• Journal of Nutrition and Health
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• v.31 no.8
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• pp.1324-1377
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• 1998

This study was conducted for two purposes ; (1) to develop a database for zinc levels in commonly usef Korean food items ; and (2) to calculated the zinc intake fo Korean adults living in a rural area. The currently used Korean food compositinotable was supplemented in term sof zinc content using several methods ; (1) analyzing 98 Korean Food items frequently consumed by Korean adults living in rural area. ; (2) adapting values from U.S Minnesota for 71 items ; and (3) imputing values from similar food for 282 items. A new zinc nutrient databse was constructed including zinc contentrs of 1,195 food items. Zinc intake of rural Korean adults was estimated by a 240hours recall method from 2 ,037 adults over 30 over 30years of age in Yeonchon -gun , Kyunggi province of Korea. Mean daily zinc intake of all subjects was 61mg an dmean intake level of males (7.0mg/day, 46.85 of RDA) was significantly thigher than females(5.2mg/day, 43.0% of RDA). Subjects in their 40's had the highest zinc intak ewhile those over 70 years of age consumed the least amount of zinc. The food group that contributed most to the dietary ainc intake of subjects was cereals and grain products supplying 38% of total zinc intake. The next most important group for zinc intak ewas the meat, poultry , and product group supplying 26% ot total intake. This group was followed by fishes and shellfishes, legumes and their products, and vegetales . For individual food items , reicecontribued most, supplying 27% of total zinc intake follwoed by beef(10%) and prok(9%) . Altogether, plant foods supplied 68% of zinc intake suggesting that the bioabailability of dietary ainc is low. In conclusion, these results show ethat the zinc intake of rural Korean adults is low and that sources of dietary zinc are mainly plant foods, suggesting low bioavailability . Further studies are needed to determine zinc intake and status of Korean population. The zinc database developed in this study will be very valuable for such studies.

• Journal of Nutrition and Health
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• v.32 no.6
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• pp.705-712
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• 1999

The purpose of this study was to assess the zinc and copper nutritional status of 102 college women by measuring zinc and copper intake, hematological parameters of zinc and copper, hair zinc and urinary excretion of zinc and copper. The mean zinc intake was 5.5mg(45.8% RDA) with food analysis and 4.5mg(37.8% RDA) with computation from food composition table. The copper intake with food analysis was 2.3mg and 1.2mg with computation. Mean serum zinc concentration was 77.02ug/dl and the proportion of subjects with zinc deficiency estimated by serum zinc(<70ug/dl)was 23.0%. Mean serum copper concentration was 121.80ug/dl and 4.1% of subjects showed serum copper less than 70ug/dl, The mean ceruloplasmin concentration was 22.63mg/dl and the proportion of subjects whose ceruloplasmin was lower than 18-40mg/dl was 6.6%. The mean hair zinc of subjects was 143.8ppm and the mean hair copper was 11.2ppm. The mean urinary excretion of zinc was 0.43mg/day and the proportion of subjects with marginal deficiency estimated by urinary zinc excretion( <0.3mg/day) was 23.3%. The mean urinary copper excretion was 0.044mg/day which was within the normal range(0.01-0.06mg/day). Assessing by zinc content in hair, urine and serum, 22.9-23.3% of college women had bordeline zinc deficiency or zinc deficiency. Whereas 4.1-6.6% of college women was assessed copper deficiency estimated by serum copper and ceruloplasmin.

• Journal of Environmental Science International
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• v.7 no.3
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• pp.401-408
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• 1998

An experimental research was preformed for the development of an effective process for zinc oxide waste(zinc ash) reuse. Zinc was selectively leached from zinc ash by 30 vol.% D2EHPA In kerosine solution, and the leaching velocity was quite fast. Zinc leached was stripped by sulfuric acid solutions, and the amount of zinc stripped was linearly Increased with the amount of sulfuric acid used. Zinc oxide fine particles were obtained by dropwise adding of sodium hydroxide solution to the resultant aqueous zinc solution at 85$^{\circ}C$.

• Molecular & Cellular Toxicology
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• v.3 no.4
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• pp.292-298
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• 2007

Zinc plays indispensable roles in metabolism, including cell growth, apoptosis, proliferation and differentiation. Kidneys are target organs for various regulators of mineral metabolism, and play a key role in zinc balance. To investigate the zinc uptake efficiency, we examined the zinc uptake and accumulation level in vivo and in vitro study. Plasma zinc concentration was peaked out at 1 hr after oral zinc administration. The renal zinc level was peaked out at 12 hr after oral zinc administration, and it was the highest in 40 mg/kg Zn-Asp administrated group in comparison with other groups. In addition, the m-RNA expression level of zinc transporter-1 (ZnT-1), zinc transporter-2 (ZnT-2) and high-affinity L-aspartate transporter (EAAT-3) in Zn-Asp administered group were increased compared with control groups and $ZnSO_4$ group. In order to investigate the intracellular zinc uptake mechanism, we performed the in vitro study by using human embryonic kidney cell line, HEK 293. Intracellular zinc level was peaked out at 3 hr after zinc treatment. In the same way, the mRNA expression level of ZnT-1 and EAAT-3 were increased compared with control group. This study showed that Zn-Asp is effective the zinc uptake into the kidney by increasing the zinc transporter expression.

