64 research outputs found
Longitudinal peak strain detects a smaller risk area than visual assessment of wall motion in acute myocardial infarction
<p>Abstract</p> <p>Background</p> <p>Opening of an occluded infarct related artery reduces infarct size and improves survival in acute ST-elevation myocardial infarction (STEMI). In this study we performed tissue Doppler analysis (peak strain, displacement, mitral annular movement (MAM)) and compared with visual assessment for the study of the correlation of measurements of global, regional and segmental function with final infarct size and transmurality. In addition, myocardial risk area was determined and a prediction sought for the development of infarct transmurality ≥50%.</p> <p>Methods</p> <p>Twenty six patients with STEMI submitted for primary percutaneous coronary intervention (PCI) were examined with echocardiography on the catheterization table. Four to eight weeks later repeat echocardiography was performed for reassessment of function and magnetic resonance imaging for the determination of final infarct size and transmurality.</p> <p>Results</p> <p>On a global level, wall motion score index (WMSI), ejection fraction (EF), strain, and displacement all showed significant differences (p ≤ 0.001, p ≤ 0.001, p ≤ 0.001 and p = 0.03) between the two study visits, but MAM did not (p = 0.17). On all levels (global, regional and segmental) and both pre- and post PCI, WMSI showed a higher correlation with scar transmurality compared to strain. We found that both strain and WMSI predicted the development of scar transmurality ≥50%, but strain added no significant information to that obtained with WMSI in a logistic regression analysis.</p> <p>Conclusions</p> <p>In patients with acute STEMI, WMSI, EF, strain, and displacement showed significant changes between the pre- and post PCI exam. In a ROC-analysis, strain had 64% sensitivity at 80% specificity and WMSI around 90% sensitivity at 80% specificity for the detection of scar with transmurality ≥50% at follow-up.</p
Analytical methodology for sulfonated lignins
There is a significant need to characterize and classify lignins and sulfonated lignins. Lignins have so far received a good deal of attention, whereas this is not true for sulfonated lignins. There is a clear demand for a better understanding of sulfonated lignins on a chemical as well as physical level. Many of the analytical methods have been developed with different goals in mind, for example, detection of sulfonated lignins in pulp-mill effluents, elucidation of structural changes in lignosulfonates during a pulping process, or identification of properties that may affect a formulation when sulfonated lignins are used as a dispersant. When sulfonated lignins are used in industrial applications, analytical data obtained using different techniques may be necessary to enable prediction of their behavior in the target application. In the present review, a critical discussion of established and promising analytical techniques for the characterization of sulfonated lignins is presented
One-dimensional and two-dimensional liquid chromatography of sulphonated lignins
One- and two-dimensional separation methods have been developed for the analysis of lignosulphonates and sulphonated kraft lignins. The evaluated sulphonated lignins are all used as dispersants in agrochemical formulations, where some give rise to physical instabilities of formulations. It is of interest to identify the properties of the sulphonated lignins that determine the formulation characteristics. Tetrapentylammonium bromide has been used as an ion-pair reagent in a gradient-elution reversed-phase liquid-chromatographic (IP-RPLC) method, as well as in aqueous size-exclusion chromatography (SEC). Clear differences in the size distribution were observed between different batches of sulphonated lignins. The RPLC and SEC methods were combined in a comprehensive two-dimensional liquid chromatography system. The retention times in the two dimensions were highly correlated. Therefore, the full potential of comprehensive two-dimensional liquid chromatography was not yet realized. However, the results did reveal that retention in IP-RPLC was not determined by the degree of sulphonation of similar-size molecules. Rather, molecules were separated according to size and the degree of sulphonation appears to be approximately constant. The information obtained in this study represents a significant step towards meaningful correlations between the requirements of surfactants within an agrochemical formulation and structural parameters, such as the size and the degree of sulphonation of lignin oligomers
Adherence to national diabetes guidelines through monitoring quality indicators – A comparison of three types of care for the elderly with special emphasis on HbA1c
