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Biomedical subjects

F Mantero

Publications and source records attributed to F Mantero.

At least 181 records · Page 10Linked to original sources
PubMed1981

HLA genotypes and HLA-linked genetic markers in Italian patients with classical 21-hydroxylase deficiency.

HLA genotype and HLA-linked marker data for 40 unrelated patients from central Italy and 2 unrelated patients from Sardinia with congenital adrenal hyperplasia due to 21-hydroxylase deficiency (21-OH-def) were analyzed. The results confirm that the HLA-linked 21-OH-def gene is associated with several different HLA determinants and complete HLA haplotypes, although the only determinant with significantly increased frequency was the complement C2 allele C2B. The HLA antigens B8 and DR3 were found in significantly decreased frequencies. The haplotype A3, Cw6, Bw47, BfF, DR7, which is exceptionally rare in the general population but which has been found in many other 21-OH-def patients from diverse geographical origins, was also found in one of the Italian patients. This and other HLA haplotype associations found among the Italian patients may represent mutations that have occurred on HLA haplotypes with genetic linkage disequilibrium or, alternatively, may represent mutations that have not yet had time to become randomly associated with different HLA complex determinants. The marked negative associations with B8 and DR3 could, however, result from an interaction between the gene products of the HLA complex and the 21-OH-def phenotype.

Adrenal Hyperplasia, Congenital↗
PubMed1981

Mineralocorticoid hypertension due to a nasal spray containing 9 alpha-fluoroprednisolone.

The finding of hypokalemia and of low plasma renin activity (PRA) in a hypertensive patient suggests a diagnosis of primary hypermineralocorticoidism. Medications containing compounds with mineralocorticoid-like activity (licorice, carbenexolone) may also cause the same syndrome. Recently, we carried out detailed studies on 10 patients with severe hypertension and hypokalemic alkalosis, suppressed PRA and low aldosterone levels. Plasma levels of cortisol and ACTH were suppressed in most of the cases. Measurement of deoxycorticosterone and corticosterone (and in some patient of 18-hydroxydeoxycorticosterone and 18-hydroxycorticosterone) was not significantly higher than normal. Therapeutic trials of dexamethasone and aminoglutethimide were ineffective. In contrast, spironolactone and amiloride treatment resulted in substantial but incomplete amelioration of both hypertension and hypokalemia. All of the patients share a common history of chronic rhinitis and habitual use of large doses of nasal spray containing 9 alpha-fluoroprednisolone and vasoconstrictor agents. Withdrawal resulted in a complete remission of hypokalemia in one to two weeks in all patients. The hypertension and depressed levels of PRA, aldosterone and cortisol took longer to return to normal, varying from case to case; in all but one patient, the values returned to normal within two months. This report reveals another cause of factitious mineralocorticoid excess which may be considered in the differential diagnosis of hypokalemic hypertensive syndromes.

Administration, Intranasal↗
PubMed1981

The primary tissue culture of human adrenocortical Conn's adenomata. I. The synergistic stimulation of adenomatous cell growth by purine cyclic nucleotides and by ACTH1-24 and angiotensin II.

Primary cultures of dissociated parenchymal cells from Conn's adenomata causing primary hyperaldosteronism were successfully set up by a method previously used with normal adult human and rat adrenocortical tissue. In such cultures the adenomatous cells largely prevailed (making up 87% of the whole cell population), could survive for lengthy terms (at least up to 30 days), and were endowed with a spontaneous, discrete capability to proliferate. The de novo RNA- and DNA-synthetic and mitotic activities of Conn's cells were markedly stimulated in cultures exposed between 16 and 21 to daily doses of exogenous cyclic AMP, either alone or in equimolar association with cyclic GMP. A significantly weaker, though still prominent enhancement of adenomatous cell growth was elicited also by daily administrations of an equimolar mixture of ACTH1-24 and angiotensin II. In contrast, little stimulation or inhibition of growth or no effect at all could be observed when cyclic GMP, ACTH1-24, and angiotensin II were respectively administered, each by itself.

Adrenal Cortex Neoplasms↗
PubMed1981

Effect of angiotensin II and converting enzyme inhibitor (captopril) on blood pressure, plasma renin activity and aldosterone in primary aldosteronism.

