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Detection of cells in confocal microscopy images
Hubálek, Michal ; Štursa, Dominik (referee) ; Škrabánek, Pavel (advisor)
The goal of the thesis was to create an application that automatically detects healthy cardiomyocytes from images captured by a confocal microscope. The thesis was created based on the specific needs of researchers from the Slovak Academy of Sciences.The application will facilitate and increase the efficiency of their research,because until now they have to evaluate the images and search for suitable cells manually. The RetinaNet convolutional neural network is used for detection and has been implemented in a user-friendly desktop application. The application also automatically records and stores coordinates of detected cells which can be used for capturing cells in higher image quality. Another advantage of the developed application is its versatility, which allows to train detection on other data, making it applicable to other projects. The result of this work is a functional, standalone and intuitive application that is ready to be used by researchers.
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Optical Measurement of Electromechanical Characteristics of Heart Cells
Čmiel, Vratislav ; Križanová,, Olga (referee) ; Babula, Petr (referee) ; Provazník, Ivo (advisor)
Dissertation is focused on the application of optical measurement methods using techniques of optical microscopy and fluorescence microscopy in measurements of electromechanical characteristics of isolated cardiac cells and clusters of differentiated cardiomyocytes. The first proposed method uses a practical combination of fluorescence microscopy equipped with fluorescent fast and high-resolution camera and atomic force microscopy for simultaneous measurement of calcium transients and contraction of cardiomyocyte clusters. The signals obtained undergoes filtration, processing and analysis. Result function parameters obtained by analyzing signals after application of caffeine are evaluated by comparison with functional parameters obtained during the control measurement. The second proposed method is applied to the cardiomyocyte clusters for the purpose of cardiomyocyte contraction signals measurement. The signals obtained by optical methods are analyzed and compared with the reference signal obtained using atomic force microscopy. Optical measurement method of cell contractins based on detection of cell ends using adjusting of microscopy images by re-sharpening and fluorescence method for cardiomyocyte contractions measurements were designed to increase realiability in simultaneous measurement of cell contractions simultaneously with calcium transients in isolated cardiomyocytes experiments.
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Electrostimulation method for cardiomyocyte life extension
Čermáková, Adéla ; Ronzhina, Marina (referee) ; Čmiel, Vratislav (advisor)
This work deals with electrostimulation cardiomyocytes and design stimulation device for their cultivation and stimulation. First part of work deals with electrophysiological myocytes and the next problems with electrostimulation and preserved their original morphology and physiology structure. The following section is designed and constructed stimulation device to improve cell viability. Stimulation took place under different conditions and the success rate depends on the number of cells that survived.
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Organic tranistors for sensorics
Marková, Aneta ; Omasta, Lukáš (referee) ; Vala, Martin (advisor)
The aim was to find the best available commercial formulation of poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate) (PEDOT:PSS) and methods and subsequent treatment of thin films for organic electrochemical transistors (OECT). These films will be used in bioelectronic sensors to measure the physiological function of cardiomyocytes. Studied material was PEDOT:PSS in six different formulations. Thin layers prepared by spin coating were modified in three ways, namely (i) immersion in ethylene glycol, (ii) drying and (iii) a combination of drying and ethylene glycol. The layers were then tested for the influence of ethylene glycol, thermal stability, the impact of storage, influence of aqueous medium, and additional thermal annealing. According to the results obtained, the most suitable treatment of most materials was immersion in ethylene glycol followed by thermal annealing of the layer. It was found that the most appropriate material formulation was Sigma Aldrich 739 316 treated by the combination of drying, immersion in ethylene glycol and thermal annealing.
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Hif1a role in cardiovascular function and heart disease
Matějková, Kateřina ; Pavlínková, Gabriela (advisor) ; Holzerová, Kristýna (referee)
Hypoxia inducible factor 1 alpha (HIF1A) is a transcriptional factor, which plays a central role in the maintenance of homeostasis under hypoxic conditions. It regulates a wide variety of genes encoding proteins that influence metabolism, extracellular matrix composition, oxidoreductase activity or angiogenesis in response to reduced oxygen levels. When HIF1A protein function is impaired, the organism is unable respond appropriately to hypoxia. Altered HIF1A regulation can result in severe tissue damage and eventually lead to death. The heart, as an organ with a huge oxygen consumption, is susceptible to various pathologies caused by hypoxic stress. The role of HIF1A in the heart is rather ambiguous and remains to be elucidated. It plays a role in cardioprotective mechanisms but also promotes the development of inflammation and apoptosis. This thesis aims to clarify the role of HIF1A in maintaining physiological functions of the heart during adaptation to hypoxic conditions using a mouse model with heterozygous Hif1a+/- deletion. Experiments involving molecular and cell biology methods performed on left ventricular tissue were preceded by bioinformatic analysis of data obtained by RNA sequencing of isolated cardiomyocytes. RNA sequencing data were analyzed using the R scripting language (packages...
