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        검색결과 40

        21.
        2009.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study was carried out to comparatively identify characteristics of turbid water influence in Imha Reservoir, Soyang Reservoir, and Daecheong Reservoir in Korea. We used 3 years dataset from 2002 to 2004 and analyzed seasonal water quality characteristics, particular parameters in association with turbidity, and light transparency to figure out the trends. All parameters to be used in the study were total phosphate (TP), total nitrogen (TN), chlorophyll-a (Chl), suspended solids (SS), Secchi depth (SD), conductivity, and vertical light extinction coefficienct (Kd), euphotic zone (Zeu), and critical depth (Zp). All parameters depend on season and watershed. Suspended solids from Soyang Reservoir were usually caused by TP, mainly related to living wastes and agricultures in upper stream. Daecheong Reservoir was influenced by organic matters related to large phytoplankton biomass in summer and inorganic suspended solids by nutrients in the winter. However, in case of Imha Reservoir, turbid water, consisted in silt and clay through heavy precipitation remained in the waterbody to decrease water transparency along with TP and caused the light limitation in winter. Overall results suggest that it was necessary to establish various management programs because the reasons occurring turbidity were varied according to the reservoir circumstances.
        4,200원
        22.
        2008.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Angiogenesis is a process with a coordinated sequence of endothelial cell division, selective degradation of vascular basement membranes, and surrounding extracellular matrix with migration of theses cells that result in a new capillary growth from preexisting vessels. These processes are controlled by numerous different molecules. Among these, Vascular Endothelial Growth Factor(VEGF) is an endothelial cell-specific mitogen with a potent ability to induce microvessel permeability and angiogenesis. In this study, tissue samples of odontogenic keratocyst(10 cases), ameloblastoma(10 cases), adenomatoid odontogenic tumor(10 cases), calcifying epithelial odontogenic tumor(10 cases), ameloblastic carcinoma(2 cases) were obtained, and all specimen were routinely fixed in 10% formalin and embedded. Serial 5μm thick sections were cut from paraffin blocks. And the immunohistochemical staining, characteristics of VEGF about the cyst & tumor were observed & obtaned the results from this study. We presume that the growth of cyst is depends on not a differentiation but an epithelium & connective tissue. But, in odontogenic tumor, we presumed that the growth of tumor is influenced on inflammation & surrounding stimulus & vascular growth and supply. Therefore, it should be suggested that study on the growth of tumor and vascularity must be carrying out in this immunohistochemical study.
        4,000원
        33.
        2007.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This is a case reporL of a ra re mi xed odontogenic tumo r, amelob lastic fibro-odontoma in the poste1'ior of r ight ma nd tlbe A 2-year - olcl ma le pa ti enL was referred to our department ['or large tumorous lesion 011 ri ght mandible Radiograph ic examination s howed la rge radi opaque and rad iolu cent lesion with impacted and unerupted tooth, #44‘ #45 , #46 #85 , AJ'Ler s urgi cal enuclea Li on & cu rettage of t he mass , the tumor was confirmed to ameloblastic fibro-odontoma. lt was composed with c1 enta l orga ns a ncl is la nd of odontogeni c epithelium embedded in a cell - ri ch mesenchymal s troma, AIso‘ we ca rri ed out an immunohi stochemical study. The resul ts s howed positive CK7 staining. and showed weekly positi ve for Bcl - 2‘ Ki - 67 s Laining, while CEA, CK8‘ CKl2, CKl6 showed l1egative, Follow-up studies have shown no tumot recurrence for 2 yea rs ,
        4,000원
        34.
        2006.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        An extremely rare case of chondromyxoid fibroma of the zygomatic arch in a 65-year-old woman is presented. Block resection and immediate reconstruction were done with calvarial bone with fixed with microplate and screws through the hemicoronal approach. Follow-up studies have shown no tumor recurrence for 7 years. Also, we carried out an immunohistochemical study. The results showed positive S-100 and vimentin staining, while showing only very weak staining for NSE. The Ki-67 staining study showed a PI-index of only 0.67%.
        4,000원
        35.
        2017.05 서비스 종료(열람 제한)
        Background : Licorice has been used as a source of medicine and a food material in East-Asia. Recently, demand for licorice increased in market due to a growing interest in health. Thus we conducted breeding research to solve the problems associated with domestically cultivated licorice such as low productivity and low glycyrrhizin content. Methods and Results : We crossed European licorice (G. glabra L.; female parent) and Chinese licorice (G. uralensis Fisch; male parent) in the greenhouse in May 2007. In September 2007, crossed and germinated seeds were retrieved and sown in the greenhouse. In June 2008, stolons were separated from the F1 licorice seedlings and cultivated, resulting in 32 clonal lines of interspecific hybrids. Among them we selected good lines and then conducted the replicated yield trials (RYT) in 2012-2013 and local adaptability test (LAT) in 2014-2015. The results, GLYES9 showed that was elect of stem, oblong of leaf shape, red-brown of root color. Glycyrrhizin conten of GLYES9 (3.0%) was higher than G. uralensis (1.9%) at four regions from 2014 to 2015. GLYES9 was less than 10% in the desease of brown spot (G. uralensis was more than 30%). The root yield of GLYES9 was 4.31 ton per hectare, which was increased 193% compared with a check variety of G. uralensis. Therfore, we named GLYES9 as new cultivar ‘Dagam’. Conclusion : Depending on the above results, we have developed a new licorice cultivar ‘Dagam’ by the medicinal crop breeding team of National Institute of Horticulture and Herbal Science, RDA, in 2015. It showed brown spot disease resistant, high-glycyrrhizn content and high-yielding than colleted Glycyrrhiza spp.
