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D Armanini

Publications and source records attributed to D Armanini.

17 recordsLinked to original sources
PubMed1992

Concomitant release of renin, angiotensin I, and angiotensin II during superfusion of human juxtaglomerular cell tumor.

Increasing evidence indicates that angiotensin II can be formed by juxtaglomerular cells (JGC) and cosecreted with renin. We investigated the existence of this local renin-angiotensin system in a human JGC tumor, using an in vitro superfusion. The JGC tumor was found concomitantly to release renin and angiotensin I and II. Sequential addition of atrial natriuretic peptide, dopamine, and a somatostatin analog in the superfusion did not affect renin or angiotensin I and II release. The data provide evidence that the human JGC tumor in vitro generates angiotensin II, and supports its possible role as a local in vivo regulator of kidney function.

Adult↗
PubMed1992

Corticosteroid receptors and lymphocyte subsets in mononuclear leukocytes in aging.

Plasma cortisol and aldosterone levels and number of related receptors in mononuclear leukocytes were measured in 49 healthy aged subjects (62-97 yr) and in 21 adult controls (21-50 yr). In all subjects, in addition, lymphocyte subsets were determined as an index of corticosteroid action. The mean number of type I and type II receptors was significantly lower in aged subjects than in controls (respectively, 198 +/- 96 and 272 +/- 97 receptors/cell for type I, and 1,794 +/- 803 and 3,339 +/- 918 for type II receptors). Plasma aldosterone and cortisol and lymphocyte subsets were not different in the two groups. All of the parameters were also tested for correlation, and a significant inverse correlation was found between age and type I and type II receptors when all subjects were plotted and between aged and CD4 and age and CD4/CD8 in the aged group. These data show that aged subjects have reductions of corticosteroid receptors that are not associated with increase of related steroids and that this situation probably represents a concomitant of the normal aging process.

Adult↗
PubMed1992

Mineralocorticoid effector mechanism in preeclampsia.

Mineralocorticoid effector mechanisms were evaluated in 29 patients with preeclampsia and in 25 uncomplicated pregnancies by measurement of plasma aldosterone, levels of mineralocorticoid receptor (MR) in mononuclear leucocytes, and subtraction potential difference (SPD; rectal minus oral values). Mean values for plasma aldosterone were not different between the two groups, but significant differences were observed for MR (preeclampsia, 81 +/- 44 receptors/cell; controls, 306 +/- 168) and SPD (preeclampsia, 65 +/- 7 mV; controls, 12 +/- 5 mV). In six cases we determined MR, plasma aldosterone, and SPD in patients with preeclampsia before and 3 months after delivery. MR were reduced before delivery (96 +/- 27 receptors/cell), and SPD increased (64 +/- 8 mV), with both parameters normalizing after delivery (MR, 242 +/- 79; SPD, 14.0 +/- 4 mV). Aldosterone levels returned to normal nonpregnant values after delivery. These data suggest an important role for abnormalities in mineralocorticoid effector mechanisms in the etiology of preeclampsia and could be an useful marker for diagnosis.

Adult↗
PubMed1991

Pseudohypoaldosteronism and mineralocorticoid receptor abnormalities.

Pseudohypoaldosteronism is a rare inherited disease characterized by renal salt loss, hyperkalemia and metabolic acidosis despite highly elevated aldosterone values. We previously reported absent or reduced numbers of mineralocorticoid receptors in mononuclear leukocytes and defective effector mechanism as shown by no response in vitro to the incubation of aldosterone in terms of intracellular electrolyte content. We have studied the inheritance of this disorder in ten families and found two different kinds of inheritance: autosomal recessive--often in interrelated families--and autosomal dominant in unrelated families. Parallel studies in the families with the autosomal dominant form of inheritance demonstrated in addition that the effector mechanism of aldosterone is impaired in vitro both in the affected patients and in the carrier relatives characterized by a low number of mineralocorticoid receptors.

Aldosterone↗
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

Plasma renin activity and urinary aldosterone in Cushing's syndrome.

The renin-angiotensin-aldosterone system has been evaluated in 19 patients with Cushing's syndrome due to bilateral adrenal hyperplasia and in 2 patients with unilateral adenoma. In the first group urinary aldosterone was within the normal limits with a mean of 8.3 +/- 1.86 microgram/24 h. Aldosterone excretion did not change significantly after furosemide administration, ACTH infusion or dexamethasone. Upright PRA was suppressed in 9/16 patients with a mean of 4.9 +/- 1.85 ng/ml/3 h and showed only a slight response to furosemide. Dexamethasone alone did not produce any change. Both aldosterone and PRA were to some extent stimulated by an association of dexamethasone and furosemide. In the 2 patients with adenoma, aldosterone excretion was also normal, but PRA was very elevated. From our data it is concluded that in Cushing's syndrome due to bilateral hyperplasia, PRA and aldosterone excretion are partially suppressed. From our results on plasma deoxycorticosterone and corticosterone concentration it seems unlikely that these mineralocorticoids are the major cause of this phenomenon. However, it may not be excluded that other yet unidentified hormones could play some role in the pathogenesis of hypertension and renin suppression in Cushing's syndrome.

