Modification of Folate Metabolis by Thyroid Status and Idenification of 10-Formyl-THF Dehydrogenase as a Folate Binding Protein

민혜선 忠北大學校 遺傳工學硏究所 1989 遺傳工學硏究 Vol.3 No.1

말뚝 간격에 따른 에너지 파일의 열적 거동분석

민혜선,정상섬,윤태섭 한국지반공학회 2011 한국지반공학회논문집 Vol.27 No.8

This study was conducted to analyze the thermal behavior of a PHC energy pile system in saturated soil conditions, various seasonal and flow-speed conditions during 100 hours of operation through numerical analysis. The examination was also conducted with a single pile as well as with group piles. For the operation of 100 hours, the average heat exchange rate appeared 55 W/m, 47 W/m during winter and summer respectively. An increase in flow-speed was associated with a rise in the heat exchange rate. And thermal behavior analysis results during winter season show that thermal efficiency has increased when there are more free thermal planes. For the operation in group pile as 3D and 5D pile spacing (D: pile diameter), average heat exchange rate increased as pile spacing grows. Compared with the heat exchange rate of single pile, thermal exchange efficiency of group pile decreased by 89% (for 3D spacing) and 93% (for 5D spacing).

乳汁中의 亞鉛(Zinc)과 乳兒의 營養

閔蕙仙 全北大學校 師範大學 1983 사대논문집 Vol.9 No.-

Zinc is a essential trace element for human. Zinc deficiency may lead to high infant mortality, abnormal development, or poor growth. So, milk, the only food of infants, should meet the zinc needs of infants. Zinc concentration of human milk is 0.5-4 ㎎/L, and the conc. of cow's milk 3-5 ㎎/L. In human milk a significant amount of zinc-binding ligand makes it cow's milk and the bioavailability of the zinc may be also low. So, the optimal levels of zinc in formulas should be adequately determined.

다량의 엽산 보충이 비타민 B12가 결핍된 쥐의 엽산 대사과정에 미치는 영향

민혜선,최준호 ( Hye Seon Min,Joon Ho Choe ) 생화학분자생물학회 1993 BMB Reports Vol.26 No.8

Effect of supplementation of high levels of folate (200 ㎎ of folate per ㎏ of diet) to vitamin B_(12)-deficient rats was studied. Increased total liver folate levels were observed in the vitamin B_(12)-deficient rats supplemented with high levels of folate although folate supplementation had no significant effect on normalizing the rate of histidine oxidation and the urinary formiminoglutamate excretion. Supplementation of high levels of folate to vitamin B_(12)-deficient rats increased hepatic non-methyl folate levels to normal or supranormal levels and shifted the polyglutamate chain distribution of folate derivatives slightly decreased. However, penta- and hexa-glutamate derivatives of non-methyl folates were found predominantly in the liver of both vitamin B_(12)-deficient and vitamin B_(12)-supplemented rats in this study. Thus the absolute hepatic levels of total folate or H₄PteGlu were not strictly related with the rate of histidine oxidation and the low rate of histidine oxidation in vitamin B_(12)-deficient rats supplemented with high levels of folate were not due to the reduced length of polyglutamate chain of folate derivatives. These data suggest that the ratio of H₄PteGlu/5-methyl-H₄PteGlu may be the more important factor in modifying folate functions and the methylfolate trap may not be circumvented by supplementation of high levels of folate in vitamin B_(12)-deficient animals.

