DNA vaccine plays an important role in the treatment of cancer, infectious disease and self-immune disease. Further enhancement of immune responses to DNA vaccines is one of the hot spots in the vaccine development. Among the research combining the electroporation with DNA vaccination improves plasmid gene expression in vivo and significantly enhances the immune responses. This review gives an overview of the application, effectiveness and prospect of electroporation in improving the efficacy of DNA vaccine.

Objective To investigate the influence of duodenal diverticula on cannulation time and complication in patients undergoing ERCP.Methods Data of 3 265 patients undergoing ERCP in Drum Tower Hospital affiliated to Nanjing Medical University between January 1,2008 and December 31,2014 were enrolled.The patients' information and endoscopic pictures/videos were collected.The duodenal diverticula,cannulation time,postoperative complications were analyzed.Results There were 2 599 (79.6％) cases of non-diverticula,445(13.6％) cases of one-diverticula,122(3.7％) patients with two or more diverticula,and 99 (3.0％) intradiverticular papilla.Patients with duodenal diverticula accounted for 20.4％ (666/3 265) of all patients who received ERCP procedure.The mean cannulation time was 6.62 minutes in all cases,6.30 minutes in non-diverticula group,7.63 minutes in one-diverticula group,8.07 minutes in two-or-more group,8.58 minutes in intradiverticular papilla group,respectively.There were significant differences in cannulation time and complication rate between the groups.Conclusion Duodenal diverticula may be one of the factors that affect the cannulation time.It may enhance the cannulation complications and prolong the cannulation time,especially in those with intradiverticular papilla.

Objective To evaluate the efficacy and safety of endoscopic therapy in the treatment of symptomatic pancreatic divisum (PD).Methods Data of 8 patients who underwent endoscopic retrograde cholangiopancreatography (ERCP) with the diagnosis of pancreas divisum at our institution from June 2006 to June 2013 was retrospectively analyzed.Results The patients were identified as pancreatic divisum with 28 ERCP procedures.All patients received stent placement,7 underwent minor papilla sphincterotomy,6 pancreatic duct stricture dilatation,and 1 stone extraction.Post-endoscopic retrograde cholangiopancreatography pancreatitis occurred in 1 patient,and no other complications occurred.After a follow-up of 2-47 months,1 patient died of pancreatic carcinoma,3 patients removed the stents,3 patients were followed up regularly,and 1 was unavailable for the interview.The episode of chronic pancreatitis and the extent of abdominal pain decreased after the operations.Conclusion Endoscopic therapy is effective and safe for the pancreatic divisum patients.It can reduce the episode of chronic pancreatitis and relieve the chronic abdominal pain in PD patients with low incidence of complication.

BACKGROUND:Self-made Distraction Reduction Fixation System is characterized by Distraction Reduction Fixation functions,which can completely fuse to the design of steel plate,and by no need to provide many surgical instruments,by reduction of bleeding and trauma.OBJECTIVE:To test changes in the stiffness of porcine short spinal segments in integrity and following destabilizing and internal fixation of the Distraction Reduction Fixation System.DESIGN,TIME AND SETTING:The control observation experiment was performed at the Laboratory of Biodynamics,Institute of Onhopedics,General Hospital of Chinese PLA from December 2004 to December 2005.MATERIALS:Twelve fresh porcine lumbar spines(T11-S2 segments)were bought from a market.Upper and lower segments were crossed and inserted with Kirschner wire to make porcine spine samples of the L1-7 segments.METHODS:Stiffness of intact samples was recorded during forward-bending,backward-bending,lateral-bending and axial rotation.Intervertebral discs,facet ioints,anterior and posterior longitudinal ligaments were removed to loose the spine.Stifrness of each motion was measured.Stiffness tests were repeated again after internal fixation on short segments using Distraction Reduction Fixation System.MAIN OUTCOME MEASURES:Stiffness in the intact,unstable and internal fixed spines during each motion.RESULTS:The stiffness iu unstable porcine spine were significantly lower than those in intact porcine spine(P<0.05),but the stiffness after internal fixation was significantly higher than in unstable porcine spine(P<0.05).No significant difference was detected in stifiness during forward-bending,lateral-bending and axial rotation(P>0.05)except that it was significantly higher during backward.bending after internal fixation compared with the intaet spine(P<0.05).CONCLUSION:Biodynamics confirms that the stiffness in short-segment fixation porcine after using Distraction Reduction Fixation System is markedly increased than in unstable porcine spine,except during backward-bending,which is comparable with that in intact porcine spine.

