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Biomedical subjects

Y Carlier

Publications and source records attributed to Y Carlier.

At least 73 records · Page 4Linked to original sources
PubMed1980

Kinetics of classes and sub-classes of total immunoglobulins and specific antibodies to Schistosoma mansoni during murine infection.

During the course of Schistosoma mansoni murine infection there is a dramatic increase of some immunoglobulins and S. mansoni-specific antibodies. The most substantial response is initiated after 40 days of infection and results in a prolonged increase of total IgG1, IgM and IgA. The maximum increase is respectively 26, 14 and 3-fold the basic immunoglobulin level in control mice. Some anti-S. mansoni classes and sub-classes were studied by an original radio-immunoadsorbent test. Anti-S. mansoni IgG1 and IgM antibodies appear and increase at the same time as that of total IgG1 and IgM. Anti-S. mansoni IgA antibodies appear later (80th day) and correspond to a second peak of total IgA.

Animals↗
PubMed1980

Physicochemical characteristics of Listeria specific antigen 2.

Listeria specific antigen 2 (Ag2) was purified to within 97% of homogeneity, with a high yield, using both gel filtration and polyacrylamide gel electrophoresis. Ag2 is a glycoprotein. Its isoelectric point is about 4.2. As determined by sodium dodecyl sulphate-polyacrylamid gel electrophoresis, its molecular weight in 16710 +/- 450. Ag2 may aggregate easily since it was previously found in gel filtration in a peak corresponding to a molecular weight of 160000. No enzyme activity has been found in Ag2.

Amino Acids↗
PubMed1980

In vitro study of immunological events in human and experimental schistosomiasis: relationships between cytotoxic antibodies and circulating Schistosoma antigens.

Complement-dependent cytotoxic antibodies were found in 54% of Schistosoma mansoni infected patients from Burundi and in 69 to 78% of Schistosoma mansoni ninfected Brazilian patients. The levels of cytotoxic Ab were not statistically different in sera from infected mothers and from their newborn children, suggesting a transfer through the placenta. A sandwich radioimmunoassay (SRIA) and the Radioimmunoprecipitaion-PEG assay (RIPEGA) technique were used in order to detect respectively total schistosome circulating soluble antigens (CSA) and schistosome antigen '4' in sera from infected patients. An inverse relationship was found between the presence of cytotoxic Ab and both total CSA and antigen '4'. The cytotoxic Ab and total CSA levels were followed in five Erythrocebus patas monkeys for 30 weeks after Schistosoma mansoni infection. As in human schistosomiasis the presence of cytotoxic Ab was found to be inversely correlated with the presence of total CAS. The blocking role of Schistosoma mansoni antigens in a complexed form was suggested by the inhibitory effect of the ultracentrifugation pellet of infected human serum on the cytotoxic activity. Moreover, the CSA absorption of infected monkey serum by passage through an anti-CSA immunosorbent significantly increased the cytotoxic activity. Possible mechanisms for the inhibitory role of circulating immune complexes on complement-dependent cytotoxic activity are discussed.

Animals↗
PubMed1980

Evaluation of circulating antigens by a sandwich radioimmunoassay, and of antibodies and immune complexes, in Schistosoma mansoni-infected African parturients and their newborn children.

Circulating Schistosoma mansoni soluble antigens (CSA), circulating anti-S. mansoni antibodies (CAb), and immune complexes (CIC) were studied in three groups of African patients living in the same area. The first two groups were composed of 26 S. mansoni-infected mothers and their 26 uninfected newborn children. The third group included 13 men and 10 non-pregnant women who were also infected with S. mansoni. CSA were quantified by using a solid phase sandwich radioimmunoassay, which was shown to be sensitive, reproducible, and S. mansoni-specific. CAb were studied by indirect hemagglutination. CIC evaluations were performed by using the Clq binding test. A high correlation was shown between the CSA levels in sera from infected mothers and from the umbilical cord of their newborn children, indicating that CSA are probably transferred through the placenta. CSA levels in mothers were significantly higher than in the third group, in which no difference was found between men and women. On the other hand, CAb and CIC were significantly higher in the third group than in the group of mothers, indicating that CSA levels may be modulated by the immune response of the host.

Adolescent↗
PubMed1980

Purification, immunochemical, and biologic characterization of the Schistosoma circulating M antigen.

