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G Santoro

Publications and source records attributed to G Santoro.

At least 109 records · Page 6Linked to original sources
PubMed1996

Immunolocalization of the costameres in human skeletal muscle fibers: confocal scanning laser microscope investigations.

BACKGROUND: The costameres in skeletal muscle fibers were first described by Pardo et al. (1983a) and have been defined as transverse circumferential elements of the cytoskeleton associated to the sarcolemma. Specific immunostaining for vinculin shows that the costameres overlie I bands. However, an exact correlation between the costameres and the Z line is uncertain, although approximately 10 proteins so far have been localized in the costameres. To define the exact localization of costameres in human skeletal muscle fibers, we carried out an immunofluorescence study using confocal scanning laser microscopy on the fascia lata muscle of adult males. METHODS: Samples were fixed in 3% paraformaldehyde; frozen sections were treated with antivinculin, antitalin, antidesmin, and anti-alpha-actinin, then immunostained with TRITC. For double localization, the TRITC-streptavidin, as a marker for vinculin and FITC-streptavidin a marker for desmin, were used. RESULTS: The distance between two subsequent transverse lines of actininf indicated that muscle fibers were well stretched. Processing, with different software functions of the images obtained using CLSM, shows that vinculin and talin are only present in the sarcolemmal lattice. Immunostaining for vinculin and double immunostaining for vinculin and desmin demonstrate that costameres superimpose underlying I bands without interruption at the Z line. Immunostaining for talin showed that the protein is located in correspondence with the I band and M line. CONCLUSIONS: We believe that costameres are "proteic machinery." The findings of the present study suggest that it is possible to determine the width and the period of each proteic component. In addition, we indicate that costameres are present in correspondence with M line.

Actinin↗
PubMed1996

Patient selection for repair of complete atrioventricular canal guided by echocardiography.

OBJECTIVE: Two-dimensional, Doppler and color-flow echocardiography is accepted as a safe diagnostic tool to guide the surgical treatment of certain congenital heart defects. Its role for surgical indication in patients with complete atrioventricular canal (cAVC) is described in this paper. METHODS: Between July 1989 and January 1995, 80 patients with cAVC underwent primary repair in our Institution. In 73 surgery was guided only by echocardiography (Group I), while in the remaining 7 patients (Group II) cardiac catheterization was performed because of unclear diagnosis and/or suspected associated malformations. RESULTS: Echocardiography showed an overall sensitivity of 100% and specificity of 93% in detecting associated malformations. DISCUSSION: Based on these data and on the knowledge of the natural history of pulmonary vascular changes in patients with cAVC we think that echocardiography might be adequate for selection of infants with uncomplicated forms of cAVC for primary repair.

Child, Preschool↗
PubMed1996

Left ventricular function during exercise in athletes and in sedentary men.

Aim of this study was to evaluate left ventricular function during exercise in 10 male elite runners and in 10 sedentary males. End-diastolic (EDV) and end-systolic volume (ESV), left ventricular ejection fraction (EF), early peak transmitral flow velocity (peak E), time-velocity integral of mitral inflow (m-TVI); mitral cross sectional area (m-CSA); mitral stroke volume (SV), and cardiac output (CO) were measured by echo-Doppler. We simultaneously analyzed: VO2max by spirometric method, mean arterial blood pressure (MAP) by sphygmomanometer, and heart rate (HR) by ECG. The parameters were measured under basal conditions (level 1), at 50% of maximal aerobic capacity (level 2), at peak of exercise (level 3) and during recovery. Ejection fraction in athletes increased significantly at peak of exercise through Frank-Starling mechanism. Stroke volume and cardiac output increased significantly in athletes at peak of exercise. Left ventricular diastolic function was superior in athletes versus controls: in fact, higher peak E in athletes enhanced early diastolic ventricular filling. Therefore, the athletes showed complex cardiovascular adjustments induced by training, which allowed an higher peak working power, a greater cardiac output, and VO2max when compared with an untrained control population.

Adult↗
PubMed1996

[Intraoperative stent implantation in congenital stenosis of pulmonary veins].

