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Biomedical subjects

S J Myung

Publications and source records attributed to S J Myung.

At least 19 recordsLinked to original sources
PubMed2005

Primary colon lymphoma in Korea: a KASID (Korean Association for the Study of Intestinal Diseases) Study.

Although almost all primary colorectal lymphomas are of B-cell lineage in Western countries, primary colorectal T-cell lymphomas are not uncommon in the East. The aim of this study was to review the clinical characteristics and treatment outcomes of primary colorectal lymphomas, with special emphasis on the differences between T-cell and B-cell lymphomas. Ninety-five cases of primary colorectal lymphomas that satisfied Dawson's criteria were identified from the clinical databases of 13 university hospitals in Korea. The mean age at the time of presentation was 51.1 years and the male:female ratio was 64:31. The clinical information, including endoscopic and histological characteristics, was retrospectively analyzed. Of the primary colorectal lymphomas, 78 cases (82.1%) were of B-lineage and 17 cases (17.9%) were of T-cell lineage. Patients with T-cell lymphomas presented at a younger age than patients with B-cell lymphomas (42.8 vs 52.9 years, respectively; P = 0.016). The most common presenting symptom was abdominal pain (87.1%) for B-cell lymphomas, whereas hematochezia or night fever was more common for T-cell lymphomas (52.9% and 35.3%, respectively). The most common endoscopic type was fungating mass (54.0%) for B-cell lymphomas and ulcerative/ulcero-infiltrative lesions (80.0%) for T-cell lymphomas. Intussusception was more common in B-cell lymphomas than in T-cell lymphomas (30.8% vs 5.9%, respectively; P = 0.035), but perforation was more common in T-cell lymphomas than in B-cell lymphomas (23.5% vs 3.8%, respectively; P = 0.005). The prognosis was significantly worse for T-cell lymphomas than for B-cell lymphomas (P = 0.002). Primary colorectal T-cell lymphomas are characterized by multifocal ulcerative lesions in relatively young patients, a high rate of hematochezia, fever, or perforation, and a poor prognosis even for cases of localized disease.

Adolescent↗
PubMed2001

The antioxidant effect of rebamipide on oxygen free radical production by H. pylori-activated human neutrophils: in comparison with N-acetylcysteine, ascorbic acid and glutathione.

Helicobacter pylori(H. pylori)-activated neutrophils produce the oxygen-derived free radicals (OFRs) which play an important role in gastric mucosal cell damage. Rebamipide (2-(4-chlorobenzoylamino)-3-[2-(1H)-quinolinon-4-yl] propionic acid) is an antiulcer compound, which protects gastric mucosa against OFR-mediated injury. In order to investigate the effects of rebamipide on OFR production and to compare the antioxidant activity of rebamipide with those of three known antioxidants, N-acetylcysteine (AC), ascorbic acid (Vit C) and glutathione (GSH), the antioxidant activities were determined by luminol-dependent chemiluminescence (ChL) assay and pyrogallol autoxidation assay. The ChL value was markedly elevated immediately after the addition of H. pylori into the medium containing neutrophils. The antioxidant activity of 1.0 mM rebamipide was greater than that of 0.1 mM rebamipide in the luminol-dependent ChL assay, while in the pyrogallol autoxidation assay, the antioxidant activity of 1.0 mM rebamipide was similar to that of 0.1 mM rebamipide. Rebamipide inhibited OFR generation in the pyrogallol autoxidation assay, with the potency being in the order of GSH > Vit C > rebamipide > AC. In the luminol-dependent ChL assay, the antioxidant activity of rebamipide was the greatest among them. These results indicate that rebamipide is a potent antioxidant and scavenges OFRs produced by H. pylori effectively in luminol-dependent ChL assays.

Acetylcysteine↗
PubMed2001

Percutaneous transhepatic cholangioscopic treatment for hepatolithiasis: an evaluation of long-term results and risk factors for recurrence.

