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Thread: Nerve growth success - this probably was posted, it's from 12/01

  1. #1
    Senior Member rdf's Avatar
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    Nerve growth success - this probably was posted, it's from 12/01

    Thursday, 6 December, 2001, 16:56 GMT

    The eye may contain chemicals which could promote
    nerve growth
    Scientists have managed to make damaged
    nerves re-grow to fill gaps of more than a
    centimetre, adding to hopes for treatments for
    spinal injury.

    The team from the University of Munster in
    Germany carried out experiments on the
    severed optic nerves of rats.

    However, they are thought to be good models
    for the human spinal cord - and scientists
    believe this, combined with other techniques,
    may provide a way to help people whose cords
    have been severed or left badly damaged.

    Normally, axons - the long strands of nerve
    tissue which make up the fibres, are highly
    resistant to regrowth in such circumstances.

    They normally start sprouting out - but never
    get very far.

    Scar block

    This is because the scar tissue at the site of
    the injury prevents the severed ends growing
    out, even prompting the exposed tip of the
    nerve to release a protein which instructs the
    nerve not to regrow.

    The German team were testing one method of
    overcoming this resistance.

    Within the lens of the eye are proteins called
    crystallins which they believe stop the nerve
    tip protein having its inhibitory effect.

    Punctured eye

    They performed an operation to rejoin the two
    ends of the sheath which normally surrounds
    the nerve fibres, then punctured the lens of
    the eye.

    The results were spectacular - in one instance
    14mm of nerve regrowth was produced.

    Three months later, approximately 30% of the
    nerve fibres had regenerated, which, according
    to the team, could be enough to produce some
    vision.

    Other research has shown that lens injury can
    promote nerve regrowth in these sorts of
    injury.

    However, this is most pronounced growth yet
    seen, and some experts suggest that the
    effect of the surgical "sticking together" of the
    sheath ends contributes by inflaming the
    surrounding tissue, which then produces
    chemicals which help the nerves grow.

    Dr James Fawcett, from the Cambridge Centre
    for Brain Repair, says that any successful
    attempt to produce nerve regrowth in humans
    would probably depend on a combination of
    treatments, both aimed at breaking down scar
    tissue and encouraging nerves to sprout.

    He said: "Lots of things can affect the ability
    of the axon to regenerate, and we a looking
    for ways to 'juice it up'."


    [URL=http://news.bbc.co.uk/hi/english/health/newsid_1696000/1696053.stm]story[/URL

  2. #2
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    So what about my friend's blindness due to lack of oxygen to his optic nerve? What sort of treatments will affect this?

    Is there a day when the blind will see again???

    Eric Texley

  3. #3
    Senior Member DA's Avatar
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    eric,
    one of the first solid proof of nerve regeneration came in 1991. yes, it was an optic nerve.

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    Senior Member bill1938's Avatar
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    Will the blind see?

    Japanese scientist makes frog eyes


    AP [ MONDAY, MARCH 25, 2002 7:01:55 PM ]

    OKYO: Professor Makoto Asashima is surrounded in his tiny laboratory by shelves cluttered with bottles of chemicals. Test tubes whirl in centrifuges while technicians pore over data at their desks.

    The scene is a typical one, but what goes on here is not. Immersed in water at the bottom of a petri dish are about a dozen frog embryos the size of a pinhead that Asashima uses to create the animal's eyes, ears and other organs.

    Technology that Asashima is developing could eventually help doctors use stem cells from humans to regenerate or replace damaged or destroyed human organs, like the way a lizard reproduces a severed tail. It would eliminate the need for donor transplants.

    "If we keep going in this direction, it'll be possible for people who have lost their sight to see again," said Asashima, professor of developmental biology at Tokyo University.

    About two decades after starting research on organ regeneration, Asashima in 1989 discovered that a protein called activin induces genes in a frog's embryonic stem cells - which produce the tissues and organs of the body - to form kidneys, livers and other organs.

    In 1998, he became one of the first scientists to create a sensory organ - a frog eye - in vitro from a stem cell. Last year, he successfully transplanted an eye formed in a test tube, restoring the sight of a blinded tadpole.

    So far, Asashima and his team have given new eyes to some 60 tadpoles, about 70 per cent of which are able to see.

    "It's a good example of his type of pioneering work. He's really on the forefront," said Carl Pfeiffer, emeritus professor of biomedical sciences at Virginia Polytechnic and State University.

    Asashima generates organs by slicing off the part of the embryo responsible for tissue development and immersing it in a solution containing activin. The activin-soaked embryo piece is sandwiched between two untreated embryo slices and set aside until the untreated parts are induced to yield an organ.

    The process takes about five days. Varying the concentration of activin and combining it with other agents such as retinoic acid brings forth different genetic instructions in the cells.

