoptosis-related protein BAX/BCL-2 and calcium transfer-related pathways VDAC1,GRP 75,and IP3R were detected using western blot assay.The expression levels of VDAC1,GRP 75,and IP3R mRNA were detected by RT-PCR.Ca2+levels were detected by Rhood-2AM Ca2+probe.Mitochondrial membrane potential detection kit was used to detect the change in mitochondrial membrane potential.The level of apoptosis was determined by flow cytometry and TUNEL staining.RESULTS AND CONCLUSION:(1)The purity of neurons cultured on day 7 had been determined to be over 90％,with few impurities,good growth status,and tight cell network connections,meeting the requirements of subsequent experiments.(2)Compared with the control group,growth of neural cell clusters in the low-fluoride group and the high-fluoride group increased;the processes were broken;the cell body was rounded,and the connection network between cells was destroyed.Compared with the low-fluoride group,the cell damage changes in the high-fluoride group were more obvious.(3)Compared with the control group,the protein expressions of VDAC1,GRP75,and IP3R were increased in the low-fluoride group and the high-fluoride group(P＜0.05),and the ratio of apoptosis-related protein BAX/BCL-2 was increased(P＜0.05).Compared with the control group,the expression of VDAC1 and GRP75 mRNA in the low-fluoride group was significantly increased(P＜0.05);the expression levels of VDAC1,GRP75,and IP3R mRNA in the high-fluoride group were significantly increased(P＜0.01).(4)The level of cell apoptosis increased significantly after fluoride exposure,and the high-fluoride group was significantly higher than the control and low-fluoride groups(P＜0.01).(5)After fluoride exposure,the concentration of mitochondrial Ca2+in nerve cells increased significantly(P＜0.05),the mitochondrial membrane potential decreased(P＜0.01),and the degree of damage in the high-fluoride group was more obvious(P＜0.05).The results show that fluoride exposure impairs the morphological structure of primary neural cells,resulting in upregulation of Ca2+transfer pathway protein expression between the endoplasmic reticulum and mitochondria,mitochondrial Ca2+overload,mitochondrial damage,and increased levels of apoptosis.

BACKGROUND:Macrophage polarization plays a key role in chronic inflammatory joint diseases such as rheumatoid arthritis.Cerium dioxide(CeO2)nanoparticles have a wide range of biomedical applications such as modulating the local inflammatory microenvironment of tissues.OBJECTIVE:To investigate the role of CeO2 nanoparticles on macrophage polarization and inflammatory factor expression,as well as inflammatory modulation in a co-culture system of macrophages and fibroblasts.METHODS:(1)CeO2 nanoparticles were dispersed and observed morphologically by transmission electron microscopy.(2)Human leukemia monocytes(THP-1)were induced to differentiate and establish the M1 macrophage pro-inflammatory cell model of rheumatoid arthritis.The cells were divided into M0 group(undifferentiated macrophages),M1 group(successful macrophage modeling),CeO2 nanoparticle treatment group(M1 group with CeO2 nanoparticle treatment),and dexamethasone control group(M1 group with dexamethasone treatment)and incubated for 48 hours.The effects of CeO2 nanoparticles on the expression of inflammatory factors(endogenous nitric oxide synthase,CD86,CD80)in M1 macrophages and M1 macrophage phenotype(CD80,CD206)were detected by RT-qPCR,western blot assay,and flow cytometry.(3)A co-culture system of macrophages and fibroblasts was established,and CeO2 nanoparticles acted on the upper macrophages.The regulation of CeO2 nanoparticles on the expression of inflammatory factors(interleukin-6,tumor necrosis factor-α,cyclooxygenase-2,and endogenous nitric oxide synthase)of fibroblasts in the co-culture system was observed at the mRNA and protein levels.RESULTS AND CONCLUSION:(1)Transmission electron microscopy showed that the diameter of CeO2 nanoparticles was(19.5±2.0)nm.(2)Compared with the M0 group,the mRNA of endogenous nitric oxide synthase and CD86,and the protein expression of endogenous nitric oxide synthase and CD80 in the M1 group were upregulated.Compared with the M1 group,the mRNA expression of endogenous nitric oxide synthase and CD86,and the protein expression of endogenous nitric oxide synthase and CD80 in the CeO2 nanoparticle treatment group were downregulated.Flow cytometry showed that 20 nm CeO2 nanoparticles downregulated the number of M1 macrophages.(3)Compared with the M1 group,20 nm CeO2 nanoparticles downregulated the mRNA and protein expression of inflammatory factors(tumor necrosis factor α,interleukin 6,cyclooxygenase 2,and endogenous nitric oxide synthase)in the co-culture system HFL1 cells.(4)The results showed that 20 nm CeO2 nanoparticles can alleviate inflammation in the co-culture system by inhibiting the expression of pro-inflammatory factors in M1 macrophages,providing a new idea for the treatment of inflammatory diseases such as rheumatoid arthritis.

