The diagnostic potential of MT in the progression of normal oesophagus through Barrett’s to adenocarcinoma has not been elucidated and is the subject of this study. METHODS Samples of approximately 200mg of normal oesophagus, premalignant www.selleckchem.com/products/Abiraterone.html tissue (clinically Barrett’s oesophagus), carcinoma and normal gastric tissue were taken from 12 patients who underwent oesophagectomy or oesophago-gastrectomy. The distance of the resected tissue from the anatomical gastro-oesophageal junction was determined and the sample was immediately frozen and stored at ?70��C until analysed. In a second study, biopsies were taken from 20 patients with a histological record of Barrett’s epithelium, and who were undergoing a yearly follow-up to determine the progression of the disease.

Nine of these patients were being followed after fundoplication surgery for severe oesophageal reflux. Multiple biopsy specimens were obtained from defined sites of Barrett’s columnar epithelium and from macroscopically normal stratified squamous epithelium at least 1�C2cm above the Barrett’s epithelium. Biopsy specimens were fixed with 10% neutral buffered formalin and sent for routine histology. A series of fresh biopsy samples was immediately frozen in liquid nitrogen and then stored at ?70��C. Tissue and biopsy samples were diluted 1:5 with cold homogenate buffer (10mM Tris-HCl, pH8.2) and homogenised using a Potter-Elvehjem homogeniser (Wheaton, NJ, USA). The homogenates were then boiled in a water bath for 2min and then centrifuged for 4min at 14000g. Metallothionein was determined by the cadmium-haemoglobin binding assay (Eaton and Toal, 1982).

Protein was determined with SERVA-G Coomasie blue dye reagent (Lott et al, 1983) using a Cobas Bio Centrifugal Analyser (Hoffman La Roche, Basel, Switzerland) and human serum albumin as standard. Results are reported as the mean��s.e.m. Where appropriate, significance was determined by the Wilcoxon signed-rank test for paired differences, paired t-test for two sample means and Student’s t-test for independent samples. This study was approved by the Research Ethics Committee of the Royal Adelaide Hospital. RESULTS Metallothionein concentrations in the macroscopically normal squamous epithelium were 193��12pmol Cd boundmg?1 protein (n=31), 195��28 (n=13) and 194��19 (n=25) in the upper, middle and lower oesophagus. MT concentration in clinically normal gastric tissue was 446��186pmol Cd boundmg?1 protein (n=59). Higher MT levels (P<0.001) were found in the upper half of the stomach (489��54, n=20) than lower half (148��14, n=20) but there was no significant difference between equivalent positions along the greater Brefeldin_A and lesser curves of the stomach.