Discussion of all aspects of cellular structure, physiology and communication.
<Copyright: Kyle Wendley 200
This may be posted elsewhere with permission. Contact at wendleykk[AT]vcu[DOT]edu>
Stem Cells: The Miracle Cure
Stem cells are a large focus of study in today’s biomedical world. They are cells that exist in an undifferentiated state, and transform into differing tissue types depending on what the cells surrounding them are. The different types of stem cells have the ability to repair many classes of damaged human tissue. However, only one type of stem cell promises to regenerate virtually any class of tissue. This is the highly controversial embryonic stem cell (ESC). Unfortunately, there is a dark side to the ESC. To obtain these cells from embryos will ultimately kill it. By definition, the acquisition of the ESC includes performing an abortion. This has created a great stir in the public world, where abortion is such a hot topic that politicians are hesitant to take either side. The embryonic stem cell is today’s Pandora’s Box. With this option now available in the medical world, everyone involved with this topic must make a difficult ethical decision: whether or not saving existing life is worth the termination of potential future life. As expected, there are two sides to the stem cell argument. One side is all in favor of their use, and the other side is dead-set against it. Stem cells come at a high price, yet this price is well worth the saved lives they can offer.
In order to develop an opinion on whether or not stem cells should be used, one first must understand what they are and how they are used. Simply stated, the definition of a stem cell is an undifferentiated cell, meaning that it has no true function yet. However, all of the genes within a human stem cell have the potential to become other types of cells. The triggering mechanism for this is for the stem cells to be placed among specialized cells. Specialized cells include skin cells, muscle cells, or any other type of cell that has a specific function in the body. One of the most popular examples—and one of the most effective—is the neuron example. This was originally discovered at the University of Madison at Wisconsin in 1997. In the disease Multiple Scleroses, the myelin sheath protecting the neuron is missing. In the absence of myelin to protect the neuron, pain is a constant sensation. Researchers at UMW gathered a group of mice, which were genetically deficient of myelin. When the undifferentiated embryonic cells were implanted into their spines, the cells were able to sense that the myelin producing cells were deficient and morphologically changed into replacement myelin cells. Immediately, these new cells began coating the spinal chord with myelin (Embryonic). Effectively, the mice were cured. Soon, other scientists found they were able to repeat this phenomenon in other laboratories around the world.
Multiple Sclerosis is not the only disease that scientists have the ability to cure. In some isolated cases, juvenile diabetes has been added to the list of cured diseases (Goldstein n.p.). This, however, is not the only disease scientists believe they will be able to cure. Stem cells show promise to have the ability to cure diseases including but not limited to Alzheimer’s Disease, Lou Gherig’s Disease, Hodgkin’s Disease, and nearly every form of cancer. With research allowing the discovery of cures to an ever-growing list of diseases, many scientists are devoting much of their time to push for more support from the people as well as the government to continue their research. The medical world has also stepped in to petition for support. Scientists and doctors alike understand the potential of stem cells, and the number of lives they can save, although, they also understand the necessity of the people’s support. Until Americans understand the vast potential of stem cells, these scientists and doctors will continue to perform their research and medical procedures without drawing undue attention to their activities. However, they strongly believe in what they are doing, and refuse to stop saving lives.
Doctor Larry Goldstein, a professor of cellular and molecular biology at the University of California in San Diego explained, when interviewed by NPR’s Joe Palca, the possible benefits of the use of ESC’s. He answered calls from listeners to try to spread awareness of stem cells. One unique part to his lecture is that he warns that stem cells are very specific. They can only be used in a patient from specific embryos, very similar to organ transplant, although slightly less specific. To counterbalance this pessimistic point is his optimistic outlook on juvenile diabetes. He portrays the use of the ESC in the pancreas of a patient with juvenile diabetes as the new wonder drug. A select few patients have already been treated with stem cells and have been completely cured of the disease. This is a great improvement over the standard pancreatic transplants that doctors have performed in previous patients. Three pancreases are required for a standard pancreatic transplant in the medical world (Goldstein). The use of stem cells makes more sense than harvesting pancreases from multiple corpses. Using one batch of stem cells makes much more sense than simply waiting for three donors to die.
