Michael Zey
futurist3000@aol.com
Earlier this year Dr. Douglas Melton published in the journal Nature conclusive evidence that the insulin-producing beta cells of a normal adult animal can give rise to new beta cells in a process of regeneration that was previously thought not to exist. Late last year, Dr. Denise Faustman published in the journal Science conclusive evidence that an adult stem cell can give rise to new beta cells in a diabetic animal if the underlying autoimmune disease is reversed.
These results were published in what many consider the two most prestigious, peer-reviewed scientific journals in the world. Dr. Shaywitz does a great disservice to Drs. Melton and Faustman and the dozens of other researchers who continue to publish groundbreaking work on tissue regeneration using adult stem cells or other non- embryonic sources by referring to their work as "limited," "junk science," and worthy of ridicule.
Dr. Shaywitz calls the adult stem cell data "preliminary, inconclusive, unsubstantiated, or all three." The same terms likely could be applied to the embryonic stem cell work since no one in that field has fully cured an animal of any disease. As a lay person I am not surprised that no conclusions have yet been reached, as these are early days in regenerative medicine. Certainly, as a scientist, Dr. Shaywitz should not be surprised either. Yet he is intent on smearing the work of dozens of dedicated professionals who believe that adult stem cells are worthy of consideration. He claims bias in others, but to this reader it seems that he suffers from a profound bias that clearly impairs his ability to judge the science on the merits.
Lisa Gross
New York
---
I was offended by Dr. Shaywitz's generalizations of conservatives on the issue of stem cell research. I am a strong conservative and oppose President Bush on this issue. In addition, I support the Castle/DeGette legislation. The majority of conservatives do not find stem cell research to be a moral issue. But there is one point never made by proponents of stem cell research when discussing this issue: restrictions are not made on state or private funding for stem cell research. Rather than focus on what we cannot get out of Congress and the administration, let's promote what we can get from the states and from private donations.
Anne Johnston
San Antonio, Texas
---
Dr. Shaywitz's contention that adult stem-cell success is "junk science" is highly erroneous. Adult stem cells are, indeed, much more versatile than was predicted. Researchers are now able to "coax" non- embryonic cells to become, just for a few examples, brain cells, bone cells and insulin. And, while embryonic stem cells remain in the "what-if" stage in laboratories, their adult counterparts are already helping thousands of actual human patients.
Brian Gillin
Broomall, Pa.