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Biomedical subjects

N Baumann

Publications and source records attributed to N Baumann.

At least 127 records · Page 7Linked to original sources
PubMed1981

Oligodendrocytes of jimpy mice express galactosylceramide: an immunofluorescence study on brain sections and dissociated brain cell cultures.

Brain sections and dissociated brain cell cultures of jimpy mouse (jp) were investigated for the presence of galactosylceramide (GC) by indirect immunofluorescence. Optic nerve and corpus callosum sections of 26-day-old jp exhibited many GC-positive cells. The GC staining pattern was similar in jp and normal cultures of the same age. These data suggest that the previously observed decreased amount of GC in jp brain is due to the inability of jp oligodendroglia to properly deposit GC in the myelin, while its synthesis is possible.

Animals↗
PubMed1981

[Neuropathy associated with ichthyosis and splenomegaly in an adult patient. Possible relationship with altered glycosphingolipid metabolism (author's transl)].

The authors report on the case of a 40-year-old woman presenting with ichtyosiform erythroderma, central and peripheral neuropathy, splenomegaly and low serum haptoglobin levels. The patient's blood and urine contained large amounts of various ceramides polyhexoside including, in particular, a ceramide tetrahexoside containing fucose. The possibility of a new form of sphingolipidosis is discussed.

Adult↗
PubMed1981

[Free and sulfo-conjugated dehydroepiandrosterone in the brain of mice with myelin biosynthesis disorders].

Dehydroepiandrosterone, either unconjugated (D) or conjugated to sulfuric acid (DS), has been identified in the brain of male Mice; DS had been previously found in Rat brain. DS amounts in posterior brain, were 0.8-2.0 ng/g in controls, and very much lower in dysmyelinic jimpy and quaking Mice of the same age. Conversely, amounts of D were increased in affected Mice, suggesting an impaired sulfoconjugation. Results may be explained by accumulation of D and DS in brain, unrelated to the endocrine system.

Animals↗
PubMed1981

Lipid analysis in nerve biopsy specimens of hypertrophic neuropathy.

We performed a lipid analysis on nerve biopsy specimens in two cases of degenerative hypertrophic neuropathy. Quantitative analysis of the major lipid classes, ie, cholesterol, cerebrosides, sulfatides, ethanolamine phospholipids, phosphatidyl-choline, phosphatidyl-serine, phosphatidyl-inositol, sphingomyelin, and gangliosides, were performed. The two cases exhibited extreme decreases in levels of lipids that could be related to the very low myelin content of these nerves. Cholesterol and phospholipid levels were especially reduced. Cerebrosides and sulfatides were not modified in the same proportion, as could have been predicted from the degree of demyelination. This relative glycolipid increase could be due to the very high Schwann cell proliferation.

Adolescent↗
PubMed1981

Lipid and lysosomal enzymes in human fibroblasts cultured with perhexiline maleate.

To understand the mechanism of the lysosomal lipid storage induced by perhexiline maleate, we performed simultaneous lipid analysis and lysosomal enzymes determinations. Human fibroblasts were cultured for 5 days in the presence of perhexiline maleate at a concentration of 2 micrograms/ml of culture medium. Lipid analysis showed that those non toxic levels determined the same changes as seen with higher concentrations of the drug (Hauw et al. 1980) i. e. increase of cholesterol and of all major phospholipids. Qualitative phospholipid pattern was not markedly changed. Lysosomal enzymes activities were not modified with the exception of sphingomyelinase which was reduced to 12% of its normal level.

Cells, Cultured↗
PubMed1981

Radioautographic evidence for the protracted proliferation of glial cells in the central nervous system of jimpy mice.

Proliferation of glial cells has been studied in the central nervous system of jimpy mice and control littermates with [3H]thymidine radioautography. It was found that the proliferation of glial precursors was protracted in the 3 regions studied: spinal cord, cerebellum and corpus callosum. The difference between jimpy and littermates became obvious in each of these regions at the onset of myelination. It is concluded that the maturation of the oligodendrocyte is the target of the mutation. The protracted proliferation of glioblasts is a consequence of the absence of stable interactions with the axons.

Aging↗
PubMed1981

Intrauterine growth retardation (malnutrition by vascular ligation) induces modifications in fatty acid composition of neurons and oligodendrocytes.

Intrauterine growth retardation (IUGR) induced by ligation of one uterine artery on day 17 of pregnancy in the rat lead to major abnormalities in the fatty acid content of neurons and oligodendrocytes but not in astrocytes. In neurons from IUGR rats, monounsaturated fatty acids were decreased; in the polyunsaturated series, omega-3 fatty acids were increased and omega-6 fatty acids were decreased. In oligodendrocytes, monounsaturated fatty acids were also decreased, but the modifications in polyunsaturated fatty acids were the opposite of those in neurons: omega-3 being decreased and omega-6 increased. Although the animals received a normal diet after birth, the alterations were still present in adulthood. In addition, fatty acid composition of brain cells is a very indicative criterion of brain maturation.

