Objective To investigate roles of superoxide dismutase-1(SOD1),phosphatidylinositol 3-kinase (PI3K) /serine/ threonine protein kinase (AKT) signal transduction pathway in protection of propofol on spinal cord ischemic reperfusion injury (SCIRI) in rabbit model before and after ischemia. Methods Sixty Japanese male rabbits were randomly divided into 3 groups (n=20),namely sham-operation group (Group S),ischemia-reperfusion group (Group I/ R) and ischemia-reperfusion group with propofol treatment (Group P). Abdominal aorta of the rabbits in group I/ R and group P were blocked by clamp for 40 min and then the clamp was removed. Propofol (30 mg·kg-1 ) was intravenously infused 10 min before blocking the aorta and at the time of reperfusion. Normal saline was intravenously infused at the same time points in the other two groups. Four rabbits of each group were randomly executed 1,2,3,5,7 days after surgery. Spinal cord tissues at L3-L4 levles were harvested. Bioactivity of SOD1 was detected by ELISA and mRNA expression levels of SOD1,PI3K and AKT were detected by RT-PCR. Results On the 1st day after the surgery,the bioactivity of SOD1 increased significantly in Group I/ R and Group P as compared with that in Group S (P<0. 05). On the 2nd day,compared with Group S,the bioactivity of SOD1 increased significantly in Group P (P<0. 05),but there was no change in Group I/ R (P>0. 05). On the 3rd,the 5th and the 7th day,compared with Group S,the bioactivity of SOD1 decreased significantly in Group I/ R (P<0. 05),but there was no change in Group P (P>0. 05). Linear regression analysis indicated that there was a positive correlation between the changes of SOD1 activity and the mRNA expression of SOD1,PI3K and AKT respectively in spinal cord tissues. Conclusion Pre- and post-ischemic conditioning with propofol shows potent protective effects against SCIRI in the rabbit model. The mechanisms may be related to increased expression of SOD1 in the spinal cord tissues by activating PI3K/ AKT signal transduction pathway.

Objective To systematically review the influence of propofol orsevoflurane on postoperative cognitive dysfunction(POCD) in elderly patients undergoing non-cardiac surgery.Methods Eight databases including Cochrane Database of Systematic Reviews, MEDLINE, EMBASE, Pubmed, CNKI, VIP, CBM and Wanfang Database were searched for randomized controlled trials (RCT) about the influence of propofol orsevoflurane on POCD in elderly patients from the time of database establishment to June, 2016.At the same time, the reference materials of included literature were retrieved manually.All data were selected and evaluated by three independent reviewers according to the inclusion and exclusion criterions.RevMan 5.1 was used for the data analysis.Results A total 14 trials were discovered involving 790 elderly patients undergoing non-cardiac surgery.The results of Meta-analysis showed that the eye opening time and extubation time in the propofol group were significant shorter than sevoflurane group[SMDeye opening=-0.83,95%CI(-1.05,-0.61),P<0.05;SMDextubation=-0.85,95%CI(-1.09,-0.62),P<0.05].The MMSE scores at 1,3 and 6 h respectivelyafter the operation were obviously higher than those of sevoflurane group[SMD1h =0.84,95%CI(0.61,1.08),P<0.05;SMD3 h=1.12,95%CI(0.86,1.38),P<0.05;SMD6h=0.61,95%CI(0.40,0.82),P<0.05].One day after the operation,the difference was not significant[SMD1d=0.14,95%CI(-0.03,0.31),P>0.05].Three days after the operation, the values returned to normal levels, and was still higher in propofol group than in sevoflurane group[SMD3d=-0.32,95%CI(-0.56,-0.07),P<0.05] until 7 d [SMD7d=-0.18,95%CI(-0.51,0.15),P>0.05].The odds ratio of POCD incidence between propofol and sevoflurane groups was 0.35 [95%CI(0.21,0.58),P<0.05].Conclusion Propofol may lead to shorter eye opening time and extubation time compared to sevoflurane in elderly patients undergoing non-cardiac surgery.Both groups may lead to POCD, while propofol is a better choice for elderly patients when choosing general anesthesia.

