BACKGROUND:The guinea pig is considered to be the most useful spontaneous model for evaluating primary osteoarthritis in humans because of its similar knee joint structure and close histopathologic features to those of humans. OBJECTIVE:To investigate the pathological process of spontaneous knee osteoarthritis in guinea pigs by analyzing the histopathology of the total knee joint of guinea pigs aged 1 to 18 months. METHODS:Eight healthy female Hartley guinea pigs in each age group of 1,6,10,14,16,and 18 months old were selected.The quadriceps femoris was taken for hematoxylin-eosin staining,and the total knee joint was stained with hematoxylin-eosin and toluidine blue.The histopathology of the cartilage,subchondral bone,synovium,meniscus,and muscles were observed under light microscope.Mankin's score and synovitis score were compared,and the correlation analysis was conducted. RESULTS AND CONCLUSION:As the guinea pig age increased,the Mankin's score increased(P<0.05),and the pathological score of synovitis also gradually increased(P<0.05),and there was a significant positive correlation between the two(r=0.641,P<0.001).The incidence rate of subchondral bone marrow lesion in 18-month-old guinea pigs was 50%,and the incidence of meniscus injury was 37.5%.In addition,osteophyte and narrowing of the joint space were observed,and only a few guinea pigs had inflammation in the quadriceps femoris.To conclude,guinea pigs develop significant cartilage defects,synovial inflammation,subchondral bone lesions,meniscus injury,osteophyte formation,and joint space narrowing as they age,all of which are similar to the pathological processes of primary knee osteoarthritis in humans,making it an ideal model of spontaneous knee osteoarthritis.

Objective: To understand 24 h physical activity levels of children aged 8-9 years in Pudong New Area and to explore its association with metabolic syndrome, so as to provide scientific basis for children s participation in physical activities and reducing the risk of metabolic syndrome. Methods: A stratified cluster random sampling method was adopted to select 13 schools in Pudong New Area, Shanghai. A total of 2 013 primary school students aged 8-9 years old were included as the research subjects. During September 2021 to December 2022, Actigraph GT3X accelerometer, height measuring gauge, electronic sphygmomanometer and waist circumference tape was used to measure physical activity, height, blood pressure and waist circumference, respectively. A total of 5 mL of venous blood was collected from students, and the levels of triglycerides (TG), highdensity lipoprotein cholesterol (HDL-C) and fasting plasma glucose (FPG) were detected, and online questionnaires were conducted. The ttest and oneway ANOVA were employed to compare the differences in 24 h physical activity levels among children with different characteristics. Multivariate Logistic regression was used to analyze the association between the 24 h physical activity levels and metabolic syndrome as well as its components. Results: Among primary school students, the average daily time of moderate to vigorous physical activity (MVPA) was (34.25±13.49)min, the attainment rate was 1.59%. The average daily sleep (SLP) time was (538.27±28.53) min, attainment rate was 1.89%. The detection rates of metabolic syndrome, abdominal obesity (AO), elevated blood pressure (BP), elevated TG, low HDL-C, and elevated FPG were 2.48%, 34.53%, 10.38%, 10.73%, 1.24% and 0.70%, respectively. Multivariate Logistic regression analysis showed that, for every 10minute increase in sedentary behavior (SB) time, the risks of AO, elevated BP, and elevated TG increased by 2% ( OR=1.02, 95%CI =1.01-1.04), 5% ( OR=1.05, 95%CI =1.01-1.08), and 6% ( OR= 1.06, 95%CI =1.02-1.11), respectively ( P <0.05). For every 10minute increase in MVPA time, the risk of metabolic syndrome decreased by 27% ( OR=0.73, 95%CI=0.57-0.93, P <0.05). For every 10 minute increase in SLP time, the risks of AO, elevated BP, and metabolic syndrome decreased by 16% ( OR=0.84, 95%CI =0.80-0.88), 9% ( OR=0.91, 95%CI =0.82- 0.99 ), and 15% ( OR=0.85, 95%CI =0.77-0.94), respectively （P <0.05). Conclusions The time of MVPA and SLP are seriously insufficient among children aged 8-9 years in Pudong New Area. There is an association between physical activity levels and metabolic syndrome as well as its components. Increasing the time of MVPA and SLP is of great significance for maintaining a relatively low risk of metabolic syndrome in children.

