101 research outputs found

    Exhaled Eicosanoids following Bronchial Aspirin Challenge in Asthma Patients with and without Aspirin Hypersensitivity: The Pilot Study

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    Background. Special regulatory role of eicosanoids has been postulated in aspirin-induced asthma. Objective. To investigate effects of aspirin on exhaled breath condensate (EBC) levels of eicosanoids in patients with asthma. Methods. We determined EBC eicosanoid concentrations using gas chromatography/mass spectrometry (GC-MS) and high-performance liquid chromatography/mass spectrometry (HPLC-MS2) or both. Determinations were performed at baseline and following bronchial aspirin challenge, in two well-defined phenotypes of asthma: aspirin-sensitive and aspirin-tolerant patients. Results. Aspirin precipitated bronchial reactions in all aspirin-sensitive, but in none of aspirin-tolerant patients (ATAs). At baseline, eicosanoids profile did not differ between both asthma groups except for lipoxygenation products: 5- and 15-hydroxyeicosatetraenoic acid (5-, 15-HETE) which were higher in aspirin-induced asthma (AIA) than inaspirin-tolerant subjects. Following aspirin challenge the total levels of cysteinyl-leukotrienes (cys-LTs) remained unchanged in both groups. The dose of aspirin had an effect on magnitude of the response of the exhaled cys-LTs and prostanoids levels only in AIA subjects. Conclusion. The high baseline eicosanoid profiling of lipoxygenation products 5- and 15-HETE in EBC makes it possible to detect alterations in aspirin-sensitive asthma. Cysteinyl-leukotrienes, and eoxins levels in EBC after bronchial aspirin administration in stable asthma patients cannot be used as a reliable diagnostic index for aspirin hypersensitivity

    Plasma proteins elevated in severe asthma despite oral steroid use and unrelated to Type-2 inflammation

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    Rationale Asthma phenotyping requires novel biomarker discovery. Objectives To identify plasma biomarkers associated with asthma phenotypes by application of a new proteomic panel to samples from two well-characterised cohorts of severe (SA) and mild-to-moderate (MMA) asthmatics, COPD subjects and healthy controls (HCs). Methods An antibody-based array targeting 177 proteins predominantly involved in pathways relevant to inflammation, lipid metabolism, signal transduction and extracellular matrix was applied to plasma from 525 asthmatics and HCs in the U-BIOPRED cohort, and 142 subjects with asthma and COPD from the validation cohort BIOAIR. Effects of oral corticosteroids (OCS) were determined by a 2-week, placebo-controlled OCS trial in BIOAIR, and confirmed by relation to objective OCS measures in U-BIOPRED. Results In U-BIOPRED, 110 proteins were significantly different, mostly elevated, in SA compared to MMA and HCs. 10 proteins were elevated in SA versus MMA in both U-BIOPRED and BIOAIR (alpha-1-antichymotrypsin, apolipoprotein-E, complement component 9, complement factor I, macrophage inflammatory protein-3, interleukin-6, sphingomyelin phosphodiesterase 3, TNF receptor superfamily member 11a, transforming growth factor-β and glutathione S-transferase). OCS treatment decreased most proteins, yet differences between SA and MMA remained following correction for OCS use. Consensus clustering of U-BIOPRED protein data yielded six clusters associated with asthma control, quality of life, blood neutrophils, high-sensitivity C-reactive protein and body mass index, but not Type-2 inflammatory biomarkers. The mast cell specific enzyme carboxypeptidase A3 was one major contributor to cluster differentiation. Conclusions The plasma proteomic panel revealed previously unexplored yet potentially useful Type-2independent biomarkers and validated several proteins with established involvement in the pathophysiology of SA

    Variable-frequency Prony method in the analysis of electrical power quality

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    The article presents a new modification of the the least squares Prony method. The so-called variable-frequency Prony method can be a useful tool for estimating parameters of sinusoidal components, which, in the analyzed signal, are characterized by time-dependent frequencies. The authors propose use of the presented method for testing the quality of electric energy. It allows observation of phenomena which, when using traditional methods, are averaged in the analysis window. The proposed modification of least squares Prony method is based on introduction and specific selection of a frequency matrix. This matrix represents frequencies of estimated components and their variability in time

    Prony's method used for testing harmonics and interharmonros in electrical power systems

