Other articles by Yong Kwan Cho on PubMed

• Helicobacter Pylori Infection Promotes Gastric Carcinogenesis in a Mice Model Journal of Gastroenterology and Hepatology. Mar, 2002  |   Pubmed ID: 11982694 Debate that Helicobacter pylori might play a causative role in gastric carcinogenesis still exists in spite of the World Health Organization's definition of H. pylori as a class I carcinogen. In order to define the exact role of H. pylori infection in gastric carcinogenesis, we established a mice model of H. pylori infection.
• Synergism of Helicobacter Pylori Infection and Stress on the Augmentation of Gastric Mucosal Damage and Its Prevention with Alpha-tocopherol Free Radical Biology & Medicine. Jun, 2005  |   Pubmed ID: 15890619 Despite evidence that Helicobacter pylori (H. pylori) infection is closely associated with stress in gastric ulcer patients, the underlying mechanism why ulcer recurrence after stress is augmented especially in patients with H. pylori remains unknown. In this study, we found that oxidative stress played a critical role in the augmented mucosal damage provoked by water immersion restraint stress (WIRS) in H. pylori infection and that an antioxidant, alpha-tocopherol, could ameliorate the aggravation of stress-associated gastric mucosal damage. Two hundred forty SD rats were divided into two groups according to H. pylori inoculation, and after 24 weeks of H. pylori infection, the water immersion restraint stress was imposed for 30, 120, or 480 min, respectively. To evaluate the therapeutic effects of an antioxidant, alpha-tocopherol was administrated 40 mg/kg daily prior to imposing WIRS. Remarkably increased hemorrhagic lesions and bleeding indexes were noted in the H. pylori-infected group with statistical significance (P < 0.05) compared to the noninfected group at the same duration of WIRS. Significantly higher oxidative stress documented by iNOS, lipid peroxides, and GSH level was detected in gastric homogenates of the H. pylori-infected group. Proteomic analysis using 2-dimensional electrophoresis showed a decrease of HSP27 and other chaperone proteins. alpha-Tocopherol pretreatment significantly prevented the gastric mucosal damage, caused by WIRS in the presence of H. pylori. alpha-Tocopherol induced HSP27 expression, which was well correlated with downregulation of iNOS mRNA. Conclusively, the presence of H. pylori caused significant deterioration of stress-induced gastric mucosal lesions through increased oxidative stress and thus antioxidant treatment such as alpha-tocopherol protected the gastric injuries.
• Modulation of E-cadherin by Hepatocyte Growth Factor Induces Aggressiveness of Gastric Carcinoma Annals of Surgery. Nov, 2005  |   Pubmed ID: 16244541 Hepatocyte growth factor (HGF) is well known as a scatter factor because it can disperse cells. E-cadherin is a protein that plays a main role in the establishment of cell-cell adhesion. This study focused on the role of HGF on the expression and distribution of E-cadherin. Furthermore, we found induction of aggressiveness of gastric carcinoma by modulation of E-cadherin by HGF.
• Multidimensional Learning Curve in Laparoscopy-assisted Gastrectomy for Early Gastric Cancer Surgical Endoscopy. Jan, 2007  |   Pubmed ID: 16960676 Laparoscopy-assisted gastrectomy (LAG) is a complex and time-consuming procedure, which is increasingly used for early gastric cancer (EGC). We provide a multidimensional analysis of the learning curve in LAG.
• 5-fluorouracil, Mitomycin-C, and Polysaccharide-K Adjuvant Chemoimmunotherapy for Locally Advanced Gastric Cancer: the Prognostic Significance of Frequent Perineural Invasion Hepato-gastroenterology. Jan-Feb, 2007  |   Pubmed ID: 17419278 Although adjuvant chemotherapy has demonstrated small but significant survival benefit in locally advanced gastric cancer in several meta-analyses, optimal chemotherapy regimen remains to be determined.
• Complications with Laparoscopically Assisted Gastrectomy: Multivariate Analysis of 300 Consecutive Cases Surgical Endoscopy. Oct, 2008  |   Pubmed ID: 18484229 Complications associated with laparoscopically assisted gastrectomy (LAG) are not significantly different from those associated with open gastrectomy. However, additional risks related to abdominal access, pneumoperitoneum, and special electrosurgical instruments result in an increased incidence of complications with LAG. This study analyzed the causes and risk factors linked to postoperative morbidity.
