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Biomedical subjects

S C Chung

Publications and source records attributed to S C Chung.

At least 55 records · Page 3Linked to original sources
PubMed2000

Diagnostic and therapeutic fistuloscopy: an adjuvant management in postoperative fistulas and abscesses after upper gastrointestinal surgery.

BACKGROUND AND STUDY AIMS: Postoperative fistulas and abscesses pose difficult management problems. We report our experience in the use of fistuloscopy in postoperative fistulas and abscesses after upper gastrointestinal surgery. PATIENTS AND METHODS: From June 1993 to January 1997, nine patients (seven men, two women; mean age 65) with postoperative fistulas and abscesses were treated with therapeutic fistuloscopy. Diagnostic fistuloscopy was carried out using a 5-mm choledochoscope under fluoroscopic guidance. Therapeutic procedures included mechanical debridement, irrigation, and sealing of fistula with fibrin sealant and gelatin sponge. RESULTS: The patients were suffering from duodenal stump fistula (three cases), gastrojejunostomy dehiscence after gastrectomy (three cases), gastropleurocutaneous fistula (two cases), and subphrenic abscesses (two cases). Fistuloscopy was performed 4-19 days (mean 12 days) after the diagnosis of the fistula. The median number of sessions required was 2 (range 1-4). The average daily fistula output prior to fistuloscopy was 154 ml (range 30-560 ml), and all fistulas healed in an average of 18.7 days (range 2-46 days) after index fistuloscopy. No procedure-related complications occurred. The mean hospital stay was 61 days. During a mean follow-up period of 12 months, no recurrent abscesses or fistulas developed. CONCLUSIONS: Fistuloscopy provides a new means of managing patients with postoperative fistula and abscess formation.

Abscess↗
PubMed2000

EUS-guided injection of cyanoacrylate for bleeding gastric varices.

BACKGROUND: Bleeding gastric varices is a highly fatal condition. Recurrent bleeding after hemostasis achieved by endoscopic methods is common, and obliteration of gastric varices is difficult to assess. Our aim was to investigate the use of endosonography (EUS) in monitoring cyanoacrylate injection to obliterate gastric varices. METHODS: Patients who presented with bleeding gastric varices were treated with bolus injection(s) of cyanoacrylate (0.5 mL cyanoacrylate mixed with 0.7 mL Lipiodol) until bleeding was controlled; 47 patients received "on-demand" injection only in response to recurrent bleeding (on-demand group). Another group of 54 patients underwent biweekly EUS followed by repeated injection of cyanoacrylate (repeated-injection group) until all gastric varices were obliterated. The primary outcome was recurrent bleeding-free interval and survival rate. RESULTS: The two groups of patients were comparable demographically. Although the rates of early (</=48 hour) bleeding recurrence were similar with repeated or on-demand injection (7.4% versus 12.8%, p = 0.5), late recurrence of bleeding (>48 hour) was significantly reduced in the repeated-injection group (18.5% versus 44.7%, p = 0.0053, odds ratio 0.28 (95% CI [0.12, 0. 69]). Cumulative probability of recurrent bleeding-free interval was higher in the repeated-injection than the on-demand group (log-rank test, p = 0.0053). There was a numeric trend toward improved survival in the repeated-injection group. CONCLUSION: Gastric varices obliteration with cyanoacrylate under EUS monitoring reduces recurrent bleeding and may improve survival.

Adult↗
PubMed2000

Prevalence and patterns of nocturnal bruxofacets on stabilization splints in temporomandibular disorder patients.

The purpose of this study was to investigate the prevalence of nocturnal bruxism, the characteristics of bruxofacets, and the reduction of symptoms in temporomandibular disorder (TMD) patients. The study involved the observation of bruxofacets on a stabilization splint. Twenty-six patients (22 women and 4 men, 16-54 years of age) with signs and symptoms of TMD were given an initial examination before using a splint, and then at intervals of one, three, six and ten weeks after a stabilization splint was first used. In 88% of the patients (n = 23) active shiny facets or scratches caused by nocturnal bruxism appeared on the occlusal surface of splints within ten weeks. In 52% of the 23 patients these facets were created by bilateral mandibular excursions, in 35% by small lateral movements, and in 13% by unilateral excursions. Subjective pain and the Craniomandibular Index in patients had decreased after ten weeks (p < 0.001), but a reduction of symptoms did not differ according to the patterns of the bruxofacets. It was concluded that most TMD patients have a parafunctional habit, namely bruxism. Further research is needed to produce more convincing evidence of a true cause-and-effect relationship between nocturnal bruxism and TMD.

