• Journal of Community Nutrition
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• v.6 no.2
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• pp.91-96
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• 2004

The purpose of this study was to evaluate the folate nutritional status of Korean pregnant women and to investigate the relation between folate levels of maternal-umbilical cord blood, placenta tissue, and pregnancy outcomes. The study subjects consisted of 25 pregnant women who have had normal term deliveries. Dietary folate intakes of the pregnants were estimated by semi quantitative frequency questionnaire and the serum and placenta tissue folate level was measured by microbiological analysis. The total folate intakes of the pregnant women was 655.6 ${\mu}$g/d, which was 131.1% of the Korean RDA for pregnants. Maternal serum folate level was 16.18ng/ml, which was significantly lower than that of umbilical cord blood (34.98ng/ml, p<0.05). Mean folate concentration of the placental tissue was 998.0ng/ml, which was the highest compared to maternal and umbilical cord serum level. Umbilical cord serum folate level and placental tissue folate level were highly influenced by maternal serum folate level. The umbilical cord folate levels of the infant group whose birth weight was higher than 3500g were significantly higher than the group whose birth weight was less than 3500g (p<0.05). The placental folate level was significantly higher in maternal group who showed desirable weight gain during pregnancy (11 - 14kg). In conclusion, the birth weigt was related to the umbilical cord folate level and the maternal weight gain was affected by the placental folate level.

• Journal of Biomedical Engineering Research
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• v.30 no.1
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• pp.18-22
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• 2009

Laser has been widely used in various fields of medicine. Recently, noninvasive low-level laser therapeutic medical devices have been introduced in market. However, low-level laser cannot deliver enough photon density to expect positive therapeutic results in deep tissue layer due to the light scattering property in tissue. In order to overcome the limitation, this study was aimed to develop a negative pressure applied low-level laser probe to optimize laser transmission pattern and therefore, to improve photon density in soft tissue. In order to evaluate the possibility of clinical application of the developed laser probe, ex-vivo experiments were performed with porcine skin samples and laser transmissions were quantitatively measured as a function of tissue compression. The laser probe has an air suction hole to apply negative pressure to skin, a transparent plastic body to observe variations of tissue, and a small metallic optical fiber guide to support the optical fiber when negative pressure was applied. By applying negative pressure to the laser probe, the porcine skin under the metallic optical fiber guide is compressed down and, at the same time, low-level laser is emitted into the skin. Finally, the diffusion images of laser in the sample were acquired by a CCD camera and analyzed. Compared to the peak intensity without the compression, the peak intensity of laser increased about $2{\sim}2.5$ times and FWHM decreased about $1.67{\sim}2.85$ times. In addition, the laser peak intensity was positively and linearly increased as a function of compression. In conclusion, we verified that the developed low-level laser probe can control the photon density in tissue by applying compression, and therefore, its potential for clinical applications.

• The Journal of Advanced Prosthodontics
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• v.12 no.5
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• pp.316-321
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• 2020

PURPOSE. The stress distribution and microgap formation on an implant abutment structure was evaluated to determine the relationship between the direction of the load and the stress value. MATERIALS AND METHODS. Two types of three-dimensional models for the mandibular first molar were designed: bone-level implant and tissue-level implant. Each group consisted of an implant, surrounding bone, abutment, screw, and crown. Static finite element analysis was simulated through 200 N of occlusal load and preload at five different load directions: 0, 15, 30, 45, and 60°. The von Mises stress of the abutment and implant was evaluated. Microgap formation on the implant-abutment interface was also analyzed. RESULTS. The stress values in the implant were as follows: 525, 322, 561, 778, and 1150 MPa in a bone level implant, and 254, 182, 259, 364, and 436 MPa in a tissue level implant at a load direction of 0, 15, 30, 45, and 60°, respectively. For microgap formation between the implant and abutment interface, three to seven-micron gaps were observed in the bone level implant under a load at 45 and 60°. In contrast, a three-micron gap was observed in the tissue level implant under a load at only 60°. CONCLUSION. The mean stress of bone-level implant showed 2.2 times higher than that of tissue-level implant. When considering the loading point of occlusal surface and the direction of load, higher stress was noted when the vector was from the center of rotation in the implant prostheses.

