Stem cell controversy
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'''Stem cell controversy''' is the ethical debate centered on research involving the creation, usage and destruction of [[human embryonic stem cell]]s. Some opponents of the research argue that this practice is a [[slippery slope]] to [[reproductive cloning]] and fundamentally devalues the worth of a [[human being]]. Contrarily, medical researchers in the field argue that it is necessary to pursue embryonic stem cell research because the resultant technologies could have significant medical potential, and that excess embryos created for [[in vitro fertilisation]] could be donated with consent and used for the research. This in turn, conflicts with opponents in the [[pro-life]] movement, who advocate for the protection of human embryos. The ensuing debate has prompted authorities around the world to seek regulatory frameworks and highlighted the fact that embryonic stem cell research represents a [[social]] and [[ethical]] challenge
== Stem cells ==
{{main|Stem cell}}
Stem cells are cells that are able to differentiate into specialized cell types but also retain the ability to renew themselves through cell division. They were first identified in embryos. In an embryonic [[blastocyst]], stem cells of the inner cell mass proceed to develop into all of the [[tissue (biology)|tissues]] and [[organ (biology)|organs]] of the body. In adults, [[progenitor cells]] and possibly [[multipotent]] [[adult stem cells]] act as a repair system for the body, replenishing more specialized cells. The existence of truly [[pluripotent]] stem cells in adult human beings is still scientifically [[controversy|controversial]].
===Therapies===
{{main|Stem cell treatments}}
Since stem cells have the potential to be differentiated into basically any type of cell, they offer promise in the development of medical treatments for a wide range of conditions. These include damage to the brain, spinal cord, skeletal muscles and the heart. Treatments that have been proposed follow either physical trauma (e.g. spinal cord injuries), degenerative conditions (e.g. [[Parkinson's disease]]), or even genetic diseases (in combination with [[gene therapy]]). Yet further treatments using stem cells could potentially be developed thanks to their ability to repair extensive tissue damage.<ref>''[http://www.sciencedaily.com/releases/2006/03/060329083653.htm Stem Cells for Tissue Regeneration and Joint Repair]'' ''[[Science Daily]]'' 29th march 2006.</ref>
Much success and potential has been demonstrated from research using adult stem cells. There are no approved treatments or human trials using [[embryonic stem cells]]. Nevertheless, some are of the opinion that the differentiation potential of [[embryonic stem cells]] is broader than most adult stem cells. In addition, embryonic stem cells are considered more useful for nervous system therapies, as researchers have struggled to identify and isolate [[nerve cell|neural progenitors]] from adult tissues. Embryonic stem cells, however, might be rejected by the immune system - a problem which wouldn't occur if the patient received his or her own stem cells.
The major controversy is that the "best" stem cells come from growing embryos. The problem with the statement above is that the majority of the adult stem cells come from bone marrow transplants; these stem cells can help cure diseases such as leukemia, but they are not near as effective to diseases such as diabetes. The other problem with using bone marrow transplants is that they do not help cure major organs; the stem cells just turn into scar tissue.
=== Alternative sources ===
Some stem cell researchers are working to develop techniques of isolating stem cells that are as potent as embryonic stem cells, but do not require a human embryo.
Some believe that human somatic cells can be coaxed to "de-differentiate" and revert to an embryonic state. Researchers at [[Harvard University]], led by [[Kevin Eggan]], have attempted to transfer the nucleus of a somatic cell into an existing embryonic stem cell, thus creating a new stem cell line.<ref name="eggan">C.Cowan, J. Atienza, D. Melton and K. Eggan. ([[August 26]], [[2005]]) [http://www.sciencemag.org/cgi/content/abstract/309/5739/1369 "Nuclear reprogramming of somatic cells after fusion with human embryonic stem cells."] ''Science'', 309:1369.</ref> Another study published in August 2006 also indicates that differentiated cells can be reprogrammed to an embryonic-like state by introducing four specific factors.<ref>{{cite journal | last = Takahashi K and Yamanaka S | title = Induction of Pluripotent Stem Cells from Mouse Embryonic and Adult Fibroblast Cultures by Defined Factors | journal = Cell | volume = 126 | pages = 663–676 | doi = 10.1016/j.cell.2006.07.024}}</ref>
