Antioxidant vitamin levels in term and preterm infants and their relation to maternal vitamin status

The effects of synbiotic supplementation on blood pressure and other maternal outcomes in pregnant mothers with mild preeclampsia: a triple-blinded randomized controlled trial

INTRODUCTION

Preeclampsia affects a significant percentage of pregnancies which is a leading cause of premature birth. Probiotics have the potential to affect inflammatory factors, and oxidative stress, which are linked to the development of preeclampsia. The study aimed to compare the effect of synbiotic and placebo on blood pressure and pregnancy duration as primary outcomes, and other pregnancy outcomes.

METHODS

This study comprised 128 pregnant women with mild preeclampsia and gestational ages exceeding 24 weeks who were referred to the high-risk pregnancy clinic. It was a randomized, controlled, phase III, triple-blinded clinical experiment. The intervention and control groups were distributed to the participants at random. Intervention group received one oral synbiotic capsule, and control group received placebo daily until delivery. Based on gestational age at the time of diagnosis, preeclampsia was stratificated as early (< 34 weeks) or late (≥ 34 weeks). Data obtained from questionnaires, and biochemical serum factors were analyzed using SPSS software version 23 software.

RESULTS

With the exception of the history of taking vitamin D3, there were no statistically significant variations in socio-demographic variables between the research groups. After the intervention, the means of systolic blood pressure (adjusted mean difference: -13.54, 95% CI: -5.01 to -22.07), and diastolic blood pressure (adjusted mean difference: -10.30, 95% CI: -4.70 to -15.90) were significantly lower in the synbiotic-supplemented group than in the placebo group. Compared to the placebo group, the incidence of severe PE (p < 0.001), proteinuria (p = 0.044), and mean serum creatinine level (p = 0.005) significantly declined in the synbiotic-supplemented group after the intervention. However, our analysis found no significant association for other outcomes.

CONCLUSION

Based on our results, synbiotic had beneficial effects on some pregnancy outcomes. Further studies with larger samples are needed to verify the advantages of synbiotic supplementation for high-risk pregnancies, particularly with regards to higher doses, and longer intervention periods.

TRIAL REGISTRATION

IRCT20110606006709N20.

Vitamin E deficiency in childhood: a narrative review

Vitamin E is an important nutrient from the earliest stages of life. It plays key roles as an antioxidant and in the maintenance of the immune system, among others. Vitamin E deficiency (VED), which occurs more frequently in children, is rarely addressed in the literature. This narrative review aims to summarise the chemistry, biology, serum indicators and clinical trials that have evaluated the impact of fortification and other relevant aspects of vitamin E, in addition to the prevalence of its deficiency, in children worldwide. Vitamin E intake in recommended amounts is essential for this nutrient to perform its functions in the body. Serum α-tocopherol is the most widely used biochemical indicator to assess the prevalence of VED. VED has been associated with symptoms secondary to fat malabsorption and may lead to peripheral neuropathy and increased erythrocyte haemolysis. Reduced concentrations of α-tocopherol may be caused by the combination of diets with low amounts of vitamin E and inadequate consumption of fats, proteins and calories. The lowest prevalence of VED was found in Asia and the highest in North America and Brazil. High proportions of VED provide evidence that this nutritional deficiency is a public health problem in children and still little addressed in the international scientific literature. The planning, evaluation and implementation of health policies aimed at combatting VED in the paediatric population are extremely important.

A review of the effects of early postnatal hyperoxia exposure on the immature brain

Preterm birth is a public health priority worldwide, with approximately 15 million premature babies born each year. Oxygen supplementation is one of the most common interventions for preterm infants. However, prolonged oxygen inhalation at supraphysiological concentrations can lead to the development of bronchopulmonary dysplasia (BPD). In addition to lifelong pulmonary sequelae, clinical evidence suggests that BPD is associated with adverse neurodevelopmental outcomes, such as motor impairment, cognitive impairment, and behavioral deficits, severely affecting the quality of life of preterm infants. However, the mechanisms underlying the combination of neurodevelopmental impairment with BPD remain unclear. Therefore, in recent years, attention has also been focused on the effects of hyperoxia on brain development in preterm infants. In this review, we outline the pathophysiological mechanisms of brain injury caused by developmental hyperoxia exposure in current animal models and briefly describe the pharmacological therapies that may be applicable to the associated brain injury. Overall, more studies are needed to assess the effects of hyperoxia on the immature brain, particularly combined analyses of the lungs and brain in the same experimental setting, to elucidate the potential causes of combined neurodevelopmental impairment in BPD.

Effect of Air Pollution on the Basal DNA Damage of Mother-Newborn Couples of México City

Environmental pollution of megacities can cause early biological damage such as DNA strand breaks and micronuclei formation. Comet assay tail length (TL) reflects exposure in the uterus to high levels of air pollution, primarily ozone and air particles (PM10), including mothers' smoking habits during pregnancy, conditions which can lead to low birth weight. In this biomonitoring study, we evaluated basal DNA damage in the cord blood cells of newborn children from Mexico City. We found a correlation between DNA damage in mothers and their newborns, including various parameters of environmental exposure and complications during pregnancy, particularly respiratory difficulties, malformations, obstetric trauma, neuropathies, and nutritional deficiencies. Mothers living in the southern part of the city showed double DNA damage compared to those living in the northern part (TL 8.64 μm vs. 4.18 μm, p < 0.05). Additionally, mothers' DNA damage correlates with exposure to NOx (range 0.77-1.52 ppm) and PM10 (range 58.32-75.89 μg/m3), as well maternal age >29. These results highlight the sensitivity of the comet assay in identifying differential in utero exposure for newborns whose mothers were exposed during pregnancy. They also suggest the importance of antioxidants during pregnancy and the role of the placental barrier in protecting the newborn from the DNA-damaging effects of oxidative pollution.

Serum Vitamins A and E at Mid-Pregnancy and Their Relationships with Both Maternal and Cord Blood Antioxidant Status and Perinatal Conditions: The NELA Cohort

INTRODUCTION

Most of the pregnant women do not achieve the recommended dietary intake of vitamins A and E. These vitamins may counteract oxidative stress involved in some adverse perinatal outcomes. We aimed to assess the associations between maternal vitamin A and E at mid-pregnancy with both maternal and fetal outcomes and to identify possible early biomarkers during pregnancy to predict and prevent oxidative stress in the offspring.

METHODS

Data on dietary and serum levels of vitamins A and E were collected from 544 pregnant women from the Nutrition in Early Life and Asthma (NELA) study, a prospective mother-child cohort set up in Spain.

RESULTS

There were large discrepancies between low dietary vitamin E intake (78% of the mothers) and low serum vitamin E levels (3%) at 24 weeks of gestation. Maternal serum vitamins A and E at mid-pregnancy were associated with higher antioxidant status not only in the mother at this time point (lower hydroperoxides and higher total antioxidant activity [TAA]) but also with the newborn at birth (higher TAA). Gestational diabetes mellitus (GDM) was negatively associated with maternal serum vitamin A (OR: 0.95 CI: 0.91-0.99, p = 0.009) at mid-pregnancy. Nevertheless, we could not detect any association between GDM and oxidative stress parameters.

CONCLUSIONS

In conclusion, maternal vitamin A and E serum levels may be used as an early potential biomarker of antioxidant status of the neonate at birth. Control of these vitamins during pregnancy could help avoid morbid conditions in the newborn caused by oxidative stress in GDM pregnancies.

Dietary sialic acids: distribution, structure, and functions

Sialic acids (Sias), a group of over 50 structurally distinct acidic saccharides on the surface of all vertebrate cells, are neuraminic acid derivatives. They serve as glycan chain terminators in extracellular glycolipids and glycoproteins. In particular, Sias have significant implications in cell-to-cell as well as host-to-pathogen interactions and participate in various biological processes, including neurodevelopment, neurodegeneration, fertilization, and tumor migration. However, Sia is also present in some of our daily diets, particularly in conjugated form (sialoglycans), such as those in edible bird's nest, red meats, breast milk, bovine milk, and eggs. Among them, breast milk, especially colostrum, contains a high concentration of sialylated oligosaccharides. Numerous reviews have concentrated on the physiological function of Sia as a cellular component of the body and its relationship with the occurrence of diseases. However, the consumption of Sias through dietary sources exerts significant influence on human health, possibly by modulating the gut microbiota's composition and metabolism. In this review, we summarize the distribution, structure, and biological function of particular Sia-rich diets, including human milk, bovine milk, red meat, and egg.

