What are stem cells ETHICS IN SCIENCE by liaoqinmei


									Embryonic Stem Cell
Why must it continue?

 Presented by: Alvin Bulahan, Areum
        Kang, William Dizon
         Goals of Stem Cell Research
   A primary goal of this work is to identify how undifferentiated
    stem cells become differentiated.

   The most important potential application of human stem cells is
    the generation of cells and tissues that could be used for cell-
    based therapies.

   These cells could be used for curing debilitating diseases, e.g.,
    Parkinson's, Alzheimer's, diabetes, stroke, spinal cord injuries,
    etc.; and screening drugs for pharmaceutical companies, instead
    of having to rely on animal models.
   http://www.cord-blood-video.com/
         What are stem cells?
   These cells are capable of dividing and
    renewing themselves for extended

   They are unspecialized cells.

   They can give rise to specialized cell
 Internal and External signals which
      control cell differentiation.
1.   Internal signals - are controlled by a cell's
     genes, which are scattered across strands of
     DNA, and carry instructions for all the
     structures and functions of a cell.

2.   External signals – for cell differentiation,
     include chemicals secreted by other cells,
     physical contact with neighboring cells, and
     certain molecules in the environment.
           Embryonic Stem Cells

   Embryonic stem cells are derived from embryos that
    develop from eggs which have been fertilized in vitro,
    in an in vitro fertilization clinic, and then donated for
    research purposes.

   The embryos are typically four or five days old and are
    a hollow microscopic ball of cells.

   Ultimately the embryos are destroyed, at the time which
    the stem cells are isolated.
    Human embryos alive or not?

                                     Dr. James Sherley
                                     Professor at MIT

   “Despite the confusion that some like to create on the
    questions of “are embryos human beings?” and “when
    does a human life begin?”, both scientists and physicians
    know very well that human embryos are alive and human.
    A human life begins when a diploid complement of
    human DNA is initiated to begin human development.”
   “The embryonic, fetal, infant, child and adolescent
    stages are stages of development of a determinate and
    enduring entity -- a human being.” - Robert P. George, a
    member of the President's Council on Bioethics
   If we know that embryos are human beings, then why
    does embryonic stem cell research continue?
   Knowing that embryos are human beings, further
    argues the fact that embryonic stem cell research is
    both morally and ethically wrong.
     Is stem cell research ethical?
   International documents
       Nuremburg Code

       World Medical Association's Declaration of Helsinki

       United Nations Declaration of Human Rights
    Is stem cell research ethical? Cont’
   Canadian Institutes of Health Research (CIHR)
       A non profit organization founded in 1975

   The ethical problem of human embryonic stem cell research is
    the source of the cells. Living human embryos must be destroyed
    in the process of taking their stem cells. It is never ethically
    acceptable to intentionally destroy a human being, no matter
    how small.

   An ethic which condones research using human embryos
    violates the standard ethical principle in medicine of non-
    maleficence. It devaluates human life, damages the integrity of
    science and medicine, and degrades society as a whole.
   Other methods exists in which stem cells could
    be collected.
          Skin and Fat
          Cord blood

          Adult stem cells

          Bone marrow stem cells

       In addition to the morality of it attention should also
        be paid to its practicality.
             Dive Into Some Truth
   Moral debate on stem cell research is abundant, yet a different
    approach to looking at stem cell research is just as, if not more,
    important in considering the ethics to it.

   While public opinions clash, the actual science of stem cell
    research has been assumed to be flawless in their eyes, and
    supporters of stem cell research point to all the medical
    advantages of stem cell transplantation in their arguments for it.

   Virtually everyone fighting stem cell research battles the claim of
    numerous medical benefits with moral and religious beliefs.
    There are significant disadvantages to
     embryonic stem cell transplantation and
     potential dangers to those procedures
     that are being overlooked.

    Questioning the ethics of stem cell
     research is even more imperative when
     the fact that there are an array of
     problems with the procedure, as well as
     medical side effects, is considered along
     with the moral arguments.

