Stem cells are cells that can be found within all multi-cellular organisms and which have the ability divide and turn in to an array of specialized cells. In other words, stem cells are blank pieces waiting to be stamped with a purpose. While all human bodies contain stem cells, in some number, the majority within the developed person lie in the bone marrow and in afterbirth and birth-organs, though it is believed that skin cells may someday be used as stem cells. Most adult stem cells, which include those cells removed from juveniles, are of the multipotent brand. Potency is the potential for a stem cell to differentiate into different cell types. Multipotent cells are limited in that they may only differentiate into the cells of a closely related family
28). So adult stem cells derived from muscle
tissue would only be able to differentiate into those cells which are closely
related to the tissue from which they were derived. However pluripotent stem cells have a much
greater potential as they are able to differentiate in to any cell of the three
major germ layers: those being the endoderm, ectoderm, and mesoderm which are
the basis of development in almost all animal groups more complex than worms (Scholer
28). The greatest source, according to most, for
pluripotent stem cells are from the undeveloped fertilized human embryos. These embryos are often obtained from in vitro fertilization clinics due to
their excess or soon expiration and as such are planned to be destroyed anyway. “The embryos from which human embryonic stem
cells are derived are typically four or five days old and are a hollow
microscopic ball of cells called the blastocyst. The blastocyst includes three structures: the
trophoblast, which is the layer of cells that surrounds the blastocoels, a
hollow cavity inside the blastocyst; and the inner cell mass, which is a group
of cells at one end of the blastocoels that develop into the embryo proper” (U.S. DHHS). The inner cell mass is removed to divide in a
culture dish; if successful the dish will fill and the fresh cells will be
divided up to be placed in new dishes for further ‘subculturing’. “The original [few] cells yield millions of
embryonic stem cells” (U.S. DHHS).
The potential uses for stem cells in medicine is virtually limitless today, however there are two that stick out as the most important. A further understanding for the genetic and molecular controls of cell division and differentiation in humans can be generated by the study of stem cell production. Many of the most serious and lifelong diseases, such as cancers and birth defects, are the result of abnormal cell division and differentiation. Better insight into how these diseases arise could lead to new strategies for therapeutics. Cell-based therapies are perhaps the greatest potential application for stem cells: because pluripotent stem cells can adapt to nearly any cell type in the body they have the potential to be used in growing new organs, or in fixing dilapidated ones in the body, and as a ‘renewable source of replacement cells and tissues’ for treating diseases. Among the diseases stem cells are believed to have the potential to aid are nervous system problems such as Alzheimer’s, spinal cord injury, and stroke, burns, heart disease, diabetes, osteaoarthritis, and rheumatoid arthritis
(U.S. DHHS ...potential..).
The greatest obstacle for the scientific and medical community to overcome are in the financial and practical limitations placed by the government, especially in the U.S., rooted in religious and moral outcry. Many opponents of embryonic stem cell research oppose its use because they believe that the use of fertilized eggs is somehow a violation of the sanctity, or value of life. Many of the arguments used against embryonic stem cell research are the same ones that have previously been used in cases of abortion and even in in vitro fertilization at one time. One of the most visible opponents to the research whom often enacts the argument for the value of life is the Roman Catholic Church. While there are many protestant groups joined together in the fight against stem cell research, the Catholic Church has a greater number of parishioners than any other single Christian group in the world. Most Catholics believe that human life begins at conception: that is, when the sperm fertilizes the egg. In 2008 the U.S. Conference of Catholic Bishops issued a treatise on the subject claiming that embryonic research is immoral and unnecessary. The document dismisses the utilitarian argument, restates the conception argument (though in more scientific, less rhetorical method), and dismisses the in vitro model. “If fundamental rights such as the right to life are based on abilities or qualities that can appear or disappear, grow or diminish, and be greater or lesser in different human beings, then there are no inherent human rights, no true human equality, only privileges for the strong”
