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Biomedical subjects

J Viac

Publications and source records attributed to J Viac.

At least 145 records · Page 8Linked to original sources
PubMed1976

Morphological, immunological and immunocytochemical identification of lymphocytes extracted from cutaneous infiltrates.

The identification of mononuclear cells extracted from various skin disorders has been investigated and the relative amount of B and T cells determined according to various assays such as E-rosette test, FITC and peroxidase anti-immunoglobulin conjugates. It has been found that: (a) there were two different patterns of distribution of the cells in the infiltrates; one with a T/B ratio above 3 (closest to a delayed type reaction), the other with a T/B ratio below 2. (b) The morphological appearance of tissue lymphocytes differs from that of circulating lymphocytes by the presence of both membrane and cytoplasmic immunoglobulins.

B-Lymphocytes↗
PubMed1976

Identification of mononuclear cells infiltrating basal cell carcinomas.

The identification of mononuclear cells extracted from 12 basal cell carcinomas has been carried out by means of various assays such as the E rosette test, FITC anti-Ig conjugates and peroxidase conjugates viewed at an ultrastructural level. The relative quantities of B and T cells have been determined as well as the morphology of the extracted cells. It was found that the T/B ratio is close to that of a delayed-type reaction to tuberculin, suggesting a possible identical immune mechanism, and also that the morphological appearance of some tissue lymphocytes differs from that of circulating lymphocytes due to the presence of both membrane and cytoplasmic Ig.

B-Lymphocytes↗
PubMed1975

[B-lymphocytes subpopulation. Rapid identification with a histoimmunological method (author's transl)].

After extraction of tissues (spleen, thymus, blood) B cell bearing surface immunoglobulins were specifically labelled with Fab-peroxidase conjugate in light and electron microscopy. Positive and negative labelled lymphocyte were counted. This procedure allowed us to quantitate B and T cell in different diseases in peripheral blood and within lesions. It may represent a new immunopathological approach.

Animals↗
PubMed1974

Comparison of the immune response of the rabbit to virulent and attenuated strains of type 1 poliovirus.

Rabbits were immunized with the attenuated LSc, 2a(1)b or the virulent Mahoney strain of type 1 poliovirus, or with a partially purified preparation of the latter. It was found that the animals responded in a heterogeneous manner to antigens with a homogeneous virion population, such as LSc,2a(1)b and, to a lesser extent, the partially purified Mahoney antigen. This heterogeneous immune response permits the preparation of specific antisera for intratypic serodifferentiation tests. However, the unpurified Mahoney strain, which has a heterogeneous virion population, induced a homogeneous immune response; all the antisera had a wide spectrum of antibodies and could not distinguish the wild from the attenuated strain. The differentiation capacity of the specific antisera was found to be linked to either the IgM or the IgG. The possible implications of these findings for human vaccination against poliomyelitis are discussed.

Analysis of Variance↗
PubMedDate not supplied

[Immune complex disease of Swan and nude mice].

Swan and Nude mice with antinuclear antibodies (AN Ab) show early deposits of Ig and C in the mesangium and the basement membrane of glomerulus, marking an immune complexes disease. We have studied the Ig class of these immune complexes after acid elution and by direct immunofluorescence with suitable conjugates. In the Swan mice, fixed Ig are chiefly IgM and IgA, but AN Ab in the eluate kidney are principally IgG2 and IgM as the circulating AN Ab. In these mice the Ag of the fixed immun complexes are AN and murine leukemia virus Ag. In the Nude mice, fixed Ab are IgM and IgG2 and in part AN Ab. The circulating AN Ab and the AN Ab of eluates are also IgM and IgG2.

Animals↗
PubMedDate not supplied

[A chronological study of thymic crystalline inclusions and autoimmune disorders in Swan and NZB mice (author's transl)].

Swan and NZB mice represent good animal model for human systemic erythematosus with autoimmune phenomena (antinuclear antibodies, deposits of immunoglobulins in kidney and skin). The level of circulating thymic factor, responsible for T lymphocyte differenciation, falls during the first month of life in NZB mice, during the third month in Swan mice, during the sixth month in control mice (Swiss). In Swan mice, cytoplasmic crystalline inclusions have been found within the epithelial cells which are said to have a thymosine-like activity. The time-sequence of the appearance of the crystalline inclusions has been studied in relation to the development of autoimmune disorders (antinuclear antibodies, immunoglobulins in tissues). In each group of mice, the drop in circulating thymic factor appears before the appearance of crystalline inclusions and of autoimmunisation. Therefore, these crystals appear to represent a store of circulating thymosine-like factor or of a precursor in an ageing thymus.

Animals↗
PubMedDate not supplied

[Viral flora (coliphages and human enteroviruses) found in river water after an urban district (Saint-Etienne). II. A virological and epidemiological survey (author's transl)].

A survey was carried out from March 1972 to February 1973 to identify viral flora found in the river Furan ater St. Etienne. The 54 samples examined revealed the following data: 1) more accurate results are obtained when viral concentration values are expressed in terms of m3/sec., taking into account the flow of the river and eliminating the seasonal dilution factor; 2) rates of enteroviruses remain constant throughout the year, in spite of a relatively rapid spontaneous inactivation of the viruses; 3) rates of coliphages vary considerably according to seasons, with a notable increase in summer; 4) the two previous data are unrelated; 5) 147 enterovirus strains were isolated, of which 44% were polioviruses; 6) virulent and attenuated types 2 and 3 polioviruses were found simultaneously at certain periods; 7) only virulent strains of type 1 poliovirus were isolated; 8) this type of survey may be useful in controlling the endemic residual poliomyelitis in the region of St. Etienne.

