Enhancing 7-dehydrocholesterol suppresses brain ferroptosis and tissue injury after neonatal hypoxia-ischemia

Neonatal hypoxic-ischemic brain injury (HIBI) results in part from excess reactive oxygen species and iron-dependent lipid peroxidation (i.e. ferroptosis). The vitamin D precursor 7-dehydrocholesterol (7-DHC) may inhibit iron-dependent lipid peroxidation. Primary neurons underwent oxygen and glucose deprivation (OGD) injury and treatment with 7-DHC-elevating medications such as cariprazine (CAR) or vehicle. Postnatal day 9 mice underwent sham surgery or carotid artery ligation and hypoxia and received intraperitoneal CAR. In neurons, CAR administration resulted in significantly increased cell survival compared to vehicle controls, whether administered 48 h prior to or 30 min after OGD, and was associated with increased 7-DHC. In the mouse model, malondialdehyde and infarct area significantly increased after HIBI in the vehicle group, which were attenuated by post-treatment with CAR and were negatively correlated with tissue 7-DHC concentrations. Elevating 7-DHC concentrations with CAR was associated with improved cellular and tissue viability after hypoxic-ischemic injury, suggesting a novel therapeutic avenue.

Chemical Inhibition of Sterol Biosynthesis

Cholesterol is an essential molecule of life, and its synthesis can be inhibited by both genetic and nongenetic mechanisms. Hundreds of chemicals that we are exposed to in our daily lives can alter sterol biosynthesis. These also encompass various classes of FDA-approved medications, including (but not limited to) commonly used antipsychotic, antidepressant, antifungal, and cardiovascular medications. These medications can interfere with various enzymes of the post-lanosterol biosynthetic pathway, giving rise to complex biochemical changes throughout the body. The consequences of these short- and long-term homeostatic disruptions are mostly unknown. We performed a comprehensive review of the literature and built a catalogue of chemical agents capable of inhibiting post-lanosterol biosynthesis. This process identified significant gaps in existing knowledge, which fall into two main areas: mechanisms by which sterol biosynthesis is altered and consequences that arise from the inhibitions of the different steps in the sterol biosynthesis pathway. The outcome of our review also reinforced that sterol inhibition is an often-overlooked mechanism that can result in adverse consequences and that there is a need to develop new safety guidelines for the use of (novel and already approved) medications with sterol biosynthesis inhibiting side effects, especially during pregnancy.

Effects of Neonatal Hypoxic-Ischemic Injury on Brain Sterol Synthesis and Metabolism

BACKGROUND

 Neonatal hypoxic-ischemic brain injury (HIBI) results from disruptions to blood supply and oxygen in the perinatal brain. The goal of this study was to measure brain sterol metabolites and plasma oxysterols after injury in a neonatal HIBI mouse model to assess for potential therapeutic targets in the brain biochemistry as well as potential circulating diagnostic biomarkers.

METHODS

 Postnatal day 9 CD1-IGS mouse pups were randomized to HIBI induced by carotid artery ligation followed by 30 minutes at 8% oxygen or to sham surgery and normoxia. Brain tissue was collected for sterol analysis by liquid chromatography with tandem mass spectrometry (LC-MS/MS). Plasma was collected for oxysterol analysis by LC-MS/MS.

RESULTS

 There were minimal changes in brain sterol concentrations in the first 72 hours after HIBI. In severely injured brains, there was a significant increase in desmosterol, 7-DHC, 8-DHC, and cholesterol 24 hours after injury in the ipsilateral tissue. Lanosterol, 24-dehydrolathosterol, and 14-dehydrozymostenol decreased in plasma 24 hours after injury. Severe neonatal HIBI was associated with increased cholesterol and sterol precursors in the cortex at 24 hours after injury.

CONCLUSIONS

 Differences in plasma oxysterols were seen at 24 hours but were not present at 30 minutes after injury, suggesting that these sterol intermediates would be of little value as early diagnostic biomarkers.

Short-Term Outcomes of Neonates with Hypoxic-Ischemic Encephalopathy Receiving Active Versus Passive Cooling During Transport

Therapeutic hypothermia (TH) is the only currently approved treatment for neonatal hypoxic-ischemic encephalopathy (HIE) and must be started within 6 hours to optimize effectiveness. This narrow therapeutic window often requires initiation of TH before or during transport. The goal of this study was to assess the effects of servo-controlled TH versus passive hypothermia during transport on short-term outcomes in newborns with HIE. This was a single-center retrospective case-control study of neonates with HIE treated with active or passive TH during transport. Primary outcomes included brain injury on magnetic resonance imaging (MRI) and presence of seizures. Seventy-six neonates were included-13 active and 63 passive. The active TH group was more likely to arrive within goal temperature. No difference was noted between groups in seizures or TH complications. Active TH was associated with increased injury on MRI. Active TH resulted in tighter temperature control, but no improvement in short-term outcomes in our cohort. The MRI findings may be due to differences in overall disease severity, which could not be adjusted for, given the modest sample size.

Association of Hospital Resource Utilization With Neurodevelopmental Outcomes in Neonates With Hypoxic-Ischemic Encephalopathy

IMPORTANCE

Intercenter variation exists in the management of hypoxic-ischemic encephalopathy (HIE). It is unclear whether increased resource utilization translates into improved neurodevelopmental outcomes.

OBJECTIVE

To determine if higher resource utilization during the first 4 days of age, quantified by hospital costs, is associated with survival without neurodevelopmental impairment (NDI) among infants with HIE.

DESIGN, SETTING, AND PARTICIPANTS

Retrospective cohort analysis of neonates with HIE who underwent therapeutic hypothermia (TH) at US children's hospitals participating in the Children's Hospitals Neonatal Database between 2010 and 2016. Data were analyzed from December 2021 to December 2022.

EXPOSURES

Infants who survived to 4 days of age and had neurodevelopmental outcomes assessed at greater than 11 months of age were divided into 2 groups: (1) death or NDI and (2) survived without NDI. Resource utilization was defined as costs of hospitalization including neonatal neurocritical care (NNCC). Data were linked with Pediatric Health Information Systems to quantify standardized costs by terciles.

