Adaptive response studies may help choose astronauts for long-term space travel

Mortazavi, S.M.J.; Cameron, John; Niroomand‐Rad, Azam

doi:10.1016/s0273-1177(03)00089-9

Cited by 54 publications

(41 citation statements)

References 40 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Consistent with our previously reported data,[4591011363738394041] radiobiological studies on the health effects of the chronic exposure to elevated levels of natural radiation in residents of areas such as Ramsar may lead to the identification of the cellular and molecular mechanisms by which susceptibility to genetic damage and cancer is decreased by chronic radiation exposure. These findings will play an important role in areas such as radiation therapy, radiation protection and even selection of appropriate candidates for long term manned space missions.…”

Section: Discussionsupporting

confidence: 90%

Does short-term exposure to elevated levels of natural gamma radiation in Ramsar cause oxidative stress?

Mortazavi

Niroomand‐Rad

Roshan-Shomal

et al. 2014

Int J App Basic Med Res

Self Cite

View full text Add to dashboard Cite

Background:Ramsar, a city in northern Iran, has areas with some of the highest recorded levels of natural radiation among inhabited areas measured on the earth.Aims:To determine whether short-term exposure to extremely high levels of natural radiation induce oxidative stress.Materials and Methods:In this study, 53 Wistar rats were randomly divided into five groups of 10-12 animals. Animals in the 1st group were kept for 7 days in an outdoor area with normal background radiation while the 2nd , 3rd , 4th and 5th groups were kept in four different outdoor areas with naturally elevated levels of gamma radiation in Ramsar. A calibrated RDS-110 survey meter, mounted on a tripod approximately 1 m above the ground, was used to measure exposure rate at each location. On days 7 and 9 blood sampling was performed to assess the serum levels of catalase (CAT) and malondialdehyde (MDA). On day 8, all animals were exposed to a lethal dose of 8 Gy gamma radiations emitted by a Theratron Phoenix (Theratronics, Canada) Cobalt-60 (55 cGy/min) at Radiotherapy Department of Razi Hospital in Rasht, Iran.Results:Findings obtained in this study indicate that high levels of natural radiation cannot induce oxidative stress. CAT and MDA levels in almost all groups were not significantly different (P = 0.69 and P = 0.05, respectively). After exposure to the lethal dose, CAT and MDA levels in all groups were not significantly different (P = 0.054 and P = 0.163, respectively).Conclusions:These findings indicate that short-term exposure to extremely high levels of natural radiation (up to 196 times higher than the normal background) does not induce oxidative stress.

show abstract

Section: Discussionsupporting

confidence: 90%

Does short-term exposure to elevated levels of natural gamma radiation in Ramsar cause oxidative stress?

Mortazavi

Niroomand‐Rad

Roshan-Shomal

et al. 2014

Int J App Basic Med Res

Self Cite

View full text Add to dashboard Cite

show abstract

“…of astronauts during long-term space flights, risk assessment and management, and cancer treatment strategies (Delone et al, 1991;Wang and Cai, 2000;Upton, 2001;Takahashi et al, 2002;Bonner, 2003;Mortazavi et al, 2003aMortazavi et al, , 2003bLiu, 2003;Schaffer et al, 2004;Preston, 2005). In preliminary cytogenetic studies, after in vitro irradiation with a test dose of gamma rays, a strong cytogenetic AR was induced in the lymphocytes of residents of the very high background radiation areas of Ramsar (Ghiassi-nejad et al, 2002).…”

Section: Relevance Of the Adaptive Responsementioning

confidence: 99%

Adaptive response: some underlying mechanisms and open questions

2008

View full text Add to dashboard Cite

Organisms are affected by different DNA damaging agents naturally present in the environment or released as a result of human activity. Many defense mechanisms have evolved in organisms to minimize genotoxic damage. One of them is induced radioresistance or adaptive response. The adaptive response could be considered as a nonspecific phenomenon in which exposure to minimal stress could result in increased resistance to higher levels of the same or to other types of stress some hours later. A better understanding of the molecular mechanism underlying the adaptive response may lead to an improvement of cancer treatment, risk assessment and risk management strategies, radiation protection, e.g. of astronauts during long-term space flights. In this mini-review we discuss some open questions and the probable underlying mechanisms involved in adaptive response: the transcription of many genes and the activation of numerous signaling pathways that trigger cell defenses -DNA repair systems, induction of proteins synthesis, enhanced detoxification of free radicals and antioxidant production.

show abstract

“…The first exposure to space radiation may elicit an increased radioresistance, as observed in subsequent space flights, if an hormetic mechanism (Calabrese and Baldwin, 2003) is involved. It is known that radioadaptive response in cytogenetic experiments present large inter-individual variability, and it has been suggested that such differences in adaptive response may be exploited to select crews for interplanetary missions (Mortazavi et al, 2003). However, other authors contend that the response variability is not a genetic trait, but is closely related to the physiological state at the time of priming irradiation (Sasaki et al, 2002).…”

Section: Fish Biodosimetrymentioning

confidence: 99%

Chromosome aberration dosimetry in cosmonauts after single or multiple space flights

Durante

Snigiryova

Akaeva

et al. 2003

Cytogenet Genome Res

View full text Add to dashboard Cite

Background and aims: Cosmic radiation is one of the main hazards for manned space exploration. Uncertainty in radiation risk estimates for crews of long-term missions are very high, and direct biological measurements are necessary. We measured chromosomal aberrations in peripheral blood lymphocytes from 33 cosmonauts involved in space missions during the past 11 years. Methods: Blood lymphocytes from the cosmonauts were stimulated to grow in vitro and were harvested at their first mitosis. Slides were either stained with Giemsa stain for dicentrics analysis, or painted with whole-chromosome DNA probes for translocation analysis (FISH). Results: A statistically significant increase in the yield of chromosomal aberrations was measured following long-term space missions in lymphocytes from cosmonauts at their first flight. No significant changes in aberration frequencies were observed for short-term taxi flights. The increase in long-term missions was consistent with the values calculated from physical dosimetry data. However, for cosmonauts involved in two or more space flights, the yield of interchromosomal exchanges was not related to the total duration of space sojourn or integral absorbed dose. Indeed, the yield of aberrations at the end of the last mission was generally in the range of background frequencies measured before the first mission. Conclusions: Chromosome aberration dosimetry can detect radiation damage during space flight, and biological measurements support the current risk estimates for space radiation exposure. However, for cosmonauts involved in multiple space missions the frequency of chromosomal aberrations is lower than expected, suggesting that the effects of repeated space flights on this particular endpoint are not simply additive. Changes in the immune system in microgravity and/or adaptive response to space radiation may explain the apparent increase in radioresistance after multiple space flights.

show abstract

Adaptive response studies may help choose astronauts for long-term space travel

Cited by 54 publications

References 40 publications

Does short-term exposure to elevated levels of natural gamma radiation in Ramsar cause oxidative stress?

Does short-term exposure to elevated levels of natural gamma radiation in Ramsar cause oxidative stress?

Adaptive response: some underlying mechanisms and open questions

Chromosome aberration dosimetry in cosmonauts after single or multiple space flights

Contact Info

Product

Resources

About