Effect of job satisfaction on depression after adjusting for satisfaction with other life domains

Background

Studies on the association between job satisfaction and depression have often been reported. However, no study has examined how job satisfaction impacts depression while considering satisfaction with other aspects of life. In this study, we evaluated the effect of job satisfaction on depression after adjusting for satisfaction with other domains of life.

Methods

We used data from the 16th wave of the Korean Welfare Panel Study. A total of 3568 current employees without depression who completed a survey were included. Depression was measured using the abbreviated version of the CES-D scale. Various types of satisfaction, including job satisfaction, were measured using single-item questions and a 5-point Likert scale. The association between job satisfaction and depression after considering satisfaction with other life domains was analyzed using a multiple logistic regression model.

Results

Crude models showed a significant association between job satisfaction and depression in males (odds ratio [OR]: 7.90; 95% confidence interval [CI]: 4.11-15.23) and females (OR: 7.12; 95% CI: 4.40-11.50). When adjusted for sociodemographic factors, health-related factors, and work-related factors, the association remained significant in males (OR: 6.20; 95% CI: 3.10-12.41) and females (OR: 6.28; 95% confidence interval (CI): 3.79-10.40). However, when satisfaction with other life domains was included, the association remained significant only in females (OR: 3.55; 95% CI: 1.93-6.50).

Conclusions

This study shows an association between job satisfaction and depression in Korean employees. However, when satisfaction with other life domains was considered, this association remained significant only in women. Regular screening of job satisfaction should be considered as a means of preventing and managing depression among female employees.

Association between Work-related Communication Devices Use during Work Outside of Regular Working Hours and Depressive Symptoms in Wage Workers

Background

This study aimed to investigate the relationship between work-related communication devices use during work outside of regular working hours and depressive symptoms in wage workers.

Methods

Data from 50,538 workers aged 15 years or older who had participated in the 6th Korean Working Condition Survey (KWCS) were used. The final sample was 32,994 wage workers. The questionnaire asked the respondents how often they used communication devices for work during work outside of regular working hours. Depressive symptoms were assessed using WHO-5 Well-Being Index. Multiple logistic regression analysis was used to analyze the association between work-related communication devices use during work outside of regular working hours and depressive symptoms.

Results

The rate of depressive symptoms was highest among workers who did not use work-related communication devices during work outside of regular working hours. After adjusting for socio-demographic and work-related factors, the odds ratio of depressive symptoms among workers who used communication devices when working outside of regular working hours was 1.20 (95% CI: 1.09-1.32); the odds ratio of depressive symptoms in the group not using communication devices for free-time work was 1.66 (95% CI: 1.37-2.00), which was higher than that of the reference group, that is, workers who did not work outside of regular working hours, and was statistically significant.

Conclusion

Regardless of whether work-related communication devices are used, working outside of regular working hours increases depressive symptoms. The use of work-related communication devices during work outside of regular working hours can reduce the rate of depressive symptoms.

Assessment of Bladder Filling Type on Radiation Dose to Organs at Risk in MR-Guided Intracavity Brachytherapy for Cervical Cancer

PURPOSE/OBJECTIVE(S)

In this study, we evaluated whether the classification of bladder shape affects the absorbed dose (Gy) of OARs and its geometrical position to normal organs in MR-guided intracavitary brachytherapy (ICBT).

MATERIALS/METHODS

In this study, 269 patients who underwent MR-guided ICBT for cervical cancer from 2016 to 2022 were included. The applicator-inserted bladder filling type (BFT) classification was divided into three types (tilted, curved, and other shapes: group E). The anatomical positional relationship between the uterus and its surroundings was measured on pre-MR images and ICBT simulation MR images. Spearman's rank correlation analysis was used for bladder volume and OAR dose according to BFT. Anatomical differences were analyzed by ANOVA by measuring the distance from the center to both bladder walls.

RESULTS

In the correlation analysis considering the shape of the bladder, the tilted, curved, and group E had Spearman's ρ of 0.211; -0.323, 0.412; -0.307 and -0.035; -0.209 for maximum absorbed dose (D2cc) of bladder and small bowel, respectively. It was statistically significant in the tilted type and curved type. The average left and right bladder lengths differences of the tilted type were the highest at 8.47 cm and 7.11 cm, respectively. It was a statistically significant between bladder shape and the difference in left and right bladder lengths differences (p< 0.01).

CONCLUSION

In this study, it was confirmed that bladder distension increased the maximum bladder dose (D2cc) and decreased the maximum bowel dose (D2cc) to the tilted type and curved type. In addition, if the left and right bladder lengths are measured in pre-MR, the degree of bladder distension can be evaluated in advance by checking the shape of the bladder in the case of the tilting type before ICBT. Based on these findings, a prospective study is needed to evaluate the effect of ICBT on cervical cancer treatment outcomes through bladder type classification.

Occupational stress changes and new-onset depression among male Korean manufacturing workers

Background

Studies on the association between occupational stress and depression have been frequently reported. However, the cross-sectional designs of studies limited insight into causal associations. In this study, we investigated the longitudinal association between occupational stress and new-onset depression among employees in a single manufacturing plant.

Methods

The annual health checkup data of employees at a manufacturing plant in Korea were collected. A total of 1,837 male employees without depression who completed a health checkup during two consecutive years were included. Occupational stress was measured using a short form of the Korea Occupational Stress Scale (KOSS-SF), and depression was assessed using a Patient Health Questionnaire-2. The association between occupational stress change over the two years and newly developed depression was investigated using two logistic regression models.

Results

Across all sub-factors of KOSS-SF, employees who reported increased occupational stress had a higher risk of new-onset depression. Newly developed depression was significantly associated with job demand (odds ratio [OR]: 4.34; 95% confidence interval [CI]: 2.37-7.96), job insecurity (OR: 3.21; 95% CI: 1.89-5.48), occupational climate (OR: 3.18; 95% CI: 1.91-5.31), lack of reward (OR: 2.28; 95% CI: 1.26-4.12), interpersonal conflict (OR: 2.14; 95% CI: 1.18-3.86), insufficient job control (OR: 1.93; 95% CI: 1.05-3.56), and the organizational system (OR: 1.84; 95% CI: 1.01-3.36).

Conclusions

For every sub-factor of the KOSS-SF, occupational stress increase and persistent high stress were associated with the risk of developing new-onset depression. Among the seven sub-factors, job demand had the most significant effect. Our results show that occupational stress should be managed to promote employee mental healthcare.

The relationship between fatigue and sickness absence from work

Background

Although many studies have been conducted on worker fatigue and sickness absence, the association between fatigue and sickness absence is unclear in Korean workers. This study was conducted to investigate the effect of worker fatigue on future sickness absence.

Methods

The study was conducted on workers who received medical check-ups at a university hospital for two consecutive years (2014-2015). During check-ups in the first year, the Fatigue Severity Scale (FSS) was used to assess fatigue levels, and during check-ups in the second year, sickness absence was surveyed to determine whether they had been absent from work due to physical or mental illness during previous 12 months. The χ2 test was used to analyze relationships between sociodemographic and occupational characteristics, fatigue levels, and sickness absence. Odds ratios (ORs) were calculated by logistic regression analysis controlled for confounding factors.

