Association between exposure to multiple metals and lung function in welders by multi-pollutant statistical models / 环境与职业医学

Background Welders' exposure to welding fumes with multiple metals leads to decreased pulmonary function. Previous studies have focused on single metal exposure, while giving little attention to the impact of metal mixtures. Objective To assess the association between metal levels in urine and blood of welders and pulmonary function indicators, and to identify key metals for occupational health risk assessment. Methods Questionnaire surveys, lung function tests, urine and blood sampling were conducted among welders and control workers in a shipyard in Shanghai. Inductively coupled plasma mass spectrometry (ICP-MS) was used to detect the concentrations of 12 metals such as vanadium, chromium, and manganese in urine and blood. Spearman correlation was applied to analyze the correlations between the metals in urine and blood. Multiple linear regression, weighted quantile sum (WQS) and Bayesian kernel machine regression (BKMR) were used to analyze the relationships between mixed metal exposure and pulmonary function parameters, such as forced vital capacity (FVC), forced vital capacity as a percentage of predicted value (FVC%), forced expiratory volume in the first second (FEV1), forced expiratory volume in the first second as a percentage of predicted value (FEV1%), and forced expiratory volume in the first second/forced vital capacity (FEV1/FVC). Results This study enrolled 445 subjects, including 322 welders (72.36%) and 123 controls (27.64%). The mean age of the 445 participants was (37.64±8.80) years, and 87.19% participants were male. The welders had significantly higher levels of urinary cadmium (0.88 vs 0.58 μg·L−1), blood chromium (5.86 vs 5.06 μg·L−1), and blood manganese (24.24 vs 21.38 μg·L−1) than the controls (P<0.05). The Spearman correlation coefficients between the metals in urine and blood ranged from −0.46 to 0.68. After adjustment for confounders, the multiple linear regression indicted that the urine molybdenum of the welders was negatively correlated with FVC and FEV1. There were also negative correlations between the molybdenum in blood and FVC, FVC%, FEV1, and FEV1%, and between the copper in blood and FEV1/FVC. The WQS model showed that FEV1 and FVC decreased by 0.112 L and 0.353 L with each quartile increase of metal mixture concentrations in urine and blood among the welders respectively, and the leading contributors were copper, zinc, vanadium, and antimony. The BKMR model showed a negative overall effect of metal mixtures in urine and blood among the welders on FVC, FVC%, FEV1, and FEV1%, and the univariate exposure response-relationship between the molybdenum concentration in urine or blood and FVC, FVC%, FEV1, or FEV1% had an approximately linear decreasing trend. Meanwhile, there may be an interaction of cadmium with manganese, nickel, or vanadium, and an interaction of vanadium with iron, molybdenum, zinc, or copper, when different metals in urine among the welders interacted with FEV1%. Conclusion Exposure to multiple metals in welders leads to a decline in lung function, with molybdenum, antimony, copper, and zinc as the leading contributors.

Analysis of the first national public health practice skills competition among college students / 中华劳动卫生职业病杂志

To analyze the difficulty, distinction and result of the first national public health practice skills competition among college students, it showed the general situation of this competition, and discussed the present situation, problems and countermeasures of skills training for students majoring in preventive medicine. Based on such competition, educators can promote teaching reform and post competency training.

An exploration of public health practical skill training among undergraduates majoring in preventive medicine / 中华医学教育探索杂志

In order to enhance the level of public health practical skills among undergraduates majoring in preventive medicine and improve the professional skills of disease prevention and control staff in case of public health emergencies,Nanjing Medical University School of Public Health performed an individual protection training for senior undergraduates majoring in preventive medicine in 2017.After related experience was summarized and students' feedback was collected,comprehensive training of public health practical skills was pedormed for senior undergraduates majoring in preventive medicine in 2018,with the inclusion of virtual experiments for public health.The results showed that the students were interested in practical skill training,mastered the contents of the training,and took pride in their major.This training has an excellent teaching effect and can enhance the ability to deal with public health emergencies among students majoring preventive medicine.

Therapeutic effect of miR-489 in a mouse model of silica-induced matured pulmonary fibrosis / 中华劳动卫生职业病杂志

Objective@#To explore the potential therapeutic role of miR-489 in silica-induced pulmonary fibrosis mouse models.@*Methods@#A total of 32 C57BL/6 male mice were randomly divided into four groups: saline, silica, silica plus miRNA control and silica plus miR-489 agomir (n=8 in each group) . The mice were instilled with silica particles suspended in saline or sterile saline intratracheally. Subsequently, miR-489 agomir or miRNA control was injected via the tail vein into each mouse at days 28, 35, 42 and 49, the miR-489 levels, histological examination, collagen deposition, fibrotic biomarkers (E-cadherin, α-SMA, Vimentin, Fibronectin) and transforming growth factor-β1 (TGF-β1) protein levels in mouse lung tissues were measured.@*Results@#miR-489 levels in silica plus miR-489 group were significantly increased in lung tissues compared with silica plus miRNA control group (P<0.05) . Histological examination showed attenuated inflammation, less severe fibrotic foci and less destruction of alveolar architecture in the silica plus miR-489 group. Additionally, both the severity and distribution of lung lesions were ameliorated in silica plus miR-489 group compared with the silica plus miRNA control group (P<0.05) . The collagen deposition and hydroxyproline levels in silica plus miR-489 group were significantly decreased compared with the silica plus miRNA control group (P<0.05) . These changes were supported by decreased protein levels of α-SMA, Vimentin, Fibronectin, TGF-β1 along with increased protein levels of E-cadherin in silica plus miR-489 group (P<0.05) .@*Conclusion@#Our data indicate that the upregulation of miR-489 has potential therapeutic role in silica-induced pulmonary fibrosis in vivo, which may be associated with the depression of TGF-β1 release.

