Search results for "Oxide"
showing 10 items of 6424 documents
No association between Glu298Asp endothelial nitric oxide synthase polymorphism and Italian sporadic Alzheimer's disease.
2003
A great amount of evidence suggests that neuroinflammation may be a major pathogenetic mechanism in the pathophysiology of sporadic Alzheimer's Disease (sAD). Recently, polymorphisms in the endothelial nitric oxide synthase (NOS3) gene have been associated to late onset Alzheimer's Disease in a British population. However, other groups failed to replicate this finding in Asiatic and Caucasian populations. We conducted a case-control study including a clinically well-defined group of 149 sAD patients and 149 age and sex matched controls to test the association between NOS3 Glu298Asp polymorphism and sAD in an ethnically homogenous Italian population. All subjects were genotyped at NOS3 and a…
Inhibition of endocannabinoid-degrading enzyme fatty acid amide hydrolase increases atherosclerotic plaque vulnerability in mice
2013
The role of endocannabinoids such as anandamide during atherogenesis remains largely unknown. Fatty acid amide hydrolase (FAAH) represents the key enzyme in anandamide degradation, and its inhibition is associated with subsequent higher levels of anandamide. Here, we tested whether selective inhibition of FAAH influences the progression of atherosclerosis in mice. Selective inhibition of FAAH using URB597 resulted in significantly increased plasma levels of anandamide compared to control, as assessed by mass spectrometry experiments in mice. Apolipoprotein E-deficient (ApoE(-/-)) mice were fed a high-fat, cholesterol-rich diet to induce atherosclerotic conditions. Simultaneously, mice recei…
Deficiency of glutathione peroxidase-1 accelerates the progression of atherosclerosis in apolipoprotein E-deficient mice.
2007
Background— We have recently demonstrated that activity of red blood cell glutathione peroxidase-1 is inversely associated with the risk of cardiovascular events in patients with coronary artery disease. The present study analyzed the effect of glutathione peroxidase-1 deficiency on atherogenesis in the apolipoprotein E-deficient mouse. Methods and Results— Female apolipoprotein E-deficient mice with and without glutathione peroxidase-1 deficiency were placed on a Western-type diet for another 6, 12, or 24 weeks. After 24 weeks on Western-type diet, double-knockout mice (GPx-1 −/− ApoE −/− ) developed significantly more atherosclerosis than control apolipoprotein E-deficient mice. Moreover…
Opposite vascular activity of (R)-apomorphine and its oxidised derivatives. Endothelium-dependent vasoconstriction induced by the auto-oxidation meta…
2003
We have synthetised a series of oxidised apomorphine derivatives (orto and para quinones 2-5), in order to analyse their vascular activity. We have performed radioligand binding assays on rat cortical membranes and functional studies on rat aortic rings. Instead the relaxant activity exhibited by (R)-apomorphine, o-quinones 2, 4, show contractile activity dependent on endothelium in rat aortic rings. Compound 2, the main metabolite of (R)-apomorphine auto-oxidation, was the product which showed enhanced contractile activity by a complex mechanism related to activation of Ca(2+) channels through release and/or inhibition of endothelial factors. Moreover, this compound disrupts the endothelia…
Superoxide Flux in Endothelial Cells via the Chloride Channel-3 Mediates Intracellular Signaling
2007
Reactive oxygen species (ROS) have been implicated in both cell signaling and pathology. A major source of ROS in endothelial cells is NADPH oxidase, which generates superoxide (O2.−) on the extracellular side of the plasma membrane but can result in intracellular signaling. To study possible transmembrane flux of O2.−, pulmonary microvascular endothelial cells were preloaded with the O2.−-sensitive fluorophore hydroethidine (HE). Application of an extracellular bolus of O2.−resulted in rapid and concentration-dependent transient HE oxidation that was followed by a progressive and nonreversible increase in nuclear HE fluorescence. These fluorescence changes were inhibited by superoxide dism…
Energetic coupling between plastids and mitochondria drives CO2 assimilation in diatoms.
2015
International audience; Diatoms are one of the most ecologically successful classes of photosynthetic marine eukaryotes in the contemporary oceans. Over the past 30 million years, they have helped to moderate Earth's climate by absorbing carbon dioxide from the atmosphere, sequestering it via the biological carbon pump and ultimately burying organic carbon in the lithosphere. The proportion of planetary primary production by diatoms in the modern oceans is roughly equivalent to that of terrestrial rainforests. In photosynthesis, the efficient conversion of carbon dioxide into organic matter requires a tight control of the ATP/NADPH ratio which, in other photosynthetic organisms, relies prin…
High atomic yield bromine-less benzylic bromination
2002
A two-phase mixture (sodium bromide, aqueous hydrogen peroxide/carbon tetrachloride or chloroform) under visible light provides a simple and convenient system for benzylic bromination of toluenes. A high atomic yield for bromine atoms is attained. Substitution of the chlorinated solvents by other more environmentally benign organic solvents has been attempted and good results are obtained for methyl pivalate.
Enthalpies of transfer of pentanol from water to sodium dodecylsulfate-dodecyl-dimethylamine oxide-water mixtures
1994
At a given surfactant-surfactant ratio, the enthalpies of transfer ΔH (W→W+S) of pentanol 0.03m from water to sodium dodecylsulfate (NaDS)-dodecyldimethylamine oxide-water mixtures as functions of the surfactants mixture concentration (m t) were determined. ForX NaDS=0.9, ΔH (W→W+S) increases monotonically withm t such as observed for pure surfactants. ForX NaDS=0.12 and 0.3, ΔH (W→W+S) increases withm t up to 0.12m beyond which it decreases withm t. AtX NaDS=0.6, two monotonic curves can be distinguished in the ΔH (W→W+S)vs. m t trend. Experimental data were fitted through an equation previously reported for additives in pure surfactants derived by assuming the pseudo-phase transition mode…
Synthesis, Characterization, and Catalysis of β3-[(CoIIO4)W11O31(O2)4],10- the First Keggin-Based True Heteropoly Dioxygen (Peroxo) Anion. Spectrosco…
1999
Reactions of hydrogen peroxide with several lacunary polyoxometalates of the 1:11 series, XW11O39m- (X = Co3+, Ga3+, Fe3+, Si4+, and P5+), are reported. Synthetic pathways to new polyoxotungstates incorporating dioxygen moieties (peroxo and/or superoxo) are developed. The key step involves treating lacunary precursors with H2O2 in strongly buffered aqueous solutions. Upon reaction of H2O2 with α-[Co3+W11O39],9- (a) the central tetrahedral Co3+ is reduced to Co2+ and (b) each of the four unshared oxygens surrounding the vacancy are replaced by a peroxide group, yielding salts of the tetraperoxide anion β3-[(Co2+O4)W11O31(O2)4]10- (1). These results are unequivocally established by a combinat…
Mass Action Model Applied to the Thermodynamic Properties of Transfer of Nonionic Copolymers from Water to the Aqueous Surfactant Solutions
2003
A thermodynamic model which enables the properties of aqueous copolymer/surfactant mixtures to be fit quantitatively was proposed. Namely, a relationship between the properties of transfer of the unassociated copolymer from water to the aqueous surfactant solutions (DeltaY(t)) and the surfactant concentration was derived. The model was based on the idea that AY, can be expressed in terms of the following contributions: (1) interaction between monomers of copolymer and surfactant, (2) displacement of the monomer-micelle equilibrium induced by the copolymer, (3) formation of the surfactant-copolymer aggregation complex, and (4) formation of the mixed micelles. Such a model was applied to most…