Oxygen for the Newborn: Friend or Foe?

Oxygen supplementation is widely used in neonatal care, however, it can also cause toxic effects if not used properly. Therefore, it appears crucial to find a balance in oxygen administration to avoid damage as a consequence of its insufficient or excessive use. Oxygen toxicity is mainly due to the production of oxygen radicals, molecules normally produced in humans and involved in a myriad of physiological reactions. In the neonatal period, an imbalance between oxidants and antioxidant defenses, the so-called oxidative stress, might occur, causing severe pathological consequences. In this review, we focus on the mechanisms of the production of oxygen radicals and their physiological functions in determining a set of diseases grouped together as "free radical diseases in the neonate". In addition, we describe the evolution of the oxygenation target recommendations during neonatal resuscitation and post-stabilization phases with the aim to define the best oxygen administration according to the newest evidence.

Effect of Supplementation of Vitamin A on Growth, Haemato-Biochemical Composition, and Antioxidant Ability in Cyprinus carpio var. communis

Vitamin A requirement in fingerling common carp, Cyprinus carpio var. communis (1.64 ± 0.02 g; ABW ± SD), was evaluated by conducting a 10 week growth experiment. Casein-gelatin-based test diets representing six graded levels of vitamin A (0, 0.03, 0.07, 0.11, 0.15, and 0.19 g/kg, dry diet) were designed and fed to the triplicate group of fish at 08:00 and 16:00 hrs at the rate of 4% body weight per day. Growth parameters like live weight gain (LWG %), feed conversion ratio (FCR), protein efficiency ratio (PER), specific growth rate (SGR), and body protein deposition (BPD) improved significantly (P < 0.05) with each elevated dietary vitamin A level and found maximum growth rate along with the best- FCR at 0.11 g/kg diet. Dietary vitamin A levels also significantly (P < 0.05) affected haematological parameters of the fish. Highest haemoglobin (Hb), erythrocyte count (RBC), haematocrit content (Hct %), and lowest leucocyte count (WBC) were observed at 0.11 g/kg vitamin A fed diet compared to all the diets. Highest protein and lowest fat content were observed in the group of fingerlings fed with 0.11 g/kg vitamin A containing diet. Blood and serum profile also showed some significant (P < 0.05) differences with elevating concentration of dietary vitamin A levels. Serum parameters like aspartate aminotransferase (AST), alanine aminotransferase (ALT), and cholesterol values decreased significantly (P < 0.05) at 0.11 g/kg vitamin A fed diet compared to control diet. However, except albumin the other electrolytes improved significantly (P < 0.05) and maximal values of these parameters were also evident at 0.11 g/kg of vitamin A fed diet. Better value of TBARS was found in the group that fed 0.11 g/kg vitamin A diet. Hepatosomatic index and condition factor improved significantly (P < 0.05) with fish fed at optimal dose 0.11 g/kg of vitamin A diet. Based on quadratic regression analysis of LWG%, FCR, BPD, Hb, and calcium values of C. carpio var. communis against the varying levels of dietary vitamin A, an optimum growth, best FCR, higher BPD, Hb, and Ca values lie in the range of 0.10 to 0.12 g/kg diet, respectively. The data generated during this study would be important in developing vitamin A balanced feed for successful intensive culture of C. carpio var. communis.

Expanding role of vitamin E in protection against metabolic dysregulation: Insights gained from model systems, especially the developing nervous system of zebrafish embryos

This review discusses why the embryo requires vitamin E (VitE) and shows that its lack causes metabolic dysregulation and impacts morphological changes at very early stages in development, which occur prior to when a woman knows she is pregnant. VitE halts the chain reactions of lipid peroxidation (LPO). Metabolomic analyses indicate that thiols become depleted in E- embryos because LPO generates products that require compensation using limited amino acids and methyl donors that are also developmentally relevant. Thus, VitE protects metabolic networks and the integrated gene expression networks that control development. VitE is critical especially for neurodevelopment, which is dependent on trafficking by the α-tocopherol transfer protein (TTPa). VitE-deficient (E-) zebrafish embryos initially appear normal, but by 12 and 24 h post-fertilization (hpf) E- embryos are developmentally abnormal with expression of pax2a and sox10 mis-localized in the midbrain-hindbrain boundary, neural crest cells and throughout the spinal neurons. These patterning defects indicate cells that are especially in need of VitE-protection. They precede obvious morphological abnormalities (cranial-facial malformation, pericardial edema, yolksac edema, skewed body-axis) and impaired behavioral responses to locomotor activity tests. The TTPA gene (ttpa) is expressed at the leading edges of the brain ventricle border. Ttpa knockdown using morpholinos is 100% lethal by 24 hpf, while E- embryo brains are often over- or under-inflated at 24 hpf. Further, E- embryos prior to 24 hpf have increased expression of genes involved in glycolysis and the pentose phosphate pathway, and decreased expression of genes involved in anabolic pathways and transcription. Combined data from both gene expression and the metabolome in E- embryos at 24 hpf suggest that the activity of the mechanistic Target of Rapamycin (mTOR) signaling pathway is decreased, which may impact both metabolism and neurodevelopment. Further evaluation of VitE deficiency in neurogenesis and its subsequent impact on learning and behavior is needed.

Carotenoid profile in breast milk and maternal and cord plasma: a longitudinal study in Southwest China

Carotenoids are increasingly being implicated to have an important role in brain and eye development. This study aimed to quantify the content and profile of carotenoids in human breast milk, maternal plasma and neonatal umbilical cord plasma in Chengdu, an urban area in Southwest China. In this study, fifty-four healthy mothers were enrolled. Maternal blood, umbilical cord blood, colostrum, transitional milk and mature milk were collected. Concentrations of carotenoids (lutein, zeaxanthin, β-cryptoxanthin, β-carotene and lycopene) were analysed by HPLC. We found that carotenoid concentrations decreased from colostrum to mature milk. Hydrocarbon carotenoids with weaker polarity decreased more than the polar carotenoids. Lycopene concentrations dropped by 99 %, β-carotene by 92 %, β-cryptoxanthin by 83 %, lutein by 32 % and zeaxanthin by 22 %. Lycopene and β-carotene accounted for 70 % of the total carotenoids in colostrum, and lutein predominated amongst carotenoids in transitional milk and mature milk (51-55 %). Carotenoid concentrations in maternal plasma were much higher than that in cord plasma. Lutein predominated in cord plasma. The concentrations of all carotenoids in maternal plasma were correlated with those of cord plasma and human milk. These results are consistent with selective transport mechanisms in the mammary gland related to the polarity of carotenoids, and each carotenoid has its own implications, which may have different priorities in the early life development of infants. These findings may help guide dietary recommendations for carotenoid inclusion in infant formulas.

The effects of vitamins and dietary pattern on epigenetic modification of non-communicable diseases

Background: Non-communicable diseases (NCDs) have received more attention because of high prevalence and mortality rate. Besides genetic and environmental factors, the epigenetic abnormality is also involved in the pathogenesis of NCDs. Methylation of DNA, chromatin remodeling, modification of histone, and long non-coding RNAs are the main components of epigenetic phenomena. Methodology: In this review paper, the mechanistic role of vitamins and dietary patterns on epigenetic modification was discussed. All papers indexed in scientific databases, including PubMed, Scopus, Embase, Google Scholar, and Elsevier were searched during 2000 - 2021 using, vitamins, diet, epigenetic repression, histones, methylation, acetylation, and NCDs as keywords. Results: The components of healthy dietary patterns like Mediterranean and dietary approaches to stop hypertension diets have a beneficial effect on epigenetic hemostasis. Both quality and quantity of dietary components influence epigenetic phenomena. A diet with calorie deficiency in protein content and methyl-donor agents in a long time, with a high level of fat, disrupts epigenetic hemostasis and finally, causes genome instability. Also, soluble and insoluble vitamins have an obvious role in epigenetic modifications. Most vitamins interact directly with methylation, acetylation, and phosphorylation pathways of histone and DNA. However, numerous indirect functions related to the cell cycle stability and genome integrity have been recognized. Conclusion: Considering the crucial role of a healthy diet in epigenetic homeostasis, adherence to a healthy dietary pattern containing enough levels of vitamin and avoiding the western diet seems to be necessary. Having a healthy diet and consuming the recommended dietary level of vitamins can also contribute to epigenetic stability.

