다중혈관 관상동맥 환자에서 y-문합을 이용하여 양쪽 내흉동맥만을 사용한 우회술의 조기 성적

Beyond cholesterol, modifications of low-density lipoprotein that increase its atherogenicity

For a long time, superoxide generation by an NADPH oxidase was considered as an oddity only found in professional phagocytes. Over the last years, six homologs of the cytochrome subunit of the phag...

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The NOX Family of ROS-Generating NADPH Oxidases: Physiology and Pathophysiology

Flavonoids are phenolic substances isolated from a wide range of vascular plants, with over 8000 individual compounds known. They act in plants as antioxidants, antimicrobials, photoreceptors, visual attractors, feeding repellants, and for light screening. Many studies have suggested that flavonoids exhibit biological activities, including antiallergenic, antiviral, antiinflammatory, and vasodilating actions. However, most interest has been devoted to the antioxidant activity of flavonoids, which is due to their ability to reduce free radical formation and to scavenge free radicals. The capacity of flavonoids to act as antioxidants in vitro has been the subject of several studies in the past years, and important structure-activity relationships of the antioxidant activity have been established. The antioxidant efficacy of flavonoids in vivo is less documented, presumably because of the limited knowledge on their uptake in humans. Most ingested flavonoids are extensively degraded to various phenolic acids, some of which still possess a radical-scavenging ability. Both the absorbed flavonoids and their metabolites may display an in vivo antioxidant activity, which is evidenced experimentally by the increase of the plasma antioxidant status, the sparing effect on vitamin E of erythrocyte membranes and low-density lipoproteins, and the preservation of erythrocyte membrane polyunsaturated fatty acids. This review presents the current knowledge on structural aspects and in vitro antioxidant capacity of most common flavonoids as well as in vivo antioxidant activity and effects on endogenous antioxidants.

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Flavonoids as Antioxidants

In recent years, there has been a great deal of attention toward the field of free radical chemistry. Free radicals reactive oxygen species and reactive nitrogen species are generated by our body by various endogenous systems, exposure to different physiochemical conditions or pathological states. A balance between free radicals and antioxidants is necessary for proper physiological function. If free radicals overwhelm the body's ability to regulate them, a condition known as oxidative stress ensues. Free radicals thus adversely alter lipids, proteins, and DNA and trigger a number of human diseases. Hence application of external source of antioxidants can assist in coping this oxidative stress. Synthetic antioxidants such as butylated hydroxytoluene and butylated hydroxyanisole have recently been reported to be dangerous for human health. Thus, the search for effective, nontoxic natural compounds with antioxidative activity has been intensified in recent years. The present review provides a brief overview on oxidative stress mediated cellular damages and role of dietary antioxidants as functional foods in the management of human diseases.

Free radicals, antioxidants and functional foods: Impact on human health

The enzyme indoleamine 2,3-dioxygenase (IDO) convertsthe amino acid tryptophan (Trp) to kynurenine (Kyn)IDO, which shares many functional similarities withiNOS [1], is also induced in sepsis [2] Here, we investi-gated whether IDO plays a role in human septic shock andmouse endotoxemia akin to iNOS

/pdf/is-kynurenine-a-novel-and-important-vasodilator-in-human-18cmfa3era.pdf

Is kynurenine a novel and important vasodilator in human septic shock

An improved method for the detection of myeloperoxidase chlorinating activity in biological systems using the redox probe hydroethidine.

Tocopherol-mediated lipid peroxidation of isolated LDL and human plasma exposed to various radical oxidants

The L-tryptophan-derived tricyclic hydroperoxide cis-WOOH was recently identified as a novel and biologically important factor for regulating vascular tone and blood pressure under inflammatory conditions and potentially other cellular redox signaling events. cis-WOOH is highly labile and currently not available commercially. In this protocol, we provide procedures for the synthesis, purification, quantification and characterization of cis-WOOH, its epimer trans-WOOH and their respective alcohols (cis-WOH and trans-WOH). Photo-oxidation of L-tryptophan (L-Trp) results in a mixture containing cis-WOOH and trans-WOOH, which are separated and purified by semi-preparative HPLC. cis-WOH and trans-WOH are then produced by sodium borohydride reduction and purified by semi-preparative HPLC. Characterization of cis-WOOH and trans-WOOH and the reduced alcohol variants is achieved using HPLC, fluorescence, NMR and liquid chromatography-tandem mass spectrometry. The protocol provides instructions for storage and quantification, as well as ways to test the stability of these hydroperoxides in commonly used buffers and media. Finally, we describe examples of how to monitor the formation of cis-WOOH in biological samples. The protocol ensures reasonable yield (11%) and purity (>99%) of cis-WOOH and control compounds in 5-6 d and outlines conditions under which cis-WOOH is stable for several months.

Preparation, validation and use of a vasoactive tryptophan-derived hydroperoxide and relevant control compounds.

Historically, studies of atherosclerosis and vascular disease have been performed in larger animal species, other than small rodents. Published information on vascular dissection in mice, because of the technical challenges it presents, has been limited. However, with the advent of transgenic technology, such procedures are becoming more commonplace. In particular, mice in which genes such as LDL or apolipoprotein E have been 'knocked-out' have recently provided powerful small animal models for such work. The methodology presented provides a clear, accurate, and detailed description for removing the entire mouse aorta for further analysis in atherogenic investigations. Thus, our article likely will provide a useful guide to those new to this technique, and for researchers undertaking similar studies, and the technique could be adapted to other species easily.

Roland Stocker

Papers

Is kynurenine a novel and important vasodilator in human septic shock

An improved method for the detection of myeloperoxidase chlorinating activity in biological systems using the redox probe hydroethidine.

Tocopherol-mediated lipid peroxidation of isolated LDL and human plasma exposed to various radical oxidants

Preparation, validation and use of a vasoactive tryptophan-derived hydroperoxide and relevant control compounds.

Vascular microdissection, perfusion, and excision of the murine arterial tree for use in atherogenic disease investigations.