Jae Kyu Sung

Chungnam National University Hospital, Sŏul, Seoul, South Korea

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Publications (50)34.38 Total impact

  • [Show abstract] [Hide abstract] ABSTRACT: Cell cloning is a laboratory routine to isolate and keep particular properties of cultured cells. Transfected or other genetically modified cells can be selected by the traditional microbiological cloning. In addition, common laboratory cell lines are prone to genotypic drift during their continual culture, so that supplementary cloning steps are often required to maintain correct lineage phenotypes. Here, we designed a silicone-made attachable cloning cylinder, which facilitated an easy and bona fide cloning of interested cells. This silicone cylinder was easy to make, showed competent stickiness to laboratory plastics including culture dishes, and hence enabled secure isolation and culture for days of selected single cells, especially, on the spots of preceding cell-plating dishes under microscopic examination of visible cellular phenotypes. We tested the silicone cylinder in the monoclonal subcloning from a heterogeneous population of a breast cancer cell line, MDA-MB-231, and readily established independent MDA-MB-231 subclones showing different sublineage phenotypes.
    No preview · Article · May 2016 · Biochemical and Biophysical Research Communications
  • No preview · Article · May 2016
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    [Show abstract] [Hide abstract] ABSTRACT: Anti-androgen therapy is the leading treatment for advanced prostate cancer and is commonly used for neoadjuvant or adjuvant treatment. Bicalutamide is a non-steroidal anti-androgen, used during the initiation of androgen deprivation therapy along with a luteinizing hormone-releasing hormone agonist to reduce the symptoms of tumor-related flares in patients with advanced prostate cancer. As side effects, bicalutamide can cause fatigue, gynecomastia, and decreased libido through competitive androgen receptor blockade. Additionally, although not as common, drug-induced liver injury has also been reported. Herein, we report a case of hepatotoxicity secondary to bicalutamide use. Typically, bicalutamideinduced hepatotoxicity develops after a few days; however, in this case, hepatic injury occurred 5 mo after treatment initiation. Based on this rare case of delayed liver injury, we recommend careful monitoring of liver function throughout bicalutamide treatment for prostate cancer.
    Preview · Article · Apr 2016 · World Journal of Gastroenterology
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    [Show abstract] [Hide abstract] ABSTRACT: . To evaluate the long-term outcome of H. pylori eradication therapy for gastric MALT lymphoma according to the presence of H. pylori infection. Methods . We retrospectively reviewed the medical records of patients between January 2001 and June 2014. The clinicopathologic characteristics and clinical outcomes were compared between H. pylori -positive and H. pylori -negative gastric MALT lymphoma groups. Results . Fifty-four patients were enrolled: 12 H. pylori -negative and 42 H. pylori -positive patients. The tumor was located more frequently in both the proximal and distal parts of the stomach ( P = 0 . 001 ), and the percentage of multiple lesions was significantly greater in the H. pylori -negative group ( P = 0 . 046 ). Forty-seven patients received initial eradication therapy, and 85% (35/41) of H. pylori -positive patients and 50% (3/6) of H. pylori -negative patients achieved complete remission after eradication therapy. The presence of multiple lesions was a predictive factor for unresponsiveness to H. pylori eradication ( P = 0 . 02 4 ). The efficacy of eradication therapy ( P = 0 . 133 ), complete remission (CR) maintenance period, and relapse after eradication therapy were not significantly different between the two groups. Conclusions . H. pylori eradication therapy could be an effective first-line treatment for localized H. pylori -negative gastric MALT lymphoma, especially for single lesions.
    Preview · Article · Feb 2016 · Gastroenterology Research and Practice
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    [Show abstract] [Hide abstract] ABSTRACT: The incidence of gastric band erosion has decreased to 1%. Gastric band erosion can manifest with various clinical symptoms, although some patients remain asymptomatic. We present a case of a mostly asymptomatic patient who was diagnosed with gastric band erosion during a routine health check-up. A 32-year-old man without any underlying diseases except for non-alcoholic fatty liver underwent laparoscopic adjustable gastric band surgery in 2010. He had no significant complications postoperatively. He underwent routine health check-ups with near-normal gastroduodenoscopic findings through 2014. However, in 2015, routine gastroduodenoscopy showed that the gastric band had eroded into the stomach. His gastric band was removed laparoscopically, and the remaining gastric ulcer perforation was repaired using an omental patch. Due to the early diagnosis, the infection was not serious. The patient was discharged on postoperative day 3 with oral antibiotics. This patient was fortunately diagnosed early by virtue of a routine health check-up, thus eliminating the possibility of serious complications.
