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        검색결과 53

        22.
        2010.09 구독 인증기관 무료, 개인회원 유료
        Plasminogen activators (PAs) are serine protease that cleave plasminogen to form the active protease plasmin and may participate in mammalian fertilization. Although correlations have been reported between reactive oxygen species (ROS) and sperm function, the relationship between PA activity and ROS is unknown. We determined the effects of ROS on sperm function and PA activities in boar spermatozoa preincubated under the X-XO system. When spermatozoa were treated with the X+XO group, a significant increase (p<0.05) was observed in the percentage of acrosome reacted spermatozoa compared with that of the control group. However, when antioxidants were added to the medium with X+XO, the rate of acrosome reaction tended to decrease. Also, a significantly lower percentage of acrosome reacted spermatozoa was observed in the X+XO+catalase group at 6 hr of incubation compared with that of X+XO group. The density of malondialdehyde (MDA) was higher in the X+XO group than in different treatment groups. In another experiment, incubation of spermatozoa in medium with X+XO was associated with a significant (p<0.05) increase in activity of tPA-PAI and tPA compared with the control group. Antioxidants decreased the increased activity of tPA-PAI and tPA by preincubation in the X-XO system. Also, a significantly lower (p<0.05) activities of tPA-PAI and tPA were observed in the X+XO+catalase group compared with the X+XO group. No significant differences, however, were observed in the activity of uPA. These results suggest that the increase of acrosome reaction by the X-XO system resulted in increase of PAs activity in the sperm incubation medium.
        4,000원
        23.
        2010.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Plasminogen activators (PAs) are serine proteases that convert plasminogen to plasmin. The PA/plasmin system has been associated with a number of physiological processes such as fibrinolysis, ovulation and fertilization. Although correlations have been reported between reactive oxygen species (ROS) and oocyte maturation, the relationship between PA activity and ROS is unknown. The present study was undertaken to determine the effects of cumulus cells on PA activity in matured porcine oocytes under xanthine (X)-xanthine oxidase (XO) system. When oocytes were matured under the X-XO system, the proportion of oocytes remaining GV stage was higher (p<0.05) in oocytes without cumulus cells. The incidence of degenerated oocytes was higher (p<0.05) in the X+XO ( and ) than in the control group ( and ). The proportion of TUNEL-positive oocytes and activity of caspase-3 were higher (p<0.05) in cumulus-free oocytes and oocytes exposed to ROS. Tissue-type plasminogen activator-plasminogen activator inhibitor (tPA-PAI) and tissue-type plasminogen activator (tPA) activity were detected in oocytes that were separated from cumulus-oocytes complexs (COCs) at 44 h of maturation culture, and only tPA was produced in oocytes that were denuded before the onset of maturation culture. On the other hand, the activities of PA were increased (p<0.05) when oocytes were cultured under the X-XO system. The higher activity of tPA was observed in denuded oocytes (DOs) underwent apoptotic changes by oxidative stress. In COCs, however, tPA-PAI as well as tPA activity was detected and apoptotic changes such as DNA cleavage or caspase-3 activation were not observed. These results suggest that tP A may be relevant to apoptotic cell death in porcine oocytes by oxidative stress.
        4,000원
        25.
        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.
        26.
        2009.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Intracellular reactive oxygen species(ROS) produced in a various pathologic state was known to intermediate many cellular response such as inflammation. Recently, low level light irradiation by HeNe laser used in many clinical field could improve inflammatory state by scavenging intracellular ROS through photo-detachment/dissociation process. The purpose of this study is to investigate the differential effects of blue and red light irradiation on ROS scavenging effects. Immortalized human oral keratinocyte HaCat cells were used. Phorbol 12-myristate 13-acetate(PMA) was treated for inflammation. Red(635nm) and blue(470nm) light irradiation was carried out. To asses the intracellular ROS by light irradiation, confocal microscopic and flow cytometric assay with DCF fluorescence for total ROS and ESR spectrometry of DMPO-O2 - for superoxide anion were caried out. And microarray was performed for mRNA expression level. Released intracellular total ROS in PMA treated HaCat cell lines was dissociated efficiently by red light irradiation, while blue light irradiation did not. Rather, blue light irradiation increased ROS formation. For superoxide anion generated the first synthetic form of ROS, red light irradiation reduced its amount but blue light irradiation did not. In the mRNA expression in line with cyclooxygenase(COX) pathway, prostagrandin endoperoxide synthase 1(PTGS 1), prostagrandin endoperoxide synthase 2(PTGS 2) and phospholipase A2(PLA2) were increased by both light irradiation and they were decreased as time flows. And genes associated with ROS releasing, mRNA expressions of tumor necrosis factor receptor (TNFR) and interleukin 1beta(IL1B) were increased by 1 hour red light irradiation but did not by blue light irradiation. As a result, red and blue light irradiation showed different response in affecting the level of ROS. These findings indicate that red light rather than blue light is more useful for anti-inflammation in clinical field
        4,000원
        29.