Adolescent↗
PubMed2000

Eradication of Helicobacter pylori prevents recurrence of ulcer after simple closure of duodenal ulcer perforation: randomized controlled trial.

OBJECTIVE: In this randomized trial, the authors sought to determine whether eradication of Helicobacter pylori could reduce the risk of ulcer recurrence after simple closure of perforated duodenal ulcer. BACKGROUND DATA: Immediate acid-reduction surgery has been strongly advocated for perforated duodenal ulcers because of the high incidence of ulcer relapse after simple patch repair. Although H. pylori eradication is now the standard treatment of uncomplicated and bleeding peptic ulcers, its role in perforation remains controversial. Recently a high prevalence of H. pylori infection has been reported in patients with perforations of duodenal ulcer. It is unclear whether eradication of the bacterium confers prolonged ulcer remission after simple repair and hence obviates the need for an immediate definitive operation. METHODS: Of 129 patients with perforated duodenal ulcers, 104 (81%) were shown to be infected by H. pylori. Ninety-nine H. pylori-positive patients were randomized to receive either a course of quadruple anti-helicobacter therapy or a 4-week course of omeprazole alone. Follow-up endoscopy was performed 8 weeks, 16 weeks (if the ulcer did not heal at 8 weeks), and 1 year after hospital discharge for surveillance of ulcer healing and determination of H. pylori status. The endpoints were initial ulcer healing and ulcer relapse rate after 1 year. RESULTS: Fifty-one patients were assigned to the anti-Helicobacter therapy and 48 to omeprazole alone. Nine patients did not undergo the first follow-up endoscopy. Of the 90 patients who did undergo follow-up endoscopy, 43 of the 44 patients in the anti-Helicobacter group and 8 of the 46 in the omeprazole alone group had H. pylori eradicated; initial ulcer healing rates were similar in the two groups (82% vs. 87%). After 1 year, ulcer relapse was significantly less common in patients treated with anti-Helicobacter therapy than in those who received omeprazole alone (4.8% vs. 38.1%). CONCLUSIONS: Eradication of H. pylori prevents ulcer recurrence in patients with H. pylori-associated perforated duodenal ulcers. Immediate acid-reduction surgery in the presence of generalized peritonitis is unnecessary.

Anti-Bacterial Agents↗
PubMed2000

Beta-endorphin infusion during exercise in rats: blood metabolic effects.

UNLABELLED: Beta-endorphin (betaE) bolus (0.05 mg x kg(-1)) infusion (0.05 mg x kg(-1) x h(-1)) was previously shown in rats to attenuate the decline in plasma glucose during exercise. PURPOSE: The present investigation compared betaE and saline infusion in rats without a bolus of betaE to determine whether 1) the attenuation in the glucose decline was attributable to the type of administration (bolus betaE + continuous betaE infusion vs continuous betaE infusion), and 2) whether circulating catecholamines or FFAs were in part involved in the glucose decline. METHODS: Forty untrained Sprague-Dawley rats were randomly assigned to one of four treatments: 1) betaE infusion at rest (betaR), 2) betaE infusion during exercise (betaX), 3) saline infusion at rest (SR), and 4) saline infusion during exercise (SX). Infusions (betaE or saline) with running (22 m x min(-1), 0% grade) lasted 90 min. RESULTS: A 2 x 2 ANOVA indicated betaE infusion significantly attenuated the decline in plasma glucose due to exercise at 90 min (SX = 4.16 +/- 0.1 vs betaX = 4.61 +/- 0.1 mM). BetaE infusion elevated plasma betaE about 2.5-fold at rest compared with SR and two-fold after exercise (betaX) compared with SX. BetaE infusion had no effect at rest on any of the other variables measured. Exercise significantly increased catecholamines, FFAs and glucagon compared with resting levels. BetaE infusion enhanced the glucagon response to exercise (SX = 577 +/- 67.5 vs betaX = 913 +/- 153 ng x L(-1), P < 0.02). Epinephrine and norepinephrine and FFAs were similar with betaE infusion either at rest or during exercise compared with saline infusion. CONCLUSION: These results suggest that betaE infusion independent of the betaE bolus can attenuate the decline in glucose during exercise by enhancing glucagon levels and the betaE infusion did not influence circulating catecholamines or FFA's response to exercise.

Animals↗
PubMed2000

Total activation change of visual and motor area due to various disturbances.

