miR-145a-5p/Plexin-A2 promotes the migration of OECs and transplantation of miR-145a-5p engineered OECs enhances the functional recovery in rats with SCI.

BACKGROUND: Olfactory ensheathing cells (OECs) serve as a bridge by migrating at the site of spinal cord injury (SCI) to facilitate the repair of the neural structure and neural function. However, OEC migration at the injury site not only faces the complex and disordered internal environment but also is closely associated with the migration ability of OECs. METHODS: We extracted OECs from the olfactory bulb of SD rats aged <7 days old. We verified the micro ribonucleic acid (miR)-145a-5p expression level in the gene chip after SCI and OEC transplantation using quantitative reverse transcription (qRT)-polymerase chain reaction (PCR). The possible target gene Plexin-A2 of miR-145a-5p was screened using bioinformatics and was verified using dual-luciferase reporter assay, Western blot, and qRT-PCR. The effect of miR-145a-5p/plexin-A2 on OEC migration ability was verified by wound healing assay, Transwell cell migration assay, and immunohistochemistry. Nerve repair was observed at the injured site of the spinal cord after OEC transplantation using tissue immunofluorescence and magnetic resonance imaging, diffusion tensor imaging, and the Basso-Beattie-Bresnahan locomotor rating scale were further used for imaging and functional evaluation. RESULTS: miR-145a-5p expression in the injured spinal cord tissue after SCI considerably decreased, while Plexin-A2 expression significantly increased. OEC transplantation can reverse miR-145a-5p and Plexin-A2 expression after SCI. miR-145a-5p overexpression enhanced the intrinsic migration ability of OECs. As a target gene of miR-145a-5p, Plexin-A2 hinders OEC migration. OEC transplantation overexpressing miR-145a-5p after SCI can increase miR-145a-5p levels in the spinal cord, reduce Plexin-A2 expression in the OECs and the spinal cord tissue, and promote OEC migration and distribution at the injured site. OEC transplantation overexpressing miR-145a-5p can promote the repair of neural morphology and neural function. CONCLUSIONS: Our study demonstrated that miR-145a-5p could promote OEC migration by down-regulating the target gene Plexin-A2, and transplantation of miR-145a-5p engineered OECs was beneficial to enhance neural structural and functional recovery in SCI rats.

The let-7f-5p-Nme4 pathway mediates tumor necrosis factor α-induced impairment in osteogenesis of bone marrow-derived mesenchymal stem cells.

Although tumor necrosis factor α (TNF-α)-mediated inflammation significantly impacts osteoporosis, the mechanisms underlying the osteogenic differentiation defects of bone marrow-derived mesenchymal stem cells (BM-MSCs) caused by TNF-α remain poorly understood. We found that TNF-α stimulation of murine BM-MSCs significantly upregulated the expression levels of several microRNAs (miRNAs), including let-7f-5p, but this increase was significantly reversed by treatment with the kinase inhibitor BAY 11-7082. To study gain- or loss of function, we transfected cells with an miRNA inhibitor or miRNA mimic. We then demonstrated that let-7f-5p impaired osteogenic differentiation of BM-MSCs in the absence and presence of TNF-α, as evidenced by alkaline phosphatase and alizarin red staining as well as quantitative assays of the mRNA levels of bone formation marker genes in differentiated BM-MSCs. Moreover, let-7f-5p targets the 3' untranslated region of Nucleoside diphosphate kinase 4 (Nme4) mRNA and negatively regulates Nme4 expression in mouse BM-MSCs. Ectopic expression of Nme4 completely reversed the inhibitory effects of the let-7f-5p mimic on osteogenic differentiation of mouse BM-MSCs. Furthermore, inhibition of let-7f-5p or overexpression of Nme4 in BM-MSCs restored in-vivo bone formation in an ovariectomized animal model. Collectively, our work indicates that let-7f-5p is involved in TNF-α-mediated reduction of BM-MSC osteogenesis via targeting Nme4.

miR-99b-3p is induced by vitamin D3 and contributes to its antiproliferative effects in gastric cancer cells by targeting HoxD3.

