1 / 62

Human embryonic stem cells – balancing on the ethical edge

There is a growing gulf between what medicine can do and what the health service can afford. Richard Gardner, chair of the Royal Society´s working group on stem cells and therapeutical cloning. 2011 Marek Vácha. Human embryonic stem cells – balancing on the ethical edge.

shanon
Download Presentation

Human embryonic stem cells – balancing on the ethical edge

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. There is a growing gulf between what medicine can do and what the health service can afford. Richard Gardner, chair of the Royal Society´s working group on stem cells and therapeutical cloning 2011 Marek Vácha Humanembryonic stem cells – balancing on the ethicaledge

  2. TotipotencyPlants

  3. Totipotency: A Frog

  4. ReproductiveCloningIanWilmutcreatedDolly the Sheep in 1997 Totipotency: Mammals

  5. Reproductive Cloning and Therapeutic Cloning

  6. Reproductive Cloning and Therapeutic Cloning

  7. Reproductive Cloning • 1996 sheep • 1997 mouse • 1998 cow • 2000 pig • 2002 cat • 2005 dog

  8. cloned animals have also be re-cloned, and clones have reproduced sexually, although many cloned males are sterile (the earliest succesful clones were all female) • K.C., a cow cloned at the University of Georgia from the cell af a dead cow, gave birth in December 2004 to Sunshine, a calf who seems normal in every way • (Pierce, J., Randels, G., (2010) Contemporary Bioethics. Oxford University Press, NY, Oxford. p. 260)

  9. Argumentsforreproductivecloning • To allowaninfertilecouple to have a childThe ItaliandoctorSeverinoAntinoriwants to offercloning as a treatment for infertility. Critics have pointed out that anyone who was a clone of one of their parents would be underunknownpsychologicalpressuresthroughout their childhood. Would they feel they were living up to the achievements of their 'original'? And how would a womanfeel about bringing up a much youngerversion of the person she fell in love with? To bring back a child killed in an accidentIn recentyears, some bereavedfamilies have contacted scientists asking them to clone a dead child. However, even if human cloning was possible, familiesmight be distraught to discover their new baby was not exactly like their deadolderbrother or sister - and the 'replacement' child mightsufferfeelings of inferiority about being bornpurely to take the place of their deadsibling.

  10. Argumentsforreproductivecloning • To replicate the talents of exceptional human beingsIf MotherTheresa or Einstein could be geneticallyreproduced, their clonesmightchoose very differentpaths in life, and disappoint the people who had chosen to create them. Out of curiosity or to attemptsome sort of immortalityThe scientist Richard Dawkins has expressed the desire to clonehimself out of purecuriosity. Immortalitythroughcloningseemsanimpossiblegoal because the clone’sexperiences and thoughts would be their own, not those of the clonedadult. To obtain a supply of stem cellsThe stem cells would be taken from a cloned embryo and used to rejuvenate and repairourbodies. The embryo would then be destroyed.

  11. Argumentsagainstreproductivecloning • cloned humans may faceproblems of identity and individuality • because they are geneticallyidentical to people who alreadylived, and there may be expectations to be like their predecessors • cloning could contribute to the commodification of children and the commercialization of reproduction • cloning could lead to eugenics, favoringparticular genetic traits • family relations might be confused, such as if the father and son were genetic twins, this also "brothers" • there might be a slipperyslopeimpact on society, leading to such things as genetic enhancement and genetic control over the next generation

  12. Embryonic Stem Cells • were firstlyisolated from mice in1981. • Human Embryonic Stem Cells were firstlyisolated in 1998 by James Thomson • J.Thomson, Wisconsin university funded by Geron corporation. • Dr. John Gearhart of JohnsHopkins University James A. Thomson says he thought “long and hard” before doing stem cell research.

  13. James A. Thomson (2007) • His laboratory was one of two that reported a new way to turn ordinary human skin cells into what appear to be embryonic stem cells without ever using a human embryo. • The fact is, Dr. Thomson said in an interview, he had ethical concerns about embryonic research from the outset, even though he knew that such research offered insights into human development and the potential for powerful new treatments for disease. • “If human embryonic stem cell research does not make you at least a little bit uncomfortable, you have not thought about it enough,” he said. “I thought long and hard about whether I would do it.”

