Post on 05-Jan-2016
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:
Streptococcus lactis and other lactic acid bacteria are used to make cheese. They ripen the cheese and provide characteristic flavour.
Historically- used in selective breeding of livestock, controlled plant pollination, and microorganisms to bake bread, brew beer, and make cheese.
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 include:
- animal modules
- pharmaceutical production
- organ donors
- livestock improvement
Benefits of Transgenic Animals:
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.
The following steps are followed to produce a transgenic animal….
Production of Transgenic Animals
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: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 fine-tune 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 ReproductiveCloning 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 fertilized egg.
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.