The optimization of 2-thiothiazolidine-4-carboxylic acid back extraction in urine and determination by HPLC / 中华劳动卫生职业病杂志

<p><b>OBJECTIVE</b>Establishment of determination method of 2-thiothiazolidine-4-carboxylic acid (TTCA) in urine with HPLC.</p><p><b>METHODS</b>A volume of 0.5 ml hydrochloric acid (2 mol/L) and 0.5 ml pure water was added into 1 ml urine, and then extracted by 4 ml of diethyl ether by shaking for 2 min. Remove the water phase in a tube with plug and extract again, mix the two extraction diethyl ether together, take 4 ml by adding 2 ml borax-monopotassium phosphate buffer and shaking for 2 min to extract, then take the water phase to detect. A C(18) column and UV detector were used for separating and detecting. The wavelength was 273 nm, the flow rate was 1.0 ml/min, and the injection volume was 20 µl.</p><p><b>RESULTS</b>TTCA has a good linearity (r = 0.9995) over the concentration of1 1 ∼ 10 µg and the minimum detectable concentration of TTCA in urine was 0.1 µg/ml. The within-day precision (RSD) were 8.4%, 3.0% and 1.7%, the between-day precision (RSD) were 11%, 3.8%, 1.9%, respectively. The extraction recovery were between 80% ∼ 102%.</p><p><b>CONCLUSION</b>The method was accurate and sensitive to detect TTCA in urine.</p>

The rervising of biological exposure index for carbon disulfide exposuring / 中华劳动卫生职业病杂志

<p><b>OBJECTIVE</b>To study the biological exposure index of carbon disulfide in China.</p><p><b>METHODS</b>High-performance liquid chromatography (HPLC) was used to detect the levels of 2-thiothiazolidine-4-carboxylic acid (TTCA) in the urine of the workers after working shift end, Gas chromatography was used to detect the concentrations of the carbon disulfide in the workplace air. The relationship between the urine TTCA levels and the concentrations of the carbon disulfide was analyzed, the biological exposure index and judgement result from PC-TWA were compared.</p><p><b>RESULTS</b>The levels of TTCA in urine of workers occupationally exposed to carbon disulfide were closely and positively related with the concentrations of the carbon disulfide in the workplace air. The regression equation was Y = 0.265X - 0.165, The biological exposure index of carbon disulfide were calculated by regression equation according to occupational exposure limits of carbon disulfide in China.</p><p><b>CONCLUSION</b>The biological exposure index of CS(2) in China might be revised for 1.2 mg/g Cr.</p>

The relationship between occupational stress and serum glycosylated hemoglobin A1c level / 中华劳动卫生职业病杂志

<p><b>OBJECTIVE</b>To explore the relationship between occupational stress and serum glycosylated hemoglobin A1c (HbA1c) level.</p><p><b>METHODS</b>A cross-sectional epidemiological study was conducted in 115 dispatchers. The occupational stressors, personality, occupational strain and coping with stress were measured using Occupational Stress Instrument. Serum HbA1c levels were measured by stratigraphic analysis of cation exchange resin.</p><p><b>RESULTS</b>Serum HbA1c level (6.63% ± 1.93%) in the shiftwork group was significantly higher than that (5.73% ± 1.57%) in the daily relay work group (P < 0.05). Spearman correlation analyses showed the positive correlation between type A behavior and serum HbA1c level (r = 0.221), the negative correlation between organizational commitment and serum HbA1c level (r = -0.218). Variance analyses revealed that serum HbA1c levels among high, middle and low job requirement groups and job control groups were significantly different (P < 0.05). There were significant differences of serum HbA1c levels among different type A behavior, internal control, susceptibility of stress and organizational commitment groups (P < 0.05). Stepwise regression analyses indicated that shiftwork affects obviously serum HbAlc level, internal control and job future were the predictors of serum HbA1c level (R2 = 0.082).</p><p><b>CONCLUSION</b>Serum HbA1c may be a potential biomarker in field investigation of the effects of occupational stress.</p>

Effects of occupational stress on serum tumor necrosis factor-α and interleukins / 中华劳动卫生职业病杂志

