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Biomedical subjects

N Ferrara

Publications and source records attributed to N Ferrara.

238 records · Page 14Linked to original sources

Colonic type adenocarcinoma of male urethra.

A case of rare primary adenocarcinoma of the bulbomembranous portion of the male urethra is presented. The histological and immunohistochemical characteristics of this tumor are identical to those of colon adenocarcinomas. The pathogenesis can be explained either by neoplastic degeneration of globet cells found in the urethral epithelium or by malignant degeneration of persistent glandular elements that are embryonal residues. The patient was successfully treated with transurethral prostatectomy and with a high dose of radiation therapy.

Adenocarcinoma↗

Effect of flecainide acetate on reperfusion- and barium-induced ventricular tachyarrhythmias in the isolated perfused rat heart.

Flecainide acetate is a new antiarrhythmic drug which suppresses different kinds of experimental arrhythmias. We studied the efficacy of flecainide acetate on reperfusion- and barium-induced ventricular tachyarrhythmias in the isolated perfused rat heart by monitoring heart rate, coronary flow rate, left ventricular systolic pressure, dp/dtmax, and the voltage of the epicardial electrogram. Seventy-five male rats were randomized into 5 groups. In group I, after a 15 min period of stabilization, hearts were perfused by ischemic perfusion and then reperfused. In group II, flecainide acetate (10(-6) M) was given after stabilization and before ischaemic perfusion. In group III, barium chloride (10(-3) M) was given after stabilization. In group IV, flecainide acetate was given after stabilization and before barium chloride administration. In group V, acetylcholine chloride (10(-6) M) was given after stabilization and before barium chloride administration. In group I, we noted during ischemia a reduction in heart rate, coronary flow rate, left ventricular systolic pressure and dp/dtmax and an increase in the voltage of the epicardial electrogram. In group II, after administration of flecainide acetate, we observed a reduction in heart rate, left ventricular systolic pressure and dp/dtmax; during the ischaemic period there was no difference in these parameters with respect to group I. Reperfusion induced ventricular arrhythmias in 12 out of 15 hearts in group I and in only 3 out of 15 in group II (p less than 0.005). Barium induced ventricular arrhythmias in the 15 hearts studied in group III as well as in group IV. On the contrary, acetylcholine chloride in group V prevented the occurrence of barium-induced ventricular arrhythmias (p less than 0.005 vs group III and IV). Thus, flecainide acetate is able to reduce reperfusion-induced ventricular arrhythmias, but is unable to reduce barium-induced ventricular arrhythmias, presumably because of a different mechanism of these two types of arrhythmias.

Animals↗

Electrical and mechanical actions of magnesium sulfate during ischemia and reperfusion on isolated perfused rat heart.

Experimental and clinical studies have shown the action of magnesium salts on myocardial tissue and its antiarrhythmic action on digitalis-induced ventricular arrhythmias. We have evaluated the effects of magnesium sulfate (2.5 mM) on heart rate (HR), coronary flow rate (CFR), left ventricular systolic pressure (LVSP), dP/dt max and voltage epicardial electrogram (VEE) during ischemia and reperfusion in isolated perfused rat heart. Forty-five male rats were randomized into 3 groups. In the control group, after a 15 min period of stabilization, hearts were perfused by ischemic perfusion for 30 min and then reperfused. In group I, magnesium sulfate was given after stabilization and before the ischemic period. In group II, calcium concentration was increased by 0.5 mM and magnesium sulfate was given after stabilization and before the ischemic period. In the control group, we observed during ischemia a reduction in HR, CFR, LVSP, dP/dt max and an increase in VEE. In group I, after the administration of magnesium sulfate, we noted a decrease in HR, LVSP, dP/dt max, VEE and during the ischemic period there was no difference in these parameters with respect to the control group. In group II, the increase of extracellular calcium concentration caused an increase in LVSP, dP/dt max and the administration of magnesium sulfate abolished these effect, bringing the values back to basal values. Reperfusion provoked ventricular arrhythmias in 11/15 and 12/15 hearts in the control group and group II respectively, and only 3/15 in group I (p less than 0.005 group I vs control and group II). Thus, our results demonstrated that magnesium sulfate has varied effects on electrical and mechanical parameters and prevents reperfusion arrhythmias according to the hypothesis of a calcium-antagonist mechanism of magnesium.

Animals↗