Biomaterial Database

Lethality of heavy ion-induced DNA double-strand breaks in mammalian cells. 1993

K J Weber, and M Flentje

Radiologische Klinik, Universität, Heidelberg, Germany.

Cell killing and the production of DNA double-strand breaks (dsbs) were measured in parallel for V79 cells and a human tumour cell line (Caski) following exposure to radiations of differing linear energy transfer (LET) including accelerated heavy ions. Dsb induction was assessed by neutral filter elution (pH 7.4) and elution from agarose plugs in pulsed-field electrophoresis. The elution data were consistent with linear lesion induction and allowed to derive dsb yields or production cross-sections (sigma dsb), respectively. Both cell lines as well as the two elution approaches gave comparable results. sigma dsb was found to rise up to the heaviest ions used (LET = 11,500 keV/microns) but relative biological effectiveness was always smaller than unity. Slopes of the exponential survival curves (final slope with 60Co-radiation) were normalized to the respective dsb yields and allowed to calculate the relative lethality per induced dsb. This parameter increased with LET up to about 300 keV/microns followed by a steep decline for the very heavy ions. The extent of dsb rejoining was concomitantly reduced with ionization density.

UI	MeSH Term	Description	Entries
D007477	Ions	An atom or group of atoms that have a positive or negative electric charge due to a gain (negative charge) or loss (positive charge) of one or more electrons. Atoms with a positive charge are known as CATIONS; those with a negative charge are ANIONS.
D012062	Relative Biological Effectiveness	The ratio of radiation dosages required to produce identical change based on a formula comparing other types of radiation with that of gamma or roentgen rays.	Biological Effectiveness, Relative,Effectiveness, Biologic Relative,Effectiveness, Biological Relative,Relative Biologic Effectiveness,Biologic Effectiveness, Relative,Biologic Relative Effectiveness,Biological Relative Effectiveness,Effectiveness, Relative Biologic,Effectiveness, Relative Biological,Relative Effectiveness, Biologic
D002460	Cell Line	Established cell cultures that have the potential to propagate indefinitely.	Cell Lines,Line, Cell,Lines, Cell
D003037	Cobalt Radioisotopes	Unstable isotopes of cobalt that decay or disintegrate emitting radiation. Co atoms with atomic weights of 54-64, except 59, are radioactive cobalt isotopes.	Radioisotopes, Cobalt
D004247	DNA	A deoxyribonucleotide polymer that is the primary genetic material of all cells. Eukaryotic and prokaryotic organisms normally contain DNA in a double-stranded state, yet several important biological processes transiently involve single-stranded regions. DNA, which consists of a polysugar-phosphate backbone possessing projections of purines (adenine and guanine) and pyrimidines (thymine and cytosine), forms a double helix that is held together by hydrogen bonds between these purines and pyrimidines (adenine to thymine and guanine to cytosine).	DNA, Double-Stranded,Deoxyribonucleic Acid,ds-DNA,DNA, Double Stranded,Double-Stranded DNA,ds DNA
D004249	DNA Damage	Injuries to DNA that introduce deviations from its normal, intact structure and which may, if left unrepaired, result in a MUTATION or a block of DNA REPLICATION. These deviations may be caused by physical or chemical agents and occur by natural or unnatural, introduced circumstances. They include the introduction of illegitimate bases during replication or by deamination or other modification of bases; the loss of a base from the DNA backbone leaving an abasic site; single-strand breaks; double strand breaks; and intrastrand (PYRIMIDINE DIMERS) or interstrand crosslinking. Damage can often be repaired (DNA REPAIR). If the damage is extensive, it can induce APOPTOSIS.	DNA Injury,DNA Lesion,DNA Lesions,Genotoxic Stress,Stress, Genotoxic,Injury, DNA,DNA Injuries
D004735	Energy Transfer	The transfer of energy of a given form among different scales of motion. (From McGraw-Hill Dictionary of Scientific and Technical Terms, 6th ed). It includes the transfer of kinetic energy and the transfer of chemical energy. The transfer of chemical energy from one molecule to another depends on proximity of molecules so it is often used as in techniques to measure distance such as the use of FORSTER RESONANCE ENERGY TRANSFER.	Transfer, Energy
D006801	Humans	Members of the species Homo sapiens.	Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man
D014407	Tumor Cells, Cultured	Cells grown in vitro from neoplastic tissue. If they can be established as a TUMOR CELL LINE, they can be propagated in cell culture indefinitely.	Cultured Tumor Cells,Neoplastic Cells, Cultured,Cultured Neoplastic Cells,Cell, Cultured Neoplastic,Cell, Cultured Tumor,Cells, Cultured Neoplastic,Cells, Cultured Tumor,Cultured Neoplastic Cell,Cultured Tumor Cell,Neoplastic Cell, Cultured,Tumor Cell, Cultured
D016521	Electrophoresis, Gel, Pulsed-Field	Gel electrophoresis in which the direction of the electric field is changed periodically. This technique is similar to other electrophoretic methods normally used to separate double-stranded DNA molecules ranging in size up to tens of thousands of base-pairs. However, by alternating the electric field direction one is able to separate DNA molecules up to several million base-pairs in length.	Electrophoresis, Gel, Pulsed-Field Gradient,Gel Electrophoresis, Pulsed-Field,Contour-Clamped Homogeneous-Field Gel Electrophoresis,Electrophoresis, Gel, Pulsed Field,Electrophoresis, Pulsed Field Gel,Field Inversion Gel Electrophoresis,Orthogonal Field Alternation Gel Electrophoresis,Orthogonal-Field Alternation-Gel Electrophoresis,Pulsed Field Gradient Gel Electrophoresis,Pulsed-Field Gel Electrophoresis,Pulsed-Field Gradient Gel Electrophoresis,Alternation-Gel Electrophoresis, Orthogonal-Field,Contour Clamped Homogeneous Field Gel Electrophoresis,Electrophoresis, Orthogonal-Field Alternation-Gel,Electrophoresis, Pulsed-Field Gel,Gel Electrophoresis, Pulsed Field,Pulsed Field Gel Electrophoresis