开口箭中甾体皂甙元含量的测定

利用香草醛—高氯酸作为显色剂，使用可见分光光度法测定了神农架民间习用药物开口箭中甾体皂甙元的含量。     

开口箭生理活性物质及其药理作用研究进展

开口箭是一种在我国民间具有悠久使用历史的中草药.近年来开口箭的生理活性物质提取和药用价值研发备受关注,开口箭中的甾体类化合物、多糖、挥发油、脂肪酸、金属元素、绿原酸、黄酮类和生物碱类生理活性物质先后被通过不同的方法提取出来,大量实验分析也表明开口箭中的生理活性物质在抗炎、抗菌、抗肿瘤、抗氧化、抗心肌肥厚、抗内毒素及免疫调节等方面具有良好的疗效.但开口箭中部分生理活性物质的提取量仍然较小,提取方法有待改进,且这些活性物质发挥药理作用的机制仍不甚清楚.本文对开口箭的生理活性物质及其药理作用的研究进展予以综述,期望有助于推进开口箭的开发利用.     

Fibronectin requirement in branching morphogenesis

Many organs, including salivary glands, lung and kidney, are formed during embryonic development by epithelial branching. In branching morphogenesis, repetitive epithelial cleft and bud formation create the complex three-dimensional branching structures characteristic of many organs. Although the mechanisms are poorly understood, one might involve the site-specific accumulation of some regulatory protein. Here we show that the extracellular matrix protein fibronectin is essential for cleft formation during the initiation of epithelial branching. Fibronectin messenger RNA and fibrils appeared transiently and focally in forming cleft regions of submandibular salivary-gland epithelia, accompanied by an adjacent loss of cadherin localization. Decreasing the fibronectin concentration by using small interfering RNA and inhibition by anti-fibronectin or anti-integrin antibodies blocked cleft formation and branching. Exogenous fibronectin accelerated cleft formation and branching. Similar effects of fibronectin suppression and augmentation were observed in developing lung and kidney. Mechanistic studies revealed that fibrillar fibronectin can induce cell-matrix adhesions on cultured human salivary epithelial cells with a local loss of cadherins at cell-cell junctions. Thus, fibronectin expression is required for cleft formation in branching morphogenesis associated with the conversion of cell-cell adhesions to cell-matrix adhesions.     

山西岩溶地貌形态特征与形成过程

山西是北方岩溶发育大省。文章介绍了其特有的一些形态特征和地貌组合，并探讨了影响其发育的因素及形成的2个主要时期。     

The morphogenesis of feathers

Feathers are highly ordered, hierarchical branched structures that confer birds with the ability of flight. Discoveries of fossilized dinosaurs in China bearing 'feather-like' structures have prompted interest in the origin and evolution of feathers. However, there is uncertainty about whether the irregularly branched integumentary fibres on dinosaurs such as Sinornithosaurus are truly feathers, and whether an integumentary appendage with a major central shaft and notched edges is a non-avian feather or a proto-feather. Here, we use a developmental approach to analyse molecular mechanisms in feather-branching morphogenesis. We have used the replication-competent avian sarcoma retrovirus to deliver exogenous genes to regenerating flight feather follicles of chickens. We show that the antagonistic balance between noggin and bone morphogenetic protein 4 (BMP4) has a critical role in feather branching, with BMP4 promoting rachis formation and barb fusion, and noggin enhancing rachis and barb branching. Furthermore, we show that sonic hedgehog (Shh) is essential for inducing apoptosis of the marginal plate epithelia, which results in spaces between barbs. Our analyses identify the molecular pathways underlying the topological transformation of feathers from cylindrical epithelia to the hierarchical branched structures, and provide insights on the possible developmental mechanisms in the evolution of feather forms.     

