- Interaction of Sodium Selenite on Neurotoxicity Induced by Methylmercuric Chloride.
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J S Park, H M Lee, Y Chung, D C Shin, J H Roh, Y H Moon
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Korean J Prev Med. 1992;25(1):13-25.
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Abstract
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- This study was conducted to investigate the mechanism of protective effect by sodium selenite in Methylmercuric chloride neurotoxicity, increasing intracellular Ca2+ concentration of the neuron. Methylmercuric chloride of 3 mg/kg of body weight was administered simultaneously with sodium selenite of 5 mg/kg and pretreatment of sodium selenite via intraperitoneal injection to rats. Also, effect of methylmercuric chloride(25 micrometer, 50 micrometer, 100 micrometer) and sodirum selenite(200 micrometer) on free intrasynaptosomal Ca2+ concentration were studied using the fluorescent Ca2+ indicator fura2 in vitro. After the treatment, at 6, 24, and 48 hours later, mercury in the cerebral cortex, liver and kidney tissues, succinic dehydrogenase activities, adenosin-5'-triphosphate concentration, acetylcholinesterase activities, and intracellular Ca2+ concentration in the cerebral cortex were determined in vivo. Cerebral synaptosomes of rats were incubated with methylmercuric chloride and sodium selenite in Hepes buffer for 10 minutes and free intrasynaptosomal Ca2+ concentration were measured with fura2 in vitro.The results were summarized as follows; 1. The combined administration of CH3HgCl and Na2SeO3 and pretreatment of Na2SeO3 according to time significantly more increased in the cerebral cortex and decreased in the liver, kidney mercury concentrations compared to the administration of CH3HgCl only. 2. The combined administration of CH3HgCl and Na2SeO3 and pretreatment of Na2SeO3 increased more succinic dehydrogense and acetylcholinesterase activities compared to the administration of CH3HgCl only. Particularly pretreatment of Na2SeO3 significantly more compared to the administration of CH3HgCl only. The concentration of adenosine-5'-triphosphate in Na2SeO3 treatment groups revealed a favourable effect compared to the administration of CH3HgCl only. 3. Intracellular Ca2+ concentration in administration of CH3HgCl only was increased significantly more than control group in all test hours but was increased significantly more at 48 hous only after treatment in combined administration of CH3HgCl and Na2SeO3 and pretreatment of Na2SeO3 according to time interval more decreased significantly intracellular Ca2+ concentration compared to the administration of CH3HgCl only. 4. Free intrasynaptosomal Ca2+ concentration in the combined administration of CH3HgCl and Na2SeO3 was decreased (24%-40%) significantly more than the administration of CH3HgCl only. From the above results, the specific dosage of Na2SeO3 decreased increment of intracellular Ca2+ concentration induced by administration of CH3HgCl. These findings suggest the protective mechanism of Na2SeO3 on the neurotoxicity of CH3HgCl.
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Summary
- A Study on Occupational Health Program and Development of Evaluation Criteria for Occupational Health.
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Y S Lee, Y H Moon, Y K Kim, H K Chung
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Korean J Prev Med. 1978;11(1):98-109.
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Abstract
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- The study was carried out for 101 establishments in Kyong-In areas to evaluate the industrial health management status utilizing the scoring method by Webb's model during the period from 1 September to October 30, 1977. To compare the results, reevaluation was made with the 45 questions' model prepared by 6 Korean professionals who were specialized in industrial health fields. The results were as follows: 1. The mean rate of affirmative answers for 101 establishments was 51.6%. The mean weighted score rate of affirmative answers was 52.3%. 2. The mean rate of affirmative answers on components of the philosophy and facility resource for 101 establishments was higher than that of average rate. The mean rate of affirmative answers on components of the health evaluation and health management among the health service program was lower than that of average rate. 3. The mean rate of affirmative answers on components was higher among the establishments with more than 500 employees. The mean rate of affirmative answers of chemical establishment was lower than that of others. 4. The mean rate of affirmative answers on 45 questions' model for 101 establishments were 67.1%. The mean weighted score rate of affirmative answers was 70.0%. 5. In case of 45 questions' model, the mean rate of affirmative answers on components of philosophy and treatment was higher than that of average rate and the mean rate of affirmative answers on components of the facility resource and the health evaluation was lower than that of average rate. 5. The mean rate of affirmative answers of the 45 Questions' model was higher than that of Webb's model in size and class of 101 establishments. Author concluded that Webb's model must be suitable for evaluation higher condition of occupational health management than is presently used in Korean establishments. According to the results, however, there were no significant differences between Webb's model and the 45 questions' model. So it could be used to evaluate Occupational Health Program. For this objective, in Korean occupational situations, further study also must be made comprehensively thereafter.
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