ABSTRACT
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.
ABSTRACT
Objective To compare the predictive power of model for end-stage liver disease(MELD) and Child-Turcotte-Pugh(CTP) on the cirrhotic patients who underwent transjugular intrahepatic portosystemic shunt(TIPS).Methods A total of 110 patients(98 males and 12 females) undergoing TIPS from January 2004 to March 2008 in our hospital were analyzed.Data of all patients were analyzed retrospectively.The main statistical tests included: Kaplan-Merier analysis to compare survival respectively,and the area of receiver operating characteristics(ROC) to compare the performance of the 2 models for predicting 3-month,1-year,and 2-year mortality.Results The survival rate rate of the patients whose MELD score under 15 showed significantly higher than the patients above MELD score 15.The area of ROC that predicting survival was 0.866 and 0.863 at 3 months,0.755 and 0.739 at 1-year,0.729 and 0.750 at 2-years respectively for the MELD and the CTP score.Conclusion Both MELD and CTP score can predict short-term survival accuracy,but poor in long-term.However,the MELD has overcome the shortcomings of CTP,and may be worth using in clinical.