After an injury of the peripheral nerve, therewould be naturally occurring the reduction oreven disappearance of FRAP from the substantiagelatinase in the corresponding part of the dorsalhorn of the spinal cord, The enzymhistochemical method was used to show the changesof FRAP activity before and after the nerveinjury. Aftcr the injury of the sciatic nerve,FRAP would be decreased in the correspondingpart of the spinal cord and gave a sharp contrastto that of the control rats and the uni...
Objective To explore the influence factors for the functional improvement after the fetal olfactory ensheathing cell (OEC) transplantation for chronic spinal cord injury(SCI). Methods The olfactory bulbs were harvested and trypsinized down to single fetal OEC. They were cultured for 12-17 days prepared for use. From November 2001 to December 2003, a total of 300 patients volunteered for the fetal OEC transplantation, among whom 222 suffered from complete chronicSCI and 78 suffered from incomplete chronic SCI. The procedures were performed on the patients with a disease course ranging from 6 months to 31 years (average 3.1 years) after their injuries. The fetal OEC was transplanted by the form of injections into the spinal cord at the upper and lower ends of the injury site. All the patients were assessed by the ASIA standard before the transplantation and 2-8 weeks after the transplantation. The influence factors including age, sex, duration after the injury, and injury degreesand levels were compared with those in the functional improvement after fetal OEC transplantation. Results The partially-improved neurological functions assessed by the ASIA standard were indicated by the motor scores increasing from 39.1±20.6 to 45.9±20.3 (Plt;0.001), the light touch scores from 51.7±24.9 to 63.4±23.0 (Plt;0.001), and the pin prick scores from 53.0±24.2 to 65.3±22.7(Plt;0.001). There was no significant difference in the functional improvement of the motor, light touch, and pin brick when compared with the age, sex, duration after theinjury, and the injury degrees and levels. The motor scores and light touch scores at the cervical level were higher than the scores at the thoracic level. Conclusion The fetal OEC transplantation can partially improve the neurological functions quickly in treatment of the chronic spinal cord injury. All the influence factors except the motor scores and light touch scores, which were higher at the cervical level than at thoracic level, have no impact on the functional improvement after the fetal OEC transplantation.
Objective To establish the artificial bladder reflex arc by the normal body reflex pathway above the horizon of spinal cord injury to reinnervate the flaccid bladder and restore bladder micturition function. Methods An intradural microanastomosis was performed on the L6 ventral root tothe S2 ventral root. After axonal regeneration,the “patellar ligament-spinal cord center-bladder” reflex pathway was reestablished. A longterm function of the reflex arc was observed in the nerve electrophysiological experiment, detrusor electromyography experiment, and urodynamic testing 8 months after anastomosis. Results Trains of the stimuli(200 μV,5 ms) in the left L6 dorsal root and the nerve at the anastomosizedsite resulted in motor evoked potential from the disal to the anastomosized site before and after the spinal cord was destroyed horizontally between S1 and S4 segment levels in 2 Beegle dogs.The figure and amplitude of the evoked potential were similar to those of the control and general stability which showed anoninterventional wave. The urodynamic test revealed a rapid increase of the bladder pressure and a minor increase in the abdominal pressure. This showed that the bladder detrusor mainly resulted in the pressure increase.The bladder pressure increased to 60% of the normal on average compared with the controls when resulted in the left L6 dorsal root and the nerve anastomosized site were stinulated. Conclusion The long-term observation by the nerveelectrophysiological experiment, detrusor electromyography experiment, and urodynamic test indicate that the new artificial reflex arc can be established successfully. The somatic motor axons can regenerate into the parasympathetic endoneurial tubes of the autonomic nerve.
