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Biomedical subjects

L Durelli

Publications and source records attributed to L Durelli.

At least 73 records · Page 4Linked to original sources
PubMed1980

Mechanisms of interaction of asymmetrical bilateral epileptogenic foci in neocortex.

The mechanisms of interaction of bilateral asymmetrical foci on cat neocortex were studied with varying concentrations of the epileptogenic agent and with callosal splitting and cortical-callosal isolation. When epilepsy was severe, a facilitatory interaction occurred. This was the result of two opposing mechanisms simultaneously operating, namely a transcallosal inhibitory mechanism and a predominant facilitatory subcortical mechanism. When epilepsy was less intense, subcortical structures were not involved and only the inhibitory transcallosal mechanism was at work, leading to an inhibitory interaction. The conclusion is put forward that two asymmetrical cortical foci do not necessarily interact in only one simple way. Their type of interaction (facilitatory or inhibitory) depends on the pathways involved in the interaction and this, in turn, depends on the severity of epilepsy.

Animals↗
PubMed1979

Epileptic laughter: electroclinical and cinefilm report of a case.

A woman, aged 30, experienced attacks of pathological laughter which began during the first months of life; they meet the qualifying criteria of epileptic laughter. Several attacks were recorded by polygraphy and cinefilm. The attack begins with a feeling of unreality associated with a forced, involuntary smile progressing to full laughter. The patient tried to mask the laughter which was not accompanied by euphoria but was followed by loss of consciousness and automatisms. Only during the latter phase of the previously normal EEG did an ictal discharge appear over the right hemisphere. On the basis of the electroclinical pattern and of a review of the literature, the seizure is tentatively explained in terms of a progressive ictal involvement of temporodiencephalic structures.

Adult↗
PubMed1979

Myotonia, potassium and taurine. A preliminary report.

The effect of taurine administration upon potassium-induced muscular hyperexcitability was studied in patients affected with dystrophic myotonia and in normal volunteers. Intra-arterial infusions of increasing concentrations of potassium chloride were given and venous potassium levels simultaneously monitored. Taurine prevented or remarkably reduced the electric signs of muscular hyperexcitability. Potassium chloride and taurine effects upon muscular excitability are discussed in terms of changes of membrane conductance, particularly for potassium ions.

Action Potentials↗
PubMed1977

Longitudinal changes of brain amino acid content occurring before, during and after epileptic activity.

In cats affected with cortical epileptogenic foci induced by penicillin application to and cobalt implantation into the pericruciate area, the brain amino acids contents were determined in the focus as well as in extrafocal areas. In different groups of animals, brain removal for biochemical determinations was performed at different times before, during and after epilepsy and the values compared to controls. The only amino acid to show a significant change before appearance of spikes in both types of epilepsy was taurine, which decreased. Cobalt epilepsy was accompanied by changes in a larger number of amino acids than penicillin epilepsy: in the former the brain content of taurine, GABA, aspartate, glutamate, serine, threonine, glycine and alanine was altered. The changes were proportional to the severity of epilepsy and more prominent in the focus area. After disappearance of spikes the levels of most amino acids returned to normal except for some amino acids, previously unaffected by penicillin epilepsy, which were decreased. It is proposed that the decrease in brain taurine, occurring before the appearance of penicillin and cobalt epilepsy, could increase the excitability of a certain neuronal population and thus, by potentiating the effects on neurons of penicillin and cobalt, contribute to the initiation of epilepsy.

Amino Acids↗
PubMed1976

Further observations on carbamazepine plasma levels in epileptic patients. Relationships with therapeutic and side effects.

Plasma levels of carbamazepine, phenytoin and phenobarbital were monitored weekly over a period of 9 weeks in 20 epileptic patients unresponsive to treatment. No attempts were made to modify phenytoin and/or phenobarbital plasma levels; emphasis was on achieving carbamazepine plasma levels of 4 to 10 mug per milliliter. A remarkable drop in seizure frequency was attained within 2 to 3 weeks of monitoring, with carbamazepine plasma and concentrations within the desired range. Children disposed of the drug faster than adults. No effects of phenytoin and phenobarbital on carbamazepine plasma levels could be observed, while phenobarbital on carbamazepine plasma levels fluctuated remarkably without any relationship to carbamazepine levels. Transient leukopenia was present in most of the patients, while a significant reversible drop in red blood cells was observed in eight patients. The data reported confirm that with a careful monitoring of drug plasma levels, carbamazepine may exert a definite passive effect on seizure frequency in epileptic patients poorly responsive to therapy.

Adult↗
PubMed1975

Levels of free amino acids in serum and cerebrospinal fluid after administration of taurine to epileptic and normal subjects.

The modifications associated with taurine treatment of the free amino acid content of serum and cerebrospinal fluid were investigated in epileptic and control subjects. In patients with epilepsy the main findings were, in the serum, the correction toward normal of the amino acid levels that were low prior to therapy, and in the cerebrospinal fluid, the increase up to above-normal levels of glutamic acid, greatly diminished before treatment. Thus taurine, which has an anticonvulsant action appears to partially correct the amino acid imbalance in epileptics. The monitoring of taurine-induced glutamate changes in the cerebrospinal fluid could help to establish the correct therapeutic dose.

Adolescent↗
PubMed1975

Free amino acids in serum of patients with epilepsy: significant increase in taurine.

More than half the amino acids determined in serum were lower in patients with epilepsy than in control subjects. Taurine was the only amino acid to be increased in epilepsy. The changes could represent a compensatory metabolic reaction to limit the imbalance of amino acids in epileptic brain and to facilitate uptake of taurine, which has an anticonvulsant action.

Adolescent↗
PubMed1975

Soradic ulcerative mutilating acropathy with imbalance of free amino acids in the cerebrospinal fluid.

A case of sporadic ulcerative mutilating acropathy is described. Muscle biopsy showed signs of neurogenic atrophy. Motor nerve conduction velocity was slightly reduced. The muscles of the foot were completely unresponsive to electric stimulation of both femoral nerves. The content of free amino acids in serum and cerebrospinal fluid was determined by ion exchange chromatography, and compared with a control group. While in serum no significant changes were found, in CSF most amino acids showed great alterations, mainly consisting in an increase. It is suggested that the primary disturbance may be located in the spinal nerve roots.

Adult↗