Olfactory ensheathing cell transplantation alters the expression of chondroitin sulfate proteoglycans and promotes axonal regeneration after spinal cord injury

Cell transplantation is a potential treatment for spinal cord injury. Olfactory ensheathing cells(OECs) play an active role in the repair of spinal cord injury as a result of the dual characteristics of astrocytes and Schwann cells. However, the specific mechanisms of repair remain poorly understood. In the present study, a rat model of spinal cord injury was established by transection of T10. OECs were injected into the site, 1 mm from the spinal cord stump. To a certain extent, OEC transplantation restored locomotor function in the hindlimbs of rats with spinal cord injury, but had no effect on the formation or volume of glial scars. In addition, OEC transplantation reduced the immunopositivity of chondroitin sulfate proteoglycans(neural/glial antigen 2 and neurocan) and glial fibrillary acidic protein at the injury site, and increased the immunopositivity of growth-associated protein 43 and neurofilament. These findings suggest that OEC transplantation can regulate the expression of chondroitin sulfate proteoglycans in the spinal cord, inhibit scar formation caused by the excessive proliferation of glial cells, and increase the numbers of regenerated nerve fibers, thus promoting axonal regeneration after spinal cord injury. The study was approved by the Animal Ethics Committee of the Medical College of Xi'an Jiaotong University, China(approval No. 2018-2048) on September 9, 2018.

Feasibility of 3.0 T diffusion-weighted nuclear magnetic resonance imaging in the evaluation of functional recovery of rats with complete spinal cord injury

Diffusion tensor imaging is a sensitive way to reflect axonal necrosis and degeneration, glial cell regeneration and demyelination following spinal cord injury, and to display microstructure changes in the spinal cord in vivo. Diffusion tensor imaging technology is a sensitive method to diagnose spinal cord injury; fiber tractography visualizes the white matter fibers, and directly displays the structural integrity and resultant damage of the fiber bundle. At present, diffusion tensor imaging is restricted to brain examinations, and is rarely applied in the evaluation of spinal cord injury. This study aimed to explore the fractional anisotropy and apparent diffusion coefficient of diffusion tensor magnetic resonance imaging and the feasibility of diffusion tensor tractography in the evaluation of complete spinal cord injury in rats. The results showed that the average combined scores were obviously decreased after spinal cord transection in rats, and then began to increase over time. The fractional anisotropy scores after spinal cord transection in rats were significantly lower than those in normal rats （P 〈 0.05）; the apparent diffusion coefficient was significantly increased compared with the normal group （P 〈 0.05）. Following spinal cord transection, fractional anisotropy scores were negatively correlated with apparent diffusion coefficient values （r = -0.856, P 〈 0.01）, and positively correlated with the average combined scores （r = 0.943, P 〈 0.01）, while apparent diffusion coefficient values had a negative correlation with the average combined scores （r = -0.949, P 〈 0.01）. Experimental findings suggest that, as a non-invasive examination, diffusion tensor magnetic resonance imaging can provide qualita- tive and quantitative information about spinal cord injury. The fractional anisotropy score and apparent diffusion coefficient have a good correlation with the average combined scores, which reflect functional recovery after spinal cord injury.

Experimental Study on Gufusheng in Treatment of Steroid-Induced Ischemic Necrosis of Femoral Head in Rabbits

Objective: To explore the mechanisim of compound Gufusheng in treatment of steroid-induced ischemic necrosis of femoral head (SINFH). Thirty-two rabbits were randomly divided into a blank control group (n=12) and a model group (n=20). The rabbits of the model group were established by intramuscular injection of prednisone acetate (0.32mg/kg/d) for 8 weeks, and 2 rabbits in each group were killed at the 6th and the 8th week respectively to investigate whether the model was successfully prepared. Then remainder in the model group was again randomly divided into group A (Gufusheng group, n=8) and group B (model group, n=8), while the rest of rabbits in the blank group constituted group C (n=8). The rabbits in group B and C were fed with normal saline. After treatment for 4 weeks, the serum insulin-like growth factor-1 (IGF-1) and tumor necrosis factor-α (TNF-α) levels in the rabbits of the 3 groups were determined by radioimmunoassay (RIA). The serum TNF-α decreased significantly and the IGF-1 level increased significantly in the Gufusheng group as compared with the model group (both P＜0.01). Compound Gufusheng can prevent SINFH and promote repair of the tissue of necrosis of femoral head possibly via decreasing the TNF-α and increasing IGF-1 level.

