Transcript Challenges to Biomedical Research

Challenges to Biomedical
Research
(Student Guided Notes)
updated 5.2012
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BT11.01
Interpret personal beliefs about
biomedical research.
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A.
Personal Beliefs About Biomedical
Research
1. There are different beliefs about
biomedical research and they vary widely.
2. What is the difference between fact,
opinions and myths
(Activity in NCABR: Unit III Ch. 1 page 1.3; 1.8 and 1.13)
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Biotechnology
• Biotechnology is basically
known as the recreation and
reinvention of nature. It deals
with the _______________ of
living organisms in order to
make or improve products,
enhance plants and animals
or generate ______________
to make human life and the
environment better.
Biotechnology has been
practiced for ___________ of
years. It dates back to when
man first learned how to
plant crops or breed animals.
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BT11.02
Analyze transgenic animals
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Transgenic Animals
Biotechnology- collection of
scientific ___________ that
use living cells and
molecules to __________
products and
_____________ problems.
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Transgenic Organisms
Plant, animal, or
bacteria that has
been ________
____________to
contain _________
species’ genes
within their
chromosomes.
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This is
accomplished by
_____________
specific genes
from one species
to another.
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A.
Early Beginnings:
Historically- used in selective breeding of
livestock, controlled plant pollination, and
_________________ to bake _________,
brew beer, and make __________.
Streptococcus lactis and
other lactic acid bacteria
are used to make cheese.
They ripen the cheese
and provide characteristic
flavour.
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Early Beginnings: (cont.)
First, transgenic
organisms were
_______________.
Remember the
bread, beer and
cheese? What about
a few of these other
items?
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Transgenic Organisms
• The first transgenic
organisms were
bacteria and were
created in a
_________________!
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BACTERIA
• Pharmaceutical companies use ___________
to produce insulin, human growth hormone,
interferons to treat cancer.
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The technologies used to produce
transgenic animals has become so well
defined that scientists around the world
use customized transgenic animals for
their own research.
- These include: sheep, goats, cows,
chickens, pigs, mice, rabbits, rats, and
fish.
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B. 1
Benefits of Transgenic Animals:
Scientific research uses animal models and mice
are used most often because they:
• They reproduce quickly
• Small and easily housed
• Their genetic makeup is easily understood
• Their lifespan is 3-4 years so researchers can
follow a disease from infancy to old age quickly
• Transgenic mice are used to study cancer,
multiple sclerosis, muscular dystrophy,
Alzheimer's and immune deficiencies
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____________ are the animals
most often used in research
laboratories!
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B.2 Pharmaceutical production or
PHARMING
•
In the past, drug companies would produce drugs by growing
mammalian cells in tissue cultures.
•
Now they use ______________ animals to produce more substances
used in medicines by introducing the gene into larger farm animals.
•
It is more economical than using bacteria in the lab.
•
These substances are then used in medicine and it is called
______________________________.
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B.3 Organ Donors –
_____________________ -using organs
from other species
• When transplanting a
major blood vessel into a
patient, what animal was
the xenograft from?
_________
• _____________ is the
biggest challenge with pig
organs in human
transplants.
• Production of pigs whose
organs look more
“____________” or
“__________” our
immune system.
PIGS
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B.4
Livestock improvement
• Agricultural researchers realized that
transgenic technology could produce
animals that are larger, leaner and more
resistant to disease.
• It is very expensive.
• Opposition-Some people are afraid to eat
the meat and drink the milk from
transgenic livestock.
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Most consumers _____ _____
_____________ to purchase
genetically modified produce.
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Genetically Modified Organisms
• A newly discovered technique in the
food industry is that of Genetic
Modification and GMO's. This is
where, through science, a tomato can
have a gene from fish added to it to
make it have a longer shelf life.
• Also, the same technique can be
used to make newly born animals
grow quicker and fatter to make more
meat more quickly.
• All of this sounds good but by
changing the way these organisms
are made up, we are altering nature in
a very unpredictable and dangerous
way.
• We simply do not know what the long
term effect will be.
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C.
Production of Transgenic
Animals:
The following steps are followed to produce
a transgenic animal.
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1.
The transgene ( which contains the
_________ the scientist wants to
transfer) is injected into a
_________ _____
_________________.
2. So it is transferred from one organism
to another (_______________)
3. The embryo is transferred to a
________________ mother of the
same strain who has been given
hormones so the eggs can implant
and grow.
