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        검색결과 25

        3.
        2020.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Gangliosides are glycolipids in which oligosaccharide is combined with sialic acids. Our previous studies have suggested an interplay between ganglioside GD1a/GT1b and meiotic maturation capacity in porcine oocyte maturation. Furthermore, ganglioside GD1a and GT1b are known for its antioxidant activity, but it is still unclear whether possible antioxidant role of GD1a and GT1b is involved in porcine embryos development competence during in vitro culture (IVC). Here, the effects of ganglioside GD1a and GT1b on the embryonic developmental competence during in vitro culture of porcine were investigated. The effects of ganglioside GD1a and GT1b on the expression of ST3GAL2 were confirmed during embryos development (2-cell, 4-cell, 8-cell and blastocyst) using immunofluorescent staining (IF). As a result, the fluorescent expression of ST3GAl2 was higher in embryos at 4-8 cells stage than blastocysts. Blastocyst development rate significantly increased in only 0.1 μM GD1a and GT1b treated groups compared with control group. To investigate the cellular apoptosis, we analyzed TUNEL assay. In case of only 0.1 μM GD1a and GT1b treated groups, the total number of cells in blastocyst compared with control group, but there was no significant difference in the rate of apoptotic cells. We identified the intracellular ROS levels using DCF-DA staining. According to the result, ROS production significantly decreased in blastocysts derived from the 0.1 μM GD1a and GT1b treated groups. These results suggest that ganglioside GD1a and GT1b improve the developmental competence of porcine embryos via reduction of intracellular ROS during preimplantation stage.
        4,000원
        5.
        2020.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Cryopreservation is used for blastocyst preservation of most mammalian embryos and is an important technique for breeding. We aimed to compare the efficiency of the cryopreservation method using the standard Cryotop device and the ReproCarrier device, a domestic product manufactured in Korea. The efficacy of the two devices was analyzed based on the survival rate, intracellular levels of reactive oxygen species (ROS), and apoptosis of the vitrified bovine blastocysts. The survival rates of the vitrified-warmed blastocysts were similar between the ReproCarrier group (58.4 ± 17.7%) and Cryotop group (59.9 ± 14.1%). Intracellular ROS levels and apoptotic index were determined by DCFDA staining and TUNEL assay. Changes in intracellular ROS levels, number of total nuclei, and cellular apoptosis of vitrified blastocysts after cryopreservation were not significantly different between the two groups. These results indicate that the ReproCarrier device method is as effective as the standard Cryotop method for vitrification of bovine blastocysts in vitro.
        4,000원
        6.
        2018.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Ganglioside GM3 is known as an inhibition factor of cell differentiation and proliferation via inhibition of epidermal growth factor receptor (EGFR) phosphorylation. Our previous study showed that the exogenous ganglioside GM3 reduced the meiotic maturation of porcine oocytes and induced apoptosis at 44 h of in vitro maturation (IVM). However, the role of ganglioside GM3 in the relationship between EGFR signaling and apoptosis during porcine oocyte maturation has not yet been studied. First, porcine cumulus-oocyte complexes (COCs) were cultured in the NCSU-23 medium with exogenous ganglioside GM3 according to maturation periods (non-treated, only IVM I: 0 - 22 h, only IVM II: 22 - 44 h and IVM I & II: 0 - 44 h). We confirmed that the proportion of germinal vesicle breakdown (GVBD) increased significantly in the IVM I treated group than in the control group. We also confirmed that the meiotic maturation until M II stage and polar body formation decreased significantly in the only IVM I treated group. Cumulus cell expansion and mRNA levels of the expansion-related factors (HAS2, TNFAIP6 and PTX3) decreased significantly in the IVM I treated group than in the control group. Protein levels of EGFR, p-EGFR, ERK1/2, and p-ERK1/2 decreased significantly in the GM3-treated groups, during the IVM I period. In addition, cellular apoptosis, determined using TUNEL assay, and protein levels of Cleaved caspase 3, were increased significantly in the GM3-treated COCs during the IVM I period. Based on these results, ganglioside GM3 exposure of porcine COCs during the IVM I period reduced meiotic maturation and cumulus cell expansion via inhibition of EGFR activity in pigs.
        4,000원
        8.