Objective To determine the safety of the fetal olfactory ensheathing cell(OEC) transplantation in patients with chronic spinal cord injury (SCI) by examination of the magnetic resonance imaging (MRI). Methods A prospective clinical study involving 16 patients with chronic SCI was designed to investigate the feasibility and biological safety of the fetal OEC transplantation in treatment of SCI. The olfactory bulbs from the 3-4-month-old aborted human fetuses following the strict ethical guidelines were harvested and trypsinized down to single fetal OEC. These cells were then cultured for 12-17 days and were prepared for a clinical use. From November 2001 to December 2002, 16 patients with chronic SCI were randomly enrolled. The patients suffered from SCI for1.5-8 years (average 4-3 years) after the injury. The suspension (50 μl) containing about 1×106 fetal OECs was transplanted by an injection into the patients’ spinal cords above and below the injury site. All the patients were assessed before thetransplantation and were followed up with MRI for 29-42 months (average 38 mon)after the transplantation. Results No cell-related adverse effects were observed in any patient during the followup period. The follow-up with MRI did not reveal any development of optic glial tumor, tumor-like mass, new hemorrhage,edema, expanding cyst, new cyst formation, infection or disruption of the neuralstructure in the transplant site of all the patients. Conclusion This is the first clinical study demonstrating the long-term safety of theOEC therapy for SCI. The results indicate that our protocol is feasible and safe in treatment of patients with chronic SCI within 38 months after the injury. Although the size of the samples for our study was not big enough, the positive results of the study have encouraged us to make a further research in this field.
To investigate the effect of propofol intra-aortic and intravenous infusion on the concentration of propofol for an ischemia-reperfusion spinal cord injury in rabbits. Methods Forty-six healthy adult New Zealand white rabbits were randomly divided into 3 groups: sal ine infusion group (group N, n=10), propofol intra-aortic infusion group (group A, n=16) and propofol intravenous infusion group (group V, n=16). The infrarenal abdominal aorta was occluded for 30 min during which propofol 50 mg/kg was infused continuously intra-aortic or intravenous with a pump in group A and V. In group N, the same volume of normal sal ine was infused in the same way and at the same rate as in group A. Upon reperfusion, propofol concentration of the spinal segments of L4-6 and T6-8 was examined in group A and V. At 48 hoursafter reperfusion, the neurological outcomes were recorded in each group. Results Mean blood pressure in group V from the time of 5 minutes after occlusion decreased more than in group N (P lt; 0.05) and than in group A from the time of 10 minutes after occlusion(P lt; 0.05). The mean blood pressure in group N increased more than in group A from 15 minutes after occlusion (P lt; 0.05). The heart rate increased more in group V from 10 minutes after occlusion than in group N and A (P lt; 0.05) in which no difference was observed. The propofol concentration in L4-6 of group A (26 950.5 ± 30 242.3) ng/g was higher than that in T6-8 of group A (3 587.4 ± 2 479.3) ng/g and both L4-6 (3 045.9 ± 2 252.9) ng/g and T6-8 (3 181.1 ± 1 720.9) ng/g of group V(P lt; 0.05). The paraplegia incidence was lower (30%) and the median of normal neurons was higher (8.4) in group A than in group N (80%, 2.2) and group V(100%, 1.9), (P lt; 0.05). There was no significant difference in group N and V in paraplegia incidenceand the median of normal neurons (P gt; 0.05). Conclusion Intra-aortic infusion shows a better neurological outcome than intravenous infusion and could contribute to higher concentration of propofol in the ischemia spinal cord.
Gene therapy develops very rapidly during the resent years. Great prospects have been demonstrated from basic study and clinic test. However, the gene therapy in CNS is still in stage of laboratory. The research status and prospects of gene therapy in spinal cord injury (SCI) were introduced. The basic principle is to transplant certain cells genetically modified with NTFs to the site of the injuried spinal cord, then NTFs are expressed in vivo and stimulate axon regrowing. Virus vectors are usually used for gene transfer because of their high rate of transfection, and the receptor cells include fibroblast, myoblast, etc. Nowadays, gene therapy in SCI is studied in many laboratories and the problems include: 1. The ideal components of transfer gene. 2. The choice of carrier. 3. Immune reaction, and prolonged survival and persistent expression of the receptor cells in the spinal cord. If these problems could be solved, the gene therapy would become the key method in the therapy of SCI.
