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Biomedical subjects

A Reale

Publications and source records attributed to A Reale.

At least 91 records · Page 5Linked to original sources

[Idiopathic dilated cardiomyopathy: clinical and prognostic significance of the morpho-functional involvement of the right heart].

Aim of this study was to evaluate whether different severity of clinical and functional impairment of right heart in patients with idiopathic dilated cardiomyopathy (IDC) might condition distinct clinical features and prognosis. From 104 consecutive patients with hemodynamically assessed diagnosis of IDC studied between 1977 and 1987 in our Institute, 39 patients (28 males and 11 females, mean age 41 +/- 14 years) were selected on the basis of ejection fraction ranging from 35 to 50%, left ventricular end-diastolic pressure ranging from 13 to 20 mmHg and left ventricular end diastolic volume less than or equal to 150 ml/m2. A significant involvement of right heart (diagnosed according to a mean right atrial pressure greater than or equal to 9 mmHg, a right ventricular end-diastolic pressure greater than or equal to 9 mmHg and a right ventricular end-diastolic diameter greater than or equal to 30 mm) was assessed in 16 patients (41%), 11 males and 5 females, aged 40 +/- 15 years (Group A). On the contrary the remaining 23 patients (59%), 17 males and 6 females, aged 42 +/- 12 years, had a normal right heart (Group B). At entry into the study, clinical features appeared similar in the 2 groups of patients whereas patients of Group A had significantly higher incidence of atrial fibrillation (25% vs 4%, p less than 0.01) and complex ventricular arrhythmia (greater than or equal to 4 Lown class) (25% vs 4%, p less than 0.01) compared with patients of Group B. With respect to conduction defects no difference was found between Group A and Group B.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

[Predictive value of myocellular hypertrophy in idiopathic dilated cardiomyopathy].

The role of endomyocardial biopsy (EMB) in assessing of idiopathic dilated cardiomyopathy (IDCM) is a well-recognised one. On the contrary, the value of correlating histological features, such as myocellular hypertrophy, with functional evaluation and outcome is still controversial. It was the purpose of the present study to appraise the correlation with hemodynamic data and the predictive role of histological features in 32 consecutive patients affected by IDCM who underwent left ventricular EMB between January 1984 and December 1986. Light microscopy findings were graded by means of a semiquantitative score system. In comparison with the 19 patients with mild myocellular hypertrophy, the 13 patients with marked hypertrophy showed significantly lower right ventricular end-diastolic pressure (10.4 +/- 5.8 vs 6.6 +/- 3.6 mmHg, p less than 0.05) and left ventricular end-diastolic pressure (26.9 +/- 9.0 vs 16.5 +/- 8.8 mmHg, p less than 0.01). On the contrary, different degrees of interstitial fibrosis, as well as of the other morphologic findings, could not identify patients with distinct hemodynamic patterns. However, there was a direct correlation between the amount of myocellular hypertrophy and interstitial fibrosis (p less than 0.01). During a mean follow-up period of 32 +/- 11 months (range: 12-48 months), 6 patients died and 3 further patients underwent heart transplantation. Univariate analysis of histological features (log-rank test) showed a mild degree of hypertrophy alone to be significantly related to a poor outcome (p = 0.02).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

Angulated transverse tomographic sections to measure cardiac dimensions by magnetic resonance imaging: a comparison with 2D-echocardiography.

Magnetic resonance imaging (MRI) has shown low accuracy in measuring cardiac dimensions in normal subjects, when transverse tomographic sections are used in comparison with 2D-echocardiography. The rationale of this study was to compare cardiac dimensions in 19 volunteers based on angulated (30 degrees caudo-cranial) transverse tomographic sections both in MRI and 2D-echo. Since the planes investigated by both techniques are superimposable, highly significant correlated Ao, LA, IVS, LW, LV, and RV dimensions are observed. Standardized MRI tomography permits reduction of total examination time and assures repeatability. Thus, using the method reported here, cardiac dimensions in humans might be obtained accurately by MRI.

Adult↗

Tightly-bound non-histone proteins in different nucleosome-like subpopulations from pig kidney chromatin.

By differential sucrose gradient centrifugation of pig kidney chromatin in the presence or absence of Na-EDTA and under varying ionic strength conditions, three nucleosome-like subpopulations with different buoyant densities can be obtained. These particles, on the basis of their histones and HMG protein pattern, of the 5-methylcytosine level of their DNA and of the RNA polymerase activity associated with them, can be considered as originating from chromatin fractions differently involved in gene expression. Two-dimensional electrophoresis of the tightly-bound non-histone proteins shows a distinct pattern for each subpopulation, such protein components being notably present in restricted numbers but in high amounts in the subpopulation which was apparently derived from condensed heterochromatin.

