• 제목/요약/키워드: Generation of Mechanisms

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Protective Effects of Chongmyunggongjin-dan on H2O2-induced C6 Glial Cell Death (H2O2로 유발된 C6 신경교세포 사멸에 대한 총명공진단의 보호 효과)

  • Hwang, Gyu-sang;Shin, Yong-jeen
    • The Journal of Internal Korean Medicine
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    • v.41 no.1
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    • pp.44-58
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    • 2020
  • Objectives: This study was conducted to identify the protective effects of Chongmyunggongjin-dan (CMGJD) on Hydrogen peroxide (H2O2)-induced apoptosis mechanisms in C6 glial cells. Method: We used CMGJD after distilled water extraction, filtration, and lyophilization. The ROS scavenging effect was examined by fluorescence microscopy. Expression levels of proteins related to ROS generation were investigated by western blotting. Functional changes in organelles related to Reactive oxygen species (ROS) generation were investigated by immunoblotting and by verifying expression level of relevant enzymes. Results: The CMGJD extract protected the cells against H2O2-induced morphological changes and DNA fragmentation, inhibited the increase of Heme_oxygenase-1(HO-1) and the decrease in catalase, protected against the loss of mitochondrial membrane potential, inhibited disturbances of lysosomal function, and induced an increase in peroxisomes. Conclusion: CMGJD was confirmed to have a protective effect on H2O2-induced C6 glial cell death possibly by blocking the pathways causing damage to subcellular organelles, such as mitochondria, lysosomes, and peroxisomes. We assume that CMGJD will be effective for the prevention and treatment of ischemic stroke in a clinical environment.

[$Ca^{2+}$ Sensitization Mechanism in Stretch-induced Myogenic Tone

  • Kim, Jung-Sup;Ryu, Sung-Kyung;Ahn, Duck-Sun;Kang, Bok-Soon;Lee, Young-Ho
    • The Korean Journal of Physiology and Pharmacology
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    • v.6 no.1
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    • pp.33-39
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    • 2002
  • It has been suggested that $Ca^{2+}$ sensitization mechanisms might contribute to myogenic tone, however, specific mechanisms have not yet been fully identified. Therefore, we investigated the role of protein kinase C (PKC)- or RhoA-induced $Ca^{2+}$ sensitization in myogenic tone of the rabbit basilar vessel. Myogenic tone was developed by stretch of rabbit basilar artery. Fura-2 $Ca^{2+}$ signals, contractile responses, PKC immunoblots, translocation of PKC and RhoA, and phosphorylation of myosin light chains were measured. Stretch of the resting vessel evoked a myogenic contraction and an increase in the intracellular $Ca^{2+}$ concentration $([Ca^{2+}]_i)$ only in the presence of extracellular $Ca^{2+}$. Stretch evoked greater contraction than high $K^+$ at a given $[Ca^{2+}]_i.$ The stretch-induced increase in $[Ca^{2+}]_i$ and contractile force were inhibited by treatment of the tissue with nifedipine, a blocker of voltage-dependent $Ca^{2+}$ channel, but not with gadolinium, a blocker of stretch-activated cation channels. The PKC inhibitors, H-7 and calphostin C, and a RhoA-activated protein kinase (ROK) inhibitor, Y-27632, inhibited the stretch-induced myogenic tone without changing $[Ca^{2+}]_i.$ Immunoblotting using isoform-specific antibodies showed the presence of $PKC_{\alpha}$ and $PKC_{\varepsilon}$ in the rabbit basilar artery. $PKC_{\alpha},$ but not $PKC_{\varepsilon},$ and RhoA were translocated from the cytosol to the cell membrane by stretch. Phosphorylation of the myosin light chains was increased by stretch and the increased phosphorylation was blocked by treatment of the tissue with H-7 and Y-27632, respectively. Our results are consistent with important roles for PKC and RhoA in the generation of myogenic tone. Furthermore, enhanced phosphorylation of the myosin light chains by activation of $PKC_{\alpha}$ and/or RhoA may be key mechanisms for the $Ca^{2+}$ sensitization associated with myogenic tone in basilar vessels.

