Background: Severe brain injury induced by neonatal stroke causes significant mortality and disability, and effective therapies are currently lacking. We hypothesized that human umbilical cord blood (UcB)-derived mesenchymal stem cells (MScs) can attenuate severe brain injury induced by permanent middle cerebral artery occlusion (McaO) in rat pups. Methods: after confirming severe brain injury involving more than 50% of the ipsilateral hemisphere volume at 1 h after McaO using diffusion-weighted magnetic resonance imaging (MRI) in postnatal day (P)10 rats, human UcB-derived MScs were transplanted intraventricularly. The brain MRI was evaluated periodically up to 28 d after McaO (P38). Sensorimotor function and histology in the peri-infarct tissues were evaluated at the end of the experiment. results: Severe brain injury induced by permanent McaO resulted in decreased survival and body weight gain, increased brain infarct volume as measured by MRI, impaired functional tests such as the rotarod and cylinder test, and histologic abnormalities such as increased terminal deoxynucleotidyl transferase nick-end labeling, reactive microglial marker, and glial fibrillary acidic protein-positive cells in the penumbra. all of these abnormalities were significantly improved by MSc transplantation 6 h after McaO. conclusion: These results suggest that human UcB-derived MScs are a promising therapeutic candidate for the treatment of severe perinatal brain injury including neonatal stroke.

Intratracheal transplantation of human umbilical cord blood (UCB)-derived mesenchymal stem cells (MSCs) protects against neonatal hyperoxic lung injury by a paracrine rather than a regenerative mechanism. However, the role of paracrine factors produced by the MSCs, such as vascular endothelial growth factor (VEGF), has not been delineated. This study examined whether VEGF secreted by MSCs plays a pivotal role in protecting against neonatal hyperoxic lung injury. VEGF was knocked down in human UCB-derived MSCs by transfection with small interfering RNA specific for human VEGF. The in vitro effects of MSCs with or without VEGF knockdown or neutralizing antibody were evaluated in a rat lung epithelial (L2) cell line challenged with H2O2. To confirm these results in vivo, newborn Sprague-Dawley rats were exposed to hyperoxia (90% O2) for 14 days. MSCs (1 × 10(5) cells) with or without VEGF knockdown were administered intratracheally at postnatal Day 5. Lungs were serially harvested for biochemical and histologic analyses. VEGF knockdown and antibody abolished the in vitro benefits of MSCs on H2O2-induced cell death and the up-regulation of inflammatory cytokines in L2 cells. VEGF knockdown also abolished the in vivo protective effects of MSCs in hyperoxic lung injury, such as the attenuation of impaired alveolarization and angiogenesis, reduction in the number of terminal deoxynucleotidyl transferase dUTP nick end labeling-positive and ED-1-positive cells, and down-regulation of proinflammatory cytokine levels. Our data indicate that VEGF secreted by transplanted MSCs is one of the critical paracrine factors that play seminal roles in attenuating hyperoxic lung injuries in neonatal rats.

Background and Aim of the Study: Total anomalous pulmonary venous connection (TAPVC) is a rare cyanotic congenital heart defect. This study aimed to evaluate the outcome of isolated TAPVC repairs and the prognoses of affected patients in the last 12 years at a single center. Methods: We retrospectively analyzed the medical records of 51 patients who underwent isolated TAPVC repair from 2007 to 2018. Results: The median age at operation was 19 days, and the median body weight was 3.3 kg. Thirteen (25.5%) patients had emergency operations, and the median followup period was 29.54 ± 36.77 months. Early mortality was noted in five patients and late mortality was noted in one patient. Pulmonary vein stenosis was observed in 22 patients within 3 to 6 months after the operation, and six patients required reoperation or transcatheter interventions. Low birth weight, small left atrial volume, long operation time, and preoperative heart failure were identified as risk factors for mortality.Conclusions: Isolated TAPVC can rapidly lead to hemodynamic instability during the neonatal period and is associated with high mortality rates. Increasing the prenatal diagnosis rate and stabilizing the patients' condition before the operation are considered important for improving the surgical outcome. K E Y W O R D S preoperative management, pulmonary vein stenosis, surgical outcome, total anomalous pulmonary venous connection

Introduction: Although patent ductus arteriosus (PDA) has been implicated to play a role in the development of cerebral ischemia and intraventricular hemorrhage (IVH) through a cerebral steal phenomenon, there is conflicting data on the impact of PDA size on cerebral blood flow (CBF). Cerebral autoregulation is the brain's innate protective mechanism to maintain constant CBF despite changes in blood pressure, and it is unclear if it is influenced by PDA hemodynamics. Objective: To delineate the relationship between PDA size and CBF velocity (CBFv) in premature infants. Methods: 113 premature infants born at 23-29 weeks' gestation had echocardiograms performed during the first week after birth to evaluate for PDA. The infants were divided into 3 groups according to PDA size: none-to-small, moderate, or large. All infants had continuous recordings of umbilical artery blood pressure (ABP) and CBFv during the first week after birth. Critical closing pressure (CrCP) was calculated from ABP and CBFv tracings. Diastolic closing margin (DCM), defined as di-astolic blood pressure minus CrCP, was calculated as a marker for the risk of developing IVH. Results: Infants with a large PDA (n = 16) had the lowest ABP across all phases of the cardiac cycle (systole [p = 0.003], mean [p = 0.005], and diastole [p = 0.012]) compared to infants with a moderate (n = 19) or none-to-small PDA (n = 78). Despite blood pressure being different, systolic, mean, and diastolic CBFv were not different across groups. Cerebral autoregulation, as measured during systole, was intact regardless of the PDA size. CrCP and DCM were also not different across groups. Conclusions: In this cohort, CBFv and cerebral autoregulation during systole were not influenced by PDA size. Intact cerebral autoregulation may play a role in maintaining CBFv regardless of PDA size and differences in ABP.