The first systematic steady-state and time-resolved emission study of firefly oxyluciferin (emitter in firefly bioluminescence) and its analogues in aqueous buffers provided the individual emission spectra of all chemical forms of the emitter and the excited-state equilibrium constants in strongly polar environment with strong hydrogen bonding potential. The results confirmed the earlier hypoth...

A branched chain alpha-keto acid dehydrogenase-dihydrolipoyl transacylase complex was purified to apparent homogeneity from bovine kidney mitochondria. As usually isolated, the complex (s(20,w) = 40 S) contained little, if any, dihydrolipoyl dehydrogenase. When saturated with the latter enzyme the complex had a specific activity of about 12 mumol of alpha-ketoisovalerate oxidized per min per mg...

Acetic acid bacteria, especially Gluconobacter species, have been known to catalyze the extensive oxidation of sugar alcohols (polyols) such as D-mannitol, glycerol, D-sorbitol, and so on. Gluconobacter species also oxidize sugars and sugar acids and uniquely accumulate two different keto-D-gluconates, 2-keto-D-gluconate and 5-keto-D-gluconate, in the culture medium by the oxidation of D-glucon...

Metal-free organic triplet emitters are an emerging class of semiconducting material. Among them, molecules with tunable emission responsive to environmental stimuli have shown great potential in solid-state lighting, sensors, and anti-counterfeiting systems. Here, a novel excited-state intramolecular proton transfer (ESIPT) system is proposed showing the activation thermally activated delayed ...

Thiotropolone isolated in argon and xenon matrices (as monomers) or a neat solid the crystalline amorphous state) at low temperature was found to exist only thione-enol form. Visible light irradiation (λ ≥ 400 nm) leads → thiol-keto tautomerization under conditions 15 K. The assignment of IR spectra two thiotropolone tautomers (thione-enol thiol-keto) carried out with support B3LYP/6-311+G(2d,p...

McCord, Gregg R., Jean-Luc Cracowski, and Christopher T. Minson. Prostanoids contribute to cutaneous active vasodilation in humans. Am J Physiol Regul Integr Comp Physiol 291: R596–R602, 2006. First published February 16, 2006; doi:10.1152/ajpregu.00710.2005.— The specific mechanisms by which skin blood flow increases in response to a rise in core body temperature via cutaneous active vasodilat...

In the present study, we evaluated the effect of 5 weeks of moderate-intensity endurance training on the basal and exercise-induced systemic release of prostacyclin (PGI(2)), as assessed by plasma 6-keto-PGF(1 alpha) concentration. Twelve physically active young men with the following characteristics participated in this study (the mean +/- SD): age, 22.7 +/- 2.0 years; body mass, 76.8 +/- 8.9 ...

We tested the hypothesis that cyclooxygenases (COXs) or COX products inhibit nitric oxide (NO) synthesis and thereby mask potential effects of NO on reactive hyperemia in the cutaneous circulation. We performed laser-Doppler flowmetry (LDF) with intradermal microdialysis in 12 healthy volunteers aged 19-25 yr. LDF was expressed as the percent cutaneous vascular conduction (%CVC) or as the maxim...

Prostaglandin release from microvessels isolated from the rabbit cerebral cortex was determined under three different atmospheric conditions: 100% O2 ("O2") room air, and 95% N2=5% CO2 ("N2-COj"). Initial studies with homogenates prepared from rabbit cerebral microvessels (RCMV) indicated two pathways of enzymatic PGH2 transformation, namely PGI2 synthase and GSH-dependent PGHPGE isomerase. We ...

BACKGROUND The role of 11beta-hydroxysteroid dehydrogenase type 1 (11beta-HSD1) in the regulation of energy metabolism and immune system by locally reactivating glucocorticoids has been extensively studied. Experiments determining initial rates of enzyme activity revealed that 11beta-HSD1 can catalyze both the reductase and the dehydrogenase reaction in cell lysates, whereas it predominantly ca...