Single injection of platelet-rich plasma as a novel treatment of carpal tunnel syndrome

Both in vitro and in vivo experiments have confirmed that platelet-rich plasma has therapeutic effects on many neuropathies, but its effects on carpal tunnel syndrome remain poorly understood. We aimed to investigate whether single injection of platelet-rich plasma can improve the clinical symptoms of carpal tunnel syndrome. Fourteen patients presenting with median nerve injury who had suffered from mild carpal tunnel syndrome for over 3 months were included in this study. Under ultrasound guidance, 1-2 m L of platelet-rich plasma was injected into the region around the median nerve at the proximal edge of the carpal tunnel. At 1 month after single injection of platelet-rich plasma, Visual Analogue Scale results showed that pain almost disappeared in eight patients and it was obviously alleviated in three patients. Simultaneously, the disabilities of the arm, shoulder and hand questionnaire showed that upper limb function was obviously improved. In addition, no ultrasonographic manifestation of the carpal tunnel syndrome was found in five patients during ultrasonographic measurement of the width of the median nerve. During 3-month follow-up, the pain was not greatly alleviated in three patients. These findings show very encouraging mid-term outcomes regarding use of platelet-rich plasma for the treatment of carpal tunnel syndrome.

Proliferation and differentiation of reactive nestin^+/GFAP^+ cells in an adult rat model of compression-induced spinal cord injury

BACKGROUND： Studies have demonstrated that astrocytes may possess similar properties to neural stem cells/neural precursor cells and have the potential to differentiate into neurons. OBJECTIVE： To observe neuroepithelial stem cell protein （nestin） and glial fibrillary acidic protein （GFAP） expression following spinal cord injury, and to explore whether nestin＋/GFAP＋ cells, which are detected at peak levels in gray and white matter around the ependymal region of the central canal in injured spinal cord, possess similar properties of neural stem cells. DESIGN, TIME AND SETTING： A randomized, controlled experiment. The study was performed at the Key Laboratory of Environment and Genes Related to Diseases （Xi＇an Jiaotong University）, Ministry of Education between January 2004 and December 2006. MATERIALS： Rabbit anti-rat nestin, β-tubulinⅢ, mouse anti-rat GFAP, galactocerebroside （GaLC） antibodies were utilized, as well as flow cytometry. METHODS： A total of 60 male, Sprague Dawley rats, aged 8 weeks, were randomly assigned to control （n = 12） and model （n = 48） groups. The spinal cord injury model was established in the model group by aneurysm clip compression, while the control animals were not treated. The gray and white matter around the ependymal region of the central canal exhibited peak expression of nestin＋/GFAP＋ cells. These cells were harvested and prepared into single cell suspension, followed by primary and passage cultures. The cells were incubated with serum-containing neural stem cell complete medium. MAINOUTCOME MEASURES： Nestin and GFAP expression in injured spinal cord was determined using immunohistochemistry and double-labeled immunofluorescence at 1, 3, 5, 7, 14, 28, and 56 days post-injury. In addition, cell proliferation and differentiation were detected using immunofluorescence cytochemistry and flow cytometry. RESULTS： Compared with the control group, the model group exhibited significantly increased nestin and GFAP expression （P 〈 0.05）, which reached peak levels between 3 and 7 days. The majority of cells in the ependymal region around the central canal were nestin＋/GFAP- cells, while the gray and white matter around the ependymal region were full of nestin＋/GFAP＋ cells, with an astrocytic-like appearance. A large number of nestin＋/GFAP＋cells were observed in the model group cell culture, and the cells formed clonal spheres and displayed strong nestin-positive immunofluorescence staining. Following induced differentiation, a large number of GaLC-nestin, β-tubulin Ⅲ-nestin, and GFAP-nestin positive cells were observed. However, no obvious changes were seen in the control group. Cells in S stage, as well as the percentage of proliferating cells, in the model group were significantly greater than in the control group （P 〈 0.01）, CONCLUSION： Spinal cord injury in the adult rat induced high expression of nestin＋/GFAP＋ in the gray and white matter around the ependymal region of the central canal. These nestin＋/GFAP＋ cells displayed the potential to self-renew and differentiate into various cells. The cells could be neural stem cells of the central nervous system.

