• Environmental Analysis Health and Toxicology
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• v.19 no.4
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• pp.359-366
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• 2004

Iron (Fe) is an essential metal in biological processes, which maintains a homeostasis in the human body. Divalent metal transporter 1 (DMT1) has been known as an iron transporting membrane protein, which is involved in the uptake Fe at the apical portion of intestinal epithelium, and may transport Fe across the membrane of acidified endosome in peripheral tissues. In this study, we studied the tissue distribution of DMT1 in the Fe supplemented (FeS) diet fed rats, and the regulation of DMT1 expression by depleting body Fe. Sprague-Dawley rats were divided into two groups, and fed FeS (120 mg Fe/kg) diet or Fe deficient (FeD, 2∼6 mg Fe/kg) diet for 4 weeks. The evaluation of body Fe status was monitored by measuring sFe, UIBC and tissue Fe concentration. Additionally, DMT1 mRNA levels were analyzed in the peripheral tissues by using the quantitative real time RT-PCR method. In the FeS diet fed rats, the tissue Fe was maintained at a relatively high level, and DMT1 was eventually expressed in all tissues studied. DMT1 was highly expressed in the testis, kidney and spleen, while a moderate levels of DMT1 expression was detected in the brain, liver and heart. In the digestive system, the highest level of DMT1 was found in the duodenum. Feeding the FeD diet caused a reduced body weight gain and depletion of body Fe with finding of decreased sFe, increased UIBC and decreased tissue Fe concentration. The depletion of body Fe upregulated DMT1 expression in the peripheral tissue. The expression of DMT1 was very sensitive to the body Fe depletion in the small intestine, especially in the duodenum, showing dramatically higher levels in the FeD rats than those of the FeS group. In the FeD diet fed animals, the expression of DMT1 was low significantly in other tissues compared with the duodenum. The expression of DMT1, however, was 60∼120% higher in the testis, kidney and spleen, and 30∼50% higher in the lung, liver and heart, compared to the FeS diet fed rats. In summary, DMT1 expression was ubiquitous in mammalian tissue, and the level of expression was the organ-dependent. The expression of DMT1 in peripheral tissues was upregulated by depletion of body Fe. Duodenum was the most sensitive tissue among organs studied during Fe depletion, and expressed the greatest level of DMT1, while other tissues were less higher than in duodenum. This study supports that DMT1 plays a role in maintaining the body Fe level through intestinal uptake as well as homeostasis of Fe in the peripheral tissue.

• Toxicological Research
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• v.23 no.3
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• pp.279-287
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• 2007

Copper (Cu) is an essential trace element indispensable for brain development and function; either excess or deficiency in Cu can cause brain malfunction. While it is known that Cu and Fe homeostasis are strictly regulated in the brain, the question as to how systemic Fe status may influence brain Cu distribution was poorly understood. This study was designed to test the hypothesis that dietary Fe condition affects Cu transport into the brain, leading to an altered brain distribution of Cu. Rats were divided into 3 groups; an Fe-deficient (Fe-D) group which received an Fe-D diet ($3{\sim}5 mg$ Fe/kg), a control group that was fed with normal diet (35mg Fe/kg), and an Fe-overload group whose diet contained an Fe-O diet (20g carbonyl Fe/kg). Following a 4-week treatment, the concentration of Cu/Fe in serum, CSF (cerebrospinal fluid) and brain were determined by AAS, and the uptake rates of Cu into choroids plexus (CP), CSF, brain capillary and parenchyma were determined by an in situ brain perfusion, followed by capillary depletion. In Fe-D and Fe-O, serum Fe level decreased by 91% (p<0.01) and increased by 131% (p<0.01), respectively, in comparison to controls. Fe concentrations in all brain regions tested (frontal cortex, striatum, hippocampus, mid brain, and cerebellum) were lower than those of controls in Fe-D rats (p<0.05), but not changed in Fe-O rats. In Fe-D animals, serum and CSF Cu were not affected, while brain Cu levels in all tested regions (frontal cortex, striatum, hippocampus, mid brain, and cerebellum) were significantly increased (p<0.05). Likewise, the unidirectional transport rate constants $(K_{in})$ of Cu in CP, CSF, brain capillary and parenchyma were significantly increased (p<0.05) in the Fe-D rats. In contrast, with Fe-O, serum, CSF and brain Cu concentrations were significantly decreased as compared to controls (p<0.05). Cu transport was no significant change of Cu transport of serum in Fe-O rats. The mRNA levels of five Cu-related transporters were not affected by Fe status except DMT1 in the CP, which was increased in Fe-D and decreased in Fe-O. Our data suggest that Cu transport into brain and ensuing brain Cu levels are regulated by systemic Fe status. Fe deficiency appears to augment Cu transport by brain barriers, leading to an accumulation of Cu in brain parenchyma.

