Joon-Youn Kim

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.

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.

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.

Comparisons of prognostic scoring systems for myelodysplastic syndromes: a Korean multicenter study

We have conducted a multicenter collaborative retrospective analysis to evaluate clinical characteristics and to compare prognostic scoring systems of 149 Korean patients with myelodysplastic syndromes (MDS). The median age of the patients was 53 years (range 17-82 years) with high of the patients being younger than 40 years. Median survival was 22.6 months, and 25 patients (17%) progressed to acute myelogenous leukemia (AML) with a median interval of 6 months (range 1-45 months). Major independent variables assessed by multivariate analysis were FAB subtypes and bone marrow (BM) blast percentages for survival and BM blast percentages for AML transformation. To compare the various scoring systems in the prediction for survival and transformation to AML, FAB, Sanz and Bournemouth scoring systems were applied to all patients, while the international prognostic scoring system (IPSS), Lille and Toyama scoring systems were applied to 91 patients. The Sanz scoring system (P < 0.0001), FAB classification (P < 0.0001), IPSS (P < 0.001), and Toyama scoring system (P < 0.005) were highly predictive for survival showed greater discrimination than that of the other systems. For AML transformation, the IPSS (P < 0.0001), Toyama scoring system (P < 0.0001), FAB classification (P < 0.0001), and Lille scoring system (P < 0.005) successfully discriminated risk groups. Although the prognostic factors and the distribution of age were different from those in Western reports, the IPSS and Toyama scoring system were applicable for predicting survival and leukemic transformation in Korean patients with MDS.

Hypermethylation of p16INK4a in Korean Non-small Cell Lung Cancer Patients

Promoter hypermethylation of the p16INK4a gene was investigated in 81 sets of samples of tumor tissue and adjacent normal tissue from Korean patients with primary lung cancer, using the modified real-time polymerase chain reaction (PCR)/ SYBR Green detection method. The results showed hypermethylation of p16INK4a in 27.2% of tumor tissues, and in 11.1% of adjacent normal tissue. No significant association was found between the overall aberrant methylation in tumor and corresponding normal specimens (r=0.137, p=0.219). In 22 cases with p16INK4a hypermethylation in tumor tissues, only 4 (18.1%) cases were found to have a hypermethylated normal tissue specimen. The findings of this study show that smoking can influence the methylation level of the promoter region of p16INK4a, and that this occurs in tumor tissues more frequently than in normal tissues. Other clinicopathological characteristics, including age, sex, tumor stage, and histologic type were not found to be correlated with p16INK4a methylation.

Investigation of MHD instabilities and control in KSTAR preparing for high beta operation

Initial H-mode operation of the Korea Superconducting Tokamak Advanced Research (KSTAR) is expanded to higher normalized beta and lower plasma internal inductance moving towards design target operation. As a key supporting device for ITER, an important goal for KSTAR is to produce physics understanding of MHD instabilities at long pulse with steady-state profiles, at high normalized beta, and over a wide range of plasma rotation profiles. An advance from initial plasma operation is a significant increase in plasma stored energy and normalized beta, with Wtot = 340 kJ, βN = 1.9, which is 75% of the level required to reach the computed ideal n = 1 no-wall stability limit. The internal inductance was lowered to 0.9 at sustained H-mode duration up to 5 s. In ohmically heated plasmas, the plasma current reached 1 MA with prolonged pulse length up to 12 s. Rotating MHD modes are observed in the device with perturbations having tearing rather than ideal parity. Modes with m/n = 3/2 are triggered during the H-mode phase but are relatively weak and do not substantially reduce Wtot. In contrast, 2/1 modes to date only appear when the plasma rotation profiles are lowered after H–L back-transition. Subsequent 2/1 mode locking creates a repetitive collapse of βN by more than 50%. Onset behaviour suggests the 3/2 mode is close to being neoclassically unstable. A correlation between the 2/1 mode amplitude and local rotation shear from an x-ray imaging crystal spectrometer suggests that the rotation shear at the mode rational surface is stabilizing. As a method to access the ITER-relevant low plasma rotation regime, plasma rotation alteration by n = 1, 2 applied fields and associated neoclassical toroidal viscosity (NTV) induced torque is presently investigated. The net rotation profile change measured by a charge exchange recombination diagnostic with proper compensation of plasma boundary movement shows initial evidence of non-resonant rotation damping by the n = 1, 2 applied field configurations. The result addresses perspective on access to low rotation regimes for MHD instability studies applicable to ITER. Computation of active RWM control using the VALEN-3D code examines control performance using midplane locked mode detection sensors. The LM sensors are found to be strongly affected by mode and control coil-induced vessel current, and consequently lead to limited control performance theoretically.

The Levels of Blood Lead and Cadmium in Urban and Rural Population in Korea

The purpose of this study was to evaluate the levels of blood lead and cadmium in urban and rural populations. Blood samples were collected from 100 urban (Busan) residents and 150 rural residents (Jinju-84, Gijang-66) from July 1 to August 30, 2007. The blood lead and cadmium levels were analyzed using flameless atomic absorption spectrophotometry and were compared by age, gender and smoking status. The mean levels of blood lead in urban-Busan, rural-Jinju and rural-Gijang residents were , and , respectively. There was a significant difference in the level of blood lead between urban-Busan residents and rural-Gijang residents. The mean levels of blood cadmium in urban-Busan, rural-Jinju and rural-Gijang residents were , and , respectively. There was a significant difference in the level of blood cadmium between urban-Busan residents and rural-Jinju residents. This study showed that the levels of blood lead and cadmium were significantly different between urban and rural populations. The level of blood lead was highest in urban-Busan residents, but the level of blood cadmium was highest in rural-Jinju residents. Further studies are needed to define the cause of high levels of blood lead and cadmium related to area of residence and personal habits.

Renal Dysfunction Indicators in Lead Exposed Workers

Real Dysfunction Indicators in Lead Exposed Workers: Kap‐Yeol Jung, et al. Department of Preventive Medicine and Industrial Medicine Research Institute, Dong‐A University School of Medicine—This study was undertaken to find out which indicators were most valuable as markers of renal dysfunction related to lead exposure. We selected 75 male workers from the secondary lead smelter, plastic stabilizer and radiator manufacturing industries (the “exposed” group) and 64 male office workers (the “control” group). Blood lead, blood zinc protoporphyrin, urine lead, urine coproporphyrin, δ‐aminolevulinic acid dehydratase activity, and urine δ‐aminolevulinic acid were chosen as indicators of lead exposure. Blood urea nitrogen, serum creatinine, serum uric acid, urine N‐acetyl‐β‐D‐glucosaminidase, urine albumin, urinea α1‐microglobulin and urine β2‐microglobulin were used as indicators of renal dysfunction. The urine α2‐microglobulin level was significantly associated with the lead exposure level. Blood urea nitrogen, urine N‐acetyl‐β‐D‐glucosaminidase and urine α1‐microglobulin levels were highly correlated with indicators of lead exposure. Urine α1‐microglobulin had the highest correlation with other indicators of renal function. Conclusively, blood urea nitrogen, urine N‐acetyl‐β‐D‐glucosaminidase and urine α1‐microglobulin are useful indicators, but urine α1‐microglobulin is the earliest and the most valuable indicator of renal dysfunction due to lead exposure.