To study the protective effect of rosuvastatin on ischemic brain injury and its mechanism, focal cerebral ischemia/reperfusion was induced by occlusion of the middle cerebral artery （MCA） using the intra-luminal fil...To study the protective effect of rosuvastatin on ischemic brain injury and its mechanism, focal cerebral ischemia/reperfusion was induced by occlusion of the middle cerebral artery （MCA） using the intra-luminal filament technique. The cerebral blood flow was monitored with laser-Doppler flowmetry （LDF）. The slices of brain tissue were stained with cresyl-violet. The cerebral volume of infarction and edema were quantified with ImageJ software. The expressions of endothelial NO synthase （eNOS） and activated caspase-3 were detected with Western blot. The inducible NO synthase （iNOS） positive cells were immunohistochemically observed. The results demonstrated that rosuvastatin （20 mg/kg） could remarkably decrease infarct volume and cerebral edema after MCAO 90 min/reperfusion 24 h. Western blots showed that the expression of eNOS in cerebral cortex before and after ischemia was （100±43.3） %, （1668.9± 112.2） % respectively （P〈0.001）, rosuvastatin significantly up-regulated the expression of eNOS in non-ischemic cortex （P〈0.001）, whereas in ischemic cortex of rosuvastatin group the expression of eNOS was （1678.8 ± 121.3） %. There was no expression of activated caspase-3 in non-ischemic cortex, nonetheless the expression of activated caspase-3 increased after ischemia, and rosuvastatin significantly diminished it （P〈0.01）. Immunohistochemistry revealed no iNOS-positive cells in non-ischemic brain area, while in ischemic brain area the number of iNOS positive cells went up, and rosuvastatin could significantly reduced them. Consequently, the mechanisms of rosuvastatin＇s neural protection on ischemic brain injury are to enhance expression of eNOS, to inhibit expression of iNOS and activated caspase-3.展开更多
Because laboratory tests are expensive and time-consuming and may not be available to farmers, soil nitrate quick tests are required for optimal nitrogen management strategies in China to increase nitrogen use efficie...Because laboratory tests are expensive and time-consuming and may not be available to farmers, soil nitrate quick tests are required for optimal nitrogen management strategies in China to increase nitrogen use efficiency and to reduce nitrogen losses. A total of 328 soil samples were collected at different soil depths from 225 sites in China, which covered a wide range of climatic and geographic regions, soil types, croplands and soil textures, to evaluate the suitability of a quick reflectometer test method for analysing soil NO3-N in a wide range of soil NO3 concentrations, soil types and cropping systems in China, mainly by comparison of soil NO3-N assessed by a quick-test method （a reflectometer） and a standard laboratory method, i.e., high-performance liquid chromatography （HPLC）. The reflectometer showed excellent agreement with the laboratory HPLC method with regard to soil nitrate contents for all analysed soil samples. The linear regression had slopes of 1 ± 0.08 and intercepts of ± 1.38 mg NO（-,3）-N L^（-1） among different soil types and croplands. Compared with the 1：1 lines, the regression analysis for each soil type showed statistically significant but small differences in slope; the relative difference between the values measured using the two analytical systems varied from -8% to 6%, and there were no differences in intercept except for paddy soil. The reflectometer showed adequate, statistically significant precision in determining soil nitrate contents, and it could therefore be directly used instead of the laboratory methods for soil NO（-,3）-N measurement in China.展开更多
基金This project was supported by a grant from National Natural Sciences Foundation of China (No. 30472234), and the National Center of Competence in Research Neural Plastic-ity and Repair of Switzerland (3200B0-100790/1).
文摘To study the protective effect of rosuvastatin on ischemic brain injury and its mechanism, focal cerebral ischemia/reperfusion was induced by occlusion of the middle cerebral artery （MCA） using the intra-luminal filament technique. The cerebral blood flow was monitored with laser-Doppler flowmetry （LDF）. The slices of brain tissue were stained with cresyl-violet. The cerebral volume of infarction and edema were quantified with ImageJ software. The expressions of endothelial NO synthase （eNOS） and activated caspase-3 were detected with Western blot. The inducible NO synthase （iNOS） positive cells were immunohistochemically observed. The results demonstrated that rosuvastatin （20 mg/kg） could remarkably decrease infarct volume and cerebral edema after MCAO 90 min/reperfusion 24 h. Western blots showed that the expression of eNOS in cerebral cortex before and after ischemia was （100±43.3） %, （1668.9± 112.2） % respectively （P〈0.001）, rosuvastatin significantly up-regulated the expression of eNOS in non-ischemic cortex （P〈0.001）, whereas in ischemic cortex of rosuvastatin group the expression of eNOS was （1678.8 ± 121.3） %. There was no expression of activated caspase-3 in non-ischemic cortex, nonetheless the expression of activated caspase-3 increased after ischemia, and rosuvastatin significantly diminished it （P〈0.01）. Immunohistochemistry revealed no iNOS-positive cells in non-ischemic brain area, while in ischemic brain area the number of iNOS positive cells went up, and rosuvastatin could significantly reduced them. Consequently, the mechanisms of rosuvastatin＇s neural protection on ischemic brain injury are to enhance expression of eNOS, to inhibit expression of iNOS and activated caspase-3.
基金the German Federal Ministry of Education and Research (BMBF) (No.00330800A)
文摘Because laboratory tests are expensive and time-consuming and may not be available to farmers, soil nitrate quick tests are required for optimal nitrogen management strategies in China to increase nitrogen use efficiency and to reduce nitrogen losses. A total of 328 soil samples were collected at different soil depths from 225 sites in China, which covered a wide range of climatic and geographic regions, soil types, croplands and soil textures, to evaluate the suitability of a quick reflectometer test method for analysing soil NO3-N in a wide range of soil NO3 concentrations, soil types and cropping systems in China, mainly by comparison of soil NO3-N assessed by a quick-test method （a reflectometer） and a standard laboratory method, i.e., high-performance liquid chromatography （HPLC）. The reflectometer showed excellent agreement with the laboratory HPLC method with regard to soil nitrate contents for all analysed soil samples. The linear regression had slopes of 1 ± 0.08 and intercepts of ± 1.38 mg NO（-,3）-N L^（-1） among different soil types and croplands. Compared with the 1：1 lines, the regression analysis for each soil type showed statistically significant but small differences in slope; the relative difference between the values measured using the two analytical systems varied from -8% to 6%, and there were no differences in intercept except for paddy soil. The reflectometer showed adequate, statistically significant precision in determining soil nitrate contents, and it could therefore be directly used instead of the laboratory methods for soil NO（-,3）-N measurement in China.
