健康报道 - 科学家首次通过克隆获取人类干细胞
From VOA Learning English, this is the Health Report.
American scientists have for the first time taken stem cells from human embryos that are genetic copies of living people. The goal is to create better treatments for disease. But the work has rasied ethical concerns about making genetic copies or cloning.
Cloning a human being is illegal in more than twelve states. Most scientists have rejected it, but some medical researchers are performing what is called "therapeutic cloning" to try to fight disease. Still, that method is banned in seven states.
One state where "therapeutic cloning" is not banned is Oregon, that is where researchers at Oregon Health & Science University in Portland were able to put human DNA into modified human eggs. They produced embryos that were genetically the same as the people who had donated their DNA. The researchers then took stem cells from the embryos, these cells are called "master cells". Scientists know how to use chemicals to cause master cells to develop into any tissue in the body.
The idea is that doctors could use tissue created this way to replaced diseased organs. The new body tissue would be a genetically match of the person receiving it, and there would be no danger that the patient's body would reject the new tissue which can happen with normal transplants.
Shoukhrat Mitalipov led the organ study, which involved more than twenty researchers. The scientists believed the stem cells could give doctors a new way to treat Parkinson's disease - a degenerative movement disorder. Scientists believe they could use this genetic material or DNA from a skin cell of someone with Parkinson's disease to create a personalized treatment.
Alta Charo is a bioethicist at the University of Wisconsin Law School, she believes it is too soon to say, whether the use of embryonic stem cells for personalized medicine would become common. Scientists could in fact find other less controversial sources of stem cells, however, she supports the use of stem cells to treat disease.
"I think that would argue for using them, I think there are moral obligation to people who are here among us, who are sick and in need. Trans-political concerns, and a public relations, and perception problems around the very earliest first two or three days worth of development of an embryo-like entity."
The research on the cloning of human embryos to harvest stem cells was published in the journal "Cell".
And that's the Health Report from VOA Learning English, I'm Mario Ritter.