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151.
Angiogenesis, new blood vessel formation, is a multistep process, precisely regulated by pro-angiogenic cytokines, which stimulate endothelial cells to migrate, proliferate and differentiate to form new capillary microvessels. Excessive vascular development and blood vessel remodeling appears in psoriasis, rheumatoid arthritis, diabetic retinopathy and solid tumors formation. Thalidomide [alpha-(N-phthalimido)-glutarimide] is known to be a potent inhibitor of angiogenesis, but the mechanism of its inhibitory action remains unclear. The aim of the study was to investigate the potential influence of thalidomide on the several steps of angiogenesis, using in vitro models. We have evaluated the effect of thalidomide on VEGF secretion, cell migration, adhesion as well as in capillary formation of human endothelial cell line EA.hy 926. Thalidomide at the concentrations of 0.01 microM and 10 microM inhibited VEGF secretion into supernatants, decreased the number of formed capillary tubes and increased cell adhesion to collagen. Administration of thalidomide at the concentration of 0.01 microM increased cell migration, while at 10 microM, it decreased cell migration. Thalidomide in concentrations from 0.1 microM to 10 microM did not change cell proliferation of 72-h cell cultures. We conclude that anti-angiogenic action of thalidomide is due to direct inhibitory action on VEGF secretion and capillary microvessel formation as well as immunomodulatory influence on EA.hy 926 cells migration and adhesion.  相似文献   
152.
A novel series of tricyclic γ-secretase inhibitors was designed and synthesized via a conformational analysis of literature compounds. The preliminary results have shown that compounds in this new series have much improved in vitro potency and in vivo profiles. More importantly, they have greatly reduced Notch related toxicity that was associated with previous γ-secretase inhibitors.  相似文献   
153.
电子供体连二亚硫酸钠,甲基紫精及电子受体亚甲蓝均能强烈的抑制棕色固氮菌表达固氮活性,并引起该菌的抗氨阻遏能力减弱,适当提高氧压,能提高菌体的固氮活性近15%,但过高的氧分压反而抑制菌体的固氮活性,此外,提高氢分压能降低棕色固氮菌菌体内的还原电位,从而达到提高菌体抗氨阻遏能力的效果。  相似文献   
154.
祁连山大野口流域青海云杉种群数量动态   总被引:2,自引:3,他引:2  
种群数量动态揭示了种群的结构特征及其潜在的驱动机制,有助于预测种群未来的动态,进而为森林生态系统的保护与恢复提供理论依据。本研究基于10.2 hm2青海云杉动态监测样地数据,以种群径级结构代替年龄结构,编制静态生命表,绘制径级结构图、存活曲线、死亡率曲线、消失率曲线和4个生存分析函数曲线,分析青海云杉种群数量特征,并利用种群数量动态变化指数和时间序列模型对种群数量动态进行预测。结果表明:(1)青海云杉种群的年龄结构近似于倒"J"型,幼苗和小树储量丰富;(2)种群存活曲线趋近于Deevey-Ⅱ型,为稳定型种群,死亡率曲线和消失率曲线变化趋势基本一致,均在第2、8龄级出现高峰期;(3)生存率曲线呈下降趋势,累计死亡率曲线呈上升趋势,死亡密度曲线缓慢下降,而危险率曲线逐渐上升,该种群具有:前期减少、中期稳定、后期衰退的生长特点;(4)种群数量变化动态指数Vpi>0,表明该种群属于增长型种群,Vpi''>0且趋近于0,则表明该种群趋近于稳定型;(5)时间序列预测分析表明,在未来2、4、6、8个龄级时间后,种群呈稳定增长趋势。研究显示,祁连山大野口流域青海云杉种群为稳定增长型种群,只要未来不遭受强烈干扰,种群数量会保持逐渐增长。针对该种群幼龄个体在前期的更新过程死亡率较高情况,建议在今后的经营管理中应重点加强对第1、2龄级植株生存环境的保护和改善,提高幼苗和小树的存活率。  相似文献   
155.
In an attempt to further improve overall profiles of the oxadiazine series of GSMs, in particular the hERG activity, conformational modifications of the core structure resulted in the identification of fused oxadiazepines such as 7i which had an improved hERG inhibition profile and was a highly efficacious GSM in vitro and in vivo in rats. These SAR explorations offer opportunities to identify potential drugs to treat Alzheimer’s disease.  相似文献   
156.

Background

Genes and signalling pathways involved in pluripotency have been studied extensively in mouse and human pre-implantation embryos and embryonic stem (ES) cells. The unsuccessful attempts to generate ES cell lines from other species including cattle suggests that other genes and pathways are involved in maintaining pluripotency in these species. To investigate which genes are involved in bovine pluripotency, expression profiles were generated from morula, blastocyst, trophectoderm and inner cell mass (ICM) samples using microarray analysis. As MAPK inhibition can increase the NANOG/GATA6 ratio in the inner cell mass, additionally blastocysts were cultured in the presence of a MAPK inhibitor and changes in gene expression in the inner cell mass were analysed.

