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망막아세포종 세포주(Y-79)의 Arylalkylamine N-acetyltransferase 활성에 미치는 Dopamine의 영향
김석민,정미영,윤경식,진병관,백행운,백형환,조용호 慶熙大學校 1997 論文集 Vol.26 No.-
The arylalkylamine N-acetyltransferase(AA-NAT, EC 2.3.1.87) in vertebral pineal gland and retina is rate-limiting enzyme in the pathway of biosynthesis of melatonin. AA-NAT activities are remarkably increased during night with 10-150 folds. Neurohormone melatonin is thought to play roles in a broad range of physiological functions in human, primarily through effects on the biological clock in the suprachiasmatic nucleus of the hypothalamus, This rhythm reflects large changes in the activities of AA-NAT. So the important regulatory role of AA-NAT has made it central interest in research on melatonin biochemistry and neurochemical signal transduction. The neurotransmitter that regulates the AA-NAT activities is norepinephrine, which acts through a cyclic AMP mechanism. The effect of dopamine on AA-NAT in human retinoblastoma Y-79 cells was studied. the obtained results are as follows; AA-NAT activities in Y-79 cells were increased by cyclic AMP, and dopamine inhibited the AA-NAT activities stimulated by forskolin. The pattern of inhibition of dopamine on the AA-NAT activities in Y-79 cells was time and concentration dependent. The results suggest that dopamine participates in the regulation of the AA-NAT activities through the inhibitory mechanism in the human pineal and retinal tissues.
Escherichia coli(M15)을 이용한 serotonin N-acetyltransferase 유전자의 발현
김용만,정미영,윤경식,진병관,백행운,조용호,백형환 慶熙大學校 1997 論文集 Vol.26 No.-
AA-NAT cDNA was obtained by RT-PCR technique from total RNA of rat sacrified at night(02:00am). pCRNAT was cloned using the pCRII vector with insertion of AA-NAT cDNA(about 1.4 kb) at EcoRI site. For the expression of the gene, pQECNAT was subcloned, in which the coding region of AA-NAT was inserted into expression vector pQE30 at BamHI and HindIII sites. According to the experimental results, Escherichia coli strain M15, transformed by the expession vector pQECNAT, was selected as a host to express AA-NAT gene with the induction of isopropyl β-D-thiogalactoside(IPTG). Optimal condition for the expression of AA-NAT gene was achieve from the experimental results, showing that the expression of the protein was inducible much 19.800 ± 2,200 dpm per ml of culture volume in 4 hours at the concentration of 2 mM IPTG. Partial purification through the affinity column(Ni-NTA agarose) binding to the continuous 6 histidine residues of protein resulted in 5 times more increase in the specific activity of AA-NAT than that of the homogenate of bacterial pellet. These experimental results will provide basic data in further study for the enzymatic kinetics and antibody production of AA-NAT.
Baik, Byung-Ryol,Yu, Jin-Young,Yoon, Hyun-Seong,Lee, Ju-Woon,Byun, Myung-Woo,Baik, Byung-Kee,Lim, Seung-Taik WILEY-VCH Verlag 2010 Die Stärke Vol.62 No.1
<P>Waxy and normal maize starches of various pH values and salt contents were prepared, irradiated with gamma rays (5–20 kGy) and their molecular structure, pasting viscosity and rheological properties determined. Average molar mass and size of both waxy and normal maize starches decreased considerably by irradiation from >338.0×10<SUP>6</SUP> to <39.4×10<SUP>6</SUP> g/mol and from >237.5 to <125.2 nm, respectively. Adjustments of pH had little influence on the average molar mass and size of irradiated starch, whereas incorporation of salt greatly reduced the molar mass and size of irradiated waxy and normal maize starches. As the pH increased from 4 to 8, the pasting viscosity of the irradiated starches decreased from 1032 to 279 mPa s in waxy and from 699 to 381 mPa s in normal starches. Pasting viscosity of both irradiated waxy and normal starch decreased from 689 to 358 mPa s and from 327 to 184 mPa s as the salt concentration increased from 1 to 5%. The G′ of gels, determined during cooling from 90 to 10°C or storage for 8 h, decreased in irradiated waxy and normal starches by pre-conditioning at pH 8 and in irradiated waxy starches by pre-conditioning at 5% NaCl. With 5% NaCl, G′ of irradiated normal maize starch during cooling increased up to the irradiation level of 10 kGy, and increased during storage for 8 h at all levels of irradiation. Incorporated salt prior to irradiation appears to induce incremental modifications in the molecular structure, rheological and retrogradation properties of starch by boosting the degradation of molecules.</P>
글루콘산계 지연제의 종류 및 혼입률 변화에 따른 시멘트 모르터의 응결 및 강도특성
윤섭,황인성,백병훈,한천구 대한건축학회 2004 대한건축학회 학술발표대회 논문집 - 계획계/구조계 Vol.24 No.1(구조계)
In this paper, fundamental engineering properties of cement mortar with gluconic based super retarding admixture(GSRA) type and content are discussed. For fresh mortar properties, flow of cement mortar exhibited an increase tendency with an increase in GSRA content. Remarkable flow loss was not observed at GSRA A with an elapse of age. For setting properties, presence of GSRA affected the setting time retarding. The effect of GSRA type on setting time retarding is in order for A, B, C. This is due to the gap of consistency. Compressive strength of cement mortar with GSRA is higher than that with plain mortar after 28days since final set.