MAIN OUTCOMES AND MEASURES

The main outcome was death or NDI. Characteristics, outcomes, hospitalization, and NNCC costs were compared.

RESULTS

Among the 381 patients who were included, median (IQR) gestational age was 39 (38-40) weeks; maternal race included 79 (20.7%) Black mothers, 237 (62.2%) White mothers, and 58 (15.2%) mothers with other race; 80 (21%) died, 64 (17%) survived with NDI (combined death or NDI group: 144 patients [38%]), and 237 (62%) survived without NDI. The combined death or NDI group had a higher rate of infants with Apgar score at 10 minutes less than or equal to 5 (65.3% [94 of 144] vs 39.7% [94 of 237]; P < .001) and a lower rate of infants with mild or moderate HIE (36.1% [52 of 144] vs 82.3% [195 of 237]; P < .001) compared with the survived without NDI group. Compared with low-cost centers, there was no association between high- or medium-hospitalization cost centers and death or NDI. High- and medium-EEG cost centers had lower odds of death or NDI compared with low-cost centers (high vs low: OR, 0.30 [95% CI, 0.16-0.57]; medium vs low: OR, 0.29 [95% CI, 0.13-0.62]). High- and medium-laboratory cost centers had higher odds of death or NDI compared with low-cost centers (high vs low: OR, 2.35 [95% CI, 1.19-4.66]; medium vs low: OR, 1.93 [95% CI, 1.07-3.47]). High-antiseizure medication cost centers had higher odds of death or NDI compared with low-cost centers (high vs. low: OR, 3.72 [95% CI, 1.51-9.18]; medium vs low: OR, 1.56 [95% CI, 0.71-3.42]).

CONCLUSIONS AND RELEVANCE

Hospitalization costs during the first 4 days of age in neonates with HIE treated with TH were not associated with neurodevelopmental outcomes. Higher EEG costs were associated with lower odds of death or NDI yet higher laboratory and antiseizure medication costs were not. These findings serve as first steps toward identifying aspects of NNCC that are associated with outcomes.

MicroRNA therapeutic targets in neonatal hypoxic-ischemic brain injury: a narrative review

Neonatal hypoxic-ischemic brain injury (HIBI) is a devastating injury resulting from impaired blood flow and oxygen delivery to the brain at or around the time of birth. Despite the use of therapeutic hypothermia, more than one in four survivors suffer from major developmental disabilities-an indication of the critical need for more effective therapies. MicroRNAs (miRNA) have the potential to act as biomarkers and/or therapeutic targets in neonatal HIBI as a step toward improving outcomes in this high-risk population. This review summarizes the current literature around the use of cord blood and postnatal circulating blood miRNA expression for diagnosis or prognosis in human infants with hypoxic-ischemic encephalopathy, as well as animal studies assessing endogenous brain miRNA expression and potential for therapeutic targeting of miRNA expression for neuroprotection. Ultimately, the lack of knowledge regarding brain specificity of circulating miRNAs and the temporal variability in expression currently limit the use of miRNAs as biomarkers. However, given their broad effect profile, ease of administration, and small size allowing for effective blood-brain barrier crossing, miRNAs represent promising therapeutic targets for improving brain injury and reducing developmental impairments in neonates after HIBI. IMPACT: The high morbidity and mortality of neonatal hypoxic-ischemic brain injury (HIBI) despite current therapies demonstrates a need for developing more sensitive biomarkers and superior therapeutic options. MicroRNAs have been evaluated both as biomarkers and therapeutic options after neonatal HIBI. The limited knowledge regarding brain specificity of circulating microRNAs and temporal variability in expression currently limit the use of microRNAs as biomarkers. Future studies comparing the neuroprotective effects of modulating microRNA expression must consider temporal changes in the endogenous expression to determine appropriate timing of therapy, while also optimizing techniques for delivery.

Opioid exposure during therapeutic hypothermia and short-term outcomes in neonatal encephalopathy

OBJECTIVE

To assess the association between opioid exposure during therapeutic hypothermia (TH) for perinatal hypoxic-ischemic encephalopathy (HIE) and in-hospital outcomes.

STUDY DESIGN

In this retrospective cohort study, linked data were accessed on infants ≥36 weeks gestation, who underwent TH for HIE, born from 2010-2016 in 23 Neonatal Intensive Care Units participating in Children's Hospitals Neonatal Consortium and Pediatric Health Information Systems. We excluded infants who received opioids for >5 days.

RESULTS

The cohort (n = 1484) was categorized as No opioid [240(16.2%)], Low opioid (1-2 days) [574 (38.7%)] and High opioid group (HOG, 3-5 days) [670 (45.2%)]. After adjusting for HIE severity, opioids were not associated with abnormal MRI, but were associated with decreased likelihood of complete oral feeds at discharge. HOG had increased likelihood of prolonged hospital stay and ventilation.

CONCLUSION

Opioid exposure during TH was not associated with abnormal MRI; its association with adverse short-term outcomes suggests need for cautious empiric use.

Inhaled Corticosteroid Exposure in Hospitalized Infants with Bronchopulmonary Dysplasia

OBJECTIVE

 The objective of this paper was to determine inhaled corticosteroid (IC) use in infants with bronchopulmonary dysplasia (BPD), define the interhospital variation of IC administration to infants with BPD, and compare clinical, demographic, and hospital factors associated with IC use.

STUDY DESIGN

 Using the Pediatric Health Information System database, a retrospective multicenter cohort of 4,551 infants born at <32 weeks of gestation with developing BPD was studied. The clinical, demographic, and hospital characteristics of infants exposed and not exposed to ICs were compared.

RESULTS

 IC use varied markedly between hospitals, ranging from 0 to 66% of infants with BPD exposed to ICs. Increased annual BPD census was not associated with IC use. In total, 25% (1,144 out of 4,551) of patients with BPD and 43% (536 out of 1,244) of those with severe BPD received ICs. Increased IC exposure was associated with lower birth weight and gestational age, days on respiratory support, need for positive pressure ventilation at 36-week postmenstrual age, need for tracheostomy, and increased use of systemic steroids, bronchodilators, and diuretics.

CONCLUSION

 IC exposure is common in infants with BPD, with substantial interhospital variability. IC use was associated with more severe disease. Hospital experience did not account for the wide variability in IC use by the hospital. Further research into the effects of ICs use is urgently needed to help guide their use in this vulnerable population.

