2015 Vol. 28, No. 9

Select articles
How Work Organization Affects the Prevalence of WMSDs:A Case-control Study
LIU Lu, CHEN Song Gen, TANG Shi Chuan, WANG Sheng, HE Li Hua, GUO Ze Hua, LI Jing Yun, YU Shan Fa, WANG Zhong Xu
2015, 28(9): 627-633. doi: 10.3967/bes2015.088
Objective In this study, we aimed at exploring the association between work-related musculoskeletal disorders (WMSDs) and work organization based on a case-control study.
Methods A total of 1938 workers who claimed to suffer from WMSDs were selected from Beijing, Henan, Hubei, and the Guangdong province. The control group consisted of 2009 workers employed in similar industries without severe disease or musculoskeletal discomforts. We used a modified version of the questionnaire developed by the NMQ and the DMQ to investigate individual and work-related factors.
Results A total of 13 variables (P<0.1) were selected by the chi-square test and finally, 7 variables entered into the equation, with 6 variables reaching statistical significance (P<0.05). The odds ratios (OR) of ‘work changing with season’ and ‘sufficient rest time’ did not reach 1 (0.749 and 0.441, respectively). In addition,‘sufficient rest time’ seemed to be the stronger protective factor according to its higher standardized coefficient. And ‘repetitive work every minute’, ‘constantly repetitive work’ (every day),‘shortage of site personnel’, and‘often switching shifts with others’ seemed to be the risk factors.
Conclusion Work organization may have comprehensive effects on the occurrence of WMSDs. This pattern of associations suggests that further investigation into the mechanism of how work organization affects the prevalence of WMSDs is required.
Flexibility Analysis of Bacillus thuringiensis Cry1Aa
ZHAO Xin Min, XIA Li Qiu, YANG Xiao Ping, PENG Xiao Yun
2015, 28(9): 634-641. doi: 10.3967/bes2015.089
Objective To investigate the flexibility and mobility of the Bacillus thuringiensis toxin Cry1Aa.
Methods The graph theory-based program Constraint Network Analysis and normal mode-based program NMsim were used to analyze the global and local flexibility indices as well as the fluctuation of individual residues in detail.
Results The decrease in Cry1Aa network rigidity with the increase of temperature was evident. Two phase transition points in which the Cry1Aa structure lost rigidity during the thermal simulation were identified. Two rigid clusters were found in domains I and II. Weak spots were found in C-terminal domain III. Several flexible regions were found in all three domains;the largest residue fluctuation was present in the apical loop2 of domain II.
Conclusion Although several flexible regions could be found in all the three domains, the most flexible regions were in the apical loops of domain II.
Association between Prenatal Environmental Factors and Child Autism:A Case Control Study in Tianjin, China
GAO Lei, XI Qian Qian, WU Jun, HAN Yu, DAI Wei, SU Yuan Yuan, ZHANG Xin
2015, 28(9): 642-650. doi: 10.3967/bes2015.090
Objective To investigate the association between autism and prenatal environmental risk factors.
Methods A case-control study was conducted among 193 children with autism from the special educational schools and 733 typical development controls matched by age and gender by using questionnaire in Tianjin from 2007 to 2012. Statistical analysis included quick unbiased efficient statistical tree (QUEST) and logistic regression in SPSS 20.0.
Results There were four predictors by QUEST and the logistic regression analysis, maternal air conditioner use during pregnancy (OR=0.316, 95% CI: 0.215-0.463) was the single first-level node (χ2=50.994, P=0.000); newborn complications (OR=4.277, 95% CI: 2.314-7.908) and paternal consumption of freshwater fish (OR=0.383, 95% CI: 0.256-0.573) were second-layer predictors (χ2=45.248, P=0.000; χ2=24.212, P=0.000); and maternal depression (OR=4.822, 95% CI: 3.047-7.631) was the single third-level predictor (χ2=23.835, P=0.000). The prediction accuracy of the tree was 89.2%.
Conclusion The air conditioner use during pregnancy and paternal freshwater fish diet might be beneficial for the prevention of autism, while newborn complications and maternal depression might be the risk factors.
Influence of Iron Supplementation on DMT1 (IRE)-induced Transport of Lead by Brain Barrier Systems in vivo
AN Dai Zhi, AI Jun Tao, FANG Hong Juan, SUN Ru Bao, SHI Yun, WANG Li Li, WANG Qiang
2015, 28(9): 651-659. doi: 10.3967/bes2015.091
Objective To investigate the potential involvement of DMT1 (IRE) protein in the brain vascular system in vivo during Pb exposure.
Methods Three groups of male Sprague-Dawley rats were exposed to Pb in drinking water, among which two groups were concurrently administered by oral gavage once every other day as the low and high Fe treatment group, respectively, for 6 weeks. At the same time, the group only supplied with high Fe was also set as a reference. The animals were decapitated, then brain capillary-rich fraction was isolate from cerebral cortex. Western blot method was used to identify protein expression, and RT-PCR to detect the change of the mRNA.
Results Pb exposure significantly increased Pb concentrations in cerebral cortex. Low Fe dose significantly reduced the cortex Pb levels, However, high Fe dose increased the cortex Pb levels. Interestingly, changes of DMT1 (IRE) protein in brain capillary-rich fraction were highly related to the Pb level, but those of DMT1 (IRE) mRNA were not significantly different. Moreover, the consistent changes in the levels of p-ERK1/2 or IRP1 with the changes in the levels of DMT1 (IRE).