<p><b>OBJECTIVE</b>To explore the effect of occupational stress on serum tumor necrosis factor-α (TNF-α), interleukin (IL)-1β, IL-2 and IL-4.</p><p><b>METHODS</b>A cross-sectional epidemiological study was conducted in 200 workers from the refrigerator assembly line in Henan province in China. Psychosocial work conditions were measured by using the job demand-control model, the effort-reward imbalance model questionnaires and occupational stress measurement scale. Serum TNF-α, IL-1β, IL-2, and IL-4 concentrations were measured by radioimmunoassay or immunoradiometric assay method respectively.</p><p><b>RESULTS</b>Serum TNF-α concentration was statistically significantly different between workers with higher affective balance level and control groups [(1.947 ± 0.173) and (2.029 ± 0.240) fmol/ml] (P < 0.05). Serum IL-1β concentration was statistically significantly different between workers with higher effort level and control groups [(0.133 ± 0.034) and (0.118 ± 0.031) ng/ml] (P < 0.05). Serum IL-2 concentration was statistically significantly different between workers with higher role ambiguity level [(1.658 ± 0.376) and (1.491 ± 0.033) ng/ml] and control groups (P < 0.05), as well as between workers with higher role conflict level and control groups [(1.774 ± 0.311) and (1.589 ± 0.380) ng/ml] (P < 0.05), between workers with higher daily life stress level and control groups [(1.759 ± 0.361) and (1.606 ± 0.381) ng/ml] (P < 0.05). Serum IL-4 concentration was statistically significantly different between workers with higher reward level and control groups [(1.449 ± 0.025) and (1.466 ± 0.041) pg/ml] (P < 0.05). Stepwise regression analysis indicated that affective balance was the predictor of serum TNF-α (R(2) = 0.029). Effort and mental health were the predictors of serum IL-1β (R(2) was 0.029 and 0.055, respectively). Role conflict, daily life stress and role ambiguity were the predictors of serum IL-2 (R(2) was 0.040, 0.078 and 0.104, respectively). Reward was the predictor of serum IL-4 (R(2) = 0.030).</p><p><b>CONCLUSION</b>Unhealthy psychological stress factor might be induce a marked increase in the concentrations of serum TNF-α, IL-1β, IL-2, as well as IL-4.</p>

Coping strategy and its effect on occupational stress among rail freight dispatchers / 中华劳动卫生职业病杂志

<p><b>OBJECTIVE</b>To analyse the relationship between coping strategy and occupational stress in rail freight dispatchers.</p><p><b>METHODS</b>115 rail freight dispatchers were investigated by using group sampling method, investigation contents included coping strategies, occupational stressors, strains and personalities.</p><p><b>RESULTS</b>The proportion of using coping strategy in rail freight dispatchers is lower. The scores of job future ambiguity, type A behavior and work locus of control in workers with insufficient coping strategy were higher than those in workers with sufficient strategy (P < 0.05 or P < 0.01), but the score of organization commitment score in workers with insufficient coping strategy was lower than those in workers with sufficient strategy (P < 0.05), the differences of scores of some occupational stressor, strain and personality variables between workers with insufficient and those with sufficient in social support, job-family balance, job involvement coping factors of coping strategy were remarkable significant (P < 0.05 or P < 0.01), the differences of scores of occupational stressor, strain and personality variables between workers with insufficient and those with sufficient in ask, logic and time management factors of coping strategy weren't significant (P > 0.05). Logistic regression analysis showed that risk of being job dissatisfaction and daily life stress in workers with insufficient social support coping was three or four times than those with sufficient coping (OR = 3.06 or 4.38, respectively), risk of being daily life stress in workers with insufficient job involvement coping was three times than those with sufficient coping (OR = 3.26).</p><p><b>CONCLUSION</b>The proportion of using coping strategy in rail freight dispatchers is lower. Coping strategy has influence on the individual's perception of occuaptional stressors, strains and personalities.</p>

