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Biomedical subjects

S C Chung

Publications and source records attributed to S C Chung.

At least 19 recordsLinked to original sources
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↗
PubMed1998

New findings of the correlation between acupoints and corresponding brain cortices using functional MRI.

A preliminary study of the correlation between acupuncture points (acupoints) for the treatment of eye disorders suggested by ancient Oriental literature and the corresponding brain localization for vision described by Western medicine was performed by using functional MRI (fMRI). The vision-related acupoint (VA1) is located in the lateral aspect of the foot, and when acupuncture stimulation is performed there, activation of occipital lobes is seen by fMRI. Stimulation of the eye by directly using light results in similar activation in the occipital lobes by fMRI. The experiment was conducted by using conventional checkerboard 8-Hz light-flash stimulation of the eye and observation of the time-course data. This was followed by stimulation of the VA1 by using the same time-course paradigm as visual light stimulation. Results obtained with 12 volunteers yielded very clean data and very close correlations between visual and acupuncture stimulation. We have also stimulated nonacupoints 2 to 5 cm away from the vision-related acupoints on the foot as a control, and activation in the occipital lobes was not observed. The results obtained demonstrate the correlation between activation of specific areas of brain cortices and corresponding acupoint stimulation predicted by ancient acupuncture literature.

Acupuncture Points↗
PubMed1998

Helicobacter pylori and the null genotype of glutathione-S-transferase-mu in patients with gastric adenocarcinoma.

BACKGROUND: Chronic Helicobacter pylori infection now is recognized as an important causative agent for gastric carcinoma. However, only a small minority of infected individuals develop the malignancy, even in areas with a high prevalence of gastric carcinoma. It has been postulated that the absence of glutathione-S-transferase-mu (GST-mu), which impairs detoxification of exogenous carcinogens, might predispose some infected individuals to the development of gastric carcinoma. METHODS: Patients with histologically confirmed adenocarcinoma of the stomach were tested for H. pylori infection and the GST-mu genotype. Prevalence of GST-mu gene deletion was compared with the H. pylori status of the patients. A group of gender- and age-matched control subjects with known H. pylori-related nonulcer dyspepsia also were tested for the GST-mu genotype and compared with patients with H. pylori positive carcinoma. RESULTS: Fifty-one patients with gastric adenocarcinoma were enrolled into the study. Thirty-five were found to have H. pylori in the resected specimens. The null genotype of GST-mu was significantly more common among those patients with H. pylori positive carcinoma compared with the H. pylori negative group (65.7% vs. 31.3%; P < 0.05). Homozygous deletion of GST-mu was significantly higher in the H. pylori positive carcinoma patients than in the H. pylori-infected, nonmalignant control group (65.7% vs. 37.1%; P < 0.05). CONCLUSIONS: The null genotype for GST-mu is found more commonly in gastric carcinoma associated with H. pylori infection. The absence of the GST-mu enzyme may increase the risk of the development of gastric carcinoma in these patients.

Adenocarcinoma↗
PubMed1998

Effects of the acoustic noise of the gradient systems on fMRI: a study on auditory, motor, and visual cortices.

MR acoustic, or sound, noise due to gradient pulsing has been one of the problems in MRI, both in patient scanning as well as in many areas of psychiatric and neuroscience research, such as brain fMRI. Especially in brain fMRI, sound noise is one of the serious noise sources that obscures the small signals obtainable from the subtle changes occurring in oxygenation status in the cortex and blood capillaries. Therefore, we have studied the effects of acoustic, or sound, noise arising in fMR imaging of the auditory, motor, and visual cortices. The results show that the effects of acoustic noise on motor and visual responses are opposite. That is, for motor activity, there is an increased total motor activation, whereas for visual stimulation, the corresponding (visual) cortical activity is diminished substantially when the subject is exposed to a loud acoustic sound. Although the current observations are preliminary and require more experimental confirmation, it seems that the observed acoustic-noise effects on brain functions, such as in the motor and visual cortices, are new observations and could have significant consequences in data observation and interpretation in future fMRI studies.

Adult↗
PubMed1998

A randomized comparison of acute phase response and endotoxemia in patients with perforated peptic ulcers receiving laparoscopic or open patch repair.

