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Vasodilatory effects of 4-methyl catechol: ex vivo mechanism of action
Kuzdřalová, Kateřina ; Pourová, Jana (advisor) ; Smutná, Lucie (referee)
Charles University Faculty of Pharmacy in Hradec Králové Department of Pharmacology and Toxicology Student: Kateřina Kuzdřalová Supervisor: doc. PharmDr. Jana Pourová, Ph.D. Title of diploma thesis: The mechanism of vasodilation effect of 4-methylcatechol ex vivo Keywords: rat, aorta, flavonoids, 4-methylcatechol, vascular smooth muscle, vasodilation Flavonoids belong to the group of polyphenolic bioactive substances found abundantly in plants, fruits and vegetables. Thanks to their pharmacological and biochemical effects, they play a crucial role for human health, especially in the prevention of numerous diseases - metabolic syndrome, osteoporosis, atherosclerosis and also diseases of a cardiovascular system. The aim of the diploma thesis was to determine the mechanism of the vasorelaxant effect of one of the most important metabolites of flavonoids - 4-methylcatechol. For the research we used a standardized ex vivo method on isolated Wistar rat aortic rings. We were able to confirm the vasodilatory effects of 4-methylcatechol. We also confirmed the fact that the flavonoid metabolite directly affects a vascular smooth muscle. Furthermore, we found that the tested compound potentiates the vasodilatory activity of sodium nitroprusside and forskolin, and that vasodilation depends on the activity of...
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Application for Recognition of Human Eye Retina
Drozd, Radek ; Hájek, Josef (referee) ; Drahanský, Martin (advisor)
The blood vessels layout in a human eye retina is unique for every person in the world, so it is one of important biometric characteristics. Processing of colour retina image may be a part of an intended biometric system. There is an algorithm for automatic blood vessels detection, optic disc and macula localisation, finding of bifurcation points and saving those as a biometric template presented in this bachelor's thesis. C++ programming language and OpenCV library were used for implementation. The application was tested on a set of colour retina images, taken by fundus camera. The final application is supposed to run on a digital signal processor, developed by Texas Instruments. The thesis gives the introduction into biometrics, signal processing and human eye anatomy.
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Influence of mechanical properties of vascular grafts on their clinical applications
Chomič, Dimitrij ; Polzer, Stanislav (referee) ; Burša, Jiří (advisor)
The theme of my bachelor’s thesis is the vascular replacement. I write about the types of blood vessels, their anatomy, physiology, pathology and mechanical characteristics. My thesis contains a part about the types of vascular replacements, I define their mechanical characteristics and I describe how the vascular replacement used in medicine. I study the artificial vascular replacement preferentially. To illustrate the application of the moment theory of cylindrical shells (Course in PP II), I solve the extreme stresses in the connection of a replacement with a vessel having mutually different geometrical and material parameters. The artery and the replacement were under pressure of 16 kPa corresponding to the systolic blood pressure.
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Study of the mechanisms of action of phenolic compounds on vascular smooth muscle
Alves Dias, Patrícia Alexandra ; Mladěnka, Přemysl (advisor) ; Kyselovič, Ján (referee) ; Štengl, Milan (referee)
Charles University, Faculty of Pharmacy in Hradec Králové Training Workplace Department of Pharmacology and Toxicology Doctoral Degree Program Pharmacology and Toxicology Candidate Patrícia Alexandra Alves Dias, M.Sc. Supervisor prof. Přemysl Mladěnka, Pharm.D., Ph.D. Advisor assoc. prof. Jana Pourová, Pharm.D., Ph.D. Title of Doctoral Thesis Study of the mechanisms of action of phenolic compounds on the vascular smooth muscle Cardiovascular diseases including hypertension, coronary artery disease, peripheral artery disease, and cerebrovascular disease remain the leading cause of death worldwide. In addition, discouraging estimations have suggested a future increase in the number of cardiovascular patients. Thus, novel treatment modalities are clearly needed to prevent or reverse these epidemic trends. Phenolic compounds contain one or more hydroxyl groups bound to a benzene ring. This class of chemicals includes: a) natural compounds (e.g., dietary polyphenols and small phenolic metabolites) referred to as nutraceuticals due to their claimed health-promoting effects and b) synthetic compounds (e.g., bisphenols) which, on the contrary, have been suggested to negatively affect human health. Even if there are claims that polyphenol-rich diet is associated with cardioprotective effects, important...
