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Biomedical subjects

A Polleri

Publications and source records attributed to A Polleri.

At least 19 recordsLinked to original sources
PubMed2000

Dexamethasone effects on cortisol secretion in Alzheimer's disease: some clinical and hormonal features in suppressor and nonsuppressor patients.

Alterations in the hypothalamic-pituitary-adrenal axis (HPAA) and failure of dexamethasone (DXT) to suppress cortisol secretion occur in Alzheimer's disease (AD). This study was aimed to settle possible differences in some clinical (age, body weight, body mass index, dementia severity) and hormonal parameters in AD patients non-responders to overnight 1 mg-DXT suppression test compared with the responder subjects. ACTH, cortisol and dehydroepiandrosterone sulphate (DHEAS) day-time levels were assessed in 25 AD patients and in 12 age-matched healthy controls before DXT administration. In view of their neuroprotective effects, plasma levels of Insulin-like Growth Factor-I (IGF-I) and of IGF-Binding Proteins (IGFBPs) were also determined. After DXT, 8 AD subjects (32%) showed cortisol levels above the conventional cut-off of 140 nmol/L. No significant differences were found in clinical parameters in suppressor vs nonsuppressor patients. AD subjects showed higher cortisol, cortisol/DHEAS ratios, and lower DHEAS levels in comparison with controls. Both ACTH and cortisol levels were not different in suppressor and nonsuppressor patients, but DHEAS levels were significantly lower in nonsuppressor cases, who also exhibited ACTH and cortisol periodicities more altered than in suppressor and in control subjects. IGF-I and IGFBP-3 levels were lower and those of IGFBP-1 higher in nonsuppressor than in suppressor cases and in healthy controls. IGF-I/IGFBPs system data were correlated with cognitive impairment and adrenal steroid levels in AD patients.

Aged↗
PubMed2000

Hippocampal perfusion and pituitary-adrenal axis in Alzheimer's disease.

The hippocampus is involved in Alzheimer's disease (AD) and regulates the hypothalamus-pituitary-adrenal axis (HPAA). Enhanced cortisol secretion has been reported in AD. Increased cortisol levels affect hippocampal neuron survival and potentiate beta-amyloid toxicity. Conversely, dehydroepiandrosterone (DHEA) and its sulfate (DHEAS) are believed to antagonize noxious glucocorticoid effects and exert a neuroprotective activity. The present study was aimed at investigating possible correlations between hippocampus perfusion - evaluated by SPECT - and HPAA function in AD. Fourteen patients with AD and 12 healthy age-matched controls were studied by (99m)Tc-HMPAO high-resolution brain SPECT. Plasma adrenocorticotropin, cortisol, and DHEAS levels were determined at 2.00, 8.00, 14.00, 20.00 h in all subjects and their mean values were computed. Cortisol/DHEAS ratios (C/Dr) were also calculated. Bilateral impairment of SPECT hippocampal perfusion was observed in AD patients as compared to controls. Mean cortisol levels were significantly increased and DHEAS titers were lowered in patients with AD, as compared with controls. C/Dr was also significantly higher in patients. Using a stepwise procedure for dependent SPECT variables, the variance of hippocampal perfusional data was accounted for by mean basal DHEAS levels. Moreover, hippocampal SPECT data correlated directly with mean DHEAS levels, and inversely with C/Dr. These data show a relationship between hippocampal perfusion and HPAA function in AD. Decreased DHEAS, rather than enhanced cortisol levels, appears to be correlated with changes of hippocampal perfusion in dementia.

Adrenocorticotropic Hormone↗
PubMed1998

Relationship between cognitive function, growth hormone and insulin-like growth factor I plasma levels in aged subjects.