RedEfish: Generation of the Polycistronic mScarlet: GSG-T2A: Ttpa Zebrafish Line

The vitamin E regulatory protein, the alpha-tocopherol transfer protein (Ttpa), is necessary for zebrafish embryo development. To evaluate zebrafish embryo Ttpa function, we generated a fluorescent-tagged zebrafish transgenic line using CRISPR-Cas9 technology. One-cell stage embryos (from Casper (colorless) zebrafish adults) were injected the mScarlet coding sequence in combination with cas9 protein complexed to single guide RNA molecule targeting 5′ of the ttpa genomic region. Embryos were genotyped for proper insertion of the mScarlet coding sequence, raised to adulthood and successively in-crossed to produce the homozygote RedEfish (mScarlet: GSG-T2A: Ttpa). RedEfish were characterized by in vivo fluorescence detection at 1, 7 and 14 days post-fertilization (dpf). Fluorescent color was detectable in RedEfish embryos at 1 dpf; it was distributed throughout the developing brain, posterior tailbud and yolk sac. At 7 dpf, the RedEfish was identifiable by fluorescence in olfactory pits, gill arches, pectoral fins, posterior tail region and residual yolk sac. Subsequently (14 dpf), the mScarlet protein was found in olfactory pits, distributed throughout the digestive tract, along the lateral line and especially in caudal vertebrae. No adverse morphological outcomes or developmental delays were observed. The RedEfish will be a powerful model to study Ttpa function during embryo development.

Vitamin C Deficiency in the Young Brain-Findings from Experimental Animal Models

Severe and long-term vitamin C deficiency can lead to fatal scurvy, which is fortunately considered rare today. However, a moderate state of vitamin C (vitC) deficiency (hypovitaminosis C)-defined as a plasma concentration below 23 μM-is estimated to affect up to 10% of the population in the Western world, albeit clinical hallmarks in addition to scurvy have not been linked to vitC deficiency. The brain maintains a high vitC content and uniquely high levels during deficiency, supporting vitC's importance in the brain. Actions include both antioxidant and co-factor functions, rendering vitamin C deficiency likely to affect several targets in the brain, and it could be particularly significant during development where a high cellular metabolism and an immature antioxidant system might increase sensitivity. However, investigations of a non-scorbutic state of vitC deficiency and effects on the developing young brain are scarce. This narrative review provides a comprehensive overview of the complex mechanisms that regulate vitC homeostasis in vivo and in the brain in particular. Functions of vitC in the brain and the potential consequences of deficiency during brain development are highlighted, based primarily on findings from experimental animal models. Perspectives for future investigations of vitC are outlined.

Fetal oxidative stress, micronutrient deficiency and risk of retinopathy of prematurity: a nested case-control study

We hypothesized that fetal oxidative stress and micronutrient deficiencies contribute to higher incidence of retinopathy of prematurity (ROP) in developing countries. In a nested case-control study, preterm infants (< 37 weeks, < 1700 g) were included at birth and followed until 40 weeks post-menstrual age (PMA). Maternal, cord, and neonatal serum/plasma samples at 40 weeks PMA were frozen. Samples of "cases" with ROP and gestational age (GA) and birth weight-matched "controls" with no ROP (in 1:4 ratio) were thawed and analyzed.

PRIMARY OUTCOME

MDA concentration in cord plasma.

SECONDARY OUTCOMES

MDA in maternal and 40-week PMA plasma; copper, zinc, and vitamin A in maternal, cord, and 40-week PMA samples. Thirty-eight cases and 151 controls had a mean (SD) GA of 29.5 (1) and 29.9 (1) weeks respectively. Following were associated with ROP: higher MDA concentration in cord and 40-week PMA samples; lower copper and zinc in maternal serum; lower zinc and vitamin A in cord sample (all p < 0.05). MDA [adjusted OR (aOR) = 4.13 (95% CI 1.83-9.27)] and vitamin A [aOR = 0.09 (95% CI 0.02-0.4)] concentration in cord plasma and weight gain (g/kg/week) [aOR = 0.97 (0.95-0.99)] independently predicted ROP.

CONCLUSION

Increased oxidative stress and deficiency of micronutrients from fetal life were associated with ROP.

CLINICAL TRIAL REGISTRATION

Clinical Trials Registry of India CTRI/REF/2014/12/008174. What is Known: • In developing countries, there is a higher incidence of retinopathy of prematurity (ROP), but micronutrient deficiencies have not been adequately investigated as risk factors. • Few observational studies have shown an association between ROP and postnatal increase in malondialdehyde (MDA) levels and deficiencies of antioxidant vitamins and minerals, but none in cord blood. What is New: • High MDA, low zinc, and low vitamin A levels in cord blood and low copper and zinc levels in maternal blood are associated with the development of ROP. • On multivariable analysis, high cord blood MDA and low cord blood vitamin A are independent predictors of ROP.

Changes in Vitamin A Levels and the Effect of Early Vitamin A Supplementation on Vitamin A Levels in Infants Throughout the First 6 Months of Life: A Prospective Cohort Study in Chongqing, China

Objectives: This study aimed to explore the changes in infant vitamin A (VA) status and the effect of early VA supplementation on VA level throughout the first 6 months of life. Methods: A prospective cohort study was conducted in Chongqing, China. A total of 1,016 healthy infants were enrolled at birth. Then, 930, 882, 854 and 822 healthy infants were followed up at postnatal day 7 and postnatal months 1, 3, and 6, respectively. Blood samples and dietary survey and physical development data were collected. Serum VA was measured by chromatography tandem-mass spectrometry and was classified according to the VA deficiency (VAD) criteria for older children aged 6-70 months (<0.70, 0.70-1.05, ≥1.05 μmol/L). Normally distributed continuous variables are presented as the mean ± standard deviation. The categorical variables are described by the frequency and percentage (%). The reference interval for the VA level was the 2.5th-97.5th percentile. Changes in VA status with age and the relationship of VA supplementation with VA level were investigated by generalized estimating equations followed by Bonferroni post hoc test, controlling for the effects of feeding pattern and sex. Results: Infant VA levels increased significantly from 0.499 ± 0.146 to 1.061 ± 0.414 μmol/L with age at 6 months, even without VA supplementation (P < 0.05). From birth to 6 months, the percentage of infants with a VA level <0.70 μmol/L decreased from 88.6 to 19.5%. During follow-up, no infant demonstrated clinical VAD conditions, such as night blindness, conjunctival xerosis or Bitot's spots. Less than 7.0% of infants were underdeveloped in terms of weight, length and head circumference. The VA status of infants with VA≥0.588 μmol/L at birth gradually increased to adequate VA (VA ≥ 1.05 μmol/L) at 6 months. For these infants, there was no significant difference in VA level between the VA supplementation and non-supplementation groups (P > 0.05). Infants with VA <0.430 μmol/L at birth still had VA <0.70 μmol/L at 6 months; in this group, VA levels increased by 0.08 μmol/L more among supplemented infants than among non-supplemented infants (P < 0.05). Conclusions: A low VA level among neonates at birth may be a normal physiological state and may increase with age; thus, not all neonates may need early VA supplementation. More multicenter studies are needed to determine a new cutoff point for the diagnosis of neonatal VAD and the administration of nutritional intervention.

Incidence and risk factors of retinopathy of prematurity in an Italian cohort of preterm infants

OBJECTIVE

Non-negligible differences in retinopathy of prematurity (ROP) and its risk factors between different neonatal intensive care units (NICUs) are reported. Our aim was to assess the incidence and risk factors for ROP development in a large cohort of very preterm infants who were assisted in two Italian NICUs.

METHODS

Preterm infants with gestational age between 23+ 0 and 29+ 6 weeks were stratified into subgroups of infants who developed ROP and those who did not; their clinical characteristics were compared with univariate and multivariable logistic regression analyses.

RESULTS

We studied a total of 178 infants of whom 67 (38%) developed ROP (stage 1: n = 12; stage 2: n = 41; stage 3: n = 14). Regression analysis demonstrated that maternal milk (OR 0.979, 95% Cl 0.961-0.998) decreased the risk of developing ROP, while intraventricular hemorrhage (IVH) (OR 2.055, 95% Cl 1.120-3.772) increased it. Moreover, maternal milk was found to decrease (OR 0.981, 95% Cl 0.964-0.997) the risk of ROP at discharge, while RBC transfusion increased it (OR 1.522, 95% Cl 1.208-1.916).

