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Biomedical subjects

L Dubertret

Publications and source records attributed to L Dubertret.

At least 343 records · Page 19Linked to original sources
PubMed1981

Surface antigens on malignant Sézary and T-CLL cells correspond to those of mature T cells.

Tumor cells from eight adult patients with T-cell chronic malignancies were investigated with a series of monoclonal antibodies recognizing T-cell differentiation antigens. This series allowed definition of discrete subpopulations of mature T cells with functional specialization. All six patients with Sézary syndrome and one patient with T-chronic lymphocytic leukemia had cells with the same phenotype as normal helper/inducer T cells, whereas the other patient with T-chronic lymphocytic leukemia had cell with the same phenotype as normal cytotoxic/suppressor T cells. Some clinical manifestations observed in these patients may reflect retention of functional activities by their malignant cells.

Antibody Specificity↗
PubMed1981

[Study of the correlation between transepidermal water loss and percutaneous penetration of steroid (author's transl)].

Modifications of transepidermal water loss due to repeated topical applications of water/oil emulsion, salicylic acid and urea, with and without occlusion, were studied on the forearms of healthy volunteers. Percutaneous absorption of three different corticosteroids was evaluated by means of the bleaching test on each treated area. It was shown that only salicylic acid significantly increased transepidermal water loss. This increase was positively correlated with an increase in the percutaneous absorption of corticosteroids. Thus it seems that a comparative evaluation of the percutaneous absorption of topical treatments in normal and lesional skin may be obtained, in vivo in man, by nonaggressive comparative evaluation of transepidermal water loss.

Adrenal Cortex Hormones↗
PubMed1980

Cellular events leading to blister formation in bullous pemphigoid.

Cellular events occurring in eight patients with bullous pemphigoid were studied by light and electron microscopy. Sections (0.5 micrometer) of large surface area, overlapping blisters and surrounding skin, were examined and correlated ultrastructural studies were performed on selected areas. The peroxidase contained in granules of neutrophils, eosinophils and young macrophages was visualized by incubation with diaminobenzidine and hydrogen peroxide. This cytochemical reaction was used as a marker to study the release of granule enzymes from these inflammatory cells. The release of such enzymes from eosinophils and occasionally from macrophages on the epidermal basement membrane (more precisely in the lamina lucida) was demonstrated in the skin surrounding the blisters in four patients. The release of these enzymes was also observed in the floor of the blisters in all eight patients. It is well known that these granules contain several proteolytic enzymes. These observations are therefore consistent with the proposal that proteolytic enzymes of eosinophils play a pathogenic role during the initial stages of blister formation in bullous pemphigoid.

Blister↗
PubMed1980

A simple method for correlating observations on skin at the light and electron microscopic levels.

A method is described which allows the embedding of 6 mm cutaneous punch biopsies for subsequent light and electron microscopic examination. Sections of 20 mm2 cut at 0.5-I micrometer are stained for light microscopy. The subtle tinctorial affinities, which approach those achieved on haematological smears, and the preservation of cellular detail frequently make subsequent ultrastructural examination unnecessary. However, when required, a special technique for trimming and resectioning the tissue blocks allows a good correlation between light and electron microscopic observations.

Azure Stains↗
PubMed1980

Endogenous peroxidases: a morphological and functional marker to study inflammatory skin diseases.

The visualization of peroxidase positive lysosomes by diaminobenzidine plus H2O2 allowed easy identification of neutrophils, eosinophils, monocytes and young tissue macrophages in 0.2 micrometer to 0.5 micrometer skin plastic sections of large surface area. Evaluation of the lysosomal functions of these phagocytic cells was greatly improved by the possibility of correlating observations on the same cell at light and electron microscopic levels.

3,3'-Diaminobenzidine↗
PubMed1979

[Experimental bases and primary trials of photochemotherapy of psoriasis by a non-cancerigenic monofunctional furocoumarin, 3-carbethoxypsoralen].

The carcinogenic risk of the photochemotherapy (PUVA) with bifunctional furocoumarins such as 8-methoxypsoralen (8-MOP) forming cross-links in cellular DNA has initiated a search for active but less dangerous psoralens. The 3-carbethoxypsoralen (3-CPs), studied in the yeast Saccharomyces cerevisiae, has been very photoactive on DNA forming only monoadditions to DNA. In Mice it was demonstrated that after local or intra-peritoneal administration, 3-CPs is non toxic, non erythematogenic and non carcinogenic in contrast to 8-MOP. A limited study on ten psoriatic patients has shown that after local application 3-CPs exhibits about the same therapeutic activity as 8-MOP.

Animals↗
PubMed1979

Photochemotherapy (PUVA) of psoriasis using 3-carbethoxypsoralen, a non-carcinogenic compound in mice.

The carcinogenic risk of photochemotherapy (PUVA) with bi-functional furocoumarins such as 8-methoxypsoralen (8-MOP) which form cross-links in cellular DNA has initiated a search for active but less hazardous psoralens. A new compound, 3-carbethoxypsoralen (3-CPs), studied in the yeast Saccharomyces cerevisiae (eukaryote), has been shown to be very photoactive on DNA and to form only mono-additions to DNA. These lesions appear to be more easily repaired than the cross-links induced by 8-MOP. 3-CPs produces less nuclear genetic events such as nuclear mutations and mitotic crossovers, but more cytoplasmic 'petite' mutations (damage to mitochondrial DNA) than 8-MOP. In mice it was demonstrated that after local or intra-peritoneal administration, in contrast to 8-MOP, 3-CPs is non-toxic, non-erythematogenic, and non-carcinogenic. A study of ten psoriatic patients had shown that local applications of 3-CPs plus UV-A exhibit about the same therapeutic activity for the clearing of psoriatic lesions as local treatment with 8-MOP plus UV-A, but without any localized hyperpigmentation.

