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        검색결과 22

        1.
        2024.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Background: Aflatoxin B1 (AFB1) is a toxic metabolite generated by Aspergillus species and is commonly detected during the processing and storage of food; it is considered a group I carcinogen. The hepatotoxic effects, diseases, and mechanisms induced by AFB1 owing to chronic or acute exposure are well documented; however, there is a lack of research on its effects on the intestine, which is a crucial organ in the digestive process. Dogs are often susceptible to chronic AFB1 exposure owing to lack of variation in their diet, unlike humans, thereby rendering them prone to its effects. Therefore, we investigated the effects of AFB1 on canine small intestinal epithelial primary cells (CSIc). Methods: We treated CSIc with various concentrations of AFB1 (0, 1.25, 2.5, 5, 10, 20, 40, and 80 μM) for 24 h and analyzed cell viability and transepithelial-transendothelial electrical resistance (TEER) value. Additionally, we analyzed the mRNA expression of tight junction-related genes (OCLN, CLDN3, TJP1, and MUC2), antioxidant-related genes (CAT and GPX1), and apoptosis-related genes (BCL2, Bax, and TP53). Results: We found a significant decrease in CSIc viability and TEER values after treatment with AFB1 at concentrations of 20 μM or higher. Quantitative polymerase chain reaction analysis indicated a downregulation of OCLN, CLDN3, and TJP1 in CSIc treated with 20 μM or higher concentrations of AFB1. Additionally, AFB1 treatment downregulated CAT , GPX1, and BCL2. Conclusions: Acute exposure of CSIc to AFB1 induces toxicity, and exposure to AFB1 above a certain threshold compromises the barrier integrity of CSIc.
        4,000원
        2.
        2017.05 구독 인증기관·개인회원 무료
        The mesenchymal stem cells (MSC) has been investigated as a source of stem cell therapy to replace and treat damaged cells. Human endometrial epithelial and stromal cells was isolated from hysterectomy tissue and the direct evidence of stem/progenitor cells in the human endometrium was identified. Endometrium derived stem cells (EnMSCs) are known to have a high proliferative ability, genetic stability, lack of tumorigenicity and low immnunogenicity during long-term cultivation. Here, we aimed to identify MSC in canine endometrium and characterize its potential to differentiate into decidua cells. EnMSCs were isolated from thrown-away spayed uterus of adult canine depending on their estrus cycle, and identified by flow cytometry, immunocytochemistry and flow cytometry with MSC specific markers. We then characterized the ability of EnMSCs by the doubling-time analysis, colony-forming units and MSC differentiation assays. Isolated EnMSCs expressed stem cell specific genes (Sox2, Oct4, Nanog, MCAM, Endoglin, Susd2 and IGTB) and MSC surface markers (CD90, CD44 and CD117). EnMSCs are also differentiated into adipogenic, osteogenic and chondrogenic cells morphologically under modified conditions with the expression of lineage specific genetic markers. EnMSCs showed higher proliferation ability than canine amniotic fluid derived MSCs which were used as a positive control. EnMSCs were cultured at low density (10, 20, cells/cm2) and initiated to form small colonies of loosely-arranged cells and gradually formed large colonies of densely-packed cells which underwent self-renewal with high proliferative potential which is similar to the clonogenicity feature of human endometrium-derived stem cells. EnMSCs were then induced to differentiate into decidua cells with 0.5 mM dbcAMP. After 14 days, EnMSCs changed their morphology into the elongated and rounded shape. The induced decidual cells expressed PRL and IGFBP1 which are typically expressed in decidua cells. In conclusion, we successfully isolated and characterized MSC in the canine endometrium which differentiated into decidua cells. These results showed that endometrium may be a promising source of stem cells, and furthermore raise the possibility of canine EnMSCs as a novel hypothetical decidualisation model of infertility associated with decidualisation insufficiency and implantation failure.
        3.
        2016.10 구독 인증기관·개인회원 무료
        Somatic cell nuclear transfer (SCNT) has been considered for preserving genetically valuable or endangered animals. Sapsaree is a Natianal Monument in Korea to maintian a pure pedigree. The aim of this study was to produce azoospermia Sapsaree using SCNT and identify normal reproductive ability of cloned azoospermia Sapsaree. Ear skin biopsy was performed on a thirteen-year-old azoospermia Sapsaree and ear skin fibroblasts were isolated for SCNT as donor cells. The fibroblasts were injected into enucleated in vivo matured oocytes, the couplets were electrical fused by two pulse of direct current (55 V for 15 μs) using titanium and platinum fusion needle and activated by calcium ionophore. Cloned embryos were surgically transferred into oviducts of natuarally estrus cycle synchronized recipient dogs. The fusion rate of platinum needle was 70%, which was higher than those of titanium needle (64.1%). Developmental rate to the 8 cells and 10 cell stages was higher in platinum needle group (24% and 16%, respectively) than those of platinum needle group (14.8% and 3.1%, respectively). Total 35 SCNT embryos were transferred into oviducts of 3 recipient dogs and one recipient finally delivered a puppy by caesarean section. As results, this study demonstrated that platinum fusion needle could be successfully make the reconstructed embryos and improve the efficiency of canine SCNT. Cloning azoospermia Sapsaree may contribute to conserve genetically valuable and unique pedigree. And further study should be confirm whether cloned live dog is azoospermia.