Adolescent↗
PubMed1978

Plasma renin activity in coarctation of the aorta before and after surgical correction.

In 37 patients with coarctation of the aorta, arterial blood pressure and ambulant plasma renin activity (PRA) were determined before and, in 15 patients, after surgical correction. The systolic blood pressure was raised in all the cases and the diastolic pressure was raised in 30 patients. Ambulant PRA was increased in 11 patients when compared with normal subjects of similar age. Twelve of the 15 operated patients had a significant decrease of systolic pressure after operation. Eight had raised PRA, and in 7 of these PRA fell to normal after operation and the blood pressure also fell; in 1 patient the decrease of PRA was unaccompanied by a fall in blood pressure. Though there was no significant correlation between the changes in blood pressure and PRA after operation it seems possible from our results that the renin-angiotensin system may be activated and contribute to the raised arterial pressure which occurs in patients with aortic coarctation.

Adolescent↗
PubMed1977

[Pheochromocytoma. Diagnostic aspects and surgical treatment. Apropos of 20 operated cases].

Reference is made to 20 cases of pheochromocytoma operated at the surgical clinic of the University of Padua since 1963. Stress is laid on the importance of modern angiographic techniques in diagnosis and their attendant risks and the main aspects of surgical management are examined. The results show that success depends on careful preoperative localisation, choice of a suitable approach route, and correct technique coupled with suitable intraoperative management.

Abdominal Neoplasms↗
PubMed1976

Aldosterone regulation in primary aldosteronism: differences between adenoma and bilateral hyperplasia.

1. The diurnal patterns of plasma aldosterone, plasma renin activity (PRA), cortisol and adrenocorticotrophic hormone (ACTH) in the supine and in the upright position have been studied in fourteen patients with primary aldosteronism, five with adenoma and nine with bilateral hyperplasia. Blood samples were drawn at intervals from 6 h to 30 min. 2. Supine patients with an adenoma showed marked diurnal variations of aldosterone, with maximal values at 08.00 hours and minimal values of 18.00 hours and secretory spurts beginning after 02.00 hours. Plasma cortisol paralleled aldosterone, and ACTH seemed to anticipate aldosterone and cortisol variations; PRA remained unchanged. In patients with hyperplasia, aldosterone was significantly lower than in the adenoma group at 08.00 hours, and its decline during the day was less marked; fluctuations rather than secretory episodes were seen. 3. After patients assumed the upright posture, aldosterone remained unchanged or decreased in patients with adenoma, whereas it significantly increased in hyperplasia; PRA remained low, although a slight increment was seen in the latter group. The different response of aldosterone in the two groups was not modified by the administration of propranolol, apparently excluding a renin-dependent mechanism. On the other hand, dexamethasone seemed to affect the response of aldosterone to the upright posture in both groups; in adenoma there was a slight but significant increase, and in hyperplasia the usual rise was partially suppressed. 4. It is concluded that ACTH has a predominant role in regulating aldosterone secretion in primary aldosteronism due to adenoma, whereas its action in bilateral hyperplasia is only permissive.

Adenoma↗
PubMed1976

[Effect of diazoxide on blood pressure, PRA and plasma aldosterone in hypertensive patients (author's transl)].

Intravenous diazoxide (300 mg) was administered to 29 hypertensive patients previously classified in subgroups according to their plasma renin and urinary aldosterone levels. The blood pressure was measured before and periodically after injection and plasma renin activity (PRA) and plasma aldosterone before and after 2 hours. The mean systolic and diastolic blood pressure fell notably from 193/118 to 155 93 mmHg; whereas PRA increased from 7.51 to 13.21 ng/ml/3 hrs and plasma aldosterone did not change significantly (71.3 and 102.8 ng%). Examining the individual sub-groups, a significant decrease in blood pressure was observed in 15 patients with low, posture unresponsive PRA, both in subjects with normal urinary aldosterone and those with surgically proven primary aldosteronism. In the former only the mean PRA showed a slight but sigificant increase, while in the latter the changes for both PRA and aldosterone were not significant. In the subgroups of patients with normal renin and urinary aldosterone the arterial pressure also significantly and promptly decreased. However, in this group the mean PRA substantially increased whereas the plasma aldosterone levels remained constant. The same blood pressure decline was observed in those patients with high PRA and aldosterone, including 1 case of pheocromocytoma. The mean PRA showed a further modest increase while the plasma aldosterone did not change significantly. These results indicate that the antihypertensive action of diazoxide is similar in the different types of hypertension (volume, vasoconstrictor or mixed form according to Laragh's classification), being independent of the basal plasma renin and aldosterone levels. Furthermore, the response of the blood pressure to diazoxide is not related in any way to the induced changes in PRA and plasma aldosterone values.

