Kam Chuen Lai

Pyogenic liver abscess: Retrospective analysis of 80 cases over a 10‐year period

Background: A total of 80 patients with pyogenic liver abscess managed at a single institution over a 10‐year period were studied.

A retrospective and prospective study on the safety of discharging selected patients with duodenal ulcer bleeding on the same day as endoscopy

BACKGROUNDnLow risk of rebleeding has been observed in patients with gastrointestinal bleeding due to peptic ulcer without high-risk stigmata of recent hemorrhage. We aimed to evaluate the safety and acceptability of an aggressive early discharge policy in those patients admitted with upper gastrointestinal bleeding due to duodenal ulcers without high-risk stigmata of recent hemorrhage.nnnMETHODnRetrospective analysis was carried out in bleeding ulcer patients less than 60 years of age with stable vital signs and no stigmata or only flat spots on endoscopy. A prospective study was then performed that included only duodenal ulcer patients less than 60 years of age with stable vital signs, no concomitant serious medical illness, and no stigmata of recent hemorrhage. These patients were discharged on the same day that endoscopy was performed.nnnRESULTSnDuring a period of 18 months, 72 patients satisfied the criteria in the retrospective study. The mean hospital stay was 1.4 days (range, 1 to 5). There were no episodes of rebleeding nor significant drops in hemoglobin level 2 weeks after discharge (10.8 gm/dL +/- 1.4 vs 11.0 gm/dL +/- 1.5). Seventy-five patients were recruited into the prospective study. None of them had rebleeding nor significant drops in hemoglobin 1 week after discharge (12.1 gm/dL +/- 1.8 vs 11.7 gm/dL +/- 2.5).nnnCONCLUSIONnWe conclude that patients with gastrointestinal bleeding who have clean-based duodenal ulcers and are stable on admission can be safely discharged on the same day as endoscopy.

Overexpression of protein kinase C-β1 isoenzyme suppresses indomethacin-induced apoptosis in gastric epithelial cells

BACKGROUND & AIMSnWe have previously reported that nonsteroidal anti-inflammatory drugs (NSAIDs) could induce apoptosis of gastric epithelial cells both in vivo and in vitro. This study investigated the role of protein kinase C (PKC) isoforms in the regulation of NSAID-induced apoptosis.nnnMETHODSnProtein levels of 12 PKC isoforms in AGS cells, in the presence or absence of indomethacin, were determined by Western blot. The effect of PKC-beta1 overexpression by transfection with its complementary DNA (cDNA) on indomethacin-induced apoptosis and apoptosis-related genes, including p53, p21(waf1/cip1), and c-myc, was further investigated.nnnRESULTSnTreatment with indomethacin decreased the abundance of PKC-beta1 and increased that of PKC-beta2, eta, and epsilon, but did not alter the expression of PKC alpha, gamma, zeta, delta, iota, and micro. Overexpression of PKC-beta1 attenuated the apoptotic response of AGS cells to indomethacin, associated with overexpression of p21(waf1/cip1) in both messenger RNA and protein levels. Inhibition of PKC-beta1-mediated overexpression of p21(waf1/cip1) by its antisense cDNA partially reduced the antiapoptotic effect of PKC-beta1.nnnCONCLUSIONSnIndomethacin-induced apoptosis in gastric cancer cells is partly mediated by differential regulation of PKC isoform expression. Enhanced expression of exogenous PKC-beta1 protects against indomethacin-induced apoptosis through up-regulation of p21(waf1/cip1).

Evaluation of an automated immunochemical fecal occult blood test for colorectal neoplasia detection in a Chinese population

Most commercial fecal occult blood tests (FOBT) used for colorectal carcinoma screening of Western populations are guaiac‐based, manually developed, subjective, and sensitive to dietary components. Preliminary studies demonstrated the unsuitability of these tests for screening a Chinese population. The goal of the current study was to evaluate the performance characteristics of a human hemoglobin–specific automated immunochemical FOBT, the Magstream 1000/Hem SP (Fujirebio, Inc., Tokyo, Japan), in a Chinese population referred for colonoscopy.

Differential apoptosis by indomethacin in gastric epithelial cells through the constitutive expression of wild-type p53 and/or up-regulation of c-myc.

