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Biomedical subjects

B Marino

Publications and source records attributed to B Marino.

At least 163 records · Page 9Linked to original sources
PubMed1994

Congenital cardiac defect in a patient with mosaic 45,X/46,XX,i(21q) karyotype.

A baby is described with 45,X/46,XX,i(21q) mosaicism. DNA analysis indicated that the abnormality arose from two independent postzygotic mutations in a 46,XX zygote, involving the paternal chromosomes 21 and X. In agreement with previous reports, most of the clinical dysmorphisms observed were consistent with Down syndrome. Moreover, congenital heart disease consisted of an atrioventricular canal associated with slight hypoplasia of the left ventricle and a mitral anulus, a complex defect including features found in both Down and Turner syndromes.

Chromosome Aberrations↗
PubMed1994

[The effect on left ventricular mass of treatment with amlodipine and diet therapy in obese patients with arterial hypertension].

Increased parietal stress, in hypertensive obese patients, produces a left ventricular hypertrophy. In this study we demonstrated that the association of amlodipine with hypocaloric diet can decrease the parietal stress. MATERIALS AND METHODS. From February to July 1993 32 hypertensive obese patients (17 males, 15 females) were treated with amlodipine 10 mg/day for six months. Sixteen patients were treated with amlodipine 10 mg/day (Group A) and 16 patients were treated with amlodipine 10 mg/day and hypocaloric diet (Group B). All patients included had a Body Mass Index > 30 and diastolic blood pressure > 100 mmHg. The patients were studied with 2D guided M-mode echocardiogram before treatment and after 6 months. RESULTS. In Group A the septal thickness, the posterior wall thickness and the left ventricular mass decreased significatively (p < 0.05). In the Group B also the left ventricular diastolic diameter and the left atrial diameter decreased. CONCLUSION. The association of a hypocaloric diet with amlodipine therapy, in hypertensive obese patients, improves the effect of the drug on ventricular hypertrophy.

Amlodipine↗
PubMed1994

Pretreatment with the adenosine triphosphate-sensitive potassium channel opener nicorandil and improved myocardial protection during high-potassium cardioplegic hypoxia.

We hypothesized that pretreatment with the potassium channel opener nicorandil might enhance myocardial protection achieved by cold (20 degrees C) high-potassium (16 mmol/L) cardioplegia (5 ml/min) during long-duration (120 minutes) myocardial hypoxia (average oxygen content 5.4 ml/dl). We tested a 15-minute infusion of nicorandil (1 mmol/L) given only before (group A, n = 8) or before and during cardioplegia (group B, n = 8) in guinea pig papillary muscle preparations contracting isometrically while stimulated (4 mA, 2 msec) at 1600 msec cycle length. Nicorandil was significantly negative inotropic before cardioplegia and shortened significantly action potential duration. During cardioplegia, time to arrest of contraction was shortened from 145 +/- 28 seconds (mean +/- standard error) in the vehicle group (dimethyl sulfoxide 1:100; n = 8) to 56 +/- 10 seconds (p < 0.02) and 68 +/- 5 seconds (p < 0.05) in groups A and B, respectively. Recovery of developed tension at 60 minutes of normothermic reoxygenation (expressed as percent of prehypoxia basal value) was ameliorated from 54% +/- 6% (vehicle group) to 92% +/- 4% (group A, p < 0.01) and to 119% +/- 19% (group B, p < 0.01). The specific potassium channel blocker glibenclamide (glib: 1 mumol/L, n = 8) prolonged action potential duration and was without effect on time to arrest. On reoxygenation, the glib group had prolonged time to half relaxation (versus group A, p < 0.02) and the worst percent developed tension at 60 minutes (40% +/- 4%). In the overall study, time to arrest and percent developed tension at 60 minutes were inversely correlated (r = -0.45, p < 0.01). Arrhythmias were never observed. Multivariate analysis showed that pretreatment with nicorandil (with or without drug adjunct to cardioplegic solution) was a significant factor (r2 = 0.65, p = 0.0001) to influence reoxygenation-mediated recovery of mechanical function. Neither the negative inotropic effect of nicorandil before cardioplegia nor its abbreviating action on time to arrest during cardioplegia was contributory to explain recovery of function on reoxygenation. In subgroup analysis, negative inotropism and the shortening of action potential duration were contributory factors. These data suggest that nicorandil pretreatment activates potassium channels and enhances the myocardial protection provided by cold cardioplegia an effect, which is evident after a long hypoxic period, late on reoxygenation.

