Objective To develop a better probe preparation method of gene chips for the further gene chips fabrication and its application in the gene expression. Method Using human leukemia K562 cells as material,applying a new kind of technology for gene differential display restriction display(RD PCR),we isolated a lot of cDNA fragments as probes of gene chips. Results This method has overcome the shortcoming of more pseudopositives in DD PCR,and was easy to be manipulated.Compared with the chip fabricated with full cDNA probes,the probe length is comparatively homogeneous,and the hybridization dynamics is apt to be controlled.Conclusion\ RD PCR technology could provide a new strategy for the probe preparation of gene chips.\;[

Objective:To evaluate the application value of small IT knife pre-cut in assistance to duodenal papillary cannulation compared with conventional guidewire cannulation.Methods:A retrospective analysis was performed on the data of 90 patients with choledocholithiasis including 52 patients with small IT knife pre-cut assisted intubation (small IT knife group) and 38 patients with conventional guidewire intubation (conventional group) in endoscopic retrograde cholangiopancreatography (ERCP) from May 2016 to July 2019 in the digestive endoscopy center of Nanjing Drum Tower Hospital. The basic data, curative effect and complications of the two groups were collected and compared.Results:There was statistically significant difference in gender composition between the small IT knife group and the conventional group ( χ2=5.679, P=0.017), but no significant difference in other baseline data between the two groups (all P>0.05). The median intubation time of the small IT knife group was significantly shorter than that of the conventional group (141.5 s VS 270.0 s, Z=1 268.0, P=0.022). There were no significant differences in the success rate of intubation [98.1% (51/52) VS 94.7% (36/38), χ2=0.760, P=0.571], the incidence of intraoperative bleeding [15.4% (8/52) VS 7.9% (3/38), χ2=1.148, P=0.345], postoperative pancreatitis [5.8% (3/52) VS 7.9% (3/38), χ2=0.159, P=0.694], and postoperative cholangitis [1.9% (1/52) VS 5.3% (2/38), χ2=0.760, P=0.571] between the two groups. No perforation occurred in the two groups. After stratifying according to the operator′s proficiency, the median intubation time was significantly different between the small IT knife expert group and the conventional expert group (116.0 s VS 258.0 s, Z=276.0, P=0.038), while there was no significant difference in the intubation time among other groups (all P>0.05). Conclusion:The small IT knife is safe and effective to pre-cut and assist intubation in ERCP, and it may shorten the intubation time.

Objective To investigate the efficacy and safety of endoscopic ultrasound-guided biliary drainage ( EUS-BD ) on obstructive jaundice patients who had failed in the endoscopic retrograde cholangiography ( ERC ) . Methods Seventeen obstructive jaundice patients who underwent EUS-BD at Nanjing Drum Tower Hospital from October 2015 to July 2017 were enrolled in the study. The types of biliary drainage, technical success rate, clinical efficacy, post-procedure adverse events, and follow-up were analyzed. Results EUS-BD was successfully performed in 16 out of 17 patients, with technical success rate of 94. 1％. Operation pathway included 12 EUS-guided hepaticogastrostomy, 2 EUS-guided antegrade stenting, 1 EUS-guided rendezvous, and 1 EUS-guided choledochoduodenostomy. All the 16 patients′bilirubin decreased at different levels after operation, and the clinical success rate was 94. 1％ (16/17). Post-operation complications included 5 cases of cholangitis, 2 of bile leakage, and 1 of pneumoperitoneum and duodenal perforation. The patients were followed up for 14-390 days after procedures. Two patients died of underlying disease one month after operation. Jaundice in another 2 patients worsened during follow-up and were improved after replacement of previous stent. Conclusion EUS-BD has a relatively high technical success rate, and can be considered as an alternative choice for patients with obstructive jaundice after failure of ERC. Operation pathway should be decided according to patient′s condition.