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    The article presents an application of Prony's method with some known components in the analysis of electric power quality. Modifications of the Prony algorithm broaden the scope of method application. Modification of the filter of known components enables more accurate analysis of the parameters of unknown components and components with known or assumed frequencies. This article presents a comparison of the results of analyses conducted with the proposed algorithm for simulated and real signals and the results obtained by means of a commercial electric power quality testing device, operating in class A and using the Fourier transform. The proposed method enables to estimate the levels of the harmonic components, the frequency of the fundamental signal and real parameters of the interharmonic components, which are grouped and averaged in the contemporary monitoring equipment. Knowledge of the individual parameters of the interharmonics has considerable diagnostic importance while removing causes of incorrect operation affecting sensitive equipment in some electric power systems. Additionally, the algorithm is capable of analyzing exponentially damped components and finds its application in analysis of disturbances, for example, transient oscillations

    Prony’S Method Used for Testing Harmonics and Interharmonics in Electrical Power Systems

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    The article presents an application of Prony's method with some known components in the analysis of electric power quality. Modifications of the Prony algorithm broaden the scope of method application. Modification of the filter of known components enables more accurate analysis of the parameters of unknown components and components with known or assumed frequencies. This article presents a comparison of the results of analyses conducted with the proposed algorithm for simulated and real signals and the results obtained by means of a commercial electric power quality testing device, operating in class A and using the Fourier transform. The proposed method enables to estimate the levels of the harmonic components, the frequency of the fundamental signal and real parameters of the interharmonic components, which are grouped and averaged in the contemporary monitoring equipment. Knowledge of the individual parameters of the interharmonics has considerable diagnostic importance while removing causes of incorrect operation affecting sensitive equipment in some electric power systems. Additionally, the algorithm is capable of analyzing exponentially damped components and finds its application in analysis of disturbances, for example, transient oscillations

    The application of SPWVD transformation in power quality measurements with DSP processor use

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    W artykule przedstawiono badania dotyczące zastosowania wygładzonej pseudo-transformacji Wignera-Ville'a w pomiarach wybranych parametrów jakości energii elektrycznej. Przeprowadzono analizę wyników badań transformacji najczęściej występujących zakłóceń sygnału elektroenergetycznego takich jak: harmoniczne, wolne (zapady, podwyższenia napięcia) i szybkie zmiany napięcia (fliker) oraz przepięcia przejściowe sinusoidalne eksponencjalnie tłumione. "Sygnałem elektroenergetycznym" autorzy nazywają sygnał sinusoidalny o częstotliwości 50Hz oraz nominalnej wartości skutecznej 230V, mający na celu modelować przebieg napięcia sieci zasilającej niskiego napięcia. Zaprezentowano również aplikację metody w systemie mikroprocesorowym zbudowanym w oparciu o procesor sygnałowy DSP.The paper presents the research concerning the Smoothed Pseudo Wigner-Ville Distribution in power quality parameters measurement. Also, some investigations of SPWVD results of most frequently appearing disturbances in the power network were done. The disturbances include harmonics, slow (sags, swells) and fast voltage changes (flicker) and fast transients. The application of the method in DSP microprocessor system were presented

    Modeling of a Three Beam Laser Anemometer

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    Niniejszy artykuł przedstawia model rozproszenia światła wykorzystywany do symulacji numerycznej właściwości i odpowiedzi trójwiązkowego laserowego anemometru dopplerowskiego, służącego do pomiaru parametrów fizycznych cząstek ośrodka dwufazowego. Przedstawiono porównanie cech objętości pomiarowej anemometru dwu i trójwiązkowego. Zaprezentowano odpowiedź: faza - wielkość i cząstki i częstotliwościową anemometru.Model of ligt scattering of tree beam laser Doppler anemometer is presented. Its numerical and functional properties as well as response of the system are investigated. A comparision between measurements volume of three and two beam system is presented. Frequency response and pase shift vs. particle diameter diagrams are presented

    Errors of the LIDFT method for classic data windows

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    Praca przedstawia rozwinięcie metody liniowej interpolacji dyskretnego przekształcenia Fouriera (LIDFT) wykorzystujące klasyczne okna danych oraz technikę uzupełniania zerami, dobrze znane z analizy widma z użyciem algorytmu FFT. Wykorzystanie klasycznych okien danych w miejsce specjalnie dedykowanego dla metody LIDFT okna parametrycznego daje bardziej różnorodne możliwości wykorzystania metody LIDFT w analizie sygnału wieloczęstotliwościowego.Development of the discrete Fourier transform linear interpolation method (LIDFT) with using classical data windows and zero padding technique well-known from spectrum analysis with FFT is presented in the paper. Using classical data windows instead of parametric data window special dedicated for LIDFT method gives wide-range possibilities of the using LIDFT method in the multifrequency signal analysis
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