Role of oxidative stress in neonatal respiratory distress syndrome

Near-infrared spectroscopy (NIRS) as a tool to prevent cerebral desaturation in newborns with bradycardia events: A systematic review

OBJECTIVE

Near infrared spectroscopy (NIRS) is a non-invasive tool providing real-time continuous measurement of regional cerebral blood oxygenation and indirect blood flow. The aim of this review is to determine the best evidence to guide the use of NIRS to detect and avoid abnormalities of cerebral perfusion and oxygenation in newborns with bradycardia.

DESIGN

For this systematic review according to PRISMA Statement, we reviewed papers from 2000 to 2023. Research articles, trial, classical articles, observational studies applying NIRS in term and preterm neonates with bradycardia were selected if the title and/or abstract suggested an association between bradycardia or bradycardia associated with apnoea and modification of cerebral oxygenation.

MAIN RESULTS

All included studies (Table 1) were conducted on male and female newborns with gestational age (GA) between 22.6 and 42 weeks and birth weight (BW) between 212 and 3460 g. The definition of bradycardia and cerebral desaturation differed among authors. Seven out of nine papers agreed on association between bradycardia and cerebral desaturation, but no author indicated the cut-off of heart rate (HR) under which cerebral desaturations occur. No study focused on long-term outcome related to cerebral desaturation.

CONCLUSIONS

Even if cut-off values of HR causing cerebral desaturation are not clear and a well-fixed definition of cerebral desaturation has not yet been standardized, the studies demonstrated that bradycardia events lead to reduction of cerebral saturation. Continuous monitoring of HR and cerebral saturation by non-invasive tools could play a key role in the assessment of newborns.

Effect of interface dead space on the time taken to achieve changes in set FiO2 during T-piece ventilation: is face mask the optimal interface for neonatal stabilisation?

BACKGROUND

T-piece is recommended for respiratory support during neonatal stabilisation. Bench studies have shown a delay >30 s in achieving changes in fraction of inspired oxygen (FiO2) at the airway when using the T-piece. Using a face mask adds dead space (DS) to the patient airway. We hypothesised that adding face mask to T-piece systems adversely affects the time required for a change in FiO2 to reach the patient.

METHODS

Neopuff (Fisher and Paykel, Auckland, New Zealand) and rPAP (Inspiration Healthcare, Croydon, UK) were used to ventilate a test lung. DS equivalent to neonatal face masks was added between the T-piece and test lung. Additionally, rPAP was tested with nasal prongs. Time course for change in FiO2 to be achieved at the airway was measured for increase (0.3-0.6) and decrease (1.0-0.5) in FiO2. Primary outcome was time to reach FiO2+/-0.05 of the set target. One-way analysis of variance was used to compare mean time to reach the primary outcome between different DS volumes.

RESULTS

In all experiments, the mean time to reach the primary outcome was significantly shorter for rPAP with prongs compared with Neopuff and rPAP with face mask DS (p<0.001). The largest observed difference occurred when testing a decrease in FiO2 with 10 mL tidal volume (TV) without leakage (18.3 s for rPAP with prongs vs 153.4 s for Neopuff with face mask DS). The shortest observed time was 13.3 s when increasing FiO2 with 10 mL TV with prongs with leakage and the longest time was 172.7 s when decreasing FiO2 with 4 mL TV and added face mask DS without leak.

CONCLUSION

There was a delay in achieving changes in oxygen delivery at the airway during simulated ventilation attributable to the mask volume. This delay was greatly reduced when using nasal prongs as an interface. This should be examined in clinical trials.

Caffeine: The Story beyond Oxygen-Induced Lung and Brain Injury in Neonatal Animal Models-A Narrative Review

Caffeine is one of the most commonly used drugs in intensive care to stimulate the respiratory control mechanisms of very preterm infants. Respiratory instability, due to the degree of immaturity at birth, results in apnea of prematurity (AOP), hyperoxic, hypoxic, and intermittent hypoxic episodes. Oxidative stress cannot be avoided as a direct reaction and leads to neurological developmental deficits and even a higher prevalence of respiratory diseases in the further development of premature infants. Due to the proven antioxidant effect of caffeine in early use, largely protective effects on clinical outcomes can be observed. This is also impressively observed in experimental studies of caffeine application in oxidative stress-adapted rodent models of damage to the developing brain and lungs. However, caffeine shows undesirable effects outside these oxygen toxicity injury models. This review shows the effects of caffeine in hyperoxic, hypoxic/hypoxic-ischemic, and intermittent hypoxic rodent injury models, but also the negative effects on the rodent organism when caffeine is administered without exogenous oxidative stress. The narrative analysis of caffeine benefits in cerebral and pulmonary preterm infant models supports protective caffeine use but should be given critical consideration when considering caffeine treatment beyond the recommended corrected gestational age.

Predictive value of serum MED1 and PGC-1α for bronchopulmonary dysplasia in preterm infants

OBJECTIVE

This study aimed to predict the bronchopulmonary dysplasia (BPD) in preterm infants with a gestational age(GA) < 32 weeks utilizing clinical data, serum mediator complex subunit 1 (MED1), and serum peroxisome proliferator-activated receptor gamma coactivator-1alpha (PGC-1α).

