Protective Effect of Extended Laminectomy on Spinal Cord Injury Induced by Spinal Shortening.

This study investigates the effect of extended laminectomy (EL) on spinal cord injury (SCI) caused by spinal shortening, and further, the timing and the optimal length of removal. Dogs received spinal column shortening at T13 segment, following which the control group underwent regular laminectomy while other groups underwent laminectomy with an additional 1-lamina length removed 6h after shortening ("1-lamina EL 6 h"), an extra 1.5-lamina length resected at 6 h or 12 h after shortening ("1.5-lamina EL 6 h" and "1.5-lamina EL 12 h"), and an extra 2-lamina length removed at 6 or 12 h after shortening ("2-lamina EL 6 h" and 2-lamina EL 12 h"), respectively. Somatosensory evoked potential (SSEP) and neurological function were recorded periodically; spinal cord blood flow (SCBF) and nerve cell apoptosis were detected. The results showed that resection of an additional 1-lamina length appeared inadequate to relieve the sharp kinking of the spinal cord, whereas the kinking disappeared with an additional 2-lamina length resection. The "1-lamina EL 6 h" and "1.5-lamina EL 12 h" groups showed no significant differences from the control in latency of SSEP, SCBF, hindlimb function and apoptosis. By contrast, significant recovery of SSEP, SCBF and hindlimb function as well as reduction of apoptosis were presented in other three groups. The "2-lamina EL 6 h" group, in particular, showed the most prominent recovery. In conclusion, an additional resection of two laminae at 6 h after shortening showed the best effect in alleviating SCI. Timely and adequately extended laminectomy could be a potential therapeutic strategy for SCI attributable to spinal shortening.

Safe range of shortening the middle thoracic spine, an experimental study in canine.

PURPOSE: To determine the safe range of shortening the spinal column at middle thoracic spine and to observe the changes in blood-spinal cord barrier (BSCB), microglia/macrophage activation and inducible nitric oxide synthase (iNOS) activity after shortening-induced spinal cord injury. METHODS: Dogs were allocated to four groups. Group A (control) underwent laminectomy of T7 without shortening the spinal column. Groups B, C and D had 1/3, 1/2, and 2/3 of T7 resected, respectively, followed by spinal shortening. Somatosensory evoked potential (SSEP) and hind-limb function were recorded periodically for 14 days after operation. Spinal cord blood flow (SCBF) and BSCB were detected at the acute phase of shortening. Microglia/macrophage reactions and iNOS activity were observed by immunohistochemistry. RESULTS: Shortening of 1/3 of a vertebral height caused no significant changes in SSEP and hind-limb function after operation, whereas shortening of 1/2 of the height caused SSEP abnormality and paraparesis, and severe neurologic deficit of hind-limb was observed when the shortening reached 2/3 of the height. SCBF increased temporarily and showed a trend of recovery when the shortening was within 1/2 of a vertebral segment height. When it reached 1/2 or 2/3 of the height, SCBF at 6 h post-operation was 86.33% or 74.95% of the baseline, and an increasing BSCB permeability was observed. In the subsequent 7 days, obvious activation of macrophage and increased number of iNOS-positive cells were observed. CONCLUSION: It is safe to shorten the spinal cord within 1/3 of a vertebral height in middle thoracic spine under two-segment laminectomy in canine. The BSCB disruption, macrophage activation, and increased iNOS activity were observed in the acute phase of the injury. These slides can be retrieved under Electronic Supplementary Material.

The hsa-miR-181a-5p reduces oxidation resistance by controlling SECISBP2 in osteoarthritis.