Nonsteroidal anti-inflammatory drug (NSAID)-induced apoptosis is considered to be an important mechanism in the antineoplastic effects and damage produced by the drugs in the gastrointestinal tract. In this study, two different gastric cancer cell lines, MKN28 (mutant-type p53) and AGS (wild-type p53), were compared as to growth inhibition, apoptosis, and cell cycle and apoptosis-related gene expression in response to indomethacin treatment. Cell growth was measured by MTT (3-(4,5-dimethylthiazole-2-yl)-2,5-diphenyl tetrazolium bromide) assay. Apoptosis was characterized by acridine orange staining and DNA fragmentation, and cell cycle kinetics by flow cytometry. The mRNA and protein levels of p53, p21waf1/cip1, and c-myc were determined by Northern and Western blotting. The results showed that indomethacin initiated growth inhibition and apoptosis in both cell lines without cell cycle shifting. AGS cells were more sensitive to growth inhibitory activity and apoptosis of indomethacin than MKN28 cells. In MKN28 cells, the levels of p53, p21waf1/cip1, and c-myc mRNA remained unchanged over the 24-hr treatment with indomethacin, but the p53 protein level was elevated after 4 hr. There was no change in the p21waf1/cip1 and c-myc protein levels in the MKN28 cells. In AGS cells, a progressive increase in c-myc mRNA and protein levels was noted, while p53 and p21waf1/cip1 remained unchanged. It can be concluded that wild-type p53 and/or up-regulation of c-myc is associated with indomethacin-mediated differential apoptosis in gastric epithelial cells.

Pathophysiology of Gastroesophageal Reflux Diseases in Chinese—Role of Transient Lower Esophageal Sphincter Relaxation and Esophageal Motor Dysfunction

BACKGROUND AND AIMS:Transient lower esophageal sphincter relaxation (TLESR) is the major mechanism for gastroesophageal reflux in the Western population. The major reflux mechanism in Chinese patients with GERD has not been studied before.METHODS:Fifty-four patients with GERD and 28 controls underwent stationary baseline manometry and the 24-h ambulatory esophageal pH monitoring. TLESRs were measured before and after an 850 kcal meal in the supine position. Primary peristalsis, secondary peristalsis, and esophageal acid clearance were measured by esophageal manometry.RESULTS:Total time esophageal pH ≤ 4 (7.3 vs 1.5, p = 0.001) was significantly higher in patients with GERD when compared to controls. Majority of acid reflux episodes was due to TLESR in both patients with GERD and controls. The frequency of TLESRs after meal was similar between patients with GERD and controls (1.0 vs 1.3/h, p = 0.34). There was no difference in the distribution of reflux mechanism between patients with GERD and controls. However, patients with GERD had a significantly lower successful primary peristalsis (59% vs 70%, p = 0.043) when compared to controls.CONCLUSION:The frequency of TLESRs was similar between patients with GERD and controls during stationary manometry. Primary peristalsis was impaired in Chinese patients with GERD. Esophageal motor dysfunction may contribute to the pathophysiology of GERD in the Chinese population.

Effects of Primary Metronidazole and Clarithromycin Resistance to Helicobacter pylori on Omeprazole, Metronidazole, and Clarithromycin Triple-Therapy Regimen in a Region with High Rates of Metronidazole Resistance

The aim of this study was to investigate the effect of metronidazole resistance (MtzR) and clarithromycin resistance (ClaR) on the eradication rate for omeprazole, clarithromycin, and metronidazole triple-therapy regimen and on the development of posttherapy drug resistance in a region of high rates of MtzR. One hundred ninety-six Helicobacter pylori isolates were recovered from patients with duodenal ulcer, gastric ulcer, or nonulcer dyspepsia during upper endoscopy. The prevalences of MtzR, ClaR, and dual resistance were 37.8%, 13.8%, and 8.7%, respectively. The intention-to-treat eradication rates for metronidazole-susceptible (87.2% vs. 67.6%; P=.001) and clarithromycin-susceptible (86.4% vs. 40.7%; P<.001) strains were significantly higher than the rates for resistant strains. Multiple logistic regression analysis implicated younger age (<40 years old), MtzR, ClaR, and the diagnosis of nonulcer dyspepsia as independent factors that predicted treatment failure. The rates of posttreatment MtzR, ClaR, and dual resistance were 88%, 88%, and 75%, respectively. MtxR and ClaR significantly affected the success of eradication therapy. Posttreatment rates of resistance were high and were related to the presence of pretreatment antibiotic resistance.

