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F Thibaut

Publications and source records attributed to F Thibaut.

12 recordsLinked to original sources
PubMed1992

SPEM impairment in drug-naive schizophrenic patients: evidence for a trait marker.

Smooth-pursuit eye movements (SPEM) were assessed in healthy subjects and in drug-naive, chronic, and residual schizophrenic patients. SPEM gain was found to be decreased in all the schizophrenic patients who also exhibited a significant increase in the rate of saccades. The frequency of square-wave jerks was the same in schizophrenic patients and normal controls, suggesting that the primary abnormality in schizophrenic patients was a low gain rather than a defect of the saccadic system. Patients were retested 1 month later, and stability of gain was high even in formerly drug-naive subjects who had been treated for 1 month with neuroleptic drugs. Altogether these results confirm the conclusions of most previous studies, extend them to drug-naive schizophrenic patients, and favor the hypothesis that SPEM impairment is a trait marker in schizophrenia.

Adult↗
PubMed1990

Microtopography of D1 dopaminergic binding sites in the human substantia nigra: an autoradiographic study.

The autoradiographic distribution of D1 dopaminergic binding sites was studied in the human ventral mesencephalon using the D1 antagonist [3H]SCH 23390. [3H]SCH 23390 binding was characterized by a single class of sites with a Kd of 2.5 nM and a Bmax of 31 fmol/mg of tissue. The density of [3H]SCH 23390 binding sites was high in the substantia nigra, moderate in the ventral tegmental area and low in the peri- and retrorubral field (catecholaminergic region A8). Binding densities were similar in pars compacta and pars reticulata of the substantia nigra, except for a peak value of high [3H]SCH 23390 in the pars reticulata, at a level just ventral to a zone of hyperdensity of melanized dopaminergic neurons in the pars compacta. The anatomical organization of the human ventral mesencephalon was analysed on adjacent sections stained for acetylcholinesterase histochemistry and tyrosine hydroxylase, substance P, dynorphin B, somatostatin and methionine-enkephalin immunohistochemistry, respectively. The similarity in distribution of [3H]SCH 23390 binding sites and substance P or dynorphin B immunoreactivity suggests that D1 binding sites are mainly located on the striatonigral projections. In accordance with these results: (1) the density of [3H]SCH 23390 binding sites was reduced in the substantia nigra of a patient with Huntington's chorea, a disease associated with a degeneration of striatonigral neurons; (2) the density of [3H]SCH 23390 binding sites was unaffected in the substantia nigra of a patient with Parkinson's disease, a disorder characterized by a marked loss in nigral tyrosine hydroxylase-positive neurons. [3H]SCH 23390 binding sites showed a characteristic, heterogeneous distribution within the human ventral mesencephalon, confirming data obtained in other species. The preferential localization of D1 dopamine receptors on striatonigral projections in human brain suggests that pharmacological manipulation of these receptors modulates the activity of striatonigral pathways, thereby affecting the various outputs of the nigral complex.

Acetylcholinesterase↗
PubMed1989

Time course of postmortem modifications in synaptosomal [3H]dopamine uptake and [3H]GBR 12783 binding to the dopamine uptake complex in the rat striatum.

The present study focuses on the changes of two biochemical markers of the striatal dopaminergic innervation evaluated after different postmortem storage periods of rat heads either at room temperature (21 degrees C) or at 4 degrees C: (i) the uptake of [3H]dopamine (DA) into striatal synaptosomes and (ii) the specific binding of [3H]GBR 12783, a selective ligand for the neuronal dopamine uptake sites, to a striatal membrane fraction. The uptake of [3H]DA was completely abolished after 24 and 72 h storage of the tissue at 21 degrees C and 4 degrees C, respectively, whereas in the same conditions, the binding of [3H]GBR 12783 was slightly decreased. The Km and Kd of these two processes were virtually unchanged after the different storage periods considered, whereas the Vmax and Bmax were markedly decreased.

Animals↗
PubMed1989

Continuous and intermittent levodopa differentially affect basal ganglia function.

The effects of continuous and intermittent levodopa treatment on behavioral and biochemical indexes of basal ganglia function were compared in rats with unilateral 6-hydroxydopamine lesions of the nigrostriatal dopamine pathway. Animals treated for 30 days with intermittent levodopa exhibited behavioral sensitization manifested by an enhanced rotational response to apomorphine; the rotational response of rats treated with an equivalent dose of levodopa by continuous infusion did not differ from that of saline-treated controls. Dopamine receptor up-regulation in the denervated striatum relative to the intact striatum was statistically significant for D1 but not D2 receptors: This asymmetry in dopamine receptor levels was diminished following intermittent levodopa treatment. Glutamic acid decarboxylase activity, modestly elevated in all groups in the denervated striatum relative to the intact striatum, increased substantially over control values bilaterally as a result of intermittent, but not continuous, levodopa treatment. These findings suggest a relation between the schedule of chronic levodopa administration and the development of behavioral sensitization, possibly as a consequence of alterations in neuronal systems located downstream from striatal dopamine receptors. The behavioral sensitization induced by chronic, intermittent dopaminomimetic treatment may serve as a model for motor fluctuations in Parkinson's disease.

Animals↗
PubMed1979

[Post-radiotherapy pericarditis. 5 cases (author's transl)].

These cases represented 2.8% of the patients admitted for pericarditis during the same period. The cause of irradiation was a carcinoma of the breast in three cases and a carcinoma of the oesophagus in two cases. Acute forms of pericarditis occured 8 and 13 months after irradiations, and chronic forms after 1, 8 and 13 years. Three clinical forms were observed; two patients had an acute form; the first one with a slight effusion was easily cured, the second with cardiac tamponnade recovered after surgical evacuation, two others patients had a chronic latent effusion; after surgical evacuation, one recovered but the other one developped an occult constrictive pericarditis diagnosed by rapid volume expansion. The fifth case was a constrictive pericarditis which was effectively traited by pericardectomy. The difficulty of etiological diagnosis varies with the time and the amount of effusion. When the effusion is moderate the distinction must be made with an acute idiopathic pericarditis; when effusion is large the distinction must be made with a tuberculosis and specially a tumoral recurrence; in three cases pericardial biopsy was carried out and eliminated these diagnosises; lesions were similar: pericard was sclerous and little in cells, inflammatory signs were slight or absent. The postoperative prognosis in constrictive pericarditis may be agravated by associated myocardial lesions.

Acute Disease↗
PubMedDate not supplied

[Lithium and aggression in adults].

The use of lithium as an antiaggressive agent independently of its action in bipolar illness is now well documented. It appears particularly effective in the control of aggressive behavior in chronically aggressive prisoners and mentally retarded patients. Approximately 70-75% of these patients are likely to show a positive response to lithium therapy. No convincing features have been identified as being predictive of a good response. The clinical effect of lithium is to reduce the frequency and the severity of both hetero and auto aggressive outbursts. The use of lithium for aggressive behavior remains controversial in epileptic disorders and inconclusive in chronically psychotic patients. Careful monitoring of lithium blood levels is necessary to ensure adequate therapeutic efficacy without toxicity. A caution is needed in patients with brain damage especially when concurrent neuroleptic treatment is used. The antiaggressive effect of lithium seems rather specific and may be associated with a serotoninergic effect.

Adult↗