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...

BACKGROUND Repeated apnoea events cause intermittent hypoxia (IH), which alters the function of various systems and produces free radicals and oxidative stress. METHODS We investigated hepatic oxidative stress in adult mice subjected to intermittent hypoxia, simulating sleep apnoea. Three groups were submitted to 21 days of IH (IH-21), 35 days of IH (IH-35), or 35 days of sham IH. We assessed...

enhanced oxidative stress in diabetes mellitus may contribute to the pathogenesis of diaetic complications. in this article, the stress oxidative generation has been studied in experimental diabetes by ferric reducing ability of plasma assay, a sensitive and simple method, and by other oxidative damage markers. the ferric reducing ability of plasma values as a total antioxidant capacity were si...

The premutagenic oxidative DNA base damage, 7,8-dihydro-8-oxoguanine, is induced in human skin fibroblasts by monochromatic radiation ranging from a UVB wavelength (312 nm) up to wavelengths in the near visible (434 nm). The oxidative damage is not generated by absorption of radiation in DNA but rather by activation of photosensitizers generating genotoxic singlet oxygen species. The spectrum f...

Background and Aims: Diabetes mellitus causes testicular damage by increasing oxidative stress and inflammation. In the present study, modulation of oxidative stress by pioglitazone, a synthetic ligand of peroxisome proliferator-activated receptor-γ, was examined in testis of streptozotocin-induced diabetic rats. Materials and Methods: Diabetes was induced by a single dose of streptozot...

Oxidative damage has long been related to carcinogenesis in human cancers and animal cancer models. Recently a rat esophageal adenocarcinoma (EAC) model was established in our laboratory by using esophagoduodenal anastomosis (EDA) plus iron supplementation. Our previous study suggested that iron supplementation enhanced inflammation and the production of reactive nitrogen species in the esophag...

Modifications to the alkaline Comet assay by using lesion-specific endonucleases, such as formamidopyrimidine-DNA glycosylase (FPG) and endonuclease III (ENDOIII, also known as Nth), can detect DNA bases with oxidative damage. This modified assay can be used to assess the genotoxic/carcinogenic potential of environmental chemicals. The goal of this study was to validate the ability of this modi...

The application of the Comet assay in environmental monitoring remains challenging in face of the complexity of environmental stressors, e.g., when dealing with estuarine sediments, that hampers the drawing of cause-effect relationships. Although the in vitro Comet assay may circumvent confounding factors, its application in environmental risk assessment (ERA) still needs validation. As such, t...

DNA is subject to constant oxidative damage from endogenous oxidants. The oxidized DNA is continuously repaired and the oxidized bases are excreted in the urine. A simple routine analytical procedure is described for urinary 8-hydroxy-2'-deoxyguanosine, an oxidative DNA damage adduct, as an indicator of oxidative damage in humans and rodents. This adduct was purified from human urine and charac...