Assessment of DNA Viability in Long Term-Stored Buffy Coat Species for the Korean Multicenter Cancer Cohort / 예방의학회지

OBJECTIVES: Peripheral blood-buffy coat fractions (N = 14, 956) have been stored at -70degrees C in the headquarter of the Korean Multicenter Cancer Cohort (KMCC), since 1993. To study the future molecular etiology of cancers using specimens of the cohort, properly stored specimens are necessary. Therefore, the DNA-viability of the buffy coat samples was investigated. METHODS: Buffy coat fraction samples were randomly selected from various collection areas and years (N = 100). The DNA viability was evaluate from the UV-absorbent ratios at 260/280nm and the PCR for beta-globin was performed with genomic DNA isolated from the buffy coat. RESULTS: PCR products were obtained from 85 and 98% of the C and H area-samples, respectively, using 50 or 100mul of the buffy coat. There were significant differences in the yields of the PCR-amplifications from the C and H areas (p < 0.05), which was due to differences in the homogenization of the buffy coat fractions available as aliquots. The PCR-products were obtained from all of the samples (N = 7) stored at the C area-local center, but the other aliquots stored at the headquarter were not PCR-amplified. Therefore, the PCR products in almost all the samples, even including the DNA-degraded samples, were obtained. In addition, an improvement in the DNA isolation, i.e. approx. 1.6 fold, was found after using extra RBC lysis buffer. CONCLUSIONS: PCR products for beta-globin were obtained from nearly all of the samples. The regional differences in the PCR amplifications were thought to have originated from the different sample-preparation and homogenization performance. Therefore, the long term-stored buffy coat species at the KMCC can be used for future molecular studies.

The Exposure Status and Biomarkers of Bisphenol A in Shipyard Workers / 예방의학회지

OBJECTIVES: Because shipyard workers are involved with various manufacturing process, they are exposed to many kinds of hazardous materials. Welders especially, are exposed to bisphenol-A (BPA) during the welding and flame cutting of coated steel. This study was conducted to assess the exposure status of the endocrine disruptor based on the job-exposure matrix. The effects of the genetic polymorphism of xenobiotic enzyme metabolisms involved in the metabolism of BPA on the levels of urinary metabolite were investigated. METHODS: The study population was recruited from a shipyard company in the K province. A total of 84 shipbuilding workers 47 and 37 in the exposed and control groups, respectively, were recruited for this study. The questionnaire variables included, age, sex, use of personal protective equipment, smoking, drinking and work duration. The urinary metabolite was collected in the afternoon and correction made for the urinary creatinine concentration. The of the CYP1A1, CYP2E1 and UGT1A6 genotypes were investigated using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) methods with the DNA extracted from venous blood. RESULTS: The urinary BPA level in the welders group was significantly higher than in the control group (p< 0.05). The urinary BPA concentration with the wild type UGT1A6 was higher than the other UGT1A6 genotypes, but with no statistical significant. From themultiple regression analysis of the urinary BPA, the regression coefficient for job grade was statistically significant (p< 0.05). CONCLUSIONS: The grade of exposure to BPA affected the urinary BPA concentration was statistically significant. However, the genetic polymorphisms of xenobiotics enzyme metabolism were not statistically significant. Further investigation of the genetic polymorphisms with a larger sample size is needed.

Cost of Work-related Cerebrovascular and Cardiac Disease / 대한산업의학회지

OBJECTIVES: The purpose of this study was to estimate the cost, with a focus on forecasting the expenditure on industrial accident compensation insurance, arising from workrelated cerebrovascular and cardiac disease. METHODS: We used a total of 4,480 work-related cerebrovascular and cardiac disease data points, collected between 1995 and 2000, based on the year of occurrence, and which had been approved by industrial accident compensation insurance. Firstly, we calculated the number of approved cases per 100,000 workers benefiting from industrial accident compensation insurance between 1995 and 2000. We then forecasted the numbers of work-related cases of cerebrovascular and cardiac disease for the period from 2001 through 2005 using a linear regression equation. Secondly, we analysed the expenditure on industrial accident compensation insurance due to work-related cerebrovascular and cardiac disease, and estimated the expenditure per capita for the former period. Thirdly, we estimated the expenditure on industrial accident compensation insurance due to work-related cerebrovascular and cardiac disease for the latter period based on the cohort of occurrence year. RESULTS: Approved cases per 100,000 workers for work-related cerebrovascular and cardiac disease were 3.36 in 1995 and 13.16 in 2000. It is expected that the approved cases would be 1,336 (95 % CI 1,211-1,460) in 2001 and 1,769 (95 % CI 1,610-1,931) in 2005, based on the year of occurrence. The mean expenditure per capita was estimated to be 75 million won, which comprised of 19 million won for medical care benefits and 56 million won for other benefits. It was anticipated that the claims for the 2001 cohort would be 107.9 billion won and 192.4 billion won for the 2005 cohort. CONCLUSIONS: The magnitude of the economic burden of work-related cerebrovascular and cardiac disease is substantial. From an economic perspective, this study proves the importance and need for the management of work-related cerebrovascular and cardiac disease.

Sex hormones among Workers Exposed to Pesticides / 대한산업의학회지

OBJECTIVE: This study was carried out to determine the effects of occupational pesticides exposure on the level of serum Luteinizing Hormone(LH), Follicle Stimulating Hormone(FSH), testosterone in male workers. METHODS: Twenty-two male workers exposed to pesticides were compared with twenty-eight male workers at same factory who were not exposed to pesticides. The selected variables for studying reproductive hormones were LH, FSH and testosterone. As part of the baseline health status, subjects were asked medical history. RESULTS: There were no statistically significant differences on the level of LH, FSH, testosterone between the exposed and non-exposed group. Also the level of sex hormones were not significant difference with each department in exposed group. And the level of LH, FSH positively correlated with age. CONCLUSIONS: These results indicate that there are no alterations in LH, FSH, testosterone at workers exposed to pesticides. But our findings are highly preliminary because of a small sample size. Thus it calls for furthur investigation of the hormonal effects at workers exposed to pesticides.

