Recognition of melanoma cell antigens with antibodies present in sera from patients with vitiligo.

BACKGROUND: Patients with vitiligo show specific losses of integumentary melanocytes, probably due to autoimmunity against melanocytes. We attempted to determine the presence of antibodies against pigment cell antigens in the sera of vitiligo patients. METHODS: Detergent-solubilized human melanoma cells were submitted to electrophoretic separation and immunoblotted against serum samples obtained from 19 patients with vitiligo and from 20 age- and sex-matched healthy individuals. RESULTS: Eighty-nine per cent of patients with vitiligo had antibodies to one or more pigment cell antigens. Similar antibodies were detected in 20% of healthy individuals. Antigens of 165, 90, and 68 kDa were recognized by the antibodies present in sera from 11%, 26%, and 37% of vitiligo patients, respectively, and in none of the normal sera. All patients with familial vitiligo also had antibodies to these three proteins. CONCLUSIONS: Proteins of 165, 90, and 68 kDa are specifically recognized by antibodies present in the sera of vitiligo patients and in all patients with genetic vitiligo. Whether or not these proteins might be implicated in the destruction of melanocytes by the immune system in vitiligo remains to be evaluated.

[Lipid peroxidation, production of PGE2 and cellular mortality induced by UV in cultured human skin fibroblasts]. / Peroxydation lipidique, production de PGE2 et mortalité cellulaire induites par les UV dans des fibroblasts cutanés humains en culture.

UV irradiation induces lipid peroxidation (LPO) and cell damage. The aim of the present work was the study of UVB radiation effects on cultured human skin fibroblasts, concerning LPO, prostaglandine E2 (PGE2) formation and cell viability. The cells were exposed to 50, 100, and 150 mJ/cm2 of UVB irradiation. Cellular TBARS and supernatant fluorescent substances were measured spectrofluorimetrically. PGE2 was measured using an immunoenzymatic method. Cell viability was evaluated by the MTT test. All determinations were done after a 2 h incubation period post-irradiation. TBARS were increased for all doses of irradiation (p < 0.001). Fluorescent substances differed from controls at 50 mJ/cm2 (p < 0.001). UVB at 100 and 150 mJ/cm2 decreased cellular viability (p < 0.001). An increase of PGE2 was observed with UVB at 150 mJ/cm2 (p < 0.001). These results confirm the occurrence of LPO and cytotoxicity after UV irradiation; on the other hand, this study showed the formation of PGE2 induced by UV light on cultured human skin fibroblasts. We propose a relationship between these phenomena.

[Madurella grisea eumycetoma. Presentation of a case]. / Eumicetoma por Madurella grisea. Relato de caso.

One case of mycetoma produced by Madurella grisea localised on the foot of a house wife is reported. The identification of the strain was made through the following features: aspect of the grains, micro e macromorphology in Sabouraud agar and capacity of assimilation of the sugars. This is the fifth case of mycetoma by Madurella grisea reported from Brasil.

A procedure to obtain long-lasting fluorescence in formaldehyde fixed tissues.

The authors made a study of the small intestine by immunofluorescence in 5% phosphate-buffered formaldehyde fixed tissues, using the Nairn (1976) technique associated with Evans blue (Fry and Wilkinson 1963). The ability of the sections to fluoresce has been maintained after a storage time of more than 4 years. Similar very good results were obtained when skin biopsies from pemphigus foliaceus patients were fixed in formaldehyde for two h and afterwards washed in 30% sucrose solution for 12 to 18 h.