Objective To observe the changes of serum 25‐hydroxy vitamin D[25‐(OH)D] level of patients with rheumatoid ar‐thritis(RA) and study its clinical significance .Methods The method of chemiluminescence was adopted to detect peripheral blood serum 25‐(OH) D of 60 cases of RA patients(RA group) and 60 cases of healthy people(control group) .Results The serum 25‐(OH) D level of patients in RA group was(34 .37 ± 8 .87) nmol/L ,while that of the control group was(61 .33 ± 7 .74) nmol/L ;after comparison ,the differences were statistically significant (t= -6 .892 ,P< 0 .05);the serum 25‐(OH) D level of patients in RA group was in negative correlation with RA patient age ,body mass index(BMI) ,time of morning stiffness ,tender joint count(TJC) , swollen joint count(SJC) ,C‐reactive protein(CRP) ,erythrocyte sedimentation rate(ESR) ,visual analog scale(VAS) for disease o‐verall pain and health assessment questionnaire (HAQ) and disease activity score (DAS28)(r= -0 .201 ,-0 .255 ,-0 .362 ,-0 .296 ,-0 .273 ,-0 .198 ,-0 .323 ,-0 .356 ,-0 .379 ,-0 .418 ;P<0 .05 in all cases);but had no correlation with course of dis‐ease ,rheumatoid factor (RF) ,anti‐cyclic citrullinated peptide (CCP) antibody (anti‐CCP) and antibody concentration (P> 0 .05) . Conclusion The serum 25‐(OH) D level of RA patients is significantly low ,which might be associated with the RA disease activi‐ty .

Objective: To explore the phenotypic and genotypic characteristics in Chinese children with classic pantothenate kinase-associated neurodegeneration (PKAN). Method: The clinical, radiographic and genetic data of all PKAN patients diagnosed at pediatric department of Peking University First Hospital from November 2006 to December 2016 were retrospectively collected and analyzed. Result: Twenty patients with classic PKAN were included in the study. The median age at onset was 3.5 years (ranging from 1.0 to 10.0 years), and the most common initial symptom was gait disturbance (16 cases). At the last evaluation, the clinical features were limbs dystonia (20 cases), dysarthria (16 cases), dysphagia (11 cases), pyramidal sign (7 cases), mental regression (3 cases) and pigmentary retinopathy (5 cases). For those classic PKAN patients, the median time from onset of disease to loss of independent ambulation was 6.9 years (ranging from 2.0 to 12.0 years). Imaging data showed, except "eye of tiger" in MRI (19 cases), globus pallidus calcification in CT was also found in four patients. In gene testing, 26 different mutations in PANK2 gene were identified, and 16 of 26 were novel mutations. Moreover, c. 1502T>C (p.Ile501Asn) was the most common mutation (4 cases). Conclusion Dystonia is the major neurologic feature of classic PKAN. Disease progression is rapid, with loss of independent ambulation within 10 years after onset. Except "eye of tiger" in MRI, globus pallidus calcification in CT may be another imaging feature of PKAN.Sixteen novel mutations of PANK2 gene were identified in the study.