        2008.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In this study, the apoptotic effects of the actin disruption agent, latrunculin B(LB) have been investigated on p53 deficient chronic myeloid leukemia cell line K562. A dose-dependent decrease in K562 cell proliferation was observed after LB treatment with maximum decrease in cell proliferation being at 1.5μM where the percent inhibition was 66.53%. F-actin stained with TRITC-phalloidin was shown as a peripheral ring or appeared diffusely distributed throughout the cytoplasm in untreated cells, this actin ring was decreased following LB treatment, and even large focal actin aggregates were formed. Treatment of K562 with LB(1.5μM) generated ROS substantially. LB activated expression in a dose-dependent manner. Therefore it can be concluded that LB, depolymerising agent of actin, induces apoptosis by producing ROS and up-regulating NF-kB and COX-2 activation.
        4,300원
        33.
        2002.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        양강추출물(Alpinia officinarum, 70% ethanol extract)과 함유 주성분인 galangin은 프리라디칼소거작용과 지질과산화억제활성을 나타내었으며, H_2O_2 또는 KO_2유도 세포독성에 대해서도 억제적으로 작용하여 세포보호효과를 나타내었다. DNA single strand breakage와 같은 산화적 스트레스에 대해서도 보호작용을 하고 있다. 또한, 마우스 소핵시험에 의하여 adriamycin과 같은 superoxide유발물질에 의한 염색체 수준에서의 손상에 대해서도 억제효과를 나타내었다. 양강추출물은 galangin을 유효성분으로하여 산소프리라디칼들에 의한 산화적 손상에 억제적으로 작용하는 기전으로 산화적 스트레스에 대한 항노화, 암예방제로서의 응용가능성이 높은 추출물로서 향후 기능성 식품으로서의 응용가능성이 높을 것으로 판단되었다.
        4,200원
        35.
        2018.05 서비스 종료(열람 제한)
        Background : This study aimed to determine the anti-osteoclastogenic effects of extracts from CK berry’s and identify the underlying mechanisms in vitro. Methods and Results : Reactive oxygen species (ROS) are signal mediators in osteoclast differentiation. AM extracts inhibited ROS production in RAW264.7 cells in a dose-dependent manner and exhibited strong radical scavenging activity. The extracts also attenuated the number of tartrate-resistant acid phosphatase (TRAP)-positive multinucleated osteoclasts. To attain molecular insights, the effect of the extracts on the signaling pathways induced by receptor activator of nuclear factor kappa B ligand (RANKL) were also investigated. RANKL triggers many transcription factors through the activation of mitogen-activated protein kinase (MAPK) and ROS, leading to the induction of osteoclast-specific genes. The extracts significantly suppressed RANKL-induced activation of MAPKs, such as extracellular signal-regulated kinase (ERK), c-Jun-N-terminal kinase (JNK), and p38, and consequently led to the downregulation of c-Fos and nuclear factor of activated T cells 1 (NFATc1) protein expression which ultimately suppress the activation of the osteoclast-specific genes, cathepsin K, TRAP, calcitonin receptor, and integrin β3. Conclusion : In conclusion, our findings suggest that AM extracts inhibited RANKL-induced osteoclast differentiation by downregulating ROS generation and inactivating JNK/ERK/p38, nuclear factor kappa B (NF-κB)-mediated c-Fos and NFATc1 signaling pathway.
        37.
