121,857 research outputs found
Stereoselective addition of phenyl selenyl chloride to methoxy alkenes derived from N-protected chiral alpha-amino acids
No full text(E)-Methoxy alkenes derived from N-Boc or NCbz alpha-amino acids undergo stereoselective addition of phenyl selenyl chloride in the presence of Ti(Oi-Pr)(4) and LiCl to give the corresponding phenylselenyl aldehydes that can be easily transformed into new enantiomericalIy pure amino acids containing an aziridine ring. (C) 1999 Elsevier Science Ltd. All rights reserved
Small ring constrained peptidomimetics. Synthesis of aziridine parallel beta-sheet mimetics
No full textThe synthesis of a series of novel amino acids and peptides containing an aziridine ring is described. Their preparation is based on the Gabriel-Cromwell reaction of amino acids or peptides with different 2-bromo acrylates and acrylamides. These products are constituted by a turned scaffold (the aziridine) where two parallel peptidic strands can be grown to produce a beta-sheet mimetic. (C) 1998 Elsevier Science Ltd. All rights reserved
Solid phase synthesis of aziridine 2-carboxylates
No full textSeveral oligopeptides and amino acids containing an aziridine 2-carboxylate group were prepared using a solid phase version of the Gabriel-Cromwell reaction. Wang resin loaded with different Fmoc amino acids was employed as the substrates and two different strategies were explored. Aziridine oligopeptides were prepared by addition of resin containing NH2 groups to alpha-bromoacrylates and alpha-acrylamides or by addition of different primary amines to bromoacrylates loaded on the resin. (C) 1999 Elsevier Science Ltd. All rights reserved
Absence of D147E mutation of CYP11B2 gene in hypertensive patients with increased corticosterone and aldosterone production.
No full textAbsence of D147E mutation of CYP11B2 gene in hypertensive patients with increased corticosterone and aldosterone production.
Mulatero P1, Glorioso N, Fallo F, Soro A, Morra di Cella S, Carra R, Filigheddu F, Veglio F.
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Abstract
OBJECTIVE:
11beta-Hydroxylase and aldosterone synthase are two highly homologous genes involved in different forms of human hypertension and in different animal models of hypertension. It has been shown that the conservative substitution D147E in the human CYP11B2 gene results in an increased production of corticosterone and aldosterone in vitro. A gene conversion between the CYP11B1 and CYP11B2 genes could be responsible for such a substitution.
METHODS:
In this study we investigated the presence of the mutation D147E of CYP11B2 in a group of 128 patients with primary aldosteronism, 68 patients with essential hypertension and increased corticosterone production and in 48 normal volunteers.
RESULTS AND CONCLUSIONS:
We did not identify any patient carrying this mutation, indicating that if it exists it is very rare and so has no relevance in determining the increased steroid excretion seen in some subtypes of human hypertension
Differential expression of microRNAs between eutopic and ectopic endometrium in ovarian endometriosis and possible role of microRNA 200c
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The atrophic effect of 1,25(Oh)2 vitamin d3 (calcitriol) on c2c12 myotubes depends on oxidative stress
No full textDysfunctional mitochondrial metabolism has been linked to skeletal muscle loss in several physio-pathological states. Although it has been reported that vitamin D (VD) supports cellular redox homeostasis by maintaining normal mitochondrial functions, and VD deficiency often occurs in conditions associated with skeletal muscle loss, the efficacy of VD supplementation to overcome muscle wasting is debated. Investigations on the direct effects of VD metabolites on skeletal muscle using C2C12 myotubes have revealed an unexpected pro-atrophic activity of calcitriol (1,25VD), while its upstream metabolites cholecalciferol (VD3) and calcidiol (25VD) have anti-atrophic effects. Here, we investigated if the atrophic effects of 1,25VD on myotubes depend on its activity on mitochondrial metabolism. The impact of 1,25VD and its upstream metabolites VD3 and 25VD on mitochondria dynamics and the activity of C2C12 myotubes was evaluated by measuring mitochondrial content, architecture, metabolism, and reactive oxygen species (ROS) production. We found that 1,25VD induces atrophy through protein kinase C (PKC)-mediated ROS production, mainly of extramito-chondrial origin. Consistent with this, cotreatment with the antioxidant N-acetylcysteine (NAC), but not with the mitochondria-specific antioxidant mitoTEMPO, was sufficient to blunt the atrophic activity of 1,25VD. In contrast, VD3 and 25VD have antioxidant properties, suggesting that the efficacy of VD supplementation might result from the balance between atrophic pro-oxidant (1,25VD) and protective antioxidant (VD3 and 25VD) metabolites
A Multi-Language Comparison of Influences on Author Verification using Character N-Grams
No full textWe create a new multi-language corpus for author verification based on Wikipedia talkpages, and evaluate the influence that differences in topic and time have on character n-gram author profiles. Topic alignment between two texts is found to increase author verification precision, and an authors writing style is found to change over time, but not more significantly after 3 years than after 1 year.Information ArchitectureWISElectrical Engineering, Mathematics and Computer Scienc
Appropriate Similarity Measures for Author Cocitation Analysis
No full textWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
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