Hemodilution이 백서의 피부피판 생존에 미치는 영향에 대한 실험적 연구
백무현,김원택,김승홍,이기룡,민대홍,윤병일 大韓成形外科學會 1984 Archives of Plastic Surgery Vol.11 No.4
In order to increase the survival rate of skin flaps, lots of studies have been made since several decades. Among them, isovolemic hemodilution, by exsanguination and crystalloid replacement, is said to augment skin flap survival in rats. Serum protein, however, is said to be a major factor which determines blood viscosity in microvasculature. So, authers planned an experiment in which hematocrit was decreased in rats without change in serum protein concentration. Some amount of whole blood was withdrawn and centrifuged, and the serum was reinjected to the rats with crystalloid replacement for maintaining isovolemia without causing hypoproteinemia. In comparison with that of control, total serum protein concentration in hemodiluted animals by auther's technique was not altered greatly. Hematocrit level was measured daily in respective animals, and mean value was 47.07±1.39% in control, and 29.66±6.28% in hemodiluted group. Mean flap survival rate on postop, 7th day was 35.33±3.09% in control, and 45.93±8.15% in hemodiluted rats without hypoproteinemia(p<0.01).
Secretory Profiles and Wound Healing Effects of Human Amniotic Fluid-Derived Mesenchymal Stem Cells
Yoon, Byung Sun,Moon, Jai-Hee,Jun, Eun Kyoung,Kim, Jonggun,Maeng, Isaac,Kim, Jun Sung,Lee, Jung Han,Baik, Cheong Soon,Kim, Aeree,Cho, Kyoung Shik,Lee, Jang Ho,Lee, Hwang Heui,Whang, Kwang Youn,You, Se Mary Ann Liebert 2010 STEM CELLS AND DEVELOPMENT Vol.19 No.6
<P>Recent evidence shows that amniotic fluid (AF) contains multiple cell types derived from the developing fetus, and may represent a novel source of stem cells for cell therapy. In this study, we examined the paracrine factors released by human amniotic fluid-derived mesenchymal stem cells (AF-MSCs) and their ability to accelerate the wound-healing process by stimulating proliferation and migration of dermal fibroblasts. AF-MSCs expressed the typical MSC marker proteins CD13, CD29, and CD44 and differentiated into adipocytes, osteoblasts, and chondrocytes when exposed to the appropriate differentiation media. In addition, AF-MSC-conditioned media (AF-MSC-CM) significantly enhanced proliferation of dermal fibroblasts. Antibody-based protein array and enzyme-linked immunosorbent assay (ELISA) indicated that AF-MSC-CM contains various cytokines and chemokines that are known to be important in normal wound healing, including IL-8, IL-6, TGF-beta, TNFRI, VEGF, and EGF. Application of AF-MSC-CM significantly enhanced wound healing by dermal fibroblasts via the TGF-beta/SMAD2 pathway. Levels of p-SMAD2 were increased by AF-MSC-CM, and both the increase in p-SMAD2 and migration of dermal fibroblasts were blocked by inhibiting the TGF-beta/SMAD2 pathway. Moreover, in a mouse excisional wound model, AF-MSC-CM accelerated wound healing. These data provide the first evidence of the potential for AF-MSC-CM in the treatment of skin wounds.</P>