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Biomedical subjects

T Barreca

Publications and source records attributed to T Barreca.

At least 73 records · Page 4Linked to original sources

Evaluation of anterior pituitary function in adult patients with craniopharyngiomas.

Serum LH, FSH, TSH, PRL, GH and cortisol levels were measured in 10 patients with a craniopharyngioma both before and after a combined insulin-induced hypoglycaemia, GnRH and TRH test. In pre-operative studies, only two patients did not show hormonal abnormalities, while eight patients had deficiencies of one or more hormones. The most frequent abnormality was GH deficiency (six cases), followed by gonadotropin (four cases), cortisol (four cases), and TSH (one case), whereas four patients showed high serum PRL values. In post-surgical studies, a significant improvement of pituitary function was observed in two cases, whereas an impairment of previously normal corticotropin reserve was recorded in another case. The data obtained suggest that endocrine abnormalities in patients with craniopharyngiomas are irreversible in most cases.

Adult↗

Pituitary secretion after administration of a new cerebroactive drug, fipexide.

The effect of a single oral dose of 400 mg fipexide on pituitary secretion was investigated in 10 elderly non-endocrine patients. Fipexide induced significant decrease (P less than 0.05) in serum prolactin (PRL) values at 90 and 120 min after drug administration, without affecting serum growth hormone (GH), gonadotropin (LH and FSH), thyrotropin (TSH) and cortisol values. Fipexide was unable to modify metoclopramide-induced PRL release in five of these patients. Our results show that this drug acts as a mild dopamine (DA) agonist, probably not directly affecting hypothalamic and/or pituitary DA receptors but indirectly via a reduced DA re-uptake at the pre-synaptic level.

Aged↗

Diurnal prolactin changes in human cerebrospinal fluid.

Eight adult male patients suffering from hydrocephalus of differing aetiologies were investigated in order to detect the existence of diurnal variations of prolactin (PRL) concentration in human cerebrospinal fluid (CSF). Blood and ventricular CSF samples were taken every 2 h during the day (0800-2200 h) and every hour during the night (2300-0700 h). CSF mean PRL levels showed significant nyctohemeral variations with low levels (2.1 +/- 0.3 ng/ml) during day-time and higher levels at night (3.3 +/- 0.1 ng/ml), similar to that observed in serum (PRL values: 16.4 +/- 5.2 and 24.8 +/- 4.3 ng/ml during day and night periods respectively). The presence of a 24 h CSF PRL secretory profile similar to that in serum was shown in six patients with normal 24 h mean PRL values and normal diurnal changes in serum. In two patients with an altered serum 24 h secretory pattern no significant nyctohemeral variations in CSF PRL levels were found. Present data show the existence in man of nyctohemeral variations in CSF PRL content related to the 24 h changes of PRL levels in serum.

Adult↗

Changes in pituitary secretion after administration of branched-chain amino acids to patients with hepatic cirrhosis.

Infusion of a mixture of branched-chain 1-amino acids (BCAA; isoleucine, leucine, and valine) in six male patients suffering from hepatic cirrhosis led to an increase in serum GH, while serum PRL was not affected. In the same patients arginine infusion stimulated GH and PRL release. These findings demonstrate that hypothalamo-pituitary responsiveness to amino acid stimulation is preserved in cirrhosis and that administration of these amino acids has some endocrine effect.

Adult↗

Nyctohemeral pattern of serum LH, FSH and PRL in patients with myotonic dystrophy.

The nyctohemeral pattern of serum luteinizing (LH), follicle-stimulating hormone (FSH) and prolactin (PRL) in eight patients with myotonic dystrophy (MD) was studied. Gonadotropin patterns were classified as adult, pubertal or infantile. Six patients showed an adult pattern, whereas two had a pubertal or infantile pattern. A normal pattern of PRL secretion was found in seven patients and a blunted sleep-related hormonal increase was observed in one. Impaired hypothalamic control of pituitary secretion in MD is proposed as the cause for these findings.

Adult↗

Changes of pituitary secretion after long-term treatment with hydergine, in elderly patients.

The aim of this study was to evaluate the effects of long-term treatment with an ergot derivative, dihydroergotoxine mesylate (hydergine) 6 mg/day, on pituitary secretion on 10 elderly patients of both sexes. Samples were drawn at 120 min intervals during a 24 h period, before and after 1 month of therapy. Serum levels of Prl, GH, LH, FSH, TSH and cortisol were measured by RIAs. Hydergine induced a significant increase in the nocturnal serum GH peak. Conversely, no appreciable changes in the pattern of the other hormones studied were found. The observed endocrine effects could be due to the chronic dopaminergic stimulation induced by hydergine.

Age Factors↗

Changes in pituitary secretion induced by an agonist-antagonist opioid drug, buprenorphine.