BACKGROUND: The phenotypes of osteoarthritis (OA) consist of cartilage extracellular matrix (ECM) metabolism disorder and the breakdown of cartilage homeostasis, which are induced by pro-inflammatory factors and oxidative stress. Selenoproteins regulated by selenocysteine insertion sequence binding protein 2 (SBP2) are highly effective antioxidants, but their regulatory mechanisms, particularly the involvement of miRNAs, are not fully understood. METHODS: To explore whether miR-181a-5p and SBP2 are involved in OA pathogenesis, we established an IL-1ß model using the chondrocyte SW1353 cell line. Next, we up- or down-regulated SBP2 and miRNA-181a-5p expression in the cells. Finally, we measured the expression of miRNA-181a-5p, SBP2 and three selenoproteins in OA cartilage and peripheral blood. RESULTS: The results showed that IL-1ß increased hsa-miR-181a-5p and decreased SBP2 in a time- and dose-dependent manner. GPX1 and GPX4, which encode crucial glutathione peroxidase antioxidant enzymes, were up-regulated along with SBP2 and miR-181a-5p. Furthermore, SBP2 showed a significant negative correlation with miR-181a-5p during induced ATDC5 cell differentiation. There was lower GPX1 and GPX4 mRNA expression and SBP2 protein expression in damaged cartilage than in smooth cartilage from the same OA sample, and hsa-miR-181a-5p expression on the contrary. Similar results were observed in peripheral blood. In conclusion, we have reported a novel pathway in which pro-inflammatory factors, miRNA, SBP2 and selenoproteins are associated with oxidation resistance in cartilage. CONCLUSION: Overall, this study provides the first comprehensive evidence that pro-inflammatory factors cause changes in the cartilage antioxidant network and describes the discovery of novel mediators of cartilage oxidative stress and OA pathophysiology. Our data suggest that miR-181a-5p may be used to develop novel early-stage diagnostic and therapeutic strategies for OA.

Management of patellar fracture with titanium cable cerclage.

Early rehabilitation after surgery for patellar fracture is challenging. The purpose of this study was to evaluate the surgical outcome of titanium cable cerclage for patellar fracture in early functional activity.We reviewed a series of 24 patients treated at our hospital with titanium cable. Functional exercises were started early. Patients were followed up for at least 12 months.Fifteen were males and 9 were females. Fracture occurred in the right knee in 13 patients and in the left knee in 11 patients. The most common mode of injury involves a tumble. None of the patients presented with any postoperative complications. The management resulted in satisfactory outcomes.Titanium cable cerclage offers a new strategy in treating patellar fracture.

Elcatonin attenuates disuse osteoporosis after fracture fixation of tubular bone in rats.

BACKGROUND: Elcatonin (ECT) is used to prevent and treat osteoporosis. However, little is known about its effect on the disuse osteoporosis (DOP). The aim of this study is to evaluate the effect of ECT on DOP caused by fracture fixation. METHODS: Forty-five male Sprague-Dawley (SD) rats, aged 6 weeks, were randomly allocated into three groups: the control group without surgery and elcatonin treatment (CTR, n = 15), the surgery group without elcatonin treatment (SUR, n = 15), and the surgery group which received elcatonin subcutaneously (SUR + ECT, n = 15). Surgery was produced by cutting the midshaft of the right femur transversely, fixing with stainless intramedullary needle, and immobilizing the right leg. All the proximal tibias from the random five rats in each group were harvested and investigated by evaluating bone mineral density (BMD), X-ray images, and histological staining respectively at the 4th, 8th, and 12th weeks after surgery. RESULTS: Both of the SUR and SUR + ECT groups obviously exhibited lower BMD values compared to the CTR group; however, the SUR + ECT group showed significantly higher BMD values (p < 0.001, p < 0.05, and p < 0.05) than the SUR group at each time point after surgery. Moreover, similar changes were observed between these groups when examining the radiographs and hematoxylin and eosin (HE) staining. CONCLUSIONS: Elcatonin attenuates disuse osteoporosis after fractures in rats, which may provide a new avenue to prevent and treat disuse osteoporosis after surgery in clinic.

A new model of tethered cord syndrome produced by slow traction.

The development of a suitable animal model is important for clarifying the pathogenesis of tethered cord syndrome (TCS). This study was undertaken to develop a new animal model for investigating the pathogenesis and therapeutic strategies for TCS. A traction device, a filum terminale tractor, was designed exclusively for this experiment. A TCS model was produced in cats using the tractor to fixate the filum terminale to the dorsal aspect of the second sacrum. The responses to tethering were evaluated by electron microscopy and electromyography for detection of somatosensory evoked potentials (SEPs) and motor evoked potentials (MEPs) at designated time points. Progressive swaying gait and lameness in clinical performance were observed with cord traction. Histopathological examination revealed an association between the increasing traction in the spinal cord and the increase in impaired nerve cells. No changes of SEPs and MEPs were detected in the untethered cats, while the latencies of SEPs and MEPs significantly increased in the tethered cats. The TCS model established in this study is simple and reproducible, in which varying degrees of tension could be applied to the neural elements.