• Proximal-releasing Stent Insertion Under Transnasal Endoscopic Guidance in Patients with Postoperative Esophageal Leakage Gastrointestinal Endoscopy. Jul, 2010  |   Pubmed ID: 20546733 Covered metallic or plastic stent placement has become an important treatment for postoperative esophageal leakage; however, fluoroscopic guidance is also required. Here we present a novel stent insertion technique with a newly designed proximal-releasing, self-expanding metallic stent (PR-SEMS) and transnasal endoscope that can enable stent insertion without fluoroscopy as a new method to prevent stent migration.
• Technical Feasibility of Robot-sewn Anastomosis in Robotic Surgery for Gastric Cancer Journal of Laparoendoscopic & Advanced Surgical Techniques. Part A. Oct, 2010  |   Pubmed ID: 20809816 Although several studies have reported on the feasibility of robot-assisted gastric cancer surgery using the da Vinci surgical system, reconstruction techniques have depended on staplers or hand sewing through minilaparotomy.
• Efficacy of Endoscopic Ultrasonography for Prediction of Tumor Depth in Gastric Cancer Journal of Gastric Cancer. Jun, 2011  |   Pubmed ID: 22076211 As the proportion of early gastric cancer (EGC) has recently been increased, minimally invasive treatment is currently accepted as main therapy for EGC. Accurate preoperative staging is very important in determining treatment options. To know the accuracy of endoscopic ultrasonography (EUS), we compared the depth of invasion of the tumor with preoperative EUS and postoperative pathologic findings.
• Operative Risk Factors in Gastric Cancer Surgery for Elderly Patients Journal of Gastric Cancer. Jun, 2011  |   Pubmed ID: 22076212 Gastric cancer surgery is a common operation in East Asia, such as Korea and Japan, and there has been a significant increase in the need for this procedure due to the aging population. As a result, surgery for the treatment of gastric cancer for elderly patients is expected to increase. This study examined the effect of old age on gastric cancer surgery, and analyzed the operative risk factors for elderly patients.
• Robotic Redo Fundoplication for Incompetent Wrapping After Antireflux Surgery: A Case Report International Journal of Surgery Case Reports. 2011  |   Pubmed ID: 22096753 Incidence of gastroesophageal reflux disease (GERD) is high. antireflux surgery with specific indications could be an option. Nissen fundoplication is the most popular surgical procedure for GERD, and recent results using laparoscopy have reported excellent short- and mid-term results. Regarding surgical outcome of antireflux surgery, the rate of complications has been reported as below 2.4%, but rare cases still require reoperation.
• Clinicopathologic Significance of Gastric Adenocarcinoma with Neuroendocrine Features Journal of Gastric Cancer. Dec, 2011  |   Pubmed ID: 22324009 Composite neuroendocrine-exocrine carcinomas are malignancies that have two distinct components residing within the same tumor: an adenocarcinomatous portion and a neuroendocrine portion. This is rare in gastric cancers; however, poorly differentiated adenocarcinomas can sometimes reveal evidence of neuroendocrine features (NEF) or be 'mixed endocrine and exocrine carcinomas'. This study aimed to review NEF in gastric adenocarcinoma and to evaluate its prognostic significance.
• Efficacy of Roux-en-Y Reconstruction Using Two Circular Staplers After Subtotal Gastrectomy: Results from a Pilot Study Comparing with Billroth-I Reconstruction Journal of Gastric Cancer. Dec, 2011  |   Pubmed ID: 22324013 The Roux en Y method has rarely been performed due to longer operation time and high risk of complication, despite several merits including prevention of bile reflux. We conducted a retrospective review of the result of Roux en Y reconstruction using two circular staplers after subtotal gastrectomy.
