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Biomedical subjects

B Ambrosi

Publications and source records attributed to B Ambrosi.

At least 19 recordsLinked to original sources
PubMed1995

[Clinical and preclinical aspects of adrenal Cushing syndrome].

Cushing's syndrome of adrenal origin encompasses different entities: besides the occurrence of adenoma and carcinoma, a not homogeneous group includes the ACTH-independent macro- or micronodular bilateral hyperplasia and the familial pigmented nodular hyperplasia (Carney's syndrome). Moreover, isolated cases of immunological origin and food-dependence have recently described. On clinical grounds no major characteristics may help to identify the adrenal origin of Cushing's syndrome, except for few situations as carcinoma or nodular dysplasia. Laboratory investigations of patients with adrenocortical tumor are based on ACTH and cortisol determinations in basal conditions and in response to high dose dexamethasone and CRH tests. However, isolated diagnostic problems may occur, as the presence of a black adrenocortical adenoma or the uncommon persistence of a circadian rhythmicity of glucocorticoid secretion. The evaluation of new markers of bone turnover (BGP, ICTP) and of collagen turnover (PIIINP) confirms the existence of corticosteroid-induced bone and collagen damages and may also be a useful prognostic index after treatment. Although up to now food-dependent Cushing's syndrome appears to be very rare, the adrenocortical sensitivity to GIP has been investigated in patients with either pituitary Cushing's disease, or clinically silent adrenal masses. No evidence of GIP-dependent cortisol secretion during the peptide infusion or after endogenous stimulation by OGTT was observed in any case. Since the wide availability of sensitive and noninvasive imaging techniques (CT and NMR), in recent years the finding of incidentalomas has become fairly common. In patients with incidentaloma abnormalities of the endocrine function are frequently encountered, and the "preclinical" Cushing's syndrome is increasingly recognized.(ABSTRACT TRUNCATED AT 250 WORDS)

Adenoma↗
PubMed1992

The silent corticotropinoma: is clinical diagnosis possible?

Up to now, the diagnosis of silent corticotroph cell pituitary adenomas has been made only on histopathological basis. In this paper we describe 6 women affected with pituitary adenomas, without evident clinical features of hypercortisolism, in whom retrospective data suggested the possibility of clinically diagnosing silent corticotropinomas in vivo. In all patients basal ACTH and cortisol levels were normal, and the low-dose dexamethasone test constantly suppressed serum cortisol and urinary 17-hydroxycorticosteroid levels. The CRH and/or lysine-vasopressin tests, performed in five patients, always induced exaggerated ACTH/cortisol rises. In three cases the response to the opiate agonist loperamide was assessed and no inhibition of ACTH/cortisol levels was found. All patients underwent pituitary surgery. In five cases evidence of corticotropinoma was obtained by immunohistochemistry or immunofluorescence studies; moreover, in one adenoma ACTH was secreted into the culture medium, and in another one CRH and arginine-vasopressin induced a marked intracellular [Ca++] rise. Electron microscopy study of the adenoma, removed from three patients, showed the presence of adenomatous corticotroph cells. Finally, in another woman no hormonal abnormalities were initially observed and she was operated for a "nonfunctioning" pituitary adenoma, but four years later an overt Cushing's disease appeared, suggesting that a silent corticotropinoma subsequently became functional, although the formation of a different adenoma cannot be excluded. In conclusion, the occurrence of ACTH/cortisol hyperresponsiveness to CRH and/or lysine-vasopressin and the lack of suppression of ACTH/cortisol secretion to opioid agonists in patients with apparently "nonfunctioning" pituitary tumors might allow the in vivo recognition of silent corticotropinomas.

17-Hydroxycorticosteroids↗
PubMed1992

Value of serum dehydroepiandrosterone sulfate assay in the evaluation of pituitary-adrenal insufficiency after pituitary adenomectomy.

