Letizia Capasso

Bile acids modulate tight junction structure and barrier function of Caco-2 monolayers via EGFR activation

Intestinal and systemic illnesses have been linked to increased gut permeability. Bile acids, whose luminal profile can be altered in human disease, modulate intestinal paracellular permeability. We investigated the mechanism by which selected bile acids increase gut permeability using a validated in vitro model. Human intestinal Caco-2 cells were grown in monolayers and challenged with a panel of bile acids. Transepithelial electrical resistance and luminal-to-basolateral fluxes of 10-kDa Cascade blue-conjugated dextran were used to monitor paracellular permeability. Immunoprecipitation and immunoblot analyses were employed to investigate the intracellular pathway. Redistribution of tight junction proteins was studied by confocal laser microscopy. Micromolar concentrations of cholic acid, deoxycholic acid (DCA), and chenodeoxycholic acid (CDCA) but not ursodeoxycholic acid decreased transepithelial electrical resistance and increased dextran flux in a reversible fashion. Coincubation of 50 muM CDCA or DCA with EGF, anti-EGF monoclonal antibody, or specific src inhibitor 4-Amino-5-(4-chlorophenyl)-7-(t-butyl)pyrazolo[3,4-d]pyrimidine (PP-2) abolished the effect. A concentration of 50 muM of either CDCA or DCA also induced EGF receptor phosphorylation, occludin dephosphorylation, and occludin redistribution at the tight junction level in the same time frame and in a reversible fashion. We conclude that selected bile acids modulate intestinal permeability via EGF receptor autophosphorylation, occludin dephosphorylation, and rearrangement at the tight junction level. The effect is mediated by the src family kinases and is abolished by EGF treatment. These data also support the role of bile acids in the genesis of necrotizing enterocolitis and the protective effect of EGF treatment.

Can neonatal lung ultrasound monitor fluid clearance and predict the need of respiratory support

IntroductionAt birth, lung fluid is rapidly cleared to allow gas exchange. As pulmonary sonography discriminates between liquid and air content, we have used it to monitor extrauterine fluid clearance and respiratory adaptation in term and late preterm neonates. Ultrasound data were also related to the need for respiratory support.MethodsConsecutive infants at 60 to 120 minutes after birth underwent lung echography. Images were classified using a standardized protocol of adult emergency medicine with minor modifications. Neonates were assigned to type 1 (white lung image), type 2 (prevalence of comet-tail artifacts or B-lines) or type 3 profiles (prevalence of horizontal or A lines). Scans were repeated at 12, 24 and 36 hours. The primary endpoint was the number of infants admitted to the neonatal ICU (NICU) by attending staff who were unaware of the ultrasound. Mode of respiratory support was also recorded.ResultsA total of 154 infants were enrolled in the study. Fourteen neonates were assigned to the type 1, 46 to the type 2 and 94 to the type 3 profile. Within 36 hours there was a gradual shift from types 1 and 2 to type 3. All 14 type 1 and 4 type 2 neonates were admitted to the NICU. Sensitivity was 77.7%, specificity was 100%, positive predictive value was 100%, negative predictive value was 97%. Four type 1 infants were mechanically ventilated.ConclusionsIn the late preterm and term neonate, the lung ultrasound scan follows a reproducible pattern that parallels the respiratory status and can be used as a predictor of respiratory support.

Neonatal Urinary Cotinine Correlates With Behavioral Alterations in Newborns Prenatally Exposed to Tobacco Smoke

Altered behavior due to prenatal smoke exposure was examined in 25 neonates born from smoking mothers who consumed at least 5 cigarettes/d during the entire gestation. Data were compared with 25 matched neonates born from nonsmoking mothers. Neonatal behavior was evaluated using the Brazelton Neonatal Behavioral Assessment Scale (BNBAS). Antenatal exposure to tobacco smoke at the end of the pregnancy was determined by measurement of urinary cotinine. Newborns from smoking mothers showed significant lower scores in various BNBAS items compared with neonates from nonsmoking mothers. A strong correlation was observed between infant irritability and urinary cotinine in newborns from smoker and nonsmoking mothers and with number of daily smoked cigarettes and maternal nicotine daily intake of infants exposed to active maternal smoking. Linear regression analysis showed that urinary cotinine was the best predictor of infant irritability (r2 = 0.727). The latter was also associated to the neonates low level of attention and poor response to inanimate auditory stimuli. Among infants from nonsmoking mothers, paternal smoking significantly correlated with infant urinary cotinine and infant irritability, being also the best predictor of irritability (r2 = 0.364). Neonatal behavior can be significantly altered in a dose-dependent manner even after modest prenatal exposure to tobacco smoke.

