| [ KAIST ] in KIDS 글 쓴 이(By): chopin (**쇼팽**) 날 짜 (Date): 2000년 11월 6일 월요일 오후 11시 23분 54초 제 목(Title): [뇌과학] New life from dead brains 죽은 사람의 뇌로 부터 뉴런을 만들어내는 Stem cell를 추출해 뉴런을 만들어낸다는 기사입니다. 놀라운 사실은 피부나 뼈, 척수등 뉴런하고 별로 관련없어 보이는 세포들에서 뉴런으로 분화시키는 실험이 성공했다는 내용입니다. ----------------------<from here>---------------------------------------- New life from dead brains: Stem cells from cadavers November 5, 2000 Web posted at: 8:25 PM EST (0125 GMT) NEW ORLEANS, Louisiana (AP) -- Scientists have coaxed new life out of dead brains. It turns out that even cadavers can supply the incredibly versatile brain stem cells -- master cells which can turn into different kinds of brain and nerve cells -- once thought available only from fetal tissue. So can skin. And it appears that just about every bone stem cell can be tweaked to produce brain cells. "It's an extraordinarily exciting field," said Ronald D.G. McKay of the National Institute of Neurological Disorders and Stroke. Several reports to the Society for Neuroscience seem to offer yet more possible solutions to the ethical dilemma blocking stem cell studies which use human fetal tissue. But they are not yet solutions and may never be, said McKay and two other scientists who discussed their findings at a news conference Sunday at the society's annual meeting. There are big differences among stem cells from embryos, from fetuses and from adult tissue, and scientists don't really know much yet about any of them, they said. "We can't look in a dish at a mixed population (of cells) and say 'That is a stem cell,"' said Fred H. Gage of the Salk Institute at LaJolla, California, where the cadaver work was done. "Different people have different ideas." The main definitions, said Ira Black of the University of Medicine and Dentistry of New Jersey, are that stem cells are immature cells which can duplicate themselves and grow into different kinds of mature cells. Gage's research used bits of tissue taken soon after death from children and young adults who had died of various neurological diseases. His lab got the tissue 10 hours to three days after death. In every case -- as well as with cells from a man who died at 72 _ researcher Theo Palmer was able to get some of the cells to divide and reproduce themselves, and to grow into different kinds of nervous system cells, Gage said. Black grew brain cells from cells taken from bone marrow, where they ordinarily would have created bone, cartilage, muscle, tendon and fat cells. He previously reported that he and his colleagues had been able to turn 80 percent of the bone marrow cells taken from rats and humans into nerve cells. Additional work has brought that up to more than 99 percent, he said. Freda Miller of McGill University had been scheduled to discuss her work turning rat skin and human scalp cells to nerve cells but could not make it. "That's yet another extraordinary finding," Black said. "It may be that there is a variety of easily accessible sources that can generate neurons," he said. If that's the case, he said, scientists will need to find out what they all have in common. McKay described turning mouse embryo stem cells into brain cells which make dopamine -- the chemical neurotransmitter whose absence causes Parkinson's disease. Researchers have transplanted dopamine-producing cells derived from fetal tissue into peoples' brains. But there is enough for only a few of the estimated 1.2 million sufferers, and research has been slowed by restrictions on the use of federal money for studies involving fetal tissue. "If you're going to use this as a routine therapy, you need access to large numbers of cells," McKay said. McKay said his laboratory has produced unlimited numbers of dopamine neurons -- but they produce high levels of dopamine only for a short time. "We need to know what kind of signals to give them" to get the best production, he said. Copyright 2000 The Associated Press. All rights reserved. This material may not be published, broadcast, rewritten, or redistributed. reference : http://www.cnn.com/2000/HEALTH/11/05/cadavers.stem.cells.ap/index.html __ 쇼팽 http://csone.kaist.ac.kr/~chopin |