[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.

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.

[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.

[CT assisted morphological study of lumbar endplate].

OBJECTIVE: To study and measure the anatomic structure of lumbar vertebral endplate structure in healthy adults by computed tomography(CT) technique in order to provide a useful guidance for the optimal design and clinical application of lumbar prostheses. METHODS: Sixty healthy adults (male and female equals) were recruited for full-waist CT scan after signing the informed consent form in the imaging department of the Second Affiliated Hospital of Xi'an Jiaotong University. The scanning data was imported into the computer aided software Mimics 16.0 for 3D reconstruction and measurement. The acquisition indexes included median sagittal diameter, maximum coronal diameter, concavity depth, median sagittal depression angle, coronal depression angle and so on. Finally, the collected data were statistically analyzed by the statistical software. RESULTS: The median sagittal diameter and the maximum coronal diameter of the upper and lower endplates were not only different between the different sexes(P<0.05), but also were increased with the increase of the lumbar spine sequence. The concavity depth of upper and lower endplates had no gender differences(P>0.05), but had a little change from L1 to L5, fluctuating from 1.5 to 2.0 mm and from 2.2 to 3.9 mm, respectively. In the same sequence, the concavity depth of lower endplate in males was greater than that of upper endplate, and the difference was statistically significant(P<0.05), but there was no significant difference in the concavity depth of upper and lower endplate in females(P>0.05). Sagittal concavity angle and coronal concavity angle of upper and lower endplates changed slightly with the increase of vertebral order, and there was no gender difference in sagittal and coronal concavity angle of most vertebral sequences (P>0.05). Statistics showed that the largest concavity near the caudal lumbar endplate was located on the dorsal side of the endplate plane. CONCLUSIONS: The anatomical structure of the lumbar endplate is very complicated. It is important to master the anatomical parameters of the endplate and make full use of CT before operation for the development and clinical application of the lumbar prosthesis.

[Validity study of Coda Motion Analysis System for measuring cervical lateral flexion in normal adults].

OBJECTIVE: To investigate the validity of Coda Motion Analysis System for measuring cervical lateral flexion in normal adults in order to explore a new measuring tool for clinical and research practice. METHODS: A total of 43 participants were involved in the study. Cervical range of lateral flexion were measured with Coda Motion Analysis System and "gold standard" X-ray simultaneously. The validity and agreement were assessed using the scatter diagram, the Pearson correlation coefficient and limits of agreement. RESULTS: Cervical range of lateral flexion measured by Coda Motion Analysis System had no statistical differences with those measured by X-ray(P>0.05). The Coda Motion Analysis System demonstrated a very good linear relation with the X-ray measurements in cervical range of right lateral flexion, left flexion and total lateral flexion, and the Pearson correlation coefficients were 0.72, 0.85 and 0.90 respectively. CONCLUSIONS: Coda Motion Analysis System showed good validity for measuring cervical lateral flexion in normal adults. Because the reliability of Coda Motion Analysis System was established previously, the results of this study suggest that the system has the potential to be used to measure cervical lateral flexion in clinical and research practice.

[Comparison of the effect of navigation template assisted spinal pedicle fixation and traditional pedicle screw fixation:a Meta-analysis].

OBJECTIVE: To systematically evaluate the efficacy of rapid prototyping drill navigation template-assisted pedicle screw fixation and traditional anatomic landmark-based fixation in the treatment of spinal disease by accessing and searching some relevant literatures home and abroad. METHODS: Randomized Controlled Trials (RCTs) and prospective case-control studies or retrospective case-control studies about rapid prototyping drill templates-assisted pedicle screw fixation and traditional anatomic landmark-based fixation for the treatment of spinal disease were searched electronically in PubMed, The Cochrane Library(Issue 5, 2017), Clinical Trial, Google Scholar, Web of Science, CNKI, Wanfang database and VIP database before June 2017. According to the inclusion and exclusion criteria, two researchers independently screened the literatures, and extracted the data. The methodological quality of randomized controlled trials were evaluated by the Cochrane Handbook, and prospective case-control studies and retrospective case-control studies were evaluated by the NOS scale. The outcomes were analyzed using RevMan 5.3 software provided by the Cochrane information management system. RESULTS: A total of 7 articles were included, including 2 RCTs, 1 prospective case-control study and 4 retrospective case-control studies. A total of 237 patients were implanted with 1 688 pedicle screws, including 898 screws in the navigation template group, 790 screws in the conventional method group. Meta-analysis results showed that there was significant difference in the excellent rate of screw implantation between navigation template group and conventional method group [OR=5.05, 95% CI(3.13, 8.16), P<0.000 01], there was significant difference in operative time, intraoperative blood loss for thoracolumbar surgery [WMD=-27.19, 95% CI(-38.21, -16.17), P<0.000 01; WMD=-100.82, 95% CI(-182.26, -19.37), P=0.02]. CONCLUSIONS: Compared with traditional pedicle screw fixation, navigation template spine pedicle screw fixation has better clinical effect, which can improve the excellent rate of screw placement, reduce the operation time and intraoperative bleeding.

