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Biomedical subjects

E A Parati

Publications and source records attributed to E A Parati.

36 records · Page 2Linked to original sources
PubMed1988

Role of dopamine in manganese neurotoxicity.

Manganese chloride increased cell mortality when added to human fibroblast cultures. The toxicity of the metal was greatly enhanced by dopamine; this effect was antagonized by the presence in the culture medium of catalase and superoxide dismutase enzymes. Manganese chloride also caused a marked decrease of striatal dopamine concentrations when infused into rat substantia nigra. Manganese neurotoxicity was lowered by pretreating the animals with drugs that reduced striatal dopamine turnover rate. Administration of an antioxidant, such as vitamin E, also partially prevented striatal dopamine decline induced by intranigral manganese infusion. Therefore, the decreased availability or autoxidation of dopamine attenuated manganese neurotoxicity. These findings are in agreement with previous observations suggesting that manganese increases toxic products originating from dopamine catabolism.

Animals↗
PubMed1986

Cryptococcal meningoencephalitis. Case report and review of Italian literature.

A case of cryptococcal meningoencephalitis, as presented by a hypertensive hydrocephalus, is described. To our knowledge, this is the 24th case described in Italy since 1953. The diagnosis was made with ventricular fluid examination: the patient was successfully treated with amphotericin B and 5-fluorocytosine, thus avoiding the risks of surgical treatment of hydrocephalus. Early diagnosis and proper therapy are necessary in order to decrease the high lethality of cryptococcosis.

Adolescent↗
PubMed1986

Clinical usefulness of a dopaminergic agonist in headache diagnosis.

The dopaminergic system seems to be involved in pain modulation. In a 1983 publication, the administration of a dopaminergic agonist has been proposed as a test able to distinguish migraine from other cephalalgia. In the present study, 123 people were tested, 102 of them being migraine patients and the others being normal subjects. The test showed highly specificity for headache patients when compared to normal subjects, and was highly specific for migraine patients when compared to headache patients. Data are discussed considering the clinical diagnostic value, pathophysiological and therapeutic aspects.

Adolescent↗
PubMed1985

Naloxone in cerebral ischemia: preliminary data.

The effect of the opiate antagonist naloxone was evaluated in 11 unselected patients with cerebral ischemia. Naloxone reversed neurological deficits in the 4 patients with less evident signs of vascular damage.

Adult↗
PubMed1985

Failure of chronic haloperidol to affect prolactin secretion due to acute haloperidol administration.

Withdrawal from chronic haloperidol exposure was associated to unaltered circulating levels of prolactin (PRL), decreased 3H-spiperone binding sites in the anterior pituitary and increased 3H-spiperone binding sites in the striatum of male rats. Haloperidol (0.1 mg/kg ip) induced similar rises in plasma PRL in haloperidol-or saline-treated rats and the dose of 0.01 mg/kg was ineffective in both groups. These findings illustrate the poor relatedness existing at the pituitary D2 receptor between biochemical and functional indices.

Animals↗
PubMed1984

Mechanisms involved in the prolactin-releasing effect of benserazide.

The mechanism(s) underlying the prolactin (PRL)-releasing effect of benserazide (Bz), a peripheral inhibitor of L-aromatic amino-acid decarboxylase, was investigated in the rat. In intact male and female rats, Bz was ineffective to increase significantly plasma PRL at 0.8 mg/kg i.p. but elicited an already maximal effect at 1.6 mg/kg. Bz added to in vitro incubated anterior pituitaries (APs) did not alter PRL secretion at the dose of 3.8 X 10(-6)M but increased PRL release at 10(-4)M. Bz, even at very high doses (up to 10(-3) M), did not displace [3H]spiroperidol binding from AP membrane preparations. In rats having had mechanical ablation of the medio basal hypothalamus (MBH), Bz (15 mg/kg i.p.) induced no rise in plasma PRL and did not counteract the striking inhibitory effect of a dopamine (DA) infusion (5 micrograms/kg per min per 120 min). Administration of Bz (15 mg/kg i.p.) into intact male rats decreased significantly the DA concentrations in the median eminence (ME) but not in the residual hypothalamus and the AP. In the same rats 1-dopa (50 mg/kg i.p.) increased significantly the DA concentrations not only in the ME but also in the hypothalamus and the AP. Bz given concurrently with 1-dopa markedly reduced the rise in DA concentrations induced by 1-dopa in the ME, and greatly potentiated the increase in DA concentrations in the hypothalamus. These data indicate that the mechanism whereby a single administration of Bz increases PRL secretion in the rat is not consistent with the postulated DA receptor antagonist action of the drug, but instead implies inhibition of the decarboxylation of 1-dopa at dopaminergic nerve terminals of the ME.

Animals↗
PubMed1984

Neuroendocrinologic findings in patients with untreated Huntington's chorea.

Huntington's chorea (HC) was studied in 14 untreated patients, in six patients receiving long-term neuroleptic treatment, and in four patients after drug withdrawal. Our results showed that patients with HC may be divided into three groups, otherwise clinically indistinguishable, on the basis of growth hormone responsiveness to dopaminergic stimuli. The existence of subpopulations of patients with HC must be considered in further studies on these subjects.

Adult↗
PubMed1984

Divry-Van Bogaert syndrome. Clinical and ultrastructural findings.

