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        검색결과 436

        181.
        2012.06 구독 인증기관·개인회원 무료
        Live offspring is obtained from in vitro production of porcine embryos, but the procedure is still associated with great inefficiencies. In mammalian oocytes, acquisition of meiotic competence coincides with a decrease in general transcriptional activity at the end of the oocyte growth phase. In this study, we investigated the expression and sub-cellular localization of positive transcription elongation factor P-TEFb (CDK9/Cyclin T1), a RNA polymerase II CTD kinase during pig oocyte growth and early embryonic development. Localization and expression of components involved in mRNA and rRNA transcription were assessed by immunocytochemistry in growing and fully-grown oocytes. In addition, meiotic resumption, germinal vesicle breakdown, nuclear transcription and embryonic genome activation (EGA) were analyzed in oocytes and embryos cultured in presence of a potent CDK9 inhibitor, flavopiridol. Our analyses, demonstrated that CDK9 became co- localized partially with phosphorylated Pol II CTD and mRNA splicing complexes. Surprisingly, CDK9 was co-localized with Pol I-specific transcription factor, UBF, and gradually localized in nucleolar peripheries at the final steps of oocyte growth. Later, CDK9 became associated with nucleolar structures at 4-cell stage. Treatment with flavopiridol resulted in arrest in meiotic resumption, germinal vesicle breakdown as well as a decline in global transcription. Flavopiridol also inhibited embryo development beyond EGA. All together, these data suggest that CDK9 has a dual role in both Pol I- and Pol II-dependent transcription in pig oocyte growth and embryonic development.
        182.
        2012.05 구독 인증기관·개인회원 무료
        In arthropods, an immune challenge triggers a serine protease cascade that leads to the activation of prophenoloxidase (proPO)-activating factors (PPAFs), which are also called proPO-activating enzymes (PPAEs) or proteinases (PAPs). PPAFs are activated by cleavage between their clip and serine protease domains. Once activated, PPAFs convert proPO to phenoloxidase (PO), which then catalyzes the production of quinones to form melanin. In this study, we identified a Bombyx mori PPAF(BmPPAF) that involves in the pupal melanization. In the fat body, expression of BmPPAF was detected on day 1 to 3 of the pupal stage. RNA interference (RNAi)-mediated BmPPAF knock-down inhibited pupal melanization, resulting in the delay of pupal melanization. Based on these results, we concluded that BmPPAF is involved in the melanization of pupal stage in silkworm metamorphosis.
        183.
        2012.03 구독 인증기관 무료, 개인회원 유료
        Cytokines are known to function as regulatory molecules that can be produced by virtually every nucleated cell type in the body, including lymphocytes, monocytes/macrophages, epithelial cells, fibroblasts, and many others. Cytokines include lymphocyte-derived factors (lymphokines), monocyte-derived factors (monokines), hematopoietic factors (colony-stimulating factors), connective tissue/ growth factors, and chemotactic chemokines. Cytokines released in response to infection can affect tumor development in different ways. When exposed to infectious agents, cytokines are secreted by sentinel cells, such as macrophages and dendritic cells. These cytokines include interleukin 1 (IL-1) and tumor necrosis factor-α, as well as others, such as IL-6, IL-12, and IL-18. When released in sufficient quantities, these molecules can cause inflammation. Chronic inflammation is highly associated with tumor initiation, promotion, and progression. In this article, we review the roles and mechanisms of cytokines in tumor development.
        4,300원
        184.
        2011.12 구독 인증기관 무료, 개인회원 유료
        The objective of this study was to determine the effect of macrophages on growth of human colon cancer cells. The results showed that co-culture of colon cancer cells with macrophages inhibited the growth of colon cancer cells (HCT116 and SW620) depending on the number of macrophages, RAW 264.7 cells, and activated THP-1 cells accompanied by down regulation of pSTAT3 in cancer cells. We also found that expression and release of cancer cell growth inhibitory cytokines, IL-1 receptor antagonist (IL-1ra) and IL-10, was increased in macrophages. Blocking of the STAT3 pathway with specific inhibitor and siRNA of STAT3 abolished the growth of colon cancer cells and expression of IL-1ra and IL-10. In addition, neutralization of IL-1ra and IL-10 with antibodies resulted in reversal of macrophage-induced inhibition of cancer cell growth. These data showed that IL-1ra and IL-10 released from macrophages inhibit growth of colon cancer cells through inhibition of the STAT3 pathway.