Action Potentials↗
PubMed1993

Risk of congenital heart defects in relatives of patients with atrioventricular canal.

OBJECTIVE: To investigate the overall occurrence of congenital heart disease in 103 pedigrees with a proband affected with atrioventricular canal. DESIGN: Family study of patient series. SETTING: Department of Pediatric Cardiology, Bambino Gesu' Hospital, Rome, Italy. PARTICIPANTS: One hundred three consecutive patients with atrioventricular canal and normal karyotype and their first- and second-degree relatives. INTERVENTIONS: None. MEASUREMENTS/MAIN RESULTS: In 12 pedigrees (11.7%), one or more relatives had concordant or discordant congenital heart disease. Congenital heart disease occurred in four (1.9%) of the 206 parents of probands, in four (3.6%) of the 111 siblings, and in five (0.8%) of the 644 uncles or aunts. None of the grandparents had congenital heart disease. Atrioventricular canal affected several family members in five pedigrees. CONCLUSIONS: Familial aggregation of atrioventricular canal in several pedigrees requires careful collection of family histories, accurate cardiologic evaluation of the first- and second-degree relatives of the probands, and fetal echocardiography in all pregnant women in at-risk families.

Adolescent↗
PubMed1993

Twenty-four-hour pattern of atrial natriuretic peptide in heart transplantation: evidence for lack of circadian rhythm. Temporal inter-relationships with plasma renin activity, aldosterone and cortisol.

We have investigated the circadian rhythm of plasma atrial natriuretic peptide in 13 stable output heart transplanted patients, all without evidence of histological rejection and cardiac impairment, following antirejection therapy with Cyclosporine, Azathioprine and Prednisone. The 24-h pattern of plasma renin activity, plasma aldosterone and plasma cortisol has been studied as well. All the investigated variables were assayed six times over the 24-h span. The circadian time-qualified data were analyzed by ANOVA and Cosinor method. The 24-h mean levels of atrial natriuretic peptide, plasma renin activity and plasma aldosterone are significantly increased, while the concentrations of plasma cortisol are reduced in the heart transplanted recipients. ANOVA detected a significant within-day variability of all these humoral variables only in healthy subjects. A statistically significant circadian rhythm was validated by Cosinor procedure for all the investigated molecules in healthy subjects but not in heart transplanted patients. In our opinion, the increase of atrial natriuretic peptide is a counterregulatory mechanism aimed to compensate the cyclosporine-mediated activation of the renin-angiotensin-aldosterone system. The disappearance of the plasma renin activity, aldosterone and atrial natriuretic peptide circadian rhythm can be ascribed to the constant activation of the renin-angiotensin-aldosterone system. The hypocortisolism is due, in our opinion, both to glucocorticoid therapy and increase of plasma ANP concentration.

Adult↗
PubMed1993

Congenital heart disease in patients with Down's syndrome: anatomic and genetic aspects.

The frequency of congenital heart disease in children with Down's Syndrome is high and ranges between 40 and 50% of cases. It was evident for many years that patients with trisomy 21 present certain congenital heart defects (atrioventricular canal, ventricular septal defect, tetralogy of Fallot) and seem to be "protected" from others (situs inversus and situs ambiguus, ventricular inversion, transposition of the great arteries). Recent observations also suggest that left-sided obstructive lesions and the muscular ventricular septal defect are very rare. The role of a suspected "increased adhesivanes of trisomy 21 cells" and of the anomalies of neutral crest needs to be investigated. The interaction between studies of clinicians and basic research will improve the knowledge of these genetically determined heart defects.

