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Biomedical subjects

U Bonuccelli

Publications and source records attributed to U Bonuccelli.

At least 91 records · Page 5Linked to original sources
PubMed1992

Phenobarbital in the prophylaxis of late posttraumatic seizures.

390 patients with severe head injuries were treated with phenobarbital (PB) orally for a period of 12 months in order to determine whether this drug could reduce the incidence of posttraumatic epilepsy (PTE). An intramuscular PB dose of 2.5-3 mg/kg body weight per day was administered within 24 hours after the trauma; after 5 days, or longer if the coma persisted, the drug was administered orally. Maintenance dosage adjustments, when necessary, were based on serial plasma concentrations of the drug, sustained at between 5 and 30 micrograms/ml. 293 patients completed the study. 66% of these presented one risk factor, while 34% presented two or more. 6 patients (2.04%) had at least one seizure during the twelve months. Plasma drug levels at the time of the seizure, with one exception of 15 micrograms/ml, ranged from 20 to 28 micrograms/ml. The results of the study indicate that PB administered during the first twelve months after the trauma, even at relatively low doses, can have a prophylactic effect on PTE.

Adolescent↗
PubMed1991

The acute convulsant effect of MPTP is dependent on intracerebral MPP+.

The administration of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) to C57 black mice causes an acute seizure syndrome the severity of which is dose dependent; there is also a good correlation between the seizure inducing potential of MPTP and the neostriatal dopamine (DA) depletion caused by MPTP. The simultaneous administration of MPTP and MAO B inhibitors attenuates both epileptiform phenomena and neostriatal DA depletion. On the contrary diethyldithiocarbamate (DDC) exacerbates both responses. All these pharmacological manipulations are known to affect the accumulation of 1-methyl-4-phenylpyridinium ion (MPP+) the main metabolite of MPTP. Thus the present data support the hypothesis of a strict dependence of the epileptiform phenomena on the presence of MPP+. Furthermore the tight correlation existing between the severity of epileptic events and DA depletion suggests that the acute excitotoxic syndrome may contribute to the long-term toxicity of MPTP. *On leave from the Department of Neurology, University of Pisa, Pisa, Italy.

1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine↗
PubMed1991

Domperidone-induced acute dystonia and polycystic ovary syndrome.

The occurrence of acute dystonic reactions (ADRs) due to domperidone administration in two young women is reported. In both patients, a typical polycystic ovary (PCO) syndrome was found. The possibility that the relative hyperestrogenism typical of PCO syndrome acted as a facilitating factor for ADR is discussed.

Adolescent↗
PubMed1991

Platelet peripheral benzodiazepine receptors are decreased in Parkinson's disease.

Peripheral benzodiazepine (BDZ) receptors are located in a variety of tissues, including platelets, in the nuclear and/or mitochondrial membranes. We studied the density of peripheral BDZ receptors in platelets of 10 de novo Parkinson's disease (PD) patients, 18 PD patients treated with a levodopa/carbidopa combination, and in 15 healthy subjects matched for sex and age. The binding assay was conducted using [3H]PK 11195, a specific ligand for peripheral BDZ receptors. A significant decrease in the density of [3H]PK 11195 binding sites has been observed in PD patients with respect to controls (p less than 0.01), but not between de novo and treated PD patients. No correlation has been found between the decrease in density of [3H]PK 11195 binding sites in platelets and either the duration or severity of PD. Peripheral BDZ receptors are implicated in the regulation of mitochondrial respiratory function. Thus, their decrease in PD might parallel the abnormalities in mitochondrial function recently found in this neurologic disease.

Aged↗
PubMed1991

Naloxone partly counteracts apomorphine side effects.

The effects of naloxone on side effects provoked by apomorphine (APO) administration in patients with parkinsonian syndrome have been studied. The group under study included eight patients with Parkinson's disease and four with parkinsonism who received 100 micrograms/kg s.c. APO acutely to test dopaminergic responsiveness. All patients were treated with 20 mg domperidone tablets t.i.d. and then for 2 consecutive days (in double blind fashion) were given a 2-hour i.v. saline infusion alone or with naloxone (8 mg) starting 30 min before APO administration. In both groups, naloxone delayed the appearance of sleepiness, and reduced the intensity of yawning, sleepiness, nausea, and vomiting as compared with saline. These findings indicate a potential usefulness of naloxone and other opioid antagonists in preventing acute APO side effects.