• Journal of Forest and Environmental Science
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• v.32 no.1
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• pp.20-26
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• 2016

DTPA (Diethelene-triamine pentaacetic acid) extractable micronutrients of surface soil samples from six different locations of Cox's Bazar and Chittagong districts were studied. All the soils under study were sufficient in DTPA extractable Fe, Mn and Cu contents. The available Zn contents in soils of Dulhazara, Chengchhari and Faissakhali under study were also above the critical limit while soils at Fulchhari, Hasnabad and CU were deficient in available Zn. The study also showed that DTPA extractable Fe content had the significant and positive relationships with clay and soil organic carbon. On the hand, negative and significant relationship was observed between extractable Mn and soil pH while DTPA extractable Zn and Cu were positively and significantly correlated with soil organic carbon of the studied area.

• Journal of the Korean Ceramic Society
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• v.17 no.2
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• pp.89-95
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• 1980

The effect of non-stoichimetry and sintering temperature on the magnetic properties of materials in the system $Ni_{0.39}Zn_{0.61}Fe_{2.0+x}O_4$ have been investigated. The value of x used in initial weighing of oxides were varied from -0.04 to -0.12. The value of x, however, appears to be from +0.04 to -0.04 after ferrite powder preparation due to iron pick up during ball mill mixing and grinding. The densities of specimens which were deficientinrion were higher than those with excess ion. Specimens with near stoichiometric composition showed maximum initial permeability an dminimum coercivity whereas high values of quality factor (Q) were observed in iron deficient specimens. The quality factor decreased monotonically with increasing sintering temperature, but the permeability showed maxima with increasing sintering temperature. Thus highest value of figure of merit $\mu$Q was obtained in composition $Ni_{0.39}Zn_{0.61}Fe_{1.98O4}$ sintered at 100$0^{\circ}C$ for 3 hrs. in an air atmosphere.

• Bulletin of the Korean Chemical Society
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• v.20 no.11
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• pp.1313-1318
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• 1999

Lewis bases were employed to control the stoichiometry of ferrite film prepared by light enhanced plating (LEP) technique. When 2,2'-bipyridyl was used as a Lewis base, conversion electron Mosbauer spectroscopy (CEMS) and x-ray powder diffraction (XRD) experiments showed that the main component of the ferrite films was metal-deficient magnetite (Fe3(1-δ)O4). Nonstoichiometry and roughness of LEP films were increased by the addition of 2,2'-bipyridyl. Using ethylenediaminetetraacetate (EDTA) as a Lewis base, produced film that was a mixture of magnetite and Υ-FeO(OH). No low temperature transition (Verwey transition) of magnetite was detected in resistivity and ac-susceptibility measurements for the LEP films. Surface morphology of the LEP films was observed by atomic force microscopy (AFM). The size of dominant particles was about 0.2 μm.

• Journal of Nutrition and Health
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• v.33 no.2
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• pp.147-157
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• 2000

This study examined the effects of excess intake of calcium (Ca) and iron (Fe) supplement on bone loss, nephrocalcinosis and renal function in osteoporotic model rats. Seven-week-old female rats were first fed a Ca-deficient diet for four weeks after ovariectomy operation, and then one of nine experimental diets for additional eight weeks, containing three levels of Ca, normal (0.5%) or high (1.5%) or excess (2.5%) and three levels of Fe, normal (35ppm) or high (210ppm) or excess (350ppm). The osteoporotic model rats showed a remarkable increase in body weight, serum alkaline phosphatase (ALP) and decrease in breaking force, Ca, P, Mg contents of femur. Serum Ca concentration was not significantly affected by dietary Ca and Fe levles. Liver Ca content increased in rats fed a high-and excess-Ca diet. Kidney Ca content and microscopic Ca deposition remarkably increased in osteoporotic model rats compared to control group, and showed a tendency to decrease in rats fed a excess-Ca diet. Breaking force of femur increased with increasing dietary Ca levels, but Ca, P contents of femur and serum ALP were not significantly affected by dietary Ca and Fe levels. Serum total protein decreased in rats fed a excess-Ca diet, BUN increased in rats fed a excess-Ca diet, while serum uric acid and creatinine were not significantly affected by dietary Ca levels. Urinary creatinine, GFR increased in rats fed a high-and excess-Ca, diet, and GFR was highest in rats fed a excess-Ca/excess-Fe diet. These results suggest that excess intake of Ca may increase breaking force of femur, but not increase mineral contents of femur, and decrease kidney function. Furthermore, excess intake of Fe and Ca concurrently may aggravate kidney function leading to potential health problems in ovariectomized osteoporotic model rats.

• Journal of Nutrition and Health
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• v.40 no.4
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• pp.362-370
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• 2007

