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Biomedical subjects

S Tagliavini

Publications and source records attributed to S Tagliavini.

At least 37 records · Page 2Linked to original sources
PubMed1989

Effect of castration and testosterone in experimental models of depression in mice.

In the behavioral despair (forced swimming) test and in the tail-suspension test, long-term (30-32 days) castration significantly increased the duration of immobility in mice. Testosterone propionate (1 or 10 mg.kg-1.day sc for 4 days), although not affecting the duration of immobility in sham-operated mice, reduced the duration of immobility in castrated mice to within normal limits. Desipramine (20 mg/kg ip) decreased the duration of immobility both in sham-operated and in castrated animals. These results indicate that castration favors an inactive behavior and that testosterone, although having no "antidepressant" effect per se, is necessary for the male animal to cope normally with adverse environmental situations.

Affect↗
PubMed1989

Reversal of haemorrhagic shock in rats by cholinomimetic drugs.

1. In an experimental model of haemorrhagic shock resulting in the death of all rats within 20-30 min, the intravenous (i.v.) injection of the tertiary amine cholinesterase inhibitor physostigmine (17-70 micrograms kg-1) induced a prompt, sustained and dose-dependent improvement of cardiovascular and respiratory function, with marked increase in the volume of circulating blood and survival of all treated animals, at least for the 2 h of observation. 2. Similar results were obtained with the i.v. injection of the cholinoceptor agonist oxotremorine (5-25 micrograms kg-1), while neostigmine (54 or 70 micrograms kg-1), a quaternary cholinesterase inhibitor which cannot cross the blood-brain barrier, had negligible effects. 3. The anti-shock activities of oxotremorine and physostigmine were blocked by the intracerebroventricular injection of either of the combined nicotinic and M2-muscarinic receptor antagonists gallamine and pancuronium, or of the nicotinic antagonist mecamylamine. They were also blocked by intraperitoneal injection of the adrenergic neurone blocking agent guanethidine, but they were not antagonized by either the combined M1- and M2-muscarinic receptor antagonist atropine, the M1-muscarinic receptor antagonist pirenzepine, or the M2-muscarinic receptor 4-diphenylacetoxy-N-methylpiperidine methobromide. 4. It is concluded that cholinomimetic drugs can reverse hypovolaemic shock through central activation (seemingly mediated by nicotinic receptors) of sympathetic tone, with mobilization and redistribution of the residual blood.

Animals↗
PubMed1989

Putrescine reverses aconitine-induced arrhythmia in rats.

Putrescine, (150-300 mg kg-1 i.v.) injected into anaesthetized rats reversed aconitine-induced arrhythmia and restored sinus rhythm. In the same experimental model, quinidine and lignocaine had a transient therapeutic effect, procainamide was practically ineffective and verapamil worsened the aconitine arrhythmia, causing the death of all treated animals. These data demonstrate that putrescine has an antiarrhythmic effect in an experimental model particularly resistant to usual antiarrhythmic treatments.

Aconitine↗
PubMed1989

[Surgical therapy of post-infarct aneurysm of the left ventricle. Immediate and long-term results].

Between January 1982 and December 1986, 62 patients (59 male and 3 female) ranging in age from 37 to 69 years (mean 53) underwent resection of postinfarction left ventricular aneurysm. The indication for operation was angina in 23 cases (37%), congestive heart failure (CHF) in 7 (11.2%), angina and CHF in 29 (46.8%), rupture in 1; 2 patients were low symptomatic. Ventricular arrhythmias were present in 6 (9.7%) cases and previous systemic embolism in 4 (6.4%). Forty-seven (75.8%) patients had lesions of three coronary arteries with involvement of left main coronary artery in 4 cases; 10 (16.1%) had lesions of two vessels [left anterior descending (LAD) and/or right coronary artery]; 4 (6.4%) had only LAD artery involvement, and 1 had no significant coronary artery stenoses. Left ventricular ejection fraction (EF) was less than 0.30 in 22% of cases, between 0.30 and 0.40 in 25.4% and greater than 0.40 in 50%. The location of the aneurysm was anterolateral or apical (83.8%), posterior (14.5%) and lateral (1.6%). Left ventricular aneurysmectomy with myocardial revascularization was performed in 61 patients (bypass/patient = 2.7), with ventricular septoplasty in 20 and concomitant mitral valve replacement in 3 patients. LAD was grafted in 59.6% of anterior aneurysm. Operative mortality (30 days) was 4.8%, the late mortality, with a follow-up between 12 and 72 months (mean 38), was 6.7% and the actuarial 5 year survival rate was 85% (91% without operative mortality). In our experience, despite no evidence of any operative risk factors, no improvement was noted in radionuclide left ventricular ejection fraction in patients undergoing aneurysmectomy with ventricular septoplasty.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1988

Treatment with polyamine synthesis inhibitors reduces the positive inotropic effect of ouabain, noradrenaline and calcium.