Vitamin D3 is known to have anticancer actions by affecting tumorigenesis including the cell cycle and cell apoptosis in gastric cancer (GC) cells; the genes including microRNAs (miRNAs) regulated by vitamin D3 signaling remain discovered. miR-99b-3p, the tumor suppressor gene, is not only decreased in GC tissues, but is also induced by vitamin D3 through the vitamin D receptor (VDR) binding on the promoter domain of miR-99b. Further study indicates that miR-99b-3p inhibits cell viability and induces cell arrest in the S-phase in GC cells, the direct target gene of miR-99b-3p is verified to be HoxD3, which is also overexpressed in GC cell lines. Overall, our results show that miR-99b-3p mediates the antiproliferative of vitamin D3 in GC cells and might hold promise for prognosis and therapeutic strategies for GC treatment.

Effect of Dome-Shaped Titanium Mesh Cages on Cervical Endplate Under Cyclic Loading: An In Vitro Biomechanics Study.

BACKGROUND This study aimed to verify the anti-subsidence ability of dome-shaped titanium mesh cage (TMC) used in anterior cervical corpectomy and fusion (ACCF). MATERIAL AND METHODS Thirty fresh human cervical vertebrae specimens were collected and randomly harvested into 2 groups: the traditional TMC group and the dome-shaped TMC group. The bone mineral density (BMD) of the specimens was recorded. Each group was biomechanically tested in axial compression with a cyclically loading range from 60 to 300 N at 0.5Hz for 10 000 cycles. The displacement data of the 2 groups were recorded every 10 cycles. RESULTS There was no significant difference in bone mineral density between the 2 groups of cervical specimens. The traditional TMC group stabilized at 535±35 cycles while the dome-shaped TMC group stabilized at 1203±57 cycles, which showed that the rate of subsidence of the dome-shaped TMC group was significantly slower than that of the traditional TMC group (p<0.05). After reaching stability, both groups had a more gradual and sustained growth. The peak displacement during fatigue testing was -2.064±0.150mm in the traditional TMC group and -0.934±0.086mm in the dome-shaped TMC group, which showed a significant difference (p<0.05). CONCLUSIONS The dome-shaped TMC showed a smaller subsidence displacement and a gentler subsidence tendency following the same cyclic loading (compared to the traditional TMC). From a biomechanical point of view, the dome-shaped TMC has stronger anti-subsidence ability due to its unique structural design that closely matches the vertebral endplate.

Prognostic Factors and Treatment Options for Patients with High-Grade Chondrosarcoma.

BACKGROUND The goal of this study was to determine the prognostic factors exclusive for high-grade chondrosarcoma and whether adjuvant radiotherapy could achieve better overall survival (OS) or cancer-specific survival (CSS) for patients with high-grade chondrosarcoma. MATERIAL AND METHODS Surveillance, Epidemiology, and End Results (SEER) cancer registry database was utilized to extract the chondrosarcoma cases diagnosed between 1973 and 2014. Among these cases, the histological grades of poorly differentiated (grade 3) and undifferentiated (grade 4) were categorized as high-grade and included in this study. Chondrosarcoma OS and CSS were the primary outcomes in the present study. The log-rank test was performed for univariate analysis, and the Cox regression model was conducted for multivariate analysis. RESULTS A total of 743 patients with high-grade chondrosarcoma were identified in this study (430 cases were poorly differentiated tumors, and 313 cases were undifferentiated tumors). Age at diagnosis, pathological grade, histo-type, SEER stage, tumor size and surgical resection were identified as independent predictors in both OS and CSS analysis of high-grade chondrosarcoma. When stratified by histological grade, surgical resection remained the effective treatment. Strikingly, radiotherapy was determined as an independent protective factor in both OS and CSS analysis of undifferentiated (grade 4) dedifferentiated chondrosarcoma, and adjuvant radiotherapy combined surgical resection could improve both the OS and CSS of patients with undifferentiated myxoid and dedifferentiated chondrosarcoma compared with other treatment regimens. CONCLUSIONS Our study first demonstrated that adjuvant radiotherapy combined surgery could improve the survival of patients with undifferentiated myxoid and dedifferentiated chondrosarcoma. These results encourage the application of adjuvant radiotherapy for patients with high-grade chondrosarcoma and maximize the patients' outcome.

Initial stability of one-stage anterior debridement and cage implantation combined with anterior-lateral fixation by a dual screw-rod construct in the treatment of lumbosacral tuberculosis: a cadaveric biomechanical study.