After reviewing these facts, one can make the conclusion that the use of stem cells is the wonder drug of the century, one that will cure all diseases. While this might appear to be the case, there is one piece left out of the above description. Stem cells are derived from a developing embryo or fetus. There is no other place to find completely undifferentiated cells than in an undeveloped human. Unfortunately, a developing human needs those cells; the process of removing them kills the unborn child. In effect, an abortion is performed whenever stem cells are obtained. This has caused an outcry from pro-life activists. The moral argument is that scientists are killing fetuses to improve the medical condition of living patients. They say that using stem cells in this manner is exactly the same thing as using fetuses to farm body parts. John Kass, a speaker against the use of stem cells, uses this argument, and even takes it further. He says that even in the case of aborted tissue, the tissue is still a human being and it is technically an abortion to use the tissue to repair damage in others’ bodies. He goes even further, stating that the idea of stem cells saving lives originated from the baby-boomer population consisting of people who were too afraid to die, and relates this to the “body harvesting” frequently seen in science fiction movies (106-10). However, this argument is vastly flawed. While it might be true that the doctors who discovered the potential use of stem cells originate from the baby-boomers, the reason they push for the use of stem cells is because they are doctors. They took an oath to save the lives of their patients, and stem cell therapy is one way to do so. Addressing his “destruction of life” argument, whenever a woman has an abortion, the fetus or embryo is thrown out, using aborted tissue to form cells lost in otherwise incurable diseases and injuries is possibly the best thing to do for both the unused stem cells and the patient. Instead of incinerating aborted tissues, there is no reason that doctors should not be able to use them to save existing life.
Because of the close connection stem cells have to abortion, the government has had a difficult time deciding whether scientists should perform research on them. Abortion is one of the most sensitive topics in the United States today. The argument against abortion has understandably been that the action kills living human beings. Currently, as interpreted by the United States Supreme Court, a result of the decision cast by Roe v. Wade, abortions are legal in a woman’s first two trimesters without motive, and in the third trimester if an apparent threat to the health of the mother can be proven (United 148-55). Many speculate that Roe v. Wade will be overturned within the next fifty years, and possibly sooner. The laws may be changed to allow abortions completely, or to forbid them completely. Stem cells will definitely play a part in this decision. It is possible that the action of using fetuses to save lives can make abortions seem less evil. To terminate one life to save others is a decision that the world must make, and not make lightly. Naturally, this is an ethical decision. However, it is not as difficult as some might think. Using stem cells from one fetus has the potential to save many lives. It is more ethical to terminate one undeveloped life by obtaining stem cells than it is to throw away many lives that are already productive members of society that just happen to have a life-threatening disease. With luck, the great scientists of today will be able to convince the courts of this fact, and will gain full support to let the doctors perform their jobs of saving lives.
With the heated debate over stem cells, rarely do scientists obtain them in the old-fashioned way. Originally, stem cells were obtained by fertilizing an egg in a Petri dish and allowing them to grow. Opposition to stem cell research included accusing scientists of aborting the tissue for the sole purpose of performing the research. Recently, scientists have looked to other sources of stem cells. When in-vitro fertilization is done, sperm and eggs are combined in a Petri dish outside the womb. Embryos are grown, and a certain number are implanted into the woman’s body in the hopes that one will develop. However, oftentimes, too many embryos actually do develop, and not all are implanted. These are frozen and stored instead of being destroyed. Very few of these will ever be used. It has been proposed that instead of aborting embryos created for the sole purpose of making stem cells, that scientists use these frozen embryos, which were created for other reasons, but have no other foreseeable use. With these embryos, many lines of stem cells could be cultured for both research and applied therapy (Lo n.p.). Controversy has developed here because many see this action of using a stored embryo to obtain stem cells as essentially an abortion. However, it is also an abortion to destroy these frozen embryos as will eventually happen to them. Even those who are using the abortion argument against stem cells must understand that if something this “evil” is going to happen no matter what happens, then at least if stem cells are harvested, then something good will come out of it.
With debates rising over whether or not this is acceptable, the federal government was forced to step in. Currently, federal laws have permitted stem cells to be developed under the condition that the biological parents of the embryos sign waivers to allow this to take place (Lo n.p.). This compromise has currently kept the majority of the protesters happy. Those who view stem cell research as evil can forbid their own cells from being used. Unfortunately, it will not take long for people to realize that those who sign waivers are allowing what pro-life activists believe are abortions to take place. When this happens, those who speak out against mothers who have abortions will begin speaking out against those who have in vitro fertilization done. The only difference is that they will not be able to obtain the information on who is signing the waivers. The same thing will happen at these clinics are happening at AIDS clinics. There are those who stand outside of AIDS clinics to harass patients walking in because they believe AIDS is a disease that can only be contracted through unprotected sex. Unfortunately, they also do not know why these people are going in. Sometimes, people contract AIDS for reasons other than fornication. However, people like these are close-minded, and do not understand this. It is probable that these people will also think the same thing about parents walking into clinics that perform in-vitro fertilization. Those who request in-vitro fertilization as well as being against the abortion of their unused embryos could potentially be misunderstood by protestors and attacked just as the innocent people walking into AIDS clinics are.