Congenital stenosis and/or hypoplasia of the pulmonary veins(s) is a rare cardiac malformation, whose treatment is difficult and not well defined, so conditioning an extremely poor prognosis. In fact, balloon angioplasty and surgery proved to be ineffective during a mid-term follow-up, thus not significantly modifying the natural history of this cardiovascular malformation. Although heart-lung transplantation is thought by someone to be the sole reliable treatment for congenital stenosis of the pulmonary vein(s), a recently available therapeutic option, the endovascular "stent" implantation during cardiac catheterization prompted to hope for a better outlook for these patients. However, this procedure is far from being an easy approach, due to technical problems that cause a high rate of failure and major complications. We report on two cases of pulmonary vein stenosis successfully treated by endoluminal "stent" implantation during open heart surgery, and suggest, and suggest that this safe and effective approach might be an alternative therapeutic option in the definitive or palliative treatment of this congenital cardiovascular malformation.

Constriction, Pathologic↗
PubMed1996

Structure-activity relationships for SNC80 and related compounds at cloned human delta and mu opioid receptors.

The racemic compound (+/-)-BW373U86 ¿(+/-)-4-((alpha R*)- alpha-((2S*,5R*)-4-allyl-2,5-dimethyl-1-piperazinyl)-3-hydroxy- benzyl)-N,N-diethylbenzamide dihydrochloride} is a potent delta opioid receptor agonist in the mouse vas deferens assay with little mu or kappa opioid receptor activity in the guinea pig ileum tissue preparation. In contrast, radioligand binding studies show that (+/-)-BW373U86 is only about 10-fold selective for delta over mu opioid receptors. Studies of the enantiomeric forms of (+/-)-BW373U86 and derivatives (SNC80 and related compounds) show that some of these isomers are significantly better in both receptor binding and pharmacological selectivity than (+/-)-BW373U86. In this study we have determined the binding affinities of 10 different SNC80-related compounds at cloned human delta and mu opioid receptors and measured the potency of SNC80 for the inhibition of forskolin-stimulated adenylyl cyclase. The most selective delta receptor ligand (SNC162) differed from SNC80 by the absence of the 3-methoxy substitution of the benzyl ring. The Ki for SNC162 at the delta receptor (0.625 nM) was over 8700-fold lower than that at the mu receptor (5500 nM), making this the most selective delta receptor ligand available. Reduction of the allyl side chain of SNC80 to produce radiolabeled [3H]SNC121 allowed direct measurement of the association and dissociation rate constants. SNC80 was 26-fold less potent than [D-Pen2, pCI-Phe4, D-Pen5]enkephalin in the delta receptor adenylyl cyclase inhibition assay, but showed full agonist activity with an EC50 value of 9.2 nM. The regulation of SNC80 binding affinity to the delta receptor by GTP analogs is undetectable in [3H]naltrindole binding inhibition studies, but direct binding studies with [3H]SNC121 in the presence of 100 microM 5'-guanylylimidotriphosphate show a 55% reduction in maximum binding site density consistent with a lower affinity for a part of the receptor population. Addition of 120 mM sodium chloride reduces SNC80 affinity nearly 40-fold in [3H]naltrindole binding inhibition studies. The results of these studies define specific structural features of these compounds responsible for opioid receptor interactions and suggest a possibly novel mechanism for delta receptor activation.

Animals↗
PubMed1996

[Myocardial lipofuscinosis of unknown etiology in a young asymptomatic woman].

An asymptomatic 32-year-old woman was examined because of a family history of unexplained sudden deaths and a left ventricular strain pattern of the ECG during a routine examination. No abnormal finding of the cardiovascular system was present but an endomyocardial biopsy showed focal interstitial fibrosis, myocyte hypertrophy with heavy perinuclear accumulation of lipofuscin. The cause of these abnormalities remains unknown.

Adult↗
PubMed1996

Type B aortic dissection involving an isolated right-sided aortic arch.

We report a case of a 48-year-old man in whom type B aortic dissection in the right aortic arch and right descending aorta was diagnosed by transesophageal echocardiography and computed tomographic scan. Angiography was necessary to define the anatomy of the branching vessels. The patient was successfully treated by interposition of a Vascutek 24-mm Dacron woven tube with a right posterolateral thoracotomy approach. Circulatory arrest in profound hypothermia and cerebral retroperfusion were used.

Aortic Dissection↗
PubMed1995

Hypertrophic cardiomyopathy in Tuscany: clinical course and outcome in an unselected regional population.

