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Thread: For stem cell experts, hopes are longterm/Human trials still years away in effort to cure paralysis

  1. #1
    Senior Member Max's Avatar
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    Unhappy For stem cell experts, hopes are longterm/Human trials still years away in effort to cure paralysis

    For stem cell experts, hopes are longterm
    Human trials still years away in effort to cure paralysis




    Carl T. Hall, Chronicle Science Writer

    Monday, September 26, 2005













    New evidence from mouse studies suggests that stem cells may help cure paralysis in cases of spinal cord injury. So that raises an obvious question: When can they be tried in humans?

    The answer: No time soon.

    That may be disappointing to paralyzed individuals with untreatable spinal cord damage, as well as champions of California's Proposition 71 stem cell research program, all anxious to see real treatments develop from the hype of regenerative medicine.

    But experts warn it would be a big mistake to rush into clinical trials before settling the many scientific and ethical issues clouding the future of stem cell biology.

    "I fully understand the impatience of patients, spinal cord injury patients in particular, who are desperate for some form of treatment. But there is risk proceeding too quickly here," said Dr. Arnold Kriegstein, a neurologist who serves as director of a stem cell and tissue biology program at UCSF.

    "The whole field could be damaged by the outcome of one failed early trial," he said. "I am not saying (a human trial) shouldn't be done, but we should really be cautious about it."

    Haste has laid waste in biomedicine before, most notably in the field known as human gene therapy. Trials were commenced in a flurry of early excitement but on shaky scientific ground. That led to shortcuts, serious ethical lapses and at least one widely reported death of a clinical trial participant.

    Stem cell biologists are keenly aware of the gene therapy story -- and hope to avoid a sequel without being accused of dawdling too long in the face of unmet medical needs. The question came to the fore last week after UC Irvine researchers Aileen Anderson and Brian Cummings and colleagues documented improved coordination and mobility in spinal cord-injured mice after they were injected with some specialized stem cells of the nervous system.


    http://sfgate.com/cgi-bin/article.cg...NG95EU12N1.DTL




  2. #2

    Wink

    Thanks Max but,

    This article presents nothing disheartening.....thankfully the World expands further than the USA and overseas therapies will ultimately hold the key.


    We'd be fools to think that the U.S would be at the very forefront anyway

  3. #3
    We might have been better served if the 3 billion pledged by California went to the China Network of South Korea.

  4. #4
    It is good that the message of 'approach with caution' is out there. This lets the protesters know that we do get that message. However, I think the majority of people, through the medium of the likes of Dr. Wise Young, Christopher Reeve and the like support the 'Go Forward' approach and are sick and tired of waiting for a mouse to say " Oh yeah, that feels better....I can feel my feet!". World renowned researchers, bioethicists and health law Directors such as Timothy Caulfield at the Canadian Law Institutes agree that science has moved to the point where human clinical trials are not very far away from being very feasible. Think positive everybody!!
    Here's Hoping!

  5. #5
    Senior Member TEION's Avatar
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    Angry Cowards...

    what a bunch of cowards. What is it with the scientist in the USA? They know the desperation of those with spinal cord injuries? Give me a break. They have no damn idea. If they did they wouldn't be dragging there asses like they do. Other countries are sailing by us...thank god. If those with SCI's had to depend on these smucks you might as well just throw in the towel. The article states that we shouldn't rush to human trials just because of this "ONE" positive outcome. ONE! WATDAFU! My wife suffered from a spinal cord injury 10 years ago and we have read about a many positive results all involving mice. I think all this is pathetic. The cure is there. Why don't they want to help anyone?

  6. #6
    Please don't be too hard on Arnold Kriegstein. He is a good friend of mine and a very good scientist. He is simply voicing caution which is something that I have done so as well, that we must be careful when all the eyes are trained on the first clinical trials of embryonic stem cells and opponents of embryonic stem cell research are waiting to pounce on the first failures. This is also a caution that Woo-suk Hwang has voiced as well when asked whether he was ready to transplant the cloned stem cells that he had obtained from 11 people, that more studies are needed to establish the safety of the cells.

    There will be spectrum of voices on the subject, some urging all-speed ahead and some urging caution. We should seriously consider both the risks and benefits of embryonic stem cell transplants before throwing all caution to the wind.

    The first embryonic stem cell transplants were made by John McDonald and his group in 1999 when they transplanted mouse embryonic stem cells into rats with contusion injury. They did it in rats with "incomplete" injury resulting from a 12.5 mm contusion. The cells were predifferentiated in culture with retinoic acid to more neural lineages before transplantation. The cells myelinated axons in the rats and they showed better locomotor recovery. Then Doug Kerr and his group transplanted pre-differentiated mouse embryonic stem cells into rats with viral-induced motoneuronal loss, showing that these cells were able to produce new motoneurons and that, when cAMP or phosphodiesterase inhibitors were used, the motoneurons sent axons out the spinal roots. The rats recovered more neurological function. Rats that did not get the cAMP or PD inhibitors did not recover as much. To my knowledge, no embryonic stem cells have been transplanted into human.

