Objective To investigate the effects of aggrecanase-2 knockdown in chondrocytes from rheumatoid arthritis patient by shRNA infection.Methods Cartilage harvested from rheumatoid arthritis patients who underwent total knee arthroplasty was digested by pancreatin and type Ⅱ collagen enzyme to obtain chondrocytes.Then chondrocytes were cultured and passaged to second or third generation.After aggrecanase-2 shRNA5,aggrecanase-2 shRNA6,aggrecanase-2 shRNA7,aggrecanase-2 shRNA8 infection,growth and morphological changes of the chondrocytes were examined.To select the best target sequence,mRNA expression of aggrecanase-2 and aggrecan was detected by RT-qPCR assay on day 2,5,10,represented with Ct (Cycle threshold) value.Expression of aggrecan protein was detected by immunocytochemistry,represented with IOD (integral optical density) value.Results aggrecanase-2 knockdown had no obvious effects on the morphology and growth of the chondrocytes.MOI (multiplicity of infection) was 100,50,25,and infection efficiency was 90％,60％,30％ with the corresponding viral load of 200 μl,100 μl,50 μl after transfection.mRNA expression of aggrecanase-2 was suppressed significantly,especially the group of shRNA5 which suppressed aggrecanase-2 expression from 0.876 3±0.115 6 to 0.069 9±0.015 1 (P ＜ 0.05).mRNA and protein expression of aggrecan were significantly upregulated after infection.mRNA expression of aggrecan increased from 0.992 1±0.201 3 to 3.049 2±0.278 2 (P ＜ 0.05) and protein expression of aggrecan increased from 496.160 5± 225.673 7 to 4 525.433 0±1 131.813 0 (P ＜ 0.05).Conclusion aggrecanase-2 suppression in chondrocytes by lentivirius infection is an effective method to protect the expression of aggrecan.

Objective To investigate the effects of oligochitosan on the humoral and cellular immunity in mice.Methods Divided the mice into four groups,test groups were given ip oligochitosan at doses of 60,120,240 mg?kg~(-1) for 14 days and the control group was given(0.9%) NS. The number of haemolytic empty spots,the level of serum hemolysin,the transform rate of T lymphocytes induced by ConA,delayed hypersensitivity were measured.Results Compared with the control group,indices including the number of haemolytic empty spots,the level of serum hemolysin,the transform rate of T lymphocytes induced by ConA,spleen ratio,ears swelling degree increased obviously in the dose of 120mg?kg~(-1) after two weeks of treatment.Conclusion Proper dose of oligochitosan can enhance the specific humoral and cellular immunity in mice.

OBJECTIVETo investigate relations between milk consumption and lactose intolerance (LI) in adults and to explore the effect of milk consumption on lactase activity.

METHODSTotal of 182 subjects aged 20-70 years were recruited and interviewed by questionnaires, and their accumulative cow's milk intake (AMI) was calculated. LI was evaluated by hydrogen breath test (HBT).

RESULTSA negative correlation was found between AMI and severity of observed LI symptom (r=-0.2884; P<0.05). Binary logistic regression analysis showed a negative correlation between LI and duration and frequency of milk consumption (OR, 0.317 and 0.465, respectively; both P<0.05) and a positive correlation between LI and amount of milk consumed per sitting (OR, 6.337; P<0.05).

CONCLUSIONLI is related to various milk consumption behaviors. Most Chinese adults with LI may tolerate moderate milk consumption <160 mL.

Adult ; Animals ; Breath Tests ; China ; epidemiology ; Drinking Behavior ; Humans ; Hydrogen ; Lactase ; metabolism ; Lactose ; Lactose Intolerance ; diagnosis ; epidemiology ; prevention & control ; Milk ; Prevalence

AIM:To investigate the mechanism of chronic stress-induced myocardial injury in atherosclerotic(AS)mice.METHODS:Eight-week-old SPF-grade male ApoE-/-mice and C57BL/6J mice used in this study.The mice received dietary intervention for 10 weeks followed by pathological examination to test the successful AS modeling.After AS establishment,the mice were exposed to chronic unpredictable mild stress(CUMS)for 6 weeks and then divided into five groups:control,CUMS,AS-regular diet(AS-r)+CUMS,AS-high-fat diet(AS-h),and AS-h+CUMS.During CUMS,open-field test and sucrose preference test were performed on mice in all groups.Blood lipids were characterized using an automatic biochemical analyzer.Hematoxylin-eosin(HE)and oil red O staining were performed to evaluate pathological changes in the aortic root.Cardiac function was assessed using echocardiography.The serum concentration of myocardial injury markers and ATP content was detected by ELISA.Transmission electron microscopy was employed to observe the ul-trastructure of myocardial mitochondria.Myocardial mitochondrial oxygen consumption rate was determined using the Oxy-graph-2k high-resolution respiratory energy metabolism analyzer.Western blot was conducted to quantify the expression of B-cell lymphoma-2(Bcl-2),Bcl-2-associated X protein(Bax),and cleaved caspase-3.RESULTS:compared with the Control group,the total distance traveled,the number of entries into the central area,and the sucrose preference rate were significantly decreased in all CUMS groups(P<0.05).All AS groups exhibited varying levels of lipid deposition and endo-thelial damage in the aortic root,along with a significant reduction in cardiac function(P<0.05)and varying degrees of myocardial injury(P<0.05).In the AS-h+CUMS and AS-r+CUMS groups,myocardial mitochondrial structure was signifi-cantly disrupted.ATP content was significantly reduced(P<0.05),and the rates of oxygen consumption associated with mitochondrial respiratory chain complex I,mitochondrial respiratory chain complexes I+II,and the maximum respiratory capacity of the electron transport system were all significantly decreased(P<0.05).Moreover,the protein levels of Bax and cleaved caspase-3 were significantly increased(P<0.05),while that of Bcl-2 protein was significantly decreased(P<0.05).CONCLUSION:Chronic stress triggers mitochondrial non-steady-state load by disrupting myocardial structure and energy metabolism in AS mice,promoting myocardial cell apoptosis and myocardial injury.