OBJECTIVES: Our aim was to study a population of patients with hypertrophic cardiomyopathy from the well defined geographic region of Tuscany in central Italy, a group virtually free of selective referral bias and therefore probably closely representative of the true patient population with this disease. BACKGROUND: Most available information on clinical course, natural history and prognosis of hypertrophic cardiomyopathy is based on data generated from tertiary referral centers and therefore constitutes a potentially biased perspective of the disease process in this complex and diverse condition. METHODS: The study group comprised 202 patients aged 1 to 74 years (mean +/- SD 41 +/- 17) at initial diagnosis and followed up for 1 to 30 years (mean 10 +/- 5). RESULTS: Largely with the use of single or multiple drug therapy, the vast majority of patients (n = 154 [76%]) were asymptomatic or mildly symptomatic and in stable or improved condition over the period of follow-up, whereas the remaining patients (n = 48 [24%]) experienced deterioration, had substantial functional impairment or died. Of the 13 patients (6%) who died of cardiovascular causes related to hypertrophic cardiomyopathy, 11 had progressive congestive heart failure (including 6 in the end-stage phase) and only 2 died suddenly. The annual mortality rate for cardiovascular disease was 0.6% and that due to sudden cardiac death was only 0.1%; the cumulative survival rate was 97%, 95% and 92%, respectively, at 5, 10 and 15 years of follow-up. Atrial fibrillation proved to be a relatively common (n = 57 [28%]) and particularly unfavorable clinical feature, with premature death occurring in 9 of the 57 patients. The cumulative survival rate after 15 years was 76% for patients with atrial fibrillation versus 97% for patients with sinus rhythm. Syncope occurred in 33 patients (16%) but did not appear to be of prognostic significance. CONCLUSIONS: In an unselected regional population, hypertrophic cardiomyopathy had a relatively benign prognosis inconsistent with its prior characterization as a generally progressive disorder, based primarily on the experience of selected referral institutions. Sudden unexpected cardiac death was distinctly uncommon, although a sizable proportion of patients (particularly the subset prone to atrial fibrillation), did experience clinical deterioration.

Adolescent↗
PubMed1995

Human delta opioid receptor: a stable cell line for functional studies of opioids.

A human delta opioid receptor cDNA clone (pREP10/hDOR) was transfected into Chinese hamster ovary (CHO) cells. The stable cell line expressed a high density of delta opioid receptors (137,000 +/- 21,600 receptors/cell). DPDPE inhibited 90% of the forskolin-stimulated cAMP accumulation in these cells with high potency (EC50 = 1.3 nM). This effect of DPDPE was antagonized by naltrindole. The pseudo-pA2 value (Ke) of 155 pM for naltrindole is consistent with that measured for delta receptor antagonism in the mouse vas deferens. This is the first detailed characterization of DPDPE activity on forskolin-stimulated cAMP accumulation mediated through a human delta opioid receptor. The data support the use of the recombinant cell line for functional studies of opioid drugs.

Animals↗
PubMed1995

Isolated atrial inversion in situs inversus: a rare anatomic arrangement.

Isolated atrial inversion in situs inversus is a rare congenital cardiac malformation. Its physiology resembles transposition of great vessels, and the best option for its surgical treatment is the atrial switch operation. In this article, we present a case of isolated atrial inversion in concordance with visceral situs inversus diagnosed at birth by echocardiography and cardiac catheterization, which was successfully treated at 8 months of age by a Senning procedure.

Coronary Circulation↗
PubMed1995

Origin of both coronary arteries from the pulmonary artery and aortic coarctation.

Single trunk anomalous origin of both coronary arteries from the pulmonary artery is a rare congenital cardiac anomaly. We report on 2 cases of its association with aortic coarctation, the diagnosis of which in living patients is very difficult. We think that the possibility of this anatomic arrangement should always be considered in patients with isolated aortic coarctation whose clinical condition seems impaired rather than improved after an apparently successful coarctectomy.

Aortic Coarctation↗
PubMed1995

Biochemical and functional identification of GABA receptors in Hydra vulgaris.

GABA binding sites labelled in vitro with [3H]GABA are present in crude membrane preparations from Hydra vulgaris. [3H]GABA binding is specific (70%), saturable and it is completely displaced by the GABA mimetic muscimol but not by bicuculline or baclofen. Scatchard analysis of saturation data indicates the presence of only one population of binding sites with a Bmax of 4, 75 pmol/mg of protein and a KD of 76 nM. In the living animal GABA and benzodiazepines increase the duration of mouth opening during the glutathione-induced feeding response. Bicuculline prevents the GABA-induced increase of the feeding response. Diazepam activity is enhanced by simultaneous GABA administration and it is suppressed by the specific antagonist flumazenil. In contrast, no [3H]-flunitrazepam binding is detected in membrane preparations. We conclude that a population of GABA receptors is present in Hydra tissues, where they are involved in the modulation of response to chemical stimulation.

Animals↗