MTA 유사체의 Purine Metabolism 에의 영향

최혜선,J . D . Stoecker ( Hye Seon Choi,J . D . Stoeckler ) 생화학분자생물학회 1992 BMB Reports Vol.25 No.1

5`-Deoxy-5`-methylthioadenosine (MTA) which is related to polyamine synthesis, is rapidly converted to 5-methylthioribose 1-phosphate (MTR-1-P) and adenine by the reaction of MTA phosphorylase (MTAPase) (Savarese et al., 1981). MTA analogs in which the ribose moiety was replaced have demonstrated to be cytotoxic (Savarese et al., 1984; Ferro et al., 1982). These results indicated that the common product, 5-modified sugar phosphate, exerted cytotoxic effect against several tumor cells. L5178Y mouse lymphoblastic leukemia cells were treated with 5`-modified adenosines, MTA, 5`-deoxy-5`-isobutylthioadenosine (SIBA), 5`-deoxy-5`-iodoadenosine (5`-IAdo) and 5`-deoxyadenosine (5`-dAdo). The phosphorolysis of 100 μM of 5`-modified nucleosides measured in intact L5178Y cells agreed well with the relative V_m of MTAPase from Sarcoma 180 cells determined by Savarese et al. (1983). 5`-IAdo showed extra inhibition of 5-phosphoribosyl 1-pyrophosphate (PRPP) synthesis at high concentration, but the inhibition by 5`-dAdo, MTA and SIBA could be due to adenine released from 5`-substituted adenosines. 5`-Modified adenosines caused greater inhibition of purine synthesis de novo than the same concentration of adenine as were generated from the 5`-substituted adenosines. No inhibition of purine salvage pathway was observed. 5`-IAdo was most cytotoxic and inhibited purine metabolism to the greatest extent in L5178Y cells. In the HL-60 human promyelocytic leukemia cells and HL-60, APRT-deficient mutant cells, the effects of 5`-IAdo on purine and pyrimidine metabolism were measured. 5`-IAdo had no significant effects on PRPP accumulation, purine synthesis de novo and purine salvage pathway.

보문 : 의복설계를 위한 비만 여성 체형의 연령층별 특징

최혜선,이진희 ( Hei Sun Choi,Jin Hee Lee ) 한국의류학회 1995 한국의류학회지 Vol.19 No.5

5 ' - Deoxy - 5 ' - Iodoinosine 존재하에 사람 적혈구에서의 5 - Iodoribose 1 - phosphate 대사

최혜선,요하나 스토클러 ( Hye Seon Choi,Johanna D . Stoeckler ) 생화학분자생물학회 1990 BMB Reports Vol.23 No.3

5`-deoxy-5`-iodoadenosine (5`-IAdo) and 5`-deoxy-5`-iodoinosine (5`-IIno) were highly cytotoxic to several cell lines in vitro. These studies indicated that the pentose 1-phosphate generated from the 5`-iodonucleosides is responsible for the cytotoxicity. The synthesized and purified 5-iodoribose 1-phosphate (5-IR-1-P) inhibited several enzymes which are related to purine, pyrimidine and sugar phosphate metabolism. Intracellular concentrations of 5-IR-1-P were measured in human erythrocytes through which are in transit to a target site. 560 uM of 5`-IIno generated 500 uM 5-IR-1-P in human erythrocytes. Intracellular concentrations of 5-IR-1-P reached plateau levels in less than 1 hr which remained unchanged for 4 hr. Following removal of extracellular 5`-IIno, the intracellular concentrations of 5-IR-1-P decreased from 500 uM to 300 uM. Intracellular concentration of 5-IR-1-P declined progressively during the subsequent incubation, indicatng that rapidly continuing degradation of 5-IR-1-P occurred in the absence of further synthesis of 5-IR-1-P from 5`-IIno.

온열적 쾌적과 의복의 보온력

최혜선,Choi Hei-Sun 대한설비공학회 1987 설비저널 Vol.16 No.3

표준실내기후 설정에 관한 기초조사연구 -열환경요소와 착의량이 온냉감반응에 미치는 영향-

최혜선,Choi Hei Sun 대한설비공학회 1987 설비저널 Vol.16 No.6

The purpose of this study was to investigate thermal environmental factors, thermal clothing properties, and thermal sensation of the office workers in four selected office buildings in Seoul, and to determine the effect of thermal environmental factors and clothing insulation to the thermal sensation of the subjects. The subjects selected from each office were 5 males and 5 females at a time. Thermal environmental factors(DBT, GT, RH, MRT, $ET^{\ast}$) and clothing variables such as clothing weight per body surface $area(g/m^2)$ and estimated clothing insulation values(clo) were significantly different among each seasons(p<0,001). Means of $ET^{\ast}$ and estimated clothing insulation values of each season were as follows; Winter; $20.84^{\circ}C$ $ET^{\ast}$ with 0.72 clo for male and 0.79 clo for female Spring and fall; $23.65^{\circ}C$ $ET^{\ast}$ with 0.59 clo for male and 0.68 clo for female Summer; $26.00^{\circ}C$ $ET^{\ast}$ with 0.47 clo for male and 0.53 clo for female. In comparison these data with ASHRAE Standard, the subjects were predicted to feel comfort-able in spring and fall, and slightly hot in summer and slightly cold in winter because of high and low clo respectively. But the result of this survey showed more than $80\%$ of the occupants were thermally comfortable at a given environmental temperature and clo.

