S.Y. Park

Konyang University Hospital, Gaigeturi, Jeju, South Korea

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Publications (10)38.62 Total impact

  • H Ko · S Y Park · E J Cha · J S Sohn ·

    Cytopathology 05/2013; 25(2). DOI:10.1111/cyt.12067 · 1.48 Impact Factor
  • S.Y. Na · S.Y. Park · H.H. Cho · J.W. Choi · M Choi · H.S. Park · K.H. Cho ·
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    ABSTRACT: Background  Erythema induratum of Bazin (EIB) is regarded to be a hypersensitive reaction to the concomitant tuberculosis. Recently, interferon-γ releasing assay (IGRA) has been focused as a promising tool in the diagnosis of latent tuberculosis. However, there has been no large scale study to investigate the usefulness of IGRA in the diagnosis of EIB. Objectives  To evaluate the diagnostic performance for the detection of EIB. Methods  We retrospectively reviewed medical records of all patients with EIB, in the Department of Dermatology, at the Seoul National University Hospital, between April 2009 and September 2011. We analysed clinicopathological features, responses to IGRA and the treatment courses. In addition, we compared positive rate of IGRA in patients with other diseases during the same period. Results  All of the 22 patients demonstrated a positive response to IGRA (100%) and showed a good response to anti-tuberculosis treatment. In contrast, positive rate was 63.64% and 66.67% in patients with psoriasis and other vasculitis respectively. We observed complete resolution of skin lesions in 14 patients. Partial resolution was attained in one patient and the other seven patients are currently on the medication and are showing good responses. Conclusion  We verified that IGRA has an excellent diagnostic performance in EIB, through this observational study. It is strongly suggested that if EIB is clinicopathologically suspected, IGRA should be performed.
    Journal of the European Academy of Dermatology and Venereology 12/2012; 28(1). DOI:10.1111/jdv.12052 · 2.83 Impact Factor
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    ABSTRACT: Background This study explored the impact of genetic polymorphisms in cytochrome P450 (CYP) enzymes and transporters on the plasma trough concentration of imatinib mesylate (IM) and clinical response in chronic myeloid leukemia (CML).Patients and methodsIn total, 82 patients with CML who had been administered 400 mg IM daily for over 6 months were genotyped for 11 single-nucleotide polymorphisms in nine genes (CYP3A4, CYP3A5, CYP2C9, CYP2C19, CYP2D6, ABCB1, SLC22A1, SLC22A2 and ABCG2) using blood samples. The trough imatinib concentration and clinical responses were assessed 6 months after the initiation of IM therapy.ResultsThe CC, CA and AA genotypes in ABCG2 421C>A gave significantly different frequencies for the major molecular response (MMR) (P = 0.02). However, no significant differences were found between the genotypes of the CYP enzymes and transporters identified in this study and the imatinib plasma trough concentrations and clinical response frequencies, except for the correlation of ABCG2 with MMR.Conclusions The results of the present study may indicate that the ABCG 421C>A genetic polymorphism influences the MMR of imatinib in patients with CML.
    Annals of Oncology 10/2012; 24(3). DOI:10.1093/annonc/mds532 · 7.04 Impact Factor
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    K J Jeong · S.Y. Park · K H Cho · J S Sohn · J Lee · Y.K. Kim · J Kang · C G Park · J W Han · H.Y. Lee ·
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    ABSTRACT: Lysophosphatidic acid (LPA) is a biolipid that has diverse biological activities implicated in ovarian cancer initiation and progression. Previous studies have shown the critical role of the Rho/Rho-associated kinase (ROCK) pathway in LPA-induced ovarian cancer progression. However, detailed underlying mechanism by which the Rho/ROCK pathway induces ovarian cancer cell invasion is still incompletely understood. In the present study, we observed that the Rho/ROCK pathway is implicated in the production of proteolytic enzymes, leading to LPA-induced ovarian cancer cell invasion. LPA induced matrix metalloproteinase (MMP)-9 expression in CAOV-3 and PA-1 cells and urokinase-type plasminogen activator (uPA) expression in SKOV-3 cells. LPA-induced proteolytic enzyme expression was required for the invasion of ovarian cancer cells expressing corresponding enzymes. Pretreatment of cells with a pharmacological inhibitor of Rho/ROCK (Y-27632) or overexpression of a dominant-negative mutant