• Journal of Nutrition and Health
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• v.22 no.6
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• pp.539-546
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• 1989

This study was carried out to investigate the effect of addition of cellulose in the diet on the metabolism in rat fed high and low level of zinc. The experimental animals were consisted of 24 male weaning rats of Sprague-Dawley strain(mean weight 72.3g), and they were devided into 4 groups of 6 rats and fed experimental diets for four weeks. Dietary zinc levels used were 10 ppm, and 300ppm and cellulose levels were 2.5% and 10% of diet by weight. Throughout the experimental period, feed consumption and body weight gain were measured and feed efficiency ratio was calculated. The weight of live, kidney and spleen were measured, and the contents of zinc in feces, urine, liver, kidney, spleen and serum were determined. The results obtained are summarized as following ; 1. Body weight gain in high zinc-adequate cellulose group was significantly higher than the other groups. Feed consumptions were significantly higher in high zinc groups and no significant difference was found with dietary cellulose levels. 2. Fecal zinc excretions of four groups were not different at the first week, but at the end of fourth week, high zinc groups experince significantly more zinc excretion than low zinc groups, and also high cellulose groups had higher zinc contents in the feces than the adequate ones within the same zinc levels(p<0.05). There was no significant difference in the urinary zinc excretion. 3. The weights of liver, kidney and spleen were heavier in the high zinc groups than the lower ones, and higher in the high cellulose groups(p<0.05). The liver zinc contents were significantly lower in the low zinc and high cellulose groups. However zinc contents in the kidney and serum were not influenced by dietary zinc level but by cellulouse level. High cellulose diet lowered serum and kidney zinc concentrations(p<0.05).

• Asian-Australasian Journal of Animal Sciences
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• v.18 no.3
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• pp.439-452
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• 2005

Zinc is ubiquitous in all living cells. Structural and catalytic properties of cellular enzymes are zinc dependent. Zinc deficiency leads to a variety of pathological abnormalities with immune impairment. It is an established fact that nutritional status contributes to overall immune response of individuals. Outcome of zinc deficiency on immune system is so drastic that it is difficult to conceive at the first instance. Zinc supplementation has been advocated to prevent diarrheal disease in children with poor nutritional status. The bioavailability of zinc depends upon its sources. Moreover it varies between monogastrics and ruminants. Controversy still prevails between inorganic and organic sources of zinc with respect to their superiority in bioavailability. Zinc exerts immunostimulatory effects in various laboratory and farm animals. Animals having congenital zinc deficiency diseases like A46 lethal trait usually die due to impairment of the immune system unless treated with zinc. The immune mechanism of zinc and its effect on animals and man are discussed. Zinc has been considered as extremely safe at higher therapeutic doses, but does not provide any beneficial effect but rather may cause immunosuppression. More recently, zinc has been prescribed for immunodeficient hosts, to modulate the immune system so that to a certain extent it can combat against opportunistic pathogens.

• Journal of Nutrition and Health
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• v.5 no.2
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• pp.91-103
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• 1972

Zinc is one of the essential trace elements in the living organism for growth and health. The first identified metalloenzyme, carbonic anhydrase, is a zinc compound and several others have been described since. Among zinc deficiency syndromes in animals porcine parakeratosis has been successfully treated with zinc supplements, and in man a syndrome of anemia, hypogonadism, hepatosplenomegaly, and dwarfism, prevalent in parts of Iran and Egypt, has been ascribed to lack of zinc in the diet. Dietary zinc excess in the rat is manifested by a hypochromic, microcytic anemia, poor growth, reduction in liver catalase and cytochrome oxidase. The present study is an attempt to delineate the changes of tissue contents of trace elements, especially of iron, copper and zinc in liver and kidneys of the rats. Weanling albino rats, weighing 60 to 80gm. were used in this experiments. The rats were housed in cages with aluminum floors and received feed and distilled water ad libitum. Animals were divided into three groups, control, low zinc diet and high zinc diet groups. The high zinc diet group was subdivided into 0.5% Zn and 0.7%Zn groups. The supplementary copper or iron was added to the high dietary zinc groups. The animals were sacrificed and the tissues were washed several times with deionized water. The wet digested samples were analyzed by Hitachi Model 207 atomic absorption spectro-photometer for the determination of iron, copper and zinc in the liver and kidney. Hemoglobin level in the blood was measured by cyanmethemoglobin method. The results of this study are as follows: 1) All rats fed high zinc diets and low zinc diets gained less weight than control. Weight gain was not improved by the supplementary copper or iron and both. 2) Hemoglobin concentration was decreased significantly in the rats fed high zinc diets and less in the low zinc diet. Supplementary copper and iron to the higher zinc diet appeared to give some improvement of anemia. 3) The iron contents of the liver and kidneys were significantly decreased in the high zinc groups and the reduction was more significantly in the rats receiving higher zinc diet (0.7%). The supplementary copper caused a further depression of liver iron. On the other hand, the iron, added to the high zinc diet lessoned the severity of the decrease in liver iron and caused kidney iron to be maintained almost at the level found in the rats fed by zinc and supplementary copper diet. 4) High zinc diets did not change copper content of the liver and kidney. Supplementary copper elevated the concentration in the liver and kidney and added iron had no effect on the accumulation of copper in the liver and kidneys. 5) The high zinc diets caused marked increases of zinc content in the liver and kidney. Supplementary iron to the high zinc diet caused increases of zinc contents of liver and kidneys.

