Nitric Oxide Synthase and Nitric Oxide Involvement in Different Toxicities

Nitric oxide (NO) is known to have a very short half‐life, and it is oxidized to nitrate (NO3−) and nitrite (NO2−). The activity and/or expression of nitric oxide synthases (NOSs) can change in response to toxins or therapeutic medications. For example, in recent studies in our laboratory and others, it has been reported that the amount of NO was increased in the serum of N‐nitroso compounds‐treated animals. N‐nitroso compounds, which are found in different types of foodstuffs, including meat, salted fish, alcoholic beverages, agricultural drugs, insecticides, cigarettes, and several vegetables, are known to have carcinogenic effects. In addition, it is experimentally used to induce liver carcinoma to study the mechanisms of liver cytotoxic injury. Uncontrolled, prolonged, and/or massive production of NO by inducible NOS may cause liver damage, inflammation, and even tumor development during N‐nitroso compound toxicity. In this chapter, we explain the roles of NOS and NO in various toxicity conditions, such as toxicity in environment pollutant or food additive, and present the evaluation of the toxicity and the importance of NOSs in human health

Učinak resveratrola na razinu ekspresije SIRT2, SIRT3 i oksidacijsko oštećenje DNK kod hepatotoksičnosti izazvane fumonizinom u BALB/c miševa

Oxidative stress, which is characterized by disruption of the oxidant/antioxidant balance, causes pathological processes, including toxicities induced by certain mycotoxins. The present study was designed to investigate the effects of resveratrol on sirtuin deacetylases (SIRT2 and SIRT3), nitric oxide (NO), reduced glutathione (GSH) and malondialdehyde (MDA) in fumonisin B1-induced hepatotoxicity. Regarding the experimental design, forty BALB/c mice were divided into four groups corresponding to the control, resveratrol (10 mg/kg, i.p), fumonisin B1 (2.25 mg/ kg, i.p) and resveratrol + fumonisin B1 (10 mg/kg + 2.25 mg/kg) groups. At the end of the 14 day-treatment, expression levels of SIRT2 and SIRT3 protein in the serum and liver were revealed by western blotting and antioxidant/oxidant activity analysis. SIRT2 and SIRT3 expression levels in the liver were significantly decreased by fumonisin B1 in comparison to the control. However, resveratrol supplementation coupled with fumonisin B1 increased the expression levels of SIRT2 and SIRT3, in relation to the fumonisin B1 treatments alone, but did not exhibit significant differences from those of the control group. As substantial indicators of stress and damage, the 8-OH-2-deoxyguanosine, NO and MDA levels of the liver tissue were assayed, and were higher in the fumonisin B1-treated groups, in relation to the control. As expected, resveratrol treatment significantly reduced the levels of NO and MDA in comparison to the fumonisin B1 treatments alone. Also, resveratrol attenuated the liver 8-OH-2- deoxyguanosine levels in the resveratrol + fumonisin B1 group. In conclusion, the findings revealed that resveratrol might possess protective effects against fumonisin-induced hepatotoxicity through modulation of the expression of sirtuin proteins, and by protecting the cell from oxidative/nitrosative stress.Oksidacijski stres, koji obilježava poremećaj ravnoteže oksidansa i antiksidansa, uzrokuje patološke procese, uključujući toksičnost potaknutu određenim mikotoksinima. U ovom je radu istražen učinak resveratrola na sirtuin-deacetilazu (SIRT2 i SIRT3), dušikov oksid (NO), sniženi glutation (GSH) i malondialdehid (MDA) kod hepatotoksičnosti izazvane fumonizinom B1. Istraživanje je postavljeno tako da je 40 BALB/c miševa podijeljeno u četiri skupine: kontrolnu, skupinu koja je dobivala resveratrol (10 mg/kg, ip.), skupinu koja je dobivala fumonizin B1 (2,25 mg/kg, ip) i skupinu koja je dobivala resveratrol i fumonizin B1 (10 mg/kg+2,25 mg/kg). Nakon 14 dana određena je razina ekspresije proteina SIRT2 i SIRT3 metodom western blotting te analiza aktivnosti antioksidansa i oksidansa u serumu i jetri. Razina ekspresije SIRT2 i SIRT3 u jetri bila znakovito smanjena u skupini s fumonizinom B1 u usporedbi s kontrolnom skupinom. U skupini s dodatkom resveratrola i fumonizina B1, međutim, povećana je razina ekspresije SIRT2 i SIRT3 u usporedbi sa skupinom koja je dobivala fumonizin B1, no bez znakovite razlike između tih skupina i kontrolne skupine. Analizirani su ključni pokazatelji stresa i oštećenja, razine OH-2-deoksigvanozin, NO i MDA u tkivu jetre, koje su bile veće u skupini s fumonizinom B1, u usporedbi s kontrolnom skupinom. Kao što se očekivalo, primjena resveratrola znakovito je smanjila razine NO i MDA u usporedbi sa skupinom kojoj je primijenjen samo fumonizin B1. Također, resveratrol je smanjio razinu 8-OH-2- deoksigvanozina u jetri u skupini kojoj su dani i resveratrol i fumonizin. Rezultati pokazuju da bi resveratrol mogao imati zaštitni učinak u slučaju hepatotoksičnosti uzrokovane fumonizinom putem modulacije ekspresije sirtuin proteina i zaštite stanice od oksidacijskog/nitrosativnog stresa

