Stem Cells

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Stem Cells
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• What is a stem cell?
• Where do stem cells come from?

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What is a stem cell?

• A stem cell is a cell that
• Is unspecialized
• Is capable of dividing and renewing itself for a
  long period of time
• Can give rise to specialized cells

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There are 3 types of stem cells

• Totipotent
• Formed from sperm and egg, has the potential to
  make every cell in the body and the placenta.
• This cell exists for only 5 days following
  fertilization

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• 2. Pluripotent
• Found between 5-10 days of embryo growth, the
  embryo is now called a blastocyst
• These cells have the potential to create every
  cell in the body
• These cells can be isolated from the inner cell
  mass (30 cells) of the of the blastocyst
• These are called embryonic stem cells and are
  used for stem cell research

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Picture of Blastocyst
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How big is a blastocyst?
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• 3. Multipotent
• Called Adult Stem Cells
• Can become a limited number of other cells
• Occur in limited numbers
• May contain DNA damage from aging, radiation,
  sunlight, toxins and random mutations that
  occurred during life

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Embryonic v. Adult Stem Cells

• Embryo
• Come from embryos that are fertilized in petri
  dishes to be used for couples that cannot
  conceive, there are 40,000 being stored
  currently
• Could also be created by joining egg/sperm
• Can become every cell type found in the body

• Adult
• Come from babies, umbilical cords, adults
• Can become some cell types
• Found in some body tissues brain, bone marrow,
  blood, eye, fat, muscle, skin and liver

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First Stem Cells

• The first successful stem cells were reported in
  November of 1998 by a research at the Univ. of
  Wisconsin who removed the cells from spare
  embryos at a fertility clinic. He was then able
  to have these stem cells kept alive without
  specializing in a petri dish.

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Stem Cell Lines

• After the stem cells are harvested they must be
  kept healthy and live for many generations
  without differentiating into specialized cells.
• This is called a stem cell line.
• Cells are then taken from these and used for
  various research projects.

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What can embryonic stem cells be used for?

• Learn how a cell becomes specialized
• Be used to test new drugs decreases amount of
  animal testing, cheaper, faster, and safer for
  human trials.
• Study causes of disease lead to possible
  treatments.
• Study how diseases spread ex Bird flu

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• Repair damaged cells paralysis and spinal cord
  damage.
• Cure diseases diabetes, heart disease,
  parkinsons disease, alzheimers disease, genetic
  diseases etc.
• Grow into new human organs

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The controversy

• Embryonic stem cells are controversial because to
  obtain them they must destroy the embryo.
• People question where the embryos will come from,
  how many embryos will have to be destroyed, what
  are the rights of the embryo?

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What can adult stem cells be used for?

• Have been used successfully for the following
• Heart disease inject new cells into heart after
  heart attacks to replace damaged cells
• Leukemia/Cancer use stem cells from bone marrow
• Rheumatoid arthritis make new cartilage
• Parkinsons disease make new cells
• Type I diabetes make new pancreas cells

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Past Policies

• On August 9th, 2001 President Bush announced that
  federal funds can be used for human embryo
  research IF
• The cells were harvested from the embryo before
  this date
• The embryo was created for reproductive purposes
  and was no longer needed
• The embryo was donated and the donors consented
  and did not receive any money

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What did that mean?

• Any stem cell lines that were already in progress
  could be used but no stem cells could be
  harvested if the project receives any federal
  money.
• Research can be done with private or state
  funding exs California, Harvard

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New Policy

• On March 9th, 2009 President Obama announced that
  federal money would be used to continue stem cell
  research.
• This lifted many of the bans that had been in
  place previously and opened up stem cell research
  to many more scientists and institutions.

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President Obama 3/09 I will ensure that my
administration never opens the door to cloning
for human reproduction. It is dangerous,
profoundly wrong and has no place in our society
or any society.
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Ethical Debate

• Are the rights of the embryo more or less
  important than the people who could benefit from
  the research?
• Some reports estimate that 100 million Americans
  suffer from diseases that may be cured using stem
  cell research.

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