Objective To investigate the diagnostic value of intraductal ultrasonography ( IDUS ) with or without brush cytology on distinguishing malignant from benign biliary stricture. Methods The data of patients with biliary stricture, who underwent endoscopic retrograde cholangiography( ERC) and IDUS in Drum Tower Hospital from September 2007 to October 2015 were retrospectively analyzed. Features of IDUS images and results of brush cytology were compared with postoperative histological results to evaluate the diagnostic yield of IDUS and brush cytology on differential diagnosis of malignant biliary stricture. Results A total of 230 patients with biliary stricture underwent ERC and IDUS, and 206 patients meanwhile received brush cytology, including 84 cases of malignant biliary stricture. Of the 230 patients, 87 cases underwent surgery, and 75 revealed malignant results, including 65 cases of cholangiocarcinoma, 8 cases of pancreatic adenocarcinoma, and 2 cases of periampullary adenocarcinoma. Using postoperative pathologic results as the gold standard, 72 malignant and 9 benign biliary strictures were correctly diagnosed by IDUS. The sensitivity, specificity, positive predictive value, and negative predictive value of IDUS for diagnosis of malignant biliary stricture was 96. 0％, 75. 0％, 96. 0％, and 75. 0％, respectively. Sixty-five patients underwent IDUS with brush cytology during ERC before surgery, and 56 out of 65 showed malignant results. Thirty-one malignant and 9 benign biliary stricture were correctly diagnosed by brush cytology. The sensitivity, specificity, positive predict value, and negative predict value of brush cytology for diagnosis of malignant biliary stricture was 55. 4％, 100％, 100％, and 26. 5％, respectively. If brush cytology combined with IDUS to diagnose malignant biliary stricture, the sensitivity rose up to 94. 6％, while the specificity went down to 77. 8％, and the positive and negative predictive value was 96. 4％ and 70. 0％, respectively. Conclusion IDUS exhibited excellent sensitivity and specificity, while brush cytology revealed perfect specificity and positive predictive value on diagnosis of malignant biliary stricture. If IDUS combined with brush cytology, the sensitivity and negative predictive value could rise significantly, while the specificity and positive predictive value mildly went down, which suggested that IDUS remained a certain degree of over judgment and false positive rate.

Objective To investigate the clinicopathologic characteristics and relevance of main and minor lesions of synchronous multiple early gastric cancers ( SMEGC) and gastric high grade intraepithelial neoplasia ( GHGIN) . Methods Thirty-two patients with SMEGC or/and GHGIN who were diagnosed and treated with endoscopic submucosal dissection in Nanjing Drum Tower Hospital from July 2012 to September 2016 were enrolled in this study. Their clinicopathologic characteristics were summed up, and the correlation between main and minor lesions on the size, location, endoscopic classification, pathologic type, invasion depth and vascular invasion were analyzed. Results Among the 32 patients, with mean age of 66. 19±7. 46 years, 90. 62％(29/32) were male, 17 cases (53. 3％) had family history of gastric cancer, 25 (78. 13％) had smoking history, and 22 ( 68. 75％) were alcohol users. There were 30 cases ( 93. 75％) and 31 cases ( 96. 88％) with mucosal atrophy and intestinal metaplasia, respectively. The size of main and minor lesions showed a positive correlation (r=0. 4167, P=0. 018). The endoscopic classification of major and minor lesions had no statistical significant consistency ( P=0. 314 ) , but the pathologic type and invasion depth between major and minor lesions demonstrated a moderate significant positive correlation ( P<0. 05 ) . The comparison of location between the main and minor lesions did not show correlation. However, it showed a significant correlation between major lesion which on the upper 1/3 of stomach and minor lesion on the lower 1/3 of stomach ( r=0. 463,P=0. 003) . Further more, when the main lesion was at posterior gastric wall, the minor lesions on lesser curvature were increased, which showed a positive correlation( r=0. 417,P=0. 009) . Conclusion Old-age male with long-term smoking and alcohol history whose lesions combined with surrounding mucosa merger atrophy and intestinal metaplasia are considered as a high risk group in patients with SMEGC or/and GHGIN. Therefore, clinicians must keep high vigilant and make carefully observations on this group of patients during endoscopic examination, and consider the correlation between main and minor lesions to avoid misdiagnosis.

