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Biomedical subjects

C Choquet

Publications and source records attributed to C Choquet.

18 recordsLinked to original sources
PubMed1987

In vitro depletion of clonogenic cells in adult acute lymphoblastic leukemia with a CD10 (anti-cALLA) monoclonal antibody.

A semi-solid medium colony assay was used in common acute lymphoblastic leukemia (cALL) to test growth inhibition of leukemic progenitors (CFU-L) after exposure to monoclonal antibodies (MoAbs) directed against CD10 and CD9 antigens. Peripheral or bone marrow cells from 15 patients were plated after exposure to various concentrations of ALB2, a CD10 cytotoxic MoAb, followed by complement lysis. CFU-L inhibition was complete (no residual colony) in 5 cases (33%), marked (greater than or equal to 95%) in 4 cases (27%), but only moderate (64% +/- 28) in 6 cases (40%). This inhibition was not related to the percentage of cALLA positive cells before exposure to MoAb. In addition, cells of 5 patients were exposed to BA1 (CD24) + complement. In these cases, the proportion of CFU-L inhibition was equal to or higher than with ALB2. In 3 cases, cells were exposed to an association of ALB2 and SB4 (CD19) MoAbs followed by complement lysis, with a marked inhibition (greater than or equal to 99%) in 2/3 cases. These observations give supplementary support to the use of several MoAbs directed against various antigens present at early stages of B differentiation.

Adolescent↗
PubMed1985

Merocyanine 540 staining of human leukemic cells: relation to stage of disease.

Previous work based on fluorescence microscopic observation has indicated that leukemic leukocytes and immature hematopoietic precursor cells show a greater permeability to the membrane stain, merocyanine 540 (MC) than normal, mature cells and that changes in MC permeability seem to be correlated with failure in membrane maturation during leukemic cell differentiation. In the interest of addressing questions concerning the efficacy of the MC staining reaction as a diagnostic tool in clinical contexts relevant to leukemia, we have looked for any correlations which might exist between the MC staining patterns displayed by circulating leukocytes, cellular morphology and the clinical status of 53 patients with leukemia and non-Hodgkin's lymphoma, using fluorescence activated cell sorting. In 85% of cases, MC staining was found to be correlated with blood status while in 15% of the cases discrepancies were found. These results are discussed in light of changes in the hematologic profiles of the patients during the clinical course.

Diagnosis, Differential↗
PubMed1983

Decrease in human lymphocyte surface glycoconjugates in leukemia as demonstrated by lectin binding.

Qualitative variations in the glycoconjugates which make up the lectin receptor sites on the membranes of leukemic lymphocytes, compared with those of normal cells, have been studied by the use of three tritiated lectins: Robinia pseudoacacia lectin, Concanavalin A and Ricinus communis (var. Sanquineus) agglutinin (RCA 120). The binding specificity of these lectins has been demonstrated using specific determinants: alpha-methylmannoside and galactose for Concanavalin A and Ricinus communis agglutinin respectively. For the Robinia lectin this specificity was determined by saturation of the receptor sites with the unlabeled Robinia lectin before the addition of isotopically labeled Robinia lectin. The results show a decrease in the number of receptor sites on the leukemia cells, especially in chronic lymphoid leukemia, relative to that on normal cells. The apparent affinity constants of leukemic cells in all cases remain higher than those of normal cells.

Cell Membrane↗
PubMed1981

Application of colored image analysis to bone marrow cell recognition.

A color processing procedure bases on the essential features of human perception of colors is presented. It allows the computation of colors in terms of the luminance, the hue and the saturation at every point of an image. Such color processing was used for segmentation and feature extraction of human bone marrow cell images acquired through successive red, green and blue broad-band filters. The efficiency of the luminance, saturation and hue parameters in discriminating cell types is illustrated and discussed.

Bone Marrow Cells↗
PubMed1978

Modifications of lectin binding on human leukemic cells after neuraminidase treatment.

Cell surface modifications after vibrio cholerae neuraminidase treatment were investigated using three different tritiated lectins: Concanavalin A, Ricinus sanguineus agglutinin (R.S.A.) and Robinia pseudoacacia lectin. Lectin binding measurements were performed on untreated and enzyme treated cells. The cells used were from chronic and acute leukemic donors. After neuraminidase treatment, a significant increase in the number of receptor sites, from 1 to 3 times, was found in all cases tested and for all three lectins utilized with only one exception. The affinity constant was generally decreased after neuraminidase treatment. The increase in number lectin binding sites, indicating extensive modification of the cell surface, is completely consistant with the known importance of sialic acid in determining immunogenicity.

Binding Sites↗
PubMed1976

Quantitative variations of three different lectin receptors as a function of establishment and metabolism of normal and leukaemic human cell lines.

Lectin binding on the cell surface was measured by the method of Kornfeld [16] using three tritiated lectins: Robinia pseudo acacia, Concanavalin A and Ricinus. It has been shown that the number of binding sites for Robinia and Con A decreases after the establishment of a leukaemic cell line, whereas the affinity constant increases for Robinia. The relationship between lectin binding and cell growth was carried out on 5 cell lines, 3 of leukaemic and 2 of normal origin. In all cases the maximum number of sites was determined at the time of doubling for the cell population; the affinity constant reciprocally decreases at this moment. For Robinia, a difference was found in both cell growth and the number of sites between an Epstein-Barr virus (EBV) negative leukaemic cell line and the other EBV positive cell lines. Lectins offer a quantitative method for measuring membrane structure variations during and after establishment of cell lines.

Animals↗