Leukocytes are a part of the immune system that plays an important role in the host’s defense against viral, bacterial, and fungal infections. Among the human leukocytes, two granulocytes, neutrophils (Ne) and eosinophils (EOS) play an important role in the innate immune system. For that purpose, eosinophils and neutrophils contain specific granules containing protoporphyrin-type proteins such as eosinophil peroxidase (EPO) and myeloperoxidase (MPO), respectively, which contribute directly to their anti-infection activity. Since both proteins are structurally and functionally different, they could potentially be a marker of both cells’ types. To prove this hypothesis, UV−Vis absorption spectroscopy and Raman imaging were applied to analyze EPO and MPO and their content in leukocytes isolated from the whole blood. Moreover, leukocytes can contain lipidic structures, called lipid bodies (LBs), which are linked to the regulation of immune responses and are considered to be a marker of cell inflammation. In this work, we showed how to determine the number of LBs in two types of granulocytes, EOS and Ne, using fluorescence and coherent anti-Stokes Raman scattering (CARS) microscopy. Spectroscopic differences of EPO and MPO can be used to identify these cells in blood samples, while the detection of LBs can indicate the cell inflammation process.
Summary
Eosinophils are acidophilic granulocytes that develop in the bone marrow. Although their population contributes only to approximately 1–6% of all leucocytes present in the human blood, they possess a wide range of specific functions. They play a key role in inflammation‐regulating processes, when their numbers can increased to above 5 × 109/l of peripheral blood. Their characteristic feature is the presence of granules containing eosinophil peroxidase (EPO), the release of which can trigger a cascade of events promoting oxidative stress, apoptosis or necrosis, leading finally to cell death. Raman spectroscopy is a powerful technique to detect EPO, which comprises a chromophore protoporphyrin IX. Another cell structure associated with inflammation processes are lipid bodies (lipid‐rich organelles), also well recognized and imaged using high resolution confocal Raman spectroscopy. In this work, eosinophils isolated from the blood of a human donor were analysed versus their model, EoL‐1 human eosinophilic leukaemia cell line, by Raman spectroscopic imaging. We showed that EPO was present only in primary cells and not found in the cell line. Eosinophils were activated using phorbol 12‐myristate 13‐acetate, which resulted in lipid bodies formation. An effect of cells stimulation was studied and compared for eosinophils and EoL‐1.
The article dealt with an assessment of the fit of typical non-linear demand models for fruit. The power function, the exponential function with the inverse and the Törnquist function for the basic goods were used in the econometric analysis. The models were estimated on the basis of income quintile groups’ data published by the Central Statistical Office. Based on the estimated model parameters, income elasticities of demand were calculated. It was found that the models described by the power function and the Törnquist function for basic goods were characterized by a better goodness of fit than the models using the exponential function with the inverse.
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