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Use of spectral analysis for the treatment of paroxysmal or persistent atrial fibrillation
Veselá, Jana ; Rosina, Jozef (advisor) ; Hána, Karel (referee) ; Vančura, Vlastimil (referee)
Introduction: Atrial fibrillation is most common sustained cardiac arrhythmia characterized by rapid, unorganized atrial electrical activation. Its incidence in- creases with age and comorbidities. The presence of AF has been demonstrated to be independently associated with increased morbidity and mortality. The tre- atment of AF remains challenging. The aim of the present work is to use the analysis of heart rate variability in prediction of AF occurrence, and during tre- atment procedures of AF for better understanding of physiology of AF. Results of time-, frequency- and non-linear analyses were used in two present studies. The first study was study of patients undergoing hybrid ablation of atrial fib- rillation. Hybrid ablation consists of surgical epicardial thoracoscopic procedure, followed by electrophysiological catheter ablation. The second part is done 1-3 months after the surgical part. The aim was to establish the coincidental damage of ganglionated plex during the first, surgical procedure, using the analysis of heart rate variability during the electrophysiological procedure. The aim of the second study was the prediction of post-operative AF in pa- tients undergoing open-chest cardiac surgery, using the pre-operative heart rate variability analysis. Methods: Study 1: Patients with...
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Intelligent nanofibres functionalized with growth factors and blood derivatives for dermatology applications
Vocetková, Karolína ; Amler, Evžen (advisor) ; Rosina, Jozef (referee) ; Arenberger, Petr (referee)
Platelet derivatives are an attractive source of natural growth factors and they are widely used in various tissue engineering and regenerative medicine applications. The aim of this study was to optimize cell culture conditions using platelet lysate and to develop platelet-functionalized fibrous scaffolds as a controlled drug delivery system for native growth factors. Fibrous scaffolds were prepared by electrostatic and centrifugal spinning of PCL and they were functionalized by the platelets by surface adhesion or their encapsulation using emulsion spinning techniques. The cell culture study determined the 7% platelet lysate to be the optimum concentration as a medium supplement in keratinocyte and fibroblast culture. Additionally, following surface adhesion of the platelets to PCL electrospun nanofibres, the platelets were activated due to their contact with the nanofibre nanotopography, resulting in formation of fibrin network. Fibrin served as a reservoir of the growth factors, prolonging the half-time of EGF release to 1.7 days. Such platelet-functionalized samples fostered proliferation of keratinocytes, fibroblasts and melanocytes. Furthermore, adhesion of platelets to centrifugally spun nanofibrous scaffolds resulted in almost two-fold increase in the amount of immobilized platelet-derived...
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Development of Scaffolds for Bone Defects Regeneration
Prosecká, Eva ; Amler, Evžen (advisor) ; Rosina, Jozef (referee) ; Gášková, Dana (referee)
A promising new smart scaffold with potential for clinical use was prepared during our experiments. The biocompatible, biodegradable, osteoconductive and also osteoinductive 3D scaffold contains 0.5% type I collagen and 50% of hydroxyapatite with pore size around 400 um suitable for cell ingrowth and vascularization. Subsequently added poly-ɛ-caprolactone nanofibers improved the mechanical properties of the scaffold. The scaffold was enriched with mesenchymal stem cells and thrombocyte rich solution. The functionalized scaffold promoted new bone tissue formation throughout the defects, with uniform distribution of the newly-formed bone in vivo in a rabbit model, while the scaffold gradually degraded and was replaced by newly-formed bone tissue. In addition, we have found a fabrication process and materials which meet the European medicines agency requirements and can be developed for human applications. Hydroxyapatite-coated coaxial poly-ɛ- caprolactone/polyvinylalcohol nanofibers have been developed as a promising novel drug-delivery system suitable for bone tissue engineering.
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Risk factors of malignant melanoma, its possibilities of prevention and early diagnosis
Kulichová, Daniela ; Čelko, Alexander (advisor) ; Rosina, Jozef (referee) ; Dohnal, Karel (referee)
Background Ultraviolet radiation is one of the most important environmental risk factors for cutaneous melanoma. Nonetheless, information concerning ultraviolet exposure in many populations, including the central European population, is lacking. Objectives The aim of our study was to investigate risk factors for malignant melanoma, particularly those related to ultraviolet exposure behavior in two European neighboring countries, Germany and the Czech Republic. Methods We conducted a hospital-based case-control study. 224 consecutive patients were diagnosed with melanoma in two dermatological clinics (Prague and Munich). Controls were 268 patients with other conditions from the same hospitals. All subjects completed a questionnaire on socio-demographic data and factors related to ultraviolet exposure. Associations between melanoma, ultraviolet exposure and other variables were assessed by multivariate logistic regression. Results Patients with red hair had higher risk of developing melanoma than those with other hair color (odds ratio 3.597, 95% confidence interval 1.341-9.646). A similar trend was seen when comparing phototypes; subjects with phototype I and II had a higher likelihood of melanoma than those with phototype III (OR 4.028 and 4.837, 95%CI 1.929-8.411 and 2.574- 9.086). Frequent...
