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        검색결과 1,603

        963.
        2005.12 구독 인증기관 무료, 개인회원 유료
        In the present study, performances of several in vitro maturation (IVM) systems for porcine follicular oocytes were evaluated, and an efficient chemically defined IVM system for porcine oocytes was proposed. The proposed one-step culture system supplemented with polyvinylalcohol (PVA) gave competitive efficiencies in terms of oocyte maturation and blastocyst development after parthenogenetic activation and in vitro culture, compared with the conventional two-step culture system by a supplementation of porcine follicular fluid (pFF). Additionally, it is identified that the proposed chemically defined one-step culture system yielded the comparable level of blastocyst production to the conventional maturation system in porcine somatic cell nuclear transfer (SCNT). Therefore, one can eliminate un-expected effects accompanied by supplementation of pFF. No medium replacement during whole maturation period is an additional benefit by applying this new system. Thus, these data support that the developed PVA supplemented chemically defined one-step IVM system for porcine follicular oocyte might be used in porcine SCNT program.
        3,000원
        964.
        2005.10 KCI 등재 구독 인증기관·개인회원 무료
        Hereditary dentin defects consists of dentin dysplasia(DD) and denti nogenesis imperfecta(Dr) ‘ The Dl associated with osteogenesis imperfecta has been classified as DI type 1. whereas isolated inherited defects have been categori zed as DI types II and III , However‘ whether DI type III should be considered a distinct phenotype 01' a variation of DI type 1I is debatable , Recent genetic findings have focused attention on the role of the dentin sialo phosphoprotein(DSPP) gene in the etiology of inherited defects of tooth dentin, We have identified novel mlltation( c,727G - > A, p,D243N) at the 243th codon of exon 4 of the DSPP gene in a Korean patient with DI type III The radiographic and histologic features of the patient revealed the classic phenotype of shell teeth These findings sllggest that DI type II and III are not separate diseases bllt rather the phenotypic variation 01' a s ingle disease
        965.
        2005.10 KCI 등재 구독 인증기관·개인회원 무료
        A novel indil‘ubin analog‘ 5’ nitro-indirubinoxime(Ol1) inhibits cell proliferation and induces apoptosis again st variolls hllman cancer cell s. ln this stlldy, we performed the microarray analysis to identify genes diffel'enti ally expressed in the KB oral sqllamollS carcinoma cells after treatment with 011 Of the 10‘ 800 genes a nalyzed , 1700 genes(15.7%) showed di fferent expression level in the 011-treated cells with respect to untreated control cel1s Arnong those‘ 263 genes(15, 5%) were down -reg띠 ated and 220 genes(12, 9%) were IIp-regulated more than 2-fold, Functionally related gene clllsters inclllde genes associated with signal transdllction(18, 1%) , especially genes re lated with a poptosis(3, 5%) and cell cycle reglllation(5. 8%) . Our application of microarray ar뻐ysis on 01l-treated 01'외 cancer cells al lows the identifi cati on of candidate genes for providing novel insights into the 011-mediated anti -tllmor actl Vl ty ,
        973.
        2005.03 구독 인증기관 무료, 개인회원 유료
        Bone remodeling is a process controlled by the action of two major bone cells; the bone forming osteoblast and the bone resorbing osteoclast. In the process of osteoclastogenesis, stromal cells and osteoblast produce RANKL, OPG, and M-CSF, which in turn regulate the osteoclastogenesis. During the bone resorption by activated osteoclasts, extracellular Ca²+/PO₄²- concentration and degraded organic materials goes up, providing the hypertonic microenvironment. In this study, we tested the effects of hypertonicity due to the degraded organic materials on osteoclastogenesis in co-culture system. It was examined the cellular response of osteoblastic cell in terms of osteoclastogenesis by applying the sucrose, and mannitol, as a substitute of degraded organic materials to co-culture system. Apart from the sucrose, mannitol, and NaCl was tested to be compared to the effect of organic osmotic particles. The addition of sucrose and mannitol (25, 50, 100, 150, or 200 mM) to co-culture medium inhibited the number of tartrate-resistant acid phosphatase (TRAP) positive multinucleated cells induced by 10 nM (). However, NaCl did exert harmful effect upon the cells in this co-culture system, which is attributed to DNA damage in high concentration of NaCl. To further investigate the mechanism by which hypertonicity inhibits -induced osteoclastogenesis, the mRNA expressions of receptor activator of nuclear factor (NF)-kB ligand (RANKL) and osteoprotegerin (OPG) were monitored by RT-PCR. In the presence of sucrose (50 mM), RANKL mRNA expression was decreased in a dose-dependent manner, while the change in OPG and M-CSF mRNA were not occurred in significantly. The RANKL mRNA expression was inhibited for 48 hours in the presence of sucrose (50 mM), but such a decrement recovered after 72 hours. However, there were no considerable changes in the expression of OPG and M-CSF mRNA. Conclusively, these findings strongly suggest that hypertonic stress down-regulates -induced osteoclastogenesis via RANKL signal pathway in osteoblastic cell, and may playa pivotal role as a regulator that modulates osteoclastogenesis.
        4,000원
        974.
        2005.03 구독 인증기관 무료, 개인회원 유료
        The elderly suffer from an impaired immune function being obvious in a higher susceptibility to infections. Although the inflammatory cells are the major immunomodulatory cells, fibroblasts also secrete a variety of inflammatory cytokines and chemokines. Therefore periodontal tissue aging might playa role in development and progress of periodontitis. In this study, we investigated the effect of in vitro periodontal ligament cellular aging on the inflammatory cytokines, chemokines, and matrix metalloprotease(MMP)-2 expression induced by lipopolysaccharide(LPS) treatment. Three different cell populations were used; passages 4-5, 14-15, and 24-25 (at passage 27, more than 90% cells were replicative senescent). LPS increased the expression of interleukin(IL)-1β, IL-6, and tumor necrosis factor-α, IL-8, RANTES, and MMP-2. However, the order of induction folds were passages 14-15 > 4-5 > 24-25. While the expression level of Toll-like receptor(TLR) 4 decreased according to the increase in passage number, the level of TLR2 was highest at passages 14-15 and then decreased at passages 24-25. While the spontaneous expression of IL-8 decreased according to the increase in passage number, that of RANTES and proMMP-2 increased according to the increase in passage number. These results suggest that the aging of periodontal ligament fibroblasts differentially affect the role as immunomodulatory cells in response to periodontopathic bacteria and therefore might be another risk factor of periodontitis progression.
        4,000원
        975.
        2004.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        We analyzed the high resolution H,6 line spectra of CH Cygni obtained at the Bohyunsan Astronomical Observatory (BOAO) on April 2004. The temporal changes in the Hβ line profiles are reported. We obtained the equivalent widths of the Gaussian components. Using this we estimated the length of the gaseous nebula which emits the Hβ line and the mass loss rate from the star.
        4,000원