Researchers at Advanced Cell Technology, led by [[Robert Lanza]], reported the successful derivation of a stem cell line using a process similar to [[preimplantation genetic diagnosis]], in which a single [[blastomere]] is extracted from a [[blastocyst]].<ref name="lanza">Irina Klimanskaya, Young Chung, Sandy Becker, Shi-Jiang Lu & Robert Lanza. ([[August 23]], [[2006]]) "Human embryonic stem cell lines derived from single blastomeres." ''Nature''. doi:10.1038.</ref> At the 2007 meeting of the International Society for Stem Cell Research (ISSCR) <ref>[http://abcnews.go.com/Health/wireStory?id=3307505 ABC News: ABC News<!-- Bot generated title -->]</ref>, Lanza announced that his team had succeeded in producing three new stem cell lines without destroying the parent embryos. "These are the first human embryonic cell lines in existence that didn't result from the destruction of an embryo." Lanza is currently in discussions with the National Institutes of Health (NIH) to determine whether the new technique sidesteps U.S. restrictions on federal funding for ES cell research.<ref>[http://sciencenow.sciencemag.org/cgi/content/full/2007/619/3/ ScienceNOW - Sign In<!-- Bot generated title -->]</ref>
According to a January 9, 2007 Daily Telegraph (London) article reporting on a statement by Dr. Anthony Atala of [[Wake Forest University]], there is another "ethical" source of stem cells. The fluid surrounding the fetus has been found to contain stem cells, that, when utilized correctly, "can be differentiated towards cell types such as fat, bone, muscle, blood vessel, nerve and liver cells", according to the article. The extraction of this fluid does not harm the fetus in any way as well. "Our hope is that these cells will provide a valuable resource for tissue repair and for engineered organs as well," said Dr Atala.<ref>{{cite news
| last = Clout
| first = Laura
| coauthors = and Agencies
| title = "Scientists report alternative stem cell source"
| publisher = Daily Telegraph (UK)
| date = 2007-09-01
| url = http://www.telegraph.co.uk/news/main.jhtml?xml=/news/2007/01/08/ustem108.xml
| accessdate = 2007-20-09}}
</ref>
===Patents===
The [[patent]]s covering a lot of work on human embryonic stem cells are owned by the [[Wisconsin Alumni Research Foundation]] (WARF). WARF does not charge academics to study human stem cells but does charge commercial users. WARF sold [[Geron Corp.]] exclusive rights to work on human stem cells but later sued Geron Corp. to recover some of the previously sold rights. The two sides agreed that Geron Corp. would keep the rights to only three cell types. In 2001 WARF came under public pressure to widen access to human stem-cell technology.<ref name = "stemcellPatent">Regalado, Antonio, David P. Hamilton (July 2006). [http://www.genetics-and-society.org/newsdisp.asp?id=1033 "How a University's Patents May Limit Stem-Cell Researcher."] ''Wall Street Journal''. Retrieved on July 24, 2006.</ref>
These patents are now in doubt as a request for review by the [[US Patent and Trademark Office]] has been filed by non-profit patent-watchdogs [http://www.consumerwatchdog.org/ The Foundation for Taxpayer & Consumer Rights] and the [[Public Patent Foundation]] as well as molecular biologist Jeanne Loring of the Burnham Institute. According to them, two of the patents granted to WARF are invalid because they cover a technique published in 1992 for which a patent had already been granted to an Australian researcher. Another part of the challenge states that these techniques, developed by [[James Thomson (cell biologist)|James A. Thomson]], are rendered obvious by a 1990 paper and two textbooks.
The outcome of this legal challenge is particularly relevant to the Geron Corp. as it can only license patents that are upheld.<ref name="Kintisch">Kintisch, Eli (July 18, 2006) [http://sciencenow.sciencemag.org/cgi/content/full/2006/718/2 "Groups Target Stem Cell Patents."] ''ScienceNOW Daily News''. Retrieved August 15, 2006.</ref><ref name="AP Patents">Associated Press. (July 19, 2006) [http://abcnews.go.com/Technology/wireStory?id=2212758&CMP=OTC-RSSFeeds0312 "Stem Cell Patents Come Under Fire."] Retrieved August 15, 2006.</ref>
== Viewpoints ==
The status of the human [[embryo]] and human embryonic stem cell research is a [[controversial]] issue as, with the present state of technology, the creation of a human embryonic [[stem cell line]] requires the destruction of a human [[embryo]]. Stem cell debates have motivated and reinvigorated the [[pro-life]] movement, whose members are concerned with the rights and status of the embryo as an early-aged human life. They believe that embryonic stem cell research instrumentalizes and violates the [[sanctity of life]] and is tantamount to [[murder]].<ref name="Bush">"The stated reason for President Bush's objection to embryonic stem cell research is that 'murder is wrong'" [http://news.bbc.co.uk/2/hi/science/nature/5197926.stm (BBC)]</ref> The fundamental assertion of those who oppose embryonic stem cell research is the belief that human life is [[inviolable]], combined with the opinion that human life begins when a sperm cell fertilizes an egg cell to form a single cell.
