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Biomedical subjects

P Magnin

Publications and source records attributed to P Magnin.

At least 91 records · Page 5Linked to original sources

Proton NMR-relaxation dispersion in meconium solutions and healthy amniotic fluid: possible applications to medical diagnosis.

In order to show that for a possible application in medical diagnosis NMR-relaxation experiments at low Larmor frequencies (v0 less than or equal to 20 kHz) are more sensitive than the up to now done high field measurements in the MHz-range, we present dispersion curves (v0 = 50 Hz to 50 MHz) of the proton longitudinal relaxation time T1 and values of the transversal relaxation time T2 for the example of amniotic fluids. Only for Larmor frequencies below congruent to 100 kHz the relaxation times for healthy amniotic fluid and pathological meconium solutions are significantly different, whereas at high Larmor frequencies, i.e. in the conventional MHz-range, the observed changes are rather small.

Amniotic Fluid↗

[Tolerance to exertion after sleep reduction and after taking a hypnotic: zolpidem].

The aim of the present study was to investigate the effects of a delayed bedtime (3 a.m.), an advanced rising (3 a.m.), a sleep under placebo and under a hypnotic compound, i.e. 10 mg of zolpidem (Stilnox) on sleep structure and on the adaptations to a subsequent exercise in 8 male athletes. The chronology of these nights was randomized and each treatment administered in a double blind fashion. During each experimental night, subjects were monitored with conventional EEG/EOG/EMG polygraphic recordings. The next day, athletic performance was tested using a bicycle ergometer. A codified exercise was performed and consisted to a 10 min warm up followed by a 30 min steady state cycling corresponding to 75% of predetermined VO2 max. Then the work load increased progressively by steps of 10 W every minute until exhaustion. The recovery lasted 30 min. Heart rate, ventilation, VO2, ERO2 were monitored during all exercise and recovery. Plasma lactates and catecholamines were also measured at the same time. The data concerning sleep recordings showed that both nights with partial sleep deprivation resulted in a drop of time spent in slow wave sleep II (decrease of 55%) and in rapid eye movement sleep (decrease of 45%) while the amount of slow wave sleep III and IV were identical to that observed after the reference night. The sleep onset latency and the amount of sleep in stage I was reduced only after the delayed bedtime. Sleep data under zolpidem did not show any significantly difference in the amount of different sleep stages.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