Diastematomyelia: a 35-year experience.

STUDY DESIGN: Retrospective case series study. OBJECTIVE: This article describes our experience of the management of diastematomyelia. SUMMARY OF BACKGROUND DATA: Diastematomyelia is a rare entity, which presents distinct clinical characteristics and requires different managements compared with other more common occult spinal dysraphism. METHODS: A total of 156 patients with diastematomyelia were reviewed. All the patients underwent neurological and radiological examinations. Surgical excision of the lesion was performed for most patients and intradural exploration of the lumbar region was done to release tethering of conus in some patients. One patient died and autopsy was performed. Follow-up was carried out for all the patients, including surgical and nonsurgical approaches. RESULTS: There were 123 cases of type I diastematomyelia and 33 cases of type II diastematomyelia. The lumbar and thoracolumbar region was the most common site for diastematomyelia, and most spinal cords were split among 6 segments. The postoperative course was complicated by cerebrospinal fluid leakage in 2 patients, temporary neurological deterioration in 4 patients, and epidural hematoma in 1 patient. All cases did not have aggravation of symptoms during the follow-up of 2 to 20 years (mean of 4.5 yr). For the 123 patients with type I diastematomyelia, clinical symptoms were improved in 96 after surgical intervention and no worsening or occurrence of new clinical signs were observed during the follow-up. Those who did not receive surgery showed stabilization of neurological manifestation. Of the 33 type II cases, 9 surgical patients remained neurologically stable during the postoperative years without significant improvement in function, and 24 nonsurgical patients neither improved nor worsened in their neural deficit. CONCLUSION: Surgical treatment is the necessary management for type I diastematomyelia causing progressive neurological deterioration or with tethered filum, whereas conservative treatment is recommended to asymptomatic type I diastematomyelia and all type II diastematomyelia. LEVEL OF EVIDENCE: 5.

[Protective effect of puerarin on the secondary spinal cord injury in rats].

OBJECTIVE: To research the protective effect of puerarin on secondary spinal cord injury (SCI) in rats. METHODS: After the models of SCI were established by improved Allen's method on adult male SD rats, SOD, MDA, Bcl-2 and Bax gene protein expression between puerarin group and model group were compared after 1, 6, 12, 24 and 48 h. RESULTS: Puerarin could significantly enhance the activity of SOD and reduce the content of MDA, increase the expression of Bcl-2 gene protein products and decrease Bax gene protein product. CONCLUSIONS: Puerarin can increase the activity of SOD, reduce the content of MDA, promote the expession of Bcl-2 and restrain the expression of Bax in the early spinal cord injury. It has protective effect on the secondary spinal cord injury.

[Isolation and culture of neural stem cells in injured region of compressive spinal cord injury in adult rat].

