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Biomedical subjects

C Tranchant

Publications and source records attributed to C Tranchant.

At least 73 records · Page 4Linked to original sources
PubMed1995

[Idiopathic Parkinson disease and mitochondrial functions].

Work on the molecular mechanisms of MPTP neurotoxicity have inspired search into the function of mitochondria in idiopathic Parkinson's disease. All the studies show a decrease of 30 to 40% in the activity of the respiratory complex I in the mitochondria of the nigra substantia. This decreased activity is not found in other degenerative Parkinsonisms treated with L-Dopa and cannot be explained simply by age. It is not found in other tissues including muscles and platelets. The causal mechanism of this mitochondrial dysfunction is unknown but it is not related to a mutation in mitochondrial DNA.

Humans↗
PubMed1994

Neurobehavioral changes following bilateral infarct in the caudate nuclei: a case report with pathological analysis.

A patient presenting with loss of psychic self activation (LPSA) was studied clinically and at autopsy. Clinically, the patient showed changes that can be ascribed to the interruption of frontal-subcortical circuits. Pathological analysis revealed bilateral lesions of the caudate nuclei. This case extends others based on radiological findings and confirms the importance of the caudate nuclei in behavioral functions.

Aged↗
PubMed1994

Presence of anti-CSL antibodies in the cerebrospinal fluid of patients: a sensitive and specific test in the diagnosis of multiple sclerosis.

The carbohydrate-binding protein (lectin) CSL is an antigen involved in the stabilization of the myelin structure by interacting with the carbohydrate moiety of myelin glycoproteins. Since anti-CSL Fab fragments were able to produce destruction of CNS myelin in vitro, CSL was considered as a potential immunological target in multiple sclerosis. The presence of anti-CSL antibodies has been examined in the cerebrospinal fluid of 1388 different patients with various neurological diseases. It is concluded that the presence of anti-CSL antibodies in the cerebrospinal fluid of patients less than 50 years old constitutes a very sensitive and specific test for multiple sclerosis.

Antibodies↗
PubMed1994

[Type II Charcot-Marie-Tooth and dopa-sensitive Parkinson disease].

The occurrence of a dopa-sensitive parkinsonian syndrome 25 years after a neuropathy suggestive of Charcot-Marie-Tooth disease type II raised the possibility of a relationship between these two diseases. Apart from Machado-Joseph-Azorean disease, an association of this kind seems to be exceptional and it can not be excluded that it was fortuitous. However, the recent description of 7 familial and sporadic cases of a syndrome characterized by a peripheral neuropathy, familial in 5 of the 7 cases, followed, a few years later, by a dopa-sensitive parkinsonian syndrome, makes it possible to consider that this association might have a common genetic origin.

Charcot-Marie-Tooth Disease↗
PubMed1993

[Intravenous immunoglobulins in neurology].

Immunoglobulins, used at first empirically in the treatment of thrombocytopenic purpura, occupy a prominent place not only in the treatment of antibody deficiencies, but also in that of antoimmune diseases. Their indications in neurology are ever extending; they include myasthenia, chronic inflammatory polyneuropathies with or without monoclonal gammopathy, polymyositis, dermatomyositis and, more recently, disseminated sclerosis and Guillain-Barré syndrome. Even the therapeutic priority of plasmapheresis in this syndrome is disputed by some authors. Immunoglobulins are costly, but they are well tolerated and easy to use. Their effectiveness must be confirmed by controlled, double-blind trials. In neurology such trials are still rare, but those recently published are devoid of methodological errors. Once the effectiveness of immunoglobulins is confirmed, their dosage must be established, and attempts should be made at a better understanding of their mechanisms of action.

Dermatomyositis↗
PubMed1993

Event-related potentials in Parkinson's disease: a 12-month follow-up study.

Auditory event-related potentials were recorded using the oddball paradigm in 26 patients with Parkinson's disease, all treated with L-Dopa. The latency of the P3 wave was significantly greater than in an age-matched controls, and was also correlated with the disease duration, but not with scores on two scales measuring cognitive deficit. One year later, when treatment with a dopaminergic agonist, bromocriptine 20-30 mg/day, had been added to the therapeutic regimen, N2 and P3 latencies had increased, whereas several clinical parameters had improved. Thus a longer P3 latency does not seem to be linked to a global cognitive deficit. The use of neuropsychological tests exploring more limited tasks should show the prospective utility of event-related potentials in Parkinson's disease.

