China′s strategy and experience in preventing and controlling the local spreading and epidemic of COVID-19 / 上海预防医学

After implementing a series of prevention and control strategies of Corona Virus Disease 19(COVID-19), China′s local epidemic situation has been basically blocked.While China has achieved a periodic success, global pandemic situation is still serious.Together with the timeline of China′s epidemic prevention and control this study reviewed the main strategies and measures in response to COVID-19 epidemic from Dec.2019 to Mar.23, 2020, and summarized China′s prevention and control plans and experiences.We hope all countries could fully understand the importance of non-pharmaceutical public health interventions, make positive and effective adjustments to the measures and strategies of prevention and control based on their own national conditions.

Effect of nitric oxide derived from endothelial nitric oxide synthase on tumor angiogenesis / 癌症

<p><b>BACKGROUND AND OBJECTIVE</b>Studies have shown that nitric oxide (NO) derived from endothelial nitric oxide synthase (eNOS) is expressed widely in tumor tissues and regulates tumor angiogenesis. However, the results are controversial. This study was to investigate the effect of NO on tumor angiogenesis and its mechanism.</p><p><b>METHODS</b>C57BL/6 mice inoculated with Lewis lung cancer cells were randomly divided into three groups. Mice in the NO group were inoculated with lung cancer cells transfected with eNOS gene, mice in the L-NAME group with L-NAME, an eNOS antagonist, and mice in the control group with normal saline. Plasma concentration of NO and the number of endothelial progenitor cells (EPCs) in peripheral blood were detected . Tumor vessel density, CD133+ cells, and the expression of VEGF-VEGFR in tumor tissues were also measured.</p><p><b>RESULTS</b>Four weeks after inoculation of Lewis cells, tumor volume was significantly larger in control group [ (3022 +/- 401) mm(3)] than in the L-NAME group [ (1204 +/-97) ) mm(3)] and in the eNOS group [(1824 +/- 239) mm(3)] (P<0.01). eNOS protein and NO production increased significantly in Lewis lung cancer cells transfected with eNOS gene. But the number of CD133-positive cells and vessel density in tumors were significantly lower in the eNOS group than in the control group [(48+/-19) / HPF vs. ( 103 +/- 27)/ HPF, (19+/- 7) HPF vs. (31 +/- 9) HPF, P<0.05]. The number of EPCs in peripheral blood was not statistically different between each group. The levels of NO in blood and tumor tissue significantly decreased after the treatment of L-NAME, while the tumor vessel density reduced to 12+/- 5/ HPF (P<0.01, vs. the control group; P<0.05, vs the eNOS transfected group). The number of EPCs in blood and that of CD133-positive cells in tumor tissue were significantly smaller in the L-NAME group than in the control group (P<0.05).</p><p><b>CONCLUSION</b>No derived from eNOS inhibits angiogenesis and tumor growth, which may be due to its suppression on either the mobilization or homing of EPCs via VEGF binding to VEGFR.</p>