PubMed Health⌕ Search

Biomedical subjects

R Meroni

Publications and source records attributed to R Meroni.

At least 19 recordsLinked to original sources
PubMed2007

Recurrent endometrial cancer: patterns of recurrent disease and assessment of prognosis.

AIM: To evaluate patterns of disease and identify factors predicting outcome in patients presenting with recurrent endometrial adenocarcinoma following primary surgery. MATERIALS AND METHODS: A retrospective review was performed of the imaging and clinical data in 86 patients (median age 66 years, range 42-88 years) presenting with recurrent endometrial adenocarcinoma following primary surgery. RESULTS: Following primary surgery recurrent disease occurred within 2 years in 64% and within 3 years in 87%. Relapse was seen within lymph nodes in 41 (46%), the vagina in 36 (42%) the peritoneum in 24 (28%) and the lung in 21 (24%). Unusual sites of disease included spleen, pancreas, rectum, muscle and brain. Univariate survival analysis showed the factors significant for poor outcome were: multiple sites of disease, liver and splenic disease, haematogenous, peritoneal and nodal spread, poorly differentiated tumour, and early relapse. The presence of disease within the vagina, bladder or lung was not associated with poor prognosis. Multivariate analysis identified multiple sites of disease, liver and splenic metastases to be independent predictors of poor outcome. CONCLUSION: The most frequently observed sites of relapse are: lymph nodes, vagina, peritoneum and lung. Significant predictors of poor outcome in recurrent disease are multiple sites of disease and liver and splenic metastases.

Adenocarcinoma↗
PubMed2003

Long-term results of balloon dilation of benign bile duct strictures.

PURPOSE: To evaluate the results of percutaneous balloon dilation of benign bile duct strictures in a series of patients with a long follow-up period. MATERIAL AND METHODS: 56 patients with benign bile duct strictures underwent balloon catheter dilation. These patients had strictures of various origins: postsurgical, postlocal not surgical treatments, associated with gallstones, due to primary sclerosing cholangitis and to Mirizzi's syndrome. In 41 cases the diagnosis was made on the basis of radiological findings and history and in 15 cases on the basis of transluminal biopsy. RESULTS: In 87.5% of cases the treatment was immediately successful. There were no early recurrences, but 7 (21%) recurrences were seen over 1 year after treatment; of these, 57% underwent another balloon dilation procedure with a positive long-term outcome. CONCLUSION: The long-term success rate obtained in 72% of this series confirms that percutaneous bile duct dilation is a valid alternative to surgery without being burdened by complications; the procedure is also a valid alternative to the approach using endoscopic stents.

Adult↗
PubMed1990

[Role of colonoscopy in the diagnosis of ischemic colitis as a complication of surgery of aneurysms of the abdominal aorta].

Ischaemic colitis is one of the complications following aortic reconstruction for abdominal aortic aneurysm. The diagnosis and monitoring of this complication can be helped by a left colonoscopy. Through an endoscopic valuation of 18 patients, the Authors value the incidence of colonic mucosal or mucosal and muscularis ischaemia following aortic aneurysmectomy with inferior mesenteric arterial ligation.

Aged↗
PubMed1987

Identification and characterization of alpha 1- and beta 2-adrenergic receptors in human liver.

Adrenergic receptors were identified in healthy human hepatic tissue from thirty-nine subjects undergoing elective abdominal surgery by using the specific alpha 1-antagonist [3H]-prazosin and the beta adrenergic antagonist [3H]-dihydroalprenolol ([3H]-DHA). [3H]-prazosin binding to plasma membranes was rapid, of high affinity, saturable and stereospecific with a maximal binding capacity (Bmax) of 74.1 +/- 5.5 fmol mg-1 of protein. The displacement curve for (-)-norepinephrine was better explained by a one-site binding and after addition of GTP 0.1 mM the curve was not right-shifted, suggesting the majority of alpha receptors in healthy human liver are of the alpha 1 subtype and not linked to a GTP-binding protein. [3H]-DHA binding to liver plasma membranes was also rapid, of high affinity, saturable and stereospecific with a Bmax 96.5 +/- 10.3 fmol mg-1 of protein of receptors. Computer aided analysis of the displacement curve of ICI 118,551, a subtype selective beta 2-antagonist (IC50 = 62 +/- 2 nM), indicated a one-site binding, thus, showing that beta adrenergic receptors are of the beta 2 subtype. The displacement curve of [3H]-DHA for (-)-isoproterenol was right shifted by GTP indicating that beta 2 adrenergic receptors are linked to a GTP-binding protein in human liver. These results indicate that alpha 1- and beta 2-receptors co-exist in human liver but only beta 2-receptors are linked to a GTP-binding protein.

