Biodosimetry for Dose Assessment of Partial-Body Exposure: A Methodological Improvement

Ano: 2009 | Volume: 52 | Número: 2

Autores: Thiago Salazar Fernandes, David C. Loyd, Ademir Amaral

Palavras-chave: biodosimetry, partial-body exposure, dicentrics, chromosome contraction

Resumo Português:

Este trabalho avaliou a estimativa da dose de
radiação simulando uma exposição parcial do
corpo através da irradiação in vitro de amostras de
sangue misturadas com amostras não irradiadas.
Foi observado que o prolongamento do tempo de
cultura permite que a real fração de linfócitos em
M1 contendo aberrações cromossômicas seja
detectada, propiciando melhores estimativas de
dose, sem a necessidade de correções matemáticas.

Resumo Inglês:

This study has explored the possibility of combining culture times with extending the duration for which Colcemid is
present in cell culture in order to obtain better dose estimations following partial-body exposures. Irradiated and
unirradiated blood was mixed to simulate a partial-exposure. Dicentric frequencies and resultant dose estimations
were compared from 48 and 72 h cultures with Colcemid added at the beginning, after 24 h or for the final 3 h. The
frequencies of dicentrics in first division cells increased with the cell culture time, providing better dose estimations.
Unwanted excessive contraction of chromosomes caused by prolonged contact with Colcemid was measured and
ways to avoid this are discussed. It is suggested that the combination of a lower than usual concentration of this
drug combined with its earlier addition and longer culture time may provide metaphases better suited for
interpreting partial-body exposures.