It is now universally accepted that DNA is the main target for damages caused by physical and chemical genotoxicants. Although there are different methods to measure directly the induced DNA damages but due to fast repair processes in cellular environment, most of the damages would be repaired even before sampling, therefore processed DNA damages, i.e. damages left unrepaired after acting repai...

Background: The total yields of direct Single-Strand Breaks (SSBs) and Double-Strand Breaks (DSBs) in proton energies varying from 0.1 to 40 MeV were calculated. While other studies in this field have not used protons with energy less than 0.5 MeV, our results show interesting and complicated behavior of these protons. Materials and Methods: The simulation has been done using the Geant4-DNA too...

Three recent books on the evolutionary biology of aging and sexual reproduction are reviewed, with particular attention focused on the provocative suggestion by Bernstein and Bernstein (1991) that senescence and genetic recombination are related epiphenomena stemming from the universal challenge to life posed by DNA damages and the need for damage repair. Embellishments to these theories on agi...

objective: the passage of ionizing radiation in living cells creates clusters of damaged nucleotides in dna. in this study, dna strand breaks induced by the beta particle of iodine-131 (i-131), have been determined experimentally and compared to monte carlo simulation results as a theoretical method of determining131i damage. materials and methods: in this experimental study, in order to create...

DNA damage is a change in the basic structure of DNA that is not itself replicated when the DNA is replicated. A DNA damage can be a chemical addition or disruption to a base of DNA (creating an abnormal nucleotide or nucleotide fragment) or a break in one or both chains of the DNA strands. When DNA carrying a damaged base is replicated, an incorrect base can often be inserted opposite the site...

objective: iododeoxyuridine-induced radiosensitivityi (iudr) is a halogenated thymidine analogue recognized to be effective in vitro and in vivo radiosensitizer in human cancers. it is reported that methoxyamine (mx) potentiates dna damages in cancer cells with blocking the repair pathway of iudr damages. but studies, entirely, are restricted on monolayer culture cells from human colon cancer c...

it is now universally accepted that dna is the main target for damages caused by physical and chemical genotoxicants. although there are different methods to measure directly the induced dna damages but due to fast repair processes in cellular environment, most of the damages would be repaired even before sampling, therefore processed dna damages, i.e. damages left unrepaired after acting repai...

The focus of this research was on UVB radiation (280-320 nm) responsible for cellular changes in skin of acute and chronically exposed individuals. This study investigated the acute cellular damages triggered by UVB exposure of cultured human fibroblasts and keratinocyte cells immediately and 24 h post exposure in order to understand damage onset and progression. The study evaluated a number of...

Received: 26/Sep/2007, Accepted: 13/Feb/2008 Objective: Iododeoxyuridine-induced Radiosensitivityi (IUdR) is a halogenated thymidine analogue recognized to be effective in vitro and in vivo radiosensitizer in human cancers. It is reported that Methoxyamine (MX) potentiates DNA damages in cancer cells with blocking the repair pathway of IUdR damages. But studies, entirely, are restricted on mono...