Coliphages↗
PubMedDate not supplied

[Immunological and immunocytochemical studies of the inflammatory infiltrating cells of cutaneous tumors].

The identication of mononuclear cells extracted from various inflammatory infiltrates of cutaneous tumours has been investigated and the relative amount of B and T cells determinated according to various assays. It has been found that there were two different patterns of distribution of the cells in the infiltrates: one with a E/EAC ratio similar 5 (squamous and basalcell carcinomas), the other with a E/EAC ratio similar 1(malignant melanoma). The identification in situ of Ig-producing cells has been developed in the same tissues fixed in Bouin's solution. The relative frequency of these cells has been determinated and appears very low in the malignant melanoma.

Cell Movement↗
PubMedDate not supplied

[The spleen in "nude" mice: an immunological and immunocytochemical study (author's transl)].

An immunological and immunocytochemical study to compare spleen cells of Nude (C57B1) and Swiss mice is reported. The percentage of surface immunoglobulins bearing lymphocytes is identical in both strains of animal (40%). An activated C3 receptor is present in the majority of these cells and has been demonstrated within the germinal centers in both cell suspensions and frozen tissue sections. The population of Fc receptor bearing cells is more heterogenous, but the percentage of these is nearly identical in both Swiss and Nude mice. T-cell specificity is identified with an anti-thymocyte and an antibrain antiserum using an indirect immunoperoxidase method. The percentage of cells detected with the anti-thymocyte antiserum is very low in the spleen of Nude mice (5%) compared to that in the Swiss mice (42%). In the Nude mice, the anti-brain antiserum detects up to 30% of the spleen cells which may be considered as precursors and, so far, these 30% of cells in the Nude mice are considered as "null" cells, compared to only 20% in normal mice. The localization of the various immunocompetent cells within the spleen tissue is determined by immunofluorescence, immunoenzymology and the EAC rosette test. This study leads to the conclusion that in the periarteriolar areas of the spleen of the Nude mice, immune cells are sparse but that thymo-independent cells are located in the same region in both species of mice.

3,3'-Diaminobenzidine↗
PubMedDate not supplied

[Ultrastructural identifaction of human T lymphocytes using a peroxidase-conjugated anti-HTLA serum].

A horse antiserum rendered specific for human T lymphocytes was conjugated with peroxidase (PO) and used for identification of tonsilar T lymphocytes in electron microscopy. This conjugate stained nearly 50% of tonsilar lymphocytes, 96% of the T of the T cell-enriched population and 4% of the B cell-enriched population. The staining was only found on the cytoplasmic membrane as irregular small spots all over the cell surface. This conjugate was used for identification of the lymphocyte sub-populations extracted from skin infiltrates, and specially in Sezary's syndrome. PO-anti-HTLA serum stained all the cells showing morphological chracteristics of Sezary cells, which confirmed the thymus-derived origin of these cells.

Epitopes↗
PubMedDate not supplied

Expression of adhesion receptors in epidermal tumors: correlation with TNF alpha expressing cells.

The expression of intercellular adhesion molecule-1 (ICAM-1), endothelial leukocyte adhesion molecule-1 (E-selectin) and vascular cell adhesion molecule-1 (VCAM-1) was investigated in a series of basal cell carcinomas and squamous cell carcinomas in comparison to benign viral-induced lesions (cutaneous warts, condyloma) and was correlated to the infiltration density and the presence of TNF alpha expressing cells. Tumor cells expressing ICAM-1 were frequently detected in squamous cell carcinoma and condyloma and were correlated with a dense infiltration of HLA-DR and LFA-1 positive cells. Tumor cells were devoid of ICAM-1 in other lesions. Tumor microvessels detected by Von Willebrand factor were consistently present but vessels expressing adhesion receptors were less frequent. E-selectin was usually intense and frequent, whereas VCAM-1 was rare except in dense infiltrated zones and in viral-induced lesions. In all samples, tumor cells strongly expressed TNF alpha. Though the cytotoxin has been reported to be an inducer of adhesion receptors, its expression in epidermal tumors did not correlate with a concomitant up-regulation of epithelial ICAM-1 or endothelial VCAM-1. This may contribute to a reduced influx of T cells into the tumors.

Adolescent↗
PubMedDate not supplied

TNF alpha expressing cells in epidermal tumors: correlation with ICAM-1 induction on keratinocytes and Langerhans cell distribution.

TNF alpha may be a locally expressed immunomediator of cutaneous diseases. An immunohistochemical technique was used to study the expression of the cytotoxin in correlation with the intercellular adhesion molecule-1 (ICAM-1) and Langerhans cell (LC) distribution in viral-induced lesions, epidermal tumors and normal skin. In most cutaneous tumors, TNF alpha immunoreactivity localized to tumor cells and some cells of the histiocytic macrophage lineage including LC. In normal human skin only rare epidermal dendritic cells were found positive. TNF alpha expression by tumor cells did not correlate with a corresponding ICAM-1 induction but coincided with drastic LC depletion in the lesions except in condyloma acuminata. These results suggest that TNF alpha expression by keratinocytes under viral infection or transformation process may contribute to the self-limiting evolution of the lesions and to the modulation of the local immune reaction. Though the cytokine is not involved in the ICAM-1 induction on keratinocytes it may influence the LC depletion observed in these lesions.

Adolescent↗