Establishment of a rat silicosis model via non-exposed tracheal instillation in combination with a ventilator / 中国职业医学

@#Objective - To establish a new non exposed intratracheal instillation method for establishing a rat silicosis model. Methods ， The specific pathogen free SD rats were randomly divided into control group and experimental group with ten rats in ， each group. Rats in the control group were given 1.0 mL of 0.9% sodium chloride solution and rats in the experimental group - were given 1.0 mL of silica suspension with a mass concentration of 50 g/L adopting to the one time intratracheal instillation ， - ， method and then followed by ventilator assisted ventilation immediately. When the tidal volume stabilized at 2.0 mL the ventilator was removed and the tracheal intubation was pulled out. Five rats in each group were sacrificed after two and four ， - Results weeks after modeling and hematoxylin eosin staining and Masson staining of lung tissue were performed. There was ， ， no death in the two groups of rats during the experiment. After two and four weeks the control group had normal lung structure ， ， ， normal alveolar cavity size no inflammatory cell infiltration thin alveolar wall only a small amount of collagen distribution ， around the lung interstitium and bronchus. At the second week of modeling the alveolar wall of the rats in the experimental ， ， ， group was slightly thickened interstitial lymphocytes and macrophages were infiltrated slight hyperplasia was found and a ， small amount of fibroblasts were visible. At the 4th week of modeling the alveolar wall of the rats in the experimental group was ， ， ， ， significantly thickened fibrous nodules were formed and fibroblasts fibrocytes collagen fibers were significantly increased. Conclusion - The combination of ventilator and non exposed intratracheal instillation method can be used to successfully ， ， . establish a rat silicosis model which is simple safe and effective

Effects of using hand-held vibration tool on work-related musculoskeletal disorders in automobile factory workers / 中国职业医学

@#Objective - To analyze the effect of using vibration tools on the prevalence of work related musculoskeletal disorders （ ） Methods ， - WMSDs in automobile factory workers. By judgment sampling method front line workers with more than one year of working experience in an automobile factory were selected as the research subjects. Musculoskeletal Disorders Questionnaire was used for investigation. The workers were divided into the control group and the vibration tool group. The propensity score ∶ ， matching method was used to balance the confounding factors of the two groups of workers by 1 1 and 568 people were Results included in each group. The prevalence of WMSDs was compared between the two groups after matching. After ， ， ， ， ， ， matching the prevalence of WMSDs in the shoulder elbow hand/wrist upper back waist hip/buttock and knee of workers in ， （ P ） the vibration tool group was higher than that in the control group and the differences were statistically significant all <0.05 .， The prevalence of WMSDs in different body parts of workers in the vibration tool group ranking from high to low was waist ， ， ， ， ， ， ， ， ， ， neck shoulder hand/wrist upper back knee ankle/foot elbow and hip/buttock with the rate of 74.3% 61.3% 54.2% ， ， ， ， ， （P ） Conclusions 54.0% 50.9% 39.4% 35.2% 31.0% and 27.1% respectively <0.01 . The use of vibration tools can ， ， ， ， ， increase the risk of WMSDs in shoulder elbow hand/wrist upper back waist hip/buttock and knee of automobile factory workers. Corresponding measures should be taken to reduce vibration intensity and reduce contact time to protect workers'

Seroprevalence of IgM and IgG Antibodies against SARS-CoV-2 in Asymptomatic People in Wuhan: Data from a General Hospital Near South China Seafood Wholesale Market during March to April in 2020.

The aim of this study was to estimate the seroprevalence of immunoglobulin M (IgM) and G (IgG) antibodies against SARS-CoV-2 in asymptomatic people in Wuhan. This was a cross-sectional study, which enrolled 18,712 asymptomatic participants from 154 work units in Wuhan. Pearson Chi-square test, t-test, and Mann-Whitney test were used to compare the standardized seroprevalence of IgG and IgM for age and gender between different groups. The results indicated the standardized seroprevalence of IgG and IgM showed a downward trend and was significantly higher among females than males. Besides, different geographic areas and workplaces had different seroprevalence of IgG among asymptomatic people, and the number of abnormalities in CT imaging were higher in IgG antibody-positive cases than IgG-negative cases. We hope these findings can provide references for herd immunity investigation and provide basis for vaccine development.

