IgA multiple myeloma presenting as Henoch-Schönlein purpura/polyarteritis nodosa overlap syndrome.

We report the unusual case of a man with a 5-year history of relapsing Henoch-Schonlein purpura (HSP) and macroscopic polyarteritis nodosa (PAN) as early manifestations of IgA kappa multiple myeloma. The glomeruli contained monoclonal IgA kappa deposits, without other immunoglobulins or lambda light chains. Glomerular deposits lacked the usual electron density but could be demonstrated by immunoelectron microscopy.

Commitment to erythroid or granulocyte-macrophage differentiation is associated with loss of macromolecular insoluble cold globulin.

In mice a macromolecular insoluble cold globulin (MICG) is present on the surface of resting and stimulated peripheral T lymphocytes, thymocytes, fetal prothymocytes and hemopoietic stem cells forming spleen colonies, colony-forming unit-spleen (CFU-S). Here we demonstrate that removal of MICG positive cells from bone marrow by treatment with antibody and complement does not affect the number of erythroid, burst-forming unit-erythroid (BFU-E) and granulocyte-macrophage, colony-forming unit-granulocyte macrophage (CFU-GM) progenitors developing in vitro. Thus, commitment of stem cells to lineage specific differentiation is associated with the loss of the MICG marker.

Effect of removal of the zona pellucida on subsequent development of mouse blastocysts in vitro.

Removal of the zona pellucida allowed mouse blastocysts incapable of hatching in vitro to develop in culture. Blastocysts denuded by pronase always developed further than those of identical age that had hatched spontaneously. More blastocysts mechanically denuded and treated with pronase developed egg cylinder-like structures than did blastocysts mechanically denuded and not treated with pronase.

Ultrastructural study of concanavalin-A binding to the surface of preimplantation mouse embryos.

Receptors for Con-A were labelled (using the peroxidase-diaminobenzidine technique) on the plasma membrane of unfertilized and fertilized mouse eggs, cleavage stage embryos, trophoblast and inner cell mass (ICM) of the blastocyst. Embryos were exposed to Con-A concentrations of 10 microgram/ml, 50 microgram/ml, or 1,000 microgram/ml and the lowest concentration was observed to be the most suitable for discerning differences between stages of embryonic development. On the surface of unfertilized and fertilized eggs and 2-cell embryos, reaction product appeared as a thin, discontinuous layer.