Objective To analyze the correlation between the Patellotrochlear index at different knee flexion angles and recurrent patellar dislocation,and to find the optimal knee flexion angle and the best diagnostic cut-off value for predicting recurrent patellar dislocation.Methods A total of 35 patients clinically diagnosed with recurrent patellar dislocation(study group)were selected.The lengths of the central sagittal plane of the patellar cartilage and the corresponding femoral trochlear cartilage were measured at knee flexion angles ranging from 0° to 70°,in 10° increments.The Patellotrochlear index was calculated and compared with the MRI data from 55 healthy volunteers(control group).Results The Patellotrochlear index in the study group and the control group showed a positive correlation with the knee flexion angle(r=0.935 and 0.909,P＜0.001).Statistically significant differences were found between the two groups at knee flexion angles of 0°,10°,20°,30°,and 40°(t=7.480,5.742,5.200,3.558,4.271,P＜0.05).The predictive efficacy of the Patellotrochlear index for recurrent patellar dislocation varied at different knee flexion angles,with the area under the curve(AUC)and the best diagnostic cut-off values of 0.891,0.834,0.778,0.710,0.741 and 0.195,0.323,0.486,0.606,0.712,respectively.Conclusion There are significant differences in the Patellotrochlear index at different knee flexion angles.A knee flexion angle of 0° is the optimal knee flexion angle for the Patellotrochlear index to predict recurrent patellar dislocation,with a recommended best diagnostic cut-off value of 0.195.

Objective To analyze the correlation between the Patellotrochlear index at different knee flexion angles and recurrent patellar dislocation,and to find the optimal knee flexion angle and the best diagnostic cut-off value for predicting recurrent patellar dislocation.Methods A total of 35 patients clinically diagnosed with recurrent patellar dislocation(study group)were selected.The lengths of the central sagittal plane of the patellar cartilage and the corresponding femoral trochlear cartilage were measured at knee flexion angles ranging from 0° to 70°,in 10° increments.The Patellotrochlear index was calculated and compared with the MRI data from 55 healthy volunteers(control group).Results The Patellotrochlear index in the study group and the control group showed a positive correlation with the knee flexion angle(r=0.935 and 0.909,P＜0.001).Statistically significant differences were found between the two groups at knee flexion angles of 0°,10°,20°,30°,and 40°(t=7.480,5.742,5.200,3.558,4.271,P＜0.05).The predictive efficacy of the Patellotrochlear index for recurrent patellar dislocation varied at different knee flexion angles,with the area under the curve(AUC)and the best diagnostic cut-off values of 0.891,0.834,0.778,0.710,0.741 and 0.195,0.323,0.486,0.606,0.712,respectively.Conclusion There are significant differences in the Patellotrochlear index at different knee flexion angles.A knee flexion angle of 0° is the optimal knee flexion angle for the Patellotrochlear index to predict recurrent patellar dislocation,with a recommended best diagnostic cut-off value of 0.195.

Objective To construct and expr es s a recombinant plasmid of nonstructural protein NS3-NS4 of hepatitis C virus ( HCV), and to identify the antigenicity of the expressed protein. Methods A gene region encompassing the nonstructural protei n NS3-NS4 of HCV was amplified by polymerase chain reaction (PCR) from the pUC1 9/HCV template. The recombinant expression plasmid containing the pBV220/NS3-NS 4 sequence was constructed, and the nonfused NS3-NS4 recombinant protein was ex pressed in E.coli DH5? efficiently. The recombinant protein was det ected by SDS-PAGE and ELISA. Results We successfully constructed and expressed the recom binant plasmid in prokaryote. Its antigenicity was detected with 50 standard ser a. Compared with the second-generation diagnostic Kit, the total detection rate was 96%. Conclusion The whole NS3-NS4 protein, a region of dominant immunogenicity, should be the effective component of the HCV diagnostic Kit and provide the clue for developing HCV DNA vaccine.

Objective:To evaluate the expression of basic fibroblast growth factor (bFGF) in fetal liver stromal cell(FLSC) during hypoxia so as to provide evidences for hematopoietic stromal cell therapy of brain ischemia. Methods: FLSCs from 14.5-day-old mouse fetuses were cultured and passaged. Subconfluent cells of the fifth passage were cultured in hypoxia condition (95% N_(2) + 5% CO_(2) ). bFGF mRNA and bFGF protein were detected at 2,4,8,16 and 32 h of culture by semi-quantitative RT-PCR and Western blot, respectively. Results: bFGF mRNA and bFGF protein were very low in normally cultured cells, but increased significantly under the condition of hypoxia. Expression of bFGF mRNA obviously increased at 2 h of hypoxia culture and reached peak at 16 h, with the peak-value being 5.52 folds that of the control (-[32.86?9.57-]% vs -[5.94?2.65-]%,P

Objective:To evaluate the expression of transforming growth factor-?1 (TGF-?1) in fetal liver stromal cells during hypoxia,in an attempt to provide evidences for cell therapy of brain ischemia. Methods: Cells from 14.5-day-old mouse fetuses were cultured and passaged. Subconfluent cells of the fifth passage were cultured in hypoxia condition (95% N2 + 5% CO2 ). TGF-?1 mRNA and TGF-?1 were detected by semi-quantitative RT-PCR and Western blot,respectively. Results: TGF-?1 mRNA and TGF-?1 levels,which are very low in normally cultured cells, increased significantly in hypoxia-cultured cells. Expression of TGF-?1 mRNA increased from (5.47?2.76)% to (10.38?3.65)% at 4 h of hypoxia(P