[A case of mucosal dryness syndrome without Sjogren disease].
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Adrenal Cortex Hormones↗
Biomedical subjects
C M Lapière
Publications and source records attributed to C M Lapière.
In vitro reconstituted skin as a tool for biology, pharmacology and therapy: a review.
Various culture procedures, suitable to maintain the differentiated phenotype of various types of cells in vitro, have been devised during the past decade. These culture systems use macromolecular components extracted from extracellular matrixes or synthetic polymers which provide cells with a three-dimensional, spatially structured support. Substantial information has come from the use of collagen lattices. Many types of cells, of mesenchymal or other origin, are able to organize collagen fibrils in these models and to form a connective tissue-like structure. Prerequisites for this process are active function of the cytoskeleton and the expression of alpha(2)beta(1) integrin collagen receptors. Interaction of cells with such a matrix has profound effects on morphologic status, proliferation, cellular metabolism, and state of differentiation. The in vitro procedures reviewed and described in this article offer the possibility to combine different types of cells to approximate the in vivo environment and to investigate such physiologic processes as cell-cell and cell-matrix interactions which are otherwise not easily accessible. In pathologic conditions of the skin, these models have proven to be useful tools in investigating diseases relating to impaired recognition of extracellular matrix structures or alterations of cytoskeletal assembly. In pharmacologic and toxicologic studies, activity of drugs and potentially useful therapeutic substances has been evaluated. The use of cells and matrix components derived from skin has lead to refined systems which could be adapted and extended to other organs in an attempt to better understand pathophysiologic mechanisms.
Journal Article↗
Comparative caustic and biological activity of trichloroacetic and glycolic acids on keratinocytes and fibroblasts in vitro.
OBJECTIVES: Beside their causticity, the biological mechanism by which trichloroacetic acid (TCA) and glycolic acid (GA), two agents extensively used for chemical peeling, might act remains unknown. The purpose of this study was to examine in vitro the effect of TCA and GA on human keratinocytes and the influence of the released epithelial mediators on collagen and matrix metalloproteinases (MMPs) production by human dermal fibroblasts. METHOD: Cultured keratinocytes were treated by TCA and GA at 10 mg/ml brought to pH 3, 5 and 7, and the conditioned media neutralized to pH 7 were added to human normal skin fibroblasts. RESULTS: TCA was cytotoxic for keratinocytes at each tested pH. The conditioned medium depressed protein and collagen synthesis and the expression of MMPs when added to fibroblasts as did also TCA when added directly to fibroblasts. GA was not cytotoxic for keratinocytes at neutral pH and the conditioned medium obtained at each pH applied to fibroblasts did not alter protein, collagen nor MMPs production while causing an elevated secretion of IL-6. CONCLUSION: TCA exerts a toxic effect on keratinocytes and fibroblasts while GA does not alter the metabolism of fibroblasts but induces the secretion of IL-6.
Caustics↗
Stimulation of collagen biosynthesis by topically applied vitamin C.
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Administration, Cutaneous↗
[Structure and mechanical properties of dermatosparactic collagen (author's transl)].
Dermatosparactic calf-tail-tendon-collagen was investigated by mechanical measurements, electron microscopy and x-ray diffraction. We suppose, that the tensile strength decrease of the fibres is due to the irregular aggregation of subfibrils to fibrils. The x-ray diagram of the fibre is not influenced by state of disorder. Cyclic extension of dermatosparactic collagen leads to a higher increase in tensile strength than in the case of normal calf tendon. The effect might be due to the increase of fibril- and area-density resulting in an augmentation of crosslinks.
Animals↗
[Vascular lesions and fibroblast metabolism in inflammatory diseases].
Alterations of the vascular endothelium are frequent in sclerodermis and are manifested by signs of tissue repair. In these patients, the serum seems to contain a cytotoxic component while their platelets are very adhesive to the collagen. During the phase of activity of the disease, sclerodermic fibroblasts show an increased collagen biosynthesis. The vascular lesion could be responsible for the migration of mobile cells of which the mediators (lymphokins, monokins, PDGF, etc...) would activate the fibrocytes.
Autoantibodies↗
[Prognosis and prevention of white atrophy].
White atrophy, defined by Milian, is a smooth ivory white plaque, slightly depressed, of variable dimensions, and surrounded by a pigmented telangiectasic area, several millimetres across. It is usually localised in the lower limbs and mostly affects middle-aged women. It is a symptom with multiple aetiopathology. It is to be bound in isolation, or forming part of the clinical picture of various affections caused by degeneration in the cutaneous vascularization. Sometimes it causes ulceration resistant to the available treatments. Some authors suggest an immunological pathology of vascular occlusion. Others consider that it is result of a localized disorder of coagulation or fibrinolysis.
Atrophy↗