Aging↗
PubMed1981

Tricyclic antidepressants induce sphingomyelinase deficiency in fibroblast and neuroblastoma cell cultures.

Tricyclic antidepressants (imipramine and desipramine) gave rise to an important decrease of sphingomyelinase activity in murine neuroblastoma and human fibroblast cell cultures. It occurred within 1 to 2 hours at a final concentration of 1 or 2 X 10(-5) M in cell culture medium. Other lysosomal enzymes such as acid lipase, arylsulfatases A and B and hexosaminidases were not modified. Low level of sphingomyelinase activity may be related to the amphiphilic characteristics of the drugs: iminodibenzyle which has the same tricyclic core but is devoid of the side chain necessary for amphiphilic properties had no effect. As iminodibenzyle has no therapeutic action, amphiphilic may be requisite to antidepressant properties of tricyclic drugs.

Animals↗
PubMed1981

[Neurochemical data concerning glial tumors. Contribution of the estimation of the G.F.A. protein to the diagnosis and prognosis of gliomas (author's transl)].

The Glial Fibrillary Acidic (G.F.A.) protein is a specific component of the gliofilaments present in the astrocytes. Its immunochemical determination on tumor fragments obtained at surgery has permitted to draw clinico-biochemical correlations between the G.F.A. content of a glioma and its histological grade. The more a glioma is dedifferentiated, the lower is its content of G.F.A. This determination is a biochemical index of dedifferentiation. However, its pronostic value is not established yet.

Astrocytes↗
PubMed1981

Ganglioside content and pattern in tumor tissue of human neuroblastomas.

The ganglioside content and composition in human neuroblastomas was examined. The densitometric pattern corresponding to the thin-layer chromatography of gangliosides showed no major differences compared to normal brain in the GT area, and variable modifications for GM1 and GD3. The most striking and common features resided in the area corresponding to the disialogangliosides for which is was clear that existed a far more complex pattern than normal human brain.

Brain Neoplasms↗
PubMed1980

Antibodies to cerebroside sulfate inhibit the effects of morphine and beta-endorphin.

Morphine and beta-endorphin inhibit the shaking response of pentobarbital-anesthetized rats to ice water. Stereotaxically guided administration of antibodies to cerebroside sulfate into the periaqueductal gray region, the most sensitive brain region in which to demonstrate inhibition of this response, antagonizes the effect of morphine and beta-endorphin. These results suggest that cerebroside sulfate may be an integral component of an opiate receptor in rat brain.

Animals↗
PubMed1980

Accumulation of GFA, the monomeric precursor of the gliofilaments, during development in normal mice and dysmyelinating mutants.

Astrocytic reactivity during the myelination period in the mouse was studied with immunochemical method, ie, quantitative determination of the soluble pool of the GFA protein. There is normally a maximum content at the time of early myelinogenesis in any structure; then the GFA level decreases and finally keeps constant for a long period during the adult life. This evolutive pattern is also observed in the dysmyelinating mutant quaking, with a permanent shift toward higher values especially in areas of earlier maturation. In the jimpy mutant, practically devoid of myelin, the increase of GFA occurs but does not stop until death, at 25 days postnatal. This study points out 1) the capacity of astrocytes to synthesize surprisingly high amounts of soluble GFA at periods of intense metabolic activity, and 2) the reactivity of astrocytes in relation to the degree of deficiency of the myelinating oligodendrocytes.

Animals↗
PubMed1980

Perhexiline maleate-induced lipidosis in cultured human fibroblasts: cell kinetics, ultrastructural and biochemical studies.

Perhexiline maleate reduced the growth of human skin fibroblasts in cell culture at a concentration range of 0.3-3 micrograms/ml. At the highest concentration, the cells survived only four days. Pleomorphic inclusions characteristic of drug-induced phospholipidoses appeared in cultured cells. Analysis of the major lipid classes was performed on cells exposed to 3 micrograms/ml at four days. Gangliosides, phospholipids and cholesterol levels four to six times above controls were found. No major qualitative abnormalities were detected in phospholipids. On the contrary, an abnormal pattern of gangliosides was seen by densitometry of silica gel thin-layer plates with increases of GD3 and of an unknown ganglioside. Drug induced lipidosis may involve other lipids than phospholipids, particularly gangliosides.

Cell Division↗