Results

Between morula and blastocyst 3,774 genes were differentially expressed and the largest differences were found in blastocyst up-regulated genes. Gene ontology (GO) analysis shows lipid metabolic process as the term most enriched with genes expressed at higher levels in blastocysts. Genes with higher expression levels in morulae were enriched in the RNA processing GO term. Of the 497 differentially expressed genes comparing ICM and TE, the expression of NANOG, SOX2 and POU5F1 was increased in the ICM confirming their evolutionary preserved role in pluripotency. Several genes implicated to be involved in differentiation or fate determination were also expressed at higher levels in the ICM. Genes expressed at higher levels in the ICM were enriched in the RNA splicing and regulation of gene expression GO term. Although NANOG expression was elevated upon MAPK inhibition, SOX2 and POU5F1 expression showed little increase. Expression of other genes in the MAPK pathway including DUSP4 and SPRY4, or influenced by MAPK inhibition such as IFNT, was down-regulated.

Conclusion

The data obtained from the microarray studies provide further insight in gene expression during bovine embryonic development. They show an expression profile in pluripotent cells that indicates a pluripotent, epiblast-like state. The inability to culture ICM cells as stem cells in the presence of an inhibitor of MAPK activity together with the reported data indicates that MAPK inhibition alone is not sufficient to maintain a pluripotent character in bovine cells.

Electronic supplementary material

The online version of this article (doi:10.1186/s12864-015-1448-x) contains supplementary material, which is available to authorized users.  相似文献   
157.
The synthesis of a novel series of iminoheterocycles and their structure–activity relationship (SAR) as modulators of γ-secretase activity will be detailed. Encouraging SAR generated from a monocyclic core led to a structurally unique bicyclic core. Selected compounds exhibit good potency as γ-secretase modulators, excellent rat pharmacokinetics, and lowering of Aβ42 levels in various in vivo models.  相似文献   
158.
The vast amount of data produced by next-generation sequencing (NGS) has necessitated the development of computational tools to assist in understanding the myriad functions performed by the biological macromolecules involved in heredity. In this work, we developed the FunSys programme, a stand-alone tool with an user friendly interface that enables us to evaluate and correlate differential expression patterns from RNA sequencing and proteomics datasets. The FunSys generates charts and reports based on the results of the analysis of differential expression to aid the interpretation of the results. AVAILABILITY: The database is available for free at https://sourceforge.net/projects/funsysufpa/  相似文献   
159.
The activities of steroid sulphatase (StS) and estrogen sulphotransferase (EST) were determined in the epididymis of 18 boars. The animals were divided into three groups (n = 6) according to age (8, 12 and 16 months). The boars were anesthetized and castrated. The tissue samples of different epididymal parts (caput, corpus and cauda) were taken and homogenized. Activities of StS and EST were assessed using 3H-estrone sulphate (3H-E1S) and free 3H-oestrone (3H-E1) as substrates, respectively. The substrate conversion rates after 60 min of incubation were 51.25% for 3H-E1S and 45.65% for 3H-E1. The activities of both enzymes were significantly higher in the caput epididymis compared to the cauda epididymis (p < 0.05). A significant age-dependent increase of StS and EST activities (p < 0.05) was observed. These results suggest that the availability of estrogens in the boar epididymis may be locally controlled also by StS and EST. The age-dependent increase of StS and EST activities may be related to the process of “biochemical maturation” of the reproductive system during the postpubertal period.  相似文献   
160.
ABSTRACT: Alexandre, D, Da Silva, C, Hill-Haas, S, Wong, DP, Natali, AJ, De Lima, JRP, Filho, MGB, Marins, JCB, Garcia, ES, and Chamari, K. Heart rate monitoring in soccer: Interest and limits during competitive match play and training-Practical application. J Strength Cond Res 26(10): 2890-2906, 2012-The identification of physiological loads imposed by soccer training or match play reveals essential information, which may help improve training and recovery strategies. Until today, the use of heart rate (HR) monitoring is not standardized in soccer. Thus, the aim of this review was to analyze, determine and compare the exercise intensity (EI) monitored by HR in professional, youth, and recreational soccer players during matches and training sessions using a meta-analysis. Heart rate is one of the most common physiological variables used to determine exercise internal training load. The mean EI recorded during competitive matches was described as 70-80% of V[Combining Dot Above]O2max or 80-90% of maximal heart rate (HRmax), independent of the playing level. With respect to HR training zones, approximately 65% of the total match duration is spent at intensity of 70-90% HRmax and rarely below 65% HRmax. However, although HRmax is mostly employed in the literature, monitoring EI should be expressed in relation to reserve heart rate, as it was described as a more reliable indicator of HR, allowing interindividual comparisons. The HR response according to the playing position indicates that midfielders are characterized by the highest EI, followed by forwards and fullbacks. Moreover, in the second half of the match, the EI is lower than that observed during the first half; this reduction could be correlated with the level of the player's physical conditioning. Consequently, coaches may favor the use of interval training or small-sided training games because these are shown to improve both aerobic capacity and the ability to repeat high-intensity actions. Small-sided games allow reaching similar HR responses to those found during interval training and match play but with greater heterogeneity values. Future investigations should include a larger sample of players with special reference to playing position and the expression of EI in percentage of the reserve heart rate, analyzing the possible intergender differences in HR response.  相似文献   
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