November 17, 2004
IT'S NOT ABOUT WHAT WORKS:
The Politics of Stem Cells: Why do some scientists and politicians insist on exploiting embryos? (Interview with C. Christopher Hook, 11/17/2004, Christianity Today)
C. Christopher Hook, director of ethics education for the Mayo Graduate School of Medicine, knows blood very well. As an experienced hematologist and a senior fellow at the Center for Bioethics and Human Dignity, he's done a lot of thinking about the debate over stem cells, which we glimpsed in an interview he gave to associate editor Agnieszka Tennant. Hook stressed that his comments are his own and do not necessarily represent the views of the Mayo Clinic.Have you used adult stem cells in therapy?
I have used adult stem cells in bone marrow and peripheral stem-cell transplantation for the treatment of diseases that otherwise would be incurable. They include acute leukemias, Hodgkin's and non-Hodgkin's lymphomas, and other serious hematologic disorders.
Are adult stem cells as good a material for healing diseases as embryonic stem cells?
Because of the limited and often disappointing use of embryonic stem cells to date, one has to honestly respond that we don't know the answer to that question. However, is it really the right or most important question to ask?
The ostensible reason cited by many scientists, clinicians, and politicians for vigorously pursuing embryo destruction or cloning is the promise for creating treatments that will help, or in the best case, heal, millions of people suffering from a whole host of diseases. If that is the real goal, and you can achieve those same therapeutic benefits without having to destroy or clone embryonic human beings, then even if embryonic stem cells might prove easier to use—still a highly debatable hypothesis—it doesn't matter. You can achieve this goal without commodifying human beings in the process.
What do we know about the effectiveness of adult stem-cell therapies?
The advances in adult stem-cell therapy development have been nothing short of astounding. I don't see any reason to believe that we will not achieve the therapeutic goals we all desire using adult stem cells. The September issue of Nature Cell Biology reviews the ability of bone-marrow derived cells to be reprogrammed after incorporation in defective tissues, healing and regenerating the organ. My friend and colleague, Dr. David Prentice, presented an excellent overview of the derivation and therapeutic use of adult stem cells before the President's Council on Bioethics (see http://bioethicsprint. bioethics.gov/background/prentice_paper.html).
Why is there such vigorous disagreement among scientists over adult stem cells?
Scientists in general do not like to hear the word no. They believe that science is an unmitigated good, and thus should not be restricted.
Scoience is, after all, just the pursuit of politics by other means. Posted by Orrin Judd at November 17, 2004 1:48 PM
Dr. Denise Faustman thinks she has a shot at curing diabetes. She has published one significant scientific paper after another on the disease. She has succeeded in curing it in mice, something no one else has accomplished. But when Dr. Faustman, an associate professor of medicine at Harvard, went looking for money to finance the next stage of her research, testing the ideas with diabetes patients, she could find no backers. . . The reason for the resistance, Dr. Faustman and some colleagues believe, was simple: her findings, which raise the possibility that an inexpensive, readily available drug might effectively treat Type 1 or juvenile diabetes, challenge widespread assumptions. Many diabetes researchers insist that a cure lies instead in research on stem cells and islet cell transplants. . . if she is correct, scientists will also have to reconsider many claims for embryonic stem cells as a cure for diabetes, and perhaps for other diseases.
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Other scientists had tried the transplants and failed - the islet cells died despite immunosuppressant drugs - but Dr. Faustman thought she would succeed.
"I thought the secret was that my islets were better than anyone else's," she said.
But when she and Dr. David Nathan, the director of the diabetes center at the hospital, tried using her islets, they also failed. So Dr. Faustman decided to go back to the laboratory and study the phenomenon in mice. Researchers had reported that islet transplants could cure diabetes in mice, but they had been making them diabetic by destroying their islet cells. Dr. Faustman decided to look at mice with a strong genetic predisposition to develop diabetes on their own. When the islet cell transplants failed in those animals, she asked why.
Diabetes occurs when a white blood cell, part of the body's immune system, migrates to the pancreas and mistakenly sees islet cells as foreign tissue. It then multiplies and destroys the islets. But, Dr. Faustman learned, she could block the white cells by supplying them with a piece of protein that signaled that the islet cells were normal cells, rather than foreign invaders. She also had to stop the attack that was under way in the pancreas. That required killing the white cells that were doing the attacking. Her solution was to give an off-patent drug, BCG, that is inexpensive, $11 a vial, and approved for use as an immune system stimulant. It elicits the release of an immune system hormone, tumor necrosis factor, that kills activated white cells.
After Dr. Faustman gave the mice the two types of treatment, the attack on the islets stopped. Then, to her astonishment, something else happened: the islet cells grew back, a development that went against everything known by scientists. The implications, Dr. Nathan said, were enormous. The diabetic mice, he said, had had extremely high blood sugar levels for weeks and would die without insulin. Researchers had successfully intervened earlier in the disease with these animals but not once diabetes was so firmly established.
"No one had cured them," he said. "Here was this treatment that we thought would get them ready for a transplant but - eureka! - the diabetes was cured."
If Dr. Faustman's findings could be applied to humans, there would be no need for islet cell transplants. Embryonic stem cells, which many researchers believed might be turned into islet cells, eliminating the need to get islets for transplants from cadavers, would also be unnecessary. In fact, the work meant that unless the underlying immune system attack on the pancreas was stopped, these replacement cells would eventually be destroyed anyway, so such treatments would never be a cure.
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Even though the islet cells were growing back, it was still unclear where the new cells were coming from. Before long, Dr. Faustman had a surprising answer. . .
In a paper last year in Science, Dr. Faustman reported that she had cured female mice of diabetes and transplanted them with spleens from male mice. The islet cells that grew back were male, and they had come from the male spleens.
The findings raised the question of what happens to people who have their spleens removed. Dr. Faustman went to the medical literature and discovered that most spleens were removed in emergency rooms and that few patients were followed afterward, with two exceptions.
One was a group of patients in England with pancreatitis. To treat them, doctors had removed half of the pancreas. When they removed the right half of the organ, the patients were fine. But when they removed the left half, along with the attached spleen, patients often developed diabetes about five years later.
The other case involved children with beta thalassemia, a genetic disease involving iron storage. Often, they developed enlarged spleens, which were removed. Five years or so later, many got diabetes.
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Posted by: Robert Schwartz at November 17, 2004 3:13 PMLets try this URL and see if it works:
Posted by: Robert Schwartz at November 17, 2004 3:25 PMScience isn't about politics, although of course there are politics in science, as there is in any human organization.
Most animal ones, too.
There are branches of science, fields of inquiry, that are politically motivated, but they don't make up the whole of "science" any more than two fingers make a human being.
Posted by: Michael Herdegen at November 17, 2004 5:55 PMScience is just a set of metaphors for explaining the world to ourselves--that's inherently political.
Posted by: oj at November 17, 2004 6:16 PM[Religion] is just a set of metaphors for explaining the world to ourselves--that's inherently political.
And those metaphors are wildly conflicting, which is why there are religious wars.
When was the last time an army of theoretical physicists battled an army of organic chemists?
Posted by: Uncle Bill at November 18, 2004 1:45 PMUncle:
Yes, science is a religion.
The chemists found ways to mass murder for WWI, then the physicists in WWII. The physicists even gave the nuclear secrets to the Bolsheviks so they'd be able to murder us back.
Posted by: oj at November 18, 2004 1:54 PM