    Preview · Article · Feb 2016 · Clinical Endoscopy
  • [Show abstract] [Hide abstract] ABSTRACT: Background/aims: To validate the AIMS65 score for predicting mortality of patients with nonvariceal upper gastrointestinal bleeding and to evaluate the effectiveness of urgent (<8 hours) endoscopic procedures in patients with high AIMS65 scores. Methods: This was a 5-year single-center, retrospective study. Nonvariceal, upper gastrointestinal bleeding was assessed by using the AIM65 and Rockall scores. Scores for mortality were assessed by calculating the area under the receiver-operating characteristic curve (AUROC). Patients with high AIMS65 scores (≥2) were allocated to either the urgent or non-urgent endoscopic procedure group. In-hospital mortality, success of endoscopic procedure, recurrence of bleeding, admission period, and dose of transfusion were compared between groups. Results: A total of 634 patients were analyzed. The AIMS65 score successfully predicted mortality (AUROC=0.943; 95% confidence interval [CI], 0.876 to 0.99) and was superior to the Rockall score (AUROC=0.856; 95% CI, 0.743 to 0.969) in predicting mortality. The group with high AIMS65 score included 200 patients. The urgent endoscopic procedure group had reduced hospitalization periods (p<0.05). Conclusions: AIMS65 score may be useful in predicting mortality in patients with nonvariceal upper gastrointestinal bleeding. Urgent endoscopic procedures in patients with high scores may be related to reduced hospitalization periods.
    No preview · Article · Nov 2015 · Clinical Endoscopy
  • [Show abstract] [Hide abstract] ABSTRACT: All present guidelines regarding surveillance intervals after index colonoscopy are based on optimal bowel preparation. However, the appropriate timing of repeat colonoscopy after suboptimal bowel preparation is not clear. To determine the appropriate timing of repeat colonoscopy following index colonoscopy with suboptimal bowel preparation. The medical records of patients who underwent colonoscopy over 5 years were retrospectively analyzed. Index colonoscopy was defined as the first colonoscopy in patients who underwent the procedure at least twice during the study period. Bowel preparation quality was classified as optimal, fair, or poor. The overall adenoma detection rate was 39.1 % (95 % confidence interval [CI], 38.0-40.1 %), but the detection rate depended significantly on bowel preparation quality (p < 0.001). The adenoma miss rate (AMR) was significant after poor (69.6 %) than after optimal (27.3 %) and fair (48.1 %) preparation (p < 0.001). At surveillance intervals ≤2 years, the odds ratio (OR) for AMR was significantly higher for poor (OR 6.25; 95 % CI, 3.76-11.83) and fair (OR 3.67; 95 % CI, 2.19-6.16) preparation relative to optimal preparation; however, no difference was observed at surveillance intervals >2 years. Bowel preparation quality significantly affects AMR. Colonoscopy should be repeated within 2 years in patients with suboptimal bowel preparation at index colonoscopy.
    No preview · Article · Jun 2015 · Digestive Diseases and Sciences
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    [Show abstract] [Hide abstract] ABSTRACT: Intussusceptions are defined as the telescoping of one segment of the gastrointestinal tract into an adjacent distal segment. In the small bowel, intussusceptions are typically caused by benign processes, but can occasionally be caused by inflammatory fibroid polyps, which often present as intussusception and bowel obstruction. These polyps are rare, benign, tumorous lesions in the gastrointestinal tract and are typically observed in the stomach, but can occur anywhere in the gastrointestinal tract. Any case of a jejunojejunal intussusception caused by inflammatory fibroid polyps is considered rare, and we report the case of a 51-year-old woman with an inflammatory fibroid polyp of the jejunum presenting as an intussusception who was successfully treated with a resection.
