Spinal cord injury (SCI) is a commen desease in clinic. We mainly introduced some trends on research of SCI. Especially, some challenging questions were primarily discussed in this paper.

BACKGROUND: The free radicals induced by cerebral ischemia/reperfusion consist mainly of xanthine oxidase, which induces cell swelling in the infarcted area.OBJECTIVE: To observe the changes of cerebral ischemia/reperfusioninduced changes in the activity of cerebral superoxide dismutase (SOD), an enzyme responsible for free radical clearance, and investigate the effect of apurin, a inhibitor of purine oxidase, on cellular water content in the brain tissue with ischemia/reperfusion injury.DESIGN: Completely randomized controlled study.SETTING: Department of Neurology of the Central Hospital Affiliated to Shenyang Medical College, Department of Neurosurgery of the First Hospital Affiliated to China Medical University, and Liaoning Provincial Orthopedic Hospital for Limb Disabilities.MATERIALS: The experiment was conducted in the Laboratory of the Central Hospital Affiliated to Shenyang Medical College from May 2003 to April 2004. Forty Wistar rats were subjected to a 6-hour cerebral ischemia and randomized into 4 equal groups to receive intragastric administration of 100 mg/kg apurin (ischemia + apurin group), oxolinic acid suspension of the same dose (ischemia+ oxolinic acid group), 100 mg/kg apurin after a 2-hour reperfusion (Ischemia/reperfusion + apurin group), or oxolinic acid of the same dosage after the 2-hour reperfusion (ischemia/reperfusion + oxolinic acid goup), respectively. The rats in apurin group had intragastric administration of 100 mg/kg apurin 48, 24 and 1 hour before occlusion of the cervical internal carotid artery (CICA) to induce the ischemia, respectively. Oxolinic acid was given in the two oxolinic acid groups in the same manner.METHODS:Water content of brain tissue of rats was measured after 6 hours of CICA occlusion in the two ischemia groups and after the 2-hour perfusion in the two ischemia/reperfusion groups. Distribution of SOD in the brain tissue was observed with SOD immunostaining.MAIN OUTCOME MEASURES: Distribution of SOD and water content in the brain tissue of rats.RESULTS: In the two oxolinic acid groups, Cu-Zn SOD staining identified obviously increased staining intensity in the ischemic foci. Mn SOD staining in ischemia+oxolinic acid group resulted in increased circular staining surrounding the vessels in the ischemic foci, with also obvious staining of the vascular wall and neural cells. The ischemic foci of the ischemia/reperfusion + oxolinic acid group showed diffuse but lightly weaker staining. Cu-Zn SOD staining in the two apurin groups revealed no significant difference. In the two oxolinic acid groups, endothelial cell nuclear swelling of the arteriole, protrusion of the mid-layer myocytes, and expansion of the vascular membrane were observed, with the tissues surrounding the vessels appearing spongy. These changes were less severe in the two apurin groups. The water content in the brain tissue was (78.56±0.30) % in ischemia + apurin group and (78.85±0.49) % in ischemia/reperfusion + apurin group, significantly lower than that of (79.08±0.33) % in ischemia + oxolinic acid group and (79.86±0.49) % in ischemia/reperfusion + oxolinic acid group (P ＜ 0.05).CONCLUSION: Apurin can relieve tissue injury after cerebral ischemia/reperfusion by inhibition of SOD.

TrkB was designated as the functional receptor of br ain derived neurotrophic factor． In these study, we investigated the distributi on of trkB-like immunoreactivity(trkB-IR) in spinal cord of adult cats using spe cific antiserum for trkB by immunohistochemistry ABC method． The results were a s following: trkB-IR was mainly distributed in neurons of spinal cord including ventrolateral horn, intermedius are and dorsal horn． 　　 The subcellular localization of positiveproduct was mainly in cytoplasm． Our results provided morphological evidence on the distribution of trkB in spinal cord of adult cats． It indicated the role o f trkB involve in physiological function of spinal cord of adult cat．