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Statistics of Transgenic animal
success:
4. Success rate is low (10%-30%) in mice
• 100 mouse embryos are microinjected
• 60% survive and are reimplanted
• 30% of these are born (18)
• 10-30% of the 18 are actually transgenic- the
transgene successfully copied itself
5. Success rate decreases even more in other
mammals because of their size. (cows)
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D. Care of Transgenic Animals
Most do not require special care.
However some develop a susceptibility
to disease which then requires special
care, food, water, antibiotics, etc.
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E.
Government’s role in transgenic
animals:
• Before you create a transgenic animal
researchers must apply for a _________
from the __ ___ _______ and ________
Office
• NIH (National Institute of Health)
guidelines are the only government
policies written for research involving
recombinant DNA molecules
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F.
Ethical Considerations
of Transgenic Animals
Opposition 
• Transgenic animals
______________ our
environment, health & food
safety.
• Some believe we are playing
____________.
• Some believe scientists will
use these techniques on
__________________.
• There was opposition in 1997
when Dolly the sheep, a
mammal was cloned.
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Those in favor, say “Aye”
• Scientist believe that through transgenic
animal research:
–
we will be able to find cures for diseases
• Cancer, sickle cell anemia
– medications to save lives
– production of organs for transplants
– and food to feed the hungry
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G.
Future of Transgenic Animals
1. Current research limited to transferring
small amount of genes at a time.
2. Much work remains to be done to finetune techniques and decrease the risks.
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Future of Transgenic Animals
(cont.)
3. Possible effects of foreign DNA remains
a concern.
4. The use of “transgenic models” is an
________________ part of biomedical
research. It is _________ to stay!
5. This is your future
in science.
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Current use of transgenic model
Remember science
is always evolving.
Biomedical
technology and
the use of
transgenic
animals are vital to
our future!!!
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BT11.03
Evaluate therapeutic vs.
reproductive cloning
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CLONING
• Cloning may be the most discussed
--- and most misunderstood --- issue in
biomedical research today.
• What do you think of when asked about
cloning?
– Dolly the sheep?
– Twins in your neighborhood? 3:1,000 births;
“natural cloning”
– Star Wars Episode II: Attack of the Clones?
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So….What is a Clone?
• Clone =
precise ______
copy.
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3 types of cloning
• ________________ DNA Cloning
– Utilizes microorganisms for new products,
manipulating DNA-most often uses bacteria
• __________________ Cloning
– Reproductive cloning is really somatic cell nuclear
transfer (SCNT) but we usually say the word
“Cloning”.
• __________________ Cloning
– Embryonic Stem Cell Production
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Cloning
Very few scientists believe human cloning
(reproductive cloning) should be permitted.
However most medical scientists support & are in
__________ of therapeutic (beneficial) cloning.
Therapeutic Cloning is the procedure used to
produce embryonic stem cells that
theoretically can be used to treat diseases.
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A.
History Of Cloning
• _________ the sheep
- First cloned
____________ in 1997.
• She is an example of
___________ Cloning
• She was euthanized in
2003 due to a lung
disease.
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Quick Discussion on Reproductive
Cloning
(how it is done)
• The nucleus is removed from an unfertilized
egg- this is called “enucleated”.
• The nucleus of a cell removed from the animal to
be “cloned” is inserted into the enucleated egg.
• The reconstituted embryo is then placed in the
uterus of a surrogate mother and carried to full
term.
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C.
Obstacles to Reproductive Cloning
Using Animals
• The Success rate is very low—3 in 100
cloned embyros
• Vast majority of problems occur during
fetal development.
• Additional problems show up after birth
and years later.
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Obstacles to Reproductive Cloning
Using Animals
“Large Offspring Syndrome”Cloned newborns 20-30% larger than usual,
making it hard to deliver unborn babies.
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Human Reproductive Cloning
(which is not being done in the US today)
• Fyi---don’t take notes, just read
• For human cloning, a female would donate
her eggs to be enucleated.
• The nuclei of her cells would be removed
and the person being cloned would donate
somatic cells for the nuclear transfer.
• A surrogate mother would then accept the
fertilized ova in hopes of carrying one to
term.
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Status of Human Reproductive
Cloning in the World
• There is ________
evidence of
_________________
human cloning in
the world.
• Remember:
Reproductive cloning
is really somatic cell
nuclear transfer
(SCNT) but we
usually say the word
“Cloning”.
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Now to discuss Therapeutic
(beneficial) Cloning
• In therapeutic cloning,
the embryo is not
placed in a surrogate,
but rather, undergoes
cell division in the lab
until it reaches
blastocyst stage.
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• This is a procedure that
allows a longer time for
the embryo to develop in
the laboratory (five days
instead of two to three)
and enables the embryo
to reach blastocyst stage.