다량의 엽산 보충이 비타민 $B_{12}$가 결핍된 쥐의 엽산 대사과정에 미치는 영향

민혜선,최준호,Min, Hye-Seon,Choe, Joon-Ho 생화학분자생물학회 1993 한국생화학회지 Vol.26 No.8

비타민 $B_{12}$의 결핍으로 인해 엽산의 생화학적인 기능이 저하되는 기작을 조사하기 위하여 비타민 $B_{12}$가 결핍된 흰쥐에게 다량의 엽산을(200mg/kg 식이) 공급한 후 간에 있어서의 엽산의 함량, non-methyl folate의 함량, pteroyl-polyglutamate 직쇄길이의 분포상태를 분석하였다. 뇨중 다량의 methylmalonic acid를 배설하는, 비타민 $B_{12}$가 심하게 결핍된 쥐에게 다량의 엽산을 보충시켰을 때 간내의 엽산함량은 정상치를 회복하였으나, 히스티딘의 산화속도를 통해 측정되는 엽산의 생화학적 기능은 회복되지 않았다. 간장내 non-methyl folate의 함량도 엽산보충에 의해 정상수준으로 증가되었으므로 non-methyl folate의 절대 함량이 엽산의 생화학적인 활성을 결정하는 주된 요인이 아닌 것으로 나타났다. 엽산의 polyglutamate 직쇄의 분포는 다량의 엽산보충에 의해 다소 짧아졌으나, 대부분 5개 이상의 glutamate를 결함하고 있는 것으로 나타났으므로 비타민 $B_{12}$가 결핍된 쥐의 히스티딘의 산화속도가 낮은 원인이 엽산의 polyglutamate 직쇄길이가 짧아지는데에 기인하지 않음을 알 수 있었다. 이 결과로부터 $H_4$PteGlu/5-methyl-$H_4$ PteGlu의 비율이 polyglutamate 직쇄분포보다 엽산의 생화학적 기능을 변화시키는 더 중요한 요인으로 보인다. Effect of supplementation of high levels of folate (200 mg of folate per kg of diet) to vitamin $B_{12}$-deficient rats was studied. Increased total liver folate levels were observed in the vitamin $B_{12}$-deficient rats supplemented with high levels of folate although folate supplementation had no significant effect on normalizing the rate of histidine oxidation and the urinary formiminoglutamate excretion. Supplementation of high levels of folate to vitamin $B_{12}$-deficient rats increased hepatic non-methyl folate levels to normal or supranormal levels and shifted the polyglutamate chain distribution of folate derivatives slightly decreased. However, penta- and hexa-glutamate derivatives of non-methyl folates were found predominantly in the liver of both vitamin $B_{12}$-deficient and vitamin $B_{12}$-supplemented rats in this study. Thus the absolute hepatic levels of total folate or $H_4$PteGlu were not strictly related with the rate of histidine oxidation and the low rate of histidine oxidation in vitamin $B_{12}$-deficient rats supplemented with high levels of folate were not due to the reduced length of polyglutamate chain of folate derivatives. These data suggest that the ratio of $H_4$PteGlu/5-methyl-$H_4$PteGlu may be the more important factor in modifying folate functions and the methyl folate trap may not be circumvented by supplementation of high levels of folate in vitamin $B_{12}$-deficient animals.