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Vasodilatory effects of 3-hydroxy phenylacetic acid: ex vivo mechanism of action
Štefancová, Monika ; Pourová, Jana (advisor) ; Vokřál, Ivan (referee)
Charles University Faculty of Pharmacy in Hradec Králové Department of Pharmacology & Toxicology Student: Monika Štefancová Supervisor: doc. PharmDr. Jana Pourová, Ph.D. Title of diploma thesis: Vasodilatory effects of 3-hydroxy phenylacetic acid: ex vivo mechanism of action It is known from clinical studies that the intake of polyphenols from food acts as a prevention of cardiovascular diseases. However, the parent compounds themselves often have low bioavailability. The emphasis is therefore on their bioactive metabolites. 3-hydroxy phenylacetic acid (3-HPAA) is among such metabolites. The aim of this study was to verify the mechanism of the vasodilatory effect of 3-HPAA using standardized ex vivo method on an isolated pig coronary artery. The administration of 3-HPAA resulted in relaxation of maximally contracted segments of porcine artery by mechanism partially dependent on the integrity of endothelium. By inhibiting endothelial nitric oxide synthase, the relaxation was significantly impaired. The blockage of SKCa and IKCa channels, muscarinic receptors, cyclooxygenase or L-type calcium channels did not affect relaxation. Thus, 3-HPPA causes dose-dependent vasodilatation of coronary arteries ex vivo at least partially mediated by endothelium with the participation of nitric oxide. Key words:...
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Vasodilatory effects of 4-methyl catechol: ex vivo mechanism of action
Kuzdřalová, Kateřina ; Pourová, Jana (advisor) ; Smutná, Lucie (referee)
Charles University Faculty of Pharmacy in Hradec Králové Department of Pharmacology and Toxicology Student: Kateřina Kuzdřalová Supervisor: doc. PharmDr. Jana Pourová, Ph.D. Title of diploma thesis: The mechanism of vasodilation effect of 4-methylcatechol ex vivo Keywords: rat, aorta, flavonoids, 4-methylcatechol, vascular smooth muscle, vasodilation Flavonoids belong to the group of polyphenolic bioactive substances found abundantly in plants, fruits and vegetables. Thanks to their pharmacological and biochemical effects, they play a crucial role for human health, especially in the prevention of numerous diseases - metabolic syndrome, osteoporosis, atherosclerosis and also diseases of a cardiovascular system. The aim of the diploma thesis was to determine the mechanism of the vasorelaxant effect of one of the most important metabolites of flavonoids - 4-methylcatechol. For the research we used a standardized ex vivo method on isolated Wistar rat aortic rings. We were able to confirm the vasodilatory effects of 4-methylcatechol. We also confirmed the fact that the flavonoid metabolite directly affects a vascular smooth muscle. Furthermore, we found that the tested compound potentiates the vasodilatory activity of sodium nitroprusside and forskolin, and that vasodilation depends on the activity of...
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Vasodilatory effects of catechol derivatives ex vivo
Šmídová, Kristýna ; Pourová, Jana (advisor) ; Carazo Fernández, Alejandro (referee)
Charles University Faculty of Pharmacy in Hradec Králové Department of Pharmacology & Toxicology Student: Kristýna Šmídová Supervisor: doc. PharmDr. Jana Pourová, Ph.D. Title of diploma thesis: Vasodilatory effects of catechol derivatives ex vivo Polyphenols, including flavonoids, are a broad group of natural substances with significant effects on human health, including the prevention of cardiovascular diseases. Their metabolites can also be active, with clinical effects which may even exceed those of the parent compounds. The aim of this diploma thesis was to verify vasodilatory effects of one flavonoid metabolite type, a series of catechol derivatives and elucidate the mechanism of action of the most potent substance. The established ex vivo method of isolated aortic rings of Wistar rats with isotonic registration of tissue contraction and dilation (software S.P.E.L. Advanced Kymograph Software) was used. In the experiments with the rat aorta precontracted by norepinephrin, 3-methoxycatechol was the most effective vasodilator (EC50 = 7,6 µmol.l-1). In the mechanistic study, we found out that its effect is endothelium-independent, and that 3-methoxycatechol enhances the vasodilatory effect of sodium nitropruside. However, the specific mechanism responsible for vasodilation was not identified and...
