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Thread: Embryonic versus Adult Stem Cells and other spinal cord injury therapies

  1. #1

    Embryonic versus Adult Stem Cells and other spinal cord injury therapies

    Znop asked if I would start a discussion concerning embryonic and adult stem cells. I said that I would start with a summary and hope that others will contribute to the discussion. ]\

    Before we begin the discussion, it is important that we define the terms because there is so much misunderstanding and misuse of the terms:
    1. Stem cells. These are cells that can make many different kinds of cells, as well as themselves. There are many types of stem cells
      1. Embryonic stem cells. These are cells that are derived from blastocysts, a very early stage of development that occurs during the first two weeks after fertilization. A blastocyst is a small ball that contains about 200-300 stem cells. The blastocyst is pre-embryonic. A developing fertilized egg becomes an "embyro" only after a midline appears. This usually occurs shortly after implantation of the egg into the uterus and a "primitive streak" develops. So, the term "embryonic stem cells" is a misnomer. They should be called "pre-embryonic stem cells".
      2. Fetal stem cells. These are cells that are derived from fetuses. A fetus refers to the stage of development when body parts are evident, including a head, arms, and legs, usually starting 6 weeks after conception and continuing until birth. Many types of stem cells are present in fetuses, associated with the various organs of the body that are developing. These include:
        • Fetal neural stem cells. These are obtained from the developing brain.
        • Fetal bone marrow stem cells. These are obtained from developing bone.
        • Fetal stem cells isolated from various tissues, including skin, blood, bone, etc.
      3. Neonatal stem cells. These are cells that are derived from cells collected from newborns. These include:
        • Umbilical cord blood stem cells. These are obtained from umbilical cord blood collected from the umbilical cord shortly after birth.
        • Umbilical cord and placental stem cells. These are obtained from the umbilical cord and placenta shortly after birth.
      4. Adult stem cells. These are cells that are derived from cells collected from any person older than newborn, from several days to elderly. They include:
        • Bone marrow stem cells. These are cells obtained from bone marrow, usually autologous or from the same person that will receive the transplant. Although the markers for bone marrow stem cells are well defined in humans, many investigators use CD34+ which is a maker for hematopoietic stem cells (i.e. stem cells that make blood cells). Please note that we did not know that there were pluripotent stem cells in bone marrow until 1999.
        • Mesenchymal stem cells. These are cells collected from a variety of tissues, including peripheral blood. There are some markers, such as CD144+ but the markers are controversial. Tuli, et al. (2003) for example reports that mesenchymal derived from human trabecular bone are CD73(+), STRO-1(+), CD105(+), CD34(-), CD45(-), CD144(-) while Mayer (2004)]Mayer (2004)[/url] suggests that bone cells are CD13+, CD44+, CD90+, CD147+, CD14-, CD34-, CD45- and CD144- in elderly women, Mitchell, et al. (2006) suggests that such cells obtained from adipose (fat) tissues are CD13, CD29, CD44, CD63, CD73, CD90, CD166 are initially low but increase progressively with passage. Kuwana, et al. (2006) report that human monocyte derived multipotential cells are expressed CD31, CD144, vascular endothelial growth factor (VEGF) type 1 and 2 receptors, Tie-2, von Willebrand factor (vWF), endothelial nitric oxide synthase, and CD146, but CD14/CD45 expression was markedly down-regulated.
        • Neural stem cells. We have only known since the mid-1990's that there are neural stem cells in adult brain that continue to make neurons throughout adult life.
        • Enteric glia. These are stem cells from the gut. Although known for a long time to be able to produce neurons, these cells are now believed to be a type of stem cell or a neuroprogenitor cell.
    2. Progenitor cells. These are cells that make several different kinds of cells but are usually more limited than stem cells and may not be able to make themselves. The difference between progenitor and stem cells is not clear and may become moot as if becomes clear that it is possible to "dedifferentiate" cells to become stem cells.
    3. Precursor cells. These are even more limited than progenitor cells and make only a few types of cells and cannot make themselves. These are further down the differentiation path from progenitor cells.


