• 약학회지
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• 제51권3호
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• pp.214-218
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• 2007

In the previous reports, we developed the CO5 by introducing genes for the first and second urea cycle enzymes, carbamoyl phosphate synthetase I (CPS I) and ornithine transcarbamoylase (OTC) into the IBE cell lines producing erythropoietin (EPO). The CO5 have been found out to have 15-20% higher cell growth rate and produce 2-times more EPO than the parental cell line, IBE. To investigate the role of CPS I in CO5 cell line for the cell growth and amount of EPO, we knock-downed CPS I gene expression via siRNA treatment. Expression level of EPO in cell lysate of CO5 was 3-5 fold higher than that of IBE. After siRNA treatment, the cell growth of CO5 was decreased 8-21% and the EPO productivity in the cell Iysate was significantly decreased. However, these changes of the cell growth and EPO productivity were not observed in IBE. These results indicate that CPS I gene expression is important for the increased cell growth and EPO productivity of CO5 cell line.

• 대한유전성대사질환학회지
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• 제3권1호
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• pp.32-37
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• 2003

저자들은 반복적이며 간헐적인 기면, 정신착란과 운동실조를 주소로 내원한 6세 여아에서, 고암모니아혈증과 혈장 glutamine, 요 orotic acid의 증가를 보여 지발형 OTC 결핍증으로 진단하고, 분자유전학적 검사상 exon 6에서 221번째 아미노산 lysine에 해당하는 염기 AAG가 AAT(asparagine)로 치환된 돌연변이를 이형접합자(heterozygote)로 보인하였던 1례를 경험하였기에 보고하는 바이다.

• 대한유전성대사질환학회지
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• 제5권1호
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• pp.76-87
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• 2005

Various disorders cause hyperammonemia during childhood. Amongthem are those caused by inherited defects in urea synthesis and related metabolic pathways. These disorders can be grouped into two types: disorders of the enzymes that comprise the urea cycle, and disorders of the transporters or metabolites of theamino acids related to the urea cycle. Principal clinical features of these disorders are caused by elevated levels of blood ammonium. Additional disease-specific symptoms are related to the particular metabolic defect. These specific clinical manifestations are often due to an excess or lack of specific amino acids. Treatment of urea cycle disorders and related metabolic diseases consists of nutritional restriction of proteins, administration of specific amino acids, and use of alternative pathways for discarding excess nitrogen. Although combinations of these treatments are extensively employed, the prognosis of severe cases remains unsatisfactory. Liver transplantation is one alternative for which a better prognosis is reported.

• Clinical and Experimental Pediatrics
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• 제54권10호
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• pp.425-428
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• 2011

Ornithine transcarbamylase (OTC) deficiency is well known as the most common inherited disorder of the urea cycle, and 1 of the most common causes of hyperammonemia in newborns. We experienced a case of a 3-day-old boy with OTC deficiency who appeared healthy in the first 2 days of life but developed lethargy and seizure soon afterwards. His serum ammonia level was measured as > $1,700{\mu}g/dL$ (range, 0 to $45{\mu}g/dL$). Continuous renal replacement therapy (CRRT) in the mode of continuous venovenous hemodiafiltration was immediately applied to correct the raised ammonia level. No seizure occurred after the elevated ammonia level was reduced. Therefore, CRRT should be included as 1 of the treatment modalities for newborns with inborn errors of metabolism, especially hyperammonemia. Here, we report 1 case of successful treatment of hyperammonemia by CRRT in a neonate with OTC deficiency.

• Preventive Nutrition and Food Science
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• 제20권4호
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• pp.238-245
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• 2015

A non-protein amino acid, L-ornithine (Orn), has been shown to stimulate the urea cycle and tissue protein synthesis in the liver. The purpose of the current study was to assess whether Orn affects the mammalian target of rapamycin (mTOR) complex 1 (mTORC1) pathway, which is involved in protein synthesis. Primary cultured cells isolated from Wistar rat liver were incubated in an amino acid-free medium, followed by addition of Orn for 3 h. The cell lysate was subjected to immunoblotting to evaluate the phosphorylation of downstream targets of mTORC1, including p70S6K, S6, and 4EBP1. To assess the involvement of mTORC1 for the effect of Orn, the cells were pretreated with the mTOR inhibitor rapamycin before the addition of Orn and the cell lysate was subjected to immunoblotting. We next examined whether the effects of Orn were exerted in vivo. Orn was orally administered to 18 h food-deprived rats, the blood and the livers were collected at 1 and 3 h after administration for immunoblotting. Orn treatment for primary cultured cells for 3 h enhanced the phosphorylation of p70S6K, S6, and 4EBP1. In addition, rapamycin blocked the effects of Orn completely (p70S6K and S6) or partially (4EBP1). The oral administration of Orn to the rat also augmented the phosphorylation of mTORC1 downstream targets notably in S6 at 1 h. Our findings demonstrate that Orn has the potential to induce the phosphorylation of downstream targets of mTORC1 in the rat liver. This may be mediated by the augmentation of mTORC1 activity.