Basal growth hormone (GH) and insulin-like growth factor I (IGF-I) as well as GH responses to GH-releasing hormone (GHRH) were studied in 22 subjects (7 females, 15 males), aged between 65 and 86 years. The study was aimed at investigating the possible correlations between the age-dependent GH-IGF-I axis decline and the cognitive function - assessed by the Mini Mental State Examination (MMSE). The relationship between hormonal data, cognition and age, body weight, body mass index (BMI), some nutritional indices (triceps skinfolds, TSF, mid-arm circumference, MAC), and physical activity - quantified by the physical functioning index (PFI)--were also analyzed. GH basal levels were within the normal range, while GH responses to GHRH were blunted in most cases. GH peaks after GHRH were directly correlated with GH basal values. IGF-I serum levels were found to be in the lower part of the reference range for adult subjects or below it. GH responses to GHRH, but not GH and IGF-I basal levels, were inversely correlated with subject age. GH secretion areas after GHRH were inversely correlated with BMI, but no further correlations between GH data and clinical or nutritional parameters were found. MMSE values directly correlated with MAC and PFI values. IGF-I levels were directly correlated with MMSE scores, being lowered in patients with more advanced cognitive deterioration, and with MAC values--the decrease of which is thought to reflect protein caloric malnutrition--but not with body weight, BMI, TSF and PFI. MMSE-related protein caloric malnutrition and decreased physical activity possibly take part in affecting IGF- I function in subjects with mild cognitive impairment and, reciprocally, IGF-I decrement might affect neuronal function.

Aged↗
PubMed1997

Menstrual cycle and ovary alterations in women with epilepsy on antiepileptic therapy.

Impaired reproductive function is thought to frequently affect women with epilepsy, mainly when seizures originate in the temporal lobe. In this study, we evaluated menstrual cycle features and assessed ovulation by determining luteal progesterone (Pg) levels in 101 consecutive women with epilepsy (36 with idiopathic generalized epilepsy -IGE; 65 with partial epilepsy -PE), aged between 16 and 50 years, treated with various antiepileptic drugs (AED). PE originated in the temporal lobe (TLE) in 40 subjects, in the frontal lobe in 13, in the parietal lobe in 2, while the origin of focal seizures remained undetermined in 10 patients. In all patients, menstrual and reproductive history, body mass index, hair distribution and hormonal pattern were assessed. Suprapubic ovary ultrasound (US) examination was carried out in 83 patients (28 with IGE, 55 with PE). Three patients with IGE and one with PE were amenorrheic. Oligomenorrhea occurred in 16 patients, polymenorrhea in 2. Changes in menstrual cyclicity were independent from epilepsy type (19.4% in IGE; 23.1% in PE) and from origin of focal discharges (22.5% of patients with TLE; 20.0% with origin in other brain areas). Luteal Pg levels remained below 2 ng/ml in 30 patients independently of epilepsy type. Corpus luteum dysfunction was combined with hyperandrogenism in 15 of these patients. In the other cases different alterations of hypothalamus-pituitary-ovary axis were observed. Valproic acid blunted luteal Pg surge more frequently than other AED. Polycystic ovaries (PCO) were observed in 14 (16.9%) patients (21.0% with IGE: 14.5% with PE). These prevalences are not higher than those reported in the general population. Among PE patients, PCO was found in 1 case with undetermined focal origin and in 7 TLE cases, who also had ovary volume significantly larger than patients with seizures originating from the frontal or parietal lobe. Epileptic women exhibited an increased occurrence of multifollicular ovaries (MFO) found in 12 cases (14.4% vs 5% in the general population). However, no defined hormonal or clinical pictures were associated with this US alteration in most patients. These findings reappraise the impact of ovary alterations in women mainly affected by mild to moderate epilepsy, on differing AED regimens, with the exception of more frequent ovulatory dysfunction and PCO occurrence in patients taking VPA.

Adolescent↗
PubMed1994

Lowered circannual urinary melatonin concentrations in episodic cluster headache.

The circannual secretion of melatonin in 14 Swedish and 15 Italian patients suffering from episodic cluster headache was compared with 14 Swedish and 15 Italian healthy controls matched for sex and age. Overnight samples of urine were collected once a month from 8 to 14 months and kept at -20 degrees C until analysed with RIA. The melatonin concentrations in nocturnal urine were permanently low in cluster headache and there was no consistent change of the melatonin concentration in relation to cluster periods occurring during the study. There was no definitive circannual or infraannual rhythmicity of melatonin in patients or controls. Multiple analysis of variance with repeated measurements showed a significant effect of disease (p < 0.05), but not of time. Sex, geographical location, age, and smoking also had significant effects (p < 0.001) on the melatonin concentrations. Lower melatonin levels in cluster headache patients than in controls may in part be related to a larger number of smokers in the patient group. The relation between tobacco use and melatonin should be further studied.

Adult↗
PubMed1994

Urinary melatonin excretion throughout the ovarian cycle in menstrually related migraine.

