Modulation of the cardiac sodium channel Nav1.5 by fibroblast growth factor homologous factor 1B

We have previously shown that fibroblast growth factor homologous factor 1B (FHF1B), a cytosolic member of the fibroblast growth factor family, associates with the sensory neuron-specific channel Na(v)1.9 but not with the other sodium channels present in adult rat dorsal root ganglia neurons. We show in this study that FHF1B binds to the C terminus of the cardiac voltage-gated sodium channel Na(v)1.5 and modulates the properties of the channel. The N-terminal 41 amino acid residues of FHF1B are essential for binding to Na(v)1.5, and the conserved acidic rich domain (amino acids 1773-1832) in the C terminus of Na(v)1.5 is sufficient for association with this factor. Binding of the growth factor to recombinant wild type human Na(v)1.5 in human embryonic kidney 293 cells produces a significant hyperpolarizing shift in the voltage dependence of channel inactivation. An aspartic acid to glycine substitution at position 1790 of the channel, which underlies one of the LQT-3 phenotypes of cardiac arrythmias, abolishes the interaction of the Na(v)1.5 channel with FHF1B. This is the first report showing that interaction with a growth factor can modulate properties of a voltage-gated sodium channel.     

Screening Fluorescent Voltage Indicators with Spontaneously Spiking HEK Cells

Development of improved fluorescent voltage indicators is a key challenge in neuroscience, but progress has been hampered by the low throughput of patch-clamp characterization. We introduce a line of non-fluorescent HEK cells that stably express Na_V 1.3 and K_IR 2.1 and generate spontaneous electrical action potentials. These cells enable rapid, electrode-free screening of speed and sensitivity of voltage sensitive dyes or fluorescent proteins on a standard fluorescence microscope. We screened a small library of mutants of archaerhodopsin 3 (Arch) in spiking HEK cells and identified two mutants with greater voltage-sensitivity than found in previously published Arch voltage indicators.     

The emergence of the oil welfare state: The case of Kuwait

Conclusion This essay provided an analytical account of the emergence and development of social welfare in the newly emerging oil-rich state of Kuwait, by delineating the particular historical conditions and socio-economic transformations which were responsible for giving this welfare state its particular structure.We relied on specific theoretical guidelines and concepts derived from the much honored holistic tradition in anthropology and political economy, as well as on formulations developed by scholars coming from the new tradition in the development approach in welfare studies.The analytical elucidation presented here indicates that a multiplicity of both internal and external factors and/or determinants have simultaneously influenced the development of the oil welfare state in Kuwait. The origins, nature, timing and interplay of all these factors appear to be specific and unique to the experience of Gulf societies, and have given rise to particular socio-political configurations and psychological effects. Thus the new soical welfare conditions which have emerged in modern Kuwait are different in many significant ways from those experienced in both the advanced industrial capitalist societies and Third World countries. Moreover, the economic, social, cultural and historical specificities of the oil-rich societies have made the overall development and the functions of the welfare state different from those found to be recurrent in advanced capitalist societies.It appears that, on one hand, the new oil welfare state has succeeded in modernizing life and bettering the human condition of its small population. Yet, on the other hand, this form of extensive oil-welfarism has in itself generated certain conditions which appear to have some-what weakened the capacities of these societies to achieve genuine development. In other words, it has failed to stimulate the development of productive social forces and other supportive infrastructural conditions from within society itself. A thorough analysis of these and other consequences which have become well embedded in the fabric of Kuwaiti society and culture requires and entirely separate paper.Sulayman Khalaf is Assistant Professor of Anthropology, Kuwait University. Hassan Hammoud is Assistant Professor of Social Work, Kuwait University.     

新疆芦荟藓属的分类及分布

以采自新疆各地的350余份芦荟藓属植物为材料,对新疆芦荟藓属植物的分类及其分布进行研究。结果显示,新疆产芦荟藓属植物3种：短喙芦荟藓（Aloina brevirostris（Hook.&Grev.）Kindb.）、斜叶芦荟藓（A.obliquifolia（Müll.Hal.）Broth.）和钝叶芦荟藓（A.rigida（Hedw.）Limpr.）。其中斜叶芦荟藓为新疆新记录种。对它们的形态特征进行了描述,明确了各种的识别特征,并提供了生境、产地与分布地等信息及显微照片,编制了新疆芦荟藓属植物分种检索表。     

青藓科中国新记录种——短尖拟青藓

该文报道了短尖拟青藓［Sciuro-hypnum ornellanum (Molendo) Ignatov & Huttunen］在新疆阿尔泰山的分布,这是该种在中国的首次记录。详细介绍了拟青藓属［Sciuro-hypnum （Hampe） Hampe］的由来,讨论了短尖拟青藓的形态特征及其地理分布,对其与形态相近种进行了比较分析,并提供了中国拟青藓属分种检索表。该种的发现不仅为中国青藓科植物研究提供了新资料,同时也进一步佐证了中国新疆植物区系与俄罗斯、中亚及欧洲的密切联系。     