Korean Red Ginseng Water Extract Restores Impaired Endothelial Function by Inhibiting Arginase Activity in Aged Mice

  • Choi, Kwanhoon;Yoon, Jeongyeon;Lim, Hyun Kyo;Ryoo, Sungwoo
    • The Korean Journal of Physiology and Pharmacology
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    • v.18 no.2
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    • pp.95-101
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    • 2014
  • Cardiovascular disease is the prime cause of morbidity and mortality and the population ages that may contribute to increase in the occurrence of cardiovascular disease. Arginase upregulation is associated with impaired endothelial function in aged vascular system and thus may contribute to cardiovascular disease. According to recent research, Korean Red Ginseng water extract (KRGE) may reduce cardiovascular disease risk by improving vascular system health. The purpose of this study was to examine mechanisms contributing to age-related vascular endothelial dysfunction and to determine whether KRGE improves these functions in aged mice. Young ($10{\pm}3$ weeks) and aged ($55{\pm}5$ weeks) male mice (C57BL/6J) were orally administered 0, 10, or 20 mg/mouse/day of KRGE for 4 weeks. Animals were sacrificed and the aortas were removed. Endothelial arginase activity, nitric oxide (NO) generation and reactive oxygen species (ROS) production, endothelial nitric oxide synthase (eNOS) coupling, vascular tension, and plasma peroxynitrite production were measured. KRGE attenuated arginase activity, restored nitric oxide (NO) generation, reduced ROS production, and enhanced eNOS coupling in aged mice. KRGE also improved vascular tension in aged vessels, as indicated by increased acetylcholine-induced vasorelaxation and improved phenylephrine-stimulated vasoconstriction. Furthermore, KRGE prevented plasma peroxynitrite formation in aged mice, indicating reduced lipid peroxidation. These results suggest KRGE exerts vasoprotective effects by inhibiting arginase activity and augmenting NO signaling and may be a useful treatment for age-dependent vascular diseases.

Pinus Densiflora Gnarl Extract for Pharmacopuncture Inhibits Inflammatory Responses through Heme Oxygenase-1 Induction in Lipopolysaccharide-Stimulated RAW264.7 Macrophages (RAW 264.7 세포에서 Heme Oxygenase-1 발현 유도를 통한 송절(松節) 약침액의 항염증 효능)

  • Lee, Kang-Pa;Moon, Jin-Young
    • Korean Journal of Acupuncture
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    • v.29 no.1
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    • pp.37-46
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    • 2012
  • Objectives : The gnarl of Pinus densiflora, called Songjeol in Korea, has been used as a medicinal herb for the treatment of inflammatory-related diseases such as arthralgia, myalgia and bruise. However, the molecular actions and mechanisms have not been clearly investigated. The aim of this study was to clarify the anti-inflammatory activity of Pinus densiflora gnarl pharmacopuncture (PDGP) in lipopolysaccharide (LPS)-stimulated RAW264.7 cells. Methods : Cytotoxicity was assessed by XTT assay. The amount of nitric oxide (NO) production was determined by nitrite assay. The mRNA expressions of interleukin-$1{\beta}$ (IL-$1{\beta}$), interleukin-6 (IL-6), cyclooxygenase-2 (COX-2) and heme oxygenase-1 (HO-1) were analyzed by RT-PCR. Reactive oxidative species (ROS) generation was measured using the fluorescence microscopy. In addition, inducible nitric oxide synthase (iNOS) and redox factor-1 (Ref-1) protein expressions were detected by Western blotting. Results : PDGP inhibited NO production and ROS generation in LPS-stimulated RAW264.7 cells. At the mRNA level, PDGP suppressed IL-$1{\beta}$, IL-6 and COX-2 expression. On the other hand, PDGP induced HO-1 mRNA expression. Furthermore, PDGP suppressed iNOS and Ref-1 protein expression. Conclusions : This result suggests that PDGP can act as a suppressor agent on NO and iNOS through induction of HO-1, and play an useful role in blocking inflammatory responses.

