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J B Chung

Publications and source records attributed to J B Chung.

At least 19 recordsLinked to original sources
PubMed2006

Endoscopic resection of benign tumors of the papilla of vater.

Most benign papillary tumors are adenomas which can potentially undergo the adenoma-carcinoma-sequence making complete removal mandatory for curative therapy. Endoscopic resection (papillectomy) of these lesions is being increasingly performed as a less traumatic alternative to surgery. Available data shows endoscopic papillectomy to be effective and safe in experienced hands with usually little morbidity and virtually no mortality. Success rates are around 80 % for lesions without intraductal involvement. Selected cases of limited distal intraductal involvement accessible after sphincterotomy may also be managed curatively by endoscopic resection. Endoscopic snare resection of entire lesions should be primarily regarded as a diagnostic procedure. It allows for an accurate histological diagnosis based on examination of the entire specimen rather than forceps biopsies and thus a reliable assessment of the need for surgical therapy. Subsequent surgery in operable patients is not precluded by previous endoscopic resection. Surgery is indicated in case of incomplete removal and if malignancy is present. The curative role of endoscopic papillectomy for early invasive carcinoma needs to be established. Histological features and individual risk for surgery are factors to be considered. Inoperable patients may still benefit from palliative endoscopic stenting. After endoscopic papillectomy has been completed, regular follow-up examinations including biopsies are warranted because of the risk of local recurrence. For benign looking papillary tumors, endoscopic papillectomy serves as a diagnostic tool and should be considered as first line procedure regardless of age. The following article details the approach to patients with benign papillary tumor and the technique of endoscopic papillectomy.

Ampulla of Vater↗
PubMed2001

Cutting edge: differential sequestration of plasma membrane-associated B cell antigen receptor in mature and immature B cells into glycosphingolipid-enriched domains.

Glycosphingolipid-enriched domains (GEDs) are believed to act as platforms for transduction of B cell Ag receptor (BCR)-induced signals from the cell surface. We sought to study whether differential sequestration of BCR into GEDs may contribute to the described intrinsic signaling differences between mature and immature B cells. In this study we found that mature B cells copolarize the BCR with GEDs following BCR aggregation, whereas transitional immature B cells do not. Although anti-BCR treatment leads to receptor aggregation by immature stage B cells, the aggregated complexes do not colocalize with GEDs. We found this difference to be independent of the isotype of the receptor, thereby associating this difference in BCR-GED colocalization to the developmental stage of the B cell. These findings suggest a structural basis for the developmentally regulated differences observed in Ag receptor-mediated signal transduction.

Animals↗
PubMed2000

Cost-effectiveness of prophylaxis against Pneumocystis carinii pneumonia in patients with Wegner's granulomatosis undergoing immunosuppressive therapy.

OBJECTIVE: To assess the incremental cost-effectiveness of 3 Pneumocystis carinii pneumonia (PCP) prophylaxis strategies in patients with Wegener's granulomatosis (WG) receiving immunosuppressive therapies: 1) no prophylaxis; 2) trimethoprim/sulfamethoxazole (TMP/SMX) 160 mg/800 mg 3 times a week, which is discontinued if patients experience an adverse drug reaction (ADR); and 3) TMP/SMX 160 mg/800 mg 3 times a week, which is replaced by monthly aerosolized pentamidine (300 mg) if patients experience an ADR. METHODS: A Markov state-transition model was developed to follow a hypothetical cohort of WG patients over their lifetimes starting from the time of initial exposure to the immunosuppressive therapy. The effect of PCP prophylaxis on life expectancy, quality-adjusted life expectancy, average discounted lifetime cost (ADLC), and incremental cost-effectiveness was estimated based on data obtained from a literature review. Direct medical costs were examined from a societal perspective, and costs and benefits were discounted at 3% annually. RESULTS: No prophylaxis resulted in a life expectancy of 13.36 quality-adjusted life years (QALY) at an ADLC of $4,538. In comparison, prophylaxis with TMP/ SMX alone increased the QALY to 13.54 and was cost saving, with an ADLC of $3,304. The addition of pentamidine in patients who had an ADR to TMP/SMX resulted in 13.61 QALY, with an ADLC of $7,428. Compared with TMP/SMX alone, TMP/SMX followed by pentamidine increased the QALY by 0.07 at an incremental cost of $58,037 per QALY. Both TMP/SMX alone and TMP/SMX followed by pentamidine prophylaxis strategies dominated the no prophylaxis strategy until the incidence of PCP fell below 0.2% and 2.25%, respectively. Institution of pentamidine therapy for patients with a TMP/SMX ADR increased quality-adjusted life expectancy compared with that with TMP/ SMX alone until the incidence of PCP rose above 7.5%. CONCLUSION: Prophylaxis using TMP/SMX alone increased life expectancy and reduced cost for patients with WG receiving immunosuppressive therapy. Replacing TMP/SMX with monthly aerosolized pentamidine in cases of ADR further increased life expectancy, although at an increased cost.