{L-End}Objective To investigate the influencing factors of work-related musculoskeletal disorders (WMSDs) that affect neck-shoulder-back among manufacturing workers. {L-End}Methods A total of 8 250 front-line workers from 27 manufacturing enterprises in Henan Province and Hubei Province were selected as the research subjects using cluster sampling method. The Musculoskeletal Disorders Questionnaire was used to investigate the prevalence of neck-shoulder-back (include neck, shoulder, upper back, and lower back) WMSDs in the past year. The log-binomial model, principal component analysis (PCA) and multivariate logistic regression analysis were used to analyze the influencing factors of WMSDs in the neck-shoulder-back. {L-End}Results The prevalence of WMSDs was 77.2%. The prevalence of neck-shoulder-back WMSDs was 50.9%. The prevalence ratios of WMSDs were relatively higher among the neck, shoulder, and upper back (all P<0.05). The results of PCA improved logistic regression analysis showed that the influencing factors of neck-shoulder-back WMSDs were individual factors, biomechanical factors, psychosocial factors and environmental factors. In terms of individual factors, the risk of neck-shoulder-back WMSDs was higher in females than in males (P<0.05). With the increase of age, length of service, and education level, the risk of neck-shoulder-back WMSDs increased among manufacturing workers (all P<0.05). The risk of neck-shoulder-back WMSDs of workers in textile, clothing, shoes and hats manufacturing industry was relatively lower than that in the other nine industries (all P<0.05). In terms of the biomechanical factors, spending a lot of effort to operate tools/machines, sitting for a long time at work,bending greatly bending and turning at the same time, neck leaning forward or maintaining this posture for a long time, neck twisting or maintaining this posture for a long time and uncomfortable position resulting in difficulty exerting exertion were all risk factors of neck-shoulder-back WMSDs among manufacturing workers (all P<0.05) Bending slightly for a long time was a protective factor for neck-shoulder-back WMSDs among manufacturing workers (P<0.05). In terms of the psychosocial factors, doing the same work every day, self-determination in resting time between works staff shortage, and frequent overtime work were risk factors for neck-shoulder-back WMSDs among manufacturing workers (all P<0.05). Adequate resting time was a protective factor for neck-shoulder-back WMSDs among manufacturing workers (P<0.01). In terms of environmental factors, working under cold or fluctuating temperature, having nothings to lean on, and soles slipping or falling at work were all risk factors for neck-shoulder-back WMSDs among manufacturing workers (all P<0.05). {L-End}Conclusion Manufacturing workers are prone to suffer from neck-shoulder-back WMSDs. The influencing factors include individual factors, biomechanical factors (force load and static load), psychosocial factors and environmental factors.

Objective To investigate the risk factors for rebleeding after emergency esophageal variceal ligation (EVL) in patients with liver cirrhosis. Methods A retrospective analysis was performed for the clinical and laboratory data of 290 patients with liver cirrhosis who underwent emergency EVL in The Fifth Medical Center of Chinese PLA General Hospital from January 2016 to December 2019, and according to the presence or absence of rebleeding within 1-year follow-up, they were divided into rebleeding group and non-rebleeding group. The t -test was used for comparison of normally distributed continuous data between two groups, and the Wilcoxon rank sum test was used for comparison of non-normally distributed continuous data between two groups; the chi-square test was used for comparison of categorical data between two groups. A multivariate logistic regression analysis was performed with the statistically significant factors as independent variables to screen out the independent risk factors for rebleeding after emergency EVL, and the receiver operating characteristic (ROC) curve was plotted to obtain the indices for predicting the probability of rebleeding and establish a predictive model. Results The univariate analysis showed that there were significant differences between the two groups in platelet count ( t =-1.888, P =0.047), Child-Pugh score ( χ 2 =5.975, P =0.049), albumin level ( t =-2.229, P =0.029), and splenic vein diameter ( t =3.808, P =0.001). The multivariate logistic regression analysis showed that Child-Pugh score (odds ratio [ OR ]=0.280, 95% confidence interval [ CI ]: 0.108-0.729, P =0.009), splenic vein diameter ( OR =1.549, 95% CI : 1.197-2.005, P =0.001) and albumin level ( OR =0.832, 95% CI : 0.729-0.949, P =0.006) were independent influencing factors for rebleeding after EVL. The predictive model based on these three factors had an area under the ROC curve of 0.796, with a sensitivity of 83.7% and a specificity of 74.5% at the cut-off value of -0.086. Conclusion Child-Pugh score, albumin level, and splenic vein diameter are independent risk factors for rebleeding after emergency EVL, and the combination of the three indices has the highest sensitivity and specificity in predicting rebleeding.

