title: Unscheduled DNA synthesis in psoriatic skin after ultraviolet irradiation and the effects of a combined treatment with 8-methoxypsoralen and longwave ultraviolet radiation: a clinical study.
abstract: Biopsies were taken from psoriatic patients undergoing photochemotherapy and then studied by autoradiography to investigate possible unscheduled DNA synthesis (UDS) following 8-MOP photodamage in epidermal cels. No sparse labelling was found in seventy samples taken from twenty-four different patients during PUVA therapy, indicating a lack of UDS. In contrast, UDS was observed in three patients irradiated with an all-spectrum UV lamp, as a test for DNA damage and excision repair activity. The incorporation of 3HTdR in these keratinocytes which were not undergoing S-phase was not affected by the dose of UV-A received during different stages of PUVA treatment. The results are discussed in terms of repair of the induced photodamage at the level of DNA, and in relation to a possible risk of this treatment when it is given over a long period of time.
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D001345:Autoradiography; D002648:Child; D004247:DNA / Q000096:biosynthesis*; D005260:Female; D006801:Humans; D008297:Male; D008730:Methoxsalen / Q000627:therapeutic use*; D008875:Middle Aged; D010778:Photochemotherapy; D011565:Psoriasis / Q000378:metabolism* / Q000473:pathology / Q000628:therapy; D012867:Skin / Q000378:metabolism* / Q000473:pathology; D014467:Ultraviolet Therapy
chemical_list: D004247:DNA; D008730:Methoxsalen