A portion of stem cell researchers use embryos that were created but not used in [[In vitro fertilization|in vitro fertility]] treatments to derive new stem cell lines. Most of these [[embryos]] are to be destroyed, or stored for long periods of time, long past their viable storage life. In the United States alone, there have been estimates of at least 400,000 such embryos.<ref name="Weiss2003">Weiss, Rick. (May 8, 2003) [http://www.washingtonpost.com/ac2/wp-dyn?pagename=article&contentId=A27495-2003May7 "400,000 Human Embryos Frozen in U.S.,"] ''Washington Post''. Retrieved August 24, 2006.</ref> This has led some opponents of abortion, such as Senator [[Orrin Hatch]], to support human embryonic stem cell research.<ref name="Connolly">Connolly, Ceci. (July 30, 2005) [http://www.washingtonpost.com/wp-dyn/content/article/2005/07/29/AR2005072900158.html "Frist Breaks With Bush On Stem Cell Research."] ''Washington Post''. Retrieved August 24, 2006.</ref>
Medical researchers widely submit that stem cell research has the potential to dramatically alter approaches to understanding and treating diseases, and to alleviate suffering. In the future, most medical researchers anticipate being able to use technologies derived from stem cell research to treat a variety of diseases and impairments. Spinal cord injuries and Parkinson's disease are two examples that have been championed by high-profile media personalities (for instance, [[Christopher Reeve]] and [[Michael J. Fox]]). The anticipated medical benefits of stem cell research add urgency to the debates, which has been appealed to by proponents of embryonic stem cell research.
In August, 2000, The U.S. National Institutes of Health's Guidelines stated:
<blockquote>"...research involving human pluripotent stem cells...promises new treatments and possible cures for many debilitating diseases and injuries, including Parkinson's disease, diabetes, heart disease, multiple sclerosis, burns and spinal cord injuries. The NIH believes the potential medical benefits of human pluripotent stem cell technology are compelling and worthy of pursuit in accordance with appropriate ethical standards."
<ref>{{cite web|url=http://www.nih.gov/news/pr/aug2000/od-23.htm
|title= NIH Publishes Final Guidelines for Stem Cell Research|publisher=[[National Institutes of Health]]|year= 2000|accessdate=2007-04-29}}</ref>
</blockquote>
Recently, researchers at Advanced Cell Technology of Worcester, Mass., succeeded in obtaining stem cells from mouse embryos without killing the embryos.<ref>{{cite web|url=http://www.medicalnewstoday.com/healthnews.php?newsid=50329|title= Deriving Stem Cells Without Killing Embryo|publisher= Medical News Today|year=2006|accessdate=2007-12-26}}</ref> If this technique and its reliability are improved, it would alleviate some of the ethical concerns related to embryonic stem cell research.
Another technique announced in 2007 may also defuse the longstanding debate and controversy. Research teams in the United States and Japan have developed a simple and cost effective method of reprogramming human skin cells to function much like embryonic stem cells by introducing artificial viruses. While extracting and cloning stem cells is complex and extremely expensive, the newly discovered method of reprogramming cells is much cheaper. However, the technique may disrupt the DNA in the new stem cells, resulting in damaged and cancerous tissue. More research will be required before non-cancerous stem cells can be created.<ref>{{cite web|url=http://www.inthenews.co.uk/news/autocodes/countries/japan/new-stem-cell-breakthrough-$1169327.htm|title= New stem cell breakthrough|publisher=inthenews.co.uk|year=2007|accessdate=2007-12-26}}</ref><ref>{{cite web|url=http://www.nytimes.com/2007/06/06/science/06cnd-cell.html?_r=1&oref=slogin|title= Biologists Make Skin Cells Work Like Stem Cells|publisher=[[The New York Times]]|year=2007|accessdate=2007-12-26}}</ref><ref>{{cite web|url=http://www.washingtonpost.com/wp-dyn/content/article/2007/06/06/AR2007060601345.html|title= Scientists Use Skin To Create Stem Cells|publisher=[[The Washington Post]]|year= 2007|accessdate=2007-12-26}}</ref><ref>{{cite web|url=http://www.pbs.org/newshour/bb/health/jan-june07/stemcell_06-07.html|title= Scientists Convert Mouse Skin Cells to Stem Cells|publisher=[[Public Broadcasting Service]]|year= 2007|accessdate=2007-12-26}}</ref>
=== Endorsement ===
====Utilitarianism====
''The benefits of stem cell research outweigh the cost in terms of embryonic life''
* Embryonic stem cells have the capacity to grow indefinitely in a laboratory environment and can differentiate into almost all types of bodily tissue. This makes embryonic stem cells an attractive prospect for [[cell therapy|cellular therapies]] to treat a wide range of diseases.<ref name = "Spinneypress">{{cite web|publisher=Spinneypress|year=2006|url=http://www.spinneypress.com.au/178_book_desc.html|title=Arguments For Stem cell Research|accessdate=2007-12-26}}</ref>
* The [[social]], [[economic]] and personal costs of the diseases that embryonic stem cells have the potential to treat are far greater than the costs associated with the destruction of embryos.
