Biomedical subjects

R De Simone

Publications and source records attributed to R De Simone.

At least 73 records · Page 4Linked to original sources

PubMed1993

Influence of ethanol consumption on brain nerve growth factor and its target cells in developing and adult rodents.

In the present study the effect of alcohol consumption on brain nerve growth factor (NGF) and the NGF-target cells of adult male rats and pups exposed prenatally to ethanol is evaluated. It is hypothesized that NGF, a trophic agent for the survival and maintenance of basal forebrain cholinergic neurons, might be affected by the neurodegenerative events which occur during ethanol consumption. To test this hypothesis, we used adult rats exposed to ethanol for 16 weeks and pregnant rats exposed to ethanol for six days. Our experiments show that ethanol ingestion causes a reduction of NGF in the hippocampus, of choline acetyltransferase activity in both the septum and hippocampus, and in the distribution of NGF receptor in the basal forebrain cholinergic neurons. The results indicate that the damaging effect of alcohol on forebrain cholinergic neurons is also associated with impairment of central NGF-target structures.

Age Factors↗

PubMed1993

[Effect of cilazapril therapy on diastolic filling and left ventricular hypertrophy in patients with arterial hypertension].

BACKGROUND: Of the main aspects of hypertension, left ventricular hypertrophy and appearance of cardiac dysfunction seem to be the most common and to produce an early and severe cardiac deterioration. Even in the presence of normal systolic function diastolic filling abnormalities are described. The efficacy of many antihypertensive drugs to decrease blood pressure and to reduce left ventricular hypertrophy has already been demonstrated. Cilazapril is a new ACE-inhibitor that in previous studies showed a very important antihypertensive effect. To assess its capacity, in long-term treatment, to reduce left ventricular hypertrophy we performed a prospective study on patients with mild hypertension. MATERIAL AND METHODS: Nineteen patients (aged 48 +/- 15 years) with mild hypertension (mean arterial pressure automatically recorded for 24 hours with blood pressure ambulatorial monitoring) were treated with cilazapril (5 mg/day) for 1 year. Doppler echocardiography was performed: at the beginning, after 6 months and after one year of therapy. The following parameters were evaluated: interventricular septal and posterior wall thickness, LV end-diastolic diameter, LV mass index, early (E) and late (A) diastolic filling flow velocities and the ratio E/A. RESULTS: A significant decrease was observed in mean arterial pressure (from 130 +/- 14 mmHg at beginning to 102 +/- 11 mmHg at six months of therapy and to 103 +/- 9 mmHg at one year of therapy). A significant reduction in LV hypertrophy and an improved diastolic filling pattern of the left ventricle was shown after six months of therapy with cilazapril; this improvement still remained after 1 year of therapy. CONCLUSIONS: In this study antihypertensive efficacy of cilazapril has been confirmed. Moreover, in long treatment, cilazapril has been useful to reduce left ventricular hypertrophy and to improve diastolic filling without significant side effects.

Adolescent↗

PubMed1992

Intraoperative transesophageal echocardiography for the evaluation of mitral, aortic and tricuspid valve repair. A tool to optimize surgical outcome.

The present study reviews the clinical applicability and usefulness of intraoperative transesophageal echocardiography (TEE) during valve repair. Intraoperative TEE was performed in 48 consecutive patients, who were divided into three groups: 1. mitral valve repair (MVR), 2. aortic valve repair (AVR), 3. tricuspid valve repair (TVR). Residual valve regurgitation was assessed by color Doppler echocardiography on a scale from 0 to 4. The ratios of the jet area (JA) to the left- and right-atrial areas (JA/LAA and JA/RAA) were analyzed before and after cardiopulmonary bypass (CPB). In group 1, 14 patients were scheduled for MVR, of which 4 patients underwent valve replacement and 10 MVR. Post-repair TEE studies showed a significant decrease of mitral regurgitation. In 2 of the 10 patients, TEE demonstrated severe residual regurgitation requiring valve replacement during the same thoracotomy. In group 2, 11 patients underwent aortic commissurotomy. Post-repair TEE showed an increase in the systolic opening diameter and opening area of the aortic valve. One patient underwent valve substitution because of severe aortic regurgitation. In group 3, 23 patients were scheduled for TVR. In 3 of them TEE showed no significant regurgitation thus rendering tricuspid valve surgery unnecessary. Twenty patients underwent TVR of whom two showed unacceptable post-repair regurgitation requiring further surgery. Eighteen patients showed a significant reduction of valve regurgitation after TVR, and a further reduction was achieved by adjusting the tricuspid annuloplasty under TEE guidance.

