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Cellular and molecular effects of accelerated heavy ions on cultivated mammalian cells; Zellulaere und molekulare Wirkungen beschleunigter schwerer Ionen auf kultivierte Saeugerzellen

Abstract

In the study described here the capacity of mammalian cells to recover from irradiation with heavy ions was determined from the survival rates observed following irradiation and incubation during damage repair. While the number of surviving cells was seen to increase considerably during the first four hours after X-irradiation, no such signs of recovery were detectable following exposure to heavy ions. Two experiments even pointed to a drastic loss of cells in the initial hours after exposure. In order to assess the degree of molecular damage, total strand breaks and double strand breaks of the DNA were measured. Taking account also of findings revealed in other studies on the induction of DNA strand breaks, it was found that the efficiency curves for the different particles vary according to LET (range investigated between 300 and 16000 kev./{mu}m), which is an observation also made in connection with other endpoints. Notably, DNA double-strand breaks measured for Ne ions (between 300 and 400 kev./{mu}m) pointed to a relative biological effectiveness of greater than One. The nature of DNA damage inflicted was ascertained on the basis of the ratio between double-strand breaks and single-strand breaks. Like the findings on strand break induction, the dependence of  More>>
Authors:
Publication Date:
Jun 01, 1991
Product Type:
Thesis/Dissertation
Report Number:
GSI-91-17
Reference Number:
SCA: 560120; PA: DEN-92:000117; SN: 92000629733
Resource Relation:
Other Information: TH: Diss. (Dr.rer.nat.)Thesis; PBD: Jun 1991
Subject:
63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.; HEAVY IONS; RBE; RADIATION INJURIES; BIOLOGICAL REPAIR; DNA; CELL CULTURES; STRAND BREAKS; LET; FIBROBLASTS; ELECTRON MICROSCOPY; OPTICAL MICROSCOPY; X RADIATION; ION BEAMS; SURVIVAL CURVES; TIME DEPENDENCE; 560120; RADIATION EFFECTS ON BIOCHEMICALS, CELLS, AND TISSUE CULTURE
OSTI ID:
10108941
Research Organizations:
Gesellschaft fuer Schwerionenforschung mbH, Darmstadt (Germany); Bonn Univ. (Germany). Mathematisch-Naturwissenschaftliche Fakultaet
Country of Origin:
Germany
Language:
German
Other Identifying Numbers:
Other: ON: DE92750162; TRN: DE9200117
Availability:
OSTI; NTIS (US Sales Only); INIS
Submitting Site:
DEN
Size:
103 p.
Announcement Date:
Jun 30, 2005

Citation Formats

Heilmann, J. Cellular and molecular effects of accelerated heavy ions on cultivated mammalian cells; Zellulaere und molekulare Wirkungen beschleunigter schwerer Ionen auf kultivierte Saeugerzellen. Germany: N. p., 1991. Web.
Heilmann, J. Cellular and molecular effects of accelerated heavy ions on cultivated mammalian cells; Zellulaere und molekulare Wirkungen beschleunigter schwerer Ionen auf kultivierte Saeugerzellen. Germany.
Heilmann, J. 1991. "Cellular and molecular effects of accelerated heavy ions on cultivated mammalian cells; Zellulaere und molekulare Wirkungen beschleunigter schwerer Ionen auf kultivierte Saeugerzellen." Germany.
@misc{etde_10108941,
title = {Cellular and molecular effects of accelerated heavy ions on cultivated mammalian cells; Zellulaere und molekulare Wirkungen beschleunigter schwerer Ionen auf kultivierte Saeugerzellen}
author = {Heilmann, J}
abstractNote = {In the study described here the capacity of mammalian cells to recover from irradiation with heavy ions was determined from the survival rates observed following irradiation and incubation during damage repair. While the number of surviving cells was seen to increase considerably during the first four hours after X-irradiation, no such signs of recovery were detectable following exposure to heavy ions. Two experiments even pointed to a drastic loss of cells in the initial hours after exposure. In order to assess the degree of molecular damage, total strand breaks and double strand breaks of the DNA were measured. Taking account also of findings revealed in other studies on the induction of DNA strand breaks, it was found that the efficiency curves for the different particles vary according to LET (range investigated between 300 and 16000 kev./{mu}m), which is an observation also made in connection with other endpoints. Notably, DNA double-strand breaks measured for Ne ions (between 300 and 400 kev./{mu}m) pointed to a relative biological effectiveness of greater than One. The nature of DNA damage inflicted was ascertained on the basis of the ratio between double-strand breaks and single-strand breaks. Like the findings on strand break induction, the dependence of the DSB-SSB ratio on the LET was seen to be largely consistent with intracellular measurements in mammalian DNA and with values determined for virus or phage DNA in solutions containing radical scavengers. This congruence appears to be suggestive of radioprotective effects of the cellular matrix. There was no evidence in confirmation of the theory that the high ionisation densities occurring in the path of heavy ions primarily lead to complex damage. (orig./MG). [Deutsch] In der vorliegenden Arbeit wurde die Erholungsfaehigkeit von Saeugerzellen nach Schwerionenbestrahlung durch Bestimmung des Ueberlebens nach Bestrahlung und anschliessender Reparaturinkubation untersucht. Waehrend mit Roentgenstrahlen ein starker Anstieg des Ueberlebens innerhalb der ersten vier Stunden nach Bestrahlung festgestellt wurde, konnte nach Schwerionenbestrahlung keine Erholung festgestellt werden. In zwei Experimenten wurde sogar ein dramatischer Zellverlust in den ersten Stunden nach Bestrahlung festgestellt. Zur Erfassung molekularer Schaeden wurden DNA-Gesamtstrangbrueche und Doppelstrangbrueche gemessen. Zusammen mit Daten aus anderen Arbeiten zur Induktion von DNA-Strangbruechen ergab sich fuer die Wirksamkeit schwerer Ionen in Abhaengigkeit vom LET im betrachteten LET-Bereich (300 - 16000 keV/{mu}m) die fuer andere Endpunkte bekannte Aufspaltung in einzelne Kurven fuer verschiedene Teilchen. Insbesondere wurden fuer DNA-Doppelstrangbrueche mit Ne-Ionen (300 keV/{mu}m - 400 keV/{mu}m) relative biologische Wirksamkeiten ueber Eins gemessen. Zur Beurteilung der Qualitaet der DNA-Schaedigung wurde das Verhaeltnis von Doppel- zu Einzelstrangbruechen herangezogen. Wie fuer die Strangbruchinduktion ergab sich auch fuer die Abhaengigkeit des DSB/SSB-Verhaeltnisses vom LET eine sehr gute Uebereinstimmung mit intrazellulaer in Saeuger-DNA und in Radikalfaenger-haltigen Loesungen mit Virus- bzw. Phagen-DNA gemessenen Werten. Diese Uebereinstimmung laesst auf eine radioprotektive Wirkung der Zellkernmatrix schliessen. Die Annahme, dass die hohen Ionisationsdichten in der Spur schwerer Ionen hauptsaechlich komplexe Schaeden ausloesen, konnte nicht bestaetigt werden. (orig./MG).}
place = {Germany}
year = {1991}
month = {Jun}
}