[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.

[CT assisted goat lumbar vertebrae anatomical measurement and comparison with human lumbar vertebrae].

OBJECTIVE: To study the anatomical measurement of goat lumbar vertebrae and to compare with human lumbar vertebrae, so as to build the foundation for establishing animal models of lumbar prosthesis. METHODS: The anatomical parameters of the vertebral body, pedicle and intervertebral disc in the fresh lumbar vertebrae of Boer goat and the lumbar vertebrae of healthy adults were collected by computer aided software Mimics16.0, and the anatomical characteristics of the two lumbar vertebrae were compared with the statistical software. RESULTS: The anterior vertebral body height(VBHa) of goat lumbar was less than the middle vertebral body height(VBHm), which was less than the posterior vertebral body height(VBHp), and the maximum values were (38.7±2.9), (40.1±2.6) and (40.7±2.7) mm respectively. Its endplate width was greater than its depth, with the whole shaped like a heart or a kidney. The cranial endplate of goats was convex while the caudal endplate was depressed and the depression was small, with a maximum value of (1.6±0.6) mm. The pedicle height of goats increased from L11 to L̀ with the maximum of (30.5±1.9) mm; its pedicle width and angle increased firstly and then decreased with the increase of vertebra level and the minimum values were (6.7±0.4) mm and(45.9±2.6)° respectively. The anterior intervertebral disc height was larger than the middle which was larger than the posterior and all varied slightly with the changes of intervertebral spaces; the height and width of intervertebral foramen separately waved at (12.9±0.3) to (14.3±1.0) mm and (5.7±1.0) to (6.7±0.9) mm. The comparative results showed that the vertebral body height, pedicle height and angle of goats were greater than those of humans (P<0.05) while the width and depth of the endplate, the intervertebral disc height, and etc. were significantly smaller than those of humans (P<0.05). In addition, some structures, such as the height of pedicle and intervertebral disc, also showed different changing laws with the increase of vertebra level. CONCLUSIONS: Although there are similarities in goat lumbar spine in some aspects, such as endplate and foramen foramen, there are still many differences in many aspects. Understanding the anatomical characteristics of goat lumbar vertebrae and the difference between goat and human is of great guiding significance for the research of goat prosthesis and related technology.

[Depressant effect of Lithium on apoptosis of nerve cells of adult rats after spinal cord injury].

