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Biomedical subjects

M Mannelli

Publications and source records attributed to M Mannelli.

At least 91 records · Page 5Linked to original sources
PubMed1983

Effects of thyroid replacement therapy on catecholamine plasma levels.

Plasma catecholamines (CA), total and free thyroid hormones (T4, FT4, T3, FT3) and thyrotropin (TSH) were measured before and during therapy in seven normotensive women with primary hypothyroidism lasting for more than 6 months. Twelve normal women matched for age were used as controls. In hypothyroid patients plasma norepinephrine (NE) was found increased in supine and upright position and plasma epinephrine (E) unchanged. After 30-60 days of therapy with dry thyroid extract, NE, T3, and FT3 levels were found in the normal range while T4 and FT4 levels, although raised, were still significantly lower than those of controls. These results seem to demonstrate that low doses of replacement therapy can restore NE levels to normal and therefore suggest that severe hypothyroidism alone is able to affect the sympathetic function.

Adult↗
PubMed1983

Role of PGE2 in the modulation of the adrenergic response in man.

The influence of sympathetic stimulation (SS) (achieved by 2 min cold application) on the plasma concentration of PGE2, PGF2 alpha (radioimmunoassay), noradrenaline (NA) and adrenaline (A) (radioenzymatic assay) and on forearm vascular resistance (indirect measurement, FVR) was studied in 16 healthy volunteers before and after cyclooxygenase inhibition by indomethacin (200 mg per day orally for 3 days) and lysine acetylsalicylate (corresponding to 10 mg X kg-1 of acetylsalicylic acid -ASA- iv). SS induced a sharp increase in PGE2 (from 8.1 +/- 4.3 pg X ml-1 before SS to 23.9 +/- 6.5, P less than 0.001 2 min after the beginning of SS and then to 18.9 +/- 10.2, P less than 0.001 to 8.4 +/- 3.9, NS, 4 and 12 min respectively after the beginning of SS). Plasma levels of PGF2 alpha remained undetectable both before and after SS. The increase in PGE2 was associated with a simultaneous increase in NA (from 13.4 +/- 24.2 to 204.1 +/- 67.2 pg X ml-1, P less than 0.001 during SS and 140.6 +/- 39.5, NS at the end of the experiment), whereas A did not vary significantly. FVR increased significantly only during SS. ASA did not affect PGE2 and NA plasma levels at rest or after SS. No PGE2 was detected during IND administration either before or after SS. IND significantly increased NA plasma concentration at the observation made 12 min after the beginning of SS (185.2 +/- 64.3 pg X ml-1 vs basal values of 135.9 +/- 46.2 pg X ml-1, P less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1983

Cholinergic receptor control mechanisms for L-dopa, apomorphine, and clonidine-induced growth hormone secretion in man.

The effect of pirenzepine, an anticholinergic agent, on GH release induced by L-dopa (500 mg po), apomorphine (0.75 mg sc), and clonidine (0.150 mg iv) administration was studied in a group of normal men. Pirenzepine, a cholinergic muscarinic antagonist, completely blocked the GH rise induced by dopamine- and adreno-receptor stimulation. In contrast, the PRL-inhibiting action of L-dopa was not modified by the cholinergic antagonist. The data suggest that acetylcholine and its receptors are important regulators of the neurosecretory mechanisms that control GH secretion in man.

Adult↗
PubMed1982

Pheochromocytoma presenting as possible cardiomyopathy.

A case of pheochromocytoma presenting as a possible hypertrophic obstructive cardiomyopathy is reported. In a 67 years old woman without previous history of hypertension, the echocardiogram showed left ventricular concentric hypertrophy and systolic anterior movement of the mitral valve. The carotid pulse was deformed with a spike-and-dome pattern. The complex interactions between myocardial adrenergic receptors sites and catecholamines, and the relation between these substances and the pattern of cardiac hypertrophy are discussed.

Adrenal Gland Neoplasms↗
PubMed1981

Spermatic and peripheral oestradiol levels in patients affected by azoospermia due to seminiferous tubular damage.

Plasma levels of testosterone, androstenedione and oestradiol were determined in the spermatic venous blood of both testes of 17 patient affected by azoospermia due to tubular damage (Group I). The results were compared with those found in 5 patients affected by azoospermia of obstructive origin and 5 patients with an inguinal hernia (Group II). Mean spermatic levels of testosterone and androstenedione were not significantly different in the two groups, while the mean (+/- SE) oestradiol spermatic level was significantly higher in patients of Group I (5.02 +/- 0.75 nM/l vs. 2.20 +/- 0.365 nM/l; P less than 0.05). Moreover, while the testosterone/androstenedione and the androstenedione/oestradiol ratios were not significantly different in the two groups, the mean (+/- SE) testosterone/oestradiol ratio was significantly lower in patients of Group I (552.71 +/- 80.94 vs. 939.86 +/- 129.45; P less than 0.025). Peripheral testosterone and androstenedione mean levels were not significantly different between the two groups while the mean peripheral oestradiol level (+/- SE) was significantly higher in Group I (0.107 +/- 0.021 nM/l vs. 0.038 +/- 0.05 nM/l; P less than 0.025). Peripheral oestradiol was not significantly related to peripheral FSH, nor to spermatic oestradiol in both groups. These results suggest the possibility that oestradiol may be involved in the pathogenesis of some cases of male infertility.

