Objective To explore the effects of intraventricular administration of insulin on the expressions of Bcl-2,Bax mRNA and neuronal hippocampus apoptosis in rats after cardiopulmonary resuscitation (CPR).Methods This experiment was implemented in the animal Laboratory center of Xuanwu Hospital of Capital Medical University.Thirty male SD rats were randomly (random number)divided into three groups:control group (n=6),CPR group (n=12),insulin treated group ( n =12).CPR was performed at 6 minutes after ventricular fibrillation induced by transesophageal overdrive pacing.Resuscitation procedures lasted until restoration of spontaneous circulation (ROSC).ROSC was defined as the recovery of the supraventricular heart rates and the increase of mean arterial pressure (MAP) ＞ 60mmHg for more than 10 minutes.Ten minutes after ROSC in rats,12.5 μL ( 1 U) regular insulin was injected into the left ventricle in the insulin group,and 12.5 μL isotonic saline was injected the control and CPR groups at least 10 minutes.Real-time PCR was used to observe the expressions of Bcl-2,Bax mRNA in hippocampus CAI after reperfusion 24 h and 72 h.TUNEL staining was used to observe the neuronal apoptosis in all groups after reperfusion 7 days.Blood glucose was monitored in rats before and after CPR.Results ① The Bcl-2mRNA in insulin groups were significantly higher than those in the CPR group after 24 h and 72 h (P ＜0.01 ).The expression of Bcl-2 mRNA in 24 h insulin group were significantly higher than those in 72 h insulin group ( P ＜ 0.01 ) ; There were no significantly different in the Bax mRNA between insulin groups and the CPR and the control group after 24 h and 72 h ( P ＞ 0.05 ) ; ②After CPR 7 d,the apoptotic neurons of hippocampal CA1 area in the CPR group ( 124.75 ± 17.35 ) were significantly higher than those in the control group (5.12 ± 3.26) ( P ＜ 0.01 ) and the insulin group (92.79 ± 7.35 )(P ＜0.01 ); the apoptotic neurons in the insulin group were higher than those in the control group (P ＜0.0l ),and the differences were statistically significant.③There were no significant difference in venous blood glucose in the CPR and insulin groups (P ＞ 0.05).Conclusions Insulin may regulate Bcl-2mRNA expression in hippocampus,inhibit neuronal apoptosis and protect neurons after CPR in rats.

Objective To compare the stability of multi-rod structures with double-headed screws and traditional connectors in posterior three-column osteotomy of the spine using finite element analysis.Methods A finite element model of the T3-L4 thoracolumbar spine was constructed based on postoperative computed tomography(CT)data of patients with severe kyphosis.Based on the patient's standard two-rod model(2R),a double-headed screw multi-rod structure model(4R-DHS)and a traditional connector multi-rod structure model(4R-TC)were constructed.The two models were evaluated under 300 N follower load and 7.5 N-m moment load,and the stability,maximum von Mises stresses on the main rods,and stress distributions of the two multi-rod structures were analyzed.Results There was little difference in the stability between the two multi-rod structures.Compared with 4R-TC,4R-DHS showed a decrease in the maximum von Mises stresses on the main rods during all motions(the stress decreased by 7.2％,8.8％,8.7％,18.5％,and 16.9％during flexion,left lateral bending,right lateral bending,left axial rotation,and right axial rotation,respectively)and more uniform stress distribution,except for a slight increase in the maximum von Mises stresses on the main rods during post-extension.Conclusions The double-headed screw multi-rod structure can reduce the maximum stress on the main rod compared with the traditional connector multi-rod structure,and there is no problem with stress concentration on the main rod near the connector,which can more effectively reduce the risk of internal fixation failure.