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李武军 发表于 2011-6-25 22:39

Health: Transplant Success 健康:移植成功

[audio]http://www.24en.com/bbc/dl_mp3/bbc_transplant_success.mp3[/audio]
[color=#3f3f3f][font=Verdana, 宋体, helvetica, arial, sans-serif][size=12px]Some people are calling it the greatest medical [b]breakthrough[/b] so far this century. Surgeons in Spain have successfully carried out the world’s first[b]organ transplant[/b] using new [b]stem cell[/b]technology.
[p=21, 2, left]But what are stem cells? Most cells in our bodies are designed to serve specific purposes – for example, a [b]liver[/b]cell develops to work in the liver and cannot become a heart cell.[/p][p=21, 2, left]But stem cells are different. They are very young, and in the laboratory scientists can grow them into different types of cell.[/p][p=21, 2, left]Claudia Castillo needed a new [b]windpipe[/b] after contracting [b]tuberculosis[/b]. Scientists from the University of Bristol in the UK took a [b]donor[/b] windpipe, or trachea, from someone who had recently died.[/p][p=21, 2, left]They used strong chemicals to remove the donor’s cells, leaving a [b]tissue scaffold[/b]. This was [b]repopulated[/b] with cells from Ms Castillo’s windpipe and nose, and stem cells from her [b]bone marrow[/b]. After four days the cells had grown sufficiently for the trachea to be transplanted into Ms Castillo.[/p][p=21, 2, left]Currently, transplant patients have to take drugs for the rest of their lives to prevent their bodies [b]rejecting[/b] the new organs. These drugs can have bad [b]side-effects[/b], and do not always prevent rejection.[/p][p=21, 2, left]But by using Ms Castillo’s own cells, doctors were able to trick her body into thinking the new trachea was her own organ. Five months on, Claudia Castillo is in perfect health.[/p][p=21, 2, left]This [b]ground-breaking procedure[/b] could be used in other transplant operations in the future. Scientists also believe stem cells might be used to treat [b]Parkinson's disease[/b], [b]Alzheimer's disease[/b], heart disease,[b]stroke[/b], [b]arthritis[/b], [b]diabetes[/b], burns and [b]spinal cord damage[/b].[/p][p=21, 2, left]However, stem cell research is extremely controversial. The most effective stem cells do not come from adults but from [b]embryos[/b] created in laboratories and which are just a few days old. Many people have religious or ethical objections to growing embryos, even if they can be used to cure diseases.[/p][/size][/font][/color]

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