C Ohrt

CHU de Lyon - Groupement Hospitalier Edouard Herriot, Lyons, Rhône-Alpes, France

Are you C Ohrt?

Claim your profile

Publications (8)12.74 Total impact

  • [Show abstract] [Hide abstract]
    ABSTRACT: We have investigated on human skin the reactivity of a panel of 42 anti-thymus monoclonal antibodies (MCA) supplied by the Third International Workshop and Conference on Human Leucocyte Differentiation Antigens, Oxford, 1986. MCA of the first cluster of differentiation (CD1) define a group of surface molecules expressed by cortical thymocytes. Some of them (OKT6, M241 and Na1/34) have been shown to react in normal human skin with the epidermal Langerhans cells (LC). Twenty-two CD1 MCA were investigated in the present study. On normal human skin, 13 MCA reacted with LC in situ. This result suggests and confirms the heterogeneity of CD1 MCA. Recently, some of them were shown to recognize biochemically different molecules and/or epitopes of thymocytes. In addition, 20 anti-thymic epithelium MCA were tested on human skin. The MCA which only reacted with the thymic epithelial cell network (except Hassall's corpuscles) decorated only the epidermal basal cell layer. The MCA which reacted with all the thymic epithelial cells (including Hassall's corpuscles) decorated all the epidermal cell layers. These results confirm the heterogeneity of the thymic epithelial microenvironment and underline the antigenic similarities between the thymic epithelial structures and the different epidermal cell layers. The existence of bone-marrow-derived CD1-positive cells (thymocytes or LC) in an epithelial cell network (the thymus and the epidermis) focus the speculation around the immunological role of the epidermal basal cell layer in the T cell education and the exact lineage of the epidermal LC.
    Dermatologica 02/1987; 175(3):109-20.
  • [Show abstract] [Hide abstract]
    ABSTRACT: 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.
    Acta Dermato Venereologica 02/1987; 67(2):93-9. · 3.49 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: We have investigated on human skin the reactivity of a panel of 42 anti-thymus monoclonal antibodies (MCA) supplied by the Third International Workshop and Conference on Human Leucocyte Differentiation Antigens, Oxford, 1986. MCA of the first cluster of differentiation (CD1) define a group of surface molecules expressed by cortical thymocytes. Some of them (OKT6, M241 and Na1/34) have been shown to react in normal human skin with the epidermal Langerhans cells (LC). Twenty-two CD1 MCA were investigated in the present study. On normal human skin, 13 MCA reacted with LC in situ. This result suggests and confirms the heterogeneity of CD1 MCA. Recently, some of them were shown to recognize biochemically different molecules and/or epitopes of thymocytes. In addition, 20 anti-thymic epithelium MCA were tested on human skin. The MCA which only reacted with the thymic epithelial cell network (except Hassall’s corpuscles) decorated only the epidermal basal cell layer. The MCA which reacted with all the thymic epithelial cells (including Hassall’s corpuscles) decorated all the epidermal cell layers. These results confirm the heterogeneity of the thymic epithelial microenvironment and underline the antigenic similarities between the thymic epithelial structures and the different epidermal cell layers. The existence of bone-marrow-derived CD1-positive cells (thymocytes or LC) in an epithelial cell network (the thymus and the epidermis) focus the speculation around the immunological role of the epidermal basal cell layer in the T cell education and the exact lineage of the epidermal LC.
    Dermatology 01/1987; 175(3):109-120. · 2.02 Impact Factor
  • The Journal of Dermatology 03/1986; 13(1):30-7. · 1.77 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: One of the most important problems in the detection of human IgG deposits at the dermo–epidermal junction is non–specific dermo–papillary fluorescence.We describe an improved technique to decrease non–specific dermal fluorescence by using either a FITC–conjugated goat anti–human IgG–Fab or a FITC–conjugated goat anti–IgG (γ chain specific) absorbed onto normal goat serum in direct and indirect immunofluorescence tests. With this procedure, human skin was found to be a better substrate than rabbit lip for indirect immunofluorescence.
    Clinical and Experimental Dermatology 08/1985; 10(4):350-7. · 1.33 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: The entity of the Dühring-Brocq's disease (11, 12, 20) has be cut off by the immunofluorescence (7, 39, 40). We have studied three of the diseases which originally were included in this description: bullous pemphigoid (BP), cicacial pemphigoid (CP) and herpes gestationis (HG). This work is at the same time prospective and retrospective. The linear IgA dermatosis are excluded (17).
    Annales de Dermatologie et de Vénéréologie 02/1985; 112(5):403-10. · 0.60 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: The purpose of the present study was to examine the phenotype of the cutaneous immunocompetent cells in lichen planus and chronic graft versus host (GVH) reaction infiltrates, by the use of monoclonal antibodies directed against T cell populations and Langerhans cells. Our results in lichen planus suggest an immunological reaction similar to the delayed hypersensitivity reaction, including all the immunocompetent cell subpopulations, with a first stage of antigenic information by Langerhans cells (OKT6+, BL6+, HLA-DR+) and helper cells, and a second stage mediated by suppressor/cytotoxic cells. The results from the study of GVH reaction also suggest an effect mediated by suppressor/cytotoxic cells (OKT3+, OKT4-, OKT8+, HLA-DR+). Our results favour the existence of a lymphocytotoxic process in lichen planus and chronic GVH reaction.
    Journal of Cutaneous Pathology 09/1982; 9(4):249-57. · 1.77 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: One hundred twenty skin biopsies from patients with different skin diseases were found to be positive for C3 cutaneous staining by immunofluorescence study. By the direct immunofluorescence method, we looked for C1q and C4 and immunoglobulin deposits in all those biopsies. C1q and/or C4 were only found in dermatoses with a recognised humoral immunologic mechanism; in some cases C1q and/or C4 deposits were found in the absence of immunoglobulins. The results showed that identification of C1q and C4 is important in routine immunopathologic studies, and provide interesting data of diagnostic value.
    Journal of Cutaneous Pathology 07/1982; 9(3):169-74. · 1.77 Impact Factor