Evaluation of comprehensive on-line liquid chromatography thermally assisted hydrolysis and methylation-gas chromatography-mass spectrometry for characterization of sulfonated lignins
Evaluation of comprehensive on-line liquid chromatography thermally assisted hydrolysis and methylation-gas chromatography-mass spectrometry for characterization of sulfonated lignins
Evaluation of comprehensive on-line liquid chromatography thermally assisted hydrolysis and methylation-gas chromatography-mass spectrometry for characterization of sulfonated lignins
Sulfonated lignins, used as dispersants in agrochemical formulations, have been characterized by hyphenation of ion-pair RPLC and thermally assisted hydrolysis and methylation-GC-MC (THM-GC-MS). The chemical structure of a series of selected lignins was evaluated, both in terms of overall composition and in terms of composition as a function of molecular size. Some sulfonated lignins give rise to unstable formulations. In the compositional analysis, these samples were found to yield additional fragments. A newly developed comprehensive method made it possible to monitor the occurrence of these fragments as a function of molecular size. In addition to differences in the molecular size between "good" and "bad" batches, clear differences in chemical composition were established
Fully automated system for the gas chromatographic characterization of polar biopolymers based on thermally assisted hydrolysis and methylation
Pyrolysis-gas chromatography (Py-GC) is a powerful tool for the detailed compositional analysis of polymers. A major problem of Py-GC is that polar (bio)polymers yield polar pyrolyzates which are not easily accessible to further GC characterization. In the present work, a newly developed fully automated procedure for thermally assisted hydrolysis and methylation (THM) of biopolymers is described. Drying of the sample, addition of the reagent, incubation and pyrolysis are performed inside the liner of a programmable temperature vaporizer injector. The new system not only allows efficient analysis of large series of samples, but also allows automated optimization of the experimental parameters based on an experimental design approach. The performance of the automated THM-procedure was evaluated by performing THM-GC of a poly(acrylic acid)-poly(maleic anhydride) copolymer (PAA/PMAH) and several polysaccharides. The optimized THM-procedure was applied for the structural characterization and differentiation of several lignins and hydroxypropylmethyl-celluloses. It was also applied to proteins. Here myoglobin and cytochrome c were used as the model compounds. Both conventional GC-mass spectrometry (MS) and comprehensive two-dimensional gas chromatography (GC × GC)-time-of-flight (TOF) MS were used for separation and identification of the species formed. The information obtained can aid in structure elucidation of polar biopolymers as well as in providing detailed compositional information which can be used to differentiate structurally similar biopolymers
Alterations in bone turnover markers in patients with noncardio-embolic ischemic stroke.
BackgroundThe major cause of ischemic stroke is unstable or thrombogenic atherosclerotic plaques. Vascular calcification, a process that appears crucial for plaque stability, shares common features with bone formation. Many bone turnover proteins exhibit metabolic properties, but the evidence is conflicting regarding their possible involvement in vascular disease. Antibodies against sclerostin and dickkopf-1 are currently being evaluated as potential therapy for treating bone disorders. It is important to carefully assess the cardiovascular and metabolic effects of these proteins. The aim of the present study was to explore serum levels of bone turnover markers in patients with acute noncardio-embolic ischemic stroke in comparison with healthy controls.MethodsIn a cross-sectional study, we compared 48 patients aged ≥75 years with noncardio-embolic ischemic stroke and 46 healthy controls. Serum levels of dickkopf-1, sclerostin, osteoprotegerin, osteopontin and osteocalcin were determined by Luminex technique.ResultsWe found clearly increased serum levels of osteoprotegerin, sclerostin, dickkopf-1 and osteopontin in patients with stroke compared with healthy controls. No difference was seen in serum levels of osteocalcin between the two groups.ConclusionOur findings strengthen the hypothesis of bone turnover markers being involved in vascular disease. Whether these proteins can be used as candidate markers for increased stroke risk or prognostic biomarkers remains to be further elucidated
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