Animals↗
PubMed1979

[Eosinophilic pustular folliculitis (Ofuji) (author's transl)].

A case, the first French observation of eosinophilic pustular folliculitis (Ofuji) is reported. The long lasting condition of unknown etiology is characterized by slightly indurated erythematous plaques and formation of follicular small papules and pustules. The lesions have a tendency to central healing and peripheral extension and proceed with remissions and exacerbations. Histological features are pustular folliculitis composed chiefly of eosinophiles. Blood eosinophila is often founded. Local corticotherapy and dapsone are sometimes a effective treatment.

Adult↗
PubMed1979

[Cutaneous psoriasis. Symptoms and therapy].

Skin psoriasis, a multi- causal disease with unknown mechanism, has several clinical aspects. Besides ordinary psoriasis with mica-like plaques and its special locations, two less known notions are underlined: the localized forms are often less typical (for example: scalp, ears, folds of the hand, foot and nails). They may be relevant to the rhumatologist for the diagnosis the inflammatory forms are often disseminated with pustules and keratosis and constitute another groups where the rhumatologic manifestations are more frequent and more severe. Various forms of treatment are active on the cutaneous symptoms, chronic or relapsing topical therapy with tar, corticoids, nitrogen mustard, photochemytherapy, oral derivatives of retinoic acid, and exceptionally immunosuppressors. Each technic has its advantages, its disadvantages on a short or long term. Therefore each patient should receive the therapy which is adapted to his form of psoriasis, the need and possibilities of the patient. Collaboration is a must and each patient should receive the adequate care making possible an improvement of his condition.

Adrenal Cortex Hormones↗
PubMedDate not supplied

[Extensive cutaneous candidiasis revealing cutaneous T-cell lymphoma: 2 cases].

BACKGROUND: During the course of immunodeficiency diseases, severe candidiasis can occur with extensive cutaneous and mucous membrane lesions. However, blood dyscrasias are very rarely revealed by diffuse candidiasis. We report two case of cutaneous T-cell lymphoma revealed by extensive and atypical cutaneous candidiasis. PATIENTS AND METHODS: Case No. 1:A 72-year-old woman presented a pruritic rash of circinate, serpiginous patches on glabrous skin and skinfolds with multiple intertrigo and rapidly worsening palmoplantar keratoderma. All mycological skin specimens tested positive for Candida albicans. Histological examination of a biopsy sample from a serpiginous patch revealed the presence of fungal elements while palmoplantar keratoderma biopsy showed an epidermotropic lymphocytic infiltrate in the superficial dermis evocative of mycosis fungoides. Blood tests showed a white cell count of 28 600/mm3 with 14% circulating Sezary cells and a T-cell clone. The T-cell lymphoma was treated with methotrexate, but the disease worsened a few months later, progressing to CD30- large T-cell pleomorphic lymphoma. The patient died of severe sepsis. Case No 2:A 60-year-old man presented a macular rash over the face, trunk and skinfolds as well as erythematous scaly annular plaques of the glabrous skin with lymphadenopathy. Cultures of skin scrapings were all positive for Candida albicans. Blood tests showed a white cell count of 15 000/mm3 with 30% circulating Sezary cells. A trunk patch biopsy revealed the histological appearance of mycosis fungoides. There was a T-cell clone in the peripheral blood and skin. DISCUSSION: In both cases, the patients presented with widespread annular and erythematous scaly lesions of the glabrous skin and skinfolds with evidence of Candida albicans on fungal tests of all skin scrapings. The discovery of circulating Sezary cells on a systematic smear for hyperleukocytosis led us to suspect underlying cutaneous T-cell lymphoma, which was confirmed by biopsy of the skin lesions accompanying the mycoses. Widespread cutaneous candidiasis can occur in patients with cell-mediated immunodepression. Cutaneous T-cell lymphoma can enhance such candidiasis through interference with skin integrity and impairment of cell-mediated immunity, with large amounts of IL10 and TGF-B, increased secretion of soluble interleukin-2 receptors (CD25) and impaired CD8 suppressor cell function.

Aged↗
PubMedDate not supplied

Photochemotherapy using pyridopsoralens.

Aiming to decrease the acute side effects and genotoxic hazards of PUVA, pyrido (3,4-C) psoralen (PP) and 7-methyl pyrido (3,4-C) psoralen (MPP) were synthesized and studied. Their UVA maximum absorption lies at 325 and 330 nm, respectively. Their photostability is comparable to that of 8-MOP. They complex to DNA in the dark, and, in the presence of UVA, produce only monoadditions to DNA, as shown by fluorescence and DNA denaturation-renaturation studies. In diploid eukaryotic yeast they are more effective than 8-MOP for the induction of lethal effects and mitochondrial damage. Their mutagenic activity per unit dose of UVA is in the same range as that of 8-MOP. However, per viable cell they are clearly less mutagenic than 8-MOP. This difference is also observed for recombinogenic activity. No oxygen effect is observed. In mammalian cells the following ranges of effectiveness are found: inhibition of DNA synthesis in human fibroblasts: MPP greater than PP greater than 8-MOP; mutagenic activity in V79 Chinese hamster cells: MPP greater than PP greater than 8-MOP; cell transforming ability in C3H embryonic mouse cells: MPP greater than 8-MOP greater than PP as a function of UVA dose, and: 8-MOP greater than MPP greater than PP as a function of survival; induction of sister chromatic exchanges (SCE) per unit dose: MPP greater than PP greater than 8-MOP in the linear part of the induction curve, and : 8-MOP greater than PP greater than MPP at the maximum level of SCE obtained.(ABSTRACT TRUNCATED AT 250 WORDS)

5-Methoxypsoralen↗