BACKGROUND:Studies have shown that sacral nerve-root stimulation based on anodes block technique can effectively reconstruct the bladder voiding function of the rabbits with spinal cord injury. But the corresponding technology of stimulating electrode has not been reported so far.
OBJECTIVE:To design and develop the stimulating electrodes matching with both rabbit sacral nerve roots and anodal blocking technique, to observe the ultrastructure and morphological change of rabbit sacral nerve roots which implanted in electrode stimulation for a long-term and to assess the safety of stimulating electrodes.
METHODS:Thirty New Zealand rabbits were included, 10 rabbits were randomly selected from them and sacrificed after anesthesia, and then cut the anterior roots of bilateral S 2 and S 3 immediately;after measuring the diameter under the light microscope, the sleeve type stimulation electrode matched with the diameter was made. The remaining 20 rabbits were randomly divided into control group and implantation group, with 10 rabbits in each group. In the implantation group, the stimulating electrodes were implanted into the forepart of S 2 and S 3 nerve roots after anesthesia, and then sacrificed after fed for half a year for col ecting the samples. Then ultrastructure change of sacral nerve roots with the implantation was observed.
RESULTS AND CONCLUSION:Structure of nerve cel s of sacral nerve roots remained in good condition under a light microscope after long-term implantation of the stimulating electrodes. No obvious degeneration of axons, no inflammatory infiltration and glial scar formation were observed. In the implantation group, myelins arranged closely without demyelination phenomenon, and there was no atrophy of neuronal nuclear, no nuclear sag, no increased nuclear decompression and heterochromatin in neurons under the light microscope. Immunohistochemical analysis showed, compared with the control group, there were no significant differences in the expressions of glial fibril ary acidic protein, Bax, Bcl-2 and Caspase-3 proteins of nerve roots in the implantation group. The stimulation electrode of rabbit sacral nerve root is developed successful y, that is, the implantation is simple and safe as it can be used for long-term implantation without histopathological changes and apoptosis.

Objective To explore the value of the prediction model based on diffusion weighted imaging(DWI)radiomic features and apparent diffusion coefficient(ADC)values in the assessment of p53 gene mutation status in endometrial cancer(EC).Methods The DWI data of 22 p53 wild-type and 60 p53 mutant EC patients were analyzed retrospectively.The DWI radiomic features of the primary lesions were extracted,and the ADC values were calculated.The prediction model was constructed based on support vector machine(SVM)algorithm.The area under the curve(AUC)of the receiver operating characteristic(ROC)curve was used to evaluate the performance of the prediction model.Internal validation was conducted using Bootstrap.Results The ADC value of p53 mutant EC was significantly lower than that of p53 wild-type EC(P=0.002).When comparing the ADC value and radiomics model,the combined ADC-radiomics model demonstrated the highest diagnostic efficacy,achieving an AUC of 0.924,sensitivity of 86.67％,and specificity of 90.91％.In Bootstrap-based validation,the combined ADC-radiomics model also showed high performance with an AUC of 0.904.The calibration curve and clinical decision curve analysis(DCA)showed that the combined ADC-radiomics model not only had better agreement between predicted and actual observed values but also provided better net benefits for the patients concerned.Conclusion The combined ADC-radiomics model achieved a more efficient assessment of p53 status in EC patients.