Constraints on the χ_(c1) versus χ_(c2) polarizations in proton-proton collisions at √s = 8 TeV

The polarizations of promptly produced χ_(c1) and χ_(c2) mesons are studied using data collected by the CMS experiment at the LHC, in proton-proton collisions at √s=8  TeV. The χ_c states are reconstructed via their radiative decays χ_c → J/ψγ, with the photons being measured through conversions to e⁺e⁻, which allows the two states to be well resolved. The polarizations are measured in the helicity frame, through the analysis of the χ_(c2) to χ_(c1) yield ratio as a function of the polar or azimuthal angle of the positive muon emitted in the J/ψ → μ⁺μ⁻ decay, in three bins of J/ψ transverse momentum. While no differences are seen between the two states in terms of azimuthal decay angle distributions, they are observed to have significantly different polar anisotropies. The measurement favors a scenario where at least one of the two states is strongly polarized along the helicity quantization axis, in agreement with nonrelativistic quantum chromodynamics predictions. This is the first measurement of significantly polarized quarkonia produced at high transverse momentum

Measurement of the azimuthal anisotropy of Y(1S) and Y(2S) mesons in PbPb collisions at √S^{S}NN = 5.02 TeV

The second-order Fourier coefficients (υ$_{2}$) characterizing the azimuthal distributions of Υ(1S) and Υ(2S) mesons produced in PbPb collisions at $\sqrt{s_{NN}}$ = 5.02 TeV are studied. The Υmesons are reconstructed in their dimuon decay channel, as measured by the CMS detector. The collected data set corresponds to an integrated luminosity of 1.7 nb$^{-1}$. The scalar product method is used to extract the υ$_{2}$ coefficients of the azimuthal distributions. Results are reported for the rapidity range |y| < 2.4, in the transverse momentum interval 0 < p$_{T}$ < 50 GeV/c, and in three centrality ranges of 10–30%, 30–50% and 50–90%. In contrast to the J/ψ mesons, the measured υ$_{2}$ values for the Υ mesons are found to be consistent with zero

Measurement of the top quark forward-backward production asymmetry and the anomalous chromoelectric and chromomagnetic moments in pp collisions at √s = 13 TeV

Abstract The parton-level top quark (t) forward-backward asymmetry and the anomalous chromoelectric (d̂ t) and chromomagnetic (μ̂ t) moments have been measured using LHC pp collisions at a center-of-mass energy of 13 TeV, collected in the CMS detector in a data sample corresponding to an integrated luminosity of 35.9 fb−1. The linearized variable AFB(1) is used to approximate the asymmetry. Candidate t t ¯ events decaying to a muon or electron and jets in final states with low and high Lorentz boosts are selected and reconstructed using a fit of the kinematic distributions of the decay products to those expected for t t ¯ final states. The values found for the parameters are AFB(1)=0.048−0.087+0.095(stat)−0.029+0.020(syst),μ̂t=−0.024−0.009+0.013(stat)−0.011+0.016(syst), and a limit is placed on the magnitude of | d̂ t| &lt; 0.03 at 95% confidence level. [Figure not available: see fulltext.

Measurement of t(t)over-bar normalised multi-differential cross sections in pp collisions at root s=13 TeV, and simultaneous determination of the strong coupling strength, top quark pole mass, and parton distribution functions

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An embedding technique to determine ττ backgrounds in proton-proton collision data

An embedding technique is presented to estimate standard model tau tau backgrounds from data with minimal simulation input. In the data, the muons are removed from reconstructed mu mu events and replaced with simulated tau leptons with the same kinematic properties. In this way, a set of hybrid events is obtained that does not rely on simulation except for the decay of the tau leptons. The challenges in describing the underlying event or the production of associated jets in the simulation are avoided. The technique described in this paper was developed for CMS. Its validation and the inherent uncertainties are also discussed. The demonstration of the performance of the technique is based on a sample of proton-proton collisions collected by CMS in 2017 at root s = 13 TeV corresponding to an integrated luminosity of 41.5 fb(-1).Peer reviewe