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        검색결과 151

        48.
        2012.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        넙치(Paralichthys olivaceus) 수정란의 부화율에 대한 중금속(Cd, Cu, Zn)의 급성독성을 조사하였다. Cd, Cu 및 Zn (0, 10, 100, 500, 1000, 2500, 5000 ppb)에 수정란을 48h 노출시킨 후, 정상 부화율을 백분율로 나타내었다. Cd, Cu 및 Zn을 포함하지 않는 대조구에서는 정상 부화율이 80% 이상을 나타냈으나, 중금속 농도가 증가할수록 정상 부화율은 급격히 감소하였다. 정상 부화율은 Cd, Cu 및 Zn에 대해 농도 의존적으로 감소하였으며, 각각 1000, 100, 100 ppb 이상의 농도에서 유의적이 차이를 나타내었다. P. olivaceus의 정상 부화율에 대한 Cd, Cu 및 Zn의 반수영향농도(EC50)를 이용한 독성은 Zn¤Cu¤Cd 순으로 강한 것으로 나타났으며, 이들 중금속에 대한 EC50는 각각 584, 1015, 1282 ppb를 나타내었다. Cd에 대한 NOEC는 500 ppb를 나타냈고 LOEC는 500 ppb를 나타내었다. Cu와 Zn의 NOEC와 LOEC 각각 100 ppb와 500 ppb로 유사한 값을 나타내었다. NOEC와 LOEC 결과로부터 자연생태계 내에서 Cu와 Zn 농도는 100 ppb, Cd 농도는 500 ppb를 초과할 경우 P. olivaceus 수정란의 정상 부화율은 감소할 것으로 판단된다. 본 연구결과를 바탕으로, P. olivaceus의 정상 부화율을 이용한 생물학적 시험은 중금속과 같은 유해물질에 대한 해양생태계의 영향을 판단하기 위한 시험방법으로 유용하게 이용될 수 있을 것으로 판단된다.
        4,000원
        49.
        2012.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Numerous reports on the immunopathogenesis of an oral lichen planus (OLP) have shown some inconsistency in terms of the role and distribution of CD4+ and CD8+ T cells, and Langerhans cells (LC). This has led to the hypothesis that although the clinical and histopathological manifestations of OLPs appear similar, they can be grouped into CD4+ predominant lesions and CD8+ ones on the varied immunopathogenesis or clinical progress. This study investigated the distribution of CD4+ T cells, CD8+ T cells, LC and the ratio of CD4/CD8 and defined the important immunocompetent cells. In addition, the clinicopathological and histopathological correlation with those immunocompetent cells were investigated. Frozen sections of 16 OLPs and 5 normal buccal mucosae were immunostained. Quantification was done using KAPPA Imagebase software and statistical analysis using SPSS 10.0 statistical package. CD8+ T cells were consistently more abundant in the epithelium of the OLP than CD4+ T cells, but no difference between the two cells was detected in the lamina propria. The intra-epithelial CD4+ T cells revealed a positive linear correlation with the intra-epithelial CD8+ T cells. In the lamina propria, the number of LC had a positive linear correlation with CD4/CD8 ratio. The number of LCs was higher in the reticular type of OLP compared to the erosive type. The histopathological features such as hyperkeratosis, acanthosis, the band-like infiltration of mononuclear cells, and liquefaction degeneration did not show significant correlation with the CD4/CD8 ratio. The results suggest that CD8+ T cells play major role in immunopathogenesis of OLP. The immunopathogenesis of OLP appears to vary from lesion to lesion in relation to the clinical progress.
        4,000원
        52.
        2011.10 구독 인증기관·개인회원 무료
        Despite of the absence of hyperacute rejection and acute humoral xenograft rejection, the organ graft of the a1,3-galactosyltransferase (GalT) gene knockouted (KO) and complement regulatory protein (CRP) expressing pig into a nonhuman primate is rejected by development of a thrombotic microangiopathy and/or a consumptive coagulopathy. Thus further introduction of genes to overcome the coagulation incompatibilities between pig and primate under GalT KO/CRP genetic background has been strongly suggested. CD73 (ecto-5'-nucelotidase) is an enzyme attached via a glycosyl phosphoinositol anchor to the extracellular membrane of endothelial cells, which catalyses the hydrolysis of adenosine triphosphate to adenosine. Loss of activity of CD73 results in activation and aggregation of platelets by a reduced capacity to convert nucleotides to adenosine. In previous study, we reported generation of GalT KO fibroblasts concurrently expressing membrane cofactor protein and produced cloned pigs by nuclear transfer of the fibroblast cells (1). In this study, we constructed a vector for expression of human CD73 under control of promoter of pig Icam2 gene expressed specifically at endothelial cells. This vector was introduced into porcine fibroblasts using the nucleofection technology, by which we had forty three fibroblasts clones carrying pIcam2- CD73 vector. Somatic cell nuclear transfer resulted in generation of two transgenic piglets survived.
        53.
        2011.10 구독 인증기관·개인회원 무료
        Successful pregnancy requires suppression of maternal immune response to the implanting conceptus, which acts as a semiallograft. During the implantation period in humans and rodents, various immune modulators are produced at the maternal-fetal interface and regulate functions of cytotoxic T cells and NK cells for protection of conceptuses from the maternal immune system. However, maternal immune responses to the conceptuses during the establishment and maintenance of pregnancy are not much understood in pigs which show true epitheliochorial type placentation. Previously, we reported that SLA-DQ molecule, a type of MHC class II molecules, is expressed in the uterine endometrium during pregnancy in a stage- and cell type specific manner, and that SLA-DQ expression is essential for the maintenance of pregnancy. Thus, to understand the role of SLA-DQ and maternal-fetal immune interaction, we examined expression of CD80 and CD86, co-stimulators for T cell activation, in the uterine endometrium during pregnancy. We also measured levels of CD80 and CD86 mRNAs in the uterine endometrium of pigs carrying conceptuses derived from somatic cell nuclear transfer (SCNT) and those from natural mating on Day 12 of pregnancy. Expression of endometrial CD80 mRNA was affected by day of pregnancy, and levels of CD80 mRNA were significantly higher on Day 15 of pregnancy than those of the estrous cycle. Expression of CD86 mRNA did not change during pregnancy. Levels of CD80 and CD86 mRNAs were not different in the uterine endometrium of pigs carrying SCNT derived conceptuses on D12 of pregnancy compared to those with conceptuses derived from natural mating. These findings suggest that CD80 and CD86 are involved in immune interactions at the maternal-fetal interface during pregnancy for the establishment and maintenance of pregnancy in pigs.
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