OBJECTIVE： To determine the cardioprotective ef- fect of magnesium lithospermate B （MLB） on myo- cardial ischemia/reperfusion （MI/R） injury and to in- vestigate the antioxidant potential in vivo and in vitro. MET...OBJECTIVE： To determine the cardioprotective ef- fect of magnesium lithospermate B （MLB） on myo- cardial ischemia/reperfusion （MI/R） injury and to in- vestigate the antioxidant potential in vivo and in vitro. METHODS： MI/R injury was induced by the occlu- sion of left anterior descending coronary artery for 30 min followed by reperfusion for 3 h in rats. After reperfusion, hearts were harvested to assess infarct size, histopathological damages, the levels of superoxide dismutase （SOD）, catalase （CAT）, glutathione peroxidase （GPx）, reduced glutathione （GSH） and malondialdehyde （MDA）. Blood samples were collected to determine serum levels of creatine kinase-MB （CK-MB）, cardiac troponin （cTnl） and lactate dehydrogenase （LDH）. Furthermore, simulatedischemia/reperfusion （SI/R） injury in vitro was established by oxygen and glucose deprivation （OGD） for 2 h followed by 24-hour recovery period in cardiomyocytes. The activity of LDH in the cultured su- pernatant and the levels of intracellular reactive oxygen species （ROS）, SOD and MDA in cardiomyo- cytes were also measured. Finally, cardiomyocytes apoptosis was determined with flow cytometry. RESULTS： MLB significantly limited infarct size, ameliorated histopathological damages and prevented leakage of CK-MB, cTnl and LDH. Additional- ly, SOD, CAT, GPx and GSH activities were notably increased by MLB, along with the MDA content decreased as compared with the model group in rats. In vitro study, MLB also decreased LDH activity in the cultured supernatant, increased SOD activity in cardiomyocytes, reduced intracellular ROS and MDA levels, and significantly suppressed cardiomyocytes apoptosis. CONCLUSION： MLB possessed remarkably cardioprotective effects on MI/R injury in vivo and in vitro. The protection of MLB may contribute to its antioxidant properties.展开更多
The mechanisms of brain ischemic insult include glutamate excitoxicity, calcium toxicity, free radicals, nitric oxide, inflammatory reactions, as well as dysfunctions of endoplasmic reticulum and mitochondrion. These ...The mechanisms of brain ischemic insult include glutamate excitoxicity, calcium toxicity, free radicals, nitric oxide, inflammatory reactions, as well as dysfunctions of endoplasmic reticulum and mitochondrion. These injury cascades are interconnected in complex ways, thus it is hard to compare their pathogenic importances in ischemia models. And the research in cellular and molecular pathways has spurred the studies in potential neuroprotections mainly in pharmacological fields, such as anti-excitotoxic treatment, calcium-channel antagonism, approaches for inhibition of oxidation, inflammation and apoptosis, etc. Besides, other protective interventions including thrombolysis, arteriogenesis, regeneration therapy, and ischemia preconditioning or postconditioning, are also under investigations. Despite the present difficulties, we are quite optimistic towards future clinical applications of neuroprotective agents, by optimizing experimental approaches and clinical trials.展开更多
The particle-size distribution and mineralogical composition of the clay （〈 2 μm） and fine-sand （0.25-0.10 mm） fractions in soils of two inland valleys in Abakaliki and Bende, Southeast Nigeria, were investigate...The particle-size distribution and mineralogical composition of the clay （〈 2 μm） and fine-sand （0.25-0.10 mm） fractions in soils of two inland valleys in Abakaliki and Bende, Southeast Nigeria, were investigated to provide basic information on soil-forming processes and agricultural potentials. These soils were silty or clayey, deriving from Cretaceous or Tertiary shale materials. The particle-size distribution and its computation on a clay-free basis revealed relatively remarkable lithologic breaks in a couple of pedons. The effect of lithologic discontinuities on soil mineralogical composition was not, however, conspicuous. Petrographic investigation revealed that quartz predominantly comprised the fine-sand fraction in the soils at both study sites. Nevertheless, the clay mineralogical composition of the soils was a mixture of kaolinite, irregularly interstratified smectite-illite intergrades （S/I）, hydroxyl-A1 interlayered 2：1 type clays （HICs）, vermiculite, smectite, halloysite and illite along with fine-sized quartz in Abakaliki. The soils of Bende predominantly contained smectite, which was partially interlayered with hydroxyl-A1 and kaolinite. It is suggested that seasonal floodwater has slowed the disintegration of weatherable clay minerals inherited from the shale, while quartz originating from the sandstone is predominant in the fine-sand fraction. Additionally, a possible soil-forming process observed at the both study sites was ferrolysis, which was indicated by a clear decreasing pattern of HICs downward in the soil profiles, The entry of S/I and vertical distribution patterns for a couple of clay minerals in the pedon suggested that the soils in Abakaliki have developed under the significant influence of aeolian dust delivered by the Harmattan. The findings might describe a site-specific deposition pattern of Harmattan dusts as well as hydromorphic soil-forming processes in the wetlands of the inland valleys.展开更多
