Search PubMed⌕ Search

Biomedical subjects

B Renaud

Publications and source records attributed to B Renaud.

133 records · Page 8Linked to original sources
PubMedDate not supplied

[Insomnia in bismuth encephalopathy (author's transl)].

Myoclonic encephatopathy caused by the insoluble salts of bismuth may be accompanied by a state of total insomnia. This insomnia has been confirmed by polygraphic recordings in 3 subjects. The recovery of sleep has a stereotyped course, with a step-wise reappearance over time of sucessive stages of NREM sleeps tarting with stage age I, and parallel re-establishment of REM sleep. Return to normal sleep lags behind clinical recovery. A pharmacological analysis with the phobenecid test was attempted in 2 of the 3 subjects. The results were the same in both as regards renewal of lumbar 5 HIAA, which paradoxically is not changed much; as regards the rate of lumbar HVA renewal, the results were quite different.

Adult↗
PubMedDate not supplied

In vivo voltammetry and microdialysis monitoring of monoamine metabolism in the rat brainstem neurons.

Two "in vivo" techniques allow the monitoring of extracellular levels of monoamines and related compounds in selected rat brainstem regions: voltammetry and microdialysis. "In vivo" voltammetry has a high regional selectivity: for example, we have been able to perform a subregional study and to show that the increase in extracellular DOPAC induced by 30 min-hypotension was twice as larg in the rostral as in the caudal rat locus coeruleus. The spatial resolution, as expressed by x 1/2 (see text), is 4 times better for voltammetry (50 microns) than for microdialysis (190 microns). Another advantage of voltammetry is its excellent time resolution. However, microdialysis has a much better biochemical specificity than voltammetry. Furthermore it allows some enzymatic activities, such as tyrosine hydroxylase, to be measured almost continuously in catecholaminergic brain nuclei. From a functional point of view, the results of our experiments (alpha 2 ligand administration, arterial hypotension or stress) illustrate the respective interest and complementarity of these two "in vivo" techniques. Their current developments will lead to a better temporal and biochemical resolution combined with an increase in the number of substances analyzed "in vivo", including peptides and nitric oxide.

3,4-Dihydroxyphenylacetic Acid↗
PubMedDate not supplied

[Platelet serotonin concentrations in autistic children and members of their families].

Children with early infantile autism have often high platelet serotonin (5 HT) levels. According to this fact, we wondered if a genetic abnormality of 5 HT metabolism could be detected in family members of autistic children. We has thus determined platelet 5 HT levels in these children's mothers, fathers and siblings. It is noteworthy to find out that: autistic children have a mean platelet 5 HT level significantly higher than their siblings' (p less than 0.01); fathers' levels are significantly lower (-29%; p less than 0.001) than those of other family members' and of control group. Furthermore, for future purposes, we studied platelet 5 HT levels at different times during pregnancy in controls and in a woman already mother of an autistic child. We observed a raise (+31%; p less than 0.01) in platelet 5 HT during the first trimester of the pregnancy with a lowering towards normal levels during the eight month, in the woman with an autistic child as well as in the controls.

Autistic Disorder↗
PubMedDate not supplied

[Effect of acute administration of antidepressive agents at 2 P.M. on plasma and pineal levels of melatonin in the rat].

The authors measured the effect of different antidepressant drugs on the pineal production of melatonin in order to see if this test can be used in an antidepressants screening protocol. Six antidepressant drugs belonging to different pharmacologic classes have been tested. The results show that all the molecules used enhance the plasmatic and pineal concentration of melatonin. However the selectivity of this test must be reinforced by using classical methods for the detection of an antidepressant effect.

Animals↗
PubMedDate not supplied

[Classification of chronic psychoses types I and II and platelet serotonin levels. Apropos of 38 cases].

The authors have examined, within a population of 38 patients, all suffering from chronic psychosis, the concentration of serotonin in the blood platelets as a function of a psychopathologic classification. The 38 patients, 17 men and 21 women, with a mean age of 46 years, diagnosed as schizophrenics (INSERM classification) were categorized according to their specific psychosis (types I and II of J. Guyotat) on examination of their clinical reports by two independent clinicians. This categorization returned 20 psychotics of type I, 16 psychotics of type II and 2 psychotics were difficult to classify. Blood samples were taken from both patients and from 47 controls at 10 o'clock in the morning, two hours after breakfast. The concentration of serotonin in the blood platelets was subsequently examined using the technique of liquid chromatography. The results obtained did not show any significant difference between the chronic psychotics and the control group. The average level of platelet serotonin is 5.09 for psychosis of type I and 3.56 for psychosis of type II, but the value of this difference does not indicate a significant statistical difference; however the tight grouping of serotonin levels in the psychotics of type II looked interesting because they were similar to those of the control in being more homogeneous than those of the psychotics of type I.

Blood Platelets↗