KEY POINTS

· The risks and benefits of IC use in infants with BPD are incompletely understood.. · IC use is common in infants with BPD (25%) and severe BPD (43%) varies widely by hospital (0-66% of patients with BPD received an IC).. · Hospital experience did not account for the wide interhospital variation in IC use..

Neonatal Hypoxic-Ischemic Brain Injury Alters Brain Acylcarnitine Levels in a Mouse Model

Hypoxic-ischemic brain injury (HIBI) leads to depletion of ATP, mitochondrial dysfunction, and enhanced oxidant formation. Measurement of acylcarnitines may provide insight into mitochondrial dysfunction. Plasma acylcarnitine levels are altered in neonates after an HIBI, but individual acylcarnitine levels in the brain have not been evaluated. Additionally, it is unknown if plasma acylcarnitines reflect brain acylcarnitine changes. In this study, postnatal day 9 CD1 mouse pups were randomized to HIBI induced by carotid artery ligation, followed by 30 min at 8% oxygen, or to sham surgery and normoxia, with subgroups for tissue collection at 30 min, 24 h, or 72 h after injury (12 animals/group). Plasma, liver, muscle, and brain (dissected into the cortex, cerebellum, and striatum/thalamus) tissues were collected for acylcarnitine analysis by LC-MS. At 30 min after HIBI, acylcarnitine levels were significantly increased, but the differences resolved by 24 h. Palmitoylcarnitine was increased in the cortex, muscle, and plasma, and stearoylcarnitine in the cortex, striatum/thalamus, and cerebellum. Other acylcarnitines were elevated only in the muscle and plasma. In conclusion, although plasma acylcarnitine results in this study mimic those seen previously in humans, our data suggest that the plasma acylcarnitine profile was more reflective of muscle changes than brain changes. Acylcarnitine metabolism may be a target for therapeutic intervention after neonatal HIBI, though the lack of change after 30 min suggests a limited therapeutic window.

Early Brain microRNA/mRNA Expression is Region-Specific After Neonatal Hypoxic-Ischemic Injury in a Mouse Model

Background: MicroRNAs (miRNAs) may be promising therapeutic targets for neonatal hypoxic-ischemic brain injury (HIBI) but targeting miRNA-based therapy will require more precise understanding of endogenous brain miRNA expression. Methods: Postnatal day 9 mouse pups underwent HIBI by unilateral carotid ligation + hypoxia or sham surgery. Next-generation miRNA sequencing and mRNA Neuroinflammation panels were performed on ipsilateral cortex, striatum/thalamus, and cerebellum of each group at 30 min after injury. Targeted canonical pathways were predicted by KEGG analysis. Results: Sixty-one unique miRNAs showed differential expression (DE) in at least one region; nine in more than one region, including miR-410-5p, -1264-3p, 1298-5p, -5,126, and -34b-3p. Forty-four mRNAs showed DE in at least one region; 16 in more than one region. MiRNAs showing DE primarily targeted metabolic pathways, while mRNAs targeted inflammatory and cell death pathways. Minimal miRNA-mRNA interactions were seen at 30 min after HIBI. Conclusion: This study identified miRNAs that deserve future study to assess their potential as therapeutic targets in neonatal HIBI. Additionally, the differences in miRNA expression between regions suggest that future studies assessing brain miRNA expression to guide therapy development should consider evaluating individual brain regions rather than whole brain to ensure the sensitivity needed for the development of targeted therapies.

Utilization of Therapeutic Hypothermia and Neurological Injury in Neonates with Mild Hypoxic-Ischemic Encephalopathy: A Report from Children's Hospital Neonatal Consortium

OBJECTIVE

This study was aimed to describe utilization of therapeutic hypothermia (TH) in neonates presenting with mild hypoxic-ischemic encephalopathy (HIE) and associated neurological injury on magnetic resonance imaging (MRI) scans in these infants.

STUDY DESIGN

Neonates ≥ 36 weeks' gestation with mild HIE and available MRI scans were identified. Mild HIE status was assigned to hyper alert infants with an exaggerated response to arousal and mild HIE as the highest grade of encephalopathy recorded. MRI scans were dichotomized as "injury" versus "no injury."

RESULTS

A total of 94.5% (257/272) neonates with mild HIE, referred for evaluation, received TH. MRI injury occurred in 38.2% (104/272) neonates and affected predominantly the white matter (49.0%, n = 51). Injury to the deep nuclear gray matter was identified in (10.1%) 20 infants, and to the cortex in 13.4% (n = 14 infants). In regression analyses (odds ratio [OR]; 95% confidence interval [CI]), history of fetal distress (OR = 0.52; 95% CI: 0.28-0.99) and delivery by caesarian section (OR = 0.54; 95% CI: 0.31-0.92) were associated with lower odds, whereas medical comorbidities during and after cooling were associated with higher odds of brain injury (OR = 2.31; 95% CI: 1.37-3.89).

CONCLUSION

Majority of neonates with mild HIE referred for evaluation are being treated with TH. Odds of neurological injury are over two-fold higher in those with comorbidities during and after cooling. Brain injury predominantly involved the white matter.

KEY POINTS

· Increasingly, neonates with mild HIE are being referred for consideration for hypothermia therapy.. · Drift in clinical practice shows growing number of neonates treated with hypothermia as having mild HIE.. · MRI data show that 38% of neonates with mild HIE have brain injury, predominantly in the white matter..

Intranasal Administration of Extracellular Vesicles Mitigates Apoptosis in a Mouse Model of Neonatal Hypoxic-Ischemic Brain Injury

INTRODUCTION

Neonatal hypoxic-ischemic brain injury (HIBI) results in significant morbidity and mortality despite current available therapies. Seeking a potential supplemental therapy for HIBI, we investigated the neuroprotective effects of extracellular vesicles derived from neural stem cells (NSC-EVs) and hypoxia-preconditioned brain cells (brain-EVs).

METHODS

HIBI was induced in postnatal day 9 mice by carotid ligation followed by hypoxia. Following injury, NSC-EVs, brain-EVs, or saline were administered intranasally. Brains were assessed for infarct size, terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) staining, and caspase-3 expression. Additionally, brain-EV microRNA (miRNA) contents were analyzed by miRNA sequencing.

