 |
 |
My "money" is on Suzuki.... muray ARTICLE: Canada: Stem cell research has potential Friday, Jun. 08, 2001 Stem cell research has potential By David Suzuki -- CNEWS Science Last month, the federal government introduced draft legislation on new reproductive technologies. It's a controversial topic and one of its most controversial aspects of the legislation is embryonic stem cell research. But this is also the area that holds the most promise for future medical treatments and advances. All of us have "stem" cells in our bodies. These cells have the potential to grow into a variety new tissues. But the stem cells with the most potential form shortly after fertilization. Early on, these embryonic cells are "totipotent," meaning that they have the capacity to develop into an entire organism. After a few days, they become "pluripotent," which means they cannot individually develop into an entire organism, but can develop into almost any type of tissue. When a fertilized egg divides, cells "differentiate" to carry out specific functions as blood, nerves, muscles and so on. In specializing, the cells lose their pluripotency. As adults, we still have stem cells in our blood and brains, but these cells appear to be more limited. Eventually, scientists may be able to rewind adult stem cells to give them the same potential that embryonic stem cells have to grow into other tissues. But most researchers say that experimentation on embryonic cells is crucial to understanding how that could be done. If scientists could use adult human stem cells to grow new tissues, it would be a tremendous breakthrough. Every one of us could have such cells which could be injected into the heart, for example, to repair damage from heart attacks, or into the brain to combat degenerative diseases like Parkinson's. It's even theoretically possible to grow entire new organs, which could be transplanted without fear of rejection because they would be genetically identical to the donor. According to the US Center for Disease Control, some 3,000 Americans die every day from diseases that in the future may be treatable using stem cells. But getting to that point will require years of research and most researchers say that the best clues to how adult stem cells work will be found in embryonic stem cells. The problem is that currently these cells can only be obtained by destroying an embryo which, if implanted in a woman's uterus, could grow into a fetus and a full-term child. For that reason, two major Canadian religious groups have opposed embryonic stem cell research. However, this argument ignores the fact that embryos used for stem cell research are those that will never grow to term. In the 1990s, some 300,000 unused human embryos created for in-vitro fertilization were destroyed. According to the proposed Canadian legislation, only these unwanted embryos leftover from fertility procedures will be used for research. And scientists say that they will only need access to a relatively small number of embryos to create a potentially limitless number of pluripotent stem cells in a lab. Recently, Britain and Germany voted in favour of allowing embryonic stem cell research, but not all nations have been as supportive. In the United States, the Bush administration has halted funding for stem cell research, prompting a group of seven scientists and quadriplegic actor Christopher Reeve to launch a lawsuit against the government. If researchers are unable to rewind adult stem cells to a pluripotent state, there is still another option to create them. In a process called therapeutic cloning, scientists could clone a human using similar techniques to those that brought us Dolly and other cloned mammals. Then, pluripotent cells extracted from the clone embryo could be used to treat a variety of illnesses in the donor, again without fear of rejection. Of course, this brings up new ethical questions because the clone embryo is being created for the purpose of being destroyed. But that currently is not an issue in the proposed Canadian legislation, which only allows existing, unused embryos to be accessed for research. And the potential for stem cells to provide us with tremendous medical advances, as well as insights into our own development, is too great to ignore. http://www.canoe.ca/CNEWSScience0106/06_suzuki-can.htm ******** ---------------------------------------------------------------------- To sign-off Parkinsn send a message to: mailto:[log in to unmask] In the body of the message put: signoff parkinsn