Nic P Mapstone

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We designed a polymerase chain reaction (PCR) for amplifying the Helicobacter pylori gene encoding 16S rRNA. Primers for the specific detection of H. pylori were designed for areas of the 16S rRNA gene in which there is the least sequence homology between H. pylori and its closest relatives. The specificity of detection was confirmed by ensuring that the(More)
BACKGROUND Helicobacter pylori is an independent risk factor for gastric cancer, and this association may be due to the bacterium causing reactive oxygen species mediated damage to DNA in the gastric epithelium. High dietary ascorbic acid intake may protect against gastric cancer by scavenging reactive oxygen species. AIMS To assess reactive oxygen(More)
BACKGROUND Despite intensive research into the molecular abnormalities associated with colorectal cancer (CRC), no diagnostic tests have emerged which usefully complement standard histopathological assessments. AIMS To assess the feasibility of using immunohistochemistry to detect replication error (RER) positive CRCs and determine the incidence of RER(More)
BACKGROUND There is increasing evidence that reflux of bile plays a part in the pathogenesis of Barrett's oesophagus. Bile injury to the gastric mucosa results in a "chemical" gastritis in which oedema and intestinal metaplasia are prominent. AIM To determine if patients with Barrett's oesophagus have more bile related changes in antral mucosa than(More)
BACKGROUND For rectal carcinoma, the presence of tumour within 1 mm of the circumferential margin is an important independent prognostic factor for both local recurrence and survival. Similar prospective data have not been reported for oesophageal carcinoma and we wished to ascertain the prognostic importance of this variable following potentially curative(More)
Sixty two patients (mean age 45.6 years) were assessed for oral hygiene and periodontal disease by dental examination before endoscopy. Information about oral care, smoking, and dentures was obtained and samples of dental plaque collected. The presence of Helicobacter pylori in plaque as sought by culture and polymerase chain reaction (PCR), and gastric(More)
Helicobacter pylori causes chronic (type B) gastritis. The 'intestinal' form of gastric cancer arises against a background of chronic gastritis, and prospective epidemiological studies have shown that H pylori is a major risk factor for this. An increase in mucosal cell proliferation increases the likelihood of a neoplastic clone of epithelial cells(More)
AIMS To determine the prevalence of Helicobacter pylori colonisation in the mouths of patients with H pylori gastritis. METHODS A nested polymerase chain reaction test for the 16S ribosomal RNA gene of H pylori was used on saliva, dental plaque, gastric juice and gastric biopsy specimens from patients attending a dyspepsia clinic. RESULTS Thirteen(More)
AIMS To determine the relation among the cytotoxin associated gene (cagA) and vacuolating cytotoxin gene (vacA) status of Helicobacter pylori isolates, the associated clinical diseases, and the severity and pattern of chronic gastritis. METHODS Helicobacter pylori was cultured from gastric biopsies obtained from dyspeptic patients. DNA was extracted from(More)
BACKGROUND Esophageal adenocarcinoma commonly arises from a precancerous condition, Barrett's esophagus, in which the normal squamous epithelium is replaced by a columnar cell-lined epithelium. Genetic alterations occurring in this process could serve as biomarkers for the risk of malignant progression, improve surveillance, and contribute to early(More)