Yong Jik Lee

Osaka University, Suika, Ōsaka, Japan

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Publications (28)146.75 Total impact

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    ABSTRACT: Ingestion of a foreign body is a common cause of esophageal injury, but hemoptysis is a rare manifestation of the esophageal penetration by a swallowed foreign body. The swallowing of a fishbone is hard to diagnose and the definite diagnosis is usually made during surgery. We describe the case of a 50-year-old man with direct injury to the lung parenchyma, the azygos vein, and the subclavian artery pseudoaneurysm due to a fishbone penetration from the upper esophagus into the lung. To our knowledge, this is the first case report that we know of in which a swallowed foreign body that penetrated from the upper esophagus into the lung caused vascular injuries and lung damage and it was solved by minimally invasive surgery and an endovascular stent. We successfully diagnosed and treated a case with the migration of the fishbone from the upper esophagus into the lung. A contrast-enhanced computed tomography (CT) scan is recommended to clarify the fact of vascular injury before surgery. Thoracoscopic operation (VATS) combined with endovascular treatment could be a safer and a more feasible treatment option in this rare condition.
    Preview · Article · Oct 2015 · Medicine
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    ABSTRACT: The γ-butyrolactone autoregulator signaling cascade is widely distributed among Streptomyces species as an important regulatory system of secondary metabolism. In Streptomyces lavendulae FRI-5, a γ-butyrolactone autoregulator IM-2 and the IM-2 specific receptor FarA control production of the blue pigment indigoidine together with two types of antibiotics: d-cycloserine and the nucleoside antibiotics. Here, we demonstrated by in silico analysis that farR2 (a farA homologue), which is located in a cluster of regulatory genes including farA, belongs to the family of pseudoreceptor regulator genes, and that the expression of farR2 is controlled by the IM-2/FarA regulatory system. Disruption of farR2 resulted in delayed production of indigoidine and in transcriptional derepression of the clustered far regulatory genes. Moreover, FarR2 bound to the FarA-binding sequences in the promoter regions of the regulatory genes that were downregulated by FarR2.
    No preview · Article · Sep 2015 · Journal of Bioscience and Bioengineering
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    ABSTRACT: A 37-year-old woman was referred to our institution for further management of a mass lesion located in the thoracic cavity. The mass had grown by more than 10 cm over the course of a year and was initially considered to be a scar from previous pulmonary tuberculosis at another hospital. The patient had complained of left-sided flank pain for a year and experienced dyspnea for one month. Chest radiography and chest computed tomography revealed an irregular-shaped mass in the left mid to lower pleural cavity. The mass was widely excised through left thoracotomy. Pathologic examination of the biopsy specimen revealed a malignant spindle cell tumor, which consisted of components of osteosarcoma, pleomorphic sarcoma, and leiomyosarcoma. The patient underwent adjuvant chemotherapy and has been doing well without any evidence of recurrence for 14 months.
    Preview · Article · Jun 2014 · Korean Journal of Thoracic and Cardiovascular Surgery
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    ABSTRACT: L-Arabinose isomerase (AI), which catalyzes the isomerization of L-arabinose to L-ribulose, can also convert D-galactose to D-tagatose, a natural sugar replacer, which is of commercial interest in the food and healthcare industries. Intriguingly, mesophilic and thermophilic AIs showed different substrate preferences and metal requirements in catalysis and different thermostabilities. However, the catalytic mechanism of thermophilic AIs still remains unclear. Therefore, thermophilic Geobacillus kaustophilus AI (GKAI) was overexpressed, purified and crystallized, and a preliminary X-ray diffraction data set was obtained. Diffraction data were collected from a GKAI crystal to 2.70 Å resolution. The crystal belonged to the monoclinic space group C2, with unit-cell parameters a = 224.12, b = 152.95, c = 91.28 Å, β = 103.61°. The asymmetric unit contained six molecules, with a calculated Matthews coefficient of 2.25 Å(3) Da(-1) and a solvent content of 45.39%. The three-dimensional structure determination of GKAI is currently in progress by molecular replacement and model building.