The value of dehydroepiandrosterone sulfate (DHEA-S), a specific marker of adrenal androgen production, in the assessment of clinical states of hypercortisolism and hypocortisolism has been suggested. Since the way to simply test for ACTH reserve in patients (pts) with pituitary tumors after adenomectomy is not standardized, in this study serum DHEA-S concentration was measured in order to establish whether its determination might be a sensitive index of ACTH deficiency. Serum DHEA-S concentration was evaluated in 29 pts with hypothalamic-pituitary tumors (16 females, 13 males, aged 20-70 yr), 14 of whom had GH-secreting adenomas, 13 nonfunctioning adenomas, 1 prolactinoma and 1 craniopharyngioma. Serum DHEA-S and cortisol (F) levels were determined both before and every day for 8 days after pituitary adenomectomy. Before surgery in all pts mean DHEA-S and F basal values were 3.57 +/- 0.42 mumol/L and 391.8 +/- 29.0 nmol/L, respectively. Eight out of 29 pts showed reduced DHEA-S levels (0.85 +/- 0.19 mumol/L), which remained lower than normal in the postsurgical period; on the contrary, F levels were reduced in only 2 and 3 cases before and after surgery, respectively. In 3 other pts DHEA-S levels were normal before surgery and then were low in the postoperative period, while serum cortisol remained normal in all cases. In most of these patients, the finding of impaired responses to hypothalamic-pituitary-adrenal tests, together with a reduced corticosteroid urinary excretion, confirmed the existence of a secondary hypoadrenalism and the necessity for an adequate replacement therapy.(ABSTRACT TRUNCATED AT 250 WORDS)

Adenoma↗
PubMed1991

In vivo detection of somatostatin receptors in patients with functionless pituitary adenomas by means of a radioiodinated analog of somatostatin ([123I]SDZ 204-090).

The recent availability of a Tyr3-substituted octreotide (SDZ 204-090) for radioiodination has allowed somatostatin (SRIH) receptor binding to be studied in vivo, and receptor-positive tumors of different origins to be visualized with a gamma-camera. This prompted us to investigate whether this compound could be used for external imaging of functionless pituitary adenomas displaying SRIH receptors. Eight patients with functionless pituitary adenomas, three patients with acromegaly, and three with macroprolactinoma were injected iv with 123I-labeled Tyr3-octreotide and then scanned with a gamma-camera. Positive scans were obtained in the three acromegalics and in two of the eight patients with functionless pituitary tumors. The patients with macroprolactinoma had negative scans. The diagnosis of functionless pituitary adenomas was confirmed by light and electron microscopic examination as well as immunocytochemical studies. In vitro binding of [125I]Tyr11-SRIH to cell membranes was evaluated in four functionless and three GH-secreting adenomas removed from seven of the patients. All of the GH-secreting as well as one of the four functionless adenomas had high affinity SRIH-binding sites, without differences in number or affinity, whereas SRIH-binding sites were not detected in the others. Positive scans were observed only in patients bearing tumors with high affinity SRIH-binding sites. In conclusion, [123I]Tyr3-octreotide appears to be a promising tool for singling out, in vivo, patients with functionless pituitary tumors displaying SRIH receptors who might potentially benefit from octreotide treatment.

Adenoma↗
PubMed1990

Failure of somatostatin and octreotide to acutely affect the hypothalamic-pituitary-adrenal function in patients with corticotropin hypersecretion.

Although somatostatin inhibits a variety of pituitary and non-pituitary hormones, not univocal data on its effects on ACTH release have been reported so far. In this study we investigated the effects of somatostatin or octreotide on ACTH levels of patients with corticotropin hypersecretion: 7 patients with Addison's disease, 2 patients previously adrenalectomized for Cushing's disease, 4 patients with Cushing's disease and 3 patients with ectopic ACTH syndrome. Plasma ACTH and cortisol levels were determined after somatostatin (500 micrograms over 60 min) infusion or octreotide (100 micrograms sc) injection. In 5 other patients with Cushing's disease ACTH and cortisol responses to CRH (1 microgram/kg iv) were evaluated in basal conditions and after octreotide acute administration. In no patients with Addison's disease any inhibitory influence of somatostatin (delta % = -21, -25) or octreotide (delta % = -38 +/- 12 vs -39 +/- 12 after saline) on plasma ACTH was found. Somatostatin did not significantly inhibit plasma ACTH in the two patients previously adrenalectomized for Cushing's disease and in 3 patients with Cushing's syndrome; in other 4 patients with Cushing's syndrome octreotide did not affect plasma ACTH levels. In 5 patients with Cushing's disease the plasma ACTH and cortisol responses to CRH were similar both before (ACTH from 9.9 +/- 1.7 pmol/L to 19.4 +/- 6.1 pmol/L; cortisol from 496 +/- 43.9 nmol/L to 923 +/- 355 nmol/L) and after octreotide injection (ACTH from 8.8 +/- 2.4 pmol/L to 19.1 +/- 8.2 pmol/L; cortisol from 510 +/- 54.6 nmol/L to 735 +/- 220 nmol/L). In conclusion, the acute administration of somatostatin or octreotide is not able to modify ACTH levels in patients with corticotropin hypersecretion either due to hypocortisolemic state or consequent to ACTH-secreting pituitary or ectopic tumors; moreover, octreotide does not affect the pituitary-adrenal responsiveness to CRH in patients with Cushing's disease.