RESULTS

Both EV treated groups showed decreased infarct size (brain-EVs p = 0.004 and NSC-EVs p = 0.052), and although NSC-EV administration resulted in significantly fewer TUNEL+ cells (p = 0.0098), there was no change in caspase-3 expression after NSC-EV administration, suggesting a caspase-3-independent mechanism. Brain-EVs resulted in a nonsignificant decrease in TUNEL+ cells (p = 0.167) but significant decreases in caspase expression (cleaved p = 0.015 and intact p = 0.026). Brain-EVs consistently expressed several miRNAs, including two which have been shown to be downregulated after HIBI: miR-342-3p and miR-330-3p.

CONCLUSION

Understanding the regenerative effects and contents of NSC-EVs and brain-EVs could allow for the development of targeted EV-based therapies that could reduce morbidity and mortality for neonates affected by HIBI.

Temporal brain microRNA expression changes in a mouse model of neonatal hypoxic-ischemic injury

BACKGROUND

Neonatal hypoxic-ischemic brain injury (HIBI) results in significant morbidity and mortality despite current standard therapies. MicroRNAs (miRNAs) are a promising therapeutic target; however, there is a paucity of data on endogenous miRNA expression of the brain after HIBI during the primary therapeutic window (6-72 h after injury).

METHODS

Postnatal day 9 mouse pups underwent unilateral carotid ligation+hypoxia (HIBI), sham surgery+hypoxia, or sham surgery+normoxia (controls). miRNA sequencing was performed on the ipsilateral brain of each of the three groups plus the contralateral HIBI brain at 24 and 72 h after injury. Findings were validated in eight key miRNAs by quantitative polymerase chain reaction.

RESULTS

Hypoxia resulted in significant differential expression of 38 miRNAs at both time points. Mir-2137, -335, -137, and -376c were significantly altered by neonatal HIBI at 24 and 72 h, with 3 of the 4 demonstrating multiphasic expression (different direction of differential expression at 24 versus 72 h).

CONCLUSIONS

Our global assessment of subacute changes in brain miRNA expression after hypoxia or HIBI will advance research into targeted miRNA-based interventions. It will be important to consider the multiphasic miRNA expression patterns after HIBI to identify optimal timing for individual interventions.

IMPACT

This study is the first to comprehensively define endogenous brain microRNA expression changes outside of the first hours after neonatal hypoxic-ischemic brain injury (HIBI). Mir-2137, -335, -137, and -376c were significantly altered by neonatal HIBI and therefore deserve further investigation as possible therapeutic targets. The expression profiles described will support the design of future studies attempting to develop miRNA-based interventions for infants with HIBI. At 24 h after injury, contralateral HIBI miRNA expression patterns were more similar to ipsilateral HIBI than to controls, suggesting that the contralateral brain is not an appropriate "internal control" for miRNA studies in this model.

Direct hyperbilirubinemia and cholestasis in trisomy 13 and 18

Trisomy 13 and 18 are common chromosomal abnormalities that affect multiple organ systems. There is a paucity of published data, however, on the hepatic complications seen in these patient populations. One of the most common pathologic hepatobiliary issues seen in the newborn period is direct hyperbilirubinemia (DH). Thus, this study sought to estimate the incidence and evaluate possible etiologies of DH in neonates with trisomy 13 or 18. This retrospective cohort study included all infants admitted to our two neonatal intensive care units between 2012 and 2020 with the diagnosis of trisomy 13 or 18. DH is most commonly diagnosed as a direct bilirubin >1 mg/dl but a cutoff of >2 mg/dl is more specific for cholestasis, so both cutoffs were evaluated. Continuous data were compared using Fisher's exact test and categorical variables by the Mann-Whitney U test. Thirty-five patients met inclusion: 13 with trisomy 13 and 22 with trisomy 18. DH of >2 mg/dl was seen in seven (53.8%) patients with trisomy 13 and five (22.7%) with trisomy 18. Using a cutoff of >1 mg/dl, the rate of trisomy 13 was unchanged, but the rate in trisomy 18 increased to 9/22 (40.9%). There was a trend toward more DH in trisomy 13 patients (p = 0.079) versus trisomy 18 and higher rates in infants who received total parenteral nutrition (TPN) (50.0 vs. 13.3%, p = 0.026). The presence of cardiac or ultrasound-defined hepatobiliary abnormalities was not correlated with DH. Due to the high rates of DH in hospitalized neonates with trisomy 13 and 18, we recommend screening newborns with trisomy 13 or 18 for DH starting in the first week of life and continuing at least weekly until 4 weeks of life or until completion of TPN, whichever comes later. Future studies should further evaluate possible etiologies of DH in this population.

Biogenesis, physiological functions and potential applications of extracellular vesicles in substance use disorders

Substance use disorder (SUD) is a growing health problem that affects several millions of people worldwide, resulting in negative socioeconomic impacts and increased health care costs. Emerging evidence suggests that extracellular vesicles (EVs) play a crucial role in SUD pathogenesis. EVs, including exosomes and microvesicles, are membrane-encapsulated particles that are released into the extracellular space by most types of cells. EVs are important players in mediating cell-to-cell communication through transfer of cargo such as proteins, lipids and nucleic acids. The EV cargo can alter the status of recipient cells, thereby contributing to both physiological and pathological processes; some of these play critical roles in SUD. Although the functions of EVs under several pathological conditions have been extensively reviewed, EV functions and potential applications in SUD remain less studied. In this review, we provide an overview of the current knowledge of the role of EVs in SUD, including alcohol, cocaine, heroin, marijuana, nicotine and opiate abuse. The review will focus on the biogenesis and cargo composition of EVs as well as the potential use of EVs as biomarkers of SUD or therapeutic targets in SUD.