Apomorphine↗
PubMed1991

Altered neuroendocrine regulation of luteinizing hormone secretion in postmenopausal women with Parkinson's disease.

The secretion of gonadotropins and the role exerted by the endogenous opioid system on luteinizing hormone (LH) secretion were investigated in 6 postmenopausal women affected by idiopathic Parkinson's disease (PD) as well as in 6 age- and weight-matched normal postmenopausal women as controls. The mean plasma follicle-stimulating hormone (FSH) and LH levels were evaluated both under basal conditions and after 20 days of conjugated estrogen administration (1.25 mg/day). At the same time, the activity of the endogenous opioid system was evaluated, as well as the LH response to the 4-hour infusion of the opioid antagonist naloxone (1.6 mg i.v. bolus followed by 1.6 mg/h). Both before and during estrogen administration, plasma FSH levels were similar in the two groups of subjects, whereas plasma LH levels were significantly lower (p less than 0.01) in parkinsonian than in control women. In each subject estrogen administration significantly blunted (p less than 0.01) plasma FSH levels. Plasma LH levels were reduced only in controls (p less than 0.05), but not in women with PD. In each subject, before estrogen administration, the plasma LH levels did not vary during naloxone infusion. In control women after 20 days of estrogen administration, the plasma LH levels significantly increased during naloxone infusion (p less than 0.01). By contrast, in women with PD, conjugated estrogens failed to restore the LH response to naloxone. The present results suggest that the neurotransmitter mechanisms, which regulate LH secretion, are altered, and, in particular, the activity of the endogenous opioid system is deficient in women with PD.

Aged↗
PubMed1990

Reduced luteinizing hormone secretion in women with Parkinson's disease.

Plasma luteinizing hormone (LH) levels were significantly lower in 10 postmenopausal women with Parkinson's disease (PD) compared to age-matched controls. The remaining hypophyseal hormones and gonadal steroids were similar in PD patients and in controls, suggesting a selective alteration of hypothalamic dopaminergic mechanisms which regulate LH secretion.

Aged↗
PubMed1990

Increased platelet 3H-imipramine binding and monoamine oxidase B activity in Alzheimer's disease.

Several biochemical abnormalities in peripheral tissues have been reported in Alzheimer's disease (AD). With this in mind we studied platelet monoamine oxidase B (MAO B) activity and 3H-imipramine (IMI) binding in both AD patients and healthy subjects and found a significantly higher level of platelet MAO B activity and 3H-IMI Bmax values in the AD patients. In view of the part that MAO B plays in metabolizing serotonin (5HT) and of the relationship which exists between 3H-IMI binding and 5HT uptake, our results would suggest that with AD there occurs a complex dysfunction in the 5HT system, at least at a peripheral level.

Aged↗
PubMed1990

Effect of naloxone on body temperature in postmenopausal women with Parkinson's disease.

The role exerted by the endogenous opioid system on thermoregulation has been studied in six postmenopausal women affected by Parkinson's disease and in 6 age-matched, normal postmenopausal women, as controls. The women randomly received an infusion of the opioid antagonist naloxone (1.6 mg/h for 4 h) or of saline on two consecutive days. Body temperature, as evaluated by rectal temperature, was significantly lower (p less than 0.05) in Parkinsonian than in normal women, and it did not vary during saline infusion, in either groups. Naloxone infusion significantly reduced (p less than 0.01) body temperature in normal postmenopausal women, but it was unable to modify body temperature in women affected by Parkinson's disease. The low basal body temperature values and the inability of naloxone to exert a hypothermic effect in women suffering from Parkinson's disease seem to constitute further evidence for an impaired regulation of body temperature and impaired activity of the endogenous opioid system in this pathology.