CONCLUSIONS

In our cohort the occurrence of ROP was similar to that previously reported. Strategies for promoting the use of mother's own milk, preventing IVH, and standardizing the approach to RBC transfusions could contribute to decreasing the risk of ROP in very preterm infants.

Oxidative stress biomarkers in the preterm infant

Oxidative stress (OS) plays a key role in the pathophysiology of preterm infants. Accurate assessment of OS remains an analytical challenge that has been partially addressed during the last few decades. A plethora of approaches have been developed to assess preterm biofluids to demonstrate a link postnatally with preterm OS, giving rise to a set of widely employed biomarkers. However, the vast number of different analytic methods and lack of standardization hampers reliable comparison of OS-related biomarkers. In this chapter, we discuss approaches for the study of OS in prematurity with respect to methodologic considerations, the metabolic source of different biomarkers and their role in clinical studies.

Oxygen Toxicity in the Neonate: Thinking Beyond the Balance

Fetal development occurs in a relatively hypoxemic environment, and birth represents significant oxidative stress. Premature infants are disadvantaged by a lack of maternal antioxidant transfer and impaired endogenous antioxidant responses. O₂ metabolism is essential for life and its biochemical reactions are dynamic, compartmentalized, and difficult to characterize in vivo. There is a growing appreciation for the role of reactive oxygen species in nonpathologic processes, including regulation of cell signaling and mitochondrial function. There are several gaps in the knowledge about the role of reactive oxygen species in normal development and how oxidative stress alters normal signaling and subsequent development.

INTRAUTERINE GROWTH AND THE VITAMIN E STATUS OF FULL-TERM AND PRETERM NEWBORNS

OBJECTIVE

To determine the concentration of alpha-tocopherol in umbilical cord serum of full-term and preterm newborns, in order to assess the nutritional status of both groups in relation to the vitamin and its possible correlation with intrauterine growth.

METHODS

A cross-sectional observational study conducted with 140 newborns, of which 64 were preterm and 76 were full-term. They did not have any malformations, they came from healthy mothers, who were nonsmokers, and delivered a single baby. Intrauterine growth was evaluated by weight-to-gestational age at birth, using Intergrowth-21st. Thealpha-tocopherol levels of umbilical cord serum were analyzed by High Performance Liquid Chromatography.

RESULTS

The mean concentration of alpha-tocopherol in umbilical cord serum for preterm and full-term infants was 263.3±129.5 and 247.0±147.6 µg/dL (p=0.494). In the preterm group, 23% were small for gestational age, whereas in the full-term group, this percentage was only 7% (p=0.017). Low levels of vitamin E were found in 95.3% of preterm infants and 92.1% of full-term infants. There was no correlation between alpha-tocopherol levels and weight to gestational age Z score (p=0.951).

CONCLUSIONS

No association was found between alpha-tocopherol levels and weight to gestational age at birth. Intrauterine growth restriction was more frequent in preterm infants and most infants had low levels of vitamin E at the time of delivery.

Anti-Oxidant Drugs: Novelties and Clinical Implications in Cerebellar Ataxias

BACKGROUND

Hereditary cerebellar ataxias are a group of disorders characterized by heterogeneous clinical manifestations, progressive clinical course, and diverse genetic causes. No disease modifying treatments are yet available for many of these disorders. Oxidative stress has been recurrently identified in different progressive cerebellar diseases, and it represents a widely investigated target for treatment.

OBJECTIVE

To review the main aspects and new perspectives of antioxidant therapy in cerebellar ataxias ranging from bench to bedside.

METHOD

This article is a summary of the state-of-the-art on the use of antioxidant molecules in cerebellar ataxia treatments. It also briefly summarizes aspects of oxidative stress production and general characteristics of antioxidant compounds.

RESULTS

Antioxidants represent a vast category of compounds; old drugs have been extensively studied and modified in order to achieve better biological effects. Despite the vast body of literature present on the use of antioxidants in cerebellar ataxias, for the majority of these disorders conclusive results on the efficacy are still missing.

CONCLUSION

Antioxidant therapy in cerebellar ataxias is a promising field of investigations. To achieve the success in identifying the correct treatment more work needs to be done. In particular, a combined effort is needed by basic scientists in developing more efficient molecules, and by clinical researchers together with patients communities, to run clinical trials in order to identify conclusive treatments strategies.

Sex-Specificity of Oxidative Stress in Newborns Leading to a Personalized Antioxidant Nutritive Strategy

Oxidative stress is a critical process that triggers several diseases observed in premature infants. Growing recognition of the detriment of oxidative stress in newborns warrants the use of an antioxidant strategy that is likely to be nutritional in order to restore redox homeostasis. It appears essential to have a personalized approach that will take into account the age of gestation at birth and the sex of the infant. However, the link between sex and oxidative stress remains unclear. The aim of this study was to find a common denominator explaining the discrepancy between studies related to sex-specific effects of oxidative stress. Results highlight a specificity of sex in the levels of oxidative stress markers linked to the metabolism of glutathione, as measured in the intracellular compartments. Levels of all sex-dependent oxidative stress markers are greater and markers associated to a better antioxidant defense are lower in boys compared to girls during the neonatal period. This sex-specific discrepancy is likely to be related to estrogen metabolism, which is more active in baby-girls and promotes the activation of glutathione metabolism. Conclusion: our observations suggest that nutritive antioxidant strategies need to target glutathione metabolism and, therefore, should be personalized considering, among others, the sex specificity.

Placental transfer and levels of mercury, selenium, vitamin E, and docosahexaenoic acid in maternal and umbilical cord blood

Methylmercury (MeHg) is a neurotoxicant known to affect the developing fetal brain as a sensitive target organ. As most mercury (Hg) in blood is MeHg, total mercury (THg) levels in blood are used to estimate the body burden of MeHg. The nutrients selenium (Se), vitamin E, and docosahexaenoic acid (DHA) are protective against MeHg toxicity. We compared maternal and cord blood concentrations of biochemical substances, THg and Se, vitamin E, DHA, and other elements, fatty acids, and amino acids in 54 Japanese mother-newborn pairs to elucidate the fetal risk of MeHg toxicity. Cord blood had higher hematocrit and amino acid values and lower concentrations of lipid components, including fatty acids compared with maternal blood. THg levels in cord blood (7.26ng/g) were 1.9 times higher than levels in maternal blood (3.79ng/g). Se concentrations in cord blood (176ng/g) were slightly higher than concentrations in maternal blood (156ng/g). Levels of vitamin E (0.31mg/dL) and DHA (58.8μg/mL) in cord blood were much lower than levels in maternal blood (1.38mg/dL and 147μg/mL, respectively). The ratios of Se/THg, vitamin E/THg, and DHA/THg in cord blood were lower than ratios in maternal blood. These results suggest that fetuses are at higher risk to MeHg toxicity.

Aurothioglucose does not improve alveolarization or elicit sustained Nrf2 activation in C57BL/6 models of bronchopulmonary dysplasia

We previously showed that the thioredoxin reductase-1 (TrxR1) inhibitor aurothioglucose (ATG) improves alveolarization in hyperoxia-exposed newborn C3H/HeN mice. Our data supported a mechanism by which the protective effects of ATG are mediated via sustained nuclear factor E2-related factor 2 (Nrf2) activation in hyperoxia-exposed C3H/HeN mice 72 h after ATG administration. Given that inbred mouse strains have differential sensitivity and endogenous Nrf2 activation by hyperoxia, the present studies utilized two C57BL/6 exposure models to evaluate the effects of ATG on lung development and Nrf2 activation. The first model (0-14 days) was used in our C3H/HeN studies and the 2nd model (4-14 days) is well characterized in C57BL/6 mice. ATG significantly inhibited lung TrxR1 activity in both models; however, there was no effect on parameters of alveolarization in C57BL/6 mice. In sharp contrast to C3H/HeN mice, there was no effect of ATG on pulmonary NADPH quinone oxidoreductase-1 ( Nqo1) and heme oxygenase-1 ( Hmox1) at 72 h in either C57BL/6 model. In conclusion, although ATG inhibited TrxR1 activity in the lungs of newborn C57BL/6 mice, effects on lung development and sustained Nrf2-dependent pulmonary responses were blunted. These findings also highlight the importance of strain-dependent hyperoxic sensitivity in evaluation of potential novel therapies.

