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Thread: Comments on embryonic stem cell research and Alzheimer's disease

  1. #11
    Alan,

    If President Bush had not clamped down on embryonic stem cell research, I think that we would have had our first clinical trial by now. Of course, the first patients that will receive therapy would probably be those with the most desperate conditions. For example, people with ALS who have a 10% chance of 5-year survival will be among the first. Likewise, people who are dying of Alzheimer's disease would be candidates. They have little to lose and, if they die, the tissues can be examined. In my opinion, such clinical trials would be ethical and the risk benefit ratios would not be any more different than, for example, the porcine fetal neuronal transplants. I think that there is also a good chance that embryonic stem cell transplants would have been tried in spinal cord injury within a year or two from now, if President Bush had not been elected. Let me explain why:

    1. Availability of human embryonic stem cells. The original proposal by the Clinton Administration to allow NIH to fund human embryonic stem cell research was to have private groups derive the stem cell lines. If NIH is funding the research, there will be a demand for the cells. The cells would have been made available. Doug Melton, for example, made 17 lines in his laboratory with limited resources. A Chicago clinic has made over 50 human embryonic stem cell lines. So, it is not unreasonable to assume that hundreds or perhaps even thousands of human embryonic stem cell lines would have been available in four years.

    2. Demonstration of safety. As I pointed out above, the first patients to receive the cells will likely be terminal patients with ALS and Alzheimer's who have little to lose. If these patients die, we will know whether or not they have a propensity to develop tumors. By the way, even in 2000 when John McDonald did his study with mouse embryonic stem cells, the method of treating the cells with retinoic acid to prevent tumor formation was already known and practiced. There is no reason why this could not be done in the human trials as well. The possibility of tumor formation is the one undefined risk of transplanting these cells. The rest of the risks are well understood and reasonable.

    3. Immune rejection. The University of Florida at Gainesville study that transplanted fetal spinal cords into people with chronic spinal cord injury did not do any tissue HLA antigen matching at all. In fact, they transplanted as many as 7 fetal spinal cords into a syrinx and MRI scans indicate that the cells survived over a year after transplantation in a majority of the patients. The patients received a short-term course of immune suppression. None of the patients had any serious side-effects from the transplantation or immunosuppression. Furthermore, Dr. Huang transplanted unmatched fetal OEG cells into the spinal cords of several hundred patients, with apparently no significant morbidity or mortality. Therefore, we can conclude that if immune rejection occured, it is not dangerous or deleterious. Even if it occurred, the transplant might still have some lasting beneficial effects. Short-term immune suppression may be sufficient to prevent rejection.

    4. Efficacy. Please note that embryonic stem cell transplants may not effective on their own and may need to be genetically modified or combined with other therapies to have maximal effect.

    In short, I think that we probably could be in the same position that we are right now for OEG transplants. Unfortunately, we have lost four years. In the meantime, of course, adult stem cells are rapidly catching up. If they do, that is great.

    Wise.

  2. #12
    Wise

    That's terrible - people who don't understand medicine shouldn't have so much power to stop research on treatments which are needed by people now - I know the President of the United States is supposed to have power over everything but a little knowledge is a dangerous thing - his medical advisers must have had their own agenda and he believes them

  3. #13
    Originally posted by Wise Young:

    Likewise, people have tried to link somatic cell nuclear transfer (SCNT) to stem cell research without recognizing that embryonic stem cell research does not require cloning. Furthermore, there are now many ways to produce cloned stem cells much more efficiently than SCNT. The tying up of embryonic stem cell research to SCNT is unnecessary.
    Dr. Young, would you please expand on your last point? I think it would be very helpful for many.

    Thanks,

    -Steven
    ...an affluent suburb. 3:30 in the afternoon. 64 degrees and cloudy. the white house declined comment.

  4. #14
    Steven,

    SCNT is only one of several methods of cloning. For example, most cloning today is not done with SCNT but rather fusion of cells. Parthenogenesis, for example, does not involve SCNT. Furthermore, SCNT is used for other purposes besides cloning. For example, SCNT may be used to create an egg for a infertile woman, so that her husband can fertilize the egg. So, SCNT is not necessarily cloning and SCNT is not the only way to get cloned stem cells.

    I also want to point out the fallacy of the widespread concept that we have to have cloned stem cells for transplantation of cells. In fact, the vast majority of cell transplantations that have been carried out to date in people and animals, have been with heterograpft cells. For example, the hundreds of fetal cell transplants to people with Parkinson's disease have been with non-matched cells from aborted fetuses. Likewise, all the transplants that were done at the University of Florida at Gainesville fetal spinal cord transplants were done with non-matched tissues from aborted fetuses. Yes, in both of these trials, it appears that the tissue will engraft. It is true that the University of Florida at Gainesville trial did use a short period of immunosuppression.