        4.
        2016.10 구독 인증기관·개인회원 무료
        Prolonged communication between oocytes and the surrounding somatic cells is one of the unique reproductive physiology in canine. Paracrine Kit ligand (KITL) signaling is a well-known communication between granulosa cells and the oocyte. KITL is a cytokine growth factor secreted by granulosa cells that signals via the c-kit receptor expressed by oocytes. Paracrine factors, including growth differentiation factor 9 (GDF9) and bone morphogenetic protein 15 (BMP15), exert their effects by binding with the kinase receptors expressed on the granulosa cells. However, the regulations of GDF9 and BMP15 in the canine KITL expression are currently poorly understood. Therefore, we investigated the effects of GDF9 and BMP15 on the expression of KITL in canine ovarian granulosa cells in vitro. In Annexin V assay recombinant GDF9 and BMP15 did not induce apoptosis in the cultured ovarian granulosa cells. When treated, FSH significantly increased KITL expression, and hCG suppressed its expression. When both FSH and hCG were treated, the expression of KITL was affected by GDF9 and BMP15 in dose and time dependent manner in the luteal granulosa cells. GDF9 (10 ng/mL) significantly decreased KITL expression after12 h. BMP15 (10 ng/mL) significantly also decreased KITL expression after 24 h. Western blot and immunochemistry results indicate that GDF9 activated Smad2/3. After blocking ALK 4/5/7 receptors by SB, GDF9 failed to activate Smad2/3, also BMP15 did not activate Smad1/5/8 after blocking ALK 2/3/6 receptors by DM. So GDF9 exerts its effects via using ALK 4/5/7 receptors to activate SMAD2/3 signaling, and BMP15 binds ALK 2/3/6 receptors to activate SMAD1/5/8 signaling. The expression of KITL was not changed by SB or DM treatment. However, the effect of GDF9 and BMP15, which decreased the expression of KITL, was suppressed by SB or DM treatment. In conclusion, this study provides the first evidence that recombinant GDF9 and BMP15 decrease KITL expression in canine ovarian granulosa cells.
        5.
        2016.10 구독 인증기관·개인회원 무료
        The cancer and Parkinson's disease associated protein DJ-1 is multifunctional protein that involves in diverse cellular process. DJ-1 protein has a cellular protective role and promoted cell survival under an oxidative stress. However, the cellular protective mechanism of DJ-1 is not fully understand, and we needs to be further study their functions in novel organisms. In the present study, we investigated the protective role of DJ-1 against induced oxidative stress in canine cell line. On the basis of these experiments, canine DJ-1 overexpressing and null cell lines were established. The stable overexpression and down regulation of DJ-1 efficiency confirmed by the western blot analysis. Subsequently, the DJ-1 gene transfected cell lines and control cells were subjected to induced the oxidative stress, and then cell viability, cell proliferation assay, cellular apoptosis detection analysis (Annexin V and TUNEL assay), intracellular ROS and mitochondrial activity were measured appropriately. The results showed that DJ-1 overexpressed cells were up-regulated cell viability under oxidative stress conditions induced by the rotenone and hydrogen peroxide (H2O2), whereas loss of DJ-1 cells were down-regulated the cell survival activity. Additionally, overexpression of DJ-1 cells increased cell resistance to oxidative stress and inhibited the elevation of cell death and cellular ROS induced apoptosis. Moreover, DJ-1 overexpressed cells was increased mitochondrial functions by using confocal microscopy with MitoTracker staining. On the contrary to this, DJ-1 null cells show defective cellular protection and mitochondria activity against oxidative stress conditions. Our data indicate that canine DJ-1 protein attenuates cellular apoptosis and ROS generation, enhances the cellular survival activity and promote mitochondrial function under the oxidative stress, likewise other mammalian cells. Importantly, DJ-1 overexpression may be an important part of a protective strategy as a sensor for oxidative stress.
        6.
        2009.08 구독 인증기관·개인회원 무료
        Thee kinds of explants, young spikes, immature and mature embryos, was compared in callus induction, embryogenic callus formation, differentiation and plant regeneration of Russian wildrye. Callus induction efficient of young spikes is highest. The imature embryos formed more somatic embryogenesis, and with highest frequency of embryogenic callus.
        7.