BACKGROUND: Although various surgical methods are used to treat lumbosacral tuberculosis, no unified surgical approach exists. Thus, exploring an optimal operation method has substantial clinical importance. Evaluate the initial stability of a new surgical method, a one-stage anterior debridement and cage implantation combined with anterior-lateral fixation by a dual screw-rod construct, in the treatment of lumbosacral tuberculosis and provide biomechanical support for its further promotion in clinical applications. METHODS: Fifteen fresh human lumbosacral spine specimens without fractures, deformities or osteoporosis were randomly divided into intact (I), anterior fixation (AF) and posterior fixation (PF) groups. All AF and PF group specimens had subtotal resections of the L5 vertebra and adjacent discs, while the I group specimens were kept intact. Then, titanium cages were implanted in the surgical site and a dual screw-rod construct was fixed anterior-laterally in the AF group, while the PF group specimens were fixed posteriorly with only the dual screw-rod construct. Mechanical tests were conducted for initial stability evaluations. RESULTS: The load at the maximum displacement (5 mm) or rotation angle (5 °) was less for the I group specimens than for the AF and PF group specimens in all directions (P < 0.05). The load at the maximum displacement (5 mm) was greater for the AF group specimens than for the PF group specimens in flexion, lateral bending and axial compression (P < 0.05) and lower than in the PF group specimens in extension (P < 0.05). In torsion, there was no difference between the loads in the AF and PF groups at the maximum rotation angle (5 °) (P > 0.05). CONCLUSIONS: The proposed surgical approach can provide better immediate stability than anterior debridement with posterior dual screw-rod fixation in the treatment of lumbosacral tuberculosis in flexion, lateral bending and axial compression.

Design and preliminary biomechanical analysis of a novel motion preservation device for lumbar spinal disease after vertebral corpectomy.

OBJECTIVE: To design a novel prosthesis, a movable artificial lumbar complex (MALC), for non-fusion reconstruction after lumbar subtotal corpectomy and to evaluate the stability, range of motion and load-bearing strength in the human cadaveric lumbar spine. METHODS: Biomechanical tests were performed on lumbar spine specimens from 15 healthy cadavers which were divided in three groups: non-fusion, fusion and intact group. The range of motion (ROM), stability and load-bearing strength were measured. RESULTS: The prosthesis was composed of three parts: the upper and lower artificial lumbar discs and the middle artificial vertebra. Both the MALC and titanium mesh cage re-established vertebral height, and no spinal cord compression or prosthesis dislocation was observed at the operative level. Regarding stability, there was no significant difference in all directions between the intact group and non-fusion group (P > 0.05). Segment movements of the specimens in the non-fusion group revealed significantly decreased T12-L1 ROM and significantly increased L1-2 and L2-3 ROM in flexion/extension and lateral bending compared with those in the fusion group (P < 0.05). Regarding load-bearing strength, when the lumbar vertebra was ruptured, there was no damage to the MALC and titanium mesh cage, but the maximum load in the non-fusion group was larger (P > 0.05). CONCLUSIONS: Compared with titanium cages, the MALC prosthesis not only restored the vertebral height and effectively preserved segment movements without any abnormal gain of mobility in adjacent inter-vertebral spaces but also bore the lumbar load and reduced the local stress load of adjacent vertebral endplates.

Metformin Protects Against Spinal Cord Injury by Regulating Autophagy via the mTOR Signaling Pathway.

Spinal cord injury (SCI) is a serious central trauma, leading to severe dysfunction of motor and sensory systems. Secondary injuries, such as apoptosis and cell autophagy, significantly impact the motor function recovery process. Metformin is a widely used oral anti-diabetic agent for type 2 diabetes in the world. It has been demonstrated to promote autophagy and inhibit apoptosis in the nervous system. However, its role in recovery following SCI is still unknown. In this study, we determined that motor function, assessed using the Basso, Beattie, and Bresnahan (BBB) locomotor assessment scale, was significantly higher in rats treated with metformin following injury. Nissl staining revealed that metformin also increased the number of surviving neurons in the spinal cord lesion. Western blot and immunofluorescent analysis revealed that mammalian target of rapamycin (mTOR) and P70S6 kinase (P70S6K) decreased, while the expression of autophagy markers increased and apoptosis markers declined in animals treated with metformin following SCI. Taken together, these findings suggest that metformin functions as a neuroprotective agent following SCI by promoting autophagy and inhibiting apoptosis by regulating the mTOR/P70S6K signaling pathway.

