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Biomedical subjects

M Faure

Publications and source records attributed to M Faure.

At least 271 records · Page 15Linked to original sources
PubMedDate not supplied

Vulvar cicatricial pemphigoid of childhood.

We report a 9-year-old girl with a vulvar autoimmune bullous dermatosis. A diagnosis of localized bullous pemphigoid or cicatricial pemphigoid was made on the basis of immunohistologic data. Since the lesions were unresponsive to topical corticosteroids but healed completely on dapsone at a dosage of 1.5 mg/kg/day, we favor the diagnosis of vulvar cicatricial pemphigoid. Only two such cases have been reported thus far. The diagnostic criteria and therapeutic modalities are discussed.

Child↗
PubMedDate not supplied

Differential expression of the cancer-associated antigens T (Thomsen-Friedenreich) and Tn in primary and recurring squamous cell carcinomas of the skin.

The T (Thomsen-Friedenreich) antigen and its precursor, the Tn antigen, are complex mucin-type carbohydrate antigens, the expression of which seems to be correlated with prognosis in some human cancers. We studied comparatively the immunohistochemical expression of these antigens in a series of primary and locally recurring squamous cell carcinomas developing in the skin of immunosuppressed (organ-transplanted) patients. 10/26 tumours were completely unreactive for both antigens; among the remaining cases, 10/14 (71%) of recurring and 6/12 (50%) of primary tumours showed a higher expression of the precursor (Tn antigen) as compared with the T antigen. Since recurring tumours are more likely to spread metastatically, our results upheld the contention that a higher expression of the Tn antigen is correlated with a more aggressive course of cutaneous squamous cell carcinomas.

Antigens, Tumor-Associated, Carbohydrate↗
PubMedDate not supplied

Expression of the hair stem cell-specific keratin 15 in pilar tumors of the skin.

Keratin 15 (K15) was recently shown to be a specific marker of stem cells of the hair-follicle bulge. We studied the reactivity of an antibody to the CD8 antigen (C8/144B), recognizing K15, on 66 cutaneous tumors with known or alleged pilar differentiation, in order to assess its usefulness in the diagnosis of this group of tumors. 2/2 basal cell nevi, 5/8 trichoepitheliomas and 1/3 trichofolliculomas showed substantial reactivity. Much weaker reactivity was observed in cases of trichilemmal tumors (trichilemmomas and trichilemmal cysts); by contrast, all cases of pilomatricomas, basal cell carcinomas and epidermoid cysts were completely unreactive. These results are in keeping with the admitted differentiation of the tumors studied, and suggest further that basal cell carcinomas do not differentiate towards hair bulge cells. From a practical point of view, immunostaining for K15 seems to be an additional useful adjunct for the differential diagnosis between basal cell carcinoma and trichoepithelioma.

Antibodies, Monoclonal↗
PubMedDate not supplied

Expression of basement membrane antigens and matrix metalloproteinases 2 and 9 in cutaneous basal and squamous cell carcinomas.

BACKGROUND: Basement membrane (BM) antigens and matrix metalloproteinases (MMP) are involved in tumor invasion and metastasis. Basal (BCC) and squamous cell carcinomas (SCC) differ with respect to their biological behavior since the former are only locally aggressive whereas the latter have a metastatic potential. MATERIALS AND METHODS: We studied the immunohistochemical expression of several BM antigens and of MMP2 and MMP9, in 13 BCC, 13 SCC, and 8 in situ skin carcinomas. RESULTS: The expression of most BM antigens was reduced in the tumors in comparison with normal skin. Hemidesmosome- and lamina lucida-associated antigens (plectin, NUT2, alpha 6/CD49f and laminin-5) were more decreased in BCC, whereas collagens type VII and IV were more decreased in SCC as compared with BCC; in BCC and SCC both collagens tended to be decreased on the leading edge of invasive tumor masses. In situ carcinomas showed a slightly diminished expression of alpha 6/CD49f integrin, plectin and NUT2. The expression of both MMP2 and MMP9 was increased in SCC as compared with BCC. CONCLUSION: Our findings further upheld the role of BM antigens and MMPs in the process of tumor aggressiveness. The reduced expression of collagen IV, combined with an increased expression of both MMP2 and MMP9 could account for the increased metastatic potential of SCC vs BCC through an increased invasion of the extracellular matrix and the vascular space.

Antigens, Neoplasm↗
PubMedDate not supplied

[Experimental models for studying the effects induced by staphylococcal toxins A and B on human keratinocytes in culture].

The toxic effects of the two serotypes of staphylococcal exotoxin: exfoliatin A (ETA) and B (ETB) on two experimental models: organotypic cultures of the skin and cellular cultures of the epidermis reconstructed "in vitro" have been studied. The results show that, in both cases, purified ETB (Fig. 4a, 6-6a, b, c) reproduces the characteristics of Lyell's Staphylococcal Syndrome that is the intraepidermal cleavage either between the granulosa and the spinous layers or at the granulosa layer of the epidermis. As the images of the LM and EM demonstrate, purified ETA behaves differently in the two experimental models; in fact, it produces the same effect as purified toxin B on the organotypic cultures (Fig. 3a, b), whereas it causes no alterations in the epithelial cultures reproduced "in vitro" (Fig. 5a, b).

Bacterial Toxins↗
PubMedDate not supplied

Proliferation of murine T cells upon stimulation by Langerhans cell depleted epidermal basal cells.

In the present study we chose to develop a murine model of Langerhans cell (LC) free epidermal cell (EC) cultures. EC were cultured in low Ca medium which results in the replication of epidermal basal cells (EBC) without stratification and differentiation. By immunofluorescence techniques using anti I-A monoclonal antibodies (mAb), LC were never detected within EBC after a 7-day culture period. Unexpectedly, when spleen-enriched T cells were added to the I-A negative EBC, a strong proliferative response occurred. The proliferating spleen cell population was Thy 1+ and, in large part, L3T4+. Syngeneic responses were as strong as allogeneic responses, which is further evidence that residual LC could not account for the observed effect. Furthermore, in vitro T cell proliferation on EBC was unable to be inhibited by the addition of anti I-A mAb during a mixed skin lymphocyte reaction. Supernatants from EBC failed to induce T cell proliferation, suggesting the absence of a soluble mitogenic factor released from EBC. The findings present evidence that murine LC depleted EBC can trigger lymphocyte proliferation through an yet, undefined stimulus.

Animals↗