Nocturnal urinary melatonin excretion was significantly decreased throughout an ovarian cycle in 12 migraine without aura patients compared to 8 healthy controls. Normal increases in urinary melatonin excretion during the luteal phase was less pronounced in the migraine patients. Melatonin excretion was further decreased during headache. The data indicate impaired pineal function in migraine.

Adult↗
PubMed1994

Sex hormones, gonadotropins and prolactin in male epileptic subjects in remission: role of the epileptic syndrome and of antiepileptic drugs.

Sex steroid peripheral pattern, pulsatile luteinizing hormone (LH) secretion, gonadotropin and prolactin responses to LH-releasing hormone (LHRH) and thyrotropin-releasing hormone (TRH) were studied in 35 male epileptics treated with phenobarbital (PB), carbamazepine (CBZ), or phenytoin (PHT), and in age-matched healthy males. Idiopathic generalized epilepsy (IGE) was diagnosed in 12 cases and partial epilepsy (PE) in 23 cases. Patients were seizure-free and did not show EEG abnormalities at repeated controls in the last 5 years, so that interfering effects of seizures were possibly excluded. The aim of the study was to evaluate both the role of epileptic syndromes and of anti-epileptic drugs on the endocrine function. Changes in sex hormone binding globulin, total and free testosterone, dihydrotestosterone and delta 4-androstenedione were found to be independent of the epileptic syndrome type. The LH response to LHRH was lower in PB-treated PE than in IGE subjects on the same drug regimen. An impairment of LH pulsatility with respect to controls was found in PE but not in IGE patients taking PB. Among antiepileptic drugs, PHT is associated with higher sex hormone binding globulin and estradiol and lower free testosterone and dihydrotestosterone levels. PB and CBZ, but not PHT, blunt the LH response to exogenous LHRH in PE. Prolactin responses to TRH were consistently enhanced in PE subjects treated with CBZ or PHT.

Adult↗
PubMed1993

Circadian secretion of melatonin and thyrotropin in hospitalized aged patients.

Alterations in periodical functions are known to occur in aging and may be regarded as markers of the aging process itself. Melatonin and Thyroid Stimulating Hormone (TSH) circadian periodicities were studied in 22 aged subjects and in 13 adult controls. The study of rhythmicity was performed by the Cosinor analysis. Elderly subjects were hospitalized because of various concomitant diseases. Circadian periodicity of both hormones was disrupted in the aged group, and the deterioration of melatonin periodicity was significantly correlated with the decay in cognitive functions, quantified by the Mini Mental State evaluation. Diabetes was also found to affect, though not significantly, melatonin, but not TSH, periodicity. Melatonin and TSH nocturnal peaks were decreased in aged people. TSH oscillation amplitudes were inversely correlated with age. No correlation was found between melatonin and TSH secretory features both in adult and in aged subjects.

Adult↗
PubMed1993

Effects of pyridostigmine, corticotropin-releasing hormone and growth hormone-releasing hormone on the pituitary-adrenal axis and on growth hormone secretion in dementia.

Alterations of neuroendocrinological indices determined by the impaired regulating effects of cholinergic neurotransmission have been described in primary dementia. In this study we have evaluated the effects of acetylcholinesterase inhibition by pyridostigmine on growth hormone (GH), adrenocorticotropic hormone (ACTH) and cortisol secretion and on their responses to GH-releasing hormone (GHRH) and corticotropin-releasing hormone (CRH) in 7 patients with primary degenerative dementia and in 8 sex- and age-matched controls. Demented subjects showed higher cortisol basal levels and lower ACTH levels than controls. Pyridostigmine increased the GH response to GHRH in both groups, the effect being significantly enhanced in patients. An increase of ACTH and cortisol levels was found in both groups after pyridostigmine and CRH administration. Pyridostigmine pretreatment significantly increased the ACTH response to CRH in controls but not in patients. The obtained data may indicate that a muscarinic receptor upregulation and an impairment of somatostatinergic function are operative in the regulation of GH secretion in dementia. An underlying hyperactivity of the hypothalamic-pituitary-adrenal axis impairs the responses of ACTH and cortisol to CRH in this disorder.

Adrenocorticotropic Hormone↗
PubMed1991

Urine melatonin in alcoholic patients: a marker of alcohol abuse?

