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Biomedical subjects

J F Nicolas

Publications and source records attributed to J F Nicolas.

195 records · Page 11Linked to original sources
PubMed1976

Cell lines derived from teratocarcinomas.

A variety of cell lines have been isolated in vitro from transplantable teratocarcinomas. Some of them correspond to embryonal carcinoma (EC) cells. They are malignant and represent the stem cells from which all differentiated tissues derive in the tumor or in vitro. EC cells share some biochemical and antigenic properties with multipotential embryonic cells. From one of these EC cell lines, variants have been isolated in vivo and in vitro. Some are of EC type but restricted in their pattern of differentiation; others are altered in their tumorigenicity or in their antigenic characteristics. Another class of such variants corresponds to non-EC types. The most interesting ones correspond to tumoral lines of extra-embryonic tissues. All these cell lines constitute a valuable material for the study of mouse development and differentiation.

Acid Phosphatase↗
PubMed1975

[Mouse teratocarcinoma: differentiation in cultures of a multipotential primitive cell line (author's transl)].

A line of primitive cells of teratocarcinoma is able of differentiating during in vitro cultures. The differentiated cell types correspond to derivatives of the three germ layers. They appear according to a reproducible schedule. The differentiated cell types exhibit a normal karyotype. They have lost their tumorigenicity and have a limited life span. Agregates containing various numbers of primitive cells have been prepared and plated in culture dishes. Their study shows that the first differentiated cell types appear only when the agregates are greater than a certain critical mass. Primitive cells carry on their surface the F9 but not the H-2 antigen. During differentiation in culture, the H-2 antigen appears rapidly on certain cells. The fraction of H-2-carrying cells increases as a function of time while that of F9-carrying cells decreases.

Animals↗
PubMedDate not supplied

[Medical treatment of Raynaud's syndrome].

The authors review the drug treatment of Raynaud's disease. Many substances have been used including nitrate derivatives, calcium antagonists, alpha blockers, angiotensin converting enzyme inhibitors, prostaglandin E1, E2 and I2, and ketanserin. The efficacy of these drugs is often partial and variable. The indications are discussed with respect to the clinical course and etiology of the Raynaud's phenomenon.

Connective Tissue Diseases↗
PubMedDate not supplied

Drug-induced urticaria.

The occurrence of acute urticaria during treatment with drugs is a frequent event which poses two problems: 1) is the urticaria connected with the drug administration or with the underlying pathology which led to the prescription of the drug; 2) is the urticaria allergic in origin, i.e. due to specific immunity triggers, in particular IgE directed against the drug, or is the urticaria pseudo-allergic in origin, i.e. due to non-specific activation of mastocytes [1]? This question is of major importance because allergic events caused by IgE are potentially fatal while pseudo-allergic events are only rarely life-threatening. In this article we will not deal with contact urticaria where the cause is easily identifiable [2].

Acute Disease↗
PubMedDate not supplied

T cells in bullous pemphigoid. Presence of activated CD4+ T cells at the basement membrane zone in pre- and peri-bullous skin.

Bullous pemphigoid (BP) is an auto-immune blistering skin disease associated with the presence of autoantibodies directed to BP antigens located at the basement membrane zone of the dermal-epidermal junction. The present study was designed to test for the involvement of cellular immune mechanisms in the pathogenesis of blister formation. An immunohistochemical analysis of the lesional, peri-lesional, and pre-lesional mononuclear cell infiltrates, performed in 7 BP patients, revealed the following observations: 1) all the skin biopsies contained a high percentage of mononuclear cells within the inflammatory cellular infiltrate; 2) T cells (CD3+, CD45RO+), with a phenotype of activated helper T cell (CD4+, CD25+) were consistently found; 3) T cells were found beneath the bullae but, more importantly, also at the dermal-epidermal junction in close contact with the basement membrane zone in pre- and peri-bullous lesions. These results show that activated T cells are found at the early phase of the onset of BP lesions and suggest that they could play a role, in association with autoantibodies, in the pathogenesis of bulla formation.

Antigens, CD↗
PubMedDate not supplied

Do epidermal cells produce thymic hormones in vivo? An immunohistochemical study using anti-thymic hormone antibodies.

Cultured human epidermal cells have been shown to produce soluble factors endowed with T cell differentiating activities. In addition, the presence of thymopoietin and FTS/thymulin-like factors has been reported in normal human and mouse epidermis using immunohistochemical methods and anti-thymic hormone antibodies. The present study was conducted to re-evaluate the presence of thymic hormones in normal epidermal cells using a panel of monoclonal antibodies (mAbs) and rabbit antisera to several well characterized thymic factors. The reactivity of the following antibodies was tested by indirect immunofluorescence on human and mouse tissue sections: a) two anti-FTS/thymulin mAbs; b) one anti-FTS/thymulin rabbit antiserum; c) one anti-thymopoietin rabbit antiserum; d) one anti-thymosin alpha 1 mAb. Our results show that: 1) all five antibodies reacted with human and/or mouse thymic epithelial cells; 2) none of the 3 antithymic hormone mAbs (2 anti-FTS/thymulin and 1 anti-thymosin alpha 1 mAbs) reacted with normal skin; 3) only 2 out of 5 antibodies, namely the anti-FTS and anti-thymopoietin antisera cross-reacted with mouse and human epidermis and labeled keratinocytes, as previously reported; these latter 2 antibodies also stained nude mouse epidermal cells and labeled non-thymic, non-epidermal normal mouse epithelial tissues, suggesting that the cross-reactive epitope is common to a number of epithelial cells; 4) the antigen defined by the anti-FTS and anti-thymopoietin antisera was not related to keratins, since absorption experiments using purified human epidermal keratins failed to abolish staining of the epidermis. We conclude from this study that epidermal cells do not produce in vivo the well characterized thymic hormones: FTS/thymulin, thymopoietin and thymosin alpha 1. The precise nature of the antigenic structure recognized within epidermis by the anti-FTS and anti-thymopoietin antibodies remains to be defined.

Adult↗