        2017.05 구독 인증기관·개인회원 무료
        Ganglioside GT1b, glycosphigolipids with three sialic acid, is known to play an important role in signal transduction such as epidermal growth factor receptor (EGFR). EGF is also known to induce resumption of meiosis and cumulus cells expansion during porcine oocyte maturation. Therefore, this study was conducted to evaluate the effects of ganglioside GT1b on resumption of meiosis and cumulus cells expansion in porcine oocyte maturation. First, porcine cumulus-oocyte complexes were cultured in NCSU-23 medium supplemented with GT1b (0, 1, 2 and 4 μM) at 44 h. We observed that the proportion of the metaphase II (M II) stage was significantly increased in the 2 μM GT1b (78.0 ± 2.3) treated group than in the other groups. Furthermore, expression of cumulus cells expansion factor genes (Has2, TNFAIP6, Ptx3) were significantly increased in the 2 μM GT1b treated group than in the other groups. Next, we investigated the meiotic maturation and the expressions of cumulus cells expansion factor genes after GT1b and/or EGF treatment. The proportion of the M II stage was significantly higher in the GT1b+EGF (90.1 ± 2.3) treated group than in the other groups. Moreover, expressions of cumulus cells expansion factor genes were significantly increased in the GT1b+EGF treated group than in the control group. After in vitro fertilization, fertilization rate, preimplantation development competence and quality of blastocyst were improved in oocytes derived from GT1b+EGF treated group. Taken together, these results suggest that exogenous ganglioside GT1b improving the developmental competence of porcine embryos via increase of resumption of meiosis and cumulus cells expansion during in vitro maturation of porcine oocytes.
        9.
        2015.04 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study aims to investigate the characteristics of the vegetation structure in the sectin stretching between the Jilmoi wetlands and the Donghae Observatory and to set the criteria for the basic data for a management plan including restoration afterwards. 12 plots(10 m×40 m, 20 m×20 m) were set up to analyse the vegetation structure. The analysis of the classification by TWINSPAN and ordination by DCA, importance percentage and property, distribution of diameter of breast height, growth increments of major woody species, species diversity and the physicochemical properties of soil were all analyzed. Vegetation classes were divided into 3 communities, which are community Ⅰ(Pinus densiflora community), community Ⅱ(Quercus mongolica community) and community Ⅲ(Quercus mongolica-Tilia amurensis community). The P. densiflora community declined when competing with Q. mongolica and Fraxinus rhynchophylla and Q. mongolica competed with T. amurensis on an understory layer in Q. mongolica community. Q. mongolica competed with T. amurensis on both canopy and understory layers in Q. mongolica-T. amurensis community. P. densiflora declined and it was assumed to succeed to F. rhynchophylla or T. amurensis through Q. mongolica based on the importance percentage and distribution of the diameter of the breast height of small and middle sized trees. The age of P. densiflora was between 47 to 51 years old and Q. mongolica was 61years old. T. amurensis was 61 years old and the growth of Q. mongolica slowed a little. As the result of Shannon's index of species diversity, community Ⅰranged from 0.9578 to 1.1862, community Ⅱranged from 0.7904 to 1.2286 and community Ⅲranged from 0.8701 to 1.0323. The contents of organic matter and cation were low compared to uncultivated mountain soil and it were analysed to be inappropriate for tree growth.
        4,500원
        10.
        2014.12 구독 인증기관 무료, 개인회원 유료
        Cows may suffer impaired ovarian function, often accompanied by reduced conception rates and increased embryonic loss. Cystic ovarian disease (COD) is one of the most frequently diagnosed gynecological findings in dairy cattle. It causes temporary infertility and is likely to affect reproduction as well as production parameters in cattle. Therefore, the purpose of this study was to determine the expression patterns of apoptosis (Bcl-2, Bax), implantation (E-cadherin) and immune related proteins (TNF-α, IL-10) in uterine endometrium of Hanwoo (Korean native cattle) with ovarian cyst and normal ovarian follicles. In the Western blot analysis, the expression of anti-apoptotic Bcl-2 protein was significantly higher in endometrium with normal ovarian follicles, whereas expression of pro-apoptotic Bax protein was significantly lower. Also, the expressions of E-cadherin and TNF-α proteins were significantly higher in uterine endometrium with normal ovarian follicles. On the other hand, the expression of IL-10 protein was significantly lower in uterine endometrium with normal ovarian follicles. Taken together, our results provided that the expressions of apoptosis, adhesion and immune related proteins in uterine endometrium with ovarian cyst were showed the aberrant patterns, and we suggest that different expression changes of these proteins may be affect to pregnancy ability of cattle.
        4,000원
        11.
