Young-Seoub Hong

Relationship between micropapillary component and micrometastasis in the regional lymph nodes of patients with stage I lung adenocarcinoma.

Aims:  To determine whether a micropapillary component is a prognostic predictor, with particular reference to nodal micrometastasis, in patients with stage I lung adenocarcinomas.

Health Effects of Chronic Arsenic Exposure

Arsenic is a unique element with distinct physical characteristics and toxicity whose importance in public health is well recognized. The toxicity of arsenic varies across its different forms. While the carcinogenicity of arsenic has been confirmed, the mechanisms behind the diseases occurring after acute or chronic exposure to arsenic are not well understood. Inorganic arsenic has been confirmed as a human carcinogen that can induce skin, lung, and bladder cancer. There are also reports of its significant association to liver, prostate, and bladder cancer. Recent studies have also suggested a relationship with diabetes, neurological effects, cardiac disorders, and reproductive organs, but further studies are required to confirm these associations. The majority of research to date has examined cancer incidence after a high exposure to high concentrations of arsenic. However, numerous studies have reported various health effects caused by chronic exposure to low concentrations of arsenic. An assessment of the health effects to arsenic exposure has never been performed in the South Korean population; thus, objective estimates of exposure levels are needed. Data should be collected on the biological exposure level for the total arsenic concentration, and individual arsenic concentration by species. In South Korea, we believe that biological exposure assessment should be the first step, followed by regular health effect assessments.

Environmental Source of Arsenic Exposure

Arsenic is a ubiquitous, naturally occurring metalloid that may be a significant risk factor for cancer after exposure to contaminated drinking water, cigarettes, foods, industry, occupational environment, and air. Among the various routes of arsenic exposure, drinking water is the largest source of arsenic poisoning worldwide. Arsenic exposure from ingested foods usually comes from food crops grown in arsenic-contaminated soil and/or irrigated with arsenic-contaminated water. According to a recent World Health Organization report, arsenic from contaminated water can be quickly and easily absorbed and depending on its metabolic form, may adversely affect human health. Recently, the US Food and Drug Administration regulations for metals found in cosmetics to protect consumers against contaminations deemed deleterious to health; some cosmetics were found to contain a variety of chemicals including heavy metals, which are sometimes used as preservatives. Moreover, developing countries tend to have a growing number of industrial factories that unfortunately, harm the environment, especially in cities where industrial and vehicle emissions, as well as household activities, cause serious air pollution. Air is also an important source of arsenic exposure in areas with industrial activity. The presence of arsenic in airborne particulate matter is considered a risk for certain diseases. Taken together, various potential pathways of arsenic exposure seem to affect humans adversely, and future efforts to reduce arsenic exposure caused by environmental factors should be made.

The Relationship between Cold Exposure and Hypertension

The Relationship between Cold Exposure and Hypertension: Joon‐Youn Kim, et al. Department of Preventive Medicine, Medical College, Dong‐A University, Korea—This study was performed to determine whether there was any relationship between cold exposure and hypertension, and to evaluate risk factors affecting hypertension in cold‐exposed workers. In 11 refrigeration industries, 68 male workers working in cold areas more than once per day were selected as the cold‐exposed group, and 68 workers not exposed to cold were selected as the control group. The questionnaire survey, clinical and laboratory tests were performed. Systolic and diastolic blood pressures were significantly higher in the cold‐exposed group, and body core temperature was significantly lower in the cold‐exposed group (p<0.05). In logistic regression analysis, age, cold exposure severity and milk intake were significant variables affecting hypertension in cold‐exposed workers, whose odd ratios were 5.204 (95% CI 1.440–18.812), 2.674 (95% CI 1.080–6.618), and 0.364 (95% CI 0.141–0.942), respectively. Cold exposure was a risk factor for hypertension, and risk factors affecting hypertension in cold exposed workers were age, cold exposure severity, and milk intake. Therefore, cold exposed workers should minimize cold exposure time as much as possible, and ingest foods containing calcium such as milk. In particular, old workers working in cold areas should check their blood pressure and electrocardiogram periodically.