Cell Membrane↗
PubMed1986

Acute and long-term haemodynamic effects of propranolol and indenolol in hypertension.

The haemodynamic effect of indenolol, a beta-adrenoceptor blocker with intrinsic sympathomimetic activity (ISA) in animals, has been evaluated in a double-blind cross-over randomized trial after acute (3 days) and long-term treatment (28 days), in 12 hypertensive patients in comparison with that of propranolol. Patients were evaluated at rest and during isometric exercise (hand grip). The overall acute effect of both beta-adrenoceptor blocking drugs was to decrease mean blood pressure, heart rate and cardiac output, while total peripheral resistance increased. In the long-term studies the haemodynamic effect of propranolol was still characterized by cardiodepression and unchanged peripheral resistance. Patients on the long-term treatment with indenolol showed normal cardiac output and reduced total peripheral resistance. The data are compatible with a relatively strong ISA of indenolol, which would be responsible for the haemodynamic pattern observed during chronic treatment.

Adult↗
PubMed1986

Alterations in norepinephrine content and beta adrenoceptor regulation in myocardium bordering aneurysm in human heart: their possible role in the genesis of ventricular tachycardia.

On the assumption that alterations in the adrenergic system may play a role in generating ventricular tachycardia in patients with myocardial post-infarction apical aneurysm, we evaluated norepinephrine concentration, number and affinity of both beta 1 and beta 2 adrenoceptors in perianeurysmatic tissue in twelve patients operated upon for congestive heart failure and recurrent sustained ventricular tachycardia. Concentration of norepinephrine in perianeurysmatic tissue was 0.1 +/- 0.05 micrograms g-1 tissue (n = 8), this value being much lower than that found in papillary muscle (n = 10) from patients with mitral valve stenosis (0.8 +/- 0.02 micrograms g-1 tissue) (P less than 0.01). The total number of beta adrenoceptors (71.4 +/- 7.8 v. 48.0 +/- 5.1 fmol mg-1 protein; P less than 0.01) and the percentage of beta 1 subtype were found to be higher in perianeurysmatic tissue (approximately 90%) than in papillary muscle (approximately 68%). Out of twelve patients with aneurysm, beta 2 adrenoceptors had considerably decreased in three patients and were absent in the remaining nine. Decrease in the neuronally released norepinephrine associated with contrasting behaviours of beta 1 and beta 2 adrenoceptors suggests the presence of a profound alteration in the sympathetic innervation of the perianeurysmatic myocardial tissue that may contribute to the genesis of sustained ventricular tachycardia in patients with postinfarction apical aneurysm.

Adult↗
PubMed1985

Role of blood osmolality in the regulation of vasopressin secretion in man: application of a new radioimmunoassay method for vasopressin.

A radioimmunoassay for plasma arginine vasopressin (AVP) has been developed based on R2 antibody of Thomas and Lee, synthetic standard (Ferring) and extraction on Sep-Pak column. High recovery of AVP (approximately 79%) was achieved with a detection limit of 0.25 pg/ml. By improving the technique of measurement of plasma osmolality an intraassay coefficient of variation less than 1% was obtained. Physiological studies performed with this method demonstrated that AVP becomes undetectable after water loading 20 ml per Kg of water po; (N = 6) and increases in response to hypertonic saline infusion (0.05 ml/kg/min; N = 15) with a linear relationship between plasma osmolality and AVP in individual subjects; this relationship is maintained when the test is repeated in the same subjects. However when pooling all data together, the relationship between plasma osmolality and AVP is best expressed by an exponential relationship. This implies that after AVP release is initiated, the concentration of the hormone increases more rapidly than plasma osmolality and the release is continuous possibly due to recruitment of increasing number of neuronal units whose osmotic threshold varies from individual to individual.

