A vector for a mutant Chinese Helicobacter pylori (Hp) strains knock out pathogenicity island (PAI) was constructed, which was the basis to establish a Chinese Hp mutant deleting pathogenicity island. Genetic engineering techniques such as polymerase chain reaction, plasmid extraction, agarose gel electrophoresis, restriction analysis, ligation, preparation of competence cell and transformation were used to make two cloning fragments containing two end regions of PAI and a selectable chloramphenicol resistance marker between them, and then engineering the recombined fragments into pBluescript plasmid. The result showed that restriction analysis demonstrated that the engineering mutant vector had been recombined. It suggested that we constructed an engineering mutant vector which targeted to delete the PAI in Chinese Hp strains. It will be useful for addressing the role of PAI in the pathogenesis of Hp infection.

The purpose of this study was to investigate clinical feasibility of treatment of pancreatic pseudocyst by endoscopy. We reported here one case of large pancreatic psuedocyst that was treated by endoscopic ultrasonography guided cystogastrostomy.The patient's symptoms resolved on the same day of operation. And one week later, the pancreatic pseudocyst decreased by more than 50% in size. Pancreatic psuedocyst resolved and didn't relapse after 6 months. So endoscopic ultrasonography guided cystogastrostomy is a safe, reliable, effective therapy for pancreatic pseudocyst with few complications.