Objective:To study the nephrotoxicity induced by triptolide ( TP) on MDCK cell model and investigate its effect on oxidative stress. Methods:Aristolochic acid was chosen as the positive control. After the MDCK cells were incubated with 0. 5, 5, 50 and 500 nmol·L-1 TP for 24h, MTT method was used to observe the cell inhibiting rate and lactate dehydrogenase (LDH) release test was used to detect the cell membrane damage caused by TP. The cell morphology was observed under an inverted microscope. After the MDCK cells were incubated with 500 nmol·L-1 TP respectively for 30min, 1h, 2h, 4h and 6h, the level of reactive oxygen species ( ROS) was detected using 2′,7′-dichlorodihydro-fluorescein diacetate ( DCFH-DA) as the fluorescent probe. Results:Compared with those of the negative control group, the cell inhibiting rates and the relative LDH release rates in TP-treated group were increased sig-nificantly(P<0. 01). The cells in TP-treated group were creased, turned into the round shape and began to shed off. After the MDCK cells were incubated with TP for 30min, the level of ROS reached the highest value, and then began to decrease (P<0. 01). Conclu-sion:TP can induce the toxic effects on MDCK cells and the mechanism may be related to oxidative stress.

Objective To investigate the MRI features and characteristics of irregular intraductal papilloma (IDP)and invasive ductal carcinoma (IDC),and to improve the diagnostic accuracy of MRI.Methods This study retrospectively included 3 3 patients with IDP and IDC confirmed by surgery and pathology,and analyzed MRI findings including lesion size,boundary,internal components,plain signal intensity,enhancement mode,ADC value and TIC curve χ.2 test,t test and rank-sum test were performed.Results Compared with the two groups,lesion boundary (P＜0.001),size (P＜0.001 ),ADC value (P＜0.001 ),enhancement mode (P＝0.001 ),TIC curve peak time (P＜0.001),slope (P＜0.001)and peak enhancement rate (P＜0.001)were statistically significant (P＜0.05);lesion (P＝0.159), internal components (P＝0.778),T2 WI signal (P＝0.438)and curve type (P＝0.406)were no statistically difference.Conclusion The irregular mass type IDP and IDC have similar MRI findings,the edge of the lesion,the ADC value,the enhancement mode,and the peak time,slope and peak enhancement rate of the curve are important for the identification of the two diseases.