    Full-text · Article · Jan 2014 · Acta Crystallographica Section F: Structural Biology Communications
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    ABSTRACT: The majority of mitochondrial proteins are encoded in the nuclear genome and imported into mitochondria posttranslationally from the cytosol. An N-terminal presequence functions as the signal for the import of mitochondrial proteins. However, the functional information in the presequence remains elusive. This study reports the identification of critical sequence motifs from the presequence of Arabidopsis thaliana F1-ATPase γ-subunit (pFAγ). pFAγ was divided into six 10-amino acid segments, designated P1 to P6 from the N to the C terminus, each of which was further divided into two 5-amino acid subdivisions. These P segments and their subdivisions were substituted with Ala residues and fused to green fluorescent protein (GFP). Protoplast targeting experiments using these GFP constructs revealed that pFAγ contains several functional sequence motifs that are dispersed throughout the presequence. The sequence motifs DQEEG (P4a) and VVRNR (P5b) were involved in translocation across the mitochondrial membranes. The sequence motifs IAARP (P2b) and IAAIR (P3a) participated in binding to mitochondria. The sequence motifs RLLPS (P2a) and SISTQ (P5a) assisted in pulling proteins into the matrix, and the sequence motif IAARP (P2b) functioned in Tom20-dependent import. In addition, these sequence motifs exhibit complex relationships, including synergistic functions. Thus, multiple sequence motifs dispersed throughout the presequence are proposed to function cooperatively during protein import into mitochondria.
    Preview · Article · Dec 2012 · The Plant Cell
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    ABSTRACT: The standard regimen in elderly patients with non-small-cell lung cancer (NSCLC) is still uncertain. Gemcitabine is one of the most widely used drugs for the treatment of NSCLC, and several phase II trials specifically designed for elderly patients with advanced NSCLC have confirmed the role of gemcitabine in this setting. In addition, oral uracil-tegafur (UFT) was associated with a survival advantage in the adjuvant setting. Therefore, we performed a phase II study using the combination of gemcitabine and UFT as first-line therapy in elderly patients with advanced NSCLC.
    Full-text · Article · Dec 2011 · Lung cancer (Amsterdam, Netherlands)
  • Tae Woo Jung · Myung Won Lee · Yong Jik Lee · Seon Mee Kim
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    ABSTRACT: Type 2 diabetes mellitus is thought to be partially associated with endoplasmic reticulum (ER) stress toxicity on pancreatic beta cells and the result of decreased insulin synthesis and secretion. In this study, we showed that a well-known insulin sensitizer, metformin, directly protects against dysfunction and death of ER stress-induced NIT-1 cells (a mouse pancreatic beta cell line) via AMP-activated protein kinase (AMPK) and phosphatidylinositol-3 (PI3) kinase activation. We also showed that exposure of NIT-1 cells to metformin (5mM) increases cellular resistance against ER stress-induced NIT-1 cell dysfunction and death. AMPK and PI3 kinase inhibitors abolished the effect of metformin on cell function and death. Metformin-mediated protective effects on ER stress-induced apoptosis were not a result of an unfolded protein response or the induced inhibitors of apoptotic proteins. In addition, we showed that exposure of ER stressed-induced NIT-1 cells to metformin decreases the phosphorylation of c-Jun NH(2) terminal kinase (JNK). These data suggest that metformin is an important determinant of ER stress-induced apoptosis in NIT-1 cells and may have implications for ER stress-mediated pancreatic beta cell destruction via regulation of the AMPK-PI3 kinase-JNK pathway.
    No preview · Article · Nov 2011 · Biochemical and Biophysical Research Communications
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    ABSTRACT: Hemangiomas that arise in cervical esophagus are extremely rare, representing 3.3% of all benign esophageal tumors. Although endoscopic mucosal resection (EMR) and potassium titanyl phosphate/yttrium aluminum garnet (KTP/YAG) laser therapy have been used with success for small tumors, the safety and efficacy in the case of large tumors remains uncertain. We report the successful resection of cervical esophageal hemangioma through a cervical esophagotomy in a patient with thyroid cancer who needed a cervical collar incision.