        2012.06 구독 인증기관·개인회원 무료
        Cordycepin, a specific polyadenylation inhibitor, is the main functional component in Cordyceps militaris that is one of the top three renowned traditional Chinese medicines. In this study, we performed in vitro experiments to investigate the anti-invasive and anti-metastatic activities of cordycepin using human prostate carcinoma LNCaP cells. Cordycepin were administered and their effects on LPS-induced cell migration and invasion by wound healing migration assay, measurement of TER and In vitro invasiveness assay. Within the concentrations which were not cytotoxic effects, cordycepin caused a concentration-dependent suppression of LPS-induced cell migration and invasion. The anti-invasive activity of cordycepin was also found to be associated with increased tightness of the TJ, which was confirmed by an increase in TER. The activity of MMP-2 in LNCaP cells was dose-dependently inhibited by treatment with cordycepin, and this was also correlated with a decrease in expression of its mRNA and proteins, and up-regulation of TIMPs expression. Additionally, cordycepin repressed the LPS-induced NF-kB activation and phosphorylation of PI3K/AKT. Taken together, these findings suggest that cordycepin inhibited LPS-induced migration and invasion of LNCaP cells by down-regulating the expression and activity of MMP-2, and the possible targets may be NF-kB and PI3K/AKT.
        12.
        2010.12 KCI 등재 구독 인증기관·개인회원 무료
        [Background] Cordyceps militaris, a traditional medicinal mushroom, produces a component compound, cordycepin (3’-deoxyadenosine). Cordycepin has been known to have many pharmacological activities including immunological stimulating, anti-cancer, and anti-infection activities. However, the molecular mechanisms of inflammatory mediator’s activity by cordycepin remain poorly understood. In the present study, we investigat-ed the effects of cordycepin on the anti- inflammation cascades in lipopolysaccharide (LPS)-stimulated BV2 microglia cells. [Methods] Cordycepin were administered and their effects on LPS-induced pro-inflammatory mediators and MAP kinases were monitored by Western blotting and RT-PCR analysis. [Result] Cordycepin significantly inhibited the production of nitric oxide (NO), prostaglandin E2 (PGE2), and pro- inflammatory cytokines such as interleukin (IL)-1β, IL-6, and tumor necrosis factor (TNF)-α in a concentration- dependent manner without causing cytotoxicity. Also, cordycepin suppressed inducible NO, synthase (iNOS) and cyclooxygenase-2 (COX-2) expression on the mRNA and protein level. In addition, cordycepin suppressed NF-κB translocation by blocking IkappaB- α (IκB-α) degradation and inhibited the phosphorylation of Akt, ERK-1/2, JNK, and p38 kinase. Our results indicate that the inhibitory effect of cordycepin on LPS -stimulated inflammatory mediator production in BV2 microglia is associated with the suppression of the NF-κB, Akt, and MAPK signaling pathways. Conclusion: Anti-inflammatory properties of cordycepin may be useful for treating the inflammatory and deleterious effects of microglial activation in response to LPS stimulation.
        14.
        2009.12 KCI 등재 구독 인증기관·개인회원 무료
        Cordycepin (3’-deoxyadenosin), a polyadenylation specific inhibitor, is the main functional component in Cordyceps militaris which is one of the top three famous traditional Chinese medicine. It has been shown to possess many pharmacological activities including immunologically stimulating, anti-cancer, anti-bacterial, and anti-virus, anti-infection effects. However, its anti-cancer molecular mechanisms are poorly understood. In this study, the apoptotic effects by cordycepin were investigates in human leukemia cells. Treatment of cordycepin significantly inhibited cells growth in a concentrationdependent manner by inducing apoptosis, as evidenced by morphological change and apoptotic cell death such as formation of apoptotic bodies, DNA fragmentation and increased populations of sub-G1. Induction of apoptosis by cordycepin was associated with modulation of Bcl-2 and inhibitor of apoptosis proteins (IAP) family expression. Cordycepin also increased reactive oxygen species (ROS) generation, activation of casepase-3, caspase-8, caspase-9, cleavage of poly(ADP-ribose) polymerase (PARP), β-catenin and phospholipase C (PLC)-γ1 protein. The quenching of ROS generation by N-acetyl-L-cysteine administration, a scavenger of ROS, reversed the cordycepin-induced apoptosis effects. Theresults suggested that cordycepin may be a potential chemotherapeutic agent for the treatment of leukemia patients [This work was supported by Blue-Bio Industry RIC at Dong-Eui University as a RIC (08-06-07) program of ITEP under Ministry of Knowledge Economy].
        16.
        2009.06 KCI 등재 구독 인증기관·개인회원 무료
        Cordycepin (3’-deoxyadenosine) is a polyadenylation specific inhibitor, one of the components of Cordyceps militaris. It has been shown to possess many pharmacological activities including immunologically stimulating, anti-tumor, anti-virus, and anti-infection effects. However, its molecular mechanisms are poorly understood. In this study, the apoptotic effects by cordycepin were investigated in human leukemia cells. Cordycepin treatment inhibited leukemia cells growth a concentration-dependent manner by inducing apoptosis,as evidenced by morphological change and apoptotic cell death such as formation of apoptotic bodies, DNA fragmentation and increased populations of apoptoticsub G1 phase. Induction of apoptosis by cordycepin in leukemia cells were associated with modulation of Bcl-2 member and inhibitor of apoptosis (IAP) proteins expression. Cordycepin also increased ROS generation, activation of caspase-3, caspase-8, caspase-9, cleavage of poly(ADP-ribose) polymerase (PARP), -catenin and phospholipase (PLC)-1 protein. Both the this effect by cordycepin treatment were significantly inhibited by NAC, a ROS scavenger, demonstrating the important role of ROS in the observed cytotoxic effect. This results suggested that cordycepin may be a potential chemotherapeutic agent for the treatment of leukemia patients.
