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.

F2L, a peptide derived from heme-binding protein, inhibits LL-37-induced cell proliferation and tube formation in human umbilical vein endothelial cells.

F2L, a peptide derived from heme-binding protein, was originally identified as an endogenous ligand for formyl peptide receptor-like (FPRL)2. Previously, we reported that F2L inhibits FPR and FPRL1-mediated signaling in neutrophils. Since endothelial cells express functional FPRL1, we examined the effect of F2L on LL-37 (an FPRL1 agonist)-induced signaling in human umbilical vein endothelial cells (HUVECs). F2L stimulated the chemotactic migration in HUVECs. However, F2L inhibited FPRL1 activity, resulting in the inhibition of cell proliferation and tube formation induced by LL-37 in HUVECs. We suggest that F2L will potentially be useful in the study of FPRL1 signaling and the development of drugs to treat diseases involving the FPRL1 in the vascular system.

Hypermethylation of p16INK4a in Korean non-small cell lung cancer patients.

Promoter hypermethylation of the p16(INK4a) 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 p16(INK4a) 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 p16(INK4a) 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 p16(INK4a), 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 p16(INK4a) methylation.

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.

[The relationship between ACE I/D polymorphism and HDL cholesterol].

OBJECTIVES: The purpose of this study is to evaluate the association of the angiotensin converting enzyme (ACE) insertion/deletion (I/D) polymorphism with cardiovascular disease risk factors. METHODS: Out of a total of 608 middle-aged adults who visited local health centers, 424 subjects (104 male, 320 female) who had not been diagnosed with hypertension, diabetes mellitus, or hyperlipidemia were included in this study. ACE genotypes were determined in all subjects by polymerase chain reaction methods. RESULTS: Statistical differences in high-density lipoprotein (HDL) cholesterol levels according to ACE genotype were observed using ANOVA (p<0.05), but no differences were found in other cardiovascular risk factors. Specifically, men with the DD and DI genotypes had significantly lower HDL cholesterol levels than those with the II genotype based on the LSD multi-comparison test (p<0.05). CONCLUSIONS: In men, the D-allele of the ACE I/D polymorphism was significantly associated with reduced HDL cholesterol levels. In the future, larger studies are needed to confirm this relationship between ACE I/D polymorphism and HDL cholesterol.

[Directions for future development of preventive medicine in Korea].

It is the actual state of the medical society in our country that many graduates of medical schools want to be clinicians, and accordingly Korea's medical situation is relatively too focused on curative medicine. However, this situation is changing due to several factors including a growing number of doctors, inappropriate regulations for medical fees, changes in social status of doctors themselves, and excessive competition between doctors. Furthermore, we expect more advances in medical field of Korea since Korean government started to attach great importance to sciences and produced policies to support sciences, and as a result, more and more interest and effort in the fields of basic research including preventive medicine is being attached especially by young doctors as compared against the past. However, decline of clinical medicine fields doesn't always mean bright future for the field of preventive medicine. True future is possible and meaningful only when we prepare for it by ourselves. In other words, as the promising future is closed to one who spares no effort, we shouldn't fear to oppose unknown challenges and simultaneously need to support colleagues who bear such a positive mind. It is the most important thing for our preventive medicine doctors to evaluate the past and the present of preventive medicine and to foster a prospective mind to prepare for the future of preventive medicine. I set forth my several views according to directions for the development of preventive medicine which we already discussed and publicized in the academic circle of preventive medicine. Those directions are recommen dation of clinical preventive medicine, promotion of preventive medicine specialty, fostering the next generations, improving the quality of genetic epidemiologic study, participation in control of environmental pollution and food safety, contribution to chronic disease control, and preparation to role in medical services for unified Korea.

[The relationship between regional material deprivation and the standardized mortality ratio of the community residents aged 15-64 in Korea].

OBJECTIVES: This study was performed to investigate the relationship between regional material deprivation and the standardized mortality ratios(SMRs) of community residents aged 15-64 in Korea. METHODS: SMRs were investigated using the registered death data from 1995 to 2000 that was obtained from the Korean National Statistics Office with the denominators being drawn from the 1995 to 2000 census. Material deprivation was measured using the Townsend score that was calculated from the 1995 to 2000 census. The relationship between the regional material deprivation and the SMRs of the community residents aged 15-64 was investigated by using ANOVA, Spearman's rank correlation analysis and Pearson's correlation analysis. The trends in mortality inequality were investigated using the concentration index. RESULTS: On the ANOVA, the SMRs of the men and women residents in the least deprived areas were the smallest and those in the most deprived areas were the largest. Spearman's rank correlation analysis, Pearson's correlation analysis and the concentration index revealed that significant positive relationships exist between the regional material deprivation and the SMRs of the community residents aged 15-64. CONCLUSIONS: This study suggests that there are mortality inequalities among the communities in Korea and part of this difference is due to the material deprivation of the community. Strategies aimed at reducing mortality inequalities among the communities will be needed to address economic inequalities. Further studies are needed to explore the mechanisms of how the regional deprivation influences on health and how the other factors of the community influence on the health of the community residents.

Comparison of disability duration of lumbar intervertebral disc disorders among types of insurance in Korea.

