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A Rubino

Publications and source records attributed to A Rubino.

At least 37 records · Page 2Linked to original sources
PubMed1996

Evidence for a P2-purinoceptor mediating vasoconstriction by UTP, ATP and related nucleotides in the isolated pulmonary vascular bed of the rat.

1. The vasoconstrictor effects of uridine 5'-triphosphate (UTP), uridine 5'-diphosphate (UDP), uridine 5'-monophosphate (UMP) and uridine were tested in the isolated pulmonary vascular bed of the rat. Comparison was made with the effects of adenine nucleotides, adenosine 5'-triphosphate (ATP), adenosine 5'-diphosphate (ADP), adenosine 5'-monophosphate (AMP) and with adenosine. The effect of P2x-purinoceptor desensitization and blockade was compared on the vascular responses to uracil and adenine nucleotides. 2. At doses ranging from 10(-8) to 10(-5) mol, UTP elicited dose-dependent vasoconstriction. UDP was equiactive to UTP, while UMP and uridine did not show vasomotor activity. Similarly, ATP showed dose-related vasoconstrictor activity. ADP was less potent than ATP in eliciting vasoconstriction, while AMP was active only at the higher doses tested and adenosine was ineffective. 3. Vasoconstriction was produced by ATP analogues with the following order of potency: alpha, beta-methylene ATP > ATP gamma S > beta, gamma-methylene ATP > 2-methylthio ATP > or = ATP. 4. Desensitization of P2x-purinoceptors by the selective agonist alpha, beta-methylene ATP did not modify the vasoconstrictor activity of UTP and UDP and only partially reduced vasoconstrictor responses to ATP, while it abolished vascular responses to alpha, beta-methylene ATP itself. 5. The antagonists of P2-purinoceptors, suramin and pyridoxalphosphate-6-azophenyl-2', 4'-disulphonic acid (PPADS), did not affect vascular responses to UTP and UDP, but reduced vasoconstriction evoked by beta, gamma-methylene ATP and ATP by about 70 and 30%, respectively. 6. This study demonstrates that uracil nucleotides, UTP and UDP, elicit vasoconstriction in the rat pulmonary vascular bed. In addition to confirming the presence of classical P2x-purinoceptors, these results also suggest the presence of a distinct purinoceptor subtype which mediates UTP- and ATP- evoked vasoconstriction in the rat pulmonary circulation.

Adenosine Triphosphate↗
PubMed1996

Augmented sensory-motor vasodilatation of the rat mesenteric arterial bed after chronic infusion of the P1-purinoceptor antagonist, DPSPX.

1. The effect of long-term antagonism of P1-purinoceptors on vascular function was examined in the perfused mesenteric arterial bed isolated from rats which had received constant infusion of either the non-selective P1-purinoceptor antagonist, 1-3-dipropyl-8-sulphophenylxanthine (DPSPX, 30 micrograms kg-1 h-1, i.p.) or saline for seven days. Sympathetic and sensory-motor neurotransmission, smooth muscle and endothelial function were assessed. 2. Basal tone was similar in mesenteric arterial preparations from control and DPSPX-treated rats. Continuous perfusion with methoxamine (7-70 microM) induced similar increases in tone in control and DPSPX-treated preparations. In the presence of guanethidine (5 microM), electrical field stimulation (EFS; 1-12 Hz, 60V, 0.1 ms, 30 s) elicited frequency-dependent vasodilatation due to activation of sensory-motor nerves. In tissues from DPSPX-treated rats the nerve-mediated vasodilator responses were markedly augmented at all frequencies. Maximal relaxation at 8 Hz was 38.34 +/- 4.76% (n = 5) in controls and 65.92 +/- 3.68% (n = 5) after DPSPX-treatment (P < 0.01). Adenosine (3 microM) inhibited the frequency-dependent sensory-motor neurotransmission similar in preparations from controls and DPSPX-treated rats. 3. In raised-tone preparations calcitonin gene-related peptide (CGRP; 5,15 and 50 pmol), the principal vasodilator transmitter of sensory-motor nerves in rat mesenteric arteries, produced similar relaxations in control and DPSPX-treated preparations. Vasodilator responses to the sensory neurotoxin capsaicin (50 and 500 pmol) were also similar between the groups. 4. Assay of tissue CGRP levels of the superior mesenteric artery by enzyme-linked immunosorbent assay showed no significant difference in tissue levels of CGRP in controls, 120.25 +/- 26.34 pmol g-1 tissue (n = 6) and with DPSPX-treatment, 82.12 +/- 24.42 pmol g-1 tissue (n = 6). 5. In raised-tone preparations dose-dependent endothelium-dependent vasodilatation to acetylcholine and ATP, and endothelium-independent vasodilatation to sodium nitroprusside were similar in control and DPSPX-treated preparations. 6. EFS (4-32 Hz, 90V, 1 ms, 30 s) elicited frequency-dependent vasoconstriction due to activation of sympathetic nerves which was similar in controls and in DPSPX-treated preparations. Adenosine (10 and 30 microM) inhibited sympathetic neurotransmission similarly in control and DPSPX-treated preparations. Dose-dependent vasoconstriction to noradrenaline (NA) and ATP, and to KCI (0.15 mmol) was similar between the groups. 7. High performance liquid chromatographic analysis of tissue NA showed no significant difference in NA content of the superior mesenteric artery from DPSPX-treated (1.38 +/- 0.09 ng mg-1, n = 6) and control rats (1.46 +/- 0.17 ng mg-1, n = 6). 8. In conclusion, in rats with hypertension due to 7 days treatment with the P1-purinoceptor antagonist, DPSPX, there is an increase in sensory-motor vasodilatation of the mesenteric arterial bed. There is no change in sympathetic nerve, endothelial or smooth muscle function. Augmented sensory-motor neurotransmission, which does not involve a change in postjunctional responsiveness to CGRP or in the CGRP content of sensory-motor nerves, could be a compensatory change in response to the DPSPX- induced hypertension.

