Rapamycin selectively inhibits interleukin-2 activation of p70 S6 kinase.

The macrolide rapamycin induces cell cycle G1 arrest in yeast and in mammalian cells, which suggests that an evolutionarily conserved, rapamycin-sensitive pathway may regulate entry into S phase. In mammals, rapamycin inhibits interleukin-2 receptor-induced S phase entry and subsequent T-cell proliferation, resulting in immunosuppression. Here we show that interleukin-2 selectively stimulates the phosphorylation and activation of p70 S6 kinase but not the erk-encoded MAP kinases and rsk-encoded S6 kinases. Rapamycin completely and rapidly inhibits interleukin-2-induced phosphorylation and activation of p70 S6 kinase at concentrations comparable to those blocking S phase entry of T cells (0.05-0.2 nM). The structurally related macrolide FK506 competitively antagonizes the actions of rapamycin, indicating that these effects are mediated by FKBP, which binds the transition-state mimic structure common to both rapamycin and FK506 (refs 4, 6, 9-11). The selective blockade of the p70 S6 kinase activation cascade by the rapamycin-FKBP complex implicates this signalling pathway in the regulation of T cell entry into S phase.     

Quantitative mapping of amplicon structure by array CGH identifies CYP24 as a candidate oncogene

We show here that quantitative measurement of DNA copy number across amplified regions using array comparative genomic hybridization (CGH) may facilitate oncogene identification by providing precise information on the locations of both amplicon boundaries and amplification maxima. Using this analytical capability, we resolved two regions of amplification within an approximately 2-Mb region of recurrent aberration at 20q13.2 in breast cancer. The putative oncogene ZNF217 (ref. 5) mapped to one peak, and CYP24 (encoding vitamin D 24 hydroxylase), whose overexpression is likely to lead to abrogation of growth control mediated by vitamin D, mapped to the other.     

Ontogenetic changes in relative levels of cyclic AMP-dependent and cyclic GMP-dependent protein kinases in prostates,epididymides and testes from guinea-pigs

Summary Changes in realtive levels of cyclic AMP-dependent protein kinase (A-PK) and cyclic GMP-dependent protein kinase (G-PK) in prostates, epididymides and testes from guinea-pigs were examined at 3 different ages. During postnatal development, a decrease in the ratio of the 2 classes of protein kinases was seen in prostates, whereas increases of the ratios of the enzymes were found in epididymides and testes.Acknowledgments. This work was supported by grant RR-08199 from the National Institutes of Health, USA. The authors thank Dr J.F. Kuo, in whose laboratory part of this work was performed, for his great advice.Undergraduate trainee of Minority Biomedical Support.     

The structure of durantoside IV tetraacetate

Summary Durantoside IV tetraacetate was isolated fromDuranta repens Linn and identified by physical and chemical evidence.     

基于JavaBean技术的EmbeddedInternet模型及实现

利用JavaBean技术,提出并建立了一种新的EmbeddedInternet模型·该模型以Web和JavaBean技术为主要方法,解决了远程用户同时控制多台接入到Internet上设备的问题,在服务器端实现了设备无关性,最大限度的避免了软件的重复开发·EmbeddedInternet模型的提出为各种不同种类的现场设备接入Internet找到了一种切实可行的方法·     

实验用比格犬戊巴比妥钠麻醉并发症的观察及处理

目的总结比格犬戊巴比妥钠麻醉并发症及其处理方法。方法选择64例使用戊巴比妥钠麻醉的比格犬,观察麻醉后各种并发症的发生情况并进行处理。结果64例戊巴比妥钠麻醉的比格犬出现并发症7例,其中治愈6例,死亡1例。结论比格犬戊巴比妥钠麻醉后并发症的及时正确处理,可降低比格犬戊巴比妥钠麻醉后并发症导致的死亡。     

水合氯醛和硫酸镁在猪肿瘤热疗实验中的麻醉效果

目的　旨在探讨水合氯醛和硫酸镁混合麻醉剂在猪的热疗实验中的麻醉效果。结果　在正确使用该麻醉剂的前提下,水合氯醛和硫酸镁麻醉剂对体重较大的猪能较好的维持长时间的麻醉,且麻醉过程平稳,不需借助任何仪器,操作简单,易于掌握,麻醉复苏时间短。     

网格应用程序的性能预测策略

通过分析网格应用程序性能信息的预测策略, 对几种主要预测策略作出了性能评价; 结合应用历史信息预测法, 以资源预测转化为应用程序预测策略为基础, 提出了网格应用程序性能预测的修正模型. 在动态网格环境下, 本模型为调度决策系统提供了调度依据; 使得网格资源的利用更加合理, 改进了应用程序的执行性能.     

葛根素-锗配合物的合成及其抗炎活性研究

以葛根素和氧化锗为原料合成葛根素-锗配合物.采用紫外及红外技术对配合物的结构进行初步表征.采用二甲苯诱导小鼠耳廓肿胀炎症模型,以肿胀度和抑制率为抗炎活性指标,测定葛根素-锗配合物的抗炎活性.结果表明,葛根素与锗离子生成了配合物,与锗发生配位的基团是葛根素分子中B环的4'-羟基,而不是A环的7-羟基及C环的羰基.葛根素-锗配合物的抗炎活性(抗炎肿胀度抑制率为75.91%)远远高于葛根素配体(抗炎肿胀度抑制率为32.49%),也远远高于临床常用的甾体抗炎药-氢化可的松(抗炎肿胀度抑制率为48.74%).