1,721,121 research outputs found
Corso di epidemiologia clinica e valutativa per funzionari degli uffici regionali di psichiatria
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[Pulsar analysis of the 24-hour secretion of GH in normal subjects, in acromegalics and in patients with non-secreting and prolactin-secreting pituitary adenoma].
No full textPossible influence of melatonin on the human prolactin circadian secretory pattern
No full textIn humans, prolactin (PRL) shows a circadian secretory
pattern characterized by a sleep-dependent rising plasma
level. In particular, PRL rises are related to non-rapid eye
movement sleep (NREMS), even though there is a
progressive rise during the night with the highest plasma
levels in the second half of nocturnal sleep just when
NREMS is less prevalent. In previous work we found that PRL rises were linked to slow wave sleep (SWS). Furthermore, we observed a statistically significant PRL circadian secretory pattern (i.e., the presence of a circadian rhythm) only in "good sleepers" (i.e., subjects having an "effìcient" sleep). In such subjects, the most commonly used "sleep efficiency index" (i.e., the ratio: (SWS + REMS)/(total sleep time); normal range, 0.35-0.60) showed values greater than 0.35. On the contrary, "poor sleepers", with an efficiency index inferior to 0.35, did not demonstrate the presence of a PRL rhythm. A circadian secretory pattern has also been found for
melatonin (MT) , to date, the most investigated substance
produced by the pineal gland. Even though there are
some discordant data, in the case of a normal recurrence of
light-dark and wake-sleep cycles, a MT plasma level
increase would usually be detectable in the first half of
nocturnal sleep and therefore would occur before the PRL
rise. The aim of this study was to evaluate whether MT is
involved in the regulation of the PRL circadian secretory
rhythm. Subjects and methods: Eight healthy volunteers,
considered as controls (five males and three females; mean
age, 34 years; range 20-41 years), and eight patients with
neuroradiological evidence of pineal tumour (six males and
two females; mean age, 33 years; range, 18- 38 years) were
examined. The latter were collected in a time interval of 5
years. In such patients, the histological diagnosis was one of a well-differentiated, low-grade fibrillary astrocytoma, noninvasive and, in five cases, sharply circumscribed (benign
astrocytomas). All the patients presented no neurological or
psychopathological symptoms during the testing period.
After two adaptation nights, each subject underwent an
all-night polysomnogram (EEG, EOG, EMG) from 22:00 to
07:00 with the lights off. Sleep was scored according to
standard criteria. Blood samples were drawn every 15
min. In all subjects PRL and MT plasma levels were
measured by a homologous double antibody radioimmunoassay (RIA). A week before and during the 3 days spent in the sleep laboratory, the duration of light-dark and wake-sleep cycles, physical activity, and diet were
standardized by a pre-established schedule. All the subjects underwent testing either in spring or autumn and the women
during the follicular phase of their menstrual cycle.
PRL and MT chronobiological characteristics were
determined by the single and population mean-cosinor
methods: i.e., the 24 h cosine function of a continuous curve
best fitted by least-squares analysis in the case of an
individual or group, respectively. Such methods provide
the possible statistical significance of a circadian secretory
curve: i.e., the presence of a rhythm according to the Fvalue
for zero amplitude test. Both the individual and group
circadian curves are characterized by the following
parameters: (a) mesor - 24 h average obtained by the best
fitting cosine function used to approximate the circadian
curve; (b) amplitude - difference between the maximum
value measured at acrophase and the mesor in the cosine
curve; (c) acrophase - crest timing of the best fitted curve.
Results: All healthy volunteers showed PRL and MT
circadian secretory rhythms. The presence of a PRL
circadian rhythm is likely due to the presence of efficient
sleep. On the contrary, in all the patients with a pineal
tumour MT circadian plasma levels were inferior to the RIA
normal minimum value and therefore the cosinor methods
failed to show significant MT curves. In addition, such
patients did not exhibit a PRL circadian rhythm even though
their sleep efficiency index was within the normal range.
Furthermore, they allow the detection ofa possible PRL circadian rhythm. Our data demonstrate the need for a polygraphic study of sleep to show the presence of a PRL circadian rhythm that in fact is detectable only in subjects having efficient sleep (sleep efficiency index greater than 0.35). Furthermore, the results concerning patients with pineal tumours permit one to nypothesize that, among possible circadian systems (regulating PRL rhythm, an important role is probably played by the pineal gland through MT. Since the PRL rhythm is sleep-dependent, it seems reasonable to infer that the nocturnal entrainment process is mediated by the pineal gland. Of course, an action by other substances (together with or independent from MT) produced by the pineal gland cannot be excIuded. Such a hypothesis awaits further examination by future research. In order to explain the possible influence of MT on PRL circadian rhythm we could suggest that in humans the PRL acrophase while it has been pointed out that in some animals pinealectomy abolishes the PRL circadian rhythm and MT enhances the PRL nocturnal secretion. On the other hand, in addition to normal PRL plasma levels, the group of patients with pineal tumors presented a normal behavioral pattern as far as the recurrence of the wake-sleep cycle and the organization of sleep cycles were concerned. Such results suggest that MT does not influence the hypothalamic- pituitary mechanisms involved in overall PRL circadian secretion and, according to others, either the wake - sleep cycle or the systems controlling the quantity and quality of sleep
Routine assessment tool in psychiatry: a case of questionnaire of family attitudes and burden.
No full textIl Clinical Reappraisal study nell'ambito dello studio ESEMED: implicazioni e prospettive degli studi epidemiologici in Italia
No full textDocumentare un'eventuale correlazione tra le soglie diagnostiche della CIDI e della SCI
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