Objective To investigate the risk factors of post-ERCP pancreatitis( PEP). Methods Data of 4,234 patients who underwent ERCP in Nanjing Drum Tower Hospital were retrospectively analysed. Information of patients and operations,including age,gender,operation history,major disease history,labora-tory examination before operation,abdominal ultrasound,CT,MRCP,detailed ERCP operation process,com-plications and treatment were carefully recorded. Then Chi-square test was used for univariate analysis,and stepwise multivariate Logistic regression for variate analysis. Linear correlations between risk factors were de-tected. Results There were totally 226 PEPs,with 5. 3% incidence rate. Univariate analysis showed that the female(χ2 =9. 715,P=0. 002),young( <60 years)(χ2 =6. 108,P=0. 013),chronic pancreatitis(χ2 =14. 703,P=0. 001),initial ERCP(χ2 =14. 899,P=0. 000),hypertension(χ2 =4. 489,P=0. 034),nor-mal bilirubin levels before operation(χ2 =19. 159,P =0. 000 ),difficult cannulation(χ2 =45. 824,P =0. 000),pancreatic guide wire(χ2 =30. 223,P=0. 000),papillary pre cut(χ2 =45. 928,P=0. 000),pan-creatography(χ2 =20. 170,P=0. 000)may be risk factors for PEP. Non conditional Logistic regression analy-sis showed that female(OR=1. 449,P=0. 011),initial ERCP(OR=1. 745,P=0. 003),normal bilirubin levels before operation(OR=1. 917,P=0. 000),difficult cannulation(OR=3. 317,P=0. 000)and pancre-atography(OR=1. 823,P=0. 004)were independent risk factors for PEP. Linear correlation analysis sugges-ted that pancreatic duct guide wire and papillary precut were related to the difficult cannulation,and the corre-lation coefficients were -0. 788 and -0. 699. Conclusion Female,young(<60 years),chronic pancreati-tis,initial ERCP,hypertension,normal bilirubin levels,difficult cannulation,pancreatic duct guide wire,pa-pillary precut,pancreatography may induce PEP. Female,normal bilirubin levels before operation,initial ER-CP,difficult cannulation and pancreatography are independent risk factors for PEP,while pancreatic duct guide wire,papillary precut are not,as they were linear correlated to difficult cannulation.

Objective To explore the correlation between wedged hepatic vein pressure (WHVP) and directly measured portal vein pressure (PVP) and further analyze the correlation between hepatic venous pressure gradient (HVPG) and portal pressure gradient (PPG).Methods From December 2012 to April 2014,the related data including WHVP,free hepatic venous pressure (FHVP),inferior vena cava pressure (IVCP) and PVP of patients who received transjugular interahepatic portosystem stentshunt (TIPS) treatment were collected,and HVPG and PPG were calculated.The correlations between WHVP and PVP,between FHVP and IVCP,between HVPG and PPG were analyzed.Pearson's correlation analysis were performed for correlation analysis.Results Twenty two patients matched the criteria were enrolled during the December 2012 to April 2014.The mean pressures of PVP and WHVP were (28.07±4.43) mmHg (1 mmHg=0.133 kPa) and (26.22±5.91) mmHg,respectively.PVPand WHVP were positively correlated,the correlation coefficient of them was 0.431 (P=0.045) and slope was0.323.The mean pressures of FHVP and IVCP were (7.31±3.37) mmHg and (6.82±4.01) mmHg,respectively.FHVP and IVCP were positively correlated,the correlation coefficient of them was 0.845 (P＜0.01) and slope was 0.711.The mean pressures of PPG and HVPG was (21.02±3.76) mmHg and (18.90±4.86) mmHg,respectively.There was no correlation between PPG and HVPG,the correlation coefficient of them was 0.014 (P=0.951).Conclusions There is a good correlation between PVP and WHVP,and so is the correlation between FHVP and IVCP.However,there is no good correlation between HVPG and PPG in this study because of the effects of many factors.

Objective To investigate the correlation between hepatic venous pressure gradient (HVPG) and clinic features ,laboratory results in patients with liver cirrhosis .Methods From December 2012 to April 2014 ,patients with liver cirrhosis who received HVPG examination were enrolled .The clinical data of the patients were collected ,which included etiology of cirrhosis ,albumin ,creatine ,total bilirubin ,international normal ratio (INR) ,history of ascite and bleeding ,degree of gastroesophageal varices under endoscopy ,the scores of Child‐Pugh and model for end‐stage liver disease (MELD) .Single factor and multiple factor linear regression method were performed to analyze the correlation between these indexes and HVPG .Results A total of 63 patients met the inclusion criteria .Among them ,six patients had abnormal shunt in liver venous and HVPG examination failed .The HVPG of the left 57 patients was 9 .50 to 33 .20 mmHg (1 mmHg = 0 .133 kPa) ,mean (16 .38 ± 5 .64) mmHg .The results of single factor regression analysis indicated that there were certain relevance between the level of albumin (r2 = 0 .145 , P= 0 .002) ,Child‐Pugh score (r2 = 0 .069 ,P= 0 .048) and HVPG .Multiple factor analysis indicated that there were certain relevance between albumin (B= - 4 .920 ,t= - 3 .521 ,P= 0 .001) ,total bilirubin (B =4 .066 ,t= 2 .206 ,P = 0 .032) and HVPG ,and there were no relevance between the other indexes and HVPG .Conclusion Only albumin and total bilirubin level in patients with liver cirrhosis are correlated with the level of HVPG .