====Human potential and humanity====
This argument often goes hand-in-hand with the utilitarian argument, and can be presented in several forms:
* Embryos, while of value, are not equivalent to human life while they are still incapable of existing outside the womb (i.e. they only have the potential for life).
* Approximately 18% of [[zygotes]] do not implant after conception.<!-- dead link: http://radiology.creighton.edu/pregnancy.htm --> Thus far more embryos are lost due to chance than are proposed to be used for embryonic stem cell research or treatments.
* Blastocysts are a cluster of human cells that have not differentiated into distinct organ tissue; making cells of the inner cell mass no more "human" than a skin cell .<ref name = "Spinneypress">Spinneypress.(2006) [http://www.spinneypress.com.au/178_book_desc.html "Arguments For Stem cell Research,"] '''Stem Cell Research'''. Retrieved August 26, 2006.</ref>
* Some parties contend that embryos are not humans, believing that the life of Homo sapiens only begins when the heartbeat develops, which is during the 5th week of pregnancy,<ref>Greenfield, Marjorie. “[http://www.drspock.com/article/0,1510,9851,00.html Dr. Spock.com]". Retrieved [[2007-01-20]].</ref> or when the brain begins developing activity, which has been detected at 54 days after conception.<ref name="Singer">Singer, Peter. ''[http://books.google.com/books?vid=ISBN0312144016&id=d5W1xE1GM2EC&pg=RA1-PA104&lpg=RA1-PA104&ots=kG4PXGCQDG&dq=%22human+life+must+be+protected+from+fifty-four+days%22&num=100&sig=PWH7KEPjVWhxAkFWTAwd3DWuyB0#PRA1-PA104,M1 Rethinking life & death: the collapse of our traditional ethics]'', page 104 (St. Martins Press 1996). Retrieved [[2007-03-04]].</ref>
====Consequentialism====
''The ends (i.e. new treatments and cures) justify the means (i.e. the destruction of embryos)''
This can be seen as a more extreme view of the utilitarianism argument.
====Efficiency====
''If an embryo is going to be destroyed anyway, isn't it more efficient to make practical use of it?
* [[In vitro fertilization]] (IVF) generates large numbers of unused embryos (e.g. 70,000 in Australia alone).<ref name = "Spinneypress">Spinneypress.(2006) [http://www.spinneypress.com.au/178_book_desc.html "Arguments For Stem cell Research,"] '''Stem Cell Research'''. Retrieved August 26, 2006.</ref> Many of these thousands of IVF embryos are slated for destruction. Using them for scientific research utilizes a resource that would otherwise be wasted.<ref name = "Spinneypress">Spinneypress.(2006) [http://www.spinneypress.com.au/178_book_desc.html "Arguments For Stem cell Research,"] '''Stem Cell Research'''. Retrieved August 26, 2006.</ref>
* While the destruction of human embryos is required to establish a stem cell line, no new embryos have to be destroyed to work with existing stem cell lines. It would be wasteful not to continue to make use of these cell lines as a resource.<ref name = "Spinneypress">Spinneypress.(2006) [http://www.spinneypress.com.au/178_book_desc.html "Arguments For Stem cell Research,"] '''Stem Cell Research'''. Retrieved August 26, 2006.</ref>
* Abortions are legal in many countries and jurisdictions. A logical argument follows that if these embryos are being destroyed anyway, why not use them for stem cell research or treatments?
====Superiority====
''Embryonic stem cells can be considered far more useful therapeutically than adult stem cells''
This is usually presented as a counter-argument to using adult stem cells as an alternative that doesn't involve embryonic destruction.