        2017.08 서비스 종료(열람 제한)
        Peroxiredoxin1 (Prdx1) is an antioxidant enzyme belonging to the peroxiredoxin family of proteins. Prdx1 catalyzes the reduction of H2O2 and alkyl hydroperoxide and plays an important role in different biological processes. Prdx1 also participates in various age-related diseases and cancers. In this study, we investigated the role of Prdx1 in pronephros development during embryogenesis. Prdx1 knockdown markedly inhibited proximal tubule formation in the pronephros and significantly increased the cellular levels of reactive oxygen species (ROS), which impaired primary cilia formation. Additionally, treatment with ROS (H2O2) severely disrupted proximal tubule formation, whereas Prdx1 overexpression reversed the ROS-mediated inhibition in proximal tubule formation. Epistatic analysis revealed that Prdx1 has a crucial role in retinoic acid and Wnt signaling pathways during pronephrogenesis. In conclusion, Prdx1 facilitates proximal tubule formation during pronephrogenesis by regulating ROS levels.
        38.
        2017.05 서비스 종료(열람 제한)
        Background : The young stem of Cinnamomum cassia (YSC) as traditional Chinese medicines has been reported to show a variety of pharmacological properties such as anti-allergy, insecticidal, antimicrobial, antiulcer, anti-inflammatory, immune-suppressive, and neuronal death prevention, tyrosinase inhibition and anticancer, antioxidant and free radical scavenging, as well as antidiabetic and aldose reductase inhibition activities. In this study, we elucidated apoptotic effect and potential molecular mechanism of hot water extracts from YSC (YSC-HW) against human colorectal cancer cells. Methods and Results : YSC-HW treatment increased ROS level and induced ROS-dependent DNA damage in human colorectal cancer cells. ROS generation mediated by YSC-HW induced DNA induced apoptosis and reduction of cell viability in human colorectal cancer cells. YSC-HW ROS-dependently induced NF-kB activation through p65 nuclear translocation via IkB-α degradation, which exerted the induction of apoptosis. In addition, YSC-HW activated ATF3 expression dependent on ROS, which resulted in apoptosis. Conclusion : Our results suggest that YSC-HW may induce apoptosis through ROS-activation of NF-kB and ATF3 in human colorectal cancer cells. From these findings, YSC-HW has potential to be a candidate for the development of chemoprevention or therapeutic agents for human colorectal cancer.
        39.
        2017.05 서비스 종료(열람 제한)
        Background : We have previously reported that Oligonol, a low-molecular polyphenol derived from lychee fruit, has protective effect on the liver and kidney of diabetic animal model. In this study, we examined whether Oligonol has any beneficial effects on pancreas of diabetic rats. Methods and Results : Oligonol was orally administered at a dose of 10 and 20 mg/kg body weight for 10 days to STZ-induced diabetic rats, and the effects were compared with those of vehicle-treated diabetic control and non-diabetic control rats. The administration of Oligonol reduced hyperglycemia in diabetic rats through an improvement of serum and pancreatic insulin levels. The increased reactive oxygen species levels in pancreas of diabetic control rats was attenuated by the Oligonol administration through inhibiting the expression of NADPH oxidase-related proteins. The enhanced expression of pro-apoptotic proteins in pancreas of diabetic control rats was significantly reduced by Oligonol administration through down-regulation of phosphor-c-Jun N-terminal kinases protein in pancreas. Furthermore, the expressions of cell proliferation-related protein were also augmented in Oligonol treated-diabetic rats. However, Oligonol treatment led to improved histological changes in the pancreas. Conclusion : These pancreatoprotective effects of Oligonol were achieved through attenuation of oxidative stress and its sensitive protein expression associated with apoptosis and cell proliferation in diabetic rats.
        40.
        2017.02 KCI 등재 서비스 종료(열람 제한)
        This paper proposes combination of a cognitive agent architecture named Soar (State, operator, and result) and ROS (Robot Operating System), which can be a basic framework for a robot agent to interact and cope with its environment more intelligently and appropriately. The proposed Soar-ROS human-robot interaction (HRI) agent understands a set of human’s commands by voice recognition and chooses to properly react to the command according to the symbol detected by image recognition, implemented on a humanoid robot. The robotic agent is allowed to refuse to follow an inappropriate command like “go” after it has seen the symbol ‘X’ which represents that an abnormal or immoral situation has occurred. This simple but meaningful HRI task is successfully experimented on the proposed Soar-ROS platform with a small humanoid robot, which implies that extending the present hybrid platform to artificial moral agent is possible.
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