BACKGROUND: Thymoma is the most common malignant tumor in anterior mediastinum, and its specific pathogenesis is still unclear. This limits the study of targeted drugs for thymoma. The aim of the study is to investigate the genes and signal pathways of thymoma, and provide help for the research of thymic tumor pathogenesis using the technology of second-generation genechip to analyze thymoma. METHODS: From January 2015 to December 2017, we analyzed 31 cases of thymoma by CapitaBio mRNA expression profile genechip technology, and then confirmed the genes by reverse transcription-polymerase chain reaction (RT-PCR). RESULTS: We found some genes with different expression levels between thymoma and surrounding thymus tissue. Among them, six driving genes (FANCI, CAPD3, NCAPG, OXCT1, EPHA1 and MCM2) were significantly abnormal in thymoma. Some specific genes affected by copy-number variation were detected: E2F2, EphA1, CCL25 and MCM2 were significantly up-regulated, while IL-6, CD36, FABP4, SH2D1A and MYOC genes were significantly down-regulated. KEGG database analysis showed that the expression of 10 signaling pathway genes was generally up-regulated or down-regulated, such as systemic lupus erythematosus, viral oncogenes, primary immunodeficiency, cell cycle genes and p53 signaling pathway, which may be related to occurrence of thymoma. CONCLUSIONS We found a variety of genes abnormally expressed in thymoma, which will provide reference for the study of pathogenesis and biomarkers of thymoma in the future.

Objective:To investigate the pollution levels and influencing factors of polybrominated diphenyl ethers (PBDEs) in household dust in five cities in northern China.Methods:Based on the "Chinese Indoor Environment and Health Surveillance" project carried out by the National Institute of Environmental Health, Chinese Center for Disease Control and Prevention in 2018-2019, during the warm season (April 2018 to September 2018) and the cold season (November 2018 to March 2019), Lanzhou in Northwest China, Shijiazhuang in North China, Panjin in Northeast China, Luoyang in Central China, and Qingdao in East China were selected as the research sites. A total of 87 families were recruited to study residences in real-life scenarios. At the same time, dust samples were collected to detect the concentration of PBDEs. The level of household environmental indicators was measured, and the residential building characteristics and family behavior habits were collected through questionnaires. A total of 142 valid dust samples and 140 valid questionnaires were obtained. The differences in PBDE concentrations across seasons, wind zones, residential building characteristics, and family habits were analyzed. The exploratory factor analysis was performed to investigate the possible sources of PBDEs, and multivariate linear regression was used to explore the factors influencing PBDEs in household dust.Results:The M ( Q1,Q3) of total PBDE concentrations in 142 household dust samples in five cities was 144.51 (106.61, 222.65) ng/g in the warm season and 145.10 (98.57, 180.65) ng/g in the cold season, respectively. There were seasonal differences in the concentration of ∑ 12PBDEs in Luoyang and Shijiazhuang ( P<0.01). The concentration of BDE-71 was highest among PBDE homologues, followed by BDE-66 and BDE-47. Three factors were extracted by exploratory factor analysis in the warm season, and the cumulative variance contribution rate was 67.90%. The multivariate linear regression showed that the house completion less than ten years [ β (95% CI): 0.186 (0.013, 0.359)], infrequent home cooking [ β (95% CI):-0.342 (-0.570, -0.114)], and increased residential PM 10 concentration [ β (95% CI): 0.001 (0.000, 0.002)] during the warm season, as well as the house far from driveway [ β (95% CI): 0.093 (0.013, 0.172)], house area less than 90 m 2 [ β (95% CI):-0.138 (-0.264, -0.013)], and lower residential xylene concentration [ β (95% CI):-0.006 (-0.011, -0.001)] during the cold season might be related to the elevated concentrations of ∑ 12PBDEs in household dust. Conclusion:The pollution of PBDEs in household dust in five northern cities is at a medium to high level. Years of house completion, frequency of cooking at home, residential PM 10 concentration, distance from house to driveway, house area, and residential xylene concentration may influence household PBDE concentrations.