• Giant Mesenteric Cystic Lymphangioma Originating from the Lesser Omentum in the Abdominal Cavity Journal of Gastric Cancer. Dec, 2011  |   Pubmed ID: 22324018 A 48 year old woman was diagnosed with a huge cystic mass in her abdominal cavity. She complained of significant abdominal discomfort due to the mass. The abdominal computed tomography revealed a giant multi-lobulated mass, measuring 26×12 cm in size, adjacent to the lesser curvature of the stomach. In the operation field, the mass was found to originate from the lesser omentum, including the right and left gastric vessels and the vagus nerves, and to invade the lesser curvature of the stomach. For curative resection, distal subtotal gastrectomy with mass excision followed by gastroduodenostomy were performed. This mass was pathologically diagnosed to be a mesenteric cystic lymphangioma; in fact, the largest ever reported. The patient had no complications during the postoperative period and was discharged from the hospital on the seventh day after surgery.
• Helicobacter Pylori Infection As an Independent Prognostic Factor for Locally Advanced Gastric Cancer Patients Treated with Adjuvant Chemotherapy After Curative Resection International Journal of Cancer. Feb, 2012  |   Pubmed ID: 21425257 A few studies reported the association between negative Helicobacter pylori infection and poor clinical outcome in resected gastric cancer patients. We investigated the H. pylori infection status and its association with the clinical outcome in 274 locally advanced gastric cancer patients (American Joint Committee on Cancer stage IB: 25, II: 82, IIIA: 80, IIIB: 39 and IV: 48) who underwent adjuvant chemotherapy after curative resection (≥ D2 dissection). H. pylori infection status in hematoxylin and eosin stained corporal and antral mucosa of non-tumor tissue was graded according to the updated Sydney System and categorized as H. pylori negative (normal or mild infection) and H. pylori positive (moderate or marked infection). Eighty-one patients received 5-fluorouracil (5-FU) and doxorubicin-based chemotherapy, while 193 patients underwent 5-FU, mitomycin-C and polysaccharide-K chemotherapy. The median follow-up duration of survivors was 144 (120-184) months. In univariate analysis, patients with H. pylori negative status (108 patients) demonstrated significantly poor 10-year overall survival (OS) compared to those with H. pylori-positive status (166 patients; 21.3% vs. 71.1%, p < 0.0001). H. pylori negative status was associated with poor outcome in all stages except stage IIIB. In multivariate analysis, H. pylori-negative status was the most significant independent prognostic factor of poor OS (hazard ratio: 3.45, 95% confidence interval: 2.43-4.89, p < 0.0001) followed by old age (>54 years, p < 0.0001), advanced stage (stage III or IV, p = 0.001), and Borrmann type IV (p = 0.027). H. pylori infection status seems to have strong prognostic significance in locally advanced gastric cancer. H. pylori-negative patients may need careful follow-up after curative resection.
• The Effects of Helicobacter Pylori on the Prognosis of Patients with Curatively Resected Gastric Cancers in a Population with High Infection Rate Journal of the Korean Surgical Society. Oct, 2012  |   Pubmed ID: 23091792 The goal of this study was to assess the correlation between the Helicobacter pylori status of patients who underwent curative resection for gastric adenocarcinoma and their prognosis in Eastern societies where H. pylori infection is prevalent.
• Comparison of Surgical Outcomes Between Robotic and Laparoscopic Gastrectomy for Gastric Cancer: The Learning Curve of Robotic Surgery Journal of Gastric Cancer. Sep, 2012  |   Pubmed ID: 23094227 Laparoscopic gastrectomy is a widely accepted surgical technique. Recently, robotic gastrectomy has been developed, as an alternative minimally invasive surgical technique. This study aimed to evaluate the question of whether robotic gastrectomy is feasible and safe for the treatment of gastric cancer, due to its learning curve.
• Trends and Outcomes of Minimally Invasive Surgery for Gastric Cancer: 750 Consecutive Cases in Seven Years at a Single Center American Journal of Surgery. Jan, 2013  |   Pubmed ID: 22906247 The aims of this study were to investigate trends in minimally invasive surgery (MIS) for gastric cancer through the experience of a single center and to predict the direction of the development of MIS.
• Comparison of Intracorporeal Reconstruction After Laparoscopic Distal Gastrectomy with Extracorporeal Reconstruction in the View of Learning Curve Journal of Gastric Cancer. Mar, 2013  |   Pubmed ID: 23610717 The intracorporeal reconstruction after laparoscopic gastrectomy can minimize postoperative pain, and give better cosmetic effect, while it may have technical difficulties and require the learning curve. This study aimed to analyze the surgical outcome of intracorporeal reconstruction according to the surgeon's experience comparing with extracorporeal procedure.