A blastocyst contains 2
layers: the inner mass
can form virtually all of
the tissues of the body.
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Therapeutic (beneficial) Cloning
cont.
• To obtain embryonic stem cells, the
blastocyst is opened, and the inner cell
mass is placed in tissue culture.
– So it is NOT placed in a surrogate; it is placed
in a tissue culture in a lab setting
• In culture, the cells divide and make the
exact copies of themselves, forming
“clones”. This means MORE embryonic
stem cells that can grow into tissues to
treat diseases.
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There are 2 classifications of stem
cells: adult and embryonic
• Adult Stem Cells are
undifferentiated cells,
found in small amounts
throughout the body after
embryonic development,
that multiply by cell
division to replenish dying
cells and regenerate
damaged tissues. Most
often found in the
________ ____________.
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When would someone need an
adult stem cell ______________?
• When _________ treatment for ________
has ____________ the person stem cell’s.
– A patient may freeze their own bone marrow
before the radiation treatments and receive a
transplant of their own bone marrow which
has adult stem cells present. These cells will
reproduce RBC, WBC and platelets.
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Embryonic Stem Cells
• A recently _____________ egg is “totipotent” which means it has
the potential to become any kind of cell
• During the first rounds of cell division, each cell has the potential to
form a fetus (this is how we get identical twins)
• After 4 days, a blastocyst develops- and the inner mass of
embyronic stems becomes pluripotent-which means they have the
potential to become many types of cells, but no longer every typewhich means they can no longer become a fetus.
• Parents of newborns can now bank baby’s umbilical cord blood in
case their child needs new stem cells later in life.
• Scientists think these stem cells work better than bone marrow
because they are less “mature”.
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Embryonic Stem Cells
• The purpose of
performing
embryonic
stem cell research
is to develop
_______ &
_____________
ways to treat
___________.
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Embryonic Stem Cells
• Embryonic Stem Cells are the so-called
starter cells that can turn into any sort of
body tissue, from brain to bone to blood.
• These unspecialized cells can divide for
indefinite periods in vitro.
• The scientists hope the embryonic stem
cells will generate specific tissues to help
repair damaged and diseased organs.
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Why are Stem Cells so important to
Medical Researchers?
They are important to
medical researchers
because they may be
used to __________
perfectly __________
_______________ to
treat an individual
_____________ or
disorder.
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E.
Differences Between reproductive
and therapeutic cloning:
• Reproductive Cloning:
– The Goal of this is to create a new organism,
human or other animal.
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• Therapeutic Cloning:
– The goal of this is to produce embryonic stem
cells.
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Remember…….
Very few scientists believe human cloning
(reproductive cloning) should be permitted.
However most medical scientists ____________ &
are in favor of ___________ (beneficial) cloning.
Therapeutic Cloning is the procedure used to
produce embryonic stem cells that
theoretically can be used to treat diseases.
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F.
Human Stem Cell Research
• In 2001 legislation allowed federal funding of
research using 64 existing human embryonic
stem cell lines.
• Same legislation declared no federal funds for
any other research or cloning of human embryos
for any purposes.
• This decision did not affect research funded by
private companies or state government so if a
scientist wants to __________ a __________
stem cell line they could with ___________
funding.
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G.
Therapeutic Potential of Stem Cells
Researchers must use existing human stem
cell lines for research or find private
funding resources.
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The creation of
embryonic stem cells
does not use a
fertilized egg.
This method instead
uses an unfertilized
egg, with its nucleus
removed and fuses it
with the genetic
material from an
adult’s body.
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Therapeutic Potential of Stem Cells
(cont.)
On the other hand. . . It does have the
potential to become a living thing if
transplanted into the uterus.
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Question
Is life destroyed if the stem cells are removed from the
blastocyst four days later? This is the question at the
core of the debate about stem cell research.
As noted in slide 48 a fertilized egg is used but it is
allowed to grow to a blastocyst stage.
After 4 days, a blastocyst develops- and the inner mass of
embyronic stems becomes pluripotent-which means they
have the potential to become many types of cells, but no
longer every type- which means they can no longer
become a fetus.
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Therapeutic Potential of Stem Cells
(cont.)
Real advantage of Stem Cells – Permits the
production of perfect-match tissue.
Scientists have found that embryonic stem
cells pick up cues from ___________ cells
and differentiate into that _______ type.
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Therapeutic Potential of Stem Cells
(cont.)
Scientists hope stem cells will be used to
treat ________ disease, Parkinson’s and
other diseases of the __________ system.
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WHAT IS YOUR OPINION?
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