엽산과 비타민 B12 결핍에 의한 호모시스테인혈증 흰쥐의 조직내 비타민 지표간의 상관관계 분석

민혜선,김미숙 한국영양학회 2009 Journal of Nutrition and Health Vol.42 No.5

Folate and vitamin B12 are essential cofactors for homocysteine (Hcy) metabolism. Homocysteinemia has been related with cardiovascular and neurodegenerative disease. We examined the effect of folate and/or vitamin B12 deficiency on biomarkers of one carbon metabolism in blood, liver and brain, and analyzed the correlation between vitamin biomarkers in mild and moderate homocysteinemia. In this study, Sprague-Dawley male rats (5 groups, n = 10) were fed folatesufficient diet (FS), folate-deficient diet (FD) with 0 or 3 g homocystine (FSH and FDH), and folate-/vitamin B12-deficient diet with 3 g homocystine (FDHCD) for 8 weeks. The FDH diet induced mild homocysteinemia (plasma Hcy 17.41 ± 1.94 nmol/mL) and the FDHCD diet induced moderate homocysteinemia (plasma Hcy 44.13 ± 2.65 nmol/mL), respectively. Although liver and brain folate levels were significantly lower compared with those values of rats fed FS or FSH (p < 0.001, p < 0.01 respectively), there were no significant differences in folate levels in liver and brain among the rats fed FD, FDH and FDHCD diet. However, rats fed FDHCD showed higher plasma folate levels (126.5 ± 9.6 nmol/L) compared with rats fed FD and FDH (21.1 ± 1.4 nmol/L, 22.0 ± 2.2 nmol/L)(p < 0.001), which is the feature of “ethyl-folate trap”by vitamin B12 deficiency. Plasma Hcy was correlated with hepatic folate (r = -0.641, p < 0.01) but not with plasma folate or brain folate in this experimental condition. However, as we eliminated FDHCD group during correlation test, plasma Hcy was correlated with plasma folate (r = -0.581, p < 0.01), hepatic folate (r = -0.684, p < 0.01) and brain folate (r = -0.321, p < 0.05). Hepatic S-adenosylmethionine (SAM) level was lower in rats fed FD, FDH and FDHCD than in rats fed FS and FSH (p < 0.001, p < 0.001 respectively) and hepatic S-adenosylhomocysteine (SAH) level was significantly higher in those groups. The SAH level in brain was also significantly increased in rats fed FDHCD (p < 0.05). However, brain SAM level was not affected by folate and/or vitamin B12 deficiency. This result suggests that dietary folate- and vitamin B12-deficiency may inhibit methylation in brain by increasing SAH rather than decreasing SAM level, which may be closely associated with impaired cognitive function in nutritional homocysteinemia. (Korean J Nutr 2009; 42(5): 423 ~ 433) Folate and vitamin B12 are essential cofactors for homocysteine (Hcy) metabolism. Homocysteinemia has been related with cardiovascular and neurodegenerative disease. We examined the effect of folate and/or vitamin B12 deficiency on biomarkers of one carbon metabolism in blood, liver and brain, and analyzed the correlation between vitamin biomarkers in mild and moderate homocysteinemia. In this study, Sprague-Dawley male rats (5 groups, n = 10) were fed folatesufficient diet (FS), folate-deficient diet (FD) with 0 or 3 g homocystine (FSH and FDH), and folate-/vitamin B12-deficient diet with 3 g homocystine (FDHCD) for 8 weeks. The FDH diet induced mild homocysteinemia (plasma Hcy 17.41 ± 1.94 nmol/mL) and the FDHCD diet induced moderate homocysteinemia (plasma Hcy 44.13 ± 2.65 nmol/mL), respectively. Although liver and brain folate levels were significantly lower compared with those values of rats fed FS or FSH (p < 0.001, p < 0.01 respectively), there were no significant differences in folate levels in liver and brain among the rats fed FD, FDH and FDHCD diet. However, rats fed FDHCD showed higher plasma folate levels (126.5 ± 9.6 nmol/L) compared with rats fed FD and FDH (21.1 ± 1.4 nmol/L, 22.0 ± 2.2 nmol/L)(p < 0.001), which is the feature of “ethyl-folate trap”by vitamin B12 deficiency. Plasma Hcy was correlated with hepatic folate (r = -0.641, p < 0.01) but not with plasma folate or brain folate in this experimental condition. However, as we eliminated FDHCD group during correlation test, plasma Hcy was correlated with plasma folate (r = -0.581, p < 0.01), hepatic folate (r = -0.684, p < 0.01) and brain folate (r = -0.321, p < 0.05). Hepatic S-adenosylmethionine (SAM) level was lower in rats fed FD, FDH and FDHCD than in rats fed FS and FSH (p < 0.001, p < 0.001 respectively) and hepatic S-adenosylhomocysteine (SAH) level was significantly higher in those groups. The SAH level in brain was also significantly increased in rats fed FDHCD (p < 0.05). However, brain SAM level was not affected by folate and/or vitamin B12 deficiency. This result suggests that dietary folate- and vitamin B12-deficiency may inhibit methylation in brain by increasing SAH rather than decreasing SAM level, which may be closely associated with impaired cognitive function in nutritional homocysteinemia. (Korean J Nutr 2009; 42(5): 423 ~ 433)

