Joon Hyuk Choi

Gangneung-Wonju National University, Gangneung, Gangwon-do, South Korea

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Publications (76)133.49 Total impact

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    Hyeong Chan Shin · Mi Jin Gu · Se Won Kim · Jae Woon Kim · Joon Hyuk Choi ·
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    ABSTRACT: Collision tumors of the stomach are rare. We report on a case of a collision tumor consisting of a gastrointestinal stromal tumor (GIST) and an inflammatory myofibroblastic tumor (IMT) of the stomach in a 16-year-old female. A polypoid mass located in the distal body of the stomach was observed on abdominal computed tomography. Laparoscopic wedge resection of the stomach and 4d lymph node biopsy was performed. On gross examination, a protruding submucosal mass, measuring 4 × 3.5 × 2.5 cm in size, was detected. Histological examination showed two distinct GIST and IMT component presenting a collision tumor. The small nodular area, composed of CD117-positive spindle cells, was typical of GIST, and the adjacent larger area, composed of myofibroblastic spindle cells with prominent chronic inflammatory cells infiltrate, mainly lymphocytes and plasma cells, had a characteristic appearance of IMT. The 4d lymph node showed metastatic inflammatory myofibroblastic tumor. To the best of our knowledge, this is the first case of a collision tumor consisting of a GIST and an IMT arising in the stomach.
    Diagnostic Pathology 10/2015; 10(1). DOI:10.1186/s13000-015-0413-y · 2.60 Impact Factor
  • Seok Ju Park · Mi Jin Gu · Dong Shik Lee · Sung Soo Yun · Hong Jin Kim · Joon Hyuk Choi ·
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    ABSTRACT: Pancreatic ductal adenocarcinoma (PDA) is an aggressive malignant tumor with poor prognosis. Epidermal growth factor receptor (EGFR) is an important cell adhesion and signaling pathway mediator. The aim of this study was to evaluate the expression of EGFR in both pancreatic intraepithelial neoplasia (PanIN) and PDA and their relationship to clinicopathologic characteristics. Formalin-fixed, paraffin-embedded tissues including 81 cases with pancreatic ductal adenocarcinoma, 27 with normal pancreas, 16 with PanIN-1A, 18 with PanIN-1B, 11 with PanIN-2, and 24 with PanIN-3 were used for construction of tissue microarrays. Imunohistochemistry for EGFR was performed. Normal pancreatic ducts, PanIN-1A, and PanIN-1B did not show EGFR overexpression. EGFR overexpression was observed in 18.2% (2/9) of PanIN-2, 41.7% (10/14) of PanIN-3, and 64.2% (52/81) of PDA, respectively. Significantly higher EGFR overexpression was observed in PDAs than in PanIN lesions (P<0.05). No statistically significant correlation was observed between EGFR overexpression and patient age, sex, tumor location, size, histological grade, vascular invasion, lymph node metastasis and stage at presentation, respectively. In conclusion, EGFR expression increased from PanIN to PDA. EGFR may be involved in early stage in development of PDA.
    International journal of clinical and experimental pathology 09/2015; 8(7):8298-304. · 1.89 Impact Factor
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    Joon Hyuk Choi · Kyung-Tae Kim · Sang Moo Kim ·
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    ABSTRACT: Squid is one of the most important commercial fishes in the world and is mainly utilized or consumed as sliced raw fish or as processed products. The biofunctional activities of enzymatic squid meat hydrolysate were determined to develop value-added products. Enzymatic squid hydrolysate manufactured by Alcalase effectively quenched 1,1-diphenyl-2-picrylhydrazyl radical, hydroxyl radical, and hydrogen peroxide radical with IC50 values of 311, 3,410, and 111.5 μg/mL, respectively. Angiotensin I-converting enzyme inhibitory activity of squid hydrolysate was strong with an IC50 value of 145.1 μg/mL, while tyrosinase inhibitory activity with an IC50 value of 4.72 mg/mL was moderately low. Overall, squid meat hydrolysate can be used in food or cosmetic industries as a bioactive ingredient and possibly be used in the manufacture of seasoning, bread, noodle, or cosmetics.