    Full-text · Article · Aug 2011 · Korean Journal of Thoracic and Cardiovascular Surgery
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    ABSTRACT: Acupuncture-related hemopericardium is a rare but potentially fatal complication. We describe a hemopericardium that occurred shortly after acupuncture in a 55-year-old woman. A chest CT scan and echocardiography revealed a hemopericardium, and pericardiocentesis was then immediately and successfully performed. Subsequently, her clinical course improved. This case increases the attention of emergency physicians for acupuncture-related complications, especially hemopericardium, and the necessity of rapid diagnosis and management.
    Full-text · Article · Jan 2011 · Yonsei medical journal
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    Preview · Article · Aug 2010 · Korean Journal of Thoracic and Cardiovascular Surgery
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    Yong Jik Lee · Shigeru Kitani · Takuya Nihira
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    ABSTRACT: Virginiae butanolide (VB) is a gamma-butyrolactone autoregulator that triggers production of the streptogramin antibiotic virginiamycin in Streptomyces virginiae. Our previous studies suggested that the barX gene, an afsA-family gene, is likely to participate in the regulatory pathway for the production of VB, rather than in the biosynthetic pathway of VB itself, in contrast to the function of other afsA-family genes. Mutation analysis now shows that BarX at least plays an enzymic role in the VB biosynthetic pathway. Heterologous expression of the afsA gene from Streptomyces griseus into the barX mutant partially restored the deficiency of virginiamycin production, suggesting that afsA-family genes have a common ability to synthesize the gamma-butyrolactone autoregulators. Taken together with previous works relating to the function of an afsA-family gene, these results support the idea that streptomycetes have two biosynthetic pathways for the gamma-butyrolactone autoregulators.
    Preview · Article · Sep 2009 · Microbiology
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    ABSTRACT: Adiponectin receptors mediate the antidiabetic effects of adiponectin. Although suggested to be mainly expressed in muscle, liver, and adipocyte cells, the expression of adiponectin receptors in beta cells is unclear. Given the primary involvement of this cell type in diabetes mellitus, we presently examined the expression level of adiponectin receptor 2 (AdiR2) in beta cells. Expression was significantly increased under acute hyperlipidemic conditions but impaired under chronic conditions. The impaired AdiR2 expression may play a role in worsened beta cell function. Clofibrate, an agonist of peroxisome proliferator-activated receptor-alpha (PPAR-alpha) delayed the palmitate-induced impairment of AdiR2 expression and PPAR-alpha; this delay was abolished by PPAR-alpha targeted small interfering RNA. The results suggest that AdiR2 expression is regulated by palmitate via PPAR-alpha.
    No preview · Article · May 2009 · Endocrine Journal
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    ABSTRACT: Adiponectin receptors mediate the antidiabetic effects of adiponectin. Although suggested to be mainly expressed in muscle, liver, and adipocyte cells, the expression of adiponectin receptors in β cells is unclear. Given the primary involvement of this cell type in diabetes mellitus, we presently examined the expression level of adiponectin receptor 2 (AdiR2) in β cells. Expression was significantly increased under acute hyperlipidemic conditions but impaired under chronic conditions. The impaired AdiR2 expression may play a role in worsened β cell function. Clofibrate, an agonist of peroxisome proliferator-activated receptor-alpha (PPAR-α) delayed the palmitate-induced impairment of AdiR2 expression and PPAR-α; this delay was abolished by PPAR-α targeted small interfering RNA. The results suggest that AdiR2 expression is regulated by palmitate via PPAR-α.
