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L.97. Warm-up. L.95 What is the difference between:. a mastectomy and a mammography? Living will and durable power of attorney? CT scan and MRI? Preciptin test and Kastle Meyer test? CDC and WHO? Allocation and procurement? In situ cancer and invasive cancer?
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L.97 Warm-up
L.95 What is the difference between: • a mastectomy and a mammography? • Living will and durable power of attorney? • CT scan and MRI? • Preciptin test and Kastle Meyer test? • CDC and WHO? • Allocation and procurement? • In situ cancer and invasive cancer? • Radiographer and radiologist? • Applied research and clinical research? • Random Question: If a patient weighs 165 pounds, how many grams does he weigh?
R.98 Transgenic Animals
Introduction • Over the past few decades, human and nonhuman animals have benefited from biotechnology. • For thousands of year, we have conducted selective breeding to improve our livestock. • 50 years after the structure of DNA was first discovered, scientists use some of those same microorganisms to produce human hormones and improve our livestock and crops.
What are transgenic organisms? • Organisms which contain other species’ genes within their chromosomes. • In order to produce a transgenic animal, scientists inject a transgene into a single cell organism.
Interesting Fact: • The first transgenic organisms were bacteria because they are the simplest forms of life. • They are still used by pharmaceutical companies today to produce a variety of human proteins such as insulin and human growth hormones.
Use of transgenic techniques in animals: • Models of human disease • A way to improve the quality and health of livestock • Another method to produce pharmaceuticals • A source of organs for humans • A model for gene therapy in humans (e.g., substituting the normal gene for hemoglobin to replace the one that causes sickle cell anemia.
First Transgenic Animal • 1975 – implanted an ape gene into a mouse. • The mouse produced the ape protein but did not pass the gene onto offspring. • Two years later, the same researchers produced the first transgenic mouse strain, whose offspring did contain the implanted transgene.
Success and growing • Transgenic animal production increased rapidly in the 1980s as scientists improved genetic engineering techniques and identified and purified more genes.
The approval process: • Biomedical researchers must go through an approval process to create a transgenic animal by applying for a patent from the US Patent and Trademark Office.
Animal models • They reproduce quickly • They are small animals and therefore easily housed. • Their genetic makeup is better understood than other mammals • Their lifespan is 2-3 years, allowing researchers to follow disease processes from infancy to old age over a relatively short time.
Animal models cont. • Hundreds of mouse strains already exist with spontaneous genetic mutations (flaws within their genes) that resemble human diseases (diabetes, dwarfism). • By producing genetically engineered mutations, scientists have more control over what genes they are studying and don’t have to wait for spontaneous mutations to appear.
Pharmaceutical production • It is reproducible • The amount of drug produced is limited only by the number of successful transgenic animals produced and its offspring. • Maintaining the animal is more economical, compared to the amount of drug produced, than growing cells in tissue culture.
Organ donors • Successful because physicians have an arsenal immosuppressive drugs. • Alternative: using xenografts’ (pigs) • Improving the success rate because of body’s want to reject these organs. • Carry few infectious agents • Reproduce quickly and have large litters • Less social opposition to using pigs than to using non-human primates
Livestock improvement • Transgenic technology could produce animals that are larger, leaner, more efficient at using feed, or more resistant to disease. • Safety of meat or dairy products – people strongly oppose the products of transgenic animals
Care of Transgenic Animals • Do not require special care • Sometimes have a disorder that makes them susceptible to disease. • Scientists use only the healthiest animals and do their best to keep the animals healthy.
Against Transgenics? • There are many ethical considerations to the opposition of transgenic animals: • Animal welfare • “Playing God” • Use the techniques in humans • Threaten our environment, health, food supply
L.97 Processing
L.95 Processing • Now that you know what transgenic animals are, draw a caricature that represents what a transgenic is. • Make it colorful and creative.