545 research outputs found

    Preclinical Applications of 3'-Deoxy-3'-[18F]Fluorothymidine in Oncology - A Systematic Review

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    The positron emission tomography (PET) tracer 3'-deoxy-3'-[18F]fluorothymidine ([18F]FLT) has been proposed to measure cell proliferation non-invasively in vivo. Hence, it should provide valuable information for response assessment to tumor therapies. To date, [18F]FLT uptake has found limited use as a response biomarker in clinical trials in part because a better understanding is needed of the determinants of [18F]FLT uptake and therapy-induced changes of its retention in the tumor. In this systematic review of preclinical [18F]FLT studies, comprising 174 reports, we identify the factors governing [18F]FLT uptake in tumors, among which thymidine kinase 1 plays a primary role. The majority of publications (83 %) report that decreased [18F]FLT uptake reflects the effects of anticancer therapies. 144 times [18F]FLT uptake was related to changes in proliferation as determined by ex vivo analyses. Of these approaches, 77 % describe a positive relation, implying a good concordance of tracer accumulation and tumor biology. These preclinical data indicate that [18F]FLT uptake holds promise as an imaging biomarker for response assessment in clinical studies. Understanding of the parameters which influence cellular [18F]FLT uptake and retention as well as the mechanism of changes induced by therapy is essential for successful implementation of this PET tracer. Hence, our systematic review provides the background for the use of [18F]FLT in future clinical studies

    Spin-resolved photoemission from Pd(111)

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    Schmiedeskamp B, Kessler B, MĂŒller N, Schönhense G, Heinzmann U. Spin-resolved photoemission from Pd(111). Solid State Communications. 1988;65(7):665-670

    Electronic Resonances in Rare-Gas Adsorbates Observed by Spin-Resolved Electron Spectroscopy

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    Schönhense G, Kessler B, MĂŒller N, Schmiedeskamp B, Heinzmann U. Electronic Resonances in Rare-Gas Adsorbates Observed by Spin-Resolved Electron Spectroscopy. Physica Scripta. 1987;35(4):541-546

    Orientation dependence of the sticking probability of NO at Ni(100)

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    Fecher GH, Volkmer M, Pawlitzky B, Böwering N, Heinzmann U. Orientation dependence of the sticking probability of NO at Ni(100). Vacuum. 1990;41(1-3):265-268

    Poincaré on the Foundation of Geometry in the Understanding

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    This paper is about Poincaré’s view of the foundations of geometry. According to the established view, which has been inherited from the logical positivists, PoincarĂ©, like Hilbert, held that axioms in geometry are schemata that provide implicit definitions of geometric terms, a view he expresses by stating that the axioms of geometry are “definitions in disguise.” I argue that this view does not accord well with Poincaré’s core commitment in the philosophy of geometry: the view that geometry is the study of groups of operations. In place of the established view I offer a revised view, according to which PoincarĂ© held that axioms in geometry are in fact assertions about invariants of groups. Groups, as forms of the understanding, are prior in conception to the objects of geometry and afford the proper definition of those objects, according to PoincarĂ©. Poincaré’s view therefore contrasts sharply with Kant’s foundation of geometry in a unique form of sensibility. According to my interpretation, axioms are not definitions in disguise because they themselves implicitly define their terms, but rather because they disguise the definitions which imply them

    Unifying candidate gene and GWAS Approaches in Asthma.

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    The first genome wide association study (GWAS) for childhood asthma identified a novel major susceptibility locus on chromosome 17q21 harboring the ORMDL3 gene, but the role of previous asthma candidate genes was not specifically analyzed in this GWAS. We systematically identified 89 SNPs in 14 candidate genes previously associated with asthma in >3 independent study populations. We re-genotyped 39 SNPs in these genes not covered by GWAS performed in 703 asthmatics and 658 reference children. Genotyping data were compared to imputation data derived from Illumina HumanHap300 chip genotyping. Results were combined to analyze 566 SNPs covering all 14 candidate gene loci. Genotyped polymorphisms in ADAM33, GSTP1 and VDR showed effects with p-values <0.0035 (corrected for multiple testing). Combining genotyping and imputation, polymorphisms in DPP10, EDN1, IL12B, IL13, IL4, IL4R and TNF showed associations at a significance level between p = 0.05 and p = 0.0035. These data indicate that (a) GWAS coverage is insufficient for many asthma candidate genes, (b) imputation based on these data is reliable but incomplete, and (c) SNPs in three previously identified asthma candidate genes replicate in our GWAS population with significance after correction for multiple testing in 14 genes