    No preview · Article · Jan 2009 · Endocrine Journal
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    ABSTRACT: The human leukocyte antigen (HLA) system is an integral component of immune response. Highly polymorphic HLA genes may play a pivotal role in the response of antiviral therapy. We investigated the effects of HLA gene polymorphism on the clinical outcome of chronic hepatitis B patients who received lamivudine treatment. Depending on their clinical response to lamivudine therapy, a total of sixty one patients were divided into following groups; non-responders, viral breakthroughers, relapsers, and seroconverters. HLA-A, -B, -Cw, -DRB and HLA-DRB1 alleles typing was performed on each group through the polymerase chain reaction and the sequence-specific oligonucleotide hybridization method. The distribution patterns of HLA-A, HLA-B, HLA-Cw, HLA-DRB, and HLA-DRB1 were then analysed. When non-responders were compared to the other groups, high frequencies in HLA-Cw1, HLA-DRB14 and HLA-DRB4 (p=0.015, 0.033 and 0.004 respectively) were evident. When seroconverters were compared to viral breakthroughers, high frequencies in HLA-A2 and HLA-DRB4 (p=0.048, 0.025 respectively) were evident. Our data suggests that HLA-A2, HLA-Cw1, HLA-DRB14 genes are related to the clinical outcomes of lamivudine treatment in chronic hepatitis B patients. These genes may be used in the prediction of the clinical outcome of lamivudine therapy in chronic hepatitis B patients.
    No preview · Article · Jan 2009 · The Korean journal of gastroenterology = Taehan Sohwagi Hakhoe chi

  • No preview · Article · Nov 2008 · Archives of Physical Medicine and Rehabilitation
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    ABSTRACT: Virginiae butanolide (VB) is a member of the γ-butyrolactone autoregulators and triggers the production of streptogramin antibiotics virginiamycin M1 and S in Streptomyces virginiae. A VB biosynthetic gene (barS2) was localized in a 10-kb regulatory island which controls the virginiamycin biosynthesis/resistance of S. virginiae, and analyzed by gene disruption/complementation. The barS2 gene is flanked by barS1, another VB biosynthetic gene catalyzing stereospecific reduction of an A-factor-type precursor into a VB-type compound, and barX encoding a pleiotropic regulator for virginiamycin biosynthesis. The deduced product of barS2 possessed moderate similarity to a putative dehydrogenase of Streptomyces venezuelae, encoded by jadW 2 located in similar gene arrangement to that in the regulatory island of S. virginiae. A barS2-disruptant (strain IC152), created by means of homologous recombination, showed no differences in growth in liquid medium or morphology on solid medium compared to a wild-type strain, suggesting that BarS2 does not play any role in primary metabolism or morphological differentiation of S. virginiae. In contrast, no initiation of virginiamycin production or VB production was detected with the strain IC152 until 18 h of cultivation, at which time full production of virginiamycin occurs in the wild-type strain. The delayed virginiamycin production of the strain IC152 was fully restored to the level of the wild-type strain either by the exogenous addition of VB or by complementation of the intact barS2 gene, indicating that the lack of VB production at the initiation phase of virginiamycin production is the sole reason for the defect of virginiamycin production, and the barS2 gene is of primary importance for VB biosynthesis in S. virginiae.
    No preview · Article · May 2008 · Archives of Microbiology
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    ABSTRACT: In plant cells, chloroplasts have essential roles in many biochemical reactions and physiological responses. Chloroplasts require numerous protein components, but only a fraction of these proteins are encoded by the chloroplast genome. Instead, most are encoded by the nuclear genome and imported into chloroplasts from the cytoplasm post-translationally. Membrane proteins located in the chloroplast outer envelope membrane (OEM) have a critical function in the import of proteins into the chloroplast. However, the biogenesis of chloroplast OEM proteins remains poorly understood. Here, we report that an Arabidopsis ankyrin repeat protein, AKR2A, plays an essential role in the biogenesis of the chloroplast OEM proteins. AKR2A binds to chloroplast OEM protein targeting signals, as well as to chloroplasts. It also displays chaperone activity towards chloroplast OEM proteins, and facilitates the targeting of OEP7 to chloroplasts in vitro. AKR2A RNAi in plants with an akr2b knockout background showed greatly reduced levels of chloroplast proteins, including OEM proteins, and chloroplast biogenesis was also defective. Thus, AKR2A functions as a cytosolic mediator for sorting and targeting of nascent chloroplast OEM proteins to the chloroplast.
