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Biomedical subjects

A Dresse

Publications and source records attributed to A Dresse.

At least 91 records · Page 5Linked to original sources
PubMed1978

Histochemical study of cobalt-induced focal epilepsy.

A previous study showed a strong relationship between human focal epilepsy and the presence in the cortex of "activated" astrocytes characterized by an intense activity of dehydrogenases (DH) involved in glucose metabolism and of glutamate DH. Using the semi-chronic model of cobalt-induced experimental focal epilepsy in the rat, we investigated a possible correlation between astrocyte modifications and the chronological development of the epileptic manifestations on the ECoG. After a few days the cobalt-implanted rats present spikes, then sharp waves followed by an electrical crisis and ultimately motor seizures. Activated astrocytes were found in each phase of this evolution. Their number increases with the intensity of the manifestations. There is a close relationship between activated astrocytes and focal epileptic phenomena. At this stage of our study it is clear that the presence of activated astrocytes is not a consequence of seizures. However, it is impossible to say whether the activation is secondary to the hyperactivity of the neurons or directly responsible for the constitution of the epileptic focus. In any case, activated astrocytes provide a new means of localizing an epileptogenic focus.

Animals↗
PubMed1978

[Phosphorylase and glucosyltransferases at the level of reactive astrocytes. A histochemical study].

Implantation of cobalt powder in the cerebral cortex of rat determines an epileptogenic focus where two types of reactive astrocytes are observed. The first type is mostly represented in the subcortical white matter but it does exist in the cortex around the implant. Phosphorylase and branching enzyme are both very active in these cells which are filled with glycogen. The second type is limited to the cortex and phosphorylase activity leads to an unbranched polysaccharid. These cells correspond to the "activated astrocytes" described by the authors in a previous paper and observed round irritative lesions which, in the cerebral cortex, produce epileptogenic foci.

1,4-alpha-Glucan Branching Enzyme↗
PubMed1978

Effect of diflunisal on the human plasma levels and on the urinary excretion of naproxen.

A double-blind placebo controlled crossover study was performed in twelve healthy volunteers receiving multiple doses of naproxen (250 mg b.i.d.) and diflunisal (250 mg b.i.d.) to study the effect of diflunisal co-administration on the naproxen levels in plasma and urine. The naproxen steady-state level was reached between the second and the third day. The peak plasma level appeared about 2 hr after drug administration and varied from 68 to 75 microgram/ml. This maximum was not modified by a simultaneous administration of diflunisal neither in its position nor in its intensity. Statistical analysis using a parametric method, did not reveal a significant influence of diflunisal on the plasma kinetics or on the urinary elimination of naproxen.

Adult↗
PubMed1977

Action of phenytoin, ethosuximide and of the carbidopa-L-dopa association in semi-chronic cobalt-induced epilepsy in the rat.

A semi-chronic model of cobalt-induced experimental epilepsy in the rat was used to investigate the action of two classic anticonvulsant drugs, phenytoin and ethosuximide. Single injections of ethosuximide lead to an inhibition of the epileptic discharges. We failed to demonstrate an inhibitory effect of phenytoin after preventive administration. The carbidopa-L-dopa association was investigated owing to the inhibitory effects of dopamine and its presence in the cortex. We showed that a dose of 100 mg/kg of L-dopa combined with 25 mg/kg of carbidopa is necessary and sufficient to produce an almost complete inhibition of the discharges.

Animals↗
PubMed1976

[Recording of the electrophysiological activity of the locus coeruleus in the rat].

After having previously studied some histochemical and biochemical aspects of the noradrenalin-containing neurons of the rat locus coeruleus (LC), we intend now to record the unitary electrophysiological activity of these neurons. In the present paper, we try to define the experimental conditions allowing a reproducible recording of this activity. In agreement with other authors, we have shown that the neurons of the LC slowly discharge, at a frequency of 1-3/sec with an amplitude of 100-150 muV. This spontaneous activity is greatly reduced by low doses of norimipramine, a tricyclic antidepressant.

Animals↗
PubMed1976

[Interaction of tricyclic antidepressants with noradrenaline and 5-hydroxytryptamine in peripheral preparations of the rat].

The potentiation of the noradrenaline (NA) actions by antidepressant drugs was studied in vitro on the rat vas deferens and in vivo on the rat blood pressure. A new dibenzazepine compound, LM 208, and two antiparkinsonian drugs, orphenadrine and its demethylated derivative, were compared to well known antidepressants. The modification by all these agents of the rat uterus response to 5-hydroxytryptamine (5-HT) was also investigated. The possible use of these interactions as models for NA and 5-HT uptake inhibition is discussed.

Animals↗
PubMed1975

Catecholamines and exercise-induced glucagon and fatty acid mobilization in the rat.

Physical exercise in rats provokes an increase in plasma glucagon and free fatty acid concentrations. The persistence of exercise-induced glucagon stimulation in adrenodemedullated animals and conversely, its inhibition by immunosympathectomy, (-)-ropranolol, and pindolol substantiate the conclusion that stimulation of the alpha2 cells in exercise involves sympathetic stimulation of the beta-adrenergic receptors. The reduction of free fatty acid mobilization by immunosympathectomy and (-)-propranolol and its persistence after adrenodemedullation suggest that it is similarly mediated, at least in part, by adipose cell beta-sympathetic receptors.

Adipose Tissue↗
PubMed1975

Chemical structure and pharmacological (curarizing) properties of various indole alkaloids extracted from an African Strychnos.

The chemical separation and identification of ten alkaloids extracted from the roots of Strychnos usambarensis are described. The elucidation of their structure by means of elementary analysis, I. R., U.V, and mass spectrometry allows their classification into bistertiary amines, hybrid and bisquaternary ammonium derivatives. This classification is reflected in the pharmacological properties. One of the tertiary amine alkaloids (usambarensine) presents atopine-like and spasmolytic activities while the bisquaternary ammonium compounds (dihydrotoxiferine, calebassine, C-curarine and afrocurarine) are competitive neuromuscular blocking agents.

Alkaloids↗