    Preventive Nutrition and Food Science 03/2015; 20(1):67-72. DOI:10.3746/pnf.2015.20.1.67

  • 01/2015; 32(1):26. DOI:10.12701/yujm.2015.32.1.26
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    Mi Jin Gu · Joon Hyuk Choi ·
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    ABSTRACT: Microcystic/reticular schwannoma is a recently described, rare, distinctive histological variant of schwannoma with a predilection for the gastrointestinal tract (GIT). The authors experienced the first case of a microcystic/reticular schwannoma occurring in the esophagus. A 39-year-old male presented for an obstructive sensation during swallowing of several months duration. Endoscopy revealed a bulging mass with intact mucosa at 30 cm from incisors in the esophagus. The mass was excised and gross examination showed it was a well circumscribed, unencapsulated nodule, measuring 3.5×3.2×1.2 cm. On microscopic examination, the tumor showed a vague multinodular appearance with a pushing border and tumor cells arranged in a microcystic and reticular growth pattern with anastomosing and intersecting strands of spindle cells in a myxoid or collagenous/hyalinized stroma. Tumor cells showed diffuse nuclear and cytoplasmic positivity for S100. The authors report the first case of microcystic/reticular schwannoma of the esophagus. Microcystic/reticular schwannoma is a distinctive histological variant of schwannoma with a benign clinical course. However, its histological findings are non-specific and may cause diagnostic difficulties. Awareness of this uncommon neoplasm with distinct histologic features is essential to prevent misdiagnosis.
    BMC Gastroenterology 12/2014; 14(1):193. DOI:10.1186/s12876-014-0193-y · 2.37 Impact Factor
  • Joon Hyuk Choi · Jae Hwang Kim · Jae Chun Chang ·
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    ABSTRACT: Dedifferentiated liposarcoma is a distinct subtype of liposarcoma showing by transition from an atypical lipomatous tumor/well differentiated liposarcoma to non-lipogenic sarcoma of variable histologic grade. Recent studies have shown that the dedifferentiated component can show lipoblastic differentiation. We describe a case of dedifferentiated liposarcoma with homologous lipoblastic differentiation arising from the abdominal cavity. The patient was a 67-year-old woman who presented with the left lower quadrant abdominal mass for one month. Abdominal CT scan showed a well defined mass with heterogeneous signal intensity in the abdominal cavity. Excision of the mass was performed. Grossly, the mass measured 20 x 12 x 6 cm. The cut surface was well circumscribed, yellow-brown, rubbery soft, with focal hemorrhage. Histologically, the tumor showed spindle and pleomorphic tumor cells in myxoid stroma with scattered lipoblasts. In addition, there were smaller foci of well differentiated liposarcoma showing atypical hyperchromatic stromal cells. The tumor cells in the dedifferentiated component were immunoreactive for MDM2 and CDK4. Fluorescence in situ hybridization showed high-level amplification of MDM2. Dedifferentiated liposarcomas with homologous lipoblastic differentiation should not be confused with pleomorphic liposarcomas and other types of pleomorphic sarcomas with fat component. We describe the histopathological features of liposarcomas.
    Pathology 10/2014; 46:S49. DOI:10.1097/01.PAT.0000454267.69246.83 · 2.19 Impact Factor
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    07/2014; 19(3):137-141. DOI:10.15279/kpba.2014.19.3.137
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    ABSTRACT: Individuals harboring germ-line DICER1 mutations are predisposed to a rare cancer syndrome, the DICER1 Syndrome or pleuropulmonary blastoma-familial tumor and dysplasia syndrome [online Mendelian inheritance in man (OMIM) #601200]. In addition, specific somatic mutations in the DICER1 RNase III catalytic domain have been identified in several DICER1-associated tumor types. Pituitary blastoma (PitB) was identified as a distinct entity in 2008, and is a very rare, potentially lethal early childhood tumor of the pituitary gland. Since the discovery by our team of an inherited mutation in DICER1 in a child with PitB in 2011, we have identified 12 additional PitB cases. We aimed to determine the contribution of germ-line and somatic DICER1 mutations to PitB. We hypothesized that PitB is a pathognomonic feature of a germ-line DICER1 mutation and that each PitB will harbor a second somatic mutation in DICER1. Lymphocyte or saliva DNA samples ascertained from ten infants with PitB were screened and nine were found to harbor a heterozygous germ-line DICER1 mutation. We identified additional DICER1 mutations in nine of ten tested PitB tumor samples, eight of which were confirmed to be somatic in origin. Seven of these mutations occurred within the RNase IIIb catalytic domain, a domain essential to the generation of 5p miRNAs from the 5′ arm of miRNA-precursors. Germ-line DICER1 mutations are a major contributor to PitB. Second somatic DICER1 “hits” occurring within the RNase IIIb domain also appear to be critical in PitB pathogenesis.