Adult↗

PubMed1992

Superiority of endocardial versus epicardial implantation of the implantable cardioverter defibrillator (ICD).

The implantable cardioverter-defibrillator (ICD) has proved to be an efficient device for the treatment of severe ventricular tachyarrhythmias (VT). From May 1985 to August 1991, the ICD was implanted in 107 patients of whom 72% suffered from coronary artery disease, 17% from cardiomyopathy, 5% from long QT-syndrome and 6% from other heart disease. All patients had a life threatening episode of VT or at least one episode of ventricular fibrillation. Of 107 implants, 12% were combined with other heart surgery, 55% were isolated epicardial implantations (epi I) and in 33%, the novel endocardial (endo I) approach was chosen. Between epi I and endo I we found no difference in operation time, but time for ICU and in-hospital stay was significantly shorter using the transvenous approach. In addition, sensing and pacing capability of the endocardial screw-in electrode was superior and the need for thoracotomy was avoided, a particular advantage in patients with previous heart surgery. Complications after epi I were: temporary low cardiac output, 1; perioperative death, 2; infection, 3, and after endo I: electrode dislocation, 2. Hence, endo I may become the method of choice for patients without concomitant surgery.

Adult↗

PubMed1992

Levocarnitine acetyl treatment promotes iris reinnervation following 6-hydroxydopamine-induced noradrenergic denervation in rats.

The effect of levocarnitine acetyl on neurite regeneration was evaluated following administration of 6-hydroxydopamine which caused a selective degeneration of peripheral catecholaminergic neurites in the irides of newborn and young rats. Levocarnitine acetyl 20 mg/kg body weight was administered either subcutaneously to newborn rats for 20 days or dissolved in drinking water to young rats for 90 days. Treatment with levocarnitine acetyl promoted neurite outgrowth following axotomy in both groups, thus demonstrating a stimulatory role of the substance in nerve regeneration of the peripheral nervous system. The results further confirm that levocarnitine acetyl is endowed with therapeutical efficacy in peripheral neuropathies.

Acetylcarnitine↗

PubMed1992

[Intraoperative evaluation of tricuspid valve annuloplasty with transesophageal echocardiography].

The present study shows a new application of transesophageal echocardiography (TEE) to optimize tricuspid valve annuloplasty. Eighteen patients with tricuspid regurgitation (TR) underwent De Vega tricuspid annuloplasty. After cardiopulmonary bypass the tension on the suture was adjusted until the surgeon could not feel any regurgitant jet by intraatrial palpation; subsequently, the tension was further adjusted on the basis of TEE. The post-pump residual tricuspid regurgitation was assessed by semiquantitative grading of tricuspid regurgitation (0 to 4+), area of regurgitant jet and percentage of right atrial area subtended by jet area. The data obtained by intraatrial palpation were compared with the data obtained by TEE. A significant reduction of residual tricuspid regurgitation was shown by TEE when compared to intraatrial palpation. After a follow-up period of 2 weeks, no significant changes in the grade of TR were observed. The results showed that the use of TEE was able to optimize the De Vega's tricuspid annuloplasty.

Adult↗

PubMed1991

Effect of acetyl-L-carnitine on forebrain cholinergic neurons of developing rats.

It has been shown that the endogenous compound, acetyl-L-carnitine (ALCAR), acts in the brain as a metabolic cofactor in the synthesis of acetylcholine. In these studies, ALCAR was injected into the brain of developing rats every other day for the first three weeks after birth in order to assess its effect on forebrain cholinergic neurons. The results showed that intracerebroventricular (icv) administration of ALCAR causes an increase of choline acetyltransferase (ChAT) activity and of nerve growth factor receptor expression in the striatum. Biological assays of brain tissues revealed that the level of nerve growth factor (NGF) in the hippocampus also increases. The ability of brain cholinergic tissues to respond to exogenous administration of ALCAR is discussed.

Acetylcarnitine↗

PubMed1991

Improvement of diastolic filling in hypertensive patients treated with cilazapril.