• Efficacy of Intraoperative Gastroscopy for Tumor Localization in Totally Laparoscopic Distal Gastrectomy for Cancer in the Middle Third of the Stomach Surgical Endoscopy. Nov, 2013  |   Pubmed ID: 23780327 Determining resection margins for gastric cancer, which generally is not exposed to the serosal surface of the stomach, is the most important priority during totally laparoscopic gastrectomy (TLG). This study aimed to evaluate the usefulness of intraoperative gastroscopy for direct marking of tumors during TLG for gastric cancer in the middle third of the stomach.
• Outcomes of Critical Pathway in Laparoscopic and Open Surgical Treatments for Gastric Cancer Patients: Patients Selection for Fast-Track Program Through Retrospective Analysis Journal of Gastric Cancer. Jun, 2013  |   Pubmed ID: 23844324 The aim of this study is to investigate the clinical factors affecting on the cure rate by invasive and open surgery for gastric cancer and to establish a subgroup of patients who can be applied by the early recovery after surgery program through this retrospective analysis.
• 5-Fluorouracil, Mitomycin-c, and Polysaccharide-k Versus Uracil-ftorafur and Polysaccharide-K As Adjuvant Chemoimmunotherapy for Patients with Locally Advanced Gastric Cancer with Curative Resection Onkologie. 2013  |   Pubmed ID: 23921761 Despite the small but significant survival benefit of adjuvant chemotherapy in locally advanced gastric cancer (LAGC), the optimal regimen remains to be determined. We conducted a randomized trial comparing oral (PO) chemoimmunotherapy (CITX) with intravenous (IV) CITX in LAGC patients (stages IB-IIIB) with curative resection (≥ D2 dissection).
• Dichloroacetate Attenuates Hypoxia-induced Resistance to 5-fluorouracil in Gastric Cancer Through the Regulation of Glucose Metabolism Experimental Cell Research. Feb, 2014  |   Pubmed ID: 24342832 In this study, we investigated whether gastric cancer with hypoxia-induced resistance to 5-fluorouracil (5-FU) could be re-sensitized following treatment with low-dose dichloroacetate (DCA), an inhibitor of the glycolytic pathway. The expression profiles of hypoxia-inducible factor-1α (HIF-1α) and pyruvate dehydrogenase kinase-1 (PDK-1) were analyzed in tissues from 10 patients with gastric cancer who had different responses to adjuvant 5-FU treatment. For the in vitro assays, cell viability and apoptosis were evaluated with and without treatment with 20mM DCA in the AGS and MKN45 cell lines, as well as in PDK1 knockdown cell lines. The expression levels of HIF-1α and PDK-1 were both elevated in the tumor tissues relative to the normal gastric tissues of most patients who showed recurrence after adjuvant 5-FU treatment. Cellular viability tests showed that these cell lines had a lower sensitivity to 5-FU under hypoxic conditions compared to normoxic conditions. Moreover, the addition of 20mM DCA only increased the sensitivity of these cells to 5-FU under hypoxic conditions, and the resistance to 5-FU under hypoxia was also attenuated in PDK1 knockdown cell lines. In conclusion, DCA treatment was able to re-sensitize gastric cancer cells with hypoxia-induced resistance to 5-FU through the alteration of glucose metabolism.
• Conventional Cytology is Not Beneficial for Predicting Peritoneal Recurrence After Curative Surgery for Gastric Cancer: Results of a Prospective Clinical Study Journal of Gastric Cancer. Mar, 2014  |   Pubmed ID: 24765534 The role of peritoneal washing cytology in determining further treatment strategies after surgery for gastric cancer remains unclear. One reason for this is the fact that optimal procedures to increase the accuracy of predicting peritoneal metastasis have not been established. The aim of this study was to evaluate the efficacy of cytology using samples harvested from two different abdominal cavity sites during gastric cancer surgery.