    Preview · Article · Mar 2008 · Nature Cell Biology
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    ABSTRACT: To investigate the effects of pioglitazone and metformin treatment during pre-diabetic period for the prevention of diabetes in a rat model. OLETF rats aged 18-weeks, were treated with pioglitazone (10 mg/kg/day) and metformin (300 mg/kg/day) for 10 weeks from their pre-diabetic period. We measured weight, lipid profiles, fat distribution, glucose tolerance, and pancreatic insulin content. Prominent weight gain (mostly subcutaneous fat area) was observed in the pioglitazone-treated OLETF (O-P) rats versus significant weight loss was observed in the metformin-treated OLETF (O-M) rats. Pioglitazone reversed the serum triglyceride (TG) and FFAs levels to normal (TG 0.46 +/- 0.04 vs 0.88 +/- 0.05 mmol/l in LETO). At the age of 28 weeks, the O-P rats showed completely normal glucose tolerance, and the glucose disposal rate (GDR) was markedly improved (25.6 +/- 0.4 vs 20.6 +/- 0.5 mg/min/kg in O-C, p < 0.05). The O-M rats also showed an improved fasting glucose and GDR level, but not as much as those with O-P rats. The pancreas insulin contents were much improved in the O-P rats (22.9 +/- 1.2 vs 18.8 +/- 1.3 nmol/pancreas in O-M rats, p < 0.05) with histological improvement. The pre-diabetic treatment with pioglitazone, despite significant weight gain, completely prevents to develop diabetes and enhances beta cell function with preservation of islet cell changes. Metformin treatment was also effective, but mainly by ameliorating the insulin resistance with marked reduction in body weight. The reversal of dyslipidaemia and the fat redistribution might contribute to the greater improvement of pioglitazone treatment compared to metformin in OLETF rats.
    Full-text · Article · Jul 2007 · Diabetes/Metabolism Research and Reviews
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    ABSTRACT: An Arabidopsis thaliana mutant defective in chloroplast protein import was isolated and the mutant locus, cia5, identified by map-based cloning. CIA5 is a 21-kD integral membrane protein in the chloroplast inner envelope membrane with four predicted transmembrane domains, similar to another potential chloroplast inner membrane protein-conducting channel, At Tic20, and the mitochondrial inner membrane counterparts Tim17, Tim22, and Tim23. cia5 null mutants were albino and accumulated unprocessed precursor proteins. cia5 mutant chloroplasts were normal in targeting and binding of precursors to the chloroplast surface but were defective in protein translocation across the inner envelope membrane. Expression levels of CIA5 were comparable to those of major translocon components, such as At Tic110 and At Toc75, except during germination, at which stage At Tic20 was expressed at its highest level. A double mutant of cia5 At tic20-I had the same phenotype as the At tic20-I single mutant, suggesting that CIA5 and At Tic20 function similarly in chloroplast biogenesis, with At Tic20 functioning earlier in development. We renamed CIA5 as Arabidopsis Tic21 (At Tic21) and propose that it functions as part of the inner membrane protein-conducting channel and may be more important for later stages of leaf development.
    Preview · Article · Oct 2006 · The Plant Cell
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    ABSTRACT: Studies for the regulation of fatty acid metabolism are deficient relatively in skeletal muscle and heart. The investigations in pathological conditions for malonyl-CoA decarboxylase (MCD) and for the relation of MCD and PPAR-α·-γ agonists are insufficient in particular.
    Preview · Article · Jan 2006

Publication Stats

901 Citations
146.75 Total Impact Points

Institutions

  • 2008-2015
    • Osaka University
      • International Center for Biotechnology
      Suika, Ōsaka, Japan
  • 2014
    • Kyungpook National University
      Daikyū, Daegu, South Korea
  • 2011-2014
    • Ulsan University Hospital
      Urusan, Ulsan, South Korea
    • University of Ulsan
      Ulsan, Ulsan, South Korea
  • 2003-2012
    • Pohang University of Science and Technology
      • Division of Molecular and Life Sciences
      Geijitsu, Gyeongsangbuk-do, South Korea
    • Yonsei University Hospital
      • Department of Internal Medicine
      Sŏul, Seoul, South Korea
  • 2008-2011
    • Seoul Medical Center
      Sŏul, Seoul, South Korea
  • 2007
    • Yonsei University
      • Department of Internal Medicine
      Sŏul, Seoul, South Korea
  • 2004
    • Keimyung University
      • Department of Microbiology
      Sŏul, Seoul, South Korea