Sung-Soo Oh

Preliminary report: A serious link between adiponectin levels and metabolic syndrome in a Korean nondiabetic population

This large-scale cross-sectional investigation highlights the relationships between adiponectin levels and a number of metabolic syndrome components in a nondiabetic Korean population (N = 6634). In a multivariate logistic regression model, after adjustment for age, homeostasis model assessment of insulin resistance, body mass index, smoking history, C-reactive protein, and low-density lipoprotein cholesterol, adiponectin levels were inversely related with metabolic syndrome in men and women (P < .05). Adiponectin level was found to be a significant contributor to metabolic syndrome. Our findings suggest that adiponectin is an important biomarker even in a nondiabetic population at high risk of metabolic syndrome.

A decade of malignant mesothelioma surveillance in Korea

BACKGROUND The objectives of this study were to examine trends in mesothelioma incidence over a decade and to identify histories of asbestos exposure among cases in Korea. METHODS In 2001, The Korea Occupational Safety and Health Agency organized a nationwide cardiopulmonary pathology group and established a malignant mesothelioma surveillance system covering all general hospitals in Korea. Mesothelioma cases were reported to this surveillance system with information about age, gender, location, occupational history, asbestos exposure environment, date of diagnosis, diagnostic method, histopathologic subtype, occurrence site, and other clinical information. Additionally, an epidemiological survey was conducted using a structured verbal questionnaire to allow further evaluation of asbestos exposures. RESULTS A total of 399 cases of malignant mesothelioma were reported in the last decade, translating to approximately 40 annual cases, and an annual average incidence rate of 0.83 cases per million. Of the 152 patients interviewed by occupational physicians, 56 had occupational asbestos exposure histories (36.8%). Their occupations and industries included construction (19.7%), automobile repair (5.9%), asbestos textile, shipbuilding and repair, refinery work, boiler making, and asbestos cement work. Another 31 patients had environmental asbestos exposure histories. CONCLUSIONS Surveillance data indicate that malignant mesothelioma incidence in Korea is, thus far, lower than that of other developed countries, and that construction and environmental asbestos exposure were the main identifiable causes of malignant mesothelioma.

Prevention of Work-Related Musculoskeletal Disorders

Editorial Work-related musculoskeletal disorders (WMSDs) constitute a major component of occupational diseases (ODs), accounting for approximately 38.1% of all ODs in Europe [1] and approximately 70% of all compensated ODs in Korea [2]. According to a recent European Union report, WMSDs tend to be underreported and are tending to increase among women, young, and migrant workers. The costs for upper extremity WMSDs alone rage from 0.5 to 3.8% of gross national product [3]. In the United States, costs for compensation, wage loss, and production loss range from 45–54 billion US dollors [4]. Research to prevent these highly costly WMSDs is being conducted in various fields including epidemiology, physiology, ergonomics, biomechanics, molegular biology, and genetics and to tackle such issues as return to work, rehabilitation, policy and compensation. One of the most important avenues of communication for these research efforts is the Intenational Conference on Prevention of Work-related Musculoskeletal Disorders (PREMUS). There are 35 active scientific committees in the International Commission on Occupational Health, and the Musculoskeletal Disorder Committee has held an international conference every 3 years under the name of PREMUS. The most recent PREMUS conference was held in Busan, Korea on July 7–11, 2013. It was the first time that PREMUS was organized outside of North America or Europe. Attending pariticipants were 290 scholars from 30 conutries all over the world, including 11 Asian countries. Among the many papers presented at the conference, 10 describing the spectrum of WMSDs research around world were chosen to public in AOEM. The study by Nur Azmar et al. shows the prevalence and psychosocial risk factors for WMSDs among Malaysian

Dermatological features in Behçet disease‐associated vena cava obstruction

Background  Behçet disease (BD) is a multisystemic disorder that is classified as vasculitis and can affect all types and sizes of blood vessels. Although vascular diseases are not regarded as essential for a diagnosis of BD, vascular complications can be fatal.

