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Biomedical subjects

M Hadam

Publications and source records attributed to M Hadam.

47 records · Page 3Linked to original sources
PubMed1984

Analysis of mast cells in rheumatoid arthritis and osteoarthritis by an avidin-peroxidase staining.

As demonstrated by labeling with peroxidase, avidin was found to bind selectively and distinctly to mast cell granules. Inhibition studies suggested that avidin is bound by heparin. Based on this new mast cell staining procedure, mast cell distribution in the inflamed synovium of rheumatoid arthritis (RA) and osteoarthritis (OA) has been investigated. In the subsynovial layer, a significant decrease in mast cell numbers was observed in RA-synovium when compared with OA-synovium. This decrease correlated with the presence of lining cell ulcers and granulation tissue and can be interpreted as the result of mast cell degranuation induced by complement-mediated or immune complex-triggered mechanisms.

Arthritis, Rheumatoid↗
PubMed1982

Cloned human T-cell lines with allospecific or natural killer-like cytotoxicity.

Cloned human T-cell lines were produced by limiting dilution of lymphocytes alloactivated in mixed leukocyte cultures, followed by expansion of clonal progeny with interleukin 2. Selected clones were analyzed for cell-mediated cytotoxicity (CTX) against a variety of targets susceptible or resistant to lytic attack by natural killer (NK) cells. Clones with classical alloantigen-restricted lytic capacity for normal lymphoid targets were found to be distinct from those mediating natural killer-like CTX against NK-susceptible cell line targets. This was established by direct CTX assays and by cold target cross-competition experiments. Moreover, clones with NK-like activity displayed heterogeneous patterns of lysis on different target cell lines in direct CTX, suggesting a clonal distribution of receptors for NK-like target antigens amongst these cultured human NK-active T-cell clones.

Clone Cells↗
PubMed1981

A subset of human cells isolated and characterized by monoclonal antibodies.

Monoclonal antibodies were induced against leukemic T cells from a patient with chronic lymphocytic leukemia exhibiting natural killer (NK) activity. Two antibodies, termed T811 and M522, reacted by indirect immunofluorescence with distinct sub-populations of normal human mononuclear blood cells. The antibody T811 defines a surface antigen which is restricted to a subset of the T cell lineage. The antigen recognized by the second antibody, M522, is expressed on monocytes and polymorphonuclear leukocytes and, in addition, on 9-17% of nonadherent peripheral blood leukocytes (NAL). It is shown that the total NK activity of NAL is confined to the subset of cells expressing the M522-defined antigen. Moreover, the portion of NK cytotoxicity associated with T lymphocytes is mediated by a subpopulation which is characterized by the simultaneous expression of the T811- and the M522-defined antigens. This population comprises about 4% of NAL and could be isolated to a purity of greater than 85%.

Animals↗
PubMedDate not supplied

Distribution of mast cells in human synovial tissue of patients with osteoarthritis and rheumatoid arthritis.

Mast cells are demonstrated in synovial membranes of patients with osteo-arthritis and rheumatoid arthritis using a new staining principle based on interaction of heparin in mast cell granules with peroxidase labeled avidin. It was found that mast cell numbers in the subsynovial layer of patients with rheumatoid arthritis were significantly lower than those in patients suffering from osteo-arthritis. This decrease can be mainly attributed to patients with rheumatoid arthritis whose synovitis was characterized by a distinct histomorphological pattern consisting of lining cell ulcers and granulation tissue. However, when mast cell numbers in rheumatoid arthritis and osteo-arthritis patients were compared without respect to mast cell distribution in the subsynovial layer or the stratum fibrosum, no statistical differences between the diseases could be observed.

Arthritis, Rheumatoid↗