Objective To observe the spatiotemporal characteristics of the micro-structural injury in a rat model of diffuse axonal injury (DAI) and quantitatively assess the axonal injury severity in the vulnerable areas. Methods The 7.0 T MRI was performed in rats in DAI group (n =20) and control group ( n = 15 ) to synthesize the diffusion tensor imaging ( DTI) parameter map and calculate the parameter value of the vulnerable areas. Immunohistochemistry was used to detect β-APP expression in the vulnerable areas and the IPP software to quantitatively assess the axonal injury severity. Results Compared with the control group, FA and AD maps showed local signal defection or reduction in the corpus callosum and their values decreased significantly in the brain stem and corpus callosum in the DAI group (P ＜0.01 ). The integrated optical density (IOD) value of the vulnerable areas in the DAI group was significantly higher than that of the control group ( P ＜ 0. 01 ) , with the highest level in the brain stem (P＜0.05). The normalized FA, AD and ADC in the vulnerable areas were correlated negatively with the IOD (P ＜ 0.05). Conclusion DTI can detect invisible micro-structural injury in the vulnerable areas and quantitatively assess the axonal injury severity in vivo in the early stage.

AIM:To investigate radiosensitization effect of apatinib, a vascular endothelial growth factor (VEGF) receptor2 tyrosine kinase inhibitor, on human gastric carcinoma cell line SGC-7901 and its mechanism.METHODS:SGC-7901 cells were divided into control group, apatinib group, radiotherapy group and combination group.The cell viability was measured by CCK-8 assay.The changes of cell apoptosis and cell cycle were analyzed by flow cytometry.The protein levels of cell apoptosis biomarkers, such as PARP, cleaved caspase-9, cleaved caspase-3 and Bcl-2, and cell proliferation biomarkers, p-PLCγ1 and p-ERK1/2, were detected by Western blot.γ-H2AX expression was detected by immunofluorescence.RESULTS:Compared with apatinib group and radiation group, the cell viability was inhibited after treatment with both apatinib and X-ray (P<0.01).The protein levels of cell proliferation markers p-PLCγ1 and p-ERK1/2 were down-regulated.The cell apoptosis was enhanced (P<0.01).The protein levels of cell apoptosis makers such as PARP, cleaved caspase-9 and cleaved caspase-3 were up-regulated, while Bcl-2 was down-regulated.The disappearance of γ-H2AX foci in the nucleus was delayed, indicating that apatinib impaired the repair of radiation-induced DNA double-strand breaks.The proportion of G2 phase was significantly increased (P<0.01).The combination treatment had more significant effect on SGC-7901 cells than treating with apatinib or radiotherapy alone.CONCLUSION:Apatinib increases the radiosensitivity of gastric cancer cells via blocking VEGF pathway.

Objective:To investigate the first aid management, doctors′ command of first aid knowledge of private dental clinics in Zhangjiakou city and the influencing factors, for references in strengthening the emergency management level of these clinics and the emergency capacity of doctors.Methods:Customized questionnaire was used in a survey of 192 doctors in 64 private dental clinics in the city from June to September in 2019, and 172 valid responses were recovered. The questionnaire covered such aspects as basics of these doctors, first-aid training received and first-aid knowledge command, as well as first-aid management of these clinics. Enumeration data were indicated with frequency number and percentage, while measurement data were indicated with ± s. Univariate analysis of first-aid knowledge scoring was made with Mann-Whitney U test. Results:The first-aid knowledge of dental doctors in private dental clinics in Zhangjiakou was poor, scoring 51.8±14.6 points in general, and those scoring above 60 points accounted for merely 19.3%. The proportion of dental doctors participating in first-aid knowledge training and emergency drill was low. Only 7.8% of the private dental clinics in Zhangjiakou had complete rescue equipment. Scoring of the dental doctors participating in emergency drill and emergency knowledge training was higher than those without such experiences, with the difference being statistically significant( P<0.001). Conclusions:Private dental clinics should regularly arrange their staff to participate in first-aid training and emergency drills; prepare an emergency plan, equip rescue facilities and first-aid medication; dental doctors should strengthen their study of first-aid knowledge.