Adolescent↗
PubMed1990

Acromegaly and thymic hyperplasia: a case report.

Growth hormone overproduction is characterized by increased size of visceral organs as well as growth of bone and soft tissues. We describe a case of a 23-year-old female acromegalic patient, who had been previously unsuccessfully operated upon by transsphenoidal pituitary surgery and then irradiated. In November 1987 a routine X-ray chest examination revealed a mediastinal mass, subsequently confirmed by CT scan. The patient underwent surgical removal of the mass: macroscopical aspect, histological sections and immunocytochemistry showed typical thymic structures without any evidence of neurosecretory activity. No GH-positive cells were found and only small amounts of immunoreactive GHRH like material (9.2 ng/g wet wg) were detected in the tumor extract. Before surgery plasma GHRH levels were not elevated (26 pg/ml); serum GH and IGF-I levels were 27.4 +/- 4.9 micrograms/l and 191 nmol/l, respectively, and remained unchanged after surgery. These data ruled out a GHRH and/or GH ectopic production, confirming the primitive pituitary origin of acromegaly in this patient. It is likely that thymic hyperplasia may be explained by longstanding overproduction of GH and the young age of the patient.

Acromegaly↗
PubMed1990

Osteocalcin levels in patients with microprolactinoma before and during medical treatment.

Osteocalcin (OC) concentration, a specific index of bone formation, was measured in 29 female patients with microprolactinoma (serum prolactin, PRL: 105 +/- 10.9 ng/ml; mean +/- SE). Mean OC levels were significantly lower than in controls (1.7 +/- 0.2 vs 5.1 +/- 0.3 ng/ml; p less than 0.001), being below the normal range in 28 out of 29 patients. All patients were treated with dopaminergic agents (dihydroergocriptine, bromocriptine or cabergoline). After treatment mean serum PRL levels were significantly reduced (12 +/- 3.1 ng/ml; p less than 0.001), a full normalization being obtained in 26 patients. There were no significant differences in both basal and after treatment PRL levels among patients treated with different drugs, although a greater PRL decrease was induced by cabergoline. Serum OC levels significantly increased after 12 month therapy (4.7 +/- 0.6 ng/ml, p less than 0.001), a normal concentration being reached in 14 of 29 cases. During treatment there were no significant differences in serum estradiol and PRL concentrations between patients who normalized or not their OC levels, while the reduction in PRL levels with respect to baseline was more pronounced in the former group. The absolute increase in OC levels positively correlated with serum PRL decrements (p less than 0.01). It is noteworthy that serum OC normalized in 1/10 patients during dihydroergocriptine, 3/8 during bromocriptine and 10/11 during cabergoline. Four patients, previously treated with dihydroergocriptine and bromocriptine without normalizing OC and PRL levels, underwent a second course of therapy with cabergoline and then normalized OC concentrations.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1990

Precocious puberty in a boy with a PRL-, LH- and FSH-secreting pituitary tumour: hormonal and immunocytochemical studies.

