0000000000083833
AUTHOR
Raquel Escrig
Consequences of neonatal resuscitation with supplemental oxygen.
There has been considerable controversy surrounding the optimal inspired oxygen concentration for resuscitation of term and preterm infants. We have developed a rat pup model to quantify both physiologic and biochemical parameters associated with normoxic vs. hyperoxic resuscitation. We have confirmed existing human data that hyperoxic resuscitation of rat pups is associated with a significant delay in onset of spontaneous respiratory efforts. Both 40% and 100% inspired oxygen delayed onset of respiratory activity when compared to 21% oxygen. We have also documented, in the rat pup model, that hyperoxic resuscitation is associated with reduced levels of glutathione at 24 hours post resuscit…
Human milk enhances antioxidant defenses against hydroxyl radical aggression in preterm infants
Background: Preterm infants endowed with an immature antioxidant defense system are prone to oxidative stress. Hydroxyl radicals are very aggressive reactive oxygen species that lack specific antioxidants. These radicals cannot be measured directly, but oxidation byproducts of DNA or phenylalanine in urine are reliable markers of their activity. Human milk has a higher antioxidant capacity than formula. Objective: We hypothesized that oxidative stress associated with prematurity could be diminished by feeding human milk. Design: We recruited a cohort of stable preterm infants who lacked perinatal conditions associated with oxidative stress; were not receiving prooxidant or antioxidant drugs…
Metabolic adaptation and neuroprotection differ in the retina and choroid in a piglet model of acute postnatal hypoxia.
Hypoxic-ischemic insults to the neonatal brain may cause neurodevelopmental disorders. Vulnerability of different areas of the neural tissue to hypoxic-ischemic stress might be explained by either heterogeneous sensitivity to oxygen or neuroprotective capability. Our understanding of regional heterogeneity is still incomplete in terms of metabolic reconfiguration and/or activation of neuroprotective mechanisms.We studied, by western blotting, reverse-transcriptase PCR, and tandem mass spectrometry, the response of retina and choroid at protein, gene, and metabolic levels during hypoxia in a piglet model of acute postnatal hypoxia.We evidenced a metabolic shift towards glycolysis in choroid …
Expression of aquaporins early in human pregnancy
Abstract Background Aquaporins (AQPs) constitute a family of channel proteins implicated in transmembrane water transport. Thirteen different AQPs (AQP0–12) have been described but their precise biologic function still remains unclear. AQPs 1, 3, 4, 8, and 9 expression has been described in human chorion, amnion and placenta; however, AQP4 is the only that has been identified in the first trimester of human pregnancy. Objective To assess multiplicity of AQPs expression from 10th to 14th week gestation. Population and methods Chorionic villi samples (CVS) collected in pregnant women for prenatal diagnosis were analysed by real time-PCR to assess cDNA expression of AQPs 1, 2, 3, 4, 5, 6, 7, 8…
Does Oxygen Concentration Used for Resuscitation Influence Outcome of Asphyxiated Newly Born Infants Treated With Hypothermia?
To the Editor. — In a recent article, Rutherford et al1 describe the neuroprotective effect of whole-body cooling and selective head cooling in newly born infants suffering from hypoxic-ischemic encephalopathy. MRI studies of infants receiving either of these therapies showed a lesser degree of basal ganglia and thalamic lesions than nontreated controls, which correlates with a better neurologic prognosis. However, no description of the resuscitation maneuvers used is present in the article's “Patients and Methods” section. Thus, the authors do not include details on how many infants were given positive pressure ventilation and, especially, what concentration of oxygen was used, if oxygen s…
Expression of Human Ubiquitous Aquaporins in Chorial Villus Samples
Background/objectives: Aquaporins (AQPs) are a family of proteins (AQP0-12) ubiquitously expressed acting as cell membrane water channels. AQP 1/3/8/9 expression has been found in human placenta and fetal membranes; however, AQP4 is the only identified in first trimester fetal tissue samples. We aimed to determine AQP mRNA expression in first trimester of pregnancy and compare it to the expression in placenta at delivery. Material and Methods: 26 Chorionic villus (CV) samples and 5 placental samples were collected and analyzed by real time-PCR using Taqman assay (Applied Biosystems®) for human AQP1, 2, 3, 4, 5, 6, 7, 8, 9, 11 and 18S. Results: CV expressed high mRNA levels of AQP1, 3, 9 and…
Preterm Resuscitation With Low Oxygen Causes Less Oxidative Stress, Inflammation, and Chronic Lung Disease
OBJECTIVE: The goal was to reduce adverse pulmonary adverse outcomes, oxidative stress, and inflammation in neonates of 24 to 28 weeks of gestation initially resuscitated with fractions of inspired oxygen of 30% or 90%. METHODS: Randomized assignment to receive 30% (N = 37) or 90% (N = 41) oxygen was performed. Targeted oxygen saturation values were 75% at 5 minutes and 85% at 10 minutes. Blood oxidized glutathione (GSSG)/reduced glutathione ratio and urinary o-tyrosine, 8-oxo-dihydroxyguanosine, and isoprostane levels, isofuran elimination, and plasma interleukin 8 and tumor necrosis factor α levels were determined. RESULTS: The low-oxygen group needed fewer days of oxygen supplementation …
Target oxygen levels in preterm neonates
To achieve postnatal adaptation newly born infant need to aerate the lungs, reduce pulmonary vascular resistance, and initiate oxygen and carbon dioxide exchange. The cornerstone of newborn resuscitation resides therefore in the establishment of a functional residual capacity and an adequate oxygenation. Recent guidelines have established guidelines concerning oxygen supplementation in preterm infants in the delivery room (DR); however, they are vague and unspecific. Herewith, we will address available information regarding the use of oxygen supplementation in the DR in preterm infants to satisfactorily overcome postnatal adaptation. Introduction: Resuscitation of the newborn is considered …
Antenatal Steroids and Antioxidant Enzyme Activity in Preterm Infants: Influence of Gender and Timing
Antenatal steroids have improved the survival of preterm infants; however, the mechanism of action is not fully understood. We aimed to establish an association between antenatal steroids and antioxidant activity and postnatal oxidative stress. In a prospective cohort study, extremely preterm neonates receiving antenatal steroids (CORT) or not (NOCORT) were enrolled. An association between antenatal steroids and activities of antioxidant enzymes and glutathione cycle enzymes in cord blood was found. In addition, reduced oxidative stress (GSH/GSSG ratio, CORT vs. NOCORT, 35.68 + or - 12.20 vs. 28.38 + or - 9.92; p < 0.01) and, decreased oxidation of proteins (ortho-tyrosine/phenylalanine rat…