Error in data analysis through Transit compartmental modeling

Phoenix Certara Forums Modelling and Simulation
1

Dear all,

I am analysing the data of time-dependent concentration of TNF-alpha concentration after LPS challenge in presence and absence o compound intervention. I have attempted to model through Transit compartment model equations as reported by Johan Grabrielsson et al from the article entitled “Modelling and design of challenge tests.”

But it showed following errors. Kindly suggest me if there were any coding errors

  • ‘“.\NLME7.exe”’ is not recognised as an internal or external command,
    operable program or batch file.

  • .\Work\Model.c: In function ‘EvalAssign’:
    .\Work\Model.c:1027:13: error: lvalue required as left operand of assignment
    S(LPS, Ci) = (1.0 + ((((A * k) * t) * _exp_cached(( -(k) * t), &_tempArg[0], &_tempResult[0])) * INHIB));

LR8P PK_PD Project 1.phxproj (746 KB)

2

Dear Santosh,
this is not a pml compatible synthax:
S(LPS,Ci)= 1 + A * k * t * exp(-kt) INHIB

try to edit your code to look like this

SLPSCi= 1 + A * k * t * exp(-kt) INHIB
deriv(E1 = (1/Tau) * (E0 * (SLPSCi-E1)))

can you express in words what are you tryint to model and achieve ? have you looked on how to use the:
transit
or delay expression in pml ?

Bests,
Samer

3

Dear colleague

You should review the rational of your model and send us the reference. This model is strange to me. The trend is to decrease the response E4 with time with drug while the data show the reverse.

Then ocne we get the reference, we can help you.

best Regards

Serge

4

gabrielsson2015 (1).pdf (1.53 MB)

5

Dear Kumar,

just to give you some ideas

cfMicro(A1, Cl / V, Cl2 / V, Cl2 / V2)
transit(R, mtt, ntr, in = R0*SLPSCi)

sequence{R = R0}
SLPSCi = (1 + A * k * t * exp(-k*t))*ICi
ICi = 1 - C/(IC50 + C)
mtt = (ntr + 1)/kout
ntr = mtt * kout - 1

dosepoint(A1, idosevar = A1Dose)
C = A1 / V

error(CEps = 0.1)
observe(CObs = C * (1 + CEps))
error(REps = 1)
observe(RObs = R + REps)

Looks strange to me that the authors didn’t mention the number of compartments for the fitted model. In such case it is impossible to reproduce the model. Just some suggestions from the plot: mtt should be about 1.

Not sure that initialization of transit compartment with sequence{} will work properly.

BR,

Mittyright