Circulating M antigen, specific for genus Schistosoma, was previously described in serum, urine, patients' milk, and in serum and urine of animals infected by S. mansoni. The M antigen was thermostable and soluble in trichloroacetic acid. It was not hydrolyzed by protease, ribonuclease, amylase, or neuraminidase but destroyed by sodium metaperiodate. In the present study, we have purified the M ag by using trichloroacetic acid solubility, DEAE Sephadex, and immunoadsorption. The M ag showed a neutral electric charge, a m.w. heterogeneity, and was only stained by periodic acid-Schiff. The composition study revealed M ag was a glycoprotein with a polysaccharide moiety (63% of the molecules) particularly rich in galactose, fucose, glucosamine, and mannose, and with a high molecular ratio of serine and threonine. The presence of O-glycosidic linkage allowed M ag to be considered as a mucin or a mucus glycoprotein-like component. It was localized in the cell wall of the gut of adult worms.

Amino Acids↗
PubMed1980

Evaluation of the enzyme-linked immunosorbent assay (ELISA) and other serological tests for the diagnosis of toxoplasmosis.

The enzyme-linked immunosorbent assay (ELISA) was evaluated in human toxoplasmosis in three laboratories using their own procedures. The same batch of serum samples was investigated in the three laboratories. ELISA results were compared by statistical analysis both with one another and with those of the dye test (DT), immunofluorescence (IF), complement fixation test (CFT), and indirect haemagglutination (IHA).Highly significant correlations were obtained between the three laboratories with ELISA using two different antigens and enzyme conjugates. The correlations between ELISA and the other serological tests showed the following sequence: CFT>IF>IHA>DT. Highly significant correlations were obtained between ELISA using anti-gamma-chain and anti-total immunoglobulin conjugates. The agreement in discrimination between sera with low and high antibody levels was good for all the different ELISA techniques but discrimination between positive and negative sera depended rather on the ELISA procedure used.

Enzyme-Linked Immunosorbent Assay↗
PubMed1979

Automation of enzyme-linked immunosorbent assay (ELISA).

A prototype of automatized enzyme-linked immunosorbent assay (ELISA) in tubes is described, using a commercially available basic material, easily modified. Nine hundred samples could be completely studied in a day by only one person. The different steps of the automatized ELISA were systematically studied to obtain the best performance. Its application is described in toxoplasmosis serodiagnosis.

Autoanalysis↗
PubMed1979

Purification of a surface-specific soluble antigen from Listeria monocytogenes.

A complex antigenic preparation obtained from Listeria monocytogenes serovariant 4b by freeze-pressing, centrifugation, and gel filtration treatment was studied by crossed immunoelectrophoresis, with the aim of preparing an antigenic fraction that could be used to investigate the serological response to listeric infection. Of 17 immunoprecipitates revealed in the soluble extract, one of three major antigens (designated antigen 2) was shown to be a strong antigen in humans or rabbits infected with L. monocytogenes serovariant 4b. A monospecific antiantigen 2 serum was obtained and used to prepare a serologically homogeneous antigen by immunoadsorption. Antigen 2, most probably located on the bacterial surface, is common to all serovariants of L. monocytogenes and to Listeria grayi and is not shared by the main bacterial species known to have common antigens with L. monocytogenes.

Antibodies, Bacterial↗
PubMed1979

Immunodiagnosis of hydatidosis using monospecific immune serum anti Ag5.

Microdouble diffusion technique using whole hydatid antigen and monospecific antiserum against Echinococcus genus-specific antigen 5 was applied to the diagnosis of human hydatid disease. The use of this simple and economical method may be extended to the specific diagnosis of parasitic diseases.

Animals↗
PubMed1978

Inhibition enzyme immunoassay, application to human apolipoprotein B.

Inhibition enzyme immunoassay was applied to human apolipoprotein B (apo-B) from plasma. The technical conditions of the assay were determined. The detection limits of the assay were 200 ng to 10 microgram/ml. Correlation coefficients obtained between enzymoassay and rocket immunoelectrophoresis on one hand and radial immunodiffusion on the other were respectively 0.84 and 0.80. The inhibition enzymoassay provides a specific and highly sensitive method for the quantitation of apo-B.

Antibodies↗
PubMed1978

Enzyme immunoassay for human apolipoprotein B, the major protein moiety in low-density- and very-low-density lipoproteins.

