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Biomedical subjects

G Mauduit

Publications and source records attributed to G Mauduit.

At least 37 records · Page 2Linked to original sources

Expression of blood group antigens by cultured human epidermal cells used as allografts.

The expression of blood-group antigens was studied on human epidermal cultures used as allografts in 13 non-immunosuppressed patients treated for leg ulcers. The study was carried out using monoclonal antibodies to A and B antigens by an indirect immunofluorescence technique. Blood-group antigens are weakly expressed on the suprabasal layers of the cultured epidermal sheets. After grafting, the donor's blood-group antigens were detected on a few cells of the suprabasal layers. Furthermore, scattered keratinocytes as well as acrosyringia were found to express the recipient's blood-group antigens.

Antigens↗

Effects of PUVA and mechlorethamine treatment of psoriatic patients on epidermal Langerhans' cells.

Using OKT6 monoclonal antibody, we investigated the number of epidermal Langerhans' cells (LCs) in involved skin from patients with psoriasis, before and after mechlorethamine (HN2) or PUVA treatment. The number of LCs remained at about pretreatment number during three weeks of HN2 treatment alone, though they were reduced after 10 systemic PUVA treatments. Therefore, in contrast to PUVA which influences LCs, HN2 seems to have little effect on LCs. LCs in psoriatic plaques were, in number, 3-4 times less numerous than those in uninvolved, nontreated epidermis.

Antibodies, Monoclonal↗

[Treatment of severe alopecia areata with topical applications of cyclosporin A].

Cyclosporin A (CyA) is a fungal peptide used as immunosuppressor in human organ transplantation. Increased hair growth appears to be a common side-effect of treatment, occurring in almost all patients treated with oral CyA. The development of hypertrichosis during CyA administration is not hormone-dependent; it may be mediated by a direct effect of the drug on the hair growth process. We used CyA topically (5 p. 100 oily solution) in 14 patients with severe alopecia areata (totalis 5, ophiasis 3, bald plaques 6). The drug was applied on the alopecia twice a day for 5 +/- 1.5 months. Patients were examined monthly. No clinical adverse effect was observed. Routine blood examination did not show any change, except for a transient increase of hepatic enzymes in one patient. CyA determinations were performed monthly by radioimmunoassay. No CyA was detected in the patients' serum. Treatment resulted in no regrowth in 8 patients, development of vellus hair in 3 patients (alopecia areata totalis 2, ophiasis 1) at the end of therapy, and normal hair growth in 3 patients with bald plaques. We may conclude that CyA is capable of inducing regrowth of hair when applied topically. However, the drug does not seem to be useful for the treatment of alopecia areata.

Administration, Topical↗

Quantitative analysis of T6-positive Langerhans cells in human skin cancers.

Epidermal Langerhans cells (LC) are required for antigen-presentation and for stimulating antigen-specific T cell activation. Similar functions may be important in the immune response to malignant skin tumours. Monoclonal anti-T6 antibody was used to examine LC population in basal and squamous cell carcinomas. Positive control labeling was performed with monoclonal anti-HLA-DR antibody. The number of T6-positive LC per mm2 of section was significantly decreased (p less than 0.01) in the tumour group in comparison with a sex and age-matched control group. The number of sun-exposed and covered regions was taken into consideration in each respective group. Within the tumours, LC were found more frequently in the tumour periphery and in most differentiated tumour areas (horn pearls) than in the rest of the tumour mass. T6-positive LC were rarely found in the dermis. Moreover, LC exhibited morphological changes in specimens from tumours. Staining with anti-HLA-DR antibody revealed less numerous positive cells within tumour nests than labeling with OKT6. A relationship between T6-positive LC quantities and extent of HLA-DR-positive infiltrates around tumours could not be established. These results suggest that immunological surveillance of neoantigen-bearing tumour cells may be impaired in skin cancer. A reason for the reduced LC number may be an altered microenvironment in tumour tissue.

Aged↗

Lipoid proteinosis with pseudomembranous conjunctivitis.

Lipoid proteinosis is a rare autosomal recessive condition characterized by a diffuse mucocutaneous infiltration with histopathologic deposits that are positive for periodic acid-Schiff reagent and a sudanophil substance. We present a 9-year-old boy with lipoid proteinosis. His parents are siblings. He had classical manifestations, such as statural-ponderal delay, hoarseness, yellowish skin papules, atrophic scars, and moniliform blepharosis. A transmission deafness was also found. There were none of the intracranial calcifications that are usual at this age. A pseudomembranous conjunctivitis was surgically treated when he was 4 months old. This clinical manifestation has not hitherto been described in lipoid proteinosis.

Child↗

A sequential study of histological and immunological changes in the skin after allogenic bone marrow transplantation.

Histological and immunopathological studies were performed on serial skin biopsies from thirteen recipients of allogenic and two recipients of autologous bone marrow transplants. Marked dermoepidermal infiltration with Leu 2a+ (OKT8+) phenotype cells was found in two patients with severe graft-versus-host disease, but the infiltration did not precede clinical onset of the graft-versus-host disease. Absence of Langerhans cells was noted during the early posttransplant period in recipients of both allogenic and autologous transplantation. Intercellular epidermal staining with anti-DR was observed in three cases, without relation to graft-versus-host disease.

Adolescent↗

Long-term survival and immunological tolerance of human epidermal allografts produced in culture.

