Defensin pattern in chronic gastritis: HBD-2 is differentially expressed with respect to Helicobacter pylori status.

BACKGROUND/AIMS: Recent reports have suggested that Helicobacter pylori infection induces the mucosal antibiotic peptide human beta defensin 2 (HBD-2). Therefore, the present study investigated mRNA and peptide expression of four different defensins in the upper gastrointestinal tract in patients with H pylori positive and negative chronic gastritis. MATERIALS/METHODS: Biopsies from the oesophagus to the duodenum were taken during routine gastroscopy in 71 individuals. Total RNA was extracted and the reverse transcription polymerase chain reaction was performed with primers for human defensins 5 and 6 (HD-5/6) or HBD-1 and HBD-2. Paraffin wax embedded tissue from gastric resections was tested for HD-5, HBD-1, and HBD-2 by immunohistochemistry. RESULTS: Helicobacter pylori colonisation was associated with an increased percentage of positive biopsies with respect to HBD-2 in the corpus (p < 0.05). Helicobacter pylori had no impact on the gastric expression of HD-5 and HBD-1, whereas HD-6 was increased in the fundus. The abundant expression of alpha defensins in the duodenum and beta defensins in the oesophagus served as a positive control in each individual. Immunohistochemical analysis confirmed the presence of the HD-5, HBD-1, and HBD-2 peptides in gastric resection specimens. CONCLUSIONS: The recently described induction of HBD-2 upon H pylori infection was confirmed in a clinical setting of chronic gastritis. This phenomenon may be mediated by components of the pathogen itself or may occur secondary to immune events in chronic inflammation.

Innate immunity and colonic inflammation: enhanced expression of epithelial alpha-defensins.

Human alpha-defensins contribute to local intestinal host defense as part of innate immunity and may be of major relevance in microbial infection and chronic inflammatory bowel disease. The objective was to investigate human defensin 5 and 6 (HD-5, HD-6) mRNA expression by RT-PCR from colonic biopsies and peptide expression by immunohistochemistry from colonic resections under basal and inflammatory conditions. Both alpha-defensins were induced by proinflammatory cytokines in cell culture. HD-5 mRNA expression was enhanced in both idiopathic and nonidiopathic inflammatory states of the large bowel [32% of control vs 73% of unspecific colitis, 69% of Crohn's disease (CD) and 73% of ulcerative colitis (UC)], whereas HD-6 was specifically related to CD and UC (14% in controls vs 20% in unspecific coltis, 49% in CD and 42% in UC). Immunohistochemistry confirmed the presence of HD-5 in colonic epithelium. Antimicrobial peptides in the colon may be of importance in maintaining the mucosal barrier and controlling microbial invasion in inflammatory bowel diseases.

[Biliary endo-to-end anastomosis with extramucosal titanium clips. Initial results of a new technique]. / Die biliäre End-zu-End-Anastomosierung mit extramukösen Titan-Clips. Erste Ergebnisse einer neuen Technik.

BACKGROUND: Bile duct anastomoses are still associated with a high failure rate. Although following iatrogenic bile duct transection only a positive selected group of patients get a primary end-to-end reconstruction, long-term results demonstrate an incidence of postoperative strictures up to 78%. Also in orthotopic liver transplantation biliary tract complications remain a significant cause of morbidity with an incidence of up to 49%. Since these complications can also be seen under optimal circumstances, the methodically based disadvantages of the conventional hand suturing like perforating needle injury of the choledochal wall with intraluminal suture material, the suboptimal approximation of the mucosal edges and an inhibited blood flow in the choledochal stumps caused by a suture related tissue strangulation may also responsible. Thus there is a search for alternative anastomosis techniques. METHOD: To test extramucous placed titanium clips for biliary reconstruction after complete division of the bile duct we performed an end-to-end-anastomosis in 9 pigs. Therefore we used the VCS (Vascular Closure Staples)-instruments (Auto Suture). RESULTS: The application of the VCS-clips (medium size) permitted the technical realization of a tension free, everted anastomosis with an exact approximation of the mucosal edges. One of the animals died from aero embolism intraoperatively. All the others showed a complication-free postoperative period without any signs of anastomotic leakage or stenosis (follow-up: 6 months). At histological examination there were smooth and intact mucosal surfaces in all pigs and--especially important for the development of strictures--only a very mild fibrosis and inflammation. CONCLUSIONS: The potential advantage of the VCS-clip-technique is the non-penetrating tissue approximation with optimal contact of the mucosal layers that does not compromise the blood flow in the choledochal stumps. Before clinical use can be recommended further studies are required.