Sang-Hee Hwang

Association between Job Stress and Insomnia in Korean Workers

Association between Job Stress and Insomnia in Korean Workers: Hwan‐Cheol Kim, et al. Department of Occupational and Environmental Medicine, Inha University Hospital, Korea—

Aspirin induces apoptosis in YD-8 human oral squamous carcinoma cells through activation of caspases, down-regulation of Mcl-1, and inactivation of ERK-1/2 and AKT.

NSAIDs and COX-2 inhibitors show anti-cancer activities in many cancer cells. In this study, we investigated the effects of NSAIDs (aspirin or indomethacin) and COX-2 inhibitor (NS-398) on growth of YD-8 human oral squamous carcinoma cells. Interestingly, among drugs tested, aspirin showed strongest inhibitory effects on viability and survival of YD-8 cells. Profoundly, aspirin treatment resulted in severe cell shrinkage and nuclear DNA fragmentation in YD-8 cells, suggesting the aspirin-induced apoptosis in YD-8 cells. Data of Western blot further demonstrated that aspirin treatment caused activation of caspases, down-regulation of Mcl-1 protein, dephosphorylation of ERK-1/2 and AKT, and also IkappaB-alpha proteolysis-dependent NF-kappaB activation in YD-8 cells. Aspirin, however, had no effect on expressions of Bcl-2, XIAP, and HIAP-1 in YD-8 cells. Importantly, pretreatment with z-VAD-fmk, a pan-caspase inhibitor blocked the aspirin-induced apoptosis and Mcl-1 down-regulation in YD-8 cells. These findings collectively suggest that aspirin induces apoptosis in YD-8 cells and the induction may be correlated to activation of caspases, caspase-dependent Mcl-1 proteolysis, inactivation of ERK-1/2 and AKT, and activation of NF-kappaB. It is suggested that aspirin may be applied a potential anti-cancer drug against human oral squamous carcinoma.

Low Serum 25-Hydroxyvitamin D Levels Are Associated with Dry Eye Syndrome

Background Dry eye syndrome (DES) is a common tear film and ocular surface disease that results in discomfort, visual disturbance, and tear film instability with potential damage to the ocular surface. Systemic diseases associated with DES include diabetes mellitus, rheumatoid arthritis, depression, anxiety, thyroid disease, allergic diseases, irritable bowel syndrome, chronic pain syndrome, and hyperlipidemia. Interestingly, it has been found that most of these are associated with low levels of serum 25-hydroxyvitamin D (25(OH)D) or inadequate sunlight exposure. Methods In this cross-sectional data analysis, noninstitutionalized adults aged ≥19 years (N = 17,542) who participated in Korean National Health and Nutrition Examination Survey 2010–2012 were included. Information regarding duration of sunlight exposure was collected from the survey participants. Serum 25(OH)D and zinc levels were measured. The confounding variables were age, gender, sunlight exposure time, region of residence, obesity, serum 25(OH)D level, diabetes mellitus, rheumatoid arthritis, depression, thyroid disorder, atopic dermatitis, history of ocular surgery, regular exercise, and walking exercise. Results Mean serum 25(OH)D levels of subjects with and without DES were 16.90 ± 6.0 and 17.52 ± 6.07 (p<0.001). Inadequate sunlight exposure time (odds ratio [OR], 1.554; 95% confidence interval [CI], 1.307–1.848), urban residence (OR, 1.669; 95% CI, 1.456–1.913), indoor occupation (OR, 1.578; 95% CI, 1.389–1.814), and low serum 25(OH)D level (OR, 1.158; 95% CI, 1.026–1.308) were the risk factors for DES. After adjusting for age, sex, obesity, diabetes mellitus, rheumatoid arthritis, depression, thyroid disorder, atopic dermatitis, history of ocular surgery, regular exercise, and occupation, low serum 25(OH)D level (OR, 1.178; 95% CI, 1.010–1.372) and deficient sunlight exposure time (OR, 1.383; 95% CI, 1.094–1.749) were the risk factors for diagnosed DES. Conclusion Low serum 25(OH)D levels and inadequate sunlight exposure are associated with DES in Korean adults. These results suggest that sufficient sunlight exposure or vitamin D supplementation may be useful in DES treatment.

A prospective study of work stressors and the common cold

BACKGROUND Psychological stress is a risk factor for infectious diseases. Although psychological stress at work is considered an important problem for many workers, there is little evidence for the effect of work-related stress on infectious diseases. AIMS To investigate whether work-related stress affected the occurrence of the common cold in South Korean workers in small- to medium-sized manufacturing companies. METHODS We conducted a prospective study, involving 1241 workers. At the outset, we collected information regarding sociodemographic and work characteristics. At follow-up after 6 months, we asked subjects whether they had experienced common cold symptoms during the preceding 4 months. RESULTS Male subjects experiencing stress at the outset were more likely to report having experienced the common cold at follow-up (odds ratios: high job demand group 1.74; 95% CI: 1.28-2.36; insufficient job control 1.42; 95% CI: 1.05-1.93; inadequate social support 1.40; 95% CI: 1.03-1.91). For females, no significant association between work stress and occurrence of the common cold was detected. CONCLUSIONS Males experiencing work stress in job demand, job control and social support reported an increased occurrence of the common cold at follow-up but this association was not seen in females.

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.