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Biomedical subjects

E Riva

Publications and source records attributed to E Riva.

At least 91 records · Page 5Linked to original sources
PubMed1997

Developmental quotient at 24 months and fatty acid composition of diet in early infancy: a follow up study.

AIM: A follow up study of developmental quotient (DQ) at 24 months of toddlers whose diets in early infancy differed in fatty acid composition, and in whom an association between diet and DQ was observed at 4 months. METHODS: 81 toddlers were distributed among three groups according to early type of diets standard infant formula (SFo, n = 30); long chain polyunsaturated fatty acid (LC-PUFA) enriched formula (LCPFo, n = 26); human milk (HM, n = 25). DQ at 24 months was assessed by Brunet-Léxine's psychomotor developmental test. A subgroup (n = 20; SFo 8; LCPFo 6; HM 6) was tested for erythrocyte phosphatidyicholine and phosphatidylethanolamine. RESULTS: No DQ differences were found by analysis of variance. Neither DQ nor erythrocyte docosahexaenoic acid at 4 months were predictors of DQ scores at 24 months. Phosphatidylcholine arachidonic and docosahexaenoic acid correlated positively, and phosphatidylcholine linoleic acid and phosphatidylethanolamine eicosapentaenoic acid negatively, with DQ. Multiple regression analysis including these variables explained 52% of inter-individual DQ variance. A strong association was found between the erythrocyte phosphatidylcholine arachidonic/ linoleic acid ratio and DQ (r = 0.75; p = 0.0001). CONCLUSIONS: The diet/DQ association found at 4 months was not predictive of DQ scores at 24 months. Irrespective of dietary or genetic factors, there appears to be a strong correlation between the LC-PUFA composition of the red cell membrane and higher neurodevelopmental performance.

Breast Feeding↗
PubMed1996

Dose-response studies with idrapril in the rat heart during acute myocardial ischaemia and reperfusion.

We assessed the effects of idrapril, a novel angiotensin-converting enzyme inhibitor, and captopril in the isolated rat heart after ischaemia and reperfusion and measured angiotensin-converting enzyme activity in myocardial tissue. Hearts were perfused and subjected to global ischaemia and reperfusion. Idrapril (0.1, 1, 10, and 50 micrograms/ml), captopril (80 micrograms/ml) or vehicle were given before ischaemia and throughout reperfusion. Post-ischaemic recovery of coronary flow was significantly decreased with 50 micrograms/ml of idrapril (43 +/- 9% compared to 64 +/- 3% in controls) whereas heart rate was unaffected. Recovery of developed pressure and activity of cardiac angiotensin-converting enzyme were significantly reduced by idrapril in a dose-dependent manner. This study suggests that protection or lack of protection by idrapril on recovery of contractile function seems to depend on the degree of inhibition of tissue angiotensin-converting enzyme activity in the setting of acute heart ischaemic insult. Our results suggest that while a certain degree of inhibition of angiotensin-converting enzyme in the heart is beneficial, marked tissue inhibition may be deleterious.

Angiotensin-Converting Enzyme Inhibitors↗
PubMed1996

Purification of glycopeptide antibiotics by isoelectric focusing in multicompartment electrolyzers with immobiline membranes.

The purification of small glycopeptides (a Hepta-Tyr of the teicoplanin family, exhibiting broad activity against highly glycopeptide-resistant enterococci) by isoelectric focusing in multicompartment electrolyzers with buffering, isoelectric membranes, is described. The main obstacle to such a preparative technique, in common with all focusing methodologies, is the poor solubility of the analyte at the pI value with resultant precipitation and coprecipitation of all impurities with the main fraction. A good solubilizing power was obtained in hydro-organic solvents, particularly a mixture of 6 M urea and 20-25% trifluoroethanol. Best results, however, were obtained with mixtures of 8 M urea and zwitterionic detergents, notably the 3-[(3-cholamidopropyl)dimethylammonia]-1-propanesulfonate (CHAPS) family. A unique behavior of the peptide was found in concentration gradients of CHAPS: solubility increases up to 3.5% CHAPS, but the curve shows a maximum and then solubility decreases again at 5% CHAPS. In mixtures of 8 M urea and 3.5% CHAPS, sample loads of 500 up to 1000 mg Hepta-Tyr could be purified in a single run, with recoveries > 90% and purity in excess of 99%. The main glycopeptide fraction (pI 8.56) was collected into an isoelectric trap delimited by pI 8.46 and pI 8.65 membranes. Attempts at purifying the glycopeptide by most known reversed phase-high performance liquid chromatography (RP-HPLC) techniques failed completely.