Surveillance guidelines for children with trisomy 13

Trisomy 13 is one of the three most common aneuploidy syndromes in live-born infants. It is associated with mortality rates as high as 90% within the first year of life, in large part, due to the high prevalence of severe congenital abnormalities that increase mortality and morbidity. However, life-saving and life-prolonging medical interventions are being performed at a higher rate for these infants, resulting in increased rates of survival. Although cardiac complications have been well described in infants with trisomy 13, these patients also experience other complications such as respiratory, neurological, genitourinary, abdominal, otolaryngologic, and orthopedic complications that can impact their quality of life. The goal of this review is to present a comprehensive description of complications in children with trisomy 13 to aid in the development of monitoring and treatment guidelines for the increasing number of providers who will be caring for these patients throughout their lives. Where the evidence is available, this review presents screening recommendations to allow for more rapid detection and documentation of these complications.

Increasing Skin-to-Skin in a Level IV NICU: A Quality Improvement Project

PURPOSE

To evaluate the effect of a bundled intervention on the number of skin-to-skin ("kangaroo care") events occurring in a level IV NICU.

DESIGN

A quality improvement effort centering around the introduction of an intervention bundle intended to safely increase the rate of skin-to-skin holding. Rates of unplanned extubations were recorded as a balancing measure to estimate safety.

SAMPLE

All infants admitted to the NICU from December 2017 through September 2019 were included. The "preintervention" period was the 6 months prior to the initiation of the intervention bundle (December 2017-May 2018).

RESULTS

The absolute number of skin-to-skin holds increased from the preintervention phase (range 7-28 holds/month, median 11 holds/month) to the postintervention phase (range 16-100 holds/month, median 55 holds/month). The total unplanned extubations showed no significant change between the preintervention and postintervention periods.

Clinical risk factors for the development of late-onset circulatory collapse in premature infants

BACKGROUND

Very low birth weight (VLBW) infants may be at risk for late-onset circulatory collapse (LCC) where otherwise stable infants develop hypotension resistant to vasoactive agents. The risk factors for LCC development are poorly defined, and it has been theorized that it may be in part due to withdrawal from exogenous prenatal steroids. The goal of this study was to define the clinical characteristics of LCC and investigate its association with antenatal steroid administration.

METHODS

This is a retrospective cohort study of infants born ≤1500 g. LCC was retrospectively diagnosed in infants requiring glucocorticoids for circulatory instability at >1 week of life. Demographic and clinical characteristics were compared between groups using Mann-Whitney test.

RESULTS

Three hundred and ten infants were included; 19 (6.1%) developed LCC. Infants with LCC were born at a median 4.6 weeks' lower gestation, 509 g lower birth weight than those without LCC. There was no difference in antenatal steroid delivery between the groups.

CONCLUSIONS

LCC occurs in a distinct subset of VLBW infants, suggesting the need for monitoring in this high-risk population. Antenatal steroids did not significantly increase the risk of LCC development in this study.

IMPACT

Late-onset circulatory collapse (LCC) is a life-threatening clinical entity occurring in around 6% in VLBW infants and is likely underdiagnosed in the United States. Targeting specific demographic characteristics such as birth weight (<1000 g) and gestational age at birth (<26 weeks) may allow for early identification of high-risk infants, allowing close monitoring and prompt treatment of LCC. No significant association was found between antenatal steroid administration and LCC development, suggesting that the theoretical risks of antenatal steroids on the fetal HPA axis does not outweigh the benefits of antenatal steroids in fetal lung maturity. To date, no studies characterizing LCC have originated outside of Asia. Therefore, providing a description of LCC in a U.S.-based cohort will provide insight into both its prevalence and presentation to inform clinicians about this potentially devastating disorder and foster early diagnosis and treatment. This study validates LCC characteristics and prevalence previously outlined by Asian studies in a single-center U.S.-based cohort while also identifying potential risk factors for LCC development. This manuscript will provide education for U.S. physicians about the risk factors and clinical presentation of LCC to facilitate early diagnosis and treatment, potentially decreasing neonatal mortality. With prompt recognition and treatment of LCC, infants may have decreased exposure to vasoactive medications that have significant systemic effects.

Surveillance guidelines for children with trisomy 18

Trisomy 18 is the second most common aneuploidy syndromes in live born infants. It is associated with high mortality rates, estimated to be 75%-95% in the first year of life, as well as significant morbidity in survivors. The low survival is largely due to the high prevalence of severe congenital anomalies in infants with this diagnosis. However, interventions to repair or palliate those life-threatening anomalies are being performed at a higher rate for these infants, resulting in increased rates of survival beyond the first year of life. While it is well documented that trisomy 18 is associated with several cardiac malformations, these patients also have respiratory, neurological, neoplastic, genitourinary, abdominal, otolaryngologic, and orthopedic complications that can impact their quality of life. The goal of this review is to present a comprehensive description of complications in children with trisomy 18 to aid in the development of monitoring and treatment guidelines for the increasing number of providers who will be caring for these patients throughout their lives. Where the evidence is available, this review presents screening recommendations to allow for more rapid detection and documentation of these complications.

Predictive Models of Neurodevelopmental Outcomes After Neonatal Hypoxic-Ischemic Encephalopathy

OBJECTIVES

To develop predictive models for death or neurodevelopmental impairment (NDI) after neonatal hypoxic-ischemic encephalopathy (HIE) from data readily available at the time of NICU admission ("early") or discharge ("cumulative").

METHODS

In this retrospective cohort analysis, we used data from the Children's Hospitals Neonatal Consortium Database (2010-2016). Infants born at ≥35 weeks' gestation and treated with therapeutic hypothermia for HIE at 11 participating sites were included; infants without Bayley Scales of Infant Development scores documented after 11 months of age were excluded. The primary outcome was death or NDI. Multivariable models were generated with 80% of the cohort; validation was performed in the remaining 20%.

RESULTS

The primary outcome occurred in 242 of 486 infants; 180 died and 62 infants surviving to follow-up had NDI. HIE severity, epinephrine administration in the delivery room, and respiratory support and fraction of inspired oxygen of 0.21 at admission were significant in the early model. Severity of EEG findings was combined with HIE severity for the cumulative model, and additional significant variables included the use of steroids for blood pressure management and significant brain injury on MRI. Discovery models revealed areas under the curve of 0.852 for the early model and of 0.861 for the cumulative model, and both models performed well in the validation cohort (goodness-of-fit χ²: P = .24 and .06, respectively).

CONCLUSIONS

Establishing reliable predictive models will enable clinicians to more accurately evaluate HIE severity and may allow for more targeted early therapies for those at highest risk of death or NDI.