Animals↗

Evaluation of 10 QT prediction formulas in 881 middle-aged men from the seven countries study: emphasis on the cubic root Fridericia's equation.

In 881 middle-aged men from one Italian cohort of the Seven Countries Study, QT and RR intervals were measured in lead 2 from resting ECGs (25 mm/sec) and fitted separately with 10 mathematically different QT prediction formulas. The relative accuracy of fit to data was assessed from the minimum mean-squared residual and the minimum Akaike Information Criterion values. Using the Minnesota code, 588 men had normal (group 1) and 293 had abnormal (group 2) ECGs. A better fit to QT-RR data by all formulas was observed in group 1, compared with group 2. Among one-parameter equations in both groups, the cubic root Fridericia's formula is better suited to fit the data than the Bazett's square root or other formulas. The former compares favorably with multiparameter equations or with the inverse relation and gives the best fit in group 2. Thus the cubic root equation might be more accurate than the square root or several complex formulas for correcting measured QT intervals for cardiac cycle length in middle-aged men.

Arrhythmias, Cardiac↗

The automatic implantable cardioverter/defibrillator: transesophageal atrial pacing discloses the potential for erroneous discharges.

We report the occurrence of erroneous discharge from an implanted automatic cardioverter/defibrillator during transesophageal atrial pacing. Transesophageal pacing was performed as part of a study protocol on the inducibility of ventricular tachycardia from the atrium in patients with ischemic heart disease. At an induced heart rate of 166 beats per minute (a value just above the cut-off rate of the device), the cardioverter/defibrillator was triggered. This observation suggests that transesophageal atrial pacing could be utilized to disclose the potential for spurious discharges in the event of fast atrial rhythms in patients with the automatic implantable cardioverter/defibrillator.

Cardiac Pacing, Artificial↗

Prevention of postischemic ventricular fibrillation late after right or left stellate ganglionectomy in dogs.

To gain insight into the differences in antiarrhythmic potential of right vs left stellate ganglionectomy, 72 dogs were randomized to either unilateral stellectomy or second intercostal space thoracotomy and left circumflex coronary arteriovenous pedicle occlusion was performed, without vagotomy, a mean of 8 weeks later under anesthesia. The type and timing of ventricular ectopic beats, including both nonsustained and sustained ventricular tachycardia and ventricular fibrillation, were investigated. Several covariates, including postischemic electrocardiographic changes, were considered. Both right and left stellate ganglionectomy reduced the incidence of early (0 to 10 min) (p = .004 and p = .001, respectively) and total (0 to 60 min) (p = .009 and p = .008, respectively) ischemia-induced ventricular fibrillation, and improved outcome (p = .0013 and p = .0012, respectively). Early sustained ventricular tachycardia was similarly reduced (p = .02) in both stellectomized groups. By contrast, neither the type nor the time distribution of the other forms of ventricular arrhythmias differed significantly among the randomized groups. The multivariate Cox's regression model showed that ST segment elevation at 3 min postocclusion, unilateral stellate ganglionectomy (either right or left), sex, and weight were significant independent predictors of the incidence of ventricular fibrillation during the occlusion period. Lower ST segment elevation and reduced incidence of sustained ventricular tachycardia in the early postischemic period might explain improved outcome in stellectomized dogs by Cox analysis. The side of intervention (either stellectomy or sham operation) did not influence survival; however, left-sided interventions were more effective than right-sided ones. These results confirm the previously reported antifibrillatory effect of left and indicate like effects of right stellate ganglionectomy in a randomized experimental study.

Animals↗

Do tightly-bound chromatin proteins play a role in DNA methylation?

When chromatin matrix, "stripped" from its loosely-bound components by extraction with 3 M NaCl, is extensively digested with DNAase I, a fraction is obtained, which carries no endogenous DNA methyltransferase activity but which is a good substrate for externally added enzyme. Under the same conditions, protein-free DNA isolated from this fraction can instead hardly be methylated, this different behaviour pointing to a role of DNA-tightly-bound proteins in favoring or promoting the catalytic action of the enzyme. A similar stimulation of enzymatic methylation could also be shown when, in the presence of this same fraction, single stranded Micrococcus luteus DNA was incubated with placental methyltransferase, using S-adenosylmethionine as a methyl donor. This finding can be correlated to the existence, in chromatin loops, of small regions which resist digestion by DNAase I also after high-salt removal of their loosely-bound components (presumably because of the presence of tightly-bound proteins) and whose DNA is characterized by high methylation levels and, at the same time, by high relative content of thymine.

Binding Sites↗