Results

A total of 12,250 workers were included in the study, and 396 (3.2%) workers experienced more than one day of sickness absence during the study period. Adjusted ORs for sickness absence were 3.35 (95% confidence interval [CI]: 2.64-4.28) in the moderate-fatigue group and 6.87 (95% CI: 4.93-9.57) in the high-fatigue group versus the low-fatigue group. For men in the moderate- and high-fatigue groups, adjusted ORs for sickness absence were 3.40 (95% CI: 2.58-4.48) and 8.94 (95% CI: 6.12-13.07), and for women in the moderate- and high-fatigue groups, adjusted ORs for sickness absence were 2.93 (95% CI: 1.68-5.10) and 3.71 (95% CI: 1.84-7.49), respectively.

Conclusions

Worker fatigue is associated with sickness absence during the following 12 months, and this association appears to be stronger for men than women. These results support the notion that sickness absence can be reduced by evaluating and managing work-related fatigue.

Development of Korean Version Burnout Syndrome Scale (KBOSS) Using WHO's Definition of Burnout Syndrome

BACKGROUND

Burnout syndrome (BOS) is defined by the World Health Organization (WHO) as a syndrome conceptualized as resulting from chronic workplace stress that has not been successfully managed. This study aims to create the Korean version burnout syndrome scale (KBOSS) that conforms to WHO's definition of BOS and present the cut-off points for screening.

METHODS

We developed the KBOSS based on WHO's definition of BOS. An online survey was conducted through a specialized online research company. We recruited 444 workers for this research. The validity of the KBOSS was assessed using factor analysis and Pearson's correlation. The KBOSS reliability was assessed using Cronbach's alpha coefficient. The cut-off points for each of the three dimensions were derived using the upper quartile score.

RESULTS

The validity and reliability of the KBOSS were good. Regarding reliability, the scale's overall Cronbach's alpha was 0.813. Cronbach's alpha of each three-dimension was as follows: exhaustion, 0.916; cynicism, 0.865; and professional inefficacy, 0.819. The cut-off points of BOS three dimensions are exhaustion ≧ 21; cynicism ≧ 18; and inefficacy ≧ 15.

CONCLUSION

The developed questionnaire (KBOSS) can be a useful tool for screening of BOS.

Employment Status Change and New-Onset Depressive Symptoms in Permanent Waged Workers

Background

This study aimed to investigate the relationship between changes in employment status and new-onset depressive symptoms through a one-year follow-up of permanent waged workers.

Methods

We analyzed the open-source data from the Korea Welfare Panel Study. Using the 2017 data, we selected 2,314 permanent waged workers aged 19 to 59 years without depressive symptoms as a base group. The final analysis targeted 2,073 workers who were followed up in 2018. In 2018, there were five categories of employment status for workers who were followed up: permanent, precarious, unemployed, self-employed, and economically inactive. Multiple logistic regression was used to determine the association between employment status change and new-onset depressive symptoms.

Results

Adjusted multiple logistic regression analysis showed that among male workers, workers who went from permanent status to being unemployed (odds ratio: 4.50, 95% confidence interval: 1.19 to 17.06) and from permanent status to being precarious workers (odds ratio: 3.15, 95% confidence interval: 1.30 to 7.65) had significantly high levels of new-onset depressive symptoms compared with those who retained their permanent employment status. There were no significant increases in new-onset depressive symptoms of male workers who went from permanent status to being self-employed or economically inactive. On the other hand, no significant differences were found among female workers.

Conclusion

Our study suggests that the change of employment status to precarious workers or unemployment can cause new-onset depressive symptoms in male permanent waged workers.

Mismatch in working hours and workaholism in permanent waged workers

OBJECTIVES

A cross-sectional study was conducted to investigate whether working hours mismatch is associated with workaholism.

MATERIAL AND METHODS

This study used the data from the 17th wave (2014) of the nationwide Korean Labor and Income Panel Study. Workaholism was evaluated using the Workaholism Analysis Questionnaire. The final study involved 3157 subjects who answered questions regarding both workaholism and working hours mismatch. To identify the association between working hours mismatch and workaholism according to weekly working hours, a stratification analysis was conducted by dividing the number of working hours/week into 3 groups (≤40 h, 41-59 h, and ≥60 h). The odds ratios were calculated using a multiple logistic regression model, which was adjusted for potential confounders.

RESULTS

The workers working more hours than desired showed the greatest frequency of workaholism. As regards workaholism, in all weekly working hours groups, the odds ratios of the group working more hours than desired were 4.28, 95% CI: 2.29-7.99 (≥40 h), 2.14, 95% CI: 1.34-3.43 (41-59 h), 3.40, 95% CI: 1.60-7.21 (≤60 h), which were statistically significant compared to the reference (matched) group. There was no statistically significant relationship between working hours and workaholism when stratified according to the mismatch in working hours.

CONCLUSIONS

The workers' working hours mismatch can be significantly related to workaholism. Int J Occup Med Environ Health. 2020;33(2):187-94.

Relationship between occupational sunlight exposure and the incidence of renal cancer

BACKGROUND

The risk factors for renal cancer include smoking, obesity, hypertension, and exposure to trichloroethylene. Recent studies have shown that low sunlight exposure increases the risk of developing a range of cancers, including renal cancer. Given that most of the daytime is spent at work, a lack of occupational sunlight exposure can be a risk factor for renal cancer. Therefore, this study examined the relationship between occupational sunlight exposure and the incidence of renal cancer.

METHODS

This was a university hospital-based case-control study on renal cancer. Of the 706 newly diagnosed patients with renal cell carcinoma (RCC), 633 cases were selected; 73 who had no occupational history were excluded. In addition, 633 controls were selected from the general population after 1:1 matching with respect to sex, age (within 5 years), and residential area (constituency-level). Information on sunlight exposure by the occupational group was referred to data from France. To estimate the association between occupational sunlight exposure and the RCC risk, the odds ratios (ORs) were calculated using conditional logistic regression analysis.

RESULTS

Sunlight exposure was divided into quartiles and the risk of RCC was analyzed. The adjusted OR of RCC (OR: 0.664, 95% confidence interval: 0.449-0.983) was significantly lower for the Q4 group than Q1 group but the Q2 and Q3 groups did not show significant results. The risk of RCC tended to decrease with increasing exposure to sunlight (p for trend < 0.028).

CONCLUSIONS

Higher occupational sunlight exposure reduces the risk of RCC.

Satisfaction with life and the risk of occupational injury

Background

Occupational injuries increase burden on society as well as personal health. Low satisfaction with life may not only increases the risk of occupational injuries directly, but also influences other factors that increase the risk of occupational injury. Along with previous studies on the risk of occupational injury, we sought to explore the relationship between satisfaction with life and occupational injury.

Methods

The study participants were 6234workers health screened at a university hospital in Incheon. Information on occupational injury and satisfaction with life scale (SWLS) was obtained in a self-report format. Participants were allocated to one of four SWLS groups; the dissatisfied group, the slightly dissatisfied group, the slightly satisfied group, and the satisfied group. The analysis was performed using the chi-square test primarily and by logistic regression adjusted for potential confounders.