METHODS

This prospective observational study enrolled 70 preterm infants with GA < 32 weeks. The infants were categorized into two groups: non-BPD group(N = 35) and BPD group(N = 35), including 25 cases with mild BPD and 10 patients with moderate/severe subgroups. We performed multifactorial regression analysis to investigate the postnatal risk factors for BPD. Furthermore, we compared serum levels of biomarkers, including MED1 and PGC-1α, among infants with and without BPD at postnatal days 1, 7, 14, 28, and PMA 36 weeks. A logistic regression model was constructed to predict BPD's likelihood using clinical risk factors and serum biomarkers.

RESULTS

Serum levels of MED1 on the first postnatal day, PGC-1α on the 1st, 7th, and 28th days, and PMA at 36 weeks were significantly lower in the BPD group than in the non-BPD group (P < 0.05). Furthermore, the predictive model for BPD was created by combing serum levels of MED1 and PGC-1α on postnatal day 1 along with clinical risk factors such as frequent apnea, mechanical ventilation time > 7 d, and time to reach total enteral nutrition. Our predictive model had a high predictive accuracy(C statistics of 0.989) .

CONCLUSION

MED1and PGC-1α could potentially serve as valuable biomarkers, combined with clinical factors, to aid clinicians in the early diagnosis of BPD.

Sema3A inactivates the ERK/JNK signalling pathways to alleviate inflammation and oxidative stress in lipopolysaccharide-stimulated rat endothelial cells and lung tissues

Semaphorin 3A (Sema3A) is a secretory member of the semaphorin family of immune response regulators. This research focuses on its effects on inflammation and oxidative stress in acute respiratory distress syndrome (ARDS). By analysing the GEO dataset GSE57011, we obtained Sema3A as the most downregulated gene in ARDS samples. Lipopolysaccharide (LPS) was used to stimulate rat pulmonary microvascular endothelial cells (PMVECs) and rats to induce ARDS-like symptoms in vitro and in vivo, respectively. LPS induced severe damage in rat lung tissues, in which reduced immunohistochemical staining of Sema3A was detected. Sema3A overexpression reduced apoptosis and angiogenesis of LPS-induced PMVECs and alleviated lung injury and pulmonary edoema of rats. Moreover, ELISA results showed that Sema3A overexpression downregulated the levels of inflammatory cytokines and oxidative stress markers both in PMVECs and the rat lung. Activation of ERK/JNK signalling aggravated LPS-induced damage on PMVECs; however, the aggravation was partly blocked by Sema3A, which suppressed phosphorylation of ERK/JNK. Overall, this study demonstrates that Sema3A inactivates the ERK/JNK signalling to ameliorate inflammation and oxidative stress in LPS-induced ARDS models. Sema3A might therefore represent a candidate option for ARDS treatment.

The role of oxygen in the development and treatment of bronchopulmonary dysplasia

Oxygen (O2) is crucial for both the development and treatment of one of the most important consequences of prematurity: bronchopulmonary dysplasia (BPD). In fetal life, the hypoxic environment is important for alveolar development and maturation. After birth, O2 becomes a double-edged sword. While O2 is needed to prevent hypoxia, it also causes oxidative stress leading to a plethora of morbidities, including retinopathy and BPD. The advent of continuous O2 monitoring with pulse oximeters has allowed clinicians to recognize the narrow therapeutic margins of oxygenation for the preterm infant, but more knowledge is needed to understand what these ranges are at different stages of the preterm infant's life, including at birth, in the neonatal intensive care unit and after hospital discharge. Future research, especially in innovative technologies such as automated O2 control and remote oximetry, will improve the understanding and treatment of the O2 needs of infants with BPD.

Extracellular vesicles derived from CD4+ T cells carry DGKK to promote sepsis-induced lung injury by regulating oxidative stress and inflammation

BACKGROUND

Sepsis is an abnormal immune response after infection, wherein the lung is the most susceptible organ to fail, leading to acute lung injury. To overcome the limitations of current therapeutic strategies and develop more specific treatment, the inflammatory process, in which T cell-derived extracellular vesicles (EVs) play a central role, should be explored deeply.

METHODS

Liquid chromatography-tandem mass spectrometry was performed for serum EV protein profiling. The serum diacylglycerol kinase kappa (DGKK) and endotoxin contents of patients with sepsis-induced lung injury were measured. Apoptosis, oxidative stress, and inflammation in A549 cells, bronchoalveolar lavage fluid, and lung tissues of mice were measured by flow cytometry, biochemical analysis, enzyme-linked immunosorbent assay, quantitative real-time polymerase chain reaction, and western blot.

RESULTS

DGKK, the key regulator of the diacylglycerol (DAG)/protein kinase C (PKC) pathway, exhibited elevated expression in serum EVs of patients with sepsis-induced lung injury and showed strong correlation with sepsis severity and disease progression. DGKK was expressed in CD4+ T cells under regulation of the NF-κB pathway and delivered by EVs to target cells, including alveolar epithelial cells. EVs produced by CD4+ T lymphocytes exerted toxic effects on A549 cells to induce apoptotic cell death, oxidative cell damage, and inflammation. In mice with sepsis induced by cecal ligation and puncture, EVs derived from CD4+ T cells also promoted tissue damage, oxidative stress, and inflammation in the lungs. These toxic effects of T cell-derived EVs were attenuated by the inhibition of PKC and NOX4, the downstream effectors of DGKK and DAG.

