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Biomedical subjects

N Ferrara

Publications and source records attributed to N Ferrara.

At least 217 records · Page 12Linked to original sources
PubMed1986

[Beneficial effects of diltiazem in exertion stable angina. Evaluation of coronary hemodynamics during cardiac pacing].

We evaluated the protective effect of Diltiazem from pacing-induced myocardial ischemia in 9 patients (pts) with coronary heart disease (CAD) and stable effort angina by studying the changes in systemic and coronary hemodynamics during pacing. Hemodynamic parameters were evaluated at baseline and at peak pacing before and after Diltiazem, 25 mg i.v. Diltiazem prevented angina in 6 of 7 pts who presented angina in the control pacing. This beneficial effect was accompanied at peak pacing rate by a significant fall in ST depression, arterial pressure, rate-pressure product and left ventricular (LV) end-diastolic pressure, while no significant changes were observed in LV dp/dt max, coronary blood flow and coronary vascular resistance. Therefore, Diltiazem exerts a protective effect from pacing-induced myocardial ischemia in pts with CAD and stable effort angina, without impairing LV function. This beneficial effect is due to a reduction in myocardial metabolic requirements, rather than to an improvement of blood supply to the ischemic myocardium.

Aged↗
PubMed1986

Effect of mexiletine on reperfusion-induced ventricular arrhythmias: comparison with lidocaine.

Thirty mongrel dogs underwent proximal occlusion of the left anterior descending coronary artery to evaluate the comparative action of mexiletine and lidocaine on ventricular arrhythmias during myocardial reperfusion. Heart rate, arterial blood pressure, left ventricular end-diastolic pressure and dp/dt max were evaluated before and at the 20th and 25th min after coronary occlusion; at the 25th min coronary occlusion was removed. Dogs were randomly assigned to one of the following groups of 10: 1) control group; 2) dogs given i.v. mexiletine; 3) dogs given i.v. lidocaine. As expected, during ischemia, myocardial contractility decreased after mexiletine or lidocaine administration more than in the control group. Ventricular arrhythmias during myocardial reperfusion occurred in 9 dogs of the control group (ventricular tachycardia in 2 cases and ventricular fibrillation in 7 cases). Among dogs given mexiletine only 1 had ventricular fibrillation (p less than 0.001 vs control). Six of the 10 dogs given lidocaine had ventricular arrhythmias (ventricular tachycardia in 5 cases and ventricular fibrillation in 1 case) (p = ns vs control group; p less than 0.05 vs mexiletine group). Thus mexiletine and lidocaine had similar effects on cardiac function during myocardial ischemia and only mexiletine showed a protective effect against reperfusion ventricular arrhythmias.

Animals↗
PubMed1984

Effect of beta-blockade on thallium-201 dipyridamole myocardial scintigraphy.

The effect of beta-blockade on dipyridamole thallium-201 images was assessed in 8 patients with coronary artery disease and positive dipyridamole test. Three dipyridamole thallium-201 tests were performed, the first in basal conditions, the second 30' after propranolol and the third with propranolol and atrial pacing. After dipyridamole heart rate and double product increased respectively from 75 +/- 7 to 98 +/- 15 b/min (p less than 0.01 vs starting values) and from 10 551 +/- 1255 to 11 740 +/- 4542 mmHg X b/min (p less than 0.05 vs starting values). Propranolol reduced heart rate to 64 +/- 6 b/min (p less than 0.05 vs basal conditions), systolic blood pressure to 136 +/- 13 and double product to 8733 +/- 1248 (p less than 0.05 vs basal conditions). Dipyridamole when infused after propranolol, induced an increase in heart rate to 70 +/- 5 b/min (p less than 0.05 vs starting values) while double product was 9133 +/- 1189 mmHg X b/min (p = NS vs starting values). Atrial pacing prevented the fall in heart rate and double product induced by propranolol so during dipyridamole infusion double product increased to 13 271 +/- 1868 (p less than 0.05 vs propranolol treatment; p less than 0.05 vs starting values). Segmental score calculated after dipyridamole was 5.2 +/- 2.0 in basal conditions, 5.1 +/- 1.3 after propranolol (p = NS) and 4.8 +/- 1.3 after propranolol plus atrial pacing (p = NS). Thus the results of the study show that beta-blockade does not worsen dipyridamole thallium-201 images. Furthermore the steal phenomenon seems to be the main mechanism of the dipyridamole induced ischemia. In fact, also when the increase, oxygen consumption is blunted with beta-blockade the disparity in myocardial blood flow resulted unaffected.

Blood Pressure↗
PubMed1983

Influence of sex steroids and prolactin on haloperidol-induced catalepsy.