Transforming growth factor-β gene silencing using adenovirus expressing TGF-β1 or TGF-β2 shRNA

Tumor cells secrete a variety of cytokines to outgrow and evade host immune surveillance. In this context, transforming growth factor-β1 (TGF-β1) is an extremely interesting cytokine because it has biphasic effects in cancer cells and normal cells. TGF-β1 acts as a growth inhibitor in normal cells, whereas it promotes tumor growth and progression in tumor cells. Overexpression of TGF-β1 in tumor cells also provides additional oncogenic activities by circumventing the host immune surveillance. Therefore, this study ultimately aimed to test the hypothesis that suppression of TGF-β1 in tumor cells by RNA interference can have antitumorigenic effects. However, we demonstrated here that the interrelation between TGF-β isotypes should be carefully considered for the antitumor effect in addition to the selection of target sequences with highest efficacy. The target sequences were proven to be highly specific and effective for suppressing both TGF-β1 mRNA and protein expression in cells after infection with an adenovirus expressing TGF-β1 short hairpin RNA (shRNA). A single base pair change in the shRNA sequence completely abrogated the suppressive effect on TGF-β1. Surprisingly, the suppression of TGF-β1 induced TGF-β3 upregulation, and the suppression of TGF-β2 induced another unexpected downregulation of both TGF-β1 and TGF-β3. Taken together, this information may prove useful when considering the design for a novel cancer immunogene therapy.

The clustering patterns of metabolic risk factors and its association with sub-clinical atherosclerosis in Korean population

Background and aims: Metabolic syndrome (MetS) is considered to be an insulin-resistance syndrome, but recent evidence suggests that MetS has multiple physiological origins which may be related to atherosclerosis. This study investigated clustering patterns of metabolic risk factors and its association with sub-clinical atherosclerosis. Subjects and methods: This study used factor analysis of 11 metabolic factors in 1374 individuals to define clustering patterns and determine their association with carotid intima-media thickness (CIMT). Eleven metabolic factors were used: body mass index (BMI), waist circumference (WC), systolic blood pressure (SBP), diastolic blood pressure (DBP), fasting blood glucose (FBG), fasting blood insulin (FBI), serum triglyceride (TG), high-density lipoprotein cholesterol (HDL-C), homeostasis model assessment-insulin resistance (HOMA-IR), high-sensitivity C-reactive protein (hsCRP) and adiponectin. Two regression analyses were done, the first using individual metabolic variables and the second using each factor from the factor analysis to evaluate their relationships with CIMT. Results: Four clustering patterns, insulin-resistance factor (FBG, FBI, HOMA-IR), obesity-inflammatory factor (BMI, WC, hsCRP), blood pressure factor (SBP, DBP) and lipid metabolic factor (HDL-C, TG, adiponectin) were categorized. In a multivariate regression model after adjustment for age, sex, low-density lipoprotein cholesterol and smoking history (pack year), insulin resistance factor (B = 11.09, p = 0.026), obesity-inflammatory factor (B = 18.50, p < 0.001), blood pressure factor (B = 12.84, p = 0.010) and lipid metabolic factor (B = − 11.55, p = 0.023) were found to be significantly associated with CIMT. Conclusion: In conclusion, metabolic risk factors have four distinct clustering patterns that are independently associated with sub-clinical atherosclerosis.

Impact of HMGB1 on melanocytic survival and its involvement in the pathogenesis of vitiligo.

Vitiligo is attributable to loss of functional melanocytes and is the most common acquired depigmenting disorder. Oxidative stress and intense ultraviolet irradiation are known to aggravate this condition. The nonhistone high‐mobility group box 1 (HMGB1) DNA‐binding protein is a physiological activator of immune responses, cellular proliferation and cell death. Although it is implicated in the pathogenesis of autoimmune diseases and cutaneous disorders, the precise role of HMGB1 in melanocytes has yet to be studied.

Radon exposure and lung cancer: risk in nonsmokers among cohort studies

Eleven cohorts of miners occupationally exposed to relatively high concentrations of radon showed a statistically significantly high risk of lung cancer, while three cohorts from the general population showed a relatively low concentration, but the results were not statistically significant. However, the risk of lung cancer tended to increase with increased radon exposure. The risk is likely to have been underestimated due to low statistical power. Therefore, additional well-designed studies on the risk of lung cancer in nonsmokers in the general population with relatively low concentrations of radon exposure are needed in the future.In addition, country-specific preventive policies are needed in order to actively reduce radon exposure and lung cancer incidence in nonsmokers.