Objective To investigate the feasibil ity of establ ishment of physiological micturition reflex arc by simultaneously reconstructing the sensory and the motorial nerve of atonic bladder after spinal cord injury. Methods Eight 1-year-old Beegle male canine were selected, weighing 7-12 kg. The left side was the experimental side, while the right side wasthe control side. Epidural microanastomosis of vertebral canal of the left L7 ventral root to S2 ventral root and L7 dorsal root to S2 dorsal root was performed to reconstruct the sensory and the motorial function of atomic bladder. The right side was used as a control without treatment. The new motor-to-motor, and sensory-to-sensory physiological bladder reflex pathway were establ ished after 12 months of axonal regeneration. Then S1-4 segmental spinal cord was destroyed for preparation of complete paraplegia. The electrophysiological examination and the bladder pressure were detected before and after paraplegia. The canine micturition was observed for 3 months after paraplegia. Nurohistological observation was performed after canine sacrifice. Results Of 8 canine, 7 canine survived. After paraplegia, canines displayed urinary incontinence and frequent micturition at first, nocturnal continence was achieved gradually without frequent micturition after 1 month. Urinary infection at different degrees occurred in 3 canines and was controlled after Norfloxacin was administered orally. The bladder pressure increased to (1.00 ± 0.13) kPa, (0.90 ± 0.12) kPa after trains of stimulation (300 mV, 0.3 ms, 20 Hz, 5 seconds) of S2 dorsal root at the experimental side before and after paraplegia respectively, showing no significant difference (P gt; 0.05). It increased to (1.90 ± 0.10) kPa after the same train of stimulation of S2 dorsal root at control side. There was significant difference between the experimental side and the control side (P lt; 0.01). Single stimulation (300 mV, 0.3 ms) of the S2 dorsal root at the experimental side resulted in evoked potentials recorded from the left S2 ventral root before and after paraplegia. Before and after paraplegia, the ampl itudes of the evoked potentials were (0.68 ± 0.11) mV and (0.60 ± 0.08) mV respectively, showing no significant difference (P gt; 0.05). It was (1.21 ± 0.13) mV while stimulating at the control side. There was significant difference between the experimental side and the control side (P lt; 0.01). Neurofibra of L7 dorsal and ventral root grew into S2 dorsal and ventral root on tissue sl ice under l ight microscope. Conclusion Reconstruction of the bladder physiological micturition reflex arc is feasible by anastomosis of sacral dorsal and ventral root below injured spinal plane with the suprasacral survival dorsal and ventral root above the plane respectively for restoration of atonic bladder after spinal cord injury.
Object ive To summa r i z e the advanc ement of cytoske l e ton and axon outgrowth of neuron. Methods The recent l iterature concerning cytoskeleton and axon outgrowth of neuron was reviewed and summarized. Results The actin filaments and microtubules in neuron were highly polarized and dynamic structures confined to the ti ps of axons and the reci procal interactions between these two major cytoskeletal polymers was also dynamic. Attractive or a repulsive cue whose final common path of action was the growth cone cytoskeleton mediated the growth of axons of neuron by intracellular signaling cascades. Regulating the actin filament and microtubule dynamics as well as their interactions in growth cones played a key role in neurite outgrowth and axon guidance. Rho-GTPases and glycogen synthase kinase 3β (GSK-3β), the two major intracellular signal ing pathways had emerged in recent years as candidates for regulating the dynamics of actin filaments and microtubules. Conclusion The axon outgrowth and guidance depend on well-coordinated cytoskeletal and reciprocal interaction dynamics which also mediate axon regeneration after spinal cord injury. Regulating activity of Rho-GTPases and GSK- 3β simultaneously may acts as key role to regulate the dynamics of cytoskeletal and to determine axon outgrowth.
