Hemorrhagic and nonhemorrhagic brain lesions: evaluation with 0.35-T fast MR imaging

Two fast magnetic resonance (MR) imaging techniques, advanced Fourier and partial-flip imaging, were used at 0.35 T to examine 21 patients with suspected intracranial lesions; the results were quantitatively compared with a conventional spin-echo study. Both of the fast MR techniques yielded a fourfold reduction in imaging time per section. The advanced Fourier sequence showed contrast that was identical to the conventional spin-echo study with signal-to-noise ratios of 58% and 57% for the first and second echoes, respectively. The partial-flip sequence showed a contrast of 109% and 57% for lesions versus substantia alba, and 107% and 78% for substantia grisea versus substantia alba relative to the first and second echoes of the conventional spin-echo study. The partial-flip sequence was particularly sensitive to magnetic susceptibility; this produced artifacts that may undermine the usefulness of partial flip for routine screening in certain parts of the brain. However, this susceptibility significantly improved the detection of intracranial hemorrhage when compared with the spin-echo sequence, particularly when combined with phase mapping of the partial-flip study.     

A role for epithelial gamma delta T cells in tissue repair

Conclusions  A balance between epithelial growth and repair versus inflammation to isolate and contain damage is critical for maintenance of the epithelial microenvironment. Epithelial γδ T cells appear to play an important role in maintaining the integrity of the epithelial tissues they survey. Insult to the epithelium likely leads to the up-regulation of self-associated stress molecules that are recognized by intraepithelial γδ T cells. The limited, and in some cases canonical, repertoire of the epithelial γδ TCRs is certainly consistent with this recognition of damaged self, rather than recognition of the vast array of possible non-self antigens that could invade these epithelial barriers. Furthermore, the cellular context of the various γδ T cell subsets and the types of antigens they engage together may contribute to the distinct requirements of γδ T cells for PTKs in their selection, homing and presumably also in their response to epithelial cell damage.     

Pancreatic pseudocysts drained through a percutaneous transgastric approach

We describe a new method for the percutaneous drainage of pancreatic pseudocysts using a transgastric approach. We used this technique in three dogs and six patients for whom no other "safe" access route was available. The procedures were performed under US guidance alone or with US combined with fluoroscopy. No complications were observed.     

Internet网上细胞凋亡研究的信息资源及其利用

0　引言　 Internet网上含有丰富的信息资源 ,科研人员可以通过 Internet网了解其所研究领域的最新发展动态 ,获取全面和系统的科研信息 ,有利于进行学术交流[1 ] .然而网上信息浩如烟海 ,当检索某一专门领域的资料时 ,有时无从下手 .我们在科研实践中对 Internet网上主要的细胞凋亡研究信息资源及其查找方法进行了归纳 .1　细胞凋亡专业网站1. 1　 The Cell death society (http:/ / www.celldeath-apoptosis.org)　为美国细胞死亡学会主办 ,概括了细胞凋亡和程序性细胞死亡研究的各个领域 ,包括与细胞凋亡有关的各种疾病 .可以免费注册…     

3－硝基－1，2，4－三唑类乏氧细胞放射增敏剂的构效关系

为了寻找毒性低、增敏作用强的乏氧细胞放射增敏剂，设计并合成了一系列５－溴－，５－甲基－，和５－未取代的３－硝基－１，２，４－三唑－１－乙酰胺类化合物，用ＨｅＬａＳ３细胞进行了体外试验。结果表明５－溴取代衍生物的增敏作用强于相应的５－甲基－或５－未取代的硝基三唑衍生物，但是它们的毒性亦增大。修饰１位乙酰胺侧链也可以改变化合物的增敏作用和亲脂性。在所测定的化合物中ＴＡ－１０１［２－（３－硝基－１－三唑基）乙酰胺］由于有高的增敏作用和低亲脂性，可能是一个有希望的放射增敏剂。     