Results

In men, the un-adjusted and adjusted odds ratios (ORs) of low satisfaction with life (SWLS< 20) were 1.98(CI1.55-2.53) and 1.81(CI 1.41-2.32), respectively. When the SWLS were divided into four groups, the adjusted ORs of the slightly satisfied (20-25), slightly dissatisfied(15-19), and dissatisfied(≤14) groups were 1.21, 1.72, and 2.70, respectively. That is ORs tended to increase linearly with decreasing SWLS score (p for trend < 0.001). In women, this relation was of borderline significance at best.When subjects were dichotomized based on SWLS scores, for males, the cured and adjusted RRs of occupational injury in the low satisfaction with life group were1.91 (95% CI: 1.50-2.42) and 1.66 (95% CI: 1.30-2.13), and for females, the adjusted-RR was marginally significant (1.67; 95% CI: 0.93-2.99).When subjects were divided into four groups by SWLS scores, adjusted RRs tended to increase linearly with decreasing SWLS score for males (slightly satisfied: 1.18, 95% CI: 0.77-1.82; slightly dissatisfied: 1.65, 95% CI: 1.08-2.52; dissatisfied: 2.22, 95% CI: 1.44-3.42; p for trend < 0.001) and for females (slightly satisfied: 1.17, 95% CI: 0.42-3.30; slightly dissatisfied: 1.56, 95% CI: 0.56-4.36; dissatisfied: 2.38, 95% CI: 0.84-6.74; p for trend = 0.040).

Conclusions

This study suggests that the risk of occupational injury was higher in workers not satisfied with life, and indicates attention to satisfaction with life may promote the health of workers.

The relationship between depression and periodontal diseases

OBJECTIVE

A cross-sectional study was conducted to investigate whether depression is associated with periodontal diseases in a representative sample of South Korean adults Methods: We used data from the sixth Korea National Health and Nutrition Examination Survey (KNHANES VI), conducted in 2014. We included in this study 4328 participants aged over 20 years (1768 males and 2560 females). Depression was assessed with the Patient Health Questionnaire (PHQ-9) and history of physician-diagnosed depression. Periodontal diseases were assessed a gingival bleeding, calculus and periodontal pockets. The data were analyzed using the chi-square test and multiple logistic regression.

RESULTS

People with any periodontal diseases tended to be old, male, married, low income, poor education, blue-collar occupation, diabetes mellitus, hypertension, overweight, smoking, not using dental floss or interdental brush in univariate analysis. Neither self-reported nor diagnosed depression was associated with the presence of any or severe periodontal disease in the total sample. In participants aged 20-29 years only, the presence of any periodontal disease was associated with self-reported depression (OR, 2.031; 95% CI, 1.011-4.078). In the same age group, the presence of severe periodontal disease was associated with both self-reported depression (OR, 6.532; 95% CI, 2.190-19.483) and diagnosed depression (OR, 7.729; 95% CI, 1.966-30.389).

CONCLUSION

Self-reported depression was significantly associated with the presence of any or severe periodontal disease, and diagnosed depression was significantly associated with severe periodontal diseases only in participants aged 20-29 years.

The effect of anti-TNF treatment on osteoblastogenesis in ankylosing spondylitis: the number of circulating osteoblast-lineage cells in peripheral blood decreased after infliximab therapy in patients with ankylosing spondylitis

OBJECTIVES

The full effect of anti-TNF therapy on new bone formation is still in debate in spondylitis fields. We sought to obtain circulating osteoblast-lineage cells in peripheral blood from ankylosing spondylitis (AS) patients and healthy control subjects, and to evaluate the effect of before and after anti TNF-α therapy on osteoblastogenesis in patients with AS.

METHODS

Sixteen male patients with AS slated for infliximab therapy and 19 controls were recruited. We cultured osteoblast-lineage cells from peripheral blood and measured the optical density of their Alizarin red S staining. We also measured serum P1NP (procollagen type 1 N-terminal propeptide) as an early osteoblast differentiation marker, osteocalcin as a late osteoblast differentiation marker, and inflammatory markers.

RESULTS

There were significantly more circulating osteoblast-lineage cells in patients than in controls. The number of circulating osteoblast-lineage cells and optical density of Alizarin red S staining decreased 14 weeks after infliximab therapy (p=0.028); serum level of P1NP decreased, but that of osteocalcin increased (p=0.002 and 0.007, respectively).

CONCLUSIONS

Our data reveals that first, the circulating osteoblast-lineage cells are recoverable and increased in AS patients, and also that they decrease after infliximab therapy; second, infliximab therapy resolves early inflammation, but allows mature osteoblast differentiation in late inflammation. The culture of osteoblast-lineage cells in peripheral blood may be a candidate for a new modality with which to study spondylitis and other autoimmune diseases.

The seroprevalence of Bartonella henselae in healthy adults in Korea

BACKGROUND/AIMS

Cat-scratch disease (CSD), caused by Bartonella henselae is one of the most common zoonosis. However, only several cases of B. henselae infection have been reported in Korea. This study investigated the seroprevalence of B. henselae in healthy adults and related risk factors.

METHODS

Serum samples from 300 healthy participants were analyzed using an immunoglobulin G immunof luorescence assay (IFA) for B. henselae isolated in Korea. Surveys on the risk factors for B. henselae infection were conducted simultaneously.

RESULTS

Of the participants, 47.7% and 15.0% raised dogs and cats, respectively. The overall seroprevalence of B. henselae was 15.0% (IFA titer ≥ 1:64). Participants who had raised cats showed 22.2% seropositivity against B. henselae, and those with no experience with cats showed 13.7% seroprevalence (p = 0.17). Participants who had cats as pets or been scratched by cats, showed 9.8% seropositivity against B. henselae (IFA titer ≥ 1:256). However, those who had not raised or been scratched by a cat showed 2.0% seropositivity (p = 0.015).

CONCLUSIONS

In Korea, the seroprevalence of B. henselae is higher than expected, suggesting that Bartonella infection due to B. henselae is not uncommon. Cats are proposed to play a more important role than dogs in transmission of CSD.

SET kinetics of electrochemical metallization cells: influence of counter-electrodes in SiO2/Ag based systems

The counter-electrode material in resistively switching electrochemical metallization cells (ECMs) is a crucial factor influencing the nucleation of conductive filaments, the equilibrium electrode potentials, and kinetics in the devices, and hence the overall switching characteristics. Here, we demonstrate the influence of the counter-electrode (CE) material on the SET events and the importance of appropriate choice and combination of materials. The counter-electrode material influences the counter-electrode processes at the CE/insulator interface and consequently determines the metal ion concentration in the cells. We measured the switching kinetics for SiO₂/Ag based ECM cells using different counter-electrode materials with different electrocatalytic activities towards water reduction, namely platinum, ruthenium, and iridium oxide, as well as titanium nitride and tantalum. The experimental results are fitted using a physical simulation model and are analysed for the limiting factors for fast SET kinetics.

Disparities in precarious workers' health care access in South Korea

BACKGROUND

This study explored whether precarious workers have difficulties in health care access as compared with non-precarious workers.

METHODS

The 2008 Korean Community Health Survey data were used for this study. Information was obtained on 51,322 participants (40,514 non-precarious workers and 10,808 precarious workers). Precarious workers were defined as part-time or contingent workers.