        17.
        2008.06 KCI 등재 구독 인증기관·개인회원 무료
        Cordyceps militarisis well known as a traditional herbal ingredient, which has been used for patients suffering from cancer in oriental medicine. In this study we have investigated the biochemical mechanisms of anti-proliferative effects by C. militarisextract(CME) in human breast cancer MDA-MB-231 cells. It was found that CME treatment induced chromatin condensation, mitochondrial energization, annexin V staining and sub-G1 phase DNAcontent. These indicators of apoptosis correlate with the mitochondrial dependent pathway, which results in the activation of caspase-3 activity. Both the cytotoxic effect by CME treatment were significantly inhibited by z-DEVD-fmk, a caspase-3 inhibitor,demonstrating the important role of caspase-3 in the observed cytotoxic effect. Cotreatment of CME and LY294002, resulted in significantly induction of apoptosis. These results indicate that caspase-3 is a key regulator of apoptosis in response to CME in human breast cancer MDAMB- 231 through downregulation of Akt, and that the C. militaris extract may therefore have therapeutic potential against human breast cancer.
        18.
        2006.09 구독 인증기관·개인회원 무료
        The microstructure and electrical conductivity of CNTs dispersed nanocomposites depending on the powder processing and CNTs content were demonstrated. The composite powders with homogeneous dispersion of CNTs could be synthesized by a catalytic route for direct formation of CNTs on nano-sized Fe dispersed powders. The sintered nanocomposite using the composite powder with directly synthesized CNTs showed homogeneous microstructure and enhanced elelctrical conductivity. The influence of powder processing on the properties of sintered nanocomposites was discussed by the observed microstructural features.
        19.
        2002.01 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The purpose of this study was to examine the effects of metastrategic exercise on a scientific reasoning strategy to control variables, and investigate the developmental patterns in the strategy usage within a given period. Two groups composed of 90 fifth grade students engaged in a scientific reasoning task over six daily sessions. Additionally, one group engaged in metastrategic exercise on fictional students' strategies of controlling variables on the task, while the other spent equivalent time on an unrelated task. Based upon results of the study, the following conclusions can be drawn. First, the metacognitive exercise on the strategy to control variables has positive and long-standing effects on the strategy performance at the reasoning task. The exercise also takes effect of near-transfer. Taking into consideration only about sixty minutes of metastrategic practice, the results provide the validity of the activity in order to develop children's reasoning strategies. Second, in a scientific reasoning task, each child seems to go through one out of two developmental patterns in their usage of reasoning strategies: gradual change or fundamental change. Considering the ratio of pattern of fundamental change between the two groups, it is clear that the metacognitive exercise influences the developmental pattern of strategy usage.
        4,300원
        20.
        2017.07 KCI 등재 서비스 종료(열람 제한)
        In this study of the oak wilt disease that has occurred in a large scale in a protected area located near South Korea’s metropolitan region, a detailed analysis has been conducted on the terrain, species and Diameters at Breast Height (DBH) of infected trees to identify the distribution of infection properties in the affected area. Taking into consideration the distribution of oak tree vegetation, a total of 4,640 quadrats in a size of 10 m by 10 m, have been set; and oak tree species, the DBH and infection damage per quadrat have been investigated. Geological properties have been analyzed according to elevation, slope direction and gradient and micro topography while a weighted value has been given according to the degree of infection in order to calculate an infection index. Through correlation analysis, the infection ratio of seriously-damaged and withered trees and the infection index have been analyzed with regards to the geological properties, tree species and DBH. The analysis shows that the disease tends to affect an area with medium elevation rather than those in the highest or lowest areas and that serious damage has been observed at rugged spots with a steep gradient (more than 30°). Although there has been no distinct tendency with regards to direction, the infection ratio is relatively high in areas facing the north while the seriously-damaged and withered ratio are high in areas facing the south. In terms of micro topography, more damage has been spotted in valley terrain. Quercus mongolica has sustained more damage than other species. When it comes to the DBH, as seen in previous studies, large trees have suffered severe damage, but the analysis has also revealed conspicuous damage to medium trees with a DBH of 15-20 cm, which had not previously been considered at high risk.
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