Comparison of Marker Intervals and Number of Sib Pairs Used for Linkage Analysis on Simulated Nuclear Family Data

Using a two‐stage global scan design, we analyzed general population replicates 1 and 42 of the Genetic Analysis Workshop (GAW) 12 simulated data set using three methods: revisited Haseman‐Elston (HER), maximum likelihood variance estimation (ML), and variance components (VC). Three marker densities, 5‐, 10‐, and 15‐cM intervals, were examined in the first‐stage scan. We found that the 10‐cM interval appears to be the most cost‐effective approach in genotyping without sacrificing power when using a first stage significance level of 0.01. Subsequently, we performed the second‐stage scan at 1‐cM intervals for those putative positive regions identified in the first‐stage scan at a significance level of 0.01. We also compared the power to detect linkage using different numbers of sib pairs for a genome‐wide scan at a 10‐cM interval and found that power decreases nonlinearly as the number of sib pairs decreases. © 2001 Wiley‐Liss, Inc.     

椎管内占位病变的CT评价

本文回顾性分析了２８例椎管内占位病变（包括椎管内肿瘤２４例、蛛网膜囊肿２例、硬膜外脓肿和椎同盘突出各１例）的ＣＴ表现。着重讨论了造影剂增强ＣＴ的特征。大多数增强ＣＴ可显示肿块的轮廓，有助于肿块定位。室管膜瘤和星形细胞瘤的增强ＣＴ表现类似，但雪旺氏瘤、海绵状血管瘤和脓肿具有增强ＣＴ特征；同时还对脂肪瘤、脊膜瘤和蛛网膜囊肿的增强ＣＴ特征进行了探讨。增强ＣＴ定位困难时，ＣＴＭ可有很大的帮助。     

对侧网状巨细胞核对大鼠脊髓背表面电位的影响

以浅麻醉和麻痹大鼠为对象,利用计算机平均技术记录强电流刺激腓肠神经诱发的脊髓背表面电位(CDP),观察对侧网状三细胞核(NGC)微量注射L一谷氨酸钠,使神经细胞兴奋后对CDP的影响.实验发现,对侧NGC神经细胞兴奋后,Aβ和Aσ纤维引起的P_1波及Aσ和C类纤维引起的N_3波减小,C类纤维引起的P_2波明显减小,N_4 波消失.以上结果提示:对侧NGC对细纤维诱发的CDP成分有抑制作用.     

呼吸电刺激训练对肺功能康复的作用

通过电流和声、光信号刺激，对２０例慢性阻塞性肺疾患（ＣＯＰＤ）患者进行呼吸电刺激训练（ＲＥＴ），结果在ＲＥＴ时呼吸频率和平均吸气流速明显下降，潮气量和吸气间期明显增加，跨膈压增大，氧耗量和能量代谢无明显变化；于ＲＥＴ１５天后ＰａＣＯ２明显下降，ＰａＯ２和运动能力明显增高，肺勇气功能明显改善。表明ＲＥＴ１５天后ＰａＣＯ２明显下降，ＰａＯ２和运动能力明显增高，肺通气功能明显改善。表明ＲＥＴ能使ＣＯＰＤ     

Fluorescence and photobleaching dynamics of single light-harvesting complexes

Single light-harvesting complexes LH-2 from Rhodopseudomonas acidophila were immobilized on various charged surfaces under physiological conditions. Polarized light experiments showed that the complexes were situated on the surface as nearly upright cylinders. Their fluorescence lifetimes and photobleaching properties were obtained by using a confocal fluorescence microscope with picosecond time resolution. Initially all molecules fluoresced with a lifetime of 1 ± 0.2 ns, similar to the bulk value. The photobleaching of one bacteriochlorophyll molecule from the 18-member assembly caused the fluorescence to switch off completely, because of trapping of the mobile excitations by energy transfer. This process was linear in light intensity. On continued irradiation the fluorescence often reappeared, but all molecules did not show the same behavior. Some LH-2 complexes displayed a variation of their quantum yields that was attributed to photoinduced confinement of the excited states and thereby a diminution of the superradiance. Others showed much shorter lifetimes caused by excitation energy traps that are only ≈3% efficient. On repeated excitation some molecules entered a noisy state where the fluorescence switched on and off with a correlation time of ≈0.1 s. About 490 molecules were examined.     

颞颌关节继发性滑膜炎的临床诊断

颞颌关节滑膜炎分为原发性和继发性两种，颞颌关节紊乱综合症的滑膜炎为继发性滑膜炎。本文通过对１０６例颞颌关节紊乱综合症患者的临床检查、关节许氏位以及关节上腔造影的Ｘ线检查，同时对４２例进行了关节内窥镜检查，在此基础上探讨了继发性滑膜炎的临床诊断标准．作者认为急性滑膜炎主要是以关节疼痛和滑膜血管的改变为主，慢性滑膜炎的临床症状与滑膜组织改变以及关节骨组织的改变均有关系。