Analysis of Health Service Utilization and its Influencing Factors among Patients with Pneumoconiosis in China.

Pneumoconiosis, an interstitial lung disease that occurs from breathing in certain kinds of damaging dust particles, is a major occupational disease in China. Patients diagnosed with occupational pneumoconiosis can avail of free medical treatment, whereas patients without a diagnosis of occupational diseases cannot not claim free medical treatment in most provinces from the government before 2019. This study aimed to analyze the priority of medical facility selection and its influencing factors among patients with pneumoconiosis. A total of 1,037 patients with pneumoconiosis from nine provinces in China were investigated. The health service institutions most frequently selected by the patients were county-level hospitals (37.5%). The main reason for the choice was these hospitals' close distance to the patients' homes (47.3%). The factors for the choice of health care institutions were living in the eastern region ( OR = 2.91), living in rural areas ( OR = 2.10), silicosis diagnosis ( OR = 2.44), employment in private enterprises ( OR = 2.91), smoking ( OR = 2.69), and quit smoking ( OR = 3.98). The diagnosis, treatment, and rehabilitation therapy of pneumoconiosis should be enhanced in primary medical institutions.

[Co-occurrence of musculoskeletal disorders and influence factors among Chinese auto workers].

OBJECTIVE: To analyze the prevalence and risk factors of multiple musculoskeletal disorders (MSDs) in auto workers and the associations between MSDs at different sites. METHODS: A cross-sectional survey was conducted in 3998 workers, who were selected from a Chinese auto corporation by cluster random sampling, using the revised Nordic MSDs standard questionnaire; 3800 completed questionnaires were returned. Multinomial logistic regression analysis was performed to assess the risk factors for multiple MSDs. The logbinomial model was used to calculate the prevalence ratios (PRs) of MSDs at different sites and evaluate the associations between MSDs at different sites. RESULTS: Of the 3800 subjects, 2452 (64.5%) had MSDs at two or more sites, and 469 (12.3%) had MSDs at one site. The PRs varied from 1.5 to 6.7, with significant differences among different sites (P < 0.01). Relatively close associations were found between the MSDs at neck and shoulders, back and shoulders/waist, elbows and wrists/hands, waist and neck, wrists/hands and waist, hip and waist, knees and waist, and ankles/feet and elbows. The multinomial logistic regression analysis indicated that the highest risk factor for MSDs was poor posture, including often working in an uncomfortable posture, neck bending forward, and neck twisting (ORs = 3.39, 1.93, and 1.38), followed by labor organization, in which break between tasks could decrease the risk of MSDs at three or more sites to 31%, staff shortage, which could increase the risk of MSDs by 75%, and pushing and pulling heavy objects (> 20 kg) (OR = 1.76). CONCLUSION: Most auto workers with MSDs have multiple sites affected, and there are high associations between the MSDs at different sites. The major risk factors for multiple MSDs in auto workers include poor posture, labor organization, and heavy physical labor.

[Risk factors analysis of low back pain among workers in a foundry factory of the automobile company].

OBJECTIVE: To study the main risk factors of low back pain of workers ina foundry factory of the automobile company using cross sectional epidemiological investigation, and to provide scientific base for preventing the disorder. METHODS: The low back pain and work loads of 1340 workers in a foundry factory of the automobile company were investigated using questionnaire, and logistic regression analysis was used to analyze the risk factors. RESULTS: The one-year morbidity of low back pain in workers was 58.9% the morbidities of low back pain in workers engaged in foundry, transportation and modeling were 64.6%, 64.6% and 62.5%, respectively. The lifting with squat postures, bending trunk heavily, bending trunk with twisting and moving the heavy objects were found to be the most dominant risk factors for low-back pain, the OR values were 2.085, 1.961, 1.967 and 1.956, respectively. The distributions of risk factors were different among the different jobs. The logistic regression analysis showed that moving the heavy objects, lifting with squat postures, bending trunk heavily, bending trunk with twisting existed simultaneously, also the work years and gender were the risk factors. CONCLUSION: The manual moving heavy objects, awkward working posture or both were the most important risk factors for low-back pain. The intervene ergonomic study should be performed in future to reduce the morbidity of low-back pain.