The im administration in 6 healthy subjects of buprenorphine, a derivative of the morphine alkaloid thebaine with agonist-antagonist properties, resulted in a significant rise of serum Prl within 45-240 min, a small and transient increase in serum GH and a significant fall in serum cortisol values. Conversely, no appreciable changes in the serum levels of the other hormones studied were found. The observed hormonal effects indicate that, in man, buprenorphine exerts an opiate agonist rather than an opiate antagonist effect.

Adult↗

Influence of low doses of naloxone on pituitary secretion in man.

Naloxone 0.8 mg im administered to eight healthy subjects did not affect the serum levels of GH, LH, FSH, PRL, TSH and cortisol. Pretreatment with naloxone 0.8 mg increased TRH-induced TSH and PRL release in six healthy subjects. The same pretreatment caused an enhancement of haloperidol-induced PRL secretion in further other group of six subjects.

Adult↗

Evaluation of Prl secretion in elderly subjects.

Prl secretion was evaluated in 76 elderly patients (71-86z years) without endocrine disorders (38 men and 38 women) in basal conditions, after TRH, sulpiride and levodopa administration and during a 24 h period. An impaired Prl response to the administered drugs was found in the elderly women but not in the men. On the contrary, normal sleep-related serum Prl changes were found in the majority of the subjects studied. These results suggest that the pituitary gland can maintain a good Prl secretory pattern in the elderly.

Age Factors↗

Hormonal changes induced by a partial opiate antagonist, nalorphine. Evaluation of PRL, GH, TSH, LH, FSH and cortisol secretion.

The effects of nalorphine 5 mg i. m., a partial opiate antagonist, on circulating levels of PRL, GH, TSH, LH, FSH and cortisol were studied in six healthy men. Nalorphine produced a produced a prompt and sharp increase in serum PRL and a small, delayed rise in serum GH. Serum LH and cortisol decreased after drug administration and no change in serum FSH and TSH was observed. These findings are discussed and a possible site of action of nalorphine is suggested.

Adult↗

Effect of a psychoactive drug, trazodone, on prolactin secretion in man.

Administration of 50 mg trazodone, an antidepressant drug, in a single oral dose to 10 normal subjects of both sexes, aged 24--41, resulted in a significant (p less than 0.01) decrease of serum prolactin (PRL) values. The mean serum PRL levels were 8.9 +/- 2.2 ng/ml in basal conditions and 4.5 +/- 1.7 ng/ml 180 min after trazodone. Pretreatment with trazodone does not modify TRH-induced PRL release.

Adult↗

Dopamine receptor blockade induced by metoclopramide and thyroid-stimulating hormone secretion in man.

20 mg metoclopramide, intramuscularly administered to 10 healthy males and 10 healthy females, induced a significant increase in serum thyroid-stimulating hormone values in female subjects only. This finding suggests that dopamine does not play a major role in the regulation of thyroid-stimulating hormone secretion and that estrogens can act in the modulation of dopamine effects at the hypothalamic and/or pituitary level.

Adult↗

Prolactin secretion in benign prostatic hypertrophy.

Prolactin secretion was evaluated in 22 patients with benign prostatic hypertrophy, before and after thyrotropin-releasing hormone stimulation. Increased prolactin reserve was found. In 11 patients, in whom the test was performed twice, the prolactin response after surgery was higher than in the pre-surgical test. The possible role of prolactin in the genesis of benign prostatic hypertrophy is discussed.

Aged↗

Comparison of mezlocillin and carbenicillin as therapy for various infectious diseases.

The efficacy and safety of mezlocillin, a new broad-spectrum semisynthetic penicillin, were compared with those of carbenicillin in a nonblind, controlled clinical study in 89 adult patients. The infections treated were primarily those of the urinary tract, skin, and gastrointestinal or hepatobiliary tract. Escherichia coli, Proteus mirabilis, Proteus morganii, and Pseudomonas aeruginosa were the causative organisms isolated most frequently. A complete resolution of signs and symptoms was achieved in 78% of the mezlocillin patients and in 71% of the carbenicillin patients. In the mezlocillin group, causative organisms were eliminated in 80% of the courses, and in the carbenicillin group the elimination rate was 86%. Two adverse reactions, rash and diarrhea, were reported in mezlocillin-treated patients; none were reported for the carbenicillin group.

Adult↗

Spontaneous nocturnal plasma prolactin and growth hormone secretion in patients with Parkinson's disease and Huntington's chorea.

Plasma prolactin (PRL) and growth hormone (GH) levels were measured in 8 patients with Parkinson's disease (PD) and in 6 patients with Huntington's chorea (HC) during the night. The sleep was evaluated with all-night poligraphic recordings. Plasma PRL levels were significantly lower in parkinsonian patients than in age-matched controls. Plasma GH values did not differ between the two groups. In HC patients no statistically significant differences were found in the PRL and GH secretory patterns when compared to the age-matched control subjects. These data indicate that changes of nocturnal PRL and GH profile in PD and HC patients in respect to age-matched healthy subjects, may be present, but a straight forward differentiation among groups is not possible because of the wide individual variations.

Aged↗