RESUMO
Depigmenting effects of 4-tertiary butyl catechol (TBC) were investigated using tissue cultured melanocytes of adult guinea pig. Black guinea pig ear epidermis was trypsinized, suspended in BME Eagle media (5 X 10(6) cells) supplemented with 10% calf serum, and seeded in Petri dishes (2 ml/ea). On the 5th day of culture, TBC dissolved in DMSO was added to the media, and the central area of Petri dishes with large numbers of melanocytes (but not keratinocytes) present were examined by light and electron microscopy. After 6 hr of treatment with 1.5 X 10(-3) mg TBC per ml of media, about 15 to 30% of melanocytes detached and about half of the remaining cells showed reversible changes in the cell shapes. An increase of TBC concentration to more than 2 X 10(-3) mg per ml of media resulted in larger numbers of melanocyte deaths. The surviving cells contained numerous, but ultrastructurally unusual premelanosomes and melanosomes. In addition, microfilaments showed a wavy appearance.
Assuntos
Antioxidantes/farmacologia , Catecóis/farmacologia , Melanócitos/efeitos dos fármacos , Pigmentação/efeitos dos fármacos , Animais , Células Cultivadas , Depressão Química , Dimetil Sulfóxido/farmacologia , Cobaias , Melanócitos/patologia , Melanócitos/ultraestruturaRESUMO
The delayed hypersensitivity to antibiotics existing in Brazil, including the systemically administered, is analyzed. The sulphanilamide, penicillin, neomycin, oxacillin, oxitetraciclyne, chloramphenicol and kanamycin were the more positive to the contact test. We do not find any difference in the test between sex and race. The positivity was 7,5 times higher in adults than in children. In spite the high positivity in atopic patients we could not demonstrate the same in patients with other allergic procesus history.