Administration, Oral↗
PubMed1985

Characterization of alpha 2-adrenoceptor binding properties of imidazoline-like drugs, azoloazepine derivatives and beta-phenethylamine-like drugs in human platelet membranes.

To characterize the agonist profile of alpha 2-adrenoceptor agonists (imidazoline-like drugs, azoloazepine derivatives, beta-phenethylamines-like drugs) on human platelets, the characteristics of alpha 2-adrenoceptors (KD, Bmax) have been evaluated and the affinity constants measured by displacement technique and computer-assisted analysis of the curves. Furthermore, since alpha 2-adrenoceptor agonists interact with the post-synaptic receptors in a calcium-operated channel, whether the effect of calcium-entry inhibitors (verapamil, nifedipine, diltiazem) is related to a competition with alpha 2-receptors has also been examined. By Scatchard analysis, it was calculated that in human platelets alpha 2-adrenoceptors have KD = 3.45 nM and Bmax = 247 fmol (mg protein)-1. As far as the potency is concerned, imidazoline-like drugs were the most potent agonists in human platelet alpha 2-adrenoceptors (guanabenz IC50 = 8.6 +/- 0.8 X 10(-8), B-HT 920 IC50 = 2.9 +/- 0.3 X 10(-7), (-)-adrenaline IC50 = 3.4 +/- 0.5 X 10(-7)). Among the calcium-entry inhibitors only verapamil antagonized [3H]rauwolscine binding: the effect was stereospecific, (-)-D 600 being more potent than (+)-D 600. Nifedipine and diltiazem did not affect alpha 2-receptor binding. It is concluded that human platelets alpha 2-receptors share the agonist potency profile of other tissues containing alpha 2-receptors (brain, pre-synaptic junction), and that among calcium-entry blockers only verapamil can antagonize alpha 2-agonists. Nifedipine and diltiazem do not appear to interact stereospecifically with alpha 2-adrenoceptors.

Adrenergic alpha-Agonists↗
PubMed1984

Comparison of rat and human left ventricle beta-adrenergic receptors: subtype heterogeneity delineated by direct radioligand binding.

Beta adrenergic receptors were identified in rat myocardial left ventricle and human papillary muscle by using the antagonist radioligand 3H-dihydroalprenolol. The number (37.3 and 44.5 fmol/mg of protein, respectively in rat and man), and the KD (1.6 and 2.8 nM, respectively in rat and man) of beta receptors were not significantly different. Adrenergic receptors of both beta 1 and beta 2 subtypes were found to coexist in the left ventricle. The relative proportions of the two beta receptor subtypes were determined by the use of competition radioligand selective binding and computer modelling techniques employing the subtype selective antagonists ICI 118,551 (beta 2 selective) and atenolol (beta 1 selective) in rat or metoprolol (beta 1 selective) in man. The rat left ventricle contained about 74% beta 1 and 26% beta 2 adrenergic receptors, human left ventricle papillary muscles contained about 69% beta 1 and 31% beta 2. Human and rat left ventricles contain both beta 1 and beta 2 adrenergic receptors with similar affinities. Rat might be a model for the study of human myocardial beta adrenergic receptors.

Adult↗
PubMed1984

Evidence for a role of a serum factor stimulated by metoclopramide in regulating aldosterone secretion.