RESULTS

Precarious workers had significantly higher risk of limited access to hospitals (OR = 1.14; 95% CI: 1.06-1.22) and dentists (OR = 1.28; 95% CI: 1.21-1.36) than non-precarious workers; disparities in doctor contacts among precarious workers were mostly linked to not having enough money. The risk of not receiving preventive care-medical checkups (OR = 0.52; 95% CI: 0.49-0.55) or cancer screenings (OR = 0.82; 95% CI: 0.77-0.86)-was also significantly elevated among precarious workers.

CONCLUSION

We found that precarious workers had more difficulty accessing health care or receiving health checkups or cancer screenings than their non-precarious counterparts. Am. J. Ind. Med. 59:1136-1144, 2016. © 2016 Wiley Periodicals, Inc.

AIMP1 downregulation restores chondrogenic characteristics of dedifferentiated/degenerated chondrocytes by enhancing TGF-β signal

Dedifferentiation and degeneration of chondrocytes critically influences the efficiency of cartilage repair. One of the causes is the defect of transforming growth factor (TGF)-β signaling that promotes chondrogenic differentiation and degeneration. In the present study, we found that aminoacyl-tRNA synthetase-interacting multifunctional protein 1 (AIMP1) negatively regulates TGF-β signaling via interactions with Smad2 and Smad3 in immunoprecipitation assay and luciferase assay. In addition, we observed that the AIMP1 expression level was significantly increased in osteoarthritis (OA) patient-derived degenerated chondrocytes compared with healthy control. So, we hypothesized that downregulation of AIMP1 using small-interfering RNA (siRNA) technology in dedifferentiated (collected at passage #6) and degenerated (obtained from OA-affected areas) chondrocytes could lead to recover TGF-β signaling in both chondrocytes. Indeed, AIMP1 downregulation restored TGF-β signaling by promoting phosphorylation of Smad2 and Smad3, which shows redifferentiated characteristics in both dedifferentiated and degenerated chondrocytes. Additionally, implantation analyses using in vivo mouse model clearly showed that AIMP1 downregulation resulted in the increased chondrogenic potential as well as the enhanced cartilage tissue formation in both dedifferentiated and degenerated chondrocytes. Histological analyses clarified that AIMP1 downregulation increased expression levels of collagen type II (Col II) and aggrecan, but not Col I expression. Taken together, these data indicate that AIMP1 downregulation using siRNA is a novel tool to restore TGF-β signaling and thereby increases the chondrogenic potential of dedifferentiated/degenerated chondrocytes, which could be further developed as a therapeutic siRNA to treat OA.

Precarious employment and the risk of suicidal ideation and suicide attempts

OBJECTIVE

Although the effect of occupation or employment status on suicide risk is notable, there are few studies on the effect of precarious employment on suicide. We compared suicidal ideation and suicide attempts in precarious workers and their non-precarious counterparts using a representative sample from South Korea.

METHOD

The 2008 Korean Community Health Survey data were used for this study. Information was obtained on 52,161 participants (41,063 employees with non-precarious work and 11,098 employees with precarious work). The outcome of the logistic regression model was the presence of suicidal thoughts and attempts, and the independent variables were the demographics, socioeconomic status, and health status.

RESULTS

Employees with precarious work were more likely to exhibit suicidal ideation (OR=1.41; 95% CI, 1.28-1.55) and suicide attempts (OR=1.52; 95% CI, 1.02-2.27) than employees with non-precarious work. After controlling for income and education (Model 2) depressive feelings (Model 6), compared with unadjusted model, remained significant but the odds ratio was largely attenuated, indicating a strong association between suicidal risk and socioeconomic and feelings of depression.

CONCLUSION

Precarious workers had a higher risk of suicidal ideation and suicide attempts than non-precarious workers. Our study suggests that precarious employment is an important risk for suicide.

Cell cycle-dependent Cdc25C phosphatase determines cell survival by regulating apoptosis signal-regulating kinase 1

Cdc25C (cell division cycle 25C) phosphatase triggers entry into mitosis in the cell cycle by dephosphorylating cyclin B-Cdk1. Cdc25C exhibits basal phosphatase activity during interphase and then becomes activated at the G2/M transition after hyperphosphorylation on multiple sites and dissociation from 14-3-3. Although the role of Cdc25C in mitosis has been extensively studied, its function in interphase remains elusive. Here, we show that during interphase Cdc25C suppresses apoptosis signal-regulating kinase 1 (ASK1), a member of mitogen-activated protein (MAP) kinase kinase kinase family that mediates apoptosis. Cdc25C phosphatase dephosphorylates phospho-Thr-838 in the activation loop of ASK1 in vitro and in interphase cells. In addition, knockdown of Cdc25C increases the activity of ASK1 and ASK1 downstream targets in interphase cells, and overexpression of Cdc25C inhibits ASK1-mediated apoptosis, suggesting that Cdc25C binds to and negatively regulates ASK1. Furthermore, we showed that ASK1 kinase activity correlated with Cdc25C activation during mitotic arrest and enhanced ASK1 activity in the presence of activated Cdc25C resulted from the weak association between ASK1 and Cdc25C. In cells synchronized in mitosis following nocodazole treatment, phosphorylation of Thr-838 in the activation loop of ASK1 increased. Compared with hypophosphorylated Cdc25C, which exhibited basal phosphatase activity in interphase, hyperphosphorylated Cdc25C exhibited enhanced phosphatase activity during mitotic arrest, but had significantly reduced affinity to ASK1, suggesting that enhanced ASK1 activity in mitosis was due to reduced binding of hyperphosphorylated Cdc25C to ASK1. These findings suggest that Cdc25C negatively regulates proapoptotic ASK1 in a cell cycle-dependent manner and may play a role in G2/M checkpoint-mediated apoptosis.

The relationship between working condition factors and well-being

OBJECTIVES

Working conditions can exert influence on the physical, mental, and even social health of workers. Well-being is an appropriate index for the evaluation of a person's overall health. This paper investigated the association between various working conditions and worker's well-being.

METHODS

Data from 10,019 interviews were collected from the second wave of the Korean Working Conditions Survey (2010) conducted by the Korea Occupational Safety and Health Agency between June and October 2010. The data from 5,995 employed workers were examined in this study. Well-being was measured through the WHO Five Well-Being Index (1998 version). Sociodemographic and working conditions were analyzed. Adjusted odds ratios for well-being were calculated with adjusted sociodemographic factors, working condition factors, or both.

RESULTS

Workers' well-being was significantly higher when they were satisfied with their working conditions (OR = 1.656, 95% CI = 1.454-1.885), when their actual working hours were the same as their anticipated working hours (OR = 1.366, 95% CI: 1.120-1.666) or exceeding less than 10 hours (OR = 1.245, 95% CI: 1.004-1.543), and when their employment was stable (OR = 1.269, 95% CI: 1.098-1.467).

CONCLUSIONS

This study supports the association between working condition factors and well-being in workers.

Early effects of tumor necrosis factor inhibition on bone homeostasis after soluble tumor necrosis factor receptor use

BACKGROUND/AIMS

Our aim was to assess whether short-term treatment with soluble tumor necrosis factor (TNF) receptor affects circulating markers of bone metabolism in rheumatoid arthritis (RA) patients.

