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Tobias Geisler Jean Booth Elli Tavlaki Athanasios Karathanos Karin Müller Michal Droppa Meinrad Gawaz Monica Yanez-Lopez Simon J. Davidson Rod H. Stables Winston Banya Azfar Zaman Marcus Flather Miles Dalby 《PloS one》2015,10(8)
Background
Prasugrel is more effective than clopidogrel in reducing platelet aggregation in acute coronary syndromes. Data available on prasugrel reloading in clopidogrel treated patients with high residual platelet reactivity (HRPR) i.e. poor responders, is limited.Objectives
To determine the effects of prasugrel loading on platelet function in patients on clopidogrel and high platelet reactivity undergoing percutaneous coronary intervention for acute coronary syndrome (ACS).Patients
Patients with ACS on clopidogrel who were scheduled for PCI found to have a platelet reactivity ≥40 AUC with the Multiplate Analyzer, i.e. “poor responders” were randomised to prasugrel (60 mg loading and 10 mg maintenance dose) or clopidogrel (600 mg reloading and 150 mg maintenance dose). The primary outcome measure was proportion of patients with platelet reactivity <40 AUC 4 hours after loading with study medication, and also at one hour (secondary outcome). 44 patients were enrolled and the study was terminated early as clopidogrel use decreased sharply due to introduction of newer P2Y12 inhibitors.Results
At 4 hours after study medication 100% of patients treated with prasugrel compared to 91% of those treated with clopidogrel had platelet reactivity <40 AUC (p = 0.49), while at 1 hour the proportions were 95% and 64% respectively (p = 0.02). Mean platelet reactivity at 4 and 1 hours after study medication in prasugrel and clopidogrel groups respectively were 12 versus 22 (p = 0.005) and 19 versus 34 (p = 0.01) respectively.Conclusions
Routine platelet function testing identifies patients with high residual platelet reactivity (“poor responders”) on clopidogrel. A strategy of prasugrel rather than clopidogrel reloading results in earlier and more sustained suppression of platelet reactivity. Future trials need to identify if this translates into clinical benefit.Trial Registration
ClinicalTrials.gov NCT01339026 相似文献42.
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Christine Beck Henner Morbach Meinrad Beer Martin Stenzel Dennis Tappe Stefan Gattenlöhner Ulrich Hofmann Peter Raab Hermann J Girschick 《Arthritis research & therapy》2010,12(2):R74
Introduction
Chronic nonbacterial osteomyelitis (CNO) is an inflammatory disorder of unknown etiology. In children and adolescents CNO predominantly affects the metaphyses of the long bones, but lesions can occur at any site of the skeleton. Prospectively followed cohorts using a standardized protocol in diagnosis and treatment have rarely been reported. 相似文献44.
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Savarese F Flahndorfer K Jaenisch R Busslinger M Wutz A 《Molecular and cellular biology》2006,26(19):7167-7177
Xist is the trigger for X inactivation in female mammals. The long noncoding Xist RNA localizes along one of the two female X chromosomes and initiates chromosome-wide silencing in the early embryo. In differentiated cells, Xist becomes dispensable for the maintenance of the inactive X, and its function for initiation of silencing is lost. How Xist mediates gene repression remains an open question. Here, we use an inducible Xist allele in adult mice to identify cells in which Xist can cause chromosome-wide silencing. We show that Xist has the ability to initiate silencing in immature hematopoietic precursor cells. In contrast, hematopoietic stem cells and mature blood cells are unable to initiate ectopic X inactivation. This indicates that pathways critical for silencing are transiently activated in hematopoietic differentiation. Xist-responsive cell types in normal female mice show a change of chromatin marks on the inactive X. However, dosage compensation is maintained throughout hematopoiesis. Therefore, Xist can initiate silencing in precursors with concomitant maintenance of dosage compensation. This suggests that Xist function is restricted in development by the limited activity of epigenetic pathways rather than by a change in the responsiveness of chromatin between embryonic and differentiated cell types. 相似文献
47.