    There are several possible goals for using stem cells for treating spinal cord injury.
    1. Bridging the gap. The injury site is frequently a "bombed out" tissue that has lost many cells and is filled with macrophages and other inflammatory cells in the weeks that follow injury. In the months and years after injury, it may be taken over by reactive glial cells that may express substances that repel axonal growth. One of the goals of spinal cord injury repair is to fill this site with cells that are conducive to axonal growth.
    2. Growth factors. Many stem cells and progenitor cells are believed to secrete growth factors that stimulate growth of cells. Many of these factors are also produced by other cells. These include neurotrophins (that stimulate neurons), proliferative factors such as fiberblast growth factor (FGF) and epidermal growth factor (EGF), survival and protective factors such as glial-derived neurotrophic factor, insulin-like growth factor (IGF), and others.
    3. Remyelinating axons. Injury damages oligodendroglial cells (the cells that provide myelin for axons). Oligodendroglia come from oligodendroglial precursor cells called O2A. These cells may be in short supply or cannot migrate well into the injury to to remyelinate axons. Note that regenerated axons are "naked" and need to be remyelinated in order to conduct efficiently.
    4. Replacing neurons. Neurons may be lost, particularly when the injury is close to the lumbar enlargement where the neurons from the legs are present or in the cervical enlargement where the neurons for the arms are located. The sacral tip of the spinal cord or conus contain neurons that innervate the bladder, anal sphincter, and other important functions.


    Tissue niches for stem cells. As investigators gain more experience with stem cell transplants, it is becoming clear that many tissues don't have the factors that tell a stem cell what to do, what kind of cells to produce. In adult tissues, stem cells must interact with other cells, sometimes called a "niche" in order to produce other kinds of cells. This may be a very important regulator of stem cells so that they do not produce the wrong type or wrong number of cells. For example, it would not be good if bone marrow stem cells produced blood cells in the spinal cord. In general, many investigators attempt to differentiate stem cells in culture before transplantation so that they will produce the right type of cells. For example, one can differentiate embryonic stem cells by treating them with a factor called retinoic acid which pushes them to differentiate towards neural stem cells and then using factors such as sonic hedghog (SHH) to differentiate the cells further to become neurons. These approaches have worked to produce neurons in the brain and motoneurons in the spinal cord.

    Neural stem cells. During development, the stem cells of the central nervous system are radial glial cells. These are very specialized looking cells that have[ur long processes that go all the way from the ventricles to the surface of the brain. These cells disappear with maturation and are absent from adult brain. However, certain populations of cells that look like glial cells (astrocytes) remain in certain areas of the brain (such as the subventricular zone or SVC) and these cells migrate to various parts of the brain and can make new neurons in the hippoaompus and the olfactory bulb. While stem cells are believed to be present in the spinal cord and several investigators have successfully isolated cells from the spinal cord that behave like stem cells, it is not clear what form these cells are in the spinal cord itself. One possibility is that they are microglia (the small non-descript cells that are activated by injury to produce large numbers of macrophages. Astrocytes also can be transformed by injury and can produce additional astrocytes. The oligodendroglial precursor O2A cells make oligodendroglial cells.

    Stem cells versus differentiated cell transplants. Most of cells transplanted into the spinal cord in animal studies and human clinical trials are not stem cells and, even if they are, it is not clear that they are performing as stem cells. For example, olfactory ensheathing glia are not stem cells. Likewise, while nasal mucosa may contain some stem cells, it is not clear transplanted nasal mucosa are producing neurons in the spinal cord after transplantation. The only exception has been embryonic stem cells. These cells appear to behave like stem ells when transplanted into the spinal cord, producing some neurons, astrocytes, and oligodendroglia. To date, neither adult bone marrow nor umbilical cord blood cells have been reported to produce neurons or glia in the spinal cord after transplantation. In fact, most umbilical cord blood and bone marrow cells simply remain undifferentiated when they are transplanted into the spinal cord. While they may proliferate (i.e. produce additional cells), it seems that they produce more of themselves and not necessarily neurons, astrocytes, or oligodendroglia. However, they may stimulate endogenous cells to remyelinate the spinal cord axons.

