Comparison of the in vitro development of mouse single blastomeres with and without the zona pellucida

Summary No difference was observed during in vitro development between mouse single blastomeres with and without the zona, pellucida, isolated from 2- and 4-cell stage eggs.     

α-Particle track autoradiographic study of the distribution of a [211At]-astatinated drug in normal tissues of the mouse

Summary The microscopic distribution of the potential endoradiotherapeutic drug, 6-[²¹¹At]-astato-2-methyl-1,4-naphthoquinol bis (diphosphate salt) in normal tissues of the mouse has been studied by -particle track autoradiography. The uptake into critical radiosensitive tissues, especially bone marrow, colon and lung, was low.     

The Lac repressor provides a reversible gene expression system in undifferentiated and differentiated embryonic stem cell

Control of mammalian gene promoters by the bacterial LacI repressor provides reversible regulation and dose-response levels of derepressed expression by the lactose analog isopropyl thiogalactose (IPTG). Here, we show that insertion of LacI-binding sites in the ubiquitous β-actin promoter confers a strong and dose-dependent IPTG-regulatable expression of transiently transfected reporter genes in mouse embryonic stem (ES) cells expressing LacI. We established ES cell lines stably expressing reporter genes under inducible control and found a five- to tenfold IPTG induction of transgene expression. The kinetics of induction is rapid and stable, and can be rapidly reversed after IPTG removal. Importantly, this regulatable expression was maintained throughout the differentiation process of ES cells, and observed in individual differentiated cardiomyocyte-like cells and neuronal-like cells. This reversible system is the first to function from undifferentiated to individual welldifferentiated ES cells, providing a very useful tool to understand molecular mechanisms underlying ES cell self-renewal, commitment and differentiation.Received 17 March 2005; received after revision 19 April 2005; accepted 25 April 2005     

Effects of retinoic acid on ascites cells of the TA3 mouse mammary carcinoma

Summary Retinoic acid caused a decrease in adhesiveness but no growth change in the allotransplantable TA3-Ha cell and no change in adhesiveness or growth in the strain specific TA3-St cell. The retinoic acid binding protein was detected in the TA3-Ha, but not the TA3-St, cell.This study was supported in pat by Public Health Service Grants CA-08418 and CA-18600 from the National Cancer Institute, National Institutes of Health. This is publication 955 of the Robert W. Lovett Group for the Study of Diseases Causing Deformities. We gratefully acknowledge the contributions of Drs Luigi M. De Luca and Anton M. Jetten of the Laboratory of Cellular Carcinogenesis and Tumor Promotion, National Cancer Institute, National Institutes of Health, Bethesda, MD, without whose help this study would not have been possible.     

(鼠标)模拟动态数字输入的识别之轨迹数据采集

在研究动态数字输入识别方法中,如何实现鼠标模拟动态数字输入的识别方法,首先最关键的问题是怎样获取鼠标轨迹的数据.在以OnMouseMove函数获取鼠标移动消息的方法中,该函数响应时间太长,其函数的数据不能完全表达鼠标的轨迹信息.通过采用连线取点的方法较好的克服以上的不足,得以获取完整的鼠标轨迹信息.     

昆明种小鼠抗疲劳试验中若干参考值测定

本文就抗疲劳功能试验中的四项指标进行研究分析,旨在了解各项指标的动态变化,确定其参考值.结果显示小鼠负重(5%体重)游泳时间参考值为196～1420 s(密度为48 cm2/只,25℃水温);小鼠基础血乳酸参考值为1.77～6.56 mmol/L;短时剧烈运动血乳酸参考值为3.55～9.29 mmol/L;小鼠基础血清尿素氮参考值为7.86～13.14mmol/L;长时运动后血清尿素氮参考值为6.97～24.90mmol/L;小鼠基础肝糖原参考值为1452.8～5279.4 mg/100g肝组织,长时大强度运动后肝糖原参考值为39.9～3163.3 mg/100g肝组织.     

基于小鼠肝炎病毒研究遗传工程小鼠隔离检疫设计

目的以小鼠肝炎病毒(MHV)为例,研究两种常用小鼠感染MHV后粪便中病毒核酸检测量与血清特异性抗体的变化,探讨实验动物病原微生物感染的检测设计。方法用MHV病毒核酸检测阳性的脏垫料持续饲养C57BL/6和BALB/c小鼠(n=20) 28 d,进行脏垫料接触感染。之后所有小鼠使用无菌垫料进行单笼饲养,每周收集新鲜粪便和血清样本,经Taqman荧光定量PCR(qPCR)和ELISA法检测后进行统计分析。结果对于BALB/c小鼠,采用qPCR法检测时,在实验第21天即有阳性检出(阳性率20%),第28天阳性检出率达到最高,为80%,第42天阳性检出率为50%,至第56天无阳性检出。血清ELISA检测发现,实验第42天才有MHV特异性抗体检出(阳性率为50%)。对于C57BL/6小鼠,采用qPCR法检测时,在第28天和第42天分别从20%小鼠粪便中检出MHV。而采用ELISA法在整个实验期均未检出特异性阳性抗体。结论在隔离检疫和常规病原检测中,建议选用BALB/c小鼠作为哨兵鼠,替代C57BL/6小鼠。由于qPCR法具有早检出和更高检出率的优点,建议在隔离检疫早期采用基于分子生物学的粪样核酸检测法替代ELISA法。     

小鼠诺如病毒分子生物学研究进展

本文对小鼠诺如病毒的分子生物学及复制的研究进展做了比较系统的综述,为小鼠诺如病毒的病原学研究及感染的防控提供参考。     

在程序中连接与使用鼠标器的一种方法

目前多数应用系统都采用菜单结构,对菜单项的选择除了利用光条的移动等传统方式之外.还可通过移动鼠标器来选择菜单项.本文介绍一种在Turbo C中使用鼠标器选择菜单项的方法.     

Preimplantation mouse embryos cultured in mouse,rat and human sera: differentiation and sister chromatid exchange

Summary Development of 4-cell and of 8-cell mouse embryos and of morulae and blastocysts is inhibited in vitro by mouse serum but not by rat or human sera which also do not influence sister chromatid exchange in cultured morulae and blastocysts.