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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%.
Uhm Chanyang,Jeong Haengdueng,Lee Su Hyon,Hwang Jae Sung,Lim Kyung-Min,Nam Ki Taek 한국독성학회 2023 Toxicological Research Vol.39 No.3
The Organization for Economic Co-operation and Development approved a reconstructed human epidermis (RHE) model for in vitro skin irritation and corrosion tests as an alternative to animal testing for cosmetics, which has been banned in the European Union since 2013. However, RHE models have several limitations, such as high manufacturing costs, a loose skin barrier, and inability to simulate all cellular and non-cellular components of the human epidermis. Therefore, new alternative skin models are needed. Ex vivo skin models have been suggested as promising tools. Here, we investigated the structural similarities in the epidermis of pig and rabbit skin, a commercial RHE model (Keraskin), and human skin. To compare the structural similarity, the thickness of each epidermal layer was compared using molecular markers. Among the candidate human skin surrogates, the epidermal thickness of the pig skin was the most similar to that of human skin, followed by rabbit skin and Keraskin. Keraskin showed thicker cornified and granular layers than human skin, while rabbit skin displayed thinner layers. Moreover, the proliferation indices of Keraskin and rabbit skin were higher than those of human skin, whereas the proliferation index of the pig skin was similar to that of human skin. Some or none of the human skin barrier proteins FLG, CLDN1, and CDH1 were expressed in pig and rabbit skin, whereas all human proteins were expressed in Keraskin. Collectively, we propose ex vivo pig skin as the most suitable model for skin irritation testing because of its similarity to human skin.
The Efficacy of Bioabsorbable Mesh as an Internal Splint in Primary Septoplasty
Kim, Jee Nam,Choi, Hyun Gon,Kim, Soon Heum,Park, Hyung Jun,Shin, Dong Hyeok,Jo, Dong In,Kim, Cheol Keun,Uhm, Ki Il Korean Society of Plastic and Reconstructive Surge 2012 Archives of Plastic Surgery Vol.39 No.5
Nasal bone fractures are often accompanied by septal fractures or deformity. Posttraumatic nasal deformity is usually caused by septal fractures. Submucosal resection and septoplasty are commonly used surgical techniques for the correction of septal deviation. However, septal perforation or saddle nose deformity is a known complication of submucosal resection. Hence, we chose to perform septoplasty, which is a less invasive procedure, as the primary treatment for nasal bone fractures accompanied by septal fractures. During septoplasty, we used a bioabsorbable mesh as an internal splint. We used the endonasal approach and inserted the mesh bilaterally between the mucoperichondrial flap and the septal cartilage. The treatment outcomes were evaluated by computed tomography (CT) and the nasal obstruction symptom evaluation (NOSE) scale. The CT scans demonstrated a significant improvement in the septal deviation postoperatively. The symptomatic improvement rated by the NOSE scale was greater at 1 month and 6 months after surgery compared to the preoperative status. There were no cases of extrusion or infection of the implant. In cases of moderate or severe septal deviation without dislocation from the vomerine groove on the CT scan, our technique should be considered one of the treatments of choice.
Germ free mice are susceptible to gastric cancer induced by N-methyl-N-nitrosourea
Jiseon Kim,Chanyang Uhm,Buhyun Lee,Haengdueng Jeong,Kwan H Kim,Sung Hee Kim,Yura Lee,Sumin Hur,Donghun Jeon,Nakyum Lee,Yejin Cho,Yeseul Oh,Kyunghee Nam,Mina Lee,Ki Taek Nam 한국실험동물학회 2022 한국실험동물학회 학술발표대회 논문집 Vol.2022 No.1
Bone and Soft Tissue Changes after Two-Jaw Surgery in Cleft Patients
Yun, Yung Sang,Uhm, Ki Il,Kim, Jee Nam,Shin, Dong Hyeok,Choi, Hyun Gon,Kim, Soon Heum,Kim, Cheol Keun,Jo, Dong In Korean Society of Plastic and Reconstructive Surge 2015 Archives of Plastic Surgery Vol.42 No.4
Background Orthognathic surgery is required in 25% to 35% of patients with a cleft lip and palate, for whom functional recovery and aesthetic improvement after surgery are important. The aim of this study was to examine maxillary and mandibular changes, along with concomitant soft tissue changes, in cleft patients who underwent LeFort I osteotomy and sagittal split ramus osteotomy (two-jaw surgery). Methods Twenty-eight cleft patients who underwent two-jaw surgery between August 2008 and November 2013 were included. Cephalometric analysis was conducted before and after surgery. Preoperative and postoperative measurements of the bone and soft tissue were compared. Results The mean horizontal advancement of the maxilla (point A) was 6.12 mm, while that of the mandible (point B) was -5.19 mm. The mean point A-nasion-point B angle was $-4.1^{\circ}$ before surgery, and increased to $2.5^{\circ}$ after surgery. The mean nasolabial angle was $72.7^{\circ}$ before surgery, and increased to $88.7^{\circ}$ after surgery. The mean minimal distance between Rickett's E-line and the upper lip was 6.52 mm before surgery and 1.81 mm after surgery. The ratio of soft tissue change to bone change was 0.55 between point A and point A' and 0.93 between point B and point B'. Conclusions Patients with cleft lip and palate who underwent two-jaw surgery showed optimal soft tissue changes. The position of the soft tissue (point A') was shifted by a distance equal to 55% of the change in the maxillary bone. Therefore, bone surgery without soft tissue correction can achieve good aesthetic results.