[Neonatal bacterial infections]. / Le infezioni batteriche neonatali.

Bacterial infections during the first months of life remain a significant cause of neonatal mortality and morbidity. This article reviews the recent knowledges of responsible bacteria and pathogenetic mechanisms as well as advancements in life support therapy, in antimicrobial agents and in immunotherapy.

Clinical pharmacology of netilmicin in preterm and term newborn infants.

Sixty-four neonates, with gestational age ranging from 27 1/2 to 40 weeks, postnatal age from 1 to 15 days, and birth weight from 800 to 3400 gm, were given netilmicin 2.5 mg/kg intramuscularly two or three times per day according to postnatal age, for 5 to 14 days. Serum concentrations were measured before and 1 hour after a dose at least twice during treatment. The serum washout profile of the drug was observed in 22 neonates after discontinuation of therapy. Renal function was studied in 37 infants by measuring serum creatinine concentrations and in 27 by urinary excretion of N-acetyl-glucosaminidase during and up to 15 days after therapy. Behavioral and impedance audiometry, and in infants failing those, auditory brainstem evoked response tests, were performed between 6 and 12 months of age. In 23.5% of the neonates, trough serum levels were greater than 3 micrograms/ml. The serum washout followed a multiexponential decay, accounting for distributional, rapid (initial), and slow (tissue) elimination phases. Linear regression analysis performed between each kinetic parameter and gestational age or birth weight showed that initial elimination half-life, steady-state volume of distribution, and total body clearance were significantly correlated with both variables. Netilmicin did not cause detectable renal or auditory damage.

Evaluation in guinea pigs of the allergenic capacity of two infant formulae based on hydrolyzed milk proteins.

The purpose of the present study was to evaluate the potential capacity of infant formulae based, respectively, on hydrolyzed casein and on hydrolyzed whey proteins to induce sensitization in guinea pigs. This potential capacity was tested by intravenous challenges with centrifuged formulae and by passive cutaneous anaphylaxis. The results showed that neither formula was sensitizing, therefore suggesting that protein hydrolyzates can be considered a suitable cow's milk substitute for infants with cow's milk protein intolerance. However, further studies are necessary in order to investigate whether these hydrolyzates are not allergenic in infants as well.

Efficacy and safety of the "integral" phototherapy for neonatal hyperbilirubinemia. Results of a follow-up at 6 years of age.

One hundred and ten full-term newborns were treated with integral phototherapy (IP) in the first week of life for hyperbilirubinemia (peak bilirubin concentration, 19.5 +/- 2.8 mg/dl). IP was provided by an apparatus which irradiated the infants over the entire skin surface with four visible blue light lamps placed around the body at a mean distance of only 20 cm. The irradiance of the lamps at the skin surface was 0.350 mW/sq cm, in the wavelength range between 425 and 475 nm. The IP resulted in a 48-hour bilirubin decline rate of 0.163 mg/dl/h. After a mean exposure of 78 +/- 32 h, the mean plasma bilirubin level was 8.4 +/- 0.8 mg/dl. One hundred and ten comparable nonjaundiced infants were studied as controls. At 6 years of age, both groups of subjects were called for a follow-up concerning growth, visual, and hearing functions, and neuro-developmental status. The follow-up was completed in 81 children of the IP group (73.6%) and in 89 of the controls (80.6%). There were no significant differences in the studied parameters between the two groups. The study concludes that IP appears to be an effective and safe treatment for jaundiced infants. IP employs less radiant energy from the lamp source than the traditional apparatus, but delivers this energy to a larger skin surface area.

The premature breech presentation: outcome of newborn infants born by vaginal or abdominal delivery.

There is ample documentation that breech full-term infants delivered vaginally have a higher perinatal morbidity and mortality rate than breech infants born via cesarean section. Until now, little emphasis has been placed on the risks to premature newborns born in breech presentation. Therefore, the authors have considered all singleton pregnancies with infants in breech presentation admitted to the Department of Obstetrics, University of Padova, from January 1978 to December 1979 and delivered before 36-weeks gestation. On the basis of obstetric management, the authors have obtained two groups: Group A comprised 36 infants born by vaginal delivery; Group B totaled 32 newborns delivered by cesarean section. Mean gestational age and birthweight were comparable. Of the neonatal events considered, the following were significantly different: Apgar score at 5 minutes less than 7 (A = 30.6%; B = 9.3%), mortality (A = 13.8%; B = 0), neurologic sequelae in the infants discharged from the neonatal intensive care unit (NICU) (A = 50%; B = 9.1%) and the sum of mortality and long term sequelae (A = 22.2%; B = 3.1%). The authors conclude that cesarean section performed in mothers with impending preterm breech delivery decreases the neonatal mortality rate and improves the long-term outcome.

The prevention of respiratory distress syndrome in premature infants: efficacy of antenatal aminophylline treatment versus prenatal glucocorticoid administration.

