Repair in acute and chronic ulcers.

The process of ulcer healing is still incompletely understood and the cause of delayed healing in chronic ulcers is unknown. The work described here is concerned with certain aspects of epithelial repair in experimental ulcers--that is, mitotic activity, cell migration, and cell re-establishment with differentiation, using light and electron microscopy. The findings have been compared with similar observations on human gastric and venous ulcers. The results have shown that increased mitotic activity and attempted cell migration are able to persist throughout epithelialisation of experimental lesions and that the chronicity of human ulcers cannot be explained by a lack of new epthelial cell production or failure of these cells to assume a migratory form. Some other basic defect in the healing process must therefore be present.