中国新疆柳叶藓科、青藓科和灰藓科植物区系研究

通过对新疆柳叶藓科(Amblystegiaceae)、青藓科(Brachytheciaceae)和灰藓科(Hypnaceae)植物标本的野外采集和室内鉴定,报道了中国新疆地区柳叶藓科15属33种,青藓科12属51种,灰藓科11属30种,共计38属114种。其中,中国青藓科新记录种2种,新疆新记录4属37种。优势属10个,且以青藓属(Brachythecium BrushSchimp.)为代表的北温带成分为主;单种属19个,体现了新疆藓类植物区系的古老性和多样性。新疆3科藓类植物区系成分可划分为9种类型,其中北温带成分居主导地位,占中国新疆3科藓类植物总种数的52.08%,东亚成分次之,占25.01%,热带成分甚微。对中国新疆与中国内蒙古、中国西藏以及俄罗斯、蒙古、哈萨克斯坦、巴基斯坦和印度7个邻近地区的区系比较发现,印度物种丰富度最高,俄罗斯和中国新疆次之;中国新疆与中国内蒙古、俄罗斯在物种组成上相似度最高。地理成分区系谱及聚类分析结果表明,中国新疆与中国内蒙古地区的植物区系关系最为接近,而且与俄罗斯密切相关。     

中国新记录——毛齿藓短蒴变种(新拟)

该研究首次报道了毛齿藓短蒴变种(新拟)在中国的分布和毛齿藓属在新疆的分布。研究表明：(1)毛齿藓短蒴变种的主要识别特征为：叶基部鞘状,突然狭窄成线状披针形,背仰,叶缘平展,中肋充满叶上部,背面粗糙,远轴面有厚壁细胞束分化,叶细胞长方形至短长方形;有假根生芽胞;孢蒴椭球形,稍弓形弯曲,蒴齿线状披针形,二裂至近基部。(2)毛齿藓属的3个分类单位在中国均有分布,毛齿藓短蒴变种以较短的孢蒴和蒴柄区别于原变种,以有根生芽胞、叶基部呈明显鞘状、叶缘平展区别于云南毛齿藓的无假根生芽胞、叶基部略呈鞘状、叶缘背卷。(3)在牛毛藓科中有许多类群与毛齿藓短蒴变种形态相似,但仅有毛齿藓属的叶在横切面上主细胞的远轴面有厚壁细胞束,而其他类群的叶在横切上主细胞的近轴面和远轴面均有厚壁细胞束。该变种的叶背仰不同于牛毛藓科其他属的叶直立;以具鞘部的叶、表面光滑的孢蒴、内弯的蒴齿区别于无鞘部的叶、表面有纵沟槽的孢蒴、直立的蒴齿的牛毛藓属。(4)该变种属北极 高山分布类型,表现出了明显的欧洲 亚洲 北美洲间断分布模式,可作为研究气候变化、海陆变迁的重要材料。     

藓类植物中国新记录种——无疣对齿藓

报道了对齿藓属中国新记录种——无疣对齿藓(Didymodon validus Limpr.)(新拟)。该种主要分布于欧洲和中亚。该种的主要特征为叶干燥时内卷或背弯,叶片较长,中肋突出叶尖呈长毛尖,叶细胞平滑无疣。该研究对无疣对齿藓的形态特征、地理分布进行了详细描述,将其与属内相似种进行了比较分析,并提供了该种的显微照片和形态线描图。     

Expression of the voltage-gated sodium channel NaV1.5 in the macrophage late endosome regulates endosomal acidification

Voltage-gated sodium channels expressed on the plasma membrane activate rapidly in response to changes in membrane potential in cells with excitable membranes such as muscle and neurons. Macrophages also require rapid signaling mechanisms as the first line of defense against invasion by microorganisms. In this study, our goal was to examine the role of intracellular voltage-gated sodium channels in macrophage function. We demonstrate that the cardiac voltage-gated sodium channel, NaV1.5, is expressed on the late endosome, but not the plasma membrane, in a human monocytic cell line, THP-1, and primary human monocyte-derived macrophages. Although the neuronal channel, NaV1.6, is also expressed intracellularly, it has a distinct subcellular localization. In primed cells, NaV1.5 regulates phagocytosis and endosomal pH during LPS-mediated endosomal acidification. Activation of the endosomal channel causes sodium efflux and decreased intraendosomal pH. These results demonstrate a functionally relevant intracellular voltage-gated sodium channel and reveal a novel mechanism to regulate macrophage endosomal acidification.