Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0026764 (multiple myeloma)
 36,148 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Human colostral IgA and myeloma dimer IgA were purified and examined in the electron microscope using a modified technique of negative staining. Both types of preparation contained double Y-shaped structures of the dimensions: Fab region, 35 x 70 A, and the sum of the two Fc regions, 40 x 140-155 A. Colostral IgA as well as myeloma dimer IgA molecules showed a tendency of bending at the point where the Fc regions joined. Secretory component bound to dimer IgA produced no visible alteration of the molecule. Mild reduction and alkylation of colostral IgA yielded single Y-shaped 7S monomers with the dimensions, Fab, 35 x 70 A, and Fc, 40 x 65-70 A.
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PMID:Further studies on the ultrastructure of dimeric IgA of human origin. 499 63

Secretory component (SC) in myeloma serum was measured by a double antibody radioimmunoassay. It was elevated in patients with IgA myeloma and the highest level was observed in a patient with macroglobulinemia. The presence of disorders of secretory surface in myeloma patients slightly but not significantly elevated the serum SC concentration. A significant correlation between serum SC and IgG is demonstrated, but not between serum SC and IgA. Over the whole patient groups, serum SC is significantly related to serum IgM but not when patients with macroglobulinemia are excluded from the calculation. Serum SC is present as SC-IgM in macroglobulinemia and SC-IgM and SC-IgA in IgA myeloma.
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PMID:Serum secretory component level in myeloma patients with disorders of the secretory surface. 676 40

It has been proposed that polymeric IgA is translocated from plasma to bile across hepatocytes of the rat liver by a secretory component-mediated, vesicular transport. To define the ultrastructural details of the proposed transport mechanism, we employed peroxidase-labeled antibody immunocytochemistry to localize secretory component in the rat liver and monitor the hepatic translocation of homologous myeloma polymeric IgA infused i.v. Secretory component was found associated with the endoplasmic reticulum, Golgi complexes, cytoplasmic vesicles, and plasma membranes of the sinusoidal and canalicular surfaces of hepatocytes; secretory component at the sinusoidal surface was most prominent in micropinocytic invaginations or pits. Livers were examined for the sites of polymeric IgA 5, 15, and 30 min after infusion. Evidence was obtained that polymeric IgA is translocated across hepatocytes by a series of events: 1) polymeric IgA binds selectively to secretory component on the external surface of the sinusoidal plasma membrane; 2) secretory component-IgA complexes are internalized in endocytic vesicles; 3) the vesicles migrate through the cytoplasm without association with lysosomes or Golgi complexes; 4) the vesicles fuse with the cytoplasmic surface of the bile canalicular membrane, where secretory component-IgA complexes are released into bile by exocytosis.
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PMID:Ultrastructural events in the translocation of polymeric IgA by rat hepatocytes. 705 34