CONCLUSIONS

This approach established the mechanism that T-cell-derived EVs carrying DGKK triggered alveolar epithelial cell apoptosis, oxidative stress, inflammation, and tissue damage in sepsis-induced lung injury through the DAG/PKC/NOX4 pathway. Thus, T-cell-derived EVs and the elevated distribution of DGKK should be further investigated to develop therapeutic strategies for sepsis-induced lung injury.

Antenatal and Postnatal Sequelae of Oxidative Stress in Preterm Infants: A Narrative Review Targeting Pathophysiological Mechanisms

The detrimental effects of oxidative stress (OS) can start as early as after conception. A growing body of evidence has shown the pivotal role of OS in the development of several pathological conditions during the neonatal period, which have been therefore defined as OS-related neonatal diseases. Due to the physiological immaturity of their antioxidant defenses and to the enhanced antenatal and postnatal exposure to free radicals, preterm infants are particularly susceptible to oxidative damage, and several pathophysiological cascades involved in the development of prematurity-related complications are tightly related to OS. This narrative review aims to provide a detailed overview of the OS-related pathophysiological mechanisms that contribute to the main OS-related diseases during pregnancy and in the early postnatal period in the preterm population. Particularly, focus has been placed on pregnancy disorders typically associated with iatrogenic or spontaneous preterm birth, such as intrauterine growth restriction, pre-eclampsia, gestational diabetes, chorioamnionitis, and on specific postnatal complications for which the role of OS has been largely ascertained (e.g., respiratory distress, bronchopulmonary dysplasia, retinopathy of prematurity, periventricular leukomalacia, necrotizing enterocolitis, neonatal sepsis). Knowledge of the underlying pathophysiological mechanisms may increase awareness on potential strategies aimed at preventing the development of these conditions or at reducing the ensuing clinical burden.

Interrelation between miRNAs Expression Associated with Redox State Fluctuations, Immune and Inflammatory Response Activation, and Neonatal Outcomes in Complicated Pregnancy, Accompanied by Placental Insufficiency

Redox disbalance in placental cells leads to the hyperproduction of reactive oxygen species (ROS), it mediates the dysregulation of the maternal immune tolerance to a semi-allogenic fetus, inducing pro-inflammatory reactions, and it plays a central role in perinatal complications and neonatal disease programming. Microvesicles, which provide transplacental communication between a mother and fetus, contain microRNAs (miRNAs) that are sensitive to oxidative stress (OS) mediators and can control the balance of ROS production and utilization in target cells. In the context of this paradigm, we evaluated the markers of redox balance—MDA and 4-HNE for OS and GPx, and SOD, CAT, and GSH for the antioxidant system in the cord blood plasma of newborns diagnosed with fetal growth restriction (FGR)—by using polarography, spectrophotometry, and Western blotting. The expression of miRNAs associated with OS, immune and inflammatory responses in the blood plasma of newborns with intrauterine pneumonia (IP), neonatal sepsis (NS) and respiratory distress syndrome (RDS) was evaluated by a quantitative RT-PCR. Significant differences in the MDA level and reduced GPx and CAT activity were co-found for early-onset FGR (i.e., <34 gestational age). Significant correlations were found with a low birth weight by Apgar scores with reduced levels of antioxidant enzymes. Indeed, the level of OS markers increased in early-onset FGR in newborns with an extremely low body weight and high echogenicity of the periventricular zones, and reduced in late-onset FGR in newborns with IP, hyperbilirubinemia, intraventricular hemorrhage (IVH) and cerebral cysts. A prognostic model (AUC = 1; cutoff—0.5) was developed to assess the risk of IVH in newborns diagnosed with FGR based on the assessment of the OS markers (i.e., MDA + 4 HNE + CAT + GSH). A significant increase in the miR-127-3p expression was found in the plasma of newborns with NS (<32 GA; p ≤ 0.03 and >32 GA; p ≤ 0.009), IP (>32 GA; p ≤ 0.0001), and RDS (>32 GA; p ≤ 0.03). At the same time, the expression of miR-25-3p (p ≤ 0.03) was increased only in newborns with NS (>32 GA; p ≤ 0.03). The risk of developing IVH for premature newborns with IP (AUC = 0.8; cutoff—0.6) and NS (AUC = 0.68; cutoff—0.49) was assessed based on the miR-25-3p and miR-127-3p expression. Several key transcription factors were identified as the targets of studied miRNA since they are involved in the regulation of OS (NRF2), signaling and activation of the immune response (PRDM1, CCL26) and, also, inflammatory responses (NFKB1). The study of these miRNAs showed that they are involved in the modulation of processes leading to perinatal complications. Moreover, miR-127-3p is related to pro-inflammatory reactions and the formation of the macrophage phenotype in newborns with IP, NS, and RDS, while miR-25-3p is associated with an inhibition of macrophage migration and activation of antioxidant enzymes, which may prevent the development of oxidative damage in newborns with NS.

