963 resultados para drug addition


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The lower alkene production by the gas-phase oxidative cracking (GOC) or catalytic oxidative cracking (COC) of hexane (C6) with added syngas was investigated. The addition of syngas to the COC process could effectively enhance the selectivity to lower alkenes and decrease the selectivity to COx, because of the preferential reaction between O-2 with H-2 contained in the syngas, whereas it has little effect on the conversion of C6 and product distribution in the GOC process. The high selectivity to lower alkenes of 70% and low selectivity to CO, of 6% at C6 conversion of 66% were achieved over 0.1% Pt/MgAl2O4 catalyst. The COC process of C6 combined with the syngas in the feed could directly produce a gas mixture of lower alkenes, H-2, and CO, which usually is a suitable feedstock for the hydroformylation process.

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In this study, an in vitro multicellular tumor spheroid model was developed using microencapsulation, and the feasibility of using the microencapsulated. multicellular tumor spheroid (MMTS) to test the effect of chemotherapeutic drugs was investigated. Human MCF-7 breast cancer cells were encapsulated in alginate-poly-L-lysine-alginate (APA) microcapsules, and a single multicellular spheroid 150 mu m in diameter was formed in the microcapsule after 5 days of cultivation. The cell morphology, proliferation, and viability of the MMTS were characterized using phase contrast microscopy, BrdU-Iabeling, MTT stain, calcein AM/ED-2 stain, and H&E stain. It demonstrated that the MMTS was viable and that the proliferating cells were mainly localized to the periphery of the cell spheroid and the apoptotic cells were in the core. The MCF-7 MMTS was treated with mitomycin C (MC) at a concentration of 0.1, 1, or 10 times that of peak plasma concentration (ppc) for up to 72 h. The cytotoxicity was demonstrated. clearly by the reduction in cell spheroid size and the decrease in cell viability. The MMTS was further used to screen the anticancer effect of chemotherapeutic drugs, treated with MC, adriamycin (ADM) and 5-fluorouracil (5-FU) at concentrations of 0.1, 1, and 10 ppc for 24, 48, and 72 h. MCF-7 monolayer culture was used as control. Similar to monolayer culture, the cell viability of MMTS was reduced after treatment with anticancer drugs. However, the inhibition rate of cell viability in MMTS was much lower than that in monolayer culture. The MMTS was more resistant to anticancer drugs than monolayer culture. The inhibition rates of cell viability were 68.1%, 45.1%, and 46.8% in MMTS and 95.1%, 86.8%, and 91.6% in monolayer culture treated with MC, ADM, and 5-FU at 10 ppc for 72 h, respectively. MC showed the strongest cytotoxicity in both MMTS and monolayer, followed by 5-FU and ADM. It demonstrated that the MMTS has the potential to be a rapid and valid in vitro model to screen chemotherapeutic drugs with a feature to mimic in vivo three-dimensional (3-D) cell growth pattern.

