1. How to establish a novel liver cell culture system that resembles the in vivo liver microenvironmentEneko Madorran, 2025, original scientific article Abstract: Subtle physiological patterns within the human organism, such as molecular fluctuations or systemic adaptations, often remain hidden from direct observation due to the inherent variability and noise within biological samples. The liver, a vital organ essential for systemic regulation and toxicological assessment, presents this challenge due to its heightened activity, which can influence enzyme dynamics and metabolic processes. Unlike direct observation, in vitro liver models offer a more precise means of understanding these trends, providing insights into the organ's (patho)physiology, and serving as a platform for toxicity evaluation. However, current liver models lack essential features required to faithfully replicate the liver's microenvironment, resulting in reduced accuracy in toxicity assessments. Furthermore, while researchers emphasize mechanistic insights, such as the molecular processes governing glucose metabolism and cellular energy production, clinicians focus on tangible health outcomes, like blood glucose levels in patients. This disconnect between the objectives and methodologies of basic researchers and clinicians amplifies this gap, hindering effective translational research. Addressing these challenges, a novel liver cell culture system that resembles the in vivo liver microenvironment with clinical instrumentation has been proposed to enhance current liver models, improving their capacity to emulate in vivo conditions. This study introduces a novel liver cell culture system, utilizing a 96-well plate format incorporating hepatic sinusoidal endothelial cells, hepatic stellate cells, Kupffer cells, and hepatocytes to replicate the liver microenvironment. The model integrates clinical instrumentation, specifically a biochemical analyzer to ensure biomarkers closely align with those observed in clinical diagnostics. This design enables researchers to fine-tune conditions that mimic the liver's microanatomy and physiological responses, enhancing its translational potential for toxicity assessments. The approach involves primary cell culture preparation, supernatant analysis through a clinical biochemistry analyzer, and cell viability assessment using the Membrane Potential Cell Viability Assay (MPCVA) method. Additionally, advanced imaging techniques and data analysis tools are incorporated to refine the model's capabilities and ensure greater translatability to clinical applications.
Keywords: in vitro toxicity, liver (patho)physiology, liver in vitro model, membrane potential cell viability assay, translational research
Published in DKUM: 14.08.2025; Views: 0; Downloads: 8
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2. Study on the compression effect of clothing on the physiological response of the athleteMarianna Halász, Jelka Geršak, Péter Bakonyi, Gabriella Oroszlány, András Koleszár, Orsolya Nagyné Szabó, 2022, original scientific article Abstract: The study aimed to analyze whether the high compression of unique, tight-fitting sportswear
influences the clothing physiology comfort of the athlete. Three specific sportswear with different
compression were tested on four subjects while they were running on a treadmill with increasing
intensity. The compression effect of the sportswear on the body of the test persons, the temperature
distribution of the subjects, and the intensity of their perspiration during running were determined.
The results indicate that the compression effect exerted by the garments significantly influences the
clothing physiology comfort of the athlete; a higher compression load leads to more intense sweating
and higher skin temperature.
Keywords: clothing physiology, tight-fitting sportswear, running test on a treadmill, thermal comfort, skin temperature, perspiration
Published in DKUM: 21.03.2025; Views: 0; Downloads: 6
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3. Critical transitions in pancreatic isletsDean Korošak, Sandra Postić, Andraž Stožer, Boštjan Podobnik, Marjan Rupnik, 2025, original scientific article Abstract: Calcium signals in pancreatic � cell collectives show a sharp transition from uncorrelated to correlated state resembling a phase transition as the slowly increasing glucose concentration crosses the tipping point. However, the exact nature or the order of this phase transition is not well understood. Using confocal microscopy to record the collective calcium activation of � cells in an intact islet under changing glucose concentration in an increasing and then decreasing way, we first show that in, addition to the sharp transition, the coordinated calcium response exhibits a hysteresis indicating a critical, first-order transition. A network model of � cells combining link selection and coordination mechanisms capture the observed hysteresis loop and the critical nature of the transition. Our results point towards an understanding of the role of islets as tipping elements in the pancreas that, interconnected by perfusion, diffusion, and innervation, cause the tipping dynamics and abrupt insulin release.
