Angiotensin II and NADPH Oxidase Increase ADMA in Vascular Smooth Muscle Cells

Asymmetric dimethylarginine inhibits nitric oxide synthase, cationic amino acid transport and endothelial function. Patients with cardiovascular risk factors often have endothelial dysfunction associated with increased plasma asymmetric dimethylarginine and markers of reactive oxygen species. We tested the hypothesis that reactive oxygen species, generated by nicotinamide adenine dinucleotide phosphate oxidase, enhance cellular asymmetric dimethylarginine. Incubation of rat preglomerular vascular smooth muscle cells with angiotensin II doubled the activity of nicotinamide adenine dinucleotide phosphate oxidase, but decreased the activities of dimethylarginine dimethylaminohydrolase by 35% and of cationic amino acid transport by 20% and doubled cellular (but not medium) asymmetric dimethylarginine concentrations (p<0.01). This was blocked by tempol or candesartan. Cells stably transfected with p22(phox) had a 50% decreased protein expression and activity of dimethylarginine dimethylaminohydrolase despite increased promoter activity and mRNA. The decreased DDAH protein expression and the increased asymmetric dimethylarginine concentration in p22(phox) transfected cells were prevented by proteosomal inhibition. These cells had enhanced protein arginine methylation, a 2-fold increased expression of protein arginine methyltransferase-3 (p<0.05), and a 30% reduction in cationic amino acid transport activity (p<0.05). Asymmetric dimethylarginine was increased from 6±1 to 16±3μmol·l(−1) (p<0.005) in p22(phox) transfected cells. Thus, angiotensin II increased cellular asymmetric dimethylarginine via type 1 receptors and reactive oxygen species. Nicotinamide adenine dinucleotide phosphate oxidase increased cellular asymmetric dimethylarginine by increasing enzymes that generate it, enhancing the degradation of enzymes that metabolize it, and reducing its cellular transport. This could underlie increases in cellular asymmetric dimethylarginine during oxidative stress

A New Upper Limit for the Tau-Neutrino Magnetic Moment

Using a prompt neutrino beam in which a nu_tau component was identified for the first time, the nu_tau magnetic moment was measured based on a search for an anomalous increase in the number of neutrino-electron interactions. One such event was observed when 2.3 were expected from background processes, giving an upper 90% confidence limit of 3.9x10^-7 Bohr magnetons.Comment: 9 pages; 1 figur

Observation of Tau Neutrino Interactions

The DONUT experiment has analyzed 203 neutrino interactions recorded in nuclear emulsion targets. A decay search has found evidence of four tau neutrino interactions with an estimated background of 0.34 events. This number is consistent with the Standard Model expectation.Comment: 12 pages, 3 figures, PD

Measurement of B(D_s+ -> mu+ nu_mu)/B(D_s+ -> phi mu+ nu_mu) and Determination of the Decay Constant f_{D_s}

We have observed $23.2 \pm 6.0_{-0.9}^{+1.0}$ purely-leptonic decays of $D_s^+ -> \mu^+ \nu_\mu$ from a sample of muonic one prong decay events detected in the emulsion target of Fermilab experiment E653. Using the $D_s^+ -> \phi \mu^+ \nu_\mu$ yield measured previously in this experiment, we obtain $B(D_s^+ --> \mu^+ \nu_\mu) / B(D_s^+ --> \phi \mu^+ \nu_\mu) =0.16 \pm 0.06 \pm 0.03$. In addition, we extract the decay constant $f_{D_s}=194 \pm 35 \pm 20 \pm 14 MeV$.Comment: 15 pages including one figur

Anion recognition by neutral receptors

In this review the design of neutral receptors for anions is described. In these receptors, selective anion recognition takes place either exclusively via hydrogen bonding or by combination of a Lewis acidic UO2-center and hydrogen bonds. An approach to neutral bifunctional receptors containing both anion and cation complexing sites is described. The results on selective H2PO4- anion transport and simultaneous transport of hydrophilic cations and anions through a supported liquid membrane are presented