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Lesson 3 Special English Program - Science in the news.
Today we tell about some major science stories of the year 2001. We tell about stem cells research and anthrax bacterial and the disease AIDS.
Last year, president Bush had approved limited Federal Government support for research on special human stem cells, for research involved stem cells taking from human eggs called embryo. Scientists believe stem cells maybe highly useful in the treatment and possible cures of many diseases. The most useful are stem cells from embryos. They're able to develop into all kinds of tissues of the body. Embryonic stem cells are taken from embryos created in laboratories to help women become pregnant. Scientists use embryonic stem cells from Embryo that are 4 or 5 days old, the cells in the embryo divide quickly for a short period of time. Each of th embryo cells is able to become any one of more than 200 different kinds of cells in the body. For great value of embryonic stem cells appears to be their ability to produce in large numbers in the lab before they become specialized cells. Researchers believe that embryonic stem cells may be used to hlep disease organs develop healthy cells again. They hope the stem cells can be used to treat disease of the brain, heart, liver, and kidney. These include diabilities, Parkinson's disease. Howeer, the Bush Administration haas only permitted this research on about 60 groups of existing stem cells. Medical researches have noted that these groups of stem cells are not useful for treating disease. Also, the treatment developed by the existing stem cells might be rejected by body of possible patients. This is because the genetic material is different . Some scientists say the best way to make stem cells for treatment is to grow them from embryo that are the exact copies of patients. Late last year, scientists working for the company Advanced Cell Technology announce they had made the first genetic copies of human embryos. The process of making genetic copies is called cloning. Cloning involves the creation of an embryo from a single adult cell. Genetic material from a sigle adult cell is joined with an egg cell whose genetic material has been removed. Scientists have used cloning to creat animals. Scientists from Advanced Cell Tech. perform the experiment in an effort to create cloned human embryo stem cells. However, the experiment did not produce stem cells because the embryo did not live long enough. Company officials siad the research on human embryos is designed only to produce embryonic stem cells to treat diseases. They have strongly stated that the company has no interest in cloning human beings.
Amrican law makers have been preparing legislation that could ban or limit cloning. President Bush said he strongly oppose human cloning. he said it's wrong to use embryos for cloning. But Catholic church opposes all kinds of stem cell research. Many other religeous groups also oppose all embryonic stem cell research they considered it the same as taking a human life. Other religeous groups accept the research with several restrictions ecause it may be the cures for some diseases. Experts say the debate about embryonic stem cell research is complex and will continue for some time.
(To be continued...) |
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