BACKGROUND: Navigation systems all can improve the accuracy rate in cervical pedicle screw insertion, but cannot achieve desired outcomes because of some shortcomings, such as poor imaging quality, complicated operation, poor real-time performance, and invasive navigation.OBJECTIVE: To study the accuracy of X-ray fluoroscopy and CT three-dimensional image navigation in cervical pedicle screw insertion.METHODS: Totally 90 patients undergoing cervical pedicle screw insertion from the First Affiliated Hospital of Nanyang Medical College were enrolled, and randomly divided into control and experimental groups (n=45 per group). 132 cervical pedicle screws were inserted into the patients in the control group manually under X-ray fluoroscopy, and 128 ones were inserted into the patients in the experimental group assisted with CT three-dimensional image navigation. The operation time and intraoperative blood loss in the two groups were recorded. Postoperative CT three-dimensional reconstruction was performed to compare the placement accuracy between two groups.RESULTS AND CONCLUSION: The excellent and good rate of placement in the experimental group (95.3%) was significantly higher than that in the control group (88.6%, P < 0.05). (2) The operation time and intraoperative blood loss in the experimental group were significantly higher than those in the control group, and the navigation matching time and radiant quantity in the experimental group were significantly less than those in the control group (P < 0.05). (3) The Japanese Orthopedic Association scores showed no significant difference between two groups before surgery (P > 0.05),and were significantly improved in the experimental group compared with the control group at 3 and 6 months postoperatively (P < 0.05). The incidence of complications in the experimental group was significantly lower than that in the control group (7% versus 16%, P < 0.05). (5) These results suggest that compared with X-ray fluoroscopy, CT three-dimensional image navigation can improve the accuracy of cervical pedicle screw insertion, showing higher safety and precision. However, it needs complicated operation skills, and long operation time results in massive intraoperative blood loss; thereafter, choosing which placement method depends on the patient condition.

Aim To study the cardiotoxicity of celastrol to zebrafish embryo.Method 48 h post-fertilization zebrafish embryos were used as model for analysis of heart toxicity and were treated with various concentrations of celastrol.6,12,24 h after treatment morphological and functional changes of embryos hearts were observed.Results Cardiotoxicity was not found in embryos during 24 h treatment with 1 ?mol?L-1 concentration of celastrol.Toxic symptoms of embryos were caused by 2,3,4 ?mol?L-1 concentrations of celastrol with appearance of heart linearization,heart membrane hemorrhage and hemocytes accumulation in cardiac region.Moreover,heart rate decreased significantly with increase of concentration and prolongation of treatment.The EC50(24 h)of decrease of heart rate was about 1.78 ?mol?L-1.Conclusion Celastrol is cardiotoxic to zebrafish embryo.