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Biomedical subjects

G Rastelli

Publications and source records attributed to G Rastelli.

36 records · Page 2Linked to original sources
PubMed1993

Acute and chronic hyperbaric oxygen exposure in humans: effects on blood polyamines, adrenocorticotropin and beta-endorphin.

Plasma beta-endorphin, adrenocorticotropin (ACTH) and blood polyamine (spermidine and spermine) concentrations were evaluated in healthy adult male athletes undergoing hyperbaric oxygen exposure for 10 days (2.8 atm, 100% O2, 60 min daily). In the "acute phase", corresponding to the first day of treatment, and in the "acute in the chronic phase", corresponding to the values obtained on the 5th and 10th days after 60 min of hyperbaric O2, both ACTH and beta-endorphin levels increased significantly, whereas no variations were observed for polyamine concentrations. In the "chronic phase", corresponding to the basal values of the 5th and 10th days of treatment, we found a different pattern. In fact, the concentration of polyamines showed a remarkable enhancement, while ACTH and beta-endorphin levels remained unchanged. No significant variations were observed during hyperbarism with air. These results demonstrate different modifications of polyamines and beta-endorphin and ACTH in subjects submitted to hyperbaric oxygen exposure.

Adrenocorticotropic Hormone↗
PubMed1992

Activity of polyphenolic crude extracts as scavengers of superoxide radicals and inhibitors of xanthine oxidase.

In view of the pharmacological interest in phenolic substances, we have determined the total amount of anthocyanins and polyphenols present in the berries of several cultivars of Ribes, Rubus, and Vaccinium genera. The in vitro antiradical activity of the crude extracts on chemically-generated superoxide radicals as well as the inhibitory activity towards the enzyme xanthine oxidase were studied. All the crude extracts examined showed a remarkably high activity towards chemically-generated superoxide radicals. The activities were greater than those expected on the basis of the quantities of anthocyanins and polyphenols present in the samples. Furthermore, the extracts showed a certain inhibitory activity towards xanthine oxidase. Ribes nigrum extracts exhibit the highest activity, being the richest in both anthocyanins and polyphenols. On the other hand, Ribes rubrum extracts seem to contain more active substances than the other crude extracts.

Flavonoids↗
PubMed1989

Calcitonin inhibition of growth hormone-releasing hormone-induced GH secretion in normal men.

Calcitonin has been shown to modulate pituitary hormone secretion in a variety of ways. In this study we examined the effects of a salmon calcitonin infusion on GHRH-induced GH secretion in 5 normal men. In addition, in vitro experiments were performed using primary cultures of rat anterior pituitary cells in order to examine whether there is a direct pituitary effect of CT. Infusion of CT significantly blunted the GH response to GHRH in all subjects without affecting basal GH secretion or plasma calcium levels. Infusion of CT was accompanied by significant increases in ACTH, beta-endorphin, cortisol and free fatty acid levels, and by a significant decrease in serum insulin levels. The addition of CT to primary cultures of rat pituitary cells did not alter basal or stimulated secretion of GH or ACTH. These results indicate that: 1) CT blunts the GH response to GHRH; 2) CT infusion results in the stimulation of the hypothalamic-pituitary-adrenal axis, and 3) this effect is probably exerted at the hypothalamic level, since no direct activity of CT was documented in vitro on either GH or ACTH secretion.

Adrenocorticotropic Hormone↗
PubMed1987

[Homeostasis of blood glucose and abuse of exogenous opiates: evaluation of fructosamine and glycosylated hemoglobin].

The study was designed to assess glycaemic homeostasis in different situations of chronic stimulation of the opiate receptors by exogenous opiates. After an OGTT, levels of glycosylated haemoglobin (HbA1c) and serum fructosamine were measured in 3 groups of male drug addicts of comparable age. Group A consisted of 10 subjects undergoing substitution treatment with oral methadone. Group B consisted of 10 subjects addicted to intravenous injection of the syrup based methadone intended for oral administration. Group C consisted of 10 heroin addicts. Ten healthy subjects of the same age and sex were used as controls. Analysis of the results showed normal glucose tolerance in all groups with tendentially higher basal glycaemia levels in group B. HbA1c levels were significantly higher, though within normal limits, in group B than in either those receiving oral methadone (p less than 0.01) or the heroin addicts (p less than 0.01). The group B subjects also showed the highest fructosamine levels that were both well above normal limits and higher than those in the other groups in whom fructosamine levels were normal. The data therefore confirm normal glycaemia compensation in those taking oral methadone and in heroin addicts during the period considered. A new type of drug addiction involving the intravenous injection of methadone was also encountered. This produces an outstanding short-term change in glycaemic homeostasis and may well lead to future alterations in glucose tolerance.

Adult↗
PubMed1987

[Diabetes insipidus after selective pituitary adenomectomy. A case with late appearance].

Diabetes insipidus is a well-known complication of hypophyseal surgery. The case is described of a women presenting with evident polyuropolydipsic syndrome arising 9 years after transphenoidal hypophyseal adenectomy. The diagnosis insipidus diabetes was secondary to intrasellar scars revealed by a hypophyseal CAT scan. The unusually long interval between surgery and the onset of the syndrome is emphasised.

Adult↗
PubMed1985

Activation of PRL secretion by combined treatment with cyproterone acetate and ethinylestradiol.

Two groups of patients affected by idiopathic androgenization have been treated with ethinylestradiol (EE) associated with two different (high and low) dosages of cyproterone acetate (CA); the aim of this study was to evaluate the possible endocrine side effects at the pituitary level. After three and six months of treatment gonadotropins secretion appeared significantly inhibited with higher evidence for LH than for FSH and especially in the patients on high dose of CA. Nevertheless the most impressive finding was represented by the increase in PRL responses to TRH documented when higher doses of CA were employed without significant change in TSH secretion. The Authors suggest that such PRL hyperresponsiveness cannot be completely disregarded in the management of idiopathic androgenization.

Adult↗
PubMed1985

Effects of dopamine receptor stimulation on opiate-induced modifications of pituitary-gonadal function.

We evaluated the effects of the dopaminergic drug bromocriptine (Br) on prolactin (PRL), luteinizing hormone (LH) and testosterone (Te) levels in a homogeneous group of opiate addicts in a methadone maintenance program (20 mg twice daily). Basal blood levels of PRL, LH and Te were determined in 15 adult male drug addicts, before 30 and 60 days after Br administration (7.5 mg/day) was started. 15 healthy volunteers served as controls for the evaluation of basal values of the hormones. Before treatment PRL values were high, while LH and Te levels were lower than normal. 30 days later, PRL lowered significantly while LH and Te increased significantly. 60 days later, the blood hormone values were still significantly different from pretreatment values, and close to the normal range. This observation shows that Br, probably through an increase of dopaminergic tone, may counteract some effects of opiates on the hypothalamic-pituitary-gonadal axis.

Adolescent↗
PubMed1984

Effect of methadone on TSH and thyroid hormone secretion.

The hypothalamus-pituitary-thyroid function was studied in 15 male patients on chronic methadone treatment (40 mg/day). No significant variations of TSH, T4, T3 and rT3 levels were documented, either in basal conditions or after TRH stimulation; however a reduced TSH pituitary response was recorded in some patients (6 out of 15).

Adult↗