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Biomedical subjects

A Reale

Publications and source records attributed to A Reale.

At least 145 records · Page 8Linked to original sources

Pathogenesis of pseudomembranous colitis.

This work is concerned with new morphologic data pointing to an immune component in the pathogenesis of pseudomembranous colitis. The focal distribution of the pseudomembranes suggests selective damage induced by Clostridium difficile toxins. The sites of attachment to the mucosa correspond anatomically to the intestinal structures specialized for immune information and response. Furthermore, viable IgA production supports the view that toxins are carried to lymphoid aggregates where plasma cell proliferation takes place. A sharp increase in the mast cell population of the colon is also reported. Mast cells, whose role in the pathogenesis of intestinal diseases is still obscure, are diffusely distributed, irrespective of the focal lesions of pseudomembranous colitis.

Colon↗

Effects of L-carnitine on exercise tolerance in chronic stable angina: a multicenter, double-blind, randomized, placebo controlled crossover study.

L-carnitine was studied in forty-four men with stable chronic angina in a multicenter, double-blind, randomized, placebo controlled crossover trial. A cycloergometer exercise test was performed after a 10-day wash-out with placebo and at the end of each 4-week treatment period with either L-carnitine (1 g twice daily) or placebo. The mean (+/- SD) exercise work load showed an increase after L-carnitine compared to placebo (102.73 +/- 22.23 and 97.05 +/- 22.77 watts respectively, p = 0.001), as did the watts to onset of angina (95.7 +/- 24.07 and 87.44 +/- 24.67, p = 0.000). On the contrary, the ST segment depression was reduced by L-carnitine compared to placebo both at the maximum work load (1.40 +/- 0.90 and 1.69 +/- 0.82 mm, p = 0.05) and at the maximum work load common to L-carnitine and placebo (1.24 +/- 0.90 and 1.66 +/- 0.79 mm, p = 0.005). 22.7% of the patients became free of angina with L-carnitine and 9.1% with placebo. Resting and exercise blood pressure, heart-rate and double product were unaffected by L-carnitine. 1 patient decided to discontinue the trial because of gastric pyrosis while taking the active drug. The results of this study show that treatment with L-carnitine increases exercise tolerance and reduces ECG indices of ischemia in stable effort-induced angina.

Angina Pectoris↗

[An anesthetic technic in dogs for studying the arrhythmogenic effects of acute coronary occlusion].

Intramuscular injection of levomepromazine (0.5 mg/kg) 30 min before intravenous injection of 10 mg/kg pentobarbital sodium induces a good surgical anaesthesia in dogs artificially ventilated with 50% N2O and 50% O2 and given 0.01 mg/kg atropine and 0.1 mg/kg pancuronium intravenously before left thoracotomy. This protocol is suitable for the study of the arrhythmogenic effects of acute one-stage coronary artery ligation in anaesthetized dogs. In fact, minor interference with the autonomic nervous system appears to be involved since heart rate is maintained slow and mean aortic pressure is kept within normal limits, as pH, PaO2, anc PaCO2 during subsequent periods. Acute circumflex coronary arterio-venous pedicle ligation close to the left main trunk division resulted in this model in a high incidence of ventricular fibrillation (10 out of 15 dogs) early (7 +/- 4 min) after occlusion. Specific interventions aimed at reducing the incidence of early post-ischemic life-threatening ventricular arrhythmias might be tested in this model.

Anesthesia, General↗

Nomogram for calculation of stenotic cardiac valve areas from cardiac output and mean transvalvular gradient.

In 15 patients (group 1) with isolated mitral stenosis and in 14 patients (group 2) with isolated aortic stenosis the stenotic valve areas were calculated according to: A) Gorlin's formula; B) Hakki's simplified formula, using mean mitral gradient by planimetry or peak-to-peak aortic gradient; C) the three-point simplified formula, using mean gradient calculated by the three-point method for both mitral and aortic valve. The three-point method is definitely easier to use than planimetry. The values (mean +/- SD) of mitral valve areas in group 1 patients were, respectively: 1.56 +/- 0.63 cm2; 1.56 +/- 0.55; 1.51 +/- 0.53. The values of aortic valve areas in group 2 patients were: 0.91 +/- 0.63; 0.77 +/- 0.41; 0.88 +/- 0.52. An excellent correlation was shown between the valve area calculated by Gorlin's formula and both Hakki's simplified formula and the three-point simplified formula. For aortic valve area the correlation is even better if the mean gradient by the three-point method is used instead of the peak-to-peak gradient. On the basis of the simplified formula, a nomogram was constructed which allows an immediate calculation of valve areas from cardiac output and transvalvular gradient.

Adult↗

Diagnostic value of electrocardiogram and vectorcardiogram in postinfarction ventricular asynergy.

