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Biomedical subjects

M Condorelli

Publications and source records attributed to M Condorelli.

At least 271 records · Page 15Linked to original sources
PubMed1980

Myocardial hypertrophy in the rat. Correlation between two experimental models.

Two different conditions responsible for cardiac hypertrophy in the rat were investigated: the first one is isoproterenol-induced myocardial infarct, the second is exposure to hypoxia (0.42 atmospheres/24 h) in hypobaric chamber. To demonstrate that in both experimental models stimulation of protein synthesis is an absolute requirement to induce cardiac hypertrophy, a variety of techniques were employed including: evaluation of dry heart weight value, concentration of radiothallium (201T1) in the heart and effects of inhibitors of protein synthesis (Puromycin). Experimental results have showed: (A) a significant increase (p<0.001 as compared to control group) of dry heart weight values both in isoproterenol-treated and hypoxic rats; (B) a significant increase over control group (p<0.001) in myocardial 201T1 concentration in isoproterenol-treated rats; (C) total inhibition of cardiac hypertrophy in Puromycin treated group subjected to hypoxia. Finally, on the basis of different mortality observed in infarcted (85.0%) or hypoxic (5.0%) rats treated with Puromycin (40 mg/Kg body weight i.p.) a different role of cardiac hypertrophy in 2 experimental conditions is postulated: in the case of infarct-like lesions the cardiac hypertrophy has compensatory significance; under hypoxic stimulus is only due to increased cardiac work.

Animals↗
PubMed1980

Hemoglobin synthesis in individual bursts from normal adult blood: all bursts and subcolonies synthesize G gamma-and A gamma-globin chains.

Gamma-globin chain synthesis has been evaluated in individual bursts and subcolonies that were generated by normal adult blood BFU-Es in methylcellulose cultures containing semipurified erythropoietin (Ep) and then analyzed via either isoelectric focusing (IEF) of globin chains or immunofluorescence techniques. At variance with previously reported results, based on plasma clot culture and immunofluorescence, all bursts and subcolonies analyzed synthesize gamma-globin chains. Identification of gamma-chains has been confirmed by preparative IEF of HbF, followed by either carboxymethylcellulose chromatography or IEF analysis of the resulting globin chains. In all bursts analyzed, the relative synthesis of the two types of gamma-globin chains (G gamma and A gamma) shows an adult ratio (i.e., approximately 1:1). The results obtained via IEF have been confirmed by immunofluorescence studies, which apparently showed presence of at least some HbF-positive cells within all scrutinized bursts or subcolonies. The significance of these studies is discussed in the light of current hypotheses on mechanism(s) underlying HbF synthesis in normal adults.

Cells, Cultured↗
PubMed1980

Effects of antiplatelet and calcium antagonist drugs on infarct size in rats.

The authors performed the experimental model of infarct-like myocardial lesions in rats treated with large doses of ISP. Myocardial necrosis was assessed on the basis of serum enzyme changes as well as of gross and microscopic findings. The infarct size was measured by a direct enzymatic method assaying creatine kinase (CK) depletion in infarcted myocardium. Pretreatment of the infarcted rats with antiplatelet (Lysin Acetyl Salicylate) or calcium antagonist drugs (Verapamil or Nifedipine) allowed the reduction of the necrotic area. Since a smaller size of infarct was achieved through different types of interventions it should be suggested that ISP-myocardial damage is due to several effects of the drug involving metabolic, vascular and/or coagulative patterns.

Acute Disease↗
PubMed1980

[Combined valvular and coronary artery surgery (author's transl)].