논문편 : 시판 임산부용 거들의 착용감 및 착용효과에 관한 연구

최혜선,이경화 ( Hei Sun Choi,Kyong Hwa Yi ) 대한가정학회 1991 Family and Environment Research Vol.29 No.3

Saccharomyces cerevisiae에서 얻은 Purine Nucleoside Phosphorylase의 반응기작과 효소에 대한 Sulfhydryl Reagent의 영향

최혜선,Choi, Hye-Seon 한국미생물학회 1994 미생물학회지 Vol.32 No.3

Saccharomyces cerevisiae에서 얻은 purine nucleoside phosphorylase (PNP)의 반응 기작을 밝히기 위해 반응속도론적 분석이 수행되어졌다. 반응기작에 PNP${\cdot}$phosphate와 PNP${\cdot}$ribose 1-phosphate의 binary complex가 형성되는 것으로 추정되어진다. Initial velocity와 product inhibition study의 결과는 반응이 ordered bi, bi reaction으로 일어난다는 것과 일치하고 있다. 두 개의 기질중 무기인산이 효소에 먼저 붙고, 그 다음에 nucleoside, 그리고 base가 효소를 떠나는 첫 번째 생성물이고 마지막으로 ribose 1-phosphate가 생성되고 효소는 원래의 상태로 돌아간다. 반응속도론적 분석에 이해 제안된 작용기작은 sulfhydryl reagents인 p-chloromercuribenzoate(PCMB) and 5,5'-dithiobisnitrobenzoate (DTNB)에 의한 효소의 불활성화에 대한 기질으 보호작용의 결과와 일치하고 있다. PNP는 ribose 1-phosphate와 phosphate에 의해 보호되지만 nucleoside나 base에 의해서는 아무런 효과과 없다는 사실은 반응 순서가 효소에 무기인산이 먼저 붙는 ordered bi, bi 기작이라는 것을 지지하고 있다. PCMB 나 DTNB에 의해 불활성화된 PNP는 dithiothreitol(DTT)에 의해서는 활성이 완전히 회복되고 2-mercaptoethanol에 의해서는 77%의 활성이 회복된다는 사실은 효소의 불활성화가 가역적이라는 것을 시사하고 있다. PCMB에 의해 불활성화된 효소는 inosine이 변화하는 기질일때 정상효소보다 높은 $K_m$과 낮은 $V_m$ 값을 보여주고 이런 현상은 DTT 처리시 원래의 상태로 돌아온다. DTNB에 의해 불활성화된 효소는 PCMB 처리시와 비슷하게 정상효소보다 높은 $V_m$ 값을 보이지만 $V_m$ 값은 큰 변화가 없다. S. cerevisiae PNP에서 발견되는 높은 무기인산의 농도에서의 하위단위체간의 음성적 협동성이 PCMB나 DTNB를 처리한 PNP에서는 보이지 않았다. Kinetic analysis was done to elucidate the reaction mechanism of purine nucleoside phosphorylase (PNP) in Saccharomyces cerevisiae. The binary complexes of PNP${\cdot}$phosphate and PNP${\cdot}$ribose 1-phosphate were involved in the reaction mechanism. The initial velocity and product inhibition studies demonstrated were consistent with the predominant mechanism of the reaction being an ordered bi, bi reaction. The phosphate bound to the enzyme first, followed by nucleoside and base were the first product to leave, followed by ribose 1-phosphate. The kinetically suggested mechanism of PNP in S. cerevisiae was in agreement with the results of protection studies against the inactivation of the enzyme by sulfhydryl reagents, p-chloromercuribenzoate (PCMB) and 5,5'-dithiobisnitrobenzoate (DTNB). PNP was protected by ribose 1-phosphate and phosphate, but not by nucleoside or base, supporting the reaction order of ordered bi, bi mechanism. PCMB or DTNB-inactivated PNP was totally reactivated by dithiothreitol (DTT) and the activity was returned to the level of 77% by 2-mercaptoethanol, indicating that inactivation was reversible. The kinetic behavior of the PCMB-inactivated enzyme had been changed with higher $K_m$ value of inosine and lower $V_m$, and was restored by DTT. Inactivation of enzyme by DTNB showed similar pattern of K sub(m) value with that by PCMB, but had not changed the $V_m$ value, significantly. Negative cooperativity was not found with PCMB or DTNB treated PNP at high concentration of phosphate.