A randomized trial comparing oxygen delivery on intermittent positive pressure with nasal cannulae versus facial mask in neonatal primary resuscitation

Aim: To compare, in a prospective clinical trial, oxygen delivery on intermittent positive pressure with nasal cannulae versus facial mask in primary resuscitation of the newborn with moderate asphyxia. Methods: 617 neonates with moderate asphyxia at birth were randomized: 303 were resuscitated by oxygen on intermittent positive pressure with nasal cannuale and 314 neonates by mask. Resuscitation followed the Neonatal Resuscitation Program guidelines of the American Academy of Pediatrics, 3rd edition. Results: Resuscitation through the nasal route less frequently requires chest compressions and intubations (26 neonates needed chest compression and 20 needed intubation out of 314 resuscitated by mask; five neonates needed chest compression and two needed intubation out of 303 resuscitated by nasal cannulae). Apgar scores, admission rates to neonatal intensive care units, air‐leak syndromes, birthweight, gestational age, use of prenatal steroids and deaths did not differ between groups.

Use of Neonatal Chest Ultrasound to Predict Noninvasive Ventilation Failure

BACKGROUND: Noninvasive ventilation is the treatment of choice for neonatal moderate respiratory distress (RD). Predictors of nasal ventilation failure are helpful in preventing clinical deterioration. Work on neonatal lung ultrasound has shown that the persistence of a hyperechogenic, “white lung” image correlates with severe distress in the preterm infant. We investigate the persistent white lung ultrasound image as a marker of noninvasive ventilation failure. METHODS: Newborns admitted to the NICU with moderate RD and stabilized on nasal continuous positive airway pressure for 120 minutes were enrolled. Lung ultrasound was performed and blindly classified as type 1 (white lung), type 2 (prevalence of B-lines), or type 3 (prevalence of A-lines). Chest radiograph also was examined and graded by an experienced radiologist blind to the infant’s clinical condition. Outcome of the study was the accuracy of bilateral type 1 to predict intubation within 24 hours from scanning. Secondary outcome was the performance of the highest radiographic grade within the same time interval. RESULTS: We enrolled 54 infants (gestational age 32.5 ± 2.6 weeks; birth weight 1703 ± 583 g). Type 1 lung profile showed sensitivity 88.9%, specificity 100%, positive predictive value 100%, and negative predictive value 94.7%. Chest radiograph had sensitivity 38.9%, specificity 77.8%, positive predictive value 46.7%, and negative predictive value 71.8%. CONCLUSIONS: After a 2-hour nasal ventilation trial, neonatal lung ultrasound is a useful predictor of the need for intubation, largely outperforming conventional radiology. Future studies should address whether including ultrasonography in the management of neonatal moderate RD confers clinical advantages.

Measuring transcutaneous bilirubin: a comparative analysis of three devices on a multiracial population

BackgroundHyperbilirubinemia can lead to potentially irreversible bilirubin-induced neurotoxicity. Transcutaneous bilirubin (TcB) determination has become a valuable aid in non invasive screening of neonatal jaundice.The aim of this study is to compare the performance of three most widespread transcutaneous bilirubinometers on a multiracial population of term and late pre-term neonates.MethodsBilirubin concentration was determined using traditional photometric determination and transcutaneously with Bilicheck, BiliMed and JM-103, in random order.Total serum bilirubin (TSB) was determined over a wide concentration range (15,8–0,7 mg/dl) with a mean of 9,5 mg/dl. Related TcB values using Bilicheck (TcB-BC), BiliMed (TcB-BM), and JM-103 (TcB-JM) are reported in Table 1.ResultsA multiracial population of 289 neonates was enrolled with a gestational age ranging from 35 to 41 weeks; birth weight ranging from 1800to 4350 grams; hours of life ranging from 4 to 424. In the total study population correlation analysis using Pearson coefficients showed good results for Bilicheck (r = 0.86) and JM-103 (r = 0.85) but poor for BiliMed (r = 0,70). Similar results were found for the non-Caucasian neonates subgroup. Bilicheck and JM-103 had a greater area under the curve than BiliMed when TSB =14 mg/dl was chosen as a threshold value both for the total study population and the non-Caucasian subgroup.ConclusionsBilicheck and JM-103, but not BiliMed, are equally reliable screening tools for hyperbilirubinemia in our multiracial neonatal population.

