http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
3,4-Dihydroxyphenyl-L-alanine의 효소적 생산에 대한 반응첨가물의 영향
이승구,노현수,홍승표,성문희 한국미생물생명공학회 ( 구 한국산업미생물학회 ) 1996 한국미생물·생명공학회지 Vol.24 No.2
재조합 대장균에서 과발현된 Citrobacter freundii KCTC 2006 유래의 tyrosine phenol-lyase(E.C.4.1.99.2) 이용 3,4-dihydroxyphenyl-L-alanine (L-DOPA)의 생산에 대한 반응첨가물의 영향을 조사하였다. 반응액 중 효소 및 조효소 농도의 영향을 조사한 결과, 효소농도는 약 2 units/ml이 적합하였으며, 조효소인 pyridoxal -5-phosphate 는 0.1 mM 이상이 필요하였다. Pyrocatechol과 결합하여 안정한 복합체를 형성하는 sodium borate는 pyrocatechol에 의한 효소의 불활성화를 감소시키는 효과가 있었으나, 효소의 반응성을 현저히 저하시켜 L-DOPA 생산의 관점에서는 불리한 단점도 있었다. 한편, 알콜류 등의 유기용매가 L-DOPA 합성반응에 미치는 영향을 조사한 결과 methanol을 5% 농도로 반응액에 첨가하였을 때, 효소의 반응과 안정성이 크게 증가하여 L-DOPA 합성반응이 지속적으로 수행됨으로써 고농도의 L-DOPA를 효율적으로 생산할 수 있게 되었다. 생산된 L-DOPA의 약 77%가 불용성 상태로 침전되어 쉽게 회수할 수 있었으며, 침전된 L-DOPA를 1N HCI에 용해한 후 재결정화 함으로써 최종적으로 99.96%의 고순도 L-DOPA를 생산할 수 있었다. The enzymatic synthesis of 3,4-dihydroxyphenyl-L-alanine (L-DOPA) was examined for the effects of the reaction additives such as sodium borate, alcohol, and organic solvents. The enzyme used was tyrosine phenol-lyase of Citrobacter freundii KCTC 2006 produced in Escherichia coli. The amounts of tyrosine phenol-lyase and pyridoxal -5-phosphate were optimized to 2.0 units/ml and 0.1 mM, respectively, for the synthetic reaction. Sodium borate, a substance that forms a complex with pyrocatechol, reduced the enzyme deactivation by pyrocatechol although it seriously inhibited the enzyme activity. Among the organic solvents tested, dimethylsulfoxide, dimethylformamide, and alcohol increased the productivity of the L-DOPA synthesis. In a reaction system with 5% methanol, L-DOPA concentration increased up to 210 mM after 24 hours, and 77.1% of which was separated as precipitates. The L-DOPA was purified to 99.96%
제조합 대장균에서 과발현된 Citrobacter freundii KCTC2006 유래의 β-Tyrosinase를 이용한 3,4-Dihydroxyphenyl-L-alanine의 생산
이승구,노현수,홍승표,이규종,왕지원,태동년,엄기남,방상구,김영준,성문희 한국미생물생명공학회 ( 구 한국산업미생물학회 ) 1996 한국미생물·생명공학회지 Vol.24 No.1
재조합 대장균에서 대량발현 시킨 Citrobacter freundii KCTC 2006 유래이 효소 β-tyrosinase를 이용하여 pyrocatechol, sodium pyruvate, ammonium acetate로부터 3,4-dihydroxy phenyl-L-alanine을 생산하기 위한 연구를 수행하였다. 이 효소반응에 적합한 온도 및 pH 조건은 각각 18℃와 8.5로 결정되었고, 반응액 중의 ammonium acetate와 sodium pyruvate의 농도는 각각 300 mM, 50 mM 이상으로 조절하는 것이 적합하였다. Pyrocatechol의 경우는 20 mM에서 가장 높은 반응성을 나타냈으나, 기질을 반복적으로 첨가하며 장시간 동안 효소반응을 수행하는 경우에는 pyrocatechol의 고갈을 피하기 위하여, 20 mM에서 50 mM 사이로 조절하였다. 한편, 반응액 중에 ethanol을 10% 첨가한 경우에는 반응속도가약 20% 증가하였다. 이상과 같은 효소반응특성에 기초하여 조제한 기질용액에 β-tyrosinase를 1 unit/㎖ 농도로 가하고, pyrocatechol과 pyruvate가 고갈되지 않도록 간헐적으로 첨가하면서 효소반응을 수행한 결과, 24시간 만에 85.2%의 수율로 31.6g/ℓ의 3,4-dihydroxyphenyl-L-alanine를 생산할 수 있었다. By using the β-tyrosinase of Citrobacter freundii KCTC2006, which was cloned and overexpressed in Escherichia coli, 3,4-dihydroxy phenyl-L-alanine (L-DOPA) was synthesized efficiently from pyrocatechol, sodium pyruvate, and ammonium acetate. Optimal temperature and pH for the reaction were determined to be about 18℃ and 8.5, respectively. The effects of substrate concentrations were also examined at different concentrations of ammonium acetate, sodium pyruvate, and pyrocatechol. Ammonium acetate and sodium pyruvate increased the reaction rate until the concentrations reached to 300 mM and 50 mM, respectively. Although pyrocatechol showed the optimal concentration at 20 mM, it was controlled between 20 mM and 50 mM to avoid the depletion of substrate during the enzymatic synthesis. Based on above results, a reaction medium for the production of L-DOPA was prepared and incubated with 1 unit/㎖ of β-tyrosinase. Pyrocatechol and sodium pyruvate was added to the reaction solution intermittently to avoid the substrate depletion during the enzymatic reaction. After 24 hour of reaction, 31.6 g/ℓ L-DOPA was accumulated in the reaction solution as soluble and precipitated ones and the conversion yield was about 85.2%.