METHODS

Thirty-three active RA patients, treated with oral disease-modifying antirheumatic drugs (DMARDs) and glucocorticoids for > 6 months, were administered etanercept for 12 weeks. Serum levels of bone metabolism markers were compared among patients treated with DMARDs at baseline and after etanercept treatment, normal controls and naive RA patients not previously treated with DMARDs (both age- and gender-matched).

RESULTS

Bone-specific alkaline phosphatase (BSALP) and serum c-telopeptide (CTX)-1 levels were lower in RA patients treated with DMARDs than in DMARD-naive RA patients. After 12 weeks of etanercept treatment, serum CTX-1 and sclerostin levels increased. In patients whose DAS28 improved, the sclerostin level increased from 1.67 ± 2.12 pg/mL at baseline to 2.51 ± 3.03 pg/mL, which was statistically significant (p = 0.021). Increases in sclerostin levels after etanercept treatment were positively correlated with those of serum CTX-1 (r = 0.775), as were those of BSALP (r = 0.755).

CONCLUSIONS

RA patients treated with DMARDs showed depressed bone metabolism compared to naive RA patients. Increases in serum CTX-1 and sclerostin levels after short-term etanercept treatment suggest reconstitution of bone metabolism homeostasis.

Digital thermography of the fingers and toes in Raynaud's phenomenon

The aim of this study was to determine whether skin temperature measurement by digital thermography on hands and feet is useful for diagnosis of Raynaud's phenomenon (RP). Fifty-seven patients with RP (primary RP, n = 33; secondary RP, n = 24) and 146 healthy volunteers were recruited. After acclimation to room temperature for 30 min, thermal imaging of palmar aspect of hands and dorsal aspect of feet were taken. Temperature differences between palm (center) and the coolest finger and temperature differences between foot dorsum (center) and first toe significantly differed between patients and controls. The area under curve analysis showed that temperature difference of the coolest finger (cutoff value: 2.2℃) differentiated RP patients from controls (sensitivity/specificity: 67/60%, respectively). Temperature differences of first toe (cutoff value: 3.11℃) also discriminated RP patients (sensitivity/specificity: about 73/66%, respectively). A combination of thermographic assessment of the coolest finger and first toe was highly effective in men (sensitivity/specificity : about 88/60%, respectively) while thermographic assessment of first toe was solely sufficient for women (sensitivity/specificity: about 74/68%, respectively). Thermographic assessment of the coolest finger and first toe is useful for diagnosing RP. In women, thermography of first toe is highly recommended.

Association among Working Hours, Occupational Stress, and Presenteeism among Wage Workers: Results from the Second Korean Working Conditions Survey

Objectives

The purpose of the present study was to identify the association between presenteeism and long working hours, shiftwork, and occupational stress using representative national survey data on Korean workers.

Methods

We analyzed data from the second Korean Working Conditions Survey (KWCS), which was conducted in 2010, in which a total of 6,220 wage workers were analyzed. The study population included the economically active population aged above 15 years, and living in the Republic of Korea. We used the chi-squared test and multivariate logistic regression to test the statistical association between presenteeism and working hours, shiftwork, and occupational stress.

Results

Approximately 19% of the workers experienced presenteeism during the previous 12 months. Women had higher rates of presenteeism than men. We found a statistically significant dose–response relationship between working hours and presenteeism. Shift workers had a slightly higher rate of presenteeism than non-shift workers, but the difference was not statistically significant. Occupational stress, such as high job demand, lack of rewards, and inadequate social support, had a significant association with presenteeism.

Conclusions

The present study suggests that long working hours and occupational stress are significantly related to presenteeism.

Workplace injustice and self-reported disease and absenteeism in South Korea

BACKGROUND

This study investigated whether experience of workplace injustice was associated with self-reported occupational health using a nationally representative sample of Korean workers.

METHODS

We used the first wave of the Korean Working Conditions Survey (KWCS) and included 7,007 wage employees as the study population. Workplace injustice included the experience of discrimination, violence, or harassment, and occupational health was measured as self-reported health problems and absenteeism. Personal, occupational, and job-related characteristics were included as covariates.

RESULTS

An average of 7.2% of workers reported experiencing at least one workplace injustice over the past 12 months. Female workers were significantly more likely to experience age and gender discrimination, and unwanted sexual attention than male workers. Both male and female workers who experienced any workplace injustice (i.e., discrimination, harassment, or violence) reported approximately two- to threefold increased risk for physical and mental health problems (i.e., backaches, muscular pain, stomach pain, overall fatigue, headaches, anxiety/depression, sleeping problems, and injury) and absenteeism due to accidents or due to health problems.

CONCLUSION

Perceived injustice at work was significantly associated with an increased risk of occupational disease and absenteeism for Korean wage employees.

Association between Workplace Risk Factor Exposure and Sleep Disturbance: Analysis of the 2nd Korean Working Conditions Survey

OBJECTIVES

Sleep is essential for human beings to live and work properly. This study was conducted to investigate the relationship between occupational exposures to workplace risk factors and sleep disturbance in Korean workers.

METHODS

The data were drawn from the second Korean Working Conditions Survey (KWCS); a total of 7,112 paid workers were analyzed. The independent variables were occupational exposures such as physical, chemical, biological, and psychosocial risk factor in the workplace, and psychosocial risk factor was divided into five categories (job demand, job control, social support, job insecurity, lack of reward). We estimated the relationship between various occupational exposures and sleep disturbance using multivariate logistic regression analysis.

RESULTS

The results showed that people who exposed to physical, chemical, biological, and psychosocial (high job demand, inadequate social support, lack of reward) risk factors were more likely to increase the risk of sleep disturbance. Furthermore, after adjusting for general and occupational characteristics, we found significant positive associations between exposures to physical (odds ratios [OR] 1.47, 95% confidence interval [CI] 1.05-2.07) and psychosocial (high job demand (OR 2.93, 95% CI 2.16-3.98), inadequate social support (OR 1.57, 95% CI 1.14-2.15), lack of reward (OR 1.45, 95% CI 1.08-1.96)) risk factors and sleep disturbance.

CONCLUSION

These results suggest that occupational exposures to physical and psychosocial workplace risk factors are significantly related to sleep disturbance.

Long working hours and emotional well-being in korean manufacturing industry employees

Objectives

Korea is well known for its long work hours amongst employees. Because workers of the manufacturing industry are constantly exposed to extended work hours, this study was based on how long work hours affect their emotional well-being.

Methods

The analysis was done using the secondary Korean Working Condition Survey (KWCS). Long work hours were defined to be more than 48 hours, and they were subcategorized into units of 52 hours and 60 hours. Based on the WHO (five) well-being index, emotional state was subdivided into three groups - reference group, low-mood group, and possible depression group- where 28 points and 50 points were division points, and two groups were compared at a time. Association between long work hours and emotional state was analyzed using binary and multinomial logistic regression analysis.