    Preview · Article · Jun 2015 · Annals of Coloproctology
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    [Show abstract] [Hide abstract] ABSTRACT: The purpose of this study is to verify the risk factors associated with Dieulafoy lesion formation in the upper gastrointestinal tract. A case-control study was performed by reviewing the electronic medical records of 42 patients who were admitted to a tertiary medical center in the Daejeon region for Dieulafoy lesions from September 2008 to October 2013, and the records of 132 patients who were admitted during the same period and who underwent endoscopic examination for reasons other than bleeding. We analyzed clinical and endoscopic findings retrospectively, and searched for risk factors associated with Dieulafoy lesion formation. All 42 patients diagnosed with Dieulafoy lesion had accompanying bleeding, and the location of the bleeding was proximal in 25 patients (59.5%), the middle portion in seven patients (16.7%), and distal in 10 patients (23.8%). Antiplatelet agents (p=0.022) and alcohol (p=0.001) use showed statistically significant differences between the two groups. The odds ratios (95% confidence intervals) of the two factors were 2.802 (1.263 to 6.217) and 3.938 (1.629 to 9.521), respectively. This study showed that antiplatelet agents and alcohol consumption were risk factors associated with Dieulafoy lesion formation in the upper gastrointestinal tract.
    Preview · Article · May 2015 · Clinical Endoscopy
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    [Show abstract] [Hide abstract] ABSTRACT: Leiomyosarcoma is an uncommon tumor that originates from various organs, including uterus, kidney, retroperitoneum, and soft tissues. In particular, leiomyosarcoma of the stomach is extremely rare. Only 9 cases have been reported worldwide since the discovery of KIT-activating mutation. A 48-year-old woman was admitted to our hospital with abdominal discomfort and generalized weakness. Upon detection of multiple nodules in both lung on chest posterior-anterior radiograph taken at the time of admission, chest CT was performed and it revealed multiple mass lesions in the lung, liver, and pancreas along with multiple lymph node metastases. On endoscopic examination, a 2.0 cm sized ulcerofungating mass lesion was found on the stomach body. Biopsy was performed and the mass lesion proved to be leiomyosarcoma confirmed by immunohistochemical staining. Chemotherapy was thus initiated, but the patient died after one year due to tumor progression. Our experience suggests that leiomyosarcoma can manifest aggressive behavior in its early stage. Herein, we report a case of gastric leiomyosarcoma with multiple metastases along with review of relevant literature.
    Preview · Article · Feb 2015 · The Korean journal of gastroenterology = Taehan Sohwagi Hakhoe chi
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    [Show abstract] [Hide abstract] ABSTRACT: Spontaneous gastric perforation is a rare complication of gastric lymphoma that is potentially life threatening since it can progress to sepsis and multi-organ failure. Morbidity also increases due to prolonged hospitalization and delay in initiating chemotherapy. Therefore prompt diagnosis and appropriate treatment is critical to improve prognosis. A 64-year-old man presented to the emergency department with severe abdominal pain. Chest X-ray showed free air below the right diaphragm. Abdominal CT scan also demonstrated free air in the peritoneal cavity with large wall defect in the lesser curvature of gastric lower body. Therefore, the patient underwent emergency operation and primary closure was done. Pathologic specimen obtained during surgery was compatible to diffuse large B cell lymphoma. Fifteen days after primary closure, the patient received subtotal gastrectomy and chemotherapy was initiated after recovery. Patient is currently being followed-up at outpatient department without any particular complications. Herein, we report a rare case of gastric lymphoma that initially presented as peritonitis because of spontaneous gastric perforation. (Korean J Gastroenterol 2015;65:43-47).
    Preview · Article · Jan 2015 · The Korean journal of gastroenterology = Taehan Sohwagi Hakhoe chi
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    [Show abstract] [Hide abstract] ABSTRACT: Small cell neuroendocrine carcinoma in the ampulla of Vater is a rare disease and there have only been three cases reported in Korea. In these three cases, the patients had symptoms of abdominal pain and jaundice. A biopsy via endoscopic retrograde cholangiopancreatography confirmed a small cell neuroendocrine carcinoma; thus, each patient underwent surgical treatment. Recently, we experienced a case of small cell neuroendocrine carcinoma in an asymptomatic patient. An ulcerative lesion was identified during screening gastroduodenoscopy. Here, we report this case and review the relevant literature.