The administration of a pre-digested fat-enriched formula prevents necrotising enterocolitis-induced lung injury in mice

Necrotising enterocolitis (NEC) is a devastating gastrointestinal disease of prematurity that typically develops after the administration of infant formula, suggesting a link between nutritional components and disease development. One of the most significant complications that develops in patients with NEC is severe lung injury. We have previously shown that the administration of a nutritional formula that is enriched in pre-digested Triacylglyceride that do not require lipase action can significantly reduce the severity of NEC in a mouse model. We now hypothesise that this 'pre-digested fat (PDF) system' may reduce NEC-associated lung injury. In support of this hypothesis, we now show that rearing newborn mice on a nutritional formula based on the 'PDF system' promotes lung development, as evidenced by increased tight junctions and surfactant protein expression. Mice that were administered this 'PDF system' were significantly less vulnerable to the development of NEC-induced lung inflammation, and the administration of the 'PDF system' conferred lung protection. In seeking to define the mechanisms involved, the administration of the 'PDF system' significantly enhanced lung maturation and reduced the production of reactive oxygen species (ROS). These findings suggest that the PDF system protects the development of NEC-induced lung injury through effects on lung maturation and reduced ROS in the lung and also increases lung maturation in non-NEC mice.

The Role and Clinical Value of Optimized Fetal Main Pulmonary Artery Doppler Parameters in the Diagnosis and Prognosis Monitoring of Neonatal Respiratory Distress Syndrome

Objective

A retrospective study was conducted to explore the role and clinical value of optimized fetal main pulmonary artery Doppler parameters in the diagnosis and prognosis monitoring of neonatal respiratory distress syndrome (NRDS).

Methods

Pregnant women admitted to our hospital for delivery from March 2019 to June 2021 were included in the study. There were 372 singleton pregnant women who voluntarily underwent ultrasound and Doppler examinations with informed consent for the study. The AT/ET ratio of the middle segment of the main pulmonary artery, the middle part of the left (or right) pulmonary artery, and the proximal segment of the intrapulmonary artery was measured by ultrasonic Doppler. According to the outcome of the newborn, it was divided into NRDS group (n =90) and non-NRDS group (n =282) to compare the differences of fetal AT/ET ratio at three Doppler sampling locations and the differences of fetal AT/ET ratio in different gestational weeks. Using Pearson's correlation analysis, the correlation among the Doppler parameters of fetal main pulmonary artery, the ratio of AT and AT/ET, gestational weeks, and the efficiency of prenatal prediction of NRDS was evaluated by receiver-operating characteristic (ROC). In addition, the diagnostic efficiency of fetal main pulmonary artery Doppler parameter AT/ET ratio and amniotic fluid method for prenatal prediction of NRDS was compared.

Results

Compared with the non-NRDS group, the gestational age, gestational age at delivery, and birth weight in the NRDS group were significantly lower than those in the non-NRDS group. The 1 min Apgar score of newborns was less than 7, and the proportion of newborns transferred to NICU was significantly higher than that in the control group. Compared with non-NRDS group, AT was significantly shortened, AT/ET ratio was significantly decreased, and ET was significantly prolonged in NRDS group. The fetal aortic blood flow parameters AT, ET, and AT/ET ratio in different gestational weeks were significantly different among the three groups. The AT/ET ratio in the middle segment of the aorta in NRDS group was lower than that in non-NRDS group. The ratio of AT/ET was still correlated with the occurrence of postpartum NRDS. The AUC value of NRDS predicted by AT/ET ratio was 0.984. In the combined determination of amniotic fluid Lh and S ratio and PG, the diagnostic accuracy of prenatal prediction of neonatal respiratory distress syndrome was 100.005%, 98.43%, and 95.56%, respectively. The accuracy of fetal aortic AT/ET ratio in prenatal prediction of neonatal respiratory distress syndrome was 100.005%, 95.28%, and 95.57%, respectively. The order of Kappa coefficient from high to low was amniotic fluid PG/L/S ratio, fetal main pulmonary artery blood flow parameter AT/ET ratio, amniotic fluid L/S ratio, OD650, amniotic fluid PG, and foam test.

Conclusion

Fetal main pulmonary artery Doppler AT/ET ratio may be a very potential parameter for prenatal noninvasive prediction of NRDS. The fetal main pulmonary artery Doppler flow spectrum may be a very potential alternative to amniocentesis to evaluate FLM.

Ultrasound Lung Image under Artificial Intelligence Algorithm in Diagnosis of Neonatal Respiratory Distress Syndrome

In order to analyze the application of ultrasonic lung imaging diagnosis model based on artificial intelligence algorithm in neonatal respiratory distress syndrome (NRDS), an ultrasonic lung imaging diagnosis model based on a deep residual network (DRN) was proposed. In this study, 90 premature infants in the hospital were selected as the research object and divided into the experimental group (45 cases) and control group (45 cases) according to whether or not they have NRDS. DRN was compared with the deep residual network (DRWSR) based on wavelet domain, deep residual network detection with normalization framework (Fisher-DRN), and distorted image edge detection preprocessor (DIEDP). Then, it was applied to the diagnosis of NRDS. The clinical data and ultrasound imaging results of infants with NRDS and ordinary premature infants were compared. The results showed that the gestational age, birth weight, and Apgar scores of the NRDS group were remarkably lower than those of ordinary children (P < 0.05). In addition, the segmentation accuracy, image feature extraction accuracy, algorithm convergence, and time loss of the DRN algorithm were better than the other three algorithms, and the differences were considerable (P < 0.05). In children with NRDS, the positive rate of abnormal pleural line, disappearance of A line, appearance of B line, and alveolar interstitial syndrome (AIS) test in the results of lung ultrasound examination in children with NRDS were all 100%. The lung consolidation became 70.8%, and the white lung-like change was 50.1%, both of which were higher than those of ordinary preterm infants, and the differences were considerable (P < 0.05). The diagnostic model of this study predicted that the AUC area of grade 1-2, grade 2-3, and grade 3-4 NRDS were 0.962, 0.881, and 0.902, respectively. To sum up, the ultrasound lung imaging diagnosis model based on the DRN algorithm had good diagnostic performance in children with NRDS and can provide useful information for clinical NRDS diagnosis and treatment.

