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H Debray

Publications and source records attributed to H Debray.

At least 55 records · Page 3Linked to original sources

[The plasma membrane glycoconjugates of normal and transformed cells (author's transl)].

After having reviewed the importance of glycoconjugates in the organisation of the cell membrane and the multiple roles played by these membrane constituants, the disorders characteristics of malignant transformation are described : First, the changes affecting cellular properties (diminution of cellular adhesivity, abolition of the control of cell growth, disturbance of membrane permeability...) and second, the modifications concerning the glycoconjugates of the cell surface in the course of malignant transformation : alterations affecting membrane glycolipids and glycoproteins. It appears that certain modifications of glycannic structures of membrane glycoproteins, for whatever cell type and transforming agent, seem at the moment to constitute the only abnormality permanently associated with the tumorigenicity of malignant cells.

Animals↗

Isolation and characterization of surface glycopeptides from adult rat hepatocytes in an established line.

The fractionation of glycopeptides isolated from the surface of an established line of adult rat hepatocytes, after 48 h metabolic labeling with [14C] glucose leads to the demonstration of the presence of two types of glycopeptides: i) O-glycopeptides containing N-acetylneuraminic acid, galactose and N-acetylgalactosamine, ii) N-glycopeptides with mannose, galactose, N-acetylgluosamine, fucose and N-acetylneuraminic acid. The former yield, by alkaline reductive degradation, a trisaccharide: sialyl-galactosyl-N-acetyl-galactosaminitol, a tetrasaccharide : di-sialyl-galactosyl-N-acetyl-galactosaminitol and a small amount of the disaccharide: galactosyl-N-acetyl-galactosaminitol. The latter are alkali-stable and can be divided by ion-exchange chromatography on DEAE-cellulose into i) acidic glycopeptides, not retained on a Concanavalin A-Sepharose column and belonging to the N-acetyllactosaminic type glycopedtides and ii) neutral glycopeptides which can be further fractionated on the Con-A-Sepharose column into non-retained glycopeptides belonging to the N-acetyllactosaminic type, and glycopeptides retained on the Sepharose-Con A column, containing only N-acetylglucosamine and mannose residues and related to the oligomannosidic type glycopeptides.

Animals↗

[Systematized papulosis of the lower scapular areas with ultrastructural anhist bodies: specific cutaneous symptoms of Hunter's disease (author's transl)].

Papulosis of the scapular areas is a characteristic dermatologic sign of Hunter's disease. It has not been described in the other mucopolysaccharidoses. This sign had been detailed by Hunter in 1917 in his princeps observation. We noted it in two cases of the disease. The ultrastructural study showed an accumulation in the connective interstitial substance of anhist bodies of intra-cellular origin.

Child↗

[Menkes' disease (new skin and hair ultrastructural abnormalities) (author's transl)].

The authors report the sixth case of Menkes' kinky hair disease. This boy has been observed for as long as 16 months, and he his still alive at the time of publication. This genetic, X linked disorder of copper metabolism is always fatal in childhood. Diagnosis is evoked when is noted the conjunction of progressive cerebral degeneration, seizures, with pili torti and monilethrix. It can be asserted with the very low copper and cerulo-plasmin blood levels. Recognition of the disease in utero might be possible. New findings in skin' electron microscopy and hair' scanning electron microscopy are reported here. And two RX scanner of the brain have been performed.

Brain Diseases, Metabolic↗

Rat alpha-fetoprotein heterogeneity. Comparative chemical study of the two electrophoretic variants and their Ricinus lectin-binding properties.

Two electrophoretic forms of rat alpha-fetoprotein were purified using immunosorbent chromatography and preparative electrophoresis on polyacrylamide gel slabs. Some of their respective chemical properties and their affinity for the Ricinus communis lectin (RCAI) were compared. Electrophoresis on polyacrylamide gradient gel in the presence of sodium dodecyl sulfate indicated a slight difference in molecular 74 000 for the slow alpha-fetoprotein (AFPA) and 72000 for the fat alpha-fetoprotein (AFPB). no significant difference in amino acid composition between AFPA and AFPB was found. A residue of valine was identified at the C-germinal end of both alpha-fetoproteins. The analysis of the CNRr-cleavage products reveals slight differences between AFPS and AFPB. The slow moving alpha-fetoprotein could be further fractionated on RCAI-sepharose column in two components, AFPA1 and AFPA2 differing by their sialic acid content.

Amino Acid Sequence↗

[A fibrogranular material on the cytoplasmic face of the cell membrane of Wistar rat liver cells adapted to established culture].

A fibrogranular material associated with the inner surface of the plasma membrane of adult Rat liver cells in long-term culture is described and studied. The electrophoretic pattern of the membrane indicates that this structure might contain actin. The filamentous material had not been observed in electron microscope preparations of cell surface membranes isolated from adult Rat liver.

Animals↗

Labeling of soybean agglutinin by oxidation with sodium periodate followed by reduction with sodium [3-H]borohydride.

Periodate oxidation of soybean agglutinin, a glycoprotein lectin, resulted in destruction of up to 5 out of the 9 mannose residues present in each of its subunits (MW 30,000) without any loss of hemagglutinating activity. The oxidation did, however, abolish the interaction of soybean agglutinin with concanvalin A, as measured by quantitative precipitation. Reduction with sodium [3-H]borohydride of soybean agglutinin in which 4 out of 9 mannose residues per subunit were oxidized, afforded a radioactive product which retained full hemagglutinating activity and was indistinguishable from the native lectin by gel filtration, gel electrophoresis, and affinity chromatography. These results establish that the integrity of the carbohydrate side chain of soybean agglutinin is not essential for the biological activity of the lectin, and suggest a general method for the preparation of radioactive glycoprotein lectins.

Borohydrides↗