OBJECTIVE: To study whether lithium agent produces neuroprotective effect by inhibiting the nerve cell apoptosis of rats after spinal cord injury. METHODS: Forty-two male SD rats weighing 200 to 250 g were randomly divided into 3 groups: blank control group(n=6) without surgery, normal saline(NS) group(n=18) with intraperitoneal injection of NS (40 mg/kg); and Lithium chloride (Licl) group (n=18) with intraperitoneal injection of Licl (40 mg/kg). After Allen method modeling, Licl group started intraperitoneal injection of Licl solution (40 mg·kg⁻¹·d⁻¹) within 15 min after operation to the second week. NS group, during the same interval, was injected with a same amount of NS. Postoperative 3, 7, 14 d, BBB scores in each group were measured;the expression of Bcl-2 and Bax protein were observed by immunohistochemisty staining;TUNEL staining was used to observe the nerve cell apoptosis. RESULTS: The BBB scores in blank control group were 21. Postoperative 7, 14 d, BBB scores of Licl group were higher than that of NS group(P<0.05). As for the Bcl-2 protein expression, black control group has a level of 0.081±0.003;7 d and 14 d postoperatively, the level in Licl group was 0.151±0.003, 0.163±0.003 and in NS group, 0.143±0.003, 0.154±0.002, respectively. Licl group showed significantly increased Bcl-2 protein expression(P<0.05). As for the Bax protein expression, black control group showed a level of 0.071±0.003; 7 d and 14 d postoperatively, the level in Licl group was 0.121±0.002, 0.106±0.002 and in NS group was 0.126±0.001, 0.120±0.002, respectively. The Bax protein expression is significantly inhibited in the Licl group(P<0.05). In nerve cell apoptosis by TUNEL staining, the positive cells were fewer in the black control group with apoptosis index (AI) of 1.98±0.19;while 7d and 14d postoperatively, the AI of Licl group was 13.12±0.69, 4.29±1.00 and of NS group, 18.26±0.87, 5.48±0.70, respectively. Licl group showed significant inhibition of the cell apoptosis(P<0.05). CONCLUSIONS: Licl can promote the Bcl-2 protein expression and inhibit the Bax proteins expression in nerve cells of rat after SCI, thereby playing a role in the inhibition of nerve cell apoptosis. This may be one of the mechanisms that Licl can promote the recovery of motor function of rats after SCI.

[Clinical effects of high frequency repeated transcranial magnetic stimulation therapy on dyskinesia in patients with incomplete spinal cord injury:a Meta-analysis].

OBJECTIVE: To systematically evaluate the clinical effect of high frequency repeated transcranial magnetic stimulation(HF rTMS)therapy on dyskinesia in patients with incomplete spinal cord injury. METHODS: Randomized controlled trials(RCTs) about HF rTMS therapy on patients with motor incomplete spinal cord injury were searched electronically in PubMed, Google scholar, Cochrane library, Clinical trial, Medline, Web of science, CNKI, VIP, and Wanfang database before October 2016. Two reviewers independently screened the literatures according to the inclusion and exclusion criteria, as well as extracted the data and assessed the methodological quality. The observed outcomes included ASIA motor score, ASIA lower extremities motor score(LEMS), Modified Ashworth score (MAS), Ten-meter walking test (10MWT) and Walking index for SCI II(WISCI II), and the outcomes were analyzed using RevMan5.2 software provided by the Cochrane information management system. RESULTS: Five RCTs involved 103 patients were included, and 61 patients(experimental group) accepted real rTMS and physical rehabilitation care for SCI, 51 patients(control group) accepted only physical rehabilitation care. There were significant differences in ASIA motor score, LEMS and 10MWT between two groups after HF rTMS therapy (statistics were Z=2.96, P=0.003; Z=3.04, P=0.002; Z=2.16, P=0.03; respectively). When stimulating the leg motor cortex, there was significant difference in MAS between two groups(Z=2.79, P=0.005), and when stimulating the vertex, there was no significant difference(Z=0.09, P=0.93). There was no significant difference in WISCI IIscore after HF rTMS therapy between two groups(Z=0.90, P=0.37). CONCLUSIONS: HF rTMS can raise motor score in patients with incomplete spinal cord injury, improve the spasticity of the lower extremities, and increase the motor ability.

[Development and application of artificial vertebral body].

Artificial vertebral body has achieved good results in treating spinal tumors, tuberculosis, fracture and other diseases. Currently, artificial vertebral body with variety of kinds and pros and cons, is generally divided into two types: fusion type and movable type. The former according to whether the height could be adjusted and strength of self-stability is divided into three types: support-fixed type, adjust-fixed type and self-fixed type. Whether the height of self-fixed type could be adjusted is dependent on structure of collar thread rotation. The latter is due to mobile device of ball-and-socket joints or hollow structures instead of the disc which retains the activity of the spine to some extent. Materials of artificial vertebral body include metals, ceramics, biomaterials, polymer composites and other materials. Titanium with a dominant role in the metal has developed to the third generation, but there are still defects such as poor surface bioactivity; ceramics with the representative of hydroxyapatite composite, magnetic bioceramics, polycrystalline alumina ceramics and so on, which have the defects of processing complex and uneven mechanical properties; biological material is mainly dominated by xenogeneic bone, which is closest to human bone in structure and properties, but has defects of low toughness and complex production; polymer composites according to biological characteristics in general consists of biodegradable type and non-biodegradable type which are respectively represented by poly-lactide and polyethylene, each with advantages and disadvantages. Although the design and materials of prosthesis have made great progress, it is difficult to fully meet requirements of spinal implants and they need be further optimized. 3D printing technology makes process of the complex structure of prosthesis and individual customization possible and has broad development prospects. However, long production cycles and high cost of defect should be overcome. Although artificial vertebral body has achieved curative effect in treating spinal disease, there were reports of implant loosening or displacement. Combining with evaluation standards not unified, short follow-up time, its exact effect needs further observation.