The effects of sex steroids and prolactin on haloperidol-induced catalepsy were investigated in male rats. Repeated administration with estradiol benzoate (5 micrograms/rat, twice daily for 10 days) significantly potentiated catalepsy induced by 0.25 or 0.5 mg/kg haloperidol, but no effect was observed 10 min or 1 h after a single injection of estradiol benzoate (5 or 50 micrograms/rat). Conversely, a single administration with the catecholestrogen 2-hydroxyestradiol (50 micrograms/rat) significantly increased haloperidol-induced catalepsy, suggesting that catecholestrogens may directly interfere with nigrostriatal dopaminergic transmission. Haloperidol-induced catalepsy has been found to be attenuated in conditions of hyperprolactinaemia resulting from anterior pituitary isograft underneath the kidney capsule. This is consistent with the hypothesis that prolactin may stimulate nigro-striatal dopaminergic function. Results obtained also indicate that medroxy-acetate progesterone, a progesterone derivative, may influence haloperidol-induced catalepsy. Specifically, a single administration with medroxy-acetate progesterone (5 mg/kg, i.p.) enhanced catalepsy but opposite effects were observed after repeated administration of medroxy-acetate progesterone (5 mg/kg, i.p., once a day for 7 days).

Animals↗
PubMed1983

[Neuroendocrine modulation of haloperidol-induced catalepsy].

Evidence has been accumulated implicating sex hormones as possible modulators of extrapyramidal motor function. In the present study we have investigated the effects of estrogens, progesterone, testosterone, prolactin and calcitonin on behavioral parameters related to nigro-striatal dopaminergic system, such as haloperidol-induced catalepsy in male rats. It was found that 7-days estradiol benzoate treatment (5 micrograms/rat/day) significantly increases haloperidol-induced catalepsy, suggesting a possible antidopaminergic activity of estrogens. On the other hand, prolactin facilitates nigro-striatal dopaminergic transmission. Interestingly, 7 day treatment with medroxy-acetate progesterone (MAP, 5 mg/Kg, i.p.) brings about a trend to a decrease in haloperidol-induced catalepsy, while no significantly effect was observed following acute MAP administration at the same dose. So, it is tempting to speculate that chronic progestinic treatment may result in an increase in dopaminergic tonus. Testosterone, acutely administered (5mg/kg.s.c.) induces changes similar to those observed following progesterone administration. Finally, also calcitonin is able to influence haloperidol-induced catalepsy by markedly increasing it.

Androgens↗
PubMed1983

Hemodynamics of the splanchnic and systemic circulation after hypotonic water load-comparison between normal subjects and patients with congestive heart failure.

The authors investigated the changes in cardiovascular and splanchnic hemodynamic, diuresis and urinary and hepatic veins osmolarity induced by hypotonic water load in five normal subjects and in five patients with congestive heart failure (CHF). Pulmonary wedge pressure increased significantly only in CHF patients while cardiac index, total pulmonary resistances and peripheral vascular resistances remained unchanged in both groups. Hepatic blood flow increased significantly in control group while in CHF showed a significant reduction 15 and 30 minutes after water load. Hepatic veins osmolarity decreased significantly in control group only at the 45th minute. Diuresis was significantly higher in normals which eliminated water load with a lower urinary osmolarity. The authors conclude that: water loading is particularly interesting in so much it resembles the physiological conditions of the absorption of the alimentary hypotonic bolus; the failing heart responds to the water load on a depressed function curve; the hepatic blood flow is reduced in CHF patients and is probably responsible for some humoral abnormalities found in these subjects; CHF patients eliminate a water load slower than a normal subject and with a higher osmolarity.

Aged↗
PubMed1983

[Effectiveness of the aorto-coronary by-pass procedure in elderly patients].

This study was undertaken to evaluate the efficacy of coronary artery by-pass grafting (CABG) in elderly patients with coronary artery disease. A consecutive series of 79 patients, 65 years of age and older, who underwent CABG from 1975 to 1981 was analysed and their follow up status ascertained. This group was compared with a consecutive series of 397 patients under the age of 65 who underwent CABG during the same period. The patients aged 65 years or greater had a higher incidence of unstable angina pectoris (p less than 0.05). Coronary angiographic and left ventriculographic features were comparable in both age groups; also comparable were the number of saphenous veins graft utilized and the number of left ventricular aneurysmectomies and mitral valve replacements performed. The hospital mortality rate for patients aged 65 years and older was 12.6%, for those aged less than 65, it was 8.3%; if the other cardiac procedures are excluded mortality rates become 12.5% and 6.0% respectively (n.s.). Survival at 6 years was 92% for patients in both age groups. However, the symptomatic status was less favourable in older patients, compared with that obtained in younger patients (p less than 0.05).

Aged↗
PubMed1982

Comparative effects of estrogens and prolactin on nigral and striatal GAD activity.