Adult↗
PubMed1993

Seronegative myasthenia gravis and familial Hodgkin's disease.

A 29-year-old woman developed a seronegative myasthenia gravis. A thorax CT scan demonstrated an anterior mediastinal mass. Thoracotomy showed a lymphofollicular thymic hyperplasia and Hodgkin's disease of the nodular sclerosing type with mediastinal lymph node localisation. This patient's brother had been suffering as well from Hodgkin's disease. Epidemiological similarities (genetic influences and the role of a viral agent) between Hodgkin's disease and myasthenia gravis and the immune abnormalities found in these two diseases suggest that their association is not fortuitous.

Adult↗
PubMed1993

A new peroxisomal disease with impaired phytanic and pipecolic acid oxidation.

Phytanic acid (PA) accumulates in patients with adult Refsum disease (ARD) and with peroxisomal disorders. In three related patients with ARD, PA levels were moderately increased in plasma, whereas phytanic oxidation was severely deficient in the fibroblasts. Two of these patients had a significant increase of pipecolic acid in plasma, a finding not reported in ARD, and a fourth related patient, a brother, died at age 17 from a progressive neurologic disorder with unusual clinical and neuropathologic (a spongy degeneration of the white matter) abnormalities for ARD. The first step of L-pipecolic acid degradation occurs in peroxisome. In these patients, the accumulation of PA could have resulted from an impaired capacity to degrade pristanic acid rather than PA. The activity of pristanic oxidase, measured in fibroblasts, was normal, as were two other peroxisomal enzymes, lignoceric acid oxidase and dihydroxyacetone phosphate transferase. Since both mitochondria and peroxisomes are involved in PA alpha-oxidation, we propose that these four related patients presented various phenotypical variants of a novel peroxisomal disease with impairment of PA and pipecolic acid oxidation.

Adolescent↗
PubMed1993

[Value of TE671 cells in the detection of anti-acetylcholine receptor antibodies].

The measurement of antibodies directed against the cholinergic receptor, produced by myasthenic patients, involves a radioimmunoassay. The use of human muscular nicotinic cholinergic receptor is highly recommended for this assay. However, difficulties in supplying and standardizing this reagent led us to consider its replacement by the homologous cholinergic receptor constitutively expressed by the human cell line TE671. TE671 cells were grown in mass cultures on microcarriers and acetylcholine receptors were solubilized using detergents. Replacement of human muscular receptor by cellular receptor in the radioimmunoassay assay was assessed by challenging these 2 antigens for numeric or diagnostic correlations. Using TE671 receptor, the correlations observed were good and, despite a slight decrease in the absolute values of the titers, about 90 p. 100 of the assays provided the same diagnostic accuracy. Some interfering proteins, perhaps immature acetylcholine receptor alpha subunits, could be expressed and could account for the slight decline in the antibody titers obtained using TE671 receptor. These interferences could be overcome by a further step of purification and concentration of the various receptor preparations. Finally, TE671 receptor could definitely replace human muscular receptor for screening and measuring myasthenic patients auto-antibodies.

Adolescent↗
PubMed1993

Establishment and characterization of B-like lymphoblastoid cell lines by long-term culture of primary explants from human myasthenic thymus.

Using a simple method of long-term culture, it was possible to obtain B-like lymphoblastoid cell lines (LyCLs) from myasthenic thymuses. Successful cultures were carried out from 14 out of 15 hyperplastic thymuses and in 1 out of 3 myasthenic thymoma, whereas none of the 8 control thymuses, nor the 2 Myasthenia gravis-associated normally involuted thymuses, nor the Myasthenia gravis-associated lymphoma gave rise to LyCL. All the LyCLs secreted immunoglobulins (Ig), either IgG or IgM. None of these Ig reacted with acetylcholine receptor or with other antigens known to be often involved in autoimmune diseases. EBV antigens were found in all the LyCLs as well as in the corresponding donors at the time of thymectomy. HLA characterization of some LyCLs and the corresponding donors showed that class II MHC antigens were expressed normally or with mild differences. However, 86% of the LyCL tested did not express class I MHC antigens.

