get_httk_params: Converts the HTTK-Pop population data table to a table of the parameters needed by HTTK, for a specific chemical.

Description

Takes the data table generated by httkpop_generate, and converts it to the corresponding table of HTTK model parameters for a specified chemical and HTTK model.

Usage

get_httk_params(indiv_dt, chemcas, model, poormetab, fup.censor,
  sigma.factor = 0.3, Clint.vary = TRUE, lod = 0.01,adjusted.Funbound.plasma=T,
  regression=T,well.stirred.correction=T,restrictive.clearance=T)

Arguments

indiv_dt

A data table generated by httkpop_generate().

chemcas

The CAS number of one of the HTTK chemicals (see get_cheminfo).

model

One of the HTTK models: "1compartment", "3compartmentss", "3compartment", or "pbtk".

poormetab

TRUE (include poor metabolizers) or FALSE (exclude poor metabolizers)

fup.censor

TRUE (draw Funbound.plasma from a censored distribution) or FALSE (draw Funbound.plasma from a non-censored distribution)

sigma.factor

The coefficient of variation to use for Clint and Funbound.plasma distributions. Default value is 0.3.

Clint.vary

TRUE (sample Clint values) or FALSE (hold Clint fixed). Default TRUE. If Clint.vary is FALSE, then poormetab will have no effect.

lod

The average limit of detection for Funbound.plasma. if fup.censor == TRUE, the Funbound.plasma distribution will be censored below lod/2. Default value is 0.01.

adjusted.Funbound.plasma

Uses adjusted Funbound.plasma when set to TRUE along with partition coefficients calculated with this value.

regression

Whether or not to use the regressions in calculating partition coefficients.

well.stirred.correction

Uses correction in calculation of hepatic clearance for well-stirred model if TRUE for model 1compartment elimination rate. This assumes clearance relative to amount unbound in whole blood instead of plasma, but converted to use with plasma concentration.

restrictive.clearance

Protein binding not taken into account (set to 1) in liver clearance if FALSE for model 1compartment elimination rate.

Value

A data.table whose columns correspond to the parameters of the HTTK model specified in model, and whose rows correspond to the individuals (rows) of indiv_dt.

@examples set.seed(42) indiv_examp <- httkpop_generate(method="d", nsamp=100) httk_param <- get_httk_param(indiv_dt=indiv_examp, chemcas="80-05-7", model="1compartment", poormetab=TRUE, fup.censor=TRUE)

References

Ring, Caroline L., et al. "Identifying populations sensitive to environmental chemicals by simulating toxicokinetic variability." Environment International 106 (2017): 105-118.