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Re: Build a cell-cycle based tumor growth model

From: Benjamin Ribba <Benjamin.Ribba>
Date: Thu, 17 Jul 2008 12:01:32 +0200

Dear Feng, a smart way could be to (actually) write down equations for the
other biomarkers.
The simplest way to do this is is to assume that when cells have evolved in
a given phase (say G1) for a particular duration, they move to the following
one (S). By doing such, you may also solve your second issue setting initial
conditions to all your derivative equations.
Best regards,

o set a phase duration and to write that when cells in G1 stayed for the
entire duration, they move to D, and so on...

Il 17-07-2008 10:49, "Feng Yang" <fyangusa

> Dear nmusers:
> Recently I am trying to build a cell-cycle based tumor growth model, i.e.
> tumor size = G1+ S + G2 + M. Meanwhile, I have quite a few simultaneous
> biomarkers to characterize the cycle behaviors. Those biomarkers could be
> calculated based on the population of G1, S, G2, and M. I have the following
> puzzles needed to be addressed:
> 1) In my data file, what is the CMT number I should give to those
> observations (such as tumor size and many biomarkers)? By the way, I need CMT
> to specify/initialize the corresponding compartment. Since I am not quite
> sure how to use L2 and PCMT, I tried many times, all failed except the
> following foolish way:
> I create one more compartment to hold the tumor size:
> DADT(iTUMROR) = DADT(iG1) + DADT(iS) + DADT(iG2) + DADT(iM)
> and in my data file, I put the CMT compartment created (iTUMOR) into the
> observation of tumor size.
> However, for all other biomarkers, there is no way to write this kind of DADT
> equations. How could I solve this in a smart way?
> 2) Since some biomarker data are collected based on certain time point, saying
> t0. In other words, they are relative fold-changes compared to the vehicle at
> t0. Therefore, I need to save the intermediate population of G1, S, G2 and M
> at t0, as constants, which will be used to scale the later-on populations so
> that the model predictions are comparable with the observations.
> However, in the both block $DES and $ERROR, there is no way to save these
> intermediate populations as global variables or constants. I guess, I have
> to use MSFO to separate the simulation to many sections? But it am not sure
> how to do it.
> Your thoughts and feedback are really appreciated! Thanks a lot!
> Feng

Received on Thu Jul 17 2008 - 06:01:32 EDT

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