Brain activation is affected by gradient acoustic noise and various disturbances as well as by other primary tasks. Therefore, we have studied the effects of various disturbances of two different levels of difficulty, that is, weak and strong difficulty levels for primary visual and motor tasks. In the case of visual task with motor and mental disturbances, we found it decreased as motor and mental disturbance difficulty-level increased, compared with the case of without motor and mental disturbances. To the contrary, in the case of motor activity, the total activation of motor cortex with weak and with strong mental disturbance increased as mental disturbance difficulty-levels increased. Therefore, one can conclude that when mental disturbance is added, the visual cortex and motor cortex have an opposite result and when the difficulty-level of the disturbance is increased, the primary tasks are affected more significantly. Although the current observation is preliminary and requires more careful experimental study, it appears that various disturbance effects on brain functions (such as motor and visual cortical responses) produce significant differences in data observations.

Brain Mapping↗
PubMed2000

Reliability and characteristics of current perception thresholds in the territory of the infraorbital and inferior alveolar nerves.

AIMS: To estimate the intra- and interrater reliability of current perception threshold (CPT) evaluation, especially within the infraorbital nerve territory (ION) and inferior alveolar nerve territory (IAN) of the orofacial region, and to characterize the CPTs of ION and IAN in the normal population. METHODS: Electrical stimulation (at 2,000 Hz, 250 Hz, and 5 Hz) was applied to ION and IAN to allow for CPT evaluation in 200 subjects, all of whom were healthy, had no systemic diseases, and were free from symptoms and history of neuropathic conditions. Twenty-five of the subjects were evaluated 3 times by 2 examiners to test reliability, and the remaining subjects were evaluated once for normative data. RESULTS: The intraclass correlation coefficient of CPTs within examiner and between examiners ranged from 0.46 to 0.95. There were no significant differences between right and left sides in CPT evaluation within the ION and IAN territory. Gender and age did not affect the CPT values for ION and IAN in the normal population. There were significant differences between each of the 3 frequency-dependent (2,000 Hz, 250 Hz, 5 Hz) measures within ION and IAN (P < 0.001). CONCLUSION: Evaluation of CPTs within ION and IAN revealed good intra- and interrater reliability. The study also provided normative data of CPTs of ION, IAN, and the between-site and within-site ratios of CPTs of ION and IAN. This should prove useful in the diagnosis of orofacial neuropathy.

Adolescent↗
PubMed1999

Endoscopic retreatment compared with surgery in patients with recurrent bleeding after initial endoscopic control of bleeding ulcers.

BACKGROUND AND METHODS: After endoscopic treatment to control bleeding of peptic ulcers, bleeding recurs in 15 to 20 percent of patients. In a prospective, randomized study, we compared endoscopic retreatment with surgery after initial endoscopy. Over a 40-month period, 1169 of 3473 adults who were admitted to our hospital with bleeding peptic ulcers underwent endoscopy to reestablish hemostasis. Of 100 patients with recurrent bleeding, 7 patients with cancer and 1 patient with cardiac arrest were excluded from the study; 48 patients were randomly assigned to undergo immediate endoscopic retreatment and 44 were assigned to undergo surgery. The type of operation used was left to the surgeon. Bleeding was considered to have recurred in the event of any one of the following: vomiting of fresh blood, hypotension and melena, or a requirement for more than four units of blood in the 72-hour period after endoscopic treatment. RESULTS: Of the 48 patients who were assigned to endoscopic retreatment, 35 had long-term control of bleeding. Thirteen underwent salvage surgery, 11 because retreatment failed and 2 because of perforations resulting from thermocoagulation. Five patients in the endoscopy group died within 30 days, as compared with eight patients in the surgery group (P=0.37). Seven patients in the endoscopy group (including 6 who underwent salvage surgery) had complications, as compared with 16 in the surgery group (P=0.03). The duration of hospitalization, the need for hospitalization in the intensive care unit and the resultant duration of that stay, and the number of blood transfusions were similar in the two groups. In multivariate analysis, hypotension at randomization (P=0.01) and an ulcer size of at least 2 cm (P=0.03) were independent factors predictive of the failure of endoscopic retreatment. CONCLUSIONS: In patients with peptic ulcers and recurrent bleeding after initial endoscopic control of bleeding, endoscopic retreatment reduces the need for surgery without increasing the risk of death and is associated with fewer complications than is surgery.

Aged↗
PubMed1999

A comparison study on physical properties of self-expandable esophageal metal stents.