Polyamines (putrescine, spermidine and spermine) are considered to act as intracellular second messengers by increasing Ca++ influx and mobilizing intracellular calcium. On the other hand, intracellular Ca++ increase is the common final step of the mechanism of action of many inotropic agents. To discover whether the functional integrity of the cardiac ornithine decarboxylase (ODC)/polyamine system is necessary to cope with a stimulated inotropism, we studied the effect of ouabain, noradrenaline, and calcium on ventricle strips obtained from rats treated with polyamine synthesis inhibitors. The combined administration of methylglioxal bis (guanylhydrazone) (MGBG) (single i.p. injection of 50 mgkg-1) and of alpha-di fluoromethylornithine (DFMO) (100 mgkg-1 every 12 h for 7 consecutive days) caused a 62.5% inhibition of ventricular ODC activity, and a significant decrease of the ventricular content of putrescine and spermidine (-59.5%, and -40.1%, respectively). While the basal isometric tension developed by ventricle strips obtained from rats treated with MGBG+DFMO was similar to that developed by ventricle strips from controls, the response to ouabain (1 microM), noradrenaline (10 microM), or Ca++ (3.6 mM) was significantly reduced. It cannot be excluded that effects of MGBG unrelated to the inhibition of polyamine synthesis may have also concurred in part to influence the effect of ouabain, Ca++ and noradrenaline adversely. However, the present results seem to indicate that the heart response to inotropic agents requires an efficient ODC/polyamine system, polyamines probably being involved in calcium ion movements or affecting the Ca++ sensitivity of contractile proteins.

Animals↗
PubMed1987

Impressive lung uptake during exercise thallium imaging with decrease of systolic blood pressure.

A case of very high thallium lung activity during exercise myocardial imaging in a patient with an old myocardial infarction but free from typical angina or heart failure symptoms is reported. The impressively abnormal lung uptake occurred in connection with a stress-induced fall in the systolic blood pressure, pointing out a causal rôle of a transient left ventricular dysfunction and interstitial pulmonary oedema in the genesis of the scintigraphic picture. Three weeks after the test, the patient suddenly died at home.

Blood Pressure↗
PubMed1987

Shaking behaviour induced by putrescine in naive rats: a pharmacological and histological study.

In untreated rats, the intraperitoneal injection of putrescine evoked a typical wet-dog shake response, that was maximal at a dose of 300 mg/kg and at room temperature (22 degrees) (number of shakes: 84.00 +/- 17.90/hr). In a hot environment (30 degrees) the number of shakes was markedly reduced (26.90 +/- 5.19/hr). The putrescine-induced shaking behaviour was unaffected by atropine, bicuculline, chlorpheniramine, cimetidine, methysergide, naloxone and noradrenaline, but was markedly antagonized by morphine. Naloxone pretreatment nullified the antagonistic activity of morphine. Histological studies showed marked alterations in brain vascular permeability, which was increased by putrescine. Morphine completely prevented this putrescine-induced vascular effect. These results suggest a correlation between WDS produced by putrescine and increase in brain vascular permeability. Furthermore they show that morphine can affect brain vascular permeability.

Animals↗
PubMed1986

Putrescine has hypothermic and antipyretic activity, in rats.

Intraperitoneal injection of putrescine induced dose-related hypothermia in rats. The effect was more pronounced at room temperature (22 degrees C) than in a warm environment (30 degrees C), the maximum hypothermia (-2.64 +/- 0.29 degrees C, 30 min. after treatment) being obtained with the dose of 300 mg/Kg and remaining significant throughout 3 hr of observation. Putrescine also had antipyretic activity, as it significantly reduced pyrogen-induced fever at a dose level (100 mg/Kg i.p.) ineffective in causing hypothermia in normal rats. The hypothermic and antipyretic effects of putrescine were not associated with any obvious sign of toxicity.

Animals↗
PubMed1986

Effects on long-term sensitivity to pain and morphine of stress induced in the newborn rat by pain or manipulation.

Four times daily from postnatal day 1 to 15, rats were stressed either by being removed from the maternity cage (manipulation stress, MS) or by being placed on a hotplate at 55 degrees C (pain stress, PS). When 70 days old, they were examined for sensitivity to pain and to the analgesic effect of morphine, and for brain opiate receptors. Pain sensitivity of MS and PS rats was not significantly different from that of controls. The analgesic activity of morphine, assessed by the hotplate test at 49 degrees C, was significantly reduced in MS rats, while in PS rats it was similar to that in controls. 3H-dihydromorphine binding studies performed on whole brain synaptic membranes showed a reduction in the maximum number of binding sites in both MS and PS rats; on the other hand, the affinity constant was higher in PS rats, while in MS rats it was similar to that of controls. These data show that the repeated stress of removal from the mother during the first 15 days of life induce a reduction in the number of brain opiate receptors with reduced activity of morphine, while in rats exposed to repeated removal stress associated with painful stimuli the reduction in the number of brain opiate receptors seems to be counterbalanced by their higher affinity.

