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Your search keyword '"Kovalcikova, Alexandra"' showing total 107 results
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107 results on '"Kovalcikova, Alexandra"'

14. Oxidative Stress Markers and Na,K-ATPase Enzyme Kinetics Are Altered in the Cerebellum of Zucker Diabetic Fatty fa/fa Rats: A Comparison with Lean fa/+ and Wistar Rats.

Author

Radosinska, Dominika, Gaal Kovalcikova, Alexandra, Gardlik, Roman, Chomova, Maria, Snurikova, Denisa, Radosinska, Jana, and Vrbjar, Norbert

Subjects
*TYPE 2 diabetes, *ACTIVE biological transport, *OXIDATIVE stress, *LABORATORY rats, BRAIN metabolism
Abstract

Simple Summary: Type 2 diabetes mellitus (T2DM) is a global health burden that adversely affects various organs, including the brain, leading to neurodegeneration. Recent research emphasizes the cerebellum's role in studying the interactions between T2DM, obesity, aging, and brain energy metabolism. This study focused on the cerebellum of Zucker diabetic fatty (ZDF) rats, a model that mirrors the diversity of T2DM in humans. The primary objective was to measure oxidative stress markers and kinetic properties of sodium–potassium ATPase (Na,K-ATPase) in relation to T2DM severity (not documented yet). Na,K-ATPase is an active transport mechanism crucial for maintaining unequal cation distributions across the plasma membrane, and its activity has been shown to be altered by diabetes in various organs. While oxidative stress is well established in the pathogenesis of diabetes, this study confirmed systemic oxidative and carbonyl damage in ZDF rats and provided new evidence of such damage in cerebellar tissue. However, no differences were found in cerebellar oxidative stress markers based on T2DM severity. Additionally, Na,K-ATPase activity was higher in the cerebellum of ZDF rats compared with controls, suggesting the presence of compensatory mechanisms in this brain region in aged ZDF animals. However, further research is needed to confirm and elucidate this phenomenon. Type 2 diabetes mellitus has been referred to as being closely related to oxidative stress, which may affect brain functions and brain glucose metabolism due to its high metabolic activity and lipid-rich content. Na,K-ATPase is an essential enzyme maintaining intracellular homeostasis, with properties that can sensitively mirror various pathophysiological conditions such as diabetes. The goal of this study was to determine oxidative stress markers as well as Na,K-ATPase activities in the cerebellum of Zucker diabetic fatty (ZDF) rats depending on diabetes severity. The following groups of male rats were used: Wistar, ZDF Lean (fa/+), and ZDF (fa/fa) rats, arbitrarily divided according to glycemia into ZDF obese (ZO, less severe diabetes) and ZDF diabetic (ZOD, advanced diabetes) groups. In addition to basic biometry and biochemistry, oxidative stress markers were assessed in plasma and cerebellar tissues. The Na, K-ATPase enzyme activity was measured at varying ATP substrate concentrations. The results indicate significant differences in basic biometric and biochemical parameters within all the studied groups. Furthermore, oxidative damage was greater in the cerebellum of both ZDF (fa/fa) groups compared with the controls. Interestingly, Na,K-ATPase enzyme activity was highest to lowest in the following order: ZOD > ZO > Wistar > ZDF lean rats. In conclusion, an increase in systemic oxidative stress resulting from diabetic conditions has a significant impact on the cerebellar tissue independently of diabetes severity. The increased cerebellar Na,K-ATPase activity may reflect compensatory mechanisms in aged ZDF (fa/fa) animals, rather than indicating cerebellar neurodegeneration: a phenomenon that warrants further investigation. [ABSTRACT FROM AUTHOR]

Published
2024
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26. Porous Nb2O5 Nanofibers Prepared via Reactive Needle-Less Electrospinning for Application in Lithium–Sulfur Batteries

Author

Shepa, Ivan, primary, Mudra, Erika, additional, Capkova, Dominika, additional, Kovalcikova, Alexandra, additional, Petrus, Ondrej, additional, Kromka, Frantisek, additional, Milkovic, Ondrej, additional, Antal, Vitaliy, additional, Balaz, Matej, additional, Lisnichuk, Maksym, additional, Marcin-Behunova, Dominika, additional, Zalka, Dóra, additional, and Dusza, Jan, additional

Published
2023
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39. Porous Nb 2 O 5 Nanofibers Prepared via Reactive Needle-Less Electrospinning for Application in Lithium–Sulfur Batteries.

