RAD51 G135C genetic polymorphism and their potential role in gastric cancer induced by Helicobacter pylori infection in Bhutan.

In order to evaluate the role of the RAD51 G135C genetic polymorphism on the risk of gastric cancer induced by Helicobacter pylori infection, we determined allele frequency and genotype distribution of this polymorphism in Bhutan--a population documented with high prevalence of gastric cancer and extremely high prevalence of H. pylori infection. The status of RAD51 G135C was examined by restriction fragment length polymorphism analysis of PCR amplified fragments and sequencing. Histological scores were evaluated according to the updated Sydney system. G135C carriers showed significantly higher scores for intestinal metaplasia in the antrum than G135G carriers [mean (median) 0·33 (0) vs. 0·08 (0), P = 0·008]. Higher scores for intestinal metaplasia of G135C carriers compared to those of G135G carriers were also observed in H. pylori-positive patients [0·3 (0) vs. 0·1 (0), P = 0·002] and H. pylori-positive patients with gastritis [0·4 (0) vs. 0·1 (0), P = 0·002] but were not found in H. pylori-negative patients. Our findings revealed that a combination of H. pylori infection and RAD51 G135C genotype of the host showed an increasing score for intestinal metaplasia. Therefore, RAD51 G135C might be the important predictor for gastric cancer of H. pylori-infected patients.

Eradication rates of Helicobacter pylori between metronidazole-sensitive and metronidazole-resistant strains with metronidazole containing regimen in Thai patients with peptic ulcer disease.

The results of the in vitro metronidazole resistance on Helicobacter pylori (H. pylori) eradication have been inconclusive. Metronidazole resistance varies among different geographical locations and a previous study from Thailand reported an in vitro metronidazole resistance of H. pylori of 51 per cent. This study was designed to investigate further the effect of the in vitro metronidazole resistance on the outcome of eradication of H. pylori in the Thai population. Fifty two patients with active gastric ulcer (GU) and duodenal ulcer (DU) who had positive culture for H. pylori were studied. All of these patients had positive rapid urease test (CLO test, Delta West, Australia) using gastric biopsy specimens from the antrum and body taken at the time of initial upper endoscopy. In vitro antimicrobial susceptibility test was performed using Epsilometer test (AB Biodisk, Solna, Sweden). All patients received a one-week triple regimen consisting of omeprazole 20 mg twice daily, clarithromycin 500 mg twice daily, metronidazole 500 mg twice daily. Patients with GU continued with another five weeks of omeprazole 20 mg twice daily and patients with DU received another three weeks of omeprazole 20 mg twice daily. Upper endoscopy was repeated at four weeks after the end of the treatment. Three antral and two body biopsy specimens were obtained for identification of H. pylori using CLO test, histology (modified Giemsa stain) and culture. All of these tests had to be negative to confirm a successful eradication. Metronidazole-resistant (MR) strains with MIC > or = 32 mg/l were identified in 27 of the 52 patients (51.92%), whereas, metronidazole-susceptible (MS) strains were isolated from 25 patients (48.08%). Five patients were lost to follow-up and one patient had drug allergy. Successful eradication as defined by negative CLO test, histology and culture was attained in 17/23 (73.91%) patients (GU = 6, DU = 16, GU and DU = 1) with MR strains. 20 out of 23 (86.96%) patients (GU = 9, DU = 12 GU and DU = 2) who had MS strains. The difference was not statistically significant in both groups (P > 0.05). The ulcer healing was, however, highly achieved in both groups (MS = 95.65%, MR = 91.30%, P > 0.05). In vitro metronidazole resistance was high in this population group although this does not predict the outcome of eradication in patients with GU and DU.

Malignant duodenal stromal tumor: the first case report in Thailand and review of the literature.

The authors presented a middle aged Thai patient with malignant duodenal stromal tumor identified at a tertially care centre in Thailand. The patient presented with obscure gastrointestinal bleeding and the small bowel endoscopy revealed a bleeding tumor mass at the fouth part of the duodenum. The patient underwent segmental duodenectomy with end to end anstosomis. The histopathology of the tumor composed of interlacing bundles of spindle cells with oval to elongated pleomorphic nuclei and eosinophilic cytoplasm. The immunohistochemistrical study confirmed the diagnosis of malignant stromal tumor with smooth muscle differentiation. The computer tomography scan (CT scan) of the abdomen showed no evidence of metastasis. Postoperatively, the patient's clinical condition showed continuous improvement without further gastrointestinal bleeding. The patient has remained healthy up to present (six months of follow-up). A high level of suspicion to detect this malignant tumor especially in a patient presenting with obscure gastrointestinal bleeding and effective surgical treatment allow better clinical outcome in this rare and fatal malignancy.