Objective: To study the expression of N-methl- D -aspartate (NMDA) receptor subunits NR2A and N R2B mRNA after audiogenic seizure in the brain of genetically epilepsy-prone ra t s-P77PMC. Methods: In situ hybridization technique was used to stud y the mRNA expre ssion of NR2A and NR2B at different times after audiogenic seizure in different b rain areas of P77PMC rats. Results: The NR2A mRNA expression showed time-depende nt down-regulation in cerebral motor and sensory cortex, hippocampus CA1-CA3, de ntate gyrus after audiogenic seizure. Down-regulation emerged 30 min after se izure, 2 hours later the mRNA reached the lowest level， 4-8 hours later re turned to the baseline, and 24 hours later decreased lower than baseline again . The mRNA expression of NR2B was quite similar to that of the NR2A af ter seizure. Conclusion: The down-regulation of NR2A and NR2B mRNA indicates that the subunit composition of the NMDA receptor complexes may be altered after aud iogenic seizure. These structural alterations could make the function of NMDA re ceptor complexes change and subsequently influence the excitability of brain as well as the susceptibility of epilepsy.

Objective:To evaluate the feasibility of measuring pulmonary venous blood flow spectrum by transesophageal ultrasound in assessing intraoperative left atrial pressure (LAP) in pediatric patients with complex congenital heart disease.Methods:Twenty-five pediatric patients with complex congenital heart disease of either sex, aged < 3 yr, of American Society of Anesthesiologists physical status Ⅲ or Ⅳ, with New York Heart Association class Ⅲ or Ⅳ, undergoing surgery with general anesthesia and requiring LAP monitoring during surgery, were selected.Transesophageal echocardiography was used to record the left pulmonary venous blood flow spectrum during surgery.S wave velocity (PV S), D wave velocity (PV D), AR wave velocity (PV AR), and deceleration time of pulmonary venous diastolic flow (DT D) were measured at 15 min after termination of CPB.The ratio of S wave peak velocity to D wave peak velocity (S/D ratio) was calculated.Measurement was carried out for 3 consecutive cardiac cycles, and the average value was calculated.The LAP was simultaneously measured through the left atrial piezometer.Pearson correlation analysis was performed between PV S, PV D, PV AR, DT D, S/D ratio and LAP. Results:PV S, PV D, PV AR and S/D ratio had no correlation with LAP ( r=-0.06, 0.21, 0.19, -0.38, respectively, P>0.05), while DT D was negatively correlated with LAP ( r=-0.84, P<0.05). Conclusions:DT D measured by transesophageal ultrasound can be used to evaluate intraoperative LAP in pediatric patients with complex congenital heart disease.