With hope, now the reader understands the argument against in-vitro derived stem cells. It is a prudent time to attack the argument. Chen Wang, a protagonist of stem cell research, describes scientists who were able to form several lines of stem cells. These were obtained from the center of blastocysts, which are the beginning of the human embryo. The origins of these ESC’s were the result of in-vitro fertilization (Wang n.p.). However, sperm and ova before fertilization have the status of any somatic (non-sperm, non-ova) cell in the body. It is known that humans rid their bodies of their excess sperm and ova on a regular basis. Those against the use of stem cells do not protest these discarded cells. However, when these two cells, habitually destroyed, are combined, they form a zygote, and receive protection from anti-abortion activists. Regardless of whether this zygote is an entity or not, a zygote and resulting cells from mitosis (cell division) are simply cells. In fact, a human zygote, fetus, and even embryo are indistinguishable from any other developing chordate animal. This is not the “body harvesting” that Mr. Kass claims it to be. In addition, the opposition to this has failed to note one of the greatest parts of the stem cells created in Wang’s report. These are lines of stem cells. Stem cell lines are cultures of stem cells that can be divided for more to be grown. An infinite number of stem cells can be the result of one culture. The lines created by the University of Madison at Wisconsin are still in existence today.
There is yet another source for embryonic stem cells that has been overlooked by the public, and with this new source is a point of view that puts the acquisition of stem cells into perspective. The President’s Council on Bioethics has estimated that up to 80% of unassisted pregnancies in America have resulted in miscarriage. These miscarriages nearly always occur while in the embryonic stage. These embryos died due to natural causes. However, their tissue still lives, and included in that tissue are stem cells. In a bit of sarcasm, the Council stated:
The Council understands that miscarriages happen. The superficial idea is that whenever an abortion occurs, the embryo should be harvested for use in curing living patients. However, the underlying message, which surfaces at the end, is that if nature kills one in four embryos, there is no reason that humans should not be able to do the same.
There are even examples of those against abortion that understand the ethics of stem cells. Gorka Orive and her fellow scientists state steadfastly that destroying a human embryo is the destruction of life. However, they argue the moral grounds that the benefit to using stem cells outweighs the inhumanities of destroying embryos. “The greatest good for the greatest number of people” is a basis for today’s medical ethics. If the use of stem cells is immoral in the first place, but these are used to benefit the greater good, the question must be asked whether they should be used. Orive believes this is so. One potential benefit is that if future tests go as predicted, the use of stem cell line could be used to provide regenerative tissue therapy for a near-unlimited number of people. One line for each “stem cell type”—similar to the eight different blood types—could be established to form this source (Orive n.p.). While roughly a hundred individuals might never exist to create the base supply of stem cells, the number that could be saved is limitless. Regardless of what moral grounds one follows, a hundred to infinite unborn life termination to lives saved ratio is more than acceptable. Fewer individuals would die if a hundred or so entities were restricted from becoming human beings. According to this practice, these entities would never die in the first place. They would never live as an individual, but they would live on in the patients they healed, as well as living immortally in their undifferentiated state in the Petri dish. These organisms would still exist, simply in a cellular, asexual form.
President George W. Bush made an attempt that has only slightly worked. He has allowed a small amount of federal funding for stem cell lines produced before 9 April 2001 (Thompson n.p.). This compromise temporarily reduced petitions for a short time. Scientists had stem cells to work with and learn from, and no more fetuses were being destroyed (Goldstein n.p.). Unfortunately, these cells were fed by mice feeder-cells. Scientists worked with these to learn as much as they possibly could. This kept their requests for funding for new stem cell lines to a minimum until recently. Today, scientists have learned all they could about these cells, and now require pure lines for study. The federal government has decided to withhold funding for any new stem cell lines, although it has no power to restrict the creation of these lines. This lack of federal funding has severely limited the scientific world’s ability to procure new cell lines. In effect, the federal government is working to destroy the medical world’s most promising ability to save lives. Stem cells are needed to save existing lives in the world, and the federal government, regardless of its beliefs has no right to prevent this from happening.
