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Biomedical subjects

C Frances

Publications and source records attributed to C Frances.

At least 55 records · Page 3Linked to original sources
PubMed1995

Alteration of cytokeratin expression in oral lichen planus.

The purpose of this investigation is to examine the possible biochemical and topographic cytokeratin alterations in lichen planus of oral mucosa. Biopsy samples of clinically normal buccal mucosa (n = 5), normal gingiva (n = 5), lichen planus from buccal mucosa (n = 5), and lichen planus from gingiva (n = 5) were obtained from patients of both sexes. Cytokeratin expression was determined by means of immunohistochemical labeling with use of a battery of monoclonal antibodies against cytokeratins and filaggrin and two-dimensional gel electrophoresis. In buccal mucosa, which is not keratinized cytokeratins 4 and 13 are expressed in the majority. In buccal mucosa lichen planus, the appearance of cytokeratins 1, 2, 10, and 11 coincides with a decrease in cytokeratins 4 and 13 and a moderate increase in cytokeratins 6, 16, 17, and 19. In normal gingiva, which is normally keratinized, the main cytokeratins are 1, 2, 10, and 11. In gingival lichen planus, a slight decrease in these cytokeratins and in cytokeratin 13 expression was noted. Finally, alterations in cytokeratins 5 and 14, explained by marked alterations of basal cells, were observed. The battery of antibodies used in this study, in correlation with two-dimensional gel electrophoresis, could represent useful diagnostic tools that enable the distinction between inflammatory keratosis and so-called quiescent lichen planus. Moreover, this work showed that cytokeratins 1, 2, 10, and 11 and filaggrin are sensitive tools that may help detect early relapse before clinical exacerbation. Finally, these biochemical techniques may be useful to follow the evolution of lichen planus under treatment.

Antibodies, Monoclonal↗
PubMed1994

Presence of gelatinase A and metalloelastase type protease at the plasma membrane of human skin fibroblasts. Influence of cytokines and growth factors on cell-associated metalloendopeptidase levels.

Gelatinase A and elastase type proteinase (Homsy, et al., 1988) present at plasma membranes of human skin fibroblasts (HSF) were separated by anion exchange chromatography on a DEAE Tris acryl M column. Elastase type proteinase (HSFE1) was able to convert 72 kDa progelatinase A to a lower 66 kDa M.W. active enzyme. Several cytokines (IL-1 beta, IL4, IL6), interferon gamma (IFN gamma) and tumor growth factor beta (TGF-beta) were studied for their ability to modify the levels of those plasma membrane associated proteinases. Among these mediators, only IL-1 beta was found to enhance the amounts of HSF membrane-bound HSFE1 and Gelatinase A.

Cell Membrane↗
PubMed1994

Involvement of cyclic AMP and nitric oxide in immunoglobulin E-dependent activation of Fc epsilon RII/CD23+ normal human keratinocytes.

Epidermal keratinocytes (EK) are exposed to multiple inflammatory stimuli and paracrine factors secreted by various dermal cells (lymphocytes, mast cells, macrophages, fibroblasts) during wounding, cutaneous allergy, and infections. We have previously demonstrated that after stimulation with interleukin 4 or interferon-gamma, human EK express the low-affinity receptor for IgE (Fc epsilon RII/CD23) on their surface. In the present study, we showed that the ligation of CD23 by IgE/anti-IgE immune complexes or specific monoclonal antibody induces a dose-dependent release of interleukin 6 and tumor necrosis factor-alpha from EK. CD23-ligation activates the nitric oxide-dependent pathway, as demonstrated by the high levels of nitrites released in cell supernatants, and the accumulation of intracellular cyclic nucleotides in EK. These second messengers are required for IgE-dependent stimulation of cytokine production by these cells, inasmuch as this is completely abolished by the use of cAMP or nitric oxide synthase antagonists. Human epithelial keratinocytes may thus participate in IgE-mediated immune responses, through their ability to express functional CD23 antigen.

Antibodies, Monoclonal↗
PubMed1994

T lymphocyte subsets in primary antiphospholipid syndrome.

OBJECTIVE: To study T, natural killer (NK) and B blood cell subsets in primary antiphospholipid syndrome (APS). METHODS: We studied 10 patients with primary APS and 12 healthy subjects. Blood lymphocytes counts, proportions of B cells (CD19+), total CD5 and CD5 B cells, NK cells (CD16+CD56+), T cells (CD3+), CD4+ helper (naive CD4+CD45RA+, memory CD4+CD45RO+ and CD4+CD29+, activated CD4+CD25+), CD8 (immunoregulatory CD8+CD57+, activated CD8+HLA-DR+) T cell subsets were measured by flow cytometry analysis. RESULTS: In the primary APS group, we observed a lower total lymphocyte count (p = 0.009), an expansion of naive CD4 cells (p = 0.025), a lower proportion of memory CD4 cells (p = 0.04) and an increased ratio of naive/memory CD4 cells (p = 0.015). CONCLUSION: Blood T cells phenotypes in primary APS differ markedly from healthy controls, indicating that immunologic abnormalities in primary APS might extend beyond autoantibody production.

Adult↗
PubMed1993

[Mechanisms of cardiac involvement in systemic scleroderma, apropos of 3 cases].

We studied myocardial manifestations of systemic sclerosis in three patients. Two patients were symptomatic. A transthoracic echocardiography, a coronary angiography, a cardiac catheterization, thallium scans with dipyridamol completed by thoracic cold exposure and endomyocardial biopsy with immunohistological study were performed. None of them have coronary stenosis. In the three cases abnormalities of myocardial perfusion were detected, two of them have fibrosis. The immunohistological study always showed an anusual expression of HLA DR on cardiac fibroblasts.

Aged↗
PubMed1993

[Sarcoidosis in a cicatrix: apropos of 5 cases].

The authors report 5 cases of sarcoidosis developed on scars. Sarcoidosis may be isolated (1 case); it may precede (1 case) or accompany systemic sarcoidosis, or occur during a relapse (3 cases). Dermatologists who observe cicatricial changes always suspect sarcoidosis. It is therefore important that physicians should examine the scars of their patients with suspected sarcoidosis, since biopsy of these scars is easily performed, confirms the diagnosis and avoids more invasive explorations.

Adult↗
PubMed1993

Disseminated histoplasmosis with glomerulonephritis mimicking Wegener's granulomatosis.

Renal complications of disseminated histoplasmosis include chronic recurrent abcesses of the interstitium and urogenital tract. To our knowledge, glomerulonephritis has never been reported in histoplasmosis. We describe a case of proven histoplasmosis presenting with oral granulomatous ulceration and segmental glomerulonephritis that mimicked Wegener's granulomatosis (WG). All symptoms and renal parameters remitted under itraconazole treatment alone. In conclusion, glomerulonephritis may complicate the course of chronic disseminated histoplasmosis. Since it can masquerade as WG, systematic tissue staining for intracellular microorganisms should be done when WG is suspected.

Diagnosis, Differential↗