Anterior Cervical Corpectomy and Fusion and Anterior Cervical Discectomy and Fusion Using Titanium Mesh Cages for Treatment of Degenerative Cervical Pathologies: A Literature Review.

Anterior cervical corpectomy and fusion (ACCF) and anterior cervical discectomy and fusion (ACDF) are 2 effective and safe surgical treatments of degenerative cervical pathologies and are associated with a high percentage of excellent clinical outcomes when a graft or device must be used during the surgery, such as an allograft, autograft, nano-hydroxyapatite/polyamide cages, poly-ether-ether-ketone (PEEK) cages, and titanium mesh cages (TMCs). Although TMCs have been used in cervical surgeries for almost 2 decades, no specific reviews have been performed introducing the state of this material. Thus, in the present review, we discuss the status of using TMCs in anterior cervical surgeries. Studies that tested the usage of TMCs in treating degenerative cervical pathologies were included in this review. The development and progress of TMCs, the biomechanical analysis of TMCs, the radiological and clinical assessment of TMCs, the advantages and disadvantages of using TMCs, and their prospects for future applications as a device of ACCF and ACDF in treating degenerative cervical pathologies are discussed. Studies included in this review showed that TMCs can provide sufficient biomechanical stability. Furthermore, the TMCs used in anterior cervical fusion avoid the donor-site morbidity and achieve a solid bony fusion. However, there are some shortcomings. The structural characteristics and the design of TMCs cause the TMC subsidence rate to remain high, thus resulting in multiple related complications. We believe that due to the virtues of TMCs, they are worthy of application and promotion. However, the structure of TMCs should be further optimized to reduce the TMC subsidence rate and subsidence-related complications, ultimately achieving excellent clinical results.

Marital Status and Survival of Patients with Chondrosarcoma: A Population-Based Analysis.

BACKGROUND Previous studies have shown that differences in marital status contribute to different prognoses for certain cancers, but the relationship between marital status and the prognosis of chondrosarcoma has not been reported previously. MATERIAL AND METHODS In this study, we selected 4502 eligible cases through the Surveillance, Epidemiology, and End Results (SEER) database from 1977 to 2014 to analyze the impact of marital status on chondrosarcoma cancer-specific survival (CSS) by Kaplan-Meier method and Cox regression model. RESULTS The sex, age, histotype, pathological grade, tumor location, tumor size, SEER stage, socioeconomic status, marital status, and treatment were identified as independent prognostic factors for chondrosarcoma CSS. Widowed patients presented the worst CSS compared with their married, divorced, and single counterparts (P<0.001). Subgroup analyses showed widowed patients also had a significantly higher risk of cancer-specific mortality compared with married patients in localized stage (HR: 1.971, 95% CI: 1.298-2.994, P=0.001), regional stage (HR: 1.535, 95% CI: 1.094-2.154, P=0.013), low pathological grade (HR: 1.866, 95% CI: 1.332-2.613, P<0.001), and high pathological grade (HR: 1.662, 95% CI: 1.139-2.426, P=0.008). CONCLUSIONS Marital status was first identified as an independent prognostic factor for chondrosarcoma CSS, and widowhood was always associated with a high risk of cancer-specific mortality. It is necessary to provide timely psychological treatment for widowed patients in clinical practice, which can improve the survival of chondrosarcoma patients.

Evaluation of Renal Function in Children with Congenital Scoliosis and Congenital Anomalies of the Kidney and Urinary Tract.

BACKGROUND The aim of this study was to compare renal function in children with congenital scoliosis and congenital anomalies of the kidney and urinary tract, with healthy children. MATERIAL AND METHODS Biochemical tests were performed before surgery (pre-therapy) and after surgery (post-therapy) in 16 children with congenital scoliosis and congenital anomalies of the kidney and urinary tract. Thirty-two healthy children were matched for age, sex, and weight (healthy controls). General renal function tests included serum electrolytes, creatinine, urea, cystatin C, and estimated glomerular filtration rate (eGFR). Tests for early renal changes included N-acetyl-beta-D-glucosaminidase (NAG), urine microalbumin, serum transferrin, immunoglobulin G (IgG), urinary alpha-1-microglobulin (A1M), and beta-2-microglobulin (B2M). RESULTS Sixteen patients with congenital anomalies of the kidney and urinary tract included eight boys (mean age, 11.38±2.00 years) and eight girls (mean age, 11.00±2.78 years). There were no significant differences in renal function between the pre-therapy and post-therapy groups (P>0.05), or between the three groups (pre-therapy, post-therapy, and healthy controls). In the pre-therapy group, there were significant differences in IgG, A1M, NAG, and serum phosphate levels between boys and girls, urine microalbumin was significantly increased in girls, but not boys (P<0.05). There were no significant differences between the pre-therapy group and post-therapy group (P>0.05). CONCLUSIONS Routine tests of renal function were normal in children with congenital scoliosis and congenital anomalies of the kidney and urinary tract, but early changes in renal function occurred before surgical treatment, indicating long-term follow-up of renal function is recommended.

