Search results for "PET"
showing 10 items of 12749 documents
Natural products as inhibitors of recombinant cathepsin L of Leishmania mexicana.
2015
Cysteine proteinases (cathepsins) from Leishmania spp. are promising molecular targets against leishmaniasis. Leishmania mexicana cathepsin L is essential in the parasite life cycle and a pivotal in virulence factor in mammals. Natural products that have been shown to display antileishmanial activity were screened as part of our ongoing efforts to design inhibitors against the L. mexicana cathepsin L-like rCPB2.8. Among them, agathisflavone (1), tetrahydrorobustaflavone (2), 3-oxo-urs-12-en-28-oic acid (3), and quercetin (4) showed significant inhibitory activity on rCPB2.8 with IC50 values ranging from 0.43 to 18.03 µM. The mechanisms of inhibition for compounds 1–3, which showed Ki values…
Synthesis and activity of phosphinic tripeptide inhibitors of cathepsin C
2004
Phosphinic tripeptide analogues Gly-Xaaψ[P(O)(OH)CH2]-Gly have been developed as inhibitors of cathepsin C (DPP I), a lysosomal, papain-like cysteine protease. The target compounds were synthesised by addition of methyl acrylate to the appropriate phosphinic acids followed by the N-terminus elongation using mixed anhydride procedure. The latter step has been demonstrated to be a suitable method for N-terminal extension of the phosphinic pseudopeptide analogues without requirement of hydroxyphosphinyl protection. The title compounds appeared to be moderate inhibitors of the cathepsin C. However, although designed as transition state analogues, they surprisingly exhibited noncompetitive mode …
Segmentando el mercado de internautas atendiendo a su nivel de afinidad: (I)fuerte, (II)medio y (III)débil
2017
Esta investigación pretende confrontar el Marketing con Causa con el Marketing de Afinidad. Para ello se descompone la audiencia de una campaña de Marketing con Causa viral en segmentos de internautas con distinto nivel de afinidad: i) fuerte (con experiencia previa de marca y de causa); ii) medio (con experiencia previa o de marca o de causa); iii) débil (sin experiencia previa ni de marca ni de causa). El objetivo es justificar la utilidad de este criterio como vía para optimizar el resultado de la comunicación segmentada. Con dicho fin, se ha estudiado un caso real planteado de forma experimental midiendo las actitudes de una muestra de 276 internautas antes y después de visualizar un sp…
Chromatin Domains and Regulation of Transcription
2007
Compartmentalization and compaction of DNA in the nucleus is the characteristic feature of eukaryotic cells. A fully extended DNA molecule has to be compacted 100,000 times to fit within the nucleus. At the same time it is critical that various DNA regions remain accessible for interaction with regulatory factors and transcription/replication factories. This puzzle is solved at the level of DNA packaging in chromatin that occurs in several steps: rolling of DNA onto nucleosomes, compaction of nucleosome fiber with formation of the so-called 30 nm fiber, and folding of the latter into the giant (50-200 kbp) loops, fixed onto the protein skeleton, the nuclear matrix. The general assumption is…
The selection of serum-independent PC12 cells for a more-reliable manganese cytotoxicity test.
2007
A major issue concerning the protocols of heavy metal cytotoxicity tests with PC12 cells was the hypothesis that serum in the culture medium might sequester the metal, thus altering the results obtained. However, serum withdrawal impairs the viability of PC12 cells themselves, thus impeding cytotoxicity testing in the absence of serum. In this study, we repeatedly selected undifferentiated, totally non-adherent PC12 cells in Petri dishes. Surprisingly, we discovered that these cells could survive and proliferate in serum-free medium. Moreover, features such as NGF-responsiveness, resazurin reduction potential, doubling rate, protein content, and basal caspase-3 enzyme activity, were equiva…
Triazolopyridyl ketones as a novel class of antileishmanial agents. DNA binding and BSA interaction
2014
A new series of triazolopyridyl pyridyl ketones has been synthetized by regioselective lithiation of the corresponding [1,2,3]triazolo[1,5-a]pyridine at 7 position followed by reaction with different electrophiles. The in vitro antileishmanial activity of these compounds was evaluated against Leishmaniainfantum, Leishmaniabraziliensis, Leishmaniaguyanensis and Leishmaniaamazonensis. Compounds 6 and 7 were found to be the most active leishmanicidal agents. Both of them showed activities at micromolar concentration against cultured promastigotes of Leishmania spp. (IC₅₀=99.8-26.8 μM), without cytotoxicity on J774 macrophage cells. These two compounds were also tested in vivo in a murine model…
Constraint Cellular Automata for Urban Development Simulation: An Application to the Strasbourg-Kehl Cross-Border Area
2017
AcknowledgementsThe research presented in this chapter is part of the Smart. Boundary project supported by the Fonds National de la Recherche in Luxembourg and CNRS in France (ref. INTER/CNRS/12/02). The authors would like also to thank the Grasp Program of LISER for allowing cross-collaboration between the two teams based in Luxembourg and France.; International audience; Urban sprawl and space consumption have become key issues in sustainable territorial development. Traditional planning approaches are often insufficient to anticipate their complex spatial consequences, especially in cross-border areas. Such complexity requires the use of dynamic spatial simulations and the development of…
SHORT-TERM PROCESSES OF RADIONUCLIDE IMMOBILIZATION IN CEMENT - A CHEMICAL APPROACH
1992
Abstract The ions released in solution by the constituents of cement (principally silicate, aluminate, OH and Ca ions) can combine with the anions and cations from nuclear wastes present in the mixing water to give very insoluble compounds that can fix these ions in the concrete matrix. In order to understand some of the particular physico-chemical processes involved in cement hydration in the presence of analogue elements, tricalcium silicate (C 3 S) was used instead of cement, which is too complex a mixture. It was found that the salt of a chemical analogue, a lanthanide salt, showed some accelerating effects when present in dilute amounts but resulted in large accelerating effects on QS …
Hunting for the high-affinity state of G-protein-coupled receptors with agonist tracers: Theoretical and practical considerations for positron emissi…
2019
Abstract The concept of the high‐affinity state postulates that a certain subset of G‐protein‐coupled receptors is primarily responsible for receptor signaling in the living brain. Assessing the abundance of this subset is thus potentially highly relevant for studies concerning the responses of neurotransmission to pharmacological or physiological stimuli and the dysregulation of neurotransmission in neurological or psychiatric disorders. The high‐affinity state is preferentially recognized by agonists in vitro. For this reason, agonist tracers have been developed as tools for the noninvasive imaging of the high‐affinity state with positron emission tomography (PET). This review provides an…
Single cell transplantation reveals interspecific cell communication in Drosophila chimeras
1990
Abstract Cell –cell communication is not only a common strategy for cell fate specification in vertebrates, but plays important roles in invertebrate development as well. We report here on experiments testing the compatibility of mechanisms specifying cell fate among six different Drosophila species. Following interspecific transplantation, the development of single ectodermal cells was traced in order to test their abilities to proliferate and differentiate in a heterologous environment. Despite considerable differences in cell size and length of cell cycle among some of the species, the transplants gave rise to fully differentiated clones that were integrated into the host tissue. Clones …