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Vasodilatory effects of catechol derivatives ex vivo
Šmídová, Kristýna ; Pourová, Jana (advisor) ; Carazo Fernández, Alejandro (referee)
Charles University Faculty of Pharmacy in Hradec Králové Department of Pharmacology & Toxicology Student: Kristýna Šmídová Supervisor: doc. PharmDr. Jana Pourová, Ph.D. Title of diploma thesis: Vasodilatory effects of catechol derivatives ex vivo Polyphenols, including flavonoids, are a broad group of natural substances with significant effects on human health, including the prevention of cardiovascular diseases. Their metabolites can also be active, with clinical effects which may even exceed those of the parent compounds. The aim of this diploma thesis was to verify vasodilatory effects of one flavonoid metabolite type, a series of catechol derivatives and elucidate the mechanism of action of the most potent substance. The established ex vivo method of isolated aortic rings of Wistar rats with isotonic registration of tissue contraction and dilation (software S.P.E.L. Advanced Kymograph Software) was used. In the experiments with the rat aorta precontracted by norepinephrin, 3-methoxycatechol was the most effective vasodilator (EC50 = 7,6 µmol.l-1). In the mechanistic study, we found out that its effect is endothelium-independent, and that 3-methoxycatechol enhances the vasodilatory effect of sodium nitropruside. However, the specific mechanism responsible for vasodilation was not identified and...
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The in vitro effects of selected fenolic substances on isolated rat vessels
Rajtmajerová, Iveta ; Pourová, Jana (advisor) ; Hrdina, Radomír (referee)
Charles University Faculty of Pharmacy in Hradec Králové Department of Pharmacology & Toxicology Student: Iveta Rajtmajerová Supervisor: PharmDr. Jana Pourová, Ph.D. Title of diploma thesis: The in vitro effects of selected fenolic substances on isolated rat vessels Silymarin flavonolignans are endowed with various aspects. Recently their hepatoprotective effect has been discussed widely as well as their positive influence on the cardiovascular system. This diploma thesis is concerned with the vasodilatory effects of silybin-A, silybin-B, silybin-A + B and isosilybin-A on rat aorta. The aim of this study was to test the vasodilatory effect of selected substances. The dependence of aortic relaxation on the increasing concentration of tested substances was measured. Isolated Wistar breed rat aorta was used. DRC curves were created and EC50 values were assessed from the obtained values of vessel tension. The results were evaluated subsequently. The vasodilator potential of silybin-A and isosilybin-A is comparable; hence the position of the substituents may be irrelevant in having any impact on relaxation of the vessels. Different vasodilatory effects of silybin-A and silybin-B have been observed thus, the relaxation could be stereoselective. The testing of the equimolar mixture of silybin-A and...
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Quantitative vessel parameters of broadleaves as a tool for reconstruction of physical geographical processes
Tumajer, Jan
Trees adjust wood anatomical structure to environmental conditions, predisposing time series of quantitative wood anatomical parameters to be valuable source of palaeoenvironmental information. In this doctoral project we analysed the response of vessel parameters of i) floodplain Quercus robur to groundwater level fluctuation, hydroclimate variability and extreme events (droughts and floods), and of ii) Betula pendula to mechanical damage caused by various disturbances. Although climatic signal as well as pointer years stored in tree-ring width chronologies of Quercus robur largely differ between sites, quantitative vessel parameters contain spatially- homogenous positive signal of previous year summer temperature and current year winter/early spring temperature. The only between-site difference in wood anatomical chronologies is negative effect of moisture on vessel size in floodplain, which does not occur in not-flooded lowland sites. We suggest that while tree productivity benefits from high water availability, the wood anatomical structure of Quercus robur is constrained by high soil water saturation in floodplain zone. In addition, the response of tree-ring widths to moisture availability is not uniform inside single stand, but subgroups of trees with completely opposite response coexist...
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