PubMed Health⌕ Search

Biomedical subjects

S Pollet

Publications and source records attributed to S Pollet.

12 recordsLinked to original sources
PubMed1979

Analysis of the major lipid classes in human peripheral nerve biopsies. Age group differences and abnormalities of ganglioside level in perhexiline maleate therapy.

We report here the results of a simple and reproducible technique which can be used in semi-routine analysis of peripheral nerve biopsy specimens, so as to have a quantitative analysis of the major lipid classes, i.e. cholesterol, cerebrosides, ethanolamine phospholipids, phosphatidyl-choline, phosphatidyl-serine + phosphatidylinositol, sphingomyelin and gangliosides. Glycolipid hexoses, cholesterol and total phospholipids have been compared in different age groups. Although all lipid classes increased from the younger to the older age group, the molar ratio of cholesterol to phospholipid differed less than the glycolipid to phospholipid ratio. Both increased significantly, even between age group 10--16 and older patients (36, 54, 61, 68, 72 and 73 years old). Although individual variations in lipid content are noteworthy, it must be emphasized that evolution with age of the lipid composition must be taken into account. Furthermore, this study confirms and extends earlier findings of increased ganglioside levels in some cases of peripheral neuropathies observed during perhexiline maleate therapy where characteristic lipid-like polymorphous inclusions have been demonstrated.

Adolescent↗
PubMed1979

Bismuth intoxication: bismuth level in pig brain lipids and in subcellular fractions.

Experimental intoxications of pigs were performed. It seems to be confirmed that bismuth crosses the blood-brain barrier. An organic derivative, trivinyl-bismuth, is more active than the inorganic salt of bismuth. In the brain, bismuth is preferentially found in synaptosomes. Bismuth is found in brain lipids of control pigs at very low levels. In intoxicated pigs, the level of bismuth is increased mainly in cerebellum and then in thalamus. Bismuth is partly associated to lipids. There is not a correlation between the level of bismuth in blood and in brain lipids. However, in the trivinyl intoxicated pig, a high level of blood bismuth is concomittant to a high level of brain lipid bismuth. The high content of this metal in cerebellum lipid extract may be of functional significance.

Animals↗
PubMed1978

[Diffuse polymorphous inclusions in a patient treated with perhexiline maleate (author's transl)].

Case report of polyneuritis and liver dysfunction induced by perhexiline maleate in a 64 years old male patient. The ultrastructural study of nerve, liver, muscle and skin biopsies shows polymorphous, membrane bound, often multilamellar, lysosome-like inclusions, the content of which is probably complex lipids. The histochemical study of liver reveals a lipid storage, consisting mainly of triglycerides and of smaller amount of phospholipids and free fatty acids, the pattern of which is abnormal. The biochemical study of nerve tissue shows a decrease of phospholipids levels and some qualitative disturbances in gangliosides. These changes, some of which are similar to those reported in amphiphilic drug intoxications, are prevalent in high lipid metabolism cells such as hepatic and Schwann cells.

Biopsy↗
PubMed1978

[Neurological disorders and perhexiline maleate therapy. Clinical study of 10 cases. Neuropathological, pharmacocinetic and biochemical studies (author's transl)].

Ten new cases of perhexiline induced peripheral neuropathies are reported. The authors emphasize the possible association of other neurological disorders: cerebellar symptoms in one case, complex tremor in two other cases, marked decrease of photomotor reflexes in one case and disgeusia in another one. The pharmacocinetic study of 4 cases revealed the presence of a low metabolism of the drug in one of them. Polymorphous inclusions have been seen in Schwann cell and endothelial cell cytoplasm in the three patients with electron microscopic study of the nerves. The pathological study of one case showed the demyelination of spinal cord posterior columns. In another case, who died from hepatic coma, the biochemical study of cerebral lipids revealed the low values of cerebrosides and sulfatides in cerebellum and cerebral white matter.

Cerebellar Diseases↗
PubMed1978

Microanalysis of brain lipids: multiple two-dimensional thin-layer chromatography.

The techniques described allow the quantitation of cholesterol, cerebrosides, sulfatides, ethanolamine phospholipids, phosphatidylcholine, -serine, -inositol, and gangliosides on 500 micrograms of lipid. Lipid extraction required sonication. Separation of the lipid classes was performed on TLC glass plates (10 x 10 cm) coated with silica gel HPTLC 60 F 254 Merck using one multiple two-dimensional chromatography. Most of the methods used for quantitation were standard methods that had been scaled down. The procedure was applied to study regional differences in the central nervous system, to analyze cell membranes or subcellular particles, or to analyze pathological biopsies in the central and peripheral nervous systems.

Animals↗
PubMed1977

Myelin consists of a continuum of particles of different density with varying lipid composition: major differences are found between normal mice and quaking mutants.

Mouse brain myelin consists of a continuum of particles of different densities, as shown by sucrose density gradient centrifugation. In normal animals most of the material (65 per cent) is concentrated between 0.6 and 0.7 M sucrose (the maximum being found at 0.66 M sucrose, corresponding to 23 per cent). The density differences among various myelin fractions are related to their protein/lipid ratios, as lighter fractions contain less protein and more lipid. Lipid analysis shows a decrease in the amount of every lipid from the lightest to the heaviest fraction: the light fraction is richer in phosphatidyl-ethanolamine, phosphatidyl-serine and cerebrosides. The distribution is highly abnormal in purified myelin from Quaking mutant ; very low quantities of myelin with normal density are found, but unexpected large amount of high density particles are found, possibly related to a "pre-myelin" material (oligodendrogial) processes which are not maturing into normal myelin).

Animals↗
PubMed1976

[Mouse brain gangliosides during development: demonstration of a new ganglioside].

The study of gangliosides as a function of age indicates that four of the main components GD1a (G3), GD1b (G2), GT1 (G1) and GQ (G0) are present at birth. They increase with age. On thin-layer chromatography, GD1a seems to be maximum at 18 days and GD1b continues to increase. GM1 increases also from birth to adult age. A new ganglioside has been detected in Mouse brain during its development. Not detected 5 days after birth, it is present at 18 days and in maximal quantity at adult age. This compound does not seem to be correlated to myelination process.

Age Factors↗
PubMed1975

[Substrates and products of fatty acid elongation in mouse brain microsomes].

In brain microsomes, palmitate and stearate elongation involve a membrane lipid-bound substrate. After elongation by malonyl-CoA, acyl-products are partially bound to proteins. Acyl-proteins are not found when endogenous fatty acid elongation takes place. In the dysmyelinating Quaking mouse mutants, "stearyl-membrane" substrate formation is normal; thus, the deficiency observed in very long chain fatty acid formation is not due to a lack in substrate formation.

Animals↗