Changes in diastolic function and collagen content in normotensive and hypertensive rats with long-term streptozotocin-induced diabetes

We investigated the relationship between left ventricular diastolic function and interstitial collagen content in the endocardium, mesocardium and epicardium of transverse sections of the heart, using an image analysis system in normotensive and hypertensive long-term streptozotocin (STZ) diabetic rats. STZ-induced diabetes was characterised by elevated blood glucose, polyuria, polydypsia and loss of body weight. In vivo systolic blood pressure was 165 +/- 4, 136 +/- 3 and 129 +/- 7 mmHg in hypertensive and normotensive diabetic rats and age-matched controls, respectively. Heart rate was significantly lower (P < 0.01) in diabetic rats (283 +/- 8 and 280 +/- 10 beats min-1 in normotensive and hypertensive rats, respectively) than controls (393 +/- 18 beats min-1). Pressure-volume (P-V) curves were studied in isolated Langendorff perfused hearts at rest and after 20 min global ischaemia and 30 min reperfusion 6 months after induction of diabetes. Left ventricular volumes were significantly smaller in diabetic rats than age-matched controls, but volumes normalised for heart weight were higher in normotensive (by 28%) and hypertensive (by 10%) diabetic rats. Slopes of end-diastolic P-V curves were similar between groups in basal conditions, but left ventricular systolic P-V curves were steeper in normotensive and flatter in hypertensive diabetic hearts. Post-ischaemic left ventricular end-diastolic pressure was significantly higher than the pre-ischaemic value at comparable increments of volume in each group. Collagen content significantly increased in the heart of rats with STZ-diabetes both in the free left ventricular wall and septum, and suggested this may play a role in the cardiac defects in contractility and relaxation in our experimental conditions. These results indicate that diabetes, irrespective of associated hypertension, can cause major changes in cardiac performance and susceptibility to ischaemia and reperfusion.

Low levels of linoleic acid in plasma total lipids of HIV-1 seropositive children

OBJECTIVE

To assess the plasma fatty acid status of a group of well-nourished children with the human immunodeficiency virus type-1 (HIV-1) and how this relates to the blood total CD4+ lymphocyte count.

SUBJECTS

Fourteen HIV-1 seropositive children at various stages of disease and with adequate growth indices were assessed and compared to a control group of 30 healthy children.

RESULTS

The concentrations (mg/dL) of plasma total fatty acids were not different between the two groups. HIV-1 seropositive children presented lower levels of 18-C essential polyunsaturated fatty acids (PUFA: linoleic acid, LA, and alpha-linolenic acid) and higher levels of their 20-C long-chain derivatives (di-homo-gamma-linolenic acid, arachidonic acid, AA, and eicosapentaenoic acid) and docosahexaenoic acid in their plasma total lipids. The lowest plasma LA levels were observed in the subgroup of patients with more advanced stages of disease. In bivariate analyses the plasma LA levels related positively (Spearman r = 0.50, p = 0.06), while the LA/AA ratio related negatively (Spearman r = -0.51, p = 0.06), to the total CD4+ count.

CONCLUSIONS

Childhood HIV-1 infection is associated with changes in plasma fatty acid profile suggestive of an increased PUFA turnover. Decreased levels of LA (together with higher plasma AA levels) appear to be associated with more advanced clinical and biochemical stages of disease.

Plasma arachidonic acid and serum thromboxane B2 concentrations in phenylketonuric children are correlated with dietary compliance

Phenylketonurics display lower arachidonic acid levels in plasma lipids, reflecting the lower intake due to the dietary treatment poor in phenylalanine-rich animal foods. Plasma arachidonic acid levels and serum thromboxane B2 concentrations have been measured in 13 treated phenylketonuric children and compared with those of 12 healthy controls. A direct relationship between plasma arachidonic acid and thromboxane B2 concentrations has been observed only in phenylketonurics, whose plasma arachidonic acid status correlated negatively with their dietary compliance. These results suggest that the low consumption of animal fats may contribute to modulate the production of arachidonic acid-derived platelet eicosanoids.

