正畸牙移动相关信号通路研究进展

<正>畸牙移动是在机械力的作用下,通过对牙周膜产生牵张或压缩的力来引起牙周组织在生理限度内的组织改建,从而达到牙齿移动、矫治畸形的目的。由于没有明显的年龄限制,正畸矫治在全球范围已变得越来越普遍。因此,相关的研究也日益增多。牙齿移动的生物学基础是正畸力作用于牙周组织激活一系列信号转导通路,进而引起牙周膜的修复改建。为指导临床、加速正畸矫治疗程提供新的思路,本文综述了近年来有关正畸牙移动相关信号通路的研究进展。发现最新的研究集中在MAPK信号通路,Wnt/β-catenin信号通路,PI3K/AKt/m TOR信号通路,BMP-2信号通路,Caspase-3介导的凋亡通路较多。但是正畸牙移动引起的牙周组织改建是一个多种生物力学信号转导通路相互调节相互作用的过程,对于上述信号通路之间的相互关系还有待于我们更进一步的探索。     

美国Gevo公司改建商业化规模生物异丁醇生产装置

2011年5月31日,美国Gevo公司宣布,为了生产以生物质为原料的异丁醇（isobutanol）,决定开始对位于美国明尼苏达州Luveme的生物乙醇生产装置进行改造,随即举行了开工典礼。随着该生产装置的改造,     

cDNA microarray reveals the alterations of cytoskeleton-related genes in osteoblast under high magneto-gravitational environment

The diamagnetic levitation as a novel ground-based model for simulating a reduced gravity environment has been widely applied in many fields. In this study, a special designed superconducting magnet, which can produce three apparent gravity levels （0, 1, and 2 g）, namely high magneto-gravitational environment （HMGE）, was used to simulate space gravity environment. The effects of HMGE on osteoblast gene expression profile were investigated by microarray. Genes sensitive to diamagnetic levitation environment （0g）, gravity changes, and high magnetic field changes were sorted on the basis of typical cell func- tions. Cytoskeleton, as an intracellular load-bearing struc- ture, plays an important role in gravity perception. Therefore, 13 cytoskeleton-related genes were chosen according to the results of microarray analysis, and the expressions of these genes were found to be altered under HMGE by real-time PCR. Based on the PCR results, the expressions of WASF2 （WAS protein family, member 2）, WIPF1 （WAS/WASL interacting protein family, member 1）, paxillin, and talin 1 were further identified by western blot assay. Results indicated that WASF2 and WIPF1 were more sensitive to altered gravity levels, and talin 1 and paxillin were sensitive to both magnetic field and gravity changes. Our findings demonstrated that HMGE can affect osteoblast gene expression profile and cytoskele- ton-related genes expression. The identification of mechanosensitive genes may enhance our understandings to the mechanism of bone loss induced by microgravity and may provide some potential targets for preventing and treating bone loss or osteoporosis.     

实验动物设施及环境钠式试剂法测定空气中氨浓度的修改建议

我们在日常实验动物设施建设和环境控制检测中发现《实验动物设施及环境GB 14925-2001》附录中对于按其浓度的检测方法存在缺陷,动态检测氨浓度指标,通常在1～7 mg/m^3范围之内,极少有出现在7～14 mg/m^3的情况。在此提出来供参考。     

几种乙型肝炎病毒DNA重组质粒的改建及其在哺乳动物细胞高效表达乙型肝炎表面抗原

将Bgl Ⅱ不完全水解pTHBV一1质粒产生的两种乙型肝炎病毒(HBV)DNA片段插入pSV2-dhft质粒的Bglll切口,构造成{种重组质粒,其结构特点是：1都含有SV40的DNA复制起点和早期启动子;2都含有二氢叶酸还原酶基因(dhfr) 3·{种重组质粒是在dhfr。基因3’末端分别插入两种大小不同,方向相反的HBV’DNA片段而成。使用这4种质粒DNA分别和tk质粒DNA共转化Ltr细胞,在HAT培养基选择压力下4种质粒都得到有效表达HBsAg。通过换用氨甲喋呤并逐渐增加其药量,从氨甲喋呤抗性细胞中获得高效表达HBsAg的B2和B16细胞系。据固相放射免疫检测结果计算,B16细胞系的HBxAF分泌量可达12．5pg／10’细胞／天．细胞传代4个月表达稳定。这些细胞在HBsAg诊断试剂和疫苗研制中具有潜在的应用价值。     

天意怜幽草人间重晚晴--国家改建中研究生活的简略回忆

我一生的学习、工作经历都是在教学、研究院校中度过的.祖辈任职官署(祖父娄春蕃,历任直隶总督幕府.外祖卢木斋,自学成才,以数学见长受到知遇,曾任直隶学务处督办、省提学使),目睹满清王朝腐朽,中国屡遭列强侵略,不断瓜分领地,老百姓受苦无穷!为挽救国家危亡,必须革新教育,勉励后辈,发奋图强.两家志同道合,遣送子女辈出国学习深造,使我的父母在联姻后得以协同留学美国四载,于满清帝制颠覆前夕回归.民国初建,祖父不幸逝世.在外祖父卢木斋的引领下,两家通力协作,开发地方实业,卓有成效;同时,继续发展教育,多年来由母亲姐妹们开设蒙养园,创办木斋小学、扩大为天津知名的木斋中学.