• 한국산업보건학회지
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• 제6권1호
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• pp.88-96
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• 1996

This study was conducted to establish model between lead and ZPP concentration in blood of workers exposed to lead. Workers employed in secondary smelting manufacturing industry showed $85.1{\mu}g/dl$ of blood lead level, exceeding $60{\mu}g/dl$, the Criteria for Removal defined by Occupational Safety and Health Act of Korea. Average blood lead level of workers in the battery manufacturing industry was $51.3{\mu}g/dl$, locating between $40{\mu}g/dl$ and $60{\mu}g/dl$, the Criteria for Requiring Medical Removal. Blood lead level of in the litharge and radiator manufacturing industry was below $40{\mu}g/dl$, the Criteria Requiring Temporary Medical Removal. Blood lead levels of workers by industry were Significantly different(p<0.05). 50(21 %) showed blood lead levels above $60{\mu}g/dl$, the Criteria for Removal and 66(27.7 %) showed blood lead levels between the Criteria for Requiring Medical Removal, $40-60{\mu}g/dl$. Thus, approximately 50 percent of workers indicated blood lead levels above $40{\mu}g/dl$, the Criteria Requiring Temporary Medical Removal and should receive medical examination and consultation including biological monitoring. Average ZPP level of workers employed in the secondary smelting industry was $186.2{\mu}g/dl$, exceeding above $150{\mu}g/dl$, the Criteria for Removal. Seventy seven of all workers(32.3 %) showed ZPP level above $100-150{\mu}g/dl$, the Criteria for Requiring Medical Removal. The most appropriate model for predicting ZPP in blood was log-linear regression model. Log linear regression models between lead and ZPP concentrations in blood was Log ZPP(${\mu}g/dl$) = -0.2340 + 1.2270 Log Pb-B(${\mu}g/dl$)(standard error of estimate: 0,089, ${\gamma}^2=0.4456$, n=238, P=0.0001), Blood-in-lead explained 44.56 % of the variance in log(ZPP in blood).

• 산업경영시스템학회지
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• 제19권37호
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• pp.31-40
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• 1996

The amount of safety stock is decided from various information such as the forecasted demand, the lead time, the size of the order quantity and the desired service level. There are two cases to consider the problem of setting safety stock when both the demand in a period and the lead time are characterized as random variables: the first case is the parameters of the demand and lead time distributions are known, the second case is they are unknown and must be estimated. The objective of this study is to present the procedure for setting safety stocks in the case the parameters of the demand and lead time distributions are unknown and must be estimated. In this study, a simple exponential smoothing model is used. to generate the estimates of demand in each period and a discrete distribution of the lead time is developed from historical data, and the optimal service level is used which determined to consider both of a backorder and lost sale.

• Journal of applied mathematics & informatics
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• 제5권1호
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• pp.253-261
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• 1998

(s,S) inventrory system of a perishable item with positive lead times and finite backlogs under N-policy Under this policy as and when the inventory level drops to s-N during a lead time local purchase is made. Three models are con-sidered. The limiting distribution on the inventory level is obtained and an associated cost analysis is made. Results ae numerically illustrated.

• Asian-Australasian Journal of Animal Sciences
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• 제13권10호
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• pp.1433-1439
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• 2000

An experiment was carried out with 48 IVRI 2CQ rats 6-8 week old, weighing 50-100 g, to study the effect of lead exposure on antioxidant defense, lipid peroxide level, status of thiol groups and concentration of lead in the liver and kidneys at the end of the exposure and also after withdrawal of lead administration. Twenty four rats were given lead at a daily dose rate of 1 mg lead/2 ml of distilled water/kg body weight as lead acetate solution intraperitoneally for a period of 30 days. Another 24 control rats received 2 ml of sterile normal saline solution (0.85% NaCl)/kg body weight in an identical manner. A many-fold increase in concentration of lead was associated with a non-significant (p>0.05) decrease in the activities of superoxide dismutase (SOD) in the liver (27%) and kidneys (12%) and catalase in kidneys (22%). A significant (p<0.05) increase in lipid peroxide level was recorded in the liver (40%) compared with control values. There were significant (p<0.05) decreases in the total thiol and protein bound thiol contents in liver and an increase in non-protein bound thiol groups in the kidneys of lead exposed rats. During the 10 day observation period after withdrawal of lead administration, no significant change was observed with respect to any of the above parameters indicating that a 10 day withdrawal period was not enough for restoration of normality. It is concluded that the magnitude of response and the resultant changes in the lipid peroxide concentration, and the activities of SOD and catalase were not identical in the liver and kidneys of lead-exposed rats.

