Human Neural Stem Cells: Translational Research for Neonatal Hypoxic-Ischemic Brain Injury

Neonatal hypoxic-ischemic (HI) brain injury is a major cause of neonatal mortality and long-term neurodevelopmental disabilities. Although promising neuroprotective interventions have been studied, the current management of HI brain injury has been limited to supportive measures and induced hypothermia. In addition to engrafting, migrating toward the damage sites and differentiating into multiple lineages, multipotent neural stem/progenitor cells (NSPCs) also provide trophic/immunomodulatory factors and integrate into the host neurons upon implantation into an HI-injured brain. However, NSPC-based therapies have shown poor cell survival and integration, poor differentiation or restricted differentiation into the glial lineages. Furthermore, to achieve full functional recovery following brain injury, the optimization of cell therapy is needed to recapitulate the precise migration of stem cells to the region of interest and the neural rewiring present in the brain microenvironment. Therefore, the efficacy of NSPCs in the treatment of CNS injury is currently insufficient. Human NSPCs (hNSPCs) were isolated from the forebrain of an aborted fetus at 13 weeks of gestation with full parental consent and the approval of the Institutional Review Board of the Yonsei University College of Medicine. Here, to enhance the regenerative ability of hNSPCs in HI brain injury, cells were either pretreated with pharmacological agents or engineered to serve as vehicles for gene delivery. Furthermore, when combined with a poly (glycolic acid)-based synthetic scaffold, hNSPCs provide a more versatile treatment for neonatal HI brain injury. Finally, hNSPCs transfected with zinc-doped ferrite magnetic nanoparticles for controlling both cell migration and differentiation offer a simple and smart tool for cell-based therapies.ope

Successful Treatment of Neonatal Pylorospasm with Intravenous Atropine

Pylorospasm is a cause of delayed gastric emptying in young infants. As in patients with hypertrophic pyloric stenosis, most pylorospasm patients present with projectile vomiting. However, unlike that in case of hypertrophic pyloric stenosis, no persistent pyloric stenotic lesions are present. As such, follow-up using serial gastrointestinal fluoroscopy or ultrasonography can be helpful in diagnosing patients with clinical signs of gastroparesis. Most cases can be treated conservatively, but some patients require pharmacologic treatment. Antispasmodics have been proposed as a treatment for pylorospasm, but their use in neonates and infants has rarely been reported. Herein, we present a case of pylorospasm diagnosed in the neonatal period and successfully treated with intravenous atropine.ope

Evaluation of Newborn Infants with Prenatally Diagnosed Congenital Pulmonary Airway Malformation: A Single-Center Experience

Purpose Congenital pulmonary airway malformation (CPAM)－a rare developmental anomaly－affects the lower respiratory tract in newborns. By comparing the reliability of diagnostic tools and identifying predictive factors for symptoms, we provide comprehensive clinical data for the proper management of CPAM. Methods We reviewed the medical records of 66 patients with prenatally diagnosed CPAM delivered at Severance Children’s Hospital between January 2005 and July 2017. Results We enrolled 33 boys and 33 girls. Their mean gestational age and birth weight were 38.8 weeks and 3,050 g, respectively. Prenatal ultrasonography and postnatal radiography, lung ultrasonography, and chest computed tomography (CT) showed inconsistent findings. Chest CT showed superior sensitivity (100%) and positive predictive value (90%). Among the 66 patients, 59 had postnatally confirmed CPAM, three had pulmonary sequestration, one had cystic teratoma, and one had a normal lung. Of the 59 patients with CPAM, 21 (35%; mean age, 23.4 months) underwent surgery, including 15 who underwent video-assisted thoracoscopy. Twenty-five and 12 patients exhibited respiratory symptoms at birth and during infancy, respectively. Apgar scores and mediastinal shift on radiography were significantly associated with respiratory symptoms at birth. However, none of the factors could predict respiratory symptoms during infancy. Conclusion Radiography or ultrasonography combined with chest CT can confirm an unclear or inconsistent lesion. Apgar scores and mediastinal shift on radiography can predict respiratory symptoms at birth. However, symptoms during infancy are not associated with prenatal and postnatal factors. Chest CT combined with periodic symptom monitoring is important for diagnosing and managing patients with prenatally diagnosed CPAM and to guide appropriate timing of surgery.ope

Glial Cell Line-derived Neurotrophic Factor-overexpressing Human Neural Stem/Progenitor Cells Enhance Therapeutic Efficiency in Rat with Traumatic Spinal Cord Injury

Spinal cord injury (SCI) causes axonal damage and demyelination, neural cell death, and comprehensive tissue loss, resulting in devastating neurological dysfunction. Neural stem/progenitor cell (NSPCs) transplantation provides therapeutic benefits for neural repair in SCI, and glial cell linederived neurotrophic factor (GDNF) has been uncovered to have capability of stimulating axonal regeneration and remyelination after SCI. In this study, to evaluate whether GDNF would augment therapeutic effects of NSPCs for SCI, GDNF-encoding or mock adenoviral vector-transduced human NSPCs (GDNF-or Mock-hNSPCs) were transplanted into the injured thoracic spinal cords of rats at 7 days after SCI. Grafted GDNFhNSPCs showed robust engraftment, long-term survival, an extensive distribution, and increased differentiation into neurons and oligodendroglial cells. Compared with Mock-hNSPC- and vehicle-injected groups, transplantation of GDNF-hNSPCs significantly reduced lesion volume and glial scar formation, promoted neurite outgrowth, axonal regeneration and myelination, increased Schwann cell migration that contributed to the myelin repair, and improved locomotor recovery. In addition, tract tracing demonstrated that transplantation of GDNF-hNSPCs reduced significantly axonal dieback of the dorsal corticospinal tract (dCST), and increased the levels of dCST collaterals, propriospinal neurons (PSNs), and contacts between dCST collaterals and PSNs in the cervical enlargement over that of the controls. Finally grafted GDNF-hNSPCs substantially reversed the increased expression of voltage-gated sodium channels and neuropeptide Y, and elevated expression of GABA in the injured spinal cord, which are involved in the attenuation of neuropathic pain after SCI. These findings suggest that implantation of GDNF-hNSPCs enhances therapeutic efficiency of hNSPCs-based cell therapy for SCI.ope

Oral characteristics and dietary habits of preterm children: A retrospective study using National Health Screening Program for Infants and Children

The rate of preterm birth is increasing worldwide and preterm infants are susceptible to oral health problems. Hence, this study aimed to investigate the effect of premature birth on dietary and oral characteristics as well as dental treatment experiences of preterm infants using a nationwide cohort study. Data was retrospectively analyzed from National Health Screening Program for Infants and Children (NHSIC) of the National Health Insurance Service of Korea. 5% sample of children born between 2008 and 2012 who completed first or second infant health screening were included and divided into full-term and preterm-birth groups. Clinical data variables such as dietary habits, oral characteristics, and dental treatment experiences were investigated and comparatively analyzed. Preterm infants showed significantly lower rates of breastfeeding at 4–6 months (p<0.001), delayed start of weaning food at 9–12 months (p<0.001), higher rates of bottle feeding at 18–24 months (p<0.001), poor appetite at 30–36 months (p<0.001) and higher rates of improper swallowing and chewing function at 42–53 months (p = 0.023) than full-term infants. Preterm infants also had eating habits leading to poor oral conditions and higher percentage of absence of dental visit compared to full-term infants (p = 0.036). However, dental treatments including 1-visit pulpectomy (p = 0.007) and 2-visit pulpectomy (p = 0.042) significantly decreased when oral health screening was completed at least once. The NHSIC can be an effective policy for oral health management in preterm infants.ope

Cellular Response of Ventricular-Subventricular Neural Progenitor/Stem Cells to Neonatal Hypoxic-Ischemic Brain Injury and Their Enhanced Neurogenesis

Purpose: To elucidate the brain's intrinsic response to injury, we tracked the response of neural stem/progenitor cells (NSPCs) located in ventricular-subventricular zone (V-SVZ) to hypoxic-ischemic brain injury (HI). We also evaluated whether transduction of V-SVZ NSPCs with neurogenic factor NeuroD1 could enhance their neurogenesis in HI. Materials and methods: Unilateral HI was induced in ICR neonatal mice. To label proliferative V-SVZ NSPCs in response to HI, bromodeoxyuridine (BrdU) and retroviral particles encoding LacZ or NeuroD1/GFP were injected. The cellular responses of NSPCs were analyzed by immunohistochemistry. Results: Unilateral HI increased the number of BrdU+ newly-born cells in the V-SVZ ipsilateral to the lesion while injury reduced the number of newly-born cells reaching the ipsilateral olfactory bulb, which is the programmed destination of migratory V-SVZ NSPCs in the intact brain. These newly-born cells were directed from this pathway towards the lesions. HI significantly increased the number of newly-born cells in the cortex and striatum by the altered migration of V-SVZ cells. Many of these newly-born cells differentiated into active neurons and glia. LacZ-expressing V-SVZ NSPCs also showed extensive migration towards the non-neurogenic regions ipsilateral to the lesion, and expressed the neuronal marker NeuN. NeuroD1+/GFP+ V-SVZ NSPCs almost differentiated into neurons in the peri-infarct regions. Conclusion: HI promotes the establishment of a substantial number of new neurons in non-neurogenic regions, suggesting intrinsic repair mechanisms of the brain, by controlling the behavior of endogenous NSPCs. The activation of NeuroD1 expression may improve the therapeutic potential of endogenous NSPCs by increasing their neuronal differentiation in HI.ope

Association between birth weight and neurodevelopmental disorders assessed using the Korean National Health Insurance Service claims data

The risk of neurodevelopmental disorders in low birth weight (LBW) infants has gained recognition but remains debatable. We investigated the risk of attention-deficit/hyperactivity disorder (ADHD) and autism spectrum disorder (ASD) in school-aged children according to their birth weight. We conducted a retrospective cohort study using the Korean National Health Insurance claims data of 2,143,652 children who were born between 2008 and 2012. Gestational age of infants was not available; thus, outcomes were not adjusted with it. Not only infants with birth weights of < 1.5 kg, but also 2.0-2.4 kg and 1.5-1.9 kg were associated with having ADHD; odds ratio (OR), 1.41 (95% confidence interval [CI] 1.33-1.50), and 1.49 (95% CI 1.33-1.66), respectively. The OR in infants with birth weights of 2.0-2.4 kg and 1.5-1.9 kg was 1.91 (95% CI 1.79-2.05) and 3.25 (95% CI 2.95-3.59), respectively, indicating increased odds of having ASD. Subgroup analysis for children without perinatal diseases showed similar results. In this national cohort, infants with birth weights of < 2.5 kg were associated with ADHD and ASD, regardless of perinatal history. Children born with LBW need detailed clinical follow-up.ope

Impact of neonatal resuscitation changes on outcomes of very-low-birth-weight infants

The improvement of delivery room care, according to the 2015 International Consensus, may affect neonatal outcome, especially in very-low-birth-weight infants. We aimed to investigate the current practice of neonatal resuscitation by year and analyze the association with neonatal outcomes. A total of 8142 very-low-birth-weight infants, registered in the Korean Neonatal Network between 2014 and 2017 were included. A significant decreasing trend of intubation (64.5% vs 55.1%, P < 0.0001) and markedly increasing trend of positive pressure ventilation (PPV) (11.5% vs 22.9%, P < 0.0001) were noted. The annual PPV rate differed significantly by gestation (P < 0.0001). The highest level of resuscitation was also shown as an independent risk factor for mortality within 7 days and for bronchopulmonary dysplasia (BPD), intraventricular hemorrhage (IVH), and periventricular leukomalacia. PPV and intubation were associated with significantly decreased risk of mortality and morbidities compared to epinephrine use. When considering association, the incidence of mortality within 7 days, IVH, PVL, and BPD or mortality showed significant differences by combination of year, gestational age, and level of resuscitation. According to updated guidelines, changes in the highest level of resuscitation significantly associated with reducing mortality and morbidities. More meticulous delivery room resuscitation focusing on extreme prematurity is needed.ope

Pulmonary Surfactant Replacement Therapy for Respiratory Distress Syndrome in Neonates: a Nationwide Epidemiological Study in Korea

Background: Pulmonary surfactant (PS) replacement therapy, as a safe and effective treatment for respiratory distress syndrome (RDS) may have further increased with the extended insurance coverage since 2011 in Korea. Thus, this study aimed to investigate the epidemiologic data of PS replacement therapy for RDS in Korea and to analyze the complications associated with RDS. Methods: We included 19,442 infants who were treated with PS and diagnosed with RDS (International Classification of Diseases-10 codes: P22.0) between 2014 and 2018 from the Health Insurance Review and Assessment database. Birth certificate data from Statistics Korea were used to estimate the incidence of RDS. Results: The average incidence of RDS within the study period was 0.99% among live births. Repeated doses of PS were administered to 1,688 infants (8.7%), ranging from 2 doses in 929 infants (4.8%) to 9 doses in 1 infant (0.01%). The incidence of RDS in term infants markedly increased over 5 years from 0.2% to 0.34%. The incidence was similarly increased among the preterm infants. The RDS mortality rate was 6.3% and showed a decreasing trend according to year. The mortality rate was significantly higher in the lower gestational age group. A decreasing trend was observed in the incidence of the complications, such as patent ductus arteriosus, intraventricular hemorrhage, and bronchopulmonary dysplasia, except for pneumothorax in term infants. The complications were also higher in the lower gestational age group and the lower birth weight group. However, pneumothorax was the most frequent complication in the term infant group and in infants with birth weight ≥ 2,500 g. Conclusion: Advancements in neonatal care and extended insurance coverage have increased the use of PS replacement therapy for RDS. This, in turn, decreased neonatal mortality and the incidence of the associated complications. The appropriate therapeutic strategy for RDS should be decided according to the gestational age and lung pathology.ope

A Patient with Tuberous Sclerosis with Hemimegalencephaly Presenting with Intractable Epilepsy in the Early Neonatal Period: A Case Report

Hemimegalencephaly (HME) is a rare disease characterized by partial or complete hypertrophy of one cerebral hemisphere. It is associated with intractable seizures, developmental delay, hemiparesis, and other neurological symptoms. Tuberous sclerosis (TSC) is a neurocutaneous syndrome that affects various organs, including the heart, brain, skin, kidney, and eyes, and is caused by mutations in TSC1 and TSC2 genes. Herein, we report the case of a patient with TSC and HME who required early neurosurgical treatment during the neonatal period. A full-term girl was suspected to have TSC prenatally because of left ventriculomegaly and cardiac masses on fetal ultrasonography. HME was confirmed by postnatal neuroimaging studies. Multiple rhabdomyomas and renal cysts were compatible with TSC. Serially performed electroencephalography (EEG) showed intractable electrical seizures in the left hemisphere with secondary generalization, despite rare clinical convulsions. As anti-epileptic drugs did not improve electrical seizures, corpus callosotomy was performed at 39 days of age. Postoperatively, the frequency of secondary generalization of seizures was significantly reduced on EEG. A novel frameshift mutation in c. 1743_1744insCAAGG (p. Thr582GlnfsTer49) in the TSC1 gene was confirmed using targeted next-generation sequencing.ope