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Biomedical subjects

C Doinel

Publications and source records attributed to C Doinel.

At least 37 records · Page 2Linked to original sources
PubMed1989

Immunohistochemical localization of a beta-galactoside-binding lectin in rat central nervous system. I. Light- and electron-microscopical studies on developing cerebral cortex and corpus callosum.

From a lectin isolated from human brain (HBL-14), that specifically binds beta-galactosides, a polyclonal antiserum was raised that also recognizes a similar rat brain lectin (RBL-16). These antibodies allowed the immunocytochemical localization of the lectin during rat brain development by optical and electron microscopy. The presence of RBL-16, first detected at embryonic day 15, was specially increased from postnatal day 1 to 10. Its level decreased thereafter but it could still be detected in adult rat brain. The lectin, predominantly neuronal until postnatal day 13, was also present in astrocytes and perivascular cells where no developmental regulation was observed in contrast to neurons. Electron microscopy showed that the lectin was transiently expressed in the axoplasm of almost all neurons in layer I around the birth date, after which it remained inside neurons, including cell bodies and dendrites, in all examined regions. The lectin was clearly localized in postsynaptic structures. This beta-galactoside-specific lectin may be involved in synaptogenesis and neurite fasciculation as well as in intracellular traffic as discussed.

Aging↗
PubMed1989

Clinical and biological features in the 12 months preceding onset of AIDS in HIV-infected subjects.

Biological markers of HIV infection were studied in 17 asymptomatic HIV seropositive subjects in the 12 months preceding the onset of the disease. No single marker of HIV infection preceded the development of AIDS. Therefore, the clinical care of asymptomatic seropositive subjects should include a number of tests to evaluate HIV activity and immune suppression.

Acquired Immunodeficiency Syndrome↗
PubMed1989

[Early disturbance of the circadian rhythm of T and B lymphocytes in human immunodeficiency virus infection].

Circadian rhythms in circulating B and T (CD3, CD4, CD8) lymphocyte subsets and in plasma cortisol were studied in 13 HIV-infected men and 14 healthy male controls. The circadian maximum (acrophase) of plasma cortisol was similar in both groups, approximately 8.00 A.M., however, a statistically significant increase was found in the 24 hour-mean value (mesor) of infected patients as compared to healthy controls. Circadian rhythms were statistically validated in all lymphocyte subsets of healthy controls, whereas, large alterations were found in patients with acquired immunodeficiency syndrome (AIDS), already in asymptomatic infected individuals. The alterations concern the mesor and the amplitude for B and CD4 lymphocytes and all cycle parameters for CD3 and CD8 lymphocytes.

Acquired Immunodeficiency Syndrome↗
PubMed1988

[Early anomalies of CD4 and CD20 lymphocyte cycles in human immunodeficiency virus].

Circadian variations in the number of circulating lymphocytes and their subpopulations have been observed in healthy subjects. These cyclic changes are characterized by a trough at 8:00 a.m. and a peak at midnight. Using multiple peripheral blood samplings, we were able to confirm that this cycle applied to CD4 T-cells (helpers) and to B-cells (CD20). No cycle of CD8 lymphocytes was observed. In a second stage, for greater comfort of the patient the number of samplings was reduced to two: one at 8:00 a.m. (trough) and one at midnight (peak). This method enabled us to calculate the amplitude of lymphocytes cycles in 18 controls and 74 human immunodeficiency virus (HIV) seropositive patients. In asymptomatic HIV carriers the amplitude of CD4 cycles was normal in 6/26 cases and that of B-cell cycles in 2/17 cases. In the group of asymptomatic HIV carriers the mean amplitude of the cycles was much less reduced than in the other two groups. These results incite us to believe that the loss of the CD4 T-cell cycles is an early sign of HIV infection antedating the decrease observed in the number of these cells.

Adult↗
PubMed1988

Evidence that the c, D and E epitopes of the human Rh blood group system are on separate polypeptide molecules.

The distribution of the epitopes, c, D, E and G of the human Rh system on red cells has been investigated using both 125I-labelled and fluorescently-labelled MAbs. There is a very wide range in the density of each epitope on individual red cells and the numbers of c, D and E epitopes on each cell are independent of each other. These observations taken together with the finding that there is no steric hindrance to binding between the antibodies, anti-c, anti-D and anti-E indicate that these epitopes are on separate Rh polypeptide molecules. The observations are taken to indicate that the total amount of Rh polypeptide on a single red cell is constant but that there is considerable heterogeneity between cells in the amount of each separate polypeptide carrying the different epitopes. In contrast, there was a mutual inhibition of binding of anti-G and anti-D monoclonals and direct positive correlation between the number of G and D sites on individual cells, indicating that the G and D epitopes are probably on the same Rh polypeptide.

Antibodies, Monoclonal↗
PubMed1988

Disappearance of CD4-lymphocyte circadian cycles in HIV-infected patients: early event during asymptomatic infection.

Circadian variations have been observed in peripheral blood lymphocyte counts in normal subjects; they usually reflect variations in absolute CD4-cell count. For this population, nadir occurs around 0800 h (basal value) and the peak value occurs at midnight (1.6 times the 0800-h value). This cycle is thought to be of major importance in the efficacy of the immune response because it expresses the migration of lymphocytes into lymphoid organs.

Acquired Immunodeficiency Syndrome↗
PubMed1988

Follow-up of subjects with isolated and persistent anti-core (anti-p24 or anti-p17) antibodies to HIV.