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Circadian regulation of the cardiovascular system
Nováková, Jessica ; Bendová, Zdeňka (advisor) ; Galatík, František (referee)
Circadian system consist of the main circadian oscillator and the peripheral oscillators. Their function is to enable the adaptation of living organisms to the diurnal environmental changes. Circadian system regulates rhythmical expression of genes in nearly every cell of the body, thereby affecting both the physiological and behavioural processes of mammals and other animals. This bachelor's thesis summarizes a knowledge from experiments which led to the demonstration of circadian rhytms in cardiovascular system. To introduce the topic, the first discoveries of circadian rhythms in the cardiovascular system are mentioned. Then, we focus on the circadian rhythms in cardiomyocytes, vascular endothelial cells and in vascular smooth muscle cells. Another focal point of my thesis is the role of transcription factor Krüppel-like factor 15. Circadian regulation of the cardiovascular system is important for the proper function of the heart and blood vessels. Circadian disruption can cause severe pathophysiological and cardiovascular conditions, such as ventricular hypertrophy, hypertension, atherosclerosis, myocardial infarction or coronary artery disease. Key words: circadian, clock genes, cardiovascular system, cardiomyocytes, vascular endothelial cells, vascular smooth muscle cells, Krüppel-like factor...
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Detection of cells in confocal microscopy images
Hubálek, Michal ; Štursa, Dominik (referee) ; Škrabánek, Pavel (advisor)
The goal of the thesis was to create an application that automatically detects healthy cardiomyocytes from images captured by a confocal microscope. The thesis was created based on the specific needs of researchers from the Slovak Academy of Sciences.The application will facilitate and increase the efficiency of their research,because until now they have to evaluate the images and search for suitable cells manually. The RetinaNet convolutional neural network is used for detection and has been implemented in a user-friendly desktop application. The application also automatically records and stores coordinates of detected cells which can be used for capturing cells in higher image quality. Another advantage of the developed application is its versatility, which allows to train detection on other data, making it applicable to other projects. The result of this work is a functional, standalone and intuitive application that is ready to be used by researchers.
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Mesenchymal stem cells and their regenerative and immunomodulatory potential
Brychtová, Michaela ; Lysák, Daniel (advisor) ; Horák, Vratislav (referee) ; Raška, Milan (referee)
Mesenchymal stem cells and their regenerative and immunomodulatory potential Abstract Mesenchymal stem cells (MSCs) possess multidirectional regenerative ability, which, together with their immunomodulatory potential, makes them promising cell type for therapy of wide variety of diseases. Despite ongoing research, which proved MSCs application to be safe, reported effect of MSCs administration on patients is not convincingly beneficial yet. In our work we focused on elucidation of MSCs role in regeneration of vital organs, heart and liver, where a large damage is life threatening for patients and any improvement in therapy would save many lives. Similar situation is in Graft versus host disease (GVHD), where MSCs immunomodulatory properties could be beneficial. Role of MSCs in heart regeneration was examined in vitro. Primary adult swine cardiomyocytes (CMCs) were co-cultured with or without swine MSCs for 3 days and morphological and functional parameters (contractions, current, respiration) of CMCs were measured. MSCs showed supportive effect on CMCs survival, especially at day 3 of the experiment, where in co-culture was significantly higher number of viable CMCs with physiological morphology and maintained function. Effect of MSCs on liver regeneration was observed in swine model of chronic liver...
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Mesenchymal stem cells and their regenerative and immunomodulatory potential
Brychtová, Michaela ; Lysák, Daniel (advisor) ; Horák, Vratislav (referee) ; Raška, Milan (referee)
Mesenchymal stem cells and their regenerative and immunomodulatory potential Abstract Mesenchymal stem cells (MSCs) possess multidirectional regenerative ability, which, together with their immunomodulatory potential, makes them promising cell type for therapy of wide variety of diseases. Despite ongoing research, which proved MSCs application to be safe, reported effect of MSCs administration on patients is not convincingly beneficial yet. In our work we focused on elucidation of MSCs role in regeneration of vital organs, heart and liver, where a large damage is life threatening for patients and any improvement in therapy would save many lives. Similar situation is in Graft versus host disease (GVHD), where MSCs immunomodulatory properties could be beneficial. Role of MSCs in heart regeneration was examined in vitro. Primary adult swine cardiomyocytes (CMCs) were co-cultured with or without swine MSCs for 3 days and morphological and functional parameters (contractions, current, respiration) of CMCs were measured. MSCs showed supportive effect on CMCs survival, especially at day 3 of the experiment, where in co-culture was significantly higher number of viable CMCs with physiological morphology and maintained function. Effect of MSCs on liver regeneration was observed in swine model of chronic liver...
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