The arguments against embryonic stem cell research are not merely limited to the religious right, though that is where the majority does lie. Another objection is put forth by those who specialize in the research of adult stem cells. Their belief is that adult stem cells, which can be obtained from sources such as umbilical cord blood, can actually produce better results than stem cells obtained from embryos, and without the negative moral implications. In addition to this their proponents claim that adult stem cells have already produced therapies, while embryonic stem cells have not. Many adult stem cell therapies can actually be made with stem cells harvested from the patient. Among the therapies of adult stem cells are the treatment of leukemia and other bone and blood cancers through the use of bone marrow transplants
(UCSF Children's Hospital). And as recently as 2008 the first transplant
of a human organ grown from adult stem cells was completed in Barcelona on a
Columbian woman and after four months had shown absolutely no signs of
The arguments for the use of embryonic stem cell research are much more varied than those against but can be summarized into four distinct groups: the utilitarian argument, the argument for efficiency, the argument of superiority, and the argument from the beginning of life. The utilitarian argument is simple: embryonic stem cell research could possibly be unethical, however the amount of good that it could potential cause outweighs the few possible violations of morality. Embryos are not human life because they do not have the viability to survive outside of the womb, more than a third of fertilized eggs do not actually implant upon the uterine wall and therefore far more embryos are lost due to this than to research or treatments, and that life does not begin until the development of the heart or brain in the fetus, are all possible utilitarian arguments. The argument for efficiency is primarily an argument related to the mandatory destruction in vitro fertilization embryos; these embryos will be destroyed anyway so why not make use of them for science? (The same thinking can apply for embryos of abortions) The argument of superiority is a claim against the argument that adult stem cells can actually provide more benefit than embryonic. Mostly this argument is based on the fact that there are a greater proportion of embryonic stem cells, they multiply faster, and have a greater, less determined set of uses
controversy). The argument from the beginning of life is
based on the fact that prior to the embryo attaching to the uterine wall at
fourteen days it has the potential to split into two individuals from one egg,
or combine from two eggs into one individual.
Therefore, the argument says that there is only the potential for a person,
but not an actual person (West).
While there is no end in sight for the debates about the uses and morality of embryonic stem cell research, there is a glimmer of light with the recent lifts by President Obama’s administration on the limits for federal funding of stem cell research in America. Further research can only improve the knowledge we have about what makes people tick and how to fix them when they’re broken.
O'Brien, Nancy Frazier. "Embryonic stem-cell research immoral, unnecessary, bishops say." 18 June 2008. American Catholic. 13 December 2009 <http://www.americancatholic.org/NEWS/StemCell/>.
Rose, David. "Claudia Castillo gets windpipe tailor-made from her own stem cells." The Times (London) 19 November 2008.
Scholer, Hans. "The Potential of Stem Cells: An Inventory." Knoepffler, Nikolaus. Humanbiotechnology as Social Challenge. Burlington, VT: Ashgate Publishing, Ltd., 2007. 28.
"Stem Cell controversy." 2010 January 7. Wikipedia. 13 January 2010 <http://en.wikipedia.org/wiki/Stem_cell_controversy#Objection>.
U.S. DHHS. "What are embryonic stem cells?" 20 April 2009. National Institute of Health. 13 December 2009 <http://stemcells.nih.gov/info/basics/basics3.asp>.
—. "What are the potential uses of human stem cells and the obstacles that must be overcome before these potential uses will be realized?" 28 April 2009. National Institute of Health. 13 December 2009 <http://stemcells.nih.gov/info/basics/basics6.asp>.
UCSF Children's Hospital. "Leukemia Treatment Options." 15 October 2009. UCSF Children's Hospital. 13 December 2009 <http://www.ucsfchildrenshospital.org/treatments/leukemia_treatment_options/index.html>.
West, Michael D. "Embryonic stem cell research is ethical." The Ethics of Genetic Engineering. USA: Thomson Gale, 2005. 100-107.
This article originally written January 13th, 2010 for OU HSCI 3423 - History of Medicine.
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