1,650 research outputs found

    AT7519, a Novel Small Molecule Multi-Cyclin Dependent Kinase Inhibitor, Induces Apoptosis in Multiple Myeloma VIA GSK3 beta

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    Dysregulated cell cycling is a universal hallmark of cancer and is often mediated by abnormal activation of cyclin-dependent kinases (CDKs) and their cyclin partners. Overexpression of individual complexes are reported in multiple myeloma (MM), making them attractive therapeutic targets. In this study, we investigate the preclinical activity of a novel small-molecule multi-CDK inhibitor, AT7519, in MM. We show the anti-MM activity of AT7519 displaying potent cytotoxicity and apoptosis; associated with in vivo tumor growth inhibition and prolonged survival. At the molecular level, AT7519 inhibited RNA polymerase II (RNA pol II) phosphorylation, a CDK9, 7 substrate, associated with decreased RNA synthesis confirmed by [(3)H] Uridine incorporation. In addition, AT7519 inhibited glycogen synthase kinase 3beta (GSK-3beta) phosphorylation; conversely pretreatment with a selective GSK-3 inhibitor and shRNA GSK-3beta knockdown restored MM survival, suggesting the involvement of GSK-3beta in AT7519-induced apoptosis. GSK-3beta activation was independent of RNA pol II dephosphorylation confirmed by alpha-amanitin, a specific RNA pol II inihibitor, showing potent inhibition of RNA pol II phosphorylation without corresponding effects on GSK-3beta phosphorylation. These results offer new insights into the crucial, yet controversial role of GSK-3beta in MM and show significant anti-MM activity of AT7519, providing the rationale for its clinical evaluation in MM

    Computational Modeling of PI3K/AKT and MAPK Signaling Pathways in Melanoma Cancer

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    Background Malignant melanoma is an aggressive tumor of the skin and seems to be resistant to current therapeutic approaches. Melanocytic transformation is thought to occur by sequential accumulation of genetic and molecular alterations able to activate the Ras/Raf/MEK/ERK (MAPK) and/or the PI3K/AKT (AKT) signalling pathways. Specifically, mutations of B-RAF activate MAPK pathway resulting in cell cycle progression and apoptosis prevention. According to these findings, MAPK and AKT pathways may represent promising therapeutic targets for an otherwise devastating disease. Result Here we show a computational model able to simulate the main biochemical and metabolic interactions in the PI3K/AKT and MAPK pathways potentially involved in melanoma development. Overall, this computational approach may accelerate the drug discovery process and encourages the identification of novel pathway activators with consequent development of novel antioncogenic compounds to overcome tumor cell resistance to conventional therapeutic agents. The source code of the various versions of the model are available as S1 Archive

    Azimuthal Anisotropy of Photon and Charged Particle Emission in Pb+Pb Collisions at 158 A GeV/c

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    The azimuthal distributions of photons and charged particles with respect to the event plane are investigated as a function of centrality in Pb + Pb collisions at 158 A GeV/c in the WA98 experiment at the CERN SPS. The anisotropy of the azimuthal distributions is characterized using a Fourier analysis. For both the photon and charged particle distributions the first two Fourier coefficients are observed to decrease with increasing centrality. The observed anisotropies of the photon distributions compare well with the expectations from the charged particle measurements for all centralities.Comment: 8 pages and 6 figures. The manuscript has undergone a major revision. The unwanted correlations were enhanced in the random subdivision method used in the earlier version. The present version uses the more established method of division into subevents separated in rapidity to minimise short range correlations. The observed results for charged particles are in agreement with results from the other experiments. The observed anisotropy in photons is explained using flow results of pions and the correlations arising due to the decay of the neutral pion

    Food safety in hospital: knowledge, attitudes and practices of nursing staff of two hospitals in Sicily, Italy

