Objective To detect the expression of human telomerase reverse transcriptase (hTERT ) and telomerase in hu‐man fetal gastric fibroblasts .Methods Human fetal gastric fibroblasts were isolated and cultured ,epithelial cells were exduded by CK‐18 immune staining .hTERT protein was determined by indirect immunofluorescence .Telomerase activity was analyzed using telomeric repeat amplification protocol assay (TRAP)while the same analysis in adult gastric fibroblast ,which as to be positive con‐trol .Results Cultured fibroblasts were CK‐18 negative .The positive hTERT immunostaining was detected in both cellular cyto‐plasm and nuclear compartments .Amplified telomeric repeats (about 170 bp) in human fetal gastric fibroblasts were longer than those (160 bp) in adult gastric fibroblasts .Conclusion hTERT and telomerase were expressed in human fetal gastric fibroblasts .

Objective Colorectal polyp is a precancerous lesion of colorectal cancer .Aim of the study was to explore the risk fac-tors of colorectal polyp malignant transformation .Methods The related information of 75 084 colonoscopies performed from 2003 to 2012 in Southwest Hospital in Chongqing were collected and the relationship between polyp malignant transformation and the pa-tient age ,sex ,polyp location ,size or histological types was analyzed .Results From 2003 to 2012 ,polyps were diagnosed in 14 806 cases of the total 75 084 patients with a 19 .72% detection rate .There were significant difference of the left-side and right-side pol-yp detection rate in different age groups ,and the frequency of polyps distributed in the whole colorectum increased with the increase of age .The rates of epithelial neoplasia and malignant transformation increased with age .At the same time ,malignant transforma-tion rate was significant higher in polyps located in left-side than that in right-side (P<0 .0167) ,in adenoma than that in inflamma-tory hyperplastic polyp (P<0 .01) .The larger diameter and the more villus ,the higher rate of malignant transformation .Conclusion Patient age ,polyp size ,location and histological type could be considered as the significant predictors of colorectal polyp malignant transformation .It may be useful to treat the polyp with endoscopy in patient with age more than 45 and adenoma whose diameter was not less than 1 cm ,located in left-side for prevention of colorectal cancer .

Advanced studying doctors play important roles in the clinical services, and how to train them to improve training quality is worth investigating. We classified them into three types such as the clinical skills-improved, the special skills-trained and clinical knowledge eextensively-spread, then employed the individual teaching methods and emphasized the medical ethics during the training, which is not only beneficial to us, but also of great importance and necessity to advanced studying doctors themselves.

Objective To detect the differential expression genes(DEGs)between Barrettg esophagus(BE)and normal esophagus with oligomicroarray,and to explore the target genes related to the development of BE.Methods The total RNAs of matched BE and normal esophagus mucosa from saIne patient were isolated with one step Trizol method.Matched RNAs were qualified with 10g/L agarose gel electrophoresis.After tRNA purification,cRNAs were synthesized and labeled with fluorescence.which were tIlen hybridized with Agilent oligomicroarray containing 30,968 probes.The fluorescence intensity features were detected by Agilent scanner and quantified by software Feature Extraction.Results On average,2 biopsies by disposable jumbo biopsy forceps provided approximately 5μg RNA required for microarray.The total RNA,reverse transcription product and fluorescence labeled cRNA were all of high quality.Among 2-fold DEGs,there were 142 up-regulated genes and 284 down-regulated genes including 15 bel-2 related genes such as bel-2,MCL1,BAX,BIK and BCLAF1 Conclusion Microarray-based studies are feasible in endoscopically obtained tissues.The development of BE is a complicated process involving multi-genes,in which abnormal expression of bel-2 family related genes might be involved,but the exact mechanism needs further research.

Objective To investigate the effect of silence of human protection of telomeres 1 (hPOT1), which was induced by RNA interference, on expression of telomeric repeat factor 1 (TRF1), telomeric repeat factor 2 (TRF2) and Tankyrase 1 in human gastric cancer cell BGC823. Methods The ex-pression of TRF1 ,TRF2 and Tankyrasel at mRNA level were determined by semi-quantitative RT-PCR. Re-sults Significant increase in expression of TRFI, marked decrease of TRF2 and Tankyrase1 at mRNA level were observed in cells of hPOT1 siRNA. Conclusion The significant increase in expression of TRF1 and the marked decease in TRF2 and Tnakyrasel at mRNA level after the inhibited expression of hPOT1 in human gastric cancer cell BGC823 indicate that hPOTI is highly correlated with the expressions of other three te-lomere-specific binding proteins.