ObjectiveTo understand the visual environment sanitation in primary and secondary school classrooms in Minhang District， Shanghai， and to investigate the factors affecting the decline in students’ visual acuity. MethodsIn 2020， among all the primary and secondary schools in Minhang District， according to different types of classroom structures， levels， orientations， unilateral lighting， and bilateral lighting， a total of 20 231 students from 674 classrooms in primary and secondary schools were selected through stratified cluster sampling. Each monitored classroom was regarded as a research unit， and the naked eye vision of students was tested using a standard logarithmic vision chart during the 2020 and 2021 academic years. The change in average visual acuity between the two measurements was taken as the dependent variable， and the visual environment indices were considered as independent variables. The relationship between classroom visual environment indices and the decline in students’ naked eye vision was analyzed. ResultsThe qualification rates for per capita classroom area， window to floor area ratio， average illuminance of the blackboard， uniformity of blackboard illuminance， average illuminance of the desks， uniformity of desk illuminance， lighting coefficient of classroom， blackboard reflection ratio， back wall reflection ratio， and distance between lamps and desks were 79.53%， 88.58%， 46.74%， 70.33%，64.69%， 80.86%， 71.81%， 20.30%， 1.63%， and 97.53%， respectively. The average naked eye vision of primary and secondary school students in the 2020 academic year was 4.75±0.37 （right eye） and 4.76±0.37 （left eye）， while in the 2021 academic year， it was 4.70±0.39 （right eye） and 4.71±0.38 （left eye）. There was a significant decrease in the naked eye vision of primary and secondary school students in the 2021 academic year compared to that of 2020 （P<0.05）. Univariate linear regression analysis showed a significant correlation between grade， average illuminance of the blackboard， average illuminance of the desks， uniformity of desk illuminance， lighting coefficient， and distance between lamps and desks， and the decline of students’ naked eye vision within one academic year （P<0.05）. After adjusting for grade， multiple linear regression analysis revealed a significant correlation between the average illuminance of the blackboard， uniformity of desk illuminance， lighting coefficient， and distance between lamps and desks， and the decline of students’ naked eye vision within one academic year （P<0.05）. Higher average illuminance of the blackboard， uniformity of desk illuminance， lighting coefficient， and distance between lamps and desks were protective factors for naked eye vision. ConclusionThe visual environment of primary and secondary school classrooms in Minhang District is a matter of concern. Average illuminance of the blackboard， uniformity of desk illuminance， lighting coefficient， and distance between lamps and desks are related to the degree of visual impairment in students over a year.

The construction of healthy schools is one of the key measures to implement the Outline of the Healthy China 2030 Plan. The establishment and implementation of the Guidelines for Healthy Primary and Secondary School Evaluation （Guidelines） is helpful for the large-scale promotion and standardization of healthy school construction by government departments in Shanghai and other major cities in China， thereby more students benefited from the Healthy China Initiative. The Guidelines integrate the efforts of multiple departments related to school health， based on internationally recognized content and strategies for health-promoting schools. They aim to foster students’ health development by combining the basic requirements for school health with priority projects for health promotion. Healthy school evaluation indicators and standardized requirements suitable for the current socio-economic development level of Shanghai have been developed， aligning with international concepts of health-promoting schools. They also reflect a high starting point and high level of investment and development in school health in Shanghai over the past decade. The Guidelines provide recommendations on the basic requirements， organization guarantees and management， social and culture environment， health promotion education， health services， and connection between school and communities， and families， of healthy school evaluation for primary and secondary schools. This paper aims to interpret the compilation process and main content of the Guidelines.

