The major mutagenic base lesion in DNA caused by exposure to reactive oxygen species is 8-hydroxyguanine (8-oxo-7, 8-dihydroguanine). In bacteria and Saccharomyces cerevisiae, this damaged base is excised by a DNA glycosylase with an associated lyase activity for chain cleavage. We have cloned, sequenced, and expressed a human cDNA with partial sequence homology to the relevant yeast gene. The ...

The oxygen-resistant strain of Chlorella sorokiniana (Shihira and Krauss), distinguished by its ability to grow autotrophically under high partial pressures of oxygen, was studied and partially characterized in heterotrophic culture. Ultrastructural analysis of glucose-grown oxygen-resistant strain and wild type cells reveals that osmiophilic deposits (possibly polyphosphate) are present only i...

BACKGROUND In 2006, three farmers died at the bottom of an agricultural shallow well where the atmosphere contained only 6% oxygen. This study aimed to document the variability of levels of oxygen and selected hazardous gases in the atmosphere of wells, and to identify ambient conditions associated with the low-oxygen situation. METHODS A cross-sectional survey, conducted in June 2007 and Jul...

Background We have discovered earlier 8-nitroguanosine 3’,5’-cyclic monophosphate (8-nitro-cGMP) formed as a second messenger for nitric oxide (NO) and reactive oxygen species (ROS), mediating a unique electrophilic cellular signaling. 8-Nitro-cGMP is formed via NO and causes protein S-guanylation. The regulation mechanism for intracellular 8-nitro-cGMP formation and its metabolic fate still re...

the influence of dissolved oxygen concentration on gill histopathology of great sturgeon (huso huso) was evaluated in two weight classes (initial weight 280.9?49.2 g and 1217.9?138.1 g respectively). oxygen treatments included hypoxia (2-3 mg/l), normoxia (5-6 mg/l) and hyperoxia (9-10 mg/l). the fish were acclimated to experimental tanks for one week then randomly distributed into 9 tanks in e...

Adequate function of the retina is dependent on proper oxygen supply. In humans, the inner retina is oxygenated via the retinal circulation. We present a method to calculate total retinal oxygen extraction based on measurement of total retinal blood flow using dual-beam bidirectional Doppler optical coherence tomography and measurement of oxygen saturation by spectrophotometry. These measuremen...