Placental Histologic Abnormalities and 2-Year Outcomes in Neonatal Hypoxic-Ischemic Encephalopathy.

OBJECTIVE: We aimed to examine the association between placental abnormalities and neurodevelopmental outcomes in a multicenter cohort of newborn infants with hypoxic-ischemic encephalopathy (HIE) that underwent therapeutic hypothermia. We hypothesized that subjects with acute placental abnormalities would have reduced risk of death or neurodevelopmental impairment (NDI) at 2 years of age after undergoing therapeutic hypothermia compared to subjects without acute placental changes. STUDY DESIGN: Among 500 subjects born at ≥36 weeks gestation with moderate or severe HIE enrolled in the High-dose Erythropoietin for Asphyxia and Encephalopathy (HEAL) Trial, a placental pathologist blinded to clinical information reviewed clinical pathology reports to determine the presence of acute only, chronic only, or both acute and chronic histologic abnormalities. We calculated adjusted relative risks (aRRs) for associations between placental pathologic abnormalities and death or NDI at age 2 years, adjusting for HIE severity, treatment assignment, and site. RESULT: 321/500 subjects (64%) had available placental pathology reports. Placental abnormalities were characterized as acute only (20%), chronic only (21%), both acute and chronic (43%), and none (15%). The risk of death or NDI was not statistically different between subjects with and without an acute placental abnormality (46 vs. 53%, aRR 1.1, 95% confidence interval (CI): 0.9, 1.4). Subjects with two or more chronic lesions were more likely to have an adverse outcome than subjects with no chronic abnormalities, though this did not reach statistical significance (55 vs. 45%, aRR 1.24, 95% CI: 0.99, 1.56). CONCLUSION: Placental pathologic findings were not independently associated with risk of death or NDI in subjects with HIE. The relationship between multiple chronic placental lesions and HIE outcomes deserves further study.

Mitochondrial dysfunction in perinatal asphyxia: role in pathogenesis and potential therapeutic interventions.

Perinatal asphyxia (PA)-induced brain injury may present as hypoxic-ischemic encephalopathy in the neonatal period, and long-term sequelae such as spastic motor deficits, intellectual disability, seizure disorders and learning disabilities. The brain injury is secondary to both the hypoxic-ischemic event and oxygenation-reperfusion following resuscitation. Following PA, a time-dependent progression of neuronal insult takes place in terms of transition of cell death from necrosis to apoptosis. This transition is the result of time-dependent progression of pathomechanisms which involve excitotoxicity, oxidative stress, and ultimately mitochondrial dysfunction in developing brain. More precisely mitochondrial respiration is suppressed and calcium signalling is dysregulated. Consequently, Bax-dependent mitochondrial permeabilization occurs leading to release of cytochrome c and activation of caspases leading to transition of cell death in developing brain. The therapeutic window lies within this transition process. At present, therapeutic hypothermia (TH) is the only clinical treatment available for treating moderate as well as severe asphyxia in new-born as it attenuates secondary loss of high-energy phosphates (ATP) (Solevåg et al. in Free Radic Biol Med 142:113-122, 2019; Gunn et al. in Pediatr Res 81:202-209, 2017), improving both short- and long-term outcomes. Mitoprotective therapies can offer a new avenue of intervention alone or in combination with therapeutic hypothermia for babies with birth asphyxia. This review will explore these mitochondrial pathways, and finally will summarize past and current efforts in targeting these pathways after PA, as a means of identifying new avenues of therapeutic intervention.

Ischemic hypoxic encephalopathy: The role of MRI of neonatal injury and medico-legal implication.

Hypoxic ischemic encephalopathy is one of the major causes of neonatal death and neurological disability in the child, and represents the most common birth injury claim. Intrapartum asphyxia often leads to several long-term sequalae, such as cerebral palsy and/or developmental delay, epilepsy. Through the neuroimaging it's possible to identify and define the different lesioned pictures and provide useful elements to establish the moment in which the damage occurred; indeed, timing of injury is a key element in the legal arena. Magnetic resonance imaging (MRI) is emerging as one of the most important tools in identifying the etiologic of neonatal encephalopathy as well as in predicting long-term outcomes. The aim of this study is to evaluate all MRI tests performed in a group of infants and young patients with possible neonatal encephalopathy, in order to determine the role of MRI in perinatal hypoxic-ischemic damage and the specific patterns that can point towards a diagnosis of the time of the damage's onset. Another goal is to assess the role of MRI in cases subject to legal-medical ligation. Since the advent of hypothermic neuroprotection, new malpractice allegations have arisen, including the failure to initiate cooling in a timely manner. In all cases, documentation of the status of the baby at birth, including a thorough neurologic exam, can be extremely helpful to the later defence of a malpractice claim, which might occur years later.

The Kynurenic Acid Analog SZR72 Enhances Neuronal Activity after Asphyxia but Is Not Neuroprotective in a Translational Model of Neonatal Hypoxic Ischemic Encephalopathy.

Hypoxic-ischemic encephalopathy (HIE) remains to be a major cause of long-term neurodevelopmental deficits in term neonates. Hypothermia offers partial neuroprotection warranting research for additional therapies. Kynurenic acid (KYNA), an endogenous product of tryptophan metabolism, was previously shown to be beneficial in rat HIE models. We sought to determine if the KYNA analog SZR72 would afford neuroprotection in piglets. After severe asphyxia (pHa = 6.83 ± 0.02, ΔBE = -17.6 ± 1.2 mmol/L, mean ± SEM), anesthetized piglets were assigned to vehicle-treated (VEH), SZR72-treated (SZR72), or hypothermia-treated (HT) groups (n = 6, 6, 6; Tcore = 38.5, 38.5, 33.5 °C, respectively). Compared to VEH, serum KYNA levels were elevated, recovery of EEG was faster, and EEG power spectral density values were higher at 24 h in the SZR72 group. However, instantaneous entropy indicating EEG signal complexity, depression of the visual evoked potential (VEP), and the significant neuronal damage observed in the neocortex, the putamen, and the CA1 hippocampal field were similar in these groups. In the caudate nucleus and the CA3 hippocampal field, neuronal damage was even more severe in the SZR72 group. The HT group showed the best preservation of EEG complexity, VEP, and neuronal integrity in all examined brain regions. In summary, SZR72 appears to enhance neuronal activity after asphyxia but does not ameliorate early neuronal damage in this HIE model.

Neonatal mortality and its associated factors among neonates admitted at public hospitals, pastoral region, Ethiopia: A health facility based study.

BACKGROUND: Neonatal mortality is a public health issue in, Ethiopia. Unfortunately, the issue is noticeably under-reported and underestimated, so the true gravity of the situation cannot be acknowledged in developing regions of the country. Regrettably, there is no single study to show the rates and predictors of neonatal mortality for Afar region. Thus, this study aims to assess neonatal mortality and associated factors in Afar region, Ethiopia. METHODS: A health facility-based cross-sectional study was conducted on 403 neonates admitted to the neonatal intensive care units (NICUs) from January 2015 to December 2019. Maternal and neonatal medical records were reviewed and audited using structured data extraction checklist. The data was collected by four trained nurses and midwives. The medical records were selected using a systematic random sampling technique. Bivariate and multivariable logistic regression analyses were done. Adjusted odds ratio with the corresponding 95% confidence interval were used to assess the association between neonatal mortality and the associated factors. Finally, the statistical significance level was declared at a p-value of less than 0.05. RESULTS: In this study, 391 medical records of newborns were included with the data complete rate of 97.02%. The prevalence of neonatal mortality was 57 (14.6%) [95% CI 11.0%-18.4%]. A multivariable logistic regression showed that lack of antenatal care (ANC) follow up [AOR = 4.69: 95%CI (1.77, 12.47)], giving birth through cesarean section [AOR 3.59, 95%CI (1.22, 10.55)], having admission temperature less than 36.5°C [AOR 10.75, 95%CI (3.75, 30.80)], birth asphyxia [AOR 7.16, 95%CI (2.22, 23.10)], and having a length of stay greater than five days in the hospital [AOR 0.23, 95%CI (0.08, 0.66)] were significantly associated with neonatal mortality. CONCLUSION: This study revealed that the rate of neonatal mortality is still high compared to the national data. Antenatal care, cesarean section delivery, length of stay in the hospital, low temperature at admission and birth asphyxia were factors associated with neonatal mortality. Thus, the health facilities should give due attention to improve antenatal care, intrapartum care and standardized care for admitted neonates. Furthermore, prospective studies are recommended.

Overexpression of long non-coding RNA H19 relieves hypoxia-induced injury by down-regulating microRNA-107 in neural stem cells.

BACKGROUND: Neonatal hypoxia-ischemia (HI) is one of the commonest conditions which seriously influences the development of infants' nervous system and causes series of neurological sequelaes. The aim of the present study was to analyze the potential regulatory mechanism of long non-coding (lnc) RNA H19 under hypoxia conditions. METHODS: Neural stem cells (NSCs) were incubated in hypoxic conditions for 8 h to induce hypoxia injury. qRT-PCR was performed to detect H19 or micro (miR)-107 expression. Cell Counting Kit-8 (CCK-8) assay and Annexin V-FITC/PI staining assay were employed to detect the effects of hypoxia on cell viability and apoptosis, respectively. Moreover, NSCs were transfected with H19 overexpressing plasmid or shRNA-H19 and then subjected to hypoxia treatment. The effects of H19/miR-107 on NSC cell biological behaviors were confirmed. Furthermore, the signaling pathways involved in HI were analyzed using western blot. RESULTS: Hypoxia treatment restrained cell viability and induced cell apoptosis in NSCs. Overexpression of lncRNA H19 attenuated hypoxia-induced NSCs injury, while knockdown of lncRNA H19 aggravated NSCs injury. Further experiments suggested that miR-107 up-regulation reversed the effects of lncRNA H19 overexpression on NSCs. Moreover, the activation of Wnt/ß-catenin and PI3K/AKT pathways triggered by H19 were reversed by miR-107 up-regulation in hypoxia-treated NSCs. CONCLUSION: LncRNA H19 overexpression attenuated hypoxia-induced NSCs injury and promoted activation of Wnt/ß-catenin and PI3K/AKT pathways through downregulating miR-107.

Preclinical neurorehabilitation with environmental enrichment confers cognitive and histological benefits in a model of pediatric asphyxial cardiac arrest.

Pediatric asphyxial cardiac arrest (ACA) often leaves children with physical, cognitive, and emotional disabilities that affect overall quality of life, yet rehabilitation is neither routinely nor systematically provided. Environmental enrichment (EE) is considered a preclinical model of neurorehabilitation and thus we sought to investigate its efficacy in our established model of pediatric ACA. Male Sprague-Dawley rat pups (post-natal day 16-18) were randomly assigned to ACA (9.5 min) or Sham injury. After resuscitation, the rats were assigned to 21 days of EE or standard (STD) housing during which time motor, cognitive, and anxiety-like (i.e., affective) outcomes were assessed. Hippocampal CA1 cells were quantified on post-operative day-22. Both ACA + STD and ACA + EE performed worse on beam-balance vs. Sham controls (p < 0.05) and did not differ from one another overall (p > 0.05); however, a single day analysis on the last day of testing revealed that the ACA + EE group performed better than the ACA + STD group (p < 0.05) and did not differ from the Sham controls (p > 0.05). Both Sham groups performed better than ACA + STD (p < 0.05) but did not differ from ACA + EE (p > 0.05) in the open field test. Spatial learning and declarative memory were improved and CA1 neuronal loss was attenuated in the ACA + EE vs. ACA + STD group (p < 0.05). Collectively, the data suggest that providing rehabilitation after pediatric ACA can reduce histopathology and improve motor and cognitive ability.

Intranasal Administration of Mesenchymal Stem Cell Secretome Reduces Hippocampal Oxidative Stress, Neuroinflammation and Cell Death, Improving the Behavioral Outcome Following Perinatal Asphyxia.

Perinatal Asphyxia (PA) is a leading cause of motor and neuropsychiatric disability associated with sustained oxidative stress, neuroinflammation, and cell death, affecting brain development. Based on a rat model of global PA, we investigated the neuroprotective effect of intranasally administered secretome, derived from human adipose mesenchymal stem cells (MSC-S), preconditioned with either deferoxamine (an hypoxia-mimetic) or TNF-α+IFN-γ (pro-inflammatory cytokines). PA was generated by immersing fetus-containing uterine horns in a water bath at 37 °C for 21 min. Thereafter, 16 µL of MSC-S (containing 6 µg of protein derived from 2 × 105 preconditioned-MSC), or vehicle, were intranasally administered 2 h after birth to asphyxia-exposed and control rats, evaluated at postnatal day (P) 7. Alternatively, pups received a dose of either preconditioned MSC-S or vehicle, both at 2 h and P7, and were evaluated at P14, P30, and P60. The preconditioned MSC-S treatment (i) reversed asphyxia-induced oxidative stress in the hippocampus (oxidized/reduced glutathione); (ii) increased antioxidative Nuclear Erythroid 2-Related Factor 2 (NRF2) translocation; (iii) increased NQO1 antioxidant protein; (iv) reduced neuroinflammation (decreasing nuclearNF-κB/p65 levels and microglial reactivity); (v) decreased cleaved-caspase-3 cell-death; (vi) improved righting reflex, negative geotaxis, cliff aversion, locomotor activity, anxiety, motor coordination, and recognition memory. Overall, the study demonstrates that intranasal administration of preconditioned MSC-S is a novel therapeutic strategy that prevents the long-term effects of perinatal asphyxia.

Animal models for neonatal brain injury induced by hypoxic ischemic conditions in rodents.

Neonatal hypoxia-ischemia and resulting encephalopathies are of significant concern. Intrapartum asphyxia is a leading cause of neonatal death globally. Among surviving infants, there remains a high incidence of hypoxic-ischemic encephalopathy due to neonatal hypoxic-ischemic brain injury, manifesting as mild conditions including attention deficit hyperactivity disorder, and debilitating disorders such as cerebral palsy. Various animal models of neonatal hypoxic brain injury have been implemented to explore cellular and molecular mechanisms, assess the potential of novel therapeutic strategies, and characterize the functional and behavioural correlates of injury. Each of the animal models has individual advantages and limitations. The present review looks at several widely-used and alternative rodent models of neonatal hypoxia and hypoxia-ischemia; it highlights their strengths and limitations, and their potential for continued and improved use.

Assessment of neonaticide in the setting of concealed and denied pregnancies.

It is known that concealed and denied pregnancy are both associated with increased health risks to the mother and infant. Whilst there is literature surrounding management and safeguarding in these instances, we are not aware of a case review of post-mortem findings in infants with a history of concealed or denied pregnancy. We performed a retrospective review of all coronial post-mortems performed between 2003 and 2018 on infants and fetuses with a history of concealment or denial of pregnancy. Maternal demographics, delivery information, post-mortem findings and results of ancillary investigations were analyzed. Twenty cases (1.8% of total coronial workload in the period of the study) were included. Four women admitted to concealing their pregnancy, eleven denied their pregnancy and in the remaining five cases the bodies of the infants had been abandoned and the mother was not traceable. The bodies of these infants were found in waste disposal sites, wooded areas and in a drainpipe. Only six infants in total were judged to have survived delivery, all others were stillborn or unascertained. Perinatal hypoxia, large subdural hemorrhage and congenital pneumonia were the reported causes of death in those infants that were liveborn. In one case there was suspicion of neonaticide. Concealment and denial of pregnancy occur in a wider demographic than perhaps anticipated and is not limited to teenage primigravids. Mothers with concealed and denied pregnancy hid the body of their deceased infant out of fear of prosecution. In many circumstances, viability at birth cannot be ascertained.

Brain temperature of infants with neonatal encephalopathy following perinatal asphyxia calculated using magnetic resonance spectroscopy.

BACKGROUND: Little is known about brain temperature of neonates during MRI. Brain temperature can be estimated non-invasively with proton Magnetic Resonance Spectroscopy (1H-MRS), but the most accurate 1H-MRS method has not yet been determined. The primary aim was to estimate brain temperature using 1H-MRS in infants with neonatal encephalopathy (NE) following perinatal asphyxia. The secondary aim was to compare brain temperature during MRI with rectal temperatures before and after MRI. METHODS: In this retrospective study, brain temperature in 36 (near-)term infants with NE was estimated using short (36 ms) and long (288 ms) echo time (TE) 1H-MRS. Brain temperature was calculated using two different formulas: formula of Wu et al. and a formula based on phantom calibration. The methods were compared. Rectal temperatures were collected <3 hours before and after MRI. RESULTS: Brain temperatures calculated with the formula of Wu et al. and the calibrated formula were similar as well as brain temperatures derived from short and long TE 1H-MRS. Rectal temperature did not differ before and after MRI. CONCLUSIONS: Brain temperature can be measured using 1H-MRS in daily clinical practice using the formula of Wu et al. with both short and long TE 1H-MRS. Brain temperature remained within physiological range during MRI.

Neonatal hypoxia-ischemia in rat elicits a region-specific neurotrophic response in SVZ microglia.

BACKGROUND: Recent findings describe microglia as modulators of neurogenesis in the subventricular zone (SVZ). SVZ microglia in the adult rat are thought to adopt a neurotrophic phenotype after ischemic stroke. Early postnatal microglia are endogenously activated and may therefore exhibit an increased sensitivity to neonatal hypoxia-ischemia (HI). The goal of this study was to investigate the impact of cortico-striatal HI on the microglial phenotype, function, and gene expression in the early postnatal SVZ. METHODS: Postnatal day (P)7 rats underwent sham or right-hemispheric HI surgery. Microglia in the SVZ, the uninjured cortex, and corpus callosum were immunohistochemically analyzed at P10, P20, and P40. The transcriptome of microdissected SVZ and cortical microglia was analyzed at P10 and P20, and the effect of P10 SVZ microglia on neurosphere generation in vitro was studied. RESULTS: The microglial response to HI was region-specific. In the SVZ, a microglial accumulation, prolonged activation and phagocytosis was noted that was not observed in the cortex and corpus callosum. The transcriptome of SVZ microglia and cortical microglia were distinct, and after HI, SVZ microglia concurrently upregulated pro- and anti-inflammatory as well as neurotrophic genes. In vitro, microglia isolated from the SVZ supported neurosphere generation in a concentration-dependent manner. CONCLUSIONS: Microglia are an inherent cellular component of the early postnatal SVZ and undergo developmental changes that are affected on many aspects by neonatal HI injury. Our results demonstrate that early postnatal SVZ microglia are sensitive to HI injury and display a long-lasting region-specific response including neurotrophic features.

Do Increased Intra-alveolar Squamous Cells at Autopsy Correlate With Acute Fetal Asphyxia?

It is a generally held concept that finding increased aspirated amniotic fluid squames at autopsy supports a diagnosis of acute fetal asphyxia, the massive aspiration of squames being an indicator of terminal gasping. To evaluate this concept, we identified autopsies on 15 third-trimester stillborns with clinical acute placental abruption (acute asphyxia); 13 also had thymic petechiae and none had severe acute thymic involution, findings also supporting acute asphyxia. Thirty third-trimester stillborns with findings supporting a subacute or chronic mode of death, including severe thymic involution and absence of thymic petechiae, comprised the comparison group. Intra-alveolar squames were scored as 0, no squames; 1+, scattered squames singly or in small groups; and 2+, squames in many alveoli, at least focally in compacted clusters. In all cases, the squames were patchily distributed, and none received a score of 0. In the abruption group, the intra-alveolar squames were scored as 1+ in 12 (80%) and as 2+ in 3 (20%) cases, while in the comparison group, the squames were scored as 1+ in 20 (67%) and 2+ in 10 (33%) cases (P = NS). There was also no difference in the quantification of intra-alveolar squames in term compared to preterm stillborns. In conclusion, quantification of intra-alveolar squames did not aid in separating an acute mode of death (acute asphyxia) from subacute or chronic modes of death.

Signal Change in the Mammillary Bodies after Perinatal Asphyxia.

BACKGROUND AND PURPOSE: Research into memory deficits associated with hypoxic-ischemic encephalopathy has typically focused on the hippocampus, but there is emerging evidence that the medial diencephalon may also be compromised. We hypothesized that mammillary body damage occurs in perinatal asphyxia, potentially resulting in mammillary body atrophy and subsequent memory impairment. MATERIALS AND METHODS: We retrospectively reviewed brain MRIs of 235 clinically confirmed full-term patients with hypoxic-ischemic encephalopathy acquired at a single center during 2004-2017. MRIs were performed within 10 days of birth (median, 6; interquartile range, 2). Two radiologists independently assessed the mammillary bodies for abnormal signal on T2-weighted and DWI sequences. Follow-up MRIs were available for 9 patients; these were examined for evidence of mammillary body and hippocampal atrophy. RESULTS: In 31 neonates (13.2%), abnormal high mammillary body signal was seen on T2-weighted sequences, 4 with mild, 25 with moderate, and 2 with severe hypoxic-ischemic encephalopathy. In addition, restricted diffusion was seen in 6 neonates who had MR imaging between days 5 and 7. For these 31 neonates, the most common MR imaging pattern (41.9%) was abnormal signal restricted to the mammillary bodies with the rest of the brain appearing normal. Follow-up MRIs were available for 9 patients: 8 acquired between 3 and 19 months and 1 acquired at 7.5 years. There was mammillary body atrophy in 8 of the 9 follow-up MRIs. CONCLUSIONS: Approximately 13% of full-term infants with hypoxic-ischemic encephalopathy showed abnormal high mammillary body signal on T2-weighted images during the acute phase, which progressed to mammillary body atrophy in all but 1 of the infants who had follow-up MR imaging. This mammillary body involvement does not appear to be related to the severity of encephalopathy, MR imaging patterns of hypoxic-ischemic encephalopathy, or pathology elsewhere in the brain.

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.

Quantitative Analysis of Punctate White Matter Lesions in Neonates Using Quantitative Susceptibility Mapping and R2* Relaxation.

BACKGROUND AND PURPOSE: It is difficult to distinguish punctate white matter lesions from focal hemorrhagic lesions in neonates on conventional MR imaging because both kinds of lesions show increased signal intensity on T1-weighted images and, frequently, decreased signal intensity on T2-weighted images. Our aim was to distinguish punctate white matter lesions and focal hemorrhagic lesions using quantitative measures. MATERIALS AND METHODS: In the current study, we acquired multiecho gradient recalled-echo MR imaging data from 24 neonates with hypoxic-ischemic encephalopathy and postprocessed them as R2* relaxation maps and quantitative susceptibility maps. Seven subjects who were found to have multifocal punctate white matter lesions and/or focal hemorrhagic lesions on R2* maps were included (mean gestational age at birth, 33 ± 4.28 weeks; mean gestational age at scanning, 38 ± 2 weeks). Manually drawing ROIs on R2* maps, we measured R2* and magnetic susceptibility values of the lesions, along with white matter regions within the corpus callosum as healthy comparison tissue. RESULTS: R2* and magnetic susceptibility values were both found to easily distinguish punctate white matter lesions, focal hemorrhagic lesions, and healthy white matter tissue from each other (P < .05), with a large Hedge g. R2* and magnetic susceptibility values were significantly increased in focal hemorrhagic lesions compared with punctate white matter lesions and healthy white matter tissue. Punctate white matter lesions were also found to have significantly increased values over healthy white matter tissue. CONCLUSIONS: R2* and quantitative susceptibility maps can be used to help clinicians distinguish and measure focal hemorrhages, punctate white matter lesions, and healthy white matter tissue.

Delayed intranasal infusion of human amnion epithelial cells improves white matter maturation after asphyxia in preterm fetal sheep.

Perinatal hypoxic-ischemic (HI) brain injury remains highly associated with neurodevelopmental disability after preterm birth. There is increasing evidence that disability is linked with impaired white matter maturation, but there is no specific treatment. In this study, we evaluated whether, in preterm fetal sheep, delayed intranasal infusion of human amnion epithelial cells (hAECs) given 1, 3 and 10 days after severe HI, induced by umbilical cord occlusion for 25 min, can restore white matter maturation or reduce delayed cell loss. After 21 days recovery, asphyxia was associated with reduced electroencephalographic (EEG) maturation, brain weight and cortical area, impaired maturation of oligodendrocytes (OLs), no significant loss of total OLs but a marked reduction in immature/mature OLs and reduced myelination. Intranasal infusion of hAECs was associated with improved brain weight and restoration of immature/mature OLs and fractional area of myelin basic protein, with reduced microglia and astrogliosis. Cortical EEG frequency distribution was partially improved, with reduced loss of cortical area, and attenuated cleaved-caspase-3 expression and microgliosis. Neuronal survival in deep grey matter nuclei was improved, with reduced microglia, astrogliosis and cleaved-caspase-3-positive apoptosis. These findings suggest that delayed intranasal hAEC administration has potential to alleviate chronic dysmaturation after perinatal HI.

Deep hypothermia reverses behavioral and histological alterations in a rat model of perinatal asphyxia.

The consequences of perinatal asphyxia (PA) include alterations which may manifest as schizophrenia. Characteristic features of this disease include a decrease in specific subpopulations of GABAergic cells and deterioration of social interaction. The purpose of this study is to assess if a deep and short-hypothermic treatment can ameliorate this damage in a model of PA. Rats offsprings were exposed to 19 min of asphyxia by immersing the uterus horns in water at 37 °C followed by 30 min in air at 10 °C that resulted in 15 °C body temperature. At postnatal day 36-38, the rats were tested in the open field and social interaction paradigms and processed for immunostaining of calbindin and reelin. A brief exposure to deep hypothermia reversed the deterioration produced by PA in play soliciting. PA decreased the density of calbindin neurons in layer II of the Anterior Insular Cortex, while deep hypothermia reversed this effect. Paradoxically, in AIC, there was a significant increase in the number of reelin-secreting neurons in layers II and III generated by PA and this increase was reversed by hypothermia. This suggests a compensatory mechanism, where reelin neurons trend to compensate for the loss of calbindin neurons, at least within Anterior Insular Cortex. Finally, the deep hypothermic shock might represent a valuable therapeutic alternative to treat PA.

Electroencephalography and brain magnetic resonance imaging in asphyxia comparing cooled and non-cooled infants.

OBJECTIVE: The aim was to establish any differences in the predictive value of EEG and MRI for outcome in infants treated and not-treated with therapeutic hypothermia (HT) for perinatal asphyxia. We hypothesize that they are equally predictive and that combining both has the highest predictive value. STUDY DESIGN: We retrospectively compared data of infants with hypoxic-ischemic encephalopathy (HIE) who received HT (n = 45) between September 2009 and December 2013 with those of infants with HIE born between January 2004 and August 2009, before HT was available (NT, n = 37). All received conventional and/or amplitude-integrated EEG during the first days and early MRI (day 4-5). Associations of EEG, MRI and severe neurodevelopmental outcome (death or Bayley's -2SD below mean), were tested with a multivariable logistic regression analysis, corrected for HT. RESULTS: Forty-eight hours' EEG background pattern had a PPV of 92% and a NPV of 81% in HT, versus 100% and 58% in NT. MRI had a PPV of 71% and a NPV of 93% in HT, versus 82% and 75% in NT. The adjusted OR for adverse outcome was 0.013 (95% CI 0.002-0.154, p < 0.001) for EEG background normalization within 48 h and 32.19 (95% CI 4.84-214.25, p < 0.001) for abnormal MRI. CONCLUSION: The predictive value of EEG and MRI is equal in cooled and non-cooled infants with HIE. Our data show a higher predictive value (death and severe outcome) for EEG compared to MRI. In HIE, persistent abnormal EEG background pattern until 48 h, combined with abnormal early MRI is strongly predictive for poor neurodevelopment.

Lack of the brain-specific isoform of apoptosis-inducing factor aggravates cerebral damage in a model of neonatal hypoxia-ischemia.

Apoptosis-inducing factor (AIF) may contribute to neuronal cell death, and its influence is particularly prominent in the immature brain after hypoxia-ischemia (HI). A brain-specific AIF splice-isoform (AIF2) has recently been discovered, but has not yet been characterized at the genetic level. The aim of this study was to determine the functional and regulatory profile of AIF2 under physiological conditions and after HI in mice. We generated AIF2 knockout (KO) mice by removing the AIF2-specific exon and found that the relative expression of Aif1 mRNA increased in Aif2 KO mice and that this increase became even more pronounced as Aif2 KO mice aged compared to their wild-type (WT) littermates. Mitochondrial morphology and function, reproductive function, and behavior showed no differences between WT and Aif2 KO mice. However, lack of AIF2 enhanced brain injury in neonatal mice after HI compared to WT controls, and this effect was linked to increased oxidative stress but not to caspase-dependent or -independent apoptosis pathways. These results indicate that AIF2 deficiency exacerbates free radical production and HI-induced neonatal brain injury.