Cyanobacterial blooms in eutrophic freshwater systems are a worldwide problem, creating adverse effects for many aquatic organisms by producing toxic mierocystins and deteriorating water quality. In this study, microc...Cyanobacterial blooms in eutrophic freshwater systems are a worldwide problem, creating adverse effects for many aquatic organisms by producing toxic mierocystins and deteriorating water quality. In this study, microcystins （MCs） in Microcystis aeruginosa, and Daphnia magna exposed to M. aeruginosa, were analyzed by HPLC-MS, and the effects of M. aeruginosa on D. magna were investigated. When D. magna was exposed to M. aeruginosa for more than 2 h, Microcystin-LR （MC-LR） was detected. When exposed to 1.5× 10^6, 3× 10^6, 0.75× 10^7, and 1.5× 10^7 cell/mL of M. aeruginosa for 96 h, average survival of D. magna for treatments were 23.33%, 33.33%, 13.33%, 16.67%, respectively, which were significantly lower than the average 100% survival in the control group （P 〈 0.05）. The adverse effects ofM. aeruginosa on body length, time for the first brood, brood numbers, gross fecundity, lifespan, and population growth olD. magna were density-dependent. These results suggest that the occurrence of M. aeruginosa blooms could strongly inhibit the population growth of D. magna through depression of survival, individual growth and gross fecundity. In the most serious situations, M. aeruginosa blooms could undermine the food web by eliminating filter-feeding zooplankton, which would destroy the ecological balance of aquaculture water bodies.展开更多
Objective： To evaluate the endothelial cell damage by detecting the circulating Tie2 mRNA level in a rat model of sepsis. Methods： The model of sepsis was established by cecal ligation and puncture （CLP） in 90 ra...Objective： To evaluate the endothelial cell damage by detecting the circulating Tie2 mRNA level in a rat model of sepsis. Methods： The model of sepsis was established by cecal ligation and puncture （CLP） in 90 rats which were divided into 6 groups： normal, sham, CLP-3 h, CLP-6 h, CLP- 12 h and CLP-24 h. Serum biochemical markers were detected by automatic biochemical analyzer. Serum IL-6 was measured with enzyme linked immunosorbent assay. The vascular permeability of liver, kidney, lung and heart was detected with Evans blue. Circulating endothelial cells （CEC） were separated using density gradient separation and counted. Total RNA of whole blood were extracted and the mRNA levels of two endothelial specific genes, Tie2 and vascular endothelial growth factor receptor 2 （VEGFR2）, were measured by quantitative real-time PCR. Results： The level of serum biochemical indexes increased after CLP. The amount of serum IL-6 in CLP-6 h, 12 h,and 24 h group was increased 6.5-fold （P〈 0.05）, 8.4-fold （P〈 0.01 ）, and 13.3-fold （P〈0.001 ） compared with normal group （ 170.68 pg/mli42.46 pg/ml） respectively （F= 14.319, P〈0.001）. Significantly increased organ vasopermeability of liver, kidney, lung and heart was observed after CLP respectively. The number of CEC peaked （11.83±1.94） 3 hours after CLP compared with normal control （5.33±1.21, P〈0.05）, and then decreased gradually （F=54.183, P〈0.001）. The mRNA level of Tie2 in CLP-3 h group （3.47±1.47） was also markedly higher than that in other groups （F=10.640, P〈0.001 ）. Conclusion： Using quantitative real-time PCR to measure the level of Tie2 mRNA in peripheral blood is a simple and relatively sensitive method to evaluate the damage of endothelial cells.展开更多
基金Supported by the Aquaculture and Fisheries Collaborative Research Support Program of USAID (No. 1366)the Shanghai Rising-Star Program (No. 08QA1405900)+1 种基金the Innovation Program of Shanghai Municipal Education Commission (No. 09YZ277)the Shanghai Leading Academic Discipline Project (No. Y1101)
文摘Cyanobacterial blooms in eutrophic freshwater systems are a worldwide problem, creating adverse effects for many aquatic organisms by producing toxic mierocystins and deteriorating water quality. In this study, microcystins （MCs） in Microcystis aeruginosa, and Daphnia magna exposed to M. aeruginosa, were analyzed by HPLC-MS, and the effects of M. aeruginosa on D. magna were investigated. When D. magna was exposed to M. aeruginosa for more than 2 h, Microcystin-LR （MC-LR） was detected. When exposed to 1.5× 10^6, 3× 10^6, 0.75× 10^7, and 1.5× 10^7 cell/mL of M. aeruginosa for 96 h, average survival of D. magna for treatments were 23.33%, 33.33%, 13.33%, 16.67%, respectively, which were significantly lower than the average 100% survival in the control group （P 〈 0.05）. The adverse effects ofM. aeruginosa on body length, time for the first brood, brood numbers, gross fecundity, lifespan, and population growth olD. magna were density-dependent. These results suggest that the occurrence of M. aeruginosa blooms could strongly inhibit the population growth of D. magna through depression of survival, individual growth and gross fecundity. In the most serious situations, M. aeruginosa blooms could undermine the food web by eliminating filter-feeding zooplankton, which would destroy the ecological balance of aquaculture water bodies.
文摘Objective： To evaluate the endothelial cell damage by detecting the circulating Tie2 mRNA level in a rat model of sepsis. Methods： The model of sepsis was established by cecal ligation and puncture （CLP） in 90 rats which were divided into 6 groups： normal, sham, CLP-3 h, CLP-6 h, CLP- 12 h and CLP-24 h. Serum biochemical markers were detected by automatic biochemical analyzer. Serum IL-6 was measured with enzyme linked immunosorbent assay. The vascular permeability of liver, kidney, lung and heart was detected with Evans blue. Circulating endothelial cells （CEC） were separated using density gradient separation and counted. Total RNA of whole blood were extracted and the mRNA levels of two endothelial specific genes, Tie2 and vascular endothelial growth factor receptor 2 （VEGFR2）, were measured by quantitative real-time PCR. Results： The level of serum biochemical indexes increased after CLP. The amount of serum IL-6 in CLP-6 h, 12 h,and 24 h group was increased 6.5-fold （P〈 0.05）, 8.4-fold （P〈 0.01 ）, and 13.3-fold （P〈0.001 ） compared with normal group （ 170.68 pg/mli42.46 pg/ml） respectively （F= 14.319, P〈0.001）. Significantly increased organ vasopermeability of liver, kidney, lung and heart was observed after CLP respectively. The number of CEC peaked （11.83±1.94） 3 hours after CLP compared with normal control （5.33±1.21, P〈0.05）, and then decreased gradually （F=54.183, P〈0.001）. The mRNA level of Tie2 in CLP-3 h group （3.47±1.47） was also markedly higher than that in other groups （F=10.640, P〈0.001 ）. Conclusion： Using quantitative real-time PCR to measure the level of Tie2 mRNA in peripheral blood is a simple and relatively sensitive method to evaluate the damage of endothelial cells.
