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        검색결과 5

        1.
        2012.06 구독 인증기관·개인회원 무료
        In this study, we examined whether Hanganutziu‐Deicher (H‐D) antigens are important as an immunogenic non‐a1,3‐galactose (Gal) epitope in pigs with a disrupted a1,3‐ galactosyltransferase gene. The targeting efficiency of the AO blood genotype was achieved (2.2%) in pig fibroblast cells. A total of 1800 somatic cell nuclear transfer (SCNT) embryos were transferred to 10 recipients. One recipient developed to term and naturally delivered two piglets. The a1,3‐galactosyltransferase activity in lung, liver, spleen, and testis of heterozygote a1,3‐galactosyltransferase gene knockout (GalT‐KO) pigs was significantly decreased, whereas brain and heart showed very low decreasing levels of a1,3‐ galactosyltransferase activity when compared to those of control. Enzyme‐linked lectinosorbent assay showed that the heterozygote GalT‐KO pig had more sialyla2,6‐ and sialyla2,3‐ linked glycan than the control. Furthermore, the heart, liver, and kidney of the heterozygote GalT‐KO pig had a higher N‐glycolylneuraminic acid (Neu5Gc) content than the control, whereas the lung of the heterozygote GalT‐KO pig had Neu5Gc content similar to the control. Collectively, the data strongly indicated that Neu5Gc is a more critical xenoantigen to overcoming the next acute immune rejection in pig to human xenotransplantation.
        2.
        2012.06 구독 인증기관·개인회원 무료
        Genomic reprogramming factors in the GV cytoplasm improved cloning efficiency in mice through the pre‐exposure of somatic cell nuclei to a GV cytoplasmic extract prior to nuclear transfer. In this study, a pig GV oocyte extract (pGV extract) was developed. Treatment of pig fibroblasts with the pGV extract promoted colony formation after 2–3 weeks in culture, concomitant with the expression of stem cell markers (Oct‐4, Rex1, Nanog, Sox2) and repression of differentiated cell markers (CKAP2, NPR3 ). Using fibroblasts transfected with human Oct‐4 promoter‐driven enhanced green fluorescent protein (Oct4‐EGFP), pGV extract treatment induced the reactivation of the Oct‐4 promoter in Oct4 ‐ EGFP cells by 10 days post‐treatment. These transgenic donor cells were injected into 8‐cell embryos. Oct‐4 promoter activity was subsequently detected in most ICM cells of the host blastocyst. Interestingly, reconstructed embryos with pGV extract‐treated Oct4‐ EGFP fibroblast nuclei showed prolonged expression of Oct4 in the ICM of embryos. Additionally, the pGV extract promoted somatic cell reprogramming and cloned embryo development when assessed by measuring histone H3‐K9 hypomethylation, the expression of Oct4 and Nanog in blastocysts, and the production of increased numbers of high‐ quality blastocysts. Under specific culture conditions, pGV extract‐treated fibroblast cells differentiated into neuronal, pancreas, cardiac, and endothelial lineages that were confirmed by antibodies against specific marker proteins. These data provide evidence for the generation of stem‐like cells from differentiated somatic cells by treatment with GV oocyte extracts in pig.
        3.
        2012.06 구독 인증기관·개인회원 무료
        Accumulating evidence suggests that chemotherapy can cause long‐term detrimental effects and alter the biology of the recipient environment. Therefore, a subsequent report claimed that the transplantation of female germline stem cells (FGSCs) into the ovaries of recipient mice that were pretreated with a high dose of busulfan and cyclophosphamide (B/C) resulted in the successful production of offspring. Therefore, this study was conducted to further clarify the impact of female germ cell transplantation on female ovaries after B/C treatment. RT‐PCR analysis showed that the period of germ cell depletion coincide with decreased Figla, Lhx8, Nobox, Kit, and Sox3 gene expression in the B/Ctreated ovary. However, depletion of female germ cells is mediated by a Fas/FasL‐, Kit/ Kitl‐, TNF‐, p53‐ and autophagy‐ independent pathway. Also, histological analysis is similar to that of Nobox null‐derived ovaries, indicating that follicle death after B/C treatment might be caused by down‐regulating of Nobox pathway. When female mice during 15 weeks after B/C treatment were checked for reproductive activity, B/C treated mice did not produce their pups. In addition, when 3×106 GFP positive primordial follicles were injected into B/C treated female mouse ovaries, donor follicle were not able to colonize into the ovaries of recipients. In conclusion, these data from a preclinical mouse model strongly suggested that female ovary until 15 weeks after B/C treatment could not support environment for maturing of exogenous FGSCs.
        4.
        2012.06 구독 인증기관·개인회원 무료
        Although there are a number of reports regarding the toxicity evaluation of inorganic nanoparticles, knowledge on biodegradable nanomaterials, which have always been considered safe, is still limited. For example, the toxicity of chitosan nanoparticles, one of the most widely used drug/gene delivery vehicles, is largely unknown. In this report, we examined the cytotoxic effects of chitosan nanoparticles on mouse embryos at the blastocyst stage and in vivo implantation by embryo transfer. Blastocysts treated with 250 nm chitosan nanoparticles exhibited significantly increased apoptosis and a corresponding decrease in total cell number, which was concentration‐dependent. Moreover, the TUNEL positive signal in the embryos exposed to chitosan nanoparticles showed an increased of the ICM and the implantation success rate was lower than that of their control counterparts. Our results collectively indicate that in vitro exposure to chitosan nanoparticles induces apoptosis and retards implantation development after transfer to host mice. The results collectively show that chitosan nanoparticles have the potential to induce embryo cytotoxicity. Further studies are required to establish effective protection strategies against the cytotoxic effects of these nanoparticles.
        5.
        2012.06 구독 인증기관·개인회원 무료
        The objective of this study was to investigate the proteome composition in pretermand term‐derived human umbilical cord. Umbilical cord samples were collected from 6 preterm infants with gestational age less than 36 weeks or 4 full terms together with medical information during prenatal period. Several biomarkers are routinely used clinically for predicting preterm labor; however, these factors are either nonspecific or detected too late. Protein profiles were performed on samples from both preterm‐ and termderived human umbilical cord by using Two‐dimensional gel electrophoresis (2‐DE). Approximately 200 different proteins were identified between preterm‐ and term‐delivered umbilical cords. Among them, differentially expressed 34 proteins were identified in 48 protein spots. In the preterm‐derived human umbilical cords, 15 proteins were present at higher levels (2.0‐ to 9.28‐fold increases) and 19 were present at lower levels (2.0‐ to 11.8‐ fold decreases or not detectable) compared to the control term‐derived umbilical cords. Proteomics approaches such as 2‐DE could greatly facilitate the discovery of new and better biomarkers. The high sensitivity and specificity achieved by the combined use of the selected biomarkers show great potential for the early detection of Adverse pregnancy outcomes such as pre‐eclampsia, small for gestational age infants, preterm delivery and placental abruption are associated with higher mortality. Increased amount of HIF‐1 α, GAPDH and HSP27 were observed in preterm‐derived umbilical cords was due to hypoxia‐ dependant and oxidative stress‐independent manner. Moreover, we isolated HUVEC (Human umbilical vascular endothelial cells) from preterm‐ and term‐derived umbilical cords and examined LDH activity. The results of the current study may provide important insights into the molecular mechanisms underlying umbilical cord development and also these data will contribute to a better understanding of the composition of preterm‐ and term ‐ derived human umbilical cord and aid the discovery of novel biomarkers for the prenatal diagnosis of fetal abnormalities