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Stepien, E. L.

Publications and source records attributed to Stepien, E. L..

2 recordsLinked to original sources

Revealing sphingolipids composition in extracellular vesicles and paternal β-cells after persistent hyperglycemia

Extended periods of hyperglycemia (HG) can lead to metabolic disorders of sphingolipids (SPs) and their subsequent accumulation in cells. This accumulation can trigger a range of complications, including kidney and neurodegenerative diseases. In our study, we compared the levels of selected ceramides (CER), hexosylceramides (HexCER), and glycosphingolipids (GSLs) in potential HG biomarkers - extracellular vesicles (EVs). These EVs were derived in vitro from human {beta}-cells cultured under both normoglycemic and high-glucose conditions (HG). We utilized Time of Flight - Secondary Ion Mass Spectrometry (ToF-SIMS) for SPs analysis. Our results confirmed that the lipid profiles of these three groups differ between large and small EVs, with some SP lipids being more enriched in EVs compared to cells. Interestingly, our study revealed that HG only regulates the lipid content from the glycosphingolipid group in relation to normoglycemia. Collectively, our findings underscore the potential applications of ToF-SIMS in characterizing the impact of different culture conditions on lipid levels. As far as we know, our study is the first which employs ToF-SIMS in analyzing the effects of HG on SP levels in EVs and their parental {beta}-cells. Graphical abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=168 SRC="FIGDIR/small/574464v2_ufig1.gif" ALT="Figure 1"> View larger version (27K): org.highwire.dtl.DTLVardef@169eed8org.highwire.dtl.DTLVardef@1bfddfforg.highwire.dtl.DTLVardef@187cdc4org.highwire.dtl.DTLVardef@d62aba_HPS_FORMAT_FIGEXP M_FIG C_FIG HighlightsO_LIToF-SIMS effectively compares glycosphingolipid content in cells and EVs. C_LIO_LIAnalysis reveals lipid profile differences between EVs and their parent cells. C_LIO_LIHyperglycemia alters glycosphingolipid content in cells and EVs per ToF-SIMS. C_LI

biophysics↗

Developing a Novel Positronium Biomarker for Cardiac Myxoma Imaging

Here, positronium imaging is presented to determine cardiac myxoma (CM) extracted from patients undergoing urgent cardiac surgery due to unexpected atrial masses. Positronium is an atom build from an electron and a positron, produced copiously in intra-molecular voids during the PET imaging. CM, the most common cardiac tumor in adults, accounts for 50-75% of benign cardiac tumors. We aimed to assess if positronium serves as a biomarker for diagnosing CM. Perioperative examinations and histopathology staining in six patients confirmed the primary diagnosis of CM. We observed significant differences in the mean positronium lifetime between tumor and normal tissues, with an average value of 1.92(02) ns and 2.72(05) ns for CM and the adipose tissue, respectively. Our findings, combined with positronium lifetime imaging, reveals the novel emerging positronium biomarker for cardiovascular imaging. One-Sentence SummaryPositronium may serve as an imaging biomarker for cancer diagnostics.

biophysics↗