92 resultados para U(VI)
Resumo:
OBJECTIVES: To evaluate the cost-effectiveness of an adapted U.S. model of pharmaceutical care to improve psychoactive prescribing for nursing home residents in Northern Ireland (Fleetwood NI Study).
DESIGN: Economic evaluation alongside a cluster randomized controlled trial.
SETTING: Nursing homes in NI randomized to intervention (receipt of the adapted model of care; n511) or control (usual care continued; n511).
PARTICIPANTS: Residents aged 65 and older who provided informed consent (N5253; 128 intervention, 125 control) and who had full resource use data at 12 months.
INTERVENTION: Trained pharmacists reviewed intervention home residents’ clinical and prescribing information for 12 months, applied an algorithm that guided them in assessing the appropriateness of psychoactive medication, and worked with prescribers (general practitioners) to make changes. The control homes received usual care in which there was no pharmacist intervention.
MEASUREMENTS: The proportion of residents prescribed one or more inappropriate psychoactive medications (according to standardized protocols), costs, and a cost-effectiveness acceptability curve. The latter two outcomes are the focus for this article.
RESULTS: The proportions of residents receiving inappropriate psychoactive medication at 12 months in the intervention and control group were 19.5% and 50.4%, respectively. The mean cost of healthcare resources used per resident per year was $4,923 (95% con?dence interval.
Resumo:
Collagen-related peptide is a selective agonist for the platelet collagen receptor Glycoprotein VI. The triple helical peptide contains ten GPO triplets/strand (single letter amino acid nomenclature, where O is hydroxyproline) and so over-represents GPO compared with native collagen sequence. To investigate the ability of Glycoprotein VI to recognize GPO triplets in a setting more representative of the collagens, we synthesized a set of triple helical peptides containing fewer GPO triplets, varying their number and spacing within an inert (GPP)(n) backbone. The adhesion of recombinant human Glycoprotein VI ectodomain, like that of human platelets, to these peptides increased with their GPO content, and platelet adhesion was abolished by the specific anti-Glycoprotein VI-blocking antibody, 10B12. Platelet aggregation and protein tyrosine phosphorylation were induced only by cross-linked peptides and only those that contained two or more GPO triplets. Such peptides were less potent than cross-linked collagen-related peptide. Our data suggest that both the sequences GPOGPO and GPO center dot center dot center dot center dot center dot center dot center dot center dot center dot GPO represent functional Glycoprotein VI recognition motifs within collagen. Furthermore, we propose that the (GPO)(4) motif can support simultaneous binding of two glycoprotein VI molecules, in either a parallel or anti-parallel stacking arrangement, which could play an important role in activation of signaling.
Resumo:
We have investigated the ability of collagen to induce signalling and functional responses in suspensions of murine platelets deficient in the FcRgamma (Fc receptor gamma) chain, which lack the collagen receptor GPVI (glycoprotein VI). In the absence of the FcRgamma chain, collagen induced a unique pattern of tyrosine phosphorylation which was potentiated by the thromboxane analogue U46619. Immunoprecipitation studies indicated that neither collagen alone nor the combination of collagen plus U46619 induced phosphorylation of the GPVI-regulated proteins Syk and SLP76 (Src homology 2-containing leucocyte protein of 76 kDa). A low level of tyrosine phosphorylation of phospholipase Cgamma2 was observed, which was increased in the presence of U46619, although the degree of phosphorylation remained well below that observed in wild-type platelets (similar to 10%). By contrast, collagen-induced phosphorylation of the adapter ADAP (adhesion- and degranulation-promoting adapter protein) was substantially potentiated by U46619 to levels equivalent to those observed in wild-type platelets. Collagen plus U46619 also induced significant phosphorylation of FAK (focal adhesion kinase). The functional significance of collagen-induced non-GPVI signals was highlighted by the ability of U46619 and collagen to induce the secretion of ATP in FcRgamma chain-deficient platelets, even though neither agonist was effective alone. Protein tyrosine phosphorylation and the release of ATP were abolished by the anti(alpha2 integrin) antibodies Ha1/29 and HMalpha2, but not by blockade of alphaIIbbeta3. These results illustrate a novel mechanism of platelet activation by collagen which is independent of the GPVI-FcRgamma chain complex, and is facilitated by binding of collagen to integrin alpha2beta1.
