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The Power of Stem CellsThe Power of Stem Cells
Frontiers In Biology
Dr. K. S. Dulai
Spring 2008
Frontiers In Biology
Dr. K. S. Dulai
Spring 2008
What's all the fuss about!
oStem cells are incredibly valuable to scienceoThey have the capacity to develop into any type of cell in the bodyoThey have the potential to be used for almost anything…
Headline news Past decade been in the news Potential use in treating diseases Political, ethical, moral, scientific concerns Need human embryos
These die as a result of harvesting embryonic stem cells
The embryos come from; Unneeded in-vitro fertilization clinics Terminated pregnancies Embryo harvesting strategies
Specialized cellsSpecialized cells
An human adult is made up of over 200 different types of specialized cells Liver Brain Heart Red blood cells Bone Photoreceptors, etc
Stem Cells Each of the specialized cells arose from a
less specialized cell - which itself arose from a lesser specialized one - these are the stem cells.
Every cell in the body (bar the red blood cells
and the gametes - [sperm and egg]) has a nucleus with the same amount and quality of DNA - so each still has the capacity to make any other cell of the body
What are stem cells?
They are cells which have the potential to develop into other specialized cells.
There are many different types of stem cells Adult Stem Cells - multipotent
• All over your body • i.e. lining of the gut• i.e. there are special stem cells that give rise to the B and T cells of the immune
system - no other just these Embryonic Stem Cells - pluripotent
• Are different - see later… Fetal stem cells - pluripotent
• Stem cells taken from aborted fetal tissue Umbilical stem cells - multipotent
• Stem cells take from umbilical cords - treatment of blood disorders
New science Stem cells are at the center of a new field of science called
regenerative or reparative medicineregenerative or reparative medicine Involves isolation of stem cells Growth of these in special environments Harvesting and use Cures for
Cancer? Diabetes? Parkinson's Disease? Organ failure?
Already used in treating leukemia
Where did all the cells come from?
When fertilization took place between a sperm and an egg there was just one cell - the zygote - which is totipotenttotipotent
This one cell underwent cell division to form 2 cells - the embryo - which is also totipotenttotipotent
These 2 cells divided to 4 cells, then 8, then 16, 32, 64…
QuickTime™ and aTIFF (Uncompressed) decompressor
are needed to see this picture.
Simple embryo At about 50-150 cells (4 days or so for humans) there is a defined structure to the embryo
We have the outer sphere of cells (which will form the placenta),
and nested within it are some very special cells, the inner cell mass - these will make the baby - these are the embryonic stem cells which are the subject of news.
Each of these has the capacity to form any tissue of the body
To harvest these one has to destroy the embryo! Is the embryo a human life at this time or not?
No federal funding of new embryonic stem cells G. W. Bush permitted cells that existed prior to 2001
to be used for research, but declared ineligible for federal funding any new
lines Private funding is OK - California voters opted to
allow $3 billion of state money to fund stem cell research here.
Research continues in other countries - U.K., China, India, Israel, etc.
All three presidential candidates have plans to fund stem cell research with federal money!
Adult stem cells Undifferentiated stem cells Also known as somatic stem cells - found in
children and adults Organ or tissue specific -
Heart stem cells can give rise to just heart tissue. Bone stem cells can give rise to just bone and blood cells.
Does not demand the destruction of an embryo! Can be grown indefinitely - they self renew!
Real world uses StemCells Inc. of Palo Alto, California, recently announced successful early-stage
trial results used stem cells to treat a patient with
Batten's disease, a fatal neurodegenerative disorder
Injected into the brain of patient stem cells designed to stimulate the production of an enzyme that's missing in such patients
IT WORKED!
Park in sons Parkinson’s is one example of successful stem
cell therapy: Primate studies show fetal stem cells can
reverse Parkinson’s disease Parkinson’s is a muscle degeneration disorder
that affects over 1,000,000 people in the United States, and new cases being added at 9 per minute.
The disease works in the exact opposite way as Alzheimer’s does…
Parkinson’s Disease Parkinson’s begins with tremors and stiffness
eventually leaving the patient unable to • Move• Speak• Swallow
It leaves a perfectly good mind trapped in a useless body, unable to move
In recent studies done on primates who were injected with a neurotoxin that causes
severe nerve damage, all symptoms were reversed after fetal stem cells
were transplanted into the animals
M. J. Fox
Ad Interview
New Promise - Reverted Adult Stem Cells Two groups have transformed skin cells into
something very similar to embryonic stem cells. Using special genes added to the cells, the
teams tricked the cells into reverting back to their embryonic state.
Early days Solves the ethical issues! Self cells can be used easily.
Watch the video and answer these questions
1. Where was the research performed?
2. Who performed this research?
3. Which organs were made in the lab?
4. Which animal had a broken back?
5. Who donated the eggs for the research?
6. Whose nuclear DNA was used for the stem cell therapy experiments?
7. How many tries did it take the scientist to get the first dividing human embryonic stem cells?
Group questions
1. Is the embryo a human being yet? Why or why not? When would you consider it to be?
2. Would you use stem cell research to help with curing a sick relative or child, if you had to?
3. What problems do you see materializing with respect to using human embryonic stem cells?
4. Should there be checks and balances to make sure the scientists behave and do not abuse the technology? What would these be?
5. Would you be willing to accept a organ grown in another animal, such as a pig?