Systematic screening of blood donations by enzyme-linked immunosorbent assay (ELISA) for HIV antibodies carries a false-positive rate: the sera involved react in Western blot to core antigens (p24 or p17) but reactivity to envelope is absent. We studied 22 subjects with persistent and isolated anti-core reactivities; 75 HIV seropositive patients were controls. The epidemiological data and the follow-up and biological tests performed in these two populations argue that donors with persistent and isolated anti-core antibodies are not seroconverting for HIV. We conclude: (1) that verification of all anti-HIV ELISA-positive sera by Western blot is essential and that the presence of at least once anti-envelope (gp120 or gp41) antibody is indispensable for the diagnosis of HIV infection; (2) that the solitary anti-p24 or anti-p17 bands observed on Western blot are false-positive. There is no evidence that donors with such reactivities are HIV-infected.

Adult↗
PubMed1988

Disappearance of CD4 lymphocyte circadian cycles after autologous bone marrow transplantation.

Circadian variations are observed in CD4 lymphocyte count in healthy people. Samples taken of the basal value occurring around 08.00 hr and peak value at midnight made it possible to define the range of cyclic variations. Movement of lymphocytes seems important in accounting for the observed circadian variations. CD4 circadian cycle amplitudes were investigated in 12 patients with autologous bone marrow transplantation. Cycle abnormalities were observed in 7 patients. Two of them had a normal CD4 lymphocyte count. It was therefore possible for functional abnormalities in CD4 lymphocytes to be detected in patients with a normal CD4 count. Because of these results, we are of the opinion that the evaluation of CD4 lymphocyte cycle might be a more sensitive test than the absolute CD4 count itself.

Bone Marrow Transplantation↗
PubMed1988

Biochemical identification and characterization of the G antigen in the human blood group Rh.

The human blood group Rh comprises erythrocyte membrane antigens which include the G antigen. In order to carry out this study, the G antigen was specifically immunofixed with a human monoclonal anti-Rh(G) antibody. After extraction and purification of the antigenic complex, a migration in SDS-PAGE showed the G antigen to be associated with a polypeptide of 28,000 MW.

Antibodies, Monoclonal↗
PubMed1984

A monoclonal antibody directed against the homologous N-terminal domain of glycophorin A and B.

A monoclonal antibody (iB5, IgG1 kappa) reacting with human red cells was produced after immunization of BALB/C mice with cord red cells, followed by fusion of the spleen cells with the murine myeloma cell line Ag 8-653. The monoclonal antibody agglutinated blood group N+ much better than M + N-red cells but did not recognize erythrocytes from rare individuals typed as M + N-S-s-U- and those from an En(a-) individual (M.E.P.). However, S-s-U- donors typed as M + N + or M-N+ and En(a-) red cells from donor G.W. were agglutinated. The erythrocyte receptors for iB5 are completely destroyed by papain treatment and significantly decreased by neuraminidase. Interestingly also, the iB5 antibody failed to agglutinate trypsin-treated N+M-S-s-U- erythrocytes. Other investigations have shown that the monoclonal antibody precipitated glycophorin A and B from N+ red cells and only glycophorin B from M+N-erythrocytes. The reactivity of iB5 was further explored by immunostaining following the electrophoretic transfer to nitrocellulose sheets of membrane proteins from common (M and N) and rare erythrocytes [En(a-),S-s-U-, MgMg, McM, St(a+), Mi.V, Mi.III, Tn] separated by SDS-polyacrylamide gel electrophoresis. These studies have clearly demonstrated that the monoclonal iB5 antibody is directed against the homologous N-terminal domain of glycophorin A and B, a specificity which explains the serological reactivity of iB5 against common and rare erythrocytes.

Animals↗
PubMed1983

[Estimation of platelet-bound IgG by means of a test using radioactive antiglobulin].

A method of evaluation of platelet bound IgG (PA IgG) is described. This method rely upon the fixation of a radio-labelled goat anti-human IgG on platelets. Each new batch of labelling of the antiglobulin is tested with a reference system using a semi-purified anti-D IgG and O R1R1 and O rr erythrocytes. This system is used for the standardization and the validation of the antiglobulin, and it allows to make correspond an amount of antiglobulin to a known quantity of IgG molecules. The normal level of PA IgG in 98 healthy controls was found to be 351 +/- 252 antiglobulin combining sites (ACS) per platelet. The upper limit (99% confident limit) in the controls is 999 ACS per platelet. 412 thrombocytopenic patients have been tested, 78.7% of ITP had an elevated PA IgG. However positive results are also frequent in other thrombocytopenia even when an immune mechanism cannot be evoked. These positive results raise the problem of the signification of PA IgG and of their exact nature. Further dates are necessary to ascertain the role of auto-antibodies, immune complexes or of platelet membrane modifications in PA IgG increase.

Adult↗
PubMed1983

Murine monoclonal antibodies against Gerbich antigens.

Two murine monoclonal antibodies (E11-1 and MR4-130) agglutinated all samples of human red cells except those of the Ge (-1, -2, -3) phenotype. It was possible to demonstrate that these antibodies recognize two different epitopes of the Gerbich antigen.

Animals↗
PubMed1983

A murine monoclonal antibody against blood group H type-1 and -2 structures.

A murine anti-H monoclonal antibody was produced. This antibody, called sp115, is an IgM that does not agglutinate classical Bombay. Sp115 may differentiate the two categories of H-deficient phenotypes. It detects H substance in both plasma and fresh saliva. Tissue antigen is found when using this antibody. The specificity of sp115 antibody was determined by adsorption with, and elution from synthetic oligosaccharide immunoadsorbents. Sp115 does not distinguish H type-1 and H type 2-structures.

ABO Blood-Group System↗