苦楝化学成份的研究

从苦楝(Melia azedarach L.)果中分得苦楝新醇(Ⅰ),苦楝醇(Ⅱ)、苦楝酮(Ⅲ)、苦楝二醇(Ⅳ)、香草醛(Ⅴ)和香草酸(Ⅵ)。根据波谱(IR,MS,~1HNMR,~(13)CNMR)分析和理化常数测定,确定了它们的结构。其中苦楝新醇(Ⅰ)为新化合物,对菜青小虫有一定的拒食活性。     

缺血性脑损伤诱导内源性神经干细胞的增殖和迁移

目的:观察缺血性脑损伤对内源性神经干细胞增殖、迁移的影响。方法:实验于2004-09/2005-03在新乡医学院人体解剖与组织胚胎重点实验室进行。10～12周体质量300～350g的健康雄性SD大鼠62只,由新乡医学院实验动物中心提供。按随机数字表方法将其分为正常组6只、假手术对照组14只、脑缺血再灌注组42只(分为再灌注1,3,5,7,10,15,20d7个时间点,每时间点6只)。参照Pulsinelli-Brierley法,夹闭大鼠双侧颈总动脉制作短暂性全脑缺血动物模型,全脑缺血10min后再灌注,假手术对照组不夹闭颈总动脉。于脑缺血再灌注不同时间点应用SABC免疫组化法染色显示5-溴-2-脱氧尿嘧啶阳性细胞和巢蛋白阳性细胞,光镜下观察并分析脑缺血损伤后内源性神经干细胞增殖、迁移的变化过程。结果:正常组、假手术对照组大鼠均存活,脑缺血再灌注组大鼠1d、5d、15d、20d各死亡1只,共58只大鼠进入结果分析。①正常组与假手术对照组室管膜下区、海马CA1区、齿状回区域均偶见5-溴-2-脱氧尿嘧啶阳性细胞和巢蛋白阳性细胞。②脑缺血再灌注后1d于海马、齿状回和室管膜下区均有5-溴-2-脱氧尿嘧啶阳性细胞和巢蛋白阳性细胞,随后逐渐增加,7～10d达高峰,术后20d仍有表达;在室管膜下区的5-溴-2-脱氧尿嘧啶阳性细胞和巢蛋白阳性细胞有向皮质、海马迁移的现象。结论:成年大鼠全脑缺血后7～10d内源性神经干细胞增殖达到高峰;增殖的内源性神经干细胞存在由增殖区向靶区迁移的现象。     

大鼠舌咽和迷走神经感觉神经节内P2X2、P2X3受体与calretinin和IB4结合位点的共存

应用免疫组织化学荧光三标方法结合激光共聚焦显微镜技术研究了大鼠舌咽和神经迷走神经感觉神经节内ATP受体P2X2、P2X3与calretinin、植物凝集素(IB4)结合位点的共存。结果显示:舌咽和迷走神经感觉神经节内可见大量P2X2、P2X3阳性的神经元胞体和纤维,P2X2受体阳性细胞多为大、中、小型神经元,P2X3阳性细胞多为中、小型神经元;可见较多的P2X2/IB4及P2X3/IB4双标神经元。有(91.1±4.7)%(结状神经节)、(78.8±2.4)%(岩神经节)、(76.8±2.7)%(颈静脉神经节)为P2X2阳性细胞;(77.0±3.2)%(结状神经节)、(91.2±3.9)%(岩神经节)、(78.4±3.6)%(颈静脉神经节)的P2X3阳性细胞结合IB4;有8.9±1.6%(结状神经节)、7.7±1.4%(岩神经节)、9.1±1.1%(颈静脉神经节)的P2X2阳性细胞呈calretinin阳性;三神经节内均观察到少量P2X2/calretinin/IB4三标细胞。P2X3/calretinin双标或P2X3/calretinin/IB4三标神经元数量较少。这些结果提示,舌咽和迷走神经感觉神经节内ATP受体P2X2、P2X3与IB4结合位点存在广泛的共存,部分P2X2受体与calretinin存在着共存。