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M Wioland

Publications and source records attributed to M Wioland.

31 records · Page 2Linked to original sources
PubMed1986

[Electrophoresis applied to the analysis and separation of cells].

The present paper describes the theory and practice of cell/particle electrophoresis: the migration of cells/particles free to move in suspension under the influence of an applied electrical field, without any undue damage of cell membranes. The technique is quite different from high voltage electrophoresis on gels and paper. The quantitative biophysical parameter, never likely to be zero, is the electrophoretic mobility, experimentally determined by the cell electrophoresis apparatus, and mathematically related to the electrokinetic or the zeta potential. A detailed description of the analytical and preparative electrophoresis is given. Data are presented on the electrophoretic properties of bone tissue cells and cells of the immune system.

Animals↗
PubMed1985

Cell surface analyses of the age-dependent changes in the electrokinetic properties of human peripheral blood lymphocytes.

The age-dependent changes in the surface electrical charge of human peripheral blood lymphocytes were analyzed by establishing the differences between the surface density of four types of chemical groups on lymphocytes isolated from the blood of individuals of increasing ages. Similar determinations were carried out on cord blood lymphocytes which were shown previously to exhibit either a low or a high electrical charge density reflected in the experimentally determined parameter, the anodic electrophoretic mobility (EPM), differing by about 30%. The surface density of carboxyl group of N-acetylneuraminic acid (NANA), protein side chain epsilon-amino groups, and phosphate groups were different for the two subpopulations of CBL. Differences were also observed between the surface density of these groups on the two subpopulations of CBL and the lymphocytes of older individuals, with the exception of carboxyl groups. In some experiments on lymphocytes from adults, the carboxyls of NANA were much more numerous on nearly 1% of the cells.

Adult↗
PubMed1985

[Value of bone scintigraphy].

Artificial radioactivity enables visualisation of the principal organs in the form is scintiscans, introduces a new order of sensitivity in quantitative hormonal analysis, thanks to radio-immunology, and remains unrivalled in compartmental analyses of the various metabolism of the diagnosis of local skeletal conditions is reviewed, and the indications for this quantitative examination are described for the diagnosis of numerous bony metabolic diseases. Finally, mono- and bi- photonic absorptiometries, the latest developments in isotopic techniques, are introduced. They are likely to provide numerical data on the state of mineralisation of bony tissue. The use of these nuclear techniques for the diagnosis and surveillance of osteoporosis is detailed.

Bone Diseases↗
PubMed1983

A baby with Di George syndrome treated with bovine thymic extracts: a 3.5 yr analysis of variations in the distribution of lymphocytes characterized by three tests of cell mediated immunity and electrophoretic mobility.

This report concerns a baby with the features of Di George syndrome. Bovine thymic extracts prepared in this laboratory were used to treat the baby between the ages of 1 and 18 months. A favourable evolution of the illness was noticed, suggesting the diagnosis of Di George syndrome in its partial form and/or a favourable response to the treatment with thymic extracts. The number of E-rosette forming T-lymphocytes in blood remained low during the 3.5 yr of the observation. The in vitro response of peripheral blood lymphocytes to phytohemagglutinin and to allogenic cells slowly increased during this period of time. Surprisingly, no change in the proportions of lymphocytes of high electrophoretic mobility and low electrophoretic mobility was observed, in contrast to the gradual change usually observed in normal individual age-matched controls.

DiGeorge Syndrome↗
PubMed1979

Age-dependent changes in the electrophoretic mobilities of human blood lymphocytes.

The distribution of the anodic electrophoretic mobilities (EPM) of human peripheral blood lymphocytes was determined for lymphocytes isolated from umbilical cord blood and from blood of individuals 6 months to 93 years of age. The distribution was bimodal in infants up to 2 years of age and suggested a small percentage of cells with a mobility of 0.95 micrometer s-1 V-1 cm. this value was chosen to discriminate between low-mobility cells (LMCs) and high-mobility cells (HMCs). The relative percentage of LMCs increased from birth to 2 years and two types of LMCs could be distinguished. The distribution was unimodal and asymmetric in children and adults and nearly Gaussian in aged people. Substantial differences between the distributions of the lymphocyte EPMs were seen on comparison of the histograms for individuals of similar ages. The analysis of the distribution of the lymphocyte EPMs on cell suspensions enriched in, or depleted of T or B cells confirmed the mobility of most T cells to be higher than the mobility of most B cells, whatever the age of the individual. The distribution of lymphocyte EPMs determined in the same adult over a 6 year period showed minor variations.

