1.Comparison of finger photoplethysmogram and cerebral state index for monitoring depth of anaesthesia
Lieliang ZHANG ; Fuzhou HUA ; Jun YING ; Jing ZHANG ; Bin ZHOU ; Zhenzhong LUO ; Yanhui HU ; Guohai XU
The Journal of Practical Medicine 2015;(19):3178-3181
Objective To explore the similarities and differences between finger photoplethysmogram (PPG) and CSI in monitoring the depth of anaesthesia in Chinese adults under general anaesthesia. Methods Ninety-three patients, ASA ⅠorⅡ, aged 20-67, under general anaesthesia were enrolled. Anaesthesia was induced with target-controlled infusion (TCI) of propofol. The initial TCI concentration of propofol was set at 0.5 mg·L-1 followed by increments of 0.5 mg·L-1 at 3-min interval until the score of Modified Observer's Assessment of Alertness/Sedation Scale (MOAAS)reached 0. PPG and CSI were continuously monitored and their values were recorded every 2-4 seconds. MOAAS was recorded every 30 seconds to evaluate the sedation level in the study period. ResultsFor the periodfrom pre-induction to pre-intubation, the difference of photoplethysmogram amplitudevalues had statistical significance between level 4 and level 3, level 3 and level 2 of MOAAS (P<0.05). CSIvalues declined along with the decrease of MOAAS levels and were statistically different between every two neighboring levels of MOAAS (P < 0.05). Photoplethysmogram amplitude (PPGA) and pulse beat interval (PBI) values showed significant differences before and after intubation, pre- and post-incision (P < 0.05). Conclusions PPGA and PBI appear to be suitable to monitor the nociceptive component of balanced general anesthesia , while the CSI exhibits a good performance in monitoring the sedation or hypnotic component of balanced general anesthesia , thusthe combination of PPGA and CSI would benefit the monitoring of the adequacy of depth of anaesthesia.
2.Saikosaponin A attenuates cognitive function via cAMP/CREB signaling pathway in mice after traumatic brain inj ury
Lieliang ZHANG ; Jun YING ; Fuzhou HUA ; Zhidong ZHOU ; Yanhui HU ; Zhenzhong LUO ; Guohai XU
The Journal of Clinical Anesthesiology 2016;32(5):484-487
Objective To investigate the effects of Saikosaponin A (SSA)on cognitive function and cAMP/CREB signaling pathway and expression of BDNF in mice after traumatic brain injury. Methods Sixty SD male mice were randomized into three groups:shame operation group (group S, n =20),trauma group (group T,n =20)and SSA treatment group (group A,n =20).Mice received an administration of SSA 5 mg/kg (group A)or equal volume saline (group S,group T)immediately and once daily for 5 consecutive days after trauma.The cognitive function was detected by Morris wa-ter maze test on day 1,3,7 and 14 after trauma.The hippocampal tissues were harvested after be-havioral tests and homogenized for measuring the levels of brain derived neurophic factor (BDNF)and cyclic AMP (cAMP)by ELISA as well as the levels of cAMP-response element binding protein (CREB)and phosphorylation-cAMP-response element binding protein (pCREB)by western bolt. Results Compared with group S,the escape latency and swimming distance were significantly pro-longed in group T on day 1,3,7 and 14 and group A on day 1,3 after trauma (P <0.05 );while compared with group T,they were significantly shorter in group A on day 7,14 after trauma (P <0.05).Compared with group S,the levels of BDNF,cAMP,CREB and pCREB were significantly de-creased in group T(P < 0.05 ).Compared with group T,the levels of BDNF,cAMP,CREB and pCREB were significantly increased in group A (P <0.05).Conclusion SSA can significantly improve cognitive dysfunction in mice after traumatic brain injury,and the mechanism may be related to the activation of cAMP/CREB signaling pathway and up-regulation of BDNF.
3.Finite element analysis of different fixation methods of partially threaded cannulated screws for treating vertical femoral neck fractures
Nengxian TAN ; Wenzheng WU ; Churong ZHENG ; Lieliang LUO ; Peng GU ; Chongzhi OUYANG ; Xiaohui ZHENG
Chinese Journal of Tissue Engineering Research 2024;28(6):873-878
BACKGROUND:The more vertical the femoral neck fracture line,the more shear force the femoral neck fracture may bear,so it may be prone to internal fixation failure,nonunion,or necrosis of the femoral head.At present,there is controversy as to which hollow nail fixation mode is ideal. OBJECTIVE:To evaluate different configurations and numbers of cannulated screw configurations to learn more about the biomechanical differences in vertical fractures of the femoral neck using finite element analysis. METHODS:Femoral CT data were collected from a 24-year-old healthy male volunteer and imported into Mimics software to build a three-dimensional geometric model of the femur.Model refinement and surface fitting processing were carried out in Geomagic software and imported into SolidWorks software to establish a vertical fracture model of the femoral neck.Six cannulated screw models were established,including three triangle configuration,three inverted triangle configuration,three double-plane double-support configuration(F scheme),three transverse configuration,four diamond configuration and four Alpha configuration.The peak stress,strain and displacement of internal fixation and femoral fracture models under different loads(350,700,1 400,and 2 100 N)were compared among different configurations. RESULTS AND CONCLUSION:(1)Under four kinds of loads,screw stress conditions were as follows:biplanar double-supported configuration(F scheme)>transverse configuration>inverted triangle configuration>positive triangular configuration>Alpha configuration>rhombus configuration.The peak value of Von mises stress was concentrated in the screw close to the fracture line.(2)Under four kinds of loads,the screw displacement was Alpha configuration>inverted triangle configuration>positive triangular configuration>biplanar double-supported configuration(F scheme)>rhombus configuration>transverse configuration,and the peak displacement was mainly concentrated on the hollow screw head.(3)Under four kinds of loads,the stress conditions of the proximal femoral bone block were biplanar double-supported configuration(F scheme)>transverse configuration>inverted triangle configuration>Alpha configuration>positive triangular configuration>rhombus configuration,and the stress peak mainly concentrated in the lower neck of femur.(4)Under 350 N load,the displacement of the proximal femur bone block was transverse configuration>biplanar double-supported configuration(F scheme)>positive triangular configuration>Alpha configuration>inverted triangle configuration>rhombus configuration.In the other three loads,the peak displacement of the inverted triangle configuration was smaller than that of the rhombus configuration.The peak displacement was mainly concentrated in the head.(5)The rhombus configuration was the most dispersed in the stress distribution of the proximal femoral bone.The rhombus configuration was the smallest in the peak displacement of the femur.The stress,displacement and peak displacement of the fracture end of each internal fixed model increased gradually with the increase of load.(6)The biomechanical performance of the four diamond-shaped models in the internal fixation of vertical femoral neck fractures is better than that of other groups of models.The four rhomboid models have stable fixation,small displacement value of fracture end and dispersed stress,which can help resist shear force and prevent varus collapse and create a good mechanical environment for fracture healing.