Objective To assess feasibility and advantages of the improved endoscopic resection of duodenal major papillary.Methods A total of 56 cases were collected in Drum Tower Hospital from October 2007 to December 2012, which were diagnosed as duodenal major papillary adenoma or carcinoma in situ, where tumor didn't extend to the biliary or pancreatic duct by the endoscopic ultrasonography, intraductal ultrasonography or histology of biopsy specimens.The diameters of these adenoma ranged from 0.3 cm to 5.0 cm.Twenty-four lesions were resected by routine endoscopic method and 32 lesions were removed by modified endoscopic method.All patients underwent ERCP and biliary and/or pancreatic stents were placed.Results En bloc resection rate was significantly higher in modified group(87.5％ ,28/32) than that in routine group (60.9％, 14/23, P ＜ 0.05).There were no significant differences in complete resection rates (93.8％ ,30/32 VS 87.0％, 20/23;P ＞0.05), or in the amount and difficulty of pancreaticobiliary stenting(P ＞ 0.05)between modified group and routine group.Short-term complication occurrence in modified group was lower than that of the routine group(15.6％ ,5/32 VS 41.6％, 10/24, P ＜ 0.05), but long-term complication occurrence showed no significant difference.There was no significant difference in recurrence rate between two groups[7.1％ (2/28) VS 15.0％ (3/20) ,P ＞0.05].Conclusion Endoscopic resection of duodenal major papillary adenoma with a modified method shows more therapeutic effect.

Objective To investigate the efficacy of pancreatic duct stent in preventing post-ERCP pancreatitis (PEP) of difficult bile duct cannulation.Methods A total of 120 patients who underwent difficult bile duct cannulation during routine ERCP were randomized to receive pancreatic duct stent placement (S group) or not (NS group),and the incidence of PEP,hyperamylasemia and scores of abdominal pain were analyzed.Results There were 15 cases of hyperamylasemia and 5 cases of PEP occurred in S group,but no severe PEP was observed.The score of abdominal pain was (3.82 ± 1.48) in S group.There were 18cases of hyperamylasemia and 14 cases of PEP occurred,including 2 severe PEP in NS group.The score of abdominal pain was (7.48 ± 1.93) in NS group.There was no significant difference in the incidence of hyperamylasemia between the two groups (P ＞ 0.05).The incidence of PEP,severe PEP and the scores of abdominal pain were lower in the S group (P ＜ 0.05).Conclusion Placement of pancreatic duct stent can reduce the PEP rate of difficult bile duct cannulation and relieve the abdominal pain.

Objective To explore the effects of different treatments on prognosis of patients with Gynura segetum caused hepatic vein occlusion disease (HVOD).Methods From July 2008 to January 2016,85 patients with Gynura segetum caused HVOD were enrolled and received treatment of liver function protection and microcirculation improvement.According to different treatment options,patients were divided into non-anticoagulation group,nowanticoagulation transfered to transjugular intrahepatic portosystem stent-shunt (TIPS) group,anticoagulation group,anticoagulation transfered to TIPS group and anticoagulation-TIPS step-by-step treatment group.The efficacy of each group was observed.Chi square test was performed for statistical analysis.Results Among 22 patients who received nonanticoagulation treatment,six (27.3％) patients were cured and 14 (63.6％) patients died during the treatment period;besides two (9.1 ％) patients received TIPS because of ineffective treatment and achieved longterm survival.Among 63 patients treated with combination of low-molecular-weight heparin and warfarin,six (9.5％) patients died and 36(57.1％) patients were cured.The cure rate was higher than that of nonanticoagulation group (x2 =5.820,P=0.016).Other 21 patients received TIPS treatment,achieved longterm survival except one patient died from surgical complications.The cure rate of anticoagulation-TIPS step treatment group was 88.9 ％ (56/63) which was higher than that of non-anticoagulation group,and the difference was statistically significant (x2 =31.350,P＜0.01).Conclusions Compared to conventional liver function protection treatment and symptomatic treatment,anticoagulation therapy significantly increases the cure rate of patients with Gynura segetum caused HVOD.Anticoagulation-TIPS step-by-step treatment further improves the cure rate.