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Serum markers of cholesterol 7α hydroxylase activity
Bohdanecká, Alena ; Leníček, Martin (advisor) ; Kovář, Jan (referee)
Cholesterol 7-hydroxylase (CYP7A1) is the rate limiting enzyme of the classical pathway of bile acid (BA) synthesis, which catabolizes approximately half of cholesterol in man. Determination of CYP7A enzymatic activity is a key subject of lipid metabolism research. Direct determination of CYP7A1 activity in hepatic biopsy is mostly not allowed for ethical reasons, so indirect methods are used with serum markers such as 7α-hydroxy-4-cholestene-3- one (C4). The first, methodical aim of the work was to convert the introduced HPLC method for the determination of C4 to LC-MS in order to increase the sensitivity. We focused on the solid phase extraction step, adjusting the composition and volumes of the washing and elution solution. By converting the method from HPLC to LC-MS, the sensitivity was increased approximately 7 times (LD = 1.39 ng/ml). In the second, clinical part of our work, we attempted to confirm the preliminary results of our laboratory on the distribution of C4 in lipoprotein fractions (LPP) in order to find parameter that would correlate with CYP7A1 activity better than C4 level itself. Preliminary results (performed in healthy individuals) showed that most of C4 is carried on HDL, and that the C4 distribution within LPP fractions is similar among examined subjects. We repeated the...
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Impact of smartphones and tablets on today's media development
Kovář, Jan ; Jirků, Jan (advisor) ; Švelch, Jaroslav (referee)
! ! Abstract This thesis explores and analyses influence of smartphones, tablets and e-readers launch on today's media development both from publisher's and media consumer's view. Main goal of this work is to map turbulent media evolution thanks possibilities, brought by revolutionary devices especially iPhone and iPad and their impact on publishing houses and traditional media. The thesis envisages the future of printed media and its co-existing together with the digital versions of traditional titles, possibilities and consumer willingness to pay for the digital content and specifics of the copyright in the digital media world. Least but not last thesis tries to discover individual target groups of each media including their typical behavior and arguing over the diversion from the traditional media towards the digital media.
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Molecular mechanisms of iron transport across plasma membrane in mammalian cells
Balušíková, Kamila ; Kovář, Jan (advisor) ; Ehrmann, Jiří (referee) ; Krijt, Jan (referee)
Iron belongs among the trace elements and its role in humans is irreplaceable. Up to 5 g of iron can be found in adult body distributed among different compounds. Iron ions are therefore essential to all cells of our body and its homeostasis is thoroughly controlled. Iron uptake into the organism is mediated by enterocyte cells in the small intestine, where heme as well as non-heme forms of iron are absorbed. Non-heme iron is absorbed via Dcytb (duodenal cytochrome b), DMT1 (divalent metal transporter 1), ferroportin, hephaestin, and ceruloplasmin molecules. Although these molecules can also participate in non-transferrin- bound iron transport across plasma membranes within the whole organism, mechanisms of this transport are not yet fully elucidated. The aim of the present work was to contribute to our understanding of molecular mechanisms that are involved in non-transferrin-bound iron transport across the plasma membrane of mammalian cells. Our project was focused on the description of non-transferrin- bound iron transport in human cells in vitro and in vivo under conditions of iron deficiency or iron overload. Transformed cell lines, that represent the three main types of cells involved in iron homeostasis, and tissue samples of duodenal biopsies were used as experimental models. The expression...
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Genetic determination of cholesterolemia regulation
Vlachová, Miluše ; Kovář, Jan (advisor) ; Vrablík, Michal (referee) ; Kazdová, Ludmila (referee)
Most types of hypercholesterolemia are of polygenic origin. Some genes related to hypercholesterolemia are known, although all genes responsible for cholesterolemia regulation have not been characterised yet. To identify these new genes, animal models with spontaneous defects in cholesterol metabolism could be very useful. Moreover, a number of variations and polymorphisms have been found to influence blood cholesterol levels in humans. Some may also affect cholesterolemia responsiveness to dietary fat. The Prague hereditary hypercholesterolemic (PHHC) rat is a unique model of hypercholesterolemia induced by dietary cholesterol alone (without administration of cholic acid or thyrotoxic drugs). It exhibits modestly increased cholesterolemia when fed chow and responds to a diet containing cholesterol with a several-fold increase of cholesterolemia to concentrations comparable to those observed in hypercholesterolemic patients. Hypercholesterolemia in this model is characterised by accumulation of very low density lipoproteins (VLDL) and intermediate density lipoproteins (IDL) enriched by cholesterol. In an experiment with tyloxapol (an inhibitor of lipoprotein lipase) we found that PHHC rats on a cholesterol diet incorporated twice as much cholesterol into VLDL as Wistar rats, although liver...