        36.
        2015.09 서비스 종료(열람 제한)
        Highly homogeneous and functional stem cell-derived hepatocyte-like cells (HLCs) are considered a promising option in the treatment of liver disease and the development of effective in vitro toxicity screening tool. However, the purity of cells and expression and/or activity of drug metabolizing enzymes in stem cell-derived HLCs are usually too low to be useful for clinical or in vitro applications. Here, we describe a highly optimized differentiation protocol, which produces more than 90% albumin-positive HLCs with no purification process. In addition, we show that hepatic enzyme gene expressions and activities were significantly improved by generating three-dimensional (3D) spheroidal aggregate of HLCs. The 3D differentiation method increased expressions of nuclear receptors that regulate the proper expression of key hepatic enzymes. Furthermore, a significantly increased hepatic functions such as albumin and urea secretion were observed in 3D hepatic spheroids and HLCs in the spheroid exhibited morphological and ultrastructural features of normal hepatocytes. Importantly, we show that repeated exposures to xenobiotics facilitated the functional maturation of HLC, as confirmed by increased expression of genes for drug metabolizing enzymes and transcription factors. In conclusion, the 3D culture system with repeated exposures to xenobiotics may be a new strategy for enhancing hepatic maturation of stem cell-derived HLCs as a cell source for in vitro high-throughput hepatotoxicity models.
        37.
        2015.09 서비스 종료(열람 제한)
        Hepatocyte-like cells (HLCs) derived from human pluripotent stem cells have received extensive attention in the development of drug screening and toxicity testing. However, it has been reported that stem cell-derived HLCs showed hepatic functions that were too limited to be of use in drug screening and toxicity testing, possibly due to the lack of sufficient intercellular communication under conventional two-dimensional (2D) culture conditions. Therefore, a 3D differentiation system may overcome the in vitro limitation of 2D culture to produce stem cell-derived hepatocytes with mature metabolic functions. In this study, the feasibility of using a silicone-based spherofilm, specifically designed to produce spherical cell clusters, to generate uniformly sized 3D hepatic spheroids from hESCs was investigated. Hepatic spheroids generated on the spherofilm showed more homogenous size and shape than those generated in conventional low-attachment suspension culture dishes. Results of immunohistochemical analysis showed that expression of the mature hepatic marker albumin (ALB) increased over time during the hepatic maturation process. Furthermore, the 3D culture system mimicked the in vivo 3D microenvironment. Laminin, which is an important component of hepatic ECM, was expressed in hepatic spheroids. The results of immunohistochemical analysis indicated that the 3D culture environment is capable of generating an in vivo-like microenvironment. In addition, quantitative PCR analysis showed that the mature hepatic marker ALB and cytochrome P450 (CYP) enzymes CYP3A4 and CYP3A7 were expressed at higher levels in 3D culture than in 2D culture. This indicates that the 3D culture system is suitable for hepatic maturation and that our size-controlled 3D culture conditions might accelerate hepatic function. These results suggest that 3D hepatic spheroids significantly enhance metabolic maturation of hepatocytes derived from hESCs
        38.
        2013.08 서비스 종료(열람 제한)
        MFG-E8 (Milk fat globule-epidermal growth factor VIII), also called lactadherin or BA46, SED1 is a glycoprotein found in milk and mammary epithelial cells, it is a major protein component associated with milk fat globule membrane. Previously, our study showed that expression of MFG-E8 is gradually increased with hepatic differentiation of human embryonic stem cells (hESCs). Therefore, we hypothesized that MFG-E8 would be an early cancer stem cell marker, which may predict cancer progression. Our results showed that MFG-E8 was expressed in various human cancer cell lines such as HepG2, Hep3B, and Huh7. Production and secretion of the MFG-E8 were also confirmed in the conditioned media of those three cell lines using enzyme-linked immunosorbent assay. Next, we analyzed the MFG-E8 expression in 11 clinical cases of cholangiocellular carcinoma (CC) and 33 cases of hepatocellular carcinoma (HCC) by immunohistochemistry and examined the potential correlation with β-catenin and AFP, which are known cancer markers. According to hitological criteria, the progression of HCC and CC was evaluated and classified into high, low, metastatic, and well-, moderate-, poor-differentiated, respectively. Statistical analysis indicated that incidence of both HCC and CC is significantly associated with male compared to female (P<0.05). Tumor size also has positive correlation with age (r2=08948). Our immunohistochemistry data showed that MFG-E8 was expressed both HCC and CC tissue. Interestingly, the MFG-E8 expression was significantly increased with cancer progression (P<0.05) in both cases. Additionally, b-cateninexpression was increased and its localization was changed from membrane to cytoplasm and nucleus with the degree of HCC. Likely b-catenin, AFP was also increased with the degree of HCC but it was not correlated with severalty of CC. Importantly, both AFP and b-catenin were highly co-localized with MFG-E8 in HCC. These results suggest that MFG-E8 may have important physiological roles and its expression in HCC and CC would be considered as an important prognostic factor.
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