Soluble amyloid β (Aβ) oligomers cause memory loss and synaptic dysfunction in Alzheimer disease (AD). Despite intensive studies on Aβ assembly in vitro and in vivo, the localization and cellular mechanism of Aβ oligomerization are not fully understood. Previously, we demonstrated that cytoplasmic superoxide radicals contribute to drusen deposition, a hallmark of age-related macular degeneratio...

BACKGROUND Oxygen-derived free radicals are thought to injure the ischemic heart during coronary microvascular embolization. METHODS AND RESULTS To test this idea, microspheres (15 microns in diameter) were repetitively administered into the left anterior descending coronary artery to cause microvascular embolization in dogs. Myocardial contractile and metabolic dysfunctions were significantl...

Cells that utilize molecular oxygen generate highly reactive oxygen-derived free radicals. Endogenous cellular oxidants inactivate oxidant free radicals and protect aerobic cells from oxidant injury. Glutathione, glutathione reductase, and superoxide dismutase are key components of this antioxidant defense. Inhibition of antioxidant components would be expected to result in cell injury. Using e...

Oxidants are compounds capable of withdrawing electrons from target atoms or molecules, thus initiating chemical reactions. In biological systems, oxidative modifications are often related to structural, functional and regulatory changes. Partially reduced oxygen species, also known as oxygen-derived free radicals, represent the most important group of biologically relevant oxidants. Significan...

Human neutrophils generate oxygen reduction products as a consequence of membrane interactions with a number of stimuli. One oxygen-centered free radical (superoxide) has been unequivocally shown to result from this "respiratory burst," and some experimental evidence for another (hydroxyl radical) has been published, although debate remains as to its significance. The role of phagocyte-derived ...

UNLABELLED The wood of mature Abies alba Mill. (silver fir) trees is used in construction and furniture industries, the bark being the main waste product. AIM This study aimed to investigate possible therapeutic applications of Abies alba bark waste. MATERIAL AND METHODS A raw extract and four extractive fractions were obtained from silver fir bark. They were also studied regarding their po...

Superoxide dismutases (SODs) and superoxide radicals in peroxisomes Peroxisomes are subcellular respiratory organelles that contain catalase and H202-producing flavin oxidases as basic enzymatic constituents [1,2]. In recent years, it has become increasingly clear that peroxisomes carry out essential functions in almost all eukaryotic cells [3-51, and an important characteristic of peroxisomes ...

The antitumor effect of oxygen radicals produced by hypoxanthine and xanthine oxidase reaction was studied in an experimental rabbit model. VX2 carcinomas were transplanted into rabbit hind legs. Hypoxanthine was administered continuously through the ear vein, while xanthine oxidase was administered simultaneously through the femoral artery. As a result, hypoxanthine and xanthine oxidase reacte...