    Acta Neuropathologica 07/2014; 128(1):111-122. DOI:10.1007/s00401-014-1285-z · 10.76 Impact Factor
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    ABSTRACT: Background and study aim: Endoscopic ultrasonography-guided transmural gallbladder drainage (EUS-GBD) has been proposed for the management of acute cholecystitis in high risk patients; however, little is known about the long-term outcomes of this treatment. The aim of this study was to evaluate the procedural and long-term outcomes of EUS-GBD with self-expandable metallic stent (SEMS). Patients and methods: Data for this retrospective study were obtained from a prospectively collected EUS database. Patients with acute cholecystitis who were deemed unsuitable for cholecystectomy were included. Study outcomes were technical and clinical success, adverse events, and stent patency. Results: EUS-GBD was technically and clinically successful in 62/63 patients (98.4 %; 95 % confidence interval [CI] 94.9 % - 100 %). Procedural adverse events included duodenal perforation (n = 1, 1.6 %) and self-limiting pneumoperitoneum (n = 2, 3.2 %), all of which resolved with conservative treatment. Long-term outcomes of EUS-GBD were evaluated in 56 patients who were followed for a median of 275 days (range 40 - 1185 days). Late adverse events developed in four patients (7.1 %; 95 %CI 5.7 % - 8.4 %), including asymptomatic distal stent migration (n = 2), and acute cholecystitis due to stent occlusion (n = 2). Two patients with occluded stent were successfully treated endoscopically (reintervention rate of 3.6 %). A total of 54 patients (96.4 %) had no recurrence of acute cholecystitis during follow-up. Median stent patency time was 190 days overall (range 15 - 1185 days) and 458 days (range 151 - 1185 days) for the 28 patients who were alive at the study end. The cumulative stent patency rate was 86 % at 3 years. Conclusions: EUS-GBD with an SEMS for acute cholecystitis showed excellent long-term outcomes and may be a definitive treatment in patients who are unsuitable for cholecystectomy because of advanced malignancy or high surgical risk.
    Endoscopy 06/2014; 46(8). DOI:10.1055/s-0034-1365720 · 5.05 Impact Factor
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    ABSTRACT: To evaluate the success rates, procedural time and adverse event rates of the modified methods in endoscopic ultrasonography-guided hepaticogastrostomy (EUS-HGS). Twenty-eight patients in a prospective case series who underwent EUS-HGS (phase I). Forty-six patients in a matched case-control study (phase II). The simplified technique for fistula dilation was the primary use of a 4 mm balloon catheter with a stainless steel stylet. The stent deployment was modified by deploying the metal stent inside a bile duct (half of the stent) under EUS and fluoroscopic guidance and gently pulling the echoendoscope after full deployment of the stent inside the echoendoscope channel (remaining portion of the stent) under fluoroscopic guidance. This cohort was compared with a matched historical cohort. In phase I, the technical and clinical success with the modified method was 96% (27/28) and 89% (24/27 as per-protocol analysis). The overall adverse event rate was 7%. In phase II, there was no difference in technical and clinical success, stent patency and overall adverse events in each group. However, the procedural time (15.3 ± 5.2 min vs 22.3 ± 6.0 min, P < 0.001) and early adverse events (0% vs 26%, P = 0.02) were statistically improved in case cohort compared with control cohort. Compared with the conventional EUS-HGS technique, the procedural time was shorter and early adverse events were less frequent with our simplified and modified technique.