Thioredoxin Reductase Inhibition Attenuates Neonatal Hyperoxic Lung Injury and Enhances Nuclear Factor E2-Related Factor 2 Activation

Oxygen toxicity and antioxidant deficiencies contribute to the development of bronchopulmonary dysplasia. Aurothioglucose (ATG) and auranofin potently inhibit thioredoxin reductase-1 (TrxR1), and TrxR1 disruption activates nuclear factor E2-related factor 2 (Nrf2), a regulator of endogenous antioxidant responses. We have shown previously that ATG safely and effectively prevents lung injury in adult murine models, likely via Nrf2-dependent mechanisms. The current studies tested the hypothesis that ATG would attenuate hyperoxia-induced lung developmental deficits in newborn mice. Newborn C3H/HeN mice were treated with a single dose of ATG or saline within 12 hours of birth and were exposed to either room air or hyperoxia (85% O2). In hyperoxia, ATG potently inhibited TrxR1 activity in newborn murine lungs, attenuated decreases in body weight, increased the transcription of Nrf2-regulated genes nicotinamide adenine dinucleotide phosphate reduced quinone oxidoreductase-1 (NQO1) and heme oxygenase 1, and attenuated alterations in alveolar development. To determine the impact of TrxR1 inhibition on Nrf2 activation in vitro, murine alveolar epithelial-12 cells were treated with auranofin, which inhibited TrxR1 activity, enhanced Nrf2 nuclear levels, and increased NQO1 and heme oxygenase 1 transcription. Our novel data indicate that a single injection of the TrxR1 inhibitor ATG attenuates hyperoxia-induced alterations in alveolar development in newborn mice. Furthermore, our data support a model in which the effects of ATG treatment likely involve Nrf2 activation, which is consistent with our findings in other lung injury models. We conclude that TrxR1 represents a novel therapeutic target to prevent oxygen-mediated neonatal lung injury.

Higher Level of Oxidative Stress Markers in Small for Gestational Age Newborns Delivered by Cesarean Section at Term

INTRODUCTION

The aim of our study was to determine lipid peroxidation products and antioxidant enzyme activity in umbilical cord blood of small for gestational age (SGA) neonates.

MATERIALS AND METHODS

Umbilical cord arterial blood samples were collected from 21-term singleton SGA newborn infants and 21 age- and sex-matched appropriate for gestational age (AGA) term neonates prospectively born by elective cesarean section for determination of malondialdehyde (MDA) as a marker of lipid peroxidation and superoxide dismutase (SOD) for antioxidant activity.

RESULTS

MDA levels were increased (5.20 vs. 3.52 nmol/mL; p < 0.001), while levels of SOD (6.24 vs. 8.99 U/mL; p < 0.01) were decreased in SGA neonates when compared with AGA newborn infants.

CONCLUSIONS

Elevated MDA levels and decreased SOD activity in umbilical cord blood may show the possibility of insufficient protective mechanisms against increased oxidative stress in SGA neonates born by cesarean section.

Potential Nutrients for Preventing or Treating Bronchopulmonary Dysplasia

Bronchopulmonary dysplasia (BPD) is a frequent complication occurring in extremely preterm infants. Despite recent advances in newborn medicine, the incidence of BPD does not appear to have changed markedly, and specific treatments and prevention strategies are still lacking. Nutrition plays an important role in normal lung development and maturation. Malnutrition may delay somatic growth and new alveoli development, thus aggravating pulmonary injury involved in the pathogenesis of BPD. However, few nutrients have been investigated for their potential to mitigate the pathogenesis of BPD. In this article, we reviewed the recent progress in research on potential nutrients useful for the prevention or treatment of BPD, including glutamine, cysteine and N-acetylcysteine, L-arginine and L-citrulline, long chain polyunsaturated fatty acids (LCPUFAs), inositol, selenium, and some antioxidant vitamins including vitamin A. Current evidence shows that vitamin A and LCPUFA can prevent BPD, and that L-citrulline might provide a new method to treat chronic pulmonary hypertension associated with BPD in premature infants. The effects of other nutrients on BPD prevention need to be further studied.

The socioeconomic variables influence in the alpha-tocopherol concentration of the maternal serum

Abstract Objectives: To evaluate the influence of the socioeconomic factors on the alpha-tocopherol concentration in maternal serum. Methods: a retrospective, observational, cross-sectional study with the participation of 103 adult parturient volunteers attended at Hospital Universitário Ana Bezerra (Ana Bezerra University Hospital) in Santa Cruz - Rio Grande do Norte. 5.0 mL of blood was collected from each participant in fasting before the delivery to extract alpha-tocopherol of the serum. Socioeconomic and demographic information were obtained by a previously structured questionnaire. Alpha-tocopherol serum was determined by a High-Performance Chromatography Liquid (Cromatografia Líquida de Alta Eficiência (CLAE). Results: The average concentration of alpha-tocopherol in the serum was 1281.4 (594.8) µg/dL, and 6% of the women presented vitamin E deficiency (DVE). Most pregnant women aged between 18 and 24 years (59%), marital status was married or consensual marriage (77%), elementary schooling complete (34%), low family income (74%) and living in the urban area (73%). No significant differences were found in the alpha-tocopherol concentration according to socioeconomic characteristics and none of the studied factors were associated to the presence of DVE ( p >0.05). Conclusions: The maternal social characteristics were not determinants for the alpha-tocopherol serum and DVE. Further investigations should be carried out during lactation to assess which factors may be involved in the presence of this deficiency.

Association between maternal vitamin E status and alpha-tocopherol levels in the newborn and colostrum

Vitamin E is important because of its antioxidant activity in situations of oxidative stress, especially postnatally. Hence, the objective was to verify whether maternal alpha-tocopherol level is associated with the alpha-tocopherol levels of the newborn and colostrum. This is a cross-sectional study of 58 women and their term newborns from a public hospital. Blood and colostrum were collected to measure alpha-tocopherol levels by high-performance liquid chromatography. Mothers with serum alpha-tocopherol levels <16.2 mmol L(-1) and newborns <11.6 mmol L(-1) were indicative of deficiency or low levels. Mothers were divided into two groups: <16.2 mmol L(-1) and those with levels ≥16.2 mmol L(-1) . The mean (95% confidence interval) serum alpha-tocopherol levels of mothers, umbilical cords and colostrum were 28 (24-32), 6 (5-8) and 39 mmol L(-1) (32-45), respectively (P < 0.001); 19% of the women and 90% of the newborns had low alpha-tocopherol levels. Maternal alpha-tocopherol level was associated with that of the umbilical cord. Newborns from mothers at risk of deficiency had low alpha-tocopherol levels (P < 0.001). Colostrum levels of vitamin E were not influenced by maternal serum. Maternal deficiency influenced the vitamin E level of the umbilical cord but does not in the colostrum, evidencing distinct transfer mechanisms via the mammary gland.

Anti-oxidant profiles and markers of oxidative stress in preterm neonates

BACKGROUND

Preterm birth is associated with an increased oxidant burden which places these infants at a higher risk of injury.

AIMS

This prospective study aimed to assess levels of antioxidants and a marker of oxidative stress in preterm neonates.

OBJECTIVES

(i) To compare levels of anti-oxidants [vitamin A, vitamin E, catalase, total anti-oxidant status (TAS)] as well as malondialdehyde level (MDA) (a marker of lipid peroxidation) between preterm and full-term neonates; (ii) to determine changes in the values of measured vitamins at birth and at discharge among preterm neonates; and (iii) to compare levels of anti-oxidants with MDA levels in relation to complications of prematurity and outcome.

METHODS

The study was undertaken in 100 preterm neonates and 100 full-term neonates as a control group. MDA was estimated by a thiobarbituric acid-reactive technique; TAS was determined using a Randox assay kit; catalase activity was measured spectrophotometrically and vitamin A and E levels were estimated by high performance liquid chromatography.

RESULTS

The plasma levels of vitamin A, vitamin E, TAS and catalase were significantly lower in the preterm than in the full-term group (P < 0.01), and the plasma level of MDA was significantly higher in preterm than full-term neonates (P < 0.01). Vitamin A and E levels in preterm neonates were significantly higher at discharge than at birth (P < 0.01). Vitamin A, vitamin E and catalase levels at birth were significantly lower in patients who developed necrotizing enterocolitis or bronchopulmonary dysplasia than in those who did not.

