RESUMO
@# Objective To compare performance of C5.0 decision tree models and radial basis function(RBF) neural network in predicting the risk of hemorrhagic transformation in acute ischemic stroke. Methods Patients with acute ischemic stroke admitted to hospital were enrolled. Hemorrhagic transformation group and non-hemorrhagic transformation group were divided according to whether hemorrhagic transformation occurred within 2 weeks after admission. Retrospectively collected patients’ case information. C5.0 decision tree models and RBF neural network model were established with the ratio of 7 :3 for training set and test set, and the prediction performance of the model was compared. Results A total of 460 patients’ case information were collected and divided in 314 training set samples and 146 test set samples. Accuracy rates of the C5.0 decision tree model were 96.5% and 80.1%, sensitivities were 98.1% and 82.6%, specificities were 94.8% and 77.9%, Kappa index were 0.93 and 0.60, and AUC were 0.97 and 0.80. Accuracy rates of the neural network model were 72.6% and 74.7%, sensitivities were 87.6% and 88.4%, specificities were 56.9% and 62.3%, Kappa index were 0.45 and 0.50, and AUCs were 0.72 and 0.75. In the training set, the prediction performance of the C5.0 decision tree model was superior to the RBF neural network model. However, there was no statistical difference in the test set.Conclusion C5.0 decision tree model is better than RBF neural network model in risk prediction.
RESUMO
Objective To investigate the risk factors and establish the Cox' s regression model on the recurrence of ischemic stroke. Methods We retrospectively reviewed consecutive patients with ischemic stroke admitted to the Neurology Department of the Hebei United University Affiliated Hospital between January 1,2008 and December 31,2009. Cases had been followed since the onset of ischemic stroke. The follow-up program was finished in June 30, 2010. Kaplan-Meier methods were used to describe the recurrence rate. Monovariant and multivariate Cox' s proportional hazard regression model were used to analyze the risk factors associated to the episodes of recurrence.And then, a recurrence model was set up. Results During the period of follow-up program, 79 cases were relapsed,with the recurrence rates as 12.75% in one year and 18.87% in two years. Monovariant and multivariate Cox' s proportional hazard regression model showed that the independent risk factors that were associated with the recurrence appeared to be age (X1)(RR=1.025,95% CI: 1.003-1.048),history of hypertension (X2) (RR= 1.976, 95% CI: 1.014-3.851), history of family strokes (X3) (RR=2.647,95%CI: 1.175-5.961), total cholesterol amount (X4) (RR= 1.485,95%CI: 1.214-1.817), ESRS total scores (X5) (RR= 1.327,95%CI: 1.057-1.666) and progression of the disease (X6) (RR= 1.889,95%CI: 1.123-3.178). Personal prognosis index (PI) of the recurrence model was as follows: PI=0.025X1 + 0.681X2+ 0.973X3 + 0.395X4+ 0.283X5 + 0.636X6. The smaller the personal prognosis index was, the lower the recurrence risk appeared, while the bigger the personal prognosis index was, the higher the recurrence risk appeared. Conclusion Age, history of hypertension, total cholesterol amount, total scores of ESRS, together with the disease progression were the independent risk factors associated with the recurrence episodes of ischemic stroke. Both recurrence model and the personal prognosis index equation were successful constructed.
RESUMO
Objective To investigate the effect of transplantation of human umbilical cord blood mesenchymal stem cells (CB-MSCs) on the levels of NGF and BDNF in rats with traumatic brain injury (TBI) and explore its possible mechanism of cerebral protection. Methods Ninety healthy male SD rats were equally randomized into sham-operated group, injury control group and treatment group.TBI models in the injury control group and treatment group were induced by the improved device of Feeney weight-dropping; the rats in the treatment group were injected Brdu-labeled 3×106 CB-MSCs solved in 1ml PBS by rat-tail vein, while the rats in the sham-operated group and the injury control group were injected the equal volume of PBS solution. No immunosuppressive agents were used in all the rats.HE staining, immunohistochemistry, in-situ hybridization were employed, respectively, to detect the morphological changes, Brdu positive cells, expressions of BDNF and NGF on the 3rd, 7th, 14th, 21st and 28th d of injection. Results Only a very small number of nerve cells were BDNF and/or NGF positive in the sham-operated group. Substantial BDNF and/or NGF positive cells in the injury control group were noted in the surrounding brain damaged area following traumatic brain injury, which peaked at their levels on about 14 d of injection (the A value of NGF=8.35±1.07, that of BDNF=9.01±1.74), following by a gradual decline; however, significant difference was still noted as compared with that in the sham-operated group (P＜0.05). BDNF and/or NGF-positive cells significantly increased in the treatment group, especially in the surrounding brain injured areas; their levels peaked on the 14th d of injection,following by a gradual decline on the 21st and 28th d, but they were still higher than those in the injury control group and sham-operated group at each time points (P＜0.05). Conclusion Transplantation of CB-MSCs can increase the secretion of BDNF and NGF in rats with TBI, improve the local micro-damage environment and promote the repair of neurons.