Feasibility of Diffusion Tensor Imaging for Assessing Functional Recovery in Rats with Olfactory Ensheathing Cell Transplantation After Contusive Spinal Cord Injury (SCI).

BACKGROUND Olfactory ensheathing cell transplantation is a promising treatment for spinal cord injury. Diffusion tensor imaging has been applied to assess various kinds of spinal cord injury. However, it has rarely been used to evaluate the beneficial effects of olfactory ensheathing cell transplantation. This study aimed to explore the feasibility of diffusion tensor imaging in the evaluation of functional recovery in rats with olfactory ensheathing cell transplantation after contusive spinal cord injury. MATERIAL AND METHODS Immunofluorescence staining was performed to determine the purity of olfactory ensheathing cells. Rats received cell transplantation at week 1 after injury. Basso, Beattie, and Bresnahan score was used to assess the functional recovery. Magnetic resonance imaging was applied weekly, including diffusion tensor imaging. Diffusion tensor tractography was reconstructed to visualize the repair process. RESULTS The results showed that olfactory ensheathing cell transplantation increased the functional and histological recovery and restrained the secondary injury process after the initial spinal cord injury. The fractional anisotropy values in rats with cell transplantation were significantly higher than those in the control group, while the apparent diffusion coefficient values were significantly lower. Basso, Beattie, and Bresnahan score was positively and linearly correlated with fractional anisotropy value, and it was negatively and linearly correlated with apparent diffusion coefficient value. CONCLUSIONS These findings suggest that diffusion tensor imaging parameters are sensitive biomarker indices for olfactory ensheathing cell transplantation interventions, and diffusion tensor imaging scan can reflect the functional recovery promoted by the olfactory ensheathing cell transplantation after contusive spinal cord injury.

Lumbar subtotal corpectomy non-fusion model produced using a novel prosthesis.

OBJECTIVE: In this study, we aimed to design a movable artificial lumbar complex (MALC) prosthesis for non-fusion reconstruction after lumbar subtotal corpectomy and to establish an in vitro anterolateral lumbar corpectomy non-fusion model for evaluating the biomechanical stability, preservation of segment movements and influence on adjacent inter-vertebral movements of this prosthesis. METHODS: Imaging was performed on a total of 26 fresh goat lumbar spine specimens to determine which of the specimens did not meet the requirements (free of deformity and fractures); the residual specimens were randomly divided into an intact group, a fusion group and a non-fusion group. Bone mineral density (BMD) was tested and compared among the three groups. Biomechanical testing was conducted to obtain the range of motion (ROM) in flexion-extension, lateral bending at L2-3, L3-4 and L4-5 and axial rotation at L2-5 in the three groups. RESULTS: Two specimens were excluded due to vertebral fractures. BMD showed no statistical significance among three groups (P > 0.05). The stability of the prosthesis did not differ significantly during flexion, extension, and lateral bending at L2-3, L3-4, and L4-5 and axial torsion at L2-5 between the intact group and the non-fusion group (P > 0.05). Segment movements of the specimens in the non-fusion group revealed significantly decreased L2-3 ROM and significantly increased L3-4 and L4-5 ROM in flexion and lateral bending compared with the fusion group (P < 0.05). CONCLUSIONS: Reconstruction with a MALC prosthesis after lumbar subtotal corpectomy not only produced instant stability but also effectively preserved segment movements, without any abnormal gain of mobility in adjacent inter-vertebral spaces. However, additional studies, including in vivo animal experiments as well as biocompatibility and biomechanical tests of human body specimens are needed.

Integrated analysis identifies cuproptosis-related gene DLAT and its competing endogenous RNAs network to predict the prognosis of pancreatic adenocarcinoma patients.