The case of a 7-year-old boy affected with precocious puberty and a large intra- and suprasellar pituitary tumour is described. He had hyperprolactinemia and elevated serum LH, FSH and testosterone concentrations. Pre-operative dynamic hormonal studies showed a rise of PRL, LH and FSH levels after TRH (200 micrograms iv) and a rise of LH and FSH after GnRH (100 micrograms iv). Dopamine infusion (4 micrograms.kg-1.min-1 for 180 min) did not affect gonadotropins and greatly reduced serum PRL. GnRH analogue (buserelin, 0.5 mg sc t.i.d. for 10 days) administration inhibited both LH and FSH, but did not affect PRL concentration. Serum LH and FSH increased after ethinyl-estradiol (0.5 mg orally) administration, and were not affected by bromocriptine (5-7.5 mg/day for 10 days), which decreased serum PRL levels. The patient underwent transfrontal neurosurgery and a large tumour mass was completely removed. Morphological study of the excised tumour, by electron microscope double label immunotechnique, revealed that a large number of tumour cells (70-85%) were positive for PRL, LH and FSH, co-localized in the same secretory granule. After neurosurgery, serum PRL, LH, FSH and testosterone levels fell to within the normal limits. Two months later the patient was well and signs of precocious puberty had partially regressed; hormone levels were in the normal range and MR imaging control did not demonstrate any residual lesion in the sellar region.

Adenoma↗
PubMed1989

A syndrome of primary gonadal failure, short stature, mitral valve prolapse, and mental retardation.

Two brothers referred for hypogonadism presented with short stature, mild mental retardation, and minor anomalies. In addition, both patients had hypogonadism due to primary gonadal failure and mitral valve prolapse, in the absence of other heart defects. A complete hormonal evaluation in one of the patients showed abnormal growth hormone (GH) and gonadotropin responses to different stimuli, findings suggestive of a disorder of hypothalamic-pituitary regulation. Both patients had normal chromosomes (46,XY) as did their mother (46,XX), who had some of the clinical manifestations found in her sons but in a milder form. We propose that this is a new syndrome.

Adult↗
PubMed1989

Pituitary-adrenal responses to CRH and insulin hypoglycemia in patients with idiopathic GH deficiency.

It is well known that the activation of the hypothalamus-pituitary-adrenal axis (HPA) by insulin-induced hypoglycemia (IIH) is more potent and multifactorial than that caused by CRH administration. In this study we compared the clinical value of both tests in assessing the integrity of the HPA system. Plasma ACTH and cortisol responses to oCRH (1 microgram/kg iv) and IIH (insulin 0.1 U/kg iv, glycemia less than 40 mg/dl) were compared in 15 patients with idiopathic GH deficiency. The CRH-induced mean ACTH response was lower, but not significantly, in patients than in controls (peak: 8.8 +/- 1.7 vs 13.4 +/- 2.2 pmol/l), while the mean cortisol response was significantly lower than in normals (peak: 585.7 +/- 49.5 vs 764.5 +/- 52.2 nmol/l, p less than 0.005). Plasma ACTH and cortisol responses to IIH were significantly lower than in normal subjects (peak: 22.3 +/- 5.3 vs 35.8 +/- 5.2 pmol/l, p less than 0.05 and peak: 566.5 +/- 55 vs 803 +/- 38.5 nmol/l, p less than 0.02, respectively). Both in controls and in patients the CRH-induced mean ACTH response was significantly lower (p less than 0.02) than that after insulin, while cortisol peaks were not different. In conclusion, in patients with GH deficiency the impairment of ACTH secretion is not evident in basal condition, but it is disclosed after appropriate dynamic tests. It is confirmed that insulin hypoglycemia is a more potent stimulus than CRH for ACTH release.

Adolescent↗
PubMed1989

Effects of the opiate agonist loperamide on pituitary-adrenal function in patients with suspected hypercortisolism.

