肝癌介入治疗现状

为探讨肝癌目前的治疗现状,综合国内外近10 a来已公开发表的论著、文献阐述肝癌介入治疗的现状,归纳总结文献中关于肝癌介入治疗的不同方法,比较各自的优劣.认为肝癌介入治疗方法较多,目前缺乏规范,主张综合治疗为主,实施个体化方案.     

用原子力显微镜观察活海马区神经元三维超微结构

在液体环境中,利用原子力显微镜成功地对体外培养的大鼠海马区神经元进行了超微结构的成像研究。分别获取了活海马神经元胞体、轴突、树突以及生长锥等结构清晰的原子力显微图像,并对其三维结构进行了定量分析。为进一步利用原子力显微镜研究海马神经元打下了基础。     

低剂量铅对神经细胞粘附分子表达的影响研究

为了探讨神经细胞粘附分子(NCAM)在铅神经发育毒性中的作用,分别从体内、体外途径观察了低水平铅暴露对海马NCAM表达的影响。结果表明:铅明显抑制了海马神经元NCAM的表达,抑制程度随时间延长逐渐减弱,随剂量增加逐渐增强。提示:无论体内还是体外,低水平铅均显著抑制了Wistar大鼠海马NCAM的表达,并造成海马NCAM表达时程上的延迟。     

中枢记忆性T细胞和效应记忆性T细胞

免疫记忆是适应性免疫应答的重要特征,其细胞学基础的阐明是疫苗开发和疾病预防的关键。近年来的研究表明,记忆性T细胞可以被进一步划分为中枢记忆性T细胞和外周记忆性T细胞2个亚群,它们的分布和功能迥异,在生物学特性上也不尽相同。二者关系的深入探讨对于免疫记忆的认识和疾病防治均具有重大的理论和实践意义。     

弱激光照射周氏新对虾心脏细胞的显微和超微结构观察

采用He-Ne激光照射周氏新对虾的心脏组织.组织学和生物统计学表明:He-Ne激光照射后,心脏组织具有明显异染色质的细胞数量有所增加.在同一照射强度的情况下,照射的时间越长,其心脏组织具有明显异染色质的细胞数量就越多;电镜观察结果表明:经过2 h照射立即取材的心肌细胞,细胞核形态发生变化,异染色质增加,线粒体出现空泡化、嵴断裂、水肿,粗面内质网出现扩张、颗粒脱落.     

Cardiovascular development: towards biomedical applicability

Advances in our understanding of cardiac development have fuelled research into cellular approaches to myocardial repair of the damaged heart. In this collection of reviews we present recent advances into the basic mechanisms of heart development and the resident and non-resident progenitor cell populations that are currently being investigated as potential mediators of cardiac repair. Together these reviews illustrate that despite our current knowledge about how the heart is constructed, caution and much more research in this exciting field is essential. The current momentum to evaluate the potential for cardiac repair will in turn accelerate research into fundamental aspects of myocardial biology.     

Surface molecules regulating rolling and adhesion to endothelium of neutrophil granulocytes and MDA-MB-468 breast carcinoma cells and their interaction

The extravasation of leukocytes and tumor cells is a multi-step process with the involvement of various adhesion molecules depending on the three steps rolling, adhesion, and diapedesis. We have developed an in vitro model, by which we investigated the rolling and adhesion of neutrophil granulocytes and MDA-MB-468 human breast carcinoma cells to lung endothelial cells under physiological flow-conditions. We found that norepinephrine had an inhibitory function on the fMLP-promoted adhesion of neutrophil granulocytes due to a down-regulation of β2-integrin. Furthermore, neutrophil granulocytes serve as linking cells for the interaction of the MDA-MB-468 cells with the endothelium, which are both β2-integrin negative, but express the β2-integrin ligand ICAM-1. In addition, we show here that N-cadherin is up-regulated on the endothelial cells and on neutrophil granulocytes in response to fMLP. This up-regulation resulted in a significant increase of adherent MDA-MB-468 cells, which are also N-cadherin positive. Received 3 September 2007; received after revision 17 October 2007; accepted 22 October 2007     

From endoderm to pancreas: a multistep journey

The formation of the vertebrate pancreas is a complex process that typifies the basic steps of embryonic development. It involves the establishment of competence, specification, signaling from neighboring tissues, morphogenesis, and the elaboration of tissue-specific genetic networks. A full analysis of this multistep process will help us to understand classic principles of embryonic development. Furthermore, this will provide the blueprint for experimental programming of pancreas formation from embryonic stem cells in the context of diabetes cell-therapy. Although in the past decade many studies have contributed to a solid foundation for understanding pancreatogenesis, important gaps persist in our knowledge of early pancreas formation. This review will summarize the current understanding of the early mechanisms coming into play to pattern the "pre-pancreatic" region within the endoderm and, gradually, specify the pancreatic tissue.     

新生大鼠大脑皮层和海马神经元体外培养方法及改进

探索用24 h内新生SD大鼠进行神经元体外培养的方法.取新生SD大鼠的大脑皮层和海马,胰酶消化5～10 min后,放入含100 g/L血清的DMEM/F12培养基中培养.24 h后,更换含B27无血清培养基.以后每隔1d,半换液.结果显示绝大部分神经元于第2天长出突起,第3天神经元间形成复杂的联系,第7天神经元发育基本成熟.经神经元特异性烯醇酶(NSE)鉴定,培养细胞均为神经元,纯度可达90%以上,可以用于实验.     

包囊游仆虫细胞的类中间纤维细胞骨架体系

应用生化分级抽提,并结合DGD包埋 去包埋透射电镜样品制备方法显示,包囊游仆虫营养细胞和休眠细胞中,均存在由直径10 nm左右的单根纤维及单根纤维聚集成的纤维束为结构单元形成的类中间纤维细胞骨架体系.其中,营养细胞的类中间纤维构成的细胞质三维网架,在细胞膜内缘以较密集的纤维网占有了整个表质层,在表质层内缘的细胞质深部纤维形成较松散的网络,网内常见附着有细胞器及一些电子密度颗粒;核纤层位于大核核膜内缘,纤维紧密聚集成网;核骨架纤维网分布比较致密,未见有电子密度颗粒附着.休眠细胞中含有与营养细胞相似的纤维网架结构,但位于细胞内不同层次的纤维网比营养细胞中的同种结构要致密得多,这可能与纤毛虫形成包囊时细胞大范围的收缩有关.并且值得注意的是,在休眠细胞包囊壁的内层壁中也观察到相似于中间纤维的纤维网络,其纤维网均匀和致密地分布在整个包囊壁层中.电泳图谱显示,纤毛虫形成包囊后,保留了营养细胞中的部分蛋白条带,失去了部分条带,新产生了一些特异的条带.结果表明,包囊游仆虫的类中间纤维 核骨架体系,是细胞在营养条件下和休眠状态下都稳定存在的结构,它可能起到比微管类骨架更重要的作用.并且休眠细胞中该体系产生的一些特异蛋白条带,可能是纤毛虫休眠生命活动中的重要蛋白.