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Biomedical subjects

M Maj

Publications and source records attributed to M Maj.

At least 109 records · Page 6Linked to original sources
PubMed1994

Circadian rhythms of melatonin, cortisol and prolactin in patients with obsessive-compulsive disorder.

Plasma melatonin, cortisol and prolactin (PRL) levels were measured over a 24-h period in 13 drug-free patients with obsessive-compulsive disorder and in matched healthy subjects. The circadian profiles of melatonin and PRL were altered in patients; the circadian rhythm of cortisol was preserved, although at a higher level compared with normal controls. These changes were significantly related to the severity of the obsessive-compulsive symptoms. Further studies need to clarify the state- or trait-dependent character of these abnormalities.

Adult↗
PubMed1994

Seasonal variation in the dexamethasone suppression test: a longitudinal study in chronic schizophrenics and in healthy subjects.

To evaluate seasonal influences on the dexamethasone suppression test (DST), cortisol and melatonin responses to dexamethasone were assessed in drug-treated chronic schizophrenics and in drug-free healthy volunteers in different seasons of the year, according to a longitudinal study design. In schizophrenic patients, there was a greater rate of cortisol non-suppression to DST in February as compared to November and May (chi 2 = 4.5, p = 0.03) with no significant differences in pre- and post-dexamethasone plasma cortisol levels. In healthy volunteers, in contrast, no seasonal variation in DST results was observed. Moreover, dexamethasone administration did not significantly affect morning plasma melatonin levels in either patients or healthy controls. These findings suggest that seasonality may be of critical importance in evaluating DST results in schizophrenic patients, but not in healthy subjects.

Adult↗
PubMed1994

Validity of rapid cycling as a course specifier for bipolar disorder.

OBJECTIVE: This study's aim was to test the validity of rapid cycling, defined by criteria consistent with those proposed in the DSM-IV draft, as a course specifier for bipolar disorder. METHOD: The study was conducted at a university center for affective disorders on patients fulfilling Research Diagnostic Criteria for bipolar disorder. Thirty-seven rapid-cycling patients, i.e., patients with at least four affective episodes during the previous year, were compared with 74 nonrapid-cycling patients on several demographic and clinical variables. All patients were then followed up prospectively for 2-5 years by monthly personal interviews. RESULTS: The rapid-cycling group was significantly older and had a significantly longer illness duration than the nonrapid-cycling group but did not have a significantly higher percentage of women or frequency of current hypothyroidism. During each year of follow-up, the mean number of affective episodes and the percentage of patients with at least four affective episodes were significantly higher among rapid-cycling patients. Rapid-cycling patients with a pole-switching pattern during the year preceding intake were significantly more likely than other rapid-cycling patients to have at least four affective episodes during each of the first 4 years of follow-up. CONCLUSIONS: These findings support the practical usefulness of rapid cycling as a course modifier for bipolar disorder, since it identifies a patient subgroup with a high recurrence rate. The predictive value of the modifier may be enhanced by the requirement of a pole-switching pattern. Since no external (i.e., unrelated to course) validator was found, the idea that rapid cycling represents one extreme of a continuum of episode frequency in bipolar disorder remains viable.

Adult↗
PubMed1994

[The role of hereditary, clinical and pharmacokinetic factors in predicting the prophylactic effect of lithium salts].

In the framework of a multicentre WHO research program results of prophylactic treatment with lithium carbonate of 77 patients with affective phasic disorders were compared with a series of clinical parameters, specificity of lithium pharmacokinetics and the background characteristics of families in the groups of responders (68.8%) and non-responders. Correlations of efficacy with pharmacokinetic parameters were absent. Better preventive effect of lithium salts took place in male patients with disharmonic features of premorbid personality if their disease and prophylactic treatment started in young or in the middle age, if the disease was diagnosed as bipolar form of manic-depressive psychosis and attained its cyclothymic level with a periodical type of the prior phases. A significant accumulation of affective psychoses was found in the families of the responders. Possibility of prognostic significance of all the analyzed indices is discussed.

Adolescent↗
PubMed1993

The human pineal gland responds to stress-induced sympathetic activation in the second half of the dark phase: preliminary evidence.

