N-Acetylcysteine Serves as Substrate of 3-Mercaptopyruvate Sulfurtransferase and Stimulates Sulfide Metabolism in Colon Cancer Cells

Hydrogen sulfide (H2S) is an endogenously produced signaling molecule. The enzymes 3-mercaptopyruvate sulfurtransferase (MST), partly localized in mitochondria, and the inner mitochondrial membrane-associated sulfide:quinone oxidoreductase (SQR), besides being respectively involved in the synthesis and catabolism of H2S, generate sulfane sulfur species such as persulfides and polysulfides, currently recognized as mediating some of the H2S biological effects. Reprogramming of H2S metabolism was reported to support cellular proliferation and energy metabolism in cancer cells. As oxidative stress is a cancer hallmark and N-acetylcysteine (NAC) was recently suggested to act as an antioxidant by increasing intracellular levels of sulfane sulfur species, here we evaluated the effect of prolonged exposure to NAC on the H2S metabolism of SW480 colon cancer cells. Cells exposed to NAC for 24 h displayed increased expression and activity of MST and SQR. Furthermore, NAC was shown to: (i) persist at detectable levels inside the cells exposed to the drug for up to 24 h and (ii) sustain H2S synthesis by human MST more effectively than cysteine, as shown working on the isolated recombinant enzyme. We conclude that prolonged exposure of colon cancer cells to NAC stimulates H2S metabolism and that NAC can serve as a substrate for human MST

Neural Control of Sensory Acquisition: The Vestibulo-Ocular Reflex

We present a new hypothesis that the cerebellum plays a key role in actively controlling the acquisition of sensory infonnation by the nervous system. In this paper we explore this idea by examining the function of a simple cerebellar-related behavior, the vestibula-ocular reflex or VOR, in which eye movements are generated to minimize image slip on the retina during rapid head movements. Considering this system from the point of view of statistical estimation theory, our results suggest that the transfer function of the VOR, often regarded as a static or slowly modifiable feature of the system, should actually be continuously and rapidly changed during head movements. We further suggest that these changes are under the direct control of the cerebellar cortex and propose experiments to test this hypothesis

B Physics at the Tevatron: Run II and Beyond

This report provides a comprehensive overview of the prospects for B physics at the Tevatron. The work was carried out during a series of workshops starting in September 1999. There were four working groups: 1) CP Violation, 2) Rare and Semileptonic Decays, 3) Mixing and Lifetimes, 4) Production, Fragmentation and Spectroscopy. The report also includes introductory chapters on theoretical and experimental tools emphasizing aspects of B physics specific to hadron colliders, as well as overviews of the CDF, D0, and BTeV detectors, and a Summary.Comment: 583 pages. Further information on the workshops, including transparencies, can be found at the workshop's homepage: http://www-theory.lbl.gov/Brun2/. The report is also available in 2-up http://www-theory.lbl.gov/Brun2/report/report2.ps.gz or chapter-by-chapter http://www-theory.lbl.gov/Brun2/report

Prevalencia de anomalías coronarias detectadas por tomografía computarizada en el Instituto Nacional Cardiovascular - INCOR

