ABSTRACT
Automated matrix deposition for matrix-assisted laser desorption/ionization (MALDI) mass spectrometry imaging (MSI) is crucial for producing reproducible analyte ion signals. Here we report an innovative method employing an automated immersion apparatus, which enables a robust matrix deposition within 5 minutes and with scalable throughput by using MAPS matrix and non-polar solvents. MSI results received from mouse heart and rat brain tissues were qualitatively similar to those from nozzle sprayed samples with respect to peak number and quality of the ion images. Overall, the immersion-method enables a fast and careful matrix deposition and has the future potential for implementation in clinical tissue diagnostics.
Subject(s)
Molecular Imaging/methods , Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization/methods , Animals , Brain Chemistry , Histological Techniques , Maleic Anhydrides/chemistry , Mice , Myocardium/chemistry , Rats , Reproducibility of Results , RotationABSTRACT
BACKGROUND: Cardiac stress leads to a dynamic increase of circulating microparticles (MPs) in healthy individuals that is diminished in individuals with vascular disease. The impact of coronary ischemia on circulating MP level is unknown. This study investigates the kinetics of circulating MPs during cardiac stress in patients with coronary artery stenosis. HYPOTHESIS: Patients with significant coronary stenosis show altered circulating MP levels after cardiac stress. METHODS: Eighty patients with stable coronary artery disease underwent dobutamine stress echocardiography (DSE) on the day before coronary angiography. Before, immediately after, at 4 hours, and at 24 hours after DSE, blood was drawn to determine CD144+ endothelial microparticles (EMPs), CD14+ CD16+ monocyte-derived microparticles (MMPs), and CD31+ CD42b+ platelet microparticles. A significant stenosis was defined as stenosis diameter ≥70% in a major native epicardial coronary artery with a diameter of ≥2.5 mm. RESULTS: Significant coronary artery stenoses were found in 41 patients. In these patients, CD144+ -EMP and CD14+ CD16+ -MMP concentrations decreased immediately after DSE. Stimulation of target endothelial cells with sera from patients with significant coronary artery stenoses significantly augmented endothelial capacity to take up EMPs, but not MMPs, in vitro. Serum-induced enhancement of endothelial phosphatidylserine receptor expression was found as a potential mechanism of increased endothelial EMP uptake and subsequently reduced circulating EMP levels after cardiac stress. CONCLUSIONS: Cardiac ischemia leads to reduced circulating MP levels under cardiac stress. Changes of endothelial MP uptake capacities could be one possible mechanism.
Subject(s)
Cell-Derived Microparticles/metabolism , Coronary Stenosis/blood , Echocardiography, Stress , Aged , Antigens, CD/blood , Biomarkers/blood , Cell-Derived Microparticles/pathology , Coronary Angiography , Coronary Stenosis/diagnostic imaging , Endothelial Cells/metabolism , Female , Humans , Kinetics , Male , Middle Aged , Prospective Studies , Receptors, Cell Surface/metabolism , Severity of Illness IndexABSTRACT
AIMS: CD31+/Annexin V+ microparticles (MPs) are increased in patients with cardiovascular risk factors and impaired coronary endothelial function. We evaluated whether MPs are an independent marker for cardiovascular events in patients with stable coronary artery disease (CAD). METHODS AND RESULTS: The number of CD31+/Annexin V+ MP was determined by flow cytometry in 200 patients (age 66.1±10.4 years) and correlated with cardiovascular outcomes. The median follow-up time for major adverse cardiovascular and cerebral event (MACCE)-free survival was 6.1 (6.0/6.4) years. Four patients were lost to follow-up. A first MACCE occurred in 72 patients (37%). Microparticle levels were significantly higher in patients with MACCE compared with patients without event (P=0.004). The prevalence of diabetes (P=0.02) and male gender (P=0.05) was significantly related to the MP level. In multivariate analysis (cardiovascular risk factors, number of diseased vessels, use of angiotensin-converting enzyme-inhibitors and statins), high MP levels were associated with a higher risk for cardiovascular death [Hazard ratio (HR) 4.0, 95% confidence interval (CI) 1.1-14.6; P=0.04], the need for revascularization (HR 2.4, 95% CI 1.3-4.4; P=0.005), and the occurrence of a first MACCE (HR 2.3, 95% CI 1.4-3.8; P=0.001). Inclusion of the MP level into a classical risk factor model substantially increased c-statistics from 0.637 (95% CI: 0.557-0.717) to 0.702 (95% CI: 0.625-0.780) (P=0.03). CONCLUSION: The level of circulating CD31+/Annexin V+ MPs is an independent predictor of cardiovascular events in stable CAD patients and may be useful for risk stratification.