Results

Working for extended working hours in the manufacturing industry showed a statistically significant increase (t test p < 0.001) in trend among the possible depression group when compared to the reference group and the low-mood group. When demographical characteristics, health behaviors, socioeconomic state, and work-related characteristics were fixed as controlled variables, as work hours increased the odds ratio of the possible depression group increased compared to the reference group, and especially the odds ratio was 2.73 times increased for work hours between 48–52 and 4.09 times increased for 60 hours or more and both were statistically significant. In comparing the low-mood group and possible depression group, as work hours increased the odds ratio increased to 1.73, 2.39, and 4.16 times, and all work hours from working 48–52 hours, 53–60 hours, and 60 hours or more were statistically significant. Multinomial logistic regression analysis also showed that among the reference group and possible group, the possible depression group was statistically significant as odds ratio increased to 2.94 times in working 53–60 hours, and 4.35 times in 60 hours or more.

Conclusions

Long work hours have an adverse effect on emotional well-being. A more diversified research towards variables that affect long work hours and emotional well-being and how they interact with each other and their relationship to overall health is imperative.

Relationship between chewing ability and depressive symptoms

OBJECTIVE

Depression, as one of the most common mental health problems, has many related factors. Recent studies have suggested chewing difficulties as a risk factor for depression in the elderly. This study seeks to investigate whether chewing ability is associated with depressive symptoms in a Korean population.

METHODS

This study used data from the Fifth Korean National Health and Nutrition Examination Survey (KNHANES V) conducted in 2010. Self-reported questionnaires assessed depressive symptoms and chewing ability for the purposes of this study. A total of 6,255 subjects aged over 19 years were included for this study (2,704 males and 3,551 females).

RESULTS

Comparing depressive symptoms with chewing ability (i.e., very poor, poor, moderate, good, and very good), the adjusted odds ratios (ORs) and confidence intervals (CI) were 1.05 (95% CI: 0.84-1.32) for good vs. very good (as a reference), 1.31 (95% CI: 1.00-1.73) for moderate vs. very good, 1.41 (95% CI: 1.12-1.78) for poor vs. very good, and 1.76 (95% CI: 1.16-2.76) for very poor vs. very good.

CONCLUSION

This study suggests that subjects with reduced chewing ability were more susceptible to having depressive symptoms.

Working hours and cardiovascular disease in Korean workers: a case-control study

OBJECTIVES

Long working hours can negatively impact a worker's health. The objective of this study was to examine the association between working hours and cardiovascular diseases (CVDs) and compare the degree of risk based on CVD subtypes in Korean workers.

METHODS

This study was a case-control study of the patients registered in the Occupational Cardiovascular Diseases Surveillance 2010. The cases included 348 patients diagnosed with a CVD (123 cerebral infarction, 69 intracerebral hemorrhage, 57 subarachnoid hemorrhage, 99 acute myocardial infarction). Controls were 769 participants with no history of CVDs matched for gender, age, type of occupation, and region. Participants' working hours in the previous week and the average working hours over the past three months were assessed to examine short-term and long-term effects.

RESULTS

After adjusting for confounding factors, the odds ratios (ORs) for CVDs in the short-term were 2.66 (95% Confidence interval (CI) :1.78-3.99) for working ≤40 hours, 1.85 (95% CI: 1.22-2.81) for working 50.1-60 hours and 4.23 (95% CI: 2.81-6.39) for working >60 hours compared with the 40.1-50-hour working group. The ORs in the long-term were 2.90 (95% CI: 1.86-4.52) for working ≤40 hours, 1.73 (95% CI: 1.03-2.90) for working 48.1-52 hours and 3.46 (95% CI: 2.38-5.03) for working >52 hours compared with the 40.1-48-hour working group.

CONCLUSIONS

Long working hours are related to an increased risk of CVDs, and the degree of risk differs based on CVD subtype. Short working hours are also related to an increased risk for CVDs. More prospective studies targeting specific disease risks are required.

Estimation of maximal oxygen uptake without exercise testing in Korean healthy adult workers

Maximal oxygen uptake is generally accepted as the most valid and reliable index of cardiorespiratory fitness and functional aerobic capacity. The exercise test for measuring maximal oxygen uptake is unsuitable for screening tests in public heath examinations, because of the potential risks of exercise exertion and time demands. We designed this study to determine whether work-related physical activity is a potential predictor of maximal oxygen uptake, and to develop a maximal oxygen uptake equation using a non-exercise regression model for the cardiorespiratory fitness test in Korean adult workers. Study subjects were adult workers of small-sized companies in Korea. Subjects with history of disease such as hypertension, diabetes, asthma and angina were excluded. In total, 217 adult subjects (113 men of 21-55 years old and 104 women of 20-64 years old) were included. Self-report questionnaire survey was conducted on study subjects, and maximal oxygen uptake of each subject was measured with the exercise test. The statistical analysis was carried out to develop an equation for estimating maximal oxygen uptake. The predictors for estimating maximal oxygen uptake included age, gender, body mass index, smoking, leisure-time physical activity and the factors representing work-related physical activity. The work-related physical activity was identified to be a predictor of maximal oxygen uptake. Moreover, the equation showed high validity according to the statistical analysis. The equation for estimating maximal oxygen uptake developed in the present study could be used as a screening test for assessing cardiorespiratory fitness in Korean adult workers.

Secondhand smoke exposure and osteoporosis in never-smoking postmenopausal women: the Fourth Korea National Health and Nutrition Examination Survey

SUMMARY

The association between secondhand smoke (SHS) exposure and lumbar and femoral neck osteoporosis was assessed in postmenopausal never-smoking Korean women. The presence of family members who actively smoked was associated with femoral neck osteoporosis. The number of cigarettes consumed by cohabitant smokers was positively associated with lumbar and femoral neck osteoporosis.

INTRODUCTION

This study aimed to assess the association between SHS and postmenopausal osteoporosis.

METHODS

Of 2,067 postmenopausal women (age, ≥55 years) participating in the Fourth Korea National Health and Nutrition Examination Survey, 925 never-smokers identified through interviews and urinary cotinine level verification were enrolled. Cross-sectional relationships between self-reported SHS exposure and osteoporosis of the lumbar vertebrae and femoral neck (defined using the World Health Organization T-score criteria) were investigated by bone densitometry.

RESULTS

Participants having actively smoking family members showed increased adjusted odds ratio (aOR) for femoral neck osteoporosis compared with participants not exposed to SHS (aOR, 3.68; 95 % confidence interval [CI], 1.23-10.92). Participants whose cohabitant smokers consumed any number of cigarettes per day showed increased occurrences for lumbar and femoral neck osteoporosis compared with the nonexposed group. Participants whose cohabitant smokers consumed ≥20 cigarettes/day showed increased aORs for lumbar (aOR, 5.40; 95 % CI, 1.04-28.04) and femoral neck (aOR, 4.35; 95 % CI, 1.07-17.68) osteoporosis compared with participants not exposed to SHS.

CONCLUSIONS

In postmenopausal never-smoking Korean women, exposure to SHS was positively associated with osteoporosis. This finding further emphasizes a need to identify vulnerable groups exposed to SHS to increase bone health.

Depressive symptoms as a risk factor for the common cold among employees: a 4-month follow-up study

OBJECTIVE

The purpose of this study was to investigate the correlation between symptoms of depression in workers and the common cold.

