The content of optical isomerism is the difficult point of organic chemistry teaching, and so case-based learning (CBL), theoretical-experimental integration teaching method and micro class teaching methods are tried to be used in classroom teaching according to the actual teaching situations. For CBL teaching method, the course is guided by the step of introduction-question-discussion and summary-exten-sions; For theoretical-experimental integration teaching method, combined with the theory class, the two experiments including the determination of optical rotation and organic molecular model are set for the opti-cal isomer content, to enhance the students' understanding of theoretical knowledge through the hands-on operation;For micro class teaching method, the key and difficult points of this chapter are dug out and about 10 minutes of video are recorded by using common video software before class, which are introduced in the classroom or provided to students after class for repeated watching, to deepen the students' understanding of the concept and phenomenon of optical isomers. In brief, it is important to combine various teaching method to improve the classroom instructing effectively and stimulate the students' interest in organic chemistry.

Objective To evaluate the efficacy of interventional catheter drainage combined with ozone therapy for the management of postoperative enterocutaneous fistula. Method A total of 70 patients with postoperative enterocutaneous fistula were enrolled and divided into group A (35, conventional surgical treatment) and group B (35, interventional catheter drainage and ozone therapy). Clinical efficiency, hospital stays, hospital expenses and complications were compared. Follow-up observations of the infection score in 2 groups before and after treatment (3 days, 1 week, 2 weeks and 1 month) were also compared. Results 30 cases in group A recovered (85.7%), and 28 cases in group B recovered (80.0%), the result of which shows no statistic significance. The hospital stays and expense in group B were significantly lower than those in group A. 4 cases of group A suffered from incision complications , 2 intra-abdominal hemorrhage , 1 severe pneumonia and 1 septic shock. 2 cases in group B suffered from stomachache. The differences can be shown significantly. The infection score between the two groups shows no significant difference, but the score was found to be obviously lower after treatment than before. The infection score decreased by an average of 19.9 in group A and 23.5 in group B,indicating a better anti-infective effect in group B. Conclusion Interventional catheter drainage combined with ozone therapy for the management of postoperative enterocutaneous fistula is safe and effective, with lower hospital stays and expense.

Objective To investigate the characteristics of nerve injury and incidence of carpal tunnel syndrome(CTS)indiabeticpatientsbymeasuringthenerveconductionvelocity(NCV). Methods Atotalof387 inpatients with type 2 diabetes were selected in Kaifeng Central Hospital from July 1, 2011 to October 1, 2014. The abnormal rates of NCV between left and right or male and female for the same name nerve were compared. The examinations to median nerves were paid particular attention and the segmental test was performed. Results Among 387 patients, 333 cases showed abnormal NCV, and 162 patients (41. 9%) presented with CTS. The incidence of sensory nerve injury was higher than that of motor nerve injury. The nerve injury often occurred in the dominant hand, but the injury of bilateral hand were also found in some patients. In 162 patients with CTS, 91 patients presented with clinical manifestations and signs, and the rest were without discomfort in their hands. The percentages of SCV(34. 1%vs 25. 6%, P=0. 012) and MCV (40. 3% vs 29. 5%, P=0. 020) abnormality in the right median nerve were higher than those in the left side. No significant difference of the other nerves was found between left and right. Significant differences in the percentages of abnormality in SCV of the left median nerve (21. 4%vs 30. 5%, P=0. 047) and the right median nerve (28. 6%vs 40. 1%, P=0. 013) between man and woman were found. The abnormal rates of other nerves were without statistically significant between man and women. Conclusions The incidence of CTS is high in diabetic patients. Usually, it firstly occurs in sensory nerves, followed by motor nerves, especially in the dominant hand.

Objective To investigate the incidence,location and morphological features of Laimer fibers between mucosal layer and inner circular muscularispropria in patients with achalasia.Methods Data of 107 patients with achalasia who underwent POEM between May 2010 and June 2013 were collected.Endoscopic video was reviewed to determine the incidence of Laimer fibers and the corresponding images were analyzed according to gender,age,Ling typing and location of Laimer fibers.Results Laimer fibers were found in lower esophageal sphincter of 44 patients (41.12％).There were no significant differences in the incidences of Laimer fiber among groups with different age or gender (P ＞ 0.05).The incidence in Ling type Ⅱb was 46.15％ (12/26),and 45.83％ (22/48) in Ling type Ⅰ,0 in Ling type Ⅲ.There was no significant difference among the groups of Ling type (x2 =2.042,P =0.564).All Laimer fibers were found in lower esophageal sphincter and the majority of which were in right wall (36.45 ％,39/107),followed by left wall (3.74％,4/107) and none was found in anterior wall (x2 =107.468,P =0.000).Conclusion Laimer fibers generally exists in lower esophageal sphincter and most of which are discovered on right wall of the esophagus.Further study is needed to explore its role in development and treatment of achalasia.

