Are ultraviolet-induced acute histological changes in irradiated nevi associated with allelic loss?
Acute histological changes demonstrated in melanocytic nevi after UV irradiation are not followed by allelic loss on identical chromosomal areas found in dysplastic melanocytes of atypical nevi. This finding supports the hypothesis that initial nonspecific genetic events may occur after UV irradiation, followed by an increase in various repair mechanisms potentially leading to specific genetic damage and loss of heterozygosity; however, loss of heterozygosity is not detectable at an early stage.
These in vitro data show that mast cells and eosinophils could be involved in modulating Crohn disease fibrosis by directly influencing intestinal fibroblast properties.