Biomedical subjects

F Dumont

Publications and source records attributed to F Dumont.

At least 91 records · Page 5Linked to original sources

PubMed1976

Electrokinetic properties of splenic lymphocytes from the low-lipopolysaccharide responder C3H/Hej mice.

Spleen cells from C3H/Hej mice (H-2k) respond poorly to the B-cell mitogen lipopolysaccharide in vitro as compared to the related strains C3H/Tif (H-2k) and CBA/Orl (H-2k). The electrokinetic properties of splenic lymphocytes from these 3 strains were investigated in parallel, in order to both quantitate low-mobility B cell and high-mobility T cell populations and measure their mean electrophoretic mobilities. C3H/Hej mice were found to possess the same proportion (55%) of LM cells as C3H/Tif and CBA/Orl mice. Therefore, the low LPS-responsiveness of C3H/Hej is not due to a numerical deficiency in B cells. Whereas the mean EPM of HM cells was identical in the 3 strains, that of LM cells was slightly (6%) but significantly (Student's t test, P less than 0.01) lower in C3H/Hej than in the high LPS-responder controls. This suggests that the membrane-structure required for activating interaction with LPS might contribute to B-cell electronegative surface-charge.

Animals↗

PubMed1975

Effect of treatment with cyclophosphamide on the electrophoretic mobility and mitogen responsiveness of mouse thymus cells.

Two days after a single intraperitoneal injection of cyclophosphamide (CY) in a dose of 300 mg/kg of body weight, the cellularity of the thymus from adult female CBA mice was reduced to 17% of its normal value. The electrophoretic mobility (EPM) analysis of the surviving cells revealed a decrease in the proportion of the slow-moving cells together with a significant diminution of their mean EPM. The proportion of fast-moving cells, which were shown to correspond to the hydrocortisone-resistant and mitogen-responsive pool of mature thymocytes, was correlatively increased by 2-3 fold. Despite this enrichment in cells with a high surface charge, the thymocytes from CY-treated mice exhibited a diminished reactivity "in vitro" to both concanavalin A and phytohemagglutinin. The possible significance of theses results is discussed with reference to the known mitostatic properties of CY.

Animals↗

PubMed1975

Electrophoretic mobility and surface immunoglobin of albumin gradient fractionated mouse spleen cells.

Spleen cells from normal CBA mice, containing B and T lymphocytes, cyclophosphamide-treated CBA mice, containing almost exclusively T lymphocytes, and athymic nudemice, containing only B lymphocytes, were fracitonated by differential flotation in adiscontinuous albumin gradient. In all three cases, four density fractions were regularly obtained. The electrophoretic mobility (EPM), which allows distinction betweenslow-EPM (B) cells and fast-EPM (T) cells and the presence of surface immunoglobulins (sIg) detectable by direct immunofluorescence, characterizing B lymphocytes, were investigated on these fractions. Both B and T cells were recovered throughout the gradient, but in different proportions. Thus, B cells (slow-EPM, sIg-bearing) were enriched in the light density fractions while T cells (fast-EPM)were more numerous in the denser fraction. The mean EPM of slow-moving cells decreased, whereas that of fast-moving cells increased, as their buoyant density increased. Less nude spleen (B) cells were found to bear sIg in the light density fractions than in the denser fractions. These findings suggest the existence of lymphocyte subpopulations with distinct physicochemical properties which might represent stages in the maturation and differentiation of B- and T-cell lineages.

Animals↗

PubMed1974