Between January 1st, 1976 and October 31st, 1978 ten patients underwent simultaneour replacement or repair of a cardiac valve and coronary revascularization surgery. Six patients age ranged within 45 and 66 years presented mitral insufficiency, subsequent to myocardial infarction in five and rheumatic disease in one. Aortic valvular disease was present in four patients, it was atherosclerotic in three and congenital in one. All patients had both symptoms and signs of coronary insufficiency. Fifteen aortocoronary bypass grafts were inserted. Five mitral valve and four aortic valve replacements were performed; one patient underwent mitral valve annuloplasty. Best results were achieved in the aortic group, in which no deaths occurred; three deaths occurred in the mitral group. At the follow-up evaluation (average 14.2 months) all but one surviving patients showed marked symptomatic improvement, having moved to the upper functional class. The frequent incidence of coronary occlusive disease in patients with valvular heart disease recommends extensive use of selective coronary arteriography in preoperative evaluation. Simultaneous repair of all significant heart lesions is recommended.

Aged↗
PubMed1980

Long term comparative study of guanfacine and alpha-methyldopa in essential hypertension.

The hypotensive action of guanfacine and alpha-methyldopa has been compared in 30 patients wth moderate essential hypertension. After 2 weeks of placebo treatment, the patients were randomly allocated to a 12 week treatment with either of the two drugs. The treatment was started with guanfacine, 1 mg twice daily p.o., or alpha-methyldopa, 250 mg three time a day p.o. This dose of guanfacine was able to induce a satisfactory control of blood pressure in all patients while the dose of alpha-methyldopa was gradually increased to a predetermined maximum daily dose (2 g) in those patients with unsatisfactory blood pressure control, i.e., systolic blood pressure above 160 mmHg and diastolic above 95 mmHg. Then the two treatments were dicontinued for one week. Both drugs induced a significant reduction of systolic and diastolic blood pressure. However, guanfacine induced a more marked decrease in systolic blood pressure after the 14th day of treatment while the reduction of diastolic blood pressure was significantly higher only at the end of the final wash-out period, thus indicating a longer lasting effect of guanfacine as compared to alpha-methyldopa. Two patients treated with guanfacine developed dryness of the mouth and three of those in the alphamethyldopa group complained of excessive sedation.

Age Factors↗
PubMed1980

[Clinical evaluation of a new antianginal drug: droprenylamine].

In this study the antianginal action of droprenylamine, a cycloaliphatic derivative of prenylamine, was evaluated. Forty patients were included in three groups: in the first group a double blind study was carried out, while in the other two groups, both treated with droprenylamine for a 12 weeks period, were evaluated the effects on workload tolerance or the efficacy in reducing the number of angina pectoris episodes per week and the assumption of nitroglycerine. The double blind study shows that droprenylamine is able to reduce significantly the nitroglycerine assumption. Furthermore, during the 12 week treatment with droprenylamine we can observe a significant reduction of the ST segment depression, at comparable workloads, a significantly increased tolerance to stress test and an early and significant reduction of the angina attacks and, subsequently, of the assumption of nitroglycerine. In conclusion, this drug, which appears free of side effects, may be useful in the treatment of angina pectoris; in particular, the possible association with other antianginal drugs should be evaluated.

Adult↗
PubMed1980

Disopyramide and mexiletine: which is the agent of choice in the long term-oral treatment of lidocaine-responsive arrhythmias? Efficacy comparison in a randomized trial.

Forty patients with serious lidocaine-responsive ventricular arrhythmias were randomly assigned to treatment with either oral disopyramide (100 mg 4 times daily) or mexiletine (200 mg 4 times daily) for 3 weeks. A satisfactory arrhythmias control (greater than 75 % reduction of premature ventricular complexes per minute as compared to the control period prior to lidocaine administration) was achieved in 19 patients in the mexiletine group and in 16 in the disopyramide treated patients. Furthermore, disopyramide failed to maintain the reduction of the number of ventricular extrasystoles per minute obtained with lidocaine, while mexiletine succeeded. Finally, the number of ventricular extrasystoles per minute in the mexiletine treated group was significantly lower than in the other group. Gastrointestinal disturbances were more frequent during mexiletine administration.

Arrhythmias, Cardiac↗
PubMed1980

[The effects of the stellate ganglion electrostimulation on the coronary circulation of the dog (author's transl)].

