70 research outputs found

    Studies on the stereochemical assignment of 3-acylidene 2-oxindoles

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    The designation of E/Z-geometrical isomers in 3-acylidene 2-oxindoles by NMR spectroscopy can lead to erroneous assignment of alkene stereochemistry because of the narrow chemical shift range observed over a large series of analogues. In contrast, UV-Vis spectroscopy offers a convenient and more reliable method for alkene stereochemical assignment. A combination of X-ray crystallography and theoretical studies shows that the observed differences in UV-Vis spectroscopic behaviour relate to the twisted conformation of the Z-isomers that provides reduced conjugation and weaker hypsochromic (blue-shifted) absorbances relative to those of the E-isomers

    Carving techniques of Fatimid rock crystal ewers (10-12th cent. AD)

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    Fatimid art is known for the production of luxury artifacts, particularly rock crystal vessels. The appearance in 2008 of the Francis Mills Ewer, which seemed to belong to a famous group of 6-8 rock crystal ewers attributed to Fatimid Egypt, prompted an investigation of the techniques used to carve them. A comparison of the carving technique of the Francis Mills Ewer with that of the other members of the group offers the best criterion for determining whether the new ewer belongs to this group. To this end, the traces of manufacture (mainly polishing and carving) were analysed on a group of fourteen artifacts. The topography of the surfaces has been measured with a confocal rugosimeter using silicon replicas. To identify and characterise the multi-scale wear signature and the traces left by the tools, a Fourier isotropic filtering technique was applied. Using these complementary methods, we were able to confirm that the Francis Mills Ewer belongs to the Fatimid group. © 2013 Elsevier B.V. All rights reserved

    Lead identification of benzimidazolone and azabenzimidazolone arylsulfonamides as CC-chemokine receptor 4 (CCR4) antagonists

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    A knowledge-based library of 2,3-dichlorophenylsulfonyl derivatives of commercially available aryl amines was synthesised and screened as human CCR4 antagonists, in order to identify a suitable hit for the start of a lead-optimisation programme. Hits were required to be more potent than an existing indazole series, have better physicochemical properties (c log P 116 μg/mL), and be stable to acid and light. The benzimidazol-2-one core was identified as a hit suitable for further investigation. Substitution at N1 with small alkyl groups was tolerated; however, these analogues were inactive in the whole blood assay (pA2 <5). Azabenzimidazolone analogues were all found to be active, with compound 38 exhibiting whole blood activity of 6.1, low molecular weight (389) and chrom log D7.4 (2.4), high LE (0.43), and solubility (152 μg/mL). In addition, 38 had human serum albumin binding of around 93% and met all the criteria for progression to lead optimisation

    Evaluation of an enzyme immunoassay for plasma-free metanephrines in the diagnosis of catecholamine-secreting tumors (vol 161, pg 131, 2009)

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    OBJECTIVE: To define the test characteristics of an enzyme immunoassay (EIA) for plasma-free metanephrines (metanephrine and normetanephrine) in the diagnosis of pheochromocytoma and paraganglioma. DESIGN: Prospective observational design from a single University Hospital. Twenty-four hour urine for catecholamines and plasma for free metanephrines were collected from patients with a clinical suspicion of pheochromocytoma or paraganglioma. Patient records were reviewed for clinical data, follow-up, imaging and laboratory results to establish or exclude the diagnosis of pheochromocytoma. PATIENTS AND METHODS: Out of 178 consecutive patients, 10 had a paraganglioma and 12 had a pheochromocytoma: 156 were finally judged not to harbour active tumors and were therefore considered as controls. The main outcome measure was the diagnosis or exclusion of paraganglioma or pheochromocytoma and test characteristics of plasma-free metanephrines measured by EIA. RESULTS: Urinary epinephrine had a sensitivity of 45.5% and norepinephrine a sensitivity of 75% (98.8% specificity) for the diagnosis of pheochromocytoma. Plasma-free metanephrine and normetanephrine both had a sensitivity of 66.7% and a specificity of 100%, but when combined (either positive) they demonstrated a 91.7% sensitivity with a preserved specificity of 100%. For the diagnosis of paraganglioma, urinary norepinephrine gave slightly better results than plasma-free metanephrines, but combined testing was of no additional value. CONCLUSIONS: Plasma-free metanephrines measured by EIA have better diagnostic test characteristics than urinary catecholamines in the diagnosis of pheochromocytoma. The EIA offers a simple and effective measurement of plasma-free metanephrines

    Evaluation of an enzyme immunoassay for plasma-free metanephrines in the diagnosis of catecholamine-secreting tumors (European Journal of Endocrinology 161, 1, (131-140))

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    OBJECTIVE: To define the test characteristics of an enzyme immunoassay (EIA) for plasma-free metanephrines (metanephrine and normetanephrine) in the diagnosis of pheochromocytoma and paraganglioma. DESIGN: Prospective observational design from a single University Hospital. Twenty-four hour urine for catecholamines and plasma for free metanephrines were collected from patients with a clinical suspicion of pheochromocytoma or paraganglioma. Patient records were reviewed for clinical data, follow-up, imaging and laboratory results to establish or exclude the diagnosis of pheochromocytoma. PATIENTS AND METHODS: Out of 178 consecutive patients, 10 had a paraganglioma and 12 had a pheochromocytoma: 156 were finally judged not to harbour active tumors and were therefore considered as controls. The main outcome measure was the diagnosis or exclusion of paraganglioma or pheochromocytoma and test characteristics of plasma-free metanephrines measured by EIA. RESULTS: Urinary epinephrine had a sensitivity of 45.5% and norepinephrine a sensitivity of 75% (98.8% specificity) for the diagnosis of pheochromocytoma. Plasma-free metanephrine and normetanephrine both had a sensitivity of 66.7% and a specificity of 100%, but when combined (either positive) they demonstrated a 91.7% sensitivity with a preserved specificity of 100%. For the diagnosis of paraganglioma, urinary norepinephrine gave slightly better results than plasma-free metanephrines, but combined testing was of no additional value. CONCLUSIONS: Plasma-free metanephrines measured by EIA have better diagnostic test characteristics than urinary catecholamines in the diagnosis of pheochromocytoma. The EIA offers a simple and effective measurement of plasma-free metanephrines

    2,8-Diazaspiro[4.5]decan-8-yl)pyrimidin-4-amine potent CCR4 antagonists capable of inducing receptor endocytosis

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    A number of potent 2,8-diazaspiro[4.5]decan-8-yl)pyrimidin-4-amine CCR4 antagonists binding to the extracellular allosteric site were synthesised. (R)-N-(2,4-Dichlorobenzyl)-2-(2-(pyrrolidin-2-ylmethyl)-2,8-diazaspiro[4.5]decan-8-yl)pyrimidin-4-amine (R)-(18a) has high affinity in both the [125I]-TARC binding assay with a pKi of 8.8, and the [35S]-GTPγS functional assay with a pIC50 of 8.1, and high activity in the human whole blood actin polymerisation assay (pA2 = 6.7). The most potent antagonists were also investigated for their ability to induce endocytosis of CCR4 and were found to internalise about 60% of the cell surface receptors, a property which is not commonly shared by small molecule antagonists of chemokine receptors
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