Metabolism of 5-Iodoribose 1-phosphate (5-IR-1-P) in Human Erythrocytes in the Presence of 5'-Deoxy-5'-iodoinosine

최혜선,요하나 스토클러,Choi, Hye-Seon,Johanna, D. Stoeckler Korean Society for Biochemistry and Molecular Biol 1990 한국생화학회지 Vol.23 No.3

5-IR-1-P는 여러 종류의 세포에 강력한 독성을 보이는 5'-iodonucleoside에서 생성이 되어지는데 이 때 생성된 5-IR-1-P는 purine, pyrimidine 및 sugar phosphate의 대사에 관계하는 여러 효소의 활성을 억제시켰다. 목표가 되는 암세포로 가는 통로가 되어지는 적혈구에서 purine nucleoside phosphorylase(PNP)의 활성이 높으므로 5'-deoxy-5'-iodoinosine(5'-IIno) 존재하에 5-IR-1-P의 농도가 측정되었다. $560{\mu}M$의 5'-IIno는 $'500{\mu}M$의 5-IR-1-P를 생성한다. 5-IR-1-P의 세포내 농도는 1시간 안에 최대 수준에 도달하여 4시간 동안 변하지 않는다. 바깥에서 공급되는 5'-IIno를 제거하면 5-IR-1-P의 세포내 농도는 $'500{\mu}M$에서 $'300{\mu}M$으로 감소한다. 이미 세포속으로 들어간 5'-IIno만이 존재할 때 5-IR-1-P의 세포내 농도는 점차적으로 감소한다. 이 사실은 5'-IIno이 계속 공급되지 않으면 5-IR-1-P가 빨리 다른 물질로 대사되거나 파괴되는 것을 의미한다. 5'-deoxy-5'-iodoadenosine (5'-IAdo) and 5'-deoxy-5'-iodoinosine (5'-IIno) were highly cytotoxic to several cell lines in vitro. These studies indicated that the pentose l-phosphate generated from the 5'-iodonucleosides is responsible for the cytotoxicity. The synthesized and purified 5-iodoribose 1-phosphate (5-IR-1-P) inhibited several enzymes which are related to purine, pyrimidine and sugar phosphate metabolism. Intracellular concentrations of 5-IR-1-P were measured in human erythrocytes through which are in transit to a target site. 560 uM of 5'-IIno generated 500 uM 5-IR-1-P in human erythrocytes. Intracellular concentrations of 5-IR-1-P reached plateau levels in less than 1 hr which remained unchanged for 4 hr. Following removal of extracellular 5'-IIno, the intracellular concentrations of 5-IR-1-P decreased from 500 uM to 300 uM. Intracellular concentration of 5-IR-1-P declined progressively during the subsequent incubation, indicating that rapidly continuing degradation of 5-IR-1-P occurred in the absence of further synthesis of 5-IR-1-P from 5'-IIno.

학령기 아동의 스트레스와 대처 및 자살 생각: 대구.경북 지역을 중심으로

최혜선,이미경,Choi, Hye-Seon,Lee, Mi-Kyoung 한국학교보건학회 2012 韓國學校保健學會誌 Vol.25 No.1

Purpose: The purpose of this study was to investigate the stress, coping and suicidal ideation among school-aged children and provide evidence for developing a stress management program for them. Methods: Data were collected and analyzed from 308 fifth graders from 6 elementary schools located in Daegu/Gyeongbuk. Results: First, for stress by general characteristics, there were significant differences in economic status, school record, self-rated health and life satisfaction. Also, subcategory stress by gender, there was a significant difference in appearance stress. Second, passive/avoidant coping had a significant difference in gender. Social support seeking coping and passive/avoidant coping were significant differences in economic status. Active coping had a significant difference in school record. Passive/avoidant coping had a significant difference in self-rated health. Aggressive coping, active coping, social support seeking coping and passive/avoidant coping had significant differences in self-rated life satisfaction. Third, stress and coping had significant differences by suicidal ideation. Fourth, stress showed positive correlations with aggressive coping and passive/avoidant coping while revealing negative correlation with active coping. Conclusion: These results from the study suggest difference by gender and need more active and positive coping strategy for suicide prevention.

An Adaptive Hot-spot Operating Scheme in Vertically Overlaid OFDMA Wireless Systems

최혜선,정희정,김낙명,Choi Hye-Sun,Chung Hee-Jeong,Kim Nak-Myeong The Korean Institute of Communications and Informa 2005 韓國通信學會論文誌 Vol.30 No.7a

OFDMA 하향링크 시스템에서 단말의 불균등한 위치 분포와 다양한 QoS 요구사항의 변화에 따라 시스템에 끼치는 부정적인 영향을 줄이기 위한 적응적 hot-spot 운용 기법에 대해 제안하였다. 매크로셀의 기지국은 셀 내 피고셀의 운용을 조절하며, 예측된 user outage probability와 AHOS 이득 파라미터 값에 의해 피코셀을 켜고 끄게된다. 제안된 AHOS 기법은 다양한 시스템 환경에서 QoS outage probability를 유지하면서 시스템의 throughput을 최대화 시키는 이득을 보였다. We develop an adaptive hot-spot operating scheme(AHOS) to mitigate the negative effects from the nonuniform distribution of user location and the variation in the mixture of QoS requirements in OFDMA downlink systems. The base station in a macrocell can control the operation of picocells within the cell, and turns on or off according to the changes in the estimated user outage probability and the AHOS gain parameter. With the computer simulation, the AHOS has been proved to maximize the system throughput while maintaining the QoS outage probability very low under various system scenarios.