The stimulatory effect of metoclopramide upon aldosterone secretion is independent of the known aldosterone-regulating mechanisms (renin, potassium, adrenocorticotropic hormone), is unrelated to its effect on prolactin and is absent when metoclopramide is directly added to isolated adrenal zona glomerulosa cells. To examine the possibility of a "humoral" mediation of aldosterone stimulation by metoclopramide, we evaluated the effect of serum of 10 normal subjects injected with metoclopramide (10 mg i.v.) on aldosterone production by collagenase-dispersed calf adrenal zona glomerulosa cells. Whereas no effect was observed with serum collected before the injection, serum collected from 5 to 30 min after the injection stimulated aldosterone production. The effect was seen 2.5 min after the injection, was significant at 5 min (P 0.05), 10, 15, 20 and 30 min (P 0.01). The effect disappeared 40 min after the injection, when plasma aldosterone in subjects was still elevated (P 0.01). The biological half-life of the factor (t1/2) is about 12.5 min. A significant correlation was found between the maximal aldosterone response to metoclopramide in vivo and the maximal effect of serum in vitro (r2=0.69;P 0.01). We suggest that metoclopramide stimulates aldosterone production in vivo by the increase in serum of a factor which, in turn, stimulates aldosterone and whose physiological significance remains to be evaluated.

Adrenal Glands↗
PubMed1984

Effects of acute administration of zetidoline, a new antidopaminergic drug, on plasma prolactin and aldosterone levels in man.

The neuroendocrinological effects of acute oral administration of 20 mg zetidoline, a new antipsychotic drug with antidopaminergic properties, were evaluated in 8 healthy volunteers, by a double-blind, crossover comparison with placebo. Zetidoline significantly increased serum prolactin (p less than 0.01 at 1-3 h; p less than 0.05 at 4-6 h). No significant change was observed in blood levels of aldosterone, renin, cortisol, growth hormone and electrolyte, or in blood pressure and heart rate. The data suggest that the drug increases prolactin through blockade of dopaminergic receptors. The lack of change in the aldosterone levels may be evidence against the hypothesis of dopaminergic control of aldosterone secretion.

Adult↗
PubMed1984

Effects of potassium supplementation on insulin binding and insulin action in human obesity: protein-modified fast and refeeding.

To investigate the role of potassium deficiency in the development of glucose intolerance during caloric deprivation, potassium balance was maintained within normality with oral potassium supplementation in a group of obese subjects who underwent protein-modified fast and the results of the study of carbohydrate metabolism (oral glucose test, insulin receptors on monocytes and peripheral glucose utilization as assessed by euglycaemic clamp) were compared with those obtained in a group of obese subjects admitted to protein-modified fast without potassium supplementation. Caloric deprivation without oral potassium supplementation was followed by a negative potassium balance and a decrease of serum potassium levels; a decrease of the peripheral levels of insulin along with an increase in insulin receptors and a striking reduction of peripheral glucose utilization were also observed. The maintenance of normal potassium balance and normal serum potassium levels with oral potassium-chloride supplementation was associated with higher peripheral levels of insulin (P less than 0.01) and improvement of peripheral glucose utilization (P less than 0.01) whereas the binding of insulin to monocytes was unchanged. The data suggest that potassium depletion during protein-modified fast causes a decrease of the peripheral levels of insulin and a resistance to insulin action at the postreceptors sites which is reversed by potassium supply.

Adult↗
PubMed1979

[2 cases of substitution of the portal vein with a dacron prosthesis during pancreatectomy for carcinoma of the head of the pancreas].

The Authors report their experience concerning two cases of pancreatic carcinoma in which growth involvement of retropancreatic venous peduncle required the removal of a tract 6 and 8 cm long of the mesenteric-portal axis and its replacement with knitted dacron graft. The first patient died 8 months later due to massive pulmonar and hepatic metastases. The second patient died in the early post-operative course due to septic shock and dacron graft did not show any evidence of lumen obstruction at post-mortem examination. In spite of the lack of controlled clinical trials which provide a well defined method of staging for carcinoma of the pancreas, the authors' experience shows the possibility of extending radical resections also to cases which usually are considered unresectable and in absence of politetrafluoroethylene graft also with the use of interposed knitted dacron graft good results can be achieved.

Aged↗