Pancreatic adenocarcinoma (PAAD) is a highly malignant tumor with poor prognosis. However, the relationship between cuproptosis-related genes (CRGs) and its competing endogenous RNA (ceRNA) network with the prognosis of PAAD patients remains unclear. To investigate this relationship, we calculated the difference in CRGs between PAAD tissues and normal tissues using the 'limma' R package. Additionally, we employed least absolute shrinkage and selection operator (LASSO) Cox regression analysis to construct a prognostic signature for CRGs. Survival analysis of patients with PAAD was performed using Kaplan-Meier analysis. Furthermore, we used bioinformatics tools to screen for CRGs-related MicroRNA (miRNA) and lncRNAs. To validate these findings, we conducted real-time quantitative polymerase chain reaction (RT-qPCR), CCK-8, colony formation, and Transwell assays to assess the effect of DLAT in vitro. Our results revealed a cuproptosis-related prognostic signature consisting of 3 prognostic genes (DLAT, LIAS, and LIPT1). Notably, patients with a high-risk score for the CRGs signature exhibited poor prognosis in terms of overall survival (OS) (P < .05). The receiver operating characteristic (ROC) curve was used to evaluate the prognostic signature of CRGs. The results showed that the 1-year, 3-year, and 5-year area under the curve values for predicting OS were 0.62, 0.66, and 0.79, respectively. Additionally, the CRGs-related ceRNA network revealed the regulatory axis of LINC00857/has-miR-1179/DLAT in PAAD. In vitro experiments demonstrated that knockdown of LINC00857 and DLAT inhibited the growth and invasion of PAAD cells. This study identified a CRG-related prognostic signature consisting of 3 biomarkers (DLAT, LIAS, and LIPT1) for PAAD. Furthermore, ceRNA network analysis suggested the involvement of the LINC00857/has-miR-1179/DLAT axis in the development of PAAD. Overall, this study provides theoretical support for the investigation of diagnostic and prognostic biomarkers as well as potential therapeutic targets in PAAD.

[Advances in olfactory ensheathing cells for the treatment of spinal cord injury].

Spinal cord injury is a highly disabled neurological disease, and there is still a lack of effective treatments. Studies have proved that olfactory ensheathing cells are one of the ideal seed cells for promoting nerve regeneration after spinal cord injury. Olfactory ensheathing cells can promote axonal germination and elongation through secretion, interaction with astrocytes, regulation of inflammatory reaction, migration characteristics, myelination, anti-oxidation, lipid regulation and other channels. Thus olfactory ensheathing cells play the role of neuroprotection and nerve repair. In recent years, some studies have used bioengineering, tissue engineering, reprogramming and other technologies to enhance the efficacy of olfactoryensheathing cells from different aspects, thereby providing new therapeutic strategies for optimizing the cell therapy of spinal cord injury. This article will summarize the mechanism of olfactory ensheathing cells in repairing spinal cord injury, and review the progress of optimizing strategy of olfactory ensheathing cells in treating spinal cord injury recently, so as to provide new research ideas for the further developing the repair potential of olfactory ensheathing cells and optimize the cell therapy effect of spinal cord injury.

Accuracy of cervical pedicle screw placement with four different designs of rapid prototyping navigation templates: a human cadaveric study.

PURPOSE: Due to the high perforation rate of cervical pedicle screw placement, we have designed four different types of rapid prototyping navigation templates to enhance the accuracy of cervical pedicle screw placement. METHODS: Fifteen human cadaveric cervical spines from C2 to C7 were randomly divided into five groups, with three specimens in each group. The diameter of pedicle screw used in this study was 3.5 mm. Groups 1-4 were assisted by the two-level template, one-level bilateral template, one-level unilateral template and one-level point-contact template, respectively. Group 5 was without any navigation template. After the surgery, the accuracy of screw placement in the five groups was evaluated using postoperative computed tomographic scans to observe whether the screw breached the pedicle cortex. RESULTS: A total of 180 pedicle screws were inserted without any accidents. The accuracy rate was 75%, 100%, 100%, 91.7%, and 63.9%, respectively, from Groups 1 to 5. All the template groups were significantly higher than Group 5, though the two-level navigation template group was significantly lower than the other three template groups. The operation time was 4.72 ± 0.28, 4.81 ± 0.29, 5.03 ± 0.35, 8.42 ± 0.36, and 10.05 ± 0.52 min, respectively, from Groups 1 to 5. The no template and point-contact procedures were significantly more time-consuming than the template procedures. CONCLUSION: This study demonstrated that four different design types of navigation templates achieved a higher accuracy in assisting cervical pedicle screw placement than no template insertion. However, the two-level template's accuracy was the lowest compared to the other three templates. Meanwhile, these templates avoided fluoroscopy during the surgery and decreased the operation time. It is always very challenging to translate cadaveric studies to clinical practice. Hence, the one-level bilateral, unilateral, and point-contact navigation templates designed by us need to be meticulously tested to verify their accuracy and safety.

