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Biomedical subjects

F F Rubaltelli

Publications and source records attributed to F F Rubaltelli.

At least 55 records · Page 3Linked to original sources

Adverse effects of prenatal glucocorticoid treatment in the preterm infant.

Several studies suggest that glucocorticoids given to the mother at risk for preterm delivery, reduce the incidence of respiratory distress syndrome, intraventricular hemorrhage, bronchopulmonary dysplasia and mortality. Only 20% of pregnancies at risk for preterm delivery are actually treated with steroids: this reluctance may be due to the theoretical adverse effect of this therapy in the mother and the newborn. Our aim was to review the studies performed during the past two decades to assess the risk/benefit ratio of antenatal steroid treatment in the preterm infant.

Animals↗

Conjugated bilirubin in neonates with glucose-6-phosphate dehydrogenase deficiency.

We used a system capable of measuring conjugated bilirubin and its monoconjugated and diconjugated fractions in serum to assess bilirubin conjugation in 29 glucose-6-phosphate dehydrogenase (G6PD)-deficient, term, male newborn infants and 35 control subjects; all had serum bilirubin levels > or = 256 mumol/L (15 mg/dI). The median value for diconjugated bilirubin was lower in the G6PD-deficient neonates than in control subjects (0.06 (range 0.00 to 1.84) vs 0.21 (range 0.00 to 1.02) mumol/L, p = 0.006). Diglucuronide was undetectable in 11 (38.9%) of the G6PD-deficient infants versus 3 (8.6%) of the control subjects (p = 0.015). These findings imply a partial defect of bilirubin conjugation not previously demonstrated in G6PD-deficient newborn infants.

Bilirubin↗

The bronze baby syndrome: evidence of increased tissue concentration of copper porphyrins.

A case regarding a newborn infant with severe Rh haemolytic disease, who presented with the bronze baby syndrome and eventually died, is reported. The postmortem examination showed marked extramedullary haematopoiesis in the liver and spleen, heavy hepatic haemosiderosis and mild intralobular cholestasis. The porphyrin content, which was assayed in different tissues, was very high in the liver, suggesting that the increased erythropoiesis seen in Rh haemolytic disease leads to an increased synthesis of porphyrins as by-products of haem synthesis. Phototherapy causes photodestruction, sensitized by bilirubin, of porphyrins (mainly copper porphyrins), yielding brown photoproducts.

Erythroblastosis, Fetal↗

The incidence of acute neonatal respiratory disorders in Padova county: an epidemiological survey.

The aim of this study was to determine the incidence of respiratory diseases in newborns and the mortality rate caused by the same disorders in an area-based survey conducted during the period extending from June 1, 1993, to May 31, 1994. These rates were related to sex, gestational age, birth weight, Apgar score, mode of delivery and obstetric pathologies. A total of 7588 newborns were studied. A simple diagnostic system was used, which was based on clinical, laboratory and instrumental criteria. The incidence of respiratory disorders was 3.3%; the overall mortality rate was 0.28% and the case fatality rate for respiratory distress syndrome was 14.8%. Neonatal asphyxia was frequently associated with respiratory diseases.

Apgar Score↗

Ketotifen in the management of infants with bronchopulmonary dysplasia.

Ketotifen, a histamine (H1) antagonist, inhibits PAF-induced eosinophil accumulation and airway hyperreactivity. Bronchopulmonary dysplasia (BPD) is a complex disorder in which bronchial hyperreactivity is usually present. An open randomized trial was carried out with this agent in infants with chronic BPD who were followed up for 6 months. The efficacy of the drug was evaluated according to respiratory symptom and medication scores, in which numerical values were assigned to various other antiasthmatic agents used to control wheezing. No adverse clinical or biochemical sequelae were noted during treatment. The mean respiratory symptom and mean medication scores were significantly higher worse in the control group in comparison with the infants treated with ketotifen.

Bronchopulmonary Dysplasia↗

Serum and bile bilirubin pigments in the differential diagnosis of Crigler-Najjar disease.

OBJECTIVE: To differentiate between Crigler-Najjar (CN) disease types 1 and 2. DESIGN: The patterns of serum bilirubins, bile pigment composition, and phenobarbital response were studied. PATIENTS: Three infants, affected by high serum unconjugated bilirubin concentrations, previously classified as type 1 CN. METHODS: Serum and bile bilirubin pigment composition, both before and after phenobarbital (PB) treatment, were determined by alkaline methanolysis and high-pressure liquid chromatography. PB was given for at least 3 weeks by oral administration (5 mg/kg bw per day). RESULTS: No diconjugated bilirubin was found either before or after PB treatment in the serum of the three studied infants. In two patients traces of monoconjugated bilirubin were detected before PB therapy, and the ratio of conjugated/total bilirubin (percent) was increased by the PB response. In the third patient, traces of monoconjugated bilirubin appeared only after PB administration. However, the serum unconjugated bilirubin concentration decreased significantly only in the second patient, following the second cycle of PB treatment, leading to the diagnosis of type 2 CN. The analysis of the methyl ester derivatives of bile pigments was also performed on bile samples obtained in two patients by Entero-Test (R) both before and after PB treatment. An absolute increment in monoesterified bilirubin concentration was found after PB administration, although the percent concentration increased in one case and decreased in the other. No diesterified bilirubin was detected in the bile samples. CONCLUSIONS: The present results show that in types 1 and 2 CN disease it is possible to detect traces of monoconjugated but not diconjugated bilirubin both in serum and in bile. Whereas PB treatment is effective in slightly increasing the serum monoconjugated bilirubin concentration even in type 1 CN disease, the diagnosis of type 1 or 2 is based on finding a substantial decrease of serum unconjugated bilirubin following PB administration.