Anti-Bacterial Agents↗
PubMed1996

PAH deficiency in Italy: correlation of genotype with phenotype in the Sicilian population.

The results of the neonatal screening for phenylalanine hydroxylase (PAH) deficiency in Sicily show that its incidence is higher than previously reported for mainland Italians and that non-PKU HPA is in excess of classical and mild PKU. The latter finding suggests that a high number of non-PKU HPA mutations would occur in the Sicilian population compared to populations with an inverted PKU/non-PKU HPA ratio. Previous studies have identified 40 mutations accounting for the majority (98%) of mutant alleles underlying PAH deficiency in Sicily. In order to study the molecular basis of the distribution of PAH deficiency phenotypes in the Sicilian population, we have correlated 31 of those mutations with clinical and metabolic phenotypes in 12 mentally retarded patients, 14 treated patients with classic or mild PKU, and 13 subjects presenting the non-PKU HPA phenotype. The present study proposes a tentative classification for a large number (26) of PAH gene mutations which may represent an additional tool for establishing a differential diagnosis for PAH deficiency in the Sicilian population.

Amino Acid Metabolism, Inborn Errors↗
PubMed1996

Fatty acid metabolism in phenylketonuria.

Children treated for phenylketonuria (PKU) have a low intake of whole animal foods. Consequently, the dietary intake of long-chain polyunsaturated fatty acids (PUFA) is just a few milligrams per day, mostly represented by arachidonic acid (AA). In a consecutive series of studies, we assessed in treated PKU children their long-chain PUFA status, the AA-related eicosanoid synthesis and the effects of specific PUFA supplementations. We found that the good compliance with the dietary regimen negatively influences the long-chain PUFA status and serum eicosanoid release from platelets. Supplementation with either marine or blackcurrant oils modifies the long-chain PUFA status of PKU children without approaching the fatty acid pattern of a healthy control population. Good-compliant PKU patients have diet-related, low levels of circulating long-chain PUFA, whose clinical and functional consequences deserve further investigation. The effects of dietary supplementations with long-chain PUFA of both the n-6 and n-3 series should be carefully evaluated.

Adolescent↗
PubMed1996

Effects of a new angiotensin-converting enzyme inhibitor (idrapril) in rats with left ventricular dysfunction after myocardial infarction.

We evaluated the effects of a new angiotensin-converting enzyme (ACE) inhibitor (idrapril) in terms of hemodynamics and ventricular remodeling after myocardial infarction in rats. The animals were randomly assigned to four experimental groups. Myocardial infarction was induced by left coronary artery ligation in the first two groups treated with either idrapril (300 mg kg-1 day-1) or vehicle for 4 weeks after myocardial infarction. Two groups of sham-operated rats were treated accordingly. Hemodynamics were measured, and the diastole-arrested hearts were analyzed morphometrically to quantify left ventricular (LV) remodeling and infarct size. In infarcted rats, idrapril reduced the arterial systolic blood pressure (SBP) from 128 +/- 10 to 97 +/- 6 mm Hg (p < 0.05) and LV end-diastolic pressure (LVEDP) from 19 +/- 3 to 13 +/- 3 mm Hg (p < 0.01). The decrease in diastolic wall stress conferred by idrapril to infarcted rats (from 499 +/- 99 to 269 +/- 68 dynes mm-2, p < 0.05) was mainly due to a reduction in LVEDP and, to a lesser extent, in LV volume. Idrapril also reduced body and heart weights as compared with those of vehicle-treated animals. Four-week treatment with idrapril initiated immediately after myocardial infarction reduced LVEDP and limited LV wall stress, a major prognostic factor for the progression toward chronic ventricular failure.

Angiotensin-Converting Enzyme Inhibitors↗
PubMed1996

Early breastfeeding is linked to higher intelligence quotient scores in dietary treated phenylketonuric children.

