MESSAGE
| DATE | 2008-01-19 |
| FROM | From: "Michael L. Richardson"
|
| SUBJECT | Re: [NYLXS - HANGOUT] Human Cloning
|
Can you post the url to this?
Ruben Safir wrote:
> Mature Human Embryos Created From Adult Skin Cells
>
> By Rick Weiss Washington Post Staff Writer Friday, January 18, 2008; A01
>
> Scientists at a California company reported yesterday that they had
> created the first mature cloned human embryos from single skin cells
> taken from adults, a significant advance toward the goal of growing
> personalized stem cells for patients suffering from various diseases.
>
> Creation of the embryos -- grown from cells taken from the company's chief
> executive and one of its investors -- also offered sobering evidence that
> few, if any, technical barriers may remain to the creation of cloned
> babies. That reality could prompt renewed controversy on Capitol Hill,
> where the debate over human cloning has died down of late.
>
> Five of the new embryos grew in laboratory dishes to the stage that
> fertility doctors consider ready for transfer to a woman's womb: a degree
> of development that clones of adult humans have never achieved before.
>
> No one knows whether those embryos were healthy enough to grow into
> babies. But the study leader, who is also the medical director of a
> fertility clinic, said they looked robust, even as he emphasized that
> he has no interest in cloning people.
>
> "It's unethical and it's illegal, and we hope no one else does it
> either," said Samuel H. Wood, chief executive of Stemagen in La Jolla,
> whose skin cells were cloned and who led the study with Andrew J. French,
> the firm's chief scientific officer.
>
> The closely held company hopes to make embryos that are clones, or
> genetic twins, of patients, then harvest stem cells from those embryos
> and grow them into replacement tissues. When transplanted into patients,
> the tissues would not be rejected because the immune system would see
> them as "self."
>
> "All our efforts are being directed toward personalized medicine and
> diseases," said Wood, adding that the scientists did not try to extract
> stem cells from the first embryos they made because they were focused
> on proving they could make the clones.
>
> Other stem cell scientists expressed optimism but said they want to see
> the work repeated and more details presented.
>
> "I'd really like to believe it, but I'm not sold yet," said Robert Lanza
> of Advanced Cell Technology (ACT) in Worcester, Mass. He said the report
> did not show the results of molecular tests that scientists typically
> do to prove that the cloning process was complete. He and George Daley,
> a stem cell scientist at Children's Hospital Boston, said the embryos
> look only marginally healthy in photos.
>
> The work is the latest evidence, however, that the field is recovering
> from the scientific and public relations debacle of 2005, when similar
> claims by South Korean scientists proved to have been fabricated.
>
> Nevertheless, opponents of research on human embryos lashed out at
> the approach.
>
> "This study seems to confirm that human cloning . . . is technically
> possible," said Richard Doerflinger of the U.S. Conference of Catholic
> Bishops. "It does not show that a viable or normal embryonic stem cell
> line can be derived this way, or that any such cell has 'therapeutic'
> value. It does not answer the ethical or social questions about
> the mass-production of developing human lives in order to destroy
> them. . . . It only tells us that these questions are more urgent
> than ever."
>
> Other critics noted that scientists in Japan and Wisconsin recently
> discovered a way to "reprogram" stem cells directly from skin cells,
> without having to make embryos as a middle step.
>
> "In light of the recent cell reprogramming developments, cloning-based
> stem cell research is less justified than ever," said Marcy Darnovsky
> of the Center for Genetics and Society in Oakland, Calif.
>
> Wood and others countered that, for now, those approaches require the
> use of gene-altered viruses, which can trigger tumor growth.
>
> "It's hard to believe the FDA would approve the use of those cells,"
> Wood said.
>
> Criticism also arose on Capitol Hill, where enthusiasm has grown for
> the newer stem cell methods that do not involve embryos.
>
> "Human cloning is now less about the science and more about the novelty,
> which makes it all the more nefarious," said Rep. Dave Weldon (R-Fla.),
> who has sought to ban all kinds of human cloning.
>
> He said he hopes to revive the legislation this year. Previous bills
> have failed because Congress, though willing to ban the creation of
> cloned babies, is divided on the issue of banning human embryo cloning
> for research.
>
> No law bans cloned-baby-making, but the Food and Drug Administration
> has said that such experiments would require its approval.
>
> Cloning involves fusing an ordinary body cell with a female's egg cell
> whose DNA has been removed. Chemical factors inside the egg reprogram the
> body cell's DNA so that the newly created cell develops into an embryo
> that is a genetic twin of the person or animal that donated the body cell.
>
> The technology has developed rapidly in animals, and scientists have
> been trying to apply it to human cells. In 2001, scientists at ACT said
> that they had made cloned human embryos but that they grew for only a
> day or two.
>
> In 2005, scientists in Britain grew human embryo clones to the
> fully mature "blastocyst" stage that the California team described
> yesterday. But the body cells they used were taken from other human
> embryos, not from adults.
>
> That approach offers no help to patients who are already born.
>
> In the new work, the team took skin cells -- some from Wood's arm and
> some from an anonymous Stemagen investor -- and fused them to eggs
> from women who were donating their eggs to help infertile women. About
> one-quarter of the resulting clones, or five in all, developed into
> five-day-old blastocysts.
>
> Wood said the key was that his lab is directly adjacent to a fertility
> clinic with which the company has an arrangement, so his team obtained
> the eggs within an hour or so of when they were retrieved from the
> women's ovaries.
>
> And although researchers are typically given the poorest quality
> "leftover" eggs from fertility patients, donors in this experiment --
> and the women for whom those eggs were intended -- agreed to give away
> several of the best eggs because, in each case, they had far more than
> were needed.
>
> "They are the heroes in this," Wood said. "Think about it. You're
> spending $25,000 [trying to get pregnant], and you're giving some of
> those eggs away."
>
> Under California law, egg donors cannot be paid for their service.
>
> DNA tests proved definitively in one case, and less clearly in two others,
> that the embryos were indeed clones. Results could not be obtained from
> two of the embryos.
>
> R. Alta Charo, a professor of law and bioethics at the University
> of Wisconsin, said the approach is attractive because the egg donors
> were not subjected to the medical risks of ovarian stimulation and egg
> retrieval just for research.
>
> "The protocol entailed no marginal increased health risks to the
> egg donors, as they were already undergoing hormonal stimulation for
> non-research purposes," Charo said.
>
> Asked what it was like to look at embryos that were replicas of himself,
> Wood said: "I have to admit, it's a very strange feeling. It is very
> difficult to look at an embryo and realize it is what you were a few
> decades ago. It is you, in a way."
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