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18 Cards in this Set
- Front
- Back
- 3rd side (hint)
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What are the 2 type of chromsome aberrations caused by radiation?
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1. Chromosome during G1 and
2. Chromatid during G2 |
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What are the 3 lethal types of chromosome aberrations?
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1. Dicentric - 2 different chromsomes break in G1 causing illegitimate union
2. Ring - same as dicentric but froms a ring 3. Anaphase bridge-post replication during G2 |
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What is the non-lethal chromosome change and why is it actually more dangerous than the lethal ones?
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the creation of oncogene, which eliminates the suppressor gene so cancerous cells can multiply unchecked
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3 main general principles of radiobiology
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1. radiation is a random event, can't predict, only by probability with large # of atoms
2. radiation damage difficult to see as chemical and heat damage similar and damage usually repairable 3. energy is deposited to cells quickly but the results take from 5 minutes to 8 yrs to see |
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What is the most damaging effect on water molecules in out body from radiation?
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creation of hydroxyl free radical OH+
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Define following terms:
1. reproductive death 2. Clonogenic 3. Clonogenic assay |
1. reproductive death is the loss of the ability to proliferate indefinetly
2. clonogenic is a surviving cell that has retained its reproductive integrity 3. clonogenic assay is an observation of reproductive integrity to end point |
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What dosage will kill a cell population for non-proliferating cells and also for proliferating cells?
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100 Gray for non and 2 for proliferating
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What is a logarithm?
What is a natural logarithm? |
The exponent of a base 10 to give a certain # is the log of that #.
A natural log is a log with a base of e instead of 10 which is the number 2.718... |
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Define the following terms:
In vitro In situ In vivo |
In vitro means in a dish in a lab
In situ means in place ie. natural setting, organ or tissue In vivo means observed in body |
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What are the 3 results of irradiating a population of cells with radiation?
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1. some cells have not divided
2. some cells form small unsuccessful colonies 3. some cells form colonies indistinguishable from non irritated cells |
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What is karyotype?
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It is a method of chromosome analysis by photographing chromosomes and arranging in descending order. further treatment by chemicals, most common being "G banding" enables detection of aberrations
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What is the formula for surviving fraction?
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Colonies counted/cells seeded X PE/100
What is PE? |
Plating efficiency
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On the survival curve the X axis represents what?
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The dose on a linear scale and the Y axis is what?
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The surviving fraction on a logarithmic scale
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High LET radiation curve will be a _______ line and low LET indirectly damaging radiation will be a _______ line
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High LET radiation curve will be a straight line and low LET indirectly damaging radiation will be a curved line
What does this indicate? |
The curved line or shoulder indicates repair and growth
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Define terms:
n D0 Dq |
n is the extrapolation point where the curve meets the Y axis
D0 is the dose where only 37% of population survives Dq is the quasi threshold dose also indicating width of shoulder |
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What is the difference between D sub 0 and D squared?
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D sub 0 is the cell killing 67% dependent on the dose and D squared is the square of the dose
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Explain the difference between mitotic death and apoptosis
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mitotic death is the most common death caused by radiation which means at the next mitosis cell cant reproduce from damage and apoptosis results from ceramide a genetic form of cell death
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Radiosensitive cells, like WBC's die from _______ death while radioresistant cells die from _______ death.
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Radiosensitive cells, like WBC's die from apoptotic death while radioresistant cells die from mitotic death.
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