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Analysis of Chromosomal Aberrations in the Blood Lymphocytes of Astronauts after Space FlightIt is a NASA requirement that biodosimetry analysis be performed on all US astronauts who participate in long duration missions of 3 months or more onboard the International Space Station. Cytogenetic analysis of blood lymphocytes is the most sensitive and reliable biodosimetry method available at present, especially if chromosome damage is assessed before as well as after space flight. Results provide a direct measurement of space radiation damage in vivo that takes into account individual radiosensitivity and considers the influence of microgravity and other stress conditions. We present data obtained from all twenty-five of the crewmembers who have participated in the biodosimetry program so far. The yield of chromosome exchanges, measured using fluorescence in situ hybridization (FISH) technique with chromosome painting probes, increased after space flight for all these individuals. In vivo dose was derived from frequencies of chromosome exchanges using preflight calibration curves of in vitro exposed cells from the same individual, and RBE was compared with individually measured physically absorbed dose and projected organ dose equivalents. Biodosimetry estimates using samples collected within a few weeks of return from space lie within the range expected from physical dosimetry. For some of these individuals chromosome aberrations were assessed again several months after their respective missions and a temporal decline in stable exchanges was observed in some cases, suggesting that translocations are unstable with time after whole body exposure to space radiation. This may indicate complications with the use of translocations for retrospective dose reconstruction. Data from one crewmember who has participated in two separate long duration space missions and has been followed up for over 10 years provides limited data on the effect of repeat flights and shows a possible adaptive response to space radiation exposure.
Document ID
20070025033
Acquisition Source
Johnson Space Center
Document Type
Conference Paper
Authors
George, K.
(NASA Johnson Space Center Houston, TX, United States)
Kim, M. Y.
(NASA Johnson Space Center Houston, TX, United States)
Elliott, T.
(NASA Johnson Space Center Houston, TX, United States)
Cucinotta, F. A.
(NASA Johnson Space Center Houston, TX, United States)
Date Acquired
August 23, 2013
Publication Date
January 1, 2007
Subject Category
Aerospace Medicine
Meeting Information
Meeting: NASA Space Radiation Investigators Meeting
Location: Sonoma, CA
Country: United States
Start Date: July 13, 2007
End Date: July 16, 2007
Distribution Limits
Public
Copyright
Other

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