Ch 3: Cell Survival Curve Flashcards
Non-mitotic death is synonymous with?
Interphase death
What happens in division delay?
Cells enter G0 and radiation is not effective
What happens in interphase death?
Cells do no need to enter into mitosis and death occurs via apoptosis
What happens in reproductive failure?
Death is not immediate but cells lose enough chromosome information that eventually cause cell death
Characterized by single strand breaks that can be repaired
(SLD) sub lethal damage
Dose is high enough to kill cells but cells may not be cycling and are therefore more likely to survive
(PLD) potentially lethal damage
If a radio-sensitizer is added to sparsely ionizing radiation, what happens to the survival curve?
The survival curve moves to the left
______ is defined as the dose required to reduce the fraction of cells surviving to 37 percent
Do
The slope of a cell survival irradiated with alpha particles is ______ than a survival curve irradiated with sparsely ionizing radiation
Steeper
The shoulder of the cell survival curve is formed by
(SLD) sub lethal damage
Dq is dependent on
Type of radiation damage (direct or indirect)
Cell type
Environmental conditions
With a plating efficiency of 90 percent, if 43 colonies of cells remaining after a dose of radiation is given to 1000 cells, what is the surviving fraction?
0.048
Radiation of neutrons or alpha particles exhibit _______ shoulder on the cell survival curves.
No
Programmed cell death is know as?
Apoptosis
How can you overcome division delay
By increasing radiation dose
Division delay is:
When cell haven’t been killed, instead they are like being stunned. Cell will enter G0 phase, which will provided them enough time to recover from any damage from radiation
True
In interphase death, cell does not need to undergo mitosis and cell death is from apoptosis or necrosis
True
Reproductive failure is:
Is NOT immediate death, but cells can be considered dead b/c cells consequently have loss aspects of their chroma tins and chromosome and thus with each division, less info will be transmitted to daughter cell
True
Dq is?
The shoulder, indicates ability to repair
D0?
Dose required to reduce the fraction of cells serving to 37 percent. It is the sensitivity.
Dq is dependent on?
Type of radiation (indirect or direct)
Cell type and cell condition
The larger the shoulder , the larger the Dq, the more radiation is required to get equivalent amount of cell death
True
How is D10 calculated?
2.3 times D0. Answer will be in Gy.
What are the 2 distant terms for DNA damage
SLD
PLD
PLD is when enough radiation is given to cause death but since the cell is NOT cycling, the damage cannot manifest fully
True
SLD is measured by?
Dq; the shoulder; the Bailey to repair
Example of a suboptimal condition in PLD
Hypoxia
Inadequate nutrient
Densely ionizing (alpha and neutrons) is NOT impacted by O2, radiosensitizer or radioprotectors
True
If you add radiosensitizer to sparsely ionizing, it will move to the ______.
Left
If you add radioprotectors to the sparsely ionizing, it will move to the ______
Right
Densely ionizing particles work through DIRECT damage, no slope means at any given dose wil cause DNA damage
True
Sparsely ionizing works though INDIRECT.
True
Low dose to densely will give same effect as sparsely
HIGH dose to sparsely will give same effect as densely
True
As D0 increases, cell becomes ore resistant
True
As DO decrease, cell become more sensitive
True
