There are many types of DNA damage that are repaired by a multiplicity of different repair pathways. All damage and repair occur in the context of chromatin, and histone modifications are involved in many repair processes. We have analyzed the roles of H2A and its modifications in repair by mutagenizing modifiable residues in the N- and C-terminal tails of yeast H2A and by testing strains conta...

1. DNA Damage 1.1. Spontaneous Alterations of DNA (by Mutator Genes) 1.2. Environmental Damage to DNA 2. DNA Repair by Reversal of Damage Without Excision 2.1. Photoreactivation 2.2. Repair of O-Alkylguanine and Alkylthymine Without DNA trand Excision 3. Base Excision Repair in Non-Mammalian Cells 3.1. DNA Glycosylase in Non-Mammalian Cells 4. Base Excision Repair in Mammalian Cells 4.1. DNA Gl...

whereas others divide at least once before death. Cells selected for their capacity to survive prolonged periods of hyperthermia are killed at approximately the same rate during subsequent heat treatments as cells that had not been heated previously. Hyperthermic cell killing is reduced in cells that are heated in the presence of certain compounds that are inhibitors of DNA and protein synthesi...

Acute toxicity and effects of sublethal concentrations of oxadiargyl herbicide (3% EC) were examined on DNA damage (Comet assay) and histopathological changes in common carp (Cyprinus carpio) fingerlings with average weight and length of 19.15±1.05 g and 10.09±0.47 cm, respectively. The fish were exposed to 0.1, 0.3 and 0.5 mg/L of the herbicide for 30 days. Estimated 96-h LC50 value for oxadia...

An in vivo transplantation technique has been developed which can be utilized to determine the reproductive survival of parenchymal hepatocytes exposed either in vitro or in vivo to both physical and chemical genotoxic agents. We have used this assay system to determine the survival of liver cells exposed to sparsely ionizing radiation. The D0 value of the survival curve was 249 rads and the ex...

The adenoviral protein E4orf6 has been shown to inhibit both in vitro V(D)J recombination and adenoviral DNA concatenation, two processes that rely on cellular DNA double strand break repair (DSBR) proteins. Most of the known activities of E4orf6 during adenoviral infection require its interaction with another adenoviral protein, E1B-55K. Here we report that E4orf6, stably expressed in RKO huma...

objective: glioblastoma multiforme (gbm), one of the most common and aggressive malignant brain tumors, is highly resistant to radiotherapy. numerous approaches have been pursued to find new radiosensitizers. we used a picogreen and colonogenic assay to appraise the dna damage and cell death in a spheroid culture of gbm cells caused by iodine-131 (i-131) beta radiation in the presence of topote...

INTRODUCTION Stereotactic body radiotherapy delivers hypofractionated irradiation with high dose per fraction through complex treatment techniques. The increased complexity leads to longer dose delivery times for each fraction. The purpose of this study is to investigate the impact of prolonged fraction delivery time with high-dose hypofractionation on the killing of cultured ACHN cells. METH...

Oxidative DNA damage causes blocks and errors in transcription and replication, leading to cell death and genomic instability. Although repair mechanisms of the damage have been extensively analyzed in vitro, the actual in vivo repair processes remain largely unknown. Here, by irradiation with an UVA laser through a microscope lens, we have conditionally produced single-strand breaks and oxidat...