[Ultrastructural aspects of active and healed duodenal ulcer].

To characterize the fine structure of active and healed duodenal ulcers, tissue specimens of patients with active duodenal ulcer disease were examined under two different treatment schedules by various electron microscopic techniques. The striking histological feature of both, the active and healed duodenal ulcer, was the appearance of PAS-positive epithelial cells. Electron microscopy revealed similarity to a special type of mucus secreting cell of the antrum. The destroyed mucous structure during the ulcerative phase regains the normal net-like structure after treatment. The ultrastructural healing process shows constant features independent from the type of treatment and shows that the repair mechanisms are incomplete after a 4 week treatment.