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Biomedical subjects

G Tridente

Publications and source records attributed to G Tridente.

At least 109 records · Page 6Linked to original sources
PubMedDate not supplied

Phenotypic analysis of human peripheral blood lymphocytes by automatic sampling flow cytometry after stimulation with mitogens or allogeneic cells.

Human peripheral blood lymphocyte (PBL) phenotypes have been analyzed before and after stimulation with phytohemagglutinin (PHA), concanavalin A (ConA) and pokeweed mitogen (PWM) for 3 days and in mixed lymphocyte culture (MLC) for 7 days. PBL labeled with each of 10 fluorescent monoclonal antibodies were automatically sampled for flow cytometry from 96-well microtiter plates using a microsample delivery system. The reference phenotypic ranges were determined in fresh cells and control cultures. PHA was mostly mitogenic for T PBL bearing the CD3, CD5, CD7, CD8 and CD25 differentiation clusters, and a low density of CD1 and CD4 had a small effect on human natural killer cells (HNK) and also did not stimulate B (CD19) and HLA-DR+ PBL. There was an incomplete phenotypic overlapping between PHA- and ConA-stimulated cultures, ConA being more mitogenic for CD4 and less mitogenic for CD8 PBL. The mitogenic effect of PWM was evident on CD3, CD5, CD7, CD4, CD25 and CD8, but not on HNK, HLA-DR and CD19 B PBL, which presumably had already differentiated into antibody-secreting cells. After MLC stimulation all T, B and HNK PBL subsets tested were increased, but the cells bearing CD1, CD4, CD5, CD7, CD25, HNK, CD19 and HLA-DR had the greatest proliferation with respect to the unmixed control PBL. The present approach to the phenotyping of PBL subsets could offer more complete and accurate data for monitoring and follow-up of patients in transplantation and immunopathology hospital wards.

Antibodies, Monoclonal↗
PubMedDate not supplied

Analysis of physical parameters of discrete cell populations. (Double data control by combining specific density and sedimentation velocity cell separation techniques).

Physical cell separations are employed in a number of investigations in cell biology, immunology, haematology, etc., when the study of homogeneous cell populations is required. Differences in physical characters are reflected in the various functions and differentiation stages of the individual cell lines, which can be concentrated and separated into discrete cell classes by these methods. The correct utilization of the separation techniques mainly depends on the knowledge of the physical laws on which they are based. This paper discusses the theoretical background and a practical application of a combined separation procedure which uses velocity sedimentation and linear density gradient and also gives a double check of the physical data obtained in the different experiments. As an example of this analysis, cells from the lymph nodes of Hodgkin's patients were separated, and the physical parameters as well as some sources of 'error' in the experimental results obtained with these 'Hodgkin's cells' are reported and discussed.

Cell Separation↗
PubMedDate not supplied

Structural analysis of the CD69 early activation antigen by two monoclonal antibodies directed to different epitopes.

The biochemical structure of CD69 early activation antigen has been characterized by means of two newly isolated mAb, namely C1.18 and E16.5. Upon analysis by SDS-PAGE, C1.18-reactive molecules immunoprecipitated from 125I-surface labeled PMA activated PBL consisted of a 32 + 32 kD dimer, a 32 + 26 kD dimer, a 26 + 26 kD dimer and a 21 + 21 kD dimer. E16.5-reactive molecules consisted of a 26 + 26 kD dimer and a 21 + 21 kD dimer. Cross absorption experiments showed that E16.5 mAb reacts with an epitope of the CD69 molecule distinct from the one recognized by C1.18 mAb and present only on a subpopulation of the CD69 molecular pool. The patterns of migration of C1.18- and E16.5-reactive molecules in two-dimensional gel-electrophoresis, under reducing conditions before and after treatment with Endoglycosidase F enzyme suggest that the two mAb recognize the same glycoprotein structure, but in two distinct glycosylation forms, both expressed on the cell surface membrane. Finally, p32, p26 and p21 of CD69 complex obtained from three distinct normal donors did not show appreciable structural polymorphism, by two-dimensional peptide mapping, not only among single subunits within the same individual, but also among homologous subunits in distinct individuals. Further, it was found that CD69 complex is expressed at the cell surface of resting PBL, although at a very reduced level in comparison to PMA activated cells. C1.18 and E16.5 mAb induced comparable cell proliferation and IL-2 production in PBL in the presence of PMA. C1.18 mAb increased intracellular free calcium concn in PMA activated PBL after cross-linking with goat anti mouse Ig, while the effect induced by E16.5 mAb after cross-linking was consistently lower. Finally, it was found that Sepharose-linked C1.18 mAb, in the presence of rIL-2 or PMA, did not induce TNF release from 6 NK cell clones.

Antibodies, Monoclonal↗
PubMedDate not supplied

The effect of levamisole on peripheral T-lymphocytes of patients with malignant lymphomas.

The effect of various concentrations (0.015 - 10 micrograms/ml) of Levamisole (LMS) on the peripheral lymphocytes of patients with malignant lymphomas (ML) and normal donors was investigated in vitro. The parameters studied include: E rosettes forming cells (total T lymphocytes), active E rosettes (early T lymphocytes) and DNA synthesis induced by pitogens PHA and Con A. LMS improved significantly lymphocyte response both in patients with ML and normal donors when the cells were stimulated by Con A. In both groups no significant effect was observed on the response to PHA nor on the percentage of E-rosettes, whereas the mean number of active E rosettes was significantly increased on all concentrations of the drug. While in the normal subjects a positive statistical correlation between active E-rosettes and Con A response was observed, in patients with ML an inverse correlation was found. This latter correlation was partially reversed by LMS. These results indicate that LMS, both in normals and in patients with ML, interacts with a specific cell subset (early rosetting lymphocytes), with different functions in normal and pathological situations. The drug shows an effect on the immunological handicap of lymphocytes of patients with ML.

Hodgkin Disease↗