        4,500원
        185.
        2011.10 구독 인증기관·개인회원 무료
        An understanding of oocyte gene expression is a necessary for the study of biological development. Recently, Oocyte has been used in many techniques such as somatic cell nuclear transfer (SCNT), intracytoplasmic sperm injection (ICSI) and embryonic stem cell derivation. However, the molecular mechanism underlying porcine oocyte is still unclear. In this study, we present the description of the porcine oocyte proteome. Proteins within the isoelectric point ranges of 3.0 to 10.0 were analyzed separately using 2‐dimensional electrophoresis (2‐DE). About 450 spots were detected in 2‐ D gel of oocytes, stained with Coomassie blue. Subsequent excision of 227 spots from gels and MALDI‐TOF MS analysis allowed the identification of 85 proteins. Our results indicated the composite profiles of proteins in the porcine oocyte. Tubulin beta chain and meiosis‐specific nuclear structural protein 1 antibody was used to confirm those antibody expression levels in immature, mature and parthenogenetic embryo. Western blot analysis showed that expressions of those proteins increased during mature and parthenogenetic embryo. These protein profiles will make available important guides for the study of oocyte function and assist in functional analysis of the proteins.
        186.
        2011.10 구독 인증기관·개인회원 무료
        In all the studies of mammalian species, chromatin in the germinal vesicle (GV) is initially decondensed with the nucleolus not surrounded by heterochromatin (the NSN configurations). During oocyte growth, the GV chromatin condenses into perinucleolar rings (the SN configurations) or other corresponding configurations with or without the perinucleolar rings, depending on species. During oocyte maturation, the GV chromatin is synchronized in a less condensed state before germinal vesicle breakdown (GVBD) in species that has been minutely studied. As not all the species show the SN configuration and gene transcription always stops at the late stage of oocyte growth, it is suggested that a thorough condensation of GV chromatin is essential for transcriptional repression. Because the GV chromatin status is highly correlated with oocyte competence, oocytes must end the NSN configuration before they gain the full meiotic competence and they must take on the SN/corresponding configurations and stop gene transcription before they acquire the competence for early embryonic development. In this study, we firstly investigated whether the layer of cumulus cells and size of oocytes could determine chromatin configurations in porcine oocytes. Using Hoechst3342 staining, the GV nucleolus and chromatin of porcine oocytes was classified into SN and NSN configurations. Next, we examined the changes in GV chromatin configurations during growth and maturation of porcine oocytes. In addition, the maturation and parthenogenetic development abilities in vitro were significant different between the SN and NSN configurations oocytes. These results indicated that chromatin changes in GV oocytes affect the development potential of parthenogenetic embryos.
        187.
        2011.10 구독 인증기관·개인회원 무료
        In vitro production of porcine embryos, including in vitro maturation of oocytes followed by in vitro fertilization and in vitro culture, may result in live offspring, but it is still associated with great inefficiencies. In mammalian oocytes, acquisition of meiotic competence coincides with a decrease in general transcriptional activity at the end of the oocyte growth phase. In this study, we investigated the expression and sub‐cellular localization of CDK9, a RNA polymerase II CTD kinase during pig oocyte growth. Localization and expression of components involved in mRNA and rRNA transcription were assessed by immunocytochemistry in growing and fully‐grown oocytes. In addition, meiotic resumption, germinal vesicle breakdown and nuclear transcription were analyzed in oocytes cultured in presence of a potent CDK9 inhibitor, flavopiridol. Our analyses, demonstrated that CDK9 became co‐localized partially with phosphorylated Pol II CTD and mRNA splicing complexes. Surprisingly, CDK9 was co‐localized with Pol Ispecific transcription factor, UBF, and gradually localized in nucleolar peripheries at the final steps of oocyte growth. Treatment with flavopiridol resulted in arrest in meiotic resumption, germinal vesicle breakdown as well as a decline in global transcription. All together, this data suggest that CDK9 has a dual role in both Pol I‐ and Pol II‐dependent transcription in pig oocyte growth.