[Meta analysis of clinical effects between intramedullary nail and volar plate internal fixation for distal radius fractures].

OBJECTIVE: To evaluate curative effects of intramedullary nail and volar plate internal fixation for distal radius fractures. METHODS: The studies concerning about randomized controlled trial of intramedullary nail and volar plate internal fixation for distal radius fractures from create database to May, 2016 were searched from PubMed, Cochrane Library, Web of Science, CNKI, Wan Fang data and VIP. Information was screen and taken out according to inclusion and exclusion criteria, quality of literature was evaluated according to Cochrane Handbook evaluating system. Meta analysis was performed by RevMan 5.2 software. Postoperative grip strength, clinical effects(results of flexion and extension, pronation, supination, deflection of ulnar and radialis) , imaging evaluation (ulnar variance, radial height, volar tilting angle and radial inclination) and the incidence of postoperative complications were analyzed. RESULTS: Totally 6 RCT including 370 patients were chosen. According to the Meta analysis, there were no statistical differences in extension[MD=5.63, 95%CI(-7.01, 18.27), P=0.38], flexion[MD=3.10, 95%CI(-0.67, 6.86), P=0.11], pronation[MD=2.58, 95%CI(-0.49, 5.65), P=0.10], supination[MD=0.82, 95%CI(-1.89, 3.54), P=0.55], radial deviation[MD=-5.16, 95%CI(-14.42, 4.11), P=0.28], ulnar deviation[MD=0.19, 95%CI(-2.39, 2.77), P=0.88], ulnar variance[MD=-0.01, 95%CI(-0.43, 0.42), P=0.97], ulnar inclination[MD=-0.31, 95%CI(-1.37, 0.73), P=0.56], radial height[MD=-0.27, 95%CI(-0.98, 0.44), P=0.45], radial inclination[MD=0.29, 95%CI(-0.41, 0.99), P=0.42] and the incidence of postoperative complications[RR=0.71, 95%CI(0.46, 1.09), P=0.12] between intramedullary nail and volar plate internal fixation. CONCLUSIONS: Compared with volar plate internal fixation, intramedullary nail has the same effect in grip strength, clinical effect, but could not reduce the occurrence of postoperative complications. However, a large number of prospective randomized controlled study should be carried out to prove clinical effect of intramedullary nail for distal radius fractures.

Gossypium barbadense genome sequence provides insight into the evolution of extra-long staple fiber and specialized metabolites.

Of the two cultivated species of allopolyploid cotton, Gossypium barbadense produces extra-long fibers for the production of superior textiles. We sequenced its genome (AD)2 and performed a comparative analysis. We identified three bursts of retrotransposons from 20 million years ago (Mya) and a genome-wide uneven pseudogenization peak at 11-20 Mya, which likely contributed to genomic divergences. Among the 2,483 genes preferentially expressed in fiber, a cell elongation regulator, PRE1, is strikingly At biased and fiber specific, echoing the A-genome origin of spinnable fiber. The expansion of the PRE members implies a genetic factor that underlies fiber elongation. Mature cotton fiber consists of nearly pure cellulose. G. barbadense and G. hirsutum contain 29 and 30 cellulose synthase (CesA) genes, respectively; whereas most of these genes (>25) are expressed in fiber, genes for secondary cell wall biosynthesis exhibited a delayed and higher degree of up-regulation in G. barbadense compared with G. hirsutum, conferring an extended elongation stage and highly active secondary wall deposition during extra-long fiber development. The rapid diversification of sesquiterpene synthase genes in the gossypol pathway exemplifies the chemical diversity of lineage-specific secondary metabolites. The G. barbadense genome advances our understanding of allopolyploidy, which will help improve cotton fiber quality.