Urinary biomarkers for the early prediction of bronchopulmonary dysplasia in preterm infants: A pilot study

BACKGROUND

This study investigated whether 8-hydroxy-2'-deoxyguanosine (8-OHdG) and N-terminal pro-brain natriuretic peptide (NT-proBNP) concentrations in the urine could predict bronchopulmonary dysplasia (BPD) in preterm infants.

METHODS

This prospective cohort study enrolled 165 preterm infants, of whom 70 developed BPD. We measured urinary 8-OHdG and NT-proBNP concentrations from day of life (DOL) 7 to 28. Then, we evaluated the prediction efficiency by receiver operating characteristic curves and assessed correlations between the two biomarkers. Finally, we identified the predictive risk factors for BPD by multivariable logistic regression.

RESULTS

8-OHdG and NT-proBNP levels were significantly higher from DOL 7 to 28 in the BPD group than in the control group (P < 0.05). Additionally, the 8-OHdG level was positively correlated with the NT-proBNP level (r: 0.655-0.789, P < 0.001), and the 8-OHdG and NT-proBNP levels were positively correlated with mechanical ventilation duration and oxygen exposure time (r: 0.175-0.505, P < 0.05) from DOL 7 to 28. Furthermore, the 8-OHdG (DOL 14-28) and NT-proBNP (DOL 7-28) levels were significantly associated with BPD development (P < 0.05).

CONCLUSION

The urine 8-OHdG concentrations from DOL 14 to 28 and NT-proBNP concentrations from DOL 7 to 28 may be practical non-invasive predictors of BPD development in preterm infants.

Nanoantioxidants: Pioneer Types, Advantages, Limitations, and Future Insights

Free radicals are generated as byproducts of normal metabolic processes as well as due to exposure to several environmental pollutants. They are highly reactive species, causing cellular damage and are associated with a plethora of oxidative stress-related diseases and disorders. Antioxidants can control autoxidation by interfering with free radical propagation or inhibiting free radical formation, reducing oxidative stress, improving immune function, and increasing health longevity. Antioxidant functionalized metal nanoparticles, transition metal oxides, and nanocomposites have been identified as potent nanoantioxidants. They can be formulated in monometallic, bimetallic, and multi-metallic combinations via chemical and green synthesis techniques. The intrinsic antioxidant properties of nanomaterials are dependent on their tunable configuration, physico-chemical properties, crystallinity, surface charge, particle size, surface-to-volume ratio, and surface coating. Nanoantioxidants have several advantages over conventional antioxidants, involving increased bioavailability, controlled release, and targeted delivery to the site of action. This review emphasizes the most pioneering types of nanoantioxidants such as nanoceria, silica nanoparticles, polydopamine nanoparticles, and nanocomposite-, polysaccharide-, and protein-based nanoantioxidants. This review overviews the antioxidant potential of biologically synthesized nanomaterials, which have emerged as significant alternatives due to their biocompatibility and high stability. The promising nanoencapsulation nanosystems such as solid lipid nanoparticles, nanostructured lipid carriers, and liposome nanoparticles are highlighted. The advantages, limitations, and future insights of nanoantioxidant applications are discussed.

Oxidative Stress and Respiratory Diseases in Preterm Newborns

Premature infants are exposed to increased generation of reactive oxygen species, and on the other hand, they have a deficient antioxidant defense system. Oxidative insult is a salient part of lung injury that begins as acute inflammatory injury in respiratory distress disease and then evolves into chronic and structural scarring leading to bronchopulmonary dysplasia. Oxidative stress is also involved in the pathogenesis of pulmonary hypertension in newborns through the modulation of the vascular tone and the response to pulmonary vasodilators, with consequent decrease in the density of the pulmonary vessels and thickening of the pulmonary arteriolar walls. Oxidative stress has been recognized as both a trigger and an endpoint for several events, including inflammation, hypoxia, hyperoxia, drugs, transfusions, and mechanical ventilation, with impairment of pulmonary function and prolonged lung damage. Redoxomics is the most fascinating new measure to address lung damage due to oxidative stress. The new challenge is to use omics data to discover a set of biomarkers useful in diagnosis, prognosis, and formulating optimal and individualized neonatal care. The aim of this review was to examine the most recent evidence on the relationship between oxidative stress and lung diseases in preterm newborns. What is currently known regarding oxidative stress-related lung injury pathogenesis and the available preventive and therapeutic strategies are also discussed.

The Role of Oxidative Stress in Sarcoidosis

Sarcoidosis is a rare, systemic inflammatory disease whose diagnosis and management can pose a challenge for clinicians and specialists. Scientific knowledge on the molecular pathways that drive its development is still lacking, with no standardized therapies available and insufficient strategies to predict patient outcome. In recent years, oxidative stress has been highlighted as an important factor in the pathogenesis of sarcoidosis, involving several enzymes and molecules in the mechanism of the disease. This review presents current data on the role of oxidative stress in sarcoidosis and its interaction with inflammation, as well as the application of antioxidative therapy in the disease.