        188.
        2011.10 구독 인증기관·개인회원 무료
        5‐aza‐2’‐deoxyctidine (5‐aza‐dC) is DNA methylation inhibitor and Trichostatin A (TSA) is histone deacytlase inhibitor, both of them can alter the level of the epigenetic modification of cells. The objective of this study was to investigate the effects of treatment with 5‐aza‐dC and TSA into fetal fibroblasts on the development of porcine nuclear transfer (NT) embryos. In this study, experiments were performed in order to modify epigenetic status in donor cells and evaluate developmental potential of NT embryos. 5‐ aza‐dC or TSA or combining treatment of TSA and 5‐aza‐dC was treated into growing donor cells for 1 h exposure and development of NT embryos was evaluated. Experiment was performed with 3 groups: control group (donor cells without treatment); TSA group (donor cell treated with 50 nM TSA for 1 h); TSA + 5‐aza‐dC group (donor cells were treated with 50 nM TSA and 5 nM 5‐aza‐dC for 1 h); TSA+1/2(5‐aza‐dC) group (donor cells were treated with 50 nM TSA for 1h and subsequently treated with 2.5 nM 5‐aza‐dC for another 1h). When donor cells were individually treated with 5 nM 5‐aza‐dC or 50 nM TSA for 1h, the blastocyst rate of NT embryos increased significantly compared with control group [18.8% vs 13.4% (5 nM 5‐aza‐dC group vs control group), and 26.2% vs 11.8% (50 nM TSA group vs control group), p<0.05]. However, the blastocyst rate in combining treatment group (50 nM TSA + 5 nM 5‐aza‐dC) did not increase compare with control group (12.3% vs 11.8%, p>0.05). When the donor cell were individually treated with 50nM TSA for 1 h firstly and then treated with 2.5 nM 5‐aza‐dC for another 1h, the blastocyst rate was significantly improved compared with control and TSA group (28% vs 10.2% and 23.7%, p<0.05). The present study suggested that donor cells treated with TSA or low concentration of TSA+5‐azadC in short time exposure may enhance the development of porcine NT embryo.
        189.
        2011.10 구독 인증기관·개인회원 무료
        X‐box binding protein‐1 (XBP‐1) is an important regulator of a subset of genes active during endoplasmic reticulum (ER) stress. In the present study, we analyzed XBP‐1 level and location to explore the effect of ER stress on oocyte maturation and developmental competency of porcine embryos in an in vitro culture system. First, we examined the localization of XBP‐1 at different meiotic stages of porcine oocytes and at early stages of parthenogenetic embryo development. Fluorescence staining showed that expression of functional XBP‐1 was weak in mature oocytes and at the one‐cell, two‐cell, and eight‐cell stages of embryos, but abundant at the GV oocyte, four‐cell, morula, and blastocyst stages. In addition, RT‐PCR revealed that both spliced XBP‐1 (XBP‐1s ) and unspliced XBP‐1 (XBP‐1u) were expressed at the GV oocyte, four‐cell, morula, and blastocyst stages. Tunicamycin (TM), an ER stress inducer, blocked porcine embryonic development at the four‐cell stage, exhibiting the effect on embryonic genome activation. Next, porcine embryos cultured in the presence of tauroursodeoxycholate (TUDCA), an ER stress inhibitor, were studied. Total cell numbers and the extent of the ICM increased (p<0.05), whereas the rate of nuclear apoptosis decreased (p<0.05). Moreover, expression of the anti‐apoptotic gene Bcl‐2 increased whereas expression of the pro‐apoptotic genes Bcl‐xl and p53 decreased. The results indicated that inhibition of ER stress enhanced porcine oocyte maturation and embryonic development by preventing ER stress‐mediated apoptosis in vitro.
        190.