Administration, Oral↗

Unconjugated and conjugated bilirubin pigments during perinatal development. IV. The influence of breast-feeding on neonatal hyperbilirubinemia.

One thousand four hundred and fifty-four consecutive full-term neonates, delivered over a period extending from February 1, 1991 to January 31, 1992 were prospectively studied during the first days of life to determine if breast-feeding and hyperbilirubinemia were related. Six hundred and five infants were exclusively breast-fed on demand, 623 received both breast- and formula-feeding, and 226 were exclusively formula-fed. Of the 1,454 newborns studied, 70 (4.8%) presented with a bilirubin serum concentration > 12.9 mg/dl (4.62% in the breast-fed group, 5.45% in the group fed with mother's milk with supplements, and 3.54% in the artificial formula group; the differences were not significant). Percent mean weight losses on the 3rd and 5th days were not significantly different. Babies breast-fed on demand seem to have a low incidence of hyperbilirubinemia similar to that found in formula-fed neonates.

Bilirubin↗

Management of neonatal hyperbilirubinaemia and prevention of kernicterus.

Hyperbilirubinaemia remains one of the most common and more important pathological conditions in the newborn. The possibility that the so-called physiological or developmental hyperbilirubinaemia, with relatively low levels of serum bilirubin, could be responsible for bilirubin encephalopathy in the small premature infant is of great concern to the neonatologist; premature newborns are prone to developing hyperbilirubinaemia. Current methodologies for suppressing severe neonatal jaundice include: (a) attempts to stimulate liver conjugating enzymes using drugs such as phenobarbital; (b) attempts to degrade bilirubin with phototherapy; and (c) exchange transfusion. It is too soon to consider tin-protoporphyrin as a drug for the prevention and treatment of neonatal hyperbilirubinaemia. However, if it can be shown that tin-protoporphyrin can serve as a safe and less costly alternate treatment, a considerable improvement in the management of neonatal jaundice would be achieved.

Bilirubin↗

Photochemical and photosensitizing properties of monomeric and dimeric Sn(IV)-protoporphyrin.

Sn(IV)-protoporphyrin IX (Sn-Pp) in aqueous media exists as a mixture of monomeric and dimeric species, which can be readily distinguished on the basis of their absorption maxima at around 410 and 386 nm respectively. Sn-Pp dimers prevail as the pH is decreased and are characterized by a lower fluorescence quantum yield, a larger tendency to undergo photobleaching and a reduced photosensitizing efficiency compared with the Sn-Pp monomer. The photosensitizing action of Sn-Pp appears to involve the intermediacy of singlet oxygen (1O2) as shown by photo-oxidation studies with N-acetyl-tryptophanamide in light and deuterated water solutions. Using 1,3-diphenyl-isobenzofuran as a substrate, the quantum yield of 1O2 generation by monomeric Sn-Pp was found to be about 0.6.

Metalloporphyrins↗

Unconjugated and conjugated bilirubin pigments during perinatal development. III. Studies on serum of breast-fed and formula-fed neonates.

The process of conjugation and secretion of bilirubin was studied in a group of healthy, full-term, exclusively breast-fed newborns and a control group of exclusively formula-fed infants by means of a reverse-phase high-performance liquid chromatographic analysis of bilirubins present in serum. The serum concentrations of unconjugated bilirubin, esterified bilirubin, and the proportion of diesterified bilirubin (as percent of esterified bilirubin) were not significantly different in breast- and formula-fed infants on the 3rd and 5th days of life. These data suggest that both bilirubin production and conjugation are not different in breast-fed and in formula-fed newborns.

Aging↗

Prevention of necrotizing enterocolitis in neonates at risk by oral administration of monomeric IgG.

Necrotizing enterocolitis (NEC) represents one of the major causes of morbidity in low-birth-weight (LBW) preterm infants. This randomized clinical trial evaluated the efficacy of an oral immunoglobulin preparation (containing monomeric IgG in a concentration of 90%) in reducing the incidence of NEC in infants of LBW for whom maternal breast milk was not available. One hundred and thirty-two formula-fed newborns with a birth weight less than or equal to 1,500 g or a gestational age less than or equal to 34 weeks were randomly studied. Five hundred mg of IgG pro die, subdivided into 5 doses, were given orally to the test group of 65 neonates during the first 2 weeks of life. Although the number of infants included in this group is limited, the results of this study are encouraging: during the first 15 days after birth, none of the subjects developed NEC, while 4 cases were confirmed in the untreated control group. It, therefore, seems possible that oral monomeric IgG administration may prevent the development of NEC in LBW infants.

