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Biomedical subjects

F Cambazard

Publications and source records attributed to F Cambazard.

At least 19 recordsLinked to original sources
PubMed1991

Eosinophilic granuloma of bone and biochemical demonstration of 49-kDa CD1a molecule expression by Langerhans-cell histiocytosis.

Histiocytic cells infiltrating the lesions in eosinophilic granuloma of bone as well as in cutaneous histiocytosis X were studied using a murine monoclonal antibody (MA) produced with proliferating cells from an eosinophilic granuloma of bone. This MA reacts with Langerhans cells (LC) of normal human skin or mucous membranes and with proliferating cells of eosinophilic granuloma of bone and skin lesions of Letter-Siwe disease, as shown by immunohistochemistry and immunogold labelling. As other murine MA's obtained after immunization with human cortical thymocytes, this MA immunoprecipitates the 49-kDa CD1a antigen found on human LC and thymic-cell surfaces but not its breakdown product after treatment with trypsin, as demonstrated by analysis of immunoelectron labelling, cytofluorometry and gel electrophoresis. This first production of a CD1a MA from an eosinophilic granuloma supports the concept of Langerhans-cell histiocytosis.

Antigens, CD↗
PubMed1991

Monoclonal antibody GB3 defines a widespread defect of several basement membranes and a keratinocyte dysfunction in patients with lethal junctional epidermolysis bullosa.

An antigen expressed at the dermal-epidermal junction as well as in some other human basement membranes (BM) has been detected by the use of a monoclonal antibody termed GB3. This antigen, synthesized by cultured normal human keratinocytes, has been identified as a 600-kilodalton glycoprotein different from other known components of BM. Using indirect immunofluorescence, GB3 was found to be not reactive with the epidermal BM in patients with lethal junctional epidermolysis bullosa. The present study demonstrates (by indirect immunofluorescence) that GB3 defines a widespread defect of several BM in these patients. Furthermore, it gives evidences for an intrinsic biologic defect of lethal junctional epidermolysis bullosa epidermal keratinocytes using in vitro culture of these cells. Whether the lack of GB3 reactivity is the consequence of a true absence of the antigen or an alteration of its molecular structure is not yet known. Nevertheless, GB3 is a useful probe for both rapid and prenatal diagnosis of lethal junctional epidermolysis bullosa, which will give new insights into the molecular comprehension of this disorder.

Antibodies, Monoclonal↗
PubMed1990

Cultured epithelia from junctional epidermolysis bullosa letalis keratinocytes express the main phenotypic characteristics of the disease.

Keratinocytes from a 1-week-old male infant with junctional epidermolysis bullosa letalis (JEBL) were grown in vitro and then grafted as multi-layered epithelia onto nude mice, to investigate whether the defect in the dermo-epidermal cohesiveness in the disease is of epidermal and not mesodermal origin. In culture, there was a birefringent ring of cells at the edges of the keratinocyte colonies and in places some cells looked as though they had been ejected from the periphery of the colony. At confluence, the multi-layered epithelia were easily detached from the culture flasks using only mechanical agitation. On microscopy the fully-differentiated epithelium on days 21, 30 and 40 after grafting sometimes showed blistering at the dermal-epidermal junction. No labelling was noted using a GB3 monoclonal antibody, that reacts with normal human keratinocytes in culture and with the dermo-epidermal basement membrane zone in normal skin. This indicates that the defect of JEBL may be reproduced in culture and also after grafting the cultured epithelial onto a wound without an epidermis. This suggests a possible role for the junctional structure recognized by GB3 in dermo-epidermal cohesiveness.

Animals↗
PubMed1990

[Ichthyosis and steroid sulfatase: study of enzymatic activity in leukocytes and fibroblasts according to the sex and type of ichthyosis].

Steroidsulfatase and arylsulfatase C were determined in fibroblasts and/or leukocytes of patients affected with different types of ichthyosis. Of the 21 patients studied, 11 showed clinical characteristics of X-linked ichthyosis (XLI) and a deficiency of these 2 enzymatic activities. Patients affected with other types of ichthyosis showed no enzymatic deficiency. In XLI families diagnosis of heterozygotes was performed by enzymatic measurements in the 5 patients' mothers studied. In 2 families enzymatic activities were studied in patients' sisters. The validity of these different enzymatic measurements is discussed.

Adolescent↗
PubMed1989

DMC1: a monoclonal antibody produced from histiocytosis X cells which reacts with the native CD1a molecule of human epidermal Langerhans cells.