Mineral Composition, Phenolic Content, and In Vitro Antidiabetic and Antioxidant Properties of Aqueous and Organic Extracts of Haloxylon scoparium Aerial Parts

Haloxylon scoparium is a plant widely used in traditional medicine for the treatment of diabetes. Hence, this study focuses on the mineralogical and chemical composition and evaluation of the antidiabetic and antioxidant activities of the aerial part of this species. The mineralogical analysis was done by inductively coupled plasma atomic emission spectrometry (ICP-AES). The phytochemical study consisted in the preparation of different extracts from the aerial part by aqueous and organic extraction using Soxhlet and cold maceration. Then, phytochemical screening was performed on the plant powder and on the extracts, which is completed by spectrophotometric quantification of total polyphenols, flavonoids, and catechic tannins. The evaluation of antidiabetic activity was done by three enzymes: a-amylase, a-glucosidase, and ß-galactosidase, and that of antioxidant activity was done by five methods: H₂O₂, DPPH, ABTS, FRAP, and reducing power (RP). Mineralogical analysis revealed the presence of iron, potassium, magnesium, phosphorus, sodium, copper, calcium, strontium, selenium, and zinc. The studied part is rich in alkaloids, flavonoids, catechic tannins, and saponins. The methanolic extract is rich in total polyphenols (161.65 ± 1.52 Ug EAG/mg E), and the ethyl acetate extract has high levels of catechic tannins (23.69 ± 0.6 Ug EC/mg E). In addition, the decoctate expresses a high flavonoid content of 306.59 ± 4.35 Ug EQ/mg E. The in vitro evaluation of the antidiabetic activity showed that the decoctate has a higher inhibitory capacity on a-glucosidase (IC50 = 181.7 ± 21.15 ug/mL) than acarbose (IC50 = 195 ± 6.12 ug/mL). The results of the antioxidant activity showed that the methanolic extract and the decoctate present a percentage of hydrogen peroxide (H₂O₂) scavenging (20.91 ± 0.27 and 16.21 ± 0.39%) higher than that of ascorbic acid (14.35 ± 0.002%). Positive correlations obtained between the total polyphenol content and the antioxidant activity of the extracts were studied. A positive correlation of a-amylase inhibitory activity was also recorded with the antioxidant activity tests.

Association of Elevated Cord Blood Oxidative Stress Biomarkers with Neonatal Outcomes in Mothers with Pre-Eclampsia: A Case-Control Study

OBJECTIVES

The objective of this study was to determine the relationship between the levels of stress biomarkers in cord blood and pre-eclampsia (PE) in a hospital-based population of pregnant patients and evaluate the effects on pregnancy outcomes.

DESIGN

This was an observational, case-control study. Participants/Materials, Setting, Methods: This case-control study included 282 patients with severe PE and 534 women with normal pregnancy. The umbilical cord was collected at delivery and tested for malonaldehyde (MDA), reactive oxygen species (ROS), superoxide dismutase, and homocysteine (Hcy) analysis. We performed a univariate general linear regression model analysis to control potential confounders and determined the underlying influencing factors for high MDA and ROS. A receiver operating characteristic curve analysis was conducted to determine the cutoff values for identifying severe PE. Further, the severe PE group was divided into the low- or high-MDA and low- or high-ROS subgroups according to the cutoff values. Finally, we created logistic regression models to estimate the adjusted odds ratio for each perinatal outcome in the high-MDA and high-ROS subgroup.

RESULTS

The levels of MDA and ROS levels were higher in women with severe PE than in normotensive pregnant patients. However, when adjusted for cord blood Hcy levels, the difference was insignificant. Additionally, both MDA (r = 0.359, p < 0.001) and ROS (r = 0.473, p < 0.001) were positively correlated with the cord blood Hcy level. The areas under the curve of MDA and ROS levels were 0.65 (95% confidence interval [CI]: 0.60-0.69) and 0.88 (95% CI: 0.86-0.90), respectively. Higher MDA and ROS levels were associated with increased risks of a low Apgar score, admission to the NICU, and assisted ventilation for the newborn.

LIMITATIONS

The study design led to the exclusion of several participants.

CONCLUSIONS

Increased levels of oxidative stress markers in the cord blood might be significantly associated with negative effects on newborns. High levels of Hcy in the cord blood might be associated with elevated MDA and ROS concentrations in women with severe PE.

Early closure mechanisms of the ductus arteriosus in immature infants

AIM

According to experimental studies, cardiopulmonary distress decreases after closure of patent ductus arteriosus. However, early closure of the ductus using ibuprofen or indomethacin has failed to increase survival without serious morbidity. We review relevant data aiming to define optimal early management strategies that promote early closure of ductus arteriosus without serious adverse effects.

METHODS

Literature in English was searched selectively focusing on the potential of using acetaminophen for early closure of the ductus.