• Quantitative Measurement of Organic Acids in Tissues from Gastric Cancer Patients Indicates Increased Glucose Metabolism in Gastric Cancer PloS One. 2014  |   Pubmed ID: 24911788 The levels of organic acids representing metabolic pathway end products are important indicators of physiological status, and may be associated with metabolic changes in cancer. The aim of this study is to investigate the levels of organic acids in cancerous and normal tissues from gastric cancer patients and to confirm the role of metabolic alterations in gastric carcinogenesis. Organic acids in normal and cancerous tissues from forty-five patients with gastric adenocarcinoma were investigated by gas chromatography-mass spectrometry in selected ion monitoring mode as methoxime/tert-butyldimethylsilyl derivatives. We analysed the significant differences in the levels of organic acids in normal and cancer tissues and investigated the correlation of these levels in cancer tissues with clinicopathological features. The levels of Krebs cycle components, including α-ketoglutaric acid, succinic acid, fumaric acid, malic acid and oxaloacetic acid, were significantly increased in cancer tissues compared to normal tissues. In addition, the levels of glycolytic products, including pyruvic acid and lactic acid, as well as the levels of ketone bodies, including 3-hydroxybutyric acid, were also significantly increased in cancer tissues compared to normal tissues. The levels of ketone bodies in cancer tissues with differentiated histology and in intestinal-type cancer tissues were significantly increased. The organic acid profiling analysis described here may be a generally useful clinical tool for understanding the complexity of metabolic events in gastric adenocarcinoma, and organic acids may have potential as metabolic markers for the future discovery of diagnostic and therapeutic modalities.
• Laparoscopy-assisted Endoscopic Full-thickness Resection with Basin Lymphadenectomy Based on Sentinel Lymph Nodes for Early Gastric Cancer Journal of the American College of Surgeons. Sep, 2014  |   Pubmed ID: 25026878
• Does the Timing of Adjuvant Chemotherapy for Gastric Cancer Influence Patient Outcome? Acta Oncologica (Stockholm, Sweden). 2015  |   Pubmed ID: 25608823
• Effects of Continuing Adjuvant S-1 for 1 Year on the Prognosis of Gastric Cancer Patients: Results from a Prospective Single Center Study Journal of Gastric Cancer. Jun, 2015  |   Pubmed ID: 26161284 Although several clinical trials have proven the efficacy of adjuvant S-1 treatment in gastric cancers, it is still unclear which patients receive the most benefit. In this study, we prospectively recruited patients with locally advanced gastric cancer who had undergone curative resection followed by adjuvant S-1 administration to investigate which factors affect the outcomes.
• Is There Any Role of Visceral Fat Area for Predicting Difficulty of Laparoscopic Gastrectomy for Gastric Cancer? Journal of Gastric Cancer. Sep, 2015  |   Pubmed ID: 26468412 Obesity is associated with morbidity following gastric cancer surgery, but whether obesity influences morbidity after laparoscopic gastrectomy (LG) remains controversial. The present study evaluated whether body mass index (BMI) and visceral fat area (VFA) predict postoperative complications.
• Universal Verification Methodology Based Register Test Automation Flow Journal of Nanoscience and Nanotechnology. May, 2016  |   Pubmed ID: 27483924 In today's SoC design, the number of registers has been increased along with complexity of hardware blocks. Register validation is a time-consuming and error-pron task. Therefore, we need an efficient way to perform verification with less effort in shorter time. In this work, we suggest register test automation flow based UVM (Universal Verification Methodology). UVM provides a standard methodology, called a register model, to facilitate stimulus generation and functional checking of registers. However, it is not easy for designers to create register models for their functional blocks or integrate models in test-bench environment because it requires knowledge of SystemVerilog and UVM libraries. For the creation of register models, many commercial tools support a register model generation from register specification described in IP-XACT, but it is time-consuming to describe register specification in IP-XACT format. For easy creation of register model, we propose spreadsheet-based register template which is translated to IP-XACT description, from which register models can be easily generated using commercial tools. On the other hand, we also automate all the steps involved integrating test-bench and generating test-cases, so that designers may use register model without detailed knowledge of UVM or SystemVerilog. This automation flow involves generating and connecting test-bench components (e.g., driver, checker, bus adaptor, etc.) and writing test sequence for each type of register test-case. With the proposed flow, designers can save considerable amount of time to verify functionality of registers.