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Biomedical subjects

S Shall

Publications and source records attributed to S Shall.

At least 91 records · Page 5Linked to original sources
PubMed1979

The significance of antibodies to poly(adenosine diphosphate-ribose) in systemic lupus erythematosus.

Poly(adenosine diphosphate-ribose) and ds-DNA binding activity have been measured in thirty-nine systemic lupus erythematosus (SLE) sera, nineteen rheumatoid arthritis sera, fourteen sera from non-SLE rheumatic and non-rheumatic diseases and in ten normal sera. Antibodies to poly(ADP-ribose) were found only in the SLE and in three SLE-like rheumatic diseases. Anti-DNA antibodies, on the other hand, were found not only in the SLE and SLE-like diseases, but also in rheumatoid arthritis and chronic active hepatitis. Estimation of poly(ADP-ribose) binding was, therefore, more specific for, and more discriminatory of SLE from other diseases, than the estimation of ds-DNA binding. The results indicate that the estimation of poly(ADP-ribose) binding in serum may be more useful in the diagnosis of SLE than the presently employed estimation of DNA binding using the Amersham kit. DNA-anti-DNA immune complexes are detected in some of the SLE sera after deoxyribonuclease I digestion, confirming earlier reports of the existence of circulating DNA-anti-DNA complexes in SLE patients. Snake venom phosphodiesterase treatment of some of the SLE sera also resulted in increased poly(ADP-ribose) binding activity, suggesting the existence of poly(ADP-ribose)-anti-poly(ADP-ribose) immune complexes in the circulation of SLE patients. This observation raises the possiblity that poly(ADP-ribose) immune complexes may play some part in the pathogenesis of some cases of SLE.

Antibody Specificity↗
PubMed1978

The effect of gamma radiation and neocarzinostatin on NAD and ATP levels in mouse leukaemia cells.

When mouse leukemia cells are treated with gamma-radiation or neocarzinostatin the intracellular NAD and ATP levels fall rapidly. We have shown that the ATP response is a consequence of the decreased NAD level. We suggest that this low NAD level results in decreased glycolytic activity and that there is a subsequent accumulation of phosphorylated sugars associated with the fall in ATP. Under these extreme conditions, therefore, the NAD level probably regulates the rate of glycolysis in cells which are utilising a rapidly metabolisable sugar as their energy source.

Adenosine Triphosphate↗
PubMed1978

Purification and properties of poly(ADP-ribose) polymerase from pig-thymus nuclei.

The nuclear enzyme poly(ADP-ribose) polymerase has been purified about 9200-fold from pig thymus nuclei with a 46% yield. An aqueous organic solvent system was used for the isolation of the polymerase from nuclei and for its purification by chromatography at sub-zero temperatures. Electrophoretic analysis under both denaturing and non-denaturing conditions revealed a single protein band suggesting that the preparation was homogeneous and that the enzyme is composed of one polypeptide chain. The molecular weight estimated from sodium dodecyl sulphate-/polyacrylamide gel electrophoresis was 63 500 and from gel filtration through columns of Sephadex G-100, 58 000. The enzyme preparation was free from poly(ADP-ribose)-degrading enzymes and from DNA. The purified polymerase showed an absolute requirement for both DNA and histones. The maximal specific activity of the homogeneous preparation measured by the standardized assay, was 20.7 mu mol NAD+ incorporated x min-1 x mg-1 of protein at 37 degree C. Amino-terminal group analysis with dansyl chloride did not reveal a terminal amino acid suggesting that the amino-terminal group may be blocked. In the presence of histones, the Km for NAD+ was 23 micrometer.

Animals↗
PubMed1977

Effects of dolichol monophosphate on galactose incorporation into glycoconjugates of cell cultures.

Cultured-cell homogenates catalysed the incorporation of galactose from UDP-galactose into protein and sphingolipid acceptors. Dolichol monophosphate stimulated the incorporation of galactose into glycoproteins, but it did not affect the rate of glycosylation of either exogenous or endogenous glycosphingolipids. It is proposed that, under certain conditions, galactose may be incorporated into glycoproteins via polyisoprenol intermediates, as is the case with N-acetylglucosamine and mannose.

Clone Cells↗
PubMed1976

The effects of detergents and phospholipids on a glycolipid galactosyltransferase.

1. Phospholipids activated the enzyme, lactosylceramide: UDP-galactose alpha-galactosyltransferase in hamster cells (NIL 2E clone 8) when assayed in the presence of neutral detergents. 2. Phosphatidylserine and phosphatidylinositol were the most effective phospholipids in activating the enzyme. Other phospholipids were also effective, but sphingomyelin and lysophosphatidylcholine were inhibitory. 3. Considerable enzyme activity was obtained in the absence of any detergent. Most of this activity was due to glycosylation of endogenous acceptors. 4. There was a complex effect of detergents on the enzyme activity. Very low concentrations were sharply inhibitory, but higher concentrations, above the critical micelle concentration for detergent, caused regeneration of activity. 5. The phospholipids, in the absence of a detergent, are required to maintain the lipid substrate, lactosylceramide, in a suitable dispersion where it can be acted upon by the enzyme. In the presence of detergents, it is proposed that the phospholipids also act by affecting the state of the lipid substrate.

Cell Line↗