    There have been many studies suggesting that fetal neural stem cells are beneficial in spinal cord injury, published by Okano, et al. at Keio University in several species including monkey. Recently, the Reeve-Irvine Center published an article in the PNAS reporting that fetal human neural stem cells transplanted into mice will remyelinate and restore function in mice after contusion injury (see http://carecure.org/forum/showthread.php?t=52269). These too were predifferentiated. Please note that this study did not emphasize the fetal origins of the cells but it was funded by a small business innovation grant from NIH. The safety of fetal cell transplants into the spinal cord appears to be reasonable. I estimate that over a thousand people have received fetal cell transplants of various kinds, except for one case that was reported in Vancouver last year, I don't think that I have ever seen or heard of a case of tumor formation from such cells. One reason may be because fetal cells are seldom matched for histocompatibility between the donor and host, and it is likely that most such transplants may be eliminated by the immune system after several months.

    I have previously summarized animal studies that showed beneficial effects of bone marrow stem cells transplanted into the spinal cord http://carecure.org/forum/showthread.php?t=21448 and there is one recent Korean human clinical trial showing that bone marrow stem cell transplants and GM-CSF http://carecure.org/forum/showthread.php?t=49996 improved recovery in patients with complete spinal cord injury. There is of course the recent much-publicized case of a Korean patient who received umbilical cord blood transplant to the spinal cord that was just recently published http://carecure.org/forum/showthread.php?t=52347 As I have pointed out before, there is a group in Zhengzhou, China, that has transplanted bone marrow stem cell autografts intrathecally into over 200 patients after spinal cord injury. I don't get the impression that they are getting dramatic recovery but I don't think that one can tell without doing controlled studies since recovery of patients during the acute phase after injury is so variable. So far, the safety record of bone marrow autografts appears to be reasonable.

    Regarding risk, many early reports suggest that direct transplantation of embryonic stem cells will result in formation of teratomas (embryonic stem cell tumors that contain many different kinds of cells). In fact, Dr. Woo-suk Hwang presented several slides in his talks showing teratoma formation from his cloned human embryonic stem cell lines when transplanted into animals. This was part of his proof that he indeed has obtained pluripotent embryonic stem cells. So, it is clear that embryonic stem cells must be pre-differentiated before transplantation. Can you imagine what would happen if the first patient that gets an embryonic stem cell transplant gets a teratoma. Opponents of embryonic stem cell research will say, "I told you so". Use of embryonic stem cells in human would be shut down for a long time.

    On the other hand, at the present time, embryonic stem cells are the only cells that have been able to produce new motoneurons in the spinal cord, in animal studies. The other cell types have so far have shown remyelination and possibly regeneration resulting from the transplants. For somebody with ALS (amyotrophic lateral sclerosis) and who is dying, there is currently no other choice. For such people, the risk of the therapy is less than the risk of death. Note, however, because ALS is a genetic disease, it is probably not appropriate to transplant autografts since that would be putting the cells with the same genetic disease into the spinal cord. HLA-matched heterografts will probably be necessary. I think that it is likely that the first embryonic stem cell therapy will probably be tried in patients with ALS or similar disease. As more experience is gathered and the risk is better defined, I think that it may be tried in patients with less deadly disease and conditions.

    Wise.
    Last edited by Wise Young; 09-27-2005 at 08:46 AM.

  7. #7
    Senior Member cali's Avatar
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    i really want to walk, obviously, but i want it to be as safe as possible so i don't mind waiting as long as i need even though i'd rather not
    Never take life seriously, nobody gets out alive anyway

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  8. #8
    Senior Member Cspine's Avatar
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    Quote Originally Posted by cali
    i really want to walk, obviously, but i want it to be as safe as possible so i don't mind waiting as long as i need even though i'd rather not
    that's exactly how i feel.

    i think what we all tend to forget is even in medicine you don't get a second chance to make a first impression. if the first clinical trials go perfectly then everybody will jump on the stem cell train and we'll all get fixed up in no time. if all the subjects of the first trial die because of a cut corner or overlooked detail then sci stem cell research will basically be writen off as quackery.
    Death and taxes

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    Thumbs down enough already

    Researchers are trained to be centered and disciplined, passive to a patient's individual needs and/or requests. Throughout their careers they've seen many desperate people die due to the ravages of a damaged Central Nervous System. With regards to SCI, since most patients are alive, there is even less pressure to deflect thier needs. It is my stern belief that the longer someone lives with a chronic SCI, the more unfixable the dead tissue, and unused body parts are going to be. It's just a matter of time before scientists start completely dismissing chronic SCI sufferers, telling us to support research for tomorrow's generation. I, for one, will not give funding for research that is aimed to help someone not even conveived yet.
    sherman brayton

  10. #10
    cspine - I believe that you are correct.

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