BACKGROUND: Percutaneous transhepatic cholangioscopy (PTCS) has a major role in the treatment of hepatolithiasis. The aims of this study were to evaluate immediate and long-term results of PTCS treatment and to elucidate the risk factors for recurrence of stones or cholangitis. METHODS: A retrospective study was conducted of patients with hepatolithiasis who underwent PTCS treatment. A total of 92 patients underwent PTCS treatment and 68 were followed for 24 to 60 months (median 42 months). RESULTS: Complete clearance of stones was achieved in 74 (80%) patients. The rate of complete clearance was significantly lower in patients with severe intrahepatic strictures compared with that for those with no strictures (14 of 24, 58% vs. 16 of 16, 100%, p < 0.01) and those with mild to moderate strictures (14 of 24, 58% vs. 44 of 52, 85%, p < 0.05). Patients with severe intrahepatic strictures had a higher recurrence rate than those with no or mild strictures (100% vs. 28%, p < 0.01). In addition the recurrence rate in patients with advanced biliary cirrhosis (Child's class B or C) was higher than in those with no or mild (Child's class A) cirrhosis (89% vs. 29%, p < 0.01). In patients with type I and II hepatolithiasis (Tsunoda classification), stones recurred in 2 (12%) patients at 28 and 32 months after successful stone removal, without further recurrence afterwards. The recurrence rate in patients with type III and IV hepatolithiasis increased gradually up to 50% at 60 months of follow-up. CONCLUSIONS: Severe intrahepatic stricture was the only factor that affected the immediate success rate of PTCS in the treatment of hepatolithiasis. Several risk factors including severe biliary stricture, advanced biliary cirrhosis and Tsunoda type III and IV affected the long-term results.

Adult↗
PubMed2000

Detection of Helicobacter pylori DNA in human biliary tree and its association with hepatolithiasis.

Recently, several authors have reported that Helicobacter pylori DNA has been found in human bile. The aim of this study is to investigate the presence of H. pylori in the biliary tree of Koreans, including the bile, biliary epithelium, and gallstones. This study analyzed intrahepatic bile, bile duct tissue, and gallstones from 43 patients with hepatobiliary disease (PTCS group), gallbladder bile and tissue from 23 patients with gallbladder disease (CCT group), and eight patients without hepatobiliary disease (control group). H. pylori was examined by PCR with two different primers. PCR was positive in 4/43 (9.3%) by 26 kDa protein antigen primer and in 5/43 (11.6%) by urease A gene primer in bile from the PTCS group. However, in intrahepatic duct tissue, PCR was positive in only one case. PCR of gallbladder bile, tissue, and intrahepatic duct stones was negative. Upon intrahepatic bile analysis, the pH was significantly lower in PCR-positive than in negative cases (P < 0.05). In conclusion, H. pylori DNA may be present in the bile when there are certain environmental changes, such as lowered pH; however, H. pylori does not colonize the bile duct epithelium. We could find no pathogenetic role for H. pylori in the formation of hepatolithiasis.

Adult↗
PubMed2000

Mucin-hypersecreting bile duct tumor characterized by a striking homology with an intraductal papillary mucinous tumor (IPMT) of the pancreas.

BACKGROUND AND STUDY AIMS: The mucin-hypersecreting bile duct tumor, which closely resembles an intraductal papillary mucinous tumor (IPMT) of the pancreas, is rare, and its clinical features are not well known. We report our experience of nine patients with this type of tumor, and analyze the data in order to elucidate its clinicopathologic characteristics. PATIENTS AND METHODS: Between 1995 and 1998, nine consecutive patients (four men, five women; mean age 54) who were diagnosed as having a mucin-hypersecreting bile duct tumor were enrolled in this study. RESULTS: Recent or previous attacks of biliary pain and acute cholangitis were reported by most of the patients. Characteristics included a widely open ampulla of Vater with extrusion of mucin, and a diffuse dilated intrahepatic and extrahepatic bile duct with amorphous filling defects on cholangiogram. On cholangioscopic examination, a papillary mass or minute mucosal lesion was found in the dilated bile duct containing thick viscid mucin. Nine patients were referred for an operation, and curative resection was performed in eight of them. Using histologic examination, well differentiated adenocarcinoma in the background of benign hyperplasia and adenoma was documented in all patients except one, who showed pure adenoma. CONCLUSION: The mucin-hypersecreting bile duct tumor can be characterized by a striking homology with IPMT of the pancreas in clinical, radiologic, and pathologic features.

