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Biomedical subjects

B Geny

Publications and source records attributed to B Geny.

88 records · Page 5Linked to original sources
PubMed1979

[Purification of a membrane protein modifying the sensitivity of Na+/K+ ATPase to ouabain from a supernatant of plasma membrane treated with EDTA].

A membrane protein of M. W. 32,000 D and pI 5 has been purified from EDTA-treated plasma membrane supernatants by Page without detergents. These membranes are purified from the MF2S cell line issued from the murine plasmacytoma MOPC 173. The purified protein was able to induce a 300 fold increase in the Na+/K+ ATPase resistance to ouabaïn thus mimicking the original resistance of the enzyme to the drug.

Animals↗
PubMed1979

Immunoelectron-microscopic localization of immunoglobulin A and secretory component in jejunal mucosa from children with coeliac disease.

Using peroxidase-labelled antibodies, the ultrastructural localization of IgA and secretory component (SC) was investigated in duodeno-jejunal biopsies from six children with coeliac disease and compared with that observed in non-coelic mucosa. In normal intestinal mucosa this study confirmed the presence of IgA in the rough endoplasmic reticulum and the perinuclear space of numerous subepithelial plasma cells and one the lateral cell membranes of villous and especially crypt epithelial cells. SC was only detected in the epithelium and principally in crypt epithelium where it was identified in endoplasmic reticulum, Golgi saccules, perinuclear spaces and on lateral cell membranes. These findings support the suggestion that SC is synthesized mainly in crypt epithelium and acts as a receptor on epithelial cell membranes for dimeric IgA. In untreated coeliac patients, SC was observed at the same sites, but SC staining was reduced in damaged surface epithelial cells. The number of IgA immunocytes was increased and heavy deposits of IgA were found on basement membranes. In post-treatment biopsies, no abnormality was apparent. After re-exposure to gluten, depositions of IgA on basement membranes were the only early change. The unaltered distribution of SC and IgA in crypt epithelium strongly suggests that the epithelial transport mechanism of secretory IgA is normal in coeliac disease.

Basement Membrane↗
PubMedDate not supplied

Immunocytochemical localization of vitamin D-dependent calcium-binding protein in the yolk sac of the rat.

The yolk sac from normal pregnant rats contains a vitamin D-dependent calcium-binding protein (CaBP). To localize CaBP within the yolk sac, a rabbit antiserum specifically directed against purified rat CaBP, in indirect immunofluorescence and immunoperoxidase, has been used. Using yolk sac sections, positive reactions indicative of the presence of CaBP were found only in the endodermal cell layer. A method for isolation of pure endodermal cells, using EDTA treatment, was developed. On smears of isolated endodermal cells exposed to anti-CaBP antiserum, CaBP was distributed throughout the endodermal cytoplasm; no CaBP was detected in the nucleus. Our results suggest that the endodermal cells, which are functional absorptive cells of the yolk sac, may play a role in vitamin D-mediated processes.

Animals↗