The ability of ECG-VCG to predict the severity of postinfarction LV asynergy was evaluated in 152 patients with previous myocardial infarction who underwent left cineventriculography in the right anterior oblique view. Various ECG and VCG signs were examined in order to predict the existence of severe asynergy in general (dyskinesia or akinesia or severe hypokinesia) and of dyskinesia in particular. In patients with inferior myocardial infarction (Group A) persistent ST segment elevation was the only specific ECG sign (100%) of severe asynergy; it had a poor sensitivity (6.2%). Four frontal VCG signs (presence of terminal bite, y- greater than 0.18 mV, maximum early superior vector along x axis = MESV greater than or equal to 1.3 mV, duration of initial superior forces = DISF greater than 50 msec) increased the sensitivity of the ECG-VCG method to 75.8% while maintaining a 100% specificity. Regarding the diagnosis of dyskinesia, only the ECG sign of persistent ST segment elevation and the VCG sign of y- greater than or equal to 0.3 mV had a 100% specificity. The sensitivity of the ECG-VCG method was 33.3% (16.6% ECG and 16.6% VCG). In patients with anterior myocardial infarction (Group B), concerning the diagnosis of severe asynergy, the ECG signs of sigma ST greater than 3 mm in anterior leads; pathologic Q wave in four or more anterior leads (including D1 and aVL); and the presence of LAH or LAH + RBBB, had a 100% specificity and a good sensitivity (60.5%). The VCG sign of a narrow horizontal QRS loop increased the sensitivity of the ECG-VCG method to 71% while maintaining a 100% specificity. As for the diagnosis of dyskinesia, the ECG signs with a 100% specificity were sigma ST greater than or equal to 5 mm in anterior leads, a pathologic Q wave in more than five anterior leads (including I and a VL) and RBBB + LAH; these variables had a sensitivity of 48.3%. The VCG sign of a narrow horizontal QRS loop increased the sensitivity of the ECG-VCG method to 79.3% while maintaining a 100% specificity. In patients with inferior plus anterior myocardial infarction (Group A + B) the signs mentioned above for each group were evaluated, confirming a 100% specificity. Regarding the diagnosis of severe asynergy, the ECG signs had a sensitivity of 61.3%, while VCG increased the sensitivity of the ECG-VCG method to 90.3%.(ABSTRACT TRUNCATED AT 400 WORDS)

Adult↗

Acute hemodynamic effects of acebutolol and propranolol.

The acute hemodynamic effects of intravenous acebutolol, 50 mg, and propranolol, 10 mg, were evaluated in 12 patients undergoing diagnostic cardiac catheterization. Each patient received acebutolol or propranolol according to a list of randomization. Both acebutolol and propranolol depressed left ventricular function. There was a significant increase in left ventricular end-diastolic pressure at rest and after isometric exercise, with a concomitant decrease in cardiac index. Systemic vascular resistance was increased by both drugs. The increment after patients received acebutolol was not statistically significant; however, with propranolol it was statistically significant. The overall hemodynamic effects of acebutolol and propranolol are similar, but a quantitative difference exists in their effect on systemic vascular resistance. Acebutolol, a cardioselective agent, produces less of a peripheral vascular beta 2-blockade than does propranolol.

Acebutolol↗

[Determination of cardiac output by thoracic electric impedance: comparison with thermodilution].

When an alternating current of high frequency is applied to the thorax, the first derivative of the impedance (dZ/dt) is affected by the cardiac cycle, resulting in a characteristic wave form. The maximum negative of this wave occurring during systole together with the length of ejection time (VET), the blood resistivity, the basal impedance (ZO) and the distance between the inner detecting electrodes (L) makes it possible to calculate stroke volume (SV) and related parameters, as cardiac output (CO) and cardiac index (Cl) by a formula developed by Kubicek. Thoracic electrical impedance has been proposed as a non invasive technique to evaluate cardiac emodinamics. In the present study we have evaluated thoracic electrical impedance by comparing it with thermodilution, simultaneously performed in 21 catheterized patients. Reproducibility was assessed by comparing Cl measured several times in the same patient during ten minutes of rest in the supine position: coefficient of variation, expressed as CV = SD/m X 100 was 8,5 +/- 4,2% and 9,4 +/- 3,2% (p = NS) for thermodilution and thoracic electrical impedance respectively. Cl values obtained by both methods correlated well, with little scatter either baseline (r = 0,784, n = 40, p less than 0,001), either after an handgrip manoeuvre (r = 0,629, n = 15, p less than 0,05). This degree of correlation is similar to that observed comparing invasive techniques (Fick, thermodilution, dye dilution) either among them, or with noninvasive methods (echocardiography, gated equilibrium blood pool scintigraphy and ultrasonic Doppler).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

[Duration of electric systole in the acute phase of myocardial infarct. Methodology, natural history, semiological value, therapeutic consequences].

Extension of the duration of electric systol in the acute phase of coronary thrombosis can be analysed in satisfying conditions whatever the physiological frequencies by the measurement (formula; see text) represents the average QT measurement of three non-consecutive complexes in five derivations (DI, DIII, aVF, VI and V6). This extension is of prognostic value when the QTc is greater than 44 c/s. Out of 1 255 acute phase thrombosis patients, 18 Out of 20 cases of ventricular fibrillation revealed a QTc greater than 44 c/s in the 24 hours preceding sudden death. Therapeutic intervention with anti-andrenergic drugs such as bretylium tosylate or beta-blocking agents appears to reduce the QTc of these patients and thus prevent sudden death.

Acute Disease↗

Criss-cross heart with discordant atrioventricular connections.

A case of criss-cross heart is presented in which there was situs solitus with atrioventricular (AV) discordance and single outlet, the aorta arising from the right ventricle. Associated lesions were pulmonary atresia and ventricular septal defect. The apparently normal AV relation in the presence of a discordant AV connection can be explained by the hypothesis that an embryonic l-bulboventricular loop developed and was followed by marked counter-clockwise rotation of the ventricles.

Electrocardiography↗