        2009.03 구독 인증기관 무료, 개인회원 유료
        A improved strength model was developed to predict the punching shear strength of interior slab-column connections without shear reinforcement. Considering the damage due to flexural cracking at slab-column connections damaged by flexural cracking, the punchingshear force was assumed to be resisted mainly by the compression zone of the critical section. The punching shear strength was defined by using the material failure criteria of concrete. In the evaluation of the punching shear strength, the interaction between the shear stress and the compressive normal stress developed by the flexural moment of the slab was considered. The proposed strength model was verified by existing test specimens.
        4,000원
        8.
        2008.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Petroleum pitch and coke with wet mixture method or with dry mixture method were investigated to develop the composite anodic carbon material of high power lithium ion battery. Cokes coated with pitch were obtained by the heat treatment of mixture of cokes and pitch with different weight ratios at 800~1200℃. The charge and discharge characteristic of the consequent composite anodic carbon material assembled in batteries was tested. Cokes with wet mixture method have a smooth surface and their capacity changed little with changing temperature and content as compared to the cokes with dry mixture method. Although the reversible capacities showed different values by the anode manufacturing method, the composite anode with the mixture of 20 wt% of petroleum pitch and 80 wt% of coke showed the higher power capability and initial efficiency than the pitch based anode. However, the reversible capacity of the composite anode showed the reduced value as compared with the pitch based anode.
        4,000원
        9.
        2008.03 구독 인증기관 무료, 개인회원 유료
        In this study, based on the results from the sinusoidal base excitation analyses of a single degree of freedom system with a tuned mass damper (TMD) , the optimal friction is computed so that the rail friction improve the performance of the TMD. The magnitude of the optimal friction increases with increasing mass ratio of the TMD and decreases with increasing structural damping. Particularly, it is observed that the optimized friction force gives better control performance than the optimized viscous damping of the TMD. However, because the performance of the TMD considerably deteriorates when the friction force increases over the optimal value, it is required to keep the friction force from exceeding the optimal value. Based on the results from this study, it is possible to economically design the TMD by avoiding the unconditional minimization of the rail friction and in some cases by removing the additional damping devices of which function can be performed by the rail friction.
        4,000원
        10.
        2006.09 구독 인증기관 무료, 개인회원 유료
        This paper presents vibration control of a real-scaled five-story steel structure subjected to horizontal excitation using a semi-active magneto-rheological (MR) damper. A large-sized double-rod MR damper, which is applicable for vibration control of the real-scaled five-story structure, is designed and manufactured on the basis of the field-dependent Bingham model of the MR fluid. The damping force of the MR damper is experimentally evaluated with respect to the excitation frequency at various magnetic fields. After formulating the governing equation of motion for the five-story structure associated with the MR damper, displacement and acceleration responses of the structure are discussed under pseudo earthquake excitation in which a hybrid mass damper is designed to reproduce seismically excited structural responses. The controllers which require only structural response of the damper installed floor for calculating the input current of the MR damper are designed to effectively suppress unwanted structural vibrations
        3,000원
        11.
        2017.05 서비스 종료(열람 제한)
        Background: Mahonia Nepalensis DC. (Hoang lien o ro), the specie of the family Berberidaceae, is widely distributed in the high mountainous areas at altitudes 1700 – 1900 m of Vietnam. It is found that the stem of Mahonia nepalensis indicated anti-inflammatory, anti-bacterial and antifungal activities and they are used particularly for the treatment of eczema, psoriasis, and other skin conditions. However, no study on the antioxidant and anti-cancer activities of Mahonia Nepalensis stem has been previously reported. The aim of this study was to evaluate anti-oxidant and anti-cancer activities of Mahonia Nepalensis stem. Methods and Results: The stem pieces of Mahonia Nepalensis were dried and extracted three times with 100% methanol. After that, the extract was suspended in distilled water and then partitioned with n-hexane, ethyl-acetate (EtOAc) and butanol (water saturated BuOH) fractions were then evaporated using a vacuum rotary evaporator. Evaluation of the anti-oxidative activity of Mahonia Nepalensis was carried out using a DPPH (2,2-diphenyl-1-picrylhydrazyl) radical-producing system. The results revealed that the ethyl acetate fraction of M. nepalensis possessed higher potential DPPH radical scavenging activity (IC50, 81.88 ± 1.33㎍/㎖) than other fractions as well as BHT (2,6-Di-tert-Butyl-4-methylphenol) (IC50, 250.49 ± 1.60㎍/㎖). The reducing power assay was also investigated and EtOAc fraction showed higher absorbance values than other fractions. At 1.0 mg/ml concentration, EtOAc fraction showed absorbance of 1.72, be higher than Ascorbic acid. Cell viability was evaluated according to the MTT (3-(4,5-Dimethylthiazol-2-yl)-2,5-Diphenyl tetrazolium Bromide) assay. By MTT assay, all fractions showed a significant reduction in cell viability on COLO 205 (Human colon carcinoma cell) at the highest concentration tested (200㎍/ ㎖) with over 70% decrease in cell viability was obtained, and the highest significantly inhibiting effect occurred in butanol fraction with approximately 90% reduction in cell viability. Conclusion: We demonstrated that Mahonia Nepalensis stem extract has highly potential in anti-cancer activity. Further studies are necessary in order to explore the variety of Mahonia Nepalensis stem to be applied as a valuable natural material.
