Biomedical subjects
N Baumann
Publications and source records attributed to N Baumann.
[The biochemistry of cerebral aging in man and in experimental models (author's transl)].
The biochemistry of cerebral aging in man is very little known. Two theories form the basis of current studies: the purely genetic theory and the catastrophic error theory (which explains senescence by a series of errors affecting protein synthesis). Whatever the mechanisms envisaged, they result in abnormalities in the biochemical structures of membranes and of cellular metabolism. However, senescence is not a chance phenomenon and certain regions, certain circuits, certain cells and certain metabolisms are more resistant than others. Cholinergic and catecholaminergic pathways are affected more than GABAergic and serotoninergic pathways. The substratum of the morphological lesions seen during senescence is poorly understood. Neurofilaments arranged in spirals characteristic of neurofibrillary degeneration have been isolated and partially analysed. There is no animal model which reproduces all the morphological changes seen in man. However, certain biochemical, structural and metabolic changes are sufficiently well reproduced in rodents in which changes in catecholamine would also seem to exist.
Allelism of two myelin deficiency mutations in the mouse.
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Transplantation of CNS fragments into the brain of shiverer mutant mice: extensive myelination by implanted oligodendrocytes. I. Immunohistochemical studies.
Solid fragments of olfactory bulb from new-born normal (B6CBA and C57BL6) mice were implanted into new-born shiverer (shi/shi) brains. The shiverer mouse being characterized by the absence of myelin basic protein (MBP), myelination due to implanted oligodendrocytes can be detected in the shiverer brain using an antiserum anti-MBP. Observation of sagittal sections of the host brains revealed very extensive areas of normal myelination from the level of the graft (rostral thalamus) up to the caudal brain (diencephalon, cerebellum, pons). Thus, oligodendrocytes contained in the implant migrate out of the graft over long distances in the host brain, before they differentiate and synthesize myelin. These results raise the question of the behaviour of oligodendrocytes in normal development.
[Assays of arylsulfatase activity in psychotic patients. Review of the literature and results of a study of 22 patients].
After a clinical and biological description of arylsulfatase A and metachromatic leucodystrophy, we present the results of a study of leucocyte arylsulfatase A in a population of 22 adult psychotic inpatients. The patients, clinically defined, filled the criteria of DSM III of schizophrenic disorders. All of them were treated by neuroleptics. None of these 22 patients showed a level of arylsulfatase A different from the range of 27 healthy adult controls. These results differ from those of most precedent studies of arylsulfatase A in "psychiatric populations". Some explanations of this difference are suggested. The concept of "purely psychiatric" form of adult metachromatic leucodystrophy is discussed.
[Review on the properties of glial cells of the central nervous system (author's transl)].
During the past 15 years, increasing studies have been devoted to glial cells, i.e. oligodendrocytes, astrocytes and microglial cells of the central nervous system. Although most of their functions remain mysterious, the concept of intracellular interactions between neurons and neuroglia becomes more and more substantiated. This review describes some aspects of phylogeny of glia, recent technical approaches to the study of these cells, their major morphological and biochemical characteristics, their maturation as well as their pathology.
[Study of 5-hydroxy-indol-acetic acid in amniotic fluid during pregnancy].
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[Toxic nervous pathology: biochemistry of myelin and demyelinizing conditions].
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[Outlooks offered by lysosomal enzyme determination in neuropediatrics].
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[Evaluation of the degree of malignancy of human gliomas by means of the determination of their GFA content (author's transl)].
The quantitative immunochemical determination of the GFA protein in a large number of brain tumors has shown a correlation between the malignancy of a glioma and its content in GFA. This dosage should help to establish the diagnosis, in addition to routine histological examinations. Its prognostic interest is currently debated.
[Interest of ganglioside analysis in the neuroblastoma (author's transl)].
As suggested by Hakomori, one of the mechanisms to explain the abnormal proliferation of tumor cells by loss of contact inhibition could be a modification of membrane gangliosides. We report here a case of neuroblastoma with opsomyoclonia in which the ganglioside profile is abnormal, with a high level of GP3 and GM2, and of other gangliosides which are not present in normal child and adult brains.
[Perhexiline maleate induces sphingomyelinase deficiency in man].
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Neurological mutations affecting myelination in the central nervous system.
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