Dietary fatty acids and cholesterol in the first 2 years of life

Both long-chain polyunsaturated (LCP) fatty acids and cholesterol are supplied by human milk. Dietary long-chain polyunsaturated fatty acids in the first 2 years of life have been associated with growth and developmental indices. Cholesterol supply does not seem relevant for structural purposes, but could have a role in the metabolism of LCP. Complex relationships between dietary fatty acids and cholesterol seem to be major determinants of blood lipid levels in the first months of life. Data from both suckling and weaned infants indicate that their blood lipid profile reacts to changes in their diet in a manner similar to adults. Early intervention trials on weaned infants (<2 years of age) have been addressed in populations at high risk for early cardiovascular disorders and seem safe for growth at short-term assessments, but the balance of all the macronutrients should be carefully considered. While the effects of plasma cholesterol concentrations in the suckling infant on the subsequent development of atheroslerosis are still unknown, both the diet composition and the way by which food is supplied to infants seem to be major determinants of their metabolic profile.

Cardiac effects of angiotensin I and angiotensin II: dose-response studies in the isolated perfused rat heart

We investigated the effects of angiotensin I (4 x 10(-9), 4 x 10(-8) and 4 x 10(-7) M) on myocardial contractility, heart rate and coronary perfusion in the isolated rat heart before and after inhibition of angiotensin-converting enzyme (ACE) by captopril (4 x 10(-4) M). We also studied the post-ischaemic recovery of cardiac function in isolated hearts subjected to global myocardial ischaemia and reperfused with various doses of angiotensin II (1 x 10(-9), 1 x 10(-8) and 1 x 10(-7) M). Angiotensin I significantly reduced coronary flow, the vasoconstrictor effect of a second identical dose was attenuated after inhibition of ACE with captopril. Angiotensin II reduced coronary flow to the same extent as angiotensin I at a concentration four times lower. Left ventricular developed pressure was reduced by angiotensin I and angiotensin II in a dose-dependent manner. Heart rate was not affected by angiotensin I and was significantly lowered by the highest doses (1 x 10(-8) and 1 x 10(-7) M) of angiotensin II. Post-ischaemic recoveries of vascular and contractile function were similar in control hearts and in hearts given angiotensin II during reperfusion. However, left ventricular end-diastolic pressure was increased by the highest dose (1 x 10(-7) M) of angiotensin II throughout reperfusion compared with controls or hearts receiving lower doses (NS). In conclusion the attenuated vasoconstrictor response to angiotensin I after captopril pre-treatment confirms the existence of an intracardiac renin-angiotensin system operative in vitro. Our results also suggest that angiotensin II, at a high concentration, may play a negative role in relaxation in the ischaemic-reperfused injured heart.

Effect of nedocromil sodium on bronchial hyperreactivity in children with nonatopic asthma

BACKGROUND AND OBJECTIVES

Although cromones inhibit immediate bronchial responses to both allergen and nonspecific challenge, their effectiveness in treating nonatopic childhood asthma is unknown. We therefore investigated a possible effect of nedocromil sodium on bronchial hyperreactivity and asthmatic symptoms in a group of children receiving this drug for nonatopic asthma.

STUDY DESIGN AND METHODS

A double-blind, placebo-controlled, randomized trial of two parallel groups was carried out in our pediatric respiratory disease clinic. Twenty children with mild, nonatopic asthma hyperreactive to fog-induced challenge were treated with inhaled nedocromil sodium 16 mg each day for 6 weeks (group N) or with a placebo (group P). Five girls and five boys (7 to 13 years of age) were randomly assigned to group N, and three girls and seven boys (aged 6 to 16 years) to group P. Symptoms and bronchodilator use were reported on diary cards. Ultrasonic nebulized distilled water PD10 was measured administering increasing doses of nebulized distilled water (2.5, 5, 10, 20, and 40 L).

RESULTS

Symptom scores were significantly affected by the active treatment. Baseline lung function was normal and remained unaltered after treatment with nedocromil sodium. Nonspecific reactivity was significantly reduced over time only in the active treatment group.

CONCLUSIONS

Nedocromil sodium can reduce the severity of asthmatic symptoms and nonspecific bronchial hyperreactivity at fog-induced challenge in children with stable, nonatopic asthma.

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.

Plasma arachidonic acid and serum thromboxane B2 concentrations in phenylketonuric children negatively correlate with dietary compliance

The study addresses the relationship of plasma arachidonic acid and thromboxane production with the dietary compliance in treated phenylketonuric patients, whose vegan-like dietary pattern makes them a useful model to evaluate the effects of the near-total avoidance of animal fats. Thirteen treated phenylketonuric children were compared with twelve healthy controls for arachidonic acid intake, plasma fatty acids and platelet thromboxane B2 production, assessed as accumulation of this eicosanoid in serum. The calculated intake of arachidonic acid was lower in phenylketonurics than in controls and this was associated with lower levels in plasma lipids. Plasma arachidonic acid concentrations and serum thromboxane B2 levels correlated with the last 12 months phenylalanine levels, taken as negative indicator of dietary compliance. A direct relationship between plasma arachidonic acid concentration and thromboxane B2 production was observed only in phenylketonuric patients (r = 0.74, P = 0.01). While well-compliant PKU subjects have low arachidonic acid and thromboxane concentrations in plasma, the low compliance with animal food avoidance, evoking higher phenylalanine levels, results in elevation of both plasma arachidonic acid and serum thromboxane B2. This gives support to the hypothesis that the consumption of animal fats may affect the production of arachidonic acid-derived platelet eicosanoids.