Adenocarcinoma, Mucinous↗
PubMed2000

Telomerase activity in pure pancreatic juice for the diagnosis of pancreatic cancer may be complementary to K-ras mutation.

BACKGROUND: The usefulness of K-ras mutation in pancreatic juice for the diagnosis of pancreatic cancer is questionable. Telomerase is positive in pancreatic cancer but rarely in benign pancreatic diseases. We conducted this study to determine the usefulness of K-ras mutation and telomerase activity in pancreatic juice for the diagnosis of pancreatic cancer. METHODS: Pancreatic juice collected during endoscopic retrograde cholangiopancreatography was examined in 31 patients: 12 with pancreatic cancer, 11 with chronic pancreatitis, and 8 control patients. The K-ras gene was detected by using the restriction fragment length polymorphism method. Telomerase activity was detected by using the telomeric repeat amplification protocol. RESULTS: K-ras mutation was positive in 75% (9 of 12) of pancreatic cancers and in 27% (3 of 11) of cases of chronic pancreatitis but in none of the control patients. Telomerase activity was detected in 92% (11 of 12) of pancreatic cancers and in 18% (2 of 11) of cases of chronic pancreatitis. The diagnostic value in pancreatic cancer was comparable between K-ras mutation and telomerase when evaluated separately. However, by combining these 2 methods, the specificity rose to 100%. CONCLUSIONS: For the diagnosis of pancreatic cancer, telomerase activity in pancreatic juice may possibly be complementary to K-ras mutation because it may decrease the rate of false-positive diagnosis.

Aged↗
PubMed2000

A new strategy to predict the neoplastic polyps of the gallbladder based on a scoring system using EUS.

BACKGROUND: A new method to predict neoplastic polyps of the gallbladder using a scoring system based on five endoscopic ultrasonography (EUS) variables is presented. METHODS: EUS data from patients with gallbladder polyps who were to undergo cholecystectomy were used for the construction of an EUS scoring system in polyps between 5 and 15 mm in diameter (reference group). The EUS scoring system developed from those patients was applied to other patients (validation group). RESULTS: In the reference group, size was the most significant predictor of neoplastic polyp. All polyps 5 mm or less in diameter were non-neoplastic and 94% of polyps of greater than 15 mm were neoplastic in the reference group. For polyps between 5 and 15 mm in diameter, the area under the receiver-operating characteristic curves (ROC) plots for the endoscopic scoring system was significantly greater than that under the ROC plots for polyp size alone (p < 0.01). In the validation group, the risk of neoplastic polyp was significantly higher for polyps with a score of 6 or greater compared with those with a score of less than 6 (p < 0.01). CONCLUSIONS: Our data show that a score based on five EUS variables identifies those patients at risk of neoplasia when polyps are between 5 and 15 mm in diameter. (Gastrointest Endosc 2000;52:372-9).

Adult↗
PubMed2000

Novel testing of human gastric motor and sensory functions: rationale, methods, and potential applications in clinical practice.