    Drug stimulation of stem cells. Some drugs seem to stimulate certain cells to produce more growth factors. For example, lithium seems to do this and this may be one of the reasons for the beneficial effects of lithium when used to treat depression. Lithium has been reported to stimulate bone marrow cells to grow. Erythropoeitin is known to stimulate bone marrow stem cells. Several bone marrow stimulation factors are known to stimulate bone marrow cell prolieration and differentiation. This approach may enhance the neuroregenerative and remyelinative effects of bone marrow and umbilical cord blood cells. This is one of the reasons why we are interested in assessing the effects of lithium on spinal cords that have been transplanted with umbilical cord blood mononuclear cells. Mononuclear cells presumably include mesenchymal stem cells. There is also substantial interest in the effects of lithium on neural stem cells because this is one of the theories as to why lithium is beneficial as a treatment of manic depression. It would be of interest to see if lithium stimulates transplanted bone marrow cells as well.

    Many therapies regenerate the spinal cord without stem cells. Marie Filbin and her colleague have reported that increased cAMP levels inside neurons will allow axons to grow despite the presence of growth inhibitors. Thus, there was a great deal of excitement when Mary Bunge and colleagues at the Miami Project showed that treatment with rolipram and dibutyryl cAMP and Schwann cells (a source of growth factors and a cell that supports axonal growth) allowed large numbers of axons to grow across the contusion site of injured spinal cords, associated with improved functional recovery. Schwann cells are not stem cells. Likewise, olfactory ensheathing glial cells are not stem cells.

    Embryonic stem cells need to be combined with other therapies. Douglas Kerr and colleagues has shown that human embryonic stem cells transplanted to the spinal cord will not only survive and produce motoneurons but, when stimulated with rolipram and dibutyryl cAMP, send axons out of the spinal cord to re-innervate muscle. So far, only embryonic stem cells have been shown to do this. But, it is important to note that embryonic stem cells alone cannot do this. They must be pre-differentiated and combined with other therapies in order to achieve the objective of replacing neurons for these neurons to regenerate and reconnect with muscle.

    Stem cells must be differentiated before they are transplanted. Much evidence suggest that it is important to differentiate the stem cells before they are transplanted. In the case of embryonic stem cells, it is necessary to differentiate them or else they may produce inappropriate types and numbers of cells in the spinal cord. Note that it is not necessary for embryonic stem cells to become cancers (i.e. cells that have lost their growth control). All they have to do is produce the wrong number and types of cells. For example, it would not be good if embryonic stem cells produced fibroblasts (skin cells) or hair cells in the spinal cord. To avoid this, most investigators pre-differentiate embryonic stem cells before they transplant them into the spinal cord. Thus, what is being transplanted are not stem cells but rather progenitor or even precursor cells that produce astrocytes, oligodendroglia, or neurons in the spinal cord. In fact, Steven Davies and his colleagues recently reported that it is helpful to differentiate fetal neural stem cells into a particular kind of astrocyte before transplanting them into the spinal cord, to encourage regeneration.

    Embryonic stem cells are important. Embryonic stem cells are potentially a source of all the cells in the body. They provide the possibility of producing cells rather than having to harvest the specific cells from different organs for transplantation. While this is controversial, I personally believe that we (not our group but scientists in general) someday should be able make many kinds of cell of the body behave like stem cells. However, in order to reach this goal, it is critical that scientists be allowed to study human embryonic stem cells, find out what makes them pluripotent, identify factors that cause them to produce or differentiate into different kinds of cells, and how to regulate them. Why can't this be done in animal cells? There are important differences between animal and human cells. In fact, for reasons that we still don't understand, scientists have had very little success growing rat embryonic stem cells even though we can grow mouse, human, and primate embryonic stem cells. The fact that we cannot grow rat embryonic stem cells should give people an idea how little we understand of the factors that control and sustain embryonic stem cells and that there are species differences that we don't understand.