    World Journal of Gastroenterology 05/2014; 20(17):5051-9. DOI:10.3748/wjg.v20.i17.5051 · 2.37 Impact Factor

  • Gastrointestinal Endoscopy 05/2014; 79(5):AB215. DOI:10.1016/j.gie.2014.05.065 · 5.37 Impact Factor
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    ABSTRACT: Purpose Kikuchi-Fujimoto disease (KFD) is a benign disease, which is characterized by a cervical lymphadenopathy with fever, and it often mimics malignant lymphoma (ML). 2-[18F]fluoro-2-deoxy-D-glucose positron emission tomography/computed tomography (18F-FDG PET/CT) is a powerful imaging modality for the diagnosis, staging and monitoring of ML, with the limitations including the nonspecific FDG uptake in infectious or inflammatory processes. This study compared clinical manifestations and PET/CT findings between KFD and ML patients. Methods We retrospectively reviewed the medical records of 23 patients with KFD and 33 patients with ML, diagnosed histopathologically, between January 2000 and May 2013 at the Department of Pediatrics, Yeungnam University Medical Center. Among them, we analyzed the clinical manifestations, laboratory findings and characteristics, and the amount of 18F-FDG uptake between 8 KFD and 9 ML patients who had 18F-FDG PET/CT. Results The 18F-FDG PET/CT maximum standardized uptake values (SUVmax) ranged from 8.3 to 22.5 (mean, 12.0) in KFDs, and from 5.8 to 34.3 (mean, 15.9) in MLs. There were no significant differences in SUVmax between KFDs and MLs. 18F-FDG PET/CT with ML patients showed hot uptakes in the extranodal organs, such as bone marrow, small bowel, thymus, kidney, orbit and pleura. However, none of the KFD cases showed extranodal uptake (P<0.001). 18F-FDG PET/CT findings of KFD with nodal involvement only were indistinguishable from those of ML. Conclusion Patients who had extranodal involvement on PET/CT were more likely to have malignancy than KFD.
    Korean Journal of Pediatrics 05/2014; 57(5):226-31. DOI:10.3345/kjp.2014.57.5.226
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    Jae Beom Hong · Kil-Ho Cho · Joon Hyuk Choi ·
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    ABSTRACT: Periosteal osteosarcoma is an extremely rare chondroblastic osteosarcoma in the flat bone. There were authors reporting of two cases of periosteal osteosarcoma in the highly unusual sites. One of them arose from the rib, in a 17-year-old male, which appeared as a hypodense juxtacortical mass with periosteal reaction on CT. The other one arose from the scapula, in a 17-year-old female, which showed the intermediate signal intensity (SI) on T1-weighted image (WI), heterogeneous high SI on T2WI, and rim-enhancement on contrast-enhanced T1WI with cortical destruction on MRI.
    Korean journal of radiology: official journal of the Korean Radiological Society 05/2014; 15(3):370-5. DOI:10.3348/kjr.2014.15.3.370 · 1.57 Impact Factor
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    ABSTRACT: Background/aims: A retrospective analysis was performed to evaluate the safety and effectiveness of extracorporeal shock wave lithotripsy (ESWL) for pancreatolithiasis on successive days under intravenous bolus of pethidine alone. Methods: Ninety patients with calcified pancreatic stones (≥5 mm) presenting with abdominal pain were selected for ESWL. ESWL was performed with an electroconductive lithotripter under fluoroscopic target systems. Fragmented calculi after ESWL were removed by endotherapy. Results: A mean of 4.2 ESWL sessions were performed for each patient, with a mean of 2,984 shocks at a mean power setting of 12.8 kV. Eighty-four (89.3%) patients underwent ESWL for three or more days in a row. Fragmentation of the stones were achieved in 83/90 (92.2%) patients. Complete clearance of the main pancreatic duct was achieved in 54/90 (60.0%) patients, and partial clearance was achieved in 27 (30.0%) patients. The mean dose of pethidine used during ESWL was 53.5±20.7 mg per session. As ESWL-related complications, four (4.3%) patients developed mild acute pancreatitis. Conclusions: In case of endoscopically difficult-to-treat pancreatic duct stones, combined therapy with ESWL is an effective method, and treatment with multiple sessions of ESWL on successive days under intravenous bolus of pethidine alone is safe and well tolerated.
