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991.
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Weirong Fang Peng Lv Xiaohan Geng Erxin Shang Qichuan Yang Lan Sha Yunman Li 《Neurochemistry international》2013
Background
Blood brain barrier (BBB) dysfunction is a common facet of cerebral ischemia, and the alteration of drug transporter, P-glycoprotein (P-gp), has been documented.Aims
This study explores influence of damaged BBB and elevated P-gp on cerebral verapamil penetration after ischemia both in vivo and in vitro.Methods
Middle cerebral artery occlusion (MCAO) induced ischemia/reperfusion (I/R) of rats, and Na2S2O4 induced hypoxia/reoxygenation (H/R) damage of rat brain mirovessel endothelial cells (RBMECs) respectively, served as BBB breakdown model in vivo and in vitro. Evans-Blue (EB) extravagation and 125I-albumin were used to quantify BBB dysfunction; UPLC–MS/MS analytical method was performed to determine accurately the concentration of verapamil in brain tissue and cell. Flow cytometry, immunohistochemistry and western blotting were applied to evaluate transport function and protein expression of P-gp.Results
Overexpressed ICAM-1 and MMP-9 mediated BBB dysfunction after ischemia, which induced EB leakage and 125I-albumin uptake increase. Enhanced accumulation of verapamil in brain tissue, but intracellular concentration reduced evidently after H/R injury. Transcellular transportation of verapamil elevated when P-gp function or expression was inhibited after H/R injury.Conclusion
These data indicated that BBB penetration of verapamil under ischemia condition was not only depending on BBB breakdown, but also regulated by P-gp. 相似文献994.
Background
Biclustering algorithm can find a number of co-expressed genes under a set of experimental conditions. Recently, differential co-expression bicluster mining has been used to infer the reasonable patterns in two microarray datasets, such as, normal and cancer cells.Methods
In this paper, we propose an algorithm, DECluster, to mine Differential co-Expression biCluster in two discretized microarray datasets. Firstly, DECluster produces the differential co-expressed genes from each pair of samples in two microarray datasets, and constructs a differential weighted undirected sample–sample relational graph. Secondly, the differential biclusters are generated in the above differential weighted undirected sample–sample relational graph. In order to mine maximal differential co-expression biclusters efficiently, we design several pruning techniques for generating maximal biclusters without candidate maintenance.Results
The experimental results show that our algorithm is more efficient than existing methods. The performance of DECluster is evaluated by empirical p-value and gene ontology, the results show that our algorithm can find more statistically significant and biological differential co-expression biclusters than other algorithms.Conclusions
Our proposed algorithm can find more statistically significant and biological biclusters in two microarray datasets than the other two algorithms. 相似文献995.
996.
目的探讨哮喘气道重塑大鼠气道上皮细线粒体超微结构变化,为哮喘的治疗寻求新的理论基础。方法雌性Wistar大鼠6只、随机分为2组,采用卵蛋白吸人法制作哮喘气道重塑大鼠模型;取两组大鼠气管制作电镜切片,观察两组大鼠气道纤毛上皮,气道上皮细胞问胶原沉积及细胞内线粒体超微结构改变。结果哮喘组大鼠气道多层纤毛上皮层,纤毛脱落,杯状细胞增多,排列不整齐,上皮细胞中线粒体基膜密度下降,线粒体峡减少,上皮细胞细胞核多切迹,形状不规则;气道上皮细胞间胶原沉积;板层小体和线粒体空泡化。结论哮喘大鼠气道上皮细胞出现早期凋亡改变,线粒体失去正常形态。 相似文献
997.
Rheotaxis is a ubiquitous phenomenon among aquatic animals and thought to be an adaptation to maintain populations in flowing waters. While many estuarine copepods can retain their populations in estuaries with net seaward flow, rheotaxis of individual copepods has not been reported before. In this study, the behavior of a calanoid copepod Pseudodiaptomus annandalei in flow was examined in a recirculating laboratory flume. This estuarine copepod displayed different responses to ambient flow fields while swimming in the water column or attaching to the flume bed (walls). Copepods in the water column showed vigorous countercurrent swimming by occasional bounding when flow velocity was increased up to 2.1 cm s?1, but none of the individuals in the water column were retained in the flume when flow speeds were higher than 4 cm s?1. This indicates P. annandalei profits little from rheotaxis to withstand flow when they were swimming in the water column. Instead, more individuals attempted sinking downwards to the slow flow region near the flume bed (walls) and showed active substrate attachment to avoid being flushed out by the high-velocity channel flow. The results suggest that P. annandalei benefits from rheotaxis and association with the substrate which allows them to hold position well at ambient flow velocities up to 3 cm s?1. These adaptive responses might be important for population maintenance. 相似文献
998.
999.
Xuefang Shang Shuanbao Tian 《Journal of receptor and signal transduction research》2013,33(5):274-279
A series of artificial 2,2′-bipyridine receptors (1, 2, 3) containing phenol group have been designed and synthesized. Their anion-binding properties are evaluated for various anions (F?, Cl?, Br?, I?, AcO? and H2PO4?) by UV-vis titration experiment in order to research the impact of different substituents on anion-recognition properties. Results indicate that the anion binding abilities can be tuned by electron push-pull properties of substituents on the phenyl ortho- or para-position of the receptors. In addition, receptor 1 is sensitive for F? detection without the interference of other studied anions, and receptors 2 and 3 are sensitive for H2PO4? detection. 相似文献
1000.