CONCLUSION

Preterm neonates are exposed to increased oxidant stress at birth and are susceptible to anti-oxidant deficiencies. A higher dose of enteral vitamin A supplementation in preterm neonates might reduce morbidity and improve outcome. Further studies are warranted to evaluate the appropriate dose of oral vitamin E supplementation for preterm neonates.

α-Tocopherol in breast milk of women with preterm delivery after a single postpartum oral dose of vitamin E

We evaluated the effect of maternal vitamin E supplementation on the α-tocopherol concentrations of colostrum, transitional milk and mature milk of women who had given birth prematurely. This longitudinal randomised-controlled trial divided eighty-nine women into two groups: a control group and a supplemented group. Blood and breast milk were collected from all the participants after delivery. Next, each woman in the supplemented group received 400 IU of RRR-α-tocopheryl acetate. Further breast milk samples were collected 24 h after the first collection, as well as 7 and 30 d after delivery. α-Tocopherol concentrations were determined by HPLC. The baseline α-tocopherol concentrations in the maternal serum of the two groups were similar: 1159·8 (sd 292·4) μg/dl (27·0 (SD 6·8) μmol/l) for the control group and 1128·3 (sd 407·2) μg/dl (26·2 (SD 9·5) μmol/l) for the supplemented group. None of the women was vitamin E deficient. Breast milk α-tocopherol concentrations increased by 60 % 24 h after supplementation in the intervention group and did not increase at all in the control group. α-Tocopherol concentration of the transitional milk in the supplemented group was 35 % higher compared with the control group. α-Tocopherol concentrations of the mature milk in both groups were similar. Maternal supplementation with 400 IU of RRR-α-tocopherol increased the vitamin E concentrations of the colostrum and transitional milk, but not of the mature milk. This study presents relevant information for the design of strategies to prevent and combat vitamin E deficiency in the risk group of preterm infants.

Alpha-Tocopherol Concentration in Colostrum and Serum of Women With Premature Labor

OBJECTIVE

The aim of the study was to evaluate and compare the levels of alpha-tocopherol in colostrum milk and serum of mothers with premature birth, classified as severe prematurity and moderate prematurity.

METHODS

Cross-sectional study with 65 women, 18 births classified as severe prematurity (<32 weeks of gestation) and 47 as moderate prematurity (≥32 weeks of gestation). The study only included mothers without any conditions associated with pregnancy and who had a single conception without any malformation. Samples of serum and colostrum were collected during fasting in the immediate postpartum, and alpha-tocopherol was analyzed by high-performance liquid chromatography. To determine the biochemical nutritional status of vitamin E, a serum cutoff (11.6 μmol/L) was adopted. The Student t test for independent variables compared the average concentrations of alpha-tocopherol in serum and colostrum among prematurity groups. Differences were considered significant when P < 0.05.

RESULTS

The alpha-tocopherol concentrations in colostrum were similar in both groups, being 34.5 ± 20.2 μmol/L for women with severe prematurity and 35.1 ± 16.3 μmol/L for moderate prematurity. For the serum of puerperal women with severe prematurity, alpha-tocopherol concentration was, however, lower than in women with moderate prematurity, 22.2 ± 4.4 μmol/L versus 27.1 ± 8.6 μmol/L (P < 0.05). The serum levels of alpha-tocopherol indicated nutritional risk at 5.6% (n = 1) of women with severe prematurity and 4.3% (n = 2) for those with moderate prematurity.

CONCLUSIONS

Severe prematurity affected the levels of alpha-tocopherol in maternal serum; however, the level of prematurity did not change the concentration of vitamin E in colostrum.

Human Milk Feeding as a Protective Factor for Retinopathy of Prematurity: A Meta-analysis

CONTEXT

Studies have suggested that human milk feeding decreases the incidence of retinopathy of prematurity (ROP); however, conflicting results have been reported.

OBJECTIVE

The aim of this meta-analysis was to pool currently available data on incidence of ROP in infants fed human milk versus formula.

DATA SOURCES

Medline, PubMed, and EBSCO were searched for articles published through February 2015.

STUDY SELECTION

Longitudinal studies comparing the incidence of ROP in infants who were fed human milk and formula were selected. Studies involving donor milk were not included.

DATA EXTRACTION

Two independent reviewers conducted the searches and extracted data. Meta-analysis used odds ratios (ORs), and subgroup analyses were performed.

RESULTS

Five studies with 2208 preterm infants were included. Searches including various proportions of human milk versus formula, any-stage ROP, and severe ROP were defined to pool data for analyses. For any-stage ROP, the ORs (95% confidence intervals [CIs]) were as follows: exclusive human milk versus any formula, 0.29 (0.12 to 0.72); mainly human milk versus mainly formula, 0.51 (0.26 to 1.03); any human milk versus exclusive formula, 0.54 (0.15 to 1.96); and exclusive human milk versus exclusive formula, 0.25 (0.13 to 0.49). For severe ROP, they were 0.11 (0.04 to 0.30), 0.16 (0.06 to 0.43), 0.42 (0.08 to 2.18), and 0.10 (0.04 to 0.29), respectively.

LIMITATIONS

Prospective randomized studies being impossible because of ethical issues, we chose observational studies for analysis. A few studies involving subgroup analyses presented high heterogeneity.

CONCLUSIONS

Based on current limited evidence, in very preterm newborns, human milk feeding potentially plays a protective role in preventing any-stage ROP and severe ROP.

[Oxidative stress after preterm birth: origins, biomarkers, and possible therapeutic approaches]

The survival of preterm babies has increased over the last few decades. However, disorders associated with preterm birth, known as oxygen radical diseases of neonatology, such as retinopathy, bronchopulmonary dysplasia, periventricular leukomalacia, and necrotizing enterocolitis are severe complications related to oxidative stress, which can be defined by an imbalance between oxidative reactive species production and antioxidant defenses. Oxidative stress causes lipid, protein, and DNA damage. Preterm infants have decreased antioxidant defenses in response to oxidative challenges, because the physiologic increase of antioxidant capacity occurs at the end of gestation in preparation for the transition to extrauterine life. Therefore, preterm infants are more sensitive to neonatal oxidative stress, notably when supplemental oxygen is being delivered. Furthermore, despite recent advances in the management of neonatal respiratory distress syndrome, controversies persist concerning the oxygenation saturation targets that should be used in caring for preterm babies. Identification of adequate biomarkers of oxidative stress in preterm infants such as 8-iso-prostaglandin F2α, and adduction of malondialdehyde to hemoglobin is important to promote specific therapeutic approaches. At present, no therapeutic strategy has been validated as prevention or treatment against oxidative stress. Breastfeeding should be considered as the main measure to improve the antioxidant status of preterm infants. In the last few years, melatonin has emerged as a protective molecule against oxidative stress, with antioxidant and free-radical scavenger roles, in experimental and preliminary human studies, giving hope that it can be used in preterm infants in the near future.

Prenatal polycyclic aromatic hydrocarbon (PAH) exposure, antioxidant levels and behavioral development of children ages 6-9

PURPOSE

Prenatal polycyclic aromatic hydrocarbon (PAH) exposure has been shown to increase DNA adduct levels and to affect neurodevelopment. Micronutrients may modify the adverse effect of PAH on neurodevelopment. Thus, we examined if micronutrient concentrations modified the association between PAH exposure and neurodevelopmental outcomes.

METHODS

151 children from a birth cohort who had micronutrient concentrations measured in cord blood and completed the Child Behavioral Checklist (CBCL), between the ages of 6 and 9 years, were evaluated. Prenatal airborne PAH exposure was measured by personal air monitoring. The betas and 95% CI for the associations of antioxidant concentrations and PAH exposure with each of the outcomes of CBCL raw score and dichotomized standardized T-score (based on clinical cutpoints) were estimated, respectively, by multivariable poisson and logistic models.

RESULTS

Children below the median for alpha-tocopherol and gamma-tocopherol concentrations, compared to those above, were more likely to have thought problems, aggressive behavior and externalizing problems (p<0.05). Lower carotenoid concentration was associated with more thought problems (MVβ=0.60, p<0.001) and externalizing problems (MVβ=0.13, p<0.05) for the same contrast. No statistically significant associations were observed between retinol concentrations and neurodevelopmental symptoms. Overall, no consistent patterns were observed when we examined the interaction between antioxidants (e.g., alpha-tocopherol) and PAH in relation to CBCL symptoms (e.g., internalizing and externalizing problems, p<0.05).