    Stem cell research can be very strongly
     opposed on the basis of its SCIENCE,
     which should be analyzed by the public
     much more than it has been so far.
                        The Science
   What caused the initial excitement over stem cell research was
    that, in culture, extracted embryonic stem cells kept the ability to
    grow into a number of various cell types when supplied with the
    proper signals.

   This led to all the theories of the replacement of targeted cells,
    and growing back needed tissues, for example, which sparked
    enormous public interest.

   While these theories are hopeful and exciting, the quest to find
    the right signals that induce the formation of targeted tissues
    from embryonic stem cells has been extremely difficult and still
    going on today.
                Totipotency Hopes
   Excitement surrounds the
    totipotency concept of
    embryonic stem cells – their
    ability to grow into any of the
    mature cell types of the body.
   For example, embryonic
    stem cells placed in a
    damaged kidney and given
    the proper signals would
    grow into kidney cells and
    generate new kidney tissue.
            Totipotency Questions
   There exists the questionability of the totipotency of
    stem cells in culture, and whether they would retain that
    property as well as they do in the body before they are
   In addition to the difficulty of finding the right signals
    to induce those implanted stem cells to grow into
    kidney tissue, there is also the danger of the cells
    themselves acting differently after being first cultured
    and artificially induced instead of being signaled
       There may be a chance that the cells hardly or DO NOT act
        like kidney cells at all physiologically.
            Quotes on Totipotency
   “Among the major obstacles is the difficulty of getting
    embryonic stem cells – master cells that generate every tissue in
    the human body – to become exactly the type of cell one
    wants… Scientists…haven’t been able to guarantee purity – cells,
    for instance, that are destined to become muscle cells and
    nothing else…
    - Jonathan Bor, Baltimore Sun

   “It is extremely laborious to keep to keep embryonic cells
    growing, well-nourished and stable in the lab so they don’t die or
    turn into a cell type with less potential.”
    - Tony Blau, Stem-cell Researcher, University of Washington
Transplantation and Immunology
                  The same immunological issues
                   associated with organ
                   transplantation also apply to stem
                   cells, since generally cells from one
                   individual will be placed into

                  Rejection of the cells would still be
                   very possible, where they would
                   eventually be targeted and
                   destroyed by the immune system.

                  Stem cells would most likely
                   provide only a temporary solution
                   instead of a permanent cure.
         Dangers in Circumvention
   To get around the immunological barriers, scientists have
    proposed to genetically engineer the embryonic stem cells to
    produce a better match with the individual receiving them.
       The procedure is very risky in that mutations may occur and produce
        potentially dangerous effects once the stem cells are implanted in the

   Another idea has been for a bank of human embryos, much like
    a blood bank, to be created so that there can be a variety of stem
    cells with different immune characteristics that can be matched
    to the appropriate patients.
       This would only fuel the moral argument against stem cell research to an
        extremely elevated level, since embryos may eventually be produced
        SOLELY for the use of research and not because they were previously
        unused by pregnancy methods.
           Quotes on Practicality
   “ES [embryonic stem] cells and their derivatives carry
    the same likelihood of immune rejection as a
    transplanted organ because, like all cells, they carry the
    surface proteins, or antigens, by which the immune
    system recognizes invaders. Hundreds of combinations
    of different types of antigens are possible, meaning that
    hundreds of thousands of ES cell lines might be needed
    to establish a bank of cells with immune matches for
    most potential patients. Creating that many lines could
    require millions of discarded embryos from IVF
    clinics.” - R. Lanza and N. Rosenthal, “The Stem Cell
    Challenge,” Scientific American
              Stem Cells in Culture
   There is undeniably a vast array of non-molecular
    factors that exist within a complete embryo that plays a
    role in stem cell differentiation and development
   The task of replicating all these factors to the EXACT
    degree so as to get the perfect results from the targeted
    stem cells presents a highly improbable goal.
   Even more danger exists in incomplete activation of the
    stem cells -
       Implanting these abnormal cells could lead to the
        uncontrolled rapid growth of deadly tumors starting in the
        implant site called tetromas.
Problems on both ends
              Not only is proper
               stimulation to encourage
               the targeted type of
               differentiation daunting,
               but controlling the
               growth of the cells and
               being able to stop them
               without causing harm to
               the patient would pose
               an even more difficult
                       Alternatives exist
   The ethics against stem cell research are clearly backed by issues of practicality
    and danger in its procedures as well as the immorality of it.

