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Thread: question for Dr. Young

  1. #1

    question for Dr. Young

    Dr. Young if a cure for recently spinal cord injured people would come out, do you think it would be possible to go into a chronics spinal cord and take out the scar tissue and have the spinal cord like if it was recently injured?

  2. #2
    Quadpro, I believe that going into the spinal cord to remove scar tissue would only create more scar tissue. I'll see if I can find out more if Dr. Young doesn't respond first.

  3. #3
    The concept that scar tissue is the reason why the spinal cord does not regenerate is an old idea that I think is being questioned by many scientists, including myself. Much of the older studies of spinal cord injury involved cutting the spinal cord. In such cases, especially when the dura is not repaired, fibroblasts (skin cells) indeed does invade into the spinal cord and can produce fibrous scar. However, in most cases of spinal cord injury, the "scar tissue" is limited to adhesions between the spinal cord and surrounding tissues. The adhesions between the spinal cord and the dura and then dura with surrounding tissues cause "tethering" of the cord and also prevent flow of cerebrospinal fluid around the cord. In such cases, removal of the adhesions and untethering of the spinal cord sometimes can restore some function.

    You will probably hear the words "glial scar" or "gliosis" used. Indeed, glial cells do proliferate at the injury site and axons do stop growing in the vicinity of such "gliosis" but several other therapies have been shown to help in such circumstances. One of the most promising is the use of the enzyme chondroitinase which breaks down a chemical called chrondroitin-6-sulfate-proteoglycan (CSPG). Injection of this enzyme appears to promote regeneration in rat spinal cords.

    Finally, as seneca pointed out, physical removal of scar tissue may cause more problems than it solves. It will in fact cause more scarring in the spinal cord. Some scientists, such as Kawaguchi in Kyoto, have been working on cutting out the injury site and trying to cleanly reconnect the spinal cord. This approach is still quite controversial.

    Wise.

  4. #4
    Senior Member dr_bubo's Avatar
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    ====
    You will probably hear the words "glial scar" or "gliosis" used. Indeed, glial cells do proliferate at the injury site and axons do stop growing in the vicinity of such "gliosis" but several other therapies have been shown to help in such circumstances. One of the most promising is the use of the enzyme chondroitinase which breaks down a chemical called chrondroitin-6-sulfate-proteoglycan (CSPG). Injection of this enzyme appears to promote regeneration in rat spinal cords.
    ====

    Yes, in rats. But when will be someone (human) injected?

  5. #5
    Senior Member dr_bubo's Avatar
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    Dear Wise,

    C. Reeve is on breathing machine (at leas he was) however he could talk. This 7 year old boy I talked about some weeks ago is also on breathing machine but I read that because of that he can not speaks, lost the speech. Why? what can be the reason? Is it because Hungarian doctors cut the vocal cord while US doctors not (or in case of rich people they do it more carefully?)
    Thanks
    Bubo

    p.s: question No2: during the human development in the womb, has anyone scrutinized how and why the spinal cord and the CNS in general is formed? Except some rare cases, everyone has a healthy complete spinal cord after birth..If we knew what factors result in such process might help to restore broken spinal cord. Am I wrong?
    Thanks
    Bubo

  6. #6
    Bubo,

    Let me answer the questions one by one:

    1. Why can some people can talk while on the respirator and others cannot?
    • To talk on a respirator, you need to have a tracheostomy, i.e. the breathing tube is placed in the trachea (the breathing tube), below the larynx (the voice box) and a special breating attachment of the tube which leaks air up into the larynx when the respirator pushes air into the lung. A person that can control his or her vocal cords can then use that flow of air to talk. The airflow should be adjusted and also the supplemented by the person's own expiratory air. Some people cannot talk if they have had injury to the brain or brainstem that control the verbal processing or motor control of the 10-11th cranial nerves.