Adrenal Gland Neoplasms↗
PubMed1976

[Indications for study of adrenal function by measurement of the cortisol secretion rate].

Results of routine methods for measurements of plasma cortisol and his urinary metabolites have been comparated with those of cortisol secretion rate (CSR) measured by simple isotopic dilution; the latter appears for his specify and precision, to be the most suitable for an exact evaluation of cortisol production by the adrenals. In normal subjects CSR resulted slightly lower than those reported in the literature; in obese subjects CSR was slightly higher than in normals, also when it was related to the urinary creatinine. In the patients with Cushing's syndrome, CSR was considerably higher, with no overlap with the obese subjects. The CSR was also useful in showing values lower than normal, in hypopituitarism, and in confirming hormone abnormal findings in thyroid diseases.

Adolescent↗
PubMedDate not supplied

Plasma renin activity and urinary aldosterone in acromegaly.

The behaviour of the renin-angiotensin-aldosterone system was evaluated in 16 acromegalic patients, of whom 7 were hypertensive. The patients were studied in basal conditions, after suppression with 9alpha-fluorohydrocortisone, and after stimulation with furosemide. Baseline and after furosemide PRA were significantly lower in acromegalic hypertensive patients than in the normotensive group. Mean urinary aldosterone excretion was found at the upper limits of the normal range; it was occasionally elevated, but the values were not satistically different in the two groups. There was a suppression after 9 alpha fluorohydrocortisone in both groups, though it did not reached the 50%. These data show that there is a disorder of the renin-angiotensin-aldosterone system in acromegalic subjects. This defective regulation is sometimes similar to that present in primary aldosteronism. In fact in two patients a typical phlebographic and scintigraphic picture of primary aldosteronism has been found; surgery, performed in both patients, revealed a large cortical adenoma in one case and a macronodular hyperplasia in the second case. However, the relationship between this adrenal abnormalities and hypertension in acromegaly are not yet completely clarified.

Acromegaly↗
PubMedDate not supplied

[Plasma renin activity in renal veins in different types of arterial hypertension (author's transl)].

Peripheral plasma renin activity (PRA), vena cava and renal veins PRA were measured in 85 patients; arterial PRA was also measured in several cases. 25 patients had essential hypertension or primary aldosteronism; whereas in 60 patients renal or renovascular abnormalities were present. Peripheral PRA was elevated in 17/30 patients with parenchimal or excretory tract diseases. The following ratios came from the results of vena cava, and renal veins PRA were calculated: Ra/Rc and Rc/P according to Stockigt et al. and V-A/A according to Vaughan et al. The ratios were calculated only when v. cava PRA was greater than 4 ng/ml/3 hrs. A good correlation was found between v. cava can arterial PRA. Among the 60 cases with renal hypertension, 26 underwent either revascularization or nephrectomy surgery. Eleven of the 15 patients operated on for renovascular diseases showed a significant reduction of blood pressure (greater than 30 mmHg); all had high peripheral PRA and 6 had significant Ra/Rc and Rc/P (respectively greater than or equal to 1,5 and less than or equal to 1,3). The same patients also had V-A/A of the affected kidney greater than or equal to 0,48 and 5 also V-A/A of the controlateral kidney less than or equal to 0,23, both values being significant for a unilateral renin secretion and controlateral suppression. Among the 4 patients who were unsuccessfully operated on, only 2 had elevated peripheral PRA and 1 had Ra/Rc and Va-A/A greater than normal, but not significant values of Rc/P and Vc-A/A. 11 patients with small kidney or other forms underwent surgery; among the 6 cases with satisfactory results, 5 had high peripheral PRA, 2 showed significant ratios Ra/Rc and 3 a significant V-A/A for both kidneys. Only 1 of the patients not cured by surgery had supernormal peripheral PRA and none had any significant ratio. Therefore both methods for elaborating data obtained from the measurement of PRA in renal veins seem to offer similar prognostic indications. The finding of significant ratios is an almost sure criterium for predicting a surgical cure of renal hypertension, whereas the cases where we may expect a failure present ratios which are not significant. However, patients of the latter group may sometimes have successful results at surgery too, which demonstrates that other mechanisms may also be involved in the pathogenesis of this form of hypertension.

Adolescent↗