Posted on 09/09/2008 9:46:05 PM PDT by neverdem
When people envision using human embryonic stem cells for regenerative medicine, they often talk about making neurons to treat Parkinsons disease, cardiac cells to...
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The idea faces other challenges beyond the huge volume of cells needed. The red cells produced from embryonic stem cells so far tend to resemble embryonic or fetal red cells more than adult ones. They tend to be larger and often contain nuclei, which could impede their passage through the body. And they have a different form of the globin molecule, which carries oxygen.
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The real test is in vivo, said Dr. Thalia Papayannopoulou, a professor of medicine at the University of Washington, adding that the manufactured cells might not last as long in the body as donated red cells because of differences in their membranes.
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But a big barrier to using induced cells for therapy is that they are created by adding genes to the skin cell using a virus. One of the genes that has been used can cause cancer, as can the use of the virus. But red cells made this way would presumably not carry the cancer risk because the cells have no nuclei, Dr. Kaufman said.
Other cells, like those from bone marrow or cord blood, can also be used to make red blood cells. But those cells cannot reproduce indefinitely in culture like embryonic stem cells. Researchers like Cornelis Murre at the University of California, San Diego, are working on ways around this.
Darpas initial blood pharming contracts will not involve human embryonic stem cells, said Mr. Seay of Cellular Dynamics. Under Bush administration policy, federal money can be spent for research on only a small number of approved embryonic stem cell lines. None of those lines is Type O negative, the universal donor that Darpa wants.
(Excerpt) Read more at nytimes.com ...
stem cell ping
Whereas adult stem cells have been very successful in various treatments, embryonic stem cells have never cured anyone of anything and have killed several people by giving them cancer.
Apparently, John McCain did not get that memo and is like Obama an advocate of embryonic stem cell research.
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