Colonoscopy Demand and Practice in a Regional Hospital over 9 Years in Hong Kong: Resource Implication for Cancer Screening

Background: The incidence of colorectal cancer (CRC) in Hong Kong is rising. The trend of colonoscopy demand is uncertain. Aim: To investigate colonoscopy demand and practice in a Hong Kong regional hospital over the past nine years. Methods: Colonoscopy data from 1st January 1997 to 31st August 2005 were retrieved and divided into two equal periods for comparison. Colonoscopy practice and findings between the two periods were compared. Results: There was no change in the number of endoscopists and colonoscopy sessions in the two periods. The number of colonoscopy done in the two periods was 2,681 and 2,871, respectively. The indications for screening of CRC/polyp (9.3 vs. 24.7%, p < 0.0001) and surveillance of CRC/polyp (4.7 vs. 10.9%, p < 0.0001) were increased, but decreased for diarrhea (18 vs. 10.2%, p < 0.0001) and per rectal bleeding (19 vs. 8.1%, p < 0.0001). The waiting time was lengthened from 2 to 4 weeks (p < 0.0001). The percentage of colonic adenomas (19.9 vs. 27.2%, p < 0.0001) was increased. A right-shift was observed in both CRC (37 vs. 50%, p = 0.018) and adenoma (21.6 vs. 38.1%, p < 0.0001). Conclusion: The number of colonoscopies performed was governed by capacity partly through lengthening of waiting time to cope with demand. Ways to improve capacity for colonoscopies is needed.

Abnormal gastro-oesophageal reflux in Chinese with atypical chest pain

Although atypical chest pain has been well described in the Western population, its frequency in Chinese is unknown. Over a period of 42 months, we studied 521 Chinese patients with chest pain and identified 108 patients (20.7%) whose pain was not related to cardiac causes, as determined by exercise ECG or cardiac catheterization. Using 24 h ambulatory pH monitoring and baseline oesophageal manometry, 28.7, 19.4 and 5.6% of these patients were found to have abnormal reflux parameters, abnormal manometric findings or both, respectively. There were significantly more patients complaining of chest pain during the study in the gastro‐oesophageal reflux disease (GERD) group than in the non‐GERD group (16/31 vs 20/77; P< 0.001). The lower oesophageal sphincter pressure was lower in those with abnormal reflex parameters than in those with normal reflux parameters (12.7±5.4 vs 17.8±5.8 mmHg; P< 0.05). There was no significant difference in symptoms, such as heartburn (54.8 vs 42.9%), regurgitation (38.7 vs 35.1%) and dysphagia (19.4 vs 24.7%), among the two groups. Non‐specific changes were the most frequent baseline motility pattern. In conclusion, atypical chest pain and gastro‐oesophageal reflux disease are not uncommon in Chinese and this deserves special emphasis as the continuation of anti‐anginal drugs may aggravate their condition.

Treatment of non-erosive reflux disease with a proton pump inhibitor in Chinese patients: a randomized controlled trial

BackgroundEvidence suggests that rates of gastroesophageal reflux disease are increasing in the Asia–Pacific region, where patients tend to have predominantly non-erosive reflux disease as opposed to erosive (reflux) esophagitis. At present, data for the responsiveness of non-erosive reflux disease to proton pump inhibition are scant. We aimed to study esomeprazole for the treatment of non-erosive reflux disease in Chinese patients.MethodsPatients with a clinical diagnosis of gastroesophageal reflux, and a locally validated reflux index, the Chinese GerdQ, of equal to or greater than 12 were recruited and randomized to receive esomeprazole 20xa0mg daily or placebo for 8xa0weeks. Reflux index scores, quality of life (SF-36), and the hospital anxiety and depression (HAD) scale and symptom relief were evaluated before, during, and after treatment.ResultsA total of 175 patients were randomized. Patients in the esomeprazole group (nxa0=xa085) demonstrated statistically significant reductions in their GerdQ index, from 19.45 to 15.37 and to 14.32 (pxa0=xa00.013, pxa0=xa00.005) at weeks 4 and 8, respectively. Compared to placebo at week 8, 57.1% of patients on esomeprazole found that their symptoms had resolved or were acceptable compared with 37.2% in the placebo group (pxa0=xa00.001). There were no statistically significant differences in overall quality-of-life measures or the HAD scale related to treatment.ConclusionsThis study suggests that esomeprazole is efficacious in treating Chinese patients with non-erosive reflux disease.