    Preview · Article · Jan 2015
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    [Show abstract] [Hide abstract] ABSTRACT: Cytomegaloviurs (CMV) usually causes severe infection only in immunocompromised patients. However, in rare cases, gastrointestinal infection can occur in patients with normal immunity. Though most such patients recover spontaneously, major complications such as massive hemorrhage have also been reported. We report a case of massive hemorrhage in an immunocompetent elderly patient which was successfully treated with angiographic embolization.
    Preview · Article · Jan 2015
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    [Show abstract] [Hide abstract] ABSTRACT: One of the most important prognostic factors in esophageal carcinoma is lymph node metastasis, and in particular, the number of affected lymph nodes, which influences long-term outcomes. The esophageal lymphatic system is connected longitudinally and transversally; thus, the pattern of lymph node metastases is very complex. Early esophageal cancer frequently exhibits skipped metastasis, and minimal surgery using sentinel node navigation cannot be performed. In Korea, most esophageal cancer cases are squamous cell carcinoma (SCC), although the incidence of adenocarcinoma has started to increase recently. Most previous reports have failed to differentiate between SCC and adenocarcinoma, despite the fact that the Union for International Cancer Control (7th edition) and American Joint Committee on Cancer staging systems both consider these separately because they differ in cause, biology, lymph node metastasis, and outcome. Endoscopic tumor resection is an effective and safe treatment for lesions with no associated lymph node metastasis. Esophageal mucosal cancer confined to the lamina propria is an absolute indication for endoscopic resection, and a lesion that has invaded the muscularis mucosae can be cured by local resection if invasion to the lymphatic system has not occurred.
    Full-text · Article · Nov 2014 · Clinical Endoscopy
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    [Show abstract] [Hide abstract] ABSTRACT: Endoscopic submucosal dissection (ESD) is a widely accepted treatment for early gastric and esophageal cancer. Compared to endoscopic mucosal resection, ESD has the advantage of enabling en bloc removal of tumors regardless of their size. However, ESD can result in a large artificial ulcer, which may lead to a considerable deformity. Circumferential mucosal defects of more than three-fourths the esophageal circumference, long longitudinal mucosal defects (>30 mm), and lesions in the upper esophagus are significant risk factors for the development of post-ESD strictures of the esophagus. In the stomach, a circumferential mucosal defects more than three-fourths in extent and longitudinal mucosal defects >5 cm are risk factors of post-ESD stricture. If scheduled early, regular endoscopic balloon dilation is effective in controlling and preventing post-ESD stricture. Moreover, intralesional steroid injections or oral steroids can achieve remission of dysphagia or reduce the need for repeated endoscopic balloon dilation. However, further study is needed to improve the prevention of stricture formation.
    Full-text · Article · Nov 2014 · Clinical Endoscopy
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    [Show abstract] [Hide abstract] ABSTRACT: Purpose A colonoscopic polypectomy is an important procedure for preventing colorectal cancer, but it is not free from complications. Delayed hemorrhage after a colonoscopic polypectomy is one infrequent, but serious, complication. The aim of this study was to identify the risk factors for delayed hemorrhage after a colonoscopic polypectomy. Methods This was a retrospective case-control study based on medical records from a single gastroenterology center. The records of 7,217 patients who underwent a colonoscopic polypectomy between March 2002 and March 2012 were reviewed, and 92 patients and 276 controls were selected. Data collected included comorbidity, use of antiplatelet agents, size and number of resected polyps, histology and gross morphology of resected polyps, resection method, and use of prophylactic hemostasis. Results The average time between the procedure and bleeding was 2.71 ± 1.55 days. Univariate and multivariate analyses revealed that the size of the polyps was the only and most important predictor of delayed hemorrhage after a colonoscopic polypectomy (odds ratio, 2.06; 95% confidence interval, 1.12-1.27; P = 0.03). Conclusion The size of resected polyps was the only independent risk factor for delayed bleeding after a colonoscopic polypectomy. The size of a polyp, as revealed by the colonoscopic procedure, may aid in making decisions, such as the decision to conduct a prophylactic hemostatic procedure.