The aim of this study was to assess the behavior of the diastolic left ventricular (LV) filling pattern and cardiac hypertrophy after treatment with cilazapril. Twelve patients (9 male and 3 female) with mild to moderate essential hypertension, aged 46 +/- 14.1 years, were treated with cilazapril for 1 year. They underwent Doppler echocardiography at the beginning (I), after 6 months (II), and after 1 year (III) of treatment. The following parameters were evaluated: mean arterial pressure (MAP) automatically recorded for 24 h, interventricular septal and posterior wall thickness, LV and end-diastolic diameter, LV mass index, early (E) and late (A) diastolic filling flow velocities, and the ratio E/A. A significant reduction in LV hypertrophy and an improved diastolic filling pattern of the left ventricle was shown after 6 months of therapy with cilazapril; this improvement still remained after 1 year of therapy.

Adult↗

PubMed1990

Changes of NGF level in mouse hypothalamus following intermale aggressive behaviour: biological and immunohistochemical evidence.

Nerve growth factor (NGF) immunoreactivity was detected in the hypothalamus of adult male mice. NGF-immunoreactive cell bodies were examined through consecutive brain sections, and it was found that most of the NGF-positive cells were located in the dorsomedial and mediolateral portions of the hypothalamus. Tissue culture bioassays showed that hypothalamic extract elicits neurite outgrowth from both chick sensory ganglia and rat superior cervical ganglia neurons, and that these effects are inhibited by addition of NGF antibodies. Our results also showed that intermale aggressive behaviour induced by 6-8 weeks of social isolation induces an NGF increase in the hypothalamic area, which is not abolished by sialoadenectomy, suggesting that the increased brain NGF is locally synthesized, and does not come from salivary sources. Likewise, the level of NGF in the hypothalamus of adrenalectomized fighting mice increased, although to a much lesser extent, when compared to hypothalamic levels of sham-operated fighting mice. The present results and a recent report showing that aggressive behaviour causes an increase of mRNANGF in hypothalamic areas are discussed in relation to a possible functional role of NGF in these brain structures.

Aggression↗

PubMed1990

Social status and nerve growth factor serum levels after agonistic encounters in mice.

Ten repeated daily interactions (20 min each) of the same pairs of isolated male mice produced a clear distinction between attacking (dominant) and defeated (subordinate) animals. The fighting level remained fairly constant over the 10 days. One hr after the end of the 10th session, the increase in serum NGF levels described previously (2) was significantly more marked in subordinate than in dominant mice. The mean level of serum NGF was correlated with the number of fighting episodes, particularly in the case of dominant individuals. Moreover, within-pair differences in NGF values were correlated with differences in locomotor activity between dominants and subordinates; this makes it possible that stimuli other than those produced by fighting per se may be responsible for the increase in circulating NGF. As is well known, the adrenal hypertrophy produced by fighting stress is more marked in subordinate than in dominant mice, while previous work has shown that stress of a nonpsychosocial kind does not elevate serum NGF levels. Therefore, the present data support the hypothesis that NGF release contributes to the modulation of adrenal function in a situation-specific fashion.

Aggression↗

PubMed1990

Nerve growth factor released into the bloodstream following intraspecific fighting induces mast cell degranulation in adult male mice.

Nerve growth factor (NGF) is stored in the salivary glands of adult male mice. Recent evidence has shown that NGF is active on cell lines of the immune system. Following isolation-induced fighting (20 min session) NGF is released into the bloodstream, causing disruption of cytoplasmic membranes and concomitant degranulation of peritoneal mast cells (MCs). Fluorometric determinations showed an increase in histamine levels in the peritoneal fluid of fighting mice. Administration of NGF antibodies or sialoadenectomy prior to the fighting session blocks MC degranulation. These results, together with other observations, suggest that endogenous NGF plays a physiological role in MC activation.

Aggression↗

PubMed1990

Transesophageal echocardiography for the diagnosis of thoracic aorta aneurysms and dissections.