Resumo:
Recent studies implicate the collagen receptor, glycoprotein VI (GPVI) in activation of platelet 12-lipoxygenase (p12-LOX). Herein, we show that GPVI-stimulated 12-hydro(peroxy)eicosatetraenoic acid (H(P)ETE) synthesis is inhibited by palmityl trifluromethyl ketone or oleyloxyethyl phosphocholine, but not bromoenol lactone, implicating secretory and cytosolic, but not calcium-independent phospholipase A(2) (PLA(2)) isoforms. Also, following GPVI activation, 12-LOX co-immunoprecipitates with both cytosolic and secretory PLA(2), (sPLA(2)). Finally, venoms containing sPLA(2) acutely activate p12-LOX in a dose-dependent manner. This study shows that platelet 12-H(P)ETE generation utilizes arachidonate substrate from both c- and sPLA(2) and that 12-LOX functionally associates with both PLA(2) isoforms. (C) 2004 Federation of European Biochemical Societies. Published by Elsevier B.V. All rights reserved.
Resumo:
We have investigated the effects of decreased levels of the complex between glycoprotein VI (GPVI) and the Fc receptor gamma-chain (FcRgamma) on responses to collagen and GPVI-specific ligands in murine platelets. We show that levels of GPVI-FcRgamma of the order of 50 % and 20 % of wild-type levels caused 2- and 5-fold shifts to the right respectively in the dose-response curve for aggregation in response to collagen, the snake toxin convulxin and the monoclonal antibody JAQ1. In addition, there is a delay in the onset of aggregation in response to collagen. In contrast, the stimulation of protein tyrosine phosphorylation by collagen (as measured after 150 s) and adhesion to a collagen-coated surface under static conditions were unaffected in platelets with 50 % and 20 % of wild-type levels of GPVI. In contrast, responses to a collagen-related peptide (CRP), made up of repeat glycine-proline-hydroxyproline motifs, were markedly inhibited and abolished in platelets expressing 50 % and 20 % of wild-type levels of GPVI respectively. We suggest that the marked effect of a reduction in GPVI levels on the CRP-induced activation of platelets is due to the multivalent nature of CRP and the fact that GPVI is its sole receptor on platelets. Thus it appears that the interaction of CRP with GPVI is determined by a combination of affinity and avidity. The observation that collagen does not behave like CRP in platelets expressing reduced levels of GPVI, even in the combined presence of blocking antibodies against integrin alpha2beta1 and GPV, suggests that collagen has a greater affinity than CRP for GPVI, and/or that other receptors are involved in its binding to platelets. The clinical significance of these results is discussed.
Resumo:
The bovine spongiform encephalopathy (BSE) outbreak in the United Kingdom is regarded as one of the worst public policy crises the British government has experienced during the postwar era. In material terms, it has led to the slaughter of 3.3 million cattle and estimated economic losses of £3.7 billion. In administrative terms, the crisis brought about the dissolution of the Ministry of Agriculture, Fisheries and Food. This article examines the istitutional context in which decisions about the scientific evidence on BSE were made. The authors argue that a centralized system in which government agencies control science for government is inherently vulnerable to alliances of experts and interest groups that undermine the credible assessment of public health and safety risks. Specific societal conditions may encourage risk-opportunistic behavior among policy makers that is conducive to delays and inaction until such time as the evidence of a health risk becomes overwhelming.
Resumo:
Historiographical essay and evaluation of textbooks and web-based resource for teaching slave emancipation. Published to coincide with re-launch of After Slavery website (www.afterslavery.com) in partnership with Lowcountry Digital Library, College of Charleston, SC.
Resumo:
We study the residential demand for electricity and gas, working with nationwide household-level data that cover recent years, namely 1997-2007. Our dataset is a mixed panel/multi-year cross-sections of dwellings/households in the 50 largest metropolitan areas in the United States as of 2008. We estimate static and dynamic models of electricity and gas demand. We find strong household response to energy prices, both in the short and long term. From the static models, we get estimates of the own price elasticity of electricity demand in the -0.860 to -0.667 range, while the own price elasticity of gas demand is -0.693 to -0.566. These results are robust to a variety of checks. Contrary to earlier literature (Metcalf and Hassett, 1999; Reiss and White, 2005), we find no evidence of significantly different elasticities across households with electric and gas heat. The price elasticity of electricity demand declines with income, but the magnitude of this effect is small. These results are in sharp contrast to much of the literature on residential energy consumption in the United States, and with the figures used in current government agency practice. Our results suggest that there might be greater potential for policies which affect energy price than may have been previously appreciated. (C) 2011 Elsevier B.V. All rights reserved.