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Biomedical subjects

B Merola

Publications and source records attributed to B Merola.

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

Effect of a short-term treatment with recombinant growth hormone (GH) on adrenal responsiveness to corticotrophin stimulation in children affected by isolated GH deficiency.

Recent evidence suggests that GH and insulin growth factor-I (IGF-I) play a role in adrenal steroidogenesis. On the other hand, it has been shown that ACTH stimulates IGF-I secretion by cultured fasciculata adrenal cells. Aim of the present study was to investigate the influence of GH administration on adrenal steroids and IGF-I responsiveness to ACTH in children affected with isolated GH deficiency. Ten children (seven males and three females, 5-10 yr old) affected with isolated GH deficiency underwent a synthetic ACTH 1-17 test before and after administration of human recombinant GH at a dose of 4 IU/day sc for 10 days. After the therapy, no significant differences were detected in the responses of cortisol, dehydroepiandrosterone-sulfate, androstenedione, and 17-hydroxyprogesterone to ACTH 1-17, whereas an increased 11-deoxycortisol responsiveness to ACTH 1-17 was noted (P less than 0.005). Surprisingly, IGF-I significantly increased in response to ACTH 1-17 after short-term rGH administration (P less than 0.006). In conclusion, our data indicate that in isolated GH deficiency a short-term GH therapy does not substantially modify the adrenal responsiveness to exogenous ACTH, even if an increased 11-deoxycortisol and an induced IGF-I responsiveness to ACTH were observed.

Adrenal Glands↗
PubMed1992

Hormonal gradients between inferior petrosal sinuses in various pituitary diseases.

The aim of this retrospective study was to evaluate the existence of a multihormonal gradient between the inferior petrosal sinuses in various pituitary diseases: Cushing's disease (8 cases), acromegaly (4 cases), prolactinomas (7 cases), GH, PRL-secreting adenoma (1 case), functionless adenoma (2 cases), empty sella (3 cases) and in non-tumoral hyperprolactinemia (5 cases). A significant intersinus gradient (more than 1.4:1) was recorded for GH, ACTH and PRL in 16 patients (80%), but in only 9 patients (45%) out of the 20 with hormone-secreting tumors for TSH, FSH and LH. Moreover, of the 10 patients in the remaining groups, only in two cases was a significant intersinus gradient present: one for GH and one for LH. In conclusion, the finding of a multihormonal release in the inferior petrosal sinus ipsilateral to the adenoma is reported, for the first time, in patients with GH- and PRL-secreting adenomas. The possible explanation for such a finding may be either an increased blood flow in this site of sampling or a pituitary multihormone release through a paracrine mechanism primed by the tumoral hypersecreted hormone. In addition, the pulsatile secretory pattern and the short half-life of polypeptide hormones may contribute to better demonstrate this phenomenon in respect to glycoprotein hormones.

Adenoma↗
PubMed1992

[Effectiveness of and tolerability to oral desmopressin in the treatment of central diabetes insipidus].

Intranasal desmopressin represents the treatment of choice in Central Diabetes Insipidus. Nevertheless, this route of administration bears some practical disadvantage, linked to either difficult delivering technique, or the status of nasal mucose. The antidiuretic effectiveness of oral desmopressin has been recently demonstrated, both in experimental animals and in man. In our study we compared oral vs. intranasal desmopressin efficacy in 13 patients affected by Central Diabetes Insipidus. The results show that the peroral administration of Desmopressin at a mean dose of 500-600 micrograms/die determines an antidiuretic effect comparable to that of intranasal route, without affecting body weight, arterial pressure and chemical analysis. Side effects, generally limited to the first week of treatment, were described (nausea, vomiting, headache, dizziness [corrected], bitter taste, epygastralgia, asthenia, epystassis), inducing 4/13 patients to withdrawal the trial.

Administration, Intranasal↗
PubMed1991

Comparison of anterior pituitary hormone levels in the inferior petrosal sinuses and peripheral blood in various pituitary disorders during perihypophysial phlebography.

The present study aimed at evaluating the anterior pituitary hormone levels in the inferior petrosal sinuses and in the peripheral blood of 55 patients affected by various pituitary disorders and undergoing perihypophysial phlebography on neurosurgical indication or for diagnostic purposes. The results indicated that in 6 patients with Cushing's disease and in 4 with hyperprolactinemia the secreting adenoma could be localized by inferior petrosal sinus sampling. Furthermore, the concentrations of all the pituitary hormones were found to be higher in the right and/or in the left inferior petrosal sinus than in peripheral blood, showing a clear gradient between central and peripheral samples. Moreover, the evaluation of hormone central/peripheral concentration ratios revealed noteworthy differences, namely, that central/peripheral concentration ratios of GH, ACTH, and PRL were significantly higher than those of TSH, FSH, and LH (p less than 0.01). On the contrary, no significant differences were found when the concentration ratios of GH, ACTH and PRL or TSH, FSH and LH were compared among themselves. This finding may be attributed to at least two factors: the increased pulsatility and the relatively short biological halftime of polypeptic hormones (GH, ACTH, and PRL) compared with glycoprotein hormones (TSH, FSH, and LH).

