• Korean Journal of Animal Reproduction
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• v.24 no.4
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• pp.419-428
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• 2000

Leptin, the product of obese (ob) gene, is an adipocyte-derived satiety factor that plays a major role in the regulation of food intake, energy homeostasis, body weight, reproductive physiology and neuropeptide secretion. The present study was designed to generate transgenic mice expressing antisense mouse ob (mob) gene. Total RNA was extracted from the adipose tissues of mouse, then reverse transcription was performed. The 303 and 635 bp fragments of anti I and II cDNAs were amplified from mob cDNAs by PCR. The two mob cDNAs were reversely ligated into between adipose tissue specific aP2 promote and SV40 poly(A) site. Transgenic mice carrying two different kinds of antisense mob transgenes were generated by DNA microinjection into pronucleus. Total 14 transgenic mice were born, and the 4 and 5 founder lines of the transgenic mice with anti I and II transgenes were respectively established. Antisense mRNA expression was detected in transgenic F$_1$ mice by RT-PCR analysis. This result suggests that the transgenic mice expressing antisense mob mRNA may be useful as an animal disease model to be obesity caused by decreased amount of leptin secretion.

• Proceedings of the KSAR Conference
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• 2001.03a
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• pp.55-55
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• 2001

Erythropoietin(EPO)는 적혈구 세포 증식, 분화 및 생존에 있어서 가장 중요한 요인이다. 또한, 빈혈성저산소증에 있어서도 EPO가 중요한 역할을 한다고 알려져 있다. 태아에서 EPO 생산부위는 간이라고 알려져 있으나, 임신 120-140일에 신장으로 이동하기 시작하여 출생 후 약 40일경 이후에는 완전히 신장에서만 분비한다 EPO단백질의 분비는 오전 8시에 가장 낮고 오후 8시에 가장 높은 2중 리듬의 형태로 발현되어진다. EPO는 27개의 leader sequence와 165개의 아미노산으로 총 193개의 아미노산으로부터 분비된다. EPO단백질의 분자량은 18 kDa이나, 약 40%의 당쇄가 첨가되어있는 당단백질으로서 분자량은 30 kDa이다 N-linked 당쇄 3개(Asn-24, 38 및 83)와 O-linked 당쇄 1개(Ser 126)의 첨가부위가 존재하며, 2개의 disulfide bridges(7-161번, 29-33번)를 형성하고 있다. 이러한 당쇄의 수식은 EPO의 대사에 있어서 매우 중요하다. EPO를 가축의 소변으로부터 생산하기 위하여 생쥐의 3.6 kb UII promoter 하류에 genome hEPO와 SV 40 poly A를 연결하여 형질전환용 발현 벡터를 구축하였으며, 과배란 유기로 채란되어진 돼지의 1-세포기 수정란의 웅성전핵에 유전자를 미세주입기로 주입 후 즉시 대리모에 이식하였다. 66두에 미세주입된 1572개의 수정란을 외과적 방법으로 이식, 평균 23개의 수정란을 이식하였다. 생산된 자돈 112두중 2두(3-5, 3-15번)에서 PCR양성반응(304, 567bp)을 나타내어, 2두의 돼지로부터 소변을 회수하였다. 회수된 소변을 이용 Elisa방법으로 EPO를 분석한 결과 3-5번 돼지에서만 분만 후 지속적으로 EPO농도가 증가되었다. EPO의 최고농도는 1.1 IU/$m\ell$였으며, 이러한 결과는 CHO 세포에서의 500-1000 IU/$m\ell$의 생산량보다도 약 500-1000배정도 낮은 수준이었다. 이상을 종합하여 보면, 1) 가축에서도 생리활성물질을 소변에서 생산할 수 있는 UII promoter의 활용가능성을 제시하였으며, 2) 현재로서는 EPO의 발현량이 너무 낮아, 사용된 생쥐의 promoter를 보완할 필요성이 있다고 사료된다. 그러나, UII promoter를 이용하여 생리활성 물질을 생산할 수 있는 형질전환 돼지 생산의 성공은, 앞으로 형질전환 가축을 이용하는 활용 면에서도 더욱 더 활발할 것으로 기대된다.