Adenosine↗
PubMed1996

Human serum immunoglobulin counteracts rotaviral infection in Caco-2 cells.

Oral administration of human serum immunoglobulin reduces the duration of diarrhea and of rotaviral excretion in children. To investigate the in vitro effects of immunoglobulin on virus-enterocyte interaction, Caco-2 cells were infected with Rotavirus strain SA11. Immunoglobulin was added prior to and at various times postinfection. Indirect immunofluorescence was performed with an antibody against VP-6 rotaviral antigen. Cell viability and monolayer transepithelial electrical resistance (TEER) were monitored. Immunofluorescence showed a perinuclear distribution in 90% of cells. Rotavirus infection induced a progressive decrease in TEER and a parallel reduction in cell viability, depending on viral load. Preincubation of the virus with immunoglobulin prevented cell infection as judged by immunofluorescence. Immunoglobulin addition to infected cells partially prevented the decrease in TEER and induced a later shift of TEER toward increasing values, suggesting restoration of monolayer's integrity. The efficacy of immunoglobulin depended on its concentration and on the time of its addition. These results indicate that immunoglobulin is effective in preventing infection and in reducing cell damage, through a direct anti-Rotavirus action and may indicate that immunoglobulin should be administered in the early phase of diarrhea, to reduce the severity of Rotavirus infection.

Administration, Oral↗
PubMed1996

High prevalence of overweight in a children population living in Naples (Italy).

OBJECTIVE: The present study estimates the prevalence of obesity among ten-year old children living in Southern Italy and compares it with the prevalence of obesity among children living in other western countries. METHODS: 110 children attending the 4th grade of a randomly selected primary school in Naples were studies in the 1992. Eighty-eight per cent of the total school population was examined: 52 girls, 58 boys: mean age = 9.6 years (SEM = +/- 0.10). Each child underwent medical examination and anthropometric assessment. The percentile values for Body Mass Index (BMI = weight/height 2) and triceps skinfolds thickness (mm) were calculated and compared to that of children of the same age and sex living in other countries, chosen from comparable studies available in the literature. RESULTS: Percentile values for triceps skinfolds thickness in Neapolitan children are similar to those reported in the other populations considered for comparison, however BMI values were different. Children in Naples have the highest BMI values at the 50th, 75th, 90th and 95th percentile. The prevalence of obesity among Neapolitan children was estimated using as a cut-off, the BMI value at the 90th percentile of each population considered for the comparison and calculating the rate ratio with 95% confidence interval (95% CI). The prevalence of obesity in Naples among girls, was 5.2 times (3.8-6.6 95% CI) as high as in France, 3.3 times (2.2-4.4) as high as in Holland, 1.7 times (0.9-2.5) as high as in USA, 2.5 times (1.7-3.4) as high as in Milan (Northern Italy); among boys it was 4.3 times (3.0-5.6) as high as in France, 4.0 times (2.7-5.2) as high as in Holland, 2.1 times (1.2-3.0) as high as in the USA, 2.5 times (1.7-3.4) as high as in Milan.

Body Mass Index↗
PubMed1996

Assessment of human exposure to pesticides in greenhouses and effectiveness of personal protective devices.

