| Alteration of structure of cauda equina andneuron in medullary cone in compression injury ofcauda equina in ratsObjective: To document that neuron in medullary cone injuryed when cauda. equinawas compressed through Observationthe structure of cauda equina and neuron in medullary cone in compression injury of cauda equina in rats.Methods: 66 male S-D rats were selected at random, they were classified as 11 groups:normal control ,sham operation, 30min,2h,4h,8h5ld,3d,lw,2w,3w after operation.The cauda equine compression model were created as the method of Kawakami and estimated neurological function as the modified Tarlov's methold when animal awaked. Animals were anesthesiaed at time above-mentioned, set an aortic cannlation through left ventricle, cuted theright auricle made blood diffluence. 0.9% Saline was instillated until outflow was transparent,changed the instillation fluid to 4% formaldehydum polymerisatum for 15-20min.cuted S2-S3 segment of spinal cord and compressed cauda equine. Those tissue were used for paraffin section and HE stain.Transmission electron microscope sample preparation:each one in five groups:sham operation^ d,lw,2w,and 3w after operation, were selected. Cuted tissue taked out to small pieces, 2.5% glutaral 15ml was used to pre-fix, two hours later, the sample was rinsed by buffer; then post-fixed by 1% osmium acid, enviromental temperature kept 4C;desiccated by ethanol; embed by epoxy resin 618.Ultrathin section was made; at last, the sample was stained by acetic acid U and lead citrate.Results:The animals in groups cauda equinea compressed wre paraplegia. The Scores of modified Tarlov's mothold were 0-2 grade only, few cases recover to 3 grade. HE stain showed that blood vessles were closed or constricted after compression,in group 3d post-operation,small vessels opened again. Myelin sheath of nerve fibers degenerated, and there was edema, inflammatory cells among nerve fibers. In group lw post-operation, fibrosis was seen in many spots of slids, and small vessles dilataltion, blood capillary proliferation were seen in most cases.To 2-3w post-operation, situation above-mentioned was worser. Individual neurons in spinal cord were dark stained,in those Id post -operation,cells shrunken can been seen.The results of electron microscope observation: Myelin sheath of nerve fibers degeneration can be finded 3d after opretion- Myelin sheath became rough and delamination in post-operation, and it became more serious in following time.There were some changes in neurons in spinal cord anterior horn in 3d after operation, Nuclears were dark stained, Heterochromatin were seen under nuclear membrane, Mitochondrion were swellingln samples lw post-operation, nuclears were pycnosis, mitochondrion were more swelling andthe crest disappeared.The manifestation was same in 2-3w after operation.Conclusions: l.The structure of neurons in medullary cone will alter due to compression injury of cauda equine. 2. The injury of medullary cone neurons maybe one of reasons of poor recovery after cauda equina compressed .SECTION 2:The effect of compressed cauda equine to neuron apoptosis in medullarycone in ratsObjective: To determine if apoptosis cells in medullary cone increase in cauda equina compressed rats and the change pattern with time through TUNEL staining.Methods: The methods of animal model and paraffin section prepareing were mentioned in section 1. TUNEL staining was carried out as the introduction of in situ cell apoptosis detection kit. The outcome's judgement: positive findings meant that nuclei was stained by brown; if not stained, negative.The area of spinal cord were determined by Photoshop 7.0 program under microscope, amplifying 20x. Statistic analysis:The positive cells in lmm2 were calculated. The data were disposaled by SPSS 11.5 program .One way analysis of variance was used.Results: The number of positive stain cells in lmm2 area in each group:negative control: 0.28+0.34, sham operation: 0.53+0.52, 30min post-operation: 0.60+0.47, 2h... |
PDF Full Text Request