Human embryonic stem cells balancing on the ethical edge

1
Human embryonic stem cells balancing on the
ethical edge

• 2008
• Marek Vácha

2
TotipotencyPlants
3
Totipotency Frog
4
Reproductive CloningIan Wilmut created Dolly 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
Embryonic Stem Cells

• were firstly isolated from mice in1981.
• Human Embryonic Stem Cells from Embryonální
  kmenové bunky were firstly isolated in 1998 by
  James Thomson (J.Thomson, Wisconsin university
  funded by Geron corporation).

James A. Thomson says he thought long and hard
before doing stem cell research.
9
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.

10
(No Transcript)
11
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.h
  tml?_r1refscienceorefslogin

12
Classification

• (ESC)Human embryonic 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)Human embryonic germ cells,
• Fetal Stem Cell (FSC) therapy involves 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)Human Adult 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.

13
(No Transcript)
14
Embryonální kmenové bunky
15
Embryonální kmenové bunky
16
Possible Sources of Embryonic Stem Cells

• Surplus embryos
• Embryos made exclusively in order to receive ESC
• SCNT Therapeutic Cloning

17
Preimplantation Diagnosis
18
Plasticity of ASC
19
(No Transcript)
20
Dr. Woo Suk Hwang

• 24. listopadu 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
21
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.

22
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 or altered human nuclear genome
  that has the potential to develop up to, or
  beyond, the stage at which the primitivestreak
  appears,
• and has not yet reached 8 weeks of development
  since the first mitotic division.

23
Status of Embryo

• Ontological personalism 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.
• Empirical Functionalism there is a diffrention
  between 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.

24
(No Transcript)
25
Arguments for obtaining Embryonic Stem Cells from
embryos

• The prospects are beyond our scope
• Only 30-50 zygote implants. 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

26
Arguments against obtainig Human Embryonic Stem
Cells

• Embryo is not, embryos are. Every embry has a
  unique genetic design
• An Embryo has a potentiality to become an adult
  human person, so we must treat an embryo as a
  person.
• Aristotle four causes
• Immanuel Kant
• the problem of freedom
• difference between cost/value and dignity

27
Aristotle

• causa materialis
• causa formalis
• causa efficiens
• causa finalis

28
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?

29
Cluster of cells Five day old embryo is
composed from150 200 cells, adult human from 5.
1014 cells
30
Arguments for obtaining Embryonic 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

31
Arguments for obtaining Embryonic 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

32
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 inport and usage was shifted to
  01/05 2007

33
Many thanks Marek Vácha