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    BACKGROUND: Food hygiene in hospital poses peculiar problems, particularly given the presence of patients who could be more vulnerable than healthy subjects to microbiological and nutritional risks. Moreover, in nosocomial outbreaks of infectious intestinal disease, the mortality risk has been proved to be significantly higher than the community outbreaks and highest for foodborne outbreaks. On the other hand, the common involvement in the role of food handlers of nurses or domestic staff, not specifically trained about food hygiene and HACCP, may represent a further cause of concern. The purpose of this study was to evaluate knowledge, attitudes, and practices concerning food safety of the nursing staff of two hospitals in Palermo, Italy. Association with some demographic and work-related determinants was also investigated. METHODS: The survey was conducted, by using a semi-structured questionnaire, in March-November 2005 in an acute general hospital and a paediatric hospital, where nursing staff is routinely involved in food service functions. RESULTS: Overall, 401 nurses (279, 37.1%, of the General Hospital and 122, 53.5%, of the Paediatric Hospital, respectively) answered. Among the respondents there was a generalized lack of knowledge about etiologic agents and food vehicles associated to foodborne diseases and proper temperatures of storage of hot and cold ready to eat foods. A general positive attitude towards temperature control and using clothing and gloves, when handling food, was shared by the respondents nurses, but questions about cross-contamination, refreezing and handling unwrapped food with cuts or abrasions on hands were frequently answered incorrectly. The practice section performed better, though sharing of utensils for raw and uncooked foods and thawing of frozen foods at room temperatures proved to be widely frequent among the respondents. Age, gender, educational level and length of service were inconsistently associated with the answer pattern. More than 80% of the respondent nurses did not attend any educational course on food hygiene. Those who attended at least one training course fared significantly better about some knowledge issues, but no difference was detected in both the attitude and practice sections. CONCLUSION: Results strongly emphasize the need for a safer management of catering in the hospitals, where non professional food handlers, like nursing or domestic staff, are involved in food service functions

    Multiplicity Distributions and Charged-neutral Fluctuations

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    Results from the multiplicity distributions of inclusive photons and charged particles, scaling of particle multiplicities, event-by-event multiplicity fluctuations, and charged-neutral fluctuations in 158⋅A\cdot A GeV Pb+Pb collisions are presented and discussed. A scaling of charged particle multiplicity as Npart1.07±0.05N_{part}^{1.07\pm 0.05} and photons as Npart1.12±0.03N_{part}^{1.12\pm 0.03} have been observed, indicating violation of naive wounded nucleon model. The analysis of localized charged-neutral fluctuation indicates a model-independent demonstration of non-statistical fluctuations in both charged particles and photons in limited azimuthal regions. However, no correlated charged-neutral fluctuations are observed.Comment: Talk given at the International Symposium on Nuclear Physics (ISNP-2000), Mumbai, India, 18-22 Dec 2000, Proceedings to be published in Pramana, Journal of Physic

    Comparison of the CBA-H and SF-36 for the screening of the psychological and behavioural variables in chronic dialysis patients

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    The aim of the study was to perform an analysis of the emotional reactions, perception of stressful life and behavioural changes related to Haemodialysis (HD) in order to identify those variables that can improve lifestyle and the adherence to treatment. Some psycho- metric assessment, such as the Cognitive Behavioural Assessment, Hospital Form, (CBA- H) and the Health Survey (SF-36), which provides two indexes: the Physical Component Score (PCS) and the Mental Component Score (MCS), are suitable to assess a patient’s psychological and behavioural style and their health-related quality of life. The study involved 37 Italian out-patients with end-stage renal disease under HD therapy. We calcu- lated the Spearman correlation between variables of CBA-H, SF-36, age and time on HD. We also performed a multivariate linear regression using the CBA-H variables as predictors and PCS and MCS as dependent variables. From the CBA-H, 95% of participants self- reported psychological characteristics comparable to Type A personality, which identifies an anxious, hyperactive and hostile subject. Physical limitations were found to be directly pro- portional to the time on dialysis (rs = -0.42). The condition of perceived stress worsens the state of mental health (rs = -0.68) and general health perception (rs = -0.44). The condition of vital exhaustion correlates both the PCS and the MCS (p<0.01) with possible outcomes of physical and mental illness. The psychological wellbeing of a dialyzed patient could be due to the combination of several factors, including life parameters, the positive perception of psychosocial outcomes, and the perceived quality of life. A multidisciplinary team (neurolo- gists, psychiatrists, psychologists, and nurses) is essential to plan effective psychological and psychotherapeutic interventions to improve a mind-body integration

    Jet energy measurement with the ATLAS detector in proton-proton collisions at root s=7 TeV