        12.
        2016.10 서비스 종료(열람 제한)
        Background : Ginseng (Panax ginseng C.A. Meyer) is one of the most important medicinal plants in Korea, but its yields are often reduced by a variety of root pathogens. The root rot of ginseng is a destructive soil-borne disease caused by Cylindrocarpon destructans (teleomorph: Ilyonectria radicicola). To monitor contamination with C. destructans in ginseng harvested in 2015 were sampled from 57 different growing fields. The spore number of C. destructans was quantified by use of a specific primers and selective media (radicicol) in soils of ginseng fields. Methods and Results : The ginseng samples were surface-sterilized and placed on potato dextrose agar plates for 7 day incubation at 20℃. Emerging fungal colonies were counted primarily based on colony and conidia morphology. Further species level identification was confirmed by ITS rDNA sequencing. For quantification of the soil-borne C. destructans, the genomic DNA was extracted from the soil using a NucleoSpin soil kit (MN, Germany). Density of C. destructans was determined by species specific real time PCR (qPCR). The qPCR was completed by running a melting curve analysis. Conclusion : The C. destructans associated with root rot disease of ginseng were detected in more than 60% in pyeongtaek-1, pochenon-1, jecheon-1, chungju-1 and jinan-4. As results of the study, the correlation between pathogen density and identification clearly clarified in the soil.
        13.
        2016.10 서비스 종료(열람 제한)
        Background : Haskap berries commonly refer to fruits of Lonicera caerulea L., recognized by the Japanese aborigines as the “The elixir of life.”. Due to their recent arrival on the North American market, haskap berries have not yet been positioned among other berries and compared in terms of their phytochemical content. And haskap berries have higher ascorbic acid and anthocyanin content than other berries known for their health-promoting benefits, such as blueberries. However, no study has reported on the antioxidant and anti-cancer activity of Lonicera caerulea stem. The purpose of this study is to present the current research on the chemical content, antioxidant and anti-cancer activities of Lonicera caerulea stem. Methods and Results : The stem of Lonicera caerulea L. ware dried in the shade at room temperature and extracted with 100% methanol. The extract was suspended in deionized water and partitioned sequentially with n-hexane, chloroform, ethyl-acetate and butanol (water saturated BuOH) fractions. Antioxidant activities were measured by determination of antioxidants, DPPH (2,2-diphenyl-1-picrylhydrazyl). Cell viability was determined by the MTT [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide] assay. All cell lines were purchased from the Korean Cell Line Bank (Seoul, Korea). All results were performed with three replications were processed statistically. By DPPH assay, the Lonicera caerulea L. the highest activity was obtained from the ethyl-acetate fraction (IC50=15.46 ㎍/㎖). By MTT assay, the chloroform fraction showed a significant growth inhibiting effect on MCF-7 (Human breast cancer, IC50=225.91 ㎍/㎖), COLO 205 (Human colon cancer, IC50=179.55 ㎍/㎖), but on AGS (Human stomach cancer) and other fractions it did not show effect. Conclusion : We demonstrated that Lonicera caerulea L. stem extract and fractions has antioxidant and antiproliferation activity in vitro. Further studies should identify the active constituents in Lonicera caerulea L stem to evaluate the potential in vitro antioxidant and antiproliferation activities of the extract.
        15.
        2014.12 KCI 등재 서비스 종료(열람 제한)
        Serine-arginine-rich nuclear protein LUC7L plays an important role in the regulation of myogenesis in mice. In the present study, we isolated and characterized the Korean rose bitterling Rhodeus uyekii Luc7l cDNA, designated RuLuc7l. The RuLuc7l cDNA is 1,688 bp long and encodes a 364-amino-acid polypeptide containing serine/arginine-rich region at the C-terminus. The deduced RuLuc7l protein has high amino acid identity (71-97%) with those of other species including human. Phylogenetic analysis revealed that RuLUC7L clustered with fish LUC7L proteins. The expression of RuLuc7l mRNA was high in the brain, kidney, and stomach of Korean rose bitterling. Expression of the RuLuc7l mRNA was detected from 1 day post-fertilization (dpf) and moderately increased until 21 dpf during the early development. Further investigations are required to elucidate the functional role of RuLUC7L in myogenesis in R. uyekii.
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