Objective To investigate the analgesic effects of different doses of dexmedetomidine(Dex)in regulating the brain-derived neurotrophic factor(BDNF)/protein kinase B(AKT)/cyclica-denosine monophosphate response element binding protein(CREB)signaling pathway in elderly rats with spinal fractures.Methods Sixty rats were randomly divided into control group(skin incision only),model group(spinal fracture without any drug treatment),positive drug group(spinal fracture+0.2 μg/kg sufentanil),low-dose Dex group(spinal fracture+0.4 μg/kg Dex),medium-dose Dex group(spinal fracture+0.6 μg/kg Dex)and high-dose Dex group(spinal fracture+0.8 μg/kg Dex),with ten rats in each group.Mechanical pain threshold and thermal pain threshold were used to assess pain and sedation effects in elderly rats with spinal fractures.Modified neurological severity score(mNSS)was employed to evaluate the degree of neurological dysfunction.Enzyme-linked im-munosorbent assay(ELISA)was performed to detect serotonin(5-HT),substance P(SP),calci-tonin gene-related peptide(CGRP)neurotransmitter levels,tumor necrosis factor-α(TNF-α)and interleukin-1 β(IL-1 β)inflammatory factor levels.Colorimetric assays were used to measure malon-dialdehyde(MDA)oxidative stress expression levels;kits were applied to determine superoxide dis-mutase(SOD)and catalase(CAT)oxidative stress indicator levels.Western blotting(WB)analy-sis was conducted to examine BDNF,phosphorylated(p)-AKT and p-CREB protein expression lev-els in the spinal dorsal horn tissues of elderly rats with spinal fractures.Results Compared with the control group,the model group showed significantly increased mNSS scores,5-HT,SP,CGRP,TNF-α,IL-1 β and MDA expression levels,and significantly decreased mechanical pain thresholds,thermal pain thresholds,SOD,CAT,as well as BDNF,p-AKT and p-CREB protein expression lev-els(P＜0.05).Compared with the model group,the positive drug group and the medium-and high-dose Dex groups exhibited significantly lower mNSS scores,5-HT,SP,CGRP,TNF-α,IL-1βand MDA expression levels,and significantly higher mechanical pain thresholds,thermal pain thresholds,SOD,CAT,as well as BDNF,p-AKT and p-CREB protein expression levels(P＜0.05).Compared with the positive drug group,the low-dose Dex group had significantly higher mNSS scores,5-HT,SP,CGRP,TNF-α,IL-1 β and MDA expression levels,and significantly low-er mechanical pain thresholds,thermal pain thresholds,as well as BDNF,p-AKT andp-CREB pro-tein expression levels(P＜0.05);the high-dose Dex group showed significantly lower mNSS scores,5-HT,SP,CGRP,TNF-α,IL-1 β and MDA expression levels,and significantly higher me-chanical pain thresholds,thermal pain thresholds,as well as BDNF,p-AKT and p-CREB protein expression levels(P＜0.05).Compared with the low-dose Dex group,the medium-and high-dose Dex groups demonstrated significantly lower mNSS scores,5-HT,SP,CGRP,TNF-α,IL-1 β and MDA expression levels,and significantly higher mechanical pain thresholds,thermal pain thresh-olds,SOD,CAT,as well as BDNF,p-AKT and p-CREB protein expression levels(P＜0.05),in-dicating dose-dependent effect.Conclusion Dex may alleviate pain and reduce its impact on neu-rological function caused by spinal fractures in elderly rats through activation of the BDNF/AKT/CREB signaling pathway.

Objective:To analyze the factors that affect patient prognosis after radical nephrectomy.Meth-ods:A total of 389 cases of renal cell carcinoma treated with radical nephrectomy between January 1 993 and December 2006 were reviewed.All the data were encoded.inserted into an Excel database and then ana-lyzed by SPSS 1 3.0 software.The cumulative survival rates were calculated by life-table method.We as-sessed the impact of multiple covariates on survival time with the Cox Regression model.Results:The patho-logical results showed that 307 cases were clear call carcinoma,51 cases were papillary renal cell carcinoma,21 cases were chromophobic renal cell carcinoma,2 cases were collecting duct carcinoma.and 8 cases were unclassified.One hundred and ninety-eight cases were of T1N0M0, 113 cases were of T2N0M0, 3 cases were of T1N1M0,10 cases were of T2N1M0, 51 cases were of T3N0M0, and 14 cases were of T3N1M0, Two hundred and sixty-eight cases were followed up.The 1-year survival rate was 96.5%,the 3-year survival rate was 90.7%.the 5-year survival rate was 75.7%.and the 10-year survival rate was 65.8%.Multivariable analysis revealed that significant prognostic factors included TNM stage,Robson stage.vena cava and supplementary treat-ment(X2=22.50.P=0.001).The most important prognostic factor was pathological stage(TNM and Robson).The regression coefficients were 0.533 and 0.674,and the relative risk was 1.941 and 2.01 1(P=0.004 and p=0.002).Conclusion:Radical nephrectomy is safe and effective.TNM stage.Robson stage and vena cava are prognostic factors.Supplementary treatment is a protective factor.