  14. James A. Thomson (2007) • Now with the new technique, which involves adding just four genes to ordinary adult skin cells, it will not be long, he says, before the stem cell wars are a distant memory. “A decade from now, this will be just a funny historical footnote,” Dr. Thomson said in the interview. • http://www.nytimes.com/2007/11/22/science/22stem.html?_r=1&ref=science&oref=slogin

  15. Classification • (ESC)Humanembryonic stem cells, • Embryonic Stem Cell (ESC) Therapy - theoretically involves the use of cells extracted from a five day old in vitro fertilized embryo (in this embryo there is approximately 100 cells, ICM is 30 of them). ESCs have been scientifically substantiated to be pluripotent for all cell types. • (FSC)Humanembryonicgermcells, • Fetal Stem Cell (FSC) therapyinvolves the use of human fetuses aborted between 1 and 3 months. Tissue with imbedded stem cells is scraped from the liver, neural or gonadal ridges. Commercial providers of these potentially pluripotent cell types do not scientifically classify the cell populations. • (ASC)HumanAdult stem cells, • ASC are undifferentiated, found among differentiated cell types in a tissue or organ. ASC can renew themselves, and can differentiate to yield the major specialized cell types of the tissue or organ. Their primary role in a living organism is to maintain and repair the tissue in which they are found. There are approximately 20 types of ASC in the human body.

  16. iPS • = induced pluripotent stem cells • by addition of four human human genes to human skin cells they can be reprogrammed back to the state of stem cells from an early embryo, with the abuility to develop into every cell type in the body

  17. iPS • iPS thus promise to provide a source of immunologically compatible tissues for treating patients currently suffering from incurable genetic diseases such as Alzheimer´s disease, without encountering the ethical objections raised by using ESC from human embryos or cybrids

  18. „In the long-term the scientific view is that it will be possible to re-programme adult stem cells with the full potential of embryonic cells but without the morally contestable need to create an embryo.“ • Liam Donaldson, the Chief Medical Officer in the UK

  19. ASC

  20. Embryonic Stem Cells ES cells that have proliferated in cell culture for 6 or more months without differentiating, and which have pluripotent and appear genetically normal, are referred to as an embryonic stem cell line.

  21. Embryonic Stem Cells

  22. Embryonic Stem Cells

  23. PossibleSources of Embryonic Stem Cells • Surplus embryos • Embryos made exclusively in order to receive ESC • SCNT = Therapeutic Cloning

  24. PreimplantationDiagnosis

  25. Dr. Woo Suk Hwang • 24/11 2005 Dr. Hwang is forced to to step down • female researchers in his own lab had supplied eggs for his research. • two key scientific papers in 2005, both published in Science Magazine, were found to have been fabricated. August 2005 Snuppy, an Afghan hound was cloned by Dr. Hwang

  26. Dr. Hwang • Dr Hwang was in March fired from his professorship at Seoul National University (SNU) and in May was charged with fraud and embezzlement. Dr Hwang had received millions of dollars' worth of funds from the state and private foundations for his research. • The downfall of Dr Hwang came as a big shock to Koreans, who had taken great pride in what appeared to be the pioneering work of the stem cell researchers at Seoul National University. • Dr Hwang at one point had 15,000 hard-core fans, who belonged to a "I love HWS" online community.

  27. Definition of Human Embryo • A human embryo is a discrete entity that has arisen from either: • (i) the first mitotic division when fertilization of a human oocyte by a human sperm is complete or • (ii) any other process that initiates organized development of a biological entity with a human nuclear genome oraltered human nuclear genome that has the potential to develop up to, or beyond, the stage at which the primitivestreakappears, • and has not yet reached 8 weeks of development since the first mitotic division.

  28. Status of Embryo • Ontologicalpersonalism – Ontological personalism states that all human beings are human persons. On this view, the intrinsic quality of personhood begins at conception and is present throughout life Such individuals are not potential persons or "becoming" persons; they are persons by their very nature. There is no such thing as a potential person or a human non-person. • EmpiricalFunctionalism – there is a diffrentionbetween „being“ and „person“. According to this conception, the moral status of zygotes, embryos, foetuses and even infants is problematic. The person must need a minimal level of mental life. The embryo can not be determined by its potentiality or by what the embryo will become, but must be assessed in terms of what it is. Therefore it is not reasonable to think that the embryo has a moral status comparable to adults.

  29. biological species cognitive capacity moral agency sentience communal relationship Revision: A Theory Based on

  30. Empirical Functionalism „person“

  31. „person“ Ontological Personalism

  32. Ontologicalpersonalism • it is morally acceptable to take stem cells when they do no serious harm to the subject, as is generally the case when tissues are taken from • an adult organism • the umbilical cord at the time of birth • fetuses that have died from natural causes.