Karin A. L. Müller Iris Müller Ulrich Kramer Reinhard Kandolf Meinrad Gawaz Axel Bauer Christine S. Zuern 《PloS one》2013,8(2)
Background
Owing to its variable course from asymptomatic cases to sudden death risk stratification is of paramount importance in newly diagnosed non-ischemic cardiomyopathy. We tested whether late gadolinium enhancement (LGE) assessed by cardiac magnetic resonance (CMR) imaging is a prognostic marker in consecutive patients with newly diagnosed non-ischemic cardiomyopathy.Methods
We enrolled 185 patients who presented for evaluation of newly diagnosed non-ischemic cardiomyopathy. Coronary artery disease was excluded by coronary angiography. Following risk markers were additionally assessed: NYHA functional class (≥II), brain natriuretic peptide (>100 ng/l), troponin I (TnI, ≥0.03 µg/l), left ventricular ejection fraction (LVEF, ≤40%), left ventricular enddiastolic diameter (>55 mm) and QRS duration (>98 ms). Endpoint of the study was the composite of all-cause mortality, heart transplantation, aborted sudden death, sustained ventricular tachycardia or hospitalization due to decompensated heart failure within three years of follow-up.Results
During median follow-up of 21 months, 54 patients (29.2%) reached the composite endpoint. Ninety-four of the 185 patients (50.8%) were judged LGE-positive. Prognosis of LGE-positive patients was significantly worse than that of LGE-negative patients (cumulative 3-year event rates of 67.4% in LGE-positive and 27.2% in LGE-negative patients, respectively; p = 0.021). However, in multivariable analysis, presence of LGE was not an independent predictor of outcome. Only LVEF ≤40% and TnI ≥0.03 µg/l were independent risk predictors of the composite endpoint yielding relative risks of 3.9 (95% CI 1.9–8.1; p<0.0001) and 2.2 (95% CI 1.2–4.0; p = 0.014), respectively.Conclusions
In consecutive patients presenting with newly diagnosed non-ischemic cardiomyopathy, LGE-positive patients had worse prognosis. However, only traditional risk parameters like left ventricular performance and cardiac biomarkers but not presence of LGE were independent risk predictors. 相似文献48.
Schmidt EM Münzer P Borst O Kraemer BF Schmid E Urban B Lindemann S Ruth P Gawaz M Lang F 《Biochemical and biophysical research communications》2011,(1):54-60
Platelets have been shown to migrate and thus to invade the vascular wall. Platelet migration is stimulated by SDF-1. In other cell types, migration is dependent on Ca2+ entry via Ca2+ channels. Ca2+ influx is sensitive to cell membrane potential which is maintained by K+ channel activity and/or Cl− channel activity. The present study explored the role of ion channels in the regulation of SDF-1 induced migration. Platelets were isolated from human volunteers as well as from gene targeted mice lacking the Ca2+ activated K+ channel SK4 (sk4−/−) and their wild type littermates (sk4+/+). According to confocal microscopy human platelets expressed the Ca2+ channel Orai1 and the Ca2+-activated K+ channel KCa3.1 (SK4). SDF-1 (100 ng/ml) stimulated migration in human platelets, an effect blunted by Orai1 inhibitors 2-aminoethoxydiphenyl borate 2-APB (10 μM) and SKF-96365 (10 μM), by unspecific K+ channel inhibitor TEA (30 mM), by SK4 specific K+ channel blocker clotrimazole (10 μM), but not by Cl− channel inhibitor 5-nitro-2-(3-phenylpropylamino) benzoic acid NPPB (100 μM). Significant stimulation of migration by SDF-1 was further observed in sk4+/+ platelets but was virtually absent in sk4−/− platelets. In conclusion, platelet migration requires activity of the Ca2+ channel Orai1 and of the Ca2+ activated K+ channel SK4, but not of NPPB-sensitive Cl− channels. 相似文献
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