Antepartum administration of aminophylline (AF) to pregnant animals resulted in accelerated and increased pulmonary maturation as well as in decreased morbidity and mortality from RDS in premature offspring. The present study was undertaken to evaluate the effect of antenatal AF treatment on the frequency of RDS among premature infants born of women who were treated (18) and to compare this group with betamethasone (GC) treated group (16 women). No statistical significant differences were noted between the AF and GC groups in the incidence of RDS (AF = 11.0%; GC = 0%) and in the frequency of perinatal deaths (AF and GC = 0%). Only a significant difference was noted between the AF group and the GC group in the incidence of neonatal signs of infection (AF = 0%; GC = 50%). The authors conclude that antenatal AF treatment may be as effective as GC in the prevention of RDS in premature infants with, for the moment, no side effects.

[Neonatal cystic lymphangioma]. / Linfangioma cistico neonatale.

The A.A. reports a case of cystic congenital linphangioma of the face and neck, recently observed on the Neonatal Intensive Care Unit. The therapeutic approach was very difficult and required three times a surgical menagement because of successively relapses. The control and normalization of the compressive and infective complications due to the massa and its removal were hard too. In spite of some aesthetical problems, the results may be considered satisfactory. Our case enphasizes the intrinsec, complex, therapeutical difficulties of the cystic linphangiomas.

Sites of action of light during phototherapy.

In order to investigate the main sites of action of phototherapy in the treatment of neonatal jaundice we studied (a) the in vivo and in vitro relationship between the hematocrit and the effectiveness of phototherapy, and (b) the effect of varying the skin area exposed to light. The results show that the hematocrit does not influence in vivo the efficacy of phototherapy, while they confirm that the total skin surface exposed to light is important in determining the effectiveness of light treatment. The authors have also studied the possible action of phototherapy on bilirubin solutions placed into the postmortem brain or the stomach. The results suggest that blue light does not penetrate strongly enough to photomodify the exposed pigment.

[Effect of obstructive malformations on the gastrointestinal tract on bilirubin levels in newborn infants]. / Influenza delle malformazioni ostruttive del tubo gastro-intestinale sui livelli bilirubinemici del neonato.

The authors have reviewed their cases of neonatal obstructive malformations of the intestinal tract and analyzed the incidence of association with indirect hyperbilirubinemia. 39 patients in four years are considered. In 23 of them there is a bilirubin level greater than 5 mg/100 ml. A great number of high bilirubin levels (greater than 15 mg/100 ml) is associated with volvulus, malrotations and intestinal atresias. Bilirubin levels between 11 and 15 mg/100 ml are often connected with meconium ileus while ano-rectal atresias have a low bilirubin level (less than 5 mg/100 ml). The reported data allow to conclude that the jaundice is an early, but unfortunately, not specific symptom of congenital intestinal obstruction. The entero-hepatic circulation seems to be an important cause of the neonatal hyperbilirubinemia.

Inhibitory effects of bilirubin and photobilirubin on neonatal and adult T lymphocytes and granulocytes.

The lymphoproliferative response to phytohemagglutinin of lymphocytes and spontaneous motility, chemotaxis and phagocytic activity of granulocytes were studied in the newborn and adult blood in the presence of bilirubin and photobilirubin. All of these activities were inhibited to the same extent by these substances. In addition, a significant difference between newborn and adult values was found. In conclusion, the authors suggest that phototherapy does not decrease bilirubin cellular toxicity.

Distribution of endogenous and injected porphyrins at the subcellular level in rat hepatocytes and in ascites hepatoma.

Different doses (0.5-20 mg/kg) of hematoporphyrin (HP) have been injected intraperitoneally into normal rats and rats affected by Yoshida ascites hepatoma. About 80% of HP reaching the liver was recovered in the extracellular compartment after liver perfusion, the ratio of extra- to intracellular HP being essentially independent of the administered dose. Similar data were obtained at different times after injection of 20 mg/kg HP. Intracellular HP largely accumulates in the mitochondria and in the membrane components of the nuclear fraction of isolated hepatocytes. Kinetic studies suggest that the cell receptors of highest affinity for HP are present in the external membrane. The latter result obtains for ascites hepatoma cells in an even more evident way, although the latter cells exhibit secondary HP binding sites probably constituted by cytoplasmatic proteins. Moreover, the clearance of intracellular HP from malignant cells occurs at a remarkably lower rate as compared with HP clearance from liver cells.

Effect of various phototherapy regimens on bilirubin decrement.

Continuous phototherapy in full-term newborns was found to be more effective than intermittent illumination. Treatment efficacy was also related to age and the initial bilirubin level of the infants. In fact, the reported data indicate an increased therapeutic effect in newborns affected with nonhemolytic hyperbilirubinemia who had an initial bilirubin level greater than 15 mg/dl as compared to neonates with an initial bilirubin level less than 15 mg/dl. The light treatment was also more effective in infants older than 3 days, possibly because of an increased ligandin and conjugating capacity. Shielding the hepatic area during illumination significantly decreases the efficiency of this treatment, suggesting that the liver could also be a phototherapeutic action site.