A case of a progressive disease with epilepsy, marble skin, and roentgenographic evidence of tapering of the distal carotid branches with corticomeningeal angiomatosis was studied. The clinical course, angiographic findings, and skin biopsy results justified the diagnosis of noncalcifying venous capillary angiomatosis, or Divry-Van Bogaert syndrome.

Adult↗
PubMed1984

Complicated migraine in AS hemoglobinopathy.

Neurological manifestations have been rarely described in sickle cell trait carriers. Almost all the patients up to now reported are black and young of age. An adult white man is reported, with AS hemoglobinopathy, affected by complicated migraine, who developed acute occlusion of two middle cerebral artery branches, with persistent neurological deficit. The possible significance of this association is discussed.

Anemia, Sickle Cell↗
PubMed1983

Long-acting ergot: clinical and neuroendocrinological aspects in migraine patients.

The possible interaction between long-acting ergot and the opiate system has been studied in 12 migraine patients, evaluating the PRL releasing effect of morphine. Our data suggest the integrity of the opiate system in migraine patients and demonstrate that long-acting ergot does not interact with the dopaminergic system. We hypothesize that the effect of ergot on migraine pain may be related to the interaction with non-opiate substances with central analgesic action. Chronic treatment with long-acting ergot significantly reduces the peak of pain intensity of the migraine attack.

Adult↗
PubMed1980

Neuroendocrine effects of quipazine in man in health state or with neurological disorders.

The endocrinological actions of quipazine, a direct serotonin receptor agonist, were investigated in both normal subjects (NS) and individuals with neurological disorders, i.e., Huntington's disease (HD), myoclonic epilepsy (ME) and cluster headache (CH). In both normal subjects and neurologic patients inconsistent and variable changes in the secretion of anterior pituitary hormones were observed. In fact, oral administration of 50 mg of quipazine elicited a rise in plasma GH in only 9/23 subjects investigated (3 NS, 2 HD, 1 ME, 3 CH), decreased GH in 4 subjects (1 NS, 2 HD, 1 CH) and left unmodified plasma GH in the remaining 10 subjects. Only 7/23 subjects showed a positive PRL response to quipazine (2 NS, 1 HD, 1 ME, 3 CH), in one subject (CH) PRL was inhibited while the drug was ineffective in the remaining 15 subjects. For gonadotropins, 5/21 subjects (2 NS, 1 HD, 2 CH) had a positive LH response and 3/20 subjects (1 NS, 1 ME, 1 CH) had a positive FSH response. In one subject (HD) there was inhibition of baseline LH levels and no effects were present in the remaining individuals. No changes in basal TSH levels were present in the 6 subjects investigated (4 NS, 2 ME). Quipazine was instead competent to increase plasma cortisol levels in 6/8 normal subjects. Pharmacodynamic, mainly gastrointestinal, effects of the drug were present in about 50% of the subjects but were not or only poorly correlated with the endocrine responses. Collectively, based on the neuropharmacologic profile of the drug, and in contrast to many animal data, these findings do not support a major role for the serotoninergic system on basal anterior pituitary hormone secretion in man, possibly with the exception of the ACTH-cortisol secretion.

Adult↗
PubMed1980

Effects of DA agonist in Huntington disease hyperkinesia.

Apomorphine, bromocryptine, lysuride, diazepam and cyproheptadine were administered to 11 patients with Huntington's disease (HD). The evaluation of the pharmacologic activity of different drugs on abnormal involuntary movements (AIM) was determined by means of an arbitrary clinical method. Apomorphine, diazepam and cyproheptadine succeeded in improving the AIM, while bromocryptine and lysuride did not modify the clinical pattern or provoked (bromocryptine) a worsening in some patients. The growth hormone (GH) responses to apomorphine and bromocryptine were determined in 6 patients. The relationship between clinical, endocrine results and pharmacologic action of apomorphine is discussed, suggesting that the reducing effect of apomorphine on AIM of HD may be due to its sedative action.

Adult↗
PubMed1979

Failure of MIF-I to affect behavioral responses in patients with Parkinson's diseases under L-dopa therapy.

In eight subjects with Parkinson's disease under an optimal daily dose of L-dopa, acute administration of MIF-I (200 mg i.v.) did not ameliorate either the total disability score or the intellectual test PM 38 when evaluated in comparison with the effect induced by acute administration of a placebo. Also concomitant evaluation of the effect of MIF-I on the secretion of anterior pituitary hormones which are under dopaminergic control i.e., growth hormone and prolactin, did not reveal any potentiation of the L-dopa-induced stimulus.

Aged↗
PubMed1979

Growth hormone hyperresponsiveness to dopaminergic stimulation in Huntington's chorea.

The effect of 3 dopamine (DA) mimetic drugs, i.e. bromocriptine (Bro), apomorphine (Apo) and L-3,4-Dihydroxpenylalanine (L-dopa), was evaluated on plasma growth hormone (GH) levels in 18 patients with Huntington's chorea (HC). 27 Nonobese hospitalized patients were used as controls. Mean baseline GH levels were not altered in patients with HC. Oral administration of Bro (2.5 mg po) or L-dopa (500 mg), or subcutaneous administration of Apo (1.0 mg) resulted in a significantly greater and more prompt (Bro, L-dopa) increase in plasma GH in patients than in controls. These results suggest that presence of an altered dopaminergic regulation of GH secretion in HC.

Adult↗