Effect of occupational stress on ambulatory blood pressure / 中华劳动卫生职业病杂志

<p><b>OBJECTIVE</b>To explore the effect of occupational stress on ambulatory blood pressure.</p><p><b>METHODS</b>30 male healthy workers from the refrigerator assembly line in Henan province in China were investigated. Psychosocial work conditions were measured by using the Job Demand-control Model, the Effort-reward Imbalance Model questionnaires and Occupational Stress Measurement Scale. Ambulatory blood pressure(ABP) was measured by using mobile ABP monitor. The t test was utilized to analyze the difference of parameters of ABP monitoring between different groups of occupational stress and other variables scores. The stepwise regression analysis was used to analyse the effect of occupational stress factors on parameters of ABP.</p><p><b>RESULTS</b>(1) As to stressors, systolic blood pressure variability (SBPV), mean arterial blood pressure variability (MABPV) and heart rate at 30 minute after work in workers with high role conflict score were significantly higher than those in workers with low score (P < 0.05). Workers with high skill utilization score had significantly lower mean systolic blood pressure (SBP) at 30 minute after work than workers with low score (P < 0.05). Diastolic blood pressure variability (DBPV) and heart rate variability (HRV) in workers with high decision latitude score were significantly higher than those in workers with low score (P < 0.05). Workers with high job psychological demands score had significantly higher SBPV, DBPV and MABPV than workers with low score (P < 0.05). Heart rate-pressure product(RPP) and SBPV in workers with high effort score were significantly higher than those in workers with low score (P < 0.05). Workers with low rewards score had higher mean heart rate and heart rate at 30 minute after work than workers with high score (P < 0.05). (2) For personalities, workers with high work locus of control score had significantly higher mean diastolic blood pressure (DBP) and mean arterial blood pressure (MABP) than workers with low score (P < 0.05). Workers with high patience score had significantly lower mean SBP at 30 minute after work than workers with low score (P < 0.05). Heart rate at 30 minute after work in workers with high organization commitment score was significantly lower than that in workers with low score (P < 0.05). (3) Concerning buffer factors, HRV in workers with high control strategies score were significantly lower than that in workers with low score (P < 0.05). Workers with low supervisor support score had higher RPP and MABPV than workers with high score (P < 0.05). (4) In the multiple stepwise regression, daily life stress affected SBPV (R2 = 0.12) and MABPV (R2 = 0.05), depression was related to DBPV at 30 minute after work (R2 = 0.15) and SBPV (R = 0.03), mental health was predictor of MABPV (R2 = 0.07) and negative affection was predictor of heart rate at 30 minute after work (R2 = 0.24).</p><p><b>CONCLUSIONS</b>Occupational stressors, personality and social support have effect on parameters of ABP. Parameters of ABP monitoring could be used to evaluate occupational stress in the field research.</p>

Job stress, gene polymorphism of beta2-AR, and prevalence of hypertension / 生物医学与环境科学（英文）

<p><b>OBJECTIVE</b>To study the interactive effect of job stress and genetic susceptibility (or gene polymorphism) on hypertension.</p><p><b>METHODS</b>A cross-sectional epidemiological study was conducted in 452 workers from a thermal power plant in China. Extrinsic effort, occupational reward, and over-commitment were measured. Hypertensive patients were defined by three phases of screening, reexamination, and final diagnosis. beta2-AR genotypes and allele frequencies at amino acid positions 16 (beta2-AR-16: Arg-->Gly) and 27 (beta2-AR-27: Gln-->Glu) were identified by PCR-RFLP.</p><p><b>RESULTS</b>Job stress was related with the prevalence of hypertension in males (P < 0.05), whereas no significant relationship was found in females (P > 0.05). Differences in genotypes and allele frequencies of the beta2-AR-16 were statistically significant between the hypertension and control groups (P < 0.05), whereas those of beta2-AR-27 were not (P > 0.05). The prevalence of hypertension was higher in individuals carrying Gly16 allele than in those carrying Arg16 allele of the high job stress group (P < 0.01 or 0.05).</p><p><b>CONCLUSION</b>High job stress and polymorphism of beta2-AR-16 have an interactive effect on the prevalence of hypertension in male workers.</p>