• Journal of Radiation Protection and Research
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• v.22 no.4
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• pp.227-235
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• 1997

Cytogenetic studies were performed in peripheral blood lymphocytes from hospital workers occupationally exposed to low doses of radiation (0.30 - 40.07mSv). The workers were divided into three groups according to their job area : 18 diagnostic radiology, 17 therapeutic radiology, and 16 nuclear medicine. The control group consisted of 49 non-radiation workers with no history of exposure to radiation. A higher percentage of cells with aberration(1.275%) was observed in the workers compared to the controls(0.677%) and the difference was statistically significant(p<0.001). The frequency of chromosomal aberration was $0.706{\times}10^{-2}$/cell in the exposed and $0.344{\times}10^{-2}$/cell in the control(p<0.05). Chromosomal exchange frequency was $0.083{\times}10^{-2}$/cell in the control vs $0.245{\times}10^{-2}$/cell in the workers. There was no evidence of significant increase of chromosome aberration related to age or to the duration of employment. The frequency of chromosomal exchange in workers of nuclear medicine was $0.313{\times}10^{-2}$/cell, which was significantly higher than in the control($0.083{\times}10^{-2}$/cell) or other working groups: therapeutic radiology($0.265{\times}10^{-2}$/cell), and diagnostic radiology($0.167{\times}10^{-2}$/cell). No dose-effect relation was found between chromosome aberration and total cumulative doses, recent 5 yr, recent 2 yr cumulative dose. But in case of last 1 yr cumulative dose, dose-dependant increase was observed when controls were considered(p<0.05). The radiation dose which workers have received was much lower than the maximum permissible dose, but there was a significant difference in the frequency of chromosome aberration between occupationally exposed workers and control. So, it is clear that chromosome aberration is a quite sensitive indicator of radiation exposure and it can be detected at very low dose level of occupational exposure.

• Asian-Australasian Journal of Animal Sciences
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• v.16 no.7
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• pp.1055-1059
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• 2003

Keratins, the constituents of epithelial intermediate filaments, are precisely regulated in a tissue and development specific manner. There are two types of keratin in bovine. The type I is acidic keratin and the type II is neutral/basic keratin. 1.5 kb of 5' flanking sequence of Korean cattle Keratin IV gene, type II keratin (59 kDa), was cloned and sequenced. A symmetrical motif AApuCCAAA are located in a defined region upstream of the TATA box. Proximal SP1, AP1, E-box and CACC elements as the major determinants of transcription are identified. When it was compared to the bovine sequence from -600 bp to ATG upstream, the homology was 97% in nucleotide sequence. Several A and T sequences, located in the promoter region, are deleted in the Korean cattle. An expression vector consisted of Korean cattle Keratin IV gene promoter/SV40 large T antigen was transfected to HaCaT cell (Epithelial keratinocyte). The transformed HaCaT cells showed active proliferation when treated with PDGF (Platelet-derived growth factor) in 0.3% soft agar compared to control cells. These results indicate that Korean cattle Keratin IVgene promoter can be used as a promoter for transfection into epithelial cell.

• Journal of Korean Society of Water and Wastewater
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• v.10 no.1
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• pp.121-130
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• 1996

Adsorption isotherms of three trihalomethanes(THMs: $CHCl_3$, $CHBrCl_2$ and $CHBr_2Cl$) and the other organics(p-chlorophenol and sucrose)on activated carbon fibers(ACFs) were measured. Adsorption capacities of the ACFs for these THMs were found to be comparable with or slightly larger than those of granular activated car bons(GACs) which have been widely used for trihalomethanes control in drinking water. Also, the breakthrough curve prediction was successfully carried out using a mathematical model on basis of the assumption that the adsorption equilibrium is instantaneously established when a THM solution contacts the ACF. In practice, THM removal from drinking water was investigated at water works using benchscale ACF adsorptJOn columns. The volume of water treated at a space velocity(SV) of about $100h^{-1}$ was approximately 40 l/g-ACF. The practical adsorption capacities of PCP and sucrose in column adsorption were in good agreement with those of theoretically calculated results using the batch adsorption measurments. And the saturation time model of these substrates in the columns was also agreed succesfully with practical measurments.

• Ocean and Polar Research
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• v.31 no.4
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• pp.283-296
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• 2009

Oceanographic survey data were analyzed to understand the characteristics of a warm eddy observed in the Ulleung Basin in July 2005. The temperature distribution at 200 db and vertical sections provided evidence of the warm eddy in the Ulleung Basin (UWE05). Based on the 5$^{\circ}C$ isothermal line on 200 db temperature, the major axis was 160 km from southwest to northeast, and the minor axis was 80 km from southeast to northwest. The homogeneous layer in the thermocline of UWE05 had mean values of 10.40$^{\circ}C$ potential temperature, 34.35 psu salinity, and 26.37 kg/m$^3$ potential density (${\sigma}_{\theta}$) and provided evidence that UWE05 also existed during the winter of 2004-2005. A warm streamer initially flowed along the circumference of UWE05 and mixed with the upper central water. Two northward current cores were found on the western side of the measured current section at the central latitude of UWE05. One was the East Korean Warm Current (EKWC) and the other was the main stream of the western part of UWE05. Geostrophic transport of the upper layer (from the surface to the isopycnal surface of 26.9 ${\sigma}_{\theta}$) was approximately 2.5 Sv in the eastern side of UWE05. However, the measured transport was twice as large as the geostrophic transport. Mass conservation of geostrophic transport was well satisfied in the upper layer. The direct current measurements and geostrophic transport analysis showed that the EKWC meandered around UWE05.

