Epidural electrical stimulation can restore limb motor function after spinal cord injury by reactivating the surviving neural circuits.In previous epidural electrical stimulation studies,single electrode sites and con...Epidural electrical stimulation can restore limb motor function after spinal cord injury by reactivating the surviving neural circuits.In previous epidural electrical stimulation studies,single electrode sites and continuous tetanic stimulation have often been used.With this stimulation,the body is prone to declines in tolerance and locomotion coordination.In the present study,rat models of complete spinal cord injury were established by vertically cutting the spinal cord at the T8 level to eliminate disturbance from residual nerve fibers,and were then subjected to epidural electrical stimulation.The flexible extradural electrode had good anatomical topology and matched the shape of the spinal canal of the implanted segment.Simultaneously,the electrode stimulation site was able to be accurately applied to the L2–3 and S1 segments of the spinal cord.To evaluate the biocompatibility of the implanted epidural electrical stimulation electrodes,GFAP/Iba-1 doublelabeled immunofluorescence staining was performed on the spinal cord below the electrodes at 7 days after the electrode implantation.Immunofluorescence results revealed no significant differences in the numbers or morphologies of microglia and astrocytes in the spinal cord after electrode implantation,and there was no activated Iba-1~+cell aggregation,indicating that the implant did not cause an inflammatory response in the spinal cord.Rat gait analysis showed that,at 3 days after surgery,gait became coordinated in rats with spinal cord injury under burst stimulation.The regained locomotion could clearly distinguish the support phase and the swing phase and dynamically adjust with the frequency of stimulus distribution.To evaluate the matching degree between the flexible epidural electrode(including three stimulation contacts),vertebral morphology,and the level of the epidural site of the stimulation electrode,micro-CT was used to scan the thoracolumbar vertebrae of rats before and after electrode implantation.Based on the experimental results of gait recovery using three-site stimulation electrodes at L2–3 and S1 combined with burst stimulation in a rat model of spinal cord injury,epidural electrical stimulation is a promising protocol that needs to be further explored.This study was approved by the Animal Ethics Committee of Chinese PLA General Hospital(approval No.2019-X15-39)on April 19,2019.展开更多
Previous studies have reported age-specific pathological and functional outcomes in young and aged patients suffering spinal cord injury,but the mechanisms remain poorly understood. In this study, we examined mice wit...Previous studies have reported age-specific pathological and functional outcomes in young and aged patients suffering spinal cord injury,but the mechanisms remain poorly understood. In this study, we examined mice with spinal cord injury. Gene expression profiles from the Gene Expression Omnibus database （accession number GSE93561） were used, including spinal cord samples from 3 young injured mice （2–3-months old, induced by Impactor at Th9 level） and 3 control mice （2–3-months old, no treatment）, as well as 2 aged injured mice （15–18-months old, induced by Impactor at Th9 level） and 2 control mice （15–18-months old, no treatment）. Differentially expressed genes （DEGs） in spinal cord tissue from injured and control mice were identified using the Linear Models for Microarray data method,with a threshold of adjusted P 〈 0.05 and ｜logFC（fold change）｜ 〉 1.5. Protein–protein interaction networks were constructed using data from the STRING database, followed by module analysis by Cytoscape software to screen crucial genes. Kyoto encyclopedia of genes and genomes pathway and Gene Ontology enrichment analyses were performed to investigate the underlying functions of DEGs using Database for Annotation, Visualization and Integrated Discovery. Consequently, 1,604 and 1,153 DEGs were identified between injured and normal control mice in spinal cord tissue of aged and young mice, respectively. Furthermore, a Venn diagram showed that 960 DEGs were shared among aged and young mice, while 644 and 193 DEGs were specific to aged and young mice, respectively. Functional enrichment indicates that shared DEGs are involved in osteoclast differentiation, extracellular matrix–receptor interaction, nuclear factor-kappa B signaling pathway, and focal adhesion. Unique genes for aged and young injured groups were involved in the cell cycle （upregulation of PLK1） and complement （upregulation of C3） activation, respectively. These findings were confirmed by functional analysis of genes in modules （common, 4; aged, 2; young, 1） screened from protein–protein interaction networks. Accordingly, cell cycle and complement inhibitors may be specific treatments for spinal cord injury in aged and young mice, respectively.展开更多