* Embryonic stem cells make up a significant proportion of a developing embryo, while adult stem cells exist as minor populations within a mature individual (e.g. in every 10,000 cells of the bone marrow, only 10 will be usable stem cells). Thus, embryonic stem cells are likely to be easier to isolate and grow [[ex vivo]] than adult stem cells.<ref name = "Spinneypress">Spinneypress.(2006) [http://www.spinneypress.com.au/178_book_desc.html "Arguments For Stem cell Research,"] '''Stem Cell Research'''. Retrieved August 26, 2006.</ref>
* Embryonic stem cells divide more rapidly than adult stem cells, potentially making it easier to generate large numbers of cells for therapeutic means. In contrast, adult stem cell might not divide fast enough to offer immediate treatment.<ref name = "Spinneypress">Spinneypress.(2006) [http://www.spinneypress.com.au/178_book_desc.html "Arguments For Stem cell Research,"] '''Stem Cell Research'''. Retrieved August 26, 2006.</ref>
* Embryonic stem cells have greater plasticity, allowing them to treat a wider range of diseases.<ref name = "Spinneypress">Spinneypress.(2006) [http://www.spinneypress.com.au/178_book_desc.html "Arguments For Stem cell Research,"] '''Stem Cell Research'''. Retrieved August 26, 2006.</ref>
* Adult stem cells from the patient's own body might not be effective in treatment of genetic disorders. [[Allograft|Allogeneic]] embryonic stem cell transplantation (i.e. from a healthy donor) may be more practical in these cases than [[gene therapy]] of a patient's own cell.<ref name = "Spinneypress">Spinneypress.(2006) [http://www.spinneypress.com.au/178_book_desc.html "Arguments For Stem cell Research,"] '''Stem Cell Research'''. Retrieved August 26, 2006.</ref>
* DNA abnormalities found in adult stem cells that are caused by toxins and sunlight may make them poorly suited for treatment.<ref name = "Spinneypress">Spinneypress.(2006) [http://www.spinneypress.com.au/178_book_desc.html "Arguments For Stem cell Research,"] '''Stem Cell Research'''. Retrieved August 26, 2006.</ref>
* Embryonic stem cells have been shown to be effective in treating heart damage in mice.<ref name = "Spinneypress">Spinneypress.(2006) [http://www.spinneypress.com.au/178_book_desc.html "Arguments For Stem cell Research,"] '''Stem Cell Research'''. Retrieved August 26, 2006.</ref>
====Beginning of life====
* Before the [[primitive streak]] is formed when the embryo attaches to the uterus at approximately 14 days after fertilization, a single fertilized egg can split in two to form [[twin#identical twins|identical twins]]. Also, rarely, two separately fertilized eggs can, instead of resulting in [[twin#fraternal twins|fraternal twins]], fuse together and develop into a single human individual (a tetragametic [[chimera (genetics)|chimera]]).<ref name = "AtIssueEthicsofGE">West, Michael D.(2005) The Ethics of Genetic Engineering (At Issue Series). (pp 100-107) USA: Thomson Gale</ref>
* Therefore before the primitive streak is formed, an individual human life does not exist at fertilization, as it can go on to split into two separate individuals. Therefore, an individual human life begins when the primitive streak is formed — beyond which the cell group cannot split to make twins — and not before. Therefore the blastocysts destroyed for embryonic stem cells do not have human life, and it is ethical to use them. <ref name = "AtIssueEthicsofGE">West, Michael D.(2005) The Ethics of Genetic Engineering (At Issue Series). (pp 100-107) USA: Thomson Gale</ref>
=== Objection ===
==== Value of life ====
''An embryo is actually a human; it should be [[Value of life|valued as highly as a human life]].''
The reasoning can be summed up by the fact that, once an egg is fertilized, unless inhibited, it will develop into a fully-developed adult. This opinion is often related to [[religion|religious]] doctrines which assert that [[conception]] marks the beginning of human life or the presence of a [[soul]]. Based upon this reasoning, the subsequent argument against embryonic stem cell research is that human life is inherently valuable and should not be voluntarily destroyed.
It has been argued that "the line at which an embryo becomes a human life remains as arbitrary as ever".<ref name="Parry">Parry, S. (August 2003). [http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=15282911&dopt=Abstract "The politics of cloning: mapping the rhetorical convergence of embryos and stem cells in parliamentary debates."] ''New Genetics and Society''. pp. 145-168. Retrieved on August 7, 2006.</ref>
[[Viability]] is another standard under which embryos and fetuses have been regarded as human lives. In the United States, the 1973 [[Supreme Court of the United States|Supreme Court]] case of [[Roe v. Wade]] concluded that [[viability]] determined the permissibility of [[abortion]]s performed for reasons other than the protection of the woman's health, defining ''viability'' as the point at which a fetus is "potentially able to live outside the mother's womb, albeit with artificial aid."<ref name="Roe">''Roe v. Wade'', [http://caselaw.lp.findlaw.com/scripts/getcase.pl?navby=CASE&court=US&vol=410&page=113 410 U.S. 113] (1973). Findlaw.com. Retrieved [[2007-05-15]]</ref> The point of viability was 24 to 28 weeks when the case was decided and has since moved to about 22 weeks due to advancement in medical technology. If further technological advances allow a sperm and egg to be combined and fully developed completely outside of the womb, an embryo will be viable as soon as it is conceived, and under the viability standard, life will begin at conception.
====Better alternatives====
''Embryonic stem cells should be abandoned in favor of alternatives, such as those involving adult stem cells.''
This argument is used by opponents of embryonic destruction as well as researchers specializing in adult stem cell research.
