The dynamic distribution of nitric oxide synthase in the small intestine of mice with intestinal radiation sickness

ＴｈｅｄｙｎａｍｉｃｄｉｓｔｒｉｂｕｔｉｏｎｏｆｎｉｔｒｉｃｏｘｉｄｅｓｙｎｔｈａｓｅｉｎｔｈｅｓｍａｌｌｉｎｔｅｓｔｉｎｅｏｆｍｉｃｅｗｉｔｈｉｎｔｅｓｔｉｎａｌｒａｄｉａｔｉｏｎｓｉｃｋｎｅｓｓＷｅｉＬｉｃｈｕｎ（魏丽春）；ＧｕｏＹａｏ（郭鹞）（...     

An Evolutionarily Conserved Region in the Second lntron of the Human Nestin Gene Directs Gene Exmession to CNS Progenitor Cells and to Early Neural Ciest Cells

Central nervous system (CNS) progenitor cells transiently proliferate in the embryonic neural tube and give rise to neurons and glial cells. A characteristic feature of the CNS progenitor cells is expression of the intermediate filament nestin and it was previously shown that the rat nestin second intron functions as an enhancer, directing gene expression to CNS progenitor cells. In this report we characterize the nestin enhancer in further detail. Cloning and sequence analysis of the rat and human nestin second introns revealed local domains of high sequence similarity in the 3' portion of the introns. Transgenic mice were generated with the most conserved 714 bp in the 3' portion of the intron, or with the complete, 1852 bp, human second intron, coupled to the reporter gene lacZ. The two constructs gave a very similar nestin-like expression pattern, indicating that the important control elements reside in the 714 bp element. Expression was observed starting in embryonic day (E)7.5 neural plate, and at E10.5 CNS progenitor cells throughout the neural tube expressed lacZ. At E12.5, lacZ expression was more restricted and confined to proliferating regions in the neural tube. An interesting difference, compared to the rat nestin second intron, was that the human intron at E10.5 mediated lacZ expression also in early migrating neural crest cells, which is a site of endogenous nestin expression. In conclusion, these data show that a relatively short, evolutionarily conserved region is sufficient to control gene expression in CNS progenitor cells, but that the same region differs between rodents and primates in its capacity to control expression in neural crest cells.     

Frequency of T-Cell Progenitors in Nude Mice

The hypothesis that prothymocytes are distinct from and regulated independently of multilineage hemopoietic progenitors was tested by enumeration of these two cell populations in normal versus congenitally athymic (nude) mice. The absence of a thymus and of peripheral T cells in nude mice had no effect on the frequency of either multilineage progenitors (day 12 CFU-S) or prothymocytes (CFU-T), suggesting that there is no feedback regulation of CFU-T frequency. Thymus seeding from the bone marrow is therefore likely to be regulated by the availability of niches for prothymocyte maturation, rather than by feedback control of prothymocyte production.     

Models of Parkinson's disease.

Parkinson's disease (PD) is a heterogenous disease likely to be caused by more than one specific aetiological factor. In rare familial cases of PD with similar clinical features to the idiopathic form of the disease, the underlying genetic cause has been identified. These PD-associated genes have been manipulated to create animal and cell culture models of the disease that have helped to further our understanding of the pathogenesis of PD, particularly concerning causes of the selective loss of dopaminergic neurons at the molecular level. In addition, these models will aid the future development of rational therapeutic strategies. This study briefly reviews toxin-induced models and the genetics of PD. It focuses on recently developed animal models of PD, as well as in vitro approaches to model the disease.     

胃癌单克隆抗体在裸鼠移植瘤中的免疫定位和显像

本文采用Ｉｏｄｏｇｅｎ法将鼠抗人胃癌单克隆抗体ＲＳＦ９（ＩｇＭ）予以１３１Ｉ标记，研究ＲＳＦ９在荷人胃癌裸鼠中的定位和显像能力。结果表明，ＲＳＦ９在体内能特异性地与肿瘤组织结合，Ｔ／ＮＴ比值随时间延长逐渐升高，９６ｈＴ／ＮＴ比值均大于２．５，瘤／血比值为２．６９，肿瘤定位指数达５．１８，ＳＰＥＣＴ得到清晰的肿瘤图像。ＲＳＦ９具有良好的体内导向定位能力。ＩｇＭ型单抗也可用于肿瘤显像。     

小剂量氯化汞对小鼠脂质过氧化物的影响

本观察小剂量１ｍｇ／ｋｇ）ＨｇＣｌ２对小鼠肝，脑组织中脂质过氧化物（ＬＰＯ）的影响，发现小剂量ＨｇＣｌ２可使肝组织中ＬＰＯ含量明显增高，与对照组比，差异有显性（Ｐ〈０．０２５），而脑组织中ＬＰＯ含量未见明显影响（Ｐ〉０．０５）。     

褪黑素和哌替啶对小鼠的镇痛作用比较

利用热板法或甩尾法测定小鼠痛阈，发现褪黑素１０～４０ｍｇ·ｋｇ－１ｉｐ后６０ｍｉｎ时镇痛作用最强，１５０ｍｉｎ时仍有镇痛作用。哌替啶１０～４０ｍｇ·ｋｇ－１ｉｐ后３０ｍｉｎ时镇痛作用最强，１２０ｍｉｎ时已无镇痛作用。在６０ｍｉｎ时两者镇痛作用相近。是示两者的作用特点不同。