    For example, a lower concentration produces blood cells and muscle tissue. Higher doses yield hearts, livers and pancreas. But Asashima concedes it is a big step from regenerating frog organs to doing the same for humans.

    For one thing, frogs produce many more embryos than humans, meaning the number of stem cells available for research on humans would be more limited.

    Then there are also political concerns about research with human stem cells.

    Anti-abortion activists and the Vatican say that human stem cell research constitutes the taking of life because embryos are destroyed to extract the cells. And President Bush decided last year to withhold federal money for research that involves the destruction of embryos not already in the research pipeline.

    In Europe, four countries - Austria, Germany, France and Ireland - ban all embryo research, while others allow it to varying degrees.

    Japan falls somewhere in between, approving guidelines last year stipulating that embryonic cells used in experiments could be taken only from those earmarked for fertility treatment that would otherwise be discarded.

    Politics aside, some experts anticipate that Asashima's research will eventually help scientists to cure debilitating diseases such as Alzheimer's, which is caused by the degeneration of brain cells.

    "The principles he develops in lower animals will be applicable to humans," Pfeiffer said.

    Despite the obvious differences, Pfeiffer said humans and frogs have much in common, including similar heart and skeletal muscles.

    Others, however, are somewhat less sanguine.

    "They (human stem cells) will form various tissues, but not intact organs, and even if they could be formed, the organs would have to be grown for months to become big enough for transplantation," said professor Jonathan Slack, who is in charge of the department of biology and biochemistry at the University of Bath in the United Kingdom.

    "This is interesting science but it would be a very long haul before it leads to a new source of transplantable organs," he said.

    Asashima's work is funded by Tokyo University and a government-linked science promotion group. His research has appeared in major international publications in his field, including The International Journal of Developmental Biology.

    Asashima plans to expand his research to mice, whose characteristics are more similar to humans, as soon as he perfects his work with frogs.

  5. #5
    Senior Member bill1938's Avatar
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    Another interesting article about regeneration

    STEM CELLS AND RETINAL RESTORATION
    By, Charles Savoie


    --------------------------------------------------------------------------------

    For as long as people have been going blind desperate hopes have been held out for a cure. The electronic retinal chip under development would be an inferior solution compared to the regeneration of living cells. There is great research into gene therapy and photoreceptor transplantation. Either of these approaches may succeed first, however there are now many claims in the scientific community and their pharmaceutical patentholder sponsors that a "stem cell" therapy may become available to reverse blindness caused by macular degeneration or RP. As with all areas of medicine and genetics, the vocabulary of stem cells is extensive. This brief summary of what stem cells are and the research into them is intended only as an introduction. Many web pages are available for additional articulation. Stem cells are of various types: embryonic and adult being the two superintending categories. There are ethical issues involved in using embryonic stem cells and such research is limited to private funding. Cell therapies developed in stem cell research have sufficient potential to solve the daunting problem of blindness!

    Stem cells are "progenitor" cells capable of becoming various types of tissue: bone, blood, muscle, nerve cells. So called signalling molecules and growth factors are necessary to the process. In mammals there is an inhibitory factor present which obstructs neural regeneration, a problem not present in amphibians. The reasons for the difference are being aggressively studied in labs of many nations, Canada, Israel, England, Japan, U.S. and all over Europe. The main difference seems to be the differences in the mammalian and amphibian immune systems. The immune system is more developed in mammals and attempts among other things to prevent runaway cellular growth (cancer). Evidently in so doing, growth of stem cells is also suppressed, preventing the regenerative effect seen in amphibians. Fortunately, the solution as I understand it will not have to do with weakening the immune system, but simply providing progenitor stem cells with the necessary signalling molecules to tell them which tissue type to differentiate into. A symposium in May 1999 at the Wistar Institute in Philadelphia entitled, "Regeneration in the 21st Century" compared the mammalian and amphibian nervous systems and stem cells, and these scientists are convinced that mammalian stem cells can be induced to regenerate tissue the way amphibians do. Wire services reported on January 4, 2000, that biologists led by Makoto Asashima at Tokyo University succeeded in growing frog eyes in culture using embryonic stem cells, with retinoic acid as the growth factor/signalling molecule. The process of culturing stem cells and directing them to become specific tissue is different from cloning, from which health solutions may be more distant. Dolly, the cloned sheep in Scotland, showed premature aging, a problem absent in the stem cell approach. It will not be necessary to grow an eyeball and transplant it into a patient's orbital socket! Patients with retinal problems will need stem cell transplantation and/or activation of their own cells with growth factors. This developing science does overlap with that of gene therapy, which seeks to correct errors in DNA so that harmful mutations aren't expressed. Wire service reports dated July 30, 1999, noted that scientists at the National Institute of Health used stem cells to treat brain and spinal cord injuries in rats. Two types of neurons, oligodendrocytes and astrocytes were made from the stem cells. Oligodendrocytes and astrocytes are neural types found in the retina.