    CHARACTERIZATION AND ANTIFUNGAL ACTIVITY OF THE ESSENTIAL OIL OF TAGETES MINUTA FRONT OF THE CRYPTOCOCCUS SPP. ISOLATES FROM THE ENVIRONMENT

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    Objective: This study evaluated the chemical composition and antifungal activity of the essential oil of inflorescences of Tagetes minuta (EOTM) belonging to the Asteraceae family against Cryptococcus spp. This microorganism is the encapsulated yeast-like and is recognized as an opportunistic fungal pathogen of great clinical importance.Methods: The inflorescences of T. minuta were collected in Itaara/RS, Brazil, in April 2013, and identification of the components was performed by GC-MS. The species of fungi are environmental isolates of Cryptococcus spp. identified by direct examination with India ink, urease test, culture and agar Niger medium canavanine glycine bromothymol blue, and all fungi isolates were confirmed by the use of automated panel MicroScan¼ Rapid Yeast ID (SIEMENS¼). ATCC strains of C. gattii, C. neoformans and C. grubii belonging to the Microbiology Laboratory of the Centro Universitário Franciscano of Santa Maria/RS, Brazil were also used. The antifungal activity of the EOTM was evaluated by microdilution.Results: Most strains of Cryptococcus spp. were sensitive to EOTM even at low concentrations, except when the microorganism in question was Cryptococcus grubii which the essential oil showed a weak antifungal action.Conclusion: The EOTM appears as promising in prospecting for new drugs for the treatment of cryptococcosis.Keywords: Cryptococcosis, Natural products, Antifungal, Marigol

    Biochemical parameters of silver catfish (Rhamdia quelen) after transport with eugenol or essential oil of Lippia alba added to the water

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    The transport of live fish is a routine practice in aquaculture and constitutes a considerable source of stress to the animals. The addition of anesthetic to the water used for fish transport can prevent or mitigate the deleterious effects of transport stress. This study investigated the effects of the addition of eugenol (EUG) (1.5 or 3.0 mu L L-1) and essential oil of Lippia alba (EOL) (10 or 20 mu L L-1) on metabolic parameters (glycogen, lactate and total protein levels) in liver and muscle, acetylcholinesterase activity (AChE) in muscle and brain, and the levels of protein carbonyl (PC), thiobarbituric acid reactive substances (TBARS) and nonprotein thiol groups (NPSH) and activity of glutathione-S-transferase in the liver of silver catfish (Rhamdia quelen; Quoy and Gaimard, 1824) transported for four hours in plastic bags (loading density of 169.2 g L-1). The addition of various concentrations of EUG (1.5 or 3.0 mu L L-1) and EOL (10 or 20 mu L L-1) to the transport water is advisable for the transportation of silver catfish, since both concentrations of these substances increased the levels of NPSH antioxidant and decreased the TBARS levels in the liver. In addition, the lower liver levels of glycogen and lactate in these groups and lower AChE activity in the brain (EOL 10 or 20 mu L L-1) compared to the control group indicate that the energetic metabolism and neurotransmission were lower after administration of anesthetics, contributing to the maintenance of homeostasis and sedation status.Fundacao de Amparo a Pesquisa do Estado do Rio Grande do Sul (FAPERGS/PRONEX) [10/0016-8]; Conselho Nacional de Pesquisa e Desenvolvimento Cientifico (CNPq) [470964/2009-0]; Coordenacao de Aperfeicoamento de Pessoal de Nivel Superior (CAPES); CNPqinfo:eu-repo/semantics/publishedVersio
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