Design and Implementation of Service Control Point(SCP) for a Next-Generation Intelligent Network based on Internet Environment (인터넷 환경에서의 차세대 지능망 적용을 위한 SCP설계 및 구현)

  • Lee, Ji-Young;Kim, Yeon-Joong;Ma, Young-Sik;Kim, Dong-Ho;An, Sun-Shin
    • Journal of KIISE:Computing Practices and Letters
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    • v.7 no.4
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    • pp.336-349
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    • 2001
  • Intelligent Network (IN) is an architectural framework for the rapid and uniform provision of advanced services. Therefore, Next-generation IN platform should support fast service handling, the dynamic adaptation of various services according to various requirements of users. In this paper, we design and implement the Service Control Point (SCP) that is based on the Internet environment. Especially, we consider the service flexibility, the dynamic distribution of service and propose a set of mechanisms to optimize the performance of this platform. This SCP consists of the platform kernel to control intemal operations, tbe service manager to control all of services, SLPI (Service Logic processing Program Instance) manager to manage each service, and SLPI to handle service interaction. In addition, we propose the Service Creation Environment (SCE) to create easily services on the implemented platfonn and show the example of Call Forwarding service operated on this platform.

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Anti-cancer Properties and Relevant Mechanisms of Cordycepin, an Active Ingredient of the Insect Fungus Cordyceps spp., (동충하초 유래 cordycepin의 항암 활성 기전 최근 연구 동향)

  • Jeong, Jin-Woo;Choi, Yung Hyun
    • Journal of Life Science
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    • v.25 no.5
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    • pp.607-614
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    • 2015
  • Cancers are the largest cause of mortality and morbidity all over the world. Cordycepin, an adenosine analog, is a major functional component of the Cordyceps species, which has been widely used in traditional Oriental medicine. Over the last decade, this compound has been reported to possess many pharmacological properties, such as an ability to enhance immune function, as well as anti-inflammatory, antioxidant and anti-cancer effects. Recently, numerous studies have reported interesting properties of cordycepin as a chemopreventive agent as well. There is an accumulating body of experimental evidences suggesting that cordycepin impedes cancer progression by promoting apoptosis, inducing cell cycle arrest, modulating intracellular signaling pathways, and inhibiting invasion and metastasis of cancer cells. In many cancer cell lines, cordycepin inhibits growth and cell cycle progression by inducing arrest of the G2/M phase, resulting from the inhibition of retinoblastoma protein phosphorylation and induction of cyclin-dependent kinase inhibitors. To induce apoptosis, cordycepin activates the extrinsic and intrinsic pathways, which promotes reactive oxygen species generation and the downstream activation of kinase cascades. Cordycepin also can activate alternative pathways to cell death such autophagy. In addition, cordycepin can inhibit the pro-metastatic processes of cancer cell detachment, migration, and invasion through a variety of mechanisms, including the nuclear factor-kappa B and activated protein-1 signaling pathways. In this review, we summarized the variety of action mechanisms by which cordycepin may mediate chemopreventive effects on cancer and discussed the potential of this natural product as a promising therapeutic inhibitor of cancer development.

CaGe: A Web-Based Cancer Gene Annotation System for Cancer Genomics

  • Park, Young-Kyu;Kang, Tae-Wook;Baek, Su-Jin;Kim, Kwon-Il;Kim, Seon-Young;Lee, Do-Heon;Kim, Yong-Sung
    • Genomics & Informatics
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    • v.10 no.1
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    • pp.33-39
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    • 2012
  • High-throughput genomic technologies (HGTs), including next-generation DNA sequencing (NGS), microarray, and serial analysis of gene expression (SAGE), have become effective experimental tools for cancer genomics to identify cancer-associated somatic genomic alterations and genes. The main hurdle in cancer genomics is to identify the real causative mutations or genes out of many candidates from an HGT-based cancer genomic analysis. One useful approach is to refer to known cancer genes and associated information. The list of known cancer genes can be used to determine candidates of cancer driver mutations, while cancer gene-related information, including gene expression, protein-protein interaction, and pathways, can be useful for scoring novel candidates. Some cancer gene or mutation databases exist for this purpose, but few specialized tools exist for an automated analysis of a long gene list from an HGT-based cancer genomic analysis. This report presents a new web-accessible bioinformatic tool, called CaGe, a cancer genome annotation system for the assessment of candidates of cancer genes from HGT-based cancer genomics. The tool provides users with information on cancer-related genes, mutations, pathways, and associated annotations through annotation and browsing functions. With this tool, researchers can classify their candidate genes from cancer genome studies into either previously reported or novel categories of cancer genes and gain insight into underlying carcinogenic mechanisms through a pathway analysis. We show the usefulness of CaGe by assessing its performance in annotating somatic mutations from a published small cell lung cancer study.

