Breakthrough in Stem Cell Research!!!!

Discussion in 'Biology & Genetics' started by TruthSeeker, Dec 1, 2007.

  1. TruthSeeker Fancy Virtual Reality Monkey Valued Senior Member

    Messages:
    15,162
    Why is nobody talking about this!?!??

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    http://www.cbsnews.com/stories/2007/11/20/health/main3525177.shtml

    "Stem Cell Breakthrough Avoids Embryo Use

    (CBS/AP) Scientists have made ordinary human skin cells take on the chameleon-like powers of embryonic stem cells, a startling breakthrough that might someday deliver the medical payoffs of embryo cloning without the controversy"
     
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  3. S.A.M. uniquely dreadful Valued Senior Member

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  5. TruthSeeker Fancy Virtual Reality Monkey Valued Senior Member

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    15,162
    That's good too! Good news for once. Isn't it amazing!!!?!?
     
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  7. invert_nexus Ze do caixao Valued Senior Member

    Messages:
    9,686
    Because it's horrible news.
    Why must the baby killing stop?
    Why?

    (Seriously. It's too soon to tell but all the bible thumpers are jumping whole hog and saying that we can dump all embroyonic stem cell research because of this.)
     
  8. draqon Banned Banned

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    35,006
    we need to continue embryonic research neverthless
     
  9. Hercules Rockefeller Beatings will continue until morale improves. Moderator

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    I was asked to write a layman’s description of this topic and put it into perspective. So I thought I would post it here first. I will incorporate feedback from here before I send it on.


    Cellular therapy is a major goal in treatment of degenerative diseases and injury. The idea is to introduce new cells into a patient to counteract the death of cells that has occurred due to the disease or injury, such as the death of brain cells in Alzheimer’s, damage to heart cells in heart disease, or spinal cord damage. The major problem is if the cells are from a different person they will be rejected by the patient’s immune system. A way around this is to use the patient’s own cells for the therapy. But this leads to another problem: the cells of an adult person are “differentiated”. In other words, they are committed to a particular cell type and function. Skin cells introduced into a person’s brain will not become brain cells.

    What is needed are stem cells. These are special cells of the body that remain “naïve” and can divide to produce various different cell types if coaxed to do so. However, stem cells are still somewhat restricted in that they can generally produce only one type of cell. For instance, brain stem cells produce only brain cells. The king of stem cells are embryonic stem (ES) cells which can potentially become any cell type of the body. So, naturally, many scientists consider them to be the stem cell type of choice for potential cellular therapies. ES cells can be grown in cell culture and used to generate whatever cell type is required for the patient. But how do you get ES cells from an adult patient?

    Now for the ethical problems. As the name implies, embryonic stem cells specifically come from early stage embryos and cannot be isolated from any tissue at any other later stage. So the grand plan for cellular therapy is therapeutic cloning:

    (i) clone a cell from the patient (eg. a skin cell) by fusing it with an ovum with its own genetic material removed, and stimulate the “fertilized” ovum to develop into a embryo which will be genetically identical to the donor cell (ie. the patient),

    (ii) isolate ES cells from the cloned embryo, and

    (iii) use the ES cells (or new cells derived from the ES cells) for cellular therapy in the patient.

    The beauty of this approach is that the cells derived from the ES cells (from the cloned embryo) will be a perfect genetic match to the patient and will not be rejected.

    But, isolation of ES cells from an embryo destroys the embryo in the process. Thus, the therapeutic cloning approach necessitates the creation of an embryo for the specific purpose of destroying it. This is an ethical, legal, political and societal ‘minefield’. But two groups of stem cell scientists have recently published exciting research that suggests it may be possible to re-program adult cells (eg. skin cells) such that they revert to an ES cell-like state where they can subsequently be directed to differentiate into any cell type. This is exciting because it would eliminate the need for cloning and the destruction of embryos in order to obtain stem cells. The scientists achieve this by introducing extra copies of particular genes into skin cells. The activity of the extra gene copies stimulates the cells to become “induced pluripotent stem” (iPS) cells that can then become other cell types in the same way that ES cells can adopt different cell fates.

    Whilst this is exciting research it should be noted that it is still in its early stages. Continuing research into ES cells (and, therefore, the destruction of embryos) will be required in order to be able to compare the abilities of iPS cells to ES cells. Furthermore, the method of introducing the extra gene copies relies on utilising a virus to shuttle of DNA into the skin cells. This makes iPS cells unsuitable for human therapeutic use in their present form as the iPS cells contain the virus. A new method of generating iPS cells will need to be developed. The ideal scenario will be to develop a drug that will boost the activity of the natural copies of the genes in question in cultured skin cells and, thus, remove the need to use viruses to introduce extra copies of the genes.