Relationship Between Blood Mercury Concentration and Waist-to-Hip Ratio in Elderly Korean Individuals Living in Coastal Areas

Objectives This study investigated the relationship between the blood mercury concentration and cardiovascular risk factors in elderly Korean individuals living in coastal areas. Methods The sample consisted of 477 adults (164 males, 313 females) aged 40 to 65 years who visited a Busan health promotion center from June to September in 2009. The relationship between blood mercury concentration and cardiovascular risk factors including metabolic syndrome, cholesterol profiles, blood pressure, body mass index (BMI), waist circumference and waist-to-hip ratio (WHR), was investigated. Variables related to blood mercury concentration were further evaluated using multiple regression analysis. Results The blood mercury concentration of the study population was 7.99 (range, 7.60 to 8.40) µg/L. In males, the blood mercury concentration was 9.74 (8.92 to 10.63) µg/L, which was significantly higher than that in females (7.21, [6.80 to 7.64] µg/L). The blood mercury concentration of the study population was related to several cardiovascular risk factors including low-density lipoprotein (LDL) cholesterol (p=0.044), high-density lipoprotein (HDL) cholesterol (p=0.034), BMI (p = 0.006), waist circumference (p = 0.031), and WHR (p < 0.001). In males, the blood mercury concentration was significantly correlated with WHR in the multiple regression analysis. Conclusions In males, the blood mercury concentration was related to waist-to-hip ratio, which is a central obesity index and cardiovascular risk factor. Our finding suggests that cardiovascular disease risk in males was increased by mercury exposure via an obesity-related mechanism.

DNMT3b 39179GT Polymorphism and the Risk of Adenocarcinoma of the Colon in Koreans

DNA-methyltransferase-3B (DNMT3b) plays an important role in the generation of aberrant methylation in carcinogenesis. DNMT3b SNP has been associated with susceptibility to lung, head, neck, and breast cancer, but its association with the development of colon cancer has not been reported. We investigated the relationship between the 39179G‎T polymorphism in the DNMT3b gene, which is involved in de novo methylation and is associated with the risk of adenocarcinoma of the colon in Koreans. The DNMT3b 39179G‎T genotypes were determined by a PCR-RFLP method in 248 adenocarcinomas of colon cancer patients and in 248 healthy controls matched as to age and sex. When stratified by sex and age, a significantly reduced risk of the combined GT and GG genotypes was observed in younger patients (<59, adjusted OR = 0.255, 95% CI = 0.133–0.489) and in male patients (adjusted OR = 0.383, 95% CI = 0.225–0.652). The DNMT3b 39179G‎T polymorphism may be a genetic determinant of adenocarcinoma of the colon, especially in younger Korean men.

Subclinical Myocardial Dysfunction in Metabolic Syndrome Patients without Hypertension

Background The aim of this study was to evaluate myocardial function in patients with non-hypertensive metabolic syndrome. Methods We selected metabolic syndrome patients (n = 42) without evidence of hypertension and compared them to age-matched control individuals (n = 20). All patients were evaluated by two-dimensional and tissue Doppler echocardiography including tissue Doppler derived strain and strain rate measurements. Results There were no significant differences between the two groups in mitral E and A inflow velocities or the E/A ratio. However, systolic and early diastolic myocardial velocities, and strain rate were significantly lower in patients with metabolic syndrome than in the control group (all p < 0.05). Multiple stepwise regression analyses revealed that age, waist circumference, and systolic blood pressure were independently associated with peak systolic myocardial velocity. Conclusion These results indicate that metabolic syndrome patients without hypertension may have decrease of myocardial systolic and early diastolic velocities on tissue Doppler imaging, even if they appear to have normal systolic and diastolic function on conventional echocardiography.

Dietary patterns in children with attention deficit/hyperactivity disorder (ADHD).