   There has not been nearly enough success in similar experimentation methods
    in animals, so shifting the focus toward human embryos is hardly called for.

   Stem cell research should also be discouraged by the fact that a breadth of
    safer and less morally controversial alternatives that have the same benefit
    hopes do exist, and have in fact been met with significant success.
        “Embryonic stem cells have too many limitations, including immune rejection and
         the potential to form tumors, to ever achieve acceptance in our lifetime. By that
         time, umbilical cord blood stem cells will have been shown to be a true ‘gift from
         the gods.’” – Dr. Roger Markwald, Medical University of South Carolina
            What is Cord Blood?
   Also known as the “placental blood”
   blood that remains in the umbilical cord and
    placenta following birth and after the cord is cut
   a valuable source of stem cells
   genetically unique
     How to collect the cord blood
   patient will bring the cord blood collection kit to the
    hospital at the time of the delivery
   After the baby has been born and the cord has been
    clamped and cut, the blood will be drawn from the
    umbilical cord into a syringe or blood bag by the doctor
   It can be performed in vaginal or cesarean deliveries
    and for multiple births
   No effect on normal delivery procedure
       http://www.cord-blood-video.com/
       Why are cord blood stem cells
         different from others?-1
   No ethical issues involved like the embryonic
    stem cell research
   Adult stem cells serve very specialized roles -
    not as proliferate as cord blood cells
   More opportunity for transplants between
    family members
   Significantly less transplant rejection
      Why are cord blood stem cells
        different from others?-2
   Cord blood collection is easy and risk-free
   Cord blood is collected in advance, tested, and
    stored frozen, ready to use – immediate
   Cord blood doesn’t require a perfect match
    unlike bone marrow - better chance for a
    suitable donor
          What are the choices?
   Public Donation

   Family Banking

   Throw it away
               Three Standard
   The unit must be large enough (typically three to
    five fluid ounces)
   The maternal and family health history must
    meet eligibility guidelines
   Tests of the cord blood unit and the mother's
    blood sample must show no signs of infection
    or other possible problems
             Public Donation
Pros                      Cons
 Can help others in       Donated cord blood
  need                      cell is not reserved for
 Provides Higher           your family
  chance of match due  Some donated cord
  to the potential of the   blood unit cannot be
  cord blood cells          stored in the public
                           Not many public
                            banks developed
             Family Banking
Pros                      Cons
 Provides the perfect     Costs involved to
  match for the child       bank privately
 Eliminating the risks    Generally, one time
  of rejection              enrollment fees
 Can be used to treat     Annual storage fees.
  family members too
      Where is it standing now?-1
   December 16th, the U.S. Senate voted by
    unanimous consent to adopt the Stem Cell
    Therapeutic & Research Act of 2005
   December 17th, the U.S. House of
    Representatives adopted, by unanimous vote,
    this amended version of the bill
   December 20th, President Bush signed this
    legislation into law
    Where is it standing
  This new legislation authorizes $79
million in new federal funding for the
collection and storage of cord blood units
from ethnically-diverse cord blood donors
and the establishment of a public cord
blood bank network
         What can we do to make a
   Write a legislative bill on making a law to require
    parents to sign a paper on what they want to do
    with the baby’s umbilical cord.
   Fundraising for increasing public banks, and
    lowering the price for family banking
   www.nih.gov
   www.stemcellresearch.org
   www.usccb.org

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