METHODS

A follow-up survey of workers at 44 small- to medium-sized companies was conducted; 1350 questionnaires were used in the final analysis. The first survey requested information regarding personal information, work characteristics and symptoms of depression (Center for Epidemiologic Studies Depression Scale); the second survey queried participants who answered the first survey about manifestations of the common cold during the previous four months. Odds ratios (ORs) were calculated using a logistic regression model, which was adjusted for potential confounders. All analyses were stratified according to gender separately.

RESULTS

The ORs for reporting symptoms of the common cold were 1.36 (95% confidence interval [CI]: 1.01-1.83) and 2.27 (95% CI: 1.49-3.45) in males and females, respectively. When adjusted for age, marital status, educational level, smoking habits, alcohol consumption, exercise, sleep duration and job type, the ORs remained significant for both genders (male: 1.38; 95% CI: 1.01-1.89; female: 2.08; 95% CI: 1.32-3.23).

CONCLUSIONS

The risk of self-reported manifestations of the common cold was higher in workers who reported symptoms of depression.

Association between job stress and insomnia in Korean workers

OBJECTIVE

We investigated the association between job stress and insomnia in a large nationwide samples of Korean workers.

METHODS

In this cross-sectional study, a total of 8,155 workers from a nationwide sample were recruited. We surveyed the subjects' socio-demographic and work-related characteristics and seven subscales of occupational stress using the Korean Occupational Stress Scale Short Form. Each subscales of job stress was dichotomized into higher or lower group by respective median scores. Insomnia was defined as having at least one of the three sleep symptoms. we performed multivariate logistic regression analysis to identify association between job stress and insomnia.

RESULTS

We found that individuals with relatively high job stress experienced insomnia significantly more frequently, and the significance was maintained even after adjustment for confounding variables(high job demand: OR: 1.30, 95% CI: 1.14-1.47; insufficient job control: OR: 1.13, 95% CI: 0.99-1.29; inadequate social support: OR: 1.30, 95% CI: 1.14-1.47; job insecurity: OR: 1.25, 95% CI: 1.11-1.44; organizational injustice: OR: 1.27, 95% CI: 1.12-1.44; lack of reward: OR: 1.18, 95% CI: 1.04-1.34; discomfort in occupational climate: OR: 1.38, 95% CI: 1.22-1.57; total job stress: OR: 1.45, 95% CI: 1.28-1.64).

CONCLUSION

This study suggested that job stress is possible risk factor for insomnia and that particularly discomfort in occupational climate and inadequate social support have more strong relation to insomnia in Korea.

Acute effects of intravenous administration of pamidronate in patients with osteoporosis

We investigated acute effects of intermittent large dose bisphosphonate therapy in osteoporotic patients. Peripheral blood mononuclear cells were incubated with alendronate (100 microM) for 18 hr, in vitro and cytokine expressions were measured by real-time RT-PCR. Pamidronate 30 mg was administered on 26 osteoporotic patients; and acute phase reactants, inflammatory cytokines and bone biomarkers were measured. The in vitro study showed significant increase in mRNA expression of IL-6, TNF-alpha and IFN-gamma. A notable rise in serum C-reactive protein (CRP) was observed over 3 days after pamidronate infusion (P=0.026). Serum levels of TNF-alpha, IL-6 and IFN-gamma were also significantly increased (P=0.009, 0.014, 0.035, respectively) and the increase in IL-6 levels were strongly correlated with CRP levels (P=0.04). Serum calcium and c-telopeptide levels rapidly decreased after the treatment (P=0.02, <0.001, respectively). This study showed that mRNA expression of inflammatory cytokines at peripheral blood mononuclear cells (PBMC) level were observed within 18 hr and marked elevation of inflammatory cytokines and acute phase reactants were demonstrated after pamidronate infusion at the dose for osteoporosis. Our studies confirmed that intermittent large dose aminobisphosphonate causes acute inflammation.

Changes in occupational safety and health indices after the Korean economic crisis: analysis of a national sample, 1991-2007

We examined how the deregulation of South Korea's labor laws during the country's 1997 to 1998 economic crisis affected occupational safety and health. Although the economic index improved after the reforms, the total injury rate declined slowly and the incidence of occupational disease increased. The withdrawal of support for occupational safety and health is likely to have a sustained effect on public health.

Job strain and the risk for occupational injury in small- to medium-sized manufacturing enterprises: a prospective study of 1,209 Korean employees

BACKGROUND

The aim of this study was to investigate whether job strain had an effect on the risk of occupational injury of workers at small- to medium-sized manufacturing companies.

METHODS

We conducted a prospective follow-up survey and finally 1,209 workers in South Korea were included in this study. At time X1, we measured job stress with the Job Demand and Decision Latitude Questionnaire; and at time X2 (after 6 months), we evaluated occupational injuries through a single question. Occupational injuries were assessed using the question "Have you ever been injured at work, including minor scratches and cuts, in the previous four-month period" by self-reporting in the previous 4-month period.

RESULTS

For men, the high job-demand group (OR = 1.71, 95% CI = 1.13-2.59) and high strain group (OR = 1.79, 95% CI = 1.02-3.14) showed the increased risk of occupational injury. For women, high job-demand (OR = 2.11, 95% CI = 1.18-3.78), low job control (OR = 1.80, 95% CI = 1.02-3.17), and high job strain (OR = 3.57, 95% CI = 1.62-7.86) were significantly associated with occupational injury.

CONCLUSION

Workers under high job strain showed higher risk for occupational injury. The efforts to minimize stress-related occupational injuries should be required.

Depressive symptoms and self-reported occupational injury in small and medium-sized companies

OBJECTIVES

This survey was designed to determine whether depressive symptoms had an effect on the risk of self-reported occupational injury in South Korea.

METHODS

We conducted a prospective follow-up survey of workers at 44 small- to medium-sized companies classified into manufacturing or service businesses; 1,350 questionnaires were used in the final analysis. The first survey requested information regarding personal characteristics, work characteristics, and depressive symptoms (CES-D); the second survey queried participants in the first survey about self-reported occupational injuries (including minor scratches or cuts) experienced in the previous 4 months. Risk ratios (RRs) were calculated through Poisson regression analysis. The number of occupational injuries during the previous 4 months served as the dependent variable, and depressive symptoms served as the independent variable.

RESULTS

After adjustment for demographic factors, the RRs were 1.75 (95% CI: 1.41-2.18) and 2.68 (95% CI: 1.98-3.64) in male and female, respectively. Additional adjustment for work-related variables did not alter the RR considerably in females (2.65; 95% CI: 1.95-3.59). Among the male workers, however, the RR was not significant (1.21; 95% CI: 0.95-1.55). On the other hand, when the analysis was limited to blue-collar workers, after adjustment for demographic and work-related factors, the RRs remained significant in both genders (male: 1.34; 95% CI: 1.03-1.74; female: 2.04; 95% CI: 1.41-2.95).

CONCLUSIONS

We found that the risk of self-reported occupational injury experience was higher in workers who reported depressive symptoms. Additional study using objective data is required to confirm our results.

Job stress and depressive symptoms among Korean employees: the effects of culture on work

OBJECTIVE

This study was conducted to investigate the association between depressive symptoms and job stress, as measured by the KOSS, among Korean employees in small- and medium-sized enterprises, and examined which components of stress are involved in the risk for depression among males and females.