    2. How does the spinal cord develop in the womb?
    • The fetus starts out as a ball of cells. A part of the ball forms a groove which invaginates to produce a neural tube. The brain and the spinal cord forms in that tube. The tube closes on itself. Babies where that tube does not close all the way have a condition called spina bifida. Occasionally, spinal cysts develop called meningomyelocoeles. Sometimes, there are curvatures of the spine and these may develop during or after birth, and are called scoliosis. Abnormalities of brain and spinal development are not as rare as we think. Scoliosis, cerebral palsy, spina bifida and other abnormalities in development of the brain and spinal cord occur in as much as 1-2% of children.

    3. When will chondroitinase be injected into the spinal cord?
    • I don't know. Injection of enzymes into the spinal cord was first practiced by the Russians as long as 30 years ago. In the 1970's, they were injecting mixtures of enzymes into people with chronic spinal cord injury. In fact, Kent Waldrep was one of the first Americans to get such enzyme treatments. In 1979, the NIH put out a special request for proposal to test this in animals and American scientists. American scientists were not able to replicate this work and therefore it was never taken to clinical trial in the U.S. It has taken over 20 years for the work to be carried out again but using a more specific form of the enzyme against an identified chemical (chondroitin-6-sulfate-proteoglycan). As I have indicated in previous postings, chondroitinase ABC (CABC) is a bacterial enzyme that is inflammatory. Although CABC has been approved for human use to inject into herniated discs, there is understandably quite a bit of nervousness about injecting CABC into the spinal cord of humans. Clearly, phase 1, 2, and 3 trials need to be carried out. Safety studies probably also need to be done on at least one large and small species. While rat studies have been carried out, I don't think that they have been formal safety studies with careful histogical and also long term examinations of animals that have been injected with differing doses of CABC to determine the safety parameters. There is also substantial interest in identifying the human version of chondroitinase, which apparently is called hyaluronidase, and seeing whether that works. Finally, there is an interesting possibility that the cells secreting hyaluronidase can be injected instead of their enzyme itself. For example, macrophages probably secrete hyaluronidase and other enzymes that dissolve extracellular matrix proteins.

    Note that there is one other enzyme that has been reported to be beneficial in spinal cord injury. This is metalloproteases. An antibiotic (a tetracycline) has been reported to alter the expression of this family of enzymes.

    Wise.

  7. #7
    Senior Member dr_bubo's Avatar
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    Dear Wise,

    Thanks for the answers. This 7 year old boy broke his C1, his brain is clear and he can move his mouth and "talk" silently.
    SO in this case why he can't talk? is it only question of such device implantation?
    Does Mr. Reeve has one?

    Thanks
    Bubo

  8. #8
    Senior Member dr_bubo's Avatar
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    • The fetus starts out as a ball of cells. A part of the ball forms a groove which invaginates to produce a neural tube. The brain and the spinal cord forms in that tube.
    --

    Why is it forming? Why is it not inhibited like in case of a SC injury?
    what guides the formation? what processes/materials allow these formations?
    What guides the axons there?

    I think these questions would help a lot if we knew the answer. do u agree? does anyone work on it? (I mean not on human, but for example taking samples of early stage spinal cord of monkey babies in the womb)?

    thanks
    Bubo

  9. #9
    bubo, the boy needs an attachment to his respirator that would leak air up into his larynx. His doctors should know about it. Christopher Reeve has one. We have many people on this site who are on respirators and who use such a device.

    Regarding your question, there is a whole field of developmental biology that focuses on the exact question that you ask. Thousands of scientists are studying development, how cells migrate, how the brain and spinal cord develops.

    Wise.

  10. #10
    Senior Member dr_bubo's Avatar
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    [QUOTE]Originally posted by Wise Young:

    bubo, the boy needs an attachment to his respirator that would leak air up into his larynx. His doctors should know about it. Christopher Reeve has one. We have many people on this site who are on respirators and who use such a device.
    --

    Thanks!!
    --

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