It is often claimed by pro-life supporters that the use of adult stem cells from sources such as umbilical cord blood has consistently produced more promising results than the use of embryonic stem cells.<ref name="Prentice">Prentice, David. (October 17, 2005) [http://www.christianitytoday.com/ct/2005/october/24.71.html "Live Patients & Dead Mice".] ''Christianity Today''. Retrieved on August 24, 2006.</ref> Furthermore, adult stem cell research may be able to make greater advances if less money and resources were channeled into embryonic stem cell research.<ref name"CARE">The Coalition of Americans for Research Ethics. [http://www.stemcellresearch.org/polisci/index.html "The "Political Science" of Stem Cells".] Retrieved on July 16, 2006.</ref>
Adult stem cells have already produced therapies, while embryonic stem cells have not.<ref name="Clarke">Clarke, Michael F. and Michael W. Becker. (July 2006). [http://www.sciam.com/article.cfm?chanID=sa006&colID=1&articleID=000B1BED-0C0A-1498-8C0A83414B7F0000 "Stem Cells: The Real Culprits in Cancer?"] ''Scientific American''. Retrieved on August 8, 2006.</ref><ref name = "embryonicstemcell">Anonymous (September 24, 2006) [http://www.genome.gov/10004765 "Cloning/Embryonic Stem Cells."] ''National Human Genome Research Institute''. Retrieved September 24, 2006.</ref> Moreover, there have been many advances in adult stem cell research, including a recent study where pluripotent adult stem cells were manufactured from differentiated fibroblast by the addition of specific transcription factors. <ref>{{cite journal | last = Cyranoski | title = Simple switch turns cells embryonic| journal = Nature | volume = 6 June 2007}}</ref> Newly created stem cells were developed into an embryo and were integrated into newborn mouse tissues, analogous to the properties of embryonic stem cells.
This argument remains hotly debated on both sides. Those critical of embryonic stem cell research point to a current lack of practical treatments, while supporters argue that advances will come with more time and that breakthroughs cannot be predicted.
====Scientific flaws====
''The use of embryonic stem cell in therapies may be fundamentally flawed.''
For instance, one study suggests that autologous embryonic stem cells generated for therapeutic cloning may still suffer from immune rejection.<ref name = "BanningCloning">Americans for Banning Cloning.(2002) [http://cloninginformation.org/info/unsuccessful_mouse_therapy.htm "Why the "Successful" Mouse "Therapeutic" Cloning Really Didn't Work
"] '''Stem Cell Research'''. Retrieved April 13, 2007.</ref> The researchers note that: "Our results raise the provocative possibility that even genetically matched cells derived by therapeutic cloning may still face barriers to effective transplantation for some disorders." In other words, therapeutic cloning may not always produce matched tissues. In contrast, there are reports of adult stem cells being successfully reintegrated into an autogenic animal.
Another concern with embryonic stem cell treatments is a tendency of stem cells from embryos to create tumors. <ref name="Clarke">Clarke, Michael F. and Michael W. Becker. (July 2006). [http://www.sciam.com/article.cfm?chanID=sa006&colID=1&articleID=000B1BED-0C0A-1498-8C0A83414B7F0000 "Stem Cells: The Real Culprits in Cancer?"] ''Scientific American''. Retrieved on August 8, 2006.</ref><ref name = "stemcelltumor">Dolan, Kerry. (July 21, 2006) [http://www.forbes.com/technology/2006/07/21/stem-cell-research-cz_kd_0721stemcell.html "Despite Bush Veto, Stem Cell Research Abounds."] ''Forbes''. retrieved July 21, 2006.</ref>
====Overstatement of research potential====
''Scientists have long promised spectacular results from embryonic stem cell research, and this has not yet occurred''<ref name="Parry"/><Ref name=Nerensini>Nerensini, F. (2000) [http://pus.sagepub.com/cgi/content/abstract/9/4/359 "And Man Descended from the Sheep: The Public Debate on Cloning in the Italian Press."] ''Public Understanding of Science'', vol. 9, pp.359-382.</Ref><ref name="nisbet et al">Nisbet, M.C., Brossard, D. & Kroepsch, A. (2003) [http://hij.sagepub.com/cgi/content/abstract/8/2/36 "Framing Science: The Stem Cell Controversy in an Age of Press/Politics."] ''The Harvard International Journal of Press/Politics''. Vol. 8, No. 2, pp. 36-70 DOI: 10.1177/1081180X02251047.</ref>
