Publications by authors named "Alfonso A"

D-Glucose uptake in isolated rabbit enterocytes was studied using confocal microscopy and 2-[N-(7-nitrobenz-2-oxa-1,3-diazol-4-yl)amino]-2-deoxy-D-glucose (2-NDBG), a D-glucose fluorescent analogue, by analysing the fluorescence of apical and basal enterocyte zones. Under normal conditions, apical fluorescence was always higher than basal, presumably due to the location of the Na+-D-glucose cotransporter in the brush-border membrane. After blocking this transporter with phlorizin, apical and basal fluorescence values were similar.

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We have studied the effect of the ciguatera-related toxin maitotoxin (MTX) on the cytosolic free calcium concentration ([Ca(2+)]i) of human peripheral blood lymphocytes loaded with the fluorescent probe Fura2 and the regulation of MTX action by different drugs known to interfere in cellular Ca(2+) signalling mechanisms and by the marine phycotoxin yessotoxin (YTX). MTX produced a concentration-dependent elevation of [Ca(2+)]i in a Ca(2+)-containing medium. This effect was stimulated by pretreatment with YTX 1 microM and NiCl(2) 15 microM.

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The early events related to intracellular signals after prolactin (PRL) activation in T lymphocytes are not clearly established. The aim of this work was to study the effect of PRL in cytosolic calcium levels in human T lymphocytes. By using the dye FURA-2 AM, the variations in cytosolic Ca(2+) were studied in peripheral human T lymphocytes isolated from extracted blood from healthy donors.

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The digitalic glicoside ouabain induces potentiation of rat mast cell histamine release in response to several stimuli, which is mediated by Na+/Ca2+ exchanger. In this work, we studied the effect of ouabain on cytosolic calcium, intracellular pH and histamine release with Ca2+ ionophore A23187 in conditions designed to maximize ouabain-induced potentiation of rat mast cells response. The effect of protein kinase C (PKC), cAMP and phosphatase inhibition was also tested.

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Background: This study compares the hemodynamic performance of stented and stentless bioprostheses used for aortic valve replacement in patients with aortic stenosis and small aortic root.

Methods: Between 1995 and 1998, 37 patients with a 21-mm aortic annulus (group 1) underwent aortic valve replacement with either a 21-mm Edwards Perimount or a 23-mm St. Jude Toronto bioprosthesis whereas 47 patients with a 23-mm aortic annulus (group 2) received either a 23-mm Medtronic Mosaic or a 25-mm Edwards Prima bioprosthesis.

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A series of 1H-pyrazolo[3,4-d]pyrimidines (3--6) substituted at positions 1 (R(1)=Ph, H, tert-butyl and ribosetribenzoate), 4 (R(2)=chlorine, nitrogen and oxygen nucleophiles), and 6 (dimethylamino) have been synthesized and their effect on the release of histamine from rat peritoneal mast cells measured. After chemical stimulation, (polymer 48/80), several compounds (i.e.

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Coeliac disease (CD) is a malabsorptive disorder of the small intestine resulting from ingestion of gluten. The HLA risk factors involved in CD are well known but do not explain the whole genetic susceptibility. Several regions of potential linkage on chromosomes 3q, 5q, 10q, 11q, 15q and 19q have already been reported in the literature.

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Yessotoxin (YTX) is a polyether toxin of marine origin that has been classified among the diarrheic shellfish poisoning (DSP) toxins group due to its lipophilic nature. However, unlike other DSP toxins, YTX does not produce diarrhea and its mechanisms of action are unknown. We studied the effect of YTX on the cytosolic calcium levels of freshly isolated human lymphocytes by means of fluorescence imaging microscopy.

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In a sham-controlled design (n = 12), slow repetitive transcranial magnetic stimulation (rTMS) was applied to the right dorsolateral prefrontal cortex for 20 min, and the subsequent effects on mood and the EEG spectrum were investigated, Analysis revealed a significant left hemisphere increase in EEG theta activity at 25-35 and 55-65 min after stimulation. In addition, participants reported significant decrease in anxiety immediately after stimulation, as well as 35 and 65 min after rTMS. These findings indicate that reductions in anxiety after slow rTMS at the right dorsolateral prefrontal cortex are associated with a contralateral increase in theta activity.

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Many authors have pointed out that sexual activity is starting at an increasingly early age in young adolescents. In 1990 pregnancies in under 15-year-olds in the United States accounted for 3% of the total, a figure that has increased by 13% over the past decade. Moreover, pregnancy in adolescence may result in a number of complications, including pre-term birth, PIH, sexually transmitted diseases.

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Calciphylaxis is a complication caused by secondary hyperparathyroidism in patients with chronic renal failure. These patients may present with clinical findings of ischemic necrosis involving the skin and muscle resulting in subsequent gangrene and vascular calcifications. We report a rare case of necrotizing mastopathy caused by calciphylaxis in a 70-year-old female with end-stage renal disease whose symptoms resolved with a total parathyroidectomy.