Strict control of phenylalanine intake is the main dietary intervention for phenylketonuric children. Whether other dietary-related factors improve the clinical outcome for treated phenylketonuric children in neurodevelopmental terms, however, remains unexplored. We retrospectively compared the intelligence quotient (IQ) score of 26 school-age phenylketonuric children who were either breastfed or formula fed for 20-40 days prior to dietary intervention. Children who had been breastfed as infants scored significantly better (IQ advantage of 14.0 points, p = 0.01) than children who had been formula fed. A 12.9 point advantage persisted also after adjusting for social and maternal education status (p = 0.02). In this sample of early treated term infants with phenylketonuria there was no associated between IQ scores and the age at treatment onset and plasma phenylalanine levels during treatment. We conclude that breastfeeding in the prediagnostic stage may help treated infants and children with phenylketonuria to improve neurodevelopmental performance.

Breast Feeding↗
PubMed1995

Lipid status and fatty acid metabolism in phenylketonuria.

Owing to dietary treatment, patients with phenylketonuria (PKU) are supplied with only small amounts of animal fats and show low blood cholesterol levels and a poor long-chain polyunsaturated fatty acid (LC-PUFA) status. Endogenous synthesis should compensate for the physiological need for cholesterol for growth, but supplementary exogenous LC-PUFA seems advisable. PKU infants could develop depletion of docosahexaenoic acid, fundamental for the functional development of the central nervous system. The availability of arachidonic acid from plasma in PKU has been found to be related to dietary compliance, and seems to influence the synthesis of arachidonate-derived eicosanoids. Trials of dietary supplementation of PKU patients with oils containing LC-PUFA are in progress, but the functional consequences of these supplementations need further investigation.

Adolescent↗
PubMed1995

The effects of n-3 and n-6 polyunsaturated fatty acids on plasma lipids and fatty acids of treated phenylketonuric children.

Dietary-treated phenylketonuric patients (PKUs) display low levels of long-chain polyunsaturated fatty acids (PUFA) in plasma lipids. In a 6-month clinical trial we observed a decrease of triglycerides and an increase of n-3 long-chain PUFA in plasma of PKUs supplemented with fish oil, while no major differences in respect to the baseline values were found in a group supplemented with blackcurrant oil. A more complete source of long-chain PUFA of both the n-6 and n-3 series should be investigated for dietary supplementation of PKU patients.

Child↗
PubMed1995

A simple, automatic method for morphometric analysis of the left ventricle in rats with myocardial infarction.

Induction of acute myocardial infarction in the rat is an established model for studying effects of therapeutic interventions. Images of sections of the rat left ventricle, stained with nitroblue tetrazolium, were digitized and several parameters estimated by dedicated software on an image analyzer (IBAS 2.0). The method was tested on 7 rats with 48-hr-old myocardial infarction and 4 sham-operated controls. Infarct size can be evaluated by two largely used methods, based on area or on angular extension of the lesion. Results of the two methods are linearly correlated, but area calculations give values half of those obtained from angular extension. Five minutes were needed for a complete evaluation of a section of the left ventricle. Estimates of the parameters showed a relatively low between- and within-operator variability and a good correlation with a classic, but time-consuming, planimetric method. The method simultaneously measures infarct size and left ventricular geometry in the rat. The advantages over previous nonautomatic methods are simplicity, good reproducibility, and speed of execution, which make it particularly useful in the evaluation of drug effects.

Analysis of Variance↗
PubMed1995

Effect of hepatitis C genotype on mother-to-infant transmission of virus.

We evaluated vertical transmission of hepatitis C virus (HCV) in 37 pregnant women, 20 of whom also had human immunodeficiency virus (HIV) antibody. The HCV subtypes 1a and 3a were prevalent among pregnant women with HIV infection. Infection with HCV was transmitted from 30.7% of the 13 mothers with HCV ribonucleic acid (RNA) and HIV antibody and from 25% of the 8 with HCV RNA alone. No mother with HCV antibody but no HCV RNA transmitted HCV to her infant. Subtypes 1b and 3a seemed to be the most common HCV genotypes transmitted.

Adult↗