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        검색결과 202

        122.
        2001.04 KCI 등재 구독 인증기관 무료, 개인회원 유료
        A total of 92 unfertilized human oocytes were treated with ethanol (EtOH), calcium ionophore A23187 (CI) or electric pulse (EP) for activating pronuclear formation and subsequent development. In Experiment 1, there was a significant (P=0.0001) treatment effect on the activation of unfertilized oocytes. No spontaneous activation was occurred in the control, but activation treatments induced PN formation with various efficacy. More unfertilized oocytes (UFOs) were activated after EtOH or EP treatment than after CI treatment. EP was as effective (63.6 %) as EtOH, but fragmentation was observed in 43% of UFOs activated by EP. Proportion of UFOs that formed presumptive haploid PN (2 PNs+1 PB or 1 PN +2 PBs) was 33.3, 0 and 28.6% after EtOH, CI and EP treatments, respectively. In Experiment 2, a significant (P=0.0362) effect of immature oocytes (IOs) status on activation was fecund. IOs at the GVBD-MI oocytes had higher potential to form PN than those at the GV stage or with abnormal morphology (25 vs. 77.8%). The results of this study clearly demonstrated that the treatment of 10% ethanol for 5 min effectively induced the activation of UFOs. IOs could form pronucleus with high efficacy by ethanol treatment, as long as they grew beyond the GVBD stage.
        4,000원
        123.
        2001.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        병해충을 막기 위해 농업용 살충제가 광범위하게 사용되고 있다. 농약사용에 따른 생물학적 위해가 우려되며 농약이 또 다른 환경유해요인과 인체에 상승적으로 작용할 경우 농업재해로 이어질 가능성이 있다. 다양한 인자에 의한 DNA손상을 감지하는데 유용한 단세포 겔 전기영동법을 이용하여 살충제와 방사선에 의한 사람 림프구 DNA손상을 평가하였다. 각기 다른 농도로 살충제를 10분간 전처리한 림프구와 정상 림프구에 0-2.0 Gy의 방사선으로 조사한 다음 DNA
        4,000원
        124.
        2000.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This experiment was conducted to investigate the effect of the cysteine and glutathione on the motility index and morphology of human spermatozoa at the sperm processing in vitro. After treating the sperm with medium containing cysteine and glutathione, we measured the motility index and morphology at 0.5 h and 24 h. 1. Following the sperm culture for 0.5 h after treating the sperm with the medium containing 0, 1, 5, 10 mM cysteine, curvilinear velocity (VCL) was significantly (p<0.05) higher in control than that in all treatments. And straight-line velocity (VSL) was high at 1 mM and average path velocity (VAP) was low at 5 mM and 10 mM. But the motility (MOT) and morphology (NOM) were not different between control and all treatments. Following the sperm culture for 24 h, the MOT was significantly high in treatment groups (58.9, 74.4 and 62.3%), compared with that in control(28.7%) and the VCL was also high in treatment groups (31.4, 37.9, and 34.0 /s), compared with that in control (21.3 /s). The VSL (18.4, 21.7, and 18.9 /s) was significantly higher than control (10.7 /s) and the VAP (20.3, 24.7, and 21.4 /s) in treatments was also compared with that in control (12.6 /s). The NOM was not difference between control and treatments. 2 Following the sperm culture for 0.5 after treating the sperm with the medium containing 0, 1, 5, 10 mM glutathione, the MOT, VCL, VSL, VAP, and NOM were not different between control and treatments. Following the sperm culture for 24 h, the MOT was higher in treatment groups (82.9, 83.6, 83.4%) than in control (51.1%) and the VCL was higher in treatment groups (50.9, 51.3, and 49.4 /s) than control (34.1 /s). The VSL was also higher in treatment (17.1 /s) and the VAP was also higher in treatment groups (30.1, 32.5, and 29.7 /s) than in control (19.8 /s). The NOM was not different between control and treatments.
        4,000원
        126.
        1999.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The flavonoids are one of the most numberous and widespread groups of natural constituents. The low molecular weight of benzo-γ-pyrone derivatives are ubiquitous in plants and are vegetables, nuts, seeds, leaves, flowers, and bark. The flavonoids constitute of a large class of compounds, ubiquitous in plants, containing a number of phenolic hydroxyl groups attached to ring structures, conferring the antioxidant activity. Epidemiologic studies suggest that the dietary intake of antioxidants constitutes a risk factor for vascular disease, indicating that oxidation may be important in the pathogenesis of human atherosclerosis. Elevated plasma low density lipoprotein (LDL) cholesterol concentration are associated with accelerated atherosclerosis, LDL is oxidized by smooth muscle cells, resulting in several chemicals and physical changes of LDL. Oxidized LDL is responsible for cholesterol loading of macrophages, foam cells formation and atherogenesis. There have been insulficient tests of the protective effects of flavonoids against LDL oxidation to make definitive statements about their structure activity relationships. However, hydroxylation of the flavone nucleas can appears to be advantageous because polyhydroxylated aglycone flavonoids are potent inhibitor of LDL modification. This identification may lead to new and more effective antioxidant strategies for abrogating the atherosclerotic process, the leading cause of death and disability in industrialized societies.
        4,000원
        129.