Previous reports by our group and by others showed that the human pineal gland is unresponsive to stress-induced systemic sympathetic activation either during the day or 3 hrs after the beginning of darkness. In the present study, we investigated whether a longer period of dark exposure is required to demonstrate a stimulatory effect of stress-induced sympathetic activation on the human pineal gland. For this purpose, plasma melatonin levels were measured in six healthy men (aged 25-34 yrs) both in resting condition and before and after a physical exercise performed between 02.40 and 03.00 h, 30 min after exposure to bright light (2000 lux). Light exposure lasted from 02.10 h up to 04.00 h. The exercise consisted in bicycling on a bicycle ergometer at 50% of the personal maximum work capacity (MWC) for 10 min, followed by another 10 min of bicycling at 80% of the MWC. In the same subjects, plasma melatonin levels were measured also without exposure to light and with no exercise (control dark condition). The results showed that physical exercise, although inducing a rapid and short-term general sympathetic activation (as shown by significant changes in cardiovascular parameters) was able to increase light-depressed plasma melatonin levels only 5 hrs after the end of the stress (p < 0.0001, group X time interaction, two-way ANOVA with repeated measures). These findings suggest that the human pineal gland is responsive to systemic sympathetic activation induced by physical stress in the second half of the dark phase.

Adult↗
PubMed1993

Pineal response to isoproterenol in rats chronically treated with electroconvulsive shock.

Chronic electroconvulsive shock (ECS) has been shown to induce a downregulation of beta 1-adrenergic receptors in the rat cerebral cortex. Because the secretion of melatonin in the pineal gland is regulated primarily by beta 1-adrenoceptors, in the present study we investigated the effect of chronic administration of ECS on pineal beta-adrenergic responsiveness to isoproterenol. To this purpose, young adult male rats received once daily for 8 days ECS (80 mA, 0.5 s) or sham ECS. On the day after the last ECS or sham treatment, they were injected with isoproterenol hydrochloride (1 mg/kg SC) or volume-matched saline at 1600 h. Two hours later they were killed by decapitation. Results showed that the isoproterenol-induced increase in the pineal melatonin content was blunted in rats treated with ECS as compared to sham-treated animals (shock x drug interaction = p < 0.01). These data indicate that chronic ECS treatment affects beta 1 receptor-mediated melatonin production in the pineal gland. Further studies need to elucidate whether the blunted melatonin response to isoproterenol in ECS-treated rats is due to a downregulation of pinealocyte beta-adrenergic receptors.

Analysis of Variance↗
PubMed1993

Evaluation of two new neuropsychological tests designed to minimize cultural bias in the assessment of HIV-1 seropositive persons: a WHO study.

In the course of the preparatory work for the WHO cross-cultural study on the neuropsychiatric aspects of HIV-I infection, two new neuropsychological tests (the WHO/UCLA Auditory Verbal Learning Test and the Color Trails 1 & 2) were developed. The evaluation of these tests was performed at four sites, two in developed and two in developing countries. The data obtained suggest that the tests are more culture fair than others currently used to assess the same functional domains, that they are sensitive to HIV-1-associated cognitive impairment, and that this sensitivity "holds" across different cultures.

Journal Article↗
PubMed1992

Blunting by chronic phosphatidylserine administration of the stress-induced activation of the hypothalamo-pituitary-adrenal axis in healthy men.

The effect of chronic administration of phosphatidylserine derived from brain cortex on the neuroendocrine responses to physical stress has been examined in a placebo-controlled study in 9 healthy men. Phosphatidylserine 800 mg/d for 10 days significantly blunted the ACTH and cortisol responses to physical exercise (P = 0.003 and P = 0.03, respectively), without affecting the rise in plasma GH and PRL. Physical exercise significantly increased the plasma lactate concentration both after placebo and phosphatidylserine. The results suggest that chronic oral administration of phosphatidylserine may counteract stress-induced activation of the hypothalamo-pituitary-adrenal axis in man.

Administration, Oral↗
PubMed1992

Melatonin and cortisol secretion in patients with primary obsessive-compulsive disorder.

Plasma levels of melatonin and cortisol were measured over a 24-hour period in seven patients with primary obsessive-compulsive disorder (OCD) and seven matched healthy control subjects. In OCD patients, the 24-hour secretion of melatonin was reduced as compared with that in healthy control subjects, whereas its circadian rhythm was preserved. In addition, in OCD patients, the overall secretion of cortisol was higher than that in control subjects, but there was no change in the circadian pattern of cortisol secretion. No correlation was found between clinical parameters and hormone levels.

Adult↗
PubMed1992

Computerized EEG topography findings in schizophrenic patients before and after haloperidol treatment.

An increase of delta and fast beta activity in schizophrenic patients when compared with normal controls has been consistently reported. Topography of these abnormalities, in particular a possible frontal localization of delta, and their relationship to drug treatment and clinical status are still debated. In order to assess these issues, a multilead CEEG investigation was carried out in a group of 20 DSM-III-R schizophrenics, both before and after haloperidol treatment. All findings are described in terms of amplitude and relative power. Drug-free schizophrenics, when compared with a group of normal controls, showed a generalized increase of delta and fast beta, and a decrease of alpha 2 relative power. After acute treatment, patients showed a significant decrease of delta, and an increase of theta 2, beta 1, and beta 2. After 28 days of haloperidol treatment, similar changes were observed for delta, together with an increase of alpha 1, and a decrease of fast beta.