光石韦药材中芒果苷的定性定量分析方法研究

为了研究光石韦药材中的芒果苷,建立定性定量分析方法,采用薄层色谱定性鉴别,高效液相色谱测定芒果苷含量。结果表明,薄层色谱鉴别方法的重现性好,芒果苷在0.0605～0.3632#g范围内呈良好线性关系（r=0.9996）,平均回收率为101.3%,RSD为2.13%（n=9）。方法简便、准确,专属性强,重现性和回收率好,可以为光石韦药材的质量标准制定提供分析方法和依据。     

Self-organizing optic-cup morphogenesis in three-dimensional culture

Balanced organogenesis requires the orchestration of multiple cellular interactions to create the collective cell behaviours that progressively shape developing tissues. It is currently unclear how individual, localized parts are able to coordinate with each other to develop a whole organ shape. Here we report the dynamic, autonomous formation of the optic cup (retinal primordium) structure from a three-dimensional culture of mouse embryonic stem cell aggregates. Embryonic-stem-cell-derived retinal epithelium spontaneously formed hemispherical epithelial vesicles that became patterned along their proximal-distal axis. Whereas the proximal portion differentiated into mechanically rigid pigment epithelium, the flexible distal portion progressively folded inward to form a shape reminiscent of the embryonic optic cup, exhibited interkinetic nuclear migration and generated stratified neural retinal tissue, as seen in vivo. We demonstrate that optic-cup morphogenesis in this simple cell culture depends on an intrinsic self-organizing program involving stepwise and domain-specific regulation of local epithelial properties.     

Orchestrating size and shape during morphogenesis

Living organisms exhibit tremendous diversity, evident in the large repertoire of forms and considerable size range. Scientists have discovered that conserved mechanisms control the development of all organisms. Drosophila has proved to be a particularly powerful model system with which to identify the signalling pathways that organize tissue patterns. More recently, much has been learned about the control of tissue growth, tissue shape and their coordination at the cellular and tissue levels. New models integrate how specific signals and mechanical forces shape tissues and may also control their size.     

庐山石韦总黄酮的提取工艺初探

分别采用微波提取法、碱液提取法、60％丙酮提取法、55％乙醇提取法提取庐山石韦中的黄酮类化合物，并以芦丁为标准品，测定各提取物中的总黄酮含量，并比较它们的黄酮得率和含量。结果表明，60％丙酮提取法、55％乙醇提取法明显优于碱液提取法和微波提取法，而且55％乙醇为提取溶剂时效果最佳。     

Requirement of yeast fimbrin for actin organization and morphogenesis in vivo

The SAC6 gene was found by suppression of a yeast actin mutation. Its protein product, Sac6p (previously referred to as ABP67), was independently isolated by actin-filament affinity chromatography and colocalizes with actin in vivo. Thus Sac6p binds to actin in vitro, and functionally associates with actin structures involved in the development and maintenance of cell polarity in vivo. We report here that Sac6p is an actin-filament bundling protein 43% identical in amino-acid sequence to the vertebrate bundling protein fimbrin. This yeast fimbrin homologue contains two putative actin-binding regions homologous to domains of dystrophin, beta-spectrin, filamin, actin-gelation protein and alpha-actinin. Mutants lacking Sac6p do not form normal actin structures and are defective in morphogenesis. These findings demonstrate an in vivo role for the well-documented biochemical interaction between fimbrin and actin.     

衰老型上海四膜虫细胞在无性生殖过程中的形态和形态发生

记述了衰老型上海四膜虫细胞在无性生殖过程中的形态和形态发生．其大核经无丝分裂,成为近似相等的两部分,分别传给前、后仔虫．小核的有无与大核的分裂机制无关．分裂前期其旧口器在新口器发生时被逐渐吸收,只剩下一些痕迹．在新口器分化趋于完全时也开始重建,最后恢复正常形态．新口器位于分裂沟后,且和旧口器在细胞的同侧,分裂末期成为后仔虫的口纤毛器,旧口器经过重组成为前仔虫的口纤毛器