• Journal of Genetic Medicine
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• 제1권1호
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• pp.5-10
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• 1997

The amino acids formed by degradation of proteins ingested produce ammonia. The ammonia which is broken down and excreted as urea through a process known as the Klebs-Hensleit cycle or the urea cycle (Rezvani, 1995). The urea cycle consists of five enzymes necessary for the synthesis of carbamyl phosphate, citrulline, argininosuccinate, arginine, and urea: carbamyl phosphate synthetase (CPS), ornithine transcarbamylase (OTC), argininosuccinate synthetase (AS), argininosuccinate lyase (AL), and arginase (ARG) (Lloyd, 1992). Congenital deficiencies of the enzymes involved in the urea cycle are diseases that are almost fatal without treatment, showing symptoms like vomiting, lethargy, dyspnea, and coma due to hyperammonemia coming from the accumulation of ammonia and metabolic precursors resulting from the deficiency of one of these enzymes (Batshaw and Brusilow, 1983). Among these, the disease manifested by the congenital deficiency of argininosuccinate synthetase (AS) which is associated with the formation of argininosuccinate in citrulline is called argininosuccinate synthetase deficiency or citrullinemia. There have been two reports on this so far in Korea; one in July 1987 by Kim et al. and the other by Park et al. in 1995. We are to report a case of successful treatment of a child with citrullinemia who was transferred to our hospital due to dyspnea, lethargy, feeding difficulties, convulsions and cyanosis together with some document studies related to this case.

• 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)

• 대한유전성대사질환학회지
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• 제18권2호
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• pp.55-61
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• 2018

OTC 결핍증은 요소 회로 대사 질환 중 가장 흔한 질환으로, X연관 유전을 하며, 고암모니아 혈증, 의식저하, 구토, 경련 등을 주증상으로 하여 나타난다. 본 증례에서는 경련 및 의식 저하로 발견된 고암모니아 혈증 및 저칼슘혈증에 대한 치료로 칼슘 보충 및 저단백섭취, sodium benzoate, phenylbutyrate sodium, L-arginine 복용 및 CRRT를 시행하여 증상을 경감시키고, 생화학적 검사 및 Targeted exome sequencing을 통하여 OTC 결핍증을 확진함으로서 신경학적 예후에 대비하도록 하였다. 이로서 현재까지 비교적 양호한 경과를 보이기에 이 증례를 보고하는 바이다.

• 대한유전성대사질환학회지
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• 제15권3호
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• pp.165-170
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• 2015

저자들은 출생 직후에서 생후 7개월까지는 특별한 과거력 없이 건강하게 지내던 여아에서 생후 11개월에 반복적인 구토 및 간헐적인 의식변화와 경련으로 시행한 검사 결과 고암모니아 혈증 및 소변 orotic acid의 증가를 통해 OTC 결핍증을 진단하고, 분자 유전자 검사로 418번째 염기인 G가 C로 치환되어 140번 아미노산이 alanine에서 proline으로 바뀌는 돌연변이(p. Ala140Pro)를 확인한 1례를 경험하였기에 보고하는 바이다. 본 증례의 돌연변이는 환아의 부모 유전자 분석 결과 정상 소견으로 de novo mutation으로 사료된다. 환아는 출생 후 수 개월간 큰 이상 없이 성장 및 발달을 보였으나 생후 7개월 경부터 주기적인 구토 증세를 보였던 지발형 OTC 결핍증에 해당한다. 진단 후 arginine 및 phenylbutylate를 지속적으로 복용하며 저단백 식이를 유지하는 보존적 치료를 지속하여 현재 발달 및 성장 속도 양호하며 일상생활에 문제없이 지내고 있다. 따라서 출생 후 수개월간 특이 질환력이 없는 환아, 특히 여아에서 주기적인 구토, 기면, 경련 및 혼수 등의 증상을 보일 때 지발형 OTC 결핍증과 같은 대사질환을 의심할 수 있어야 한다. 본 증례는 반복적인 구토 및 의식변화를 보인 기저질환 없는 11개월 여아에서 OTC 결핍증을 진단하고 즉각적인 대처를 통해 7세까지 심각한 신경학적 장애 없이 정상적인 성장과 발달을 보인 환자를 보고하는 바이다.

• Applied Biological Chemistry
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• 제47권4호
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• pp.409-413
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• 2004

상온에서 60일 동안 저장한 ‘양산’ 품종의 국내산 완숙호박 과육의 pH, 당도, 중량, 수분함량, 총단백질 함량 및 단백질을 구성하고 있는 아미노산 함량의 변화에 대하여 조사하였다. 그 결과 당도는 저장기간에 따라 큰 차이가 없었으며, pH는 약간 산성화 되었다. 중량과 과육 내 수분함량은 소폭 감소하는 경향을 보였다. 총단백질 함량과 단백질 내 구성아미노산 함량에서는 저장기간이 길어질수록 증가하는 경향을 보였다. 그러나 아미노산 조성에는 큰 차이가 없었으며 glutamic acid(15.5%), aspartic acid(10.1%), lysine(8.7%), valine(7.5%), leucine(7.1%) 및 alanine(6.6%)의 순서로 존재하였다. 또한 $121^{\circ}C$ 고온 및 $1\;kg/cm^2$의 고압 조건에서 1시간 동안 일정한 간격으로 처리한 완숙호박의 유리아미노산 함량 및 색도 변화를 조사하였다. 유리아미노산 분석결과 모든 처리구에서 필수아미노산 8종(histidine, isoleucine, leucine, lysine, phenylalanine, methionine, threonine, 및 valine)과 이뇨작용과 관련된 아미노산류 3종(ornithine, citrulline, arginine)을 비롯하여 총 29종이 검출되었으며, 이 중에서 aspartic acid와 asparagine이 각각 20.3%와 15.4%를 차지하여 가장 많은 함량을 차지하였다. 이와 같은 유리아미노산 조성은 고온고압 처리시간이 길어질수록 arginine과 glutamic acid는 대폭 감소하였고, ammonium chloride는 오히려 증가하는 경향을 보였다. 처리시간별 과육의 색도는 처리시간에 길어질수록 황색을 나타내는 b값이 줄어, 처리 1시간째에 17.45에서 9.14로 낮아졌다. 이것은 ${\beta}-carotene$을 비롯한 황색계통의 색소들이 상당히 파괴되었기 때문에 생긴 현상으로 보여진다.