BACKGROUND: In patients with peritonitis from perforated peptic ulcers, we compared acute stress responses, endotoxemia, and bacteremia following laparoscopic or open surgery. PATIENTS AND METHODS: Consecutive patients with peritonitis from perforated peptic ulcers were randomized to receive laparoscopic sutured or open omental repair. Undiluted peritoneal fluid was obtained at surgery for quantitative bacterial and endotoxin (Limulus Amoebocyte Lysate) assay. Serial blood samples were taken at 0, 30, 60, 90, 120, and 180 minutes, and at 12, 24, 48, 72, and 120 hours for determinations of quantitative bacterial and endotoxin assays, interleukin-6 (IL-6), C-reactive protein (CRP), and cortisol. RESULTS: Twenty-two patients were randomized: laparoscopy group (n = 12), open repair group (n = 10). Conversions were required in 3 patients assigned to laparoscopy, leaving 9 patients for analysis. The two groups were comparable in their demographic data, median duration of perforation (13.5 hours versus 10 hours), severity of peritoneal contamination as indicated by viable bacterial count (5.9 x 102 versus 1.5 x 10(2) colony forming unit/mL) and endotoxin concentration in peritoneal fluid (27.2 versus 24.6 EU/mL). No significant endotoxemia or bacteremia was detected in these patients. Median interleukin-6 was highest at 0 hour (1520 versus 962 pg/mL) and fell rapidly following surgery. C-reactive protein peaked at 24 hours and plateaued thereafter. Cortisol was highest intraoperatively and fell thereafter. No difference was noted between the two treatment groups with respect to these inflammatory markers (IL-6 P = 0.19, CRP P = 0.14, cortisol P = 0.56, multivariate analysis of variance). CONCLUSION: Endotoxemia and bacteremia are insignificant in most patients with perforated peptic ulcers. In patients with perforated peptic ulcers, laparoscopic patch repair does not reduce acute stress responses when compared with open surgery.

Acute-Phase Proteins↗
PubMed1998

Tissue injury of Injection Gold Probe.

BACKGROUND: The Injection Gold Probe, which incorporates an injection needle and a bipolar electrocoagulation probe, potentially offers better anchoring of the probe for electrocoagulation. This study compares the tissue injury caused by the Injection Gold Probe with or without protrusion of the needle. METHODS: A 10F Injection Gold Probe was applied perpendicularly on the antrum of porcine stomach. At each site of testing, one pulse of treatment at 12 W was given for 10 seconds. The extent of tissue injury was studied under different forces of application (light touch or maximal force) and different probe conditions (needle-in, needle-out, needle-out plus 1 mL saline solution injection). Each maneuver was repeated 8 times. The depth and width of tissue injury were assessed histologically by a pathologist blinded to the treatment. RESULTS: The depth and width of tissue injury did not differ significantly with needle-in, needle-out, or needle-out plus 1 mL saline solution injection on both light touch. But the tissue injury was significantly deeper and wider with maximal force applications than with light touch under the same probe condition. CONCLUSION: The extent of tissue injury inflicted by electrocoagulation using the Injection Gold Probe is not affected by the position of the injection needle.

Analysis of Variance↗
PubMed1998

Injection sclerotherapy for variceal bleeding in patients with hepatocellular carcinoma: cyanoacrylate versus sodium tetradecyl sulphate.

BACKGROUND: Patients with hepatocellular carcinoma complicated by variceal bleeding have a very limited life span. Recurrent bleeding after endoscopic injection sclerotherapy is common. Our aim was to compare the efficacy of endoscopic injection of cyanoacrylate versus sodium tetradecyl sulphate in the control of variceal bleeding in patients with hepatocellular carcinoma. METHODS: Patients known to be suffering from inoperable hepatocellular carcinoma who presented with upper gastrointestinal bleeding underwent endoscopy within 24 hours of admission. After bleeding from esophageal varices was confirmed, they were randomized to receive endoscopic injections of either cyanoacrylate (1:1 mixture with Lipoidol) or sodium tetradecyl sulphate (1.5%). Injection were given intravariceally into each visible column for up to four injections for cyanoacrylate and up to 30 mL for sodium tetradecyl sulphate. RESULTS: A total of 50 patients were recruited for this study with 25 cases randomized to each endoscopic treatment group. Control of acute bleeding failed in four patients (16%) in both treatment groups, and two patients in each group died during the index episode of bleeding. Six patients (24%) in the cyanoacrylate group and four patients (16%) in the sodium tetradecyl sulphate group developed recurrent bleeding during their hospital stay (p = 0.48). Recurrent bleeding within 30 days after the index episode of bleeding was documented in seven patients (28%) who received cyanoacrylate injection and five patients (20%) who received sodium tetradecyl sulphate injection (p = 0.51). Median survival in the cyanoacrylate group was 16 days (range 1 to 485 days) and that of the sodium tetradecyl sulphate group was 13 days (range 1 to 407 days). There was no difference in cumulative survival between the two groups as analyzed by the Kaplan-Meier method. Patients with portal vein thrombosis had a higher risk of recurrent hemorrhage. Patients with Child's C liver disease had a significantly higher mortality. CONCLUSIONS: Cyanoacrylate did not improve the outcome of hepatocellular carcinoma patients with variceal hemorrhage.

