Biomedical subjects

M J Demares

Publications and source records attributed to M J Demares.

4 recordsLinked to original sources

PubMed1990

New evaluations of circulating granulocyte and macrophage stem cells in healthy adults using conditioned media and recombinant human growth factors.

Peripheral human blood contains granulo-monocyte (CFU-GM) and eosinophil (CFU-Eo) progenitors. In vitro, the number of colony forming units is thought to range from 0.1-14 per 2 x 10(5) plated cells. We show that the number of CFU-GM, Eo depends on culture methods. By modifying the usual assay method (using human umbilical cord plasma and the association of 2 stimulating conditioned media: activated lymphocyte conditioned medium and bone marrow fibroblast conditioned medium), we found different circulating CFU-GM, Eo numbers. The mean number of circulating CFU-GM, Eo in 107 healthy adults was 22.4 per 2 x 10(5) plated cells (range: 1-84). There was a slight difference between males (mean number: 23.6) and females (mean number: 20.4). The mean number of CFU-GM, Eo harvested on Percoll gradient was 123/ml of peripheral blood (range: 7-513). These results are far over those commonly reported in literature. This suggests that these latter results were probably underestimated. The use of recombinant human interleukin 3 and recombinant human GM (granulocyte-monocyte) colony-stimulating factors shows that CFU-GM, Eo numbers are found to be comparatively increased compared to that obtained with our modified method (using rhIL-3 alone), or that the size of those colonies is notably increased (using rhIL-3 + rhGM-CSF).

Adult↗

PubMed1990

Prevalence of the 1.8 kb complement factor H mRNA in human lung.

Human complement factor H, described as a 155,000 molecular weight (MW) component, is a key factor in the control of the alternative pathway of complement activation. Using two human factor H cDNA clones, designated R2a (a clone derived from the 3' end of the factor H coding sequence) and B38-1 (a clone derived from the 5' end of the factor H coding sequence), as probes, three factor H-specific transcripts of 4.3 kb, 1.8 kb and 1.5 kb are usually detected in human liver, in equal abundance. Using these two factor H cDNAs to probe human lung RNA, there was evidence of a singular distribution of the factor H mRNA species in human lung compared to liver, in equal prevalence of the 1.8 kb factor H mRNA over the 4.3 kb factor H mRNA (a three- to fourfold difference). No significant expression of the 1.5 kb mRNA was detected. The prevalence of the 1.8 kb complement factor H mRNA leads to the speculation that the predominant factor H form biosynthesized in lung tissue is a truncated form of the factor H molecule.

Blotting, Northern↗

PubMed1989

Truncated forms of human complement factor H.

By the use of Western-blot analyses with polyclonal anti-(Factor H) antibodies, two low-Mr protein species of Mr 41,000 and 37,000 under non-reducing conditions and 43,000 and 40,000 under reducing conditions are consistently detected together with the well-known 155,000-Mr Factor H in human plasma and serum. These two additional species are also found in plasma, urine and synovial fluids. The 41,000-Mr species but not the 37,00-Mr species is detected by a monoclonal anti-(Factor H) antibody directed at the N-terminal part of Factor H. The 37,000-Mr species but not the 41,000-Mr species is detected by a monoclonal anti-(Factor H) antibody directed at the C-terminal part of Factor H. The 41,000-Mr and 37,000-Mr species are different from the well-characterized 36,000-Mr N-terminal tryptic fragment of Factor H. They are likely to represent translational products of the short Factor H mRNA species of 1.8 kb and 1.2-1.5 kb occurring in human liver that we have recently described.

Antibodies, Monoclonal↗

PubMed1989

Membrane-associated complement factor H on lymphoblastoid cell lines Raji expresses a co-factor activity for the factor I-mediated cleavage of C3b.

Evidence of factor H was found on the surface of Raji cells derived from two different lines; a 150,000 MW species identical to 150,000 MW plasma factor H was detected. Rosette experiments performed at physiological ionic strength using EAC3b or EC3b were negative. In contrast, Raji cells expressed a co-factor activity in the factor I-mediated cleavage of fluid-phase C3b. This activity was cell number dependent and was inhibited by anti-factor H but not by anti-CR1. Raji cells did not secrete factor H in the extracellular medium.

B-Lymphocytes↗