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Evalution individual and group gaming skills of players at AC Sparta Praha U 12 (Year 2002)
Kovář, Jan ; Buzek, Mario (advisor) ; Frýbort, Pavel (referee)
Title of the thesis: Evaluation of individual and group gaming skills of players at AC Sparta Praha U12 (Year 2002) Objectives: To determine the error of players in matches AC Sparta Praha U 12 from the perspective of both quantity and quality Method used: Observational analysis with the method of indirect observation. This is a joint research. Results: Using the indirect observational method on AC Sparta Praha U12, I have found out that during 6 games, players had made in total 431 mistakes. Out of all, the most common mistake was pass - 136 errors (31,55%), followed by the circumvention of the teammate - 73 errors (16, 93%). I have noticed a comparable number of errors in takeover - 43 errors (9, 98%) and while handling the ball - 45 errors (10, 44%). From team activities I observed an error while defending an opponent along with one teammate - 14 errors (3, 25%) and ensuring teammate - 26 mistakes (6, 03%). From the quality point of view, the greatest problem is the sense for the ball, when they were not able to choose the right strength or while processing the ball not being able to cushion the ball. Another cause of errors was pressing on an opponent. When opponents did not give the players of Sparta enough time and space for a game, they had a big problem to resolve the situation properly....
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Impact of smartphones and tablets on today's media development
Kovář, Jan ; Jirků, Jan (advisor) ; Švelch, Jaroslav (referee)
! ! Abstract This thesis explores and analyses influence of smartphones, tablets and e-readers launch on today's media development both from publisher's and media consumer's view. Main goal of this work is to map turbulent media evolution thanks possibilities, brought by revolutionary devices especially iPhone and iPad and their impact on publishing houses and traditional media. The thesis envisages the future of printed media and its co-existing together with the digital versions of traditional titles, possibilities and consumer willingness to pay for the digital content and specifics of the copyright in the digital media world. Least but not last thesis tries to discover individual target groups of each media including their typical behavior and arguing over the diversion from the traditional media towards the digital media.
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The Use of Mirror therapy in patients after stroke
Kovář, Jan ; Senohrábková, Eva (advisor) ; Drábová, Zuzana (referee)
BACHELOR THESIS ABSTRACT Title of bachelor thesis:The Use of Mirror therapy in patients after stroke Abstract: The topic of my bachelor thesis consisting of theoretical and practical parts relates to Mirror therapy and its use in patients after stroke from the physiotherapeutical point of view. The theoretical part is conceived as a review of the background art. I summarize present information concerning stroke and describe certain methods and concepts which have proved to be useful in the therapy of stroke patients. The Mirror therapy principle consists in observation of the unaffected limb in a mirror being vertically attached to the sagittal axis of the patient's body. Movements performed by the unaffected limb give illusion these are likewise performed by the impaired limb. While watching the reflection in the mirror, the mirror neurons system is activated. The system thereafter provokes activation of motor and somatosenzory areas of the cerebral hemispheres controlling the affected limb. Central nervous system effectively uses reparation neuroplasticity and provides both motor and senzory function improvement. In the Mirror therapy chapter, I focus on the principles of the method as well as on its therapeutic effects and ways of application. Results of present studies evaluating Mirror therapy efficacy...
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Molecular mechanisms of the resistence of breast cancer cells to taxanes: the role of ABC transporters
Kopperová, Dana ; Kovář, Jan (advisor) ; Hrdý, Jiří (referee)
Resistance to chemotherapeutics is a widespread phenomenon in cancer cells that may counteract the successful therapy of many patients. In resistant cells, higher level of ABC transporters, among others, often can be detected. This high level of ABC transporters represents a suspected mechanism of acquired cancer resistance. We studied the molecular mechanism of resistance to taxanes in cancer cells using SK-BR-3 and MCF-7 breast cancer cell lines. We analyzed the effect of paclitaxel on apoptosis induction in the originally sensitive cells of these lines as compared to their counterpart resistant cells, developed by gradual adaptation to paclitaxel. In resistant cells of the SK-BR-3 and MCF-7 lines, we did not detected ongoing induction of apoptosis but we did detect significantly increased expression of ABCB1 transporter after paclitaxel application. By silencing the expression of the transport via employment of small interfering RNA (siRNA), we tested the role of the ABCB1 transporter in cells resistant to paclitaxel. We found that resistant cells with silenced expression of the ABCB1 transporter had a statistically significant increase of sensitivity to paclitaxel as compared to control resistant cells with high expression of this transporter. Along with increased sensitivity, we demonstrated...
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The role of cholesterol-7alpha-hydroxylase in cholesterolemia regulation
Procházková, Martina ; Kovář, Jan (advisor) ; Zelenka, Jaroslav (referee)
Cholesterol 7α-hydroxylase (CYP7A1) is an enzyme catalyzing the first step of conversion of cholesterol to bile acids. The enzyme activity is regulated to supply enough bile salts necessary for absorption of fats in the intestine. In some species it contributes to cholesterol elimination from the body when dietary cholesterol intake is high and, in such a way, protects against the development of hypercholesterolemia. CYP7A1 activity can be therapeutically affected by administration of bile acid sequestrants that increase the enzyme activity and thus lower cholesterolemia, and also by administration of bile salts. The enzyme deficiency in humans results in hypercholesterolemia. Several single nucleotide polymorphisms were identified in gene encoding CYP7A1 in humans. They form three large haplotype blocks. The most attention has been paid to the -203A>C polymorphism that has an impact on cholesterol and lipoprotein concentrations, on the response of cholesterolemia to dietary intervention and on the response to hypolipidemic drugs. Key words: Bile acids, cholesterol, cholesterol 7α-hydroxylase, diet, genetics, treatment of hypercholesterolemia
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