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In a non-isotonic environment, cells can shrink or swell and return to their normal shape by activating ion transport pathways. Changes in intracellular pH (pHi) after osmotic stress have been identified in several cells. In order to study the mechanisms that regulate cytosolic pH of rat mast cells in a hypertonic medium, we used the pH sensitive dye, BCECF.

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Stimulation of lymphocytes by specific antigens is followed by the activation of different signal transduction mechanisms, such as alterations in the cytoplasmic levels of Ca(2+), H(+) and variations in membrane potential. To study interrelationships among these parameters, changes in pHi and Ca(2+) were measured with the fluorescent probes BCECF and Fura-2 in freshly isolated blood human lymphocytes. Moreover, membrane potential qualitative alterations were recorded with the fluorescent dye bis-oxonol.

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Objective: In the last years has been a progressive increase of tabagism in the female sex. This study wanted to examine the influence of the pregnancy on voluntary practices and especially on smoking.

Patients And Methods: 140 women with a mean age of 33.

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The aim of this work was to study the relationship between intracellular alkalinization, calcium fluxes and histamine release in rat mast cells. Intracellular alkalinization was induced by nigericin, a monovalent cation ionophore, and by NH(4)Cl (ammonium chloride). Calcium cytosolic and intracellular pH were measured by fluorescence digital imaging using Fura-2-AM and BCECF-AM.

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Background: It has been reported that a high consumption of alcohol during pregnancy is correlated to fetal alcohol syndrome and other perinatal problems. Less is known about the effects linked to moderate and limited drinking during pregnancy.

Methods: A study was carried out in 140 pregnant women: the mean age was 33.

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The effects of high-frequency repetitive transcranial magnetic stimulation (rTMS) at the left or right posterior parietal cortex were studied using a spatial working memory task. Eight subjects were stimulated over the P3 and P4 electrode site at 115% of the motor threshold (frequency 25 Hz, trains of 200 ms) during the 1000-ms delay of the spatial working memory task, or received sham stimulation. It was found that the reaction times were slower during right-parietal rTMS than during left-parietal rTMS.

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The crosstalk between 3', 5'-cyclic adenosine monophosphate (cAMP), intracellular calcium, and histamine release in rat mast cells using the stimulatory effect of three different drugs, thapsigargin, sodium fluoride (NaF), and compound 48/80 were studied. Each of these drugs induces histamine release by different mechanisms. The transducting pathways modulating cAMP and intracellular calcium levels were modified by using, cholera toxin (CTX) which ADP-rybosylates Gs-protein, pertussis toxin (PTX) which ADP-rybosylates Gi-protein, and okadaic acid (OA) which inhibits phosphatases 1 and 2a.

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Purpose: Younger or older age has a significant impact on the outcome of patients with head and neck cancer. However, the data regarding outcomes based on age are conflicting. The aim of this article is to determine the impact of age on the outcome of laryngeal cancer.

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Recently, several experiments have indicated that the left and right prefrontal cortex (PFC) are differently involved in emotional processing. The aim of this study was to investigate the role of the left and right PFC in selective attention to angry faces by using a pictorial emotional Stroop task. Slow repetitive transcranial magnetic stimulation (rTMS) was applied to the left and right PFC of 10 female subjects for 15 min on separate days.

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Background: Over the past few years numerous techniques have been developed, allowing an evaluation of fetal physiopathology that was unthinkable until recently. The authors describe 20 cases of fetal malformations and chromosomal abnormalities diagnosed by scan and amniocentesis at the Centre for Diagnosis and Obstetric Prophylaxis at L'Aquila University.

Methods: Between January 1995 and April 1998 a total of 1180 amniocentesis and 4000 obstetric scans were performed in a group of 1650 pregnant women.

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The fluorescent probe FM1-43 has been used extensively for imaging vesicle recycling; however, high nonspecific adsorption resulting in elevated background levels has precluded its use in certain tissues, notably brain slices. We have found that a sulfobutylated derivative of beta-cyclodextrin (ADVASEP-7) has a higher affinity for FM1-43 than the plasma membrane. ADVASEP-7 was used as a carrier to remove FM1-43 nonspecifically bound to the outer leaflet of the plasma membrane or extracellular molecules, significantly reducing background staining.

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Background And Aim Of The Study: In asymptomatic prosthetic valve recipients, high-intensity transient signals (HITS) observed with transcranial Doppler (TCD) are a phenomenon of obscure clinical relevance which nature has not yet been elucidated convincingly.

Methods: Eighty-three patients without carotid disease, history of cerebrovascular accidents, and with negative preoperative TCD undergoing either valve replacement (mitral, n = 11; aortic, n = 56; mitral + aortic, n = 6; 40 mechanical prostheses, 29 biological prostheses, 10 homografts) or mitral repair (n = 10) were evaluated prospectively by means of TCD at discharge, three months and one year after surgery, to analyze the presence, incidence and characteristics of HITS. Furthermore, in 12 patients positive for HITS, TCD was repeated during a 30-min period of 100% O2 inhalation.

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