서비스실패의 심각성과 통제성이 공정성지각과 신뢰성 및 충성도에 미치는 영향: 패밀리레스토랑을 중심으로

민혜선,고재윤 한국외식경영학회 2008 외식경영연구 Vol.11 No.2

The purpose of the study is to find out the effects of service failure on perceived fairness and trust and loyalty. The object of this study is the customer who ever visited the high rank sales top five restaurant chain (Monthly Restaurant, 2006.2) at least more than twice within recent one year. Convenience random sampling was adopted for the customers in Seoul and Pusan. Collected data were executed for reliability analysis and EFA, and regression analysis was executed for the test of hypotheses.The followings are the results of the analysis. First, seriousness and unsuccessful service affected service recovery perception(procedural, interaction, distribution). Second, control of unsuccessful service also affected service recovery perception. Third, procedural service recovery perception did not affect trust and loyalty. Fourth, interaction service recovery perception and distribution service recovery perception of a service recovery affected reliability and a loyalty. Fifth, trust in service recovery affected loyalty. The seriousness unsuccessful service affected strongly distribution of service recovery perception more than control of service recovery perception. And control of unsuccessful service affected procedural and interaction service recovery perception.

심포지움초록 : 엽산 영양상태의 판정법과 한국인의 엽산영양

민혜선 한국영양학회 1996 춘계학술대회초록 Vol.- No.-

연구논문 : 호텔 직원의 개인 성향에 따른 감정 조절전략이 고객지향성에 미치는 영향 -서울과 부산의 특1급 호텔을 중심으로-

민혜선 ( Hae Sun Min ),조은정 ( Eun Jung Cho ) 대한관광경영학회 2009 觀光硏究 Vol.23 No.4

조리 및 저장에 따른 시금치 엽산 함량의 변화 - 조리시간에 따른 엽산의 열파괴 손실과 조리수를 통한 손실의 비교 -

민혜선(Hye-Sun Min) 한국식품영양과학회 1998 한국식품영양과학회지 Vol.27 No.2

가열조리가 시금치의 엽산 함량에 미치는 영향을 조사하기 위하여, 증류수에 시금치를 넣고 1, 2, 3, 4, 5, 10, 20분간 가열 조리하였다. 조리된 시금치의 엽산 함량은 1분 후 80.7%, 2분 후 33.4%, 3분 후 12.6%로 급격하게 감소되었고, 20분 후 5.5%로 감소되었다. 그러나, 시금치와 조리수의 엽산 함량을 합하면 가열조리 1분 후 101.1%, 2분 후 68%, 3분 후 51.3%, 20분 후 52.0%를 나타내어 4분 이상의 가열조건에서는 총 엽산 함량이 크게 변하지 않았으나 대부분의 엽산이 조리액으로 유출되었다. 가열조리에 의한 시금치내 엽산 함량의 저하현상은 2분과 3분 사이에 급속히 진행되었으며, 조리수를 통한 유출에 의한 엽산의 상대적 손실율은 가열조리 시간이 1분일 때 20.2%, 20분일 때 88.8%로 조리시간이 길어짐에 따라 크게 증가하였다. 시금치를 전자레인지로 가열 조리했을 때 보유된 총 엽산 함량은 물로 끓여서 조리한 경우와 유사하였으나, 전자레인지를 이용한 조리에서는 소량의 조리수를 사용하므로 조리수를 통한 엽산의 손실이 낮아서 시금치 조직에 보유되는 엽산량은 더 높았다. 시금치를 냉장보관하였을 때 1~2주 후의 엽산 보유량이 90% 이상으로서 시금치의 엽산이 냉장저장 조건에서는 비교적 잘 보유되는 것으로 조사되었다. The effects of cooking methods and storage time on folate content in spinach were determined by boiling for 1, 2, 3, 4, 5, 10, and 20min in distilled water or by microwave blanching for 20, 40, 60, 80, 100 sec. The folate content of cooked spinach was decreased to 80.7% after 1min boiling, and to 5.5% after 20min boiling. The folate recovered from the cooked spinach and cooking water was 101.1% after 1min, 68.0% after 2min and 51.3% after 3min. The relative folate content leached out of the cooked spinach into the cooking water varied from 20.2% after 1min boiling to 88.8% after 20min boiling. Total folate content of spinach was decreased to 45% by microwave heating for 40sec. However, the spinach cooked by microwave heating retained more folate due to the minimal loss of folate into cooking water. More than 90% of folate content of spinach was retained during 1 to 2 weeks of storage at 4℃.