• Journal of Nutrition and Health
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• v.19 no.5
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• pp.304-314
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• 1986

To observe the effect of the different level of PUFA and marginal tocopherol supplement on HDL-chol, tissue tocopherol content and fatty acid composition, the rats were supplied either safflower oil or conconut oil with or without tocopherol supplement to the experimental diet. Plasma tocopherol level was not greatly influenced by the different dietary fat and similar effect was observed in the liver but not in the adipose tissue. HDL-chol level was reduced in the high PUFA diet regardless of tocopherol content. No effect by tocopherol supplement was observed in the fatty acid composition of liver and adipose tissue lipid in both dietary PUFA levels . There was also no increase in the content of tissue polyenoid acid by tocopherol in the high PUFA diet . Fatty acid composition of tissue lipid was rather more influenced by dietary fat. Lauric and myristic acid contents were higher in the low PUFA diet and linoleic acd and total polynoic acid content were higher in the high PUFA diet. With tocopherol supplement tocopherol /PUFA ratio of tissue was increased but the ratio of high PUFA diet was significantly lower than that of low PUFA diet. Marginal tocopherol supplement could not reduce the peroxidizability index of high PUFA diet.

• Nuclear Engineering and Technology
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• v.51 no.1
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• pp.303-309
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• 2019

Tritium is an important nuclide that must be monitored for radiation safety management. In this study, HTO was orally administered to rats at the level of 37 kBq ($1{\mu}Ci$) or 370 kBq ($10{\mu}Ci$) to examine tissue distribution and excretion levels. After sacrifice, wet and dry tissue samples were weighed and analyzed for tissue free-water tritium (TFWT) and organically bound tritium (OBT). The mean tissue concentrations of TFWT (OBT) were 30.9 (17.8) and 4.4 (8.1) Bq/g on days 7 and 13 at the 37 kBq level and 30.8 (64.6) Bq/g on day 17 at the 370 kBq level. To assess the cytogenetic damage due to tritium exposure, a cytokinesis-blocked micronucleus (MN) assay was performed in blood samples from rats exposed to HTO for 14 and 21 days after oral administration. There was no significant difference in the MN frequencies between the control and exposed rats.

• The Journal of Korean Physical Therapy
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• v.22 no.6
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• pp.77-83
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• 2010

Purpose: The aim of this study was to do numerical analysis of the wavelength dependence in low level laser therapy (LLLT) using a finite element method (FEM). Methods: Numerical analysis of heat transfer based on a Pennes' bioheat equation was performed to assess the wavelength dependence of effects of LLLT in a single layer and in multilayered tissue that consists of skin, fat and muscle. The three different wavelengths selected, 660 nm, 830 nm and 980 nm, were ones that are frequently used in clinic settings for the therapy of musculoskeletal disorders. Laser parameters were set to the power density of 35.7 W/$cm^2$, a spot diameter of 0.06 cm, and a laser exposure time of 50 seconds for all wavelengths. Results: Temperature changes in tissue based on a heat transfer equation using a finite element method were simulated and were dominantly dependent upon the absorption coefficient of each tissue layer. In the analysis of a single tissue layer, heat generation by fixed laser exposure at each wavelength had a similar pattern for increasing temperature in both skin and fat (980 nm > 660 nm > 830 nm), but in the muscle layer 660nm generated the most heat (660 nm ${\gg}$ 980 nm > 830 nm). The heat generation in multilayered tissue versus penetration depth was shown that the temperature of 660 nm wavelength was higher than those of 830 nm and 980 nm Conclusion: Numerical analysis of heat transfer versus penetration depth using a finite element method showed that the greatest amount of heat generation is seen in multilayered tissue at = 660 nm. Numerical analysis of heat transfer may help lend insight into thermal events occurring inside tissue layers during low level laser therapy.