Conclusion These results suggest that Pb is transported into the brain through DMT1 (IRE), and the ERK MAPK pathway is involved in DMT1 (IRE)-mediated transport regulation in brain vascular system in vivo.
Effects of Nephrolithiasis on Serum DNase (Deoxyribonuclease I and II) Activity and E3 SUMO-Protein Ligase NSE2 (NSMCE2) in Malaysian Individuals
Faridah Yusof, Atheer Awad Mehde, Wesen Adel Mehdi, Raha Ahmed Raus, Hamid Ghazali, Azlina Abd Rahman
2015, 28(9): 660-665. doi: 10.3967/bes2015.092
Objective Nephrolithiasis is one of the most common disorders of the urinary tract. The aim of this study was to examine a possible relationship between DNase I/II activity and E3 SUMO-protein ligase NSE2 in the sera of nephrolithiasis patients to evaluate the possibility of a new biomarker for evaluating kidney damage.
Methods Sixty nephrolithiasis patients and 50 control patients were enrolled in a case-control study. Their blood urea, creatinine, protein levels and DNase I/II activity levels were measured by spectrometry. Serum NSMCE2 levels were measured by ELISA. Blood was collected from patients of the government health clinics in Kuantan-Pahang and fulfilled the inclusion criteria.
Results The result indicated that mean levels of sera NSMCE2 have a significantly increase (P<0.01) in patients compared to control group. Compared with control subjects, activities and specific activities of serum DNase I and II were significantly elevated in nephrolithiasis patients (P<0.01).
Conclusion This study suggests that an increase in serum concentrations of DNase I/II and E3 SUMO-protein ligase NSE2 level can be used as indicators for the diagnosis of kidney injury in patients with nephrolithiasis.
Statistically Non-significant Papers in Environmental Health Studies included more Outcome Variables
Pentti Nieminen, Khaled Abass, Kirsi Vhkanga, Arja Rautio
2015, 28(9): 666-673. doi: 10.3967/bes2015.093
Objective The number of analyzed outcome variables is important in the statistical analysis and interpretation of research findings. This study investigated published papers in the field of environmental health studies. We aimed to examine whether differences in the number of reported outcome variables exist between papers with non-significant findings compared to those with significant findings. Articles on the maternal exposure to mercury and child development were used as examples.
Methods Articles published between 1995 and 2013 focusing on the relationships between maternal exposure to mercury and child development were collected from Medline and Scopus.
Results Of 87 extracted papers, 73 used statistical significance testing and 38 (43.7%) of these reported ‘non-significant’ (P>0.05) findings. The median number of child development outcome variables in papers reporting ‘significant’ (n=35) and ‘non-significant’ (n=38) results was 4 versus 7, respectively (Mann-Whitney test P-value=0.014). An elevated number of outcome variables was especially found in papers reporting non-significant associations between maternal mercury and outcomes when mercury was the only analyzed exposure variable.
Conclusion Authors often report analyzed health outcome variables based on their P-values rather than on stated primary research questions. Such a practice probably skews the research evidence.
Bartonella Species Detected in the Plateau Pikas (Ochotona curzoiae) from Qinghai Plateau in China
RAO Hua Xiang, YU Juan, GUO Peng, MA Yong Cheng, MA Zhong Wen, GE Hua, WANG Chun Xiang, SHI Yan
2015, 28(9): 674-678. doi: 10.3967/bes2015.094
Dynamic Changes in DNA Damage and Repair Biomarkers with Employment Length among Nickel Smelting Workers
WU Shan, BAI Ya Na, PU Hong Quan, HE Jie, ZHENG Tong Zhang, LI Hai Yan, DAI Min, CHENG Ning
2015, 28(9): 679-682. doi: 10.3967/bes2015.095
Analysis on Serum Trace Element Levels of Echinococciasis Patients in Garze Tibetan Autonomous Prefecture in Sichuan, China, 2011
LI Jun Jian, LI Wei, XU Guang Rong, XU Ke Jun, YE Ping, QUAN Yu, NING Rong Bing, GAO Hai Jun, HE Qian Jun, ZHOU Ying, WU Wei Ping
2015, 28(9): 683-686. doi: 10.3967/bes2015.096
Assessing Adverse Effects of Aroclor 1254 on Perinatally Exposed Rat Offspring
TANG Wei, CHENG Jin Ping, YANG Yi Chen, WANG Wen Hua
2015, 28(9): 687-690. doi: 10.3967/bes2015.097
Protective Effects of Tetramethylpyrazine on Cerebrovascular Regulations in Rats with Chronic Alcoholic Encephalopathy
LI Hui, YANG Xue, SHI Wei, MA Zhao, FENG Guang Kun, YIN Yan Ling, FAN Yan Xia, JIANG Jie
2015, 28(9): 691-695. doi: 10.3967/bes2015.098
Fluoride Exposure, Follicle Stimulating Hormone Receptor Gene Polymorphism and Hypothalamus-pituitary-ovarian Axis Hormones in Chinese Women
ZHAO Ming Xu, ZHOU Guo Yu, ZHU Jing Yuan, GONG Biao, HOU Jia Xiang, ZHOU Tong, DUAN Li Ju, DING Zhong, CUI Liu Xin, BA Yue
2015, 28(9): 696-700. doi: 10.3967/bes2015.099