PubMed Health⌕ Search

Biomedical subjects

Kirill V Tyurin

Publications and source records attributed to Kirill V Tyurin.

2 recordsLinked to original sources

Hemostasis as an optimal system.

Zymogen and procofactor concentrations in physiological biochemical systems (PBS) have not yet been explained. The problem in question is to determine optimal plasma clotting factor (factors II, VII, IX, and X and cofactors V and VIII) concentrations for coagulation system (CS) as a whole. Constrained optimization technique is used to solve this problem. The constraint is determined by the ability of the CS to perform its physiological function--thrombin generation (and hence clot formation)--under vessel injury conditions. The constraint statement is based on the CS dynamics equations. In solving the problem the Lagrange multiplier is used. A hypothesis is advanced that this problem can be solved based on principle of minimum protein consumption subject to an above constraint. The results obtained indicate that the optimal clotting factor concentrations are in good agreement with those measured by biochemical techniques. A comparison between the theoretical results and experimental data lends support for our hypothesis that zymogen and procofactor concentrations in the CS (and, probably, for other biochemical systems) are determined by the principle of minimum protein consumption.

Algorithms↗

Optimality principle and determination of kinetic constants for biochemical reactions.

An optimality principle is applied to determine kinetic constants for biochemical (enzymatic and second-order) reactions involved in a physiological system, a minimum protein consumption criterion being adopted. A direct optimization problem is to determine optimal zymogen concentrations. An 'inverse' optimization problem is also considered; this problem is to determine the kinetic constants for the biochemical reactions involved in a physiological system such that the optimal and observed zymogen and procofactor concentrations coincide. In solving an 'inverse' optimization problem we assume that the scheme of biochemical reactions and zymogen and procofactor concentrations are known. Good agreement is observed between the model results for the extrinsic blood coagulation pathway and relevant biochemical data. The proposed method is also applicable to determining kinetic constants for other physiological biochemical-reaction systems.

Blood Coagulation↗