Ethanol is known to alter central neurotransmission and endocrine functions. Urine melatonin was studied in 10 male chronic alcoholic patients, before and after two weeks of controlled alcohol abstinence, and in sex and age matched healthy controls. In both groups, 24-hour urines were collected in two fractions corresponding to day- (D) (08:00-20:00) and night- (N) (20:00-08:00) time. Urine melatonin was assayed by RIA after methylene chloride extraction. Twenty-four hour urine melatonin levels were calculated adding up D and N values. In patients during alcohol intake, the 24-hour urine melatonin levels were significantly higher than in controls (p = 0.004, Student's t test). A disruption of the physiological ratio between N and D values was also observed, since the higher melatonin levels occurred in the D fraction. In drinking alcoholics, melatonin D values were significantly higher than the D values found in controls (p less than 0.01, Student's t test) and in the same patients after alcohol withdrawal (p less than 0.05). The N/D ratio approximated 1 during alcohol intake and became larger than 1 after alcohol withdrawal, as in the controls. The melatonin data were correlated with the suppressive effects of dexamethasone (DXT) on cortisol secretion evaluated both during alcohol intake and during abstinence. After alcohol withdrawal, the two (out of 10) patients, who remained unresponsive to the DXT suppression test, showed high D melatonin values and a low N/D ratio. These preliminary data indicate that in chronic alcoholism the pattern of urinary "melatonin- like immunoreactivity" is altered.

Adult↗
PubMed1990

Sex steroids and cluster headache: hypotheses.

The pathophysiological significance of the changes in gonadal function observed in cluster headache is far from clear. Some features of the disease, such as the sex predominance, the lateralization of symptoms and the character of pain itself may be connected to some biological effects of gonadal steroids.

Animals↗
PubMed1989

Cluster headache in the male: sex steroid pattern and gonadotropic response to luteinizing hormone releasing hormone.

Serum testosterone, dihydrotestosterone, delta 4-androstendione and 17 beta-estradiol, sex hormone binding globulin (SHBG) and gonadotropic response to luteinizing hormone releasing hormone (LHRH) were studied in 34 male subjects with episodic or chronic cluster headache (CH). The sex steroid free fractions and those bound to SHBG and albumin were determined by a simulatory computerized method based on the mass action law. Individual steroid values were dispersed over a wide range in CH patients. Total, free and carrier protein-bound testosterone levels were significantly diminished only in chronic CH, where luteinizing hormone (LH) peak values after intravenous administration of LHRH were also decreased. Basal and peak follicle stimulating hormone (FSH) levels were significantly increased in episodic and in chronic CH groups, in comparison to healthy controls.

Adult↗
PubMed1987

Luteinizing hormone pulsatile secretion and pituitary response to gonadotropin releasing hormone and to thyrotropin releasing hormone in male epileptic subjects on chronic phenobarbital treatment.

Endocrine changes have been reported in treated epileptic subjects, who often exhibit sexual dysfunctions, but the endocrine effects of single antiepileptic drugs have not been completely elucidated. In this study we have investigated the influence of phenobarbital (PB) on adenopituitary function and on peripheral sexual steroid pattern in 8 epileptic males. Chronic PB treatment does not modify luteinizing hormone (LH) pulsatile secretion. In the same subjects, LH and follicle stimulating hormone (FSH) response to Gonadotropin Releasing Hormone was blunted with respect to healthy controls both in terms of absolute values and of secretion areas. No difference was found in prolactin (PRL) response to Thyrotropin Releasing Hormone. In the epileptic group a significant increase in the levels of sex hormone binding globulin and a consequent decrease of the percent free testosterone have been observed. PB treatment also significantly lowers 17-beta-estradiol mean levels. These data suggest that PB independently affects both gonadotropin secretion and peripheral steroid pattern.

Adult↗
PubMed1987

Thyroid-stimulating hormone and prolactin responses to thyrotropin-releasing hormone in common migraine.

Intravenous administration of 50 micrograms or 200 micrograms thyrotropin-releasing hormone (TRH) to men with common migraine elicited blunted prolactin (PRL) responses, when compared with healthy controls. The thyroid-stimulating hormone (TSH) response was enhanced after 50 micrograms TRH in the migraineurs, but not after 200 micrograms. The physiologic TSH dose-response relationship was abolished in migraine sufferers. The data may be interpreted in the light of dopaminergic and noradrenergic supersensitivity, for PRL and TSH, respectively. The TSH response in migraine differs from the one that occurs in depression.

Adult↗