Search results for "Enos"

Villanos y hombres buenos. La élite campesina en el mundo rural hispano durante la época moderna

2021

Severity of Asymptomatic Carotid Stenosis and Risk of Ipsilateral Hemispheric Ischaemic Events: Results from the ACSRS Study

2005

Objectives. This study determines the risk of ipsilateral ischaemic neurological events in relation to the degree of asymptomatic carotid stenosis and other risk factors. Methods. Patients (n = 1115) with asymptomatic internal carotid artery (ICA) stenosis greater than 50% in relation to the bulb diameter were followed up for a period of 6-84 (mean 37.1) months. Stenosis was graded using duplex, and clinical and biochemical risk factors were recorded. Results. The relationship between ICA stenosis and event rate is linear when stenosis is expressed by the ECST method, but S-shaped if expressed by the NASCET method. In addition to the ECST grade of stenosis (RR 1.6; 95% CI 1.21-2.15), histor…

Catalysis in glycine N-methyltransferase: testing the electrostatic stabilization and compression hypothesis.

2006

Glycine N-methyltransferase (GNMT) is an S-adenosyl-l-methionine dependent enzyme that catalyzes glycine transformation to sarcosine. Here, we present a hybrid quantum mechanics/molecular mechanics (QM/MM) computational study of the reaction compared to the counterpart process in water. The process takes place through an SN2 mechanism in both media with a transition state in which the transferring methyl group is placed in between the donor (SAM) and the acceptor (the amine group of glycine). Comparative analysis of structural, electrostatic, and electronic characteristics of the in-solution and enzymatic transition states allows us to get a deeper insight into the origins of the enzyme's c…

Expanding the chemical scope of RNA:methyltransferases to site-specific alkynylation of RNA for click labeling.

2010

This work identifies the combination of enzymatic transfer and click labeling as an efficient method for the site-specific tagging of RNA molecules for biophysical studies. A double-activated analog of the ubiquitous co-substrate S-adenosyl-l-methionine was employed to enzymatically transfer a five carbon chain containing a terminal alkynyl moiety onto RNA. The tRNA:methyltransferase Trm1 transferred the extended alkynyl moiety to its natural target, the N2 of guanosine 26 in tRNA(Phe). LC/MS and LC/MS/MS techniques were used to detect and characterize the modified nucleoside as well as its cycloaddition product with a fluorescent azide. The latter resulted from a labeling reaction via Cu(I…

Homocysteine and S-adenosylated metabolites in cardiovascular disease

2010

A major unanswered question is whether direct cellular toxicity of homocysteine (Hcy) is causally involved in cardiovascular disease (CVD) in humans or whether homocysteinemia is simply a passive and indirect indicator of a more complex mechanism. Alternatively or additionally, the association between Hcy and CVD may result from its metabolic precursor S-adenosyl-Hcy (SAH), or from the altered ratio of S-adenosylmethionine SAM/SAH. This competition is based on the known effects of these adenosylated metabolites on cellular methylation, disturbances of which may lead to endothelial dysfunction and/ or CVD. Thus, it is of great significance to know how these adenosylated metabolites (SAM, SAH…

DILATION TREATMENT OF BENIGN STRICTURED OF COLOCOLONIC ANASTOMOSES

2009

SCOPO DI QUESTO ARTICOLO E' DI METTERE IN LUCE LA COMPLIANCE, I BENEFICI ED IL MIGLIORAMENTO DELLA QUALITA' DELLA VITA, NEI SOGGETTI AFFETTI DA STENOSI BENIGNA POST-ANASTOMOTICA COLO-COLICA E COLO-RETTALE E TRATTATI CON DILATAZIONE ENDOSCOPICA DEL TRATTO STENOTICO. LA DILATAZION PER VIA ENDOSCOPICA RISULTA ESSERE SICURA E DI SEMPLICE ESECUZIONE E PERMETTE DI OTTENERE RISULTATI SODDISFACENTI ANCHE PER PERIODI PROLUNGATI. I CRITERI STANDARD PER UNA EFFICACE DILATAZIONE VARIANO TRA 1 10 E 13 MM.

Valutazione retrospettiva sull'uso dei sistemi interspinosi per il trattamento mini-invasivi della stenosi spinale lombare: stato dell'arte e prospet…

2012

A short-range gradient of histone H3 acetylation and Tup1p redistribution at the promoter of the Saccharomyces cerevisiae SUC2 gene.

2003

Chromatin immunoprecipitation assays are used to map H3 and H4 acetylation over the promoter nucleosomes and the coding region of the Saccharomyces cerevisiae SUC2 gene, under repressed and derepressed conditions, using wild type and mutant strains. In wild type cells, a high level of H3 acetylation at the distal end of the promoter drops sharply toward the proximal nucleosome that covers the TATA box, a gradient that become even steeper on derepression. In contrast, substantial H4 acetylation shows no such gradient and extends into the coding region. Overall levels of both H3 and H4 acetylation rise on derepression. Mutation of GCN5 or SNF2 lead to substantially reduced SUC2 expression; in…

Specific Defects in Different Transcription Complexes Compensate for the Requirement of the Negative Cofactor 2 Repressor in Saccharomyces cerevisiae

2007

Abstract Negative cofactor 2 (NC2) has been described as an essential and evolutionarily conserved transcriptional repressor, although in vitro and in vivo experiments suggest that it can function as both a positive and a negative effector of transcription. NC2 operates by interacting with the core promoter and components of the basal transcription machinery, like the TATA-binding protein (TBP). In this work, we have isolated mutants that suppress the growth defect caused by the depletion of NC2. We have identified mutations affecting components of three different complexes involved in the control of basal transcription: the mediator, TFIIH, and RNA pol II itself. Mutations in RNA pol II in…

Partial purification and characterization of succinyl-CoA synthetase from Saccharomyces cerevisiae

1983

Succinyl-CoA synthetase from Saccharomyces cerevisiae was partially purified (20-fold) with a yield of 44%. The Michaelis-Menten constants were determined: Km (succinate) = 17 mM; Km (ATP) = 0.13 mM; Km (CoA) = 0.03 mM. The succinyl-CoA synthetase has a molecular weight of about 80000 dalton (as determined by polyacrylamide gradient gel electrophoresis). The pH optimum is at 6.0. During fermentation the activity of succinyl-CoA synthetase is lower than in aerobically grown yeast cells. The presence of succinyl-CoA synthetase in fermenting yeasts may be regarded as an indication for the oxidative formation of succinate. In fermenting yeast cells succinyl-CoA synthetase is repressed by glucos…