Objective To observe the clinical effect of ropivacaine erector spinae plane block assisting general anesthesia in lumbar spine surgery. Methods A total of 60 cases of male patients with selective lumbar spine surgery under general anesthesia were chosen and randomly divided into control group(group C) and erector spinae plane block group(group E) (n= 30).Group C was directly treated with total intravenous anesthesia.In group E,the erector spinae were blocked with 0.375%ropivacaine before skin incision.The patient's vital signs during operative period were recorded,as well as the operation time, anesthesia time,drug dosage and satisfaction of muscle relaxation.Postoperative VAS scores at 4,8,24 and 48 h were recorded. Remedied analgesic drug use,the number of PCIA press,complications such as nausea and vomiting,patients' satisfaction degree within 48 h of postoperative were all recorded. Results There were no statistical difference in the vital signs,operation section, operation time,anesthesia time and postoperative complications(all P>0.05) in two groups. Compared with group C,the dosage of propofol,rifentanyl and benzene sulfonate in group E were significantly reduced.In group C and group E,dosage of propofol was(1 526.2±134.5) mg and(1 305.8±212.8) mg;dosage of remifentanil was(2 452.2±232.5) μg and(2 076.8±311.6) μg; dosage of benzene sulfonate was(31.8±4.2) mg and (22.3±5.1) mg]( P<0.05 or P<0.01).Satisfaction of muscle relaxation in the operation area of group E was significantly increased(P<0.05).The VAS scores at 4 h and 8 h after operation in group E were all significantly reduced(P<0.01).In group E,the frequency(or total) of remediation analgesic drugs usage and PCIA compressions times were significantly reduced in 48 h after surgery(P<0.01).The satisfaction degree of the patients in group E was significantly increased(P<0.01). Conclusion Ropivacaine erector spinae plane block assisting general anesthesia in lumbar spine surgery can reduce perioperative general anesthesia drug dosage,the number of postoperative remediation of analgesic drugs,PCIA compressions times,and can improve satisfaction of operative doctors and patients with anesthesia.

Objective To investigate the effects of remote ischemic preconditioning(RIPC)on the expression of brain-derived neurotrophic factor(BDNF),Serine/threonine protein kinase Cε(PKCε)in spinal cord tissues and change in mRNA content after spinal cord ischemic reperfusion injury(SCIRI). Methods A total of 36 cases of Japanese white rabbits were randomly divided into sham(group S),is-chemic reperfusion injury(group IR)and group IR+ RIPC(12 rabbits in each group).Each group was further divided into two sub-groups according to time points after reperfusion(2 and 5 days),six rabbits of each group were sacrificed at each time point.In group S,abdominal aorta were only separated and ex-posed and were not camped.In group IR and group IR+RIPC,the abdominal aorta were camped for 30 min,and the SCIRI models were established.In group IR+RIPC,RIPC was performed 1 h before aortic calmping.Hind-limb neurological function of each group was evaluated using Tarlov Scale at 2,5 d after surgery,then rabbits were sacrificed,and L4-L6 spinal cord segments were taken.Pathological change in spinal cord tissues were observed,the protein and mRNA expression of BDNF and PKCε were detected by Western blotting analysis and PT-PCR.Results In comparison with group IR,hind-limb neurologic func-tion scores at the same time point were significantly higher(P<0.05),and the protein and mRNA expres-sion of BDNF and PKCε were significant increased in group IR+RIPC(P<0.05).Conclusion RIPC has an important role in prevention and treatment of SCIRI in rabbits.The mechanisms may be that RIPC activates the PKCε/PKC signaling pathway and up-regulates the expression of BDNF and PKCε in spinal cord tissues after spinal cord injury.

