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Biomedical subjects

D Kemali

Publications and source records attributed to D Kemali.

At least 19 recordsLinked to original sources
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

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↗
PubMed1991

Lateralization patterns of event-related potential and performance indices in schizophrenia: relationship to clinical state and neuroleptic treatment.

In a previous study we assessed lateralization patterns of verbal stimuli processing, by means of behavioural and neurophysiological measures, in a sample of drug-free schizophrenics and one of normal controls. The main findings obtained were the following: (1) a right visual field (RVF) advantage on reaction time (RT) and late positive complex (LPC) peak of the ERPs in normal subjects but not in schizophrenics; (2) a left visual field (LVF) significant advantage on P360 and slow wave (SW) amplitude in schizophrenics but not in controls; (3) a significantly longer RT and smaller P360 and SW for RVF stimuli in schizophrenics as compared to normals; (4) a significant contralateral effect of visual field on N180 at both the left and the right parietal site in normal controls and only at the right parietal site in schizophrenics. As a further step of this investigation we re-tested 9 schizophrenics after 28 days of haloperidol treatment. The post-treatment lateralization pattern of verbal stimuli processing was characterized by a RVF advantage on LPC peak amplitude and no visual field effect on P360 and SW, resembling the normal group pattern. Moreover, the N180 amplitude was found to be reduced. Relationships between lateralization pattern and clinical picture changes induced by haloperidol treatment are discussed.

Adult↗
PubMed1991

CEEG mapping in drug-free schizophrenics. Differences from healthy subjects and changes induced by haloperidol treatment.

A topographic CEEG investigation was carried out in 20 drug-free, DSM-IIIR diagnosed schizophrenics and in a group of matched healthy controls. The effects of acute and chronic haloperidol treatment were then assessed in the patient group. On the baseline recording, schizophrenics showed a widespread increase in delta, theta 1 and beta 3 amplitude. Acute haloperidol administration produced a decrease in delta and an increase in slow beta amplitude. After 28 days of treatment, delta and fast beta were reduced while theta 2 and alpha 1 were increased. CEEG abnormalities in schizophrenic subjects appear, therefore, to be reduced by chronic neuroleptic treatment.

Adult↗
PubMed1990

Physical exercise at night blunts the nocturnal increase of plasma melatonin levels in healthy humans.

The effects of physical exercise on nighttime melatonin secretion have never been investigated in humans. For this purpose, plasma melatonin levels were measured at different times during the day and the night in seven healthy men (aged 26-33 yrs), both in resting condition and before and after a physical exercise performed between 10.40 and 11.00 p.m.. The exercise consisted in bicycling on a bicycle ergometer at 50% of the personal maximal work capacity (MWC) for 10 min, followed by other 10 min of bicycling at 80% of the MWC. The results clearly showed that physical stress at night significantly blunts the nocturnal increase in plasma melatonin levels (group X time interaction: p less than 0.00001; two-way ANOVA with repeated measures). These findings, taken together with the data of the literature, suggest that the response of the pineal gland to provocative stimuli may depend on its level of activity when the stimulus is applied.

Adult↗
PubMed1990

Factors associated with increased noradrenaline levels in schizophrenic patients.

1. CSF NA levels were determined in a sample of DSM III-diagnosed schizophrenics and in a non-psychiatric control group. Schizophrenics with NA levels above and below the median were compared with respect to several clinical, historical, neuropsychological and biological variables. 2. Mean CSF NA levels were significantly higher in schizophrenics than in controls. 3. Schizophrenics with high CSF NA levels, as compared to those with low levels, had significantly higher scores on the CPRS subscale for positive symptoms. Moreover, in the former subgroup, C-EEG alpha relative activity was significantly lower and C-EEG beta relative activity was significantly higher in frontal and central leads. Two of the three patients who had been never treated with neuroleptics, and three of the six patients who had been neuroleptic-free for more than four weeks had high CSF NA levels. 4. These data support the relationship between increased CSF NA levels and the condition of overarousal of the schizophrenic patients, and suggest that prior neuroleptic treatment is not a major determinant of high CSF NA concentration in schizophrenics.

Adolescent↗
PubMed1990

C-EEG brain mapping in DSM-III schizophrenics after acute and chronic haloperidol treatment.

