胰岛素样生长因子-Ⅰ对软骨细胞凋亡的抑制

目的:探讨胰岛素样生长因子-Ⅰ(IGF-Ⅰ)对软骨细胞增殖及白细胞介素-1(IL-1)诱导软骨细胞凋亡的影响,揭示其抗损伤作用机制,为关节软骨损伤治疗提供理论依据。方法:分离培养人胚胎关节软骨细胞,采用四氮甲基唑蓝(MTT)法测定不同含量软骨细胞增殖活性的变化,利用光镜、电镜、DNA电泳及流式细胞仪测定作为凋亡检测指标。结果:IGF-Ⅰ呈剂量依赖式促软骨细胞增殖,当IGF-Ⅰ含量达50μg/L时,促软骨细胞增殖作用达最大值。IL-1组光镜、电镜下可见典型的细胞凋亡形态学改变,琼脂糖凝胶电泳示特征性的DNA梯状条带,IGF-Ⅰ处理组未见明显凋亡征象。流式细胞仪检测发现,IGF-Ⅰ处理后软骨细胞凋亡率显著降低。结论:IGF-Ⅰ能促进软骨细胞增殖,对IL-1诱导的软骨细胞凋亡具有保护作用。     

Dynamic evaluation of 18F-FDG uptake by microPET and whole-body autoradiography in a fibrosarcoma-bearing mouse model.

BACKGROUND AND PURPOSE: Fluorine-18-2-deoxy-D-glucose (18F-FDG) has been used in the clinic as a diagnostic radiotracer for monitoring many kinds of tumors, but its value for monitoring fibrosarcoma is not well established. METHODS: In this study, the uptake of 18F-FDG in a fibrosarcoma-bearing mouse model was evaluated using the high resolution positron emission tomography (PET) system microPET. Tumor cells were implanted in 3 FVB/N mice, and static microPET scanning was performed on day 1, 7, 12 and 15 after implantation. A dynamic microPET image was scanned on day 12 to determine the 18F-FDG uptake in 3 other tumor-bearing mice. Time-activity curves were plotted by drawing regions of interest in the tumor, liver, kidneys and muscles. The mice were sacrificed after dynamic microPET imaging and whole-body autoradiography (WBAR) was performed. For biodistribution study, 9 tumor-bearing mice, 3 per experimental group, were studied at 3 time points and the results were compared with the static microPET images. RESULTS: MicroPET images suggested that 18F-FDG could be used to monitor the growth of tumors 7 days after implantation. Dynamic scans of 18F-FDG uptake reached a plateau in the tumor after 20 minutes on day 12 after implantation. Both microPET and WBAR revealed evidence of tumor necrosis. The results of biodistribution and WBAR agreed with those from microPET images. CONCLUSION: MicroPET was useful for monitoring the growth of fibrosarcoma and determination of the maximal uptake time point of 18F-FDG in tumors in this tumor-bearing mouse model.     

Model invariant method for extracting single-channel mean open and closed times from heterogeneous multichannel records.

We present a proof that the mean open (and closed) times of the individual channels in a multichannel record can be found in a model-independent fashion. As the results are model independent, they can be derived by assuming the simplest model for all the channels, namely that they all have the basic CLOSED in equilibrium with OPEN scheme. In particular, the method can be applied to patches where the channel population is heterogenous with respect to open probability. Multichannel simulations are performed to test the limits of applicability of this method to restricted amounts of data. One conclusion is that increasing the number of channels does not substantially reduce the errors in estimating the mean times, in spite of the 'increased information' present. We also prove the general applicability of the algorithm of Fenwick et al. (1982) in estimating the mean times without knowledge of the number of channels present, and discuss its limitations. An illustration using experimental data is also given.     

Announcement

The name of one of the contributing authors to this paper was omitted from the list of authors that appeared on page 373. The correct list of authors and affiliations are printed below:     

单片机自动灌流系统设计及其医学应用

介绍一种用单片机构成的自动灌流控制系统。它以灌流压为控制指标，以ＬＤＢ－Ｍ电子蠕动泵作为执行机构，构成闭环控制系统，能实现用户设定的各种液流压曲线。系统内采用了ＥＥＰＲＯＭ存储器，可对用户设定的多达１０条灌流曲线进行长期保存。     

深圳宝安3～7岁健康幼儿血清糖、离子、非蛋白含氮类化合物表达水平观察

目的观察深圳宝安3～7岁健康幼儿血清糖、离子、非蛋白含氮类化合物表达水平。方法采用OLRPUSAU-640全自动生化仪及OLRPUS诊断试剂、东欧生物诊断试荆，检测316例体检健康幼儿血清中Ca^＋＋、Mg^＋＋、P^＋＋＋、GLU、BUN、Cr、UA的含量。结果①．1组与4组及2组与3、4组Ca^＋＋组间方差分析，差异有统计学意义，P〈0.05。②．1组与2、3、4组Cr组间方差分析，差异有统计学意义P〈0．05。而Mg^＋＋、P^＋＋＋、GLU、BUN、UA组间方差分析差异无统计学意义，P〉0．05。结论笔者证实了3～4岁健康幼儿与6～7岁健康幼儿及4～5岁健康幼儿与5～7岁健康幼儿血清Ca^＋＋表达水平有差异。也证实了3～4岁健康幼儿与4～7健康幼儿Cr含量存在差异。由此可见，3～7岁健康幼儿建立自己的参考值是必要的。