    The Korean journal of gastroenterology = Taehan Sohwagi Hakhoe chi 04/2014; 63(4):231-8. DOI:10.4166/kjg.2014.63.4.231
  • Joon Hyuk Choi · Kyung Tae Kim · Sang Moo Kim ·
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    ABSTRACT: Enzymatic hydrolysis of squid meat was optimized and the biochemical properties of solubility, amino acid composition, and contents of nucleic acid related compounds were determined. Optimal hydrolysis conditions were a pH of 7.0, a hydrolysis time of 5.9 h, a temperature of 55°C, and an enzyme/substrate ratio of 2.4%. More than 75% of squid meat hydrolysate was soluble in a wide pH range. The sweet and savory tasting amino acid contents of the squid hydrolysate were higher than the contents of bitter tasting amino acids. The hydrophilic amino acid content of squid meat was lower than the content of hydrophobic amino acids. The inosine monophosphate content of squid hydrolysate was highest among nucleic acid related compounds. Based on a sensory evaluation, squid complex seasoning was similar or superior to commercial complex seasonings. A squid hydrolysate can be used as an ingredient for manufacture of food products.
    Food science and biotechnology 04/2014; 23(2):417-423. DOI:10.1007/s10068-014-0057-9 · 0.65 Impact Factor
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    ABSTRACT: BackgroundsCombined hepatocellular-cholangiocarcinoma (cHC-CC), a malignant liver tumor with poor prognosis, is composed of hepatocellular carcinoma (HCC), cholangiocarcinoma (CC) and diverse components with intermediate features between HCC and CC, which correspond to hepatic progenitor cells.AimsAccording to the WHO classification 2010, we surveyed the prevalence and clinicopathological significance of each subtype with stem cell features (SC subtype; typical subtype [TS], intermediate cell subtype [INT] and cholangiolocellular type [CLC]) in cHC-CC and HCC.Methods Sixty-two patients with cHC-CC (19 women and 43 men) and 26 patients with HCC (all men) were examined. The prevalence of each component was histologically assessed with assistance of mucin and immunohistochemical stainings.ResultsSC subtypes were observed in all cHC-CCs in various amount and combination. The prevalence of each SC subtype in cHC-CC was as follows; TS, 10 (16.1%); INT, 53 (83.9%); and CLC, 44 (71.0%). The proportion of INT was significantly correlated to gender (female-dominant) (p<0.05), tumor size (p<0.05), histological grading of HCC (p<0.01) and inversely correlated to the degree of stromal fibrosis (p<0.05). The proportion of CLC was significantly correlated to the degree of fibrosis (p<0.01) and inflammation (p<0.01), and inversely correlated to tumor size (p<0.01) and histological grading of HCC (p<0.05). The proportion of TS was significantly inversely correlated to the degree of inflammation (p<0.01). Histological diversity score was significantly correlated to vascular invasion and the positivity for α-fetoprotein.Conclusion The proportion of each SC subtype was significantly associated with certain clinicopathological factors, suggesting different properties of each SC subtypes.This article is protected by copyright. All rights reserved.