Conspicuously, such criticism has even come from researchers themselves. For example, in November 2004, [[Princeton University]] president and geneticist [[Shirley Tilghman]] said, "Some of the public pronouncements in the field of stem-cell research come close to overpromising at best and delusional fantasizing at worst."<ref name="Tilghman">Tilghman, Shirley M. (November 11, 2004) [http://www.princeton.edu/president/speeches/20041111/index.xml "Address to the Stem Cell Institute of New Jersey,"] Retrieved August 22, 2006.</ref> Similarly, [[fertility]] expert and former president of the [[British Association for the Advancement of Science]], [[Lord Winston]] has warned of a public backlash against stem cell research if it fails to deliver on some of the "hype" surrounding potential treatments.<ref name="winston">Amos, Jonathan. (September 5, 2005) [http://news.bbc.co.uk/1/hi/sci/tech/4213566.stm "Winston warns of stem cell 'hype'."] BBC News. Retrieved August 14, 2006.</ref>
==Policy debate in the United States==
===Origins===
In 1969, the first human ''[[in vitro fertilization]]'' was accomplished and in 1973, [[Roe v. Wade]] legalized abortion nationwide. These developments prompted the federal government to create regulations barring the use of federal funds for research that experimented on human embryos. In 1995, the NIH Human Embryo Research Panel advised the Clinton administration to permit federal funding for research on embryos left over from ''in vitro'' fertility treatments and also recommended federal funding of research on embryos specifically created for experimentation. In response to the panel's recommendations, the [[Bill Clinton|Clinton]] administration, citing moral and ethical concerns, declined to fund research on embryos created solely for research purposes,<ref name = "stemcellclinton"> {{cite web
| title = "President Clinton's Comments on NIH and Human Embryo Research"
| work = U.S. National Archives
| url = http://clinton6.nara.gov/1994/12/1994-12-02-president-on-nih-and-human-embryo-research.html
| creationdate = December 2, 1994
| accessdate= 2006-07-19
}} </ref> but did agree to fund research on left-over embryos created by ''in vitro'' fertility treatments. At this point, the Congress intervened and passed the [[Dickey Amendment]] in 1995 (the final bill, which included the Dickey Amendment, was signed into law by Clinton) which prohibited any federal funding for the Department of Health and Human Services be used for research that resulted in the destruction of an embryo regardless of the source of that embryo.
In 1998, privately funded research led to the breakthrough discovery of Human Embryonic Stem Cells (hESC). This prompted the [[Bill Clinton|Clinton]] Administration to re-examine guidelines for federal funding of embryonic research. In 1999, the president's National Bioethics Advisory Commission recommended that hESC harvested from embryos discarded after ''in vitro'' fertility treatments, but not from embryos created expressly for experimentation, be eligible for federal funding.<!-- Apparently stale link: [http://www.georgetown.edu/research/nrcbl/nbac/execsumm.pdf] --> Even though embryos are always destroyed in the process of harvesting hESC, the Clinton Administration decided that it would be permissible under the Dickey Amendment to fund hESC research as long as such research did not itself directly cause the destruction of an embryo. Therefore, HHS issued its proposed regulation concerning hESC funding in 2001. Enactment of the new guidelines was delayed by the incoming Bush administration which decided to reconsider the issue.
President Bush announced, on [[August 9]], [[2001]] that federal funds, for the first time, would be made available for hESC research on currently existing stem cell lines; however, the Bush Administration chose not to permit taxpayer funding for research on hESC cell lines not currently in existence, thus limiting federal funding to research in which "the life-and-death decision has already been made".<ref>[http://www.whitehouse.gov/news/releases/2001/08/20010809-2.html The White House, Press Release, August 9, 2001]</ref> The Bush Administration's guidelines differ from the Clinton Administration guidelines which did not distinguish between currently existing and not-yet-existing hESC. Both the Bush and Clinton guidelines agree that the federal government should not fund hESC research that directly destroys embryos.
Neither Congress nor any administration has ever prohibited private funding of embryonic research. Public and private funding of research on adult and cord blood stem cells is unrestricted.{{Fact|date=April 2007}}
<div id="Congressional response"><!-- Please do not delete anchor linked from other articles. -->
===U.S. Congressional response===
In [[April 2004]], 206 members of [[United States Congress|Congress]] signed a letter urging President Bush to expand federal funding of embryonic stem cell research beyond what Bush had already supported.
