reactive oxygen species (ros) are produced in many normal and abnormal processes in humans, including atheroma, asthma, joint diseases, cancer, and aging. basal levels of ros production  in  cells  could  be  related  to  several  physiological functions  including  cell proliferation, apoptosis and homeostasis. however, excessive ros production above basal levels would impair and oxidize dna, ...

It is shown that oxygen is not absolutely needed for stress-induced synthesis of catalase T in the yeast Saccharomyces cerevisiae. Yeast cells develop heat resistance after exposure to elevated temperatures in anoxia. The levels of catalase activity and thermotolerance are comparable to those in aerobically stressed cells. While these results obviously do not exclude a stress signaling role of ...

Aerobic life has evolved a dependence on molecular oxygen for its mere survival. Mitochondrial oxidative phosphorylation absolutely requires oxygen to generate the currency of energy in aerobes. The physiologic homeostasis of these organisms is strictly maintained by optimal cellular and tissue-oxygenation status through complex oxygen-sensing mechanisms, signaling cascades, and transport proce...

Kobayashi-Miura M, Shioji K, Hoshino Y, Masutani H, Nakamura H, Yodoi J. Oxygen sensing and redox signaling: the role of thioredoxin in embryonic development and cardiac diseases. Am J Physiol Heart Circ Physiol 292: H2040–H2050, 2007. First published February 9, 2007; doi:10.1152/ajpheart.01316.2006.—It is important to regulate the oxygen concentration and scavenge oxygen radicals throughout t...

Maternal heat stress reduces oocyte competence for fertilization and post-fertilization development, but the mechanism is unknown. The present experiment investigated two potential mechanisms: (1) reduced oxygen delivery to the preovulatory follicle (due to increased thermoregulatory vascular perfusion of skin and respiratory tract); (2) reduced follicular steroid synthesis. These hypotheses we...

The reaction of molecular oxygen with the Si(111)-7 x 7 surface is investigated at room temperature using in situ scanning tunneling microscopy and surface stress measurements to reveal the quantitative relationship between site-specific oxygen coverage and a decrease in tensile surface stress. This relationship is described using a modified form of the reaction model originally proposed by Duj...

The incorporation of monolayers of cultured hepatocytes into an extracorporeal perfusion system has become a promising approach for the development of a temporary bioartificial liver (BAL) support system. In this paper we present a numerical investigation of the oxygen tension, shear stress, and pressure drop in a bioreactor for a BAL composed of plasma-perfused chambers containing monolayers o...

Formation of reactive oxygen species (ROS) in mitochondrial isolates from gill tissues of the Antarctic polar bivalve Laternula elliptica was measured fluorimetrically under in vitro conditions. When compared to the rates measured at habitat temperature (1 degrees C), significantly elevated ROS formation was found under temperature stress of 7 degrees C and higher. ROS formation correlated sign...

Copper is one of the heavy metal in plant that causes toxicity at high concentration via producing reactive oxygen species. Nitric oxide can protect cells from oxidative stress produce by reactive oxygen species. Effect of different concentrations of copper (1000, 1500 and 2000 μM) and interaction with nitric oxide (100 and 150 μM) were studied on growth parameters (shoot and root length) and s...