The President’s Council on Bioethics recently released a report they composed while monitoring stem cell research. The Council addresses and explains in detail both sides of the argument. However, it makes no definite assertion on which way the country should go on the issue. While there are a few parts that strongly defend stem cells, the Council wishes the people to decide. One of the more open-ended descriptions is as follows: “…the developing human organism might become deserving of protection as it becomes able to feel pain, or to exhibit neural activity, or rudimentary self-awareness, or some elements of the human form, or the capacity to function independently, or as it progressively exhibits more and more of these criteria.” With the word might inserted into the text, the Council asks each person to make his or her own conclusion. While in the embryo stage of the gestation period, it is nearly impossible to distinguish the human embryo from even that of a fish. Only size is different. Only in the fetus stage does the developing organism begin to show speciation into the final form. If there is no difference between human and non-human embryos, there are essentially no human qualities to the developing organism. The only difference would be genetic material…a mere chemical in the first place. Therefore, while in the embryo stage, a stage where not one part of the criteria listed by the Council applies, the developing human is not quite human yet. If it is not human, then there is no reason why it cannot be used to save a life.
With the heavy resistance in America against stem cells, the country runs the risk of losing its long-held claim to have the most superior medicine. In Great Britain, the Ministry of Health has publicly—as well as monetarily—endorsed and allowed the study of all embryonic stem cell. With the rest of Europe following the lead of America and moving more toward restricting stem cells, Great Britain has a good chance of becoming the world’s leader in medicine (Orive). America has led the way in modern medicine for several decades. The entire country stands to lose this superiority simply because the government allows a few protesters to hold modern medicine back. Should stem cells become a mainstream practice in Great Britain, then Americans that require stem cell therapy to live will be forced to travel for this. Not only is this a grave inconvenience, it is expensive, and it would be strengthening the British economy instead of America’s.
In an attempt to avoid the heat from those fighting the embryonic stem cell, scientists have looked for other sources of stem cells. After years of research, they discovered the adult stem cell. These are stem cells not derived from an embryo, and thus not even flawed arguments can be made against them. The most common adult stem cell is the blood stem cell. Trigg, a medical doctor involved in doing the research, has termed these hematopoietic stem cells. These stem cells are found in the bone marrow and spleen, and are normally used in the germination of new blood cells, both red and white. Red cells are used in the distribution of food, oxygen, and waste throughout the body. White blood cells come in various forms, and are all used for immunity from pathogens (harmful microscopic particles and organisms that include bacteria and viruses). Unfortunately, there are very few hematopoietic stem cells in an adult’s bone marrow. Approximately one in one hundred thousand bone marrow cells are actually stem cells. Other sources of adult stem cells include those of the umbilical cord at birth. But all of these cells are very limited in what they can do. They can only reliably form blood cells. Scientists have found that they can repair minor tissue damage with them (Trigg 1051-2). For example, if the heart muscle is damaged, hematopoietic stem cells can be implanted. These cells will specialize to take the structure of their surrounding cells. However, these cells do not perform the intended function of the muscle cell. They can only be used as “gap fillers” in the tissue. Another added drawback to these adult stem cells is that they do not store well in culture. Not completely undifferentiated, they require being in an environment that they were designed to work with. They can only replicate themselves about ten times before dying off completely. Only the embryonic stem cell can make tissue other than blood cells as well as survive outside the body. While they have their use, the adult hematopoietic stem cell can only be used in very specific applications.
This does not mean to say that hematopoietic are useless and cannot be used. Dr. Michael E. Trigg is a pediatrician who has been working with the applications of stem cells in children. Severe aplastic anemia, a malady found most commonly in children, is a disease where the patient has a dangerously low blood cell count. Bruising and bleeding result too few platelets being present. Using stem cell therapy shows promise to cure severe aplastic anemia completely. The stem cells are directly implanted into the bone marrow where they replenish or even repair the damaged hematopoietic cells (Trigg 1051). Stem cell therapy in children shows a large amount of promise with very little risk. While this procedure is always held as a last resort, children who undergo this therapy are usually expected to make a full recovery. Useful in a small amount of diseases, and more effective in humans, the adult stem cell shows great potential and should continue be explored by the scientific and medical community.
Hematopoietic stem cells are not the only type of adult stem cell, however. There is a form of stem cell called the neurogenic multipotent progenitors. They are involved in the formation of new nervous tissue within the brain itself. There are two places where these can be found. The first place is the hippocampus, a region involved in temporary storage for long-term memory. This is an important region to be kept in perfect working condition, as it takes days to weeks to consolidate the memory enough to store it away permanently. The second place is in the olfactory bulb. For an unknown reason, the human body has seen fit to evolve the region of the brain that controls smell to be extremely regenerative (while the reason for this is unknown, it explains how smell is the strongest sense tied to memory) (Wang n.p.). These neurogenic multipotent progenitors, like the hematopoietic stem cells, are severely limited in the types of neurons they are able to become. They are scarce when in the body, and do not multiply well in the Petri dish. Embryonic stem cells are still the best promise scientists can offer to cure disease and repair damage.