We used enzyme immunoassay to measure apolipoprotein B concentration in human plasma. Pure lipoprotein B was isolated from serum samples of fasting normolipidemic subjects by sequential preparative ultracentrifugation and coated to a polystyrene tube surface by adsorption. Human serum samples and rabbit antiserum to human apolipoprotein B were incubated with the solid-phase lipoprotein B. Soluble antigen competed with solid-phase antigen for binding to antibodies. After washing, peroxidase-labeled sheep antibodies against rabbit immunoglobulins were added, and after further washing the bound label was assayed. This provided a direct measurement of the soluble antigen. The best technical conditions for the assay were determined. The minimum detectable concentration was 1 microgram per assay. The enzyme immunoassay yielded values that compare favorably with those obtained by radial immunodiffusion (r = 0.84) and by rocket immunoelectrophoresis (r = 0.80). The assay offers several advantages over existing techniques: sensitivity, specificity, simplicity, ane non-use of radioisotopes.

Apolipoproteins↗
PubMed1977

Immunological studies in human schistosomiasis. II. Antibodies cytotoxic for Schistosoma mansoni schistosomules.

Complement dependent cytotoxic antibodies for Schistosoma mansoni schistosomules were studied in a Brazilian population. The sera of S. mansoni-infected patients gave a high percentage of cytotoxicity (63.4%) compared with sera from persons not infected (8.7%). The IgG class and the specificity of these cytotoxic antibodies are defined. The index of lethality appeared to be independent of the titers of other specific anti-S. mansoni antibodies. A statistical correlation was found between the index of lethality and both the severity of the disease and delayed hypersensitivity to S. mansoni antigen. The significance of cytotoxic antibodies in human schistosomiasis and their relevance to immunity in man are discussed.

Antibodies↗
PubMed1977

Immunological studies in human schistosomiasis. III. Immunoglobulin levels, antibodies, and delayed hypersensitivity.

Levels of IgG, IgE, IgM, and IgA were determined, specific antibodies were detected by the fluorescent antibody test, hemagglutination test, complement fixation test and immunoelectrophoresis, and intradermal tests for delayed hypersensitivity to Schistosoma mansoni antigens were performed in Brazilian patients with schistosomiasis mansoni. The results were compared according to the clinical forms of the disease. IgG levels and antibody titers increased progressively in the subclinical, hepatomegalic, and hepatosplenic forms and there was a statistical relationship between IgG levels and the intensity of responses to the four serological tests; Delayed hypersensitivity (DHS) was found more frequently in hepatosplenic patients and more particularly in those with splenomegaly. DHS also correlated with age, but not with sex or with skin color. The strongest DHS reactions were observed in patients 20 to 34 years old, and in those having the highest fecal egg output. IgG levels, antibody titers, and DHS responses decreased after splenectomy and portal filtration of the worms. No significant variation was observed between untreated subjects, patients who were splenectomized and a group not subject to reinfection for 4 yearsk0

Antibodies↗
PubMed1977

Circulating immune complexes in schistosomiasis.

Circulating immune complexes (CIC) were investigated by the [125I]Clq binding test, the complement fixation test (CFT) and optical density measurement after redissolving 3% polyethylene glycol precipitates of serum from patients infected by Schistosoma mansoni. A highly significant correlation was obtained among these three techniques. More than 60% of the patients demonstrated significantly higher values than control individuals. The level of CIC was found to be higher in the mild than in the hepatosplenic form of the disease. Parasite antigen, IgG, IgM and IgE were characterized in these CIC. In experimental schistosomiasis in mice, maximum levels of CIC, evaluated by the CFT, were observed between the 40th and the 70th day of infection.

Animals↗
PubMed1976

Sensitization to Schistosoma mansoni antigen in uninfected children born to infected mothers.

Sensitization to Schistosoma mansoni antigen in uninfected children born to infected or uninfected mothers was studied by intradermal reaction. Immediate skin reaction, Arthus phenomenon, and delayed skin responses were noted. The skin response at 24 hr was positive in 48.1% of the uninfected children born to infected mothers, and in only 7.5% of uninfected (control) children born to uninfected mothers. Areas of skin reactions were also larger in the group born to infected mothers. Both of these differences were statistically significant. There were no significant variations according to age or sex. Only one immediate skin reaction was noted in each group, and Arthus phenomenon was never observed.

Antigens↗