The exposure to pesticides in a group of workers growing vegetables in greenhouses in farms near Rimini in Italy was evaluated. The pesticides used were organophosphorus compounds, organochlorine compounds, carbamates, pyrethroids, amide and anilide derivatives. Measurements were carried out in seven greenhouses randomly selected. The environment was free of atmospheric agents which could have influenced the pesticide concentrations in the indoor air. Two types of chemical sampling were performed: environmental and personal. The latter was done in the liquid for washing hands and by means of pads applied directly to the worker's skin and to the clothes. The aim of the determination of airborne pesticide concentrations was to evaluate mean environmental exposure to pesticides in the sprayed areas. The sampling went on from a fixed point during the entire spraying period. The aim of individual sampling was to determine the active ingredients as contaminants. The values obtained showed a risk of exposure for the greenhouse personnel working without using personal protective devices (masks, gloves and waterproof clothes), considering that pesticides could be absorbed through the skin in between the spraying intervals.

Agricultural Workers' Diseases↗
PubMed1996

Comparing reconstruction with Roux-en-Y to a pouch following total gastrectomy.

BACKGROUND: Although more than 50 methods of gastric replacement after total gastrectomy have been used, none of them has demonstrated a substantial nutritional advantage. The Roux-en-Y esophagojejunostomy is still the preferred type of reconstruction, more because of its simplicity than the lack of postprandial disturbances. STUDY DESIGN: A randomized controlled trial was conducted to compare two reconstructive procedures, Roux-en-Y esophagojejunostomy (n = 24) and Hunt-Rodino-Lawrence pouch (HRL, n = 24), by evaluating nutritional status (body weight, arm circumference, and serum nutritional parameters), nutritional habits (number of meals, energy intake, and postprandial disturbances), and emptying time of the jejunal loop. RESULTS: Twenty-seven patients were studied two years after operation (12 had undergone Roux-en-Y and 15 had undergone HRL). No difference was found in either postoperative morbidity or mortality, emptying time, frequency of meals, or variation of body weight. Postprandial disturbances were more frequent in patients having Roux-en-Y. In a subset of patients, there was a correlation between nutrient intake and change of body weight, but not between nutrient intake and type of reconstruction. CONCLUSIONS: The simple use of a reservoir such as the HRL pouch after total gastrectomy is of no benefit to the patient as compared with the Roux-en-Y reconstruction.

Anastomosis, Roux-en-Y↗
PubMed1996

[Modified technique for dilatation of pulmonary valve stenosis (nearly atresia) in a neonate].

A modified technique for pulmonary valvuloplasty is described in a 1-day-old newborn with near pulmonary atresia. A transumbilical venous approach and a complete set of devices for coronary angioplasty were utilized; the principal technical innovation was the use of a 7 French right coronary artery guiding catheter. This allowed a firm support to advance the first balloon catheter (a 3.5 coronary angioplasty catheter) through the pulmonary valve, maintaining the guidewire in a stable position in the descending aorta. The dilation was easily completed with progressively larger balloons. The total procedure time was 82' (fluroscopy time 20'), significantly shorter than the previous personal experience and the data from the literature.

Catheterization↗
PubMed1995

Human intestinal cryptosporidiosis: secretory diarrhea and enterotoxic activity in Caco-2 cells.

A cell line model to detect enterotoxic effect was used to test fecal specimens of patients with enteric cryptosporidiosis. Fecal samples were obtained from 11 patients with Cryptosporidium diarrhea, and osmotic gap was determined. Caco-2 cell monolayers grown on filters were mounted in Ussing chambers, and electrical parameters were measured before and after the addition of fecal supernatant. A significant increase in short-circuit current was seen in 9 of 11 specimens. The enterotoxic effect was time- and dose-dependent, saturable, and Cl(-)- and Ca(2+)-dependent. Fecal osmotic gap was consistent with secretory diarrhea in the 9 enterotoxin-positive but not in the 2 enterotoxin-negative samples. In conclusion, a cell line model for studying the pathophysiology of enteric cryptosporidiosis was established. Enterotoxic activity was observed in most patients with enteric cryptosporidiosis and was strictly associated with secretory diarrhea.

Adult↗
PubMed1995

Contribution of P1-(A2b subtype) and P2-purinoceptors to the control of vascular tone in the rat isolated mesenteric arterial bed.