Author

Shepa, Ivan, Mudra, Erika, Capkova, Dominika, Kovalcikova, Alexandra, Petrus, Ondrej, Kromka, Frantisek, Milkovic, Ondrej, Antal, Vitaliy, Balaz, Matej, Lisnichuk, Maksym, Marcin-Behunova, Dominika, Zalka, Dóra, and Dusza, Jan

Subjects
LITHIUM sulfur batteries, SCANNING transmission electron microscopy, NANOFIBERS, CARBON nanofibers, ELECTROSPINNING, CERAMIC fibers
Abstract

This contribution describes the preparation, coupled with detailed characterization, of Nb2O5 nanofibers and their application in lithium–sulfur batteries for the improvement of electrochemical performance. The utilization of reactive needle-less electrospinning allowed us to obtain, in a single step, amorphous pre-ceramic composite PAN/Nb2O5 fibers, which were transformed into porous ceramic Nb2O5 nanofibers via calcination. Thermogravimetric studies defined that calcination at 600 °C results in crystalline ceramic fibers without carbon residues. The fibrous morphology and mean diameter (614 ± 100 nm) of the ceramic nanofibers were analyzed via scanning and transmission electron microscopy. A surface area of 7.472 m2/g was determined through nitrogen adsorption measurements, while a combination of X-ray diffraction and Raman spectroscopy was used to show the crystallinity and composition of the fibers after calcination—single T-phase Nb2O5. Its performance in the cathode of lithium–sulfur batteries was defined through electrochemical tests, and the obtained results were compared to a similar blank electrode. The initial discharge capacity of 0.5 C reached a value of 570 mAh∙g−1, while the reversible capacity of 406 mAh∙g−1 was retained after 200 cycles, representing a capacity retention of 71.3%. The presence of Nb2O5 nanofibers in the carbon cathode inhibits the shuttle effect through polysulphide confinement, which originates from porosity and chemical trapping. [ABSTRACT FROM AUTHOR]

Published
2023
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45. Dynamics of Plasma and Urinary Extracellular DNA in Acute Kidney Injury

Author

Jancuska, Alexander, Potocarova, Alena, Gaal Kovalcikova, Alexandra, Podracka, Ludmila, Babickova, Janka, Celec, Peter, and Tothova, Lubomira

Subjects
Male, Organic Chemistry, glycerol-induced nephropathy, non-invasive marker, cell-free DNA, mitochondrial DNA, rhabdomyolysis, General Medicine, Acute Kidney Injury, urologic and male genital diseases, DNA, Mitochondrial, female genital diseases and pregnancy complications, Catalysis, Rats, Computer Science Applications, Inorganic Chemistry, Plasma, Animals, Humans, Rats, Wistar, Physical and Theoretical Chemistry, Molecular Biology, Biomarkers, Spectroscopy
Abstract

Early and reliable markers of acute kidney injury (AKI) are essential. One such candidate marker of tissue damage is extracellular DNA (ecDNA). The aim of our present study is to describe the unknown dynamics of ecDNA in an animal model of AKI. Glycerol-induced nephropathy was used to model AKI in adult male Wistar rats (n = 93). Blood and urine samples were collected 1, 3, and 24 h after model induction. Total ecDNA and its sub-cellular origin was assessed. In the plasma, total ecDNA and nuclear ecDNA were significantly increased in the AKI group already after 1 h (160% and 270%, respectively, p = 0.02 and p = 0.04). Both nuclear and mitochondrial ecDNA were higher after 3 h (180% and 170%, respectively, p = 0.002 and p = 0.005). Urinary ecDNA concentrations in the AKI group were significantly increased only 24 h after model induction (130% for total ecDNA, p = 0.009; 210% for nuclear ecDNA, p = 0.02; and 200% for mitochondrial ecDNA, p = 0.0009). Our results indicate that plasma ecDNA has the potential to serve as an early and sensitive, albeit non-specific marker of AKI. Further studies should elucidate the source of ecDNA and the dynamics of ecDNA in other animal models of AKI and patients with AKI. publishedVersion

Published
2022

46. Extracellular DNA concentrations in various aetiologies of acute kidney injury

Author

Gaal Kovalcikova, Alexandra, Janovicova, Lubica, Hodosy, Julius, Babickova, Janka, Vavrincova-Yaghi, Diana, Vavrinec, Peter, Boor, Peter, Podracka, Ludmila, Sebekova, Katarina, Celec, Peter, and Tothova, Lubomira

Subjects
Deoxyribonucleases, Multidisciplinary, Adenine, Reperfusion Injury, Animals, Acute Kidney Injury, Kidney, DNA, Mitochondrial, Biomarkers
Abstract

Scientific reports 12, 16812 (2022). doi:10.1038/s41598-022-21248-7, Published by Macmillan Publishers Limited, part of Springer Nature, [London]

Published
2022
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50. Nanostructure and Luminescent Properties of Bimetallic Lanthanide Eu/Gd, Tb/Gd and Eu/Tb Coordination Polymers

Author

Brunckova, Helena, primary, Mudra, Erika, additional, Rocha, Lucas, additional, Nassar, Eduardo, additional, Nascimento, Willian, additional, Kolev, Hristo, additional, Lisnichuk, Maksym, additional, Kovalcikova, Alexandra, additional, Molcanova, Zuzana, additional, Strečkova, Magdalena, additional, and Medvecky, Lubomir, additional

Published
2021
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