Objective To investigate the influence of aerobic exercise on the vulnerability of atherosclerotic plaques and to observe the concentration of matrix metalloproteinase-9 ( MMP-9 ) and matrix metalloproteinase-14(MMP-14) in carotid atherosclerotic plaques in apolipoprotein E (APoE) gene deficient mice.Methods Eighty male, APoE gene deficient mice were divided into two equal groups: an aerobic exercise group and a limited action control group. Carotid atherosclerotic lesions were induced by perivascular constrictive collars placed on the right common carotid artery. Blood lipid levels in the exercise group were measured after 8 weeks of treadmill running and also in the control group. The morphological characteristics of carotid atherosclerotic plaques were observed in the two groups. Plaque area and fibrous cap thickness were measured. Lipid and collagen positive areas were quantified and the ratios correlated with the entimal areas were calculated. Plaque rupture rate and vulnerable index were calculated.Immunostaining was used to detect MMP-9 and MMP-14 expression in the atherosclerotic plaques. The mRNA levels of MMP-9 and MMP-14 mRNA in the fresh carotid plaques were quantified using a real-time reverse-transcriptase polymerase chain reaction (RT-PCR). Western blotting was performed for examining MMP-9 and MMP-14 protein expression in the fresh carotid plaques.Results No significant difference in serum lipid profiles or plaque area was found between the exercise and control groups. Compared with the control group, mean fibrous cap thickness, cap/core ratio and collagen content were all significantly higher in the exercise group, and lipid content was significantly lower. Plaque rupture rate and the vulnerable index were both significantly lower in the exercise group. Immunostaining showed that MMP-9 and MMP-14 expression were lower in the exercise group compared with the control group.The mRNA expression of MMP-9 and MMP-14 was also significantly lower.Conclusions Aerobic exercise can decrease the expression of MMP-9 and MMP-14 in carotid atherosclerotic plaques in ApoE gene deficient mice. Aerobic exercise may play a role in forestalling atherosclerosis by increasing the stability of plaque and decreasing plaque vulnerability.

Objective To understand the application and effect of problem based,case based and evidence based (PCE) combined teaching method in urology surgery clinical teaching.Methods A total of 50 clinical medicine students were selected.PCE combined teaching method was applied in urology surgery clinical teaching and the teaching effect was evaluated.Results The ratios of student who thought PCE combined teaching method could stimulate learning enthusiasm,improve learning efficiency and improve the abilities of logical thinking,inductive analysis,practical application,self-study,literature retrieval,innovation and team cooperation were 96％,94％,95％,94％,100％,88％,100％,96％ and 95％ respectively.All students thought this new teaching method could be extended in other subjects.Conclusions Application of PCE combined teaching method in urology surgery clinical teaching can achieve good teaching effect and it is worth recommending in clinical teaching.

Objective To investigate a feasibility of using dose constraint template (DCT) to increase conformity index (CI) of planning target volume (PTV) and improve intensity modulated radiation therapy (IMRT) planning efficiency for early stage nasopharyngeal carcinoma. Methods Ten patients with pathological diagnosed and treated by IMRT were selected for this study. Target volumes were delineated with Corvus 6.3 of treatment planning system, two dose limiting regions(DLR) around PIN were added by extending from PIN,each DLR was 1 cm thick. We created three plans:Plan0,Planl and Plan2. PianO was without DLR and DCT, Planl without DLR but with DCT, Plan2 with both condition;but to compare dose distribution in PLTV and normal tissue using three plans. Results Three plans could fill equal request of dose distribution in PLTV and normal tissue, and their difference was not statistical significant. CI of Plan2 was increased and planning time was decreased significantly compared with Piano and Planl. Conclusloa Usage of DCT together with DLR can increase CI of PTV and improve IMRT planning efficiency for early stage nasopharyngeal carcinoma, planning time is shortened significantly.