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Biomedical subjects

M Lecha

Publications and source records attributed to M Lecha.

At least 73 records · Page 4Linked to original sources
PubMed1981

Hepatoerythropoietic porphyria: a new uroporphyrinogen decarboxylase defect or homozygous porphyria cutanea tarda?

Uroporphyrinogen decarboxylase levels were measured in haemolysed whole blood or fibroblasts from 3 unrelated patients with hepatoerythropoietic porphyria (HEP) and in 4 unrelated patients with familial porphyria cutanea tarda, a condition in which the enzyme is defective. In HEP patients enzyme activities were 7% of normal in erythrocytes and 8% of normal in cultured skin fibroblasts. All the features of HEP, including the characteristic accumulation of protoporphyrin in erythrocytes, are secondary to this enzyme defect. The father of 1 HEP patient was heterozygous for the same enzyme defect. He also had uroporphyrinuria and was therefore indistinguishable from patients with subclinical familial porphyria cutanea tarda. It is suggested that patients with HEP are homozygous for the gene that causes porphyria cutanea tarda.

Child↗
PubMed1977

[Focal epidermal necrolisis. A variation of lupus erythematosus of a new disease?].

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?

Adult↗
PubMed1977

[Desmoplastic melanoma].

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.

Aged↗
PubMed1975

[Disseminated plane xanthoma with photosensitization].

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.

B-Lymphocytes↗
PubMed1975

[Scleromyedema with special hyperkeratosis lesions and calcifications].

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.

Aged↗
PubMedDate not supplied

Photoprotection in the infrared radiation range.

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.

Erythema↗
PubMedDate not supplied

[The importance of data].

Decisions have to be made about what data on patient characteristics and processes and outcome need to be collected, and standard definitions of these data items need to be developed to identify data quality concerns as promptly as possible and to establish ways to improve data quality. The usefulness of any clinical database depends strongly on the quality of the collected data. If the data quality is poor, the results of studies using the database might be biased and unreliable. Furthermore, if the quality of the database has not been verified, the results might be given little credence, especially if they are unwelcome or unexpected. To assure the quality of clinical database is essential the clear definition of the uses to which the database is going to be put; the database should to be developed that is comprehensive in terms of its usefulness but limited in its size.

Databases, Factual↗