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Biomedical subjects

L Dubertret

Publications and source records attributed to L Dubertret.

At least 199 records · Page 11Linked to original sources
PubMed1992

Genetic linkage of recessive dystrophic epidermolysis bullosa to the type VII collagen gene.

Generalized mutilating recessive dystrophic epidermolysis bullosa (RDEB) is characterized by extreme skin fragility owing to loss of dermal-epidermal adherence. Immunohistochemical studies have implicated type VII collagen, the major component of anchoring fibrils, in the etiology of RDEB. In this study, we demonstrate genetic linkage of the type VII collagen gene and the generalized mutilating RDEB phenotype. We first identified a Pvull polymorphic site by digestion of an amplified product of the type VII collagen gene, which was shown to reside within the coding region. Genetic linkage analysis between this marker and the RDEB phenotype in 19 affected families which were informative for this polymorphism showed no recombination events, and gave a maximum lod score of 3.97 at a recombination fraction (theta) of 0, demonstrating that this DNA region is involved in this form of RDEB. These data provide strong evidence that the type VII collagen gene, which has also been linked with the dominant form of the disease, harbors the mutation(s) causing the generalized mutilating form of RDEB in these families, thus underscoring the major functional importance of type VII collagen in basement membrane zone stability.

Base Sequence↗
PubMed1992

[Ultraviolet A radiation and the skin. Implications of activated forms of oxygen. Current trends and newest results].

Involvement of activated oxygen species in the responses of skin to solar ultraviolet radiations, especially ultraviolet A radiations, is being addressed by an increasing number of studies. The aim of this review is to outline the concept of "photooxidative stress". The various activated oxygen species, mechanisms involved in their formation, potential cellular targets, and cell defense mechanisms are discussed. Recently published findings are briefly described to illustrate this fast developing line of research.

DNA↗
PubMed1992

[Deep lupus erythematosus in children].

Deep cutaneous lesions are seldom encountered in lupus erythematosus. The disease described in the literature as lupus erythematosus profundus or lupus erythematosus panniculitis usually occurs in middle-aged women. The authors report a case of deep lupus erythematosus which was exceptional in that it occurred in an 11-year old girl. The lesions were situated on the face and consisted of solid subcutaneous nodules and clear-cut ulcerations leaving atrophic pigmented scars. The histological image of a nodule was one of lobular lymphocytic panniculitis with homogeneous hyalinization of adipose nodules, to which must be added periadnexal and perivascular dermo-epidermal lymphocytic infiltrates. Granular IgM deposits arranged along the dermo-epidermal junction were observed at direct cutaneous immunofluorescence. Laboratory examinations showed leucopenia (3,300/mm3) with neutropenia (1,100/mm3) and the presence of antinuclear antibodies at 1/100 speckled fluorescence, as well as antibodies directed against native DNA. Studies of renal function and for complement gave normal results. The other causes of lobular panniculitis were excluded. The lesions regressed within 3 weeks under hydroxychloroquine; this drug was also successful in arresting a relapse consecutive to withdrawal of treatment. The authors have analysed the 17 paediatric cases of deep lupus erythematosus and were able to determine their main characteristics: 1. The lesions occur mostly in girls (70 p. 100). They are located electively on the face and the lateral aspect of the shoulders. They consist of well-limited, solid or hard subcutaneous nodule which may congregate to form plaques. The epidermis may be normal or pathological, poikilodermic, looking like a discoid or ulcerated lupus erythematosus. The lesions regress, leaving a characteristic atrophic scar.(ABSTRACT TRUNCATED AT 250 WORDS)

Antibodies, Antinuclear↗
PubMed1992

[Nail psoriasis].

Explore the source record for details and available documents.

Administration, Topical↗
PubMed1992

[Dermo-epidermal interactions and skin pharmacology].

Reconstruction of a living skin equivalent provides an in vitro model for the study of skin biology and pharmacology in a tissue organization whose cells differentiate similarly to skin cells in the body. This simplified skin equivalent, composed of normal or abnormal cells, is obtained in two steps: formation of a dermal equivalent is achieved first and this dermis is then covered with an epidermal equivalent. Each of these tissues, as well as the interactions between them, can then be studied. Using this model, we have demonstrated that normal fibroblasts promote epidermal growth, that psoriatic fibroblasts induce increased proliferation of normal keratinocytes, and that the effects of pharmacological agents (such as retinoids) on keratinocyte growth are modulated by fibroblasts.

Cell Communication↗
PubMed1992

[Studying the mast cell. Recent data].

In the light of recently published data, the mast cell can now be viewed as a key cell, not only in allergic reactions such as immediate hypersensitivity responses, but also in a broad spectrum of other biologic responses including host-parasite interactions, nonspecific inflammatory reactions, fibrosis, angiogenesis, tissue reconstruction, and wound healing. Nevertheless the molecular basis for the intervention of mast cells in many of these biologic responses is still unclear. Very recent studies have demonstrated that mast cells are capable of producing a wide range of cytokines, a property which may influence various physiologic, immunologic and disease processes. Furthermore, although substantial differences have been reported between mast cells located in different tissues, the reasons and mechanisms underlying this heterogeneity long remained obscure. The recent development of two original experimental approaches, i.e., in vitro culture of mast cells, mainly derived from mouse bone marrow precursors, and replenishment of mast cell-deficient mice, has provided new insight into the mechanisms by which tissue microenvironment influence of regulation mast cell phenotype. Extrapolation to humans of data obtained in rodents is, however, hazardous. In the review presented here, the most recent data from the literature provide the basis for outlining avenues of research which can be expected, in the near or remote future, to solve what mast cell experts term "the riddle of the mast cells".

Animals↗
PubMed1992

[Ultraviolet rays and the skin. Modulation of immune functions].

Ultraviolet radiations (UV) are one of the most common environmental stimuli. In the skin, UVs induce selective biological alterations whose effects include suppression of the normal immune response. This immune suppression may play an important part in the development of skin cancers, infectious diseases, and autoimmune responses. The review presented here focuses on UV-induced biological disorders and on the role of UV-exposed epidermal cells in the mechanisms of immunosuppression.

Adjuvants, Immunologic↗