Adult↗
PubMed2000

Loss of pendimethalin in runoff and leaching from turfgrass land under simulated rainfall.

A field study was undertaken to investigate runoff and leaching loss of the herbicide pendimethalin in turfgrass land of loamy sand soil. A series of plots constructed in a golf course fairway were surface-applied with pendimethalin SC formulation at the rate of 2. 25 or 4.50 kg a.i./ha and subjected to simulated rainfall at 2.0 cm/day for 10 consecutive days. Runoff losses of pendimethalin were the highest at the first rainfall and then gradually decreased with time. The first runoff event contained pendimethalin in its highest concentration, and in subsequent runoff samples the concentration decreased exponentially. The ranges of pendimethalin concentration were 80.9-18.2 and 177.4-48.6 microgram/L in the standard and double doses, respectively. Total losses by 20 cm of rainfall for 10 days reached 0.81 and 1.22% of the initial deposits at 2.25 and 4.50 kg a. i./ha, respectively. Pendimethalin concentration in the leachate collected at 30-cm soil depth was quite lower than that in the runoff, and the concentration rapidly decreased from 4.3-4.7 to 0. 2-0.4 microgram/L during the 10 days of rainfall treatment. Soil residue analysis at 45 and 90 days after pendimethalin treatment showed that more than 90% of the residue remained at the top 10 cm of soil depth. Low runoff and leaching confirmed that lateral and downward movement of the herbicide should be limited in turf soil. The half-life of pendimethalin under field conditions was 23-30 days and was not affected by application dose and rainfall treatment, but longer persistence was observed under laboratory conditions. Considering low runoff and leaching, as well as relatively short persistence in soil, it is concluded that little environmental carryover of pendimethalin would be expected in turfgrass land.

Aniline Compounds↗
PubMed2000

Tissue plasminogen activator and plasminogen activator inhibitor-1 in human choledochal bile.

Fibrinolytic properties have been detected in animal and human gallbladder (GB) bile. Plasminogen activator inhibitor-1 (PAI-1) has been reported in greater concentration in GB stone bile and may be a nucleating factor in the pathogenesis of GB stone formation. It is unknown whether or not human choledochal bile has similar properties, which could have a role in choledocholithiasis. The aims of this study were to determine the presence of fibrinolytic properties of human choledochal bile and to compare those properties among normal, acalculous, and calculous-infected choledochal bile. Tissue plasminogen activator (t-PA) and PAI-1 of choledochal bile were measured by enzyme linked immunosorbent assay in patients with cholangitis due to acalculous bile duct obstructions (n = 9), choledocholithiasis with cholangitis (n = 20), and normal bile (n = 7). The t-PA concentration of choledochal bile was no different among the three groups (acalculous-infected bile, median 4.61 ng/ml, and calculous-infected bile, 4.61 ng/ml, versus normal bile, 7.33 ng/ml). PAI-1 was detected in choledochal bile in significantly greater concentrations in patients with acalculous cholangitis due to bile duct obstructions and choledocholithiasis with cholangitis (acalculous-infected bile, median 0.36 ng/ml, and calculous-infected bile, 0.1 ng/ml, versus normal bile, 0.02 ng/ml, p < 0.05), but the bile concentration of PAI-1 was no different between the acalculous and calculous-infected choledochal bile. Human choledochal bile possesses t-PA and PAI-1. PAI-1 was present in greater concentrations in both acalculous and calculous-infected choledochal bile. Increased levels of PAI-1 may be an epiphenomenon of cholangitis rather than a factor in the pathogenesis of choledocholithiasis.