B-Lymphocytes↗
PubMed1992

Specific effect of corticoids on acetylcholine receptor expression in rat skeletal muscle cell cultures.

The potential effect of different classes of steroids on the expression of acetylcholine receptors (AChR) was studied in different primary cultures of newborn-rat skeletal muscle cells. Comparison among three techniques for preparing newborn skeletal muscle cells showed that these systems were equivalent to study AChR expression. Only corticoids stimulated myogenesis as a twofold increase in AChR expression indicated. Among the corticoids, the glucocorticoids were the more potent, whereas the mineralocorticoid aldosterone had less marked effect. The sex hormones progesterone and testosterone partially blocked these effects, without inducing any significant effect when given alone. The steroids tested differed in efficacy in correlation with their different chemical structures. Among the glucocorticoids a clear structure-activity relationship could be established. These results emphasize the specificity of corticoid action on muscle cells and suggest an explanation for the effects induced by glucocorticoids used in treating human muscular or neuromuscular diseases.

Adrenal Cortex Hormones↗
PubMed1992

Familial motor neuron disease with Lewy body-like inclusions in the substantia nigra, the subthalamic nucleus, and the globus pallidus.

In a familial case of motor neuron disease (MND), 2 unusual features were noted in the necropsy. The first was a pallidoluysonigral degeneration, observed in only 4 other cases of MND and which was here asymptomatic. The second was the presence in degenerated spinal cord anterior horns and in degenerated basal ganglia of neuronal Lewy body-like inclusions stained by antibodies against ubiquitin.

Genes, Dominant↗
PubMed1992

[Prion encephalopathies].

Spongiform encephalopathies, also called prion encephalopathies, are characterized, in human as well as in animals, by (1) their clinical picture which indicates strict localisation in central nervous system, (2) their histological aspect: spongiform degeneration and neuronal loss, and (3) their transmissibility in the same animal species but also from man to animal. The nature of the pathogenic agent is still debated. This agent could be one isoform of the prion protein which, probably because of a modification of its tertiary structure, is partially resistant to proteolytic enzymes. Recent description of a bovine spongiform encephalopathy caused by meat flour absorption has raised again the question of the transmissibility of these animal diseases to human.

Animals↗
PubMed1992

Gerstmann-Sträussler-Scheinker disease in an Alsatian family: clinical and genetic studies.

The clinical progression of Gerstmann-Sträussler-Scheinker disease in a family of Alsatian origin is reported. The age of onset and the duration of evolution were variable. The clinical picture became more complex over the generations: in the first generations, isolated dementia and in later generations a triad of pyramidal, pseudobulbar syndromes and dementia associated with spinal cord and cerebellar features. Prion gene analysis showed that four surviving patients carry double missense changes at codons 117 and 129, identical to those found in one case at necropsy and 10 other healthy members of the family. The missense changes were not found in 100 controls. No member of the family had modification of condons 102, 178, or 200. The lod score suggests linkage between the missense change at codon 117 and Gerstmann-Sträussler-Scheinker disease in this family.

Adult↗
PubMed1992

[Ubiquitin and degenerative diseases of the central nervous system].

Ubiquitin is an ubiquitous 76 aminoacids protein that is present in all cellular compartments. It intervenes in numerous functions of cell metabolism, and in particular in non-lysosomal (but also lysosomal) lysis of altered or short-lived proteins. Immunohistochemical studies have shown that it is present in many inclusions characteristic of neurodegenerative diseases, notably in Lewy bodies, neurofibrillary tangles of Alzheimer's disease, Pick bodies and also in inclusions characteristic of certain motor neuron diseases. The presence of ubiquitin in these inclusions raises 2 questions: (1) the nature of the target proteins, probably altered proteins of the cytoskeleton; (2) the significance of ubiquination: it might reflect the degeneration process or participate in the protection of cells against degeneration or be an active factor in programmed cell death.

Brain Chemistry↗