Natural history of mesenchymal stem cells,from vessel walls to culture vessels

Mesenchymal stem/stromal cells (MSCs) can regenerate tissues by direct differentiation or indirectly by stimulating angiogenesis, limiting inflammation, and recruiting tissue-specific progenitor cells. MSCs emerge and multiply in long-term cultures of total cells from the bone marrow or multiple other organs. Such a derivation in vitro is simple and convenient, hence popular, but has long precluded understanding of the native identity, tissue distribution, frequency, and natural role of MSCs, which have been defined and validated exclusively in terms of surface marker expression and developmental potential in culture into bone, cartilage, and fat. Such simple, widely accepted criteria uniformly typify MSCs, even though some differences in potential exist, depending on tissue sources. Combined immunohistochemistry, flow cytometry, and cell culture have allowed tracking the artifactual cultured mesenchymal stem/stromal cells back to perivascular anatomical regions. Presently, both pericytes enveloping microvessels and adventitial cells surrounding larger arteries and veins have been described as possible MSC forerunners. While such a vascular association would explain why MSCs have been isolated from virtually all tissues tested, the origin of the MSCs grown from umbilical cord blood remains unknown. In fact, most aspects of the biology of perivascular MSCs are still obscure, from the emergence of these cells in the embryo to the molecular control of their activity in adult tissues. Such dark areas have not compromised intents to use these cells in clinical settings though, in which purified perivascular cells already exhibit decisive advantages over conventional MSCs, including purity, thorough characterization and, principally, total independence from in vitro culture. A growing body of experimental data is currently paving the way to the medical usage of autologous sorted perivascular cells for indications in which MSCs have been previously contemplated or actually used, such as bone regeneration and cardiovascular tissue repair.     

网路辅助教学之教学支援服务 :以逢甲大学图书馆资讯素养强化工程为例

新的教育科技为许多大专校院带来更多元、更具弹性的教育劳务提供方式 .将学习的空间由教室局促的场景 ,扩展到超越时空限制的学习型态 ;由传统教师面对学生单向的传输 ,转换成为多面向、多感官的教学情境 ;学习的过程也由重视个人的理解、领悟 ,转变为强调协同学习 (collabo rativelearning)的相互酝酿与启发 ,本文由文献探讨了解教学活动设计各阶段目标任务、探讨教学方法于网路辅助教学应用模式 ,以及课程评量策略 ,并以逢甲大学图书馆协助校内教师进行网路辅助教学之经验为验证 ,依据教师教学历程三阶段 :课程开始前———课程需求分析阶段、课程进行中———学科馆员与教师之协同教学模式、课程结束———教学评量阶段 ,说明图书馆推动网路辅助教学在人力、资源上所投入支援服务以及其运作模式 ,以期能检讨过程并发现问题 ,作为未来发展出合适之教学支援服务 (facultysupport)模式之参考     

The origins and uses of mouse outbred stocks

Outbred mouse stocks, often used in genetics, toxicology and pharmacology research, have been generated in rather haphazard ways. Understanding the characteristics of these stocks and their advantages and disadvantages is important for experimental design. In many studies these mice are used inappropriately, wasting animals' lives and resources on suboptimal experiments. Recently, however, researchers from the field of complex trait analysis have capitalized on the genetics of outbred stocks to refine the identification of quantitative trait loci. Here we assess the most widely used outbred stocks of mice and present guidelines for their use.     

食盐中微量碘的分析研究

一引言碘是防御和治疗由缺碘而引起的各项病症的药剂,而食盐中的碘又是人们从食料中得到这一元素的经常来源,所以对于食盐中含碘量的分析研究是很重要的。因此,轻工业部盐务总局委托高等教育部将「食盐中含微量碘的分析研究」作为科学研究专题,发给各校院研究,并指定西北大学,四川大学,福建师范学院和华东航空学院四校同时进行研究。     

cdc2 links the Drosophila cell cycle and asymmetric division machineries

Asymmetric cell divisions can be mediated by the preferential segregation of cell-fate determinants into one of two sibling daughters. In Drosophila neural progenitors, Inscuteable, Partner of Inscuteable and Bazooka localize as an apical cortical complex at interphase, which directs the apical-basal orientation of the mitotic spindle as well as the basal/cortical localization of the cell-fate determinants Numb and/or Prospero during mitosis. Although localization of these proteins shows dependence on the cell cycle, the involvement of cell-cycle components in asymmetric divisions has not been demonstrated. Here we show that neural progenitor asymmetric divisions require the cell-cycle regulator cdc2. By attenuating Drosophila cdc2 function without blocking mitosis, normally asymmetric progenitor divisions become defective, failing to correctly localize asymmetric components during mitosis and/or to resolve distinct sibling fates. cdc2 is not necessary for initiating apical complex formation during interphase; however, maintaining the asymmetric localization of the apical components during mitosis requires Cdc2/B-type cyclin complexes. Our findings link cdc2 with asymmetric divisions, and explain why the asymmetric localization of molecules like Inscuteable show cell-cycle dependence.