  33. ArgumentsforobtainingEmbryonic Stem Cells from embryos • The prospects are beyond our scope • Only 30-50% zygoteimplants. If Mother Nature is so prodigal, we may not to bother with embryos. • individual is „in-dividium“, non-divisible. • Human embryo is nothing than cluster of cells • if we approved abortions, there is no discussion about status of embryos • utilitarianism: we have to consider the ethical calculation, gains and losts: happy and healthy patient/destroyed embryo

  34. ArgumentsforobtainingEmbryonic Stem Cells from embryos • If abortions are legal, protection of embryos is inproportionate, inadequate • ES cells are not embryos. These cells are no more totipotent. If we already have these lines, they are cells, not embryos. • individuum is etymologically indivisible • MZ twins could arise until the end of the second week. Until this time we cannot speak about individuum

  35. ArgumentsforobtainingEmbryonic Stem Cells from embryos • Argument of utilitarianism: on the one side of the ethical scale is healthy happy patient, on the other side of the scale embryo which can not feel neither pain, nor pleasure

  36. Should there be any agelimits for using IVF? • the world´s olders mothers were Omkari Panwar and Rajo Devi of India, who both gave birth at age seventy in 2008

  37. ArgumentsagainstobtainigHumanEmbryonic Stem Cells • Embryo is not, embryosare. Every embryo has a unique genetic design • An Embryo has a potentialityto become an adult human person, so we must treat an embryo as a person. • every embryo has two livingbeings, parents • Aristotle: four „causes“ • Immanuel Kant: • the problem of freedom • differencebetween cost/value and dignity

  38. Aristotle • causa materialis • causa formalis • causa efficiens • causa finalis

  39. Aristotle • causa materialis: „cluster of atoms“, „cluster of cells“, „C,H,O,N,“ etc. • causa formalis – form of living matter is a soul • causa efficiens „where from I came?“ • causa finalis „what is goal of my life?“

  40. „Cluster of cells“ Five day old embryo is composed from150 – 200 cells, adult human from 5. 1014 cells

  41. Germany • The German Parliament established the 2002 Stem Cell Act, which allows the import of hESCs for high-ranking research objectives. • These must be evaluated by the Robert Koch Institute, a federal institute in Berlin, and its central ethics committee for stem-cell research (http://www.rki.de). • Moreover, only hESC lines produced from surplus embryos from in vitro fertilization (IVF) before 1 January 2002 can be legally imported. This key date was chosen to ensure that no hESC lines are directly produced for German research; in other words, that no human embryos are destroyed 'on German order'

  42. Regulation of Research in  EU • Germany: prohibition to destroy embryos for obtaining hES. Allowance to work with hES if the lines were created before 01/01 2002 • 22/05 2008 this import and usage was shifted to 01/05 2007

  43. USA • August 2000: scientists could apply for federalfunding only for research utilizing 78 existing stem cell lines. • the truenumber of available and suitable lines appears to be closer to twenty than the higher number. • President Bush agreed to finance embryonic stem cell research, but limited federally financed research to 21 cell lines already in existence by 2001.

  44. USA • the restriction do not hamper the use of privatefunds for the other lines, only federalfunds • 09/03/2009 BarackObamareleasesfederalfundshttp://edition.cnn.com/video/#/video/offbeat/2009/03/12/moos.sesame.street.layoffs.cnn • 23/08/2010 A federal district judge blockedPresident Obama’s 2009 executive order that expanded embryonicstem cell research, saying it violated a ban on federal money being used to destroy embryos.

  45. USA 23/08/2010 • With the case back in his court, Judge Lamberth ruled that the administration’s policy violated the clear language of the Dickey-Wicker Amendment, a law passed annually by Congress that bans federal financing for any “research in which a human embryo or embryos are destroyed, discarded or knowingly subjected to risk of injury or death.” • The Obama administration said that its rules abided by the Dickey-Wicker Amendment because the federal money would be used only once the embryonic stem cells were created but would not finance the process by which embryos were destroyed. The judge disagreed, writing that embryonic stem cell research “necessarily depends upon the destruction of a human embryo.” • http://www.nytimes.com/2010/08/24/health/policy/24stem.html?pagewanted=2&_r=1&ref=science

  46. http://www.nytimes.com/2008/12/04/us/04embryo.html?_r=1

More Related