Human epidermal Langerhans cells express two (CD1a and CD1c) of the three human thymic cell surface differentiation antigens (CD1a, CD1b, and CD1c). The first cluster of differentiation antigens (CD1) is defined by a group of monoclonal antibodies (MCA). All these MCA were obtained after immunization of mice or rats with human cortical thymocytes. OKT6 MCA (a CD1a MCA) was the first to be described as reactive with human epidermal Langerhans cells. We produced a murine MCA, called DMC1, after immunization with proliferating Langerhans cells of Eosinophilic Granuloma of the bone (Histiocytosis X). In tissues DMC1 MCA reacted with epidermal dendritic cells (Langerhans cells) in the skin and cortical thymocytes in the thymus as observed on indirect immunofluorescence. At the ultrastructural level, DMC1 MCA was specific for Birbeck granule-containing Langerhans cells and did not react with melanocyte and keratinocyte populations. The quantitative analysis of immunoelectron labeling and the cytofluorometric study showed that the intensity of labeling was inversely correlated with the concentration of trypsin used in the preparation of epidermal cell from skin samples. DMC1 MCA precipitated a protein with a relative mass of 49,000 (CD1a molecule) from lysates of iodinated epidermal Langerhans cells under reducing conditions. It recognized the original CD1a molecule (Mr 49,000) but not the membrane breakdown product of CD1a (Mr 27,000) brought about by trypsin.

Animals↗
PubMed1988

Congenital self-healing histiocytosis (Hashimoto-Pritzker). An ultrastructural and immunohistochemical study.

Congenital self-healing histiocytosis (CSHH) is a rare primary histiocytic skin disorder. Only a few cases have been studied by ultrastructure and immunohistochemistry. Here we report a new case that was investigated using an electron microscope and a panel of monoclonal (MCA) and polyclonal (PCA) antibodies. CSHH cells were found to bear the immunohistochemical phenotype of normal epidermal Langerhans cells (LC) and histiocytosis X (HX) cells (CD1a/c+, CD1b-, CD4+/-, human leukocyte antigen [HLA]-DR/DQ+, S-100+). However, an electron microscope showed a paucity of Birbeck granule (BG)-containing cells. This contrasted with their immunophenotype. This finding, along with other ultrastructural characteristics of CSHH cells, suggests that histologic differences exist between CSHH and HX. However, because no absolute histologic criterion is known that allows unequivocally the differential diagnosis between the two diseases, this distinction currently has to rely on clinical criteria, mainly the regressive course observed within a few months in CSHH. The precise nosologic position of CSHH among other histiocytic syndromes remains unsettled.

Antibodies, Monoclonal↗
PubMed1988

Treatment of nine cases of pemphigus vulgaris with cyclosporine.

The effects of cyclosporine were studied in nine patients suffering from pemphigus vulgaris. Of four patients treated with cyclosporine alone, only one cleared. Of four corticosteroid-resistant pemphigus vulgaris patients, all improved after cyclosporine addition to corticosteroids. The last patient treated from the beginning with a combined treatment (cyclosporine-corticosteroids) did not respond. The main advantage of using cyclosporine is to allow a decrease in corticosteroid dosages and to permit treating corticosteroid-resistant pemphigus vulgaris patients. No detectable irreversible side effects were noted. The treatment was discontinued in two patients because of reversible side effects. Cyclosporine alone does not seem to be an adequate treatment of the acute phase of pemphigus vulgaris but could be used in addition to corticosteroids. The most important drawback of cyclosporine treatment is the occurrence of clinically silent renal dysfunction (tubular involvement and interstitial fibrosis), which may occur during long-term treatments. More studies need to be carried out to determine the effects of low doses of cyclosporine on renal function in patients who have normal renal functions.

Administration, Oral↗
PubMed1988

[Hashimoto-Pritzker congenital self-healing histiocytosis].

A full-term female infant was born with numerous purple firm indolent papulonodular lesions, occasionally ulcerated, ranging in size from 1 to 8 mm, scattered all over the body. The liver, spleen, lymph nodes were normal, as were the blood count, skull and chest X-ray. Biopsy of a skin lesion showed a deep dermal infiltrate consisting of histiocytic cells which were OKT6 +, HLA-DR + and S 100 +. Electron microscopy revealed numerous dense bodies, often with a myelin-like core and some Birbeck granules. The clinical course was favourable with a spontaneous regression of all lesions, sometimes through a central necrosis or atrophy, within 8 weeks. Congenital self-healing reticulohistiocytosis (CSHR) is characterized by a neonatal onset, with purple or necrotic nodular lesions showing the histopathologic aspect of histiocytosis X (although Birbeck granules are less numerous), an absence of visceral involvement and a spontaneous regression within the first 3 months of life. The place of CSHR among histiocytosis is discussed.

Female↗
PubMed1988

[Immature angiomas in infants].

Immature hemangiomas are frequent during infancy. Strawberry or cavernous hemangiomas have a specific evolution with an extensive phase, followed with a spontaneously regressive phase. Complications (cutaneous necrosis, pain and infection) are most often benign. More severe evolutions may occur, such as disseminated intravascular coagulation, which needs specific treatment. Most often, immature hemangiomas regress spontaneously and a clinical follow-up is sufficient. Systemic steroid therapy may be used in the case of important growing, vital or functional impairment (laryngeal or eyelid involvement). The dosage (more than 2 mg/kg/d prednisone) and the length of such treatment must be adequate. Surgery with or without embolization is rarely needed.

Female↗
PubMed1988

[Lichen planus].

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Child↗