PubMed HealthSearch

Biomedical subjects

D Pringuey

Publications and source records attributed to D Pringuey.

6 recordsLinked to original sources

Circadian variation in total plasma tryptophan. Antidepressant treatment: drugs and phase advance.

The authors investigated hourly total plasma tryptophan concentrations over a 24 hour period in 3 patients with bipolar depression during 2 types of treatment: a phase advance process and conventional antidepressant therapy. Both treatment modalities increased the 24 hour mean tryptophan levels and the amplitude of circadian tryptophan concentrations. By contrast, in a previous study, moderately decreased tryptophan levels and a blunted amplitude in the circadian rhythm were observed in these same patients in a depressive phase.

Adult

Trimipramine: acute and lasting effects on sleep in healthy and major depressive subjects.

The acute effects of trimipramine on sleep EEG patterns were investigated in six depressed inpatients and six healthy volunteers. The effects of long-term administration were then assessed in depressed patients after 4 weeks of treatment. Sedative effects of the drug were more pronounced in healthy subjects while sleep parameters of depressed patients seemed less sensitive to the drug. Chronic effects tended to correct most of the sleep disturbances seen in depressed subjects with respect to the natural organization of sleep. The major sleep effect of trimipramine concerned REM latency which was lengthened in both groups, independently of the treatment protocol.

Adult

Circadian rhythm in plasma noradrenaline of healthy sleep-deprived subjects.

Under normal sleep-wake conditions, noradrenaline (NA) secretions in supine subjects exhibit a weak circadian variation with a peak that occurs around noon; the sleep span is characterized by reduced NA secretion. Some investigators have reported that the circadian NA rhythm is completely obliterated during sleep deprivation. In our laboratory, plasma NA was assayed every hour for 24 h in nine healthy men 20-23 years of age. All men were deprived of sleep and were required to eat and walk around every hour to prevent sleep. However, subjects remained supine for 20 min before blood samples were collected to eliminate the effect of activity. Persistence of a slight decrease in the night concentration in several subjects, despite sleep deprivation, suggests that NA secretion may be influenced by a biological clock whose activity becomes visible when the influence of posture is removed.

Adult

[Disorders of circadian rhythms in depression].

The authors make a synthesis of studies about circadian rhythms in depression and of hypothesis to explain them. They successively study trials on the phases, on the average levels, on the amplitude of rhythms. They conclude the most significant troubles are, shortening of latency on paradoxical sleep for phases, slump of melatonin levels, blunded amplitude of every parameter. Among possible explanations, they present and discuss a trouble of oscillators, a decrease of sensitivity to external synchronizers and a trouble in rhythm coupling.

Adrenocorticotropic Hormone

[Transsexualism].

According to the literature, the transsexual phenomenon can be assessed as a distinct psychiatric illness. Transsexualism, a rare but spectacular disorder, realizes a gender identity reversal raising questions regarding systems of psychiatric diagnosis, nosology and treatment. A better clinical knowledge of this "experiment" and its follow-up allow studying processes contributory to marked deviation of gender identity and furthering concepts of development of masculinity and feminity. Current research deals with hypotheses that can be stated as testable propositions about underlying dynamics in various fields: learning factors, psychoanalytic components and psycho-biological data. Focusing on the early infantile development and the environmental influences reflects a variety of non specific psychogenetic precursors. The treatment of "gender dysphoria syndrom", i.e. hormonal treatment, sex-reassignment surgery and psychotherapic processes, aims towards réduction of psychic pain and social adjustment in the cross-gender role. Transsexual phenomenon largely overlaps the psychopathological area; beyond surgical and medical aspects, social implications and legal positions refer to an ethical problem.

Adult