Objective To determine the incidence and clinical factors associated with bleeding after endoscopic submucosal dissection (ESD) of gastric mucosal lesions.Methods Clinical,endoscopic and pathological data of 223 lesions in 215 ESD patients between January 2009 and October 2011 were collected.The following factors associated with bleeding were analyzed:( 1 ) patient-related factors:sex,age,concomitant diseases including hypertension and diabetes mellitus,history of administration of anticoagulants or antiplatelet agents; (2) lesion-related factors:size,location,ulcer or scar findings,macroscopic types and pathological types; (3) procedure-related factors:en-bloc resection,spray of porcine fibrin sealant and operation time. Results Thirteen patients (13 lesions ) developed bleeding after ESD,among whom 7(53.8％) occurred within 24 hours after the procedure,5 (38.5％) within 1 week and 1 (7.7％) on the sixteenth day after ESD.Univariate and multivariate analysis revealed that lesion size ( ≥5 cm; odds ratio 8.663 ; 95％ CI:2.081 - 36.075) was an independent risk factor for bleeding.Conclusion Lesion size is the independent risk factor for bleeding after ESD,so careful preparation and close monitoring are required during and after ESD.In the meantime efforts should be made to identify and exactly demarcate lesions to minimize the size of resected specimens and reduce the risk of bleeding after ESD.

ObjectiveTo evaluate preoperative biopsy in the treatment of gastric mucosal lesions by endoscopic submucosal dissection (ESD).MethodsClinical data of 195 patients diagnosed as having gastric intraepithelial neoplasia (GIEN) or early cancer by preoperative biopsy were retrospectively analyzed.The discrepancy between endoscopic biopsies and pathological diagnosis after ESD were studied.ResultsThe overall consistency rate between preoperative biopsies and postoperative pathological diagnosis was 93.8％ (183/195) and complete consistency rate was 50.8％ (99/195).For low-grade and highgrade gastric intraepithelial neoplasia ( LGIEN),the complete consistency rates were 49.4％ (42/85)and 38.0％ (30/79),respectively,which were not different ( P ＞ 0.05 ).For early cancer it was 87.1％(27/31 ),which was significantly higher than those in the LGIEN group and HGIEN group ( P ＜ 0.05 ).Post-ESD diagnosis was more severe than biopsy in 66 patients (33.8％,66/195 ),including 36 LGIEN (42.4％,36/85) and 30 HGIEN (38.0％,30/79).Final pathological diagnosis was milder than biopsy in 18 patients (9.2％,18/195),i.e.14 HGIEN (17.7％,14/79) and 4 early cancer (12.9％,4/31).Gastritis was diagnosed in 12 patients (6.2％,12/195),i.e.7 LGIEN (8.2％,7/85) and 5 HGIEN (6.3％,5/79).ConclusionPreoperative biopsy is insufficient for accurate diagnosis of gastric mucosal lesions,but facilitates resection of gastric mucosal lesions by ESD.

Objective To evaluate the curative effect of asymptotic full-thickness myotomy type of peroral endoscopic myotomy(POEM) for achalasia.Methods Data of 41 patients who underwent asymptotic POEM at our digestive endoscopy center from December 10th 2010 to January 10th 2014 were retrospectively studied.The postoperative and preoperative symptoms and reflux were compared.Results The postoperative Eckardt scores of symptoms of 41 patients improved significantly(P ＜ 0.001) compared with before.Esophageal dynamic pressure also showed the effectiveness of symptom relief.The incidence of postoperative reflux in symptoms and gastroscopy were 26.83％ and 27.27％,respectively.Conclusion Asymptotic fullthickness myotomy POEM can alleviate the symptoms of achalasia and the effect of inhibiting reflux is generally satisfactory.

