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Biomedical subjects

Joo Young Cho

Publications and source records attributed to Joo Young Cho.

11 recordsLinked to original sources

Variation in expression of gastric leptin according to differentiation and growth pattern in gastric adenocarcinoma.

Leptin is an adipocyte-derived hormone that regulates body fat stores and feeding behavior. The presence of leptin in stomach epithelium was recently demonstrated in the rat and humans, and gastric leptin has been linked to the control of meal size, local inflammatory responses, and paracrine and autocrine functions through leptin receptors in the stomach. We compared the expression patterns of leptin and of the long variant of the leptin receptor (Ob-Rb) between areas with non-ulcerated mucosa and with hyperplastic polyps, adenoma, or adenocarcinoma to evaluate the expression relative to different disease states. Leptin and Ob-Rb were expressed in hyperplastic polyps, adenoma, and adenocarcinoma. In the gastric adenocarcinoma, leptin was expressed significantly less in the poorly differentiated and diffuse-type groups than in the well-differentiated and moderately differentiated groups or in the intestinal type. Based upon our findings, we suggest the possibility that leptin expression can have a pathophysiologic role about the differentiation or growth pattern of gastric adenocarcinoma. A further series of experiments is necessary to elucidate the pathophysiological role of leptin in the differentiation of gastric adenocarcinoma.

Adenocarcinoma↗

[Magnifying endoscopy in upper gastrointestinal tract].

For the diagnosis of upper gastrointestinal (GI) lesions, magnification method is usually used in conjunction with chromoscopy, enabling the endoscopist to view subtle mucosal patterns in exquisite detail. Recently published datas have shown that magnifying endoscopy might be a valuable adjunct for the diagnosis, detection, and characterization of inflammatory and neoplastic lesions of the upper GI tract. It is also proven to be an useful surveillance protocol in identifying dysplastic epithelium or early cancer within a segment of Barrett's esophagus. Possible indications for magnifying endoscopy in upper GI tract include screening and surveillance of Barrett's esophagus, defining the extent of esophageal and gastric adenocarcinoma, detecting synchronous/metachronous gastric and esophageal cancers, diagnosing Helicobacter pylori infection, and recognizing minimal mucosal changes in gastroesophageal reflux disease. By grading the quality of evidence for the currently published trials, it is clear that the majority are case series, case reports, and/or observational studies without randomization, control, or blinding. Moreover, other evidence-based criteria such as independent, blind comparisons of magnifying endoscopy with a standard method which evaluates this technology in an appropriate spectrum of patients to whom the test may be applicable, and standardizing methodology would be crucial before magnifying endoscopy becomes a standard procedure in clinical practice. In the future, a uniform classification system for staining and magnifying patterns should be devised and observer agreement should be tested. Futher studies then could be performed based upon consistent, validated, and standardized terminologies and criteria.

Diagnosis, Differential↗

[The expression of p53, p16, cyclin D1 in esophageal squamous cell carcinoma and esophageal dysplasia].

BACKGROUNDS/AIMS: p53 is known to play a central role in sensing and signaling for the growth arrest and apoptosis in cells with DNA damage. Mutation of p53 is a frequent event in esophageal squamous cell carcinoma (ESCC). p16 protein binds to cyclin dependent kinase 4 (CDK4) inhibiting the ability of CDK4 to interact with cyclin D1, and stimulates the passage through the G1 phase of cell cycle. We observed the expression patterns and frequencies of p53, p16, and cyclin D1 in esophageal dysplasia and in esophageal squamous cell carcinomas. METHODS: In 15 patients of ESCC, 5 patients of esophageal dysplasia and 5 volunteers with normal esophagus, tissue specimens were taken from esophageal lesions during the operation or endoscopic examination. We used specific monoclonal antibodies for p53 protein, p16(INK4 ) protein and cyclin D1. Immunoreactivity was scored. RESULTS: Mean age of all groups was 66 years old (range 47-93) and men to women ratio was 19:1. p53 mutation was observed in 87% (13/15) of ESCC, in 80% (4/5) of esophageal dysplasia, in 0% (0/5) of normal mucosa (p=0.001). p16 expression was seen in 40% (2/5) of esophageal dysplasia, 27% (4/15) of ESCC and 100% (5/5) of normal mucosa (p=0.016). Cyclin D1 expression was not significantly different among 20% (1/5) of esophageal dysplasia, 53% (8/15) of ESCC and 20% (1/5) of normal mucosa. Either the expression of p53 mutation or the loss of p16 occurred in 80% (4/5) of esophageal dysplasia and in 93% (14/15) of ESCC. CONCLUSIONS: The expression of p53 mutation and the loss of p16 might play a central role in the pathogenesis of esophageal squamous cell carcinoma (ESCC), and contribute to the development of precancerous lesion such as dysplasia. In addition, there is a possibility that the mutations of p53 and p16 silencing would be the early events in ESCC development.