    Embryonic stem cells alone are not a cure. It is important that people don't expect a cure from just by transplanting human embryonic stem cells into the spinal cord for several reasons. First, there is no reason why embryonic stem cells should or would know what to do when they are plugged into an injured spinal cord. Second, the studies with embryonic stem cell transplants in animal spinal cord injury models have been done shortly after injury and in chronically injured spinal cords. Third, there is the problem of immune rejection of transplanted cells. Although several laboratories have hypothesized that embryonic stem cells are not rejected when transplanted into the spinal cord, this is not the experience of most investigators. That is the reason why there is strong interest in cloning of embryonic stem cells. Fourth, the mechanisms of immune rejection in the central nervous system may be different from immune rejection in other parts of the body.

    Adult stem cells alone are not a cure. Likewise, it is important that people don't expect a cure from just infusing umbilical cord blood cells into people. Many clinics are advertising umbilical cord blood treatments as if umbilical cord blood stem cells injected into the bloodstream will go directly to the spinal cord and start to produce the right types of cells and the right types of growth factors to repair the spinal cord. I am very skeptical of claims that are saying that umbilical cord blood cells are doing this. For the past two years, at the Rutgers Keck Center, we have been transplanting umbilical cord blood cells into the spinal cord and finding that the cells do not produce neurons, astrocytes, or oligodendroglial cells. Yes, when they are transplanted directly into the spinal cord, umbilical cord blood cells do produce growth factors that may be beneficial for the spinal cord. However, when we have injected human or rat neonatal blood cells intravenously into rats after spinal cord injury, we find that few or none of the cells go into the spinal cord, even when we suppress the immune system.

    Stem cells are one of several tools that we should use to repair the spinal cord and stimulate regeneration. Scientists must be allowed to study a diversity of human embryonic stem cells to understand what and how they do what they do. By understanding stem cell biology, we should be able to make any cell behave like a stem cell. After all, a stem cell is just a cell that is expressing certain genes. Also, it is important to understand how the central nervous system recognize "foreign" cells and reject them. If we know the mechanisms, we may be able to trick the spinal cord to accept transplanted cells are "native" to the spinal cord. Finally, we need to know the factors needed to get the cells to do what we would like them to do, to stimulate regeneration, to provide a substrate that is conducive to axonal growth, to replace neurons, and to remyelinate the spinal cord.

    No reason to be discouraged. After reading the above, many may conclude that it will take a long time before treatments become available to restore function to people with spinal cord injury. I don't think so for the following reasons. First, stem cells do provide an important substrate of regeneration in the spinal cord. For regeneration, it may not be necessary for the transplanted cells to stay there forever. For example, once the cells have created a bridge and the axons have grown across, it may not be necessary to keep the bridge. In fact, it might even be a good idea for the bridge to go away. In fact, this may be one reason why stem cell transplants have been relatively safe. Second, stem cells are a very efficient way of delivering growth factors to the spinal cord. I am quite excited by the discovery that umbilical cord blood cells secrete most of the growth factors that are known to stimulate regeneration and remyelination in the spinal cord. Third, although we may not understand the mechanisms, many studies have reported beneficial effects of stem cell transplants to the spinal cord.

    Nogo receptor blockers. Many studies indicating that blockade of axonal growth inhibitors will allow regeneration to occur in the spinal cord. For example, there are phase 1 trials of the Nogo antibody by Novartis and Cethrin (the blocker of Nogo receptor intracellular messenger rho) by Bioaxone. Dozens of studies have shown the beneficial effects of chondroitinase in animal studies. Likewise, Biogen has identify other blockers of the Nogo receptor. These need to be taken to clinical trial. When these are combined with cell transplants and sustained growth factor support, I hope that we will see substantial regeneration in human spinal cords. It is not trivial to get such complicated combination therapy trials tested. We have to develop the clinical trial infrastructure now so that we are ready when the therapies are available to be tested in humans.

    Wise.

  2. #2
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    Wow Dr. wise, I love your enthusiasm & your power in believing going to happen. Of course the multimillion dollar question is when? I know you don't have a crystal ball, everybody is just hoping for sooner than later. Keep up the good work.
    keiffer66

  3. #3
    Quote Originally Posted by Keith
    Wow Dr. wise, I love your enthusiasm & your power in believing going to happen. Of course the multimillion dollar question is when? I know you don't have a crystal ball, everybody is just hoping for sooner than later. Keep up the good work.
    Keith, don't thank me. I am just doing what I can to help. One doesn't need a crystal ball to be able to see the increasing exponential slope of research progress in the field. Techniques to grow human embryonic stem cells were discovered less than a decade ago (1997). In the past ten years, we have gone from just the theoretical possibility of creating neurons from embryonic stem cells to actually being able to do it in culture and using the resulting cells to repair and replace central nervous tissues in animals. As I predicted in 2001, we would make significant progress in stem cell research.