Objective: To determine the prevalence of coronary anomalies (CA) in patients evaluated by 64-detector computed tomography (CT) at the Instituto Nacional Cardiovascular in Peru between 2016 and 2020. Materials and methods: Retrospective observational study, coronary artery CT scans of 1486 patients were performed on a 64-detector row CT scanner and reviewed in search for coronary anomalies. Results: The prevalence of CA detected by CT was 4.71% (70 cases) of which 64.3% were male. Abnormalities of origin were the most frequent, of which the origin of a coronary artery from the opposite coronary sinus was the most common (48.6%), with the right coronary being the main anomalous artery (31%), and the main path was interarterial (31%). Anomalous origin of the left main coronary from the pulmonary artery was found in 5 patients. Among the anomalies of the intrinsic coronary arterial anatomy the most frequent was the double left anterior descending artery (10%). Coronary fistulas accounted for 11.4% of cases. Conclusions: The prevalence of CA detected by 64-detector CT in a Peruvian institute was 4.71%. The most frequent coronary anomaly was the origin of the right coronary artery from the left coronary sinus with interarterial trajectory.Objetivo: determinar la prevalencia de anomalías coronarias (AC) en pacientes evaluados por tomografía computarizada (TC) de 64 detectores en el Instituto Nacional Cardiovascular en el Perú entre los años 2016 a 2020. Materiales y métodos: estudio observacional retrospectivo, en el cual se revisaron las TC de arterias coronarias de 1486 pacientes, realizadas en un tomógrafo de 64 filas de detectores, en busca de anomalías coronarias. Resultados: la prevalencia de AC detectada por TC fue de 4,71% (70 casos) de ellos 64,3% varones. Las anomalías de origen fueron las más frecuentes, de ellas el nacimiento de una arteria coronaria desde el seno coronariano opuesto fue la más común (48,6%), siendo la coronaria derecha la principal arteria anómala (31%), y el principal trayecto fue el interarterial (31%). El origen anómalo del tronco coronario izquierdo desde la arteria pulmonar se encontró en cinco pacientes. Entre las anomalías de la anatomía arterial coronaria intrínseca, la principal fue la doble arteria descendente anterior (10%). Las fístulas coronarias representaron el 11,4% de casos. Conclusiones: la prevalencia de AC detectadas por TC de 64 detectores en un instituto del Perú fue de 4,71%. La principal anomalía coronaria fue el origen de la arteria coronaria derecha desde el seno coronariano izquierdo con trayecto interarterial

Measurement of the lepton charge asymmetry in W-boson decays produced in p-pbar collisions

We describe a measurement of the charge asymmetry of leptons from W boson decays in the rapidity range 0 enu, munu events from 110+/-7 pb^{-1}of data collected by the CDF detector during 1992-95. The asymmetry data constrain the ratio of d and u quark momentum distributions in the proton over the x range of 0.006 to 0.34 at Q2 \approx M_W^2. The asymmetry predictions that use parton distribution functions obtained from previously published CDF data in the central rapidity region (0.0<|y_l|<1.1) do not agree with the new data in the large rapidity region (|y_l|>1.1).Comment: 13 pages, 3 tables, 1 figur

Combined search for the standard model Higgs boson decaying to a bb pair using the full CDF data set

We combine the results of searches for the standard model Higgs boson based on the full CDF Run II data set obtained from sqrt(s) = 1.96 TeV p-pbar collisions at the Fermilab Tevatron corresponding to an integrated luminosity of 9.45/fb. The searches are conducted for Higgs bosons that are produced in association with a W or Z boson, have masses in the range 90-150 GeV/c^2, and decay into bb pairs. An excess of data is present that is inconsistent with the background prediction at the level of 2.5 standard deviations (the most significant local excess is 2.7 standard deviations).Comment: To be published in Phys. Rev. Lett (v2 contains minor updates based on comments from PRL

Evidence for t\bar{t}\gamma Production and Measurement of \sigma_t\bar{t}\gamma / \sigma_t\bar{t}

Using data corresponding to 6.0/fb of ppbar collisions at sqrt(s) = 1.96 TeV collected by the CDF II detector, we present a cross section measurement of top-quark pair production with an additional radiated photon. The events are selected by looking for a lepton, a photon, significant transverse momentum imbalance, large total transverse energy, and three or more jets, with at least one identified as containing a b quark. The ttbar+photon sample requires the photon to have 10 GeV or more of transverse energy, and to be in the central region. Using an event selection optimized for the ttbar+photon candidate sample we measure the production cross section of, and the ratio of cross sections of the two samples. Control samples in the dilepton+photon and lepton+photon+\met, channels are constructed to aid in decay product identification and background measurements. We observe 30 ttbar+photon candidate events compared to the standard model expectation of 26.9 +/- 3.4 events. We measure the ttbar+photon cross section to be 0.18+0.08 pb, and the ratio of the cross section of ttbar+photon to ttbar to be 0.024 +/- 0.009. Assuming no ttbar+photon production, we observe a probability of 0.0015 of the background events alone producing 30 events or more, corresponding to 3.0 standard deviations.Comment: 9 pages, 3 figure