1. The direct vascular effects of adenosine and ATP were compared in the isolated and perfused mesenteric arterial bed of the rat. The actions of analogues of adenosine and ATP were also examined. 2. In preparations at basal tone, adenosine lacked vasoconstrictor actions, while ATP elicited dose-dependent vasoconstrictor responses. When the tone of preparations was raised by adding methoxamine to the perfusate, adenosine and its stable analogue, 2-chloroadenosine (2-CADO) elicited dose-dependent vasodilation. The A2 adenosine receptor agonist, 5'-N-ethylcarboxamidoadenosine (NECA) was active at lower doses than adenosine, while the A2a-selective agonist, CGS 21680 and the selective A1 agonist, N6-cyclopentyladenosine (CPA) failed to induce vasodilatation. ATP and its analogue, 2-methylthio ATP, elicited dose-dependent vasodilatation at doses 400 fold lower than adenosine. 3. Vasodilator responses to adenosine and 2-CADO were sensitive to antagonism by 1 microM 8-sulphophenyltheophylline (8-SPT) and were unaffected by inhibition of nitric oxide synthase by N omega-nitro-L-arginine methyl ester (L-NAME). In contrast, vasodilator responses to ATP were not sensitive to antagonism by 8-SPT and were almost abolished by L-NAME treatment. 4. These results indicate that in the rat mesenteric arterial bed, while both adenosine and ATP participate in the purinergic control of vascular tone, adenosine appears to be a weaker vasodilator than ATP and lacks vasoconstrictor action. A2b adenosine receptors account for the adenosine-induced vasodilatation which is independent of the production of nitric oxide.

2-Chloroadenosine↗
PubMed1995

Effects of vitamin E deficiency on vasomotor activity and ultrastructural organisation of rat thoracic aorta.

1. The effects of vitamin E deficiency were evaluated in aortic rings isolated from rats maintained on a diet deficient in vitamin E. 2. Endothelium-dependent vasodilator responses to acetylcholine (ACh) and calcium ionophore, A23187, were reduced in preparations from treated animals, compared to the age-matched controls. The maximal vasodilation to ACh was 66.4 +/- 9 (n = 4) and 38.8 +/- 7 (n = 4) % in control and 10 month-treated preparations, respectively. 3. The endothelium-independent vasodilator responses to sodium nitroprusside as well as the concentration-dependent contractile responses to noradrenaline, did not differ between treated and control preparations. 4. Electron microscopic examination of vascular segments and revealed that, following vitamin E deficiency, normal tissue organisation was disrupted, the endothelial monolayer either not being in contact with the underlying tissue or being absent in most of the areas analysed. 5. It is concluded that during vitamin E deficiency both morphological disruption and functional impairment of endothelium occur without observable modification of muscle cell function and morphology.

Acetylcholine↗
PubMed1995

Enhanced sympathetic neurotransmission in the tail artery of 1,3-dipropyl-8-sulphophenylxanthine (DPSPX)-treated rats.

1. Sympathetic neurotransmission and noradrenaline content of the tail artery of Wistar rats treated for 7 days with the adenosine antagonist, 1,3-dipropyl-8-sulphophenylxanthine (DPSPX), were examined. 2. Systolic blood pressure of the DPSPX-treated rats (164.0 +/- 2.9 mmHg; n = 6) was significantly greater than saline-treated controls (140.0 +/- 2.8 mmHg; n = 5) after 7 days treatment. 3. The pressor responses of the arterial rings to transmural nerve stimulation (65 V, 0.1 ms, 4-64 Hz, for 1 s) were markedly enhanced in the DPSPX-treated compared with the saline-treated animals. Both noradrenergic and purinergic components of perivascular sympathetic neurotransmission were enhanced during DPSPX-induced hypertension. 4. Vasoconstrictor responses to exogenous noradrenaline (0.1-300 microM) and adenosine 5'-triphosphate (0.01-3 mM) were unaffected after DPSPX treatment, indicating prejunctional alteration of sympathetic cotransmission during DPSPX-induced hypertension. 5. Acute exposure to DPSPX (10 microM) did not modify vasoconstrictor responses to transmural nerve stimulation, thus supporting the claim that the enhancement of sympathetic neurotransmission only results from long-term DPSPX treatment. 6. The noradrenaline content of the tail arteries of DPSPX-treated (4.498 +/- 0.26 ng cm-1; n = 4) was significantly greater than saline-treated (3.440 +/- 0.30 ng cm-1; n = 5) animals. 7. These findings show that chronic inhibition of the actions of endogenous adenosine by DPSPX results in an elevation of systolic blood pressure accompanied by enhanced sympathetic cotransmission and enhanced noradrenaline content of the rat tail artery.

Animals↗
PubMed1995

In vivo and in vitro effects of human growth hormone on rat intestinal ion transport.

