AIM:ToinvestigatetheroleofMALAT1incolorectalcancermetastasis.METHODS:ThemRNA expression levels of MALAT1 and Rac1b in the tumor and adjacent normal tissues were examined by real-time PCR. MALAT1 was knocked down by siRNA in colorectal cancer cell lines .The expression of Rac1b and the epithelial-mesen-chymal transition markers was examined by Western blot .Cell proliferation was determined by EdU analysis .The effects of MALAT1 on the cell migration and invasion were examined by Transwell assay .RESULTS: The expression of MALAT1 was down-regulated in colorectal cancer .Down-regulation of MALAT1 induced Rac1b overexpression, which in turn in-creased the expression levels of E-cadherin and β-catenin.Furthermore, down-regulation of MALAT1 promoted the cell proliferation, invasion and migration.CONCLUSION:MALAT1 is associated with metastasis of colorectal cancer through regulating the expression of Rac1b and the downstream factors.

Objective To evaluate the applicability of the comprehensive index method for assessing occupational health risks on chemical hazards in key work sites of a metal product enterprise. Methods A metal product enterprise in Beijing City was chosen as the research subject using the convenience sampling method. Occupational health investigations and chemical hazard monitoring were conducted at four work sites: grinding machine operation, welding, cutting, and painting. The comprehensive index method was used to determine the risk levels of chemical hazards. Results The grinding dust in the grinding machine operation work site was assessed as moderate risk. The nitrogen oxides and ozone in the welding (southeast) work sites were assessed as moderate risk. The nitrogen oxides ozone and welding fumes in the welding (northwest) and cutting work site were assessed as moderate risk. Benzene in the painting work site was assessed as moderate risk. All chemical hazards in other work sites were determined to pose low risks. Co-exposures to nitrogen oxides and ozone in the two welding work sites and cutting work site were classified as moderate risk. Co-exposure to ethylbenzene, xylene, methanol, ethyl acetate, and butyl acetate in the painting work site also posed moderate risk, while the co-exposure to toluene and methanol in the painting work site was assessed as low risk. Conclusion The comprehensive index method could be used for the occupational health risk assessment in the metal product enterprise. The enterprise should strengthen hazard control measures for exposure to grinding dust, welding fumes, nitrogen oxides, ozone, and benzene, and closely monitor the health risks associated with co-exposures of chemical hazards.

Objective To analyze the current situation of depressive symptoms among medical staff in Beijing City and its correlation with symptoms of anxiety, occupational stress and insomnia. Methods A total of 2 687 medical staff from 28 medical institutions in eight municipal districts of Beijing City were selected as study subjects using multi-stage sampling method. The basic situation, depression symptoms, anxiety symptoms, occupational stress and insomnia symptoms were investigated using the National Occupational Health Literacy Monitoring Questionnaire for Key Groups, Patient Health Questionaire-9, 7-item Generalized Anxiety Disorder Scale, Core Occupational Stress Scale, and Self-Sleep Management Questionnaire. Results The detection rate of depressive symptoms was 28.3%, and the detection rates of moderate, moderate-severe and severe depressive symptoms were 18.9%, 6.9% and 2.5%, respectively. The detection rate of anxiety symptoms was 41.3%, and the detection rates of mild, moderate and severe anxiety symptoms were 29.7%, 7.7% and 3.9%, respectively. The detection rate of occupational stress was 26.7%. The detection rate of insomnia symptoms was 36.6%. The results of multivariate logistic regression analysis showed that the risk of depressive symptoms in male medical staff was higher than that in female (P<0.05). The risk of depressive symptoms in night shift staff was higher than that in staff without night shift (P<0.05). The more severe the anxiety symptoms, the higher the risk of depressive symptoms (all P<0.01). The risk of depressive symptoms in medical staff with occupational stress was higher than those without occupational stress (P<0.01). The risk of depressive symptoms in medical staff with insomnia symptoms was higher than those without insomnia symptoms (P<0.01). Conclusion The detection rate of depressive symptoms among medical staff in Beijing City is relatively high. Gender, night shift, anxiety symptoms, occupational stress, and insomnia symptoms were independent risk factors of depressive symptoms.