Cholesterol metabolism and brain injury in neonatal encephalopathy

Neonatal encephalopathy (NE) results from impaired cerebral blood flow and oxygen delivery to the brain. The pathophysiology of NE is complex and our understanding of its underlying pathways continues to evolve. There is considerable evidence that cholesterol dysregulation is involved in several adult diseases, including traumatic brain injury, stroke, Huntington's disease, and Parkinson's disease. Although the research is less robust in pediatrics, there is emerging evidence that aberrations in cholesterol metabolism may also be involved in the pathophysiology of neonatal NE. This narrative review provides an overview of cholesterol metabolism in the brain along with several examples from the adult literature where pathologic alterations in cholesterol metabolism have been associated with inflammatory and ischemic brain injury. Using those data as a background, the review then discusses the current preclinical data supporting the involvement of cholesterol in the pathogenesis of NE as well as how brain-specific cholesterol metabolites may serve as serum biomarkers for brain injury. Lastly, we review the potential for using the cholesterol metabolic pathways as therapeutic targets. Further investigation of the shifts in cholesterol synthesis and metabolism after hypoxia-ischemia may prove vital in understanding NE pathophysiology as well as providing opportunities for rapid diagnosis and therapeutic interventions. IMPACT: This review summarizes emerging evidence that aberrations in cholesterol metabolism may be involved in the pathophysiology of NE. Using data from NE as well as analogous adult disease states, this article reviews the potential for using cholesterol pathways as targets for developing novel therapeutic interventions and using cholesterol metabolites as biomarkers for injury. When possible, gaps in the current literature were identified to aid in the development of future studies to further investigate the interactions between cholesterol pathways and NE.

Neonatal Vitamin D Status Is Associated with the Severity of Brain Injury in Neonatal Hypoxic-Ischemic Encephalopathy: A Pilot Study

OBJECTIVE

The primary aim of this study was to evaluate the association between 25-hydroxyvitamin D (25OHD) concentration at birth and the short-term outcomes in neonatal hypoxic-ischemic encephalopathy (HIE). Our secondary aim was to evaluate the effect of postnatal vitamin D supplementation on outcomes in the perinatal period after hypoxic injury.

STUDY DESIGN

This retrospective cohort study included all infants ≥35 weeks gestation admitted to a regional level IV neonatal intensive care unit and diagnosed with moderate or severe HIE. Spearman correlation coefficients were used to evaluate associations between clinical outcomes including standardized brain magnetic resonance imaging (MRI) scores and either 25OHD concentrations in the first 48 hours of life or total vitamin D supplementation.

RESULT

A total of 43 infants met inclusion criteria; 22 had 25OHD concentrations drawn within the first 48 hours. There was a significant inverse association between 25OHD concentration and brain injury on MRI (p = 0.017). There was a trend toward decreased ventilator days in infants receiving higher doses of vitamin D in the first week of life (p = 0.062), but there was no association between vitamin D dosing and MRI injury.

CONCLUSION

These results support an association between lower vitamin-D levels and early adverse outcomes in HIE, including radiographic severity of brain injury.

Reevaluating 30-day head ultrasound screening for preterm infants in the era of decreasing periventricular leukomalacia

Objective: Neonatal brain injury is a potentially devastating cause of neurodevelopmental impairment. There is no consensus, however, on the appropriate timing and frequency of routine head ultrasound (HUS) screening for such injuries. We evaluated the diagnostic utility of routine HUS screening at 30 days of life ("late HUS") for detecting severe intraventricular hemorrhage (IVH) or cystic periventricular leukomalacia (c-PVL) in preterm infants with a negative HUS before 14 days of life ("early HUS").Methods: Single-center retrospective cohort analysis of infants born at ≤ 32 weeks gestational age (GA) admitted to the University of Nebraska Medical Center NICU from 2011-2018. Demographics, HUS and MRI diagnoses were abstracted from clinical records. Fisher's exact test and t-test assessed associations between categorical and continuous variable, respectively.Results: 205 infants were included-120 very preterm (28-32 weeks GA) and 85 extremely preterm (<28 weeks GA). Negative predictive value of early HUS for predicting any clinically significant anomalies (severe IVH or c-PVL) on late HUS was 100% for extremely and 99.2% for very preterm infants. Term-equivalent MRI detected previously undiagnosed c-PVL in 16.7% of the 24 patients that received MRI; all infants with new c-PVL on MRI had severe IVH on early HUS.Conclusion: Following negative early HUS, late HUS detected significant new abnormalities in one infant. These data suggest that in a unit with low prevalence of c-PVL, 30-day HUS may have limited clinical utility following negative screening. In infants with abnormal early HUS, clinicians should consider obtaining term-equivalent MRI screening to detect c-PVL.

Combined Treatment with Insulin-Like Growth Factor 1 and AMD3100 Improves Motor Outcome in a Murine Model of Neonatal Hypoxic-Ischemic Encephalopathy

Stem cell transplantation is a promising intervention for neonatal hypoxic-ischemic encephalopathy (HIE); however, universal feasibility and safety have not been thoroughly evaluated. AMD3100 and insulin-like growth factor 1 (IGF1) mobilize progenitor cells into peripheral circulation. The objective of this study was to assess the short-term efficacy of inducing endogenous stem cell mobilization after injury in a model of neonatal HIE. Postnatal day 9 CD1 pups received sham surgery or unilateral carotid artery ligation and 30 min of hypoxia followed by saline, AMD3100, IGF1, or both agents. Intraperitoneal injections of 5-ethynyl-2'-deoxy-uridine (EdU) and 5-bromo-2'-deoxyuridine were used to -label replicating progenitor cells. At P14, animals underwent rotarod testing, and the brains were sectioned for area measurements and immunofluorescence staining. Comparisons were made using one-way analysis of variance. Spearman's rho was calculated to assess correlation between rotarod results and markers of brain injury. Pups treated with both agents had improved rotarod performance (p = 0.02) and increased EdU+ progenitor cells in the subgranular zone (SGZ) compared to injured controls (p = 0.10). An increase in active cells within the SGZ was correlated with improved rotarod performance (r = 0.84, p = 0.04). There were no differences in overall injury score or in brain area or number of activated cells in the subventricular zone between the treatment groups. Combined treatment with AMD3100 and IGF1 shows promise for decreasing brain injury and improving motor function in pups after HIE which correlated with changes in the number of active progenitor cells in the SGZ.

