Reading...
Play button
Play button
Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
12 Cards in this Set
- Front
- Back
- 3rd side (hint)
|
What is a "label"?
|
In radiopharmacy it is the radioactive tag on a molecule
|
|
|
|
What is an isotope exchange reaction?
|
Simply an atom in a molecule is replaced with the same atom but it is a radioactive isotope
do radioactive isotopes have the same chemical properties as their stable counterparts? |
Yes, except in some rare conditions
|
|
|
What is the process of introducing a foreign label in labeling pharmaceuticals?
|
the most frequently used method in labeling. introduction of a foreign radionuclide atom to a biologically active molecule.
What is an example of this? |
All Tc99m compounds and F18 fluorodeoxyglucose
|
|
|
What is biosynthesis and how is it incorporated into radiopharaceutical labeling?
|
It is when a radioactive tracer is added to a living culture which is ingested and the organism produces metabolites with the tracer.
what is an example of this? |
Co60 or 57 added to steptomyces griseus, which produces vitamin B12, which can be chemically seperated
|
|
|
What are 2 important desirable results of a labeling product?
|
1. high efficiency
2. chemical stability what is the term for when the biological properties of a compound are altered by temp, pH, O2 and other factors? |
Denaturing
|
|
|
What is the isotope effect?
|
rare situation occurring only in very light elements where the change in mass number effects the chemical and biological properties
|
|
|
|
When the radiation from a radiopharmaceutical breaks down bonds in a pharaceutical it is a condition called __________ and when the isotpe breaks its own bonds it is called ______________
|
When the radiation from a radiopharmaceutical breaks down bonds in a pharaceutical it is a condition called radiolysis and when the isotpe breaks its own bonds it is called autoradiolysis
|
|
|
|
What is another danger besides radiolysis in shelf life of a radiopharmaceutical?
|
radiation can break bonds in the solvent (water) whch can cause the creation of free radicals, which can then attack the bonds of the radiopharaceutical.
What helps prevent this? |
A neutral Ph
|
|
|
Name the 4 conditions that indicate greater chance of Radiolysis
|
1. isotope half life is long
2. radiation energy is high 3. specific activity is high 4. particulate radiation (beta) |
|
|
|
What is Iodination?
|
attachment of radioactive isotope of iodine to biologically active molecule
What are some examples? |
I123 used in thyroid imaging, I131 used in therapy
|
|
|
What is the problem with using the sodium pertechnetate ion directly from generator eluate?
|
It has a 7+ oxidation state, is quite stable and not very reactive.
What is done to change its reactivity? |
It is reduced (gain electrons) by introducing a reducing agent: stannous chloride, which reduces the Tc to 4+
|
|
|
Stannous chloride is present in excess in radiopharmaceutical kit preps since Tc needs to be reduced. What are the 2 compounds that don't use this reducing agent?
|
sulfur colloid and DMSA
|
|