    Unfortunately, progress in applying the human embryonic stem cells to human central nervous system injury has been held back for three reasons. First and foremost, we don't have diverse enough lines of human embryonic stem cell (hESC) to study and particularly to use for clinical tests. Second, funding for such research has been limited. Total NIH funding for all stem cell research has been in the range of $220 million with less than $30 million for human ESC research. Third, we still have not solved the problem of genetically compatible cell transplants. Efforts at cloning human embryonic stem cells have failed to date and was also held back to some extent by the fraudulent activities in South Korea that convinced many scientists to stop working on the cloning problem because they had solved the problem in Korea.

    I am not convinced yet that cloning of human embryonic stem cells will be a feasible approach to creating immune-compatible stem cells that can be applied to large numbers of people. At the present, cloning of embryonic stem cells require successful implementation of two low probability events. The first is the cloning of blastocysts. It may take nuclear transfer of a dozen or more eggs to get one cloned blastocyst. At the present, even the best laboratories around the world have not been able to derive a viable and pluripotent embyronic stem cell line with an efficiency better than 1 cell line per four blastocysts. At the present, this is still quite a labor-intensive approach. Even if we were to assume that the efficiency improves by tenfold over the coming decade, it may take a very skilled technician with the help of good robotics a week or more of effort to create one stem cell line. It is difficult to conceive this process being carried out for millions of people. The cost will be staggering.

    Fortunately, other techniques may become more efficient and economical. For example, i t is known that embryonic stem cells have propensity to fuse with somatic cells. The resultant cells have two nuclei and some of these cells behave like embryonic stem cells. If an efficient method becomes available for inactivating the original nucleus from the embryonic stem cell, allowing the somatic cell nucleus to take over, this will allow the creation of embryonic stem cell-like lines by fusing billions of somatic cells with standardized embryonic stem cells and selection of the appropriate fused cells where the somatic nucleus dominates. This is an exciting possibility that should allow large-scale production of individual embryonic cell lines from millions of individuals.

    An alternative approach is to select embryonic stem cells that have common HLA antigens. HLA antigens are proteins expressed in the surface of the cells that stimulate the immune system to reject the cells. Because some HLA antigens are commonly expressed by many people, it is conceivable that one can make a library of several thousand embryonic stem cell lines that can match 90% of the population. Such a library of the cells can be used to treat millions of people. Of course, additional technology need to be developed to screen the cells for genetic abnormalities and to ensure the quality of the cells. This, however, is something that industry does well and it will allow production of cells for therapeutic purposes.

    As we know, the speed of research depends in part of the amount that is invested into the research. If 100 laboratories worked on a problem, not only is the likelihood of success 100 times greater but the research should progress more rapidly. At the present, with NIh spending only $220 million per year on all stem cell research (adult and embryonic), we don't have enough of the best scientists in the United States working on the problem. When California starts investing >$300 million per year and New Jersey investing $30 million per year in the area, this will more than double the research in the field. Finally, if the Stem Cell Research Enhancement Act (SCREA) of 2006 were to pass, it would allow NIH to fund derivation of human embryonic stem cell lines.

    We need more funding spinal cord injury research. At the present, NIH is spending less than $100 million per year on all spinal cord injury research, including rehabilitation. This is a pitifully small investment considering the importance and difficulty of the research. Achieving regenerative and remyelinative therapies for spinal cord and getting them successfully through clinical trials is much more difficult and challenging than flying to the moon. It is estimated that it take industry over $800 million to move one therapy from discovery to market. At this rate of investment, e.g. $100 million per year spread out over dozens of therapies, progress on any indivdiual treatment will necessarily be slow. Considering that spinal cord injury now costs the country over $10 billion per year, you would think that Congress would be willing to consider investing 10% of this amount or $1 billion per year to develop regenerative and remyeliative therapies. Note that such therapies will be useful not only for spinal cord injury but multiple sclerosis and peripheral nerve diseases.