基金Supported by the National Natural Science Foundation of China (No. 81173514,No.81001673)the Xijing Research Boosting Program (No. XJZT10D02)the Excellent Civil Service Training Fund of Fourth Military Medical University(No. 4138C4IDK6)
文摘OBJECTIVE： To determine the cardioprotective ef- fect of magnesium lithospermate B （MLB） on myo- cardial ischemia/reperfusion （MI/R） injury and to in- vestigate the antioxidant potential in vivo and in vitro. METHODS： MI/R injury was induced by the occlu- sion of left anterior descending coronary artery for 30 min followed by reperfusion for 3 h in rats. After reperfusion, hearts were harvested to assess infarct size, histopathological damages, the levels of superoxide dismutase （SOD）, catalase （CAT）, glutathione peroxidase （GPx）, reduced glutathione （GSH） and malondialdehyde （MDA）. Blood samples were collected to determine serum levels of creatine kinase-MB （CK-MB）, cardiac troponin （cTnl） and lactate dehydrogenase （LDH）. Furthermore, simulatedischemia/reperfusion （SI/R） injury in vitro was established by oxygen and glucose deprivation （OGD） for 2 h followed by 24-hour recovery period in cardiomyocytes. The activity of LDH in the cultured su- pernatant and the levels of intracellular reactive oxygen species （ROS）, SOD and MDA in cardiomyo- cytes were also measured. Finally, cardiomyocytes apoptosis was determined with flow cytometry. RESULTS： MLB significantly limited infarct size, ameliorated histopathological damages and prevented leakage of CK-MB, cTnl and LDH. Additional- ly, SOD, CAT, GPx and GSH activities were notably increased by MLB, along with the MDA content decreased as compared with the model group in rats. In vitro study, MLB also decreased LDH activity in the cultured supernatant, increased SOD activity in cardiomyocytes, reduced intracellular ROS and MDA levels, and significantly suppressed cardiomyocytes apoptosis. CONCLUSION： MLB possessed remarkably cardioprotective effects on MI/R injury in vivo and in vitro. The protection of MLB may contribute to its antioxidant properties.
基金supported by 211 Project Special Fund for Key Laboratory of Neuroimmunology,Science and Technology Projects for Returned Overseas Chinese Scholars of Heilongjiang Province (LC06C26)China Postdoctoral Science Foundation (No.20060390236)
文摘The mechanisms of brain ischemic insult include glutamate excitoxicity, calcium toxicity, free radicals, nitric oxide, inflammatory reactions, as well as dysfunctions of endoplasmic reticulum and mitochondrion. These injury cascades are interconnected in complex ways, thus it is hard to compare their pathogenic importances in ischemia models. And the research in cellular and molecular pathways has spurred the studies in potential neuroprotections mainly in pharmacological fields, such as anti-excitotoxic treatment, calcium-channel antagonism, approaches for inhibition of oxidation, inflammation and apoptosis, etc. Besides, other protective interventions including thrombolysis, arteriogenesis, regeneration therapy, and ischemia preconditioning or postconditioning, are also under investigations. Despite the present difficulties, we are quite optimistic towards future clinical applications of neuroprotective agents, by optimizing experimental approaches and clinical trials.
基金Project supported by the Grant-in-Aid of Japan Society for the Promotion of Science, Ministry of Education, Culture,Sports, Science and Technology (Nos. 15101002 and 19002001)
文摘The particle-size distribution and mineralogical composition of the clay （〈 2 μm） and fine-sand （0.25-0.10 mm） fractions in soils of two inland valleys in Abakaliki and Bende, Southeast Nigeria, were investigated to provide basic information on soil-forming processes and agricultural potentials. These soils were silty or clayey, deriving from Cretaceous or Tertiary shale materials. The particle-size distribution and its computation on a clay-free basis revealed relatively remarkable lithologic breaks in a couple of pedons. The effect of lithologic discontinuities on soil mineralogical composition was not, however, conspicuous. Petrographic investigation revealed that quartz predominantly comprised the fine-sand fraction in the soils at both study sites. Nevertheless, the clay mineralogical composition of the soils was a mixture of kaolinite, irregularly interstratified smectite-illite intergrades （S/I）, hydroxyl-A1 interlayered 2：1 type clays （HICs）, vermiculite, smectite, halloysite and illite along with fine-sized quartz in Abakaliki. The soils of Bende predominantly contained smectite, which was partially interlayered with hydroxyl-A1 and kaolinite. It is suggested that seasonal floodwater has slowed the disintegration of weatherable clay minerals inherited from the shale, while quartz originating from the sandstone is predominant in the fine-sand fraction. Additionally, a possible soil-forming process observed at the both study sites was ferrolysis, which was indicated by a clear decreasing pattern of HICs downward in the soil profiles, The entry of S/I and vertical distribution patterns for a couple of clay minerals in the pedon suggested that the soils in Abakaliki have developed under the significant influence of aeolian dust delivered by the Harmattan. The findings might describe a site-specific deposition pattern of Harmattan dusts as well as hydromorphic soil-forming processes in the wetlands of the inland valleys.