Carcinoma, Hepatocellular↗
PubMed1998

The use of a detachable mini-loop for the treatment of esophageal varices.

BACKGROUND: Endoscopic variceal ligation is facilitated by multiband ligating devices, but these have limitations including a fixed number of bands, occasional failure to firmly ligate a variceal column, and relatively high cost. We report the use of a mini-loop for treatment of esophageal varices. METHODS: A detachable nylon ring (mini-loop), maximum diameter 11 mm, passed through the accessory channel of a standard endoscope is opened at the rim of a transparent ligation chamber attached to the instrument. By suction, a varix is brought into the chamber, the mini-loop is maneuvered over the varix, closed, and detached. RESULTS: Five ligation sessions (four to seven loops per session) were performed in four patients with upper gastrointestinal bleeding. There were variceal stigmata of bleeding, but no active hemorrhage. Application of all mini-loops was successful and did not induce uncontrolled bleeding. Endoscopy at 1 week disclosed superficial ulcers at ligation sites. Post procedure epigastric pain occurred in one patient. CONCLUSION: Detachable mini-loop ligation of esophageal varices is simple and safe, and a comparison study with a multi-band ligator device is warranted.

Esophageal and Gastric Varices↗
PubMed1998

One-week use of ranitidine bismuth citrate, amoxycillin and clarithromycin for the treatment of Helicobacter pylori-related duodenal ulcer.

BACKGROUND: Proton pump inhibitors have been widely used in combination with amoxycillin, clarithromycin or metronidazole for the treatment of Helicobacter pylori infection. AIM: To study the effects of 1-week ranitidine bismuth citrate (RBC)-based triple therapy in the treatment of H. pylori-related duodenal ulcers. METHOD: Patients with duodenal ulcers and H. pylori infection were prospectively randomized to receive either RBC with amoxycillin and clarithromycin for 1 week (RAC), or omeprazole with amoxycillin and clarithromycin for 1 week (OAC). No additional ulcer healing drug was used after the 1-week medication. Patients were assessed for H. pylori eradication, ulcer healing and side-effects after receiving the therapies. RESULTS: One hundred consecutive patients were recruited to this study, with 50 patients randomized to each treatment group. In the intention-to-treat analysis, duodenal ulcers were completely healed in 45 (90%) patients in the RAC group and 43 (89.6%) in the OAC group (P = 1.0). H. pylori eradication was confirmed in 47 (94%) in the RAC group and 42 (87.5%) in the OAC group (P = 0.31). There was no significant difference in the severity of side-effects experienced by the two treatment groups. CONCLUSION: One-week RBC-based triple therapy is an effective treatment for H. pylori-related duodenal ulcers. The therapeutic effects are comparable to a 1-week course of proton pump inhibitor-based triple therapy.

Adolescent↗
PubMed1998

Does eradication of Helicobacter pylori impair healing of nonsteroidal anti-inflammatory drug associated bleeding peptic ulcers? A prospective randomized study.

BACKGROUND: Despite the widely accepted view that Helicobacter pylori is the most important cause of peptic ulcer disease, recent studies have suggested that the microbe protects against nonsteroidal anti-inflammatory drug (NSAID)-associated gastroduodenal lesions and promotes ulcer healing. We investigated the effects of H. pylori eradication on the healing of NSAID-associated bleeding peptic ulcers. METHODS: Chronic NSAID users presenting with peptic ulcer haemorrhage underwent endoscopy to secure haemostasis and to document H. pylori infection by rapid urease test and culture. They were prospectively randomized to receive either omeprazole (20 mg once daily) for 8 weeks or a 1-week course of triple therapy (bismuth subcitrate 120 mg, tetracycline 500 mg, metronidazole 400 mg, all given four times daily) plus omeprazole (20 mg once daily) for 8 weeks. Endoscopy was repeated after 8 weeks. Final H. pylori status was determined by a 13C-urea breath test that was performed at least 4 weeks after discontinuation of omeprazole. RESULTS: 195 H. pylori-infected NSAID users, complicated by bleeding ulcers, were randomized to receive omeprazole alone (102) or triple therapy plus omeprazole (93). 174 patients returned for second endoscopy at 8 weeks (91 in the omeprazole group, 83 in the triple therapy group). Urea breath test was negative in 14% in the omeprazole group vs. 92% in the triple therapy group (P < 0.001). Complete ulcer healing was achieved in 88 (97%) patients in the omeprazole group and 77 (93%) in the triple therapy group (P=0. 31). On intention-to-treat analysis, ulcers were healed in 86% of the omeprazole group and 83% of the triple therapy group (P=0.50). There was no significant difference in the healing rates of gastric or duodenal ulcers between the two groups. CONCLUSION: Eradication of H. pylori did not impair the healing of NSAID-associated bleeding peptic ulcers.

