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dc.contributor.authorHendry, Jolyon H
dc.contributor.authorCowie, F G
dc.contributor.authorVon Wangenheim, K
dc.date.accessioned2010-12-07T18:12:55Z
dc.date.available2010-12-07T18:12:55Z
dc.date.issued1985
dc.identifier.citationThe reversion phenomenon in irradiated fern prothalli: effects of acute or chronic anoxia and LET. 1985, 24 (1):45-56 Radiat Environ Biophysen
dc.identifier.issn0301-634X
dc.identifier.pmid3975349
dc.identifier.doi10.1007/BF01212652
dc.identifier.urihttp://hdl.handle.net/10541/117365
dc.description.abstractIn several systems a paradoxical reduction of radiation damage with increasing dose, termed reversion, has been observed. In the fern Osmunda regalis the percentage of cells which does not die but stays alive, although reproductively sterile, increases with dose. The assumed mechanism of this effect is a continuation of cytoplasmic growth during radiation-induced mitotic delay which induces terminal differentiation (early differentiation) thus preventing mitosis and the expression of chromosomal injury. Suppression of cytoplasmic growth after irradiation should abrogate reversion. This was tested using anoxia. Reversion was suppressed by storage of the sporelings in nitrogen for 8 h or more after X-rays, but was not suppressed by storage in 0.27 microM oxygen nor by a 60-min exposure to air after irradiation and before storage in nitrogen. Anoxia before irradiation in air had no effect. Anoxia only during irradiation showed an OER of about 2 for the reversion peak. The partial abrogation of reversion is consistent with the assumed mechanism. Marked reversion also was observed after 14.7 MeV neutrons.
dc.language.isoenen
dc.subject.meshCell Survival
dc.subject.meshDose-Response Relationship, Radiation
dc.subject.meshEnergy Transfer
dc.subject.meshMitotic Index
dc.subject.meshNeutrons
dc.subject.meshOxygen
dc.subject.meshPlants
dc.subject.meshTime Factors
dc.subject.meshX-Rays
dc.titleThe reversion phenomenon in irradiated fern prothalli: effects of acute or chronic anoxia and LET.en
dc.typeArticleen
dc.contributor.departmentPaterson Laboratories, Christie Hospital and Holt Radium Institute, Manchester M20 9BX, United Kingdomen
dc.identifier.journalRadiation and Environmental Biophysicsen
html.description.abstractIn several systems a paradoxical reduction of radiation damage with increasing dose, termed reversion, has been observed. In the fern Osmunda regalis the percentage of cells which does not die but stays alive, although reproductively sterile, increases with dose. The assumed mechanism of this effect is a continuation of cytoplasmic growth during radiation-induced mitotic delay which induces terminal differentiation (early differentiation) thus preventing mitosis and the expression of chromosomal injury. Suppression of cytoplasmic growth after irradiation should abrogate reversion. This was tested using anoxia. Reversion was suppressed by storage of the sporelings in nitrogen for 8 h or more after X-rays, but was not suppressed by storage in 0.27 microM oxygen nor by a 60-min exposure to air after irradiation and before storage in nitrogen. Anoxia before irradiation in air had no effect. Anoxia only during irradiation showed an OER of about 2 for the reversion peak. The partial abrogation of reversion is consistent with the assumed mechanism. Marked reversion also was observed after 14.7 MeV neutrons.


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