The study was designed to assess the effect of iron and cereal supplementation on children's iron nutritional status in social welfare institutions. Dietary survey was carried out methods of food weighing and record by interview (n=74). A nutritional intervention study was carried out through supplementing iron supplements and cereal for 4 weeks in 4-12 years old children. Children received daily 40 mg elemental Fe as iron protein succinylate (n=23) and 3.6 mg elemental Fe as 100 g cereal (n=24), respectively. Blood samples were drawn before and after supplementation. Nutrients which children's intake was less than two-thirds of the RDA were vitamin A, vitamin B-1, vitamin B-2, calcium and iron. The mean daily intake of iron was 5.1 mg for male and 4.9 mg for female, and 52.3% for male and 45.4% for female of Korean RDA. The proportion of children with iron depletion assessed by TIBC (> 360 ${\mu}g$/dl) and serum ferritin (< 20 ng/ml) were 56.6% and 58.7%, respectively. The proportion of children with the iron deficient erythropoiesis assessed by serum iron (< 70 ${\mu}g$/dl), Hb (< 12 g/dl), Hct (< 36%) were 76.0%, 58.7%, 64.0%, respectively. After iron supplements treatment, Hb (p<0.001), Hct(p<0.001), serum iron (p<0.001), transferrin saturation (p<0.001) and serum ferritin (p<0.Ol) increase significantly and only TIBC decreased slightly. After cereal supplementation, in anemic children, Hct (p<0.001), serum iron (p<0.001) and transferrin saturation (p<0.001) were significantly increased. The effect of iron supplements and cereal supplementation in children with iron deficient erythropoiesis were more effective to improve the iron nutritional status than children with iron depletion. It was concluded that cereal supplementation program in anemic children was also effective to improve iron nutritional status.

• Journal of the Korean Society of Food Culture
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• v.18 no.6
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• pp.575-583
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• 2003

To evaluate the effect of cereal supplementation on children's iron nutritional status of Korean institutionalized was designed. Dietary survey was carried out methods of food weighting in the breakfast or/and dinner, and record interview in lunch (n=74). A nutritional intervention study was carried out through supplementing cereal for 4 weeks in 24 children of 1 institution from 4 to 12 years. The children received 3.6mg elemental Fe(as 100g cereal) per day. Blood samples were drawn before and after supplementation. Nutrients which children's intake was less than two-thirds of Korean RDA were Vit A, Vit B1, Vit B2, Ca and Fe. The mean daily intakes of iron were 5.1mg for male and 4.9mg for female and 52.3% for male and 45.4% for female of Korean RDA. The proportions of children with iron depletion assessed by TIBC(>360mg/dl) and serum ferritin(<20ng/ml) were 56.6% and 58.7%, respectively. The proportions of children with the iron deficient erythropoiesis assessed by serum iron(<70ml/dl), Hb(<12g/dl), and Hct(<36%) were 76.0%, 58.7%, and 64.0%, respectively. After cereal supplementation, in anemic children, levels of Hct(p<0.001), serum iron(p<0.001) and transferrin saturation(p<0.001) were significantly increased. The effect of cereal supplementation in children with iron deficient erythropoeisis was more effective to improve the iron nutritional status than children with iron depletion. It was concluded that cereal supplementation program in anemic children was also effective to improve iron nutritional status.

• Korean Journal of Soil Science and Fertilizer
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• v.8 no.4
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• pp.195-198
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• 1975

Boron deficiency appeared as a cause of poor growth of sunflower(Helianthus annuus) according to soil and plant analysis. The investigated results are as follows; 1. Boron deficiency was due to low content of available boron (hot water soluble) in soil and clitical concentration appeared as 0.17 ppm. 2. Clitical concentrations in plant appeared to be 20 ppm for head(flower), 25 for leaf, 15 for stem and 10 for root. Boron concentration among positional leaves was greatly decreasing in the upper leaves. 3. Soils low in boron were relatively higher in calcium, silica and pH than in normal soil but relationship between boron and organic matter or other nutrients was uncertain. 4. The content of Ca and P is high in the head of boron deficient plant but low in root. Plants deficient in boron also showed a tendency of high N and low K but no clear tendency was shown in Mg and Fe. 5. Symptoms of boron deficinicy were yellowing of upper leaves, browning and drying of upper part of stem, cracking and blackening of stem and roots resulting short stem and poor growth.

• Journal of the Korean Society of Food Science and Nutrition
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• v.39 no.10
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• pp.1446-1451
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• 2010

Silk sericin protein was hydrolyzed by seven proteolytic enzymes to examine the effectiveness of the hydrolysates to bind iron. The amino acid nitrogen contents of hydrolysates by Flavourzyme were higher than the others enzymes, and its iron binding capacity showed dose-dependent increase. The bioavailability of iron binding peptide from sericin hydolysates was investigated in iron-deficient rats. Three-week-old male rats were fed iron-deficient diet for three weeks. Rats were divided into four groups (DD: no treated group on iron deficient diet, DD+HI: heme-iron treated group, DD+OI: sericin-Fe, and DD+II: inorganic iron ($FeSO_4$) treated group, and then iron supplemented by injection for one week. After oral administration for one week, the iron contents of serum and liver were significantly higher in DD+OI ($4.2\;{\mu}g/mL$ and $80.1\;{\mu}g/mL$) and DD+HI ($3.2\;{\mu}g/mL$ and $70.6\;{\mu}g/mL$) than DD ($2.0\;{\mu}g/mL$ and $47.9\;{\mu}g/mL$). Hemoglobin content of treated groups was significantly higher than DD, but the significant difference among groups was not shown. Aspartate aminotransferase (AST) and alanine aminotransferase (ALT) levels did not show any significant difference among all groups. Binding iron to peptide from sericin hydolysates seems to improve its bioavailability and to hasten the cure of iron deficiency in experimental rat.