of Rho (Rho N19) profoundly inhibited LPA-induced proteolytic enzyme expression as well as the invasive potential of ovarian cancer cells. In addition, transfection with dominant-negative Ras (Ras N17) significantly inhibited LPA-induced Rho activation as well as MMP-9 and uPA expression. Consistently, Y-27632 reduced LPA-induced nuclear factor (NF)-κB activation that is critical for proteolytic enzyme expression and cellular invasion. Collectively, we demonstrate a mechanism by which LPA promotes ovarian cancer progression through coordinate activation of a Ras/Rho/ROCK/NF-κB signaling pathway and the proteolytic enzyme secretion, providing novel biomarkers and promising therapeutic targets for ovarian cancer cell progression.
    Oncogene 01/2012; 31(39):4279-89. DOI:10.1038/onc.2011.595 · 8.46 Impact Factor
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    S.Y. Park · K J Jeong · N Panupinthu · S Yu · J W Han · J M Kim · J-S Lee · J Kang · C G Park · G B Mills · HY Lee ·
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    ABSTRACT: Lysophosphatidic acid (LPA), produced extracellularly by autotaxin (ATX), has diverse biological activities implicated in tumor initiation and progression, including increasing cell survival, angiogenesis, invasion and metastasis. ATX, LPA and the matrix metalloproteinase (MMP)-9 have all been implicated in hepatocellular carcinoma (HCC) invasion and metastasis. We, thus sought to determine whether ATX with subsequent LPA production and action, including induction of MMP-9 could provide a unifying mechanism. ATX transcripts and LPA receptor type 1 (LPA1) protein are elevated in HCC compared with normal tissues. Silencing or pharmacological inhibition of LPA1 significantly attenuated LPA-induced MMP-9 expression and HCC cell invasion. Further, reducing MMP-9 activity or expression significantly inhibits LPA-induced HCC cell invasion, demonstrating that MMP-9 is downstream of LPA1. Inhibition of phosphoinositide-3 kinase (PI3K) signaling or dominant-negative mutants of protein kinase Cδ and p38 mitogen-activated protein kinase (MAPK) abrogated LPA-induced MMP-9 expression and subsequent invasion. We thus demonstrate a mechanistic cascade of ATX-producing LPA with LPA activating LPA1 and inducing MMP-9 through coordinate activation of the PI3K and the p38 MPAK signaling cascades, providing novel biomarkers and potential therapeutic targets for HCC.
    Oncogene 11/2010; 30(11):1351-9. DOI:10.1038/onc.2010.517 · 8.46 Impact Factor
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    N.S. Lim · S. Das · S. Y. Park · M.C. Kim · C.G. Park ·
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    ABSTRACT: In the present investigation, the microstructure of nano tungsten carbide/cobalt (WC/Co) coating layers fabricated by detonation-gun spraying has been studied. Phase identification and three-dimensional distribution of constituent elements have been accomplished by using an ultra high-resolution transmission electron microscope (TEM) and a three-dimensional atom probe tomography (3D-APT), respectively. The microstructures of WC/Co coating layer containing superfine carbides were observed in various forms, i.e., unmelted, partially melted and fully melted regions. TEM and APT results revealed that the WC phase has been decomposed into crystalline W2C, W and complex amorphous phases during high temperature detonation spraying and rapid quenching process.
    Surface and Coatings Technology 10/2010; 205(2):430-435. DOI:10.1016/j.surfcoat.2010.07.004 · 2.00 Impact Factor
  • K.M. Lim · S.Y. Park · J. Namkung · M.C. Kim · C.G. Park ·
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    ABSTRACT: The effects of Si addition on microstructure and magnetic properties of permalloy strips fabricated by the melt drag casting method were investigated. Permalloy strips with 200 mm width were successfully fabricated by melt drag casting followed by homogenizing, cold rolling and annealing. In order to understand the relationship between microstructure and magnetic properties, we measured permeability and analyzed microstructure as a function of Si content by optical microscopy, X-ray diffraction and transmission electron microscopy. The effective permeability went through a maximum value in 2 at.% Si added permalloy strips and then decreased with increasing Si content. Increasing Si content enlarged grain size, which resulted in improvement of permeability. Permalloy strips with 5 at.% Si, however, showed drastically reduced permeability than that of 2 at.% Si added ones notwithstanding their coarse grain size and little oxide inclusion. The degradation of permeability in over-added Si above 2 at.% could be explained by formation of Ni3Fe ordered phase, which increase magneto-crystalline anisotropy.
