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Biomedical subjects

P Mandel

Publications and source records attributed to P Mandel.

At least 415 records · Page 23Linked to original sources
PubMed1977

Purification and properties of rat brain succinic semialdehyde dehydrogenase.

Succinic semialdehyde dehydrogenase from rat brain has been purified to electrophoretic homogeneity. It has a molecular weight of about 140, 000 and is composed of two apparently identical subunits. The reaction catalized by the pure protein is entirely dependent on endogenous --SH groups. The Kim (limits) for NAD and succinic semialdehyde are 2 X 10(-5) M and 1 X 10(-4) M respectively at the optimum pH of 8.6. Inhibition studies show that the reaction mechanism is a compulsory ordered on where NAD binds first followed by succinic semialdehyde.

Aldehyde Oxidoreductases↗
PubMed1977

Essential fatty acid metabolism in cultured astroblasts.

The fetal calf serum on which two astroblast cell lines were grown was shown to be deficient in essential fatty acids. The fatty acid profiles of lipids of these two cell lines showed very low amounts of polyunsaturated fatty acids. In order to know if this low level of unsaturation was due to the lack of essential fatty acids in serum, or to a lack of desaturase activities in the cells, we have investigated the modifications of the cell lipid fatty acid patterns when serum was enriched in essential fatty acids. Linoleic acid was incorporated in rather high amounts in the cell lipids, while linolenic acid was very poorly incorporated. These two essential fatty acids were converted into polyunsaturated fatty acids only when they were added alone to the serum. Both cell clones exhibited a lack in the delta 4 desaturase activity. No morphological changes of the cells occured after nine days of culture with modified serum.

Astrocytes↗
PubMed1977

[Experimental nephrotic syndrome in the rat. Biologic parameters and study of several hydrolases in different purified kidney fractions].

The induction of nephrotoxic nephritis in rats with rabbit antibodies preparation results in proteinuria, hypoproteinemia and hyperlipidemia with little glomerular lesions. A study of some hydrolases in cortex and medulla on one hand and glomerular and tubules on the other, showed changes in the activities of following enzymes. 1) A 20-30 % decrease in Na+, K+ dependent ATP-ase in whole kidney. 2) A 20 % decrease in beta-galactosidase activity in glomerular and medulla. 3) A 20 % increase of arylsulphatase A activity in tubules. These results are discussed in the light of the present knowledge of sulphatide metabolism in kidney.

Animals↗
PubMed1977

[Effect of differentiation of GABA levels in various cell cultures].

The effect of factors inducing somatic differentiation on cellular GABA level has been investigated. C6 glial cells from a rat astrocytoma present a significantly higher GABA level than the other glial or neuronal cells studied. A significant decrease in GABA levels in most cases parallels the somatic differentiation induced either by withdrawal of fetal serum, or by addition of dibutyryl cyclic AMP to the culture medium.

Aminobutyrates↗
PubMed1977

Recent developments in the biochemistry of globoid and metachromatic leucodystrophies.

Galactosylceramides and their sulphates are the main constituents of myelin sheath of the nerve cell. Two genetically determined disorders are the results of an inability to enzymatically hydrolyse these glycolipids. Thus the deficiency of galactosylceramide beta-galactosidase results in globoid cell leucodystrophy and the reduced activity of enzyme, arylsulphatase A is responsible for the disease Metachromatic leucodystrophy. Both these disorders are fatal and are characterized by marked demyelination and severe mental retardation. Since homognenous enzyme preparations of galactosylceramide beta-galactosidase and arylsulphatase A are now available, a possibility of enzyme replacement therapy in globoid and metachromatic leucodystrophies has been discussed.

Brain↗