    Finally, we need a clinical trial infrastructure to test these therapies. I know that this sounds like an old saw to people on these forums but much of the delay in moving therapies from laboratories to clinical trial results from delays in organizing and funding clinical trials. Once set up, clinical trial networks significantly reduce the activation energy barrier for therapies to go into clinical trial. An efficient network can cut years off the average 11.4 years required for treatments to go from discovery to FDA approval. It may still take a number of years for the work to be done but I know that if we don't start now, it will still take the same amount of time 10 years from now.

    Thus, we know what is needed for the cure. It is difficult for me to comprehend why our Congress has failed to understand the above. It is not as if the problem has not been articulated before and told to Congress over and over again. Even after the debate has been won and public opinion polls indicate that majority of American voters strongly support embryonic stem cell research and I know of almost nobody who opposes adult stem cell research, Congress has failed to act on this matter. Perhaps the urgency of the situation has not yet dawned on our political leaders. Many senators and representatives of course "get it" and are pushing hard for stem cell research. What we have to do is make sure that stem cell research doesn't become a political football.

    Wise.
    Last edited by Wise Young; 11-26-2006 at 10:49 AM.

  4. #4

    Stem cells in peripheral blood

    Dr Young, what do you think of stem cells derived from peripheral blood, reportedly CD34 positive? In terms of their use for regenerative therapies. I know a recent Japanese paper, which I´ll try to find an dpost, reported that these cells can differentiate into nervous system cells.
    I would also think that the number of stem cells in peripheral blood must be minimal. How good is the technology for replicating and storing the cells?
    Also, is there a possibility that the Korean fraud might be partial? That there has indeed been a good amount of work that is valid in cloning? What is the inside view?

  5. #5
    Quote Originally Posted by Cripply
    Dr Young, what do you think of stem cells derived from peripheral blood, reportedly CD34 positive? In terms of their use for regenerative therapies. I know a recent Japanese paper, which I´ll try to find an dpost, reported that these cells can differentiate into nervous system cells.
    I would also think that the number of stem cells in peripheral blood must be minimal. How good is the technology for replicating and storing the cells?
    Also, is there a possibility that the Korean fraud might be partial? That there has indeed been a good amount of work that is valid in cloning? What is the inside view?
    Cripply, you have crammed many questions into one short paragraph. Let me try to take each of the questions in turn.
    Peripheral blood does have circulating mesenchymal stem cells. Normally, the number of CD34+ cells is very low. However, these can be increased dramatically by having the blood donors take bone marrow stimulants. This is what they do in many countries when there are no HLA-matched bone marrow or umbilical cord blood available for transplantation. Infusion of peripheral blood from bone marrow stimulated donors can be used to replace bone marrow and many people believe that these cells are mesenchymal stem cells, even though CD34 is not a particularly good marker for such cells.
    There are no reliable marker(s) for mesenchymal stem cells in blood or bone marrow. Neither CD34 or other markers have been shown to be reliable indicators of stem cells. This is the main reason why we are planning to use mononuclear cells (rather than CD34+ or other markers) for our trial. If one selected cells with one marker and expanded them, one may not have pluripotent stem cells.
    Intravascularly administered cells may not engraft in the central nervous system. in the case of bone marrow replacement therapies, it is all right to infuse the umbilical cord blood or peripheral blood cells intravascularly and there is evidence that the cells will engraft in many cases. However, there is no convincing evidence that intravascularly infused cells will engraft in the brain or spinal cord. There has been some controversy about this because early studies suggest that peripheral stem cells will get into and occasionally engraft into the central nervous system.
    The importance of HLA-matching. Cells must be HLA-matched or else they are immune-rejected, particularly if they are injected into the peripheral blood. This is one other reason why I am skeptical about the Beike claims (Shenzhen) that they are getting good results on spinal cord injury from intravascularly or even intrathecally infused umbilical cord blood cells that have been expanded. They are not using HLA-matched cells and I believe that the cells will be rejected, particularly if they are injected into the peripheral blood. If the cells are injected into the spinal cord directly, immune rejection tends to be slower.
    Technology for expanding adult stem cells. It is possible to grow stem cell-like cells from peripheral blood, bone marrow, and umbilical cord blood. However, it is not a slam dunk. For example, we have now been trying for several years to expand umbilical cord blood cells. While it is possible to grow these cells occasionally from peripheral blood, bone marrow, and umbilical cord blood, it is by no means reliable. For example, even under optimal conditions, we were unable to grow stem cell-like cells from umbilical cord blood in 3 out of 4 units of umbilical cord blood or other sources of mesenchymal stem cells. Many companies are trying to do this now and we are workiing with several companies to test the cells that they are growing out.
    Cloning fraud in Korea. After extensive investigation by Seoul National University, there is no evidence that Woo-Suk Hwang had successfully cloned any human embryonic stem cell line. He had of course claimed to have cloned 11 stem cell lines. If he had successfully cloned even one line, I think that the authorities would not have treated him with such disdain. Before he submitted his paper to Science, he had claimed to have lost all the cell lines in an freezer "accident". After exhaustive checks of all the cells contained in all the laboratories and hospitals that his work involved, the investigators were unable to find a single example of a cloned human stem cell line. I think that I would be more optimistic about his approach if there were evidence that even one line was cloned. However, there were no lines at all. That is why I believe that the his whole claim was fraudulent and why I find it hard to believe that this was just a matter of his underlings deceiving him. I wish this weren't so and that he had succeeded.

