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Biomedical subjects

J M Gaillard

Publications and source records attributed to J M Gaillard.

At least 145 records · Page 8Linked to original sources
PubMed1974

Spectral analysis of electroencephalographic recordings of long duration by means of band-pass filters.

A method is proposed for spectral analysis of EEG recordings of long duration, using a set of band-pass filters. The sensitivity of the filters varies continuously over their full range, and the input signal is sampled at every sensitivity level. The full spectrum is presented as an array of numbers where the columns are the frequencies and the rows the sensitivity levels, printed as a percentage of the total possible responses of the filter (percent of activity). The logarithm of the numbers expressing the activity of a filter are used for the calculation of the regression line. Thus, the activity in each frequency is characterized by two parameters, the slope and the ordinate at origin, the slope being the more interesting one.

Computers↗
PubMed1971

Passage into the rat brain of dopa and dopamine injected into the lateral ventricle.

1. The green fluorescence of catechols of the brain was studied in rats after intraventricular injection of L-dopa or dopamine in untreated rats as well as in rats in which dopa decarboxylase (DC) was inhibited by Ro 4602, or the monoamine oxidase by nialamide.2. From the patterns of fluorescence obtained in these conditions, it is concluded that in the areas close to the liquor space dopa is rapidly taken up by the endothelium of the brain capillaries and then converted into dopamine; when the DC is inhibited the dopa passes freely from the endothelium into the brain tissue.3. On the other hand, dopamine passes from the liquor space via the ependyma directly into the brain tissue and from there into the capillary endothelium which is thus permeable to the amine in the direction from the brain tissue, in contrast to the impermeability in the direction from the capillary lumen.

Animals↗
PubMedDate not supplied

Reversible in vitro decrease of L-tyrosine and L-tryptophan influx across the human erythrocyte membrane induced by cytochalasin B, the specific inhibitor of D-glucose transport.

For many years, we have been studying, in psychiatric conditions, the influx of tyrosine (TYR) and tryptophan (TRP), the two amino acid precursors of monoamines, across the membrane of human blood cells. We have also attempted to characterize better the transport mechanisms. In a previous paper, we suggested a close relationship between glucose and the two neuter amino acid transports in vitro. The purpose of the present study is to test the effect of cytochalasin B, the specific and potent inhibitor of glucose transport. Our data show that at high concentrations, the cytochalasin B induces a reversible inhibition of about 70% or more on the temperature-dependent influx of the two amino acids, depending on the medium of incubation. The effect of cytochalasin B was about 200 times less for TYR and TRP transport than for glucose. The cytochalasin E, claimed to be a nonspecific inhibitor, decreased both these transports only when used at very high concentrations, as described for sugar influx in the same structure. In conclusion, we suggest that there is a relationship between the transport of glucose and nucleosides, both carried into the cells by the glycoprotein band 4.5, and the two amino acid precursors of monoamines.

Adult↗