Background：The treatment for long bone defects has been a hot topic in the field of regenerative medicine.This study aimed to evaluate the therapeutic effects of calcium sulfate （CS） combined with platelet-rich pla...Background：The treatment for long bone defects has been a hot topic in the field of regenerative medicine.This study aimed to evaluate the therapeutic effects of calcium sulfate （CS） combined with platelet-rich plasma （PRP） on long bone defect restoration.Methods：A radial bone defect model was constructed through an osteotomy using New Zealand rabbits.The rabbits were randomly divided into four groups （n =10 in each group）：a CS combined with PRP （CS-PRP） group,a CS group,a PRP group,and a positive （recombinant human bone morphogenetic protein-2） control group.PRP was prepared from autologous blood using a two-step centrifugation process.CS-PRP was obtained by mixing hemihydrate CS with PRP.Radiographs and histologic micrographs were generated.The percentage of bone regenerated bone area in each rabbit was calculated at 10 weeks.One-way analysis of variance was performed in this study.Results：The radiographs and histologic micrographs showed bone restoration in the CS-PRP and positive control groups,while nonunion was observed in the CS and PRP groups.The percentages of bone regenerated bone area in the CS-PRP （84.60 ± 2.87%） and positive control （52.21 ± 4.53%） groups were significantly greater than those in the CS group （12.34 ± 2.17%） and PRP group （16.52 ± 4.22%） （P 〈 0.001）.In addition,the bone strength of CS-PRP group （43.l 0 ± 4.10%） was significantly greater than that of the CS group （20.10 ± 3.70%） or PRP group （25.10 ± 2.10%） （P 〈 0.001）.Conclusion：CS-PRP functions as an effective treatment for long bone defects through stimulating bone regeneration and enhancing new bone strength.展开更多
基金supported by the National Natural Science Foundation of China,Nos.81601052(to XRJ),81520108017(to PFT)the Beijing Nova Program of Science and Technology of China,No.2018034(to XRJ)+1 种基金the Beijing Municipal Science and Technology Project of China,No.D16100002816005(to PFT)the Subsidiary of PLA Major Project of China,No.AWS17J004(to PFT)。
文摘Epidural electrical stimulation can restore limb motor function after spinal cord injury by reactivating the surviving neural circuits.In previous epidural electrical stimulation studies,single electrode sites and continuous tetanic stimulation have often been used.With this stimulation,the body is prone to declines in tolerance and locomotion coordination.In the present study,rat models of complete spinal cord injury were established by vertically cutting the spinal cord at the T8 level to eliminate disturbance from residual nerve fibers,and were then subjected to epidural electrical stimulation.The flexible extradural electrode had good anatomical topology and matched the shape of the spinal canal of the implanted segment.Simultaneously,the electrode stimulation site was able to be accurately applied to the L2–3 and S1 segments of the spinal cord.To evaluate the biocompatibility of the implanted epidural electrical stimulation electrodes,GFAP/Iba-1 doublelabeled immunofluorescence staining was performed on the spinal cord below the electrodes at 7 days after the electrode implantation.Immunofluorescence results revealed no significant differences in the numbers or morphologies of microglia and astrocytes in the spinal cord after electrode implantation,and there was no activated Iba-1~+cell aggregation,indicating that the implant did not cause an inflammatory response in the spinal cord.Rat gait analysis showed that,at 3 days after surgery,gait became coordinated in rats with spinal cord injury under burst stimulation.The regained locomotion could clearly distinguish the support phase and the swing phase and dynamically adjust with the frequency of stimulus distribution.To evaluate the matching degree between the flexible epidural electrode(including three stimulation contacts),vertebral morphology,and the level of the epidural site of the stimulation electrode,micro-CT was used to scan the thoracolumbar vertebrae of rats before and after electrode implantation.Based on the experimental results of gait recovery using three-site stimulation electrodes at L2–3 and S1 combined with burst stimulation in a rat model of spinal cord injury,epidural electrical stimulation is a promising protocol that needs to be further explored.This study was approved by the Animal Ethics Committee of Chinese PLA General Hospital(approval No.2019-X15-39)on April 19,2019.