BACKGROUND: Many studies showed that neural stem cells (NSC) transplantation can promote functional improvements in rats subjected to spinal cord injury. However, the underlying molecular mechanisms remain poorly understood.OBJECTIVE: To observe the effects of NSC transplantation on expressions of Bax, Bcl-2 and Caspase-3 in the motor cortex in rats subjected to spinal cord transection.DESIGN, TIME AND SETTING: The randomized controlled animal experiment was performed at Institute of Neuroscience,Kunming Medical College from July 2007 to December 2008.MATERIALS: Five green fluorescent protein transgenic mice with 14-15 embryonic days were prepared for NSC. Additionally 88 adult female Sprague-Dawley (SD) rats were randomly divided into sham operation group (n=8), model group (n=40) and NSC transplantation group (n=40).METHODS: Model of spinal cord transection was established by cut transversely Sprague-Dawley (SD) rats T_9 segment. Rats in the sham operation group were subjected to laminectomy at T_8, without spinal cord injury. After the spinal cord was exposed at the lesion site, a small piece of 2 mm~3 gel foam soaked with 3×10~5 NSC were implanted into the gap to fill the lesion site of the T_9 level in rats of the NSC transplantation group. The measurements of relative indexes were performed at the days 3, 7,14, 21 and 28 after transplantation.MAIN OUTCOME MEASURES: Changes of Bax, Bcl-2 and Caspase-3 expressions were detected by RT-PCR.RESULTS: Compared to the sham operation group, the Bax expression in the model group had no significant difference (P >0.05), the expression of Bcl-2 was decreased obviously at days 14 and 28 after operation (P < 0.05), while a significant increase on the expression of Caspase-3 at day 3 (P < 0.05). Compared to the model group, the expression of Bax was dramatically decreased in the NSC transplantation group at day 3 (P < 0.05), with a notably increased Bcl-2 expression at days 14 and 21 after transplantation (P < 0.05), but the expression of Caspase-3 presented a significant decrease at days 3 and 7 after transplantation (P < 0.05).CONCLUSION: NSC transplantation probably regulates the expression of apoptosis genes (Bax, Bcl-2 and Caspase-3 mRNA) to promote neurological function recovery in rats subjected to cord transection.

Objective To observe the effect of neural stem cell (NSC)transplantation on the hindlimb motor function and caspase-3 expression of motor cortex (MC) in spinal cord transected (SCT) rats. Methods S prague-Dawley (SD) rats were randomly divided into sham operated group, operation group( T9 transection), and subacute NSC transplantation group. The MC of each group( n= 8 )was harvested 7 days post operation (dpo), then western blot was employed to detect the level of caspase-3( β-actin was used as control ). The left 5 animals of each group were subjected to BBB score evaluation at 16th week,then the animals were sacrificed and the MC was harvested and performed immunostain by using caspase-3 rabbit antibody. Results Following NSC transplanta tion, BBB scores( ( 7.58 ± 0. 99 ) ) increased significantly than seen in the SCT animals( ( 5.16 ± 1.19) ). The expressional level of caspase-3 at 7day post operation was( (0.89 + 0.12)) in MC of SCT rats,while it decreased significantly to( (0.76 + 0.11 ) ) in NSC transplantation rats(P＜0.05). The immunoreactive stain of caspase-3 was seen in the cytoplasm of pyramidal neuron in the cortex. Conclusion NSC engraft can downregulate the expression of caspase-3, corresponding to a significant improvement in hindlimb motor function. These findings indicate that NSC transplantation probably regulate the expression of apoptosis genes in MC to promote neurological function recovery in rats subjected SCT.

The present study investigated different types of eoexpression of brain derived neumtmphic factor(BDNF),nerve growth factor(NGF)and neutmphin-3(NT-3)mRNA and/or proteins in the left sixth lumbar dorsal root ganglion(DRG)of cats and discuss themechanism of coexpression in order to provide foundation for elucidating the relationship between the expression of neurotrophic factors andspinal cord plasticity.The eats used in this study were normal animals without any interventional treatment.They were subjected to renloveof the left L6 DRG and their DRG were processed for immunohistechemistry and in situ hybridization double staining to observe whetherthere are coexpression of mRNA and proteins of BDNF,NGF and NT-3.The results showed that the pmteios and mRNA of BDNF,NGFand NT-3 were all expressed in the DRG of cats,but the types of coexpression of mRNA and proteins were different and diverse amongthese three neumtrophic factors.The results of immunohiatochemistry showed that BDNF immunoreactivities were mainly observed in thecytoplasm and nucleus,and the staining of nucleus was weaker than that of cytoplasm;NGF immunoreactivities were mainly observed innucleus while NT-3 mainly in cytoplasm.The results of in situ hybridization showed that BDNF and NGF positive signals mostly distributedin the cytoplasm,NT-3 positive signals were observed in both the cytoplasm and nucleus.Our results suggest that the proteins and mRNAof BDNF,NGF and NT-3 have different types of coexpression which indicate they may have autocrine and/or paracrine mechanism contrib-uting to the plasticity of spinal cord in the left L6 DRG of cats.