OBJECTIVE: To investigate the prevalence of lower extremity work-related musculoskeletal disorders(WMSDs) among manufacturing workers, and to explore the association of lower extremity WMSDs and different types of working. METHODS: A total of 7 908 workers were selected as study subjects from four manufacturing factories in China using the cluster sampling method. The Musculoskeletal Disorders Investigating Questionnaire was adopted to investigate the prevalence of lower extremity WMSDs and the distribution of types of working. The prevalence ratio(PR) of WMSDs, calculated by log-binomial model, was used to estimate the correlation of WMSDs in different parts of lower extremity. The multi-factor logistic regression was used to analyze the association of lower extremity WMSDs and different types of working. RESULTS: The total annual prevalence of lower extremity WMSDs was 41.0%(3 241/7 908) among manufacturing workers. The annual prevalence of WMSDs of different parts in lower extremity from high to low were knee(29.5%), ankle/foot(23.9%) and hip/thigh(16.7%). The correlation of WMSDs of the three parts in lower extremity was close, and the range of PR values was 2.21-3.88. The result of logistic regression analysis showed that the workers who frequently sat for long periods had higher risk of lower extremity WMSDs than those who never/rarely sat for long periods(odds ratio=1.39, P<0.01). The higher the frequency of standing, kneeling/squatting for long periods, carrying heavy loads ≥5 kg and driving, the higher the risk of lower extremity WMSDs(the odds ratios were 1.33, 1.41, 1.16 and 1.12, respectively, P<0.01). CONCLUSION: The prevalence of lower extremity WMSDs was relatively high among manufacturing workers. There is a dose-effect relationship between the types of working and lower extremity WMSDs.

OBJECTIVE: To explore the influencing factors of neck work-related musculoskeletal disorders( WMSDs) and their effects in airport porters. METHODS: A total of 413 airport porters were chosen as study subjects using judgment sampling method. Chinese version of Musculoskeletal Questionnaire was used to investigate the prevalence of WMSDs.Then structural equation model was constructed and used to analyze the influencing factors of neck WMSDs. RESULTS: The prevalence of neck WMSDs in airport porters was 37. 3%( 154/413). Postural load,mental workload and length of service had a direct effect on neck WMSDs of porters( path coefficients were 0. 405,0. 166,0. 296,P < 0. 05),and mental workload also had an indirect effect on neck WMSDs through postural load( path coefficient was 0. 103,P < 0. 01).CONCLUSION: Posture load,mental workload and length of service are risk factors of neck WMSDs in airport porters.

OBJECTIVE: To investigate the correlation of mental workload and prevalence of work-related musculoskeletal disorders musculoskeletal disorders( WMSDs) in railway vehicle manufacturing workers.METHODS: A total of 362 male workers in assembling and welding workshop from a railway vehicle manufacturing enterprise were selected as study subjects by cluster sampling method.The level of mental workload and prevalence of WMSDs were investigated using a revised Subjective Workload Assessment Technique and China Musculoskeletal Questionnaire.RESULTS: The median score of mental workload was 67 and the prevalence rate of WMSDs was 56.9%.The multivariate logistic regression analysis results indicated that the higher the mental workload of railway vehicle manufacturers,the higher their risk for WMSDs after excluding the influence of confounding factors( P < 0.05).Workers in welding work showed a higher risk than those in assembling work( P < 0.01).Workers with fast work rhythm showed higher risk of WMSDs than those with regular working rhythm( P < 0.01).Workers with comfortable working environment and temperature showed lower risk of WMSDs than those with uncomfortable working environment and temperature( P < 0.01).CONCLUSION: The mental workload can increase the risk of WMSDs,with a dose-effect relationship in railway vehicle manufacturing workers.The type of work,work frequency and the temperature in working environment are also influencing factors of WMSDs.