Objective:To investigate the pollution levels and influencing factors of polybrominated diphenyl ethers (PBDEs) in household dust in five cities in northern China.Methods:Based on the "Chinese Indoor Environment and Health Surveillance" project carried out by the National Institute of Environmental Health, Chinese Center for Disease Control and Prevention in 2018-2019, during the warm season (April 2018 to September 2018) and the cold season (November 2018 to March 2019), Lanzhou in Northwest China, Shijiazhuang in North China, Panjin in Northeast China, Luoyang in Central China, and Qingdao in East China were selected as the research sites. A total of 87 families were recruited to study residences in real-life scenarios. At the same time, dust samples were collected to detect the concentration of PBDEs. The level of household environmental indicators was measured, and the residential building characteristics and family behavior habits were collected through questionnaires. A total of 142 valid dust samples and 140 valid questionnaires were obtained. The differences in PBDE concentrations across seasons, wind zones, residential building characteristics, and family habits were analyzed. The exploratory factor analysis was performed to investigate the possible sources of PBDEs, and multivariate linear regression was used to explore the factors influencing PBDEs in household dust.Results:The M ( Q1,Q3) of total PBDE concentrations in 142 household dust samples in five cities was 144.51 (106.61, 222.65) ng/g in the warm season and 145.10 (98.57, 180.65) ng/g in the cold season, respectively. There were seasonal differences in the concentration of ∑ 12PBDEs in Luoyang and Shijiazhuang ( P<0.01). The concentration of BDE-71 was highest among PBDE homologues, followed by BDE-66 and BDE-47. Three factors were extracted by exploratory factor analysis in the warm season, and the cumulative variance contribution rate was 67.90%. The multivariate linear regression showed that the house completion less than ten years [ β (95% CI): 0.186 (0.013, 0.359)], infrequent home cooking [ β (95% CI):-0.342 (-0.570, -0.114)], and increased residential PM 10 concentration [ β (95% CI): 0.001 (0.000, 0.002)] during the warm season, as well as the house far from driveway [ β (95% CI): 0.093 (0.013, 0.172)], house area less than 90 m 2 [ β (95% CI):-0.138 (-0.264, -0.013)], and lower residential xylene concentration [ β (95% CI):-0.006 (-0.011, -0.001)] during the cold season might be related to the elevated concentrations of ∑ 12PBDEs in household dust. Conclusion:The pollution of PBDEs in household dust in five northern cities is at a medium to high level. Years of house completion, frequency of cooking at home, residential PM 10 concentration, distance from house to driveway, house area, and residential xylene concentration may influence household PBDE concentrations.

Objective To investigate the epidemiological characteristics of local visceral leishmaniasis in Beijing Municipality from 2021 to 2023, so as to provide insights into formulation of the visceral leishmaniasis control strategy. Methods Epidemiological data of visceral leishmaniasis cases reported in Beijing Municipality from 2021 to 2023 were collected from the National Health Informatization Disease Prevention and Control Information System, and the epidemiological characteristics of local visceral leishmaniasis cases were analyzed using a descriptive epidemiological method. In November 2021 and 2023, 50 to 100 permanent residents were voluntarily selected within a 100 meter radius of sites where patients lived or acquired Leishmania infections, and venous blood was sampled for anti-Leishmania antibody testing. Venous blood was sampled from dogs for anti-Leishmania antibody testing in natural villages where patients lived or acquired Leishmania infections, or in districts where Leishmania infected dogs were reported. In addition, sandflies were captured with CO₂ mosquito traps and fine mesh nets in natural villages where patients lived or acquired Leishmania infections from May to September, 2021 and 2023, for sandfly species identification. Results A total of 4 local visceral leishmaniasis cases were reported in Beijing Municipality from 2021 to 2023, with ages of 2 to 77 years, and acquiring Leishmania infections in Mentougou District (2 cases), Changping District (1 case), and Yanqing District (1 case). The anti-Leishmania antibody testing was all negative in 73 human blood samples and the sero-prevalence of anti-Leishmania antibody was 25.00% in 36 venous blood samples from domestic dogs in 2021, with a total of 4 520 Phlebotomus chinensis captured. The sero-prevalence of anti-Leishmania antibody was 0.51% in 198 human blood samples and 13.58% in 243 venous blood samples from domestic dogs in 2023, with 16.10%, 25.00%, 17.78% and 3.13% sero-prevalence in dogs sampled from Mentougou District, Changping District, Yanqing District and Haidian District, respectively (P = 0.011), while a total of 1 712 Ph. chinensis were captured, including 1 421 female sandflies (86.54%). Conclusions The prevalence of local visceral leishmaniasis was low in Beijing Municipality from 2021 to 2023; however, there is a risk of further spread in the epidemic foci. Intensified visceral leishmaniasis surveillance and control is recommended.