A Study of Validity Used Quantitative Indices on the Evaluation of Korean Medical Schools in 1996 / 한국의학교육

The purpose of this study is to review the validity of quantitative indices on the Evaluation of Korean Medical Schools in 1996. The data required for the indices were obtained from the 1996's edition of the Directory of Korea Medical Education and compared to the results of the evaluation. Among the quantitative indices of the evaluation the number of professors and assistants of basic medical science was the most valuable index to differentiate the better group from lesser groups of medical schools in Korea.

Sister Chromatid Exchanges in Workers Occupationally Exposed to Ethylene Oxide / 대한산업의학회지

Operators of hospital sterilizers who use ethylene oxide (EtO) were studied to determine the exposure of EtO level and the frequency of sister chromatid exchanges (SCEs) from June 12 to July 20, 1997. To evaluate SCEs in the peripheral blood cells, we selected 22 workers at the central supply room of 4 university hospitals and 22 unexposed workers at the same hospitals according to match sex, age, and smoking habit and also did questionnaires. The mean air concentrations (8-hr TWA) of EtO at 4 university hospitals were less than 1 ppm. The SCE frequencies in exposed workers to EtO and controls were normally distributed. The SCE frequencies in exposed workers to EtO and controls were 6.42+/-.63, 5.86+/-.69, respectively and their differences were statistically significant (p=0.0093). But there were no statistically significant differences in smoking, alcohol intake, coffee drinking. Especially smokers who exposed to EtO were increased SCE statistically significant than the exposed group who did not smoke.

Lipid Peroxidation and Antioxidants in Workers Exposed to Lead / 예방의학회지

This study was started to find out if plasma malondialdehyde(MDA), alpha-tocopherol and erythrocyte superoxide dismutase(SOD) activity could be markers of biological activity resulting from exposed to lead in workers. Blood samples were randomly obtained from lead -exposed workers(n=29), CO2 welders(n=60) and office workers(n=60). We used whole blood to analyse blood lead with atomic absorption spectrophotometer. Superoxide dismutase activity in erythrocyte was measured with spetrophotometer. MDA and alpha-tocopherol in plasma were measured with high performance liquid chromatography. Lead-exposed workers was significantly high in blood lead concentration(29.37 ng/dl) compared with welders(6.42 ng/dl) and office workers(5.01 ng/dl). The level of plasma MDA was significantly higher in the lead-exposed workers(1.87 nmol/g cholesterol) than the welders(1.41 nmol/g cholesterol) and office workers(1.41 nmol/g cholesterol). Erythrocyte SOD activity in lead-exposed workers(56.80 U/g Hb) was significantly increased than those of welders(37.63 U/g Hb) and office workers(20.47 U/g Hb). The plasma alpha-tocopherol level of lead-exposed workers(4.93 ng/g cholesterol) was statistically different from welders(4.25 ng/g cholesterol) and office workers(4.28 ng/g cholesterol). Neither age nor smoking was related to SOD or MDA level. Blood lead was significantly correlated with erythrocyte SOD activity(r=0.405), plasma MDA(r=0.296) and alpha-tocopherol(r=0.207). Plasma MDA was also significantly correlated with SOD (r=0.217). In multiple regression analysis, the change of MDA and SOD activity level related to the blood lead concentration. These results suggested that the increase of plasma MDA and erythrocyte SOD activity in lead-exposed workers had a close relationship with the oxidative stress induced by lead.

The Changes in the Educational Goals and Objectives of Medical Schools in Korea / 한국의학교육

We reviewed the educational goals and objectives of the 32 medical schools in Korea, which is based on the 1992's, 1994's, and 1996's edition of the Directory of Korea Medical Education. The purpose of this study is to find trend of their changes and to help revise them. Among the 32 medical schools in Korea, 31(96.9%) described goals and objectives separately on 1996's edition, while 26(81.3%), 19(59.4%) on 1994's, 1992's, respectively. The medical ethics and morality was becoming more important; 30(93.8%) medical schools on 1996's and 1994's edition, while 26(81.3%) on 1992's. There were more emphases on the promotion of the ability of community services in health and of self study. For the promotion of the ability of community services in health; 26(81.3%) medical schools on 1996's edition, while 23(71.9%), 19(59.4%) on 1994's, 1992's, respectively. For the promotion of the ability of self study; 25(78.1%) medical schools on 1996's edition, while 21(65.6%), 15(46.9%) on 1994's, 1992's, respectively. The cultivation of primary care physician was becoming the primary goal of medical schools; 23(71.9%) medical schools on 1996's edition, while 12(37.5%), 9(28.1%) on 1994's, 1992's respectively. Teaching medical knowledge and clinical skills were still regarded as important; 21(65.6%) medical schools on 1996's edition, while 20(62.5%), 23(71.9%) on 1994's, 1992's, respectively. The inclusion of medical scientists in the possible job lists was also eminent; 14(43.8%) medical schools on 1996's edition, while 11(34.4%), 6(18.8%) on 1994's, 1992's, respectively. The ultimate educational goal of university was becoming prominent; 21(65.6%) medical schools on 1996's edition, while 15(46.9%), 11(34.4%) on 1994's, 1992's, respectively.