Objective To explore the manipulation,feasibility and safety of laparoscopy assisted natural orifice translumenal endoscopic surgery(NOTES).Methods The technique was performed in 4 female porcine models.Diagnostic laparoscopy was performed first,and followed by transgastric access through the anterior gastric wall under the monitor of laparoscopy.The stoma was extended with the dilation ballon and the endoscope was sent to the abodominal cavity.Such procedures as endoscopic peritoneoseopy,fallopian tube ligation,oophorectomy,eholeeysteetomy and closure of gastrostomy were performed.The drainage tube and antibiotics of 3 days were used after operation according to the bleeding and potential risk of fistula and peritonitis.The animals were feeded on a semiliquid diet.Two weeks later,routine gastroseopy was pedbrmed to examine the healing of luminal incision.Subsequently,all models were sacrificed for the evaluation of the validity of NOTES.Results With the assistance of the laparoscope,endoscopic peritoneoseopy and,fallopian tube ligation,oophorectomy and cholecystectomy,twice for each,were successfully performed in all models.Abdominal drainage were used in two animals'after eholecystectomy.All porcines survived for 2 weeks postoperatively with no weight loss.Autopsic examination showed good healing of transgastric incisions,with little adhesion,no massive heinan'hage,abcesses,or injury to adjacent organs.Conclusion Combined laparoscopy and endoscopy for NOTES is feasible with relative safety.Laparoscopic assistance could facilitate the NOTES procedures at the present stage.

Objective To investigate the diagnostic potential of magnifying narrow-band imaging endoscopy (NBI-ME) for different intrapapillary capillary loop (IPCL) for the diagnosis of esophageal lesion.Methods Patients with abnormal esophageal mucosa found by white light gastroscopy in digestive endoscopy center,Chinese PLA General Hospital during the period of November 2009 to November 2010 were enrolled in this study.IPCL was observed and divided into different types by NBI-ME.Histopathology of biopsy or endoscopic submucosal dissection (ESD) specimens was evaluated and used as the gold standard to evaluate the diagnostic value of NBI-ME for IPCL.Results A total of 146 lesions from 145 subjects with esophageal mucosa abnormal were collected. Among them, 88 were pathology-proven inflammation,5 were pathology-proven esophageal cancers,20 were pathology-proven low intraepithelial neoplasia (LIN) and 33 were pathology-proven high intraepithelial neoplasia (HIN) detected with NBI-ME.By a per-lesion analysis,the accuracy of inflammation and cancer were 100％ (88/88) and 7/7.For the sensitivity,specificity,accuracy,positive predictive value,negative predictive value,positive likelihood ratio,negative likelihood ratio of LIN and HIN were 7/10,69.8％ ( 30/43 ),69.8％ ( 37/53 ),35.0％ (7/20),90.9％ (30/33),12.5％ (70/559),2.3％ (30/1290) and 87.1％ (27/31),72.7％ ( 16/22),81.1％ ( 43/53 ),81.8％ ( 27/33 ),80.0％ ( 16/20 ),634.1％ ( 837/132 ) and 35.2％ ( 124/352 ),respectively.Conclusions NBI-ME can classify the different esophageal IPCL.Higher diagnostic accuracy of IPCL indicates the feasibility of NBI-ME for the efficacious diagnosis of esophageal inflammation and cancer.There is the higher diagnostic accuracy of HIN than LIN.

Objective To evaluate the technique of transpancreatic septum precut for cannulation of inaccessible common bile duct in endoscopic retrograde cholangiopancreatography (ERCP). Methods Data of 109 patients with difficult biliary cannulation in ERCP, of whom 56 underwent transpancreatic septum precut and 53 had needle-knife sphincterotomy from January 2006 to July 2008, were analyzed retrospectively, and the success rate of cannulation and the occurrence of complications were compared between the two methods. Results Of 109 patients accepted precut papillotomy, common bile duct cannulation was successfully achieved in 97. The success rates of transpancreatic septum precut group and needle-knife sphincterotomy group were 96.4% (54/56) and 81.1% (43/53) respectively, which was significantly different (P<0.05). Complications occurred in 11 cases, including bleeding(n =4), acute pancreatitis(n=5), cholangitis(n=2). The tolal frequency of complications of the transpancreatic septum pre-cut papillotomy group was lower than that of needle-knife sphincterotomy group(3.6% vs. 17.0%, P<0.05). Conclusion In patients with inaccessible bile ducts, transpancreatic septum precut is a safe and effective procedure in cannulation, exhibiting a higher success rate and lower occurrence of complication when compared with needle-knife sphincterotomy.