Objective:To compare the clinical effects of dexmedetomidine assisted lumbar plexus nerve block and propofol-remifentanil general anesthesia in the patients aged over 70 years undergoing total hip replacement. Methods:Totally 58 patients(≥70 years old) with selective total hip replacement were divided into dexmedetomidine assisted lumbar plexus nerve block group(group A,28 cases) and propofol-remifentanil general anesthesia group (group B,30 cases) according to the time order of operation. The perioperative stability of respiratory and circulatory,postoperative recovery,anesthesia complications in 24 h after the surgery and anes-thesia satisfaction were evaluated and compared between the groups. Results:The vital signs of group A during the operation had no significant difference among each time point(P>0.05). There was statistical signification in blood pressure and heart rate before and after the anesthesia induction and the tracheal intubation in group B(P<0.05). Perioperative cardiovascular drug use in group B was significantly more than that in group A(P<0.01). Totally 20 cases in group A were directly sent back to the ward after the operation, another 8 cases was in anesthesia recovery room for 0.5~1-hour observation. Totally 12 cases with postoperative controlled breathing in group B were directly sent back to the intensive care unit,another 7 cases pulled out the endotracheal tube and were sent back to the intensive care unit and another 11 cases were observed in anesthesia recovery room for 1-2 h. The occurrence of postoperative cognitive dysfunction in group B was significantly higher than that in group A(P<0.05),while the anesthesia satisfaction was extremely lower than that in group A(P<0.01). Conclusion:For the patients aged over 70 years undergoing total hip replacement,dexmedetomidine at moderate dose assisted lumbar plexus nerve block is more ideal anesthesia.

Objective To propose a deep learning-based retinal image quality classification network, FA-Net,to make convolutional neural network ( CNN) more suitable for image quality assessment in eye disease screening system. Methods The main network of FA-Net was composed of VGG-19. On this basis,attention mechanism was added to the CNN. By using transfer learning method in training, the weight of ImageNet was used to initialize the network. The attention net is based on foreground extraction by extracting the blood vessel and suspected regions of lesion and assigning higher weights to region of interest to enhance the learning of these important areas. Results Total of 2894 fundus images were used for training FA-Net. FA-Net achieved 97. 65％ classification accuracy on a test set containing 2170 fundus images,with the sensitivity and specificity of 0. 978 and 0. 960,respectively,and the area under curve(AUC) was 0. 995. Conclusions Compared with other CNNs,the proposed FA-Net has better classification performance and can evaluate retinal fundus image quality more accurately and efficiently. The network takes into account the human visual system ( HVS) and human attention mechanism. By adding attention module into the VGG-19 network structure, the classification results can be better interpreted as well as better classification performance.

Objective:To evaluate the efficiency of ResNet50-OC model based on deep learning for multiple classification of color fundus photographs.Methods:The proprietary dataset (PD) collected in July 2018 in BenQ Hospital of Nanjing Medical University and EyePACS dataset were included.The included images were classified into five types of high quality, underexposure, overexposure, blurred edges and lens flare according to clinical ophthalmologists.There were 1 000 images (800 from EyePACS and 200 from PD) for each type in the training dataset and 500 images (400 from EyePACS and 100 from PD) for each type in the testing dataset.There were 5 000 images in the training dataset and 2 500 images in the testing dataset.All images were normalized and augmented.The transfer learning method was used to initialize the parameters of the network model, on the basis of which the current mainstream deep learning classification networks (VGG, Inception-resnet-v2, ResNet, DenseNet) were compared.The optimal network ResNet50 with best accuracy and Micro F1 value was selected as the main network of the classification model in this study.In the training process, the One-Cycle strategy was introduced to accelerate the model convergence speed to obtain the optimal model ResNet50-OC.ResNet50-OC was applied to multi-class classification of fundus image quality.The accuracy and Micro F1 value of multi-classification of color fundus photographs by ResNet50 and ResNet50-OC were evaluated.Results:The multi-classification accuracy and Micro F1 values of color fundus photographs of ResNet50 were significantly higher than those of VGG, Inception-resnet-v2, ResNet34 and DenseNet.The accuracy of multi-classification of fundus photographs in the ResNet50-OC model was 98.77% after 15 rounds of training, which was higher than 98.76% of the ResNet50 model after 50 rounds of training.The Micro F1 value of multi-classification of retinal images in ResNet50-OC model was 98.78% after 15 rounds of training, which was the same as that of ResNet50 model after 50 rounds of training.Conclusions:The proposed ResNet50-OC model can be accurate and effective in the multi-classification of color fundus photograph quality.One-Cycle strategy can reduce the frequency of training and improve the classification efficiency.