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M.Sc. Yuri Kheifetz

After completing his B.Sc studies in Life Science and Mathematics at the Hebrew University of Jerusalem Yuri spent two more years in studying Near Field microscope applications to micro-manipulations in biophysics, under the supervision of Prof Aharon Lewis of the Hebrew University of Jerusalem (see 1). Yuri holds M.Sc. degree in Applied Mathematics from the Technion, Israel Institute of Technology. His M.Sc. study involved mathematical combustion theory. In IMBM Yuri employs his skills in applied mathematics for developing mechanism based models of cancer drug therapy and its accompanied physiological side effects.

Scientific activity in 2007

Over the past year, Yuri has been involved in investigating the general questions of models robustness, dependence on feedback controls, dependence on data uncertainty and models predictability. In particular, he was engaged in two research projects:

Mathematical modeling of the beneficial and toxic effects of the chemotherapy-supportive treatment interleukin-11 (IL-11). A novel mathematical approach was used for ODE modeling of IL-11 pharmacokinetics and pharmacodynamics, allowing analysis of plausible physiological mechanisms, investigation of model and parameter sensitivity, and development of improved therapeutic approaches with increased efficacy/toxicity ratios. This work was a joint project with Moran Elishmereni and Smadar Horowitz.

Mathematical modeling of cancer immunotherapy by interleukin-21 (IL-21): The characterization of IL-21 as an immune regulator was investigated using ODE modeling, and utilized multiple and varied experimental information. The model, which is currently being expanded to include drug pharmacokinetics and validated using retrospective data, supports different tumor models, drug administration routes, and various characteristics of tumor growth in a murine system. The model also serves a basis for finding effective IL-21 therapeutic strategies intended for futuristic cancer treatment. Optimization methods have also been implemented for more quantitative analysis of therapeutic schedules. This work was a joint project with Antonio Cappuccio and Moran Elishmereni.

Development of effective algorithms for parameters identification and optimal treatment regimen finding. Application to the models ofIL-11 and IL-21.

Work program for 2008

This year, Yuri's research subjects continue to be focused on mathematical and computer modeling of immunotherapy of cancer. This work is in tight collaboration with Moran Elishmereni. The main focus is on development of strategy for proper incorporation of experimental data, which generally is incomplete and is supplied non-systematically.

Publications

Elishmereni M, Kheifetz Y, Agur Z. New strategies of Interleukin-11 therapy for thrombocytopenia based on a mathematical PK/PD analysis. (In preparation).
Kheifetz Y, Elishmereni M, Horowitz S, Agur Z. Fluid-retention side-effects of the chemotherapy-supportive treatment Interleukin-11: Mathematical modelling of putative underlying mechanisms. Computational and Mathematical Methods in Medicine. 2006; 7(2-3):71-84.
Kheifetz Y, Kogan Y, Agur Z. Long-range predictability in models of cell populations subjected to phase-specific drugs: growth-rate approximation using properties of positive compact operators, Mathematical Models and Methods in Applied Sciences(M3AS) - Vol. 16, No. 8 (August 2006).
Forys U, Kheifetz Y, Kogan Y. Critical point analysis for three-dimensional cancer angiogenesis models, Mathematical Biosciences and Engineering. 2005; August vol.2, Number 3, pp 511-525.
Kheifetz Y, Kogan Y, Agur Z. Matrix and compact operator description of resonance and antiresonance in cell populations subjected to phase specific drugs, Journal of Medical Informatics & Technologies, October 2004; Vol. 8: MM-11 – MM-29.
Lewis A, Kheifetz Y, Shambrodt E, Radko A, Khachatryan A. Fountain pen nanochemistry: Atomic force control of chrome etching. Applied physics letters, 1999; vol. 75, no. 17: 2689-2691.