The incidence of work-related musculoskeletal disorder including low back pain sharply increased since 2000 in Korea. The objectives of the present study are to compare disability duration of lumbar intervertebral disc displacement among types of insurances, and to obtain its appropriate duration. The medical records of all patients whose final diagnosis in discharge summary of chart was lumber specified intervertebral disc displacement (LIVD) in 6 large general hospitals in Korea were reviewed to compare the length of admission and disability among different types of insurances. The information on age, gender, the length of admission, the length of follow-up for LIVD, occupation, operation, combined musculoskeletal diseases, and type of insurance was investigated. 552 cases were selected and analyzed to calculate arithmetic mean, median, mode, and geometric mean of disability duration. There was a significant difference in the length of admission and disability among types of insurance after controlling covariates such as age and combined diseases by the analysis of covariance. The length of admission in cases of IACI and AI was much longer than that of HI, and the length of disability in cases of IACI was much longer than that of HI. Prolonged duration of admission and disability was not assumed due to combined diseases, complication or other unexplainable personal factors in cases of those with industrial accidents compensation insurance and automobile insurance. This means that proper management of evidence-based disability duration guidelines is urgently needed in Korea.

Prevalence of carpal tunnel syndrome in meat and fish processing plants.

This study was carried out to survey the prevalence of carpal tunnel syndrome (CTS) in a high-risk job. The experimental group was composed of 69 workers sampled from meat and fish processing plants, who were using their upper extremities repetitively. The control group was composed of 28 workers sampled from managers, secretaries and keepers in the same companies. All the employees were examined for their work history, their symptoms, as well as physical examinations and a nerve conduction study (NCS). Fifty-one (73.9%) workers in the experimental group had findings compatible to the NIOSH definition of Work-Related CTS. The positive rates for Tinel and Phalen's signs were higher in the workers who had shorter working duration (<7 yr), but the positive rate in the NCS was higher in the workers who had longer working duration (>/=7 yr). The prevalence of CTS in a meat and fish processing plant was much higher. Therefore this job should be managed as a high-risk industry.

The C677 mutation in methylene tetrahydrofolate reductase gene: correlation with uric acid and cardiovascular risk factors in elderly Korean men.

The C677T mutation in the methylene tetrahydrofolate reductase (MTHFR) gene results in elevated homocysteine levels and, presumably, in increased cardiovascular risk. Moreover, elevated homocysteine levels are reportedly associated with high serum uric acid levels. We evaluated the MTHFR genotype and a panel of biochemical, hematological variables, and lifestyle characteristics in 327 elderly Korean men (age range 40-81 yr; mean, 51.87). This study shows that mutation of the MTHFR gene may be a risk for hyperuricemia. The mean uric acid levels for the C/C, C/T and T/T genotypes were 5.54, 5.91 and 6.33 mg/dL, respectively (p=0.000). The T/T genotype was significantly more frequent in subjects with high uric acid levels (p=0.003). Thus, this mutation of the MTHFR gene is implied by the study results to be a risk factor of hyperuricemia in elderly Korean men. However, the relationship between the MTHFR mutation and uric acid metabolism remains unclear. Therefore, further studies are necessary to explain the associated between the MTHFR mutation and elevated uric acid levels, and to examine potential relationships between it and conventional cardiovascular risk factors.

Prevalence of metabolic syndrome and waist circumference estimation in some korean adults.

OBJECTIVE: The purpose of this study was to estimate the prevalence of metabolic syndrome, as defined by the ATP III report, in some Korean adults and use the Asian-Pacific proposed waist circumference to investigate waist circumference in some Korean adults using ROC curves. METHODS: Study subjects were seventy-five thousands and ninety one persons (47, 979 men and 27, 111 women) who were selected among the patients who visited hospital for health evaluation from January 2000 to December 2001. All subjects were measured by height, weight, waist and hip circumferences, blood pressure and blood chemistry (lipid profile). RESULTS: The mean age was 41.6+/-8.5 years in men, 41.1+/-10.4 years in women (p< 0.05). Body mass index was in the normal range in 35.3% of men, and 55.9% of women. In both men and women, blood pressure, blood sugar, total cholesterol and triglyceride were positively correlated with BMI. waist circumference, and Broca's index (p< 0.01). However HDL. choloesterol was correlated negatively (p< 0.01). Using ROC curve, the calculated waist circumferences were 84 cm in men (sensitivity 61.4% and specificity 64.1%) and 74 cm in women (sensitivity 65.0% and specificity 73.2%). The age adjusted prevalences of the metabolic syndrome as defined by NCEP ATP III were different for men (6.4%) and women (14.6%). The prevalence increased from 1.2% among participants aged 20 through 29years to 15.0% among participants aged over 60years in men (p< 0.05) and from 1.6% to 27.4% respectively, in women. The age adjusted prevalences, as defined by using the waist circumference that was recommended by WHO's regional office for the western Pacific, were 10.6% in men and 18.5% in women. The age adjusted prevalences, as defined by using the waist circumference that was calculated by the ROC curves, were 17.1% in men and 22.4% in women. And All prevalences were increased following increased BMI and Broca's index. CONCLUSIONS: The prevalence of metabolic syndrome in some Korean adults was lower than that in western adults. Nevertheless because waist circumference was differed among race and region, application of the same criteria was not proper. Morcover, a higher awareness was required in women, because the prevalence of metabolic syndrome was rapidly increased with increment of age.

The relationship between cold exposure and hypertension.

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.