It has been reported that: 1) ovine growth hormone stimulates intestinal water, sodium, and chloride absorption and 2) specific growth hormone receptors are present in the rat intestine. Aims of this work were to investigate the effects of acute administration of hGH on water and ion transport in the rat ileum in vivo and in vitro. In vivo, the absorption rates of water, sodium, chloride, and potassium were determined in the rat perfused ileum, during a basal period and after i.v. administration of 6 micrograms/kg recombinant DNA-derived hGH. In vitro, electrical parameters were measured before and after the hormone addition to the mucosal or the serosal side of rat ileal mucosa mounted in Ussing chambers. In vivo, growth hormone induced a rapid increase in the absorption rates of water, sodium, chloride, and potassium. In vitro, the serosal, but not the mucosal, addition of growth hormone induced a rapid decrease of transepithelial potential difference and of short-circuit current. The effect was time- and dose-dependent, saturable, but not reversible in the short time. The electrical effect was abolished in the absence of chloride, indicating that it was related, at least in part, to inhibition of basal active chloride secretion. Growth hormone also reduced the short-circuit current increase induced by the secretagogues Escherichia coli heat-stable enterotoxin, theophylline, and calcium ionophore A23187. These results indicate that hGH has a rapid absorptive effect that is related, at least in part, to a direct intestinal antisecretory mechanism. It also reduces active intestinal secretion induced by various secretagogues.

Animals↗
PubMed1995

Changes in sympathetic neurotransmission and adrenergic control of cardiac contractility during 1,3-dipropyl-8-sulfophenylxanthine-induced hypertension.

We have explored the hypothesis that systemic hypertension induced by long-term treatment with the purinoceptor antagonist 1,3-dipropyl-8-sulfophenylxanthine (DPSPX) might be associated with functional modifications of the adrenergic mechanisms of control of cardiac performance comparable to those described in other models of hypertension. Seven days continuous i.p. infusion of rats with DPSPX (30 micrograms/kg/hr) significantly increased systolic blood pressure. When sympathetic neurotransmission was evaluated via electrical field stimulation of atrial tissue, contractile responses were significantly reduced in hypertensive animals compared to controls. Similarly, contractile responses to exogenous norepinephrine were attenuated in tissue from hypertensive animals, thus suggesting that DPSPX treatment affects cardiac sympathetic neurotransmission via postjunctional rather than prejunctional changes. Inotropic responses of ventricular myocardium to both alpha- and beta-adrenoceptor stimulation were also significantly reduced in DPSPX-treated tissue. The responsiveness of atrial and ventricular myocardium to adenosine was unaffected by DPSPX treatment. The present study indicates that DPSPX-induced hypertension is associated with altered adrenergic regulation of the cardiac function that results in reduced inotropic responses of both atrial and ventricular myocardium to endogenous norepinephrine, as well as to adrenoceptor agonists applied exogenously. These alterations are comparable to those described in other models of genetic or induced hypertension, thus supporting the view that purinergic mechanisms may contribute to the onset and development of systemic hypertension.

Adenosine↗
PubMed1995

Advances in infant nutrition.

Recent advances in the nutrition of low birth weight infants are discussed, with special emphasis on concepts and methods to establish parameters for the control of growth and nutrition. Furthermore, the recent developments of methods in the research on newborn nutrition, the problems related to the use of breast milk, the timing of feeding and the problems of the intravenous alimentation are discussed in some detail. Secondly, the effects of breast feeding on infant health are summarised, with particular emphasis on the long term consequences (occurrence of diseases later in life) and on the effects on some surgical diseases of infancy. Recent acquisitions in the field of enteral and parenteral nutrition are also mentioned, and the problems related to composition of the nutritive solutions and indications in pediatric age are covered in some detail. Finally, the dietary management of infant with cow's milk protein allergy or intolerance is discussed, with special regard to composition and indications of hydrolysed protein formulas (casein based, whey based, soy and collagen based), soy based formulas and aminoacid based formulas.

Breast Feeding↗
PubMed1994

Recovery after dietary vitamin E supplementation of impaired endothelial function in vitamin E-deficient rats.

1. Thoracic aortae, isolated from rats supplemented with dietary vitamin E after vitamin E deficiency, were analysed for changes in vascular reactivity. 2. Following 4 or 12 months of dietary vitamin E deficiency, endothelium-dependent vasodilator responses to acetylcholine were significantly impaired. However, when animals were fed after the first 4 months of vitamin E deprivation with a vitamin E-supplemented diet for 8 months, endothelium-mediated responses were completely restored. 3. In contrast, the endothelium-independent vasodilator or vasoconstrictor responses to sodium nitroprusside and noradrenaline, respectively were not altered either by vitamin E deficiency or supplementation. 4. These data indicate that vitamin E supplementation reversed the impairment of endothelial cell function which occurs during vitamin E deficiency.

Acetylcholine↗