Dihydrorhodamine (DHR) 123 is a fluorophore commonly used for measuring reactive oxygen species (ROS), often after exposing cells to ultraviolet (UV) irradiation or oxidative burst inducers such as Phorbol 12-myristate 13-acetate (PMA). However, the negative effects of UV irradiation on oxidation of DHR123 itself to green fluorescence rhodamine (R) 123 under different experimental conditions (e...

Cr(VI) genotoxicity is caused by products of its reductive metabolism inside the cells. Reactive oxygen species (ROS) and Cr(V,IV) intermediates are potential sources of oxidative damage by Cr(VI). Here, we investigated seven fluorescent probes for the detection of ROS and non-ROS oxidants in Cr(VI) reactions with its main reducers. We found that Cr(V)-skipping metabolism of Cr(VI) by ascorbate...

A tissue-equivalent three-dimensional dosimeter is being developed to verify dose distributions for radiotherapy. Recently, we have reported a nanocomposite fluorescent gel (NC-RFG) that enables readout by the fluorometry, which more sensitive than absorption method in principle. However, irradiating an excitation light information also produces dyes and not negligible low-dose irradiation rang...

Background: The objective of present study was to assess potential of DHR123 (dihydrorhodamine 123) fluorescent probe for measurement of H2O2 produced by human spermatozoa and comparing the results with DCFH-DA (2', 7'-dichlorodihydrofluorescein diacetate). Materials and Methods: Fluorescent intensity and percentage R123 and DCF positive sperm measured by flow cytometry. The suitable ...

PURPOSE The production of reactive oxygen species (ROS) can lead to oxidative stress, which is a strong contributory factor to many ocular diseases. In this study, the removal of trophic factors is used as a model system to investigate the effects of stress in the retina. The aims were to determine if both rod and cone photoreceptor cells produce ROS when they are deprived of trophic factor sup...

Reactive oxygen species (ROS) production by phagocytic leukocytes is a critical factor in immunity against microorganisms. Human neonates are susceptible to overwhelming infections, for which abnormal granulocyte function may play an important role. In this study, we aimed to identify a convenient and quantitative method to measure ROS production by human granulocytes after cellular activation....

The primary pharmacological target of acetaminophen is prostaglandin endoperoxide H2 synthase (PGHS). The enzymatic catalytic mechanism is radical-based, initiated, and maintained by the persistent presence of peroxides, particularly peroxynitrite, which is termed "peroxide tone". Whereas the prevailing concept assumes a direct reduction of the active, oxidized enzyme by acetaminophen, here we ...

When studying the effects of oxidative stress on mammalian and yeast cells, we observed that the media without cells generated reactive oxygen species. Mammalian cell media such as RPMI 1640 medium with Glutamax-I (GibcoBRL, Cat. No. 31996) and Dulbecco’s Modified Eagle Medium with Glutamax-I, sodium pyruvate and pyridoxine (GibcoBRL, Cat. No. 31966; DMEM), as well as the yeast extract-peptone-...

BACKGROUND Interleukin-33 (IL-33) is a new member of the IL-1 cytokine family. The objectives of present study are to assess whether IL-33 can protect cardiomyocytes from anoxia/reoxygenation (A/R)-induced injury and the mechanism involved in the protection. METHODS Cardiomyocytes derived from either wild type or JNK1(-/-) mice were challenged with an A/R with or without IL-33. Myocyte apopto...