• Title/Summary/Keyword: Retrograde signal

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Mitochondrial defect-responsive gene signature in liver-cancer progression

  • Lee, Young-Kyoung;Woo, Hyun Goo;Yoon, Gyesoon
    • BMB Reports
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    • v.48 no.11
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    • pp.597-598
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    • 2015
  • Mitochondrial respiratory defect is a key bioenergetics feature of hepatocellular carcinoma (HCC) cells. However, their involvement and roles in HCC development and progression remain unclear. Recently, we identified 10 common mitochondrial defect (CMD) signature genes that may be induced by retrograde signaling-mediated transcriptional reprogramming in response to HCC mitochondrial defects. HCC patients with enriched expression of these genes had poor prognostic outcomes, such as shorter periods of overall survival and recurrence-free survival. Nuclear protein 1 (NUPR1), a key transcription regulator, was up-regulated by Ca++-mediated retrograde signaling. NUPR1-centric network analysis and a biochemical promoter-binding assay demonstrated that granulin (GRN) is a key downstream effector of NUPR1 for the regulation of HCC cell invasiveness; association analysis of the NUPR1-GRN pathway supported this conclusion. Mitochondrial respiratory defects and retrograde signaling thus play pivotal roles in HCC progression, highlighting the potential of the NUPR1-GRN axis as a novel diagnostic marker and therapeutic target for HCC.

Artifacts due to Retrograde Flow in the Artery and Their Elimination in 2D TOF MR Angiography (2D TOF 자기공명 혈관조영술에서 동맥혈류의 역류로 인한 영상훼손과 이의 제거)

  • Jung, K.J.;Lee, J.K.;Kim, S.K.;Park, S.H.
    • Investigative Magnetic Resonance Imaging
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    • v.5 no.1
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    • pp.38-42
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    • 2001
  • Dark band artifacts are often observed in angiograms of arteries obtained by 2D time-of-flight (TOF) angiography with saturation of veins by presaturation RF pulses. At some arteries the arterial blood velocity varies in a triphasic pattern during a cardiac cycle. The arterial blood, that is saturated by presaturation RF pulses in the saturation band, can flow back into the imaging slice during the retrograde flow phase of the triphasic variation. When such saturated retrograde flow occurs during the acquisition of the central part of the K space, a signal void can result in base images and consequently dark band artifacts can appear in angiograms. This phenomenon is experimentally demonstrated by varying the gap between the imaging slice and the saturation band. Furthermore, a new pulse sequence is proposed to eliminate the dark band artifacts by changing the profile of the saturation band front a rectangle to a ramp.

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Development of Computerized Spirometer (Computerized spirometer의 개발)

  • Cha, E.J.;Park, I.S.;Song, C.H.;Kim, D.W.;Goo, Y.S.;Lee, T.S.
    • Proceedings of the KOSOMBE Conference
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    • v.1996 no.11
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    • pp.189-191
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    • 1996
  • Computerized spirometer was developed in a form of proto type system. The system consisted of pneumotachometer, flow measurement unit, fan ventilator unit, and software program. Patient's respiratory flow signal was first converted to corresponding pressure drop signal by a screen type pneumotachometer, sensed by a differential pressure transducer, amplified and low pass filtered, and digitized at a rate of 100 Hz, then fed into a PC thru RS-232C serial port. Customized application software controls data acquisition followed by computation of test parameters. The fan ventilator unit dries and eliminates microorganism in the pneumotachometer after each test. The system performs conventional spirometic tests and manages the test results in a database for retrograde research. The proto type system was fully developed and the commercialized system is currently being built up.

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Clinical Report of two TGA cases (일과성 전기억상실증으로 진단된 환자 치험 2례)

  • Oh, Kyong-Min;Yang, Dong-Ho;Cho, Youn-Song;Kim, Bo-Kyong
    • Journal of Oriental Neuropsychiatry
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    • v.19 no.3
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    • pp.265-276
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    • 2008
  • Transient global amnesia(TGA) is a clinical syndrome characterized by sudden, temporary dysfunction of anterograde and recent retrograde memory without other neurologic deficits. Different hypotheses have been considered for its etiology, but it still remains obscure. Recently the diffusion-weighted magnetic resonance imaging(DWI), has been considered as the sensitive tool to detect small punctate hyperintense lesions in the hippocampus in transient global amnesia(TGA). We report two TGA cases, all of them answers to TGA clinical criteria, and one of them showed two dot like high signal intense foci in Rt. hippocampus on DWI.