BACKGROUND: Currently available esophageal expandable stents differ in design, material, and method of deployment. We compared the expansile force and the susceptibility to buckling force in five commercially available stents. METHODS: The Esophacoil, Wallstent, Ultraflex, Gianturco-Z and Song stents were tested. The middle sections of fully expanded stents were subjected to compression force using a universal tensile testing machine. The distortion of the stent was measured electronically and the expansile force was calculated. Bending moments were applied to the ends of the stents until buckling occurred in the inner parts. The buckling radius was measured as the radius of the inner curvature of the stent when this occurred. RESULTS: The stents tested were significantly different in their expansile forces and buckling radii. Song stent and Gianturco-Z stent were similar due to their similar designs. Esophacoil was the strongest with regard to withstanding compressive force and angulation force, followed by Wallstent. Ultraflex stent was the weakest in expansile force but withstood angulation force better than the Song and Gianturco stents. CONCLUSION: Esophageal stents differ greatly in their elasticity and resistance to angulation. Knowledge of their mechanical properties will be another helpful factor to consider in selecting the appropriate stent in addition to the geometry and consistency of the tumor.

Equipment Design↗
PubMed1999

Use of color Doppler EUS in assessing azygos blood flow for patients with portal hypertension.

BACKGROUND: Azygos blood flow is an index of blood flow through gastroesophageal collateral vessels and varices in portal hypertension. Conventional measurement of azygos blood flow involves catheterization of the azygos vein. We studied the feasibility of assessing azygos blood flow with color Doppler endosonography and of monitoring the effects of vasoactive agents on azygos blood flow. METHODS: Patients with portal hypertension were examined by means of linear array color Doppler endoscopic ultrasonography (EUS). Patients who had taken propranolol or nitrates in the 4 weeks before the day of measurement of azygos blood flow were excluded. After identification of the azygos vein and recording of baseline readings of mean arterial blood pressure, pulse rate, and azygos blood flow, patients were selected in a random manner to receive a bolus injection of 2 mg terlipressin, 250 microg somatostatin, or saline solution (control). Azygos blood flow was measured 1, 5, and 10 minutes after injection (AzBF-1, AzBF-5, AzBF-10). RESULTS: Six patients were recruited in each treatment group. Basal azygos blood flow showed a positive association with the Child-Pugh grade of cirrhosis (p < 0.005). After bolus injection of terlipressin and somatostatin, there was a marked decrease in AzBF-1 (24% and 37%), AzBF-5 (42% and 19%), and AzBF-10 (40% both) compared with baseline. The control group showed no significant change in azygos blood flow. CONCLUSIONS: Color Doppler EUS is useful in assessing azygos blood flow in portal hypertension and in monitoring the effects of vasoactive agents.

Adult↗
PubMed1999

Evaluation of three commercial enzyme-linked immunosorbent assay kits for diagnosis of Helicobacter pylori in Chinese patients.

Most of the commercial serological assays for H. pylori are developed and validated in western countries. We evaluated the accuracy of three popular commercial ELISA tests for H. pylori in the Chinese population. Eighty dyspeptic patients were recruited and diagnosis of H. pylori infection was based on biopsy urease test, histology and urea breath test. Thirty-six patients (45%) were positive for H. pylori infection by two or more positive reference tests. Anti-H. pylori IgG antibody was detected by three commercial ELISA tests: GAP IgG (Bio-Rad), HM-CAP (Enteric Products) and Pyloriset EIA-G (Orion). The respective sensitivity, specificity, positive and negative predictive values of the three tests were: GAP IgG (50%, 97.4%, 93.8%, 71.7%), HM-CAP (72.7%, 68.4%, 66.7%, 74.3%) and Pyloriset EIA-G (75%, 86.4%, 81.8%, 80.9%). Despite the high accuracy reported in the West, the performance of these commercial serological tests was unsatisfactory when used in Chinese patients.

Adult↗
PubMed1999

Total gastrectomy with extended lymphadenectomy for "curable" stomach cancer: experience in a non-Japanese Asian center.

BACKGROUND: Gastrectomy with extended lymphadenectomy is the advocated treatment in Japan for patients with "curable" stomach cancer. Attempts in units elsewhere adopting this approach failed to show any survival advantage, and the high operative mortality has prevented global acceptance of the operation. This study examines the safety and efficacy of radical gastrectomy in a Far East center outside Japan. STUDY DESIGN: A consecutive series of 121 patients with gastric cancer who fulfilled criteria for radical surgery had total gastrectomy with extended lymphadenectomy equivalent to D3 dissection over a 6-year period in a single unit. RESULTS: The operation carried a morbidity of 50%, with a perioperative mortality of 5%. Survival was best predicted by tumor stage: 5-year survival for patients with intact gastric serosa was 64%, versus 10% for those with serosal penetration (p < 0.001). The majority of documented metastases occurred by transperitoneal route in serosa-positive patients, but via the hematogenous mechanisms in those who were serosa-negative. CONCLUSIONS: Radical gastrectomy with extended lymphadenectomy carries high operative morbidity. Increased mortality occurred because of loco-regional recurrence in patients with T3/T4 diseases. Novel approaches including neoadjuvant treatment or regional therapy should be explored.