    Liver international: official journal of the International Association for the Study of the Liver 04/2014; 35(3). DOI:10.1111/liv.12563 · 4.85 Impact Factor
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    ABSTRACT: Background/aims: Biliary drainage is performed in many patients with cholangiocarcinoma (CCA) to relieve obstructive jaundice. For those who have undergone biliary drainage, bile cytology can be easily performed since the access is already achieved. This study aims to determine the clinical usefulness of bile cytology for the diagnosis of CCA and to evaluate factors affecting its diagnostic yield. Methods: A total of 766 consecutive patients with CCA underwent bile cytology via endoscopic nasobiliary drainage or percutaneous transhepatic biliary drainage from January 2000 to June 2012. Data were collected by retrospectively reviewing the medical records. We evaluated the diagnostic yield of bile cytology with/without other sampling methods including brush cytology and endobiliary forcep biopsy, and the optimal number of repeated bile sampling. Several factors affecting diagnostic yield were then analyzed. Results: The sensitivity of bile cytology, endobiliary forceps biopsy, and a combination of both sampling methods were 24.7% (189/766), 74.4% (259/348), and 77.9% (271/348), respectively. The cumulative positive rate of bile sampling increased from 40.7% (77/189) at first sampling to 93.1% (176/189) at third sampling. On multivariate analysis, factors associated with positive bile cytology were perihilar tumor location, intraductal growing tumor type, tumor extent ≥ 20 mm, poorly differentiated grade tumor, and three or more samplings. Conclusions: Although bile cytology itself has a low sensitivity in diagnosing CCA, it has an additive role when combined with endobiliary forceps biopsy. Due to the relative ease and low cost, bile cytology can be considered a reasonable complementary diagnostic tool for diagnosing CCA.
    The Korean journal of gastroenterology = Taehan Sohwagi Hakhoe chi 02/2014; 63(2):107-13. DOI:10.4166/kjg.2014.63.2.107
  • Min Jong Kim · Mi Jin Gu · Joon Hyuk Choi · Se Won Kim · Kyeong Ok Kim ·

    Endoscopy 01/2014; 46(S 01):E441-E442. DOI:10.1055/s-0034-1377501 · 5.05 Impact Factor
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    O Hyun Kwon · Kil Ho Cho · Jang Ho Suh · Joon Hyuk Choi ·
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    ABSTRACT: Nodular fasciitis, a benign soft tissue tumor consisting of myofibroblastic proliferation, is commonly located in the subcutaneous or inter- or intra-muscular layer of extremites. Intra-articular nodular fasciitis is extremely rare. We report a case of MRI findings of a nodular fasciitis in the knee of a 13-year-old boy which was removed by arthroscopic surgery and pathologically confirmed.
    01/2014; 71(5):254. DOI:10.3348/jksr.2014.71.5.254
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    ABSTRACT: Immunoglobulin G4-related sclerosing cholangitis (IgG4-SC) is a rare disease characterized by increased serum levels of IgG4 and dense infiltration of IgG4-positive plasma cells with fibrosis in the bile duct wall. IgG4-SC is frequently associated with autoimmune pancreatitis (AIP) and typically shows an excellent response to steroid therapy. Despite recent progress in understanding the clinical presentation of IgG4-SC, its diagnosis still remains a challenge, particularly if it manifests as an isolated hilar stricture with normal serum IgG4 concentrations. In this article, we report the case of a 75-year-old man with IgG4-SC in whom it was difficult to distinguish hilar cholangiocarcinoma due to the normal serum IgG4 concentration and no accompanying AIP. He had an indolent clinical course and showed slow progression of a bile duct lesion over 6 years.
    01/2014; 87(2):182. DOI:10.3904/kjm.2014.87.2.182

Publication Stats

419 Citations
133.49 Total Impact Points


  • 2014-2015
    • Gangneung-Wonju National University
      • Department of Marine Food Science and Technology
      Gangneung, Gangwon-do, South Korea
    • Asan Medical Center
      • Department of Gastroenterology
      Sŏul, Seoul, South Korea
  • 2013-2014
    • Ulsan University Hospital
      Urusan, Ulsan, South Korea
    • University of Ulsan
      • Department of Internal Medicine
      Urusan, Ulsan, South Korea
  • 2002-2014
    • Yeungnam University
      • • Department of Pathology
      • • Division of Internal Medicine
      • • College of Medicine
      Daikyū, Daegu, South Korea
  • 2010
    • Inje University
      • College of Medicine
      Kimhae, South Gyeongsang, South Korea
  • 2009-2010
    • Sungkyunkwan University
      • • Samsung Medical Center
      • • Department of Internal Medicine
      Seoul, Seoul, South Korea