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Biomedical subjects

E Tendi

Publications and source records attributed to E Tendi.

27 records · Page 2Linked to original sources

A new programmable calculator procedure for individualizing phenytoin dosage.

A programmable calculator procedure allowing nonlinear least-squares fit to pharmacokinetic data conforming to the Michaelis-Menten model is described. Model parameter estimation is performed according to the iterative Gauss-Newton technique as modified by Hartley. This procedure thus employs the same theoretical approach used by most pharmacokinetic computer programs. No programming skill is needed to run the program described. The proposed procedure is discussed in detail and applied to some sets of pharmacokinetic data.

Computers↗

Iterative least-squares fitting programs in pharmacokinetics for a programmable handheld calculator.

Programs that perform a nonlinear least-squares fit to data conforming to one-compartment oral or two-compartment intravenous pharmacokinetic models are described. The programs are designed for use on a Hewlett-Packard HP-41 CV programmable calculator equipped with an extended-functions module and one or two extended-memory modules. Initial estimates of variables in the model are calculated by the method of residuals and then iteratively improved by the use of the Gauss-Newton algorithm as modified by Hartley. This modification minimizes convergence problems. The iterative-fitting procedure includes a routine for estimation of lag time for the one-compartment oral model. Clinical applications of the programs are illustrated using previously published data. Programming steps and user instructions are listed. The programs provide an efficient and inexpensive method of estimating pharmacokinetic variables.

Absorption↗

A calculator program for least-squares parameter estimation according to the one-compartment kinetic model with zero-order input.

A calculator program that performs a nonlinear least-squares fit to data conforming to the one-compartment model with zero-order input is described. The program, which is designed for the Hewlett-Packard HP-41 CV calculator, is based on the Gauss-Newton iterative algorithm as modified by Hartley. A subroutine for calculation of initial parameter estimates is incorporated into the program. Plasma concentration data relative to a single oral dose of a sustained-release theophylline formulation are used to demonstrate the practical application of the program.

Computers↗

Treatments for newly diagnosed multiple myeloma: analysis of survival data and cost-effectiveness evaluation.

The main therapeutic options currently available to induce remission in newly diagnosed cases of multiple myeloma include: i) melphalan at conventional doses without concurrent administration of interferon; ii) melphalan at conventional dose combined with interferon; iii) autologous bone marrow transplantation (ABMT). We conducted an analysis of the survival data reported in five large-scale published clinical trials and we evaluated the cost-effectiveness ratio. We determined the mean lifetime survival (MLS) for each treatment group using the Gompertz model. The cost data of patients given ABMT or standard chemotherapy were estimated from published information. The values of MLS were 3.47 years per patient for melphalan at conventional doses without interferon, 3.74 years for melphalan at conventional doses combined with interferon, and 7.28 years for ABMT. As compared with conventional melphalan treatment, ABMT yielded a significantly better survival. Survival after melphalan combined with interferon was not significantly different from that following melphalan alone. Using melphalan at conventional doses without interferon as reference term, the marginal cost-effectiveness ratio of ABMT was of about $26,000 per life year gained. For the induction treatment in patients with newly diagnosed myeloma, ABMT seems to be more effective and more cost-effective than the standard treatment with melphalan at conventional doses.

Antineoplastic Agents↗