    Preview · Article · Aug 2014 · Annals of Coloproctology
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    [Show abstract] [Hide abstract] ABSTRACT: Hyperplastic polyps are the most common type of gastric polyps that constitute 30~93% of all benign epithelial gastric polyps. The overall prevalence of dysplasia in patients with hyperplastic polyps is believed to be <2%, and higher in patients with large polyps (>2 cm). We aimed to identify the clinical features of hyperplastic polyps that undergo neoplastic transformation.
    Preview · Article · Jan 2014
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    [Show abstract] [Hide abstract] ABSTRACT: Carcinosarcoma of the stomach is a rare biphasic tumor that consists of both carcinomatous and sarcomatous components. In the gastrointestinal tract, carcinosarcoma is most frequently seen in the esophagus and rarely in the stomach. Tubular or papillary adenocarcinomas are common carcinomatous components, whereas mesenchymal sarcomatous components may vary. Neuroendocrine carcinomatous differentiation in carcinomatous components is extremely rare. We report a 62-year-old female patient with a history of dyspepsia for one-month-history. Endoscopic findings showed a ulcerofungating lesion, which infiltrated from the posterior wall of the antrum to the posterior wall of the gastric angle. Radical subtotal gastrectomy was performed. In the resected specimen, immunohistochemical studies showed two positive reactions for epithelial and mesenchymal markers. Based on the above findings, the patient was diagnosed with a gastric carcinosarcoma with neuroendocrine differentiation.
    Preview · Article · Jan 2014
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    [Show abstract] [Hide abstract] ABSTRACT: Anterograde jejunojejunal intussusception after total gastrectomy is a very rare postoperative complication. We report a 54-year-old man with a history of total gastrectomy, uncut Roux-en-Y gastric bypass, and Braun's jejunojejunal anastomosis. An upper gastrointestinal endoscopy revealed a bulky, reddish mass in the efferent loop with congestion, edema, and mucosal bleeding. An emergency computed tomography showed a target-like multilayered wall thickening in the afferent loop and a lamellar structure arranged in a concentric circle. Surgical exploration revealed an anterograde intussusception of the afferent proximal jejunum adjacent to the jejunojejunostomy site. This is a very uncommon occurrence because most intussusceptions after total gastrectomy are of the retrograde type. Moreover, anterograde jejunojejunal intussusception tends to occur in the early postoperative period. We report a case of late postoperative anterograde jejunojejunal intussusception after total gastrectomy with Braun's jejunojejunal anastomosis in a 54-year-old Korean man and review the related literature.
    Preview · Article · Jan 2014
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    [Show abstract] [Hide abstract] ABSTRACT: Previous studies reported that oxaliplatin is associated with sinusoidal obstruction syndrome. However few reports on oxaliplatin induced liver fibrosis are found in the literature. Furthermore pathogenesis of liver fibrosis is not well known. We report a case of 45-yr-old Korean man in whom liver fibrosis with splenomegaly developed after 12 cycles of oxaliplatin based adjuvant chemotherapy for colon cancer (T4N2M0). Thorough history taking and serological examination revealed no evidence of chronic liver disease. Restaging CT scans demonstrated a good response to chemotherapy. Five month after chemotherapy, he underwent right hepatectomy due to isolated metastatic lesion. The liver parenchyma showed diffuse sinusoidal dilatation and centrilobular vein fibrosis with necrosis without steatosis. We could conclude that splenomegaly was due to perisinusoidal liver fibrosis and liver cell necrosis induced portal hypertension by oxaliplatin. In addition, to investigate the pathogenesis of liver fibrosis, immunohistochemical stains such as CD31 and α-smooth muscle actin (α-SMA) were conducted with control group. The immunohistochemical stains for CD31 and α-SMA were positive along the sinusoidal space in the patient, while negative in the control group. Chemotherapy with oxaliplatin induces liver fibrosis which should be kept in mind as a serious complication.
    Full-text · Article · Dec 2013 · Journal of Korean medical science