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【bio-news】能体内追踪细胞的新技术
New technique developed for tracking cells in the body
This press release issued by Eurekalert says that scientists' inability to follow the whereabouts of cells injected into the human body has long been a major drawback in developing effective medical therapies.
Now, researchers at Johns Hopkins have developed a promising new technique for noninvasively tracking where living cells go after they are put into the body. The new technique, which uses genetically encoded cells producing a natural contrast that can be viewed using magnetic resonance imaging (MRI), appears much more effective than present methods used to detect injected biomaterials.
Described in the February edition of Nature Biotechnology, the method was developed by a team of researchers from Johns Hopkins' Russell H. Morgan Department of Radiology and Radiological Science, the Hopkins Institute for Cell Engineering, and the F.M. Kirby Research Center for Functional Brain Imaging at the Kennedy Krieger Institute in Baltimore.
In their study, the researchers used a synthetic gene, called a reporter gene, which was engineered to have a high proportion of the amino acid lysine, which is especially rich in accessible hydrogen atoms. Because MRI detects energy-produced shifts in hydrogen atoms, when the "new" gene was introduced into animal cells and then "pelted" with radiofrequency waves from the MRI, it became readily visible. Using the technique as a proof of principle, the researchers were able to detect transplanted tumor cells in animal brains.
"This prototype paves the way for constructing a family of reporter genes, each with proteins tailored to have a specific radiofrequency response," says MRI researcher Assaf Gilad, Ph.D., lead author of the study.
"The specific frequencies can be processed to show up as colors in the MRI image," adds collaborator Mike McMahon, Ph.D., an assistant professor of radiology at the Johns Hopkins School of Medicine "In a way, it's the MRI equivalent of the green and red fluorescent proteins found in nature and used by labs everywhere in the world for multiple labeling of cells."
The problem with using fluorescent proteins, however, is that tissue must be removed from the body for examination under a microscope, which means that the method isn't suitable for use in patients. "In contrast," says Hopkins radiology professor Jeff Bulte, Ph.D., "MRI is noninvasive, allowing serial imaging of cells and cellular therapies with a high resolution unmatched by any other clinical whole-body imaging technique."
Current MRI contrast agents also have several disadvantages. "Their concentration becomes lower every time cells divide," says Peter van Zijl, Ph.D., founding director of the Kirby Research Center for Functional Brain Imaging, "so our ability to see them diminishes.. Also, using magnetic metal allows us to detect only one type of labeled cell at a time." The new approach is not hampered by these limitations.
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Sci. & Tech. 本人已认领该文编译，48小时后若未提交译文，请其他战友自由认领 This press release issued by Eurekalert says that scientists' inability to follow the whereabouts of cells injected into the human body has long been a major drawback in developing effective medical therapies.
Now, researchers at Johns Hopkins have developed a promising new technique for noninvasively tracking where living cells go after they are put into the body. The new technique, which uses genetically encoded cells producing a natural contrast that can be viewed using magnetic resonance imaging (MRI), appears much more effective than present methods used to detect injected biomaterials.
美国Eurekalert新闻报道，长久以来，科学家开发有效医疗方法的主要障碍是未能对注入人体的细胞进行跟踪定位。而现在，Johns Hopkins的研究人员已经建立起一种非侵入性示踪技术来定位注入人体的活细胞行踪。这种新技术利用遗传编码基因能产生自然对比度的细胞通过磁共振成像，比现有的其它用于检测体内生物活性物质的方法显得更有成效。
Described in the February edition of Nature Biotechnology, the method was developed by a team of researchers from Johns Hopkins' Russell H. Morgan Department of Radiology and Radiological Science, the Hopkins Institute for Cell Engineering, and the F.M. Kirby Research Center for Functional Brain Imaging at the Kennedy Krieger Institute in Baltimore.
在《自然》生物技术卷二月份期刊上报道说，这种方法是由Johns Hopkins大学的Russell H. Morgan放射学与放射科学系、Hopkins细胞工程学院和位于Baltimore市 Kennedy Krieger学院 F.M. Kirby功能性脑成像研究中心的研究者开发的。
In their study, the researchers used a synthetic gene, called a reporter gene, which was engineered to have a high proportion of the amino acid lysine, which is especially rich in accessible hydrogen atoms. Because MRI detects energy-produced shifts in hydrogen atoms, when the "new" gene was introduced into animal cells and then "pelted" with radiofrequency waves from the MRI, it became readily visible. Using the technique as a proof of principle, the researchers were able to detect transplanted tumor cells in animal brains.
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作者:admin@医学,生命科学 2011-09-17 17:14
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