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Oxidative stress induced by neutrophils and hypoxia in COVID-19 pneumonia leads to albumin modification. This may result in elevated levels of advanced oxidation protein products (AOPPs) and advanced lipoxidation end-products (ALEs) that trigger oxidative bursts of neutrophils and thus participate in cytokine storms, accelerating endothelial lung cell injury, leading to respiratory distress. In this study, sixty-six hospitalized COVID-19 patients with respiratory symptoms were studied. AOPPs-HSA was produced in vitro by treating human serum albumin (HSA) with chloramine T. The interaction of malondialdehyde with HSA was studied using time-resolved fluorescence spectroscopy. The findings revealed a significantly elevated level of AOPPs in COVID-19 pneumonia patients on admission to the hospital and one week later as long as they were in the acute phase of infection when compared with values recorded for the same patients 6- and 12-months post-infection. Significant negative correlations of albumin and positive correlations of AOPPs with, e.g., procalcitonin, D-dimers, lactate dehydrogenase, aspartate transaminase, and radiological scores of computed tomography (HRCT), were observed. The AOPPs/albumin ratio was found to be strongly correlated with D-dimers. We suggest that oxidized albumin could be involved in COVID-19 pathophysiology. Some possible clinical consequences of the modification of albumin are also discussed.

The unique plasmonic properties of the noble metal colloidal nanoparticles make them promising enhancement substrates for surface-enhanced Raman scattering. Obtaining of systems that provide ever-increasing enhancement of the Raman scattered light is a big challenge. Silver colloids studied here are prepared by LeeMeisel's method.Rhodamine 6G and rhodamine B are used as probe adsorbates. The raw colloids obtained in this way exhibit a characteristic extinction band proving surface plasmons excitation, but do not enhance the Raman signal.Theoretical calculations indicate that the extremely large electromagnetic eld is induced in the junctions between metallic nanostructures so some degree of their aggregation is necessary to achieve a sucient gain value. The addition of aggregating agents (KCl or HCl) leads to signicant changes in the extinction spectrum and to signicant increase in the intensity of surface-enhanced Raman scattering. The experiments show that chloride can not only promote the aggregation process but also eectively aect chemical mechanisms contributing to surface-enhanced Raman scattering.