In this study we have investigated the effects of the stellate ganglion electrostimulation on the perfusion pressure of coronary vascular bed perfused at constant flow. We always observed systemic hypertension and two kinds of response in the coronary district: vasodilatation or vasoconstriction. These responses were blocked by propranolol and phentolamine i.a. administration respectively, while both the phenomena were blocked by i.v. infection of guanethidine. These results seem to suggest that nervous sympathetic stimulation induces catecholamines release by means of either pregangliar adrenergic fibers directed to coronary vessels either postgangliar adrenergic fibres directed to the myocardium. The occurrence of vasodilatation or vasoconstriction could be explained by the prevalent stimulation of myocardial or coronary adrenoceptors.

Animals↗
PubMed1980

[Correlations between polygraphic and hemodynamic parameter changes induced by high concentrated oxygen administration in patients with mitral valvulopathy (author's transl)].

The goal of this study was to identify, utilizing apexcardiogram, other noninvasive parameters useful to evaluate the functional condition of the pulmonary vascular bed in patients with mitral stenosis and insufficiency. The patients of both sexes with mitral stenosis and insufficiency underwent left and right heart catetherization and simultaneously a polygraphic study was performed. Recordings of polygraphic as well as hemodynamic parameters were performed under control condition and after 5 min breathing of 100% Oxygen administered by facial mask. These results indicate that changes in rapid filling angle have a close relationship with changes in pulmonary capillary wedge pressure and variation of rapid filling interval are correlated with changes in pulmonary capillary wedge pressure and variation of rapid filling interval are correlated with changes in cardiac output.

Administration, Intranasal↗
PubMed1980

[The use of echocardiography for diagnosis of right ventricular hypertension (author's transl)].

Echocardiographic right ventricular wall thickness (RVWT) and right ventricular dimension (RVD) were performed in 65 patients, undergoing diagnostic heart catheterization. Patients were divided in two groups: 28 patients with right ventricular hypertension (group 1) and 37 patients with normal right ventricular systolic pressure (RVSP) (group 2). 24 patients of group 1 (85.7%) had increased RVWT and 34 patients of group 2 (91.9%) had normal RVWT. In group 1 RVSP was significantly correlated with RVWT (r = 0.92; p < 0.001); an inverse correlation was found between RVSP and RVD (r = -0.63; p < 0.001). Non significative correlations were found in group 2. Our study proves that the echocardiographic evaluation of RVWT can be helpful in separating patients with right ventricular systolic hypertension from patients with normal values of RVSP, and that a positive correlation exists between the increase of RVWT and the increase of RVSP.

Adolescent↗
PubMed1980

[Effects of metoprolol on myocardial performance in hypertensive patients during exercise (author's transl)].

In this study the effects of metoprolol administration (200 mg daily per os) to 20 hypertensive subjects (WHO stage I and II), as a 20-days course, on heart rate (HR), systolic blood pressure (BP) and myocardial performance evaluated by systolic time intervals, were studied both at rest and during exercise. This treatment was able to reduce significantly HR and BP in all the patients, both at rest and during exercise. After the 20 days treatment, the left ventricular ejection time corrected for HR (LVETc) did not show any significant change both at rest and during exercise. On the other hand, the pre-ejection period (PEP) changed at rest in all the subjects studied after metoprolol treatment, but increased significantly during exercise only in patients in the I WHO class and only at the highest work load (at 70 watts, from 63 +/- 2 to 78 +/- 7 msec, P ¿ 0.05). Furthermore, in the same group of patients the maximal work load increased significantly after metoprolol treatment (from 67.5 +/- 6 to 85 +/- 8 watts, P < 0.05).

Adult↗
PubMed1979

Effect of furosemide on plasma concentration and beta-blockade by propranolol.