OBJECTIVE: To investigate the division, proliferation and differentiation abilities of nestin+/GFAP+ cell after spinal cord injury and to identify whether it has the characteristic of neural stem cells (NSCs). METHODS: Twelve male SD rats, aged 8 weeks and weighing 200-250 g, were randomized into 2 groups (n=6 per group): model group in which the spinal cord injury model was established by aneurysm clip compression method, and control group in which no processing was conducted. At 5 days after modeling, T8 spinal cord segment of rats in each group were obtained and the gray and the white substance of spinal cord outside the ependymal region around central tube were isolated to prepare single cell suspension. Serum-free NSCs culture medium was adopted to culture and serum NSCs culture medium was applied to induce differentiation. Immunohistochemistry detection and flow cytometry were applied to observe and analyze the type of cells and their capability of division, proliferation and differentiation. RESULTS: At 3-7 days after injury, the model group witnessed a plenty of nestin+/GFAP+ cells in the single cell suspension, while the control group witnessed few. Cell count of the model and the control group was 5.15 +/- 0.71 and 1.12 +/- 0.38, respectively, indicating there was a significant difference between two groups (P < 0.01). Concerning cell cycle, the proportion of S-phase cell and proliferation index of the model group (15.49% +/- 3.04%, 15.88% +/- 2.56%) were obviously higher than those of the control group (5.84% +/- 0.28%, 6.47% +/- 0.61%), indicating there were significant differences between two groups (P < 0.01). In the model group, primary cells gradually formed three-dimensional cell clone spheres, which were small in size, smooth in margin, protruding in center and positive for nestin immunofluorescence staining, and large amounts of cell clone spheres were harvested after multiple passages. While in the control group, no obvious cell clone spheres was observed in the primary and passage culture of single cell suspension. At 5 days after induced differentiation of cloned spheres in the model group, immunofluorescence staining showed there were a number of galactocerebroside (GaLC) -nestin+ cells; at 5-7 days, there were abundance of beta-tubulin III-nestin+ and GFAP-nestin+ cells; and at 5-14 days, GaLC+ oligodendrocyte, beta-tubulin II+ neuron and GalC+ cell body and protruding were observed. CONCLUSION: Nestin+/GFAP+ cells obtained by isolating the gray and the white substance of spinal cord outside the ependymal region around central tube after compressive spinal cord injury in adult rat has the ability of self-renewal and the potential of multi-polarization and may be a renewable source of NSCs in the central nervous system.

[Study on repair of subacute spinal cord injury by transplantation of olfactory ensheathing cells combined with chondroitinase ABC in adult rats].

OBJECTIVE: To investigate the synergetic effect and possibility of repairing spinal cord injury (SCI) by transplantation of olfactory ensheathing cells (OECs) and chondroitinase ABC (ChABC) in adult rats. METHODS: Three adult male SD rats were used to isolated olfactory bulb and primarily cultured OECs. In the 8th or 9th day, OECs were transplanted, the concentration of cells was modulated to 1 x 10(5)/microL. Fifty-four SD rats were made the models of T8 spinal cord crush injury and divided into 4 groups. In group A (control, n = 36), injured site was not treated; in groups B, C and D (n = 6), OECs, ChABC and OECs+ChABC were injected into injured site, respectively. At 1, 2, 3, 7 and 14 days after injury, the BBB score system was used to evaluate the motion function. At 0, 1, 2, 3, 7, 14 days in group A and at 14 days in groups B, C, D after injury, the maximal transverse diameter and gross area of necrosis were evaluated on HE stained sections. The immunofluorescence double labeling staining for glial-fibrillary acidic protein (GFAP)/CS56, GFAP/growth associated protein 43 (GAP-43) and GFAP/neurofilament 160 (NF160) was carried out to evaluate the regeneration of nerve fiber. RESULTS: At 14 days after injury, there were significant difference in the BBB scores between group A and groups B, C, D (P < 0.05), and between groups B, C and group D (P < 0.05), HE staining showed that the formation of cavity was observed in each group at 14 days after injury. There were significant difference in the maximal transverse diameter and gross area of necrosis between groups B, C, D and group A (P < 0.01), and between groups B, C and group D (P < 0.01). The immunofluorescence staining indicated that expression of GFAP were more intense in group A than in other groups, and the cavity of the lesion site was apparent, but it was moderate in groups B and C. The expression of GAP-43 was more intense in group D than in groups B and C. The expression of NF160 was more intense in group D. CONCLUSION: Transplantation strategy of OECs combined with ChABC was effective in the repair of SCI in some extent.

[Reactive astrocytes and nestin expression in adult rats following spinal cord compression injury].