Adolescent↗
PubMed1976

Modifications of the thymocyte membrane during redistribution of concanavalin A receptors.

The modifications of the thymocyte membrane which are induced by concanavalin A (Con A) were studied by means of the variation of electrophoretic mobility which the lectin induces on the cell. The electrophoretic mobility of thymocytes is increased when Con A is used under conditions expected to induce a cap formation and the subsequent endocytosis. This increase persists as long as the lectin is present in the medium and disappears as soon as the lectin is eliminated. The redistribution of the Con A receptors into spots and caps may partially explain this electrical modification. The ionized groups of the thymocyte membrane are drastically modified during these phenomena with: 1) a diminution by 61% in the density of the sialic carboxyl groups, 2) a decrease of 40% in the density of phosphate groups and of 60% in the density of amino groups, 3) a 20 times higher density of unidentified negatively charged groups. The electrophoretic mobility of normal human blood lymphocytes is similarly increased by Con A. A marginal difference exists in the shape of the dose response curves obtained when normal and cancerous thymocytes react with increasing doses of Con A. No measurable electrical modification was observed during redistribution of H-2 and Thy-1.2 antigens on EL4 cells. Some experiments suggest a possible correlation between the mitogenicity of the lectin and a measurable modification of the cell electrophoretic mobility.

Animals↗
PubMed1975

Relationships between H-2 Region and surface characteristics of mouse spleen cells.

The purpose of this investigation was to study whether allelic variations at the H-2 region which induce differences in the peptide composition of some glycoproteins of cell surface, also induce variations in electrical charges at the cell membrane. The surface charge was assessed by the electrophoretic mobility of the cell. Tests with different congenic strains were undertaken on spleen cells which were assumed to contain two major lymphocyte populations with different surface charge. The data show that the mean electrophoretic mobility of the low mobility lymphocytes was independent of the strain. By contrast, some H-2 haplotypes give 8% difference in surface charge of high mobility lymphocytes. These results suggest that the H-2 region plays a role in the regulation of ionized groups of cell surface in some but not all populations of spleen lymphocytes. The high and low mobility lymphocyte populations are assumed to represent T and B lymphocytes, respectively. The proportions of T lymphocytes obtained with electrophoretic marker were higher than those observed in other strains with currently available markers. It is suggested that the high mobility population contains T and "null" lymphocytes. Moreover, the data show that the H-2 region controls the relative proportions of T (or T and "null") and B lymphocytes, the H-2s specificity inducing a B/T ratio different from that induced by other specificities.

Animals↗
PubMedDate not supplied

Isolation procedures for blood lymphocytes produce artifacts. Detection by changes of electrophoretic mobilities of lymphocytes.

The changes induced in the distribution of the electrophoretic mobility (EPM) of human peripheral blood lymphocytes (HPBL), by various methods used to prepare the lymphocyte suspensions and eliminate platelets from them, were investigated on blood samples collected from healthy individuals and thrombopenic patients. Data showed that the distribution of the lymphocyte EPMs, i.e., the "lymphocyte electrophoregram," was dependent on the method chosen to enrich the suspension in the cell type of interest. The relative percentages of the low and high mobility cells, the two main subpopulations defined by lymphocyte electrophoresis, were different. The most striking artifactual differences in the lymphocyte electrophoregram were induced by the method of elimination of platelets; the distribution was unimodal and asymmetric when thrombin was used and bimodal when the blood sample, or the lymphocyte suspension, was placed on ice for 30 min (as is the practice in some laboratories). The "split" of the lymphocyte electrophoregram was found to be reversible within 90 min. Similar changes were observed on lymphocyte suspensions and blood samples of thrombopenic patients when the step for the elimination of platelets was not involved.

Adult↗
PubMedDate not supplied

Changes in biophysical parameters and in phospholipid composition associated with resistance to doxorubicin.

Friend leukemia cells (FLC) resistant to different concentrations of doxorubicin were used to investigate the biochemical and biophysical changes associated with resistance. We have found that fluorescence polarization of 1,6-diphenyl-1,3,5-hexatriene analyzed on single cell level increased in resistant as compared to sensitive FLC. Furthermore, phospholipid analysis of sensitive and doxorubicin-resistant cells revealed changes in ratios of phosphatidyl-choline to phosphatidyl-ethanolamine and phosphatidyl-choline to sphingomyelin. These results correlate with decreased electrophoretic mobility in resistant cells. Our results indicate that changes in cell structure occur with the level of resistance to doxorubicin. These changes are probably the consequence rather than the cause of resistance.

Cells, Cultured↗