Aged↗
PubMed1990

Possible involvement of dopaminergic mechanisms in the antimigraine action of flunarizine.

Flunarizine, a calcium antagonist widely used in the prophylactic treatment of migraine, may interfere with dopaminergic systems. Flunarizine therapy can in fact induce extrapyramidal side effects and can increase basal as well as stimulated prolactin levels. To better define the mechanism of flunarizine action in migraine, we studied prolactin and growth hormone responses to thyrotropin releasing hormone and sulpiride in 13 female migraineurs before and after 60 days of flunarizine therapy. The treatment did not modify basal prolactin and growth hormone levels, but prolactin response to thyrotropin releasing hormone was enhanced. A paradoxical increase of growth hormone to thyrotropin releasing hormone observed before therapy was blunted after flunarizine treatment. These data indicate a modulatory action of flunarizine on dopaminergic systems which might to some extent explain the antimigraine action of this drug.

Adult↗
PubMed1990

Platelet monoamine oxidase B activity in parkinsonian patients.

Monoamine oxidase B (MAO B) plays a pivotal role in N-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) induced Parkinsonism. An increased MAO B activity in platelets of patients with idiopathic Parkinson's disease (PD) is reported in this study. The possibility that high MAO B activity may represent a trait of vulnerability for PD by enhancing the neurotoxic effects of environmental compounds is discussed.

Aged↗
PubMed1989

Evidence for an epileptogenic action of 1-methyl-4-phenyl-1,2,3,6,-tetrahydropyridine.

Based on behavioral observation alone, poorly characterized paroxysmal motor abnormalities have been reported in mice after acute MPTP administration. This study investigated electroencephalographic (EEG) and behavioral effects of acute MPTP in young and older mice. Single MPTP injections (30 mg/kg i.p.) produced limbic and/or generalized seizures in older (6 mo) and frank epileptiform interictal hippocampal spikes in younger (6-8 wks) mice. These latter showed behavioral seizures only after the 3rd drug administration. Studies of the acute effects of MPTP must take in consideration that seizures "per se" modify brain biochemical and metabolic activity and alter the permeability of the blood brain barrier, adding several confounding variables.

Aging↗
PubMed1988

Flunarizine increases PRL secretion in normal and in migraineous women.

Flunarizine (FLU) treatment has proved effective for migraine but there have been reports--though controversial--of depression and/or extrapyramidal signs and symptoms in cases of chronic therapy. It has been suggested that FLU may interfere with the activity of central dopaminergic systems. In this study, prolactin (PRL) secretion was chosen as a parameter for functional exploration of central dopaminergic systems in normal and migraineous women before and after FLU treatment. Five healthy women were given FLU (20 mg) and placebo per os, each for one day. A significance increase of serum PRL levels was found after FLU administration, but not after placebo. Ten women with common migraine underwent TRH stimulation test (200 micrograms i.v.) before and after a 30-day FLU therapy (10 mg per os). Basal PRL levels were not modified by the treatment, but TRH stimulated PRL values were significantly enhanced after a 30-day FLU therapy. These results seem to confirm the hypothesis that FLU interferes with central dopaminergic activity.

Adult↗
PubMed1988

Oral thyrotropin-releasing hormone treatment in inherited ataxias.

We studied the effectiveness of orally administered thyrotropin-releasing hormone (TRH) (40 mg/day) for 10 days against placebo in 11 patients with hereditary ataxias (HA). All patients completed the trial and none reported any noticeable side effects. A clinical rating scale for inherited ataxias and the Northwestern University Disability Scale for clinical disability showed no significant variation over the duration of the study. Manual dexterity, studied with the peg board test, showed a significant improvement after TRH compared with basal values, which persisted after washout. Eye movement alterations, as revealed by electroculography were reduced after TRH and washout when compared with placebo and basal scores. Hormonal monitoring showed only a transitory effect on the hypothalamus-hypophysis-thyroid axis. These results demonstrate that orally administered TRH has a mild but significant effect only on some cerebellar symptoms in HA.

Administration, Oral↗