포스터 전시 : 췌담도 ; 간이식후 합병된 Biliary cast syndrome에 의한 폐쇄성 황달 1예
백상현 ( Baeg Sang Hyeon ),최호순 ( Choe Ho Sun ),조경란 ( Jo Gyeong Lan ),김종표 ( Kim Jong Pyo ),이오영 ( Lee O Yeong ),손주현 ( Son Ju Hyeon ),한동수 ( Han Dong Su ),함준수 ( Ham Jun Su ),이민호 ( Lee Min Ho ),이동후 ( Lee Dong 대한소화기학회 2003 대한소화기학회 추계학술대회 Vol.2003 No.-
<서론> 간이식후에 발생될 수 있는 담도계의 합병증은 16~35% 정도로 보고되고 있다. 가장 빈도가 높은 합병증으로는 담즙누수(Bile leak), 문합부 협착 등을 들 수 있으며, 그 외에도 T-관 누수, 담석증, biliary cast sydrome 등을 들 수 있다. 특히 biliary cast syndrome은 간이식후 생기는 후기 담도계 합병증으로 드물게 세계적 보고는 있었으나 국내보고가 미흡한 실정이다. 대개 내시경적 역행성 담도 조영술을
Cancer risk in patients with Peutz-Jeghers syndrome in Korea: a retrospective multi-center study
( Su Hwan Kim ),( Eun Ran Kim ),( Jae Jun Park ),( Eun Sun Kim ),( Hyeon Jeong Goong ),( Kyeong Ok Kim ),( Ji Hyung Nam ),( Yehyun Park ),( Sang Pyo Lee ),( Hyun Joo Jang ) 대한내과학회 2023 The Korean Journal of Internal Medicine Vol.38 No.2
Background/Aims: There have been little research on the cancer risks of patients with Peutz-Jeghers syndrome (PJS) in Korea. We aimed to investigate the clinical features of PJS patients and their cancer incidence rate. Methods: Patients with PJS from nine medical centers were enrolled. In those patients diagnosed with cancer, data obtained included the date of cancer diagnosis, the tumor location, and the cancer stage. The cumulative risks of gastrointestinal cancers and extra-gastrointestinal cancers were calculated using the Kaplan-Meier method. Results: A total of 96 PJS patients were included. The median age at diagnosis of PJS was 23.4 years. Cancer developed in 21 of the 96 patients (21.9%). The age of PJS diagnosis was widely distributed (0.9 to 72.4 years). The most common cancers were gastrointestinal cancer (n = 12) followed by breast cancer (n = 6). The cumulative lifetime cancer risk was calculated to be 62.1% at age 60. The cumulative lifetime gastrointestinal cancer risk was 47.1% at age 70. The cumulative lifetime extra- gastrointestinal cancer risk was 40.3% at age 60. Conclusions: PJS onset may occur at any age and the risks of gastrointestinal and extra-gastrointestinal cancer are high. Thorough surveillance of PJS patients for malignancies is vital.
Yon Su Kim,Be Long Cho,김우식,Sang Hyun Kim,In Hyeon Jung,Won Yong Sin,Dong Hoon Choi,Sang Jae Lee,Chun Soo Lim,Kyung Pyo Kang,Byung Yeon Yu,Wonju Jeung,Chang Gyu Park 대한가정의학회 2019 Korean Journal of Family Medicine Vol.40 No.4
Background: We assessed the frequency and severity of hypoglycemia in type 2 diabetes mellitus patients treated with sulfonylurea monotherapy or sulfonylurea+metformin.Methods: We conducted a retrospective, observational, cross-sectional study in 2011 and 2012 including patients with type 2 diabetes mellitus aged ≥30 years who were treated with ≥6 months of sulfonylurea monotherapy or sulfonylurea+metformin at 20 university-affiliated hospitals in Korea. At enrollment, glycated hemoglobin (HbA1c) was assessed; participants completed self-reported questionnaires describing hypoglycemia incidents over the past 6 months. A review of medical records up to 12 months before enrollment provided data on demographics, disease history, comorbidities, laboratory results, and drug usage. Results: Of 726 enrolled patients, 719 were included (55.6% male); 31.7% and 68.3% were on sulfonylurea monotherapy and sulfonylurea+metformin, respectively. Mean±standard deviation age was 65.9±10.0 years; mean HbA1c level was 7.0%±1.0%; 77.8% of patients had hypertension (89.4% used antihypertensive medication); 60.5% had lipid disorders (72.5% used lipid-lower-ing medication); and 52.0% had one or more micro- or macrovascular diseases. Among patients with A1c measurement (n=717), 56.4% achieved therapeutic goals (HbA1c <7.0%); 42.4% (305/719) experienced hypoglycemia within 6 months of enrollment; and 38.8%, 12.9%, 12.7%, and 3.9% of patients experienced mild, moderate, severe, and very severe hypoglycemia symptoms, respec-tively. Several reported hypoglycemia frequency as 1–2 times over the last 6 months. The mean number of very severe hypoglyce-mia episodes was 3.5±5.5.Conclusion: Among type 2 diabetes mellitus patients treated with sulfonylurea-based regimens, glycemic levels were relatively well controlled but hypoglycemia remained a prevalent side effect.