Aged↗
PubMed2000

Radiologic findings of Mirizzi syndrome with emphasis on MRI.

We have reported a case of Mirizzi syndrome preoperatively diagnosed using MR cholangiopancreatography. MRCP and T2-weighted image using a single-shot fast spin-echo sequence accurately depicted all components of Mirizzi syndrome, including impacted stone in the neck of the gallbladder compressing the common hepatic duct and wall-thickening of the gallbladder without any evidence of malignancy. The combination of MRCP and T2-weighted image can be counted on to replace conventional modalities of diagnosing Mirizzi syndrome without any loss of diagnostic accuracy.

Bile Duct Diseases↗
PubMed2000

Endoscopic snare resection for tumors of the ampulla of Vater.

Though surgical resection has been the traditional treatment for tumors of the ampulla of Vater, endoscopic maneuvers such as snare resection, laser photodestruction and electrofulguration have recently been introduced to avoid operation-related morbidity and mortality. From 1994 to 1996, 6 patients with ampullary tumor were managed by endoscopic snare resection and regularly followed. Endoscopic snare resection of the ampullary tumor was technically feasible in all patients and each procedure was performed in a single session. Histologic diagnoses of the resected specimens were adenoma in 4 patients and adenoma with coexistent adenocarcinoma in 2 patients. Resection margins were negative in all patients except 1 with coexistent adenocarcinoma and a radical pancreaticoduodenectomy was performed in that case. For the other patient with adenocarcinoma foci, no further treatment was persued since he was 72-year-old and refused operation. Acute pancreatitis developed in 2 patients after endoscopic therapy, but was resolved with conservative management. There was no procedure-related death. Surveillance duodenoscopy performed at 1 and 6 months after endoscopic resection revealed no evidence of recurrent tumor in 4 patients with adenoma. Among them, 3 patients are alive without evidence of recurrence at 16-37 months after resection, but 1 patient was lost after 9 months of follow-up. The patient with adenocarcinoma in whom a pancreaticoduodenectomy was performed, has been alive without recurrence for 12 months. Oral 5-fluorouracil was administered for the other patient with adenocarcinoma foci. Though he experienced local recurrence at 13 months after the procedure, he has been alive for 28 months after resection. In conclusion, endoscopic snare resection may be applied as a viable alternative to surgery in selected patients with small ampullary tumors.

Aged↗
PubMed2000

A case of minute intraductal papillary mucinous tumor of the pancreas presenting with recurrent acute pancreatitis.

Intraductal papillary mucinous tumor (IPMT) of the pancreas, a lesion consisting of mucin-producing cells with neoplastic potential, is characterized by duct ectasia, mucin hypersecretion, often extensive papillary intraductal growth, varying degrees of cytologic atypia, and relatively indolent growth. The clinical presentation of IPMT of the pancreas is characterized by chronic or recurrent attacks of abdominal discomfort often in association with low level pancreatic enzyme elevations. Less commonly these lesions may be detected as asymptomatic radiographic abnormalities. Interestingly, a case of a minute IPMT (2 mm in height and 7 mm in length, adenoma) in the main pancreatic duct presenting with acute pancreatitis in a 55 year-old man has been reported in the Japanese literature. Recently, we also experienced a case of a minute IPMT in a branch pancreatic duct causing repeated bouts of acute pancreatitis in a 75 year-old man. A filling defect at the neck of the main pancreatic duct seen on an endoscopic retrograde pancreatogram performed after recovery of the second attack of acute pancreatitis led the patient to undergo an exploratory laparotomy. After a near-total pancreatectomy was carried out, a minute (3 x 7 mm) IPMT of borderline malignancy was discovered in a branch duct at the head portion near the pancreatic neck without any lesions in the main pancreatic duct. Surprisingly, despite the resective surgery the patient died of carcinomatosis 8.5 months after the operation. We herein report a case of a minute but aggressive IPMT of the pancreas with a review of the literature.