RESULTS

Prophylactic ibuprofen or indomethacin intended to close the ductus, predisposes infants to ischaemia, bleeding and immune dysfunction. Acetaminophen appears to have a similar efficacy as indomethacin or ibuprofen, and all three dose-dependently constrict the ductus. Ibuprofen and indomethacin cause non-specific inhibition of prostaglandin synthesis, while acetaminophen predominantly inhibits prostaglandin E synthesis. Owing to low CYP450 activity in infancy, acetaminophen toxicity has been rarely evident. However, increasing the dosage increases the oxidative stress. We review prophylactic treatments that may increase the safety and efficacy of acetaminophen. These include vitamin A, cysteine and glutamine, and low-dose corticosteroid supplementation.

CONCLUSION

The current challenge is to define a safe perinatal management practice that promotes cardiorespiratory adaptation in immature infants, particularly the seamless closure of the ductus before significant cardiopulmonary distress develops.

A comparison of the effect of bi-level positive airway pressure and synchronized intermittent mandatory ventilation in preterm infants with respiratory distress syndrome

OBJECTIVE

Bi-level positive airway pressure (BiPAP) and synchronized intermittent mandatory ventilation (SIMV) can be used to achieve peak inspiratory pressure and positive end-expiratory pressure to avoid alveolar collapse and improve oxygenation in preterm infants during the treatment of respiratory distress syndrome (RDS), and there is an urgent demand for evaluating the effects and prognoses of these two ventilation modes.

STUDY DESIGN

We conducted a retrospective study on preterm infants (≤32 weeks and <2500 g) from March 2015 to March 2020 with BiPAP (n = 63) and SIMV (n = 63). The primary outcomes were successful treatment and weaning within 72 h, the demand for a second pulmonary surfactant supply and the need for a second respiratory support. The secondary outcome was the incidence of complications.

RESULTS

There were no significant differences (p > .05) in the primary outcomes or the incidence of complications (pneumonia, apnea, respiratory failure, air leak syndrome, persistence of patent ductus arteriosus, neonatal sepsis, necrotizing enterocolitis, retinopathy of prematurity, and intraventricular hemorrhage). There were significant differences (p < .05) in the incidence of pulmonary hemorrhage, bronchopulmonary dysplasia and IVH (≥grade II).

CONCLUSIONS

Although both BiPAP and SIMV achieved good early treatment outcomes of RDS in preterm infants, BiPAP support is recommended for reducing the incidence of pulmonary hemorrhage, bronchopulmonary dysplasia and IVH (≥grade II) if infants are tolerant. Attempts should be made to prevent these complications from happening with the use of SIMV support if infants are intolerant.

Biomarkers of Oxidative Stress for Neonatal Lung Disease

The transition from prenatal to postnatal life causes a significant increase in arterial oxygen tension and the activation of metabolic pathways enabling the newborn's adaptation to the extra-uterine environment. The balance between pro-oxidant and anti-oxidant systems is critical to preserve cellular functions. Indeed, oxidative stress (OS) occurs when the production of free radicals is not balanced by the activity of intracellular antioxidant systems, contributing to cellular and tissue damage. Perinatal OS may have serious health consequences during the postnatal period and later in life. Namely, OS has been recognized as the major cause of lung injury in newborns, especially those preterm born, due to their immature lung and antioxidant systems. The development of OS biomarkers has gained increasing research interest since they may provide useful insights about pathophysiological pathways underlying OS-mediated pulmonary diseases in newborns. Moreover, their implementation in clinical settings may help to early identify high risk-newborns and to provide targeted treatment. Ideally, a biomarker should demonstrate ease of use, biological validity and reproducibility, high sensitivity and specificity. However, none of the clinically validated biomarkers so far have been qualified for neonatal lung disease. Additionally, the complex technical procedures and the high cost of such determinations have hampered the use of OS biomarkers in clinical practice. This review aims to evaluate the current evidence on the application of biomarkers of oxidative stress for neonatal lung disease and exploring the most relevant issues affecting their implementation in practice, as well as the associated evidence gaps and research limitations.

[A single-center retrospective study of neonatal acute respiratory distress syndrome based on the Montreux definition]

OBJECTIVE

To investigate the epidemiology, clinical features, treatment, and prognostic factors of neonatal acute respiratory distress syndrome (NARDS) through a retrospective study of NARDS based on the Montreux definition.

METHODS

A retrospective analysis was performed on the medical records of neonates who were hospitalized from January 2017 and July 2018, among whom 314 neonates who met the Montreux definition were enrolled as subjects. According to oxygen index, they were divided into a mild NARDS group with 130 neonates, a moderate NARDS group with 117 neonates, and a severe NARDS group with 67 neonates. The clinical features were compared among the three groups to investigate the influencing factors for the severities of NARDS and the length of hospital stay.

RESULTS

The neonates with NARDS accounted for 2.46% (314/12 789) of the neonates admitted to the neonatal ward during the same period of time and had a mortality rate of 9.6% (30/314). The multivariate ordinal logistic regression analysis showed that the neonates who used pulmonary surfactant (PS) or had a long duration of assisted ventilation tended to have a higher risk of severe NARDS (P < 0.05). The Cox regression analysis showed that the neonates with low birth weight/macrosomia, preterm birth, invasive ventilation, PS therapy, or positive pathogenic detection had a higher risk of prolonged hospital stay (P < 0.05).