Administration, Oral↗

The prognostic significance of acute neonatal renal failure.

We evaluated 38 newborns with acute renal failure (plasma creatinine (Pcr) concentration greater than = 1.5 mg/dl), measured between the 2nd and 5th days. We used renal ultrasound to exclude the possibility of congenital renal anomalies, obstructive pathology or vascular disorders. We calculated the glomerular filtration rate (GFR) using Schwartz' formula and the maximal concentrating capacity using intranasal administration of desamino-cis-1-D-arginine-8-vasopressin (DDAVP test). Two newborns were treated with peritoneal dialysis and died during the first month of life. Thirty-six had a follow-up blood sample drawn: 24 preterm babies between 1 and 12 months, and 12 full-term babies between 1 and 36 months of life. From this sampling 4 babies (11.1%) showed defective maximal concentrating ability. Our data reveal the persistence of altered concentrating ability in newborns affected by renal failure and shows that this problem needs a longitudinal study and further diagnostic investigations.

Acute Kidney Injury↗

Unconjugated and conjugated bilirubin pigments during perinatal development. II. Studies on serum of healthy newborns and of neonates with erythroblastosis fetalis.

A recently developed reverse-phase high-performance liquid chromatography procedure was applied to the analysis of bilirubins present in serum of neonates. In normal newborns, unconjugated (UCB) and conjugated bilirubins (CB) rose in parallel from day 2 to day 4: the average conjugated fraction remained between 1.2 and 1.6% of total pigment, significantly below the 3.6% documented in adults. However, the absolute concentration of conjugates was 2- to 6-fold higher than the serum levels in adults. Bilirubin conjugates were detected in all samples, but only 20% of these were bilirubin diconjugates, in contrast to a mean of 54% in the adult population. The increased absolute concentrations of UCB and CB together with the decreased fractional amount of conjugates and with the decreased diconjugates seem to be the result of an increased bilirubin production combined with a relative defective biliary secretion. Serum bile acids were high but did not correlate with the levels of bilirubin conjugates. The pattern of serum bilirubins was not different in 4 newborns with hemolytic syndromes. Cholestasis occurred in another child with hemolysis; this was evident from the high concentration and the high fractional amount of conjugates and from the high serum bile acids level.

Bile Acids and Salts↗

Bronze baby syndrome: an animal model.

We evaluated the appropriateness of an animal model for the bronze baby syndrome. Ligation of the common bile duct in adult Wistar rats induces an accumulation of porphyrins and copper in the liver and a 20% conversion of protoporphyrin IX into (Cu(II)-protoporphyrin IX. Upon irradiation of these animals with super-blue lamps, the plasma content of Cu(II)-protoporphyrin increases by about 30%. Cholestasis also increases the recovery of porphyrins in the urine, although light treatment of ligated rats further increases urinary porphyrin excretion. The spectroscopic changes induced by irradiation of sera of ligated rats are consistent with the formation of products that have the typical spectrum found in bronze baby syndrome patients, i.e. a reduced absorbance in the visible region and an increased absorption in near-UV and red spectral regions. The products responsible for the brown discoloration found in bronze baby syndrome seem to result from phototransformation of copper-porphyrins subsequent to an electron transfer between photoexcited bilirubin and the copper ion.

Animals↗

Dexamethasone in the treatment of bronchopulmonary dysplasia.

Sixteen chronically ventilator-dependent newborns with BPD were treated with one or more cycles of dexamethasone (0.5 mg/kg/day). In 11 cases extubation was possible during the therapy period. Ventilatory parameters were lowered in 3 other newborns. FIO2, respiratory rate, PIP, and PEEP, assessed before and after dexamethasone administration, decreased in a statistically significant way. Our data confirm the utility of dexamethasone in the extubation in chronically ventilated infants with BPD.

Bronchopulmonary Dysplasia↗

In vivo clearance of natural and modified surfactant.

The loss of radiolabelled phosphatidylcholine associated with surfactants and lipid extracts of surfactants from different species sources was measured following tracheal injection into the lungs of adult and 3 day old rabbits. Clearance was more rapid from the lungs of adult than 3 day old rabbits. The percent labelled phosphatidylcholine cleared per 24 h did not change independently of dose injected indicating that clearance and catabolic pathways were not saturable in either group of rabbits. Different species sources or lipid extraction of natural surfactants did not alter clearance rates very much in the 3 day old rabbits. Small differences in clearance rates were identified by comparing rabbit surfactant with calf surfactant or Surfactant-TA in the adult rabbits. These results indicate that the lungs of developing and adult rabbits can clear large doses of surfactants from multiple sources at rates comparable to the species common natural surfactant.

Animals↗