Adenocarcinoma↗
PubMed1999

Oral manifestations and salivary flow rate, pH, and buffer capacity in patients with end-stage renal disease undergoing hemodialysis.

OBJECTIVE: The aim of this study was to investigate oral manifestations and salivary changes in patients with end-stage renal disease undergoing hemodialysis. STUDY DESIGN: Eighty-two patients undergoing hemodialysis for renal insufficiency were examined; 22 of these patients were randomly selected for salivary tests. Unstimulated whole saliva and stimulated parotid saliva were collected, and flow rate, pH, and buffer capacity were examined. Twenty-two healthy volunteers were included as controls. RESULTS: Uremic odor, dry mouth, and taste change were common symptoms. Petechia and/or ecchymosis and increase of tongue coating were major signs. The flow rates of unstimulated whole and stimulated parotid saliva were decreased in the patient group. The pH and buffer capacity of unstimulated whole saliva were increased in the patient group, but stimulated parotid saliva did not show any significant differences. CONCLUSIONS: Patients with end-stage renal disease undergoing hemodialysis showed apparent oral and salivary changes. The results help us understand the relationship between oral changes and renal insufficiency.

Adolescent↗
PubMed1999

One-week ranitidine bismuth citrate in combinations with metronidazole, amoxycillin and clarithromycin in the treatment of Helicobacter pylori infection: the RBC-MACH study.

BACKGROUND: We have previously shown that ranitidine bismuth citrate (RBC)-based triple therapy is comparable to proton pump inhibitor-based triple therapy in eradicating Helicobacter pylori infection. AIM: To test the efficacy of different combinations of antimicrobials with RBC in the treatment of H. pylori infection. METHODS: Dyspeptic patients with H. pylori infection were prospectively randomized to receive one of the following regimens: (i) RBC 400 mg, amoxycillin 1 g, clarithromycin 500 mg [RAC]; (ii) RBC 400 mg, metronidazole 400 mg, clarithromycin 500 mg [RMC]; (iii) RBC 400 mg, metronidazole 400 mg, tetracycline 1 g [RMT] (all given twice daily for 1 week); or (iv) RBC 400 mg plus clarithromycin 500 mg twice daily for 2 weeks [RC-2]. Endoscopy (rapid urease test and culture) and 13C-urea breath test (UBT) were performed before randomization. Four weeks after finishing medication, the 13C-UBT was repeated in all cases and endoscopy was offered to patients with peptic ulcers. RESULTS: Four hundred patients were randomized but in two (one in the RAC group and one in the RMC group) H. pylori infection was not confirmed. Successful eradication of H. pylori (intention-to-treat analysis and 95% CI) of RAC (86% [79-93%]), RMC (90% [84-96%]), RMT (79% [71-87%]) and RC-2 (82% [75-90%]) were comparable, with a trend favouring clarithromycin-containing triple therapy regimens. Among 276 isolates tested for antibiotic sensitivity, primary resistance to metronidazole, clarithromycin and amoxycillin was found in 56%, 2% and 0.4%, respectively. When given RMC or RMT, patients infected by metronidazole-resistant H. pylori had success in eradicating H. pylori similar to patients infected by metronidazole-sensitive H. pylori. CONCLUSION: One-week RBC triple therapy is effective in curing H. pylori infection.

Adolescent↗
PubMed1999

New wire-guided basket for intrahepatic stone extraction.

BACKGROUND: Endoscopic extraction of intrahepatic ductal stones with conventional stone retrieval baskets sometimes is difficult when the stones are deep in the segmental ducts or in a tortuous duct. We evaluated the use of a new wire-guided basket for endoscopic bile duct stone extraction. METHODS: The new wire-guided basket has a separate lumen for the guidewire on one side of the catheter. It is rail-loaded and advanced over a guidewire into the desired segmental duct. After they are engaged, the stones are dragged into the duodenum and the guidewire is left in the segmental duct. The basket then can be reinserted into that particular ductal segment over the wire for further stone extraction. RESULTS: The basket was used to treat three patients. Two patients had multiple intrahepatic stones. Repeated passage of the basket back to the desired location was accomplished without difficulty. All stones were removed successfully. CONCLUSION: The new wire-guided basket is a useful device for removing intrahepatic stones, particularly from patients with multiple ductal stones.

Bile Duct Diseases↗