    Materials Science and Engineering A 03/2007; 449-451:444-447. DOI:10.1016/j.msea.2006.02.449 · 2.57 Impact Factor
  • S.Y. Park · M.C. Kim · C.G. Park ·
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    ABSTRACT: Effects of post heat treatment of thermally sprayed nano WC–Co coatings on their mechanical properties were studied. The thermal behavior of WC particles in the coatings was also investigated. WC–Co coatings containing nano carbide particles in the 100–200 nm range were fabricated by detonation gun spraying. Considerable phase decomposition of WC to W2C and amorphous phase was detected, which degrades the mechanical properties of coatings. In order to improve the mechanical properties of the coatings by recovery of dissociated carbide phases, post heat treatment was conducted in an Ar environment in the temperature range of 400–900 °C. Microhardness and fracture toughness were measured by Vickers indentation testing and wear resistance was also evaluated by using a scratch tester. Phase evolution and microstructural changes due to post heat treatment were investigated by optical microscopy, X-ray diffractometry and field-emission scanning electron microscopy. After heat treatment in all temperature ranges, microhardness increased. Fracture toughness and wear resistance of coatings were increased by increasing temperature to 800 °C but decreased after heat treatment at 900 °C. Amorphous phase disappeared and other carbide phases such as W3Co3C and W6Co6C formed during heat treatment above 700 °C. The improved properties were elucidated and discussed in terms of microstructural changes and the relationship between mechanical properties and carbide phase was also discussed.
    Materials Science and Engineering A 03/2007; 448:894-897. DOI:10.1016/j.msea.2006.02.444 · 2.57 Impact Factor
  • S.Y. Park · K.M. Lim · J. Namkung · M.C. Kim · C.G. Park ·
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    ABSTRACT: Permalloy strips with 200 mm width were successfully fabricated by melt drag casting, and their microstructure and consequent magnetic properties were analyzed as a function of Si content. The effective permeability went through a maximum value for 2% Si-containing permalloy strips and then decreased with increasing Si content. Increasing Si content enlarged grain size, which improved permeability. However, addition of Si above 2% caused the formation of Ni3Fe ordered phase, which drastically reduced permeability in 5% Si-added permalloy strips.
    Scripta Materialia 02/2006; 54(4):621-625. DOI:10.1016/j.scriptamat.2005.10.033 · 3.22 Impact Factor
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    ABSTRACT: Fabrication of two different types of functionally graded tungsten carbide cobalt (WC-Co) coatings has been tried by using detonation gun to enhance both the hardness in the surface region and the toughness of the coating. Five layers with a continuous compositional change of 75 to 92 wt.% of WC were sprayed to obtain 'layer-structured gradient' coatings. Each layer was controlled to have both minimum porosity and minimum phase decomposition of WC. New types of 'continuously graded' coatings were also fabricated to eliminate any obvious interfaces between layers by the 'shot control method' of detonation gun spraying. The wear resistance of these coatings was measured and compared to that of conventional WC-Co coatings by using dry sand abrasion tests under the condition of 20kg load and 200rpm rotating wheel. Present functionally graded coatings revealed more improved wear resistance than that of conventional coatings.
    Materials Science Forum 01/2005; 475-479:1507-1510. DOI:10.4028/www.scientific.net/MSF.475-479.1507

Publication Stats

132 Citations
38.62 Total Impact Points


  • 2013
    • Konyang University Hospital
      Gaigeturi, Jeju, South Korea
  • 2012
    • Seoul National University
      Sŏul, Seoul, South Korea
    • Seoul National University Hospital
      Sŏul, Seoul, South Korea
  • 2010-2012
    • Konyang University
      • College of Medicine
      Ronsan, South Chungcheong, South Korea
    • University of Texas at Dallas
      Richardson, Texas, United States
  • 2005-2007
    • Pohang University of Science and Technology
      • Department of Materials Science and Engineering
      Geijitsu, Gyeongsangbuk-do, South Korea