Two novel PAH gene mutations detected in Italian phenylketonuric patients

We report the identification by denaturing gradient gel electrophoresis and sequence analysis of two new phenylalanine hydroxylase (PAH) gene mutations (IVS4nt-2 and N207S) in single chromosomes of two unrelated Italian phenylketonuric (PKU) patients. Interestingly, mutation Y204C, found on the second mutant allele of family F1, has been previously detected in Chinese patients. Haplotype analysis showed that the latter mutation is linked to the same haplotype (H4) in both Chinese and Italian patients, suggesting a common origin. In vivo assessment of mutation severity indicates that N207S is associated with classic PKU. The identification of these two new mutations further extends the remarkable heterogeneity of the PAH locus in the Italian population.

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.

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.

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.

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.

Preliminary results of a nutritional survey in a sample of 35,000 Italian schoolchildren

An investigation of the nutrient intake of a large-scale sample (n = 35,072), drawn from the Italian school-age population (7-10 years) was carried out in a nationwide survey of nutritional patterns. Friuli, the Piedmont, Latium and Sicily regions were selected as representative of the nation's north-south and east-west socio-economic divisions. A food frequency questionnaire was used to assess nutritional intake. Traditional methods of 24-h dietary recall and a weighted food diary were used in subsamples to assess the validity of the food frequency questionnaire. Our data suggest that the average diet of Italian schoolchildren is rich in protein (especially animal proteins) and lipids (prevalently saturated fatty acids), but that carbohydrate and fibre intakes remain generally low. The relatively low calcium intake among girls and a widespread, more than adequate iron intake are also noteworthy. The food and nutrient intakes assessed suggest a dietary pattern with several positive points, but also reveal potential hazards for a wider population spectrum. The type of large-scale nutritional monitoring with a multi-method approach can be used in Italy and elsewhere to describe the dietary trends of a school-age population.

Granulocyte-colony stimulating factor and erythropoietin therapy in children with human immunodeficiency virus infection

To determine whether granulocyte-colony stimulating factor and erythropoietin are effective in the therapy of neutropenia and anaemia related to human immunodeficiency virus (HIV) infection and to anti-retroviral agents, we recruited 11 HIV-infected children (mean age 4 years 10 months). All the children were given granulocyte-colony stimulating factor at a dosage of 5 micrograms/kg twice or three times a week while erythropoietin was administered additionally to three patients at a dosage of 50 U/kg twice a week. Both agents were administered subcutaneously for at least 4 months. Leukocyte and neutrophil counts significantly increased during the treatment (after 1 months, P = 0.003 and P = 0.009, respectively). Erythropoietin prevented blood transfusions and increased haemoglobin levels in the three children treated. No side-effects were recorded during the administration of either agent. Granulocyte-colony stimulating factor and erythropoietin appear to be safe and useful agents in the management of HIV-infected children.

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.

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.

4p(-) syndrome: a chromosomal disorder associated with a particular EEG pattern

We report an electroclinical and cytogenetic study of 4 patients with Wolf-Hirschhorn syndrome (WHS). In all cases, we observed a stereotyped EEG and clinical picture characterized by generalized or unilateral myoclonic seizures followed later by brief atypical absences. Electrographically, these were accompanied by a sequence of centroparietal or parietotemporal sharp waves; high-voltage wave with a superimposed spike becoming unusual spike-wave complexes, often elicited by eye closure; burst of diffuse spikes and waves; and frequent jerks. This electroclinical pattern is very similar to the one described in Angelman syndrome (AS) in which a defect in GABAA receptor function has been suggested. Moreover, the genes encoding the GABAA receptor subunit have been mapped to the p12-p13 bands of chromosome 4. Even though the deletion in these cases does not encompass the 4p12-p13 region, we suggest that the electroclinical picture common to WHS and AS might represent a characteristic type of epilepsy linked to a common genetic abnormality.