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Thiol-Based Peroxidases and Ascorbate Peroxidases: Why Plants Rely on Multiple Peroxidase Systems in the Photosynthesizing Chloroplast?

  • Dietz, Karl-Josef
    • Molecules and Cells
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    • v.39 no.1
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    • pp.20-25
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    • 2016
  • Photosynthesis is a highly robust process allowing for rapid adjustment to changing environmental conditions. The efficient acclimation depends on balanced redox metabolism and control of reactive oxygen species release which triggers signaling cascades and potentially detrimental oxidation reactions. Thiol peroxidases of the peroxiredoxin and glutathione peroxidase type, and ascorbate peroxidases are the main peroxide detoxifying enzymes of the chloroplast. They use different electron donors and are linked to distinct redox networks. In addition, the peroxiredoxins serve functions in redox regulation and retrograde signaling. The complexity of plastid peroxidases is discussed in context of suborganellar localization, substrate preference, metabolic coupling, protein abundance, activity regulation, interactions, signaling functions, and the conditional requirement for high antioxidant capacity. Thus the review provides an opinion on the advantage of linking detoxification of peroxides to different enzymatic systems and implementing mechanisms for their inactivation to enforce signal propagation within and from the chloroplast.

Sengmaek-san-mediated Enhancement of Axonal Regeneration after Sciatic Nerve Injury in the Rat

  • Baek, Kyung-Min;Kim, Yoon-Sik;Ryu, Ho-Ryong;Jo, Hyun-Kyung;An, Jung-Jo;Namgung, Uk;Seol, In-Chan
    • Journal of Physiology & Pathology in Korean Medicine
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    • v.22 no.2
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    • pp.431-437
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    • 2008
  • Sengmaek-san(Shengmai-san; SMS) is used in oriental medicine as one of the key herbal medicine for treating diverse symptoms including cardiovascular and neurological disorders. In the present study, the effects of SMS on axonal regeneration were investigated in the rat model given sciatic nerve injury. SMS treatment enhanced axonal regrowth into and the number of non-neuronal cells in the distal area after crush injury. GAP-43 protein levels were increased in the injured sciatic nerve compared to intact nerve and further upreguated by SMS treatment. GAP-43 protein was increased similarly in the dorsal root ganglion (DRG) at lumbar 4 - 6 by nerve injury and SMS treatment, suggesting GAP-43 induction at gene expression level. SMS-mediated increase in phospho-Erk1/2 protein was observed in the DRG as well as in the injured nerve implying its retrograde transport into the cell body as the process of lesion signal transmission. The present findings suggest that SMS may be involved in enhanced axonal regeneration via dynamic regulation of regeneration-associated proteins.

Growth Promoting Effects of Oriental Medicinal Drugs on Sciatic Nerve Regeneration in the Rat

  • Jo Hyun-Kyung;NamGung Uk;Seol In-Chan;Kim Yoon-Sik
    • Journal of Physiology & Pathology in Korean Medicine
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    • v.19 no.6
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    • pp.1666-1672
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    • 2005
  • Oriental medicinal drugs have a broad spectrum of clinical use for the cure of nervous system diseases including brain ischemic damages or neuropathies. Yet, specific drugs or drug components used in the oriental medicine in relation to none fiber regeneration are not known. In the present study, possible growth promoting effects of oriental medicinal drugs were investigated in the injured sciatic nerve system in the rat. By immunofluorescence staining, we found that Jahageo (JHG, Hominis placenta) increased Induction levels of axonal growth associated protein GAP-43 in the rat sciatic none. Small growth promoting activity was found in Golsebo (GSB, Drynariae rhizoma) and Baikhasuo (BHSO, Polygoni multiflori radix) drugs. JHG also increased cell cycle protein Cdc2 levels in the injured area of the sciatic nerves. Immunofluorescence staining indicated that induced Cdc2 protein was mostly localized in the Schwann cells in the injury area, implying that JHG activity might be related to increased Schwann cell proliferation during axonal regeneration. Moreover, levels of phospho-extracellular signal-regulated (ERK) pathway in the injured neNes were elevated by JHG treatment while levels of total ERK were unaltered. In vivo measurement of axonal regeneration using retrograde tracer showed that JHG, GSB and BHSO significantly enhanced Dil-labeled regenerating motor neurons compared with saline control. The present data suggest that oriental medicinal drugs such as JHG, GSB, and BHSO may be a useful target for developing specific drugs of axonal regeneration.