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    The jet energy scale and its systematic uncertainty are determined for jets measured with the ATLAS detector at the LHC in proton-proton collision data at a centre-of-mass energy of √s = 7TeV corresponding to an integrated luminosity of 38 pb-1. Jets are reconstructed with the anti-kt algorithm with distance parameters R=0. 4 or R=0. 6. Jet energy and angle corrections are determined from Monte Carlo simulations to calibrate jets with transverse momenta pT≄20 GeV and pseudorapidities {pipe}η{pipe}<4. 5. The jet energy systematic uncertainty is estimated using the single isolated hadron response measured in situ and in test-beams, exploiting the transverse momentum balance between central and forward jets in events with dijet topologies and studying systematic variations in Monte Carlo simulations. The jet energy uncertainty is less than 2. 5 % in the central calorimeter region ({pipe}η{pipe}<0. 8) for jets with 60≀pT<800 GeV, and is maximally 14 % for pT<30 GeV in the most forward region 3. 2≀{pipe}η{pipe}<4. 5. The jet energy is validated for jet transverse momenta up to 1 TeV to the level of a few percent using several in situ techniques by comparing a well-known reference such as the recoiling photon pT, the sum of the transverse momenta of tracks associated to the jet, or a system of low-pT jets recoiling against a high-pT jet. More sophisticated jet calibration schemes are presented based on calorimeter cell energy density weighting or hadronic properties of jets, aiming for an improved jet energy resolution and a reduced flavour dependence of the jet response. The systematic uncertainty of the jet energy determined from a combination of in situ techniques is consistent with the one derived from single hadron response measurements over a wide kinematic range. The nominal corrections and uncertainties are derived for isolated jets in an inclusive sample of high-pT jets. Special cases such as event topologies with close-by jets, or selections of samples with an enhanced content of jets originating from light quarks, heavy quarks or gluons are also discussed and the corresponding uncertainties are determined. © 2013 CERN for the benefit of the ATLAS collaboration

    Measurement of the inclusive and dijet cross-sections of b-jets in pp collisions at sqrt(s) = 7 TeV with the ATLAS detector

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    The inclusive and dijet production cross-sections have been measured for jets containing b-hadrons (b-jets) in proton-proton collisions at a centre-of-mass energy of sqrt(s) = 7 TeV, using the ATLAS detector at the LHC. The measurements use data corresponding to an integrated luminosity of 34 pb^-1. The b-jets are identified using either a lifetime-based method, where secondary decay vertices of b-hadrons in jets are reconstructed using information from the tracking detectors, or a muon-based method where the presence of a muon is used to identify semileptonic decays of b-hadrons inside jets. The inclusive b-jet cross-section is measured as a function of transverse momentum in the range 20 < pT < 400 GeV and rapidity in the range |y| < 2.1. The bbbar-dijet cross-section is measured as a function of the dijet invariant mass in the range 110 < m_jj < 760 GeV, the azimuthal angle difference between the two jets and the angular variable chi in two dijet mass regions. The results are compared with next-to-leading-order QCD predictions. Good agreement is observed between the measured cross-sections and the predictions obtained using POWHEG + Pythia. MC@NLO + Herwig shows good agreement with the measured bbbar-dijet cross-section. However, it does not reproduce the measured inclusive cross-section well, particularly for central b-jets with large transverse momenta.Comment: 10 pages plus author list (21 pages total), 8 figures, 1 table, final version published in European Physical Journal

    Are ant assemblages of Brazilian veredas characterised by location or habitat type?

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    Wetland areas in the Brazilian Cerrado, known as “veredas”, represent ecosystems formed on sandy soils with high concentrations of peat, and are responsible for the recharge of aquiferous reservoirs. They are currently under threat by various human activities, most notably the clearing of vegetation for Eucalyptus plantations. Despite their ecological importance and high conservation value, little is known about the actual effects of human disturbance on the animal community. To assess how habitat within different veredas, and plantations surrounding them affect ant assemblages, we selected four independent vereda locations, two being impacted by Eucalyptus monoculture (one younger and one mature plantation) and two controls, where the wetland was surrounded by cerrado vegetation. Ant sampling was conducted in May 2010 (dry season) using three complementary methods, namely baits, pitfall traps, and hand collection, in the wetland and in the surrounding habitats. A total of 7,575 ants were sampled, belonging to seven subfamilies, 32 genera and 124 species.Ant species richness and abundance did not differ between vereda locations, but did between the habitats. When impacted by the monoculture, ant species richness and abundance decreased in wetlands, but were less affected in the cerrado habitat. Ant species composition differed between the three habitats and between vereda locations. Eucalyptus plantations had an ant species composition defined by high dominance of Pheidole sp. and Solenopsis invicta, while natural habitats were defined by Camponotus and Crematogaster species. Atta sexdens was strictly confined to native habitats of non-impacted “veredas”. Eucalyptus monocultures require high quantities of water in the early stages, which may have caused a decrease in groundwater level in the wetland, allowing hypogeic ants such as Labidus praedator to colonise this habitat
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