In [[May 2005]], the House of Representatives voted 238-194 to loosen the limitations on federally funded embryonic stem-cell research — by allowing government-funded research on surplus frozen embryos from [[in vitro fertilization]] clinics to be used for stem cell research with the permission of donors — despite Bush's promise to veto the bill if passed.<ref>{{cite web|url=http://www.wired.com/news/medtech/0,1286,67627,00.html|title=A Step Closer to Stem-Cell Heaven|publisher=[[Wired (magazine)|Wired]]|year=2005|accessdate=2008-02-28}}</ref> On [[July 29]], [[2005]], [[Senate Majority Leader]] [[Bill Frist|William H. Frist]] (R-[[Tennessee|TN]]), announced that he too favored loosening restrictions on federal funding of embryonic stem cell research.<ref name = "stemcell14"> {{cite journal
| first = Ceci
| last = Connolly
| authorlink =
| coauthors =
| year = 2005
| month = July
| title = "Despite Bush Veto, Stem Cell Research Abounds"
| journal = Washington Post
| volume =
| issue =
| pages = A01
| id =
| url = http://www.washingtonpost.com/wp-dyn/content/article/2005/07/29/AR2005072900158.html
| date of work = July 30, 2005
| accessdate= 2006-07-21
}} </ref> On [[July 18]], [[2006]], the Senate passed three different bills concerning stem cell research. The Senate passed the first bill ([[Stem Cell Research Enhancement Act]]), 63-37, which would have made it legal for the Federal government to spend Federal money on embryonic stem cell research that uses embryos left over from ''in vitro'' fertilization procedures.<ref name = "stemcell3"> {{cite web
| first = Laurie
| last = Kellman
| title = "Senate Approves Embryo Stem Cell Bill"
| work = Associated Press
| url = http://www.breitbart.com/news/2006/07/18/D8IUKSRO0.html
| date of work = July 18, 2006
| accessdate= 2006-07-18
}} </ref> On [[July 19]], [[2006]] President Bush vetoed this bill. The second bill makes it illegal to create, grow, and abort fetuses for research purposes. The third bill would encourage research that would isolate pluripotent, i.e., embryonic-like, stem cells without the destruction of human embryos.
In 2005 and 2007, Congressman [[Ron Paul]] introduced the Cures Can Be Found Act,<ref>H.R. 457, 110th Congress</ref> with 10 cosponsors. With an [[income tax]] credit, the bill favors [[stem-cell research|research]] upon nonembryonic stem cells obtained from [[placenta]]s, [[umbilical cord]] [[blood]], [[amniotic fluid]], humans after birth, or unborn human offspring who died of natural causes; the bill was referred to committee. Paul argued that hESC research is outside of federal jurisdiction either to ban or to subsidize.<ref>{{cite web|url=http://www.ronpaullibrary.org/document.php?id=839|title=Rights of Taxpayers is Missing Element in Stem Cell Debate|publisher=The Ron Paul Library}}</ref>
Bush vetoed another bill, the [[Stem Cell Research Enhancement Act|Stem Cell Research Enhancement Act of 2007]],<ref>{{USBill|110|S.|5}}</ref> which would have amended the [[Public Health Service Act]] to provide for human embryonic [[stem cell research]]. The bill passed the [[United States Senate|Senate]] on April 11 by a vote of 63-34, then passed the [[United States House of Representatives|House]] on June 7 by a vote of 247-176. President Bush vetoed the bill on July 19, 2007.<ref>[http://www.abcnews.go.com/Politics/wireStory?id=3031459 "Senate Approves Embryonic Stem Cell Bill"], David Espo, [[Associated Press]], April 12, 2007</ref>
===Funding===
Currently, the National Institutes of Health has 399 funding opportunities for researchers interested in hESC.{{Fact|date=January 2008}} In 2005 the NIH funded $607 million worth of stem cell research, of which $39 million was specifically used for hESC.<ref>{{cite web|url=http://www.nih.gov/news/fundingresearchareas.htm|title=Estimates of Funding for Various Diseases, Conditions, Research Areas|publisher=[[National Institutes of Health]]|year=2007|accessdate=2008-01-21}}</ref> Of the 514 currently recruiting clinical trials that are using stem cells as treatment, the federal government is supporting 206 of them; however, none of these trials are using hESC.{{Fact|date=January 2008}} [[Sigrid Fry-Revere]] has argued that private organizations, not the federal government, should provide funding for stem-cell research, so that shifts in public opinion and government policy would not bring valuable scientific research to a grinding halt<ref>{{cite web|url=http://www.cato.org/pub_display.php?pub_id=8205|title=Best Hope Lies in Private Stem-Cell Funding|accessdate=2008-01-31}}</ref>
==See also==
* [[Stem Cell Research Enhancement Act]]
* [[Genetics Policy Institute]]
* [[Stem cell research policy]]
==References==
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<references/>
</div>
==External links==
<!-- Please use the talk page to propose any additions to this list of links. If you do not do this, the link will almost certainly be deleted. -->
*[http://www.wilsoncenter.org/index.cfm?topic_id=116811&fuseaction=topics.event_summary&event_id=161696 Video: The Stem Cell Controversy]January 18, 2006, [[Woodrow Wilson Center]] event featuring [[Robin Cook (novelist)]], [[William B. Hurlbut]], and [[Michael D. West]]
*[http://www.hinxtongroup.org The Hinxton Group: An International Consortium on Stem Cells, Ethics & Law]
*[http://www.cato.org/pub_display.php?pub_id=7768 A Scientific-Industrial Complex? By Sigrid Fry-Revere]
{{Stem cells}}
[[Category:Stem cells]]
[[ca:Controvèrsia amb les cèl·lules mare]]