phosphorus-radioisotopes and Erythema

Understanding the basis for individual susceptibility to skin cancer requires an understanding of the factors contributing to tumorigenesis. One such factor is the ability of the cell to repair DNA lesions induced following insult to the genome. Currently, research in this field is hampered by the lack of a suitably sensitive and specific method for the detection of DNA lesions. Developed previously 32P-HPLC in vitro analysis is applied in this study to measure UVB-induced dipyrimidine photolesions in human keratinocyte cultures. The high sensitivity of this method permitted the detection of individual cyclobutane pyrimidine dimers and 6-4 photoproducts in cells irradiated with UVB at doses below one minimal erythema dose. Using this technique one could detect approximately a 2-fold difference in a base sequence repair of photolesions. The rates of repair in the chromosomally unstable HaCaT keratinocyte cell line and in cultured primary human keratinocytes were compared. The presented data indicate the potential of the 32P-HPLC method for the study of DNA repair in cultured cells as well as for biomonitoring studies in humans.

Topics: Cells, Cultured; Chromatography, High Pressure Liquid; DNA Adducts; DNA Damage; DNA Repair; Erythema; Humans; Keratinocytes; Phosphorus Radioisotopes; Phosphorylation; Photochemistry; Pyrimidine Dimers; Skin Neoplasms; Ultraviolet Rays

Topics: Aged; Erythema; Follow-Up Studies; Humans; Male; Paraneoplastic Syndromes; Phosphorus Radioisotopes; Polycythemia Vera; Thiophenes; Ticlopidine

Ten percent polysorbate 85, a nonionic surfactant, was applied on the upper arm of 15 healthy individuals under occlusive dressing daily for 4 days. The other arm was similarly treated with the ointment base (white petrolatum USP) to provide the control area. At the end of treatment, macroscopic observations indicated minor erythema in 11 cases and no visible changes were noted on the surfactant-treated areas of 4 persons or any of the control areas. No definite histologic changes were observed by microscopic evaluations. The results of biochemical assays, however, were more definitive. The content of the epidermal phospholipids was elevated within a range of 5 to 65 percent as a result of the treatment with polysorbate 85 preparation. Radioactive tracer studies indicated higher rates of 32P incorporation into epidermal phospholipids, TCA-soluble, DNA and RNA fractions of the surfactant-treated skin. Results resemble those that were documented in earlier studies with rabbit skin.

Topics: Adult; Biopsy; DNA; Erythema; Female; Humans; Male; Occlusive Dressings; Phospholipids; Phosphorus; Phosphorus Radioisotopes; RNA; Skin; Surface-Active Agents

Topics: Age Factors; Anaphylaxis; Animals; Burns; Coloring Agents; Electric Stimulation; Endothelium; Erythema; Guinea Pigs; Histamine; In Vitro Techniques; Inflammation; Leukocytosis; Phosphorus Radioisotopes; Rabbits; Rats; Serotonin; Time Factors; Ultraviolet Rays