Biomedical subjects

A M Lebacq

Publications and source records attributed to A M Lebacq.

3 recordsLinked to original sources

PubMed1986

Deoxythymidine and deoxycytidine incorporation into DNA in B leukemic cells.

Measurements of radioactive DNA after incubation of normal and B leukemic peripheral mononuclear cells, from c-ALL and CLL with labeled deoxythymidine (dTh) and deoxycytidine (dCt) showed that for dTh, incorporation into DNA was similar for normal and c-ALL cells but lower in B-CLL cells and that for dCt, incorporation was highest in c-ALL and lowest in CLL cells. These results contrast with those of dTh and dCt kinase activities; the former has been previously found elevated in c-ALL cells, and the latter is found, in the present study, similar in the three groups tested.

B-Lymphocytes↗

PubMed1979

B-cell precursors in early chicken embryos.

The ontogeny of B-cell precursors in chicken embryos from day 3 of incubation onwards has been studied. Purified antibodies to chicken Ig L, gamma, mu, alpha chains were used in a sensitive indirect immunofluorescence assayed on fixed cell smears and wax-embedded tissue sections; the location and morphology of immunoglobulin positive (Ig+) cells were determined either in phase contrast or after histological staining. Lymphoid cells containing small amounts of cytoplasmic immunoglobulin were found in 3 day and older embryonic yolk sac, 11 and 12 day blood, 11, 12 and 13 day bursal mesenchyme. cIg+ large basophilic cells were first seen in 14 day bursal follicles. It is concluded that cells enter the embryonic bursa at different developmental stages: some appear to be uncommitted stem cells, whilst others have already commenced B-cell maturation in an extra-bursal site.

Animals↗

PubMed1977

Embryonic bursa development in vitro.

An in vitro culture system for embryonic chicken bursa is described, in which development, as measured by follicle formation (site of B lymphocyte development), position of large basophilic cells (stem cells), and presence of lymphocytes and cells containing cytoplasmic immunoglobulin (B cells), was comparable to that of the bursa in vivo. Using this system, preliminary studies on B lymphocyte differentiation were made. These support the view that bursal lymphocytes develop from precursors that migrate through the surrounding mesenchyme and into the follicles, but indicate that at least some of these cells may be "pre-B cells" rather than pluripotent stem cells.

Animals↗