• The Journal of Korean Society of Virology
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• v.29 no.1
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• pp.33-38
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• 1999

Retroviral vector provide a highly efficient method for gene transfer into eukaryotic cells. This vector system can be divided into two components; the retroviral vector itself and the retroviral packaging cell line. The key improvement in the design of these two components are, focused on two aspects; the reduction of helper virus production and high titer-virus. We used PA317 for retrovirus packaging cell line, for its high producibility of viral titer. To test the ability of the vectors to generate high titer-virus, we have chosen four different retroviral vectors; LN, LNSX, LNCX and LXSN. To test easily the viral titer, we have made recombinant construction with CD4 and CD8, checked their viral titer and stained their surface expression. LXSN which contain SV40 early promoter in front of neo gene showed best results in viral transient transfection assay, dot blot assay and surface expression. In addition, recombinant containing CD8 generally showed much higher viral titration and surface expression than CD4.

• Journal of Aquaculture
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• v.13 no.1
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• pp.29-37
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• 2000

In previously study we isolated several fish matrix attachment regions (MARs) capable of replicating the plasmid by itself. In this study we construct a fish expression vector pBaEGFP(+) containing mud loach ${\beta}$-actin promoter EGFP as reporter gene and SV40 signal. To analyze the effects of the fish expression vector respectively. The fish ARS containing constructs pBaEGFP(+)-ARSs were transfected cells with pBaEGFP(+)-ARS101 and pBaEGFP(+)-ARS223 reduced 10 days to 25 days and then was constant to 30 days after transfection while that of the control vector without ARS element was basal level. The intensity of both constructs showed about 30fold of the intensity compared with the control vector on 30days after transfection individually .E. coli back-transformation analysis shows that pBaEGFP(+)-ARS223 and pBaEGFP(+)-ARS905 maintain in episomal state at least 30 days after transfection. The result indicates that both may be able to replicate the vector in BF-2 cell. Therefore the matrix-attached ARSs enhancing expression of the reporter gene might be useful as a component o the expression vector for transgenic studies.

• Ocean and Polar Research
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• v.21 no.2
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• pp.99-108
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• 1999

With sectional data obtained in September of 1987, 1988 and 1989 by quadrireciprocal ADCP measurement and CTD cast, the current structure, volume transport and vorticity in the Western Channel of the Korea Strait were studied. The characteristics of Tsushima Current water persisted throughout the summer especially in the homogeneous water of temperature $14-16^{\circ}C$ located at the depth of 50-100m below seasonal termocline. Thickness and velocity of the homogeneous layer are about 10-170m and 20-60cm/s. and the relative vorticity for this layer is shown to be nearly constant and it is smaller than the planetary vorticity. Potential vorticity of $2.70-7.10{\times}10^{-6}m^{-1}s^{-1}$ is found to be dependent mainly on planetary rather than on the relative vorticities. The Tsushima Current water represented by the homogeneous layer R14-16^{\circ}C$ may keep the potential vorticity at the area of strong current in the Strait. The ADCP current structure is similar to geostrophic current and the core of the current with the speed of 30-50cm/s is situated in the middle layer over the deep trough. With large tidal fluctuation the volume transport has mean value of 1.17sv which was about 40% larger than that of geostrophic calculation.

• Imaging Science in Dentistry
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• v.37 no.2
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• pp.93-102
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• 2007

Purpose: Cone beam computed tomography (CBCT) provides a lower dose and cost alternative to conventional CT, promising to revolutionize the practice of oral and maxillofacial radiology. The purpose of this study was to evaluate the absorbed and effective doses of Implagraphy and VCT (Vatech Co., Hwasung, Korea) and compare them with those of panoramic radiography. Materials and Methods: Thermoluminescent dosimeter (TLD) chips were placed at 27 sites throughout the layers of Female ART Head and Neck Phantom for dosimetry. Implagraphy, VCT units, and Planmeca Proline XC panoramic unit were used for radiation exposures. Radiation weighted doses and effective doses were measured and calculated using 1990 and 2005 ICRP tissue weighting factors. Results: Effective doses in Sv (ICRP 2005, ICRP 1990) were 90.19, 61.62 for Implagraphy at maxillay molar area, 123.20, 90.02 for Implagraphy at mandibular molar area, 183.55, 139.26 for VCT and 40.92, 27.16 for panoramic radiography. Conclusion: Effective doses for VCT and Implagraphy were only about 2.2 to 4.5 times greater than those for panoramic radiography. VCT and Implagraphy, CBCT machines recently developed in Korea, showed moderately low effective doses.