• Clinical and Experimental Reproductive Medicine
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• v.29 no.1
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• pp.37-44
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• 2002

Objective : Heat shock protein family is related to protective mechanism of cells by environmental changes. This study was performed to evaluate the effect of cryopreservation on the heat shock protein 90 (Hsp90) expression in mouse ovarian tissue. Methods : Cryopreservation of mouse ovarian tissue was carried out by slow freezing method. The mRNA level of Hsp90 expression in both fresh and cryopreserved mouse ovarian tissue was analyzed by RT-PCR. The protein expression of Hsp90 was evaluated by Western blot analysis and immunohistochemistry. Results: The mRNA and protein of Hsp90 were expressed in both fresh and cryopreserved mouse ovarian tissue. The amount of Hsp90 mRNA was increased in cryopreserved ovarian tissue after 60 and 90 minutes after thawing and incubation. The amount of Hsp90 protein was increased in the cryopreserved ovarian tissue after 6 hours of the incubation in Western blot analysis. In immunohistochemical study, Hsp90 protein was localized in cytoplasm of oocytes and granulosa cells. Significant level of immunoreactive Hsp90 protein was detected in theca cells contrast to the weak expression in ovarian epithelial cells. Conclusion: This results showed the increase of Hsp90 expression in both mRNA and protein level in the cryopreserved mouse ovarian tissue. It can be suggested that Hsp90 may play a role in the protective or recovery mechanism against the cell damage during cryopreservaion.

• 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.5 no.2
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• pp.79-87
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• 1989

Changes in urinary $Na^+$ and $K^+$ excretions, renal cortical microsomal $Na^+$ -K-ATPase activity, cortical tissue electrolyte content and plasma aldosterone level were studied in rats treated with CdCl2 (2 mg Cd/kg/day, s.c. injection) for 7-14 days. After 7 days of cadmium exposure, urinary excretion of $Na^+$ was markedly reduced. This change was accompanied by an increase in $Na^+$-$K^+$-ATPase activity, a fall in tissue $Na^+$ content, a rise in tissue $K^+$ content and an elevation of plasma aldosterone level.

• Nutritional Sciences
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• v.3 no.1
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• pp.11-17
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• 2000

This study was intended to examine whether dehydroepiandrosterone (DHEA) and dietary fat level or source could modulate glutathione utilizing detoxifying system activity and the cytosolic NADPH generation in rat liver. Male Sprague-Dawley rats were fed semipurifed diet containing either 2%(w/w) corn oil (low level of corn oil diet: 5 ca% of fat) 15% corn oil (high level of corn oil diet: 31 cal% of fat) or 13% sardine oil plus 2% corn oil(high level of fish oil diet: 31 cal% of fat) for 9 weeks. Half of the rats in each diet group were fed a diet supplemented with 0.2% DHEA (w/w). DHEA administration increased plasma total cholesterol level in low corn oil diet-fed rats. The high fish oil diet significantly decreased plasma total cholesterol level compared to the high corn oil diet. Plasma triglyceride level was not significantly changed by DHEA administration and dietary fat level and source. Fasting plasma glucose level was increased by DHEA administration and fish oil diet. Glucose 6-phosphate dehydrogenase activity in liver tissue was significantly increased by DHEA administration and high fat diet, especially fish oil diet. Malic enzyme activity in liver tissue was significantly increased by DHEA administration and high fat diet, especially fish oil diet. Malic enzyme activity in liver tissue was significantly increased by DHEA administration. DHEA suppressed the glutathione peroxidase, glutathione-dependent enzymes compared to the low corn oil diet, while fish oil diet elevated the activity of glutathione peroxidase and glutathione reductase compared to corn oil diet. These results suggest that DHEA administration and high level of corn oil diet may suppress the cellular detoxifying system activity through reduction of glutathione utilization, while the fish oil diet did not show these effects.