ObjectiveTo analyze the status of and family-related factors associated with extracurricular screen time (ST) among the primary and middle school students in a district of Shanghai, and to provide a scientific basis for the development of targeted intervention measures. MethodsA total of 819 students and their parents from one primary school and one middle school were selected by stratified cluster sampling method from November to December 2022 in a district of Shanghai. A questionnaire survey was conducted to investigate the total extracurricular ST and entertainment ST during school days, weekends and summer and winter vacation, as well as the underlying family-related factors. Taking daily total extracurricular ST>2 h as excessive extracurricular ST and daily extracurricular entertainment ST>1 h as excessive extracurricular entertainment ST. ResultsAmong the 795 valid questionnaires, the proportions of excessive extracurricular ST during school day, weekend and summer and winter vacation were 10.9%, 42.1% and 51.1%, respectively, and the proportions of excessive extracurricular entertainment ST were 16.2%, 63.0% and 71.3%, respectively. The proportion of excessive extracurricular ST on weekend and summer and winter vacation was higher for middle school students than for primary school students, and the proportion of excessive extracurricular ST was higher for the students whose father’s educational level was high school and below than for those whose father’s educational level was junior college and above (both P<0.05). Multivariate logistic regression analysis after controlling confounding factors showed that the students with poor parent-child relationships (aOR=1.40‒1.96) and parental daily ST>2 h (aOR=1.83‒3.85) were more likely to have an excessive total extracurricular ST and entertainment ST. ConclusionThe proportion of excessive extracurricular ST for the primary and middle school students in Shanghai is relative high during weekend and summer and winter vacation, especially for entertainment purposes. Improving parent-child relationships and reducing parental excessive ST may be important intervention measures.

ObjectiveTo investigate the general situation of defect of vertebral column among primary and middle school students in Minhang District of Shanghai and analyze the related factors， to provide a scientific basis for prevention and treatment. MethodsFrom September to October 2022， a total of 5 715 students were selected from two primary schools， two middle schools， and two high schools in Minhang District for physical examinations and screening for defect of vertebral column. ResultsTotally 219 students had defect of vertebral column， accounting for 3.83% of the sampled population. Anteroposterior spinal abnormalities were found in 4 individuals， accounting for 0.07%， and 218 students had scoliosis， accounting for 3.81%. The detection rate of defect of vertebral column was higher in girls （6.27%） than that in boys （1.51%）， and higher in high school students （10.74%） than in primary school students （1.31%） and middle school students （10.97%）. Students who are mildly underweight （5.95%） and who are moderately to severely underweight （7.46%） had a higher detection rate of defect of vertebral column than those with normal weight （4.54%）， overweight （2.83%）， and obesity （1.60%）. The detection rate among students with poor vision （4.32%） was significantly higher than those with normal vision （2.24%）， with all differences statistically significant （all P<0.05）. ConclusionThe positive rate of defect of vertebral column in primary and middle school students in Minhang District， Shanghai is nearly 4%， with most cases being scoliosis. Factors such as being female， increasing age， being underweight， and poor vision are associated with a higher probability of detecting defect of vertebral column.

Objective: To develop an assessment questionnaire for screen based behaviors among primary and secondary school students, so as to provide a basis for comprehensive assessment among the population. Methods: Nineteen experts were invited to take part in this study from August to September 2022. The initial framework and item pool of the assessment questionnaire were developed based on literature review and a series of guidelines and standards issued by the national education and health authorities, as well as relevant domestic and foreign guidelines, and were combined with existing assessment tools that were used to evaluate screen based behavior among these age groups. Experts in related fields were selected for two rounds of Delphi consultation to determine the dimensions, items and corresponding weights of the assessment questionnaire. Results: The response rates from two rounds of consultation were 95.0% and 100.0% respectively, the opinion submission rates were 89.5% and 63.2% respectively, and the authority coefficient ( Cr ) was 0.87. An assessment questionnaire was finally designed, consisting in 44 items and four dimensions, namely screen use type and time, screen use related health behaviors, safety and civilization in screen use, and reasonable arrangement of screen and non screen activities. The coefficient of variation( CV ) of each item ranged from 0.00 to 0.19, and the Kendall s W increased from 0.22 to 0.34( P <0.01). Expert opinions were in agreement and credible. Conclusion The designed assessment questionnaire can be used to comprehensively evaluate screen based behavior among primary and middle school students, and provides a basis for subsequent intervention measures to improve screen based behavior among this population.