Hydrogen-Related Gate Oxide Degradation Investigated by High-Pressure Deuterium Annealing (고압 중수소 열처리 효과에 의해 조사된 수소 결합 관련 박막 게이트 산화막의 열화)

  • 이재성
    • Journal of the Institute of Electronics Engineers of Korea SD
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    • v.41 no.11
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    • pp.7-13
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    • 2004
  • Experimental results are presented for the degradation of 3 nm-thick gate oxide under -2.5V $\leq$ V$_{g}$ $\leq$-4.0V stress and 10$0^{\circ}C$ conditions using P and NMOSFETs that are annealed with hydrogen or deuterium gas at high-pressure (5 atm). The degradation mechanisms are highly dependent on stress conditions. For low gate voltage, hole-trapping is found to dominate the reliability of gate oxide both in P and NMOSFETs. With increasing gate voltage to V$_{g}$ =-4.0V, the degradation becomes dominated by electron-trapping in NMOSFETs, however, the generation rate of "hot" hole was very low, because most of tunneling electrons experienced the phonon scattering before impact ionization at the Si interface. Statistical parameter variations as well as the gate leakage current depend on and are improved by high-pressure deuterium annealing, compared to corresponding hydrogen annealing. We therefore suggest that deuterium is effective in suppressing the generation of traps within the gate oxide. Our results therefore prove that hydrogen related processes are at the origin of the investigated oxide degradation.gradation.

The Study of Silver Generation Smart Service Customer Experience: The Effect of Fun and Challenge (실버세대 스마트 서비스 사용경험 연구: 흥미와 도전감 효과)

  • Jiyoung Kim
    • The Journal of the Convergence on Culture Technology
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    • v.9 no.2
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    • pp.459-466
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    • 2023
  • This study aims to provide implications by exploring the experiences of elderly customers using smart wearable devices. The proportion of the elderly among all customers is increasing day by day, and they are gradually trying to use smart devices more actively and improve the quality of life. It is known that the elderly have difficulty using smart devices compared to the younger generation, but this study aims to identify psychological mechanisms in the use process to help the elderly users use related devices more conveniently and joyfully and to actively apply them to service and product development. In particular, theoretical and practical implications were provided by investigating the causal relationship between variables that play a major role in the process of using smart devices, such as convenience, fun, and challenge.

Effect of Film-Temperature Boundary Conditions on the Lubrication Performance of Parallel Slider Bearing (유막온도경계조건이 평행 슬라이더 베어링의 윤활성능에 미치는 영향)

  • Park, TaeJo;Kim, MinGyu
    • Tribology and Lubricants
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    • v.33 no.5
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    • pp.207-213
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    • 2017
  • In sliding bearings, viscous friction due to high shear acting on the bearing surface raises the oil temperature. One of the mechanisms responsible for generating the load-carrying capacity in parallel surfaces is known as the viscosity wedge effect. In this paper, we investigate the effect of film-temperature boundary conditions on the thermohydrodynamic (THD) lubrication of parallel slider bearings. For this purpose, the continuity equation, Navier-Stokes equation, and the energy equation with temperature-viscosity-density relations are numerically analyzed using the commercial computational fluid dynamics (CFD) code FLUENT. Two different film-temperature boundary conditions are adopted to investigate the pressure generation mechanism. The temperature and viscosity distributions in the film thickness and flow directions were obtained, and the factors related to the pressure generation in the equation of motion were examined in detail. It was confirmed that the temperature gradients in the film and flow directions contribute heavily to the thermal wedge effect, due to which parallel slider bearing can not only support a considerable load but also reduce the frictional force, and its effect is significantly changed with the film-temperature boundary conditions. The present results can be used as basic data for THD analysis of surface-textured sliding bearings; however, further studies on various film-temperature boundary conditions are required.