Objective. The aim of this study was to elucidate the relationship between mechanical ventilation and hypocarbia in infants with periventricular leukomalacia (PVL). Study Design. Matched pair analysis was conducted for 26 infants with PVL and 26 with normal development, who were born between 27 and 32 weeks9 gestational age and required mechanical ventilation. The time-averaged carbon dioxide (CO₂) index, Paco₂, and pH were calculated every 24 hours for samples obtained from indwelling arterial catheters within the first 72 hours of life. The time-averaged respiratory rate of the ventilator (RR), peak inspiratory pressure (PIP), mean airway pressure (MAP), and ventilator index (VI) were also determined. The time-averaged total respiratory rate (TRR) was determined by observing the movement of the chest wall. The patients9 characteristics, antenatal and neonatal variables, and electroencephalographic findings were also compared. Results. The time-averaged CO₂ index was larger, the time-averaged CO₂ lower and the time-averaged pH higher in infants with PVL than in those with normal development on the third day of life. There was no significant difference in the time-averaged RR, PIP, MAP, or VI on any day. TRR was larger in the PVL group than in the control group on each day, but there was no significant difference. No significant difference was observed in the clinical characteristics or neonatal variables. Electroencephalographic abnormalities within 48 hours of life were more frequent in infants with PVL than in those with normal development. Conclusion. Hypocarbia was associated with PVL because the time-averaged CO₂ index was larger and the time-averaged Paco₂ lower in infants with PVL than in those with normal development. However, the ventilator settings were similar among the infants with and without PVL.

This study aimed to investigate whether the administration of mononuclear cells derived from human umbilical cord blood cells (UCBCs) could ameliorate hypoxic-ischemic brain injury in a neonatal rat model. The left carotid arteries of 7-day-old rats were ligated, and the rats were then exposed to 8% oxygen for 60 min. Mononuclear cells derived from UCBCs using the Ficoll-Hypaque technique were injected intraperitoneally 6 h after the insult (1.0 × 107 cells). Twenty-four hours after the insult, the number of cells positive for the oxidative stress markers 4-hydroxy-2-nonenal and nitrotyrosine, in the dentate gyrus of the hippocampus in the UCBC-treated group, decreased by 36 and 42%, respectively, compared with those in the control group. In addition, the number of cells positive for the apoptosis markers active caspase-3 and apoptosis-inducing factor decreased by 53 and 58%, respectively. The number of activated microglia (ED1-positive cells) was 51% lower in the UCBC group compared with the control group. In a gait analysis performed 2 weeks after the insult, there were no significant differences among the sham-operated, control and UCBC groups. An active avoidance test using a shuttle box the following week also revealed no significant differences among the groups. Neither the volumes of the hippocampi, corpus callosum and cortices nor the numbers of neurons in the hippocampus were different between the UCBC and control groups. In summary, a single intraperitoneal injection of UCBC-derived mononuclear cells 6 h after an ischemic insult was associated with a transient reduction in numbers of apoptosis and oxidative stress marker-positive cells, but it did not induce long-term morphological or functional protection. Repeated administration or a combination treatment may be required to achieve sustained protection.

OBJECTIVE. The aim of this study was to assess whether periventricular leukomalacia findings are sufficiently sensitive for predicting the severity of motor prognosis by conventional MRI in the near term.METHODS. Preterm infants with T1 hyperintensity or cysts in the periventricular regions on term MRI were selected, and their gross motor functions were evaluated at the age of 3 to 5 years. Sixty-two infants had findings of T1 hyperintensity or cysts, and except for infants with these findings, none were diagnosed later as periventricular leukomalacia.RESULTS. All 37 patients with cerebral palsy had periventricular lesions with T1 hyperintensity or cysts in the corona radiata above the posterior limb of the internal capsule on coronal sections. Small T1 hyperintensity lesions were seen on coronal slices and were often difficult to detect on axial slices. All of the 17 infants with T1 hyperintensity findings sparing the corona radiata above the posterior limb of the internal capsule showed normal motor development, irrespective of findings of ventriculomegaly. There was a tendency for the presence of widespread lesions in corona radiata above the posterior limb of the internal capsule to be correlated with the severity of motor handicap.CONCLUSIONS. Lesions in the corona radiata above the posterior limb of the internal capsule on a coronal view by term MRI were useful for predicting motor prognosis in preterm infants with periventricular leukomalacia.