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Biomedical subjects

A Catania

Publications and source records attributed to A Catania.

At least 109 records · Page 6Linked to original sources
PubMed1991

Clinical experience with the adrenal scanning agents iodine 131-19-iodocholesterol and selenium 75-6-selenomethylcholesterol.

Adrenocortical scintigraphy with iodine 131-19-iodocholesterol or selenium 75-6-selenomethylcholesterol was performed in 94 patients with proven or suspected adrenal disease. According to the final diagnosis, 36 patients suffered from primary aldosteronism, 33 from Cushing's syndrome, 8 from low renin hypertension, 6 from nonfunctioning adrenal tumour, 4 from simple obesity, 3 from adrenal metastases, 1 from congenital adrenal hyperplasia, 1 from virilizing adrenal adenoma, 1 from extraadrenal phaeochromocytoma, 1 from ganglioneuroma. Surgical confirmation of the diagnosis was obtained in most cases. With a few exceptions, the scintigraphy results were consistent with the final diagnosis. The two tracers were equally effective adrenal scanning agents. Tracer concentration was measured in a number of surgical specimens, mostly from patients given selenocholesterol. This measurement in surgical samples has not been reported in previous studies with this agent. The results provided a direct validation of uptake measurements in vivo. The data, collected over a 17-year period, demonstrate that despite the advent of new imaging techniques, adrenal scintigraphy that gives both functional and morphologic information still has an important role in the diagnosis of adrenal disease.

19-Iodocholesterol↗
PubMed1991

Dexamethasone facilitates release of the neuropeptide alpha-MSH.

alpha-Melanocyte stimulating hormone (alpha-MSH) has important host defense properties, in part similar to those of corticosteroids. Previous research suggests that secretion of alpha-MSH and of ACTH are controlled separately. The relationship between release of alpha-MSH and the activity of the hypothalamic-pituitary-adrenal axis in the rabbit was examined by monitoring changes in circulating alpha-MSH, ACTH, and corticosterone in response to endotoxin and corticotropin-releasing hormone (CRH), both with and without dexamethasone pretreatment. Endotoxin (1 microgram/kg IV) did not cause alpha-MSH release, but it did increase plasma concentrations of ACTH and corticosterone. Similarly, CRH (1 and 10 micrograms/kg IV) did not affect plasma alpha-MSH, whereas it stimulated ACTH and corticosterone release. Dexamethasone pretreatment abolished the responses of ACTH and corticosterone to either stimulus and did not modify circulating alpha-MSH after CRH. In contrast, dexamethasone pretreatment did result in a significant increase in plasma alpha-MSH after a dose of endotoxin that was ineffective alone. These data indicate that corticosteroids can facilitate the release of alpha-MSH, a powerful anti-inflammatory hormone. Since corticosteroids are released with certain challenges, this facilitatory activity may be important to the host response.

Adrenocorticotropic Hormone↗
PubMed1991

Effect of chronic clonidine administration on GH secretion in adult human subjects.

It is well known that the acute administration of clonidine, an alpha 2-adrenergic agonist commonly used as an antihypertensive drug, stimulates GH secretion, likely via hypothalamic growth hormone releasing hormone (GHRH) release. Conversely, evidences of a hyperactivity of GHRH-GH-somatomedin C (SMC) axis during chronical administration of clonidine are controversial. In this study, GH and SMC levels have been evaluated in 16 hypertensive patients chronically treated with clonidine. The subjects were randomized to receive either TRH or saline with the aim of evaluating the non specific GH response to TRH as compared to spontaneous fluctuations during a control test. In basal conditions, GH and SMC concentrations in clonidine treated patients were similar to those observed in an age and sex matched group of normal untreated subjects. An abnormal increase in plasma GH occurred in 5 out of the 10 patients who received TRH, while plasma GH did not show significant variations during testing in the subjects who received saline. It is suggested that chronical administration of clonidine does not induce an hyperactivity of GHRH-GH-SMC axis as estimated by plasma GH and SMC concentrations, but may induce a disorder in hypothalamic control of GH secretion, possibly implicated in the abnormal GH responsivity to TRH.

Aged↗
PubMed1991

ACTH and cortisol secretion in patients with Alzheimer's disease.

The "glucocorticoid cascade hypothesis" for pathological ageing of the brain is supported by strong experimental data, but the clinical correlates are far less clear. The basal ACTH and cortisol secretion have been studied before and after the dexamethasone suppression test in patients in the early stages of clinically probable Alzheimer's disease and in controls, and the results were all normal. These findings do not support the hypothesis that the pathological brain ageing of Alzheimer's type is caused by hyperactivity of the pituitary-adrenal axis.

Adrenocorticotropic Hormone↗
PubMed1991

Red cell membrane dynamic properties and erythrocyte metabolic parameters in essential hypertension: preliminary report.

In a group of 12 subjects with essential hypertension (EH), we evaluated the erythrocyte membrane fluidity and red cell membrane transverse fluidity gradient. We also evaluated the total red cell Ca content, the red cell cytosolic free calcium, the red cell membrane cholesterol/phospholipid ratio and the red cell membrane individual phospholipids. From the data obtained, it is evident that the erythrocyte membrane fluidity and red cell membrane transverse fluidity gradient discriminate normals from hypertensives. None of the red cell metabolic parameters is able, however, to differentiate normals from hypertensive subjects. Our data underline the abnormality of the red cell membrane dynamic properties in hypertension; this abnormality is not, however, related to the red cell metabolic parameters considered.

Adult↗
PubMed1991

Rheological determinants and red cell lipidic pattern in essential obesity, in obese subjects with non-insulin-dependent diabetes mellitus (NIDDM) and in obese subjects with impaired glucose tolerance (IGT).

In a group of subjects with essential obesity, in a group of obese subjects with non-insulin dependent diabetes mellitus (NIDDM), and in a group of obese subjects with impaired glucose tolerance (IGT), we evaluated whole-blood filtration, mean erythrocyte aggregation, erythrocyte membrane fluidity and red cell lipid pattern. From these data, it is evident that the macro- and microrheological determinants are able to discriminate normals from each group of obese subjects. Regarding the red cell lipids, few are the variations between each group of obese subjects and normal controls.

Adult↗
PubMed1991

[The criteria for choosing the surgical approach to cervicomediastinal goiters].

The retrospective analysis of a series of 350 cases of intrathoracic goiters, out of a total of 5,000 thyroid operations derived from the joined case records of the 3rd General Surgery Institute (Director: Prof. G. Di Matteo) and the 8th Chair of Surgical Pathology (Director: Prof. F.P. Campana), has induced the authors to reconsider the surgical approach to this pathology on the basis of anatomo-surgical factors.

Goiter, Substernal↗
PubMed1990

CRH and lysine-vasopressin stimulation tests in the diagnosis of hypoadrenalism secondary to hypothalamic or pituitary disorders.

Ten patients with secondary hypoadrenalism have been tested with corticotropin releasing hormone (CRH) and lysine-vasopressin (LVP). One patient had isolated ACTH deficiency; 9 had deficiency of other pituitary hormones attributable to a primary pituitary disease in 3 and to an hypothalamic disorder in 6. After CRH administration, a definite increase in plasma ACTH was observed in all 6 patients with hypothalamic disorder. No response was elicited in the 3 patients with pituitary disease and in the patient with isolated ACTH deficiency. In the responsive patients. ACTH showed a delayed and prolonged pattern of response. Lysine-vasopressin administration produced an increase in plasma ACTH in 4 of the 6 hypothalamic patients and no response in those with pituitary disease and in the patient with isolated ACTH deficiency. These findings suggest that CRH represents a reliable test in differentiating hypothalamic from pituitary adrenal failure; LVP appeared a less sensitive diagnostic test.

Adolescent↗
PubMed1990

Vascular atherosclerotic disease: evaluation of the whole-blood filterability and red cell membrane microrheological pattern after intravenous administration of a single dose of pentoxifylline.

A study was carried out in 10 patients with vascular atherosclerotic disease to investigate the effects of a single dose of 300 mg pentoxifylline, given by intravenous infusion over 30 minutes, on various macrorheological and microrheological parameters. Measurements were made at baseline, at the end of the intravenous infusion and again 30 minutes later, of whole-blood filterability, erythrocyte membrane fluidity (using pyrene as probe) and transverse fluidity gradient (using fluorescent fatty acids as probes). The results showed that there was a significant variation in whole-blood filterability and the red cell membrane fluidity gradient after pentoxifylline. No difference, however, was noted for the membrane fluidity. These data suggest, therefore, that pentoxifylline plays a role in affecting the red cell membrane microrheological pattern.

Aged↗
PubMed1990

Growth hormone and ACTH secretory dynamics in Turner's syndrome.

The secretory dynamics of GH and ACTH were studied in 14 patients with Turner's syndrome. The parameters investigated were plasma GH and cortisol responses to hypoglycemia, plasma cortisol circadian rhythm and suppressibility by dexamethasone, and response of urinary Porter-Silber chromogens to metyrapone. The results were mostly normal. These data do not support the hypothesis suggesting an abnormality of hypothalamic-pituitary function in Turner's syndrome.

17-Hydroxycorticosteroids↗
PubMed1990

Total red cell Ca2+ content and rheological determinants in a group of subjects with vascular atherosclerotic disease.

We evaluated the total red cell Ca2+ content and the macro- and microrheological determinants in a group of subjects with vascular atherosclerotic disease (VAD). From the results obtained it is evident that, compared to controls, the VAD group presents an alteration of the macro- and microrheological parameters. No difference is evident for the red cell Ca2+ content in normals and in VAD subjects. No relationship is present between total red cell Ca2+ content, VBC (volume blood cells), MEA (mean erythrocyte aggregation) and red cell membrane fluidity expressed as Iex/Im ratio. In contrast to the latter, are the correlation between the red cell Ca2+ content and the degree of polarization obtained with fatty acid probes.

Aged↗
PubMed1989

Male pseudohermaphroditism due to 17-hydroxylase deficiency.

A 27-year-old phenotypic female presented with primary amenorrhea, severe hypertension, and hypokalemia. At the age of puberty sexual development had not occurred; in particular, sexual hair had not grown. Past history revealed an episode of subarachnoid hemorrhage and several episodes of ventricular tachyarrhythmia. Karyotype was 46, XY. The steroids requiring 17-hydroxylation (cortisol, testosterone, pregnanetriol, 17-ketosteroids, 17-hydroxycorticosteroids) were low, while those not requiring 17-hydroxylation (progesterone, deoxycorticosterone, corticosterone) were high, demonstrating 17-hydroxylase deficiency. The corticosterone/deoxycorticosterone ratio was relatively low, suggesting an associated partial deficiency of 11-hydroxylase.

Adrenal Hyperplasia, Congenital↗