Biomedical subjects
Publications and source records attributed to M Lecha.
The authors report the experiments about incubation of uroporphyrinogen with sonified fibroblasts of normal individuals and prophyrics and present the hypothesis of the absence of deficiency in the activity of uroporphyrinogendecarboxylase.
Four cases with clinical characteristics closely related to Lupus Erythematosus Disseminatum are reported by the authors. The evolution, progress and the biochemical, immunological and photobiological data were different from those usually found in L.E.D. The histopathological picture was also dissimilar, the most characteristic finding being a sharply limited epidermal necrolysis with focal distribution. In view of the peculiarities of the clinico-pathological syndrome presented by these patients, the authors raise the questions does it represent a special modality of L.E.D. or a new lupus-like disease?
Conley et al., in 1971, described a special type of melanoma characterized by a superficial melanic lesion at the onset; repeated local relapses as subcutaneous tumorations with an histological picture closely resembling an atypical fibroxantoma or fibrosarcoma. After a review of all the published material the autors presents a personal case with the clinical, histological and evolutive characteristics of this disease. The most interesting findings of the published case are the following: The special stains for the melanocytes (silver stain, Dopa, tyrosinase and cholinesterase) were all negative. There was an intense positivity for the lisosomal enzymes (non specific sterases, and acid phosphatases). The ultrastructural study of the tumoral tissues as well as the cells of cultures showed abundant cells with tumoral aspects, with prominent nucleoli somewhat dilated granular endoplasmic reticulum, myelin-like figures, lipidic vacuoles and abundant lisosomes. No melanosomes or premelanosomes were observed. Beside these tumoral cells abundant typical fibroblastic elements were found. There was a great amount of collagen fibers with periodicity superior to the normal. The conclusion is that the desmoplastic melanoma must be considered as a tumor of mesenchimatous origin intervening in its development multiple local and general factors.
A case of diffuse normolipemic plane xanthome showing no association with systemic disease (multiple myeloma, leukemia, reticulosis, or dysglobulinaemia), in a 50 year old female, is reported. The patient presented hypersensitivity to the erythrogenic spectrum with pathological response and lowered MED. The B lymphocytes in the peripherical blood was raised. The authors postulated that B lymphocytes probably play an important role in the pathogenesis of the skin light-induced reactions.
An observation of Scleromyxedema is repported by the authors. The remarkable peculiarities of this case are the following: 1. Absence of abnormal paraprotein. 2. Positive direct and indirect immunofluorescence. 3. Slight increase of plasma cells of bone marrow. 4. Presence of calcifications. 5. The hyperkeratotic lesions. Those of the fingertips with histology of porokeratosis. 6. Scarcity of the metachromatic depots of muchopolisacharids in the dermis evident only with the Alcian-PAS stain.
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The solar spectrum reaching the earth contains a portion of wavelengths corresponding to the infrared range. Along with ultraviolet radiation, infrared radiation contributes to the biological effects of sunlight on the skin. In recent years several sunscreens have appeared that claim to protect against infrared radiation. We have evaluated the immediate erythema induced by infrared radiation, and the protection offered by such sunscreen. We found it offered a minimal but real protective effect against infrared-induced erythema.
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