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Although, it is too early to reach to the final conclusion (as stem cell research is only in the early stages), there is a
growing consensus among researchers that many effective medical treatments can be realized through cloning stem cells. This is
because these cells can be made to replicate specific human tissues. These cells offer the possibility of a renewable source of
replacement cells and tissue to treat a myriad of diseases, conditions, and disabilities including Parkinson's and Alzheimer's
diseases, spinal cord injury, stroke, burns, heart disease, diabetes, osteoarthritis and rheumatoid arthritis. There is almost
no realm of medicine that might not be touched by this innovation.
Stem cells are currently obtained in one of three ways. They can be obtained from tissues within an aborted fetus, from
embryos donated through in vitro fertilization programs, and from adult tissues. However, research on one kind of stem
cell — human embryonic stem cells — has generated much interest and public debate. Pluripotent stem cells
(cells that can develop into many different cell types of the body) are isolated from human embryos that are
a few days old. Pluripotent stem cell lines have also been developed from fetal tissue (older than 8 weeks of development).
Current research projects have obtained stem cells from tissue, which has been removed during terminated pregnancies,
or from embryos produced by in-vitro fertilization clinics. Once isolated, the cells can be grown up in the laboratory
and stored for future use. Each reservoir of cells, derived from a single embryo, is known as a cell line. Copying or
cloning embryos specifically for their stem cells would obtain a more reliable supply.
As science and technology continue to advance, so do ethical viewpoints surrounding these developments. It is important
to educate and explore the issues, scientifically and ethically. Especially in last few years, this topic has gathered
much attention amongst every social group e.g. the NIH has a bioethics special interest group, which maintains a list of
online resources about the ethics of stem cell research. For further details, you can visit their website.
Most controversy concerns the use of stem cells from embryos and fetuses. Congress has banned the use of federal funds
for any research that results in the destruction of human embryos, including research that would improve the accuracy
of prenatal diagnosis of inherited disorders.
A number of ethicists believe that human embryos should not be created or destroyed for the purpose of medical
experimentation. However, most of the stem cell cultures currently in use were derived from embryos leftover from
those created during in vitro fertilization. Normally, more embryos are formed than are implanted into the uterus
of the woman desiring to become pregnant. With the consent of the couple, the excess are usually frozen and will
eventually be destroyed. While forming stem cells from an embryo will destroy that embryo, it would most likely be
destroyed anyway. The stem cells themselves, while still capable of forming many different tissues, cannot form an entire human being.
Stem cells obtained from fetal tissue are obtained from the fetuses of women who have chosen to undergo abortion
and have given consent for the use of the resulting tissue. It is considered unethical for a woman to choose to
undergo an abortion simply because it will give fetal tissue, or to sell the tissue. The use of fetal tissue is
legal in the United States, and there are a number of "banks" for storing samples. Stem cells obtained from fetal
tissue do not have the ability to become a human being .
Why the controversy?
Because stem cells are obtained from destroyed embryos, the concerns are similar to those surrounding abortion.
Most opponents of legal abortions also oppose this research. In addition, the possibility that cell lines could be
developed from cloned embryos raises ethical concerns associated with propriety of human cloning. One of the most
prominent global opponents of this research is the Catholic Church although many individual American Catholics do not
take this view. In fact the official Catholic position is also opposed to in vitro fertilization because it is unnatural
and it results in the production of embryos, which are not used. During President Bush's visit to Europe, the Pope urged
the President not to support funding of this research.
While the potential has always existed, the problem has been that in order to obtain these human ES cells, the embryo is
destroyed during the harvesting procedure. In addition, while ES cells had been obtained and grown successfully in culture
from several mammals, including mice, efforts at producing ES cells from other mammals had failed. Nobody was sure human
ES cells could even be successfully produced until November 1998 when James Thomson from the University of Wisconsin
announced the establishment of five independent human ES cell lines . Geron Corporation funded Thomson's work, so it
did not violate the federal ban on government funds being used for such purposes. But his announcement immediately
opened up a desire by federally funded researchers to use his already established human ES cells.
So, there are many potential problems and uncertainties in both adult and ES cells. While the ethical difficulties are
non-existent for adult stem cells, they may not prove as helpful as ES cells. ES cells have the potential for universal
application, but this may not be realized. As stated earlier, establishing ES cell lines requires destruction of human
embryos. An ethical dilemma is unavoidable.
Whereas adult stem cells can be coaxed into producing the needed cells by proximity to the right tissue, the cues
needed to get ES cells to produce the desired cells is not known yet. Some in the biotech industry estimate that we
may be twenty years away from developing commercially available treatments using ES cells . Clinical trials using
adult stem cells in humans are already under way.
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