Background The decline of physical activity in the elderly due to aging may increase the risk of sarcopenia. Currently, there is a lack of evidence from large natural populations on the relationship between PA and sarcopenia. Objective To explore the relationship between PA and sarcopenia in the elderly aged 60 years and above in 10 provinces (autonomous regions) of China. Methods Data were retrieved from the 2022—2023 round of the China Development and Nutrition Health Impact Cohort. Personal basic information and PA data were collected by questionnaire survey. Skeletal muscle mass was measured by bio-electrical impedance analysis, muscle strength was measured using a grip dynamometer, and physical performance was reflected by 6-meter walk speed. The Asian Working Group for Sarcopenia (AWGS) 2019 criteria were used to diagnose sarcopenia. Light physical activity (LPA) duration, moderate-to-vigorous physical activity (MVPA) duration, and total physical activity volume were calculated. A total of 3326 residents aged ≥60 years with complete data were selected as the survey participants. Multiple logistic regression models and restricted cubic splines (RCS) were used to assess the association between PA duration/volume and sarcopenia. Results In 10 provinces (autonomous regions) of China, the prevalence of sarcopenia in the elderly aged 60 years and above was 5.5% (95%CI: 4.7%, 6.2%). The logistic regression analysis showed that compared with the elderly reporting 0-7.0 h·week⁻¹ in LPA duration, the risk of sarcopenia in the elderly with LPA duration of >14.0-21.0 h·week⁻¹ was reduced by 51% (OR=0.49, 95%CI: 0.26, 0.96). Compared with the elderly with total physical activity ≥15.0 metabolic equivalent of task (MET)-h·week⁻¹, those with <7.5 MET-h·week⁻¹ had a 2.24-fold increased risk of sarcopenia (OR=2.24, 95%CI: 1.17, 4.29). The RCS results found that LPA duration and total physical activity volume each showed a nonlinear dose-response relationship with the risk of sarcopenia (P_overall<0.05, P_non-linear<0.05). Compared with the elderly with an LPA duration of 0 h· week⁻¹, the risk of sarcopenia in the elderly with an LPA duration of 12.6 h· week⁻¹ was the lowest (OR=0.42, 95%CI: 0.21, 0.83). Compared with the elderly with a total physical activity volume of 15.0 MET-h· week⁻¹, the elderly with a total physical activity volume of 46.0 MET-h· week⁻¹ had the lowest risk of sarcopenia (OR=0.57, 95%CI: 0.38, 0.84). There was no statistically significant association between weekly MVPA duration and the risk of sarcopenia (P>0.05). Conclusion Increasing weekly LPA duration and total physical activity volume would help to reduce the risk of sarcopenia.

Objective To explore the mediating role of activities of daily living (ADL) in pain and depressive symptoms in the elderly in China. Methods Utilizing the data from 2020 China Health and Retirement Longitudinal Study, 4403 Chinese elderly individuals aged ≥ 60 years old were selected as the research subjects. Depression Scale (CES-D 10) of the Center for Epidemiological Survey and ADL scale were used in the study. The PROCESS4.1 macro was used to test the mediating effect of daily living activities between pain and depressive symptoms, and the Bootstrap method was applied for verification of the mediating variables. Results A total of 2368 cases of depressive symptoms were detected in the elderly in China, with a detection rate of 53.78%. Pain was positively correlated with depressive symptoms (r=0.27, P<0.01), and activities of daily living were negatively correlated with pain and depressive symptoms (r=-0.27, -0.337, P<0.01). The results showed that the total effect value of pain on depressive symptoms was 0.33, the direct effect value was 0.24, and the mediating effect value of daily living activities was 0.09, accounting for 27.27%. Conclusion Pain and activities of daily living are important factors influencing depressive symptoms in the elderly, and activities of daily living play a partial mediating role in the relationship between pain and depressive symptoms in the elderly.

Objective To understand the distribution of M protein gene (emm) of group A streptococcus (GAS) infections among children in Xicheng District of Beijing. Methods Throat swab samples from scarlet fever and pharyngeal infection cases were collected in sentinel hospitals of Xicheng District, Beijing from 2011 to 2024. GAS strains were isolated and identified, and emm gene was amplified and sequenced by PCR to determine the genotype. The differences in emm genotype between different groups were compared. Results A total of 3 130 throat swab samples were collected, and 400 GAS strains were isolated, with a positive rate of 12.78%. The highest positive rate was 19.93% in 2011. The positive rate of scarlet fever (45.71%) was higher than that of pharyngeal infection (6.14%) (P<0.001). There were 391 emm gene positive strains, and the differences in the positive rate of emm gene among different cases were statistically significant (P<0.001). A total of 7 genotypes and 27 gene subtypes were detected. Among different groups, the emm genotypes were mainly emm12 and emm1. The emm gene subtypes were mainly emm12.00 and emm1.00. Except for some years, the genotypes and their subtypes were dominated by emm12 and emm12.00, and the distribution differences of the two major genotypes and their subtypes were statistically significant from 2011 to 2019 (P<0.001). There were differences in genotypes and subtypes among different age groups (P=0.002). Conclusion The dominant types of emm genes in group A streptococcus infections among children were emm12 and emm1 in Xicheng District of Beijing from 2011 to 2024, and the dominant gene subtypes were emm12.00 and emm1.00. It is necessary to comprehensively strengthen the monitoring of the epidemic situation and genotype, timely grasp the distribution and variation of emm gene.