• Journal of Preventive Medicine and Public Health
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• 제38권4호
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• pp.401-407
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• 2005

Objectives : We wanted to investigate the relationship between heavy metal, especially lead and mercury, to the blood pressure and cholesterol level in children. Methods : This study was undertaken in three primary schools and the study subjects were a total of 274 children. The lead in the blood and the urine mercury were analyzed by performing atomic absorption spectroscopy. Results : All of participants' blood lead levels and urine mercury concentrations were below the suggested level of concern according to the criteria of the CDC and ATSDR. We found no significant correlation between lead, mercury and the blood pressure. The blood lead level did not show any relationship with the blood pressure and cholesterol. However, the urine mercury levels were associated with the serum cholesterol. Conclusion : Our study suggests that mercury can induce an increase of cholesterol as a risk factor of myocardial infraction and coronary/cardiovascular disease.

• Journal of Nutrition and Health
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• 제29권6호
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• pp.597-607
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• 1996

This study has been investigated the potenial of increased dietary cysteine to alter the effects of cadmium and lead on tissure and bone metal concentrations, excretion and tissue metallothionein(MT) concentrations. Fifty-four male rats of Sprgue-Dawley strain weighing 149$\pm$17g were divided into 9 groups according to body weight. Nine experimental diets with different cadmium (0ppm, 400ppm), lead(0ppm, 710ppm) and cysteine (0.06%, 0.45%, 0.90%) levels were given to rats for 30 days ; Food intake, weight gain, F.E.R, and weights of liver, kidney and femur were decreased in cadmium supplied groups than in cadmium free groups. Urinary and fecal cadmium excretions were increased and MT synthesis we induced in liver, kidney and small intestine in cadmium supplied groups. In lead supplied groups, weight gain and F.E.R were decreased. With cysteine supplementation in cadmium supplied groups, weight gain and F.E.R, and weights of liver, kidney and femur were increased. Cadmium excretion in feces and MT concentrations in liver and kidney were also increased with cysteine supplementation. In lead supplied groups, there was no significant increase in food intake, weight gain and F.E.R with cysteine supplementation. Lead excretion in feces was increased in cysteine supplemented groups. In conclusion, effect of cadmium administration was more toxic than lead adminstration. Cysteine alleviated cadmium and lead toxicity by increasing metallothionein concentration and fecal excretions of heavy metals. Especially, effect of cysteine supplementation was more effective in cadmium groups than in lead groups. Effect of cysteine supplementation was not different with level of cysteine supplementation in both cadmium and lead groups.

• Environmental Analysis Health and Toxicology
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• 제6권1_2호
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• pp.7-23
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• 1991

The present study was undertaken to examine the effect of butylhydroxyanisole (BHA) on the lead poisoning in Wister female rats. All experimental rats except normal group were fed with diets formulated by adding BHA in a range of 0.1% to 3.2% and aqueous solution of 1% lead acetate ad libitum through the experimental period. The results obtained are summarized as follows: 1) Lead sedimentation in kidney tissue was decreased with increasing experimental period and BHA level of lead plus BHA-treated groups in comparison with that of lead-treated control group. 2) The weights of lung, spleen and left/right (L/R) kidney were significantly decreased in comparison with those of lead-treated control group after 2 weeks of experimental period, but no difference was shown with those of normal group. 3) The weights of lung, spleen and L/R kidney were increased in lead-treated control group as compared with normal group after 2 weeks of experimental period, but no difference was shown with increasing experimental period. 4) Water intake was remarkably decreased in lead-treated control group as compared with normal group, but water intake by increasing BHA level of lead plus BHA-treated groups showed no significant difference from that of normal group. 5) These results suggest that BHA is effective for reducing the toxic effect of lead in rats.

