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41.
ThedynamicdistributionofnitricoxidesynthaseinthesmallintestineofmicewithintestinalradiationsicknessWeiLichun(魏丽春);GuoYao(郭鹞)(... 相似文献
42.
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. 相似文献
43.
I. Nicholas Crispe 《Clinical & developmental immunology》1995,4(4):257-261
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. 相似文献
44.
Models of Parkinson's disease. 总被引:2,自引:0,他引:2
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. 相似文献
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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。 相似文献
48.
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)。 相似文献
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褪黑素和哌替啶对小鼠的镇痛作用比较 总被引:2,自引:0,他引:2
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。 相似文献