    Embryonic stem cells are termed "totipotent," signifying they can develop into any form of tissue, while adult stem cells appear more limited. However, in nature, adult amphibians need no infusion of embryonic stem cells with which to regenerate tissue-their own adult stem cells suffice. It is now coming to be more believed that adult stem cells of mammals, such as "mesenchymal" (bone marrow derived) stem cells, can be directed to become responsive to more than limited cellular lines of expression (The Scientist, March 16, 1998). Such stem cells have been coaxed to become cartilage, fat and muscle. It will become possible to see a dentist, have fillings removed, and replaced with regrown tooth tissue, even regenerate an entire dental structure so that false teeth may be discarded! Bone marrow derived stem cells have also been engineered to become liver cells, and cirrhosis of the liver in rats has been cured with gene transfers. Retinal stem cells in rats have been isolated by Dr. Iqbal Ahmad of the University of Nebraska Medical Center, as announced on May 29, 1998. This is considered a major signpost on the road to retinal regeneration. Dr. Ahmad is of the view that embryonic stem cells will not need to be tapped as a resource for repairing a human retina. We are all weary of experiments with rats, mice and other creatures. However, the foundation knowledge acquired helps the goal closer to fruition. The stem cell/gene therapy revolution in science is being broadly termed "regenerative medicine," and appearances are that it will be a win-win situation for developers of the cell therapies and the spinal cord, stroke, retinal, liver, heart, and so on, patients in need of restored function.

    Opinions as to when a clinical stem cell treatment for retinal degeneration patients will be available vary. Sorry I don't have the exact documentation here, but I heard a Harvard researcher say on national news around November/early December 1999 that a blindness cure is still up to 15 years off. When we take a car for repair we want it fixed quickly and don't want to be charged a warehousing fee. My private opinion is that some researchers may want to milk research grants for longer than necessary so the money they live on will continue! Actually there is a high stakes RACE going on right now, on a 24 hour basis, to develop a stem cell based method of reversing blindness. At least several dozen, possibly over one hundred, pharmaceutical, biomedical corporations are aggressively chasing this stem cell "genie," for repair of stroke, spinal cord, retinal and many other problems. The corporations that get there first will of course have patents of colossal profitability. My belief is that in a projected time frame of up to 15 years for clinical breakthrough applications of stem cells, those who may be deliberately dragging their feet will end up holding an empty bag. An official for Osiris Therapeutics admitted (verbatim) that stem cell treatments are "well along in the commercialization process," meaning that as soon as each breakthrough in the laboratory is made, a patent is secured. In order to attain full return to shareholders they MUST make treatments available to the public. Osiris alone already reports over 50 such patents for stem cell procedures. It is well known that nerve tissue is the most challenging to treat. In a television broadcast on Channel 4 (United Kingdom) called "EQUINOX-CURING THE INCURABLE," which aired at 9pm on Monday, October 4, 1999, it was admitted that even blindness will be cured with stem cell therapies! The programme (British spelling) noted that Paul Sanberg of the University of Southern Florida used stem cells to repair stroke damage in rats. The cells migrated to damaged brain areas, integrated with the surrounding neurons and axons, restoring memory and coordinated limb movement! Since that experiment the same researchers announced improvement in human stroke patients treated with stem cells. An aspect of their approach was faulted by Irving Weissman of Stanford University in California, who is noted to be an advisor to "a rival corporation." There is an overpowering desire on the part of management of these bioscience corporations to be first to patent a stem cell cure for stroke, spinal cord, retinal and other injuries, for the clear reason that the shareholders of the firms that arrive first at the finish line will become embarrassingly wealthy. The Equinox telecast also noted a powerful British firm, ReNeuron, and its advanced research status. Perhaps the Japanese or the British or the French will upstage American researchers. Have some bags ready to pack just in case the FDA is worried that a retinal restoration process may cause a hangnail. As the Equinox telecast noted (verbatim):

    "Within the field there seems much confidence that these endeavours will pay off. The race to get a product on the market is attracting more runners, and in such a competitive environment, the goal is not far off."

    (Submitted by Charles Savoie on behalf of my dog Frosty, who has canine stem cells and awaits a high tech treatment. His retinal degeneration was arrested through the efforts of this lay person using substances such as are advocated in this forum. He continues to have daylight vision 8 months after an "expert" assured me every nerve cell in his eyes would certainly die. While we await an absolute cure we owe our beloved every effort to stop disease progression, and this starts with ignoring those who commit neglected aspect fallacies by refusing to investigate nonpatentable substances!)

    I found this article from a website called Vision
    http://focusnewsletter.org/stemcell/htm

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