Objective To investigate the influence of different transplantating times on the survival and immigration of the bone marrow mesenchymal stem cells (BMSCs) in injured spinal cord by subarachnoid administration, and to evaluate the most optimal subarachnoid administration times for BMSCs. Methods Eight adult male rats (weighing 120 g) were used to isolate BMSCs that were cultured, purified and labeled with Hoechst 33342 in vitro. Another 75 adult Wistar rats (weighing 220 g) were made the spinal cord injury (SCI) models at T9,10 level according to the improved Allen’s method and were randomly divided into 5 groups (groups A, B, C, D, and E, n=15). The labeled BMSCs at 1 × 107/mL 0.1 mL were injected into subarachnoid space of the rats via a catheters under the subarachnoid space in groups A (one time at 1 week), B ( two times at 1 and 3 weeks), C (3 times at 1, 3, and 5 weeks) and D (5 times at 1, 3, 5, 7, and 9 weeks) and 0.2 mL phosphate-buffered sal ine (PBS) was injected in group E (5 times at 1, 3, 5, 7, and 9 weeks) as blank control. The neurological functions were evaluated using the Basso-Beattie-Bresnahan (BBB) scale 1, 3, 5, 7, 9, and 12 weeks after transplantation. The migration, survival, differentiation, and histomorphological changes of BMSCs were observed by HE, immunohistochemistry, and fluorescence microscopy. Results At 3 weeks after injury, there were significant differences in the BBB scores between group E and groups A, B, C, D (P lt; 0.01), and between groups A, B and groups C, D (P lt; 0.01). At 7, 9, and 12 weeks, the BBB scores were significantly higher in groups C and D than in groups A and B (P lt; 0.01), and in group B than in group A (P lt; 0.01). There were no significant differences in the BBB scores between groups C and D (P gt; 0.05). The fluorescence microscopy showed that the transplanted BMSCs survived and grew in the injured region at 3 weeks after injury and as time went on, the transplanted cells gradually decreased in group A; in groups B, C, and D, BMSCs count reached the peak values at 5 and 7 weeks and then gradually decreased. At 12 weeks, the survival BMSCs were significantly more in groups C and D than in groups A and B (P lt; 0.01). HE staining showed that the formation of cavity was observed in each group at 3 weeks after injury and the area of cavity gradually decreased in groups A, B, C, and D. At 12 weeks, the area of cavity was the miximal in groups C and D, moderate in groups A and B, and the maximal in group E. The immunohistochemistry staining indicated that the expression of NF-200 was more intense in groups C and D than in groups A and B. The expression of NF-200-positive fibers was more intense in group C. Conclusion Multiple administration of BMSCs promotes the restoration of injured spinal cord and improves neurological functions, and three times for BMSCs transplantation is best
OBJECTIVE To study the early protective effects of basic fibroblast growth factor(bFGF) on the experimental acute spinal cord injury. METHODS Thirty-four SD rats were randomly divided into three groups, and were subjected to contusion of thoracolumbar spinal cord. A thin plastic tube was placed in subarachnoid space below the injury level for perfusion. The bFGF-treated rats were received 20 microliters bFGF(containing bFGF 100 U) at once, 30 min, 1, 2, 3, 4, 6, 12, 24 and 48 hours after injury, and an equal volume of normal saline was given to the control group at the same time. The injured spinal cord was detected by morphological observation and biochemical index after injury. RESULTS The degree of ionic disorder in bFGF-treated rats was significantly ameliorated and the contents of H2O were also markedly decreased. The morphological finding showed that the damages of gray and white matter in bFGF-treated rats were slighter than those of saline-treated rats. CONCLUSION bFGF has some protective effects on the secondary lesion of early spinal cord injury in rats.