ObjectiveTo study the effect of bone mesenchymal stem cells (BMSC) transplantation into traumatic brain injury(TBI) rats by the external carotid artery on neurological function and learning and memory.MethodsTen adult SD rats were randomly divided into TBI group ( n =5 ) and BMSC transplantation group ( n=5).Feeney free falling method was used to establish TBI models.The experimental rats were administrated with BMSC via external carotid artery (ECA),while TBI rats were injected with sterile liquid medium of equal volume via right ECA.Neurological function were evaluated according to the modified neurological severity score (NSS) at 1,3,7,15 days.Morris water maze test was used to observe the animal capabilities of place navigation and space exploration at 15 days,then animals were sacrificed.Survival and migration of implanted BMSC in brains under fluorescence microscope. ResultAfter traumatic brain,varying degrees convulsions,paralysis,loss of balance function in rats were found.Compared with TBI group,BMSC transplantation decreased significantly NSS (P ＜0.01 ).BMSC transplantation significantly decreased on escape latency ( ( 20.48 ± 2.29 ) s ) than the TBI group ( ( 85.93 ± 47.48 ) s) (P ＜ 0.01 ).Moreover,BMSC group in the target quadrant dwell time ( ( 28.62 ± 1.72) ％ )and distance ( (29.05 ± 3.08 )％ ) as well as the number of passing the platform (8.00 ± 2.45 ) were significantly higher than the TBI group ( ( 19.37 ± 2.81 ) ％,(21.78 ± 3.06) ％,(2.00 ± 1.87) respectively,P ＜ 0.01 ).Transplanted BMSC could survive and migrate around injury brain through Hochest mark immunofluorescence.ConclusionBMSC can survive and migrate around injury brain by transplantation of external carotid artery,which results in a significant neurological function improvement and learning and memory increase in rats with traumatic brain injury.

Objective To evaluate the curative effect and value of dilatation technique with double balloon in the treatment of cardia achalasia.Methods 52 patients with cardia achalasia were treated by the dilatation technique with double balloon.Results The effective rate was 100% in short term while.In long term,the effective rate was 96% and 100% with one time dilatation and double time dilatations respectively.Conclusion The dilatation technique with double balloon is a safe,effective and easy operated method in the treatment of cardia achalasia.

Objective To establish a serial of stable and mature methods of primary culture hippocampus neurons of GFP-transgene embryonic mice,to get the morphologic data of cultured neurons.Based on this research,in future,we can give an important theoretical and practical support for the therapy of nervous system diseases by transplanting with hippocampus neurons of GFP-transgene embryonic mice.Methods We primarily cultured the hippocampus neurons derived from the GFP-transgene embryonic mice in vitro.Under the microscope,we found cultured hippocampus neurons could live for more than one month and appeared to be the best status in 5～7 d after culture.During this time,the processes of the neurons are thick and the neurons connected one another to form the"cells-net" through their processes.After 14 d,the growth of the hippocampus neurons became slow.Results A serial of culture methods of hippocampus neurons had been successfully established.These cultured neurons were identified by the immuno-histochemical methods.They grow well in different phases before 14 d after culture.Conclusion Culturing hippocampus neurons of GFP-transgene embryonic mice is a simple,stable and effective method which can be applied to scientific research by other researchers.

To explore the characteristic features of morpho logical changes of neurons in the spinal dorsal horn result from different types of spinal cord in jury, the adult Srague-Daweley fat models of crushed, hemi-sected and transected spinal cord injury established in our laboratory were used, and the intact spin al cords were as control． 　　These rats were sacrificed after 24 hours, 7 days and 2l days of operation, and the L3, segments were removed out and sectioned continuously into sections of 20 μm in thickness． The sections were stained by hematoxylin and observed under ． 　　 microscope． In addition, neurons in the dorsal horn were counted． 　　 Results: In the crushed spinal horns, bodies of neurons were atrophy, but neuron counting did not decrease markedly; in the hemi-sected and transected dorsal horn, a batch of empty cavities were presented, and neuron counting decreased greatly． The results indicated that different injuries of spinal cord resulted in different damage to neurons in the dorsal horn, i． e． the crushed one, the bad, the hemi-sected one, the worse; and the transected one, the worst．