1. Patients with idiopathic hyperaldosteronism (IHA) show a response of aldosterone to posture which is not present in patients with aldosterone-producing adenoma (APA). We have determined whether this could be explained by a different sensitivity to angiotensin II. 2. Angiotensin II was infused in gradually increasing doses in six patients with APA and in seven patients with IHA. No changes in aldosterone concentration were found at the end of each period in APA, whereas there was a significant increase in IHA; blood pressure rose by a similar extent in both groups. 3. In order to evaluate the role of endogenous angiotensin II, captopril, a converting enzyme inhibitor, was administered to six patients with APA and five patients with IHA at a dose of 75 mg/day for 1 week. There was a significant fall of mean blood pressure in IHA and only minimal changes in APA. Plasma renin activity and plasma in urinary aldosterone were unchanged in APA. In IHA there was a small increase in upright plasma renin activity and a slight decrease in both plasma and urinary aldosterone, but these changes were not significant. 4. These findings further support the idea that idiopathic hyperaldosteronism is a clinical state different from that occurring in primary aldosteronism due to adenoma, and may be more closely related to essential hypertension.

Aldosterone↗
PubMed1981

Effect of metoclopramide on plasma aldosterone in normal subjects, primary aldosteronism and hypopituitarism.

The behaviour of plasma renin, aldosterone, cortisol and prolactin after administration of a drug with antidopaminergic action, metoclopramide, was evaluated in 6 normal subjects, 8 patients affected by primary aldosteronism and in 5 patients affected by anterior hypopituitarism. In the first two groups, besides the predictable increase of prolactin under metoclopramide, a significant aldosterone increase was noted. Cortisol remained unchanged, and PRA was not significantly increased. A similar pattern of aldosterone, cortisol and PRA was also found in patients with hypopituitarism. However, the plasma prolactin did not increase in this group. The comparative examination of three groups of patients leads us to conclude that aldosterone increase is not imputable to ACTH, renin or to prolactin. This may be explained by a possible direct effect of the antidopaminergic drug at the adrenal level, which is more likely than an effect through some yet undetermined factor.

Aldosterone↗
PubMed1981

Genetic and hormonal characterization of cryptic 21-hydroxylase deficiency.

Cryptic 21-hydroxylase deficiency has been previously described in asymptomatic family members of patients with classical congenital adrenal hyperplasia (CAH). These family members were detected by high baseline 17-hydroxyprogesterone levels found in the course of family studies. The hormonal responses to ACTH of the family members with cryptic 21-hydroxylase deficiency were determined and compared to the responses of patients with CAH, patients with acquired adrenal hyperplasia, family members predicted to be heterozygous for CAH, family members predicted to be unaffected, and the general population. The ACTH-stimulated levels of 17-hydroxyprogesterone and delta 4-androstenedione in the cryptic family members were elevated above the level of the general population or family members heterozygous for classical CAH, but below that of patients with CAH. The hormonal profile of patients with cryptic 21-hydroxylase deficiency is similar to that of patients with acquired adrenal hyperplasia. The response of family members heterozygous for the cryptic gene (21-OH CRYPTIC/21-OH NORMAL) was indistinguishable from that of family members heterozygous for the classical CAH gene (21-OH CAH/21-OH NORMAL). These studies support our previous proposal that patients with cryptic 21-hydroxylase deficiency are genetic compounds, having one gene for a severe enzyme deficiency and one gene for a mild 21-hydroxylase deficiency. Thus, the 21-hydroxylase genotype in cryptic 21-hydroxylase deficiency is 21-OH CAH/21-OH CRYPTIC.

Adolescent↗
PubMed1981

Plasma aldosterone response to acute stimulation in panhypopituitarism.

The influence of acute stimulation by ACTH, upright posture and angiotensin II on plasma aldosterone levels was assessed in human panhypopituitarism. While stimulation by ACTH in hypopituitary patients induced a plasma aldosterone increase similar to that observed in healthy controls, stimulation by upright posture or by infusion of angiotensin II resulted in a lower plasma aldosterone response than in controls in most of the patients. These results suggest that the presence of an anterior pituitary hormone, most likely ACTH, directly or indirectly exerts a permissive action on aldosterone secretion in man.

Adrenocorticotropic Hormone↗
PubMed1981

[Surgical and medical treatment of renovascular hypertension (author's transl)].

We have studied a group of 47 patients with unilateral or bilateral renal artery stenosis; 27 of them have been operated, while 20 have been subjected to medical treatment. Among the surgically treated patients, 18 out of the 22 cases with an unilateral stenosis had satisfactory results and didn't assume any treatment after surgical cure. All the 5 cases of bilateral stenosis presented a regular blood pressure after surgery. Nine among the 12 patients affected by unilateral stenosis and 3 among the 8 patients presenting bilateral forms who received medical treatment had successful results with the conventional therapy. The parameters that seems give a better prognostic indication for the surgical cure are either significant renal veins renin ratios (Ra/Rc and Rc/P), either high peripheral PRA values combined with a renal artery stenosis greater than or equal to 70%, in all the cases without evident damages in the opposite kidney, even if the renin ratios are not significant. The results of the medical treatment may be predicted from the entity of the renal stenosis. Failures are more likely to occur in the bilateral forms. In these cases the most satisfactory results can be obtained using minoxidil or the inhibitor of the converting enzyme of angiotensin I.

