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J de Biasi

Publications and source records attributed to J de Biasi.

5 recordsLinked to original sources
PubMed1996

Minimal experimental requirements for structural identifiability in linear compartmental models. The software 'IDEXMIN'.

Identifiability is a structural property of compartmental systems and is of a great interest in the pharmacokinetic field. Preliminary testing for identifiability, independent of the detailed experimental data but based on the model used and the experimental schedule, enables the researcher to design precise and straightforward experiments which will lead to the structural identifiability of the system. A computer program for PC (denoted IDEXMIN) has been designed in order to test for identifiability in any n compartment system and, in the case of non-identifiability, to define the minimal experimental data required to enable the model to be identifiable. All identifiability calculations are based on the K matrix of Delforge. Commandability and controllability of a system are verified before testing for identifiability.

Computer Simulation↗
PubMed1993

Effect of drug transit time between exchange locus with plasma and sampling site.

In pharmacokinetic models used to describe the behavior of drugs in living organisms, generally neither the amount of drug flowing in pipes between compartments nor the transfer delay between the plasma-lymph exchange areas and a site of measurement are taken into account. Several former publications dealt with exchanges between two or more different organs assuming that the blood flow was constant or that the variation of the lymphatic flow was negligible or noting that the amount of drug present in pipes was not easily taken into account. In this article, we deal with concentration in a site of interstitial exchanges with regard to concentration in a sampling site with a varying blood flow, assuming that the transit time depends both on the fluid flow and the path length through pipes. In all considered cases, the plasma concentration profile may be highly altered by a change in the flow rate.

Humans↗
PubMed1992

Application of a pharmacokinetic model with multiple enterohepatic cycles to a new inotropic drug after infusion and oral administration.

A pharmacokinetic model with multiple, unequal, enterohepatic recirculations was developed to fit the experimental data of a new inotropic drug after intravenous infusion and oral administration. Optimized model parameters were used to derive theoretical values of the area under the curves of concentration versus time that were in good agreement with the experimental values.

Administration, Oral↗
PubMed1991

Four compartment mammillary model applied to the pharmacokinetics of a spiroarsorane administered orally to rabbits.

Rekik et al. dealt with the pharmacokinetics of two spiroarsoranes molecules administered intravenously or orally to rabbits. For the intravenous study they used an open two-compartment model. For the oral study they admitted that they were unable to fit the data to a model. In this paper the plasma concentration profile of molecule 2 after oral administration using a four mammillary open compartment model is described. This type of model (which requires a fourth degree equation) has been previously described. Here it is applied to a concrete situation.

Administration, Oral↗