Adult↗
PubMed1998

Randomized trial of early versus delayed laparoscopic cholecystectomy for acute cholecystitis.

BACKGROUND: The aim of this prospective randomized study was to define the optimum management between early and delayed laparoscopic cholecystectomy for patients with acute cholecystitis. METHODS: Patients were randomized to receive either early laparoscopic cholecystectomy within 24 h of randomization or initial conservative treatment followed by delayed laparoscopic cholecystectomy 6-8 weeks later. RESULTS: There were 53 patients in the early group and 51 in the delayed group. There was no significant difference in conversion rate (early 21 per cent versus delayed 24 per cent), postoperative analgesic requirement (1 versus 2 doses) and postoperative complications. However, the early group had significantly longer operating time (122.8 versus 106.6 min, P = 0.04) and shorter total hospital stay (7.6 versus 11.6 days, P < 0.001). CONCLUSION: Early laparoscopic cholecystectomy is safe and feasible for acute cholecystitis with the additional benefit of shorter total hospital stay. Apart from a shorter operating time, treating patients with delayed laparoscopic cholecystectomy does not offer additional benefit.

Acute Disease↗
PubMed1998

Common bile duct stones become smaller after endoscopic biliary stenting.

BACKGROUND AND STUDY AIMS: Endoscopic biliary stenting is often used for large or difficult common bile duct (CBD) stones that cannot be extracted at one session. We compared the sizes of the CBD stones after a period of stenting. PATIENTS AND METHODS: Over a 6-year period, a total of 444 patients with large CBD stones (> 2 cm diameter) or difficult CBD stones were managed in our endoscopy unit, of which 46 were treated by endoscopic stenting. Twenty-eight had second ERCP for stone removal after a median period of 63 days (range 17-1002 days). The largest diameter of the stones and the CBD (after correction of magnification) before and after stenting were compared using the Wilcoxon signed test. RESULTS: Before stenting the largest diameters of CBD stones were 11-46 mm (mean 24.9 mm) and decreased to 5-46 mm (mean 20.1 mm) after stenting. The difference in stone sizes was statistically significant although the CBD diameter pre- and post-stenting was not significantly different. The reduction in stone sizes was not significantly correlated with the duration of stenting. CONCLUSION: CBD stones became smaller after stenting. As the difficulty of stone extraction increases with stone size, a period of stenting may make subsequent removal easier for patients with large or difficult CBD stones.

Aged↗
PubMed1998

The evolution of stigmata of hemorrhage in bleeding peptic ulcers: a sequential endoscopic study.

BACKGROUND AND STUDY AIMS: Stigmata of hemorrhage in bleeding peptic ulcers have prognostic characteristics. In the present study, the evolution of these stigmata was studied prospectively using daily endoscopic examinations. PATIENTS AND METHODS: From January 1989 to October 1989, 778 consecutive patients with bleeding peptic ulcers underwent endoscopy within 24 hours of admission. The bleeding peptic ulcers were assigned by three endoscopists to five categories, those with: a) active bleeding, b) a nonbleeding visible vessel, c) adherent clot, d) dot, or e) a clean base. Actively bleeding ulcers were treated by epinephrine injection. Ulcers with nonbleeding visible vessels, adherent clots, or dots were left untreated. Daily endoscopic examinations were carried out for three subsequent days, or until the ulcer base became clean. RESULTS: On day 0, there were 56 actively bleeding ulcers (7%), 62 ulcers with visible vessels (8%), 104 with adherent clots (13%), 182 with flat dots (23%), and 374 with a white base (48%). On the subsequent three days, 24 of 62 ulcers with visible vessels (39%), 30 of 104 with adherent clots (29%), 24 of 182 with dots (13%), and 19 of 374 with a clean base (5%) on day 0 re-bled endoscopically or clinically, or both. The overall rebleeding risk was 9.9%, 4.9%, and 2.7% on days 1, 2, and 3, respectively. CONCLUSIONS: Stigmata of hemorrhage in bleeding peptic ulcers are predictive of rebleeding. They represent intermediate phases in the evolution of bleeding vessels into clean-based ulcers. The associated rebleeding risk diminishes as the vessel disappears from the ulcer base.

Endoscopy, Gastrointestinal↗
PubMed1998

Ulcer recurrence after gastric surgery: is Helicobacter pylori the culprit?