基金supported by the National Science Fund for Distinguished Young Scientists of China,No.81601052
文摘Previous studies have reported age-specific pathological and functional outcomes in young and aged patients suffering spinal cord injury,but the mechanisms remain poorly understood. In this study, we examined mice with spinal cord injury. Gene expression profiles from the Gene Expression Omnibus database （accession number GSE93561） were used, including spinal cord samples from 3 young injured mice （2–3-months old, induced by Impactor at Th9 level） and 3 control mice （2–3-months old, no treatment）, as well as 2 aged injured mice （15–18-months old, induced by Impactor at Th9 level） and 2 control mice （15–18-months old, no treatment）. Differentially expressed genes （DEGs） in spinal cord tissue from injured and control mice were identified using the Linear Models for Microarray data method,with a threshold of adjusted P 〈 0.05 and ｜logFC（fold change）｜ 〉 1.5. Protein–protein interaction networks were constructed using data from the STRING database, followed by module analysis by Cytoscape software to screen crucial genes. Kyoto encyclopedia of genes and genomes pathway and Gene Ontology enrichment analyses were performed to investigate the underlying functions of DEGs using Database for Annotation, Visualization and Integrated Discovery. Consequently, 1,604 and 1,153 DEGs were identified between injured and normal control mice in spinal cord tissue of aged and young mice, respectively. Furthermore, a Venn diagram showed that 960 DEGs were shared among aged and young mice, while 644 and 193 DEGs were specific to aged and young mice, respectively. Functional enrichment indicates that shared DEGs are involved in osteoclast differentiation, extracellular matrix–receptor interaction, nuclear factor-kappa B signaling pathway, and focal adhesion. Unique genes for aged and young injured groups were involved in the cell cycle （upregulation of PLK1） and complement （upregulation of C3） activation, respectively. These findings were confirmed by functional analysis of genes in modules （common, 4; aged, 2; young, 1） screened from protein–protein interaction networks. Accordingly, cell cycle and complement inhibitors may be specific treatments for spinal cord injury in aged and young mice, respectively.
文摘Background：The treatment for long bone defects has been a hot topic in the field of regenerative medicine.This study aimed to evaluate the therapeutic effects of calcium sulfate （CS） combined with platelet-rich plasma （PRP） on long bone defect restoration.Methods：A radial bone defect model was constructed through an osteotomy using New Zealand rabbits.The rabbits were randomly divided into four groups （n =10 in each group）：a CS combined with PRP （CS-PRP） group,a CS group,a PRP group,and a positive （recombinant human bone morphogenetic protein-2） control group.PRP was prepared from autologous blood using a two-step centrifugation process.CS-PRP was obtained by mixing hemihydrate CS with PRP.Radiographs and histologic micrographs were generated.The percentage of bone regenerated bone area in each rabbit was calculated at 10 weeks.One-way analysis of variance was performed in this study.Results：The radiographs and histologic micrographs showed bone restoration in the CS-PRP and positive control groups,while nonunion was observed in the CS and PRP groups.The percentages of bone regenerated bone area in the CS-PRP （84.60 ± 2.87%） and positive control （52.21 ± 4.53%） groups were significantly greater than those in the CS group （12.34 ± 2.17%） and PRP group （16.52 ± 4.22%） （P 〈 0.001）.In addition,the bone strength of CS-PRP group （43.l 0 ± 4.10%） was significantly greater than that of the CS group （20.10 ± 3.70%） or PRP group （25.10 ± 2.10%） （P 〈 0.001）.Conclusion：CS-PRP functions as an effective treatment for long bone defects through stimulating bone regeneration and enhancing new bone strength.