Transplantation of sh-miR-199a-5p-Modified Olfactory Ensheathing Cells Promotes the Functional Recovery in Rats with Contusive Spinal Cord Injury.

MicroRNAs (miRNAs) function as gene expression switches, and participate in diverse pathophysiological processes of spinal cord injury (SCI). Olfactory ensheathing cells (OECs) can alleviate pathological injury and facilitate functional recovery after SCI. However, the mechanisms by which OECs restore function are not well understood. This study aims to determine whether silencing miR-199a-5p would enhance the beneficial effects of the OECs. In this study, we measured miR-199a-5p levels in rat spinal cords with and without injury, with and without OEC transplants. Then, we transfected OECs with the sh-miR-199a-5p lentiviral vector to reduce miR-199a-5p expression and determined the effects of these OECs in SCI rats by Basso-Beattie-Bresnahan (BBB) locomotor scores, diffusion tensor imaging (DTI), and histological methods. We used western blotting to measure protein levels of Slit1, Robo2, and srGAP2. Finally, we used the dual-luciferase reporter assay to assess the relationship between miR-199-5p and Slit1, Robo2, and srGAP2 expression. We found that SCI significantly increased miR-199a-5p levels (P < 0.05), and OEC transplants significantly reduced miR-199a-5p expression (P < 0.05). Knockdown of miR-199a-5p in OECs had a better therapeutic effect on SCI rats, indicated by higher BBB scores and fractional anisotropy values on DTI, as well as histological findings. Reducing miR-199a-5p levels in transplanted OECs markedly increased spinal cord protein levels of Slit1, Robo2, and srGAP2. Our results demonstrated that transplantation of sh-miR-199a-5p-modified OECs promoted functional recovery in SCI rats, suggesting that miR-199a-5p knockdown was more beneficial to the therapeutic effects of OEC transplants. These findings provided new insights into miRNAs-mediated therapeutic mechanisms of OECs, which helps us to develop therapeutic strategies based on miRNAs and optimize cell therapy for SCI.

Transplantation of ACE2- Mesenchymal Stem Cells Improves the Outcome of Patients with COVID-19 Pneumonia.

A coronavirus (HCoV-19) has caused the novel coronavirus disease (COVID-19) outbreak in Wuhan, China. Preventing and reversing the cytokine storm may be the key to save the patients with severe COVID-19 pneumonia. Mesenchymal stem cells (MSCs) have been shown to possess a comprehensive powerful immunomodulatory function. This study aims to investigate whether MSC transplantation improves the outcome of 7 enrolled patients with COVID-19 pneumonia in Beijing YouAn Hospital, China, from Jan 23, 2020 to Feb 16, 2020. The clinical outcomes, as well as changes of inflammatory and immune function levels and adverse effects of 7 enrolled patients were assessed for 14 days after MSC injection. MSCs could cure or significantly improve the functional outcomes of seven patients without observed adverse effects. The pulmonary function and symptoms of these seven patients were significantly improved in 2 days after MSC transplantation. Among them, two common and one severe patient were recovered and discharged in 10 days after treatment. After treatment, the peripheral lymphocytes were increased, the C-reactive protein decreased, and the overactivated cytokine-secreting immune cells CXCR3+CD4+ T cells, CXCR3+CD8+ T cells, and CXCR3+ NK cells disappeared in 3-6 days. In addition, a group of CD14+CD11c+CD11bmid regulatory DC cell population dramatically increased. Meanwhile, the level of TNF-α was significantly decreased, while IL-10 increased in MSC treatment group compared to the placebo control group. Furthermore, the gene expression profile showed MSCs were ACE2- and TMPRSS2- which indicated MSCs are free from COVID-19 infection. Thus, the intravenous transplantation of MSCs was safe and effective for treatment in patients with COVID-19 pneumonia, especially for the patients in critically severe condition.