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Ebolaviruses (EBOVs) are among the most virulent and deadly pathogens ever known, causing fulminant haemorrhagic fevers in humans and non-human primates. The 2014 outbreak of Ebola virus disease (EVD) in West Africa has claimed more lives than all previous EVD outbreaks combined. The EBOV high mortality rates have been related to the virus-induced impairment of the host innate immunity reaction due to two virus-coded proteins, VP24 and VP35. EBOV VP35 is a multifunctional protein, it is essential for viral replication as a component of the viral RNA polymerase and it also participates in nucleocapsid assembly. Early during EBOV infection, alpha-beta interferon (IFN-α/β) production would be triggered upon recognition of viral dsRNA products by cytoplasmic retinoic acid-inducible gene I (RIG-I)-like receptors (RLRs). However, this recognition is efficiently prevented by the double-stranded RNA (dsRNA) binding activity of the EBOV VP35 protein, which hides RLRs binding sites on the dsRNA phosphate backbone as well the 5’-triphosphate (5’-ppp) dsRNA ends to RIG-I recognition. In addition to dsRNA binding and sequestration, EBOV VP35 inhibits IFN-α/β production preventing the activation of the IFN regulatory factor 3 (IRF-3) by direct interaction with cellular proteins. Previous studies demonstrated that single amino acid changes in the VP35 dsRNA binding domain reduce EBOV virulence, indicating that VP35 is an attractive target for antiviral drugs development. Within this context, here we report the establishment of a novel method to characterize the EBOV VP35 inhibitory function of the dsRNA-dependent RIG-I-mediated IFN-β signaling pathway in a BLS2 cell culture setting. In such system, a plasmid containing the promoter region of IFN-β gene linked with a luciferase reporter gene was transfected, together with a EBOV VP35 mammalian expression plasmid, into the IFN-sensitive A549 cell line, and the IFN-induction was stimulated through dsRNA transfection. Through alanine scanning mutational studies with biochemical, cellular and computational methods we highlighted the importance of some VP35 residues involved in dsRNA end-capping binding, such as R312, K282 and R322, that may serve as target for the development of small-molecule inhibitors against EBOV. Furthermore, we identified a synthetic compound that increased IFN-induction only under antiviral response stimulation and subverted VP35 inhibition, proving to be very attractive for the development of an antiviral drug. In conclusion, our results provide the establishment of a new assay as a straightforward tool for the screening of antiviral compounds that target i) dsRNA-VP35 or cellular protein-VP35 interaction and ii) dsRNA-dependent RIG-I-mediated IFN signaling pathway, in order to potentiate the IFN response against VP35 inhibition, setting the bases for further drug development.

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Enot, D. and King, R. D. (2003) Application of Inductive Logic Programming to Structure-Based Drug Design. 7th European Conference on Principles and Practice of Knowledge Discovery in Databases (PKDD '03). Springer LNAI 2838 p156-167

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David P. Enot and Ross D. King (2003). Structure based drug design with inductive logic programming. The ACS National Meeting Spring 2003, New Orleans

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David P. Enot and Ross D. King (2002) The use of Inductive Logic Programming in drug design. Proceedings of the 14th EuroQSAR Symposium (EuroQSAR 2002). Blackwell Publishing, p247-250

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James Macduff, Neil Raistrick and Mervyn Humphreys (2002). Differences in growth and nitrogen productivity between a stay-green genotype and a wild-type of Lolium perenne under limiting relative addition rates of nitrate supply. Physiologia Plantarum, 116 (1), 52-61. Sponsorship: BBSRC RAE2008

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Wydział Filologii Polskiej i Klasycznej: Instytut Filologii Polskiej

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Projeto de Pós-Graduação/Dissertação apresentado à Universidade Fernando Pessoa como parte dos requisitos para obtenção do grau de Mestre em Ciências Farmacêuticas

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Projeto de Pós-Graduação/Dissertação apresentado à Universidade Fernando Pessoa como parte dos requisitos para obtenção do grau de Mestre em Ciências Farmacêuticas

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Projeto de Pós-Graduação/Dissertação apresentado à Universidade Fernando Pessoa como parte dos requisitos para obtenção do grau de Mestre em Ciências Farmacêuticas

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Introduction: Despite being available for more than 50 years, there is still much to learn about paracetamol. Postoperative analgesic regimens that maintain good pain control while minimising exposure to opiates are beneficial and paracetamol has had a resurgence in this role since an IV formulation came to market. However there is evidence to suggest currently licensed doses are sub-therapeutic, especially when administered orally or rectally. Higher, unlicensed doses are now being advocated but, prior to this study, there was little evidence of their safety in surgical patients. When assessing drug safety in surgical patients a number of surgery and patient related factors influence results, and these must be considered. Methods: Major and intermediate surgical patients were recruited from two hospitals in Ireland. They were administered IV paracetamol at either 9g or 4g daily doses. In addition they received daily sub therapeutic doses of four other medicines to indicate the activity of their CYP450 enzymes that are involved in paracetamol metabolism. Urine and blood samples were collected to determine paracetamol pharmacokinetics, CYP450 activity, inflammatory cytokine concentration and for evidence of hepatotoxicity. Results: There were 33 patients that participated in the study. There was no evidence of clinically significant hepatotoxicity occurring in any patient during the study period, but there could have been changes following this time. Paracetamol disposition was shown to change, however half-life remained relatively constant. There were a number of changes to the way paracetamol was metabolised following surgery that maintained this rate of elimination. Conclusion: Doses of up to 9g per day given to major surgical patients for up to five days postoperatively produced no evidence of hepatotoxicity. Further research is warranted to determine the clinical utility of these higher doses

