Modelagem computacional do efeito bystander das radiações ionizantes via autômato celular e técnica Monte Carlo

AUTOR(ES)
FONTE

IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia

DATA DE PUBLICAÇÃO

28/02/2012

RESUMO

Until the 1990s it was believed that the DNA was the only target molecule of ionizing radiation. But some observations have questioned this theory. In 1992, the bystander effect was described by Nagasawa and Little. This effect is responsible for a series of answers as death, chromosomal instability or other abnormalities that occur in non-irradiated cells, which get in contact with irradiated or irradiated medium from irradiated cells. Understanding the bystander effect may have important consequences for therapy and exposure risk studies to low doses of ionizing radiation. Living organisms are composed of millions of cells that together perform tasks of great complexity. Although each cell has an internal structure that obeys the biochemistry laws, it is the interaction between the cells that generate a range of different phenomena. Mathematical models seek elegant solutions to simulate nature. In this work, we developed a computer model to simulate the bystander effect of ionizing radiation in cell cultures. This computational model is a two-dimensional cellular automata, consisting of two overlapping networks, where the first represents the cells culture and the second, the medium in which cells are embedded. The computational model describes the behavior of the bystander effect for different configurations and cells density where different signal levels are released by cells irradiated in the medium. The signals re-emission effect was also introduced in this model. From the simulations data, equations capable of predicting the experimental results were obtained. The results obtained from the computational model and the mathematical model are in excellent agreement with experimental data available in the literature. It was observed that there are two inflection points in the dose-response curves in the low dose regime and they may represent a cell culture adaptability to ionizing radiation by transforming it into more or less radio-resistant.

ASSUNTO(S)

simulação computadorizada método monte carlo radiações ionizantes cultura celular modelos matemáticos fisica computerized simulation monte carlo method ionizing radiations cell cultures mathematical models

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