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.

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: 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.

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.

AIM: The aim of this study was to explore the expression of nerve growth factor(NGF) in spinal dorsal horn following crushed spinal cord injury. METHODS: The adult Srague-Dawley rat model of crushed spinal cord injury was established by the method in our laboratory, and intact spinal cord was used as control. The rats were sacrificed respectively after 24 hours, 7 days, and 21 days of operation, and the L3 spinal segments were removed out and fixed in 4% polyformaldehyde. The segments were sectioned into sections of 20 μm in thickness. The sections were stained with anti-NGF antibody by ABC method of immunohistochemistry technique. The immunoreactive intensity of NGF and the number of positive neurons as well as glial cells in dorsal horn were observed and counted under light microscope. RESULTS: The number of positive cells and immunoreactive intensity of NGF increased gradually in the dorsal horn at 24 hours, 7 days and 21 days following crushed spinal cord injury compared with control group (P＜0.01). CONCLUSION: These results indicated that NGF plays an important role in the postoperative reaction during the early period of the crushed spinal cord injury.

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.

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.

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.

AIM: It is well known that different injuries will result in different consequences. In this paper, we investigated the morphological change of spinal cord following crushed, hemi-sectioned and transected injury. METHODS: Sixty Wistar rats were randomly divided into 4 groups: intact group, crushed spinal cord injury group (cSCI), hem-sectioned SCI group (hSCI) and transitioned SCI group (tSCI). The models of SCI were established by the method in our laboratory. The animals in each group were sacrificed respectively at 24 hours, 7 and 24 days after operation. The L2 spinal cord which located in the caudal of injury site was taken respectively from each animal in each group and sectioned into frozen sections (20 μm). The sections were stained by hematoxylin and observed under light microscope. The number of neurons in dorsal and ventral horn was also counted. RESULTS: In cSCI group, some neurons appear to atrophy compared with that of intact group, but the number of neurons did not decrease apparently than that of intact group (P＞0.05). Comparatively, some cavities were observed in dorsal and ventral horn in hemi-sectioned and transitioned SCI group. And the number of neurons in dorsal horn and ventral horn decreased greatly at 24 hours, 7 and 21 days compared with intact group (P＜0.05). The results indicated that the decrease of neuronal number in dorsal horn and ventral horn after injury resulted from hSCI and tSCI, but not from cSCI. As a result, some different strategies should be considered for different injuries. For example, some neurotrophic factors may be useful in cSCI, but, many neurons have disappeared following hSCI and tSCI, therefore, other strategies that increase the number of neurons should be considered too. CONCLUSION: Our results provide the important morphological evidences on the change of spinal cord following cSCI, hSCI and tSCI. The data will be useful in treatment of SCI in the future.