## Parameter estimation of repair process following radiation

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### Parameter estimation of repair process following radiation

Hello,

I am mathematician doing modeling the effect of ionizing radiation to mammalian cell. Here i wanted to know is it biologically makes sense if we assume that two types of experiments on cell killing effect due to radiation are dependent each other. For this i mean that:

Two experiments which containing

1. the data for cell surviving fraction versus dose for 0 hour replating time (no repair process)

2. the data for cell surviving fraction versus dose for 24 hours replating time (with repair process)

The fucntion of repair rate is given by Michaelis-Menten equation:

Vmax*k/(Km+k), k is number of lesion.

Here i want to estimate the repair parameters Vmax and Km. In my model i have also want to estimate another 4 parameters which come from cell death rate(but i prefer not to put in the discussion here as they are completely messy).

My question is, can i assume that the death rate parameters value in experiment (1) are the same in experimnt (2)?...even though we knew that cell is actually not isolating .

Many thanks for those who are willing to further explain this to me....

Cheers!

Fuaada

I am mathematician doing modeling the effect of ionizing radiation to mammalian cell. Here i wanted to know is it biologically makes sense if we assume that two types of experiments on cell killing effect due to radiation are dependent each other. For this i mean that:

Two experiments which containing

1. the data for cell surviving fraction versus dose for 0 hour replating time (no repair process)

2. the data for cell surviving fraction versus dose for 24 hours replating time (with repair process)

The fucntion of repair rate is given by Michaelis-Menten equation:

Vmax*k/(Km+k), k is number of lesion.

Here i want to estimate the repair parameters Vmax and Km. In my model i have also want to estimate another 4 parameters which come from cell death rate(but i prefer not to put in the discussion here as they are completely messy).

My question is, can i assume that the death rate parameters value in experiment (1) are the same in experimnt (2)?...even though we knew that cell is actually not isolating .

Many thanks for those who are willing to further explain this to me....

Cheers!

Fuaada

### Re: Parameter estimation of repair process following radiation

Thanks for replying...

The reason why i am using Michaelis-menten is the repair process mimics an enzymatic, as lesion k got larger, the enzyme repairs will be saturated.

I am not doing experiment, just to obtain the simulation data using my proposed model...with several assumptions to simplify the model development. One of the assumption is:

there are two different cell surviving data:1) with no repair process allows;2) with repair process. cell in (1) and (2) are share the same behaviour(such as the same cell radiosensitivity).

I have for an example 3 parameters:

alpha, Vmax and Km. I want to estimate these parameters.Obviously, from experimental data (1), Vmax=Km=0, so that i can estimate alpha. With the assumption that the value of alpha does not change(?does this assumption makes sense?) i can estimate Vmax and Km using experimental data from (2).

Please....especially who is oncologist................

Cheers!

Fuaada

The reason why i am using Michaelis-menten is the repair process mimics an enzymatic, as lesion k got larger, the enzyme repairs will be saturated.

I am not doing experiment, just to obtain the simulation data using my proposed model...with several assumptions to simplify the model development. One of the assumption is:

there are two different cell surviving data:1) with no repair process allows;2) with repair process. cell in (1) and (2) are share the same behaviour(such as the same cell radiosensitivity).

I have for an example 3 parameters:

alpha, Vmax and Km. I want to estimate these parameters.Obviously, from experimental data (1), Vmax=Km=0, so that i can estimate alpha. With the assumption that the value of alpha does not change(?does this assumption makes sense?) i can estimate Vmax and Km using experimental data from (2).

Please....especially who is oncologist................

Cheers!

Fuaada

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