Although propranolol and furosemide are used together for hypertension, the effects of furosemide on plasma levels and beta-blocking action of propranolol are not known. Ten healthy subjects received propranolol 40 mg orally; the mean plasma propranolol levels in 60, 90, 180, and 300 min were 85 +/- 16, 90 +/- 7, 82 +/- 8, and 58 +/- 8 ng/ml. Propranolol was then given together with furosemide (25 mg orally) and the propranolol blood level was measured. Mean propranolol plasma levels were 106 +/- 11 ng/ml at 60 min, 120 +/- 12 ng/ml at 90 min (p less than 0.01), 102 +/- 8 ng/ml at 180 min (p less than 0.05), and 78 +/- 8 ng/ml at 300 min (p less than 0.01). Six additional subjects were given an infusion of 1 microgram/min isoproterenol increased by 0.5 microgram/min every 2 min until the heart rate rose by 25% after oral administration of furosemide 25 mg. This procedure was repeated after propranolol (40 mg orally) and propranolol with furosemide (25 mg orally). The amount of isoproterenol which raised the heart rate by 25% was 2.6 +/- 0.3 micrograms after furosemide alone and 17.7 +/- 2 micrograms after propranolol (p less than 0.01). After propranolol with furosemide the dose of isoproterenol required to elevate heart rate by 25% was 109 +/- 15 micrograms (p less than 0.001).

Adolescent↗
PubMed1979

Hemodynamic response to exercise after propranolol in patients with mitral stenosis.

Hemodynamic response to exercise before and 10 minutes after propranolol (5 mg intravenously) was studied in 10 young patients with pure mitral stenosis who had normal sinus rhythm and no cardiac failure. After propranolol the mean heart rate and cardiac index at rest were lower than during the control state (respectively, 95 +/- 4 versus 82 +/- 3 beats/min, P less than 0.005; 3.4 +/- 0.2 versus 2.8 +/- 0.1 liters/min per m2, P less than 0.025). As a result, the mean pulmonary wedge pressure and mean mitral valve gradient at rest were lower (respectively, 22 +/- 2 versus 18 +/- 2 mm Hg, P less than 0.005; 24 +/- 2 versus 17 +/- 2 mm Hg, P less than 0.001). During exercise after propranolol the values of pulmonary wedge pressure and mitral valve gradient were lower than control values during exercise (respectively, 39 +/- 3 versus 30 +/- 2 mm Hg, P less than 0.005; 44 +/- 3 versus 32 +/- 3 mm Hg, P less than 0.005), again because of the lower heart rate and cardiac index (130 +/- 6 versus 104 +/- 6 beats/min, P less than 0.001; 4.6 +/- 3 versus 3.7 +/- 2 liters/min per m2, P less than 0.01). Left ventricular end-diastolic pressure and stroke index showed no significant changes. Thus, propranolol may benefit patients with pure mitral stenosis with sinus rhythm and no cardiac failure whose symptoms occur during those reversible conditions characterized by an increase in heart rate or cardiac output, or both.

Adult↗
PubMed1979

Automatic "scanning" by radiofrequency in the long-term electrical treatment of arrhythmias.

The use of programmed electrical stimulation in the long term treatment of re-entry tachycardia offers encouraging perspectives. Among the others proposed, the "scanning" system seems to be the most effective. However, an implantable stimulator with these features is not yet available and, thus, a temporary external lead is required. These difficulties have been overcome by utilizing radiofrequency to synchronize and stimulate. An implantable device was therefore designed which is triggered by the patient and automatically searches the interruption zone of the tachycardia by exploring the R-R cycle. The external transmitter, which can produce one or two synchronized impulses, is programmed to scan the R-R cycle with progressive steps of 5 or 10 ms; when tachycardia is interrupted, further stimulation is inhibited. The implanted module connected to an endocavitary lead does not have any power supply and, therefore, is very small. The efficacy of this method has been demonstrated in 4 patients with supraventricular tachycardia (3 with WPW syndrome) resistant to conventional pharmacologic therapy.

Chronic Disease↗