Transcript Challenges to Biomedical Research

Challenges to Biomedical
Research
Personal Beliefs About
Biomedical Research
1. There are different beliefs about
biomedical research
2. Differences between fact and opinion
There are Facts and Myths in
research
What do you believe
is the role of
animals in society?
Biotechnology
• Biotechnology = recreation
and reinvention of nature
• It deals with the manipulation
of living organisms in order
to make or improve products
• Biotechnology has been
practiced for thousands of
years. It dates back to when
man first learned how to
plant crops and breed
animals.
Transgenic Animals
Early beginnings of
Biotechnology = collection
of scientific techniques that
use living cells and
molecules to make
products and solve
problems.
Historically used in selective
breeding of livestock, controlled
plant pollination, and
microorganisms to bake bread,
brew beer and make cheese
Transgenic Organisms
Plant, animal, or
bacteria that has
been genetically
modified to
contain a gene
from a different
species.
Transgenic Organisms
• First created
in a
laboratory!
• A biomedical researcher must apply for a
patent from the US Patent & trademark
office to receive an approval once they
create a transgenic animal or product.
Most consumers do not want to
purchase genetically modified
produce.
Genetically Modified Organisms
• New tecnique = 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.
• Can be used to make newly born
animals grow quicker and fatter to
make more meat more quickly.
• Problem = 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 of genetically modified
organisms.
Early Beginnings:
Historically- used in selective breeding of
livestock, controlled plant pollination, and
microorganisms to bake bread, brew beer,
and make cheese.
Streptococcus lactis and
other lactic acid bacteria
are used to make cheese.
They ripen the cheese
and provide characteristic
flavour.
This is
accomplished by
transferring
specific genes
from one species
to another.
First, transgenic
organisms
were bacteria !
Scientists around the world use customized
transgenic animals for their research.
Including: sheep, goats, cows, chickens,
pigs, mice, rabbits, rats, and fish.
MICE are used mostly in
research laboratories!
Transgene = a gene transferred
from one organism to another
• When producing a
transgenic animal
scientists get a
transgene into
another organism
by injecting it into a
single cell
embroyo.
Benefits of Transgenic Animals:
Benefits include:
- animal modules
- pharmaceutical production
- organ donors
- livestock improvement
PHARMING
• Use of transgenic
animals to produce
substances used in
medicine.
Xenograft
• When transplanting a
major blood vessel
into a patient, where
would the xenograft
come from?
• Rejection is the
biggest challenge with
pig organs in human
transplants.
PIGS
BACTERIA
• Pharmaceutical companies use bacteria to
produce insulin.
Current use of transgenic
model
• Transgenics are
an established
part of biomedical
research.
Production of Transgenic
Animals
The following steps are followed to produce
a transgenic animal….
Production of Transgenic Animals
1. The transgene ( which contains the
DNA, the scientist wants to transfer)
is injected into a single-cell embryo.
2. The embryo is transferred to a
surrogate mother of the same strain.
Production of Transgenic animals cont.
•
•
Success rate is low (10%-30%) in mice
Success rate decreases in mammals
Care of Transgenic Animals
1. Most do not require special care.
2. Some develop a susceptibility to disease.
Government’s role in transgenic animals:
1. U.S. Patent and Trademark Office issues patents for transgenic animals.
2. Only government policy is NIH guidelines for research involving
recombinant DNA molecules.
Ethical Considerations
Opposition
• Transgenic animals
threaten our
environment, health
& food safety.
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.
Future of Transgenic Animals
(cont.)
3. Possible effects of foreign DNA remains
a concern.
4. The use of transgenic models is an
established part of biomedical research.
Evaluate therapeutic vs. reproductive
cloning
History Of Cloning
Dolly the sheep - First
cloned mammal in 1997
Very few scientists
believe human cloning
(called reproductive
cloning) should be
permitted.
History Of Cloning
Most medical scientists support and are in
favor of therapeutic (beneficial) cloning.
The procedure used to produce embryonic
stem cells that, theoretically, can be used
to treat diseases.
What is a Clone?
• Clone = precise
genetic copy.
• Reproductive cloning
is really somatic cell
nuclear transfer
(SCNT).
What is a Clone?
• In therapeutic cloning,
the embryo is not
placed in a surrogate,
but rather, undergoes
cell division in the lab
until it reaches a
specific (blastocyst)
stage.
• This is a procedure that
allows a longer time for
the embryo to develop in
the laboratory (five days
instead of two to three).
This enables the embryo
to reach the Blastocyst
stage, which is the
natural embryonic stage
for implantation in the
uterus.
C.
Obstacles to Reproductive Cloning
Using Animals
• The Success rate is very low
• Vast majority of problems occur during
fetal development.
• Additional problems show up after birth
and years later.
Obstacles to Reproductive Cloning
Using Animals
“Large Offspring Syndrome”Cloned newborns 20-30% larger than usual,
making it hard to deliver unborn babies.
Status of Human Reproductive
Cloning in the World
• There is NO evidence
of successful human
cloning in the world.
Stem Cells
• Adult Stem Cells are
undifferentiated cells,
found throughout the
body after embryonic
development, that
multiply by cell division
to replenish dying cells
and regenerate
damaged tissues.
Embryonic Cells
• The purpose of
performing embryonic
stem cell research is
to develop new and
better ways to treat
disease.
They come from a
fertilized egg.
Why are Stem Cells so important
to Medical Researchers?
They are important to
medical researchers
because they are
needed to create
perfectly matched
tissues to treat an
individual disease or
disorder.
When would someone need an
adult stem cell transfusion?
• When radiation treatment for Cancer has
destroyed the patient’s stem cells.
• When antibiotics are no longer successful
in fighting infection.
• When a person is severely anemic as a
result of gastrointestinal bleeding.
Differences Between…
• Reproductive Cloning:
– The Goal of this is to create a new organism,
human or other animal.
• Therapeutic Cloning:
– The goal of this is to produce embryonic stem
cells.
Human Stem Cell Research
• In 2001 legislation allowed federal funding
of research using 64 existing human
embryonic stem cells.
• Same legislation declared no federal funds
for additional research.
• To create a new human stem cell line,
scientists would have to receive private
funding!
Therapeutic Potential of Stem
Cells
Researchers must use existing human stem
cell lines for research
or find private
funding resources.
Creation of embryonic
stem cells does not
use an egg fertilized
in a woman’s body.
Therapeutic Potential of Stem
Cells
On the other hand. . . It (the stem cell) does
have the potential to become a living thing
if transplanted into the uterus.
Question
Is life destroyed if the stem cells are
removed from the blastocyst four days
later?
Therapeutic Potential of Stem
Cells
Real advantage of Stem Cells – Permits the
production of perfect-match tissue.
Scientists have found that embryonic stem
cells pick up cues from neighboring cells
and differentiate into that cell type.