In the present work the possible use of loperamide, an opiate agonist, in the dynamic evaluation of patients with suspected hypercortisolism was investigated. The effects of loperamide on plasma ACTH and cortisol levels were evaluated in normal subjects and in 58 patients with suspected Cushing's syndrome. The results were compared to those obtained after the overnight dexamethasone suppression test. In normal subjects plasma ACTH and cortisol levels were significantly (p less than 0.005) suppressed by both loperamide (16 mg po) and dexamethasone (1 mg po). In 17 patients, in whom the diagnosis of Cushing's syndrome was confirmed by subsequent investigations, neither loperamide or dexamethasone inhibited cortisol (from a baseline of 606 +/- 55 nmol/L) to a nadir of 502 +/- 43 nmol/L and 539 +/- 50 nmol/L, respectively) and ACTH concentration (from a basal level of 70.1 +/- 11.8 pg/ml to a nadir of 46.0 +/- 8.6 pg/ml and 54.3 +/- 7.5 pg/ml, respectively). In 34 patients, in whom the suspect of hypercortisolism was ruled out, either loperamide or dexamethasone suppressed the pituitary-adrenal axis: cortisol and ACTH levels significantly fell from 417 +/- 24 nmol/L and 28.3 +/- 3.5 pg/ml to 60 +/- 6 nmol/L and 14.4 +/- 1.4 pg/ml after loperamide and to 26 +/- 4 nmol and 16.4 +/- 1.7 pg/ml after dexamethasone. In 7 patients discordant responses were observed. In 3 patients treated with antiepileptic drugs ACTH and cortisol levels were inhibited by loperamide, but not by dexamethasone.(ABSTRACT TRUNCATED AT 250 WORDS)

Adrenocortical Hyperfunction↗
PubMed1989

Mediastinal malignant carcinoid with Cushing's syndrome: immunohistochemical and ultrastructural study.

A case of thymic atypical carcinoid with Cushing's syndrome and unfavorable clinical course is reported. Immunohistochemical analysis reveals distinct staining of tumor cells for ACTH, neuron-specific enolase, chromogranins (CG) and S-100 protein and with PHE-5 monoclonal antibody. At an ultrastructural level, the cells are undifferentiated with only a few neurosecretory granules. In the present case, immunohistochemical stainings for CG and with PHE-5 antibody seem reliable diagnostic tools, easily demonstrating the neuroendocrine nature of the neoplasm. NSE immunoreactivity can be an additional criterion. S-100-positive cells, which are present throughout the tumor, recall 'sustentacular cells', described in other neuroendocrine tumors.

Adrenocorticotropic Hormone↗
PubMed1989

[Severe hypopotassemia and rhabdomyolysis in a normotensive subject after use of a nasal spray containing 9-alpha-fluoroprednisolone].

We report the case of a 16-year-old boy who was admitted to our hospital for acute urinary retention, flaccid paralysis of the legs and arms and rhabdomyolysis due to a nasal spray containing 9-alpha-fluoroprednisolone. In our normotensive subject, rhabdomyolysis occurred after vigorous physical activity performed before the administration. The case emphasizes the need to avoid the use of 9-alpha-fluoroprednisolone considering its intense mineralocorticoid activity.

Administration, Intranasal↗
PubMed1988

Patterns of lateralization and performance levels for verbal and spatial tasks in congenital androgen deficiency.

The effects of congenital deficiency of gonadal hormones on verbal and spatial performance and on the establishment of hemispheric asymmetries were investigated in a group of patients with idiopathic hypogonadotropic hypogonadism. The patients showed a left hemispheric advantage for verbal material and were mildly impaired, mainly on tasks involving a short-term memory load, in comparison with a matched control group. These results do not indicate a specific role of gonadal hormones on the establishment of hemispheric asymmetries. Lack of exposure during brain development results in a decrease in memory functions which is not specific for verbal or spatial material.

Adolescent↗
PubMed1988

Addison's disease and empty sella.

A 47-year-old woman affected by Addison's disease, inadequately treated with corticosteroids for 14 yr, was referred to our clinic. As a x-ray of skull revealed an enlarged sella turcica, a more thorough study of hypothalamic-pituitary function and of the sellar region was performed. The normal suppression of high plasma ACTH levels induced by hydrocortisone infusion and the normal pattern of ACTH, TSH, PRL, LH and FSH to appropriate stimuli (CRH, TRH, GnRH) excluded the possible existence of an ACTH-secreting adenoma; the CT scan images showed the presence of an empty sella. The impaired GH rise after GHRH may be attributed to either the empty sella or the adrenal failure. This is the first patient with Addison's disease and empty sella, in whom the hypothalamic-pituitary function has been studied by the administration of four releasing hormones.

Addison Disease↗