Objective: To investigate the prevalence of reproductive system diseases among female workers in a city and related occupational influencing factors. Methods: From June to September, 2016, a cross-sectional survey was used to select 9 944 female workers from six districts of Beijing and then a face-to-face questionnaire survey was performed. Univariate analysis using chi-square test and multivariate logistic regression analysis were used to investigate the risk factors for reproductive system diseases. Results: The age of 9944 female workers ranged from 18 to 65 years (mean 35.53±9.52 years) , and among them, 7 351 (73.92%) were married. The overall prevalence rate of reproductive system diseases among these 9944 female workers during the past three months was 28.29%, and the prevalence rates of hyperplasia of mammary glands, vaginitis, and hysteromyoma were 15.54%, 11.25%, and 6.77%, respectively. After adjustment for age, marital status, education level, and annual family income, the multivariate logistic regression analysis showed that frequent overtime work (odds ratio[OR]=1.119, 95% confidence interval[CI]: 1.070-1.343) , frequent night shifts (OR=1.198, 95%CI: 1.054-1.361) , standing for a long time (OR=1.197, 95%CI: 1.063-1.347) , sitting for a long time (OR=1.327, 95%CI: 1.191-1.479) , heavy workload (OR=1.429, 95%CI: 1.262-1.615) , exposure to lead (OR=1.696, 95%CI: 1.307-2.201) , exposure to mercury (OR=1.452, 95%CI: 1.086-1.940) , and exposure to ionizing radiation (OR=1.679, 95%CI: 1.424-1.980) were associated with reproductive system diseases. Conclusion The prevalence of reproductive system diseases among female workers in Beijing is not optimistic. Reproductive system diseases are associated with frequent overtime work, frequent night shifts, standing for a long time, sitting for a long time, heavy workload, and exposure to lead, mercury, and ionizing radiation.

Objective: To investigate the application of Symptom Checklist-90 (SCL-90) in Chinese nurses. Methods: We performed a literature search for articles in Chinese on the mental health of nurses investigated using the SCL-90 that were published from January 2007 to December 2016. A total of 129 articles were included, involving 178 groups of valid samples as well as 36316 subjects in 27 provinces or cities in China. The metafor package of R 3.2.1 software and Excel were used for meta-analysis and data statistics. Results: Heterogeneity was identified for the nine factors included in the literature data (Q test: P<0.05; I² test >40%) , so a random effects model was used. For all factors except interpersonal relationship factor, the 95% confidence intervals of the pooled effect sizes did not include 0. For all factors except interpersonal relationship factor (Egger test: P<0.05) , no significant asymmetry or incompleteness appeared in the funnel plots. The fail-safe number of each factor was much larger than 5k+10. The merger scores and mean values of nine factors were higher than the national norm. Conclusion The SCL-90 is widely used in the study of mental status of Chinese nurses, but the SCL-90 norm for nurses is lacking.

Objective: To investigate the status of abnormal menstruation in female nurses in a comprehensive hospital in Beijing, China and related influencing factors. Methods: In July 2016, a cross-sectional survey was performed, and a self-administered questionnaire was used to investigate the status of menstruation and occupation in female nurses in a comprehensive hospital in Beijing. The chi-square test and a multivariate logistic regression analysis were used for statistical analysis. Results: A total of 892 female nurses were investigated, and among them, 485 experienced abnormal menstruation within the past three months, resulting in an abnormal menstruation rate of 54.37%. The female nurses who were exposed to harmful factors during work, negative life events, or high workload had a significantly higher abnormal menstruation rate than those who were not exposed to such factors (χ²=5.199, 16.186, and 10.227, P<0.05 or P<0.01) . Negative life events (odds ratio [OR]=1.813, 95% confidence interval[CI]: 1.317-2.496) and high workload (OR=1.461, 95%CI: 1.112-1.918) were risk factors for abnormal menstruation. Conclusion Nurses have an abnormal menstruation rate as high as 54.37%, and high workload and negative life events were risk factors for abnormal menstruation in nurses.

