Objective To develop a better method for preparation of porcine model of acute myocardial infarction by permanent occlusion of the left circumflex coronary artery and minimally invasive surgery, evaluate its validity and stability, and explore its application in experimental studies of ischemic heart diseases.Methods 25 healthy female 3-month-old Bama minipigs, body weight 25±3 kg, were used in this study.The porcine model of myocardial infarction was established by minimally invasive surgery and the left circumflex artery ligation at the site of OM1 posterior position under general anesthesia.Heart function was assessed by echocardiography at 15 min before surgery, 1 hour and 4 weeks after surgery.Pathological examination was performed at 4 weeks after the left circumflex artery occlusion.The mortality and cause of death were statistically analyzed.Results The 1-hour and 4-week postoperative cardiac function was considerably decreased, showing a decreased ejection fraction from 64.2±4.6% to 48.2±5.3% (1hour after MI) and 49.7±6.1% (4 weeks after MI) (P<0.01).Pathological examination revealed that the ventricular wall was thinner and the amount of collagens was increased in the infracted area.The ventricular fibrillation rate at 1-hour after myocardial infarction was 17.3% and the infarction area was 19.2%.Conclusions A pig model of acute myocardial infarction can be prepared by our modified left circumflex coronary artery ligation at the obtuse marginal artery (OM1) and minimally invasive surgery.This model exhibits advantages such as minimal surgical trauma, high stability of the model, and low mortality, therefore, provides an ideal and economic animal model for experimental studies on acute ischemic heart diseases.

Objective To investigate the correlation of single nucleotide polymorphism of rs3731055 and rs2607775 of xeroderma pigmentosum group C (XPC) and smoking with genetic susceptibility to pancreatic cancer.Methods The clinical data of 214 patients with pancreatic cancer who were admitted to the First and Third Affiliated Hospitals of Xinjiang Medical University from January 2009 to June 2011 and 214 healthly individuals were retrospectively analyzed.The samples of venous blood of 214 patients with pancreatic cancer (case group) and 214 healthy individuals (control group) were analyzed by the Multiplex SNaPshot method.The count data were analyzed using the chi-square test.The association between the single nucleotide polymorphism of rs3731055 and rs2607775 with genetic susceptibility to pancreatic cancer was analyzed using the Logistic regression method.Results Four hundred and twenty-three samples of gene were successfully typed,including 210 in the case group and 213 in the control group.The frequency of G allele of XPC rs3731055 was 75.95％ (319/420) in the case group and 77.00％ (328/426) in the control group,with no significant difference between the 2 groups (x2 =0.12,P ＞ 0.05).The frequencies of genotypes GG,GA and AA were 58.57％ (123/210),34.76％ (73/210) and 6.67％ (14/210) in the case group,and 60.09％ (128/213),33.80％ (72/213) and 6.10％ (13/213) in the control group,with no significant difference between the 2 groups (x2=0.12,P ＞ 0.05).The frequency of C allele of XPC rs2607775 was 87.86％ (369/420) in the case group and 93.43％ (398/426) in the control group,with significant difference between the 2 groups (x2=7.75,P ＜ 0.05).The frequencies of genotypes CC,CG and GG were 77.62％ (163/210),20.48％ (43/210) and 1.90％ (4/210) in the case group,and 86.85％ (185/213),13.15％ (28/213) and 0(0/213) in the control group,with significant difference between the 2 groups (x2=8.54,P ＜ 0.05).Patients with rs2607775 GC genotype were associated with a significantly increased risk of pancreatic cancer compared with patients with rs2607775 CC genotype (adjusted OR =1.81,95％ CI:1.06-3.10,P ＜ 0.05).Patients with rs2607775 GC + GG genotype were associated with a significantly increased risk of pancreatic cancer compared with patients with rs2607775 CC (adjusted OR =1.98,95％ CI:1.16-3.36,P ＜ 0.05).The ratio of patients in the case group who smoked cigarettes ≥ 17 pack years was 25.24％ (53/210),which was significantly higher than 13.15 ％ (28/213) of the control group (x2 =11.37,P ＜ 0.05).The results of univariate analysis showed that patients who smoked cigarettes ≥ 17 pack years had higher risk of getting pancreatic cancer (adjusted OR =2.82,95％ CI:1.27-6.29,P ＜ 0.05).Patients who smoked cigarettes ≥ 17 pack years and with rs2607775 CC also had higher risk of getting pancreatic cancer (adjusted OR =2.87,95％ CI:1.18-6.99,P ＜0.05).No significant gene-environment interaction was observed between rs2607775 GC + GG and smoking ≥ 17 pack years (adjusted OR =3.65,95％ CI:0.67-20.03,P ＞ 0.05).Conclusions The polymorphisms of XPC rs2607775 may play a role in the onset of pancreatic cancer.Patients who smoke cigarettes ≥ 17 pack years are more easily to have pancreatic cancer.There is no interaction between smoking and XPC rs2607775 in influencing the progression of pancreatic cancer.

Objective To systematically review the clinical efficacy of transanastomotic pancreatic ductal stents placement after pancreaticoduodenectomy.Methods According to the Cochrane reviewers handbook (version 5.0 ),literatures were retrived from PubMed,Embase,Cochrane,VIP database,China Biology Medicine disc and CNKI database,and then the quality of the literatures was analyzed.Meta analysis was carried out using the RevMan software ( version 5.0.18 ).A random effects model was adopted,and the results of the meta analysis were presented with odds ratio (OR) and 95％ confidence interval (95％ CI).Results Four randomized controlled trials including 557 patients were retrieved.External stents were used in 160 patients and internal stents in 115 patients.The results of meta analysis showed no significant difference in the rate of fistula,overall postoperative morbidity and mortality between patients who did or did not receive pancreatic stents placement (OR =0.66,0.70,0.63,P ＞ 0.05 ).There were significant differences in the rate of pancreatic fistula and overall postoperative morbidity between patients who received external pancreatic stents placement and those did not receive pancreatic stents placement ( OR =0.48,0.55,P ＜ 0.05 ).There was no significant difference in the mortality rate between patients who received external pancreatic stents placement and those did not receive pancreatic stents placement (OR =0.71,P ＞ 0.05 ).There were no significant difference in the incidence of pancreatic fistula,overall postoperative morbility and mortality between patients who received internal pancreatic stents placement and those did not receive pancreatic stents placement ( x2 =0,0.75,2.11,P ＞ 0.05 ).Conclusions External pancreatic stents placement after pancreaticoduodenectomy can reduce the incidence of postoperative complications.The effects of internal pancreatic stents placement need to be proved by further highquality prospective randomized trials.

The application and significance of learning method of self-evaluation and mutual-evaluation for practical teaching ofcurriculum were investigated. The practical teaching followed theory teaching in the curriculum plan, which applied grouping pattern to provide demonstration, practice and assessment. According to the technique points of practical teaching, the teachers established evaluation form and listed detailed points of self-evaluation and mutual evaluation. The focus was student assessment, including individual self-evaluation, subject-evaluation intra-group evaluation, external-group evaluation and teacher evaluation. 100 points were taken as maximum score, including 10 points in the self-evaluation from operator, 20 points in the evaluation from receiver, 20 points in the intra-group evaluation, 20 points in external-group evaluation and 30 points in teacher evaluation. Through practical application, it was found learning system of self-evaluation and mutual-evaluation had important significance in promoting mutual learning among students, improving students' learning enthusiasm and initiative, and helping teachers understand and improve their roles.