The role of diet in the behavior of children has been controversial, but the association of several nutritional factors with childhood behavioral disorders has been continually suggested. We conducted a case-control study to identify dietary patterns associated with attention deficit hyperactivity disorder (ADHD). The study included 192 elementary school students aged seven to 12 years. Three non-consecutive 24-h recall (HR) interviews were employed to assess dietary intake, and 32 predefined food groups were considered in a principal components analysis (PCA). PCA identified four major dietary patterns: the “traditional” pattern, the “seaweed-egg” pattern, the “traditional-healthy” pattern, and the “snack” pattern. The traditional-healthy pattern is characterized by a diet low in fat and high in carbohydrates as well as high intakes of fatty acids and minerals. The multivariate-adjusted odds ratio (OR) of ADHD for the highest tertile of the traditional-healthy pattern in comparison with the lowest tertile was 0.31 (95% CI: 0.12–0.79). The score of the snack pattern was positively associated with the risk of ADHD, but a significant association was observed only in the second tertile. A significant association between ADHD and the dietary pattern score was not found for the other two dietary patterns. In conclusion, the traditional-healthy dietary pattern was associated with lower odds having ADHD.

Blood Mercury Concentration and Related Factors in an Urban Coastal Area in Korea

OBJECTIVES This study was carried out for the purpose of evaluating the blood mercury concentration of the residents of Busan, Korea, as well as the relationship between the mercury concentration and the pattern of fish consumption along with other epidemiological factors. METHODS Two hundred ninety-three subjects (147 men and 146 women), who were aged 40 years or more, were recruited into this study between June and October 2009. The mean age of the subjects was 54.3 years (with a range of 40-70 years). Mercury concentrations in blood samples were measured using a gold-amalgam collection method. RESULTS The geometric mean concentration of mercury in the total subjects was 8.63 µg/L [range: 1.48~45.71 µg/L]. The blood mercury concentration of the men (9.55 µg/L) was significantly higher than that of the women (7.76 µg/L). The blood mercury concentration of those who eat fish more than 4 times per week was higher than others, and was statistically significant (male p = 0.0019, female p = 0.0002). According to the multiple analysis, the blood mercury concentration was significantly affected by the consumed fish but other epidemiological factors were not related. CONCLUSIONS It was found that the subjects who have consumed a large amount of fish may have high blood mercury concentration. It appears that fish consumption can influence blood mercury concentration. Therefore, guidelines for fish consumption that will decrease blood mercury concentration might be necessary in Korea.

The relationship between the fish consumption and blood total/methyl-mercury concentration of costal area in Korea

The purpose of this study was to evaluate the relationship between fish consumption and blood THg/MeHg concentration in Korean adults by measuring MeHg concentration in blood directly. The study subjects consisted of 400 adults aged 20 or older from 30 subareas in Busan, Ulsan and Gyeongsangnam-do province in Korea from August to October, 2010. We tried to recruit the same number of male and female participants in different age groups (20s, 30s, 40s, 50s and 60s) and allocated 13-16 subjects by district to represent Hg concentration in the research areas. The geometric means of THg and MeHg concentration in blood were 5.27 μg/L (5.00-5.57) and 4.05 μg/L (3.81-4.32), respectively. The proportion of MeHg/THg concentration was 78.53% (77.09-79.97). MeHg concentration was higher in coastal areas (4.26 μg/L) than in inland areas (3.52 μg/L) and was higher in men (4.68 μg/L) than in women (3.52 μg/L). In male participants, blood MeHg concentration increased with increasing annual fish consumption, and the proportion of MeHg/THg concentration showed an upward trend as THg concentration increased. However, none of the measures of the proportion of MeHg/THg showed significant differences. This is the first report in Korea about the relationship between blood MeHg concentration and related factors. Our findings suggest that MeHg concentration is affected by fish consumption as well as by gender difference and drinking status. Since the pathological mechanism has not been clarified, additional studies are needed for explaining the biological and lifestyle differences in the risk of adverse health effects by Hg exposure.