Unconjugated Bilirubin Modulates the Intestinal Epithelial Barrier Function in a Human-Derived In Vitro Model

Unconjugated bilirubin promotes intestinal secretion without affecting nutrient digestion or absorption. In the current study, the effects of unconjugated bilirubin (UCB) on the barrier function of the intestinal epithelium were investigated. The apical side of human intestinal cell line Caco-2 monolayers was challenged with purified UCB. Transepithelial electrical resistance and paracellular fluxes of 10 kD Cascade blue conjugate dextran were measured. Cell monolayer viability was studied using LDH release and trypan blue exclusion tests. Redistribution of enterocyte tight junction occludin was studied by confocal microscopy. Bilirubin induced a dose-dependent decrease of transepithelial electrical resistance (TEER). This effect was maximal at 6 h and tended to be reversed at 48 h. Oxidated bilirubin was ineffective. Bilirubin significantly increased fluorescent dextran paracellular passage. Cell viability was not affected by UCB over the 5–200 nmol/L concentration range. Finally, bilirubin triggered a reversible redistribution of tight junctional occludin. UCB increases the permeability of intestinal epithelium. This effect is reversible, dependent on the redox status of the molecule and the rearrangement of the tight junction. These data attribute to bilirubin a novel role of functional modulator of intestinal paracellular permeability in vitro.

Early cord clamping protects at-risk neonates from polycythemia

Neonatal polycythemia is a potentially lethal, multi-organ disease. We have performed a prospective, open-label study to test the hypothesis that an early cord clamping proximally to the neonate’s abdomen could avert from the neonatal circulation a blood volume critical to the occurrence of polycythemia in at-risk neonates. Newborns were divided into group 1 (clamping time within 10 s) and group 2 (clamping time 11–120 s). Group 1 had statistically significant more blood volume sequestered in the cord and less manifestations of polycythemia. Conclusion: An early cord clamping is an effective and zero-cost way to prevent polycythemia in at-risk neonates.

Italian guidelines for management and treatment of hyperbilirubinaemia of newborn infants ≥ 35 weeks' gestational age.

Hyperbilirubinaemia is one of the most frequent problems in otherwise healthy newborn infants. Early discharge of the healthy newborn infants, particularly those in whom breastfeeding is not fully established, may be associated with delayed diagnosis of significant hyperbilirubinaemia that has the potential for causing severe neurological impairments. We present the shared Italian guidelines for management and treatment of jaundice established by the Task Force on hyperbilirubinaemia of the Italian Society of Neonatology.The overall aim of the present guidelines is to provide an useful tool for neonatologists and family paediatricians for managing hyperbilirubinaemia.

Lung ultrasound-guided emergency pneumothorax needle aspiration in a very preterm infant

Pneumothorax is a frequent critical situation in the neonatal intensive care unit. Diagnosis relies on clinical judgement, transillumination and chest radiogram. We report the case of a very preterm infant suddenly developing significant and persistent desaturation and bradycardia. Re-intubation and cardiopulmonary resuscitation were performed. Clinical and cold light examination were not suggestive of pneumothorax according to two experienced neonatologists. A lung ultrasound scan showed evidence of right pneumothorax that was promptly aspirated. Approximately 20 min later, a chest radiogram confirmed the ultrasound diagnosis. Point-of-care lung ultrasound is a useful tool for detecting symptomatic pneumothorax and accelerating its treatment.