Acute Disease↗
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 retrograde pancreatographic findings of pancreatic lipomatosis.

Pancreatic lipomatosis is characterized by fatty infiltration or replacement of the pancreas, and has been associated with many conditions. We recently experienced two cases of pancreatic lipomatosis in patients with pancreatic pseudocyst and a case of lipomatosis in diabetes mellitus. In these patients, abrupt obstruction of the main pancreatic duct with smooth tapering is a typical endoscopic retrograde pancreatography (ERP) finding of pancreatic lipomatosis and must be differentiated with pancreatic carcinoma.

Adult↗
PubMed1999

Villous adenoma of the bile ducts: a case report and a review of the reported cases in Korea.

Villous adenomas are benign epithelial lesions with malignant potential which can occur at any site in the gastrointestinal tract. They are usually encountered in the rectum and colon, less frequently in the small bowel and very rarely in the biliary trees. Nine cases of bile duct villous adenomas have been reported in the literature. However, 4 cases of bile duct villous adenomas have been reported in the Korean literature. Recently, we experienced a case of villous adenoma in the common hepatic duct in a 77-year-old man presenting with obstructive jaundice in which preoperative histologic diagnosis of villous adenoma played a critical role in managing this patient. Herein, we present a case report of bile duct villous adenoma and a review of the reported cases in Korea to help define and manage this rare disease entity in the bile ducts. In addition, confusing nomenclature of bile duct adenomas is discussed.

Adenoma, Villous↗
PubMed1999

Obstructive jaundice and acute cholangitis due to papillary stenosis.

Papillary stenosis is characterized by fixed fibrosis leading to structural outflow obstruction and it is usually secondary to inflammation and fibrosis from the chronic passage of gallstones, episodes of acute pancreatitis, chronic pancreatitis, sclerosing cholangitis, peptic ulcer disease, and cholesterolosis. However, obstructive jaundice with or without acute cholangitis which leads the physician to suspect the presence of malignancy as a cause is a rare manifestation of papillary stenosis. We report here a case of papillary stenosis presenting with obstructive jaundice and acute cholangitis. The lesion was so difficult to exclude the presence of malignancy preoperatively and intraoperatively that a pylorus-preserving pancreaticoduodenectomy was performed. Histologic examination of the resected specimen revealed fibrosis, adenomatoid ductal hyperplasia, and mild chronic inflammation of the papilla of Vater and distal common bile duct.

Acute Disease↗
PubMed1999

Non-alcoholic duct-destructive chronic pancreatitis: recognition before definitive treatment.

Non-alcoholic duct-destructive chronic pancreatitis is a new entity that differs morphologically and pathogenetically from alcoholic chronic pancreatitis. Some clinical and imaging features of this entity resemble those of pancreatic cancer, and hence most of the reported cases underwent pancreatic resections including an invasive pancreaticoduodenectomy. Recognition of this new entity before a definitive treatment is therefore important to avoid an unnecessary pancreatic resection. Recently, we experienced a case of non-alcoholic duct-destructive chronic pancreatitis in an 80-year-old man presenting with obstructive jaundice and whose radiologic features were characteristic as originally described. Recognition of this new entity before definitive treatment enabled us to manage this patient optimally. In addition, the relation between non-alcoholic duct-destructive chronic pancreatitis and chronic pancreatitis with diffuse irregular narrowing of the main pancreatic duct is discussed.

Aged↗