Search

Regular intake of aspirin or other nonsteroidal anti-inflammatory drugs (NSAIDs) is associated with a decreased incidence of colorectal, esophageal, gastric, and lung cancer. The relative risk of colorectal cancer is about 0.6 in large cohort studies--in other words, the risk is reduced by 40%. Also, in experimental models, the frequency of colonic cancer is reduced by NSAIDs. Both human and experimental tumors contain increased amounts of prostaglandin E(2), which may have a role in the accelerated proliferation taking place in tumor tissue. This may be the result of activation of cyclooxygenase-2 (COX-2) in response to mitogens and growth factors, for example, which will result in an increased production of prostaglandins. The current theory is that the mechanism for the suppressor effect of NSAIDs on carcinogenesis is COX-2 inhibition. However, reliable data on the dose of aspirin or other NSAIDs for optimal benefit for tumor suppression are lacking, and it is still premature to give general recommendations on using NSAIDs for chemoprevention of gastrointestinal cancer.

Background & Aims: Crohn's disease (CD) is associated with a disturbed intestinal barrier. Permeability studies have focused on inert molecules, but little is known about transepithelial transport of macromolecules with antigenic potential in humans. The aim of this study was to quantify permeation and to characterize passage routes for macromolecules in ileal mucosa in CD. Methods: Noninflamed and inflamed ileal mucosa specimens from patients with CD (n = 12) and ileal specimens from patients with colon cancer (n = 7) were studied regarding transmucosal permeation of ovalbumin, dextran (mol wt, 40,000), and 51 Cr-EDTA for 90 minutes in vitro in Ussing chambers. Transepithelial passage routes for fluorescent ovalbumin and dextran 40,000 were investigated by confocal microscopy. Results: Noninflamed ileum from CD patients showed increased permeation of ovalbumin compared with ileum from colon cancer patients ( P 51 Cr-EDTA permeability was increased in inflamed ileum. Ovalbumin passed both transcellularly and paracellularly, but dextran followed a strictly paracellular route. Both markers were subsequently endocytosed by cells of the lamina propria. Conclusions: Noninflamed ileal mucosa from patients with CD shows increased epithelial permeability to ovalbumin, probably by augmented transcytosis. This increase in antigen load to the lamina propria could be an initiating pathogenic event in CD. GASTROENTEROLOGY 1999;117:65-72

Long-term endoscopic remission in a case of Crohn's disease after autologous bone marrow transplantation.

Background: The relationship between the endoscopic appearance of the ileal mucosa in Crohn's disease and the symptoms has not been studied. Although surgery is important, morbidity caused by intestinal resections and its relation to recurrent inflammation have been poorly evaluated. Methods: The relationship of symptoms to various ileoscopic signs of inflammation and previous intestinal resection was prospectively studied in 75 postresection Crohn patients. Results: Multivariate analysis showed that a combination of anastomotic width, pus, and length of previous small-bowel resection best explained a symptom score (r = 0.53, p < 0.001). Of 40 patients with the anastomosis strictured to less than 15 mm, only 9 had moderate to severe symptoms. Patients with a stricture diameter < 10 mm differed significantly in symptom score (p < 0.05) from those with wider anastomoses. Conclusions: The study indicated that intestinal resection was as important for symptoms as endoscopically viewed recurrent ileal inflamma...