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81.
本研究应用分子生物学技术 ,构建小鼠 β2 m反义核酸重组荧光蛋白表达载体pEGFP β2 mAN ,经过酶切、PCR鉴定 ,以及序列分析证实克隆的正确性。然后用脂质体转染NIH3T3细胞 ,经过RT PCR及Westernblot检测 ,观察重组质粒对细胞β2 mmRNA和蛋白表达的影响 ,同时在荧光显微镜下直接观察细胞转染的结果。结果证明pEGFP β2 mAN已成功导入NIH3T3细胞中 ,且有效表达 ,在荧光显微镜下可见梭形绿色荧光细胞 ;与同步转染的小鼠 β2 m正、反义核酸表达载体pcDNA3 β2 mSN、pcDNA3 β2 mAN的转染结果一起进行分析 ,转染pcDNA3 β2 mSN细胞的 β2 mmRNA和蛋白表达水平升高 ,而转染pcD NA3 β2 mAN和pEGFP β2 mAN的细胞 β2 mmRNA和蛋白表达水平降低。小鼠 β2 m反义核酸重组荧光蛋白表达载体pEGFP β2 mAN的转染结果显示 :它不但可以降低NIH3T3细胞 β2 m基因的表达 ,而且为观察脂质体转染效果提供了直观、即时的方法 相似文献
82.
Zebrafish SmyD1 is a SET and MYND domain-containing protein that plays an important role in myofiber maturation and muscle contraction. SmyD1 is required for myofibril organization and sarcomere assembly during myofiber maturation. Whole-mount in situ hybridization revealed that smyd1 mRNAs are specifically expressed in skeletal and cardiac muscles in zebrafish embryos. However, it is unknown if smyd1 is expressed in other striated muscles, such as cranial and fin muscles, and moreover, the regulatory elements required for its muscle-specific expression. We report here the analyses of smyd1 expression using smyd1-gfp transgenic zebrafish. smyd1-gfp transgenic zebrafish were generated using the 5.3-kb smyd1 promoter and its 5'-flanking sequence. GFP expression was found in the skeletal and cardiac muscles of smyd1-gfp transgenic embryos. GFP expression appeared stronger in slow muscles than fast muscles in transgenic zebrafish larvae. In addition, GFP expression was also detected in cranial and fin muscles of smyd1-gfp transgenic zebrafish larvae. In situ hybridization confirmed smyd1 mRNA expression in these tissues, suggesting that the expression of the smyd1-gfp transgene recapitulated that of the endogenous smyd1 gene. Deletion analysis revealed that the 0.5-kb sequence in the proximal promoter of smyd1 was essential for its muscle specificity. Together, these data indicate that smyd1 is specifically expressed in most, if not all, striated muscles, and the muscle specificity is controlled by the 5.3-kb promoter and flanking sequences. 相似文献
83.
免疫耐受机制研究进展 总被引:1,自引:1,他引:1
免疫耐受是机体免疫系统在接触某种抗原后所产生的对该抗原特异性免疫无应答状态,是免疫应答的一种特殊形式,免疫应答的复杂性决定了免疫耐受诱导的复杂性和困难性.随着免疫学的发展,人们对免疫耐受产生机制有了较多的认识.本文对免疫耐受与细胞凋亡、调节性T细胞及树突状细胞的研究进展进行综述. 相似文献
84.
以小鼠心肌组织异位移植和混合淋巴细胞反应为整体和离体模型,观察了阿片受体阻断剂纳曲酮对移植排异反应的影响。结果显示:给动物从术前开始腹腔注射纳曲酮共10天(每日二次,每次5mg/kg)可明显延长移植心肌组织的存活时间;加入纳曲酮(10-4~10-8mol/L)对混合淋巴细胞反应有抑制作用并呈量效关系。同时还观察到,给正常小鼠腹腔注射纳曲酮3天以上,可引起动物脾细胞由ConA诱导的淋巴细胞转化反应受抑制。以上结果说明纳曲酮可抑制移植排异反应,此作用有可能是通过阻断内源性阿片肽所致。 相似文献
85.