    Cloning stem cells and autografts of human adult stem cells of course would be nice because such cells would be less likely to be rejected. However, people shouldn't be jumping to the conclusion that heterografts are useless and even that non-matched heterografts are useless.

    Wise.

  5. #15
    Thanks for the informative reply. Would therapies including heterografts require more development time than those using autografts [for fear of immune rejection or whatever else]?

    -Steven
    ...an affluent suburb. 3:30 in the afternoon. 64 degrees and cloudy. the white house declined comment.

  6. #16
    Steven,

    We should not be treating fear but treating people. There is no reason why fear of immunorejection [or anything else] should hold back clinical trials of heterografts. After all, all organ transplants today are heterografts.

    Wise.

  7. #17
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    Posted on Mon, Jun. 14, 2004

    Bush pressed to expand stem-cell research

    EX-FIRST LADY, LAWMAKERS JOIN EFFORT

    By Kristin Reed and Kristen Hallam

    Bloomberg News



    ........The worldwide market for Alzheimer's drugs may grow to $2.5 billion this year, according to Lehman Brothers' estimates. Drugmakers including Pfizer and Wyeth are working on treatments or have developed drugs for Alzheimer's. But they've shown little interest so far in stem-cell research.

    Most Alzheimer's medicines ease only symptoms, and there's little to substantially slow the onslaught of the disease. Better treatments may lead to an annual Alzheimer's market of more than $6 billion, according to Mara Goldstein, an analyst at CIBC World Markets in New York.

    ``It is a market that could be potentially tremendous,'' Goldstein said.

    In the Aug. 9, 2001, speech announcing his funding policy, Bush acknowledged Nancy Reagan's letter and said he would limit federal research funding to existing lines of stem cells out of ``moral concerns.'' A line is a group of cells cultivated from a single human embryo, which is destroyed in the process.

    Bush isn't considering a change of policy, White House spokesman Trent Duffy said Wednesday. ``There's a perception that if we go forward, there would be a cure tomorrow,'' Duffy said. ``That's not the case.''

    Research limited

    Under the Bush policy, research has been limited. Many of the approved stem-cell lines wound up being unusable, and scientists say the restrictions have delayed progress.

    Geron, which specializes in stem-cell science, had a loss of $29.9 million last year on revenue of $1.2 million. The lack of federal underwriting means Geron funds basic university research, said Chief Executive Thomas Okarma.

    ``It's a strain,'' Okarma said. ``We're not a company that makes a significant amount of revenue.''

    Geron may begin testing stem-cell treatments in patients with spinal-cord injuries in 2006, Okarma said. The company has tested the technology in animals.

    Advanced Cell cloned a human embryo in 2001. The company's efforts have been slowed by the difficulty in attracting funding, according to Robert Lanza, chief medical officer.

    ``We've already lost several years -- we should be in the clinic already,'' Lanza said. Companies are working ``with two hands tied behind our backs, because we're hampered by both policy and funding.''

    The National Institutes of Health awarded about $20 million for work on embryonic stem cells last year, compared with almost $300 million for work in adult stem cells -- which many scientists say hold less promise. Adult cells don't require federal approval for funding.

    Four-term Sen. John Kerry of Massachusetts, the presumptive Democratic presidential candidate, has said he will reverse Bush's ban on stem-cell research if he is elected.

    ``With Alzheimer's and diabetes on the rise, and with 40 percent of Americans likely to get cancer in our lifetimes, we need to be pushing the boundaries of research, not letting partisan politics hold us back,'' Kerry said in a speech in October in Lebanon, N.H.

    National sentiment may be changing in favor of more research. A survey

    Source

    "As our cause is new, so must we think anew and act anew" - Lincoln

  8. #18
    Maybe this has been discussed before, but what I don't understand is that there seems to be so little political risk for President Bush to rescind the ESC funding ban. He might slightly alienate his right-wing supporters, but they're not going to jump ship .. and he could actually gain among moderates. He's just such an inflexible, brittle man .. though he'd call it "being decisive" I suppose. What gives?

    - Bruce

  9. #19
    bruce, I was just thinking that it is a strategic decision that was made by Bush's advisors for the following reasons:
    1. He does not want to be seen as "flip-flopping" on this policy.
    2. His own Council of Bioethics has come out with a split opinion on the subject.
    3. The Pope probably implied to him that the Catholic Church will oppose him (as they do Kerry) if Bush allows embryonic stem cell research.
    4. The main reason that his "core" religious conservatives support him is because of his social views. Many probably are having questions about his policies regarding Iraq.

    Wise.

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