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Goyang, South Korea

Sohn D.K.,Research Institute and Hospital
Annals of Coloproctology

Purpose: Several guidelines have been proposed for surveillance colonoscopy after polypectomy. However, some discrepancies still exist between the guidelines and clinical practice. This study was conducted to identify Korean doctors' recommendations for the colonoscopic surveillance interval after polypectomy. Methods: A survey of the attendees at the symposium of the 64th Annual Congress of the Korean Surgical Society was conducted. When the prepared clinical scenarios were given, attendees answered using a wireless radio-frequency audience response system. All responders' results were automatically counted immediately. Frequencies of different answers to each question were calculated, and our results were compared with those of previous surveys performed using the same questionnaire in the United States or Japan. Results: The number of responder varied from 38 to 41. About 50% of valid responders selected 'follow-up in 3 years' for low-risk lesions, such as a 6-mm hyperplastic polyp, a 6-mm tubular adenoma, or two 6-mm tubular adenomas. Responders most-commonly selected 'follow-up in 1 year' for high-risk lesions, such as a 12-mm tubular adenoma with high grade dysplasia or a 12-mm tubulovillous adenoma. The majority of Korean doctors recommend postpolypectomy colonoscopic surveillance more frequently than American physicians did. Conclusion: A discrepancy between the guidelines and clinical practice for the surveillance after polypectomy still exists in Korea. A surveillance program that can be easily and widely applied in clinical practice needs to be established. © 2014 The Korean Society of Coloproctology. Source

Tak Y.K.,Seoul National University | Naoghare P.K.,Indian National Environmental Engineering Research Institute | Kim B.J.,Seoul National University | Kim M.J.,Seoul National University | And 2 more authors.
Nano Today

Successful therapeutic modalities against breast cancer (BC) are highly dependent on the accurate prognosis and quantitative simultaneous classification of BC subtypes. Current methods based on semi-quantitative analysis or subjective interpretations are not efficient for BC prognosis and classification considering tumor heterogeneity. In this work, simultaneous monitoring and quantitative estimation of four targeted receptors (EGFR1, HER2, ER and PR) was carried out using quantum dot (QD) based hypermulticolor high-content single cell imaging cytometry. Four different QD-antibody conjugates (QD525-EGFR1, QD565-HER2, QD605-ER, and QD655-PR) were used as QD immunoassay probes for the subtype classification of biopsied samples from BC patients. The molecular profiling obtained by QD imaging cytometry was in line with that of conventional immunohistochemistry and Western blot analysis with regard to the expression profiles of known predominant target receptors in in vitro model. Multi-target-single cell imaging cytometry facilitated the quantitative classification of BC subtypes with deeper insights into the existence of heterogeneity and homogeneity in BC cell lines (MCF-7, SK-BR-3, JIMT-1, and HCC-70) and primary cells from biopsied tissues. Quantitative estimates showed 36.96%, 41.45%, 23.14%, 57.45% and 63.21% heterogeneity in MCF-7, SK-BR-3, JIMT-1, HCC-70 and MCF-10A cell lines, respectively, in addition to the remarkable heterogeneity of primary cells. In consideration of BC tumor heterogeneity, highly sensitive QD immunohistochemistry was executed on different regions of BC tumors. Significant heterogeneous subtypes that have to be considered for proper drug treatment were determined depending on the tumor regions of BC patients. Herein, we presented a quantitative hypermulticolor high-content QD single cell imaging cytometry as a new model for BC prognosis and classification based on accurate quantification of tumor heterogeneity. © 2012 Elsevier Ltd. All rights reserved. Source

Kang S.,Research Institute and Hospital | Dong S.M.,Research Institute and Hospital | Park N.-H.,Seoul National University
Gynecologic Oncology

Objectives: Using pharmacologic unmasking and genome-wide differential methylation analysis, we identified a novel methylated gene in ovarian cancers. Methods: Two ovarian cancer cells (OVCAR-3, ES-2) that showed synergistic growth inhibition by 5-aza-dC and cisplatin were selected. After treatment with 5-aza-dC, differential expression profiles were compared using microarray that contained 38,500 genes. Reactivation of candidate genes and their promoter methylation were validated by real-time RT-PCR, MS-PCR and bisulfite sequencing. Methylation status was tested by MS-PCR in 56 patients with epithelial ovarian cancer and compared to the 38 normal ovarian tissues. Results: We identified 103 candidate genes that were reactivated by 5-aza-dC treatment. Among those, SFN and TGFBI were commonly reactivated in both cells. Since SFN is a well known methylated marker, we selected TGFBI for further validation. Bisulfite sequencing revealed complete promoter methylation in ES-2 and partial methylation in OVCAR-3. In addition, silencing of TGFBI at the transcription level was reversed by 5-aza-dC treatment. TGFBI methylation was observed in 23 out of 38 (60.5%) cases of ovarian cancer, in no normal ovarian tissues (0 of 38, P = 0.001), and in 5 out of 18 (27.8%) borderline tumors (P = 0.044). In our cohort, we did not observe any association between methylation of TGFBI and clinicopathologic variables or clinical outcomes. Conclusion: Our results confirm that TGFBI is frequently methylated in ovarian cancer. Its methylation can be used as a novel epigenetic biomarker in discriminating ovarian cancer from non-cancer or borderline tumors. © 2010 Elsevier Inc. All rights reserved. Source

Park J.B.,Research Institute and Hospital | Lee C.S.,Pohang University of Science and Technology | Lee C.S.,University of Virginia | Jang J.-H.,Pohang University of Science and Technology | And 6 more authors.
Nature Reviews Cancer

Phospholipases (PLC, PLD and PLA) are essential mediators of intracellular and intercellular signalling. They can function as phospholipid-hydrolysing enzymes that can generate many bioactive lipid mediators, such as diacylglycerol, phosphatidic acid, lysophosphatidic acid and arachidonic acid. Lipid mediators generated by phospholipases regulate multiple cellular processes that can promote tumorigenesis, including proliferation, migration, invasion and angiogenesis. Although many individual phospholipases have been extensively studied, how phospholipases regulate diverse cancer-associated cellular processes and the interplay between different phospholipases have yet to be fully elucidated. A thorough understanding of the cancer-associated signalling networks of phospholipases is necessary to determine whether these enzymes can be targeted therapeutically. © 2012 Macmillan Publishers Limited. All rights reserved. Source

Lee H.-S.,Research Institute and Hospital | Jang H.-J.,Research Institute and Hospital
Seminars in Thoracic and Cardiovascular Surgery

Mediastinal lymph node staging is an important component of the assessment and management of patients with operable non-small cell lung cancer and is necessary to achieve complete resection. During minimally invasive surgery, performance of an equivalent oncologic resection, including adequate lymph node dissection similar in extent to open thoracotomy, is absolutely necessary. We describe our techniques for video-assisted thoracic surgery (VATS) and Robotassisted VATS (R -VATS) mediastinal lymph node dissection when performing thoracoscopic lobectomy for lung cancer. Between 2008 and 2011, 200 consecutive patients who underwent VATS or R-VATS lobectomies for early stage lung cancer were analyzed. In our series, we removed about 25 lymph nodes per case in both complete VATS and R -VATS. A thorough lymph node dissection in lung cancer is possible with either VATS or R-VATS technique without onological compromise. © 2012 Elsevier Inc. All rights reserved. Source

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