54 research outputs found

    Characterization of the Phytochelatin Synthase of Schistosoma mansoni

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    Treatment for schistosomiasis, which is responsible for more than 280,000 deaths annually, depends exclusively on the use of praziquantel. Millions of people are treated annually with praziquantel and drug resistant parasites are likely to evolve. In order to identify novel drug targets the Schistosoma mansoni sequence databases were queried for proteins involved in glutathione metabolism. One potential target identified was phytochelatin synthase (PCS). Phytochelatins are oligopeptides synthesized enzymatically from glutathione by PCS that sequester toxic heavy metals in many organisms. However, humans do not have a PCS gene and do not synthesize phytochelatins. In this study we have characterized the PCS of S. mansoni (SmPCS). The conserved catalytic triad of cysteine-histidine-aspartate found in PCS proteins and cysteine proteases is also found in SmPCS, as are several cysteine residues thought to be involved in heavy metal binding and enzyme activation. The SmPCS open reading frame is considerably extended at both the N- and C-termini compared to PCS from other organisms. Multiple PCS transcripts are produced from the single encoded gene by alternative splicing, resulting in both mitochondrial and cytoplasmic protein variants. Expression of SmPCS in yeast increased cadmium tolerance from less than 50 µM to more than 1,000 µM. We confirmed the function of SmPCS by identifying PCs in yeast cell extracts using HPLC-mass spectrometry. SmPCS was found to be expressed in all mammalian stages of worm development investigated. Increases in SmPCS expression were seen in ex vivo worms cultured in the presence of iron, copper, cadmium, or zinc. Collectively, these results indicate that SmPCS plays an important role in schistosome response to heavy metals and that PCS is a potential drug target for schistosomiasis treatment. This is the first characterization of a PCS from a parasitic organism

    Treatment of Open-Angle Glaucoma and Ocular Hypertension with Preservative-Free Tafluprost/Timolol Fixed-Dose Combination Therapy : The VISIONARY Study

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    Funding Information: Funding was provided by Santen SA for the study, medical writing services and Rapid Service Fees. All authors had full access to all of the data in this study and take complete responsibility for the integrity of the data and accuracy of the data analysis. The contribution of IRCCS Fondazione Bietti to this work was supported by the Italian Ministry of Health and by Fondazione Roma. Publisher Copyright: © 2020, The Author(s). Copyright: Copyright 2020 Elsevier B.V., All rights reserved.Introduction: A non-interventional, multicenter, European, prospective evaluation of the effectiveness, tolerability, and safety of a topical preservative-free tafluprost (0.0015%) and timolol (0.5%) fixed-dose combination (PF tafluprost/timolol FC) in adults with open-angle glaucoma (OAG) and ocular hypertension (OHT) demonstrating insufficient response to topical beta-receptor blockers or prostaglandin analogue (PGA) monotherapy. Methods: Mean intraocular pressure (IOP) change from baseline was measured at study visits following a switch to PF tafluprost/timolol FC. Primary endpoint was absolute mean IOP change at month 6. Change from baseline concerning ocular signs and symptoms was also explored. Results: Analyses included 577 patients (59.6% female). Mean age (SD) was 67.8 (11.67) years. Mean (SD) IOP reduction from baseline was significant at all study visits; 5.4 (3.76) mmHg (23.7%) at week 4, 5.9 (3.90) mmHg (25.6%) at week 12, and 5.7 (4.11) mmHg (24.9%) at month 6 (p < 0.0001 for all visits). At month 6, 69.2%, 53.6%, 40.0%, and 25.8% were responders based on ≥ 20%, ≥ 25%, ≥ 30%, and ≥ 35% cutoff values for mean IOP, respectively. Significant reductions were observed concerning corneal fluorescein staining (p < 0.0001), dry eye symptoms, irritation, itching, and foreign body sensation (p < 0.001 for each parameter). Conjunctival hyperemia was significantly reduced at all study visits (p < 0.0001 at each visit). Overall, 69 treatment-related adverse events (AEs) were reported, one of which was serious (status asthmaticus). Most AEs were mild to moderate in severity, and the majority had resolved or were resolving at the end of the study period. Conclusion: In clinical practice, PF tafluprost/timolol FC provided statistically and clinically significant IOP reductions in patients with OAG and OHT insufficiently controlled on or intolerant to PGA or beta-receptor blocker monotherapy. The full IOP reduction appeared at week 4 and was maintained over the 6-month study period. Key symptoms of ocular surface health improved. Trial Registration: European Union electronic Register of Post-Authorisation Studies (EU PAS) register number, EUPAS22204.publishersversionPeer reviewe

    Agent Tools, Techniques and Methods for Macro and Microscopic Simulation

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    © Springer Science+Business Media B.V. 2012. Many situations exist that require virtual crowds to be modelled via computer simulations on varying scales. Such simulations often have conflicting goals; the need for large and complex worlds with rich behaviours in agents, but at the same time, the need for fast performance provided by simpler agents with reasonable crowd authoring. Our goal in this chapter is to establish the tools and -techniques required for simulating large-scale virtual crowds. We identify both macroscopic and microscopic simulation methods and detail application areas where there is the need for navigation and behaviour of agents around the simulation environment, to correspond to realism. Hence, we actively identify different classes of applications that form balances between the conflicting goals that exist in simulating virtual populations
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