        2011.09 구독 인증기관 무료, 개인회원 유료
        This study was undertaken to evaluate the relationship between in vitro maturation and plasminogen activators (PAs) activity on porcine cumulus-oocytes complexes (COCs) exposed to oxidative stress. When COCs were cultured in maturation medium with hydrogen peroxide (H2O2), the proportion of the germinal vesicle breakdown (GVBD) and oocytes maturation were decreased with addition of H2O2, and were significantly (p<0.05) lower in medium with 0.1 mM H2O2 than control group. Also, the rate of degenerated oocytes was increased in as H2O2 concentration increased. When COCs were cultured for 48 h, three plasminogen-dependent lytic bands were observed: tissue-type PA (tPA); urokinase-type PA (uPA); and tPA-PA inhibitor (tPA-PAI). PA activity was quantified using SDS-PAGE and zymography. When H2O2 concentration was increased, tPA and tPA-PAI activities also increased in porcine oocytes cultured for 48 h, but not uPA. In other experiment, embryos were divided into three groups and cultured in (1) control medium, (2) control medium with 1.0 mM H2O2 and (3) control medium with 1.0 mM H2O2 along with catalase in concentrations of 0.01, 0.1, and 1.0 mg/ml, respectively. H2O2 decreased the rate of GVBD and maturation in porcine COCs but catalase revealed protective activity against oxidative stress caused by H2O2. In this experiment, tPA and tPA-PAI activities were higher in media with 1.0 mM H2O2 alone. Increasing concentration of catalase decreased tPA and tPA-PAI activities in porcine oocytes. These results indicate that the exposure of porcine follicular oocytes to ROS inhibits oocytes maturation to metaphase-II stage and increase the oocytes degeneration. Also, we speculated that increased ROS level may trigger tPA and tPA-PAI activities in porcine oocytes matured in vitro.
        4,000원
        191.
        2011.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        농촌진흥청 원예특작과학원에서는 2003년에 황색 폼 폰 화형인 ‘Restone’에 자주색 폼폰 화형인 ‘Lollipop’을 교배하여 획득한 실생 집단으로부터 황색 적심 폼폰 화형의 겹꽃 ‘03B1-82’ 계통을 선발하였다. ‘03B1-82’ 계통은 2005년 겨울부터 2007년 3년에 걸쳐 1, 2차 특성검정을 통해 안정성, 균일성 및 흰녹병저항성 검정 및 절화수명에 대해 조사되었고, 2008년에는 우수선발 계통으로 ‘원교B1-142호’ 계통번호를 부여받아 3차 특 성검정을 실시하여 안정성, 균일성에 대한 연차별 재현 성 그리고 주년생산성(촉성, 억제재배), 생산자 및 소 비자 기호성을 평가 받았다. ‘원교B1-142호’는 2008년 에 직무육성품종심의회를 거쳐 ‘옐로우캔디’로 명명되 어졌다. 국화 ‘옐로우캔디’는 10월 하순에서 11월 상 순에 자연 개화하는 절화용 스프레이 추국이다. 황색의 적색화심을 지닌 폼폰화형의 겹꽃으로 초세 및 줄기가 강건하다. 특히 여름철 고온기에도 통상화가 많이 발생 하지 않으며, 촉성 및 억제재배 등 주년생산이 가능하 다. 꽃의 직경이 4.3 cm 내외, 꽃잎수는 소화당 180매 이상, 착화수는 본당 8화 내외의 중형화로 절화수명은 18일 정도이다. 재배상 유의점으로는 둥근모양의 폼폰 형이기 때문에 수확시 꽃이 서로 엉키면 꽃이 떨어지는 경우가 있으며, 여름 장마철 또는 겨울철 환기 부족시 흰녹병 발생을 주의하고 주기적인 방제가 필요하다.
        4,000원
        197.