        1998.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The pronuclear injection of metallothionein-human growth hormone (MT-hGH) gene into rabbit zygotes was performed to establish in vitro developmental system and to detect the presence of the injected gene by nested PCR. Mature female New Zealand White rabbits were superovulated by eGG and hCG treatments. The rabbits were mated and the zygotes were collected from the oviducts 18-22 h after hCG injection by flushing with D-PBS. Two to three picoliters of MT-hGH gene was microinjected into male pronuclei. The foreign gene-injected zygotes were cultured in TCM-199 or RD mediurn containing 10% FCS with a monolayer of rabbit oviductal epithelial cefls in a 5% incubator. The presence of injected DNA in rabbit embryos or blastomeres at different developmental stages .vas detected by a nested PCR analysis. The results are summarized as follows ; 1.The developmental rate of the MT-hGH gene-injected zygotes to blastocyst was significantly higher in TCM-199 medium (68.1%) than in RD medium (42.9%). 2.The gene injection into pronuclei at 18 or 22 hours post hCG treatment during pronuclear stage did not much affect on the in vitro development of the rabbit embryos. 3.The rate of gene-positive embryos detected by the nested PCR analysis was significantly decreased when they developed to blastocysts. The results indicate that the screening of transgene in rabbit embryos by nested PCR analysis could be a prornisible method for the preselection of transgenic embryos. Furthermore, the preselection of transgenic embryos would greatly reduce hoth the cost and effort of production of transgenic animals.
        4,000원
        132.
        1998.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        해양 미생물로부터 사람 Low Density Lipoprotein(LDL)에 대한 항산화 활성 균주를 검색 하였든 바 부산 인근연안에서 항산화 활성이 높은 Bacillus sp. RH-5를 분리 동정하였다. Bacillus sp. RH-5의 항산화 활성물질의 생산 거 배지는 1.0% glucose, 0.25% polypeptone, 0.25% yeast extract, 0.01% FeSO_4?7H_2O, 50% sea water이였다. 이때 최적 조건은 pH 7.0, 배양 온도는 30℃ 및 배양 시간은 48시간에서 항산화 활성이 가장 높았다. 사람 LDL을 1~5 μM CuSO_4 존재하에서 산화 시킨 결과 Bacillus sp. RH-5 배양액의 ethyl acetate 추출물의 500 및 1,000 ㎍/ml에서 산화가 억제되었으며 또 5 μM CuSO_4 존재하에서 산화시킨 LDL의 전기영동거리는 native LDL보다 다소 높았으나 LDL에 ethyl acetate추출물을 첨가한 경우 그 이동거리는 native LDL과 거의 비슷하였다.
        4,000원
        133.
        1997.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        4,900원
        134.
        1997.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        사람의 미토콘드리아에 있는 aldehyde dehydrogenase(ALDH2)는 체내에서 알코올 대사 과정 중에 생성되는 아세트알데히드를 산화시키는 주된 역할을 담당하고 있다. 이 ALDH2가 알코올 대사에 미치는 영향을 연구하기 위하여 가용화된 효소가 팔요하다. 알려져 있는 유전자의 염기서열 데이터를 바탕으로 ALDH2의 cDNA는 cDNA 라이브러리에서 선별하였으며, 이를 여러 가지 대장균 발현벡터에 연결하였다. 제조한 발현벡터를 형질전화시킨 대장균을 사용하여 단백질의 발현을 확인한 결과 대부분의 계에서 ALDH가 과발현되고 있었다. 그러나 발현된 단백질의 대부분은 inclusion body로 형성되어, 실제로 가용화된 효소의 양은 전체 발현된 양의 5% 이하였고 이들 몇 가지 발현 system으로 재조합 ALDH2의 발현을 확인하였다.
        3,000원
        136.
        1997.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study was pcrformed to evaluate the antioxidant activity of silymarin against human low density lipoproteins(LDL) oxidation. Silymarin extracted from Silybum marianum was successively purified with solvent fractionation and followed by silica gel column chromatography. The active substances were separated by HPLC and the isolated active substances, silymarin were identified by IR, NMR, GC-MS as silymarin. Silymarin inhibited at the 5 uM Cu^(2+)-mediated oxidation of human low density lipoprotein (LDL) in a dose dependent manner. Silymarin completely inhibited LDL oxidation at 50 ug/ml concentration. These findings suggest that silymarin may protect LDL against oxidation in atherosclerotic lessions.
        4,000원
        139.
        1994.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        최근 의약적으로 유용한 단백질을 대량 생산키 위한 실현 가능한 방법이 유전자변환 가축의 이용과 관련되어 발전되어 왔다. 이러한 유전자 변환동물은 이종의 단백질을 유즙속으로 분비시키는 생체반응기로서 이용되고 있다. 이러한 전략적 목적을 위해 현재 유전자 변환동물의 생산을 위한 이용에 있어 여러 가지 방법들이 보고되고 있다. 그러나 ES 세포의 사용이 이러한 방법들 사이에서 가장 실질적인 것으로 추정되고 있다. 본 실험에서는 유전자 구축을 위해 사람 황체
        4,000원
        140.
        1994.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This experiment was carried out to develop the model system for mass production of biomedical and nutritional proteins (human proteins) through mamraary gland of the transgenic cattle produced by gene manipulation and embryological technologies. Human growth hormone gene fused with rat -casein gene promoter was microinjected into pronuclei of one cell bovine embryos produced by in vitro fertilization. After microinjection, embryos were cultured in vitro for 6 or 7 days. Twenty embryos reaching to blastocysts were transferred to 10 beef recipients, each receiving two embryos. Recipients were diagnosed for pregnancy by rectal palpation at 76 days after embryo transfer. One of them was pregnant to term and produced a female calf weighing 21 kg at 280 days following embryo transfer. DNA was extracted from umbilical cord tissue and blood of calf born for confirming gene insertion. As determined by Southern hybridization, the transgene was not found.
        4,000원