OBJECTIVE: To analyze the prevalence and influencing factors of multisite work-related musculoskeletal disorders(WMSDs) of workers in a railway vehicle manufacturing enterprise. METHODS: A total of 366 male workers in the assembly and riveting workshop of a railway vehicle manufacturing enterprise were selected as the research subjects using the cluster sampling method. The Chinese Musculoskeletal Questionnaire was used to investigate the prevalence of multiple sites of WMSDs. Multiple logistic regression analysis was used to analyze the influencing factors. RESULTS: The total prevalence of WMSDs was 56.3%(206/366). The prevalence of WMSDs in all parts from high to low was as follows: lower back(35.5%), hand and wrist(27.6%), neck(23.2%), shoulder(21.0%), knee(19.9%), upper back(18.6%), hip and leg(18.0%), ankle/foot(15.8%) and elbow(12.3%)(P<0.01). The total prevalence of multisite WMSDs was 38.0%(139/366). The prevalence of WMSDs in different numbers of parts from high to low was as follows: 6 or more parts(12.0%), 2 parts(10.7%), 3 parts(6.6%), 5 parts(5.5%) and 4 parts(3.3%)(P<0.01). Multiple logistic regression analysis results showed that the overweight and obese workers had higher risk of multi site WMSDs than those with normal body mass index(P<0.05).Those with long-term low heads, frequent bending, long bending of the elbows, and higher frequency of work requirements, and less frequently communicated with the leader had higher risk of multi site WMSDs(P<0.05). CONCLUSION: The prevalence of multisite WMSDs in railway vehicle manufacturing enterprise is relatively high. The influencing factors include individual factors, adverse ergonomic factors and psychosocial factors.

OBJECTIVE: To explore the occurrence pattern of work-related musculoskeletal disorders( WMSDs) in electronic parts processing workers. METHODS: A total of 498 workers from an electronic parts processing factory were selected as study subjects by judgement sampling method. The prevalence of WMSDs in the past 1 year was investigated by using the China Musculoskeletal Questionnaire. The potential category model was used to classify the categories of WMSDs. RESULTS: The incidence of WMSDs in the past 1 year was 46. 8%( 233/498). Among them,the incidence of WMSDs involving only one site was 13. 1%( 65/498),and those involving at least 2 sites were 33. 7%( 168/498). The multi-site WMSDs were about 6-58 times of the single-site WMSDs. According to potential category analysis,the occurrence patterns of WMSDs were divided into three categories: i) cervical and shoulder occurrence group( 135 persons,27. 1%); ii) all parts group( 31 persons,6. 2%); iii) few or no site group( 332 persons,66. 7%). CONCLUSION: The occurrence of multi-site WMSDs in electronic parts processing workers were more common than the single-site. Analysis of potential category can be used to explore the occurrence pattern of WMSDs.

OBJECTIVE: To compile the Chinese Musculoskeletal Questionnaire(CMQ) and test its reliability and validity. METHODS: The initial CMQ was formed through studying literatures, interviewing professional workers who have work-related musculoskeletal disorders(WMSDs) and investigation with occupational health and ergonomics experts. Then, 436 and 443 manufacturing workers were selected as prediction and verification samples respectively by convensence sampling method. The reliability and validity of the CMQ were tested by item analysis, exploratory factor analysis and confirmatory factor analysis. RESULTS: i) The CMQ composed of 48 items with item analysis. ii) Nine common factors of CMQ were extracted using exploratory factor analysis, which explained 70.721% of WMSDs variance. iii) The results of confirmatory factor analysis showed that the ratio of chi-square to degree of freedom was 3.380, the comparative fit index was 0.781, the Tucker-Lewis index was 0.764, the root mean square error of approximation was 0.073, and the standardized root mean square residual was 0.068. iv) The results showed that the item reliabilities of the 9 common factors of CMQ such as upper and lower limbs posture load, neck posture load, back posture load, job demand, social support, job control, job environment, job system and job facilities were 0.205-0.841, the composite reliabilities were 0.545-0.894, and the convergence efficiencies were 0.377-0.834. The correlation coefficients between the common factors were less than its square root of the convergence validities. CONCLUSION: The CMQ has good reliability and validity, and is a reliable and effective tool for evaluating WMSDs.