    The concept of therapeutic cloning took a major hit when it was revealed that the leading advances in this field, reported by the South Korean scientist Hwang Woo-Suk, were fraudulent. However, new research published at the same time as the iPS publications has re-ignited interest in therapeutic cloning. Stem cell scientists reported that they had cloned monkey embryos, isolated ES cells and stimulated them to differentiate into a variety of cell types that were genetically matched to the donor monkey. That this was achieved in a primate is significant and, given the previous case of fraud, these results were rigorously and independently confirmed before publication.

    But already there is some evidence that iPS cells can be used therapeutically – scientists have reported that they have treated sickle-cell anaemia in mice using iPS cells. It is unclear at this early stage whether iPS cells will displace the need for ES cells and the destruction of embryos. One thing is for sure, it continues to be an exciting time in stem cell science.

    http://www.sciencedaily.com/releases/2007/09/070911090159.htm

    http://www.sciencedaily.com/releases/2007/11/071120095400.htm

    http://www.sciencedaily.com/releases/2007/12/071206145301.htm
     
  10. leopold Valued Senior Member

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    17,455
    bad choice of words.
    you aren't really creating an embryo, you are duplicating one.
    the embryo already exists (you), all that is happening is that another is being duplicated for the express purpose of remedying a genetic defect in the first one. as long as the second one is destroyed, save for the needed cells, i have no problems with that.

    the above is assuming everyone plays fair.

    how about this:
    when you are born, snip off an inch or two from the umbilical cord and save it until it has been determined that you have no genetic defects?

    in time we may even be able to correct for defects that don't manifest themselves until later in life. in other words we would be able to scan your genome into a computer and be able to tell where the problems are and correct for them shortly after birth.

    for accidents your proposal is a viable one, if people play fair. i'm positive we could enact laws to prevent abuse.
     
  11. Hercules Rockefeller Beatings will continue until morale improves. Moderator

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    I don’t see how/why you are equating an adult with an embryo. They are not the same thing; not even close.

    Yes, exactly. You are using the word “duplicate” whereas I’m using the word “create”, but we are both referring to the same thing. An embryo is being duplicated/created/made/formed/produced (or whatever other verb you care to use) by fusing a donor cell with an enucleated ovum.

    Cellular therapy doesn’t necessarily cure a genetic disease. That will only occur if (i) the genetic defect is somehow ‘repaired’ in the introduced cloned cells, and (ii) the genetic defect in the remaining endogenous cells in the tissue/organ in question is not going to cause the disease to reoccur within the lifetime of the patient.

    This is a reality when it comes to bone marrow transplants – use radiation to destroy all the bone marrow cells carrying the genetic defect, then repopulate the marrow with patient-derived stem cells that have had the defect “repaired”. But this is the only tissue that is amenable to this sort of treatment.

    Neither do I. Many people don’t, but many other people do.

    Umbilical cord blood is a source of haematopoietic stem cells. HSCs produce all the blood cell lineages. So this is fine if you want to treat genetic defects involving blood cells and the immune system, but no use for any other genetic disease affecting other tissues. There have been some indications that HSCs can be differentiated into other lineages, such as neural cells and heart cells. Some animal model experiments have been performed where HSCs introduced into rodent brains have seemingly produced neurons. But there are many problems with these experiments and this is a long way from becoming applicable to human therapeutics, if ever.

    Possibly. But I think you are vastly underestimating the complexity of the interaction of genes with environment. There are all sorts of alleles that predispose to all sorts of diseases. That doesn’t mean that you end up developing the disease. Of all the conditions and diseases that are known to medical science, only a small percentage are definitively linked to specific genes that confer a 100% chance of contracting the disease.

    And how do you propose to correct a genetic defect in all the cells of a new-born baby? At the moment this is sci-fi. But you did say “in time…” and who knows what technologies the future will bring?

    No, therapeutic cloning to produce patient-matched ES cells (or the new prospective application of iPS cells) is potentially applicable to all sorts of congenital degenerative disease, not just acute damage from an accident.
     
  12. leopold Valued Senior Member

    Messages:
    17,455
    not physically no, but genetically they are identical.
    bad choice of words on my part. maybe i should have said entity.

    the point i was trying to make is that your parents "created" the first embryo, the second is merely a copy, a clone.
     

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