Adult↗
PubMed1978

Klinefelter's syndrome: a study of its hormonal plasma pattern.

Plasma testosterone (T), dihydrotestosterone (DHT), 17 beta-estradiol (E2), 17-hydroxyprogesterone (17-OHP), androstenedione (delta), dehydroepiandrosterone (DHEA), dehydroepiandrosterone sulphate (DHEAS), 5-androstene-3 beta-17 beta-diol (A-diol) and cortisol (F) have been measured in a group of normal males and in a group of patients with Klinefelter's syndrome (KS) before and after hCG stimulation. Significantly lower baseline levels of T and DHT and significantly higher baseline levels of E2 were found in patients with KS. No significant differences were found between baseline levels of 17-OHP, delta, DHEA, DHEAS, A-diol, and F. After hCG stimulation between T, DHT, E2 and 17-OHP levels showed a significant increase in the two groups of subjects. The percentage variation of T and DHT, however, was much less important in Klinefeiter patients, while E2 and 17-OHP did not show a significantly different pattern from that of normal controls, hCG administration did not produce any significant variation of delta, DHEA, DHEAS, and F in the two groups of subjects, while A-diol levels increased significantly in normal subjects, but not in Klinefelter patients. Our data may be consistent with the hypothesis that testicular steroidogenesis in Klinefelter patients is impaired below the 21-C-steriod level not only at delta 4 but also at the delta 5 pathway.

Adolescent↗
PubMed1977

Digoxin and congestive heart failure.

The purpose of our study was to evaluate the absorption of digoxin in alcoholic solution in normal subjects and in patients on congestive heart failure whose water and electrolyte balances were determined. While the parameters of the distribution kinetics were not significantly different between the two groups, the areas under the serum concentration curve resulted increased in the patients on congestive heart failure indicating a more efficient absorption respect to the normal subjects.

Aged↗
PubMedDate not supplied

Hypoglycemia unawareness in a patient with dumping syndrome: report of a case.

We report the case of a 49-yr-old man affected by coma and hypoglycemia unawareness following repetitive hypoglycemic episodes due to dumping syndrome. The dumping syndrome, which was due to partial gastrectomy and vagotomy performed for recurrent peptic ulcer, was responsible for reactive hyperinsulinemia as demonstrated by an oral glucose tolerance test. While the glucose counterregulatory hormones were all normally sensitive to specific stimulation tests, insulin-induced hypoglycemia failed to induce an adequate counterregulatory response, causing no response in plasma norepinephrine, a slight and short increase in plasma cortisol, ACTH and glucagon and an insufficient increase in plasma epinephrine and GH. This case demonstrates that hypoglycemia unawareness has to be taken into account not only in patients affected by IDDM or insulinoma but also in any case of reactive hypoglycemia.

Adrenocorticotropic Hormone↗
PubMedDate not supplied

A study on human adrenal secretion. Measurement of epinephrine, norepinephrine, dopamine and cortisol in peripheral and adrenal venous blood under surgical stress.

Epinephrine (E), norepinephrine (NE), dopamine (DA) and cortisol (F) were measured in samples drawn simultaneously by direct venepuncture from the brachial and the adrenal vein of 12 patients undergoing surgery for left kidney diseases. In 7 patients the influence of anesthesia on peripheral plasma levels was also assessed. Catecholamines were measured by a radioenzymatic assay and F by radioimmunoassay. Compared to basal values (mean +/- SE) (E: 53.6 +/- 6.2 pg/ml; NE: 209.4 +/- 24.4 pg/ml; DA: 24.5 +/- 3.3 pg/ml; F: 12.9 +/- 1.2 micrograms/dl) only NE peripheral levels were significantly modified by anesthesia (NE: 343.7 +/- 67.4 pg/ml p less than 0.05), whereas under surgery a significant increase in the peripheral levels was found for every substance measured (mean +/- SE) (E: 332.5 +/- 46.6 pg/ml p less than 0.001; NE: 633.6 +/- 114.2 pg/ml p less than 0.005; DA: 85.8 +/- 15.7 pg/ml p less than 0.005; F: 21.3 +/- 1.9 micrograms/dl p less than 0.01). Catecholamine and F levels in adrenal vein showed a high variability suggesting an intermittent secretion. In the adrenal venous blood E levels were, in the mean, 381 times higher, NE levels 45 times, DA levels 27 times and F levels 23 times higher than in peripheral blood. E, NE and DA concentrations in the adrenal vein were all significantly correlated to the others but not to cortisol, suggesting that the medulla secrets E, NE and DA in rather constant ratios and that the cortex and the medulla respond differently to surgical stress.

Adrenal Glands↗