CONCLUSIONS

Lower alpha-tocopherol, gamma-tocopherol and carotenoid levels may adversely affect healthy neurodevelopment, even after accounting for PAH exposure. Future research to confirm these findings are warranted given the importance of identifying modifiable factors for reducing harmful PAH effects.

Influence of prematurity and birth weight on the concentration of α-tocopherol in colostrum milk

OBJECTIVE:

To assess vitamin E levels in the breast milk, analyzing the prematurity and the birth weight influence in α-tocopherol concentration of colostrum milk.

METHODS:

Cross-sectional study, in which the colostrum was collected from 93 nursing mothers in a public maternity of Natal, Rio Grande do Norte, Northeast Brazil. The newborns were classified based on gestational age and birth weight. The analysis of α-tocopherol in the milk was carried out by high performance liquid chromatography.

RESULTS:

The α-tocopherol concentration in the colostrum of lactating women whose children were born at term was 1,093.6±532.4µg/dL; for preterm infants, the concentration was 1,321.6±708.5µg/dL (p=0.109). In the preterm group, the α-tocopherol concentration in the colostrum of lactating women whose children were born with low and normal birth weight was 1,316.0±790.7 and 1,327.2±655.0µg/dL, respectively (p=0.971). In the term group, the α-tocopherol levels were higher in mothers of children with birth weight >4000g, being 1,821.0±575.4µg/dL, compared to 869.5±532.1µg/dL and 1,039.6±477.5µg/dL with low and adequate birth weight, respectively (p>0.05).

CONCLUSIONS:

Prematurity did not influence α-tocopherol levels in the colostrum milk. Mothers who had macrossomic term neonates presented increased α-tocopherol levels. These results indicate that birth weight can influence α-tocopherol leves in the colostrum milk.

Maternal vitamin C deficiency during pregnancy results in transient fetal and placental growth retardation in guinea pigs

PURPOSE

Recently, we reported that preferential maternal-fetal vitamin C (vitC) transport across the placenta is likely to be impaired by prolonged maternal vitC deficiency. Maintenance of a basal maternal vitC supply at the expense of the fetus may impair fetal development; however, the knowledge of vitC's impact on intrauterine development is sparse. The aim of this study was to explore the effect of maternal vitC status on fetal and placental development in guinea pigs.

METHODS

Twenty pregnant Dunkin Hartley guinea pigs were randomized into four groups to receive diets either sufficient (918 mg/kg CTRL) or deficient (100 mg/kg DEF) in vitC. Cesarean sections at gestational day (GD) 45 or 56 allowed for fetal and placental measurements.

RESULTS

At GD45, body, brain and placental weights were significantly reduced in DEF pups compared with CTRL (p < 0.05, p < 0.001 and p < 0.05, respectively). DEF plasma vitC levels were ~6% of those of CTRL (p < 0.0001), and the fetal/maternal plasma vitC ratio was significantly reduced at GD56 in the DEF animals compared with controls (p = 0.035). Placental vitC levels were reduced in DEF animals (p < 0.0001) and the ascorbate oxidation ratio and glutathione elevated compared with controls (p < 0.0001).

CONCLUSIONS

Although no clinical differences between CTRL and DEF pups were observed at GD56, the present data suggest that vitC plays a role in early fetal development. Although no clinical differences between CTRL and DEF pups were observed at GD56, the present data suggest that vitC plays a role in early fetal development. Low maternal vitC intake during pregnancy may compromise maternal weight gain, placental function and intrauterine development.

The thioredoxin system in neonatal lung disease

SIGNIFICANCE

Fetal lung development takes place in hypoxia meaning that premature birth is hyperoxia for the prematurely born infant. The most common respiratory morbidity afflicting premature infants is bronchopulmonary dysplasia (BPD). Pathophysiologically, BPD represents the impact of injury, including O2 toxicity, to the immature developing lung that causes arrested lung development.

RECENT ADVANCES

The thioredoxin (Trx) system, which is predominantly expressed in pulmonary epithelia in the newborn lung, acts as an antioxidant system; however, it is increasingly recognized as a key redox regulator of signal transduction and gene expression via thiol-disulfide exchange reactions.

CRITICAL ISSUES

This review focuses on the contribution of Trx family proteins toward normal and aberrant lung development, in particular, the roles of the Trx system in hyperoxic responses of alveolar epithelial cells, aberrant lung development in animal models of BPD, O2-dependent signaling processes, and possible therapeutic efficacy in preventing O2-mediated lung injury.

FUTURE DIRECTIONS

The significant contribution of the Trx system toward redox regulation of key developmental pathways necessary for proper lung development suggests that therapeutic strategies focused on preserving pulmonary Trx function could significantly improve the outcomes of prematurely born human infants.

Effects of supplemental oxygen on urinary 8-hydroxy-2'-deoxyguanosine levels in extremely low birth weight infants

As the effects of supplementary oxygen on urinary excretion of 8-hydroxy-2'-deoxyguanosine (8-OHdG) are poorly understood, urinary 8-OHdG levels (ng/mg creatinine) were determined longitudinally on the postnatal day (PND) 1, 3, and 30 in 16 neonates with birth weight < 1000 g. No supplementary oxygen was required in 9 neonates during the first 24 h of life. Urinary 8-OHdG level on PND 1 was inversely correlated with birth weight in these 9 neonates (P = 0.0323) and was higher in four with birth weight < 750 g than five with birth weight > 750 g (41.0 ± 6.9 vs. 5.6 ± 2.7, respectively, P = 0.0200). Median urinary 8-OHdG on PND 1 of these 9 neonates was significantly lower than that of 7 neonates with oxygen (9.3 vs. 60.2, respectively), although there were no significant differences in clinical background, such as birth weight, between the two groups. Five of the 9 did not require supplemental oxygen at all during the first 30 days of life. Median urinary 8-OHdG levels were consistently significantly lower in the 5 neonates than in 11 neonates with oxygen transiently or persistently (9.3 vs. 54.6, 19.1 vs. 61.4, and 28.3 vs. 145 on PND 1, 3, and 30, respectively), although there were no differences in clinical background, such as birth weight, between the two groups. Urinary 8-OHdG on PND 30 was significantly positively correlated with supplemental oxygen dose on PND 30 (P < 0.0001), but not with birth weight in the 16 neonates. These results suggest that higher supplemental oxygen tension caused higher urinary 8-OHdG in this population.

VitaminA, E, and D deficiencies in tunisian very low birth weight neonates: prevalence and risk factors

BACKGROUND

Preterm neonates are at high risk of vitamin deficiencies, which may expose them to increased morbidity and mortality. This study aimed to determine the prevalence and risk factors for vitamin A, E, and D deficiencies in Tunisian very low birth weight (VLBW) neonates.

METHODS

A total of 607 VLBW and 300 term neonates were included in the study. Plasma vitamins A and E were assessed by high performance liquid chromatography and vitamin D was assessed by radioimmunoassay.

RESULTS

Prevalence of vitamin A, E, and D deficiencies were dramatically elevated in VLBW neonates and were significantly higher than term neonates (75.9% vs. 63.3%; 71.3% vs. 55.5%; and 65.2% vs. 40.4%, respectively). In VLBW neonates, the prevalence of vitamin deficiencies was significantly higher in lower classes of gestational age and birth weight. Vitamin E deficiency was associated with pre-eclampsia [odds ratio (OR) (95% confidence interval, 95% CI), 1.56 (1.01-2.44); p < 0.01] and gestational diabetes [4.01 (1.05-17.0); p < 0.01]. Vitamin D deficiency was associated with twin pregnancy [OR (95% CI), 2.66 (1.33-5.35); p < 0.01] and pre-eclampsia [2.89 (1.36-6.40); p < 0.01].

CONCLUSION

Vitamin A, E, and D deficiencies are very common in Tunisian VLBW neonates and are associated with pre-eclampsia. Improved nutritional and health support for pregnant women and high dose vitamins A, E, and D supplementation in VLBW neonates are strongly required in Tunisia.

Oxidative stress markers and micronutrients in maternal and cord blood in relation to neonatal outcome

BACKGROUND/OBJECTIVES

Oxidative stress and micronutrient deficiencies have been related to lower birth weight (BW), small for gestational age (SGA) offspring and preterm delivery.