감자 ( Solanum tuberosum ) 의 기내 소괴경 형성 단계에 따른 Peroxidase 와 Esterase 동위효소의 양상 변화
정현숙(Hyeon Sook Cheong),송규상(Kyu Sang Song),박진수(Gene Su Park),김성준(Sung Jun Kim),양영기(Young Ki Yang),표병식(Byoung Sik Pyo),황백(Baik Hwang),강영희(Young Hee Kang) 한국식물학회 1993 Journal of Plant Biology Vol.36 No.1
The microtuber was efficiently formed on SH medium containing 9% sucrose from the in vitro propagated shoot of potato (Solanum tuberosum cv. Sumi). In order to investigate gene expression depending on the developmental stage of microtuber, we examined the changes of peroxidase and esterase activities, and their isozyme patterns as well. Peroxidase and esterase activities were the highest at the 7 day-culture of the microtuber and subsequently decreased on the stage of microtuberization, whereas esterase activity increased at the stage of 60 day-culture. However, their activities in the ordinary tuber were higher than those of 60 day-cultured microtuber. In addition, in the peroxidase isozyme pattern two new bands of pI 7.05 and pI 4.65 were appeared at the 15- day and 60 day-cultures, respectively, as shown by isoelectric focusing. Various bands in the esterase isozyme pattern were shown at the 7 day-culture, and the band patterns were a large difference, comparing those of shoot and tuber. New bands in the esterase isozyme pattern also appeared at the 15 day- (pI 4.52) and 60 day-cultures (pI 4.48). These results suggest that the changes of peroxidase and esterase activities and isozyme patterns are an important factor in the differentiation and development of potato.
윤현수(Hyeon Soo Yoon),이미화(Me Hwa Lee),이수진(Su Jin Lee),김건영(Kun Young Kim),유연표(Yun Pyo You),정도영(Do Young Jung),노경환(Gyoung Hwan Roh),한현영(Hyun Young Han),박성규(Sung Kyu Park),최덕례(Duck Yeii Choi) 대한소화기학회 2001 대한소화기학회지 Vol.38 No.2
Pyogenic liver abscess is a serious clinical disease with severe complications in 10-20% of the cases. Metastatic septic endophthalmitis is a rare complication associated with liver abscess. Despite appropriate treatment, the outcome is devastating. We experienced a case of pyogenic liver abscess complicated with endophthalmitis. The bacterial organism cultured from liver abscess was Klebsiella pneumoniae. Treatment of this patient was composed of percutaneous drainage under ultrasonographic guidance, systemic and intravitreal antibiotic therapy. After treatment for 6 weeks, the liver abscess was resolved completely, but the visual outcome was very poor despite intensive treatment. We report a case of pyogenic liver abscess complicated with endophthalmitis. (Korean J Gastroenterol 2001;38:120-123)
Impact of minimum winter temperature on Lycorma delicatula (Hemiptera: Fulgoridae) egg mortality
Jung-Su Lee,Il-Kwon Kim,Sang-Hyun Koh,Sung Jong Cho,Suk-Jun Jang,Seung-Hyeon Pyo,Won IL Choi 한국응용곤충학회 2011 Journal of Asia-Pacific Entomology Vol.14 No.1
Climate change, especially winter temperature increase, may be a factor the recent occurrence and range expansion of Lycorma delicatula (White) in South Korea. Egg mortality increased as minimum winter temperature decreased. Egg mortality was highest (93.32%) in Chuncheon, where the mean minimum winter temperature was lowest. The temperature that induced complete mortality of fulgorid eggs was estimated to be−3.44 °C on the basis of mean daily temperatures from December 2009 to February 2010 and−12.72 °C on the basis of mean daily minimum temperatures in January 2010. Mean winter temperatures during the last 30 years have gradually increased to above the temperature for 100% mortality of the fulgorid egg. This suggests that the winter temperature increase may contribute to the successful settlement of the fulgorid in South Korea and its subsequent outbreak and expansion.