The diagnosis of acute aortic pathology is decisive for the prognosis of the patient, since an effective surgical and medical therapy can improve the high rate of mortality due to this pathology. Conventional transthoracic echocardiography (TTE) fails to detect abnormalities of the descending thoracic aorta. Aim of this study was the evaluation of the actual usefulness of transesophageal echocardiography (TEE) in the diagnosis of aneurysm (AN) and/or dissection (DISS) of the aorta. Fifty-six consecutive patients with clinical suspicion of AN or DISS underwent TEE. Of these, 24 (42.8%) did not show any abnormality, while 32 (57.2%) had a severe pathology of the aorta requiring angiography (ANG) or cardiac surgery (SURG). All the patients underwent computed tomography scanning examinations (CT) even if TEE did not show any abnormality. The diagnoses obtained by TTE, TEE and CT were compared with those obtained by reference methods (ANG and/or SURG). Non-dissecting aorta aneurysms were detected in 11 patients; dissecting aorta aneurysms were found in 21 patients; 5 patients showed an isolated aortic dissection (without aneurysm). The sensitivity of TTE for detecting pathology of the aorta resulted very low (56.3%) when compared to TEE (96.8%) and CT (90.6%). The specificity for diagnosing aortic pathology was for TTE 63.1%, for TEE 96.0% and CT 88.8%; the accuracy of TTE resulted 75.0%, TEE 98.2% and CT 94.6%; the predictive value of TTE was 85.7%, TEE 96.8% and CT 93.5%. In conclusion, TEE provides a reliable non-invasive diagnosis of AN and/or DISS superior to TTE and CT; it may be considered the method of choice to detect acute aorta pathology.

Adult↗

PubMed1989

NGF primed spleen cells injected in brain of developing rats differentiate into mast cells.

The aim of this work was to study the topographic distribution and the morphological behaviour of nerve growth factor (NGF) primed spleen cells injected into the lateral ventricles of developing rat brain. Serial coronal brain sections showed that these transplanted cells acquire phenotypical characteristics similar to those of mast cells (MCs) and that they enhance local neovascularization. These results, together with the observation that these cells are located in proximity to the hippocampus, a brain tissue which contains one of the highest levels of NGF, provide a model for studying the relationship between NGF and MC differentiation and secretion.

Animals↗

PubMed1989

Nerve growth factor mRNA and protein increase in hypothalamus in a mouse model of aggression.

The effects of intermale aggressive behavior induced by social isolation on the level of nerve growth factor (NGF) mRNA and protein were investigated in central and peripheral mouse tissues. A large increase in NGF mRNA and protein was observed in hypothalamus, with no changes in cerebral cortex, hippocampus, and cerebellum. No change in NGF mRNA levels was found in heart, spleen, vas deferens, and submaxillary salivary gland. The cellular localization of NGF mRNA in the central nervous system was investigated by in situ hybridization. Numerous nerve cells were specifically labeled in preoptic and ventrolateral nuclei of the hypothalamus, as well as in the cornu ammonis region of the hippocampus and throughout all layers of the cerebral cortex, with the highest concentration in layer III. The present results firmly establish that nerve cells constitute the major source in NGF in the brain. They also open the way to understanding the regulation of NGF biosynthesis in the central nervous system.

Aggression↗

PubMed1989

[Clinical usefulness of the Doppler-echocardiographic method for evaluating intracardiac shunts. Combined Doppler and hemodynamic study].

The purpose of this study was to assess the accuracy of a quantitative two-dimensional Doppler echocardiographic method for estimating systemic and pulmonary blood flows in atrial and ventricular septal defects. Twenty-eight patients (mean age 22 +/- 14), with atrial septal defect (ADS) or ventricular septal defect (VSD) underwent Doppler-echocardiography and cardiac catheterization in order to assess pulmonary blood flow (QP), systemic blood flow (QS), the left to right shunt (SH) and the ratio of pulmonary to systemic flow (QP/QS ratio). Cardiac output was also determined by the oximetry method according to Fick principle. Pulmonary output assessed by Doppler was 7.9 +/- 0.61/min, by catheterization 9.0 +/- 3.9. Linear regression analysis showed a low correlation coefficient (r = 0.10; p = NS). Systemic output evaluated by Doppler resulted 4.6 +/- 1.4 l/m, while at catheterization 5.1 +/- 1.5 l/min (r = 0.25; p = NS). Doppler evaluation of left-to right shunt was 3.3 +/- 1.5 l/min, at catheterization 3.9 +/- 3.1 (r = 0.74; p less than 0.001). Doppler QP/QS ratio resulted 1.7 +/- 0.5, at catheterization 1.8 +/- 0.5 (r = 0.96; p less than 0.0010. The results showed that, in spite of the lack of correlation between the pulmonary and systemic outputs assessed by Doppler vs catheterization, QP/QS ratio, as well as SH, are useful noninvasive indexes in order to evaluate intracardiac shunts.

Adolescent↗

PubMed1989

[Gallopamil and chlorthalidone versus atenolol and chlorthalidone in the treatment of obstructive hypertrophic cardiomyopathy in patients with arterial hypertension: polycardiographic evaluation of the systolic and diastolic function of the left ventricle].