    Wise.
    Last edited by Wise Young; 11-27-2006 at 04:56 AM.

  6. #6
    Wise, thank you very much for the time and expertise you are sharing here.
    I hope other people post and this thread continues to expand.

  7. #7

    thanks...as always

    I just want to thank you for taking the time to give us such an in depth explanation. I have been continuously checking this site since my accident (6/5/05) and find it extremely helpful. I am absolutely baffled by our government's economics and lack of basic human compassion. The amount of misinformation and contradictory policies burns me up! I know it's not much but I started a myspace site dedicated solely to educating others about SCIs & current research(www.myspace.com/sci_cure). It's my hope that through awareness people will care enough to vote wisely and support research. Knowing that there is a possibility for a cure to be found (before I'm old & grey) keeps me going forward every day <3

    PS- I don't know if you've seen this, but I think it makes for a great introduction into the topic:
    http://www.eurostemcell.org/Outreach/Film/film_eng.htm
    Last edited by tskushi26; 11-26-2006 at 11:47 PM.

  8. #8
    Hi tskushi2;

    Thanks for posting. Your site is outstanding as is the smile in your profile pic. Welcome to CC.

    John
    "Hope is like a road in the country; there was never a road, but when many people walk on it, the road comes into existence." Lin Yutang

  9. #9
    Senior Member Schmeky's Avatar
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    Thus, we know what is needed for the cure. It is difficult for me to comprehend why our Congress has failed to understand the above. It is not as if the problem has not been articulated before and told to Congress over and over again. Even after the debate has been won and public opinion polls indicate that majority of American voters strongly support embryonic stem cell research and I know of almost nobody who opposes adult stem cell research, Congress has failed to act on this matter. Perhaps the urgency of the situation has not yet dawned on our political leaders. Many senators and representatives of course "get it" and are pushing hard for stem cell research. What we have to do is make sure that stem cell research doesn't become a political football.


    Dr. Young,

    It would make sense to have ESC "breakthroughs" in the lab be represented by the scientists involved. How feasible is it to have people like Douglas Kerr and Stephen Davies present their latest research findings to Congress? If you want to shoot down an elephant, you need to muster the best firepower you have available.

    In my opinion, these 2 gentlemen have proven, in the lab at least, that hESC's hold promise. Our generation has to fight to ensure the next generation will not have to suffer this abominable condition.

  10. #10
    Thank you DR Wise for this explanation. I didn't know there were so many different stem cell. I emailed it to my self so I can read it over again so I will be able to explain it to others that think that the cells just come from a fetus.
    Mary
    I want to Rock you Gypsy soul and together we will flow into the Mystic.
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