Higher urinary excretion of essential amino acids in preterm infants fed protein hydrolysates.

AIM: Protein hydrolysates have been introduced in preterm formulae, but it is not clear whether they are needed for the feeding of preterm infants. We designed a randomized, controlled trial to test the effects of a preterm formula with hydrolysed cow's milk proteins on short-term growth and urinary and plasma amino acids levels. METHODS: Infants with a birthweight < or = 1750 g and gestational age < or = 34 wk fed a conventional preterm infant formula (formula B) or a hydrolysed formula (formula A). Weight was measured daily; length, head circumference, mid-arm circumference and total skinfold thickness were measured weekly. Blood and urine were analysed for amino acid concentrations at start, 14 and 28 d. RESULTS: Twenty-one infants met the criteria for randomization. The daily feeding volumes were: formula A 172.8 +/- 5.6 vs formula B 170.1 +/- 2.8 ml/kg/d. Infants fed with formula A showed slower weight gain (17.4 +/- 3.4 vs 20.5 +/- 3.3 g/kg/d; p = 0.045) and lower mean change in Z-scores for weight (-0.18 +/- 0.16 vs 0.00 +/- 0.09; p = 0.009) and for head circumference (-0.06 +/- 0.13 vs 0.06 +/- 0.13; p = 0.049). After 14 d, infants receiving formula A had statistically significant higher urinary levels of essential amino acids compared to infants receiving formula B. CONCLUSION: Our results support the hypothesis of less nutritional value of hydrolysed versus conventional preterm formulae. Higher renal excretion of essential amino acids may be one of the mechanisms involved. These findings must be confirmed by further studies with larger sample sizes and protein hydrolysates with different degrees of hydrolysis.

[Evaluation of a minimally mineralized spring water in the nutritional management of newborns and infants]. / Valutazione della validità d'impiego di un'acqua naturale minimamente mineralizzata nell'alimentazione del neonato e del lattante.

The use of bottled mineral water during the pediatric age is increasing, both for powdered formula milk reconstitution and for diluted cow's milk. The aim of this report is to compare a bottled spring water with a very low mineral content with tap water in the reconstitution and/or dilution of 6 different infant starting formulas and cow's milk. The osmolality, buffering power and renal solute load potential of the formulas reconstituted with the bottled water were all significantly lower than when tap water was used (P < 0.01). When the bottled water was used to dilute cows' milk, the morphology of milk casein precipitates (after addition of rennet) was finer and more dispersed than when tap water was used. For formula reconstitution and milk dilution, a benefit, in terms of solute/electrolyte balance, appears to be conferred on infants by the improved rheological characteristics of modified milks reconstituted or diluted with this bottled mineral water.

Biochemical investigation of histidinemia in schizophrenic patients.

Our results suggest that the association between the clinical diagnosis of schizophrenic disorder and heterozygosis for histidinemia is not a chance one. The real meaning of this relationship has to be further investigated.

Serotonin and noradrenaline concentrations and serotonin uptake in platelets from hyperphenylalaninaemic patients.

In three untreated patients with phenylketonuria (PKU), three PKU and six hyperphenylalaninaemic (HPA) patients in good metabolic control, the kinetic constants of platelet in vitro uptake of [14C]serotonin (5HT) did not significantly differ from those in 12 control subjects matched for age. The platelet concentrations of endogenous 5HT and noradrenaline (NA), taken as long-term indices of the amount of these amines circulating in plasma, were lower than normal in PKU and HPA patients, whether or not they were kept on a diet. However, a reduction in plasma NA concentrations at the moment of blood collection was seen only in untreated PKU patients. These data indicate that there may be a chronic inhibition of 5HT and possibly of NA synthesis even in PKU or HPA subjects in good metabolic control, with normal psychomotor development and only slightly raised plasma phenylalanine levels.

Pattern reversal visual evoked potentials in phenylketonuria.

The pathogenesis of brain dysfunction in phenylketonuria (PKU) is still under investigation. Hyperphenylalaninaemia results in increased turnover of myelin. In order to demonstrate the derangement of myelinization in PKU we studied the visual evoked potentials (VEP) in 14 PKU patients and in 20 normal subjects. VEP findings were correlated with the metabolic control of the disease and with the electroencephalographic findings. VEP were more sensitive than the EEG in detecting a neurological dysfunction. VEP are influenced by dietary control and are normal only in children with good metabolic control.

Cranial computerized tomography in dihydropteridine reductase deficiency.

Dihydropteridine reductase deficiency is a rare cause of hyperphenylalaninaemia, characterized by severe and progressive neurological impairment, despite early and accurate dietary control of plasma phenylalanine. We describe two girls, diagnosed at 17 and 14 months of age, respectively, and immediately treated with L-dopa, 5-hydroxytryptophan and carbidopa. In spite of an adequate dietary and pharmacological treatment, the clinical and neurological pictures progressively worsened. Repeated cranial computerized axial tomography scans showed degeneration of the white matter and, in one case, calcification of the basal ganglia. The possible association of this last finding with folate depletion is discussed.