In 13 patients, affected by hypertrophic obstructive cardiomyopathy (HOCM) and essential hypertension, antihypertensive-efficacy and effects of a new calcium-channel blocker (gallopamil) associated with a diuretic agent (chlorthalidone) on left ventricular systolic and diastolic performance assessed by phonocardiographic methods. The results were compared to those obtained, in the same group of patients, with a selective beta-blocker (atenolol) associated with the same diuretic agent (chlorthalidone). With both therapeutic regimens a statistically significant reduction of systolic and diastolic arterial pressure was observed; both agents were able to reduce hemodynamic gradient in systole which characterize HOCM; however, the treatment with gallopamil plus chlorthalidone determined greater effects on left ventricular diastolic function as compared to the treatment with atenolol plus chlorthalidone; both treatments determined bradycardia.

Adult↗

PubMed1989

[Effect of coronary revascularization by percutaneous coronary transluminal angioplasty on the diastolic filling of the left ventricle].

Percutaneous transluminal coronary angioplasty (PTCA) is useful to study the cardiac function in patients with coronary artery disease (CAD). Left ventricular (LV) diastolic filling is often altered in CAD and Doppler-echocardiography can be used in order to assess the behavior of LV diastolic filling. Thus, 68 patients, divided into 2 groups (52 with CAD and 16 normal subjects as controls), underwent Doppler-echocardiography to evaluate the following diastolic filling indexes: peak velocity of early- (E) and late- (A) diastolic filling, the velocity-time integrals of early- (VTI E) and late- (VTI A) diastolic filling, the ratios E/A and VTI E/A. The CAD group was divided into 4 subgroups according to the severity of coronary disease. The overall CAD group showed a significant reduction of E/A and VTI E/A when compared to controls (E/A: 1.10 +/- 0.27 vs 1.67 +/- 0.48; p less than 0.001) (VTI E/A: 1.84 +/- 0.43 vs 2.84 +/- 0.82; p less than 0.001). No differences were found between the 4 subgroups. PTCA was performed in 21 patients: 15 successfully and 6 not. The latters did not show significant changes in diastolic filling parameters (E/A: 0.71 +/- 0.21 vs 0.72 +/- 0.25; NS) (VTI E/A: 1.24 +/- 0.31 vs 1.25 +/- 0.43; NS). The other 15 patients showed significant improvement of E/A ratio (1.07 +/- 0.21 vs 1.37 +/- 0.19; p less than 0.01) and VTI E/A (1.78 +/- 0.30 vs 2.31 +/- 0.29; p less than 0.001). In conclusion, LV diastolic filling indexes are significantly altered in patients with CAD and seem reversible after PTCA.

Angioplasty, Balloon, Coronary↗

PubMed1989

[Effectiveness of diltiazem in controlling ventricular response and improving exercise capacity in chronic atrial fibrillation. Double-blind, cross-over study].

Although digoxin is often the drug of choice to control the ventricular response in chronic atrial fibrillation, it fails to control exercise-induced increase in heart rate. The efficacy of diltiazem to control ventricular response and to improve cardiovascular performance during maximal exercise was investigated in 13 digitalized patients with chronic atrial fibrillation. A placebo controlled prospective randomized double-blind study, was preceded by open titration phase. During the diltiazem treatment phase, mean ventricular response diminished at rest (85 +/- 12 versus 107 +/- 19 during digoxin therapy and versus 101 +/- 18 during digoxin and placebo therapy; p less than 0.001), as well as during maximal exercise (142 +/- 13 versus 159 +/- 17 during digoxin treatment and versus 160 +/- 14 during digoxin plus placebo treatment; p less than 0.001). During exercise (50 W), in a subgroup of 7 patients, mean ventricular rate dropped: 109 +/- 19 versus 142 +/- 21 during digoxin treatment and versus 143 +/- 17 during digoxin plus placebo treatment; p less than 0.001). In all patients, the mean rate at rest decreased about 19.3 +/- 6.9% and at maximal exercise about 10.3 +/- 4.9%. In the subgroup of the 7 patients ventricular mean rate at a load of 50 W decreased about 23.6 +/- 7.9%. In all the patients, maximal exercise capacity improved: the MET mean value increased from 3.59 +/- 1.3 to 4.52 +/- 1.18 (p less than 0.001); the mean value of the maximum exercise (MEC), according to the Redfords formula, increased from 65 +/- 48 to 132 +/- 70 (p less than 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)

Atrial Fibrillation↗