Objective: To evaluate the mental health of female doctors and nurses. Methods: Investigat the psychologic status of female doctors and nurses using symptom checklist 90. And statistical software was applied to analyze results of symptom checklist 90. Results: There were differences in the score of SCL-90 between doctor and nurse groups, the difference was statistically significant (P<0.05) . Negative life events (OR=2.940) , relative suffer from mental illness (OR=3.683) , shift work (OR=1.611) and heavy workload (OR=2.265) were found to risk factors for the positive of SCL-90. Conclusion There were differences in the score of SCL-90 between doctor and nurse groups. Negative life events, relative suffer from mental illness, shift workand heavy workload are risk factors for SCL-90 positive of female doctors and nurses.

Objective: To evaluate the mental health of occupational females in different industries. Methods: We investigated the psychologic status of Chinese occupational females using symptom checklist 90. And statistical software was applied to analyze results of symptom checklist 90. Results: There were 41, 166 effec-tive questionnaires. The number of positive questionnaires was 14 361, and the positive rate was 34.89%. The positive rate of obsessive-compulsive factor was 24.07%. The positive rate of somatization factor was 16.12%. The positive rate of depression was 15.50%. The median positive item number was 20 (IQR: 34) , and the median split of positive symptoms was 2.11 (IQR: 0.37) . There were differences in the positive rate of SCL-90 scale among different age groups, different regions and different industries, the difference was statistically significant (P<0.05) . The positive rate of SCL-90 for the occupational females was 34.89%. The top three factors of the high-est positive SCL-90 were obsessive-compulsive symptoms, somatization and depression. Conclusion There were differences in the psychological status of occupational females for different regions, different ages and different occupations.

This study aims to analyze the biomechanical stability of Magic screw in the treatment of acetabular posterior column fractures by finite element analysis. A three-dimensional finite element model of the pelvis was established based on the computed tomography (CT) and magnetic resonance imaging (MRI) data of a volunteer and its effectiveness was verified. Then, the posterior column fracture model of the acetabulum was generated. The biomechanical stability of the four internal fixation models was compared. The 500 N force was applied to the upper surface of the sacrum to simulate human gravity. The maximum implant stresses of retrograde screw fixation, single-plate fixation, double-plate fixation and Magic screw fixation model in standing and sitting position were as follows: 114.10, 113.40 MPa; 58.93, 55.72 MPa; 58.76, 47.47 MPa; and 24.36, 27.50 MPa, respectively. The maximum stresses at the fracture end were as follows: 72.71, 70.51 MPa; 48.18, 22.80 MPa; 52.38, 27.14 MPa; and 34.05, 30.78 MPa, respectively. The fracture end displacement of the retrograde tension screw fixation model was the largest in both states, and the Magic screw had the smallest displacement variation in the standing state, but it was significantly higher than the two plate fixations in the sitting state. Magic screw can satisfy the biomechanical stability of posterior column fracture. Compared with traditional fixations, Magic screw has the advantages of more uniform stress distribution and less stress, and should be recommended.
Biomechanical Phenomena ; Bone Plates ; Bone Screws ; Finite Element Analysis ; Fracture Fixation, Internal/methods* ; Fractures, Bone/surgery* ; Humans ; Spinal Fractures

Objective To investigate the relationship between lesion size of solitary bone cyst ( SBC) and pathological fracture of calcaneus, so as to provide references for the treatment of SBC. Methods The three dimensional (3D) finite element model of foot and ankle was established based on CT images. Four models with gradient spherical bone defects were constructed in the focal area to simulate different SBC lesion sizes, and the biomechanical characteristics of calcaneus in different gait phases were analyzed. Results With the increasement of SBC size, the kinematics of calcaneus did not change significantly, but the peak stress of calcaneus increased gradually. When the SBC size exceeded 75% of the calcaneal width, the stress in calcaneal sulcus and cortical bone below SBC increased by 1. 48 times and 7. 74 times, respectively. Conclusions The risk of pathological fracture increases when the SBC diameter exceeds 75% of the calcaneal width, and early surgical intervention should be recommended. The calcaneal sulcus and the cortex bone below SBC are stress concentration regions and can be used as important areas to evaluate pathological fractures.