There is an optimistic side to the adult stem cell, however. Another type of stem cell found in the bone marrow was discovered. They are more abundant than the hematopoietic, but are closely linked to the bone marrow, making them as specific as marrow transplant matches. These cells are called mesenchymal stem cells. They are primarily used to create more bone marrow, but have the ability to transform into the “scaffolding” cells of most types of tissue. This is very useful in repairing damaged cartilage, damage usually resulting from the effects of arthritis (Embryonic n.p.). While the specificity of these stem cells may make them appear to be nearly useless, this is not completely true. Since they are abundant in the body, they can be harvested from the body to be placed elsewhere. A patient with juvenile arthritis could be cured by simply using stem cells from their own body and implanting them into the degrading joints. While they are limited, mesenchymal stem cells are much more useful than any other form of adult stem cell. The embryonic stem cell would be able to perform the same task more efficiently. However, the controversial issues do not apply, and potentially could be very helpful in showing the people how beneficial stem cells can be.
Stem cell research is unavoidable if the medical world wishes to be able to repair damage within the human body. While it is true that obtaining stem cells destroys life, the benefit to the greater good greatly outweighs the destruction of potential life resulting from a fertilized egg. With an infinite supply of stem cells from just a few lines, all defective tissues can be replaced. Those working in the medical world can greatly improve the quality of human life. With stem cells used in general practice in hospitals, people will live longer, healthier, lives. Many diseases would be completely eradicated, and injuries would cease to be crippling to so many people. However, only when scientists and doctors fully understand how to implement the embryonic stem cell, can all this happen. With funding and support for just a handful more stem cell lines, the medical world could be supplied with an infinite number of stem cells to cure patients. When doctors have all of the lines they need, then they can cease destroying embryos to obtain the stem cells they require. The biological world and the field of stem cells specifically, require the support of the federal government as well as the people to make this possible.[/i]
Last edited by biostudent84 on Mon Jan 10, 2005 4:59 am, edited 1 time in total.
You write very well. As I was reading your paper, I noticed the statements about the human embryo being virtually identical to others even fish until it is considered a fetus. This brought to my mind a question. Why can't stem cells from other creatures be used to study how cells differentiate into the varieties necessary to form a viable new being. Surely it works in the same manner for all mammals? This is a serious question on my part. I am not trying to start a fight or anything like that. I just like to talk about scientific possibilities. Have a nice day. Sandra
When blood is transplanted, two different blood types MUST match...the ABO and the RH types. When an organ is transplanted, 14 different blood types MUST match...please don't ask me to list all 14...
Implanting stem cells have a specificity similar to that organs require. Not just any ESM can be implanted into just any patient. Protein markers must match, or the culture will be rejected.
I do not mind at all! I love it when I am forced to defend my own work...lets me know just how much I know about my topic, and where my knolwege needs to improve.
Thanks for the input!
A nice topic you have done.
Let me know something concerned with this.
From a undifferentiated stem cells to an mature organs or mature differentiated cells, there may need to stimulate specific metabolic pathways.
All these pathways known?
If it is wrong, guide me to the truth.
The second i want to know is that ABO and RH systems of blood is important in blood transfusing.
One thing i've heard of is that there is 'artificial blood' without these antigens on the surface and so it can be transfused to anyone.
Is that in use now?
Same answer for both questions: If there is, I haven't heard of them.
How exactly a cell knows when to and how to specialize is a mystery. Different genes becoming dormant or active is a process we do not yet understand.
Af for ABO and RH protein markers, I thought they were used by the cell for self/non-self recognition. If so, then an exact match is needed, or the body's leukocytes will destroy them.
If there is no protein marker (only for determining self and non-self) on the surface of the cell, how can the immune cells know the foreign cells.
If so, there will be no immune response or no rejection.
But there will be other defects that will harm the body system.
Please tell me what can happen when these markers are lost or whether it is possible or not.
Actually, wired magazine just had a feature article on artificial blood. This stuff has the abilitiy to carry oxygen but that's about it so it's not a long term solution. I believe it's only used in long surgeries.
About blood groups:
In the ABO groups there is one gene with 3 alleles: A, B and nothing (O), each of our chromosome carry one of these alleles. So one belongs to group A if the genotype is AA or AO, to the group B with genotype BB or BO, group AB if AB, and group O if OO.
The rhesus group is Rh+ if you got the marker, Rh- if you don't.
Hence a O Rh- blood has no marker and can be transfused to everyone, and an AB+ individual will accept any kind of blood, having no antibody directed toward any of the markers...
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