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Detection and visualization of native and artificial chondrogenous tissue using biophysical methods
Rampichová, Michala ; Amler, Evžen (advisor) ; Rosina, Jozef (referee) ; Kolářová, Hana (referee)
Tissue engineering is a rapidly developing field, based on using scaffolds made from natural or synthetic materials in combination with cells and stimulating factors for the replacement of damaged or lost tissue. It is very important to evaluate qualities of these scaffolds, which are necessary for cell proliferation and their mechanical support. The aim of this study was to develop a suitable scaffold for chondrocyte proliferation, scaffold functionalization and detection of cells and proteins of extracellular matrix (ECM) using methods of fluorescence and confocal microscopy. Another aim was to test an appropriate scaffold on a big animal model in vivo. Several scaffolds from natural and synthetic materials, in the form of microfibers, non-woven textiles, gels and foams were prepared for this study. Scaffolds were seeded with chondrocytes and cell adhesion, proliferation and synthesis of ECM proteins were detected. Methods of fluorescence microscopy, confocal microscopy and second harmonic generation (SHG) were used for visualization of cells and proteins. A hydrogel based on fibrin and hyaluronan was used as an scaffold for osteochondral defect regeneration in minipigs study. Prepared scaffolds showed high biocompatibility, good chondrocyte adhesion and ECM proteins synthesis. Moreover, microfibrous...
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Identification of changes in mechanical characteristics of human axial system as a result of loading and relaxation regime
Van der Kamp Kloučková, Kateřina ; Jelen, Karel (advisor) ; Maršík, František (referee) ; Rosina, Jozef (referee)
Problem: A lot of attention is given to the safety of the driving and the possibility to register fatigue of the drivers. Driving cars is monotony and static. Vibration loading, which causes changes in the axial system. This causes discomfort and fatigue to drivers after some time of exposure to the loading. Hypothesis: It is possible to prove the changes of mechanical characteristics (indicators) of the axial system using the TVS (transfer vibration through spine) method. By using TVS method before and after different types of loading or before and after relaxation it is possible to detect changes of the viscoelastic properties. This can be done by checking changes in the way of waves transfer through the axial system of the observed participants. Objective: Verify the possibility of use of TVS method to register changes of the viscoelastic characteristics of the axial system. Method: The TVS was chosen as a detection method. The method is based on the use of five-msec semi-bandwidth γ pulse stimuli and consequent application of continuously changing harmonic stimuli which periodically differ between 5Hz and 160Hz to the vertebrae C7 and L5. This wave is carried through the axial system and its acceleration on the spinous processes between C7 and S1 is scanned with the help of accelerometric...
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Characterization of functionalized fibres for mesenchymal stem cells cultivation and differentiation
Greplová, Jarmila ; Amler, Evžen (advisor) ; Rosina, Jozef (referee)
Modification of nanofibers is an actual trend in tissue engineering. Polyvinylacohol (PVA) is nontoxic and biodegradable polymer suitable for preparation of submicron fibers by electrospinning. Main disadvantage of PVA fibers is rapid degradation in aqueous environment. On the other hand surface of fibers contains free hydroxyl group that could be chemically modified. In recent work, chemical modification of PVA nanofibers prepared by needleless electrospinning was investigated. Polyethylenglykol (PEG) linker was introduced to the fiber surface by acylation (PVA-PEG) and further modified by biotin (PVA-PEG-b) as a function agent. Process of chemical modification does not affected fibrous morphology of samples. Interestingly, linkage of PEG-b linker promoted stability of PVA in aqueous environment. PVA-PEG-b sample was stable for 41 days. Stability of samples was strongly dependent on amount of introduced PEG-b linker, thus proposed method of modification allows to prepare nanofibers of different solubility. Additionally, biocompatibility of chemically modified nanofibers with both mesenchymal stem cells (MSC) and chondrocytes was determined. Proliferation of both cell types was not sufficient and number of cells decreased in time, probably because of high hydrophility of modified PVA scaffold. To...
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Physical factors influencing the development of corneal damage by UV rays
Čejka, Čestmír ; Rosina, Jozef (advisor) ; Štípek, Stanislav (referee) ; Amler, Evžen (referee) ; Salminen, Lotta (referee)
Purpose: The purpose of the Thesis "Physical factors influencing the development of corneal damage by UV rays" was a) to determine the light absorption properties in the rabbit cornea irradiated with UVB rays by measuring of physical values of absorbance A and transmittance T as functions of wavelength ; b) To investigate the absorption coefficient as a function of wavelength ; c) To evaluate the importance of this coefficient for corneal light absorption properties; d) To determine the light absorption properties in the rabbit cornea irradiated with UVA by measuring of physical values of absorbance A and transmittance T as functions of wavelength (to compare the effect of UVA with UVB rays). Material and Methods: To achieve individual aims, the new spectrohotometrical method was developed and following experimets were performed: a) Repeted irradiation of the rabbit cornea with UVB rays (daily dose 1.01 J/cm2 during 5 days); b) Repeated irradiation of the rabbit cornea with UVA rays (daily dose 1.01 J/cm2 or 2.02 J/cm2) during five days; c) Repeated irradiation of the rabbit cornea with the daily dose of 1.01 J/cm2 during 4 days and in individual time intervals investigation of corneal light absorption and hydration changes; d) The anti-UV efficacy of UV filter (actinoquinol combined with hyaluronic acid,...
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Risk factors for malignant neoplasms of skin and prevention options
Rosina, Jozef ; Čelko, Alexander (advisor) ; Kolářová, Hana (referee) ; Dohnal, Karel (referee) ; Navrátil, Leoš (referee)
Skin tumors are the most common types of tumors in humans. Their incidence is steadily increasing. Increases and mortality, especially in malignant melanoma. Risk factors playing an important role in the development of skin cancer, solar radiation belong. UV spectrum of sunlight is the most important cause of skin cancer. Therefore, the degradation of the ozone layer and the associated increased levels of UV radiation reaching the world so much studied. Among other known risk factors belong phenotype of human acute intermittent sunburn, especially in children and adolescents, increased tendency to form freckles skin after exposure to sunlight and the presence of pigmented nevi. Some people may find a genetic basis. The risk of malignant melanoma is also rising in people who have a history had already been diagnosed with this disease. Significant for the possibility of skin malignancy is immunosuppression. The work is focused on statistical analysis of most of the above mentioned risk factors.
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