• 한국응용약물학회:학술대회논문집
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• 한국응용약물학회 2001년도 추계학술대회 및 정기총회
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• pp.91-91
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• 2001

Nramp2, also known as DMT1 and DCT1, is a 12-transmembrane domain protein responsible for dietary iron uptake as well as metal ions such as lead, manganese, zinc, copper, nickel, cadmium, and cobalt. High expression of DMT1 increase lead uptake, and DMT1-dependent lead transport was H -dependent and inhibited by iron ions. The molecular mechanism of lead transport in CNS is as yet unknown. although interactions between iron and lead at the level of absorption have been known for some time. The process of lead uptake into astrocytes was not known yet. Nramp2 may mediate transport of heavy metal into astrocytes. We investigated whether Nramp2 mediate transport of lead into astrocytes. And we do whether Nramp2 was expressed highly by deprivation of iron in Astrocytes, and lead uptake into astrocytes was influenced by expression of Nramp2. Immortalized human fetal astrocyte(SV-FHA) cells were cultured in medium containing Dulbecco's modified Eagle's medium and treated with Deferoxamine. Northern blot analysis was done for determining mRNA level of DMT1 and lead uptake assay was done in incubation condition of pH 5.5 and 7.4.

• Molecular & Cellular Toxicology
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• 제4권1호
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• pp.61-65
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• 2008

Although dietary intake of pregnant is supposed to have beneficial effects on development of infants, it may be harmful for fetal growth and development since specific food is a common source of toxicants including heavy metal. The purpose of this study was to investigate the association of maternal food intake and mid-pregnancy and their newborns blood lead levels. Pregnant women of 18-20 weeks of gestation were recruited from prenatal clinic in Seoul, Cheonan and Ulsan. In 422 pregnant women, dietary intake during pregnancy was assessed by a 24-hour recall method. Blood sample from pregnant (18-20 wks) and their cord blood at delivery were collected. Blood leas levels were analyzed by atomic-absorption spectrometry methods. Pregnant blood lead levels whose meat and meat products intake were in the highest quartile was significantly higher compared to the lowest quartile. Maternal meat and meat products intake was positively correlated maternal blood lead level (r=0.120, P=0.014). After adjusting for age, maternal blood lead level was positively correlated with their newborn blood lead level (r=0.303, P=0.030). As maternal food intake effects on blood lead levels of pregnant, careful regulation of food intake during pregnancy is perceives to be important in order to bring about desirable pregnancy outcomes.

• 한국식품영양학회지
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• 제6권3호
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• pp.211-218
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• 1993

This study was carried out to estimate the dally intake of lead and the relationship among dietary In take, serum level, and urinary excretion of calcium In 30 healthy adults living In rural area of Korea (12 males and 18 females). Analyses for the nutritional status of the subjects were performed by 3-day dietary intake record, duplicated diet collection, 24-hour urine collection, and venous blood sampling. The results were as follows The mean daily intake of energy was 2,176.3kcal and 1,613.9kcal in males and (tamales of 20∼49years, and 1,914.8kcal and 1,517.9kcal in males and females of 50∼59years, respectively The ratio of carbohydrate : fat : protein was 73.4:13.6:13.0 in males and 76.4:10.3:13.3 In females. The mean daily intake of lead was 277.2Pg in males and 192.0ug in females. The mean daily intake, serum level, and urinary excretion of calcium were 491.1mg, 8.9mg/dl, and 80.7mg in males and 426.7mg, 8.8mg /dl, and 80.3mg in females, respectively. No significant correlation was found between the daily lead intake and the dietary intake, serum level, and urinary excretion of calcium. It was concluded that the daily lead intake was lower than the acceptable daily lead intake of FAO/WHO but a little higher than that of other investigations. And the daily lead intake was not level that relate to calcium status seriously.