        2011.05 구독 인증기관·개인회원 무료
        The silkworm-baculovirus expression system has distinct advantages, such as a high yield and safe usage in vertebrates. Here, we report a novel strategy for the large-scale production of a classical swine fever virus (CSFV) envelope glycoprotein E2 in the larvae of a baculovirus-infected silkworm, Bombyx mori. We constructed a recombinant B. mori nucleopolyhedrovirus (BmNPV) that expressed recombinant polyhedra together with the N-terminal 179 amino acids of CSFV E2 (E2ΔC). BmNPV-E2ΔC-infected silkworm larvae expressed native polyhedrin and approximately 44-kDa fusion protein that was detected using both anti-polyhedrin and anti-CSFV E2 antibodies. Electron and confocal microscopy both demonstrated that the recombinant polyhedra contained both the fusion protein and native polyhedrin were morphologically normal and contained CSFV E2ΔC. The CSFV E2ΔC antigen produced in BmNPV-E2ΔC-infected silkworm larvae reached 0.68 mg per ml of hemolymph and 0.53 mg per larva at 6 days post-infection. Six-week-old female BALB/c mice that were immunized with the E2ΔC protein purified from solubilized recombinant polyhedraelicited CSFV E2 antibodies, which indicated that the CSFV E2ΔC protein from recombinant polyhedra was immunogenic. The virus neutralization test showed that the serum from mice that were treated with E2ΔC protein from recombinant polyhedra contained significant levels of virus neutralization activity. These results demonstrate that the present strategy can be used for the large-scale production of CSFV E2 antigen.
        198.
        2010.12 구독 인증기관 무료, 개인회원 유료
        Oleanolic acid is a natural triterpenoid that exists widely in foods and some medicinal herbs. The purpose of this study was to determine the antimicrobial activity of oleanolic acid against Streptococcus mutans strains isolated from a Korean population. Antimicrobial activity against these bacteria was evaluated by minimal inhibitory concentration (MIC) and time kill curves. The tolerance of human gingival fibroblasts and human periodontal ligaments to oleanolic acid was tested using a methyl thiazolyl tetrazolium (MTT) assay. The MIC90 value of oleanolic acid for both S. mutans and S. sobrinus isolated from Koreans was 8μg/mℓ. Oleanolic acid showed bactericidal effects against S. mutans ATCC 25175T and S. sobrinus ATCC 33478T at 1 × MIC(8μg/mℓ) and had no cytotoxic effects against KB cells at this dose. The results suggest that oleanolic acid could be useful in the future development of oral hygiene products for the prevention of dental caries.
        4,000원
        199.
        2010.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study was to investigate the effects of upper and lower limb composing patterns of PNF(proprioceptive neuromuscular facilitation) on the static balance ability by 20 subjects for 6 weeks. This study was measured left one leg standing and right one leg standing with closed eyes on Good Balance system. These results led us to the conclusion that the mean speed of X, Y direction, COP(center of Pressure) velocity moment showed a statistical decrease when applying post-exercise. The above results from this study indicated that upper and lower limb composing patterns of PNF exercise has improved the static balance ability. As a result, this study showed that upper and lower limb composing patterns exercise improve the ability of balance in young adults. Based on this study, it may be applied to old people.
        4,000원
        200.
        2010.10 구독 인증기관·개인회원 무료
        Bee venom contains a variety of peptides and enzymes, including serine proteases. While the presence of serine proteases in bee venom has been demonstrated, the role of these proteins in bee venom has not been elucidated. Furthermore, there is currently no information available regarding the melanization response or the fibrin(ogen)olytic activity of bee venom serine protease, and the molecular mechanism of its action remains unknown. Here we show that bee venom serine protease (Bi-VSP) is a multifunctional enzyme. In insects, Bi-VSP acts as an arthropod prophenoloxidase (proPO)-activating factor (PPAF), thereby triggering the phenoloxidase (PO) cascade. Bi-VSP injected through the stinger induces a lethal melanization response in target insects by modulating the innate immune response. In mammals, Bi-VSP acts similarly to snake venom serine protease, which exhibits fibrin(ogen)olytic activity. Bi-VSP activates prothrombin and directly degrades fibrinogen into fibrin degradation products, defining roles forBi-VSP as a prothrombin activator, a thrombin-like protease, and a plasmin-like protease. These findings provide a novel view of the mechanism of bee venom in which the bee venom serine protease kills target insects via a melanization strategy and exhibits fibrin(ogen)olytic activity.