National Repository of Grey Literature 874 records found  1 - 10nextend  jump to record: Search took 0.18 seconds. 

The influence of the membrane transport on the heart mechanical activity
Převorovská, Světlana ; Maršík, František
The mechanical activity of the heart muscle is the response of the electrochemical processes at the myocardial cells level. The influence of the sodium, potassium and calcium ions transport through the myocyte cells membrane and the generation of the myocardial action potential on heart mechanical activity has been simulated by the numerical model.

Evaluation of elastic parameters for models of isolated cells
Krbálek, Jaroslav ; Fuis, Vladimír (referee) ; Burša, Jiří (advisor)
This diploma thesis focuses on computational modeling of the cell mechanical tests. The goal of this thesis is to build a cell model and to simulate compression test on this model. If necessary, the model should be adjusted so the model reflects real cell behavior. It was created the cell model reflecting cytoplasm, nucleus, membrane and cell cytoskeleton. Cytoskeleton was modeled as tensegrity structure. After this, the pressure test was simulated on this model. The behavior of the cell model and real cell was compared using the stress force. The stress force - cell deformation curve was markedly different for the cell model and the real cell. For this reason, the cytoplasm material model was adjusted. The difference between the curves was acceptable after this modification. It was found during computations that the cytoskeleton model influence on the cell load is minimal. These results does not reflects real cell behavior, which means that the model is considered inadequate for performing stress load simulation.

Preparation and characterization of thin organic photovoltaic layers
Kratochvíl, Matouš ; Zmeškal, Oldřich (referee) ; Weiter, Martin (advisor)
This bachelor thesis focuses on preparation of organic solar cells and characterization of their properties. The theoretical part consists of literature search focused on current findings in this area and basic theoretical knowledge of the mechanisms of solar cells functioning. The experimental part of the thesis deals with the preparation of solar cells, targeting large cells, and characterization of basic electrical and optical properties of these cells.

Ultrasonographic evaluation of cardiovascular abnormalities in patients with Fabry disease
Paleček, Tomáš ; Bultas, Jan (advisor) ; Pudil, Radek (referee) ; Kittnar, Otomar (referee)
Fabry disease is an X-linked glycosphingolipid storage disorder caused by deficient activity of the lysosomal enzyme α-galactosidase A. This leads to progressive intracellular accumulation of neutral glycosphingolipids, mainly globotriaosylceramide. Besides various extracardiac disease-related abnormalities, cardiovascular involvement represents a typical manifestation of Fabry disease. The primary underlying mechanism relies on pathological substrate accumulation in cardiomyocytes, conduction system cells, valvular fibroblasts, endothelial cells and vascular smooth muscle cells. The development of cardiac and vascular hypertrophy represents a characteristic cardiovascular feature of Fabry disease. The aim of our studies was to describe in detail cardiovascular abnormalities in patients with Fabry disease using ultrasonography, which currently represents basic noninvasive imaging modality in cardiology. We focused on structural and functional abnormalities of ventricles, valvular apparatus and their relationship to vascular involvement expressed on common carotid arteries. We also compared the diagnostic accuracy of the two novel echocardiographic methods used for the left ventricular diastolic function assessment. The possible existence of circulating proliferative factor, which might be associated with...

název v anglickém jazyce není uveden
Kolesová, Hana ; Grim, Miloš (advisor) ; Slípka, Jaroslav (referee) ; Nečas, Emanuel (referee)
Branchial arches region and its blood vessels are extensively transformed in the embryonic development. Aim of this study is to investigate mechanisms of the branchial arches region development and to study how a morphogen Sonic hed gehog (Shh) participate on the formation and remodeling of branchial arches and their blood vessels. Influence of Shh was evaluated based on the changes caused by its inhibition in vivo. Shh function was inhibited with an anti-Shh antibody, which was produced into the embryo from the applied hybridoma cells. Shh signaling cascade was also inhibited by cyclopamine. Results show that Shh is important for dc novo format,ion of the blood vessels in the branchial arches region. Further Shh is necessary for stabilization of the vessel wall, mainly for anterior cardinal vein. Shh also alfects later vessel development and transformation, which includes i.e. fusion of the dorsal aorta, branching of the internal carotid artery and outflow tract development. Short time inhibition of Shh has minor effect on the apoptosis and proliferation activity of the branchial arches region mesenchymal cells. We assume that Shh signals directly to the blood vessels endothelial cells, as Shh receptor ptel is also expressed in endothelial cells and its signal is reduced with Shh inhibition. In studied...