Trends in research on indoor radon exposure and lung cancer in South Korea

Editorial Radon is recognized by the World Health Organization as a lung cancer-causing carcinogen in humans, and is the second most common cause of lung cancer after smoking [1]. A causal relationship between radon and lung cancer was first described in epidemiological studies on underground mine workers. Thereafter, case–control studies further demonstrated that exposure to low concentrations of radon carries a risk for lung cancer. Recently, pooling studies have set out to investigate lung cancer risk in relation to exposure to radon indoors. In South Korea, a total of 47,869 men died from cancer in 2014, comprising 32.5 % of all male deaths that year. Among these Korean men, lung cancer had the highest mortality rate, compared to all other cancer types, and accounted for 12,785 deaths, corresponding to 26.7 % of all deaths from cancer. Meanwhile, in the same year, a total of 28,742 women died from cancer in South Korea, comprising 23.9 % of all deaths among women. As in men, lung cancer exhibited the highest mortality rate, accounting for 4655 deaths (16.2 % of all deaths from cancer) [2]. As the incidence of lung cancer has continued to increase, studies have been undertaken to outline the etiology thereof. Histologically, lung cancer is primarily classified into small cell lung cancers (about 20 % of all lung cancers) and non-small cell lung cancers (80 %); non-small cell lung cancer is further subdivided into adenocarcinoma (40 %), squamous cell carcinoma (30 %), and large cell carcinoma (15 %). Small cell lung cancer is typically malignant, and in most cases, metastasizes to other organs before it is detected. Generally, smoking is considered to be the main cause of lung cancer: small cell lung cancers and squamous cell carcinoma are positively associated with smoking, whereas adenocarcinoma exhibits relatively lower correlation with smoking [2–4]. Meanwhile, however, 10–25 % of all cases of lung cancer are not directly related to smoking [5]. Reports suggest that passive smoking increases the risk of lung cancer by 35 % in men and 25 % in women [6]. Lung cancer has also been found to be related with radon exposure, exposure to potential lung carcinogens (asbestos, polycyclic hydrocarbons, silica, heavy metals, etc.), oil vapor when cooking, coal combustion, hormonal factors, and air pollution [7]. Despite awareness of radon’s association with lung cancer, Koreans are less aware of the potential risks of indoor radon exposure. This paper aimed to review trends in studies on indoor radon exposure and lung cancer in South Korea, to suggest the need to establish reference levels for indoor radon levels specific to South Korea, and to highlight the necessity of continuous indoor radon exposure-related research. In this article, we outline eight papers published on indoor radon exposure and lung cancer with respect to Korea, covering topics related to epidemiological studies, mathematical-statistical modeling, environmental burden of disease, genetics biomarkers, and radon measurement methods. The following summarizes our findings from reviewing research on indoor radon exposure:

Emotional labor and dysmenorrhea in women working in sales and call centers.

ObjectivesThis study was conducted to investigate the association between emotional labor and dysmenorrhea among women working in sales and call centers in Seoul, South Korea.MethodsWorking women in sales jobs and call centers in Seoul were interviewed face-to-face by well-trained interviewers. In total, 975 participants were analyzed in the final model. Emotional labor was measured using a constructed questionnaire with two components: an emotive effort component with three questions and an emotive dissonance component with five questions. To examine the association between emotional labor and dysmenorrhea, chi-squared tests and logistic regression were applied.ResultsThe prevalence of dysmenorrhea among sales workers and call center workers were 43.0% and 61.1%, respectively. The adjusted odds ratios (OR) of emotive effort and emotive dissonance for dysmenorrhea in call center workers were 1.88 (95% confidence interval [CI], 1.07–3.28) and 1.72 (95% CI, 1.13–2.63), respectively. The adjusted OR of emotive effort and emotive dissonance for dysmenorrhea in sales workers were 1.71 (95% CI, 0.92–3.16) and 1.15 (95% CI, 0.67–1.98), respectively.ConclusionsEmotional labor was found to be associated with dysmenorrhea in call center workers. Further studies to investigate other factors, such as management strategies and the relationship between emotional labor and dysmenorrhea, are needed to support interventions to prevent dysmenorrhea that will further promote the quality of health and life of working women.