BACKGROUND. The fortification of milk and infant formula with vitamin D has had an important role in eliminating rickets in children and osteomalacia in adults. A recent outbreak of vitamin D intoxication caused by drinking milk fortified with excess vitamin D has led to questions about the level of vitamin D in milk from other producers. METHODS. We used high-performance liquid chromatography to measure vitamin D in samples of 13 brands of milk with various fat contents and 5 brands of infant formula purchased at random from local supermarkets in five Eastern states. RESULTS. Only 12 (29 percent) of the 42 samples of the 13 brands of milk and none of the 10 samples of the 5 brands of infant formula contained 80 to 120 percent of the amount of vitamin D stated on the label. Twenty-six of the 42 milk samples (62 percent) contained less than 80 percent of the amount claimed on the label. No vitamin D was detected in 3 of the 14 samples of skim milk tested (lower limit of assay, 4.7 IU per quart [5.0 IU per liter]). One milk sample labeled as containing vitamin D2 (ergocalciferol) contained vitamin D3 (cholecalciferol). Seven of the 10 samples of infant formula contained more than 200 percent of the amount stated on the label; the sample with the highest concentration contained 419 percent of the stated amount. None of the samples of infant formula contained less than the amount stated. CONCLUSIONS. Milk and infant-formula preparations rarely contain the amount of vitamin D stated on the label and may be either underfortified or overfortified. Since both underfortification and overfortification are hazardous, better monitoring of the fortification process is needed. 相似文献
86.
87.
G.-Y. Wang B. Sun Q.-F. Kong Y. Zhang R. Li J.-H. Wang D.-D. Wang G. X. Lv & H.-L. Li 《Scandinavian journal of immunology》2008,68(6):589-597
Interleukin (IL)-17 is a proinflammatory cytokine primarily secreted by Th17 cells, which are a CD4+ T-cell subset. Th17 cells and IL-17 are important in the pathogenesis of multiple sclerosis and in its established animal model, experimental autoimmune encephalomyelitis (EAE). However, it is unclear whether IL-17 contributes to EAE immune tolerance. We used the myelin basic protein (MBP) peptide MBP 68–86 to induce nasal tolerance to EAE, and simultaneously interfered with the tolerance by treatment with different doses of IL-17. We found that IL-17 dramatically interfered with MBP 68–86-induced immune tolerance. IL-17 administration increased IL-6 release, skewing T cell differentiation towards Th17 cells and decreasing the number of Treg cells. This led to an imbalance between Treg cells and Th17 cells and spurred the development of EAE. 相似文献
88.
Sun Y Shao H Li Z Liu J Gao L Peng X Meng Y Li W 《International journal of molecular medicine》2004,14(6):971-975
The advancement in gene knockout and transgenesis have brought about enormous improvement in our understanding of mouse embryogenesis in the past decade or so. On the other hand, relatively little is known about human embryogenesis due largely to the lack of easy access to human embryos and tissues for biomedical studies. We have previously isolated a novel zinc finger gene, ZNF268, from a 3-week-old human embryo cDNA library in an effort to identify genes important for human embryonic development. To investigate the potential involvement of ZNF268 in human embryogenesis, we report here the spatial and temporal regulation of its expression during development. Northern blot and Western blot analyses revealed that ZNF268 is expressed in early embryos, predominantly, if not exclusively, in fetal liver with little detectable expression in other fetal organs. Interestingly, unlike most zinc finger proteins, ZNF268 protein was found to be localized mainly in the cytoplasm of embryonic hepatocytes. This subcellular localization was substantiated by the localization of EGFP-ZNF268 fusion protein overexpressed in the transfected COS7 cells. These results suggest that ZNF268 plays a role in early human liver development most likely by functioning through a cytoplasmic mechanism. 相似文献
89.
90.
Anthony J Sharp Paul E Polak Vittoria Simonini Shao X Lin Jill C Richardson Ernesto R Bongarzone Douglas L Feinstein 《Journal of neuroinflammation》2008,5(1):33