Glycocalyx shedding by cercariae of bird schistosomes
Chaloupecká, Jana ; Mikeš, Libor (advisor) ; Štěrba, Ján (referee)
Trichobilharzia spp. are avian schistosomes related to medically important human parasites of the genus Schistosoma. Penetrating cercariae are well known as causative agent of cercarial dermatitis in humans. Cercariae actively penetrate the skin of definitive hosts and transform into schistosomula. This process is preceded by cercarial tail detachment and includes emptying of penetration glands and extensive surface changes. One of these changes is the loss of highly immunogenic glycocalyx which represents a protective coat in the aquatic environment. The glycocalyx has specific composition of saccharide molecules which are bound to lipids or proteins on the membrane of cercarial tegument. There is only limited information about the mechanism of shedding. Hypotheses based on indirect evidences suggest that peptidases or (phospho)lipases from penetration glands could be involved. This work describes the changes in surface glycosylation during transformation of cercariae into schistosomula by fluorescently labelled lectins and monoclonal antibodies against Lewis X antigen. Lectins UEA-I, LTA and PNA have been chosen as markers of transformation of T. regenti. Further, our experiments have been focused on shedding of cercarial glycocalyx. During in vitro induction of penetration gland emptying and...

Emergent properties of the G1/S network
Dražková, Jana ; Tomášek, Petr (referee) ; Palumbo,, Pasquale (advisor)
Tato práce se zabývá buněčným cyklem kvasinky Saccgaromyces cerevisiae. Oblastí našeho zájmu je přechod mezi G1 a S fází, kde je naším cílem identifikovat velikosti buňky v době počátku DNA replikace. Nejprve se věnujeme nedávno publikovanému matematickému modelu, který popisuje mechanismy vedoucí k S fázi. Práce poskytuje detailní popis tohoto modelu, stejně jako časový průběh některých důležitých proteinů či jejich sloučenin. Dále se zabýváme pravděpodobnostním modelem aktivace replikačních počátků DNA. Nově uvažujeme vliv šíření DNA replikace mezi sousedícími počátky a analyzujeme jeho důsledky. Poskytujeme také senzitivní analýzu kritické velikosti buňky vzhledem ke konstantám popisujícím dynamiku reakcí v modelu G1/S přechodu.

Aspects of Gene Regulation of CYP3A4 in Hepatic Tissue.
Krausová, Lucie ; Štaud, František (advisor) ; Mičuda, Stanislav (referee) ; Skálová, Lenka (referee)
1 Summary CYP3A4 is an important enzyme involved in elimination of majority of metabolized xenobiotics. It plays a major role in the detoxification system of the human body, therefore it is responsible for many drug-drug interactions (DDIs). DDI present a complication of current pharmacotherapy, in the extreme they can lead in failure of therapy or in life-threatening toxic effects. DDIs are caused by changes in enzymatic activity of CYP3A4, which is highly variable among individuals. An important mechanism of modulating CAP3A4 activity is the regulation of inducible transcription by nuclear receptors, especially PXR, CAR and GR. The structure of CYP3A4 promoter and mechanisms of transcriptional regulation has been studding intensively for many years, but the research of relationship of nuclear receptors and transcriptional cofactors in CYP3A4 transactivation is still incomplete. Present work contributes to elucidation of some questions concerning the effects of azole antimycotics on CYP3A4 transcription via PXR, potency of valproic acid to activate PXR and CAR or determinants of CYP3A4 expression via GR in placental cells. The experiments were performed with up-to-date molecular biology methods and using in vitromodels of the primary human hepatocytes and hepatoma cell lines. To the aims of the doctoral...

Impact of pesticides on the gut microbiota of human
Kočová, Kateřina ; Rada, Vojtěch (advisor) ; Jakub, Jakub (referee)
Pesticides are substances or mixtures of substances used in agriculture against pests (animals, plants and parasitic fungi), who damage the crops, stocks of agricultural products, food and reduce livestock utility or threaten human health. The thesis consists of two parts. The first (theoretical) part describes composition and function of gut microbiota; pesticides and their classification, environmental transport and effects of these substances on human health, and glyphosate as the active substance of herbicide Roundup, its mechanism of action, environmental fate and proven effects of glyphosate on human. The aim of second (practical) part of this thesis was to test impact of pesticide Roundup on the gut microorganisms of human. The impact of pesticide was tested in in vitro pure cultures. Roundup was added in concentrations of glyphosate 17 g/L, 1,7 g/L and 0,17 g/L to the complex media and after cultivation the growth of microorganisms was evaluated. The next samples of stool were collected from human volunteers; these were cultivated similarly in the complex media with different concentrations of glyphosate. The total numbers of microorganisms, bifidobacteria, lactobacilli, enterococci and coliformn bacteria were defined after cultivation. When the pesticide was tested in pure cultures, concentration of 17 g/L glyphosate significantly inhibited total bacterial growth (P < 0.05), at lower concentrations no difference was observed. The cultivated microorganisms from samples of stool demonstrated only that bifidobacteria are sensitive to glyphosate at the highest used concentration of this pesticide compared with the control sample.

Tick-borne encephalitis - from pathogenesis to therapy
PALUS, Martin
The proposed thesis contributes to the knowledge about tick-borne encephalitis and its pathogenesis. The thesis describes pathogenesis and immunopathogenesis of tick-borne encephalitis, impact of host's genotype in clinical course determination, immune response of patients with acute tick-borne encephalitis, the mechanism of tick-borne encephalitis virus migration into central nervous system and virus interaction with cells of neurovascular unit as well as potential medical interventions.