Human epidermal cells from a small skin specimen can be grown in culture into multilayered sheets suitable for the permanent coverage of large burn wounds when used as epidermal autografts. We report here on the long-term survival of such cultured epidermal sheets used as epidermal allografts (EAG) across a major histocompatibility barrier in three nonimmunosuppressed adult patients, suffering from large chronic grafted leg ulcers, where the EAG have been placed to cover the conventional split-thickness skin autograft donor site. The absence of rejection was based upon clinical, histological, and immunopathological observation of the allografted sites at various intervals after grafting of the EAG. The identity of the epidermal cells on the grafted area with cultured cells from allogeneic donor was then established after blood substance typing by indirect immunofluorescence. Furthermore, epidermal cells from cultured sheets, but not control human cells from freshly excised normal epidermis, failed to stimulate the recipient peripheral blood cells in the mixed epidermal cell lymphocyte culture reaction, a finding that is related to the complete absence of class-II-antigen-bearing cells in cultured epidermis. This absence of T cell stimulation was noted not only on the day of grafting but throughout the follow-up. Altogether, these findings show that Langerhans cell and other class-II-antigen-bearing cell-depleted cultured epidermal allografts, are tolerated in unrelated recipients. EAG may serve as a skin substitute in patients with large wounds or burns. Since EAG may be grown continuously, the coverage of burns may not then be limited by the availability of the donor site, or by the time necessary to produce epidermal tissue in cultures.

Adult↗

[Cyclosporin in the treatment of bullous pemphigoid: preliminary study].

Bullous pemphigoid is a typical autoimmune disease. It is classically treated with systemic corticosteroids alone or combined with immunosuppressants. Cyclosporine A (CyA), a new immunosuppressive agent with high activity in organs and bone marrow transplantation, could be expected to prove effective in this disease owing to its action on lymphocytes. Seven patients with bullous pemphigoid were treated with CyA in daily doses of 6 to 8 mg/kg bodyweight. Treatment was monitored by measurements of serum CyA, creatinine and liver enzyme levels. The effectiveness of treatment was assessed on clinical changes. The seven cases are dealt with individually, with a brief case-report for each of them. The only side-effects observed were reversible rises in serum creatinine levels and hypertrichosis in two cases; these are usual reactions to the drug. Hormonal assays were normal in two female patients. Concerning results, our patients fell into two groups. Among those treated with CyA alone there were two failures and two sustained satisfactory results. Treatment was successful in all patients treated with CyA during relapses under corticosteroid therapy, but two patients relapsed after CyA was discontinued. It is concluded that CyA is of no interest in the acute phase of bullous pemphigoid, that the long-term stability of the results obtained is doubtful and that this potentially nephrotoxic drug should be avoided or administered with extreme caution in elderly people, since their renal function may be at the limit of normality.

Adrenal Cortex Hormones↗

PUVA therapy prevents sensitization to mechlorethamine in patients with psoriasis.

Two groups of 20 patients with psoriasis were treated with mechlorethamine applied topically (group A) or with PUVA combined with mechlorethamine (group B). In group B mechlorethamine was started after six PUVA treatments. Results showed a significant decrease of the incidence of contact dermatitis in group B (30%) compared with group A (75%). Allergic dermatitis, demonstrated by a positive patch test to mechlorethamine with an histology of eczema, was observed in 55% of patients in group A and 20% in group B. The incidence of irritant dermatitis was not significantly different in the two groups. Allergic dermatitis was observed later in group B: after an average of 32.2 applications of mechlorethamine compared with 25 applications in group A. Possible mechanisms responsible for these results are reduction of epidermal Langerhans cells by PUVA therapy and induction of antigen-specific suppressor T cells. Patients living far from a specialized centre might be treated initially with PUVA therapy then with mechlorethamine alone, at home. This schedule may reduce the incidence of contact dermatitis to mechlorethamine.

Adult↗

[Granular-cell tumor (Abrikosov). Immunohistological study of 4 cases with review of the literature].

Granular-cell tumour (GCT) is a benign neoplastic proliferation first described by Abrikossoff (1), who considered it to be of muscular origin. Since then, however, the histogenesis of GCT has been a matter of serious controversy, and various cell types have been considered as being the origin of GCT. In this work we investigated the immunohistochemical profile of four cases of GCT using antibodies to several neural differentiation markers: S-100 protein, neurofilaments (NF), glial fibrillary acidic protein (GFAP). The results were compared to those obtained on three cases of schwannomas (S) and to those already reported in literature. Four cases of GCT were retrieved from the files of the Laboratory of Histopathology of the Clinic of Dermatology, Hôp. E.-Herriot. The tumours had been observed during a two-year-period (1983-1984), fixed in Bouin's fixative and embedded in paraffin. In parallel, three cases of S that were treated in the same way were also studied. This was performed on 3 mu-thick paraffin sections using the avidin-biotin-peroxidase complex method (kit Vectastain, Vector Lab., Burlingame, USA). The following antibodies were used: a) antiserum to protein S-100 (Dakopatts, Denmark) (working dilution 1: 50); b) monoclonal antibody to 200 Kd NF (Labsystem, Helsinki) (working dilution 1: 40): C) monoclonal antibody to GFAP (Biosoft, Paris) (working dilution 1: 10).(ABSTRACT TRUNCATED AT 250 WORDS)

Antibodies↗

[Paraneoplastic erythroderma: apropos of a case].

A 63-year-old male patient had severe exfoliative dermatitis (erythroderma) which led to the discovery of squamous cell carcinoma of the larynx. The possibility of paraneoplastic erythroderma is discussed. Although such an aetiology is rare, 5 cases with a similar paraneoplastic syndrome have been previously reported, which cannot be considered as a merely fortuitous association of exfoliative dermatitis and visceral cancer.

Carcinoma, Squamous Cell↗