Objective To construct the expressing vector of shRNA/mrp1 and study its expression in vitro. Methods 64bp oligonucleotides of pSUPER and the targeted senquence of siRNA/mrp1 were synthesized and annealed to form duplex strand, then were cloned into pSUPER to construct pSUPER-shRNA/mrp1 vector. Competenced Ecoli was transfected by vector of pSUPER-shRNA/ mrp1 to screen the positive clones for sequencing and extracting plasmid. The plasmids extracted were used to transfected HepG2/mrp1 cells with a control groups by negative vectors. The expression of mrp1 mRNA and MRP1 was measured by real-time PCR and resistance of HepG2/mrp1 by flowcytometry. Results pSUPER-shRNA/mrp1 was established successfully and was sequenced to test its accuracy. Expression of mrp1 mRNA in HepG2/mrp1-si was lower than that in HepG2/mrp1 (1-fold vs 179.76-fold, P<0.001). Compared to HepG2/mrp1, the expression of MRP1 in HepG2/mrp1-si was lower (11.2% vs 97.6%, P<0. 05). The sensitivity of HepG2/mrp1-si to adiramycin was higher than that of HepG2/mrp1(45.0-fold vs 1.2-fold, P<0.01). Meanwhile, the accumulation of DNR in HepG2/mrp1-si increased significantly as compared with the control (78.58 % vs 38.44%,P<0.05).Conclusion Vector of pSUPER-shRNA/mrp1 can be constructed by the technique of enzymatic incision. The multidrug resistance of HepG2/mrp1 can be reversed by RNA interference.

Objective:To investigate the application value of P-loop digestive tract recons-truction in pancreaticoduodenectomy (PD).Methods:The retrospective and descriptive study was conducted. The clinicopathological data of 21 ampullary disease patients undergoing PD in the Liuzhou People′s Hospital Affiliated to Guangxi Medical University from April to December 2020 were collected. There were 13 males and 8 females, aged from 35 to 76 years, with a median age of 60 years. All the 21 patients underwent PD and digestive tract reconstruction using P-loop method based on the Child reconstruction. Observation indicators: (1) surgical situations; (2) postoperative situations; (3) follow-up. Follow-up was conducted using outpatient examination or telephone interview to detect survival and discomfort symptoms of patients up to December 2020. Measurement data with normal distribution were represented as Mean± SD, and measurement data with skewed distribution were represented as M(range). Count data were described as absolute numbers or persentages. Results:(1) Surgical situations: all the 21 patients underwent PD successfully. The operation time, time of P-loop anastomosis and volume of intraoperative blood loss of 21 patients were (317±74)minutes, (14±3)minutes and 375 mL(range, 100-800 mL), respectively. Of the 21 patients, 17 cases had pancreatic texture as soft, 4 cases had pancreatic texture as hard, 3 cases had diameter of pancreas ≤3 mm, 18 cases had diameter of pancreas >3 mm, 14 cases were placed pancreatic duct stent, 7 cases were not placed pancreatic duct stent. (2) Postoperative situations: 2 of the 21 patients had grade A pancreatic fistula, and none of patient had grade B or grade C pancreatic fistula. One case had hepaticojejunal anastomotic fistula, 2 cases without pancreatic fistula had delayed gastric emptying and none of patient had abdominal infection or bleeding. The duration of postoperative hospital stay of 21 patients was (16±5)days, and none of patient died during postoperative 30 days. Results of postoperative histopathological examination showed there were 10 cases with duodenal papillary carcinoma, 4 cases with lower bile duct carcinoma, 3 cases with pancreatic head ductal adenocarcinoma, 1 case with duodenum stromal tumors, 1 case with gastric antrum carcinoma, 1 case with mass in the head of the pancreas of IgG4 and 1 case with choledochal cyst of type 3. (3) Follow-up: all 21 patients were followed up for 1.0 to 7.0 months, with a median follow-up time of 4.3 months. None of patient died. There was no abdominal pain, distension or dyspepsia during follow-up. One case was diagnosed as tumor liver metastasis at postoperative 5 months.Conclusion:P-loop digestive tract reconstruction in PD is safe and effective, with good short-term effect.