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The administration of psychotropic and psychoactive medication for persons with learning disability and accompanying mental illness and/or challenging behaviour has undergone much critical review over the past two decades. Assessment and diagnosis of mental illness in this population continues to be psychopharmacological treatment include polypharmacy, irrational prescription procedures and frequent over-prescription. It is clear that all forms of treatment including non-pharmacological interventions need to be driven by accurate and appropriate diagnoses. Where a psychiatric diagnosis has been identified, it greatly aides the selection of appropriate medication, although a specific medication for each diagnosis, as was once hoped, is simply no longer a reality in practice. Part one of the present thesis seeks to address many of the current issues in mental health problems and pharmacological treatment to date. The author undertook a drug prevalence study within both residential and community facilities for persons with learning disability within the Mid-West region of Ireland in order to ascertain the current level of prescribing of psychotropic and psychoactive medications for this population. While many attempts have been made to account for the variation in prescribing, little systematic and empirical research has been undertaken to investigate the factors thought to influence such prescribing. While studies investigating the prescribing behaviours of General Practitioners (GP's) have illustrated the complex nature of the decision making process in the context of general practice, no similar efforts have yet been directed at examining the prescribing behaviours of Consultant Psychiatrists. Using The Critical Incident Technique, the author interviewed Consultant Psychiatrists in the Republic of Ireland to gather information relating not only to their patterns of prescribing for learning disabled populations, but also to examine reasons influencing their prescribing in addition to several related factors. Part two of this thesis presents the findings from this study and a number of issues are raised, not only in relation to attempting to account for the findings from part one of the thesis, but also with respect to implications for improved management and clinical practice.

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Endospore-forming bacteria are often isolated from different marine sponges, but their abundance varies, and they are frequently missed by culture-independent studies. Within endospore-formers, Bacillus are renowned for the production of antimicrobials and other compounds of medical and industrial importance. Although this group has been well studied in many different environments, very little is known about the actual diversity and properties of sporeformers associated with marine sponges. Identification of the endospore-forming bacteria associated with the marine sponges; Haliclona simulans, Amphilectus fucorum and Cliona celata, has uncovered an abundant and diverse microbial population composed of Bacillus, Paenibacillus, Solibacillus, Halobacillus and Viridibacillus species. This diversity appears to be overlooked by other non-targeted approaches where spore-formers are masked by more dominant species within the ecosystem. In addition to the identification of two antibiotic resistant plasmids, this bank of sporeformers produce a range of bioactive compounds. New antimicrobial compounds are urgently needed to combat the spread of multidrug resistant pathogens, as few new options are entering the drug discovery pipelines for clinical trials. Based on the results of this project, endospore-formers associated with marine sponges may hold the answer. The power of coupling functional based assays with genomic approaches has enabled us to identify a novel class 1 lantibiotic, subtilomycin, which is active against several clinically relevant pathogens. Subtilomycin is encoded in the genomes of all the marine sponge B. subtilis isolates analysed. They cluster together phylogenetically and form a distinct group from other sequenced B. subtilis strains. Regardless of its potential clinical relevance, subtilomycin may be providing these strains with a specific competitive advantage(s) within the stringent confines of the marine sponge environment. This work has outlined the industrial and biotechnological potential of marine sponge endospore-formers which appear to produce a cocktail of bioactive compounds. Genome sequencing of specific marine sponge isolates highlighted the importance of mining extreme environments and habitats for new lead compounds with potential therapeutic applications.