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Biomedical subjects

E A Davidson

Publications and source records attributed to E A Davidson.

At least 109 records · Page 6Linked to original sources
PubMed1975

Properties of acidic saccharides produced by B16 melanoma cells treated with 1-methyl-3-isobutylxanthine.

A cyclic nucleotide phosphodiesterase inhibitor, 1-methyl-3-isobutylxanthine, promoted the differentiation and maturation of B16 melanoma cells, phenomena associated with biological alterations in the surface properties of the cells. 1-Methyl-3-isobutylxanthien inhibited cell replication and increased the intracellular content of melanin and cyclic adenosine 3':5'-monophosphate. Significantly greater amounts of sialoglycoproteins were associated with 1-methyl-3-isobutylxanthine-treated cells. However, the total amount of [3H] glucosamine incorporated into anionic polysaccharide (both sialoglycopeptide and mucopolysaccharides) was not significantly changed.

2',3'-Cyclic-Nucleotide Phosphodiesterases↗
PubMed1973

Production of mucopolysaccharides by normal and transformed cells.

The rate of hyaluronic acid and sulfated mucopolysaccharide production was measured for hamster embryo fibroblasts and for general oncogenic lines derived by virus transformation. A striking increase in both the rate of hyaluronic acid synthesis and the amount of cell-associated polymer was observed after transformation by herpes simplex type-2 or SV40 virus. Although no corresponding change was observed for the sulfated polysaccharides, the proportion of heparan sulfate increased significantly after transformation.

Animals↗
PubMed1972

Protein-polysaccharide biosynthesis. Membrane-bound saccharides.

Membrane-bound saccharides obtained from ear cartilage from rabbits recovering from papain injection were examined for glycosyl acceptor properties, alkali lability, molecular size and degree of sulphation. Although considerable glucuronosyl transfer from UDP-glucuronic acid could be demonstrated, less than one-third could be identified as representing chondroitin linkage formation; there was little or no effect of molecular size on acceptor properties. Approximately one-half of the membrane-associated chondroitin-like saccharide chains are solubilized by alkali, whereas one-half require proteolysis for solubilization. These fractions are analytically indistinguishable and both contain xylose and galactose as well as uronic acid and sulphated N-acetyl-galactosamine. All fragments that were examined contained stoicheiometric amounts of axial sulphate ester, strongly suggesting a close relationship between chain extension and sulphation.

Animals↗
PubMed1969

Effect of 5-bromodeoxyuridine on expression of cultured chondrocytes grown in vitro.

Exposure of cultured cartilage cells to 5-bromodeoxyuridine results in a rapid loss of the ability to synthesize the chondroitin 4-sulfate-protein complex characteristic of the extracellular matrix of differentiated cartilage. UDP-glucose dehydrogenase, UDP-N-acetyl hexosamine 4-epimerase and the enzyme system responsible for catalyzing 3'-phosphoadenosine-5'-phosphosulfate synthesis all progressively decline in activity, while several other cellular processes seem unaffected. However, there are marked morphological changes which may be associated with plasma membrane components or the synthesis of the protein-polysaccharide complex.

Bromodeoxyuridine↗