The comparative effects of a 10 day estrogen treatment and estrogen independent hyperprolactinemia on nigral and striatal glutamic acid decarboxylase (GAD, EC 4.1.1.15) activity were investigated in male rats. Data obtained show that estrogen treatment decreases GAD activity in substantia nigra, while an increase was observed in conditions of hyperprolactinemia induced by adenohypophysis homograft or acute and chronic sulpiride injection. The possibility of an opposite modulation of strio-nigral GABAergic system by estrogens and prolactin is suggested.

Animals↗
PubMed1981

[Effects of guaiacolic ester of acetylsalicylic acid on spirometric and plethysmographic parameters in subjects with chronic obstructive bronchopneumopathy].

The effects of oral administration of guaiacolic ester of acetyl salicilic acid in 24 patients with chronic obstructive lung disease have been evaluated. 1.5 g of this drug were given daily into 3 administrations improving both objective and subjective symptomatology in 19 of the 24 patients after 1 or 3 weeks of treatment. Moreover, a statistically significant improvement of FEV 1" (p less than 0.001), Raw (p less than 0.005) and FEV 1"/VC (p less than 0.01) was observed. The remaining 5 patients discontinued the treatment failing the improvement of the subjective symptomatology.

Aged↗
PubMed1981

Comparison of the antihypertensive activities of xipamide and chlorthalidone: a double-blind, randomized, crossover trial.

The effectiveness of a new potent diuretic, xipamide, was evaluated in the treatment of patients with mild to moderate essential hypertension. The effects of daily doses of 40 mg xipamide were compared with those of 100 mg chlorthalidone with respect to systolic and diastolic blood pressure, using a double-blind crossover design. Patients received each drug for 6 weeks, the order of treatments being at random and the periods being separated by a 'washout' period of 7 days. The results showed that xipamide was as effective as chlorthalidone in controlling blood pressure, both in the upright and supine positions, and when administered after chlorthalidone produced a further reduction. No such further reduction occurred when chlorthalidone was given after xipamide. Serum electrolyte changes induced by the two diuretics were comparable. Both drugs were well tolerated and caused few side-effects.

Adult↗
PubMed1981

[The hemodynamic effects of reproterol in patients with chronic obstructive lung disease (author's transl)].

Our study was undertaken in order to evaluate hemodynamic effects of intravenous administration of Reproterol in patients with chronic obstructive lung disease (COLD). Reproterol is a monomulecolar combination of catecholamine and theophilline. Diastolic pulmonary pressure and wedge pressure decreased 20 minutes after Reproterol while total pulmonary resistances were reduced 10 minutes after drug administration; sistolic pulmonary pressure and cardiac index increased only after 10 minutes; heart rate increased until 15th minute. Reproterol, as a catecholamine-theophylline combination, has an additional site of action over and above the pure catecholamine effect owing to inhibition of phosphodiesterase; so an increase in cAMP content is achieved either by increasing the synthesis or by blocking the breakdown. Our results assess that Reproterol has a beneficial effect on pulmonary hemodynamics in COLD.

Adult↗
PubMed1979

Potassium sparing effect of amiloride in patients receiving diuretics: a quantitative study.

This study was undertaken in order to assess the K+ sparing ability of amiloride. Thirty patients with liver cirrhosis and ascites or congestive heart failure were divided into three groups and treated with amiloride (Group A), hydrochlorothiazide (Group B) and amiloride plus hydrochlorothiazide (Group C) for 15 days. In all groups there was an increased diuresis while only in group A and C there was a statistically significant rise of K+ serum levels and a slight increment of K+ urinary loss. Total body K+ evaluated by 42K increased in group A and C while decreased in group B. Our results seem to confirm that amiloride has a mild diuretic action with a powerful K+ sparing capacity; amiloride is also able to counterbalance and reverse hydrochlorthiazide induced K+ urinary loss.

Adult↗
PubMed1979

[Changes in plasma renin activity induced by acute administration of nifedipine in hypertensive patients (author's transl)].

In the present study we assessed plasma renin activity (PRA) variations induced by Ca++ antagonist antihypertensive drug Nifedipine in 8 normoreninaemic or hyporeninaemic hypertensive patients. On two successive days three venous blood samples were sampled, two in clinostatic position and the last one 120 min later in orthostatic position; on the second day 20 mg of nifedipine were administered sublingually. Nifedipine increases significantly PRA after orthostatic position compared with starting conditions (p < 0.01) and compared with the values recorded without the drug at the same times (p < 0.01). Both systolic and diastolic blood pressure decreased 15 and 120 min after nifedipine administration while heart rate increased at the same times. Acute nifedipine administration augments PRA in hypertensive subjects; explanatory hypoteses are proposed.

Humans↗