Adult↗
PubMed1992

Temporal relationship between melatonin and cortisol responses to nighttime physical stress in humans.

It has been shown that, in the rat, physical stress decreases pineal melatonin levels at night, whereas it increases melatonin production during the day. We have demonstrated that nighttime physical exercise is able to blunt the nocturnal surge of plasma melatonin in healthy subjects. Since this effect might be mediated by exercise-induced cortisol secretion from the adrenal gland, in the present investigation we studied the relationship between cortisol and melatonin responses to nighttime physical stress in six healthy men, aged 28-33 yr. The physical stress consisted of bicycling on a bicycle ergometer at 50% of personal maximum work capacity (MWC), followed by another 10 min of bicycling at 80% of MWC. According to our previous data, physical exercise performed between 2240 h and 2300 h significantly reduced the nocturnal surge of plasma melatonin and increased the levels of cortisol. The surge in plasma cortisol preceded the decrease in plasma melatonin concentration. These findings suggest a temporal relationship between plasma cortisol and melatonin responses to physical stress; the causal nature of this relationship remains to be elucidated.

Adult↗
PubMed1992

Depressed nocturnal plasma melatonin levels in drug-free paranoid schizophrenics.

The 24-h profiles of plasma melatonin and cortisol were evaluated in 7 drug-free male paranoid schizophrenics and in 7 healthy subjects matched to the patients for age, sex, body weight, height and season of testing. Blood samples were obtained at 20.00, 22.00, 24.00, 01.00, 02.00, 06.00, 08.00 and 12.00 h. Light was turned off from 21.00 to 07.00 h. Compared with that of the normal controls, the circadian rhythm of plasma melatonin was absent in paranoid schizophrenics (F7.84 = 7.30, p less than 0.0001; two-way ANOVA with repeated measures) whereas the 24-h profile of plasma cortisol was preserved, although at a slightly higher level (F1.12 = 26.810, p less than 0.0002). The melatonin/cortisol ratio was significantly higher in healthy subjects than in the schizophrenic patients. A functional relationship between disturbances in the melatonin rhythm especially and schizophrenia may be proposed, although the significance of this relationship remains to be elucidated.

Adult↗
PubMed1992

Physical stress in the middle of the dark phase does not affect light-depressed plasma melatonin levels in humans.

The human pineal gland has been shown to be unresponsive to stress-induced sympathetic activation during the day. However, the effects of stress on human melatonin production have received little investigation at night, when the pinealocytes should be physiologically responsive to noradrenergic stimulation. For this purpose, plasma melatonin and cortisol levels were measured in 7 healthy men (aged 25-34 years), both in resting condition and before and after a physical exercise performed between 23.40 and 24.00 h, 30 min after exposure to bright light (2,500 lx). The exercise consisted in bicycling on a bicycle ergometer at 50% of the personal maximum work capacity (MWC) for 10 min, followed by another 10 min of bicycling at 80% of the MWC. The results clearly showed that physical exercise does not affect light-depressed plasma melatonin levels, whereas it clearly increased plasma cortisol concentrations (p less than 0.002, two-way ANOVA with repeated measures), systolic blood pressure, pulse pressure and heart rate. These findings suggest that the human pineal gland is not responsive to systemic sympathetic activation induced by physical stress even in the middle of the dark phase.

Adult↗
PubMed1992

Pattern of recurrence of illness after recovery from an episode of major depression: a prospective study.

OBJECTIVE: This study assessed prospectively the pattern of recurrence of illness after recovery from an episode of major depression. METHOD: Seventy-two patients who had recovered from an episode of primary, nonbipolar, nonpsychotic major depression were evaluated bimonthly with the Comprehensive Psychopathological Rating Scale for a period ranging from 20 to 108 months (median = 66 months). New ("prospective") episodes were ascertained with a structured diagnostic interview. The probabilities of remaining well after the index episode and after the first prospective episode were assessed by the life-table method. The severity and duration of prospective episodes and the index episode were compared by linear regression analysis. RESULTS: The probability of remaining well after recovery from the index episode was 76% at 6 months, 63% at 1 year, and 25% at 5 years. The risk of recurrence was lower among patients receiving prophylactic treatment with antidepressants and/or lithium and among those with histories of fewer than three previous episodes. The probability of remaining well was significantly lower 2 years after the first prospective episode than 2 years after the index episode. A pattern of increasing severity from the index episode to the first, second, and third prospective episodes was observed and was not affected by treatment. CONCLUSIONS: Major depression has a high rate of recurrence, even when bipolar and psychotic cases are excluded. The highest rate is observed during the first months after recovery from an episode. Prophylactic drug treatment reduces the risk of recurrence but apparently does not affect the trend toward increasing severity of subsequent episodes.

Adult↗