Effect of ranitidine on gastric and duodenal mucosal enzyme activities in duodenal ulcer patients

The activities of 11 marker enzymes from the gastric and duodenal mucosa were determined in 19 patients with active duodenal ulcer disease (DU) before therapy, after 4 weeks of therapy with ranitidine, 300 mg/day, and after another 4 weeks without treatment. The activities were measured in homogenized material obtained with forceps through an endoscope. The healing rate at 4 weeks was 68%. In the descending duodenum the activities of the membrane enzymes increased during the treatment period compared with pre-treatment activities. Although not as extensive as in the descending duodenum, an increase of membrane enzyme activities was also noted in the duodenal bulb during treatment. In the gastric mucosa only minor enzymic activity changes were seen. The altered enzyme activities in duodenum and stomach during treatment were independent of ulcer healing, smoking, antacids, and mucosal inflammation. Previously, significant differences in mucosal enzyme activities have been demonstrated between DU patients and controls. During ranitidine treatment the enzyme activities in the duodenal mucosa of the same DU patients tended to normalize, whereas they were mostly unchanged in the gastric mucosa. Four weeks after treatment the mucosal enzyme activities in the duodenum were as before treatment started, without occurrence of ulcer relapse. The altered enzymic activities of the duodenal mucosa in DU patients therefore seem to be largely independent of the presence of active ulcer.     

DNA ploidy, tumour site, and prognosis in colorectal cancer. A flow cytometric study of paraffin-embedded tissue

DNA ploidy patterns were studied by flow cytometry in nuclear suspensions from 149 paraffin-embedded colorectal adenocarcinomas. The DNA ploidy of rectal tumours was not significantly different from that of colonic tumours. Patients with DNA diploid tumours had a significant survival advantage compared with patients with non-diploid tumours, but DNA ploidy did not confer any significant additional prognostic information when tumour site, Dukes's stage, the invasiveness of the tumour, and the number of lymph node metastases were adjusted for in a proportional hazards regression analysis (Cox). It is concluded that DNA ploidy does not contribute significantly to the explanation of why patients with rectal cancer have a poorer prognosis than those with colonic cancer.