Background:The tumor suppressor,X-linked inhibitor of apoptosis(XIAP)-associated factor 1(XAF1)is a XIAP-binding protein that antagonizes the anti-caspase activity of XIAP,thereby enhancing apoptosis. Transcriptional variants of XAF1 have been detected in various tumor cells,however,the expression profile of these transcriptional variants in colorectal neoplasms remains unclear. Aims:To investigate the expressions of XAF1 and its transcriptional variants in different colorectal tissues and their roles in tumorigenesis and development of colorectal neoplasms. Methods:Samples of colorectal cancer and paired adjacent tissue,hyperplastic polyp,adenomatous polyp,and normal colorectal mucosa were collected from surgical operation or endoscopic biopsies. XAF1 protein expression was detected by immunohistochemistry and Western blotting,and the transcriptional variants of XAF1 were detected by RT-PCR. Results:Compared with normal colorectal mucosa,the expression level of XAF1 protein in nucleus was significantly reduced( P < 0. 05)and that in cytoplasm was slightly increased(P >0. 05)in hyperplastic polyp,adenomatous polyp,and cancerous tissue,and the overall expression level of XAF1 protein was decreased(P <0. 05). XAF1A protein expression in cancerous tissue was significantly reduced when compared with the paired adjacent tissue(P < 0. 05). mRNA expressions of three transcriptional variants of XAF1,XAF1A,XAF1B and XAF1C were all significantly lower in neoplastic tissues than in normal mucosa(P < 0. 05). Conclusions:XAF1 and its transcriptional variants are differentially expressed in colorectal neoplasms and normal colorectal mucosa. These changes occurred initially in adenomatous polyp accompanied by a redistribution of XAF1 from nucleus to cytoplasm. Post-transcriptional modification may affect XAF1 gene function.

Objective To evaluate the clinical manifestations, endoscopic features and the clinical pathological characteristics of H. heilmannii-associated gastritis, and to compare these variables with those of H. pylori-ussociated gastritis. Methods The clinical data, endoscopic findings and pathologic characteristics of 3107 patients, who underwent endoscopy from 2005 to 2007, were retrospectively analyzed. Results Twenty-five cases of H. heilmannii infection were identified, the infection rates of H. heilmannii and H. pylori were 0.80% (25/3107) and 4.12% (1060/3107) respectively. Three cases were mixed infections. Of 25 patients, 20 showed such gastroenterologic symptoms to a greater or less extent as abdominal distending pain,nausea and anorexia, and other 5 cases were asymptomatic. All 25 patients showed chronic gastritis by en-doscopy, including chronic superficial gastritis (7/25, 28% ), erosion ( 3/25, 12% ), chronic atrophic gastritis (4/25, 16%), bile reflux(1/25, 4%), ulcer (1/25, 4%), polyp (1/25, 4%) and duodenal bulbar inflammation (2/25, 8% ). In rapid urease test, 3 cases were hyper-positive, 3 cases positive, 7 ca-ses mild-positive and 12 cases negative. According to histological observation, H. heilmannii scattered or ac-cumulated within the gastric pits, glandular lumen or mucus. The organism was observed in parietal cells with cell damage in one case. Sporadic lymphatic and plasmic infiltration were found in all patients with H.heilmannii infection, infiltration of neutrophils (12/25), gland atrophy and intestinal metaplasia (4/25)and lymphoid follicles (6/25) were also observed. Compared with H. pylori-associated gastritis, H. heilman-nii-associated gastritis showed less inflammation, less helicobacter density, mononuclear cell infiltration and neutrophilic activity ( P < 0.05 ). Conclusion H. heilmanaii mainly induces chronic gastritis, which is less severe than H. pylori-associated gastritis.