Sensitive and reproducible tests are essential to investigate the mechanisms of gastric motility and sensation in healthy humans and patients with unexplained upper gastrointestinal symptoms. Electrogastrography, manometry, scintigraphic emptying, and barostat studies with an intragastric balloon were initially used to understand physiology and pathophysiology of gastric motility. However, manometry and barostat studies are time-consuming, costly, and invasive, thus reducing their widespread clinical application. To overcome these shortcomings, several novel approaches have been proposed: water/nutrient drink test, paracetamol absorption test, 13C-octanoic acid or spirulina breath tests, ultrasonography, magnetic resonance imaging (MRI), single photon emission computed tomography (SPECT), and tensostat. The water/nutrient (satiety) test is a noninvasive test proposed as an alternative to sensory studies performed with an intragastric balloon. The satiety test cannot measure gastric accommodation; interpretation of sensory tests usually has required independent assessment of accommodation or compliance. The tensostat can be used as a gastric sensation test because it measures gastric wall tension, which is related to the perception of gastric distention. To measure gastric emptying, the paracetamol absorption test, 13C breath tests, ultrasound, or MRI can be used. The paracetamol absorption test can measure the gastric emptying of liquids. 13C breath test can measure the gastric emptying of solids or liquids and can achieve accuracy comparable with gastric scintigraphy. Ultrasonography requires special skills, and MRI requires costly equipment. To measure gastric accommodation to a meal, ultrasound, MRI, and SPECT have been proposed. The recently introduced SPECT requires an intravenous injection of 99mTc-pertechnetate, which the gastric mucosa specifically takes up, and specialized imaging and analysis, which have potential to be automated. Thus, novel, noninvasive approaches assess different dimensions of gastric motility and sensation testing. With further development of these techniques, refinement of their conduct and analysis, and validation of clinical usefulness, they are likely to be applicable in clinical practice to enhance cost-effective, evidence-based management of upper gastrointestinal symptoms. Such applications may provide an alternative to sequential empirical trials for symptoms.

Acetaminophen↗
PubMed1999

Appendiceal orifice inflammation as a skip lesion in ulcerative colitis: an analysis in relation to medical therapy and disease extent.

BACKGROUND: Although several reports have claimed that the appendix can be involved as a skip lesion in ulcerative colitis, they do not exclude the possibility that this skip lesion occurs as a result of medical therapy. Also, little is known about the relation between the presence of appendiceal orifice inflammation and the extent of the disease. METHODS: The presence of appendiceal orifice inflammation was prospectively assessed both endoscopically and histologically in 94 patients with active ulcerative colitis, the extent of whose disease had not been beyond the hepatic flexure. To evaluate the effect of prior medical therapy on the prevalence of appendiceal orifice inflammation, all cases were divided into two groups. Group A consisted of 66 patients who had been treated before inclusion; group B was composed of 28 patients newly diagnosed at inclusion. RESULTS: Appendiceal orifice inflammation was diagnosed in 24 (26%) of 94 patients with active subtotal ulcerative colitis, with no statistical difference observed between group A (23%) and group B (32%). In all 94 patients, the frequency of appendiceal orifice inflammation decreased significantly as the extent of disease increased, i.e., 37% in proctitis (n = 49), 17% in left-sided colitis (n = 36), and 0% in extensive colitis (n = 9) (p < 0.05). CONCLUSIONS: Appendiceal orifice inflammation as a skip lesion of ulcerative colitis is not rare, is more frequently observed in patients with less extensive disease, and is not the result of patchy improvement due to medical therapy.

Adult↗
PubMed1999

Usefulness of cholangioscopy in patients with focal stricture of the intrahepatic duct unrelated to intrahepatic stones.

BACKGROUND: Intrahepatic duct strictures are usually caused by intrahepatic duct stones and cholangitis. However, focal strictures of the intrahepatic duct unrelated to intrahepatic stones often pose diagnostic problems. This study was undertaken to prospectively evaluate the usefulness of percutaneous transhepatic cholangioscopy in patients with focal intrahepatic duct stricture and no evidence of a stone. METHODS: Seventeen patients with focal strictures of the intrahepatic duct without any evidence of a stone were included. Percutaneous transhepatic cholangioscopic examination including procurement of biopsy specimens was performed after percutaneous transhepatic biliary drainage. RESULTS: A histopathologic diagnosis was obtained in all patients (9 adenocarcinomas, 1 squamous cell carcinoma, 2 hepatocellular carcinomas, 2 adenomas, and 3 benign strictures). Of the 9 patients with bile duct adenocarcinoma, 8 underwent surgery and a curative resection was possible in 7 patients (88%). Five patients (63%) had early-stage bile duct cancer in which cancer invasion was limited to the mucosa or fibromuscular layer and there was no evidence of lymph node metastasis. CONCLUSIONS: Percutaneous transhepatic cholangioscopy in patients with focal stricture of the intrahepatic duct unrelated to choledocholithiasis is useful for diagnosis including the detection of early bile duct cancer.