Objective:To investigate the safety and long-term outcomes of fully covered self-expanding metal stent (FCSEMS) placement in patients with benign refractory pancreatic stenosis.Methods:Data of 18 patients with benign refractory pancreatic stenosis who underwent endoscopic treatment with FCSEMS in Nanjing Drum Tower Hospital between March 2013 and July 2020 were collected. The technical success, clinical success, adverse events and long-term outcomes were analyzed.Results:FCSEMS placement was successful in all 18 patients, with technical success rate of 100.0% (18/18). After stenting, the visual analogue scale (VAS) significantly decreased [2.00 (1.75, 3.00) VS 6.00 (5.00, 7.00), Z=-3.572, P<0.001]. The VAS decreased by more than 50% in 15 cases, and the clinical success rate was 83.3% (15/18). Stent-related adverse events included intolerable pain in 3 patients, stented-induced de novo stricture in 2 patients, and distal migration of stent in 2 patients. The stents were successfully removed in all patients after 137.5 (59.0, 417.0) days. There was significant reduction in terms of decreased upstream ductal dilatation after stent removal [9.1 (6.7, 14.1) mm VS 11.0 (7.6, 16.2) mm, Z=10.508, P<0.001]. After stent removal, 10 of the 14 patients maintained the response to pancreatic stenting and 4 recurred during the follow-up of 37-1 246 days. Conclusion:FCSEMS placement appears to be safe and effective in the treatment of benign refractory pancreatic stenosis and can provide persistent improvement in the stricture.

Objective:To investigate the efficacy and safety of a new China-made direct visualization system of peroral cholangiopancreatography in the diagnosis and treatment of biliopancreatic diseases.Methods:Clinical data of 37 patients who underwent endoscopic examination through the direct visualization system of peroral cholangiopancreatography at Digestive Endoscopy Center of Nanjing Drum Tower Hospital from April 2020 to June 2021 were retrospectively analyzed. Technical success rate and complications were analyzed.Results:The examination was completed in 37 patients through the system. The technical success rate was 100.0%. The nature of biliary stricture was confirmed in 24 cases, presenece or absence of bleeding or residual stones in the bile duct was confirmed in 6 cases, neoplasm or residual stones in the pancreatic duct was determined in 2 cases, biliary stricture was passed assisted with visualized guidewire in 2 cases, and lithotripsy was performed assisted with biliary laser in 3 cases. Nine patients were pathologically diagnosed as having malignant biliary stricture, and 8 of them were confirmed malignant by the system. Drainage was performed in 34 cases after the examination. There were 3 cases of cholangitis, 4 cases of bacteremia and 2 cases of postoperative pancreatitis after the operation, which were relieved in a short time after conservative treatment. Bleeding occurred in 1 case which was improved after two times of endoscopic hemostasis.Conclusion:The new direct visualization system of peroral cholangiopancreatography is safe and effective in the diagnosis and treatment of biliopancreatic diseases.

Objective:To explore the effectiveness and safety of endoscopic ultrasound-guided pancreatic duct drainage (EUS-PD).Methods:A retrospective analysis was conducted on data of 16 patients who underwent EUS-PD because of endoscopic retrograde pancreatography (ERP) failure, poor effectiveness or anatomical changes and couldn't undergo the routine ERP in Nanjing Drum Tower Hospital from June 2018 to July 2022. The technical success of EUS-PD, clinical efficacy and post-procedure adverse events were analyzed.Results:In the 16 patients, there were 14 males and 2 females, with age of 50.69±12.95 years. A total of 19 times of EUS-PD operations were included, 3 of them were rendezvous-assisted endoscopic retrograde pancreatography (RV-ERP), 15 transgastric or transenteric EUS-guided stent placement and 1 was EUS-guided nasopancreatic duct placement. Technical success was achieved in 84.21% (16/19) patients, and among whom 93.75% (15/16) achieved clinical success. The overall incidence of postoperative adverse events was 52.63% (10/19) including 47.37% (9/19) abdominal pain, 15.79% (3/19) fever and 15.79% (3/19) postoperative pancreatitis. All adverse effects were relieved after general conservative treatment and no primary disease or surgery-related death occurred. The mean follow-up was 17.6 (8.2,22.3) months and 93.75% (15/16) of the patients were followed up. By the time of follow-up, 76.92% (10/13) of the patients who had successfully received EUS-PD had no recurrence of abdominal pain or distension.Conclusion:EUS-PD is a safe and effective alternative therapy for those with pancreatic diseases with ERP failure, poor efficacy or anatomical changes.