• Journal of Microbiology and Biotechnology
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• 제13권2호
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• pp.217-224
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• 2003

Previously, we developed a CHO cell line (CHO-OTC1-Al9) that expresses the first two enzymes in the urea cycle and exhibits a higher ammonia-removing ability and faster growth rate than a vector-controlled CHO cell line (CHO-neo-5). The current study was undertaken to develop a cell line with an ammonia-removing ability higher than the cell line developed previously. To accomplish this, CHO cell lines expressing the first three, first four, or all five enzymes of the urea cycle were constructed using a stable transfection method. Finally, the CHO-AS-16, CHO-AL-19, and CHO-Arg-11 cell lines expressing the first three, first four, and all five enzymes of the urea cycle, respectively, were selected and found to exhibit higher ammonia-removing ability than the CHO-OTC1-Al9 cell line. Among the three selected cell lines, CHO-AL-19 showed the highest ammonia-removing ability and highest cell viability at a higher cell density, with 40% and 15% lower ammonia concentration in the, culture media than that of CHO-neo-5 and CHO-OTC1-A19 cell lines, respectively. CHO-AL-19 also showed 44% and 10% higher cell viability than the CHO-neo-5 and CHO-OTC-Al9 cell lines, at a higher cell density, respectively. The ammonia concentrations in the culture media were expressed as the ammonia concentration/cell, and the CHO-AL-19 cells revealed 45-60% and 20% lower ammonia concentration/cell than the CHO-neo-5 and CHO-OTC1-Al9 cells, respectively.

• 대한유전성대사질환학회지
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• 제18권1호
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• pp.18-22
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• 2018

Carbamoyl phosphate synthetase I (CPS1) 결핍은 상염색체 열성 유전을 하는 드문 요소회로 대사 이상 질환으로, 요소회로의 첫번째 단계 효소인 CPS1 결핍에 의해 고암모니아혈증이 발생하여 신경학적 이상을 초래하게 되는 질환이다. CPS1 결핍은 신생아기부터 성인까지 여러 시기에 발현될 수 있으나, 주로 신생아기에 증상이 발현하고, 신생아기에 증상이 발생할 경우 치명적인 고암모니아혈증이 발생하여 예후가 불량하여 사망에 이를 수 있다. 본 증례는 고암모니아혈증이 발견되어 투석 및 집중 치료하였음에도 심한 뇌손상이 빠르게 진행되어 사망한 신생아로, CPS1 유전자의 동종 접합자 변이를 확인하여 확진 되었으며 이후 시행한 가족 검사에서 부모와 생존한 자매가 모두 이종 접합자 보인자로 확인되어 보고하는 바이다.

• Journal of Microbiology and Biotechnology
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• 제14권4호
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• pp.844-851
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• 2004

Efficient mammalian erythropoietin (EPO)-expression systems are required for therapeutic applications. The accumulation of ammonia is a major problem in the production of recombinant proteins in cultured animal cells. To counter this problem we introduced the first two genes of the urea cycle, carbamoyl phosphate synthetase (CPSI) and ornithine transcarbamylase (OTC), into IBE Chinese Hamster Ovary (CHO) cells by stable transfection. The resulting cell line, CO5, had a higher growth rate and accumulated less ammonia per cell than the parental cell line, IBE. In addition, it produced 2 times more EPO than the parent, and the purified EPO contained a higher proportion of acidic isoforms with approximately 15% more sialic acid.

• Journal of Nutrition and Health
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• 제7권2호
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• pp.37-51
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• 1974

This Study was carried out to observe the effect of nutritional condition on the change of protein metabolism in the animal body by feeding on imbalanced protein diet. A total 242 growing male albino rats, weighing $115{\sim}120$ gm, were used for the experimental animals. The rats were fed on the standard diet(st), protein flee diet(pf) and imbalanced protein diet(ib) for twelve weeks respectively. Hemoglobin, packed cell volume in blood, and total nitrogen, amino acid nitrogen, urea-nitrogen, creatinine, transaminases(GPT, GOT) in liver and serum, and total nitrogen in small intestine, and total nitrogen, urea-nitrogen In small intestine, and total nitrogen, urea-nitrogen, creatinine, urea-nitrogen/creatinine ratio in urine were measured. The results obtained are as follows; 1. The gained body weight were lower in pf group and ib group than those of st group. The gained body weight fed for 12 weeks, were 80% lower in pf group than those of st group, and the body weight of pf group for $50{\sim}75$ days feeding were $40{\sim}60%$ decreased, compared with the stating weight, and then all of them died. 2. The change of the brain, liver, kidney, spleen and small intestine by feeding on imbalanced diet for 12 weeks were no remarkable difference with the starting weight, but those of protein free diet group were half or more decrease and those were significantly lower in spleen and small intestine especially than the other organ 3. The contents of hemoglobin in pf group for 8 weeks feeding, and the packed cell volume in pf group for 8 weeks feeding and in ib group for 12 weeks feeding were decreased. but those of the other feeding group were almost same value. 4. The total nitrogen in the liver, small intestine and serum of each diet group were no remarkable difference respectively. The contents of amino acid nitrogen in pf group for 2 and 6 weeks feeding were increased. 5. On transaminases: a) The cycle of increase and decrease of GPT activities were come periodically and the interval of cycle were fast in the early stage of feeding and slow there-after. b) The GPT activities were decreased gradually in pf group after feeding and those were increased in ib group for 6 weeks feeding but decreased there-after. The frequency of cycle were more GPT than GOT and specially those of GPT in early stage of feeding were two or three times while GOT was one. c) The interval of increase and decrease in GOT and amino acid nitrogen cycle were similar tendency. 6. The contents of total nitrogen, creatinine and urea-nitrogen of pf group in urine were decreased very sharply from sharting feeding to one week but increased dully from six weeks to eight weeks feeding. The contents of urea-nitrogen of ib group were increased dully by feeding on ten weeks but decreased by feeding on twelve weeks. From the above results, it is concluded that the trend of the metabolic change is maintained equally by homeostatic mechanism using the endogenous protein source during a certain period by imbalanced protein diet feeding. The homeostatic mechanism is come peridically, very fast in early stage of feeing and than slow there-after.

