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Biomedical subjects

G Rebel

Publications and source records attributed to G Rebel.

At least 73 records · Page 4Linked to original sources
PubMed1977

Gangliosides of active and inactive neuroblastoma clones.

It is possible to divide neuroblastoma cells into clones able to synthesize neurotransmitters (active clones) or not (inactive clones). The analysis of gangliosides of active and inactive clones shows that their total lipid sialic acids is markedly lower than that of neuron-enriched fractions prepared from brain. The ganglioside pattern of the cultured cells also differs notably from those obtained with neuronal fractions from brain. The absence of tri- and tetrasialogangliosides and the presence of appreciable amounts of the simplest monosialogangliosides are particularly noticeable in the neuroblastoma. Morphological differentiation obtained by serum deprivation, dibutyryl cyclic AMP or bromodeoxyuridine does not restore a true neuronal pattern. Gangliosides could not therefore be used as a marker of neuronal differentiation in this type of cell. No correlations can be found between the ganglioside pattern and the ability of cells to synthesize neurotransmitters.

Bromodeoxyuridine↗
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

Glycosphingolipids from cultured astroblasts.

The glycolipids of two clonal lines astroblasts, NN clone and C6 clone, were studied. Glucosylceramide and lactosylceramide were present at very low levels in both clones, but the most common myelin glycolipids galactosylceramide and sulfatide, were not detected. The ganglioside pattern of these cells was rather simple, with GM3 as main compoenent, accompained in one clone by GD3. These results are quite different from those observed on astroglia-enriched fractions isolated from brain. The fatty acid composition of these glycolipids was studied. Long chain fatty acids, up to lignoceric acid, were found in appreciable amounts, even in gangliosides. It is difficult to conclude if these glycolipid patterns are due to the properties of normal astroblasts, to transformation, or to a tumoral character of our cell lines.

Astrocytes↗
PubMed1976

Arylsulphatase A and 2',3'-cyclic nucleotide 3'-phosphohydrolase activities in the brains of myelin deficient mutant mice.

Arylsulphatase A and 2',3'-cyclic nucleotide 3'-phosphohydrolase activities of myelin deficient mutant mice brains were studied. The results indicated that there were no changes in arylsulphatase A activity of the developing mutant brain, whereas the activity of 2',3'-cyclic nucleotide 3'-phosphohydrolase decreased considerably. The data obtained in this study suggest that in brain arylsulphatase A activity is localized in cells other than oligodendroglia.

2',3'-Cyclic-Nucleotide Phosphodiesterases↗