CONCLUSIONS

Preterm birth, low birth weight/macrosomia, and perinatal infection may be associated with an increased risk of severe NARDS. The neonates requiring invasive ventilation, prolonged assisted ventilation, or PS therapy tend to have a poor prognosis.

Efficacy of Intravenous Hydrocortisone Treatment in Refractory Neonatal Seizures: A Report on Three Cases

Neonatal seizures are the most common neurological emergency, and neonatal status epilepticus (NSE) remains a controversial entity, with no general consensus about its definition and treatment. Here, we report on three newborns with NSE refractory to first- and second-line antiepileptic drugs successfully treated with intravenous (IV) hydrocortisone. The patients had previously failed therapy with levetiracetam, phenobarbital and midazolam, showing persistent clinical and electrical seizures. Modulation of brain inflammation triggered during prolonged epileptic activity has been thought to potentially explain the beneficial effects of anti-inflammatory treatment.

Care of Infants Born to Women with Diabetes

PURPOSE OF REVIEW

Infants of women with diabetes are at risk for specific morbidities including congenital anomalies, abnormalities of fetal growth, neonatal hypoglycemia, electrolyte abnormalities, polycythemia, hyperbilirubinemia, and respiratory distress syndrome. Recent studies have shed light on long-term outcomes of these infants and presented advances in treatment. The purpose of this review is to outline the most common neonatal morbidities affecting infants of women with diabetes, the pathophysiology and prevalence of these conditions, and contemporary approaches to treatment.

RECENT FINDINGS

Recent investigative findings have led to advances in treatment approaches for these infants, particularly regarding risks of neonatal hypoglycemia. Optimizing maternal glycemic control during pregnancy is imperative to improving infant outcomes. However, on a population level, maternal diabetes still poses significant risks to the infant. Timely and appropriate treatment of infants of women with diabetes is imperative to decrease short- and long-term morbidity.

Ventilation, oxidative stress and risk of brain injury in preterm newborn

Preterm infants have an increased risk of cognitive and behavioral deficits and cerebral palsy compared to term born babies. Especially before 32 weeks of gestation, infants may require respiratory support, but at the same time, ventilation is known to induce oxidative stress, increasing the risk of brain injury. Ventilation may cause brain damage through two pathways: localized cerebral inflammatory response and hemodynamic instability. During ventilation, the most important causes of pro-inflammatory cytokine release are oxygen toxicity, barotrauma and volutrauma. The purpose of this review was to analyze the mechanism of ventilation-induced lung injury (VILI) and the relationship between brain injury and VILI in order to provide the safest possible respiratory support to a premature baby. As gentle ventilation from the delivery room is needed to reduce VILI, it is recommended to start ventilation with 21–30% oxygen, prefer a non-invasive respiratory approach and, if mechanical ventilation is required, prefer low Positive End-Expiratory Pressure and tidal volume.

Oxidative Stress in Preterm Infants: Overview of Current Evidence and Future Prospects

Preterm birth (PTB), defined as parturition prior to 37 weeks of gestation, is the leading cause of morbidity and mortality in the neonatal population. The incidence and severity of complications of prematurity increase with decreasing gestational age and birthweight. The aim of this review study is to select the most current evidence on the role of oxidative stress in the onset of preterm complication prevention strategies and treatment options with pre-clinical and clinical trials. We also provide a literature review of primary and secondary studies on the role of oxidative stress in preterm infants and its eventual treatment in prematurity diseases. We conducted a systematic literature search of the Medline (Pubmed), Scholar, and ClinicalTrials.gov databases, retroactively, over a 7-year period. From an initial 777 articles identified, 25 articles were identified that met the inclusion and exclusion criteria. Of these, there were 11 literature reviews: one prospective cohort study, one experimental study, three case-control studies, three pre-clinical trials, and six clinical trials. Several biomarkers were identified as particularly promising, such as the products of the peroxidation of polyunsaturated fatty acids, those of the oxidation of phenylalanine, and the hydroxyl radicals that can attack the DNA chain. Among the most promising drugs, there are those for the prevention of neurological damage, such as melatonin, retinoid lactoferrin, and vitamin E. The microbiome also has an important role in oxidative stress. In conclusion, the most recent studies show that a strong relationship between oxidative stress and prematurity exists and that, unfortunately, there is still little therapeutic evidence reported in the literature.

Brain oxidative damage in murine models of neonatal hypoxia/ischemia and reoxygenation

The brain is one of the main organs affected by hypoxia and reoxygenation in the neonatal period and one of the most vulnerable to oxidative stress. Hypoxia/ischemia and reoxygenation leads to impairment of neurogenesis, disruption of cortical migration, mitochondrial damage and neuroinflammation. The extent of the injury depends on the clinical manifestation in the affected regions. Preterm newborns are highly vulnerable, and they exhibit severe clinical manifestations such as intraventricular hemorrhage (IVH), retinopathy of prematurity (ROP) and diffuse white matter injury (DWMI) among others. In the neonatal period, the accumulation of high levels of reactive oxygen species exacerbated by the immature antioxidant defense systems in represents cellular threats that, if they exceed or bypass physiological counteracting mechanisms, are responsible of significant neuronal damage. Several experimental models in mice mimic the consequences of perinatal asphyxia and the use of oxygen in the reanimation process that produce brain injury. The aim of this review is to highlight brain damage associated with oxidative stress in different murine models of hypoxia/ischemia and reoxygenation.