Adrenocorticotropic Hormone↗
PubMed1991

Oral and injectable long-lasting bromocriptine preparations in hyperprolactinemia: comparison of their prolactin lowering activity, tolerability and safety.

Bromocriptine, a D2 receptor agonist, has been widely used in tumoral and non-tumoral hyperprolactinemia, in reducing both plasma prolactin levels and in restoring fertility and/or menses in most patients. In this study a comparison between the injectable repeatable and the oral slow release formulations of bromocriptine (Parlodel LAR and Parlodel SRO) is reported, with respect to their effectiveness, tolerability and safety. Eleven patients with hyperprolactinemia, submitted to both treatments, were studied for a period of 1-24 months. Among the four patients with macroprolactinoma, three reached normoprolactinemia without complaining of side-effects, with both formulations, while the remaining patient became intolerant of the oral form after 1 year, and is presently being treated with the injectable formulation without presenting any side-effects. Among the five patients with microprolactinoma, two patients had a good response to both drugs; two patients did not reach normoprolactinemia with the injectable formulations, but a progressive decrease of prolactin levels was obtained with Parlodel SRO therapy, and the remaining patient was completely intolerant of the oral form without complaining of side-effects with Parlodel LAR. Two patients had non-tumoral hyperprolactinemia: one was intolerant of both drugs and one tolerated both formulations very well. In conclusion, Parlodel LAR and Parlodel SRO are very effective compounds in the medical treatment of hyperprolactinemic syndromes. The availability of these differing formulations improves the medical therapy, allowing a better choice of therapeutic regimen according to the effectiveness of, and tolerability to, the different drug formulations. In this way also, with poorly tolerant patients, it is possible to choose the better tolerated and more effective formulation of the drug.

Adult↗
PubMed1990

Rapid and long-lasting suppression of prolactin secretion and shrinkage of prolactinomas after injection of long-acting repeatable form of bromocriptine (Parlodel LAR).

Five patients with PRL-secreting macroadenoma and nine patients with PRL-secreting microadenoma or idiopathic hyperprolactinaemia were treated with monthly administrations of long-acting bromocriptine suitable for repeatable injections (Parlodel LAR) for 1-12 cycles of treatment. A significant shrinkage of tumour mass and the recovery of visual field defects were observed in patients with macroprolactinoma. Plasma PRL levels decreased to 16.8 and 18.1% of pretreatment values, in macroprolactinoma and idiopathic or microadenomatous hyperprolactinaemic subjects, respectively, during the first cycle of treatment, reaching the normal range in three patients of each group. During the following cycles of treatment, two patients with macroprolactinoma and one patient with idiopathic or microadenomatous hyperprolactinaemia became normoprolactinaemic. Adverse reactions generally did not last beyond the first days of administration and decreased with the progression of the treatment. In conclusion, its effectiveness and the fact that it is well tolerated, may suggest that this form of bromocriptine may be used as a first therapeutic approach for patients with PRL-secreting adenomas, particularly when shrinkage of a macroadenoma is urgently required.

Adolescent↗
PubMed1989

[Antiemetic effect of the levo isomer of sulpiride (L-sulpiride) in humans].

Vomiting represents one of the most dangerous complications of general anesthesia. L-sulpiride has been able to control this complication very effectively. We studied the effect on vomiting of two doses of L-sulpiride (50/100 mg). Both these doses have been effective in reducing the episodes of vomiting other than in preventing nausea and retching if considered versus controls and also versus droperidol at the doses of 5 mg (50 mg L-sul = 12%, 100 mg = 4%, droperidol = 20%, controls = 28%). L-sulpiride is an antagonist of dopamine on D2 receptors therefore inhibits the action of dopamine increasing the secretion of prolactin. During the surgical distress per se prolactin levels are increased. Together with the increment of catecholamines, high concentration of prolactin can evoke arrhythmias. In view of this possibility we studied the time course of the administration of the two doses of L-sulpiride and of droperidol on prolactin secretion. Both of the drugs increased the plasma levels of prolactin. Droperidol-induced increase in prolactin secretion was significant already at ten minutes after the administration reaching the peak after 20 minutes. L-sulpiride increased prolactin secretion reaching the maximum increase 20 minutes after the administration of 50 mg of the drug, and 30 minutes after the administration of 100 mg doses. The hyperprolactinemizing action of droperidol lasts for at least 8 hours, whereas L-sulpiride action lasts 4 hours.

Adolescent↗
PubMed1988

Effectiveness of a single injectable dose of bromocriptine long acting in the treatment of macroprolactinomas.