OBJECTIVES: Helicobacter pylori is the most important cause of recurrent peptic ulcer disease. However, its role in ulcer recurrence after peptic ulcer surgery is unclear. We aimed at studying the prevalence and distribution of H. pylori in patients who had undergone peptic ulcer surgery, and any association between H. pylori infection and ulcer recurrence in these patients. METHODS: Patients with previous vagotomy or partial gastrectomy presenting with dyspepsia or ulcer bleeding were recruited. Ulcer recurrence was documented by endoscopy. Biopsy specimens were taken from the gastric remnant and gastroenteric anastomosis in patients with previous partial gastrectomy, or from the antrum and corpus in vagotomized patients. H. pylori infection was detected by either a positive rapid urease test or the presence of the bacteria on histology. RESULTS: Ninety-three patients were studied; 73 patients (78%) had partial gastrectomy and 20 (22%) had vagotomy with drainage. H. pylori infection was documented in 36 patients (49%) in the gastrectomy group and in 13 (65%) in the vagotomy group. Thirty-six patients in the gastrectomy group had recurrent ulcers and 15 (42%) of them had H. pylori infection. Twelve patients in the vagotomy group had recurrent ulcers and eight (67%) of them were H. pylori positive. The prevalence of H. pylori infection did not differ between patients with or without ulcer recurrence. CONCLUSION: H. pylori infection cannot account for ulcer recurrence after peptic ulcer surgery.

Adult↗
PubMed1998

Evaluation of a selective transport medium for gastric biopsy specimens to be cultured for Helicobacter pylori.

Since the means of culturing Helicobacter pylori may not be available in some laboratories, prolonging the survival of this organism during transportation is a major concern in terms of improving detection rates. A selective transport medium was evaluated for the preservation of H. pylori from 254 gastric biopsy specimens collected from a rural area in China where culturing is not feasible. Gastric biopsy specimens were inoculated in sterile broth consisting of brain heart infusion (BHI) broth, horse serum, and yeast extract supplemented with vancomycin, amphotericin B, and nalidixic acid (VAN). Of the 254 biopsy specimens, 238 were identified by histology to have H. pylori infection. Total rates of recovery of H. pylori from the H. pylori-positive gastric biopsy specimens stored in the BHI-VAN broth ranged from 76 to 46% after storage of specimens for 5 to 9 days. In conclusion, the selective medium is useful for prolonging the survival of H. pylori in gastric biopsy specimens for which immediate culture is not feasible.

Adult↗
PubMed1997

Randomised trial of eradication of Helicobacter pylori before non-steroidal anti-inflammatory drug therapy to prevent peptic ulcers.

BACKGROUND: Helicobacter pylori infection is common in patients with peptic ulcers caused by the use of non-steroidal anti-inflammatory drugs (NSAIDs). But the pathogenic role of H pylori in this disease is controversial. We studied the efficacy of eradication of H pylori in the prevention of NSAID-induced peptic ulcers. METHODS: We recruited patients with musculoskeletal pain who required NSAID treatment. None of the patients had previous exposure to NSAID therapy. Patients who had H pylori infection but no pre-existing ulcers on endoscopy were randomly allocated naproxen alone (750 mg daily) for 8 weeks or a 1-week course of triple therapy (bismuth subcitrate 120 mg, tetracycline 500 mg, metronidazole 400 mg, each given orally four times daily) before administration of naproxen (750 mg daily). Endoscopy was repeated after 8 weeks of naproxen treatment or when naproxen treatment was stopped early because of bleeding or intractable dyspepsia. All endoscopic examinations were done by one endoscopist who was unaware of treatment assignment. The primary endpoint was the cumulative rate of gastric and duodenal ulcers. FINDINGS: 202 patients underwent endoscopic screening for enrolment in the trial, and 100 eligible patients were randomly assigned treatment. 92 patients completed the trial (47 in the naproxen group, 45 in the triple-therapy group). At 8 weeks, H pylori had been eradicated from no patients in the naproxen group and 40 (89%) in the triple-therapy group (p < 0.001). 12 (26%) naproxen-group patients developed ulcers: five had ulcer pain and one developed ulcer bleeding. Only three (7%) patients on triple therapy had ulcers, and two of these patients had failure of H pylori eradication (p = 0.01). Thus, 12 (26%) patients with persistent H pylori infection but only one (3%) with successful H pylori eradication developed ulcers with naproxen (p = 0.002). INTERPRETATION: Eradication of H pylori before NSAID therapy reduces the occurrence of NSAID-induced peptic ulcers.

Anti-Bacterial Agents↗