BACKGROUND: Microsatellite instability (MSI), an important gene change type, plays animportant role in the occurrence of tumor. Mismatch repair gene induces its occurrence. Although the effect of mismatch repair gene hMLH1 mutation in the hereditary nonpolyposis colorectal cancers (HNPCC) has been reported, its effect on the sporadic colorectal carcinoma lacks in-depth study.OBJECTIVE: To investigate the effect of mismatch repair gene hMLH1 mutation on colorectal carcinogenesis, and its correlation with MSI.DESIGN: Single-sample experiment.SETTING: Department of Gastroenterology, Southwest Hospital of Third Military Medical University of Chinese PLA.PARTICIPANTS: Seventy-six cases of sporadic colorectal carcinoma and corresponding normal tissues were obtained from surgically resected specimens of coloreetal carcinoma in Southwest Hospital between January 2001and December 2003. No patients had family history of tumor, or had received radiotherapy and chemotherapy. Patients were informed of the experiment.METHODS: Mutation of hMLH1 was detected by two-dimensional electrophoresis and DNA sequencing; MSI was analyzed by PCR-based methods.MAIN OUTCOME MEASURES: ① Detection rate of hMLH1 mutation of colorectal carcinoma and MSI. ② The relationship of MSI and hMLH1 mutation.RESULTS: Seventy-six cases of sporadic colorectal carcinoma were studied for hMLH1 mutation and MSI. hMLH1 mutation was detected in 8 (10.5%) cases of colorectal carcinomas while MSI was detected in 20 (26.3%) cases of colorectal carcinomas. Frequency of hMLH1 mutation and MSI was significantly higher in right colorectal cancer than in left colorec tal cancer (6/26 vs 2/50, x2=4.739, P=0.029; 11/26 vs 9/50,x2=5.212,P=0.022). No association was observed between hMLH1 mutation or MSI and tumor size, differentiation, histological type, depth of invasion, metastasis or clinical pathological stages. ② MSI was divided into high-frequency group (≥ 2 loci, n=10) and low-frequency group (1 locus, n-10), and MSI negative group (n=56). 8 hMLH1 mutations were all detected in high frequency MSI group, but no mutation was found in low frequency MSI or MSI negative groups.CONCLUSION: hMLH1 mutation and MSI occur in cancer of the right large intestine and hMLH1 mutation is involved in carcinogenesis of some sporadic colorectal cancer with high-frequency MSI.

Objective To study the expression of hTERT in human gastric carcinoma and its precancerous lesions and to explore the relationship between hTERT expression and Helicobacter pylori (Hp) infection. Methods hTERT expression was detected by immunohistochemical method. Hp was detected by rapid urease test and Warthin-Starry silver staining. Results The expression level of hTERT in human gastric carcinoma (78.95%) was significantly higher than that in gastric dysplasia (64.29%), in intestinal metaplasia (46.67%), and in atrophic gastritis (25.00%, P

Objective To investigate the expression and significance of Claudin 3 in adenocarcinoma of esophagus and gastric cardia.Methods We subjected pathologically confirmed 16 cases of esophageal adenocarcinoma(EAC),20 cases of esophageal squamous cell carcinoma(ESC),and 40 cases of gastric cardiac adenocarcinoma(CAC,including 15 diffuse and 25 intestinal cases).Tissue samples were collected with aid of gastroscope.Fifteen samples of normal esophageal mucosa and 15 samples of normal cardiac mucosa served as control.RT-PCR and Western blotting were used respectively to detect the mRNA and protein expression of Claudin 3 in these tissue samples.Results The mRNA and protein expressions of Claudin 3 were increased in EAC and intestinal CA compared with those in normal tissues,ESC and diffuse CAC.There was no significant difference of the expression of Claudin 3 between normal group and ESC and diffuse CAC group.Conclusion Claudin 3 might be related to the development of EAC and intestinal CAC,and expected to be the tumor maker and therapeutic target of this kind of carcinoma.

Objective To investigate the microsatellite instability(MSI) and monomorphism at microsatellite DNA BAT 26 locus in esophageal mucosa. Methods Genomic DNA extracted from tissues was amplified by PCR. PCR products were run on 9% denaturing polyacrylamidegel and stained with silver. Then MSI and monomorphism of microsatellite at BAT 26 locus in normal tissues at the incised edge and esophageal cancer tissues in 45 cases of esophageal caner were analyzed. Results All normal specimens showed no change in the length of MS DNA at BAT 26 locus. MSI was detected in 3 out of 45(6 7%) cases of esophageal cancer. Conclusion BAT 26 has complete monomorphism in genome of normal esophageal tissues, but is not sensitive to the identification of MSI.