SUBJECTS/METHODS

The relation between neonatal outcome (BW, head circumference, SGA, preterm delivery) with markers of oxidative stress and micronutrients in maternal and cord blood was to be examined. Oxidative stress markers (protein carbonyls (PrCarb), 3-nitrotyrosine (3NT), malondialdehyde (MDA)), total protein concentration and lipid-soluble micronutrients (carotenoids, retinol, tocopherols) were measured in 200 newborns (11% preterms, 13% SGA) and 151 mothers. Associations between target parameters in cord plasma and maternal serum with BW, head circumference and risk of being SGA or preterm were explored.

RESULTS

Maternal protein concentration, PrCarb, MDA and all lipid-soluble micronutrients were significantly higher compared with newborns, except for 3NT, which was significantly elevated in newborns. Newborn parameters correlated positively with those of mothers. Preterms had lower proteins and retinol but higher PrCarb than terms. Maternal PrCarb and retinol were inversely associated with BW and head circumference. Mothers with PrCarb, MDA and retinol in the highest quintile had a 3.3-fold (0.9; 12.1), 2.1-fold (0.7; 6.4) and 3.3-fold (1.2; 9.4) risk, respectively, for delivering an SGA newborn, whereas the lowest quintile of retinol in cord blood was associated with an increased risk for preterm delivery.

CONCLUSIONS

Oxidative stress (elevated PrCarb) was associated with lower BW/head circumference and SGA. Inadequate hemodilution may explain the inverse relation of maternal retinol with BW and head circumference, and the association between highest maternal retinol and risk for SGA.

Metabolic syndrome: role of maternal undernutrition and fetal programming

Development of metabolic syndrome is attributed to genes, dietary intake, physical activity and environmental factors. Fetal programming due to maternal nutrition is also an important factor especially in developing countries where intrauterine growth retardation followed by excess nutrition postnatally is causing mismatch predisposing individuals to development of metabolic syndrome and its components. Several epidemiological and animal studies have provided evidence for the link between intrauterine growth retardation and adult metabolic diseases. Deficiency of macronutrients, protein and carbohydrates, during pregnancy and gestation results in lower infant birth weight, a surrogate marker of fetal growth and subsequently insulin resistance, glucose intolerance, hypertension and adiposity in adulthood. The role of micronutrients is less extensively studied but however gaining attention with several recent studies focusing on this aspect. Several mechanisms have been proposed to explain the developmental origin of adult diseases important among them being alteration of hypothalamic pituitary axis, epigenetic regulation of gene expression and oxidative stress. All of these mechanisms may be acting at different time during gestation and contributing to development of metabolic syndrome in adulthood.

Current thoughts on maternal nutrition and fetal programming of the metabolic syndrome

Chronic diseases such as type 2 diabetes and cardiovascular disease are the leading cause of death and disability worldwide. Although the metabolic syndrome has been defined in various ways, the ultimate importance of recognizing this combination of disorders is that it helps identify individuals at high risk for both type 2 diabetes and cardiovascular disease. Evidence from observational and experimental studies links adverse exposures in early life, particularly relating to nutrition, to chronic disease susceptibility in adulthood. Such studies provide the foundation and framework for the relatively new field of developmental origins of health and disease (DOHaD). Although great strides have been made in identifying the putative concepts and mechanisms relating specific exposures in early life to the risk of developing chronic diseases in adulthood, a complete picture remains obscure. To date, the main focus of the field has been on perinatal undernutrition and specific nutrient deficiencies; however, the current global health crisis of overweight and obesity demands that perinatal overnutrition and specific nutrient excesses be examined. This paper assembles current thoughts on the concepts and mechanisms behind the DOHaD as they relate to maternal nutrition, and highlights specific contributions made by macro- and micronutrients.

Inhibition of hepatic methionine adenosyltransferase by peroxides contaminating parenteral nutrition leads to a lower level of glutathione in newborn Guinea pigs

Premature newborn infants on total parenteral nutrition (TPN) are at risk of oxidative stress because of peroxides contaminating TPN and low glutathione level. Low cysteine availability limits glutathione synthesis. In this population, the main source of cysteine derives from the hepatic conversion of methionine. The first enzyme of this conversion, methionine adenosyltransferase (MAT), contains redox-sensitive cysteinyl residues. We hypothesize that inhibition of MAT by peroxides contaminating TPN leads to a lower availability of cysteine for glutathione synthesis. At 3 days of life, animals were fitted with a jugular catheter for intravenous infusion. Four groups were compared by ANOVA (P<0.05): (1) Control, without surgery, fed regular chow; (2) Sham, fitted with an obstructed catheter, fed orally regular chow; (3) TPN, fed exclusively TPN (dextrose, amino acids, fat, vitamins) containing 350 μM peroxides; (4) H2O2, fed regular chow orally and infused with 350 μM H2O2. Four days later, MAT activity and glutathione in liver and blood were lower in TPN and H2O2 groups. The redox potential was more oxidized in blood and liver of the TPN group. In conclusion, peroxides generated in TPN inhibit methionine adenosyltransferase activity with, among consequences, a low level of glutathione and a more oxidized redox potential.

Antioxidant status and peroxidative stress in mother and newborn -A pilot study

Serum antioxidant status and peroxidative stress was estimated in 30 pregnant women, their newborn infants and 25 non-pregnant women. Serum Ascorbic acid, α-tocopherol, retinol & β-carotene levels were found to be significantly reduced and peroxidative stress was significantly higher in mothers as compared to matched non-pregnant women. Newborn had significantly higher levels of ascorbic acid as compared to their mother but had significantly lower levels of lipid soluble vitamins. The peroxidative stress in newborn was found to be significantly less as compared to their mothers. A positive correlation of ascorbic acid and α-tocopherol levels between mother and newborn reflects that their status in mother does influence the newborn status.

Influence of shielding TPN from photooxidation on the number of early blood transfusions in ELBW premature neonates

OBJECTIVES

The smallest premature neonates often receive blood transfusions early in life. Nonrestrictive transfusion policies are linked to deleterious outcomes. Exposure of total parenteral nutrition (TPN) to ambient light generates oxidation products associated with haemolysis in vitro. Shielding TPN from light limits oxidation. Our hypothesis was protecting TPN from light decreases haemolysis and therefore the need for early blood transfusions.

METHODS

Comparison of haemolysis between animals fed enterally and those receiving TPN, and exploratory case-control retrospective analysis of transfusion counts in premature infants receiving light-exposed or light-protected TPN. The statistical analysis was analysis of variance and longitudinal binomial regression model adjusting for potential covariables of transfusion counts.

RESULTS

In animals, TPN is associated with higher (P<0.05) haemolysis compared with enteral feeds; photoprotection induces lower peroxide load with no effect on the level of haemolysis. In premature infants, light-exposed (n=76) or light-protected (n=57) populations exhibited similar clinical characteristics. Initial haematocrit, gestational age, and index of disease severity had a significant effect on the number of transfusions. When adjusting for these covariables, photoprotection was no longer significant.

CONCLUSIONS

Even though peroxides are associated in vitro with haemolysis, shielding TPN from light to reduce infused peroxides does not significantly decrease the need for early transfusions in premature infants.

Lung injury in preterm neonates: the role and therapeutic potential of stem cells

Continuous improvements in perinatal care have allowed the survival of ever more premature infants, making the task of protecting the extremely immature lung from injury increasingly challenging. Premature infants at risk of developing chronic lung disease or bronchopulmonary dysplasia (BPD) are now born at the late canalicular stage of lung development, just when the airways become juxtaposed to the lung vasculature and when gas-exchange becomes possible. Readily available strategies, including improved antenatal management (education, regionalization, steroids, and antibiotics), together with exogenous surfactant and exclusive/early noninvasive ventilatory support, will likely decrease the incidence/severity of BPD over the next few years. Nonetheless, because of the extreme immaturity of the developing lung, the extent to which disruption of lung growth after prematurity and neonatal management lead to an earlier or more aggravated decline in respiratory function in later life is a matter of concern. Consequently, much more needs to be learned about the mechanisms of lung development, injury, and repair. Recent insight into stem cell biology has sparked interest for stem cells to repair damaged organs. This review summarizes the exciting potential of stem cell-based therapies for lung diseases in general and BPD in particular.