• Journal of Nutrition and Health
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• v.30 no.4
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• pp.394-405
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• 1997

Endogenous zinc is important for maintaining zinc homeostasis because the size of endogenous zinc pool is almost 3-4 times bigger than that of dietary zinc. The purpose of this study was to examine the phytate effect on the reabsorption of endogenous zinc and the additional Ca effect on the phytate effect. Rats were fed a casein-based diet with added sodium phytate containing either high(1.6%) or low(0.8%) Ca concentrations for 4 weeks to reduce the body zinc pool. After the depletion period, $^{65}$ Zn was given by intraperitoneal injection to label the endogenous zinc pool. Rats were then assigned into phytate or non-phytate group within the same Ca group. feces were collected for 2 weeks of the initial collection period and 1 week after dietary crossover. The ratios of excreted fecal $^{65}$ Zn radioactivity of phytate group non-phytate group were determined as a measure of the phytate effect on the endogenous zinc. Mean fecal $^{65}$ Zn radioactivity was higher in the phytate group than in the non-phytate group during the entire 3 weeks of the collection period in the low Ca group, and during the initial collection period in the high Ca group(p <0.0001). This study showed an adverse phytate effect on endogenous zinc at both high and low dietary Ca levels. Elevated dietary Ca levels showed a synergistic effect on the phytate effect on endogenous zinc(p <0.05). These results imply greater phytate effect on zinc homeostasis rather than on zinc bioavailability through complexing with the endogenous zinc which is larger portion than the dietary zinc on zinc homeostasis.

• Preventive Nutrition and Food Science
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• v.9 no.1
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• pp.79-84
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• 2004

Zinc intake and status of South Koreans from rural, urban and metropolitan areas were investigated. The dietary habits of 760 healthy male and female adult subjects with a mean age of 54 were assessed using a food frequency questionnaire and were verified using 24 h dietary recall. Daily Zn intakes for men and women were 7.4$\pm$5.4 mg and 7.0$\pm$5.4 mg, respectively, which were 62% and 70% of the Korean RDA. The phytate : zinc and phytate ${\times}$ calcium : zinc molar ratios were 38 and 398, respectively. Both the low intake of zinc and the high extremely phytate and phytate ${\times}$ calcium ratios with Zinc suggest that South Koreans may be at risk of zinc deficiency. Plasma zinc (86$\pm$61 $\mu\textrm{g}$/dL), urinary zinc (33$\pm$27 $\mu\textrm{g}$/dL) and plasma alkaline phosphatase (102$\pm$52 mU/mL) levels within the normal range did not however suggest marked Zinc deficiency in these subjects. However, conventional zinc biomarkers aye known to be unreliable for assessment of marginal zinc deficiency. Based on zinc intake alone, it is likely that at least a proportion of these subjects were marginally zinc deficient and the wider consumption of zinc rich, phytate deficient foods, particularly in rural areas, would be beneficial.

• Nuclear Engineering and Technology
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• v.11 no.1
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• pp.47-54
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• 1979

A field experiment has been carried out to evaluate the residual effect of zinc fertilizers by rice plant grown under flooded conditions in the field. The results obtained are summarized as fellows ; Residual effect of zinc fertilizers on yields of rough and hulled grains showed slight increases. Effect of zinc application methods on yields of the grains were shown that zinc mixed treatment could be more effectively utilized than treatment of zinc on the soil surface. In case of levels of zinc application, 5 kg zinc per hectare represented high yields of the grains than those obtained from 10kg and 20kg zinc placement per hectare respectively. Regarding the form of zinc fertilizers, the urea-zinc complex showed less effective on yields of the grains than did the zinc sulfate. This phenomenon was consistent with the previous result. Yields of total zinc in rice plant grown on the rice straw added soils (Treatment No. 2 and 8) and the urea-zinc complex treated soil were increased markedly as compared to those data obtained from the previous year. The percentage of zinc derived from fertilizer decreased largely as compared to that of the first year crop. The yield of fertilizer zinc in rice plant decreased slightly in the most zinc treatments but in the case of treatments of zinc mixed with the straw added soil and the urea-zinc complex increased reversely as compared to the previous results. The mixed application of zinc with soil showed higher yield of fertilizer zinc than the soil surface placement. Approximately from 4.6 to 24.3 per cent of zinc taken up by rice plants were derived from the fertilizer zinc. Zinc fertilizer use efficiency ranged from 0.213 to 0.584 per cent when 5 kg zinc per hectare applied.