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The in vitro effects of selected isoflavonoids on isolated rat aorta
Novýsedláková, Alena ; Pourová, Jana (advisor) ; Vopršalová, Marie (referee)
Charles University in Prague Faculty of Pharmacy in Hradec Králové Department of Pharmacology and Toxicology Student: Alena Novýsedláková Supervisor: PharmDr. Jana Pourová, PhD. Title of Thesis: In vitro effects od selected isoflavonoids on isolated rat aorta Abstract: The aim of this study was to determine whether the selected isoflavonoids are able to vasodilate aorta, what structural features might be responsible for a relaxing activity and estimate the mechanism of action. The experiment we carried out the classical in vitro method on the isolated rat aorta, and the results evaluated by the computer program GraphPad. Only glycitin did not show statistically significant relaxation of blood vessels, which can be attributed to ineffective glycosidic form. Other izoflavonoids- glycitein, daidzein and tectorigenin seem to be promising in terms of potential vasodilatation. Further studies would be needed to verify also the in vivo effects. Likely structural features include the hydroxy group at 7-position and a methoxy group at position 8 of the core od isoflavonoids. The mechanism of action is not yet known, but most likely appears endothelium-dependent mechanisms, alpha 1 receptor antagonism and agonism of muscarinic M3 receptor. It may be also involved in the effect of the antioxidant and...
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Intra Aortic Balloon Counterpulsation from the Perspektive of Nurse in the Intensive Care Unit of Cardiac Surgery
Ebertová, Barbora ; Sojková, Monika (advisor) ; Kukol, Václav (referee)
The thesis is focused on the intra-aortic balloon counterpulsation (IABP) from the perspective of nurses in the cardiac intensive care. It consists of two parts. Theoretical and empirical. The theoretical part will deal with the intra-aortic balloon counterpulsation, including basic anatomy of the heart and blood vessels, the principle of IABC, its indications, contraindications, technology IABC and specific nursing care of patients with established IABC. The empirical part is treated as quantitative research, which is used for the data collection method anonymous questionnaire. The aim of the thesis is to determine nurses' knowledge of IABC in the cardiac intensive care and subsequent drafting of guidance for postoperative cardiac surgery department KARIM University, Prague. In this section are also included important questions and answers from the perspective of the specified variables obtained from the questionnaire and subsequent actions arising in practice. Key words Counterpulsation, Cardiac cycle, Aorta, Heart, Nursing care
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Analysis of possibilities of analytical approaches suitable for evaluating of stress-strain states of idealized aortic shapes
Turčanová, Michaela ; Burša, Jiří (referee) ; Novák, Kamil (advisor)
The bachelor's thesis deals with possibilities of analytical solution of stress-strain states of arteries. The first part of the thesis gives an information about cardiovascular system and continuum mechanics. The calculation was performed analytically and also numerically using ANSYS program. The analytical calculation was carried out considering non-linear theory of thin and thick-walled vessels involving the residual stress and fictitious temperature approach. Furthermore, the analysis of solutions of abdominal aortic aneurysms was done based on linear theory. Description of other methods of linear theory and techniques of calculating with residual stress are briefly summarized.
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Intra-Aortic Balloon Counterpulsation
Žbánková, Alena ; Tannenberg,, Milan (referee) ; Sekora, Jiří (advisor)
The thesis is concerned with intraaortic balloon counterpulsation, which serves as a supporting method for the operation of failing heart. In the teoretical part is described principle of this method, its effects and the basic indications and contraindications of using. In the practical part of this work is proposed method for detecting triggering points realized in graphical program LabVIEW. The program outputs are detected ends of T wave for balloon inflation and R wave for its deflation.
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Analysis of residual stresses in arterial wall
Novák, Kamil ; Fuis, Vladimír (referee) ; Burša, Jiří (advisor)
This thesis deals with computational modeling of the influence of residual stresses in idealized geometry of blood vessels and subsequent application of acquired knowledge to abdominal aortic aneurysm. In the terms of quality of the computational model, we reduced the uncertainties that are included in the computational model without considering the influence of residual stresses. The basic assumption of homogenization significant peaks of the stress between inner and outer vessel wall was met for each level of the computational model Methods that have been used are: deformation method (opening angle method), inverse mechanics of large deformations, fictitious temperature – for linear elastic material and hyperelastic material defined by the constitutive model. Numerical verification was carried out using program ANSYS.
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Influence of strain rate on stress-strain dependencies of aortic tissues
Slažanský, Martin ; Fuis, Vladimír (referee) ; Burša, Jiří (advisor)
The thesis deals with the influence of strain rate on stress-strain dependencies of aortic tissues to estimate the error of hyperelastic models, which are neglecting the viscoelastic effects that are typical for soft biological tissues. It was found by the experiment and the subsequent evaluation that in the range of the strain rate from 0,167 to 5,000 mm/s the influence of strain rate on stress-strain dependencies is negligible. The deviation by transition from experimental data to a constitutive model was significantly larger than the deviation between the data sets varying at different strain rates, which means that the use of stress-strain curves varying at different strain rates in given range of the strain rate has no effect on the resulting model. The best of analysis models that were examined in this thesis appears to be the Yeoh hyperelastic model using the FEM.
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Influence of the contrast medium iodine concentration on quality of the CT examination
RANŠOVÁ, Pavlína
Our work focused on determining absolute and relative density of various contrast agents in relation to iodine contents using in vitro and in vivo methods. It was documented that the relative density of contrast agents increases with the decreasing contents of iodine, i.e. density absolute values vary inversely as iodine content in these substances. Four various agents, bearing commercial names Visipaque 270, Visipaque 320, Ultravist 370 and Iomeron 400, in their original glass packing were used for our in vitro measurements. The measurements were carried out using CT equipment Emotion Duo (Siemens, Forchheim, Germany). Individual packing of the contrast agents were scanned by means of a standard protocol and under standard conditions. The obtained data were entered into tables. A retrospectively selected array of patients with standard scan of their stomachs was used for our in vivo measurements with a defined standard protocol using the same CT equipment and pressure injector CT 9000 Advantage (Liebel-Flarsheim, Mallinckrodt, the U.S.A.). The following data from 258 patients were recorded: age, sex, blood density after administering contrast agent in vitro on the level of diaphragm hiatus and on the bifurcation level, AP dimension of the patients on the hiatus level. Mean densities of the individual kinds of contrast agents were compