Inhibition of Microglial Activation by Delayed Mild Hypothermia Reduced Preoligodendrocyte Injury in a Neonatal Rat Brain Slice Model.

Periventricular leukomalacia (PVL), characterized by distinctive form of white matter injury, often arises after neonatal cardiac surgery. Proven therapies for PVL are absent. In this study, we designed to quest therapeutic effects of delayed mild hypothermia on PVL and its mechanism in a neonatal rat brain slice model. With the increase of delayed mild hypothermia-treating time, the reduced expression of myelin basic protein and loss of preoligodendrocytes were significantly attenuated after oxygen-glucose deprivation. In addition, the proportion of ionized calcium binding adapter molecule 1 (Iba-1)-positive cells and the expression of Iba-1 were apparently reduced with the increased duration of mild hypothermia treatment. Furthermore, the levels of tumor necrosis factor alpha and interleukin-6 reduced after the mild hypothermia treatment relative to the control. Inhibition of microglial activation with prolonged mild hypothermia may be a potential strategy for white matter protection during cardiopulmonary bypass and hypothermic circulatory arrest.

Amniotic fluid stem cells as a novel strategy for the treatment of fetal and neonatal neurological diseases.

Even in the context of modern medicine, infants with fetal and neonatal neurological diseases such as cerebral palsy and myelomeningocele suffer serious long-lasting impairment due to the irreversible neuronal damage. The promotion of neurologically intact survival in patients with perinatal intractable neurological diseases requires the development of novel strategies. One promising strategy involves the use of human amniotic fluid stem cells (hAFSCs), which have attracted much attention in recent years and are known to exert anti-inflammatory and neuroprotective effects. In recent years, the therapeutic effects of hAFSCs on fetal-neonatal neurological diseases have become evident as per intense research efforts by our group and others. Specifically, hAFSCs administered into the nasal cavity migrated to the brain and controlled local inflammation in a rodent model of neonatal hypoxic-ischemic encephalopathy. In contrast, hAFSCs administered intraperitoneally did not migrate to the brain; they rather formed spheroids in the abdominal cavity, resulting in the suppression of systemic inflammation (including in the brain) via the secretion of anti-inflammatory cytokines in concert with peritoneal macrophages in a rodent model of periventricular leukomalacia. Moreover, studies in a rat model of myelomeningocele suggested that hAFSCs administered in utero secreted hepatocyte growth factor and protected the exposed spinal cord during pregnancy. Importantly, autologous hAFSCs, whose use for fetal-neonatal treatment does not raise ethical issues, can be collected during pregnancy and prepared in sufficient numbers for therapeutic use. This article outlines the results of preclinical research on fetal stem cell therapy, mainly involving hAFSCs, in the context of perinatal neurological diseases.

Improvement by Human Oligodendrocyte Progenitor Cells of Neurobehavioral Disorders in an Experimental Model of Neonatal Periventricular Leukomalacia.

The effects of human oligodendrocyte progenitor (F3.olig2) cells on improving neurobehavioral deficits were investigated in an experimental model of periventricular leukomalacia (PVL). Seven-day-old male rats were subjected to hypoxia-ischemia-lipopolysaccharide injection (HIL), and intracerebroventricularly transplanted with F3.olig2 (4 × 105 cells/rat) once at post-natal day (PND) 10 or repeatedly at PND10, 17, 27, and 37. Neurobehavioral disorders were evaluated at PND14, 20, 30, and 40 via cylinder test, locomotor activity, and rotarod performance, and cognitive function was evaluated at PND41-45 through passive avoidance and Morris water-maze performances. F3.olig2 cells recovered the rate of use of the forelimb contralateral to the injured brain, improved locomotor activity, and restored rotarod performance of PVL animals; in addition, marked improvement of learning and memory function was seen. It was confirmed that transplanted F3·olig2 cells migrated to injured areas, matured to oligodendrocytes expressing myelin basic protein (MBP), and markedly attenuated the loss of host MBP in the corpus callosum. The results indicate that the transplanted F3.olig2 cells restored neurobehavioral functions by preventing axonal demyelination, and that human oligodendrocyte progenitor cells could be a candidate for cell therapy of perinatal hypoxic-ischemic and infectious brain injuries including PVL and cerebral palsy.

Perinatal Brain Injury: Mechanisms, Prevention, and Outcomes.

Perinatal brain injury may lead to long-term morbidity and neurodevelopmental impairment. Improvements in perinatal care have resulted in the survival of more infants with perinatal brain injury. The effects of hypoxia-ischemia, inflammation, and infection during critical periods of development can lead to a common pathway of perinatal brain injury marked by neuronal excitotoxicity, cellular apoptosis, and microglial activation. Various interventions can prevent or improve the outcomes of different types of perinatal brain injury. The objective of this article is to review the mechanisms of perinatal brain injury, approaches to prevention, and outcomes among children with perinatal brain injury.

Infantile Spasms and Injuries of Prematurity: Short-Term Treatment-Based Response and Long-Term Outcomes.

The association of infantile spasms and periventricular leukomalacia and/or intraventricular hemorrhage is well documented. Data regarding early treatment-based and long-term outcomes are limited. A retrospective chart review identified children with infantile spasms born prematurely (<37 weeks) with diagnoses of periventricular leukomalacia and/or intraventricular hemorrhage. Thirteen children were included. Median gestational age was 30 weeks and age of onset of infantile spasms was 8 months. Nine children had intraventricular hemorrhage, 10 had periventricular leukomalacia, and 6 children had both. Twelve of 13 children had resolution of spasms. In responders, the successful medication was adrenocorticotropic hormone (ACTH) in 7, topiramate in 3, and vigabatrin in 2. Follow-up after a median of 7.1 years found that all patients had developmental delay but only 1 had refractory epilepsy. Standard therapies (ACTH and vigabatrin) appeared to be more effective than other treatments. Developmental delay is common in children with periventricular leukomalacia / intraventricular hemorrhage and infantile spasms, but refractory epilepsy might be less frequent.

Human iPSC-Derived Immature Astroglia Promote Oligodendrogenesis by Increasing TIMP-1 Secretion.

Astrocytes, once considered passive support cells, are increasingly appreciated as dynamic regulators of neuronal development and function, in part via secreted factors. The extent to which they similarly regulate oligodendrocytes or proliferation and differentiation of oligodendrocyte progenitor cells (OPCs) is less understood. Here, we generated astrocytes from human pluripotent stem cells (hiPSC-Astros) and demonstrated that immature astrocytes, as opposed to mature ones, promote oligodendrogenesis in vitro. In the PVL mouse model of neonatal hypoxic/ischemic encephalopathy, associated with cerebral palsy in humans, transplanted immature hiPSC-Astros promoted myelinogenesis and behavioral outcome. We further identified TIMP-1 as a selectively upregulated component secreted from immature hiPSC-Astros. Accordingly, in the rat PVL model, intranasal administration of conditioned medium from immature hiPSC-Astros promoted oligodendrocyte maturation in a TIMP-1-dependent manner. Our findings suggest stage-specific developmental interactions between astroglia and oligodendroglia and have important therapeutic implications for promoting myelinogenesis.

Perinatal outcome comparing triplets and singleton births at a reference maternity hospital.

OBJECTIVE: The objective of the present study was to evaluate adverse perinatal outcome in a group of high order pregnancies pared with singletons by BW and GA at birth. METHODS: Data was reviewed for all admissions of triplets and quadruplets in a 7 year period. For each study neonate we selected two singleton infants to constitute a control group. Variables analyzed included: respiratory distress syndrome, patent ductus arteriosus, intraventricular hemorrhage, necrotizing enterocolitis (NEC), bronchopulmonary dysplasia, retinopathy of prematurity and periventricular leukomalacia. RESULTS: We studied a total of 128 multiple and 260 singleton infants. Mean gestational age and birth weight were similar in both groups (31.3 ± 2,5 wks e 31.5 ± 2,8 wks; 1470 ± 461 g vs 1495 ± 540 g). There was no significant difference between the groups in the majority of main morbidities. The incidence of NEC was higher in triplets (6.3 vs 0.8%, p value <0.01). Mortality was higher in singletons (9.6 vs 3.1%, p value <0.037). CONCLUSIONS: Results show that major neonatal outcomes are very similar between multiples and singletons births when paired by gestational age and birth weight. NEC remained a significant morbidity in infants born from multiple gestations after adjustment for maternal and neonatal risk factors.

Management of the Preterm Infant with Congenital Heart Disease.

The premature neonate with congenital heart disease (CHD) represents a challenging population for clinicians and researchers. The interaction between prematurity and CHD is poorly understood; epidemiologic study suggests that premature newborns are more likely to have CHD and that fetuses with CHD are more likely to be born premature. Understanding the key physiologic features of this special patient population is paramount. Clinicians have debated optimal timing for referral for cardiac surgery, and management in the postoperative period has rapidly advanced. This article summarizes the key concepts and literature in the care of the premature neonate with CHD.

Cell-based strategies to reconstitute vital functions in preterm infants with organ failure.

Infants born preterm face a number of challenges. Depending on the degree of prematurity, they are at a risk of developing several specific conditions and diseases related to organ immaturity and complications of long-term neonatal intensive care. Various organ systems are affected, such as the lung, resulting in bronchopulmonary dysplasia (BPD); the vascular system, resulting in pulmonary hypertension; the brain, with the risk of intracranial hemorrhage; the eye with retinopathy of prematurity; and the gut, manifesting in the severe complication of necrotizing enterocolitis. A common hallmark for all these prematurity-related conditions is that inflammation seems to be a major driving force in the pathogenesis, and that injury repair is essential for recovery and long-term health. In addition, the available treatment options are often only supportive, not curative. This chapter reviews the recent advances of stem cell therapy that have opened up new possibilities to restore organ function following prematurity.

The Neurological Outcome of Isolated PVL and Severe IVH in Preterm Infants: Is It Fair to Compare?

OBJECTIVE: We compared the neurological outcome of isolated periventricular leukomalacia and severe intraventricular hemorrhage in a cohort of very low birth weight infants born and managed at single tertiary-care center in Saudi Arabia. METHODS: We undertook a descriptive retrospective chart review of the neurological status of very low birth weight infants who were born and managed over a 5-year period at King Abdulaziz Medical City, Riyadh. The neurological outcome of neonates with isolated periventricular leukomalacia and severe intraventricular hemorrhage (grades III and IV) was studied and compared in relation to developmental delay and cerebral palsy. RESULTS: A total of 20 patients with isolated periventricular leukomalacia and 26 with severe intraventricular hemorrhage (grades III and IV) were identified for this study. Of 20 patients with isolated periventricular leukomalacia, 9 (45%) had good developmental outcome and 11 (55%) had bad developmental outcome. Of 26 patients of severe intraventricular hemorrhage, 14 (54%) had good developmental outcome and 12 (46%) had bad developmental outcome (P = 0.55). Significant motor neurological deficit affecting function is distributed as follows: 11/20 (55%) in the isolated periventricular leukomalacia group and 7/26 (27%) in the severe intraventricular hemorrhage group (P = 0.05). Cerebral palsy was diplegic in 7/11 (64%) and quadriplegic in 4/11 (36%) in the isolated periventricular leukomalacia group, and hemiplegic 3/7 (43%), diplegic in 1/7 (14%), and quadriplegic in 3/7 (43%) in the severe intraventricular hemorrhage group (P = 0.03). Distribution of the neurological outcome according to periventricular leukomalacia grade was as follows: for periventricular leukomalacia grade I (n = 8), 6/8 (75%) had good neurological outcome and 2/8 (25%) had bad neurological outcome. In periventricular leukomalacia grade II (n = 4), good neurological outcome was seen in three patients (75%) and bad neurological outcome was seen in one patient (25%). All patients (n = 8) with periventricular leukomalacia grade III had bad outcome (P < 0.01). CONCLUSION: About half of patients with isolated periventricular leukomalacia and severe intraventricular hemorrhage had a poor developmental outcome. However, the severity of cerebral palsy was greater in the isolated periventricular leukomalacia patients and correlates highly with periventricular leukomalacia grade. Symmetrical diplegic cerebral palsy is the most common motor deficit associated with isolated periventricular leukomalacia, whereas asymmetrical hemiplegic cerebral palsy is seen exclusively with severe intraventricular hemorrhage.

The whole spectrum of cystic periventricular leukomalacia of the preterm infant: results from a large consecutive case series.

PURPOSE: The purpose of this study is to describe features of cystic periventricular leukomalacia (PVL) in a large consecutive cohort study including long-term neurodevelopmental follow-up. METHODS: We performed a retrospective single-centre cohort study including all preterm infants ≤35 weeks of gestational age with PVL diagnosed by ultrasound scans (US) from a tertiary care university hospital between 1988 and 2012. RESULTS: The majority of 160 consecutively diagnosed cases had a gestational age between 28 and 32 weeks (60.6%), and male sex was predominant (60.6%). The most common associated clinical findings included respiratory distress syndrome, preterm premature rupture of the membranes, and chorioamnionitis (57.5, 49.4, and 39.4%, respectively). Infants presented with apnoeas in 66.3 and neonatal seizures in 23.1%. Any kind of respiratory support was present in 75.0%. Associated low-grade intraventricular haemorrhage was evident in 33.1, high-grade haemorrhage in 9.4%. Cysts were located on both hemispheres in 75% and PVL grades 3 and 4 were predominant (75.6%). Neurodevelopmental follow-up of 146 cases at a median age of 72 months revealed normal development in 11.0, mental retardation in 50.0, and cerebral palsy in 83.6%. Visual impairment was diagnosed in 21.9% and hearing impairment in one case. A quarter of cases (27.4%) developed seizure disorders. Outcome data were significantly better in unilateral compared to bilateral PVL. CONCLUSIONS: Long-term neurodevelopmental outcome of bilateral PVL always was adverse and different from unilateral PVL. The latter might be negatively influenced by associated intra- and periventricular haemorrhages.

Improvement of human umbilical cord mesenchymal stem cell transplantation on glial cell and behavioral function in a neonatal model of periventricular white matter damage.

Periventricular white matter damage (PWMD) also termed periventricular leucomalacia in the preterm infant is of particular importance because no targeted therapy is presently available. Human umbilical cord mesenchymal stem cells (hUC-MSCs) have been studied in a variety of adult brain injury-related neurological disorders. Our aim was to determine whether hUC-MSC transplantation improves glial cell function in cerebral white matter and long-term behavioral function in a PWMD rat model. Rats on postnatal day (P) 3 underwent a permanent ligation of the left common carotid artery followed by 6% O2 for 4h. Immediately after the hypoxic-ischemic (HI), rats received a single intraperitoneal injection of hUC-MSCs, which were co-cultured with 5-bromodeoxyuridine (BrdU). BrdU(+) cells in the brain were tested 24h after transplantation. Second, rats received hUC-MSC treatment once a day for 3 consecutive days. Glial cells (oligodendrocytes, astrocytes and microglia) were examined on 7 and 18 days post-HI, and behavioral outcomes were tested 27 days post-HI. Significantly, hUC-MSCs migrated mainly into the injured hemisphere. In addition, hUC-MSC treatment improved the long-term functional outcomes of rats, increased mature oligodendrocyte counts, and decreased the number of reactive astrocytes and activated microglia quantities after HI-induced damage in the premature brain. These results suggest that hUC-MSCs can pass through the blood-brain barrier and migrate towards the lesion site to improve brain damage. Therefore, hUC-MSCs have the potential to be utilized as a novel therapeutic strategy for PWMD.

[Chronic morbidities of premature newborns]. / Koraszülöttek krónikus utóbetegségei.

The most important chronic morbidities of premature newborns, deeply influencing quality of life, are retinopathy of prematurity, bronchopulmonary dysplasia, intraventricular hemorrhage and periventricular leukomalacia. Since the rate of premature birth has not decreased in recent years in Hungary, and treatments of these end stage disorders are extremely difficult, prevention gains tremendous significance. Effective prevention is based on detailed knowledge of the pathophysiological mechanisms of these special diseases having multifactorial nature sharing several common risk factors, and one is the pathological angiogenesis. This sensitive system is affected by several stress situations which are the consequences of prematurity leading to abnormal vascular growth. After birth, relative hyperoxia, compared to intrauterine life, and decreasing concentrations of vascular growth factors result in vascular injury, moreover, may cause vessel apoptosis. The consequence of this phenomenon is the activation of hypoxia responsible genes resulting in robust pathological neovascularization and organ damage during the later phase. Saving normal angiogenesis and inhibiting reactive neovascularization may lead to better quality of life in these premature infants.

[Advances in medical care for extremely low birth weight infants worldwide].

Dramatic advances in neonatal medicine over recent decades have resulted in decreased mortality and morbidity rates for extremely low birth weight infants. However, the survival of these infants is associated with short- and long-term morbidity, including severe intraventricular hemorrhage, periventricular leukomalacia, nosocomial infection and necrotizing enterocolitis, bronchopulmonary dysplasia, retinopathy of prematurity and adverse long-term neurodevelopmental sequelae. This article reviewed the latest advances in the medical care for extremely low birth weight infants including survival rate, ethical issues and short- and long-term morbidity, domestically and abroad.

Devastating coagulase-negative staphylococcal septicaemia in an extremely low birth weight infant.

In developed countries, coagulase-negative staphylococci (CoNS) are responsible for the majority of late-onset infections in very low birth weight infants undergoing neonatal intensive care. As a common skin commensal, they are often considered as mere contaminants of peripheral blood cultures or as relatively benign bacteria clinically. We present a case of invasive CoNS septicaemia in an extremely low birth weight infant which had devastating effects.

Effects on motor development of kicking and stepping exercise in preterm infants with periventricular brain injury: a pilot study.

BACKGROUND: Preterm infants with periventricular brain injury (PBI) have a high incidence of atypical development and leg movements. OBJECTIVE: Determine whether kicking and treadmill stepping intervention beginning at 2 months corrected age (CA) in children with PBI improves motor function at 12 months CA when compared with control subjects. METHOD: In a multi-center pilot study for a controlled clinical trial, sixteen infants with PBI were randomly assigned to home exercise consisting of kicking and treadmill stepping or a no-training control condition. Development was assessed at 2, 4, 6, 10, and 12 months CA with the Alberta Infant Motor Scale (AIMS). At 12 months children were classified as normal, delayed, or with cerebral palsy (CP). RESULTS: At 12 months CA 3 of 7 (43%) of the exercise group children walked alone or with one hand held versus 1 of 9 (11%) in the control group (p=0.262), but no significant differences in AIMS scores were found at any age. Half of the subjects had CP or delay; the outcomes of these infants were not improved by exercise. Compliance with the home program was lower than requested and may have affected results. CONCLUSION: Although not statistically significant with a small sample size, self-produced kicking and treadmill exercise may lower age at walking in infants with normal development following PBI, but improvements of the protocol to increase and document compliance are needed before a larger study is implemented.

Correlation between periventricular leukomalacia and retinopathy of prematurity.

PURPOSE: To investigate the correlation between periventricular leukomalacia (PVL) and retinopathy of prematurity (ROP), which are complications of perinatal and postnatal hypoxic-ischemic insults in premature infants. METHODS: In this retrospective case series study, from 1996 to 2008, after excluding cases with follow-up of less than 3 months, we reviewed medical charts of babies who had gestational age (GA) less than 30 weeks or birthweight (BW) less than 2000 g. A total of 195 patients were diagnosed with ROP and/or PVL and were enrolled in this analysis. We investigated the correlation between ROP and PVL with Pearson chi-square test and evaluated BW, GA, and Apgar scores at 1 minute and 5 minutes after birth as risk factors by independent t test. RESULTS: There were no significant differences in the prevalence of PVL between patients who received ROP treatment and those who did not receive ROP treatment. The BW was significantly lower in patients with PVL than in patients without PVL. Gestational age, BW, and Apgar scores significantly differed between patients who did and did not receive retinal treatment for ROP. CONCLUSIONS: Periventricular leukomalacia did not increase the severity of ROP or requirement of ROP treatment. Birthweight, GA, and Apgar scores were the principal factors that determined the necessity of ROP treatment.

Enrollment of extremely low birth weight infants in a clinical research study may not be representative.

BACKGROUND AND OBJECTIVE: The Surfactant Positive Airway Pressure and Pulse Oximetry Randomized Trial (SUPPORT) antenatal consent study demonstrated that mothers of infants enrolled in the SUPPORT trial had significantly different demographics and exposure to antenatal steroids compared with mothers of eligible, but not enrolled infants. The objective of this analysis was to compare the outcomes of bronchopulmonary dysplasia, severe retinopathy of prematurity, severe intraventricular hemorrhage or periventricular leukomalacia (IVH/PVL), death, and death/severe IVH/PVL for infants enrolled in SUPPORT in comparison with eligible, but not enrolled infants. METHODS: Perinatal characteristics and neonatal outcomes were compared for enrolled and eligible but not enrolled infants in bivariate analyses. Models were created to test the effect of enrollment in SUPPORT on outcomes, controlling for perinatal characteristics. RESULTS: There were 1316 infants enrolled in SUPPORT; 3053 infants were eligible, but not enrolled. In unadjusted analyses, enrolled infants had significantly lower rates of death before discharge, severe IVH/PVL, death/severe IVH/PVL (all < 0.001), and bronchopulmonary dysplasia (P = .003) in comparison with eligible, but not enrolled infants. The rate of severe retinopathy of prematurity was not significantly different. After adjustment for perinatal factors, enrollment in the trial was not a significant predictor of any of the tested clinical outcomes. CONCLUSIONS: The results of this analysis demonstrate significant outcome differences between enrolled and eligible but not enrolled infants in a trial using antenatal consent, which were likely due to enrollment bias resulting from the antenatal consent process. Additional research and regulatory review need to be conducted to ensure that large moderate-risk trials that require antenatal consent can be conducted in such a way as to ensure the generalizability of results.

Neuroprotective effect of oligodendrocyte precursor cell transplantation in a long-term model of periventricular leukomalacia.

Perinatal white matter injury, or periventricular leukomalacia (PVL), is the most common cause of brain injury in premature infants and is the leading cause of cerebral palsy. Despite increasing numbers of surviving extreme premature infants and associated long-term neurological morbidity, our understanding and treatment of PVL remains incomplete. Inflammation- or ischemia/hypoxia-based rodent models, although immensely valuable, are largely restricted to reproducing short-term features of up to 3 weeks after injury. Given the long-term sequelae of PVL, there is a need for subchronic models that will enable testing of putative neuroprotective therapies. Here, we report long term characterization of a neonatal inflammation-induced rat model of PVL. We show bilateral ventriculomegaly, inflammation, reactive astrogliosis, injury to pre-oligodendrocytes, and neuronal loss 8 weeks after injury. We demonstrate neuroprotective effects of oligodendrocyte precursor cell transplantation. Our findings present a subchronic model of PVL and highlight the tissue protective effects of oligodendrocyte precursor cell transplants that demonstrate the potential of cell-based therapy for PVL.