Keywords: cellular organization, physiology & dynamics, phase transitions in biological systems, complex networks, endocrine system, optical microscopy
Published in DKUM: 19.03.2025; Views: 0; Downloads: 2
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4. Ultrafast multicellular calcium imaging of calcium spikes in mouse beta cells in tissue slicesJurij Dolenšek, Viljem Pohorec, Maša Skelin, Marko Gosak, Andraž Stožer, 2025, original scientific article Abstract: Background: The crucial steps in beta cell stimulus-secretion coupling upon stimulation with glucose are oscillatory changes in metabolism, membrane potential, intracellular calcium concentration, and exocytosis. The changes in membrane potential consist of bursts of spikes, with silent phases between them being dominated by membrane repolarization and absence of spikes. Assessing intra- and intercellular coupling at the multicellular level is possible with ever-increasing detail, but our current ability to simultaneously resolve spikes from many beta cells remains limited to double-impalement electrophysiological recordings. Methods: Since multicellular calcium imaging of spikes would enable a better understanding of coupling between changes in membrane potential and calcium concentration in beta cell collectives, we set out to design an appropriate methodological approach. Results: Combining the acute tissue slice method with ultrafast calcium imaging, we were able to resolve and quantify individual spikes within bursts at a temporal resolution of >150 Hz over prolonged periods, as well as describe their glucose-dependent properties. In addition, by simultaneous patch-clamp recordings we were able to show that calcium spikes closely follow membrane potential changes. Both bursts and spikes coordinate across islets in the form of intercellular waves, with bursts typically displaying global and spikes more local patterns. Conclusions: This method and the associated findings provide additional insight into the complex signaling within beta cell networks. Once extended to tissue from diabetic animals and human donors, this approach could help us better understand the mechanistic basis of diabetes and find new molecular targets.
Keywords: beta cell, calcium imaging, calcium oscillations, calcium spikes, physiology
Published in DKUM: 24.01.2025; Views: 0; Downloads: 9
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5. Application of transmission electron microscopy to detect changes in pancreas physiologyMaša Skelin, Jurij Dolenšek, Ismael Valladolid-Acebes, Andraž Stožer, Saška Lipovšek Delakorda, 2022, independent scientific component part or a chapter in a monograph Keywords: pancreas physiology, exocrine cells, endocrine cells, ultrastructure, metabolic syndrome, type 2 diabetes mellitus, western diet
Published in DKUM: 24.09.2024; Views: 0; Downloads: 9
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6. Influence of undergarments on the comfort level of scoliosis brace wearersO. Nagy Szabó, Jelka Geršak, András Koleszár, Marianna Halász, 2023, original scientific article Abstract: Bracing has proven to be an effective method for the conventional treatment of scoliosis in young people. A brace, a therapeutic device, covers the upper body and promotes healing by applying pressure to specific areas. However, wearing a scoliosis brace negatively affects the user’s thermo-physiological well-being and often leads to discomfort. In this study, we investigated the influence of T-shirts as an undergarment on the thermo-physiological well-being of the brace wearer. For this purpose, we performed a comparative analysis of six T-shirts made from different special knitted fabrics. We carried out wearing tests in a computer-controlled climate chamber according to a predetermined protocol. The test subject wore the orthopedic brace over the different T-shirts at three different temperatures. The results indicate that the knitted fabrics of undergarments and environmental conditions considerably impact the wearer’s thermo-physiological comfort. In the tests, the T-shirts made from the selected functional fabrics performed very well. The T-shirt made from the classic cotton fabric containing elastane yarn also performed well and was the most environmentally friendly. Currently, due to its lower price and easier availability, this cotton T-shirt can be recommended for wearing under a scoliosis brace.
Keywords: clothing physiology, undergarment, knitted fabrics, scoliosis brace, climate chamber, textile material testing
Published in DKUM: 05.09.2023; Views: 350; Downloads: 39
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7. Alpha cell stimulus-sehttps://dk.um.si/teme/dkumDev2/img/NovoOkno.pngcretion coupling and intercellular interactions in health and type 2 diabetesViljem Pohorec, Nika Zadravec, Marko Turk, Jurij Dolenšek, Andraž Stožer, 2023, review article Keywords: Alpha cell, calcium imaging, epinephrine, physiology, type 2 diabetes mellitus
Published in DKUM: 18.07.2023; Views: 378; Downloads: 64
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