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Biomedical subjects

M Seligmann

Publications and source records attributed to M Seligmann.

At least 163 records · Page 9Linked to original sources
PubMed1972

Anti-human immunoglobulin G activity of membrane-bound monoclonal immunoglobulin M in lymphoproliferative disorders.

Lymphocytes from a patient with Waldenström's macroglobulinemia and known anti-immunoglobulin IgG activity of serum monoclonal IgM and lymphocytes from selected patients with chronic lymphocytic leukemia were studied by the membrane immunofluorescence procedure. Freshly drawn lymphocytes were shown to bear simultaneously mu, gamma, [unk], and lambda chain determinants. Experiments combining redistribution induced by antibody and double labeling proved that IgG was bound to surface IgM. After removal of surface immunoglobulins by treatment with trypsin followed by incubation in culture medium, or after redistribution induced by antibody, the exclusive presence of a newly synthetized monoclonal IgM was demonstrated. Several experiments showed that this surface IgM does specifically bind normal human IgG molecules devoid of aggregated material. The IgG molecules could be removed from the cell surface by lowering the pH. In addition to its high incidence among serum monoclonal macroglobulins, anti-IgG activity of membrane-bound monoclonal IgM is not uncommon in patients with chronic lymphocytic leukemia, a disease that provides homogeneous populations of lymphocytes derived from bone marrow, with receptor sites of defined antibody activity.

Cell Membrane↗
PubMed1972

Immunoglobulins on the surface of lymphoid cells in Waldenström's macroglobulinemia.

Immunofluorescence study of viable and fixed cells was performed on marrow and blood samples from 25 patients with Waldenström's macroglobulinemia. Whereas intracytoplasmic staining for IgM was restricted to the plasma cells and to a limited number of lymphocytic cells, the vast majority of the pleomorphic "lymphoid" proliferating cells in the marrow were shown to bear the monoclonal IgM on their surface. All IgM-secreting plasma cells displayed membrane positivity. Most lymphocytic proliferating cells carried the monoclonal IgM on their surface in the absence of detectable amounts of intracytoplasmic IgM. Despite the usual absence of increase in blood lymphocyte counts, a large number of circulating lymphocytes were shown to bear membrane-bound monoclonal IgM in patients with active disease. The number of fluorescent spots, their size and brightness varied greatly from cell to cell in marrow and blood samples of a given patient, and this finding is in contrast to the homogeneous fluorescent pattern observed in chronic lymphocytic leukemia. The data suggest that macroglobulinemia represents the proliferation of a clone of B cells which continues to mature and differentiate.

Bone Marrow↗