[Cultivation, screening, identification and transplantation of Muse cell from human umbilical cord-derived for spinal cord injury in rats].

OBJECTIVE: To investigate multilineage-differentiating stress-enduring (Muse) by immunomagnetic bead screening from Wharton's jelly mesenchymal stromal cells(WJ-MSCs), and explore transplantation of Muse cell for safety and effectivensess of sub acute cord injury in rats. METHODS: Donated Wharton's Jelly-mesenchymal stromal cells (WJ-MSCs) were successfully derived from a human umbilical cord by a series of procedures namely physical isolation of Wharton's Jelly from cord membrane, collagenase and trypsin treatment and density gradient centrifugation. Magnetic activated cell sorting was performed to specifically select SSEA3+ Muse cells, and flow cytometry and immunocytochemistry were used to identify further. In vivo, spinal cord contusion injury model in rats was induced by NYU-III impactor, and were randomly divided and equally into four groups, namely group A (sham), group B (control), group C (Non-Muse cells transplantation) and group D (Muse cells transplantation). Laminectomy was conducted in group A but no spinal cord contusion injury. Laminectomy and cord injury were performed in group B, C and D, 10 g trip rod was freely falling down from 12.5 mm. Two weeks later, group B, C and D were received PBS injection, Non-Muse cells transplantation and Muse cells transplantation respectively, four-point injection were performed in each cord with totally 4×105 cells. BBB scores were evaluated on 1 day, 1, 2, 3, 4, 5 and 6 week after injury. Four weeks after cell transplantation, the rats were sacrificed, and immunohistochemistry were carried out to observe survival, migration and differentiation of the injected cells. RESULTS: The expression of CD105, CD90 and CD73 were over 99.5% in the derived WJ-MSCs population, but CD45 and CD14 were lower than 0.5%, positive rate of SSEA3+ was 1.46% under flow cytometer, However, after MACS sorting, the percentage of 92.0% Muse cells expressed SSEA3 and CD105, and immunohistochemistry results of SSEA3 showed typically membrane morphology with special processes. In vivo, BBB scores was 21 in group A at different time points. One-way ANOVA and LSD analysis showed that BBB scores in group C and D were significantly higher than that in group B (P=0.004, 0.002), but there was no significantly difference between group C and D. Further intra-group paired t test showed that BBB score was significantly higher at 4 weeks than that 3 weeks in group C (P=0.005). However, in group D, BBB scores were significantly higher at 4 and 6 week than those at 3 and 5 weeks, P values were 0.005 and 0.016 respectively. Immunohistochemistry results showed that both Muse cells and Non-Muse cells could survive for 4 weeks in rats and they migrated from the four-point injection to injury site. But there showed more Muse cells survival than Non-Muse cells in the cord. CONCLUSIONS: Immunomagnetic bead screening is efficient to select large number of purified SSEA3+ Muse cells. Muse cells could survive and target-migrate in injured cord to improve BBB scores continuously. Muse cells are a novel kind of seed cells in the spinal cord injury treatment.

[Rapid prototyping navigation template assisted cervical screw implantation:a review].

The cervical screw fixation has been used widely in the clinic setting due to the high fusion rate, immediate fixation of the surgical segment and good correction of the deformity. However, owing to the variation of anatomical structures and the narrow pedicle screws, it's rather difficult to implant the screws through traditional methods. The perforation rate of the screw is high, which can cause serious complications such as neurovascular injury. In recent years, rapid prototyping navigation templates have been reported in the appilication to assist cervical screw placement for improving the accuracy of screw placement. In this paper, we reviewed and summarized published literatures about navigation template assisted cervical screw implantation in the past 20 years, systematically introduced the methods of producing and using of navigation templates, the development of design concept and the status of application in cervical spine surgery. To date, relevant clinical and cadaveric studies confirm that the use of rapid prototyping navigation template assisted cervical screw placement in cervical surgery can reduce screw perforation rate, intraoperative ionizing radiation injury and operation time, which is worth applying in the clinical practice. However, specific clinical effects of different design types of navigation templates are not well summarized. As a result, more clinical and cadaveric studies comparing the accuracy and safety of navigation templates of different design types are needed to help clinicians select the appropriate navigation template for surgery.