Effects of Xianzhong Injection on the Function of Knee Joint and the Content of Insulin-Like Growth Factor-1 in Rabbits of Early Osteoarthritis

Objective: To evaluate the effect of Xianzhong Injection (仙仲注射液) into the articular cavity on the function of the joints and the content of insulin-like growth factor-1(IGF-1) in rabbits with early knee osteoarthritis (OA). Methods: 120 rabbits were randomly divided into five groups: blank group, model group (injecting 0.5ml of normal saline, once a week), positive control group (injecting 0.5ml of sodium hyaluronate, once a week), Xianzhong group I (injecting 0.5ml of Xianzhong Injection, once a week), Xianzhong group II (injecting 0.5ml of Xianzhong Injection, twice a week). Changes of the articular function and IGF-1 levels in the serum and joint fluid were investigated 8 weeks later. Results: The function of knee joint in the Xianzhong group I and II was improved significantly as compared with that in the model group (P<0.01), and there was no significant difference between the Xianzhong group I and the positive control group (P>0.05), but a significant difference was seen between the Xianzhong group I and the Xianzhong group II (P<0.05); in the positive control group, the Xianzhong group I and the Xianzhong group II , the levels of IGF-1 in the joint fluid and serum were significantly increased as compared with that in the model group (P﹤0.01). Conclusion: Xianzhong Injection can improve the function of knee joint in rabbits with early knee OA, and can substitute sodium hyaluronate Injection for treating this disease.

Immune reactions and nerve repair in mice with sciatic nerve injury 14 days after intraperitoneal injection of Brazil

BALB/c mice were intraperitoneally injected with 10, 5 or 2.5 mg/kg Brazil for 14 days after sciatic nerve injury. Results demonstrate that the spleen T/B lymphocyte stimulation index and serum circulating immune complex concentration were significantly reduced, and the morphology of the soleus muscle was restored in mice with sciatic nerve injury. These effects of Brazil were dose-dependent. Our experimental findings indicate that Brazil can regulate immune responses after nerve injury and promote sciatic nerve repair.

Scapular bone grafting with allograft pin fixation for repair of bony Bankart lesions: A biomechanical study

BACKGROUND Severe bony Bankart lesions are a difficult challenge in clinical treatment and research.The current treatment methods consist mostly of Latarjet-Bristow surgery and its modified procedures.While good results have been achieved,there are also complications such as coracoid fracture,bone graft displacement,and vascular and nerve injury.AIM To analyze the techniques and biomechanical properties of transversely fixing a bone block from the scapular spine using bone allograft pins with suture threads to repair bony Bankart lesions.METHODS Fresh human shoulder joint specimens and a cadaver specimen model for scapular bone grafting with allograft pin fixation for repair of bony Bankart lesions were used.When the humeral rotation angles were 0°,30°,60°and 90°,and the axial loads were 30 N,40 N,and 50 N,the humerus displacement was studied by biomechanical experiments.RESULTS When the angle of external rotation of the humerus was 0°,30°,60°,and 90°,with axial loads of 30 N,40 N,and 50 N,the data of the normal control group,allograft pin repair group,and titanium alloy hollow screw repair group were compared with each other by the q-test,which showed that there were no statistically differences among the three groups(P>0.05).CONCLUSION The joints repaired with bone block from the scapular spine transversely fixed with allograft bony pins to repair bony Bankart lesions show good mechanical stability.The bone block has similar properties to normal glenohumeral joints in terms of biomechanical stability.

Nogo-A expression in injured spinal cord following human olfactory mucosa-derived olfactory ensheathing cells transplantation

Transplantation of olfactory bulb-derived olfactory ensheathing cells （OECs） promotes motor functional recovery in rats with acute spinal cord injury, possibly by Nogo-A expression changes at the injury site. The present study transplanted OECs derived from the olfactory mucosa （OM） of rats OM-derived OEC （OM-OEC） transplantation significantly reduced the increase of Nogo-A protein and mRNA expression caused by spinal cord injury, supporting the hypothesis that OM-OECs improve spinal cord regeneration by reducing Nogo-A expression.

Semaphorin 3A expression in spinal cord injured rats after olfactory ensheathing cell transplantation

Semaphorin 3A expression is thought to increase following spinal cord injury.The impact of olfactory ensheathing cell transplantation remains unclear.The current study demonstrated that spinal cord hemorrhage,edema,degeneration,necrosis,cyst formation,proliferation of glial cells,regeneration of nerve fibers and various pathological reactions occurred following a simple cross-section of spinal cord injury.Transplantation of olfactory ensheathing cells was found to significantly relieve the pathological reactions in the spinal cord described above,decrease the extent of necrosis in damaged neurons and nerve fibers,and downregulate semaphorin 3A expression in the injured zone.The results confirmed that olfactory ensheathing cell transplantation plays a protective role on the injured spinal cord by reducing the expression of semaphorin 3A.