Clinical features and magnetic resonance imaging evaluation of encephalopathy in high-risk late preterm infants / 中国当代儿科杂志

<p><b>OBJECTIVE</b>To investigate the risk factors, clinical features, and magnetic resonance imaging (MRI) changes of encephalopathy in high-risk late preterm infants.</p><p><b>METHODS</b>Head MRI scan was performed for late preterm infants with high-risk factors for brain injury who were hospitalized between January 2009 and December 2014. The risk factors, clinical features, and head MRI features of encephalopathy in late preterm infants were analyzed.</p><p><b>RESULTS</b>A total of 1 007 late preterm infants underwent MRI scan, among whom 313 (31.1%) had imaging features in accordance with the features of encephalopathy of prematurity. Of all infants, 76.7% had white matter damage. There was no association between the development of encephalopathy and gestational age in late preterm infants, but the detection rate of encephalopathy gradually increased with the increasing birth weight (P<0.05). The logistic regression analysis showed that a history of resuscitation was an independent risk factor for encephalopathy of prematurity (P<0.01).</p><p><b>CONCLUSIONS</b>Encephalopathy of prematurity is commonly seen in high-risk late preterm infants, especially white matter damage. A history of resuscitation is an independent risk factor for encephalopathy in late preterm infants.</p>

Expression of phosphorylated NMDA receptor 1 in the cerebral cortex after NMDA microinjection in vivo / 中国当代儿科杂志

<p><b>OBJECTIVE</b>The activation of N-methyl-D-aspartate(NMDA) receptors plays critical roles in the pathogenesis of diseases of the brain. This study aimed to examine the expression of phosphor-NR1 S897 in the cerebral cortex after NMDA microinjection in vivo.</p><p><b>METHODS</b>Forty seven-day-old Sprague-Dawley rats were randomly assigned into normal control and NMDA injection groups. The rats from the NMDA injection group were injected with 10 mmol of NMDA and were sacrificed 1 hr after injection. 2, 3, 5-triphenyltetrazolium chloride (TTC) and fluorescent immunohistochemical stainings were conducted and the fluorescence intensity OD value between the two groups was compared.</p><p><b>RESULTS</b>TTC staining from the two groups was normal. Expression of phosphor-NR1 S897 in the cerebral cortex of the ipsilateral hemisphere to injection in the NMDA injection group decreased significantly compared with the normal control group, with OD values of 0.366 +/- 0.087 vs 1.364 +/- 0.268 (P < 0.01).</p><p><b>CONCLUSIONS</b>NMDA microinjection, as a hypoxia-ischemia (HI) insult, significantly decreased the expression of phosphor-NR1 S897. This indicates the importance of the "HI-NMDA-phospho-NR1 S897 dephosphorylation-cell damage" pathway in HI brain damage.</p>