Assessment and Management of Gastroesophageal Reflux in The Newborn

Gastroesophageal reflux is the involuntary retrograde passage of gastric contents into the esophagus with or without regurgitation and is considered a normal physiologic process, occurring daily in greater than one-third of all infants. Gastroesophageal reflux disease (GERD) is pathologic reflux associated with poor weight gain, irritability, dysphagia and often requires evaluation and treatment. No gold-standard testing for GERD exists. Measurements made by pH probe or multichannel intraesophageal impedance may provide insight into the quantity and character of reflux. Those events do not correlate well with clinical symptoms. Most cases of GERD can be treated conservatively with alterations in the infant's environment and/or feeding pattern. Proton pump inhibitors remain the mainstay for pharmacotherapy of GERD, although these have been associated with increased rates of infection, especially in the preterm population. Neonatal GERD remains a difficult entity to define and manage, and additional studies to aid in the clinical diagnosis and management are needed. [Pediatr Ann. 2020;49(2):e77-e81.].

Neuronal-derived extracellular vesicles are enriched in the brain and serum of HIV-1 transgenic rats

Despite the efficacy of combination antiretroviral therapy (ART) in controlling human immunodeficiency virus (HIV-1) replication, cytotoxic viral proteins such as HIV-1 transactivator of transcription (Tat) persist in tissues such as the brain. Although HIV-1 does not infect neuronal cells, it is susceptible to viral Tat protein-mediated toxicity, leading to neuroinflammation that underlies HIV-associated neurocognitive disorders (HAND). Given the role of extracellular vesicles (EVs) in both cellular homoeostasis and under pathological conditions, we sought to investigate the alterations in the quantity of neuronal-derived EVs in the brain - as defined by the presence of cell adhesion molecule L1 (L1CAM) and to evaluate the presence of L1CAM⁺ EVs in the peripheral circulation of HIV-1 transgenic (HIV-1 Tg) rats. The primary goal of this study was to investigate the effect of long-term exposure of HIV-1 viral proteins on the release of neuronal EVs in the brain and their transfer in the systemic compartment. Brain and serum EVs were isolated from both wild type and HIV-1 Tg rats using differential ultracentrifugation with further purification using the Optiprep gradient method. The subpopulation of neuronal EVs was further enriched using immunoprecipitation. The current findings demonstrated increased presence of L1CAM⁺ neuronal-derived EVs both in the brain and serum of HIV-1 Tg rats.

Magnetic Resonance Imaging Findings of Term and Preterm Hypoxic-Ischemic Encephalopathy: A Review of Relevant Animal Models and Correlation to Human Imaging

Background:

Neonatal hypoxic-ischemic encephalopathy is brain injury caused by decreased perfusion and oxygen delivery that most commonly occurs in the context of delivery complications such as umbilical cord compression or placental abruption. Imaging is a key component for guiding treatment and prediction of prognosis, and the most sensitive clinical imaging modality for the brain injury patterns seen in hypoxic-ischemic encephalopathy is magnetic resonance imaging.

Objective:

The goal of this review is to compare magnetic resonance imaging findings demonstrated in the available animal models of hypoxic-ischemic encephalopathy to those found in preterm (≤ 36 weeks) and term (>36 weeks) human neonates with hypoxic-ischemic encephalopathy, with special attention to the strengths and weaknesses of each model.

Methods:

A structured literature search was performed independently by two authors and the results of the searches were compiled. Animal model, human brain age equivalency, mechanism of injury, and area of brain injury were recorded for comparison to imaging findings in preterm and term human neonates with hypoxic-ischemic encephalopathy.

Conclusion:

Numerous animal models have been developed to better elicit the expected findings that occur after HIE by allowing investigators to control many of the clinical variables that result in injury. Although modeling the same disease process, magnetic resonance imaging findings in the animal models vary with the species and methods used to induce hypoxia and ischemia. The further development of animal models of HIE should include a focus on comparing imaging findings, and not just pathologic findings, to human studies.

Evaluating a Targeted Bedside Measure of Cerebral Perfusion in a Nonhuman Primate Model of Neonatal Hypoxic-Ischemic Encephalopathy

OBJECTIVES

To compare ultrasound-derived resistive indices (RIs) obtained at the level of the thalamus via fast Doppler ultrasound with traditional anterior cerebral artery measures in a model of neonatal hypoxic-ischemic encephalopathy and to correlate each with clinical outcomes.

METHODS

Nine nonhuman primate neonates underwent no umbilical cord occlusion (n = 3), umbilical cord occlusion without hypothermia (n = 3), or umbilical cord occlusion with hypothermia (n = 3). The RI was measured in the anterior cerebral artery and thalamus on days 0, 1, and 4 of life. Magnetic resonance imaging with spectroscopy was performed on day 4.

RESULTS

Mean thalamus and anterior cerebral artery RI values in the first 36 hours of life were statistically different in neonates who died (+0.13; P = .019) or developed cerebral palsy (-0.08; P = .003). Thalamic RI values showed stronger associations with serum and spectroscopic lactate values than those in the anterior cerebral artery. The umbilical cord occlusion-with-hypothermia group showed a significant increase in the RI in the thalamus but not the anterior cerebral artery.

CONCLUSIONS

Resistive index measurements in the thalamus may eventually supplement other bedside measures for predicting outcomes in the HIE population, but further studies need to differentiate the effect of hypothermia from illness severity on thalamic perfusion.

The impact of hypoxic-ischemic brain injury on stem cell mobilization, migration, adhesion, and proliferation

Neonatal hypoxic-ischemic encephalopathy continues to be a significant cause of death or neurodevelopmental delays despite standard use of therapeutic hypothermia. The use of stem cell transplantation has recently emerged as a promising supplemental therapy to further improve the outcomes of infants with hypoxic-ischemic encephalopathy. After the injury, the brain releases several chemical mediators, many of which communicate directly with stem cells to encourage mobilization, migration, cell adhesion and differentiation. This manuscript reviews the biomarkers that are released from the injured brain and their interactions with stem cells, providing insight regarding how their upregulation could improve stem cell therapy by maximizing cell delivery to the injured tissue.

Vitamin D and Its Role in Neonatal Hypoxic-Ischemic Brain Injury

Emerging evidence has demonstrated that vitamin D plays an important role in many adult neurologic disorders, but is also critical in neuronal development and pruning in the neonatal and pediatric populations. Neonates are at a particularly high risk of vitamin D deficiency, in part due to the high prevalence of maternal deficiency during pregnancy. Several preclinical studies have demonstrated that infants born to vitamin D-deficient mothers are at a high risk of developing neonatal brain injury, and recent clinical studies have shown that neonates with hypoxic-ischemic encephalopathy (HIE) tend to be vitamin D-deficient. There are limited data, however, on whether additional prenatal or postnatal supplementation may alter the prevalence or severity of neonatal HIE. This review examines the current data supporting the neuroprotective role of vitamin D, with a focus on how these findings may be translated to neonates with HIE.

An evaluation of hydrocortisone dosing for neonatal refractory hypotension

OBJECTIVE

The objective of the study was to compare blood pressure, vasoactive medication requirements and adverse outcomes after administration of high- versus low-dose hydrocortisone (HC) in preterm infants.

STUDY DESIGN

This is a retrospective analysis of 106 infants ⩽28 weeks gestational age with hypotension requiring vasoactive infusions and high-dose (4 mg kg^-1 per day, n=50), low-dose (1 to 3 mg kg^-1 per day, n=20) or no HC (n=36) from 2011 to 2015. Groups were compared by two-tailed t-test or χ², and correlation estimated by multivariable logistic regression.

RESULTS

There were no differences in measured efficacy between the low- and high-dose groups. Infants with pre-treatment cortisol >15 mcg dl^-1 who received HC therapy showed less improvement in vasoactive burden, increased hyperglycemia (P=0.015) and increased death independent of HC dose (odds ratio 26.3, 3.5 to 198.3, P=0.002).

CONCLUSION

These results support using the lowest effective HC dose in preterm infants. In addition, HC therapy should likely be avoided in infants who are not cortisol deficient.

Evaluating an Association between Ampicillin and Intraventricular Hemorrhage in Preterm Infants

Intraventricular hemorrhage (IVH) is a common and potentially devastating adverse outcome affecting up to 30% of preterm infants. β-Lactam antibiotics affect platelet activation through interaction with platelet surface receptors. The objective of this study was to evaluate an association between ampicillin use and the development of IVH in preterm infants. This was a single-center and a retrospective case-control study of preterm low-birth-weight infants diagnosed with IVH and matched controls without IVH. Conditional logistic regression was performed on 10 clinical features from the first week of life to evaluate the association with IVH. Data were obtained for 174 subjects with no significant differences between groups in demographic factors and level of illness indicators. Earlier administration of the first dose of ampicillin was associated with increased odds of developing IVH (odds ratio [OR]: 0.95, p = 0.028) when controlling for other common associations. Longer courses of ampicillin were not significantly associated with the development of IVH (OR: 1.13, p = 0.089). The odds of developing IVH in our population increased with earlier, but not longer initial courses of ampicillin. Further research into the associations with IVH should include the assessment of ampicillin dose, timing, and duration.

Fast Doppler as a novel bedside measure of cerebral perfusion in preterm infants

BACKGROUND

Altered cerebral perfusion from impaired autoregulation may contribute to the morbidity and mortality associated with premature birth. We hypothesized that fast Doppler imaging could provide a reproducible bedside estimation of cerebral perfusion and autoregulation in preterm infants.

METHODS

This is a prospective pilot study using fast Doppler ultrasound to assess blood flow velocity in the basal ganglia of 19 subjects born at 26-32 wk gestation. Intraclass correlation provided a measure of test-retest reliability, and linear regression of cerebral blood flow velocity and heart rate or blood pressure allowed for estimations of autoregulatory ability.

RESULTS

The intraclass correlation when imaging in the first 48 h of life was 0.634. We found significant and independent correlations between the systolic blood flow velocity and both systolic blood pressure and heart rate (P = 0.015 and 0.012 respectively) only in the 26-28 wk gestational age infants in the first 48 h of life.

CONCLUSION

Our results suggest that fast Doppler provides reliable bedside measurements of cerebral blood flow velocity at the tissue level in premature infants, acting as a proxy for cerebral tissue perfusion. Additionally, autoregulation appears to be impaired in the extremely preterm infants, even within a normal range of blood pressures.

Albumin, a new biomarker of organophosphorus toxicant exposure, identified by mass spectrometry

The classical laboratory tests for exposure to organophosphorus toxicants (OP) are inhibition of acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) activity in blood. In a search for new biomarkers of OP exposure, we treated mice with a biotinylated organophosphorus agent, FP-biotin. The biotinylated proteins in muscle were purified by binding to avidin-Sepharose, separated by gel electrophoresis, digested with trypsin, and identified from their fragmentation patterns on a quadrupole time-of-flight mass spectrometer. Albumin and ES1 carboxylesterase (EC 3.1.1.1) were found to be major targets of FP-biotin. These FP-biotinylated proteins were also identified in mouse plasma by comparing band patterns on nondenaturing gels stained for albumin and carboxylesterase activity, with band patterns on blots hybridized with Streptavidin Alexa-680. Two additional FP-biotin targets, AChE (EC 3.1.1.7) and BChE (EC 3.1.1.8), were identified in mouse plasma by finding that enzyme activity was inhibited 50-80%. Mouse plasma contained eight additional FP-biotinylated bands whose identity has not yet been determined. In vitro experiments with human plasma showed that chlorpyrifos oxon, echothiophate, malaoxon, paraoxon, methyl paraoxon, diazoxon, diisopropylfluorophosphate, and dichlorvos competed with FP-biotin for binding to human albumin. Though experiments with purified albumin have previously shown that albumin covalently binds OP, this is the first report of OP binding to albumin in a living animal. Carboxylesterase is not a biomarker in man because humans have no carboxylesterase in blood. It is concluded that OP bound to albumin could serve as a new biomarker of OP exposure in man.