The general population cohort study in Beijing-Tianjin-Hebei area is a large-scale prospective longitudinal study conducted since 2017, which covers over 114 850 diverse populations from early life to senior age. Up to December 2021, 106 031 people had completed at least one follow-up, with an overall follow-up rate of 92.3%. Considering of the characteristics of the environmental and health problems in Beijing-Tianjin-Hebei area, in this cohort study we have focused on health problems of children and adolescents' growth and development, cardiometabolic diseases and their risk factors, aging and comorbidity, health hazards caused by air pollution. The long-term follow up of the general population cohort study in Beijing-Tianjin-Hebei area will contribute to establishing unique and invaluable data and biobank resource for scientific research. This paper aims to comprehensively describe the background, significance, current status and outcomes, limitations and challenges, and future plan and development of general population cohort study in Beijing-Tianjin-Hebei area, thus to provide reference for professionals both at home and abroad to carry out related research.

The National Health and Nutrition Examination Survey (NHANES) of America has been running for more than 60 years and has achieved many significant achievements with international influence. The application of modern information technologies in NHANES provides a supplementary tool for the project's high quality and refined implementation. This paper introduces the information system of NHANES from seven aspects: project management, survey participant interview, physical examination, laboratory examination, field follow-up, data sharing, and social services. The construction and application prospects of the China National Health Survey Information System, suitable for China's native conditions, are also discussed in this article.

Objective:To explore the association between chest high resolution CT (HRCT) scoring and prognostic factors of interstitial lung disease (ILD) in patients with anti-melanoma differentiation-associated gene 5 (MDA5) antibody-positive dermatomyositis (DM).Methods:The patients with DM admitted to Kailuan General Hospital between January 2017 and December 2019 were included into the study including 13 patients with positiveanti-MDA5 antibody (7 survivors, 6 deaths) and 18 patients with anti-synthase (ARS)-antibody positive. All patients underwent chest HRCT prior to treatment. The consolidation, ground-glass opacity (GGO) and fibrosis were scored to assess HRCT findings. The clinical manifestations were compared between the two groups. Cox regression analysis adjusted for age and sex was used to determine the prognostic factors for anti-MDA5 antibody-related ILD.Results:Compared with ARS patients, glutamyl transferase (GGT) and ferritin levels were significantly higher in MDA5-ILD patients [70.0(37.0, 122.5) vs 21.0(16.5, 33.5), Z=-3.37, P=0.001; 977.0(502.5, 1 366.0) vs 307.1(72.3, 546.9) , Z=-3.44, P=0.001]. The cumulative survival rate was significantly lower in patients with positive anti-MDA5 antibody than in those with positive anti-ARS antibody (100% vs 70%, P=0.001). The DM complicated with acute/subacute interstitial pneumonia (A/SIP) were found to significantly relate to death. There were no significant differences in chest HRCT scoringbetween the survivors and the deceased patients [ HR=1.08, 95% CI(0.95, 1.23), P=0.229; HR=0.97, 95% CI(0.72, 1.30), P=0.814]. Conclusion:Anti-MDA5 antibody is an important index for early diagnosis of DM complicated with acute/subacute interstitial pneumonia (A/SIP). The chest HRCT scoreis is not associated with the prognosis of anti-MDA5 antibody-related ILD patients.