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Biomedical subjects

M Donner

Publications and source records attributed to M Donner.

152 records · Page 9Linked to original sources
PubMedDate not supplied

Changes in lymphocyte subpopulations in mice receiving a single injection of poly-A:U.

The electrophoretic mobility (EPM) of lymphoid cells from the spleen and thymus of A/Sn mice was studied after a single injection of a double-stranded synthetic polynucleotide, poly-A:U. The proportion of spleen T lymphocytes with a high EPM increased markedly and rose to 80% of the total cell population on the 3rd day. The percentage of high mobility lymphocytes began to decrease on the 4th day, but normal values were not reached until the 15th day. Important variations in electrophoretic distribution profiles of the thymic cells were also observed after poly-A:U inoculation. In the untreated athymic Nude mice, 5% of the spleen cells have a high mobility and are presumed to be T-cell precursors. After a single inoculation of poly-A:U, the percentage of these cells increased to 18%. This increase correlated well with the increase in theta-positive spleen cells.

Adjuvants, Immunologic↗
PubMedDate not supplied

Effects of Poly A. Poly U in vivo alterations of proportions of T and B cell subsets.

Spleens and thymuses of mice were examined for changes in lymphocyte subpopulations after in vivo treatment with a double stranded synthetic polynucleotide: Poly A.Poly U. The cell populations were characterized on a biophysical basis: the electrical charge of cell surface assessed by the anodic electrophoretic mobility. The proportion of spleen cells exhibiting a high electrophoretic mobility (T lymphocytes) increased markedly on the 3rd day after a single intravenous injection of Poly A.Poly U. In thymuses, early important variations in electrophoretic distribution profiles were observed after Poly A.Poly U injection, suggesting that adjuvant acts on T cells.

Animals↗
PubMedDate not supplied

Strikingly different effects of dinitrobenzene sulfonic and trinitrobenzene sulfonic acids on various subpopulations of murine lymphoid cells.

Different changes according to T- or B-cell origin occur in dinitrophenyl (DNP)- and trinitrophenyl (TNP)-modified lymphoid cells. The electrophoretic mobility (EPM) or nylon-wool adherent splenic cells (B cell-enriched) modified by TNP and DNP and that of nylon-wool non-adherent splenic cells (T cell-enriched) and thymic cells modified by TNP increase respectively as follows: +24%, +20%, + 6%, and +16%. A relation has been found between these EPM amounts and amino groups which are positively charged on cell surface. The EPM decreases in the case of nylon-wool non-adherent splenic cells (T cell-enriched, -9%) and thymic cells modified by DNP (-4%). The hydrophobic fluorescent probe 1-anilino-8-naphthalene sulphonate used to study conformational changes of cells revealed a slight fluorescence decrease for TNP-modified cells (-11% for thymic cells, -38% for T cells of spleen, and -66% for B cells of spleen), and a fluorescence increase for DNP-modified cells. This fluorescence increase is more important for spleen T cells (+130%) and thymic cells (+233%) than for spleen B cells (+30%).

Animals↗
PubMedDate not supplied

Introduction to hemorheology: theoretical aspects and hyperviscosity syndromes.

Whole blood behaves like a deformable colloidal particle suspension in a macromolecular medium. Pathological variations in the rheological properties of blood and the clinical symptoms they produce form the "hyperviscosity syndromes". The term "hyperviscosity" was originally used for characterising the plasma hyperviscosity observed during macroglobulinemia and it is only recently that the chapter covering hyperviscosity syndrome has been enlarged to describe the syndromes as a state which the increased blood viscosity and increase in flow resistance must be considered as the result of the rheological behaviour of blood taken as a whole (plasma and blood cells). The etiology of hyperviscosity syndromes can be: (a) an increase in total plasma protein levels, or the appearance of a monoclonal protein; (b) the increase in the number of blood cells; (c) the increase in the erythrocyte's internal viscosity; (d) the changes in the erythrocyte's viscoelastic properties; (e) the excessive aggregating tendency of the erythrocytes and perhaps that of the platelets.

Blood Proteins↗
PubMedDate not supplied

Erythrocyte aggregation: experimental approaches and clinical implications.

From a clinical point of view, quantitative studies of erythrocyte aggregation or rouleau formation is of great interest. However, in order to approach the phenomenon, structural parameters (rouleau shape), kinetic parameters (rouleau formation and dissociation velocity) and rheological parameters (dissociation thresholds) must be determined. At present, optical dynamic methods are available for use in clinical hemorheology. They involve optical measurements in a viscometer. The first method consists of a study of the light intensity transmitted through the measuring chamber of a cone plan viscometer. A device calculates and index I, which provides a whole approach to the aggregation kinetics. On the other hand, a systemic which also involves a cone-plain viscometer and an inverted microscope (Rheoscope) allows to collect data by means of microphotographs, microcinematography or numerical image processing. In that case, an adimensional K index typical of the morphology of the aggregates can be determined. The second method involves the analysis of the light intensity backscattered by the red blood cells sheared in a Couette flow. An automatic system has been developed and aggregation times, orientation and structure index, total and partial disaggregation thresholds can be determined on the basis of the curves of variations of backscattered light.

Blood Viscosity↗
PubMedDate not supplied

Oscillatory nature of DNA, RNA, protein and lipid metabolisms in antigen-stimulated lymphocytes.

The primary immune response in inbred strain C3H/He to SRBC, or BSA is induced. The DNA, RNA, lipid precursor uptakes and total proteins are studied for 14 successive days following immunization, in splenic lymphocytes. Significant variations are noticed in the course of immune response of stimulated lymphocytes concerning their DNA, RNA, lipid and protein metabolisms respectively. The results reveal that there are several wave-metabolisms. The kinetic studies further indicate that course of different metabolisms would be of oscillatory nature. The activity peaks of synthesis may vary according to different antigens. Oscillatory systems would be 'excited' by antigenic stimulation. These results and hypotheses are discussed here.

Animals↗