The aim of the present study was to investigate the effect of a new galenic injectable form of bromocriptine (Parlodel LA), characterized by sustained release of bromocriptine for 4-6 weeks, in 3 patients with prolactin-secreting macroadenomas through a 42-day follow-up. The following parameters were considered: decrease of plasma prolactin levels, reduction of tumor size studied by seriate CT scan controls and recovery of eventual visual fields impairments. Parlodel LA induced a sharp decrease of plasma prolactin levels for at least 42 days, without reaching normal values. This treatment also caused a rapid and marked shrinkage of tumors in all patients. Moreover, in two patients with constriction of visual fields a clear and progressive improvement in one and only a slight amelioration in the other were observed. There were almost no side effects except for mild nausea in one patient and transient orthostatic in another. These results demonstrate that Parlodel LA produces a long-lasting reduction of plasma prolactin levels and a rapid shrinkage of the tumor with almost no side effects.

Adenoma↗
PubMed1987

Plasma prolactin levels in the inferior petrosal sinuses in various pituitary disorders during perihypophyseal phlebography.

The use of intercavernous sinus phlebography for the diagnosis and neurosurgical treatment of pituitary adenomas has enabled the collection of selective venous samplings of the inferior petrosal sinuses (IPSs), where prolactin (PRL) levels can be measured before the hormone becomes excessively diluted in the systemic circulation. In the present study, plasma PRL levels were studied in the right and/or left IPS and, simultaneously, in the peripheral circulation of: (1) normoprolactinemic patients affected with various pituitary disorders which required phlebographic procedures; (2) hyperprolactinemic patients with negative radiological and computed tomographic (CT) signs of pituitary adenomas and (3) adenomatous hyperprolactinemic patients. In the 17 normoprolactinemic patients, the plasma PRL concentration in the IPSs was significantly higher (3.5 times; p less than 0.01) than in the peripheral circulation. In the 11 hyperprolactinemic patients with negative radiological and CT signs of pituitary adenomas, the central gradient for PRL was significantly higher (2.8 times; p less than 0.05) than in the peripheral circulation. No significant difference was detected between PRL concentrations in the left and right IPSs. In the 11 adenomatous hyperprolactinemic patients, there was a significant (p less than 0.01) central gradient for PRL 3.8 times higher than in the peripheral circulation on the ipsilateral side of the tumor. Furthermore, the plasma PRL concentration in the ipsilateral IPS was significantly higher (3.4 times; p less than 0.05) than that in the contralateral sinus. In conclusion, the present study shows that a clear-cut concentration gradient exists between plasma PRL levels in the IPSs and in the peripheral circulation of normoprolactinemic and hyperprolactinemic patients with negative radiological and CT signs of pituitary adenomas.(ABSTRACT TRUNCATED AT 250 WORDS)

Adenoma↗
PubMed1987

Hyperthyroidism due to a thyroid-stimulating hormone (TSH)-secreting pituitary adenoma associated with functional hyperprolactinaemia. A case report.

This paper reports the case of a 31-year-old woman with hyperthyroidism, increased TSH and thyroid hormone levels, evidence of a pituitary adenoma, hyperprolactinaemia, amenorrhoea, and galactorrhoea. Following trans-sphenoidal pituitary adenomectomy, mild hyperthyroidism and increased TSH and alpha subunit levels persisted, whereas hyperprolactinaemia, amenorrhoea, and galactorrhoea disappeared. Serum TSH levels were not affected by administration of TRH, metochlopramide, domperidone, l-dopa or somatostatin. Serum TSH chromatography showed a normal pattern. Following a second trans-sphenoidal pituitary adenomectomy and radiotherapy, hyperthyroidism disappeared, and the TSH and alpha subunit levels returned to normal. Light microscopy showed no specific TSH immunostaining although electron microscopy revealed numerous secretory granules alined along the plasma membrane. The post-operative follow-up confirmed the presence of a TSH-secreting pituitary adenoma associated to functional hyperprolactinaemia.

Adenoma↗
PubMed1986

Prolactin and TSH response to TRH and metoclopramide before and after l-thyroxine therapy in subclinical hypothyroidism.

The effects of the dopamine (DA) receptor antagonist metoclopramide on the plasma thyroid stimulating hormone (TSH) and prolactin (PRL) levels were studied in 8 patients with subclinical hypothyroidism (defined as absence of clinical signs of hypothyroidism with normal thyroid hormone levels, normal or slightly increased basal plasma TSH levels and increased and long-lasting TSH response to TRH) before and after l-thyroxine replacement therapy. Metoclopramide induced a significant (p less than 0.01) TSH release in the subclinical hypothyroid patients. Two weeks after l-thyroxine replacement therapy (50 micrograms/day), the TSH response to metoclopramide was completely blunted in subclinical hypothyroidism. In these patients a significant (p less than 0.01) inhibition of TSH response to intravenous thyrotropin-releasing hormone (TRH) was also observed after treatment with thyroid hormone. In analogy to the TSH behavior, plasma PRL secretion in response to metoclopramide and TRH administration was significantly (p less than 0.05) inhibited in the subclinical hypothyroid patients after l-thyroxine replacement therapy.

Adult↗