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Effect of pulsatility of blood flow on parametres of vascular damage in patients with mechanical circulatory support
Ivák, Peter ; Netuka, Ivan (advisor) ; Štádler, Petr (referee) ; Ošťádal, Petr (referee)
Ventricular assist devices are an important therapeutic modality in advanced surgical therapy of end-stage heart failure. Devices mainly used until recently generate primarily non- pulsatile blood flow. Despite indisputable clinical success of this therapy, we encounter complications specific to the devices with continuous flow. Complications are mostly attributed to increased shear stress and changes in blood vessels, blood elements and endothelium. The aim of this study was to determine the effect of continuous blood flow on the vasculature and blood elements by longitudinal monitoring of selected biomarkers of vascular health. During the study we monitored circulating microparticles, endothelial progenitor cells and stem cells and examined degradation dynamics of von Willebrand factor and its function. Results obtained in our study confirm the hypothesis of changes in the dynamics of studied markers dependent on the change of characteristics of blood flow. The possible negative effect of continuous flow on monitored parameters was observed in tracked period. In degradation of the high molecular weight von Willebrand factor multimers the probable positive effect of arteficial pulsatility was observed. Further research can provide important data for the development of specific characteristics...
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Allooimmunosensitization in left ventricular assist device recipients and impact on post-transplantation outcome
Urban, Marián ; Netuka, Ivan (advisor) ; Ošťádal, Petr (referee) ; Mrázek, František (referee)
Background: In recent years mechanical circulatory assist devices became an established option in bridging patients with refractory heart failure to heart transplantation. One of the alleged limitations of mechanical devices is a high degree of antibody production with possible deleterious effect on subsequent heart transplantation outcome. Aim: The main goal of this study is to assess the role of antibodies on the outcome of surgical treatment of patients with end- stage heart failure. Method: Firstly, we present a literature review on the current state of knowledge of possible immunologic mechanisms involved in antibody production in left ventricular assist device (LVAD) recipients, new methods of antibody detection, desensitization strategies and overview of published evidence assessing the impact of sensitization on post-transplantation outcome. In the experimental part of our study we prospectively evaluated the presence of anti-Angiotensin II Type 1 Receptor (AT1R) antibodies in 83 Heart Mate II (HMII) recipients who were implanted at our institution between 2008 and 2012 and survived the first 60 days. On-device survival and device malfunction, major infection, major bleeding and neurologic dysfunction were compared between antibody positive and antibody negative recipients. Out of a total...
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Baire and Harmonic Functions
Pošta, Petr ; Lukeš, Jaroslav (advisor) ; Benyaiche, Allami (referee) ; Netuka, Ivan (referee)
Title: Baire and Harmonic Functions Author: Petr Pošta Department: Department of Mathematical Analysis Supervisor: prof. RNDr. Jaroslav Lukeš, DrSc., Department of Mathematical Analysis Abstract: The present thesis consists of six research papers. The first four articles deal with topics related to potential theory, Baire-one functions and its important subclasses, in particular differences of semicontinuous functions. The first paper is devoted to the stability of the Dirichlet problem for which a new criterion in terms of Poisson equation is provided. The second paper improves the recent result obtained by Lukeš et al. It shows that the classical Dirichlet solution belongs to the B1/2 subclass of Baire-one functions. A generalization of this result to the abstract context of the Choquet theory on functions spaces is provided. Finally, an abstract Dirichlet problem for the boundary condition belonging to the class of differences of semincontinuous functions is discussed. The third paper concentrates on the Lusin-Menshov property and the approximation of Baire- one and finely continuous functions by differences of semicontinuous and finely continuous functions. It provides an exposition of topologies (various density topologies as well as the fine topologies in both linear and non-linear potential...
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Effect of pulsatility of blood flow on parametres of vascular damage in patients with mechanical circulatory support
Ivák, Peter ; Netuka, Ivan (advisor) ; Štádler, Petr (referee) ; Ošťádal, Petr (referee)
Ventricular assist devices are an important therapeutic modality in advanced surgical therapy of end-stage heart failure. Devices mainly used until recently generate primarily non- pulsatile blood flow. Despite indisputable clinical success of this therapy, we encounter complications specific to the devices with continuous flow. Complications are mostly attributed to increased shear stress and changes in blood vessels, blood elements and endothelium. The aim of this study was to determine the effect of continuous blood flow on the vasculature and blood elements by longitudinal monitoring of selected biomarkers of vascular health. During the study we monitored circulating microparticles, endothelial progenitor cells and stem cells and examined degradation dynamics of von Willebrand factor and its function. Results obtained in our study confirm the hypothesis of changes in the dynamics of studied markers dependent on the change of characteristics of blood flow. The possible negative effect of continuous flow on monitored parameters was observed in tracked period. In degradation of the high molecular weight von Willebrand factor multimers the probable positive effect of arteficial pulsatility was observed. Further research can provide important data for the development of specific characteristics...
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Geometric properties of subspaces of continuous functions
Petráček, Petr ; Lukeš, Jaroslav (advisor) ; Netuka, Ivan (referee)
In this thesis we study certain geometric properties of Müntz spa- ces as subspaces of continuous functions. In the first chapter we present some of the most important examples of the Müntz type theorems. Namely, we present the classic Müntz theorem and the Full Müntz theorem in the setting of the space of continuous functions on the interval [0, 1]. We also mention several extensions of these theorems to the case of continuous functions on the general interval [a, b] as well as an analogy of the Full Müntz theorem for the Lp ([0, 1]) spaces. The second chapter is divided into three sections. In the first section we present some definitions and well-known theorems of Choquet theory, which we use to characterize the Choquet boundary of Müntz spa- ces. In the second section we present the result concerning non-reflexivity of Müntz spaces as well as its corollary describing the non-existence of an equiva- lent uniformly convex norm on these spaces. In the third section, we concern ourselves with the question of Müntz spaces having the Radon-Nikodym pro- perty. As a main result of this part we show that a certain type of Müntz spaces doesn't have the Radon-Nikodym property. The final chapter contains a summary of some known results as well as open problems related to the theory of Müntz spaces....
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Topological and descriptive methods in the theory of function and Banach spaces
Kačena, Miroslav ; Spurný, Jiří (advisor) ; Netuka, Ivan (referee) ; Kalenda, Ondřej (referee)
The thesis consists of four research papers. The first three deal with the Choquet theory of function spaces. In Chapter 1, a theory on products and projective limits of function spaces is developed. It is shown that the product of simplicial spaces is a simplicial space. The stability of the space of maximal measures under continuous affine mappings is studied in Chapter 2. The third chapter employs results from the previous chapters to construct an example of a function space where the abstract Dirichlet problem is not solvable for any class of Baire-n functions with $n\in N$. It is shown that such an example cannot be constructed via the space of harmonic functions. In the final chapter, the recently introduced class of sequentially Right Banach spaces is being investigated. Connections to other isomorphic properties of Banach spaces are established and several characterizations are given.
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