Gene variance in microsomal epoxide hydrolase and the susceptibility of coal workers' pneumoconiosis / 中华劳动卫生职业病杂志

<p><b>OBJECTIVE</b>To explore whether the tagging single nucleotide polymorphisms (SNPs) within EPHX1 gene were involved in the genetic susceptibility to coal worker's pneumoconiosis (CWP) by case-control study.</p><p><b>METHODS</b>This study consisted of 697 CWP patients and 694 controls. All the subjects were Han Chinese, underground coal miners and recruited from coal mines of Xuzhou Mining Business Group Co Ltd.. The venous blood samples were obtained from all subjects and extracted genome DNA from the isolated leucocytes. Three SNPs were selected from the HapMap and the genotyping was done by the TaqMan method with the ABI 7900HT Real Time PCR system.</p><p><b>RESULTS</b>The Single SNP analyses showed that the genotype frequencies of EPHX1 (rs2234922) was significantly associated with decreased risk of CWP under co-dominant model (OR = 0.22, 95% CI = 0.06~0.79, P = 0.020), recessive model (OR = 0.23, 95% CI = 0.06~0.82, P = 0.023), and addictive model (OR = 0.75, 95% CI = 0.58~0.96, P = 0.022). The further stratification analysis showed that the risk of CWP will significantly decreased in non-smoking groups (OR = 0.10, 95% CI = 0.01~0.83, P = 0.033).</p><p><b>CONCLUSIONS</b>Our results suggest that individuals with the EPHX1 (rs223492) GG genotype was associated with a dereased risk of CWP, and it has a protective effect on the developing CWP.</p>

Effect of carbon disulfide exposure on fatty acid metabolism in ApoE knockout and C57BL/6J mice / 中华劳动卫生职业病杂志

<p><b>OBJECTIVE</b>To study the influences of carbon disulfide (CS2) exposure on fatty acid metabolism in apolipoprotein E (ApoE) knockout mice and C57BL/6J mice.</p><p><b>METHODS</b>Twenty-four male ApoE knockout mice were randomly and equally divided into four groups: a CS2-exposed normal diet group, a CS2-unexposed normal diet group, a CS2-exposed high-fat diet group, and a CS2-unexposed high-fat diet group. Twenty-four C57BL/6J male mice were divided into four groups in the same way. The CS2-exposed groups were exposed to CS2 (1 g/m(3)) by static inhalation for 5 hours a day, 5 days a week. After two weeks, the whole blood of mice was collected. Methyl ester derivatization of fatty acids was performed using an acid-catalyzed method. Fatty acid contents before and after exposure were compared by gas chromatography-mass spectroscopy.</p><p><b>RESULTS</b>There were significant differences in fatty acid contents of mice between the four groups. For the C57BL/6J mice, the arachidic acid contents in the CS2-exposed high-fat diet group were significantly lower than those in the CS2-unexposed high-fat diet group (P = 0.045 0). For the ApoE knockout mice, the arachidonic acid contents in the CS2-exposed normal diet group were significantly lower than those in the CS2-unexposed control diet group (P = 0.045 2). For the ApoE knockout mice, the γ-linolenic acid contents in the CS2-exposed high-fat diet group were significantly higher than those in the unexposed high-fat diet group (P = 0.044 7).</p><p><b>CONCLUSION</b>Exposure to CS2 can induce fatty acid metabolism disorder in mice, indicating that CS2 may increase the risk of atherosclerosis and other cardiovascular diseases.</p>

Regulatory effect of miR-149 on interleukin-6 expression in silica-induced pulmonary fibrosis / 中华劳动卫生职业病杂志