A multi-lead C-EEG investigation was carried out, in order to evaluate changes induced by acute and chronic treatment with haloperidol in DSM-III-R schizophrenics. After the acute treatment the main C-EEG changes were (1) a significant decrease of delta relative power (RP) over all the explored leads and of theta 1 over the occipital leads; (2) an increase in alpha 2 and beta 2 RP, as well as a decrease of beta 3 RP confined to the anterior temporal leads (T3, T4). During chronic treatment, C-EEG changes observed were (1) a significant decrease of delta RP and an increase of theta 1 RP; (2) an increase of alpha 1 and alpha 2 RP; (3) a significant decrease of beta 1, beta 2 and beta 3.

Adult↗
PubMed1990

Dexamethasone suppression test in patients with primary obsessive-compulsive disorder and in healthy controls.

The dexamethasone suppression test (DST) was performed in 18 patients (11 women and 7 men) who met the DSM III-R criteria for obsessive-compulsive disorders (OCD), and in 20 healthy volunteers (12 women and 8 men). At 4.00 p.m., following dexamethasone administration, 5 patients (27.7%) and 1 healthy subject (5%) displayed plasma cortisol values well above the cut-off value of 50 ng/dl. A significantly different sex ratio was observed between suppressor and nonsuppressor patients with OCD (chi 2 = 4.40, p less than 0.03), because all nonsuppressor patients were male. Compared to the suppressors, nonsuppressor patients with OCD did not differ in any of the clinical and demographic variables investigated. Moreover, in our patient sample, the mean +/- SD total Hamilton Depression Rating Score (HDRS) was 14.8 +/- 2.5, and none of the nonsuppressors with OCD had a total HDRS greater than 17. These data suggest that a subgroup of OCD patients, particularly males, may escape the DST independently from the coexistence of depressive features.

Adolescent↗
PubMed1990

Effects of phosphatidylserine on the neuroendocrine response to physical stress in humans.

The activity of brain cortex-derived phosphatidylserine (BC-PS) on the neuroendocrine and neurovegetative responses to physical stress was tested in 8 healthy men who underwent three experiments with a bicycle ergometer. According to a double-blind design, before starting the exercise, each subject received intravenously, within 10 min, 50 or 75 mg of BC-PS or a volume-matched placebo diluted in 100 ml of saline. Blood samples were collected before and after the exercise for plasma epinephrine (E), norepinephrine (NE), dopamine (DA), adrenocorticotropin (ACTH), cortisol, growth hormone (GH), prolactin (PRL) and glucose determinations. Blood pressure and heart rate were also recorded. Physical stress induced a clear-cut increase in plasma E, NE, ACTH, cortisol, GH and PRL, whereas no significant change was observed in plasma DA and glucose. Pretreatment with both 50 and 75 mg BC-PS significantly blunted the ACTH and cortisol responses to physical stress.

Adrenocorticotropic Hormone↗
PubMed1989

Lithium decreases retinal melatonin levels in the frog.

The effect of the acute i.p. administration of lithium chloride (1 mg/kg) and of haloperidol (1 mg/kg) on retinal melatonin levels was studied in light-adapted and dark-adapted frogs of the species Rana esculenta. Two hours following drug administration, animals were killed by decapitation and a single retina from each frog was collected and homogenized in 1 ml of chilled 0.1 N HCl. After centrifugation, the pH of the supernatant was adjusted to 7.0. Melatonin was extracted by diethylether and assayed by double antibody radioimmunoassay (RIA). Lithium induced a significant decrease of retinal melatonin levels both in light-adapted (P less than 0.006) and in dark-adapted (P less than 0.01) animals, whereas no change was observed after haloperidol treatment. These results suggest that the scleral aggregation of pigment granules induced by lithium in the frog retina is not mediated by a stimulation of melatonin synthesis.

Animals↗
PubMed1989

Long-term outcome of lithium prophylaxis in patients initially classified as complete responders.

The long-term outcome of lithium prophylaxis was explored in 43 bipolar and 36 unipolar patients who had been classified as complete responders after the first 2 years of treatment. These patients were followed up prospectively for a further period of 5 years (treatment period II), during which their psychopathological state was assessed monthly or bimonthly. Forty-nine patients completed treatment period II, 2 died during this period, 7 did not attend the unit any more and could not be traced, and 21 definitively interrupted lithium treatment before the end of the period. In 18 cases the decision to stop lithium was taken by the patient. Twenty-five patients relapsed during the treatment period II. Four relapsers had three or more episodes concentrated during the last 2 years of treatment. These results suggest that the predictive value of an initial favourable response to lithium should not be overrated, and that the impact of the drug on the long-term course of major affective disorders in ordinary clinical conditions might be less dramatic than currently believed.

Adult↗