Animals↗
PubMed1985

Low-pressure receptor activity and exaggerated natriuresis in essential hypertension.

Urinary sodium excretion, central hemodynamics, and mean arterial pressure (MAP) were studied in 7 normal subjects and 19 hypertensive patients during both central hypervolemia by water immersion to the neck (NI) and extracellular volume expansion by i.v. saline infusion. During 2-hour NI, 12 out of the 19 hypertensives exhibited a significant fall in MAP (p less than 0.001). Exaggerated natriuresis did not occur in these patients (ns). In the remaining 7 hypertensive patients in whom, during NI, MAP was unchanged, exaggerated natriuresis was found (p less than 0.001). During saline infusion, MAP was either unchanged or increased and exaggerated natriuresis was found in all hypertensive patients (p less than 0.001) previously submitted to NI. Our findings suggest that a high MAP is a major determinant of exaggerated natriuresis in arterial hypertension.

Adolescent↗
PubMed1981

[Selective coronary scintiscanning].

30 patients, undergoing coronary angiography for diagnostic and/or bypass surgery evaluation, have been studied also by intracoronary scintigraphy (IS). Scintigraphic and angiographic data have been compared: --21 cases had concordant results: normal in 2 patients (quite normal coronary system); pathological in 19, accounting for a damage both of the principal coronary artery branches and the arteriolar-capillary system: --6 cases had a pathological angiography with a normal IS: an indication of a normal myocardial perfusion; --in 3 cases a normal angiography was coupled with a pathological IS, pointing out a damage of the arteriolar-capillary system. On the basis of these results and of the literature, the AA. emphasize that the IS, allowing an exact evaluation of the myocardial perfusion, complete the essential morphological informations of the coronary angiography and it is specifically useful: --in the candidates to bypass coronary surgery; a viable myocardium is important both for surgery indication and results; --in bypassed patients to assess patency and the actual blood delivery (also for the low reliability of e.v. Thallium); --in patients with typical angina and positive stress test but with normal coronary angiography, to establish an organic lesion of the arteriolar-capillary system.

Adult↗
PubMed1980

[Changes on release of MB isoenzyme of creatine kinase by propranolol in acute myocardial infarction (author's transl)].

MB isoenzyme of creatine kinase was measured every 3 hours during the first 24 hours of admission to C.C.U. and successively every 4-6 hours in the next 24-48 hours in 42 patients with acute transmural myocardial infarction. The pain-C.C.U. admission time interval was less than 6 hours in all cases. 22 patients were treated by propranolol (2 mg bolus followed by 0.1 mg/Kg/die for the next 48 hours in continuous i.v. infusion), 20 patients served as a control. Cumulated activity, peak plasma value, rate of release and total duration of release of MB-CK did not differ significantly between the two groups. In patients treated within 3 hours from pain onset (n = 12) cumulated activity, peak plasma value and rate of release of MB-CK were significantly inferior than control group. In patients treated between the 3rd and 6th hour from pain onset (n = 10) the total duration of release of isoenzyme was significantly prolonged. No treated patients developed clinical or radiologic signs of cardiac insufficiency. The incidence of ventricular arrhythmias was 17% in the treated group vs. 62% in the control group (P < 0.05). The data show that propranolol, if started early in the course of acute myocardial infarction, reduces significantly infarct size and slows down the evolution of necrotic process.

Clinical Trials as Topic↗
PubMed1978

[Acute myocardial infarction in a case of obstructive cardiomyopathy of the left ventricle (author's transl)].

A case of acute myocardial infarction in 64 year old man with idiopathic hypertrophic obstructive cardiomyopathy of left ventricle is described. The Authors emphasize the rarity of association and that the diagnosis of obstructive cardiomyopathy in the elderly is always almost misinterpreted. This depends on the poor specificity of clinical and phonocardiographic findings, both basal and under pharmacological tests. The Authors point out that in adult patients with left ventricular idiopathic obstructive cardiomyopathy who must be operated also selective coronary angiography should be performed.

Cardiomyopathy, Hypertrophic↗
PubMed1975

[Junctional bradycardia and junctional non-paroxysmal tachycardia. A study with atrial and His electrogram and influence of neurovegetative system (author's transl)].

Two cases of unusual A-V nodal rythms, very slow junctional bradycardia and junctional non paroxysmal tachycardia, are described. The Authors emphasize the study of the His bundle electrograms, the atrial electrograms and the time of the intrinsecoid deflection for correct diagnosis of these dysrrhythmias. From the results of the clinical and electrofisiological study and neurovegetative responses some conclusions about the mechanism and clinical significance of these arrhythmias are drawn.

Adult↗