METHODS

Data were collected from a work-stress survey of full-time employees of small- and medium-sized enterprises in Incheon, South Korea. A total of 3,013 participants were included in the analysis. Job stress was measured using 24 items (7 sub-scales) of the short form of Korean occupational stress scale (KOSS-SF), and depressive symptoms were evaluated using Center for epidemiologic studies depression scale (CES-D).

RESULTS

After adjustment for confounding variables, most of subscales of job stress contributed to an increased risk of depressive symptoms, and job insecurity (male; OR = 2.02, 95%CI: 1.61-2.40, female; OR = 1.95, 95%CI: 1.42-2.70) and occupational climate (male; OR = 1.84, 95%CI: 1.49-2.28, female; OR = 1.78, 95%CI: 1.30-2.49) showed strong associations in both male and female. Other subscales revealed different effects for males and females; for males, job demands (OR = 1.68, 95%CI: 1.43-2.20), inadequate social support (OR = 1.55, 95%CI: 1.23-1.94), and lack of rewards (OR = 1.88, 95%CI: 1.48-2.37) were associated with depressive symptoms, whereas for females, organizational injustice (OR = 1.62, 95%CI: 1.14-2.30) was associated with depressive symptoms.

CONCLUSION

These results indicate that job stress may play a significant role in increasing the risk of depressive symptoms, and that further preventive efforts and research are needed to reduce job stress and address health problems caused by job stress among Korean employees.

G1 to S phase transition protein 1 induces apoptosis signal-regulating kinase 1 activation by dissociating 14-3-3 from ASK1

Apoptosis signal-regulating kinase 1 (ASK1), a member of the mitogen-activated protein kinase kinase kinase family, plays a critical role in mediating apoptosis signals initiated by a variety of death stimuli such as hydrogen peroxide and tumor necrosis factor-alpha. Owing to its critical role in inducing apoptosis, the activity of ASK1 is tightly regulated by various mechanisms such as post-translational modifications and protein-protein interactions. Here we describe the identification of G(1) to S phase transition protein 1 (GSPT1), which is associated with protein translation, as a regulator of ASK1. GSPT1 interacts with ASK1 and enhances ASK1-induced apoptotic activity through the activation of caspase-3. In vitro kinase assay data show that GSPT1 enhances ASK1 autophosphorylation and its kinase activity. Cell cycle-dependent GSPT1 induction and small interfering RNA analyses show that ASK1 autophosphorylation is dependent on the expression level of endogenous GSPT1 in cells. GSPT1 inhibits the binding of ASK1 to the 14-3-3 protein, an ASK1 inhibitor, while GSPT1 has no effect on the interaction between ASK1 and TRAF2, a C-terminal-binding activator of ASK1. Thus, our results reveal a novel role of GSPT1 in the regulation of ASK1-mediated apoptosis.

A promoter nucleotide variant of the dendritic cell-specific DCNP1 associates with serum IgE levels specific for dust mite allergens among the Korean asthmatics

Dendritic cells (DCs), the most abundant antigen-presenting cells in the lung, have been drawing attention for their roles in specific allergic responses to aeroallergens with support of Th lymphocytes, and in persistent inflammatory changes in allergic asthma. To identify genetic factors that may be involved in the asthma susceptibility and development of the disease phenotypes, we examined association of DC-specific DCNP1 polymorphisms with the disease risk. The case-control study revealed association of the nucleotide variants with serum immunoglobulin E (IgE) levels specific for Dermatophagoides farinae (Der f 1) and Dermatophagoides pteronyssinus (Der p 1), major aeroallergens of dust mites, among subjects with asthma. In particular, the T-allele-carrying genotype frequencies for one of the variants (c.-1289C>T) located in the promoter region were found increased in the asthmatic group with low levels of the mite-specific IgE (odds ratio (OR)=0.63 (0.48-0.83) for Der p 1). Results from functional analyses indicated that the promoter variant would affect the gene expression by modulating DNA-protein interaction. We propose that the genetic polymorphism of DCNP1 may influence production of specific IgE by altering DC functions in the mite allergen presenting and/or processing. The functional relevance of the genetic variation would provide an important insight into the genetic basis of allergic response to the mite antigens.

GSTM1 and GSTP1 polymorphisms as potential factors for modifying the effect of smoking on inflammatory response

Inflammation has been known to be an important underlying condition for development of various diseases including cancer. The aims of this study were to investigate whether tobacco smoke exposure increases the level of inflammation biomarkers and the GSTM1 and GSTP1 gene polymorphisms are associated with inflammatory response due to tobacco smoke exposure. We measured urinary cotinine level in 300 healthy university students. Total serum TNF-alpha levels and blood WBC counts were determined to evaluate inflammatory response. Allelic loss of the GSTM1 and the GSTP1 (Ile105Val) polymorphism were determined by PCR and RFLP. Tobacco smoke exposure was found to be associated with increase of both TNF-alpha level and WBC count. Particularly, smokers with combination of GSTM1 null and GSTP1 AG or GG genotypes showed higher TNF-alpha level than those with the other genotype combinations (p=0.07). This result suggests that smoking may induce inflammation measured as TNF-alpha level or WBC count and combinations of the GSTM1 and GSTP1 polymorphisms may modify the effect of smoking on serum TNF-alpha level.

[Serum gamma-glutamyltransferase levels and the risks of impaired fasting glucose in healthy men: a 2-year follow-up]

OBJECTIVES

An increase in the serum gamma-glutamyltransferase (GGT) concentration has been regarded as a marker of alcohol drinking or liver disease. Some reports, however, have suggested that the serum GGT may be a sensitive and early biomarker for the development of prediabetes and diabetes. In this study we investigated whether serum GGT is a reliable predictor of the incident impaired fasting glucose (IFG), including diabetes.

METHODS

We performed a prospective study for two years (2002-2004). We analyzed the periodic health examination data from a total of 4,711 men. The examinations were done in the years 2002 and 2004. The analyzed data included a self-questionnaire, a physical examination and the laboratory results. Both IFG and diabetes were defined as a serum fasting glucose concentration of more than 100 mg/dL and 126 mg/dL, respectively.

RESULTS

A total of 738 cases (15.7%) of incident IFG and 13 cases (0.3%) of diabetes occurred. The mean serum GGT concentrations were quite different between the normal (38.0 IU) and incident IFG groups (50.3 IU), and the incident diabetes group (66.0 IU) (p <0.001). After multivariable adjustment, the relative risks for incident IFG or diabetes across the baseline GGT categories (<10th, 10th-20th, 30th-40th, 50th-60th, 70th-80th and >90th percentile) were 1.0, 1.172 (0.769-1.785), 1.107 (0.725-1.689), 1.444 (0.934-2.232), 2.061 (1.401-3.031) and 2.545 (1.784-3.631) (p-value for trend: <0.001). The risks significantly increased with increasing levels of GGT for 2 years; when comparing the increased groups (<10%, .10-20%, >20%) versus the decreased over 20% group of GGT, the risks for IFG or diabetes were 1.334 (1.002-1.776), 1.613 (1.183-2.199) and 1.399 (1.092-1.794).

CONCLUSIONS

Our findings suggest that serum GGT concentrations within its normal range may be an early predictor of the development of IFG and diabetes. As serum GGT is a relatively inexpensive test and a reliable marker, it might have important implications in public health promotion.