Down Syndrome↗
PubMed1993

Mechanisms of incomplete cardioplegia distribution during coronary artery surgery. An intraoperative transesophageal contrast echocardiography study.

BACKGROUND: Cardioplegia is used to protect the myocardium from ischemic injury during open-heart surgery. However, the delivery of cardioplegic solutions may be impaired by anatomic and/or functional conditions, such as the development of transient aortic regurgitation during antegrade administration of cardioplegia or shunting through a foramen ovale during retrograde administration. In this study, the authors used a new method of cardioplegia administration, based on intraoperative contrast echocardiography, to detect on-line causes of inadequate cardioplegia delivery. METHODS: Forty patients with coronary artery disease and a competent aortic valve, who were treated consecutively, were enrolled in this study. Patients were monitored intraoperatively by transesophageal contrast echocardiography during cardioplegia delivery. Antegrade cardioplegia was administered into the aortic root following aortic occlusion in all patients. Twenty-two patients also received retrograde cardioplegia, administered through the right atrium. The echo-contrast agent consisted of a stable suspension of 5% human albumin microbubbles with a concentration of 4 x 10(8) microbubbles/ml and a diameter of 4 +/- 1 mu. RESULTS: Antegrade cardioplegia was not associated with aortic regurgitation in 23 of 40 (58%) patients. Seven patients (17%) had only mild aortic regurgitation, four patients (10%) had moderate regurgitation, and six (15%) had severe aortic regurgitation. The percent of myocardial opacification was 76.0 +/- 10.5 in the 23 patients who did not have aortic regurgitation, 76.0 +/- 17.0 in the 7 patients who had mild regurgitation, 52.5 +/- 18.1 in the 4 patients who had moderate regurgitation, and 48.5 +/- 18.3 in 6 patients who had severe aortic regurgitation (Kruskal-Wallis stat, 12.9; P < 0.005). Retrograde cardioplegia was not associated with right-to-left shunt in 11 of 22 patients (50%). In seven patients (32%), there was only a mild passage of contrast material to the left atrium. In the remaining four patients (18%), there was a moderate (one patient) to severe (three patients) right-to-left shunt at the level of the fossa ovalis. CONCLUSIONS: This study shows that incomplete myocardial distribution of cardioplegia, secondary to transient aortic valve incompetence or shunting through the foramen ovale, is not uncommon in patients undergoing coronary surgery.

Cardioplegic Solutions↗
PubMed1993

Lack of circadian rhythm of plasma concentrations of vasoactive intestinal peptide in patients with orthotopic heart transplants.

OBJECTIVE: To study the circadian pattern of plasma concentrations of vasoactive intestinal peptide (VIP) in patients with orthotopic heart transplants. Circulating VIP is known to have neural and immunological sources. PATIENTS AND METHODS: 13 patients with orthotopic heart transplants were studied 12-53 months (mean 31.8 months) after operation. All were haemodynamically compensated and had no histological evidence of rejection. They were being treated with cyclosporin, azathioprine, and prednisone. Ten healthy individuals were studied as controls. Circulating VIP was assayed six times within a 24h period. Time qualified data were analysed by ANOVA and the cosinor method. Student's t test for unpaired data and Bingham's test for cosinor-derived parameters were used for statistical comparisons. RESULTS: Plasma concentrations of VIP were lower in the patients with orthotopic heart transplants than in the controls (p < 0.001). ANOVA and the cosinor method respectively showed a statistically significant within-day variability and circadian rhythm in the controls but not in the patients with heart transplants. DISCUSSION: The low plasma concentrations of VIP in the patients with heart transplants could be the result of the lack of contribution by the cardiac VIPergic fibres, a reduction of VIP release by the pharmacologically suppressed immune system, the inhibitory effects of cyclosporin on neural function and humoral secretions, and the effects of negative feedback on VIP release of high concentrations of atrial natriuretic peptide. The lack of the circadian rhythm suggests a structural disorder, which should be further investigated.

Adult↗