OBJECTIVE: To observe the expressions of nestin and glial fibrillary acidic protein (GFAP) and their association with reactive astrocytes following spinal cord injury in adult rats. METHODS: Adult rats with compression injury of the spinal cord were divided into 7 groups (n=6) and examined at 1, 3, and 5 days and at 1, 2, 4 and 8 weeks after the injury. The recovery of the locomotor function after the injury was evaluated with Basso, Beattie and Bresnahan (BBB) scale, and the degree and scope of the spinal injury were assessed using toluidine blue staining. Immunohistochemistry, double immunofluorescent labeling and an image analysis system were employed to observe nestin and GFAP expression and cell proliferation in different regions of the spinal cord. RESULTS: The bilateral hind limb locomotor function of the rats declined severely 24 h after the spinal cord injury and underwent substantial recovery in 1 or 2 weeks after the injury, but followed by rather slow recovery afterwards. Toluidine blue staining of the spinal cord 24 h after the injury showed significant pathological changes in the neurons. The extension of the tissue injury increased with time till 1 week after the spinal cord injury. The site of injury and the adjacent tissues presented with markedly increased nestin and GFAP expressions 24 h after the injury, and nestin+/GFAP(-) cells dominated in the ependymal region around the central canal, whereas nestin+/GFAP+ dominated in the in other regions, showing significant difference from the control group. Nestin and GFAP expression reached the peak level 3 to 7 days after the injury and declined gradually till reaching nearly the control level at 2 weeks. CONCLUSION: Compression injury of the spinal cord induces up-regulated expressions of nestin and GFAP, and nestin expression is positively correlated to the reactive astrocytes, which, along with the neural stem cells, respond to spinal nerve injury and possibly play a role in repair of the central nervous system injury.

Biomechanical study of anterior cervical corpectomy and step-cut grafting with bioabsorbable screws fixation in cadaveric cervical spine model.

STUDY DESIGN: An in vitro biomechanical study. OBJECTIVE: To determine the initial stability of a novel construct in a 1-level cadaveric cervical spine model by comparing it with a conventional method. SUMMARY OF BACKGROUND DATA: Lots of endeavors have been made to enhance fusion rates and reduce complications in the anterior cervical spine procedure. METHODS: There were 12 fresh human cadaveric cervical spines (C3-C7) randomly divided into 2 groups: group 1, 1-level corpectomy of C5 and step-cut grafting with bioabsorbable screw fixation (SCAS); and group 2, 1-level corpectomy of C5 and strut grafting with anterior plate fixation (SP). For each specimen, the intact underwent a flexibility test first, followed by the instrumented construct. Rotational angles of the C4-C6 segment were measured to study the immediate stability of anterior cervical corpectomy and SCAS, compared with the intact and anterior cervical corpectomy and SP. RESULTS: Both anterior cervical corpectomy with SCAS and with SP significantly (P < 0.01) decreased the motions of C4-C6 in all 6 degrees of freedom after instrumentation. Compared with anterior cervical corpectomy and SP, anterior cervical corpectomy and SCAS had higher stability (P < 0.05) in extension, and comparable stability (P > 0.05) in flexion and axial rotation, but lower stability (P

[Expression of nestin and glial fibrillary acidic protein in injured spinal cord of adult rats at different time].

OBJECTIVE: To explore the expression of nestin and glial fibrillary acidic protein (GFAP) at different time and sites after spinal cord injury in adult rats. METHODS: Seventy-two adult Sprague-Dawley rats, aging 8 weeks and weighing from 180 to 220 g, were randomly divided into 11 experimental groups (66, n=6) and 1 control group (n= 6). In the experimental groups, the rat spinal cord injury models were established by aneurysm clip compression, and the expression and proliferation of nestin and GFAP at different time (1 day, 3 days, 5 days, 1 week, 2 weeks, 3 weeks, weeks, 5 weeks, 6 weeks, 7 weeks and 8 weeks) and at different sites (injured site and adjacent site) were observed with toluidine blue staining, immunofluorescent staining and the analytical system of photographs. In control group, the same site of the rat spinal cord was exposed without aneurysm clip compression. The same preparation and examination were done as the experimental groups. RESULTS: Toluidine blue staining results showed that contour of neurite and pericaryon were distinct and nucleus were deep blue in normal control rats. One day after injury, the number of big and medium-sized neuron decreased obviously; neurite was deep blue with clouding Nissl bodies and ellipse or triangular typed nucleus. In the normal control group, the expression of nestin was hardly seen except ependymal cells of central canal, and the low expression of GFAP was seen. In the experimental groups, the nestin and GFAP expressions increased obviously in the injured sites and adjacent sites 24 hours after injury, reached the peak value after 3-7 days and followed by gradual decrease. There were statistically significant differences in the nestin and GFAP expressions between the experimental groups and the control group. CONCLUSION: The above results suggest that spinal cord injury can induce the expression of nestin and GFAP. There is a positive correlation between nestin expression and the proliferation of the reactive astrocytes.