Objective To investigate the effect of dexmedetomidine on corrected QT (QTc)and Tp-e interval from the peak of the T wave to the end of the T wave in patients undergoing knee joint replacement with spinal anesthesia.Methods Seventy patients 45-75 years,ASA Ⅰ or Ⅱ,who were scheduled to knee joint replacement with spinal anesthesia were divided into group C and group D ran-domly according to random number table (n=35 each group).Dexmedetomidine 0.6 μg/kg was ad-minstered over 10 min intravenously,followed by a continuous infusion at a dose of 0.4 μg·kg-1 · h-1 in group D and volume-matched normal saline infusion was adminstered in group C 1 5 min after spinal anesthesia.Time points for QT (QTc)and Tp-e intervals and hemodynamic parameters were:before spinal anesthesia (T0 ),5 (T1 ),10 (T2 ),and 1 5 (T3 )minutes after spinal anesthesia and 10 (T4 ),30 (T5 ),and 60 minutes (T6 )after infusion of dexmedetomidine or normal saline.The side effects in 24 h were also recorded.Results QTc intervals (T1-T3 )in both groups were significantly prolonged compared with T0 (P < 0.05 ).Compared with T3 ,QTc values in group D during T4-T6 were significantly shorter (P <0.05).QTc interval in group D during T4-T5 was significantly shorter than that in group C (P <0.05).There was no difference in side effects during postoperative 24 hours between two groups.Conclusion Dexmedetomidine could promote the return of a prolonged QTc in-terval in patients undergoing knee joint replacement with spinal anesthesia.

Objective To systematically review the changes in the intensity of postoperative pain under ketamine anesthesia in children.Methods We searched the Cochrane Library,PubMed,OVID,EMBASE,and Chinese Biomedical Database for prospective randomized controlled trials involving the changes in the intensity of postoperative pain under ketamine anesthesia in children.The quality of the studies was evaluated by the method recommended by Cochrane Collaboration.Evaluation indexes included pain score and analgesic consumption during 6 h after operation,pain score and analgesic consumption during 6-24 h after operation,duration of sensory block (caudal block),side effects during 24 h after operation (postoperative nausea and vomiting and psycho-mimetic manifestations).Meta-analysis was conducted using the Cochrane Collaboration's RevMan 5.0 software.Results Fifteen prospective randomized controlled trials involving 955 patients were included in our Meta-analysis.The patients were divided into 2 groups:control group ( n =455) and ketamine group ( n =500).The pain score and analgesic consumption during 6 h after operation were significantly decreased after general anesthesia with ketamine.The pain score during 6-24 h after operation and analgesic consumption during 6 h after operation were significantly decreased after local anesthesia with ketamine.The duration of sensory block was prolonged and the analgesic consumption during 6 h after operation was significantly reduced after caudal block with ketamine.There was no significant difference in the incidence of postoperative nausea and vomiting and psycho-mimetic manifestations between the two groups.Conclusion The intensity of pain and analgesic requirement during 6 h after operation are significantly reduced under ketamine anesthesia in children.

Objective To compare the efficacy of rcmifentanil combined anesthesia and fentanyl or sufentanil combined anesthesia in patients undergoing cardiac surgery.Methods We searched the Coehrane library,PubMed,EMBASE,OVID and Chinese Biomedical Database for prospective randomized controlled trials involving the comparison of the efficacy of remifentanil combined anesthesia and fentanyl or sufentanil combined anesthesia in patients undergoing cardiac surgery.The quality of the studies was evaluated by the method recommended by Cochrane Collaboration.Evaluation indexes included the mechanical ventilation time after operation,duration of stay in hospital,and level of cardiac troponin,mortality,requirement for positive inotropic drugs and incidence of hyperalgesia and myocardial infarction during perioperative period.Meta-analysis was conducted using the RevMan 5.0 software.Results Sixteen prospective randomized controlled trials involving 1473 patients were included in our Meta-analysis.The patients were divided into 2 groups:fentanyl or sufentanil group ( n =644) and remifentanil group ( n =573).Compared with fentanyl or sufentanil group,the mechanical ventilation time after operation and duration of stay in hospital were significantly shortened,the level of cardiac troponin during the perioperative period was significantly decreased and the requirement for positive inotropic drugs during the perioperative period was significantly reduced ( P ＜ 0.05),and no significant change was found in the incidence of hyperalgesia or mortality of myocardial infarction during the perioperative period in remifentanil group ( P ＞ 0.05 ).Conclusion The efficacy of remifentanil combined anesthesia is better than that of fentanyl or sufentanil combined anesthesia in patients undergoing cardiac surgery.

Objective To establish a tandem affinity purification(TAP) system of innate immune-regulatory protein PKR and analyze PKR function, for the future screen and identification of novel PKR-interaction proteins. Methods PKR gene was amplified by PCR, and then cloned into a mammalian expression vector pcTAP-A. Recombinant pcTAP-PKR was transfected into PKR knock-down(PKRkd) HeLa cells by LipofectAMINE 2000,and the PKR overexpressed HeLa cells were harvested for mitogen-activated protein kinases(MAPK) activation analysis. Cell extracts of PKR overexpressed cells were purified using TAP kit and examined by Western blot. Results Cal modulin resin(CBP) and streptavidin resin(SBP) tagged PKR was detected in PKRkd HeLa cells as early as 24 h upon transfection with pcTAP-PKR, and its expression decreased at later time points. The overexpression of PKR was autophosphorylated, and thus involved in the regulation of MAPK actviation. After small-scale TAP kit purification, PKR protein was detectable by Western blot. Conclusion We have successfully established a TAP system that over-expresses functional PKR, providing a useful tool for the future study on the identification of PKR interacting proteins.