• Carbon letters
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• 제19권
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• pp.40-46
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• 2016

Nitrogen-atom doped graphene oxide was considered to prevent the dissolution of polysulfide and to guarantee the enhanced redox reaction of sulfur for good cycle performance of lithium sulfur cells. In this study, we used urea as a nitrogen source due to its low cost and easy preparation. To find the optimum urea content, we tested three different ratios of urea to graphene oxide. The morphology of the composites was examined by field emission scanning electron microscope. Functional groups and bonding characterization were measured by X-ray photoelectron spectroscopy. Electrochemical properties were characterized by cyclic voltammetry in an organic electrolyte solution. Compared with thermally reduced graphene/sulfur (S) composite, nitrogen-doped graphene/S composites showed higher electroactivity and more stable capacity retention.

• 한국생물공학회:학술대회논문집
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• 한국생물공학회 2005년도 생물공학의 동향(XVII)
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• pp.604-605
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• 2005

• 대한약학회:학술대회논문집
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• 대한약학회 2002년도 Proceedings of the Convention of the Pharmaceutical Society of Korea Vol.1
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• pp.78-78
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• 2002

• 한국해양학회지
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• 제28권4호
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• pp.323-331
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• 1993

만경·동진강 하구와 과부영양의 연못에서 식물플랑크톤이 요소의 분해시 갖고 있 는 적응 기작을 연구하기 위해, 요소 분해에 있어서 요소 농도의 의존성, 빚의 영향, 그리고 암모늄 이온 농도의 증가에 의한 억제 효과서 연구하였다. 하구에서 크기 구배 의 실험 결과는 박테리아가 요소 분해에 있어서 작은 (14%) 역할을 함을 나타냈다. 그 러나 과부영양의 연못에서는 박테리아에 의한 요소 분해의 역할이 증가하는 것으로 보 였다. 자연산 식물플랑크톤 군집에 의한 요소의 분해는 넓은 범위의 농도(7.7 mM까 지)에 있어서 monophasic 또는 biphasic kinetics를 나타냈다. 요소의 분해 속도는 높은 암모륨 이온이 존재시와 빚이 없는 상태에서 감소하였다. 이러한 연구 결과들은 식물플랑크톤에 의한 요소분해의 적응에 대한 이해가 현장에서 요소 분해의 시공간적 변이와 질소 순환에서 요소의 중요성을 이해할 때 도움이 될 것으로 제시하였다.

• Journal of Yeungnam Medical Science
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• 제24권2호
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• pp.322-328
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• 2007

Ornithine transcarbamylase (OTC) deficiency is the most common inborn error of urea cycle metabolism; it is inherited in an X-linked manner. The OTC catalyzes the third step of the urea cycle, the conversion of ornithine and carbamyl phosphate to citrulline. Deficiency of OTC leads to the accumulation of ammonia, causing neurological deficits. In most affected hemizygote males, OTC deficiency manifests as hyperammonemic coma that often leads to death in the newborn period, and those who recover from the coma may be neurologically impaired due to the sequelae of the hyperammonemic encephalopathy. In some, late-onset manifestations develop. We report a male neonate with early onset OT deficiency that had apnea and was comatous. On mutation analysis using DNA sequencing after polymerase chain reaction (PCR) amplification of the 10 exons, deletions of 10 bases in codon 285, causing a frame shift was detected in exon 8. The mother and a sister were diagnosed as female carriers. Therefore, genetic counseling and the risk assessment could be provided to the family.

• 대한약학회:학술대회논문집
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• 대한약학회 2003년도 Proceedings of the Convention of the Pharmaceutical Society of Korea Vol.2-2
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• pp.170.3-171
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• 2003

An efficient Erythropoietin (EPO)-expression system in mammalian cells is required for massive production for therapeutic use. Ammonium ion is a major problem in the production of valuable recombinant proteins in cultured animal cells. Therefore, it is of importance to devise a system by which a high productivity of human therapeutic recombinant protein can be maintained or enhanced under low ammonium concentration. To reduce the ammonium ion accumulated in EPO producing Chinese Hamster Ovary (CHO) ceels, IBE, we introduced the first two genes of the urea cycle, carbamoyl phosphate synthetase (CPSI) and arnithine transcarbamoylase (OTC), into IBE using a stable transfection method. (omitted)