Adult↗
PubMed1999

Epidemiological study on Korean gallstone disease: a nationwide cooperative study.

To clarify the epidemiological characteristics of gallstone disease in Korea and to evaluate the chronological changes in gallstone disease, the authors performed this first prospective nationwide cooperative study. The subjects were 1263 gallstone patients who were admitted at 19 hospitals in Korea from February to July 1997. Questionnaires were recorded on 1263 patients and gallstones were harvested from 1133 patients. The proportion of patients with gallbladder (GB), common bile duct (CBD), and intrahepatic duct (IHD) stones among total gallstone patients was 64.0%, 21.9%, and 14.1%, respectively. GB stones were categorized as cholesterol (58.1%), black pigment (25.2%), and brown pigment (12.1%) stones. CBD stones were classified as brown pigment (76.1%), cholesterol (18.4%), and black pigment (3.5%) stones. IHD stones were classified as brown pigment (61.4%) and mixed (35.6%) stones. Intrahepatic mixed stones had mean cholesterol and bilirubin contents of 63.4 +/- 20.8% and 23.1 +/- 9.9%, respectively. In contrast, IHD brown pigment stones had mean cholesterol and bilirubin contents of 35.1 +/- 20.5% and 39.6 +/- 17.4%, respectively. Our study showed that the type and composition of gallstones in Korea was somewhat different compared with those in the West. This study also demonstrated that there have been chronological changes in the type and composition of gallstones when compared with previous domestic data. Another nationwide cooperative study may be needed to elucidate and confirm the changing pattern of gallstone disease.

Adolescent↗
PubMed1999

Endoscopic hemostasis in sphincterotomy-induced hemorrhage: its efficacy and safety.

BACKGROUND AND STUDY AIMS: Hemorrhage is induced in approximately 0.5-12% of endoscopic biliary sphincterotomy (ES) procedures. We prospectively investigated the risk factors for ES-induced hemorrhage and evaluated the safety as well as the effectiveness of endoscopic hemostasis. PATIENTS AND METHODS: The study included 1304 patients who underwent ES between July 1996 and June 1998. Epinephrine spray was used initially for hemostatic treatment. If bleeding persisted, an epinephrine injection was given consecutively. In patients with exposed vessels, epinephrine injection followed by alcohol injection was given. RESULTS: ES-induced hemorrhage occurred in 136 (10.4%) patients. The type of sphincterotome used (needle-knife sphincterotome, P=0.025) and the cutting speed (the so-called "zipper" cut, P = 0.049) were revealed as significant variables with regard to the occurrence of bleeding. Mild, moderate, and severe bleeding were noted in 108 (79.4%), 22 (16.2%), and six (4.4%) patients, respectively. Once bleeding occurred, patients with an associated ampullary lesion (impacted stone or cancer) or with coagulopathy were more likely to bleed profusely. Initial hemostasis was achieved in all patients. However, rebleeding occurred in eight patients who were initially classified as having moderate or severe bleeding. Finally, ES-induced hemorrhage was successfully controlled in all patients after 1-3 treatment sessions (mean 1.1 sessions). The difference in the incidence of complications between the groups treated or not treated by endoscopic hemostasis was not statistically significant. CONCLUSIONS: ES-induced hemorrhage occurred in 10% of the patients studied. The use of needle-knife sphincterotomy and the cutting speed were independent risk factors for the occurrence of bleeding. Once bleeding occurred, its severity was affected by an associated ampullary lesion (impacted stone or cancer) or coagulopathy. Endoscopic hemostasis with epinephrine and/or alcohol was effective and safe in ES-induced hemorrhage.

Biliary Tract Diseases↗