Aged↗

[Indications and limitations of endoscopic mucosal resection in gastric cancer].

Endoscopic mucosal resection (EMR) has come to play an increasingly important role in treatment of early cancer in gastrointestinal tract. Recent advances in EMR are very remarkable. These allow minimally invasive treatment of diseases that would otherwise require major surgery. The most important factors of EMR are accuracy and safety. Further improvement in both staging and resection technologies, as well as safety and short procedure time will ultimately conspire to make this an even more effective tool in the management of early cancer in gastrointestinal tract. EMR must prove to be safe for the majority of patients when performed by competent endoscopist. The new techniques will continue to solve the limitations of endoscopic treatment and its use will also continue to expand increasingly. Also, further studies are required to refine and standardize EMR. As EMR technology becomes more complex, necessitating the use of multiple accessories simultaneously, technical ease may be enhanced by simple adjunct devices. The future of EMR depends on extending its boundaries safely in a controlled setting of prospective clinical trials. I believe that current EMR techniques and devices are only the beginning of a new age in therapeutic endoscopy, the age of minimal invasive endosurgery, the next frontier.

Gastric Mucosa↗

Usefulness of three-dimensional, multidetector row CT (virtual gastroscopy and multiplanar reconstruction) in the evaluation of gastric cancer: a comparison with conventional endoscopy, EUS, and histopathology.

BACKGROUND: The aim of this study was to assess the role of three-dimensional multidetector row CT for detection, precise localization, and staging of gastric cancer by comparison with conventional endoscopy, EUS, and histopathology. METHODS: Sixty-three patients with gastric cancer (31 early stage, 32 advanced) were evaluated by EGD with biopsies, EUS, and three-dimensional multidetector row CT between January 2003 to August 2003. Three-dimensional multidetector row CT findings were analyzed by a single radiologist blinded to the endoscopic findings. Among 63 patients, the findings were confirmed in 48 at surgery or by EMR. In the remaining cases, the findings were confirmed by EGD and biopsy specimen. The accuracy of three-dimensional multidetector row CT for detection, localization, and staging of gastric cancer was determined, compared with endoscopy, EUS, and histopathology. RESULTS: Among the 63 patients, there were 67 gastric cancers. The overall accuracy of three-dimensional multidetector row CT for detection of gastric lesions was 94% (63/67), with accuracies of 96.7% (30/31) and 100% (32/32) for detection of, respectively, early and advanced stage gastric cancer. The overall accuracy, sensitivity, and specificity for EUS and three-dimensional multidetector row CT in the pre-operative determination of depth of invasion (T stage) were, respectively, 87.5%, 82.4%, and 96%; and 83.3%, 69.1%, and 94.4%. The accuracy, sensitivity, and specificity of EUS and three-dimensional multidetector row CT for lymph node staging was, respectively, 79.1%, 57%, and 89.5%; and 75%, 57.4%, and 89.3%. CONCLUSIONS: Three-dimensional multidetector row CT, along with virtual gastroscopy is a promising method for pre-operative evaluation of gastric cancer.

Adult↗

A case of primary esophageal B-cell lymphoma of MALT type, presenting as a submucosal tumor.

The primary esophageal lymphoma is extremely rare, and shows various morphologic characteristics. Only a single case of mucosa-associated lymphoid tissue (MALT) type lymphoma confined to the esophagus has been reported in the literature. A 61-yr-old man was referred to our hospital for evaluation of an esophageal submucosal tumor (SMT) that had been detected incidentally by endoscopy. He had a history of pulmonary tuberculosis with long-term anti-tuberculosis medication 15 yr before, and also had a history of syphilis, which had been treated one year before. He had been taking a synthetic thyroid hormones for the past 10 months because of an autoimmune thyroiditis. Endoscopy showed a longitudinal round and tubular shaped smooth elevated lesion, which was covered with intact mucosa and located at the mid to distal esophagus, 31 cm to 39 cm from the incisor teeth. Endoscopic ultrasonography (EUS) showed a huge longitudinal growing intermediate- to hypo-echoic mass located in the submucosal layer with internal small, various sized honeycomb-like anechoic lesions suggesting germinal centers. Subsequently, he underwent a surgery, which confirmed the mass as a primary esophageal low-grade B-cell lymphoma of MALT type.

Alcoholism↗

Use of detachable snares and elastic bands for endoscopic control of bleeding from large gastric varices.

BACKGROUND: Bleeding from gastric varices larger than 2 cm in diameter represents a major limitation for endoscopic hemostasis. METHODS: Endoscopic ligation of gastric varices was performed with detachable snares and elastic bands in 41 patients who had recent bleeding from gastric varices larger than 2 cm in diameter. Gastric varices larger than 2 cm were ligated with detachable snares, and then adjacent small gastric varices were ligated with elastic bands. RESULTS: Among the 41 patients, 10 of 12 patients with active bleeding and 28 of 29 patients with red color signs at initial endoscopy were successfully treated by endoscopic ligation by using detachable snares and elastic bands. Bleeding recurred early (before variceal eradication) in 4 of 38 patients (10.5%). The overall hemostatic rate for endoscopic ligation was 82.9% (34/41). In 33 of 36 patients (91.7%) who underwent repeated ligation treatments, variceal eradication was nearly complete. Mean follow-up in 30 of 33 patients after eradication of varices was 16.4 months (3-32 months), and 29 of 30 did not have recurrent bleeding. During and after ligation there were no serious complications. CONCLUSIONS: Endoscopic ligation therapy with large detachable snares and elastic bands is safe and effective for treatment of large bleeding gastric varices.

Acute Disease↗

Wire-guided intraductal US in the assessment of bile duct strictures with Mirizzi syndrome-like features at ERCP.

BACKGROUND: Mirizzi syndrome refers to common hepatic duct obstruction caused by extrinsic compression that is usually from a stone impacted in the cystic duct. The utility of transpapillary intraductal US for assessment of biliary strictures with radiographic features of Mirizzi syndrome was studied retrospectively. METHODS: Intraductal US was performed in 16 patients with a common hepatic duct stricture caused by extrinsic compression and nonvisualization of the gallbladder by endoscopic retrograde cholangiography. An over-the-wire catheter US probe (20 MHz) was inserted into the bile duct. Intraductal US findings were compared with the final diagnoses at surgery. RESULTS: Intraductal US was successful in all patients. The extraluminal cause of the common hepatic duct stricture was detected in 14 patients (87.5%). In 9 patients, intraductal US detected an impacted stone outside the common hepatic duct. Intraductal US demonstrated extraluminal lesions without evidence of a stone in 5 patients, including a mass in 4 and asymmetrical, irregular thickening of the bile duct wall in 1 patient. In the remaining 2 patients, intraductal US demonstrated only a distended gallbladder. CONCLUSIONS: Transpapillary wire-guided intraductal US is useful for assessing biliary strictures with features that suggest Mirizzi syndrome and optimizes management of patients with these findings.

Aged↗

The role of extracorporeal shock wave lithotripsy combined with endoscopic management of impacted cystic duct stones in patients with high surgical risk.

BACKGROUND/AIMS: Cholecystoscopic lithotripsy can be an alternative procedure for the treatment of impacted cystic duct stones in patients who are high risk for surgery. Conventional methods, including electrohydraulic lithotripsy (EHL), occasionally fail due to the inability to access or capture the impacted stones in the narrow, spirally long cystic duct. Using extracorporeal shock wave lithotripsy (ESWL) may be more effective to disintegrate cystic duct stones. The aim of the study is to evaluate the role of ESWL in the endoscopic treatment of impacted cystic duct stones in patients with high operative risk. METHODOLOGY: Eleven patients with impacted cystic duct stones who were at high risk for surgery were included in this study. All of them had had a failed initial attempt of percutaneous transhepatic cholecystoscopic lithotripsy (PTCCS-L) followed by percutaneous transhepatic cholecystostomy. Patients underwent ESWL to disintegrate cystic duct stones with endoscopic removal of fragmented stones. RESULTS: Complete removal of cystic duct stones was achieved in 9 of 11 patients (81.8%). One of the 9 patients (11.1%) was treated solely with ESWL, but the other 8 patients (88.9%) required cholecystoscopic removal of residual fragmented stones after ESWL. Fragmented stones passing through the cystic duct impacted in ampullary region in 3 patients after ESWL. Two patients required transpapillary removal of stones. CONCLUSIONS: Endoscopic stone removal after ESWL for impacted cystic duct stones is a difficult and time-consuming procedure. But, it seems to be a relatively safe alternative to surgery in patients with high surgical risk.

Adult↗