<p><b>OBJECTIVE</b>To investigate the regulatory effect of miR-149 on interleukin-6 (IL-6) expression in silica-induced pulmonary fibrosis.</p><p><b>METHODS</b>A mouse model of pulmonary fibrosis was established using silica dust; the level of miR-149 in the lung tissues of mice with silica-induced pulmonary fibrosis was measured by quantitative real-time polymerase chain reaction (qRT-PCR), while the protein expression of IL-6 was measured by immunohistochemistry and Western blot. Type II alveolar epithelial cells (A549) and bronchial epithelial cells (HBE) were exposed to silica dust to establish a model; the level of miR-149 was measured by qRT-PCR, while the protein expression of IL-6 was measured by Western blot. A549 cells were transfected with miR-149 mimics and inhibitor in vitro, and the cellular expression of IL-6 was measured by Western blot. Serum samples from patients with coal workers' pneumoconiosis were examined by double-antibody sandwich ELISA to measure the protein expression of IL-6.</p><p><b>RESULTS</b>At three time points after silica treatment, the miR-149 expression in lung tissues was significantly down-regulated while an evident increase in IL-6 expression was observed in lung tissues (P < 0.01). Silica-stimulated epithelial cell (A549 and HBE) had up-regulated IL-6 expression and down-regulated miR-149 expression (P < 0.01). Increased levels of miR-149 attenuated IL-6 expression, whereas adverse results were found when miR-149 was inhibited. Compared with that in control group, serum level of IL-6 was significantly increased in patients with stage II and III coal workers' pneumoconiosis (P < 0.01).</p><p><b>CONCLUSION</b>Down-regulation of miR-149 and up-regulation of IL-6 might be involved in the progression of silica-induced pulmonary fibrosis; miR-149 could negatively regulate IL-6 expression.</p>

Effects of carbon disulfide inhalation on lipid levels of ApoE gene knockout mice and C57BL/6J mice / 中华劳动卫生职业病杂志

<p><b>OBJECTIVE</b>To investigate the effects of carbon disulfide (CS(2)) inhalation on the lipid levels of ApoE knockout gene mice and C57BL/6J mice.</p><p><b>METHODS</b>Fifty-one male ApoE gene knockout mice were randomly divided into four groups: CS(2)-exposed normal diet group, CS(2)-unexposed normal diet group, CS(2)-exposed high-fat diet group, and CS(2)-unexposed high-fat diet group. Fifty male C57BL/6J mice were divided into four groups in the same way. The exposed groups received 1000 mg/m3 CS(2) by static inhalation (5h/d, 5d/w) for four weeks. The weight of each mouse was determined and recorded once a week. On the 14th day of exposure, six mice in each group were randomly selected to measure serum total cholesterol (TC) levels. On the 28th day of exposure, the serum levels of TC and low-density lipoprotein (LDL) in the remaining mice were measured.</p><p><b>RESULTS</b>The mean weight gain of exposed groups was less than that of the unexposed groups. On the 14th and 28th days of experiment, the TC levels of the CS2-exposed high-fat diet group were significantly higher than those of the CS(2)-unexposed high-fat diet group among ApoE knockout gene mice (P < 0.01 for both). On the 14th day of experiment, the TC levels of the CS(2)-unexposed high-fat diet group were significantly higher than those of the CS(2)-unexposed normal-diet group among C57BL/6J mice group (P < 0.05). On the 28th day of experiment, the LDL levels of the CS(2)-exposed high-fat diet group were significantly higher than those of the CS(2)-unexposed high-fat diet group among ApoE knockout gene mice (P = 0.003).</p><p><b>CONCLUSION</b>CS(2) exposure, high-fat diet, and ApoE gene knockout can elevate blood lipids in mice, thus increasing the risk of atherosclerosis.</p>

Survey on satisfaction degree of preventive medicine undergraduates on tutorial system / 中华医学教育探索杂志

Objective To survey on satisfaction degree of preventive medicine undergraduates on tutorial system and to improve the effects of tutorial system.Methods Totally 73 students of preventive medicine,who would graduate in 2012,were asked to fill the questionnaires by themselves.Main contents of questionnaires include effects,satisfaction score,expectations and reality benefits,requirements for the tutors and problems of the tutorial system.Chi-square was used to test the differences between expectations and reality benefits and the significance level was set as P ＜ 0.05.Results More than half of the students thought that the effect of tutorial system was general while 43.8％students thought good and excellent.Percentages of satisfaction score over 50,over 80 and over 90 were 75.3％,41.1％ and 12.3％,respectively.Statistical analysis shown that the real benefits from research activities were more than expectation (P ＜ 0.001),while the real benefits from tutor's academic encouragement,job guidance and life values were lower than expectation (P =0.026,P =0.003,P =0.010).Students expected to have more opportunities with the professors in the future.However,there were 17.8％ students hardly attended the activities of tutorial system,in which lack of understanding of tutorial system was the main reason and without enough time was another reason.Conclusions Students basically satisfies with tutorial system and the satisfaction degree needs to be improved.Roles of tutorial system should be fully strengthened by the management department,tutors and students.

Reflection on strengthening practical ability for master of public health / 中华医学教育探索杂志

Practical ability training is one of the core tasks during the education for master of public health (MPH).We got a deeper understanding of practical ability cultivation situation for MPH in our school and got a more accurate recognition of the existed problems through conducting questionnaire for three grades MPH of professional degree and related tutors.We analyzed the advantages and disadvantages of the existing mode and reflected on curriculum design,teaching method reform and practical ability training reform,etc based on the results of the questionnaire and years of experiences.