Adolescent↗
PubMed1980

Cryptic 21-hydroxylase deficiency in families of patients with classical congenital adrenal hyperplasia.

Serum androgens and 17-hydroxyprogesterone concentrations and HLA genotypes were determined in 124 families of patients with congenital adrenal hyperplasia due to 21-hydroxylase deficiency (CAH). In 8 pedigrees, we discovered 16 pubertal or postpubertal family members of either sex who had biochemical evidence of 21-hydroxylase deficiency but were without clinical symptoms of excess virilism, amenorrhea, or infertility. We designated these family members as individuals with cryptic 21-hydroxylase deficiency. Within each generation, the family members with cryptic 21-hydroxylase deficiency were HLA identical. It is proposed that these family members are genetic compounds, having 21-hydroxylase deficiency as a result of two recessive gene defects: 1) a severe 21-hydroxylase gene defect present in the index case with classical CAH (21-OHCAH) and 2) a mild 21-hydroxylase gene defect (21-OHCRYPTIC). Thus, the CAH genotype in the family members with cryptic 21-hydroxylase deficiency is 21-OHCAH/21-OHCRYPTIC. Lod score analysis for linkage between the cryptogenic 21-OH trait and HLA gave a combined Lod score for males and females of theta = 0.00 of 3.409. Close genetic linkage between HLA and 21-OHCRYPTIC was thus established. This study provides support for the previously reported heterogeneity of 21-hydroxylase deficiency which may result from allelic variability at the locus for steroid 21-hydroxylase.

17-alpha-Hydroxypregnenolone↗
PubMed1979

[Diaxozide-induced acute stimulation of plasma renin activity in renal veins for diagnosis and prognosis in hypertensive patients (author's transl)].

Vena cava and renal veins PRA were measured and their ratios calculated (Ra/Rc and Rc/P) in 15 hypertensive patients before and after diazoside infusion (300 mg i.v.). Among the 4 patients with unilateral renal artery stenosis, 3 had both ratios significant in basal conditions. After diazoxide infusion, the ratios became significant in the 4th case, successfully operated. Surgery induced normalization of blood pressure also in 2 of 3 cases affected by renoparenchimal alterations: of these patients 1 had ratios significant in basal conditions and both after diazoxide. One patient had unilateral renal artery stenosis and controlateral small kidney: his ratios was significant in favour of small kidney both before and after diaxozide infusion. The correction of renal artery stenosis gave no results in blood pressure. In patients with essential hypertension the PRA values in renal veins were not significantly different either before and after diazoxide. In conclusion the acute diazoxide stimulation seems to improve the prognostic value of renal veins PRA and their ratios for the detection of surgically curable forms of renal hypertension.

Adolescent↗
PubMed1978

Effects of ACTH and 3',5'-cyclic purine nucleotides on the morphology and metabolism of normal adult human adrenocortical cells in primary tissue culture.

Stereological studies showed that treatment of normal adult human adrenocortical cells in primary culture with ACTH or cyclic-AMP for 2 days results in similar increases in the volume of cells, of the mitochondrial and "membrane space" compartments and of the surface area of the smooth endoplasmic reticulum and mitochondrial cristae, and decrease in the lipid content of the cells. These changes were more marked after 8 days of treatment. Treatment for 2 days with cyclic-GMP had no striking effects on cell ultrastructure, whereas an 8-day treatment led to ultrastructural changes similar to those obtained after 2 days of ACTH- or cyclic-AMP-treatment. A discrete population of untreated cortical cells maintained a slow proliferation that was not effected by exposure to cyclic-GMP, but was significantly increased in cultures treated with ACTH or cyclic-AMP. Radioimmunological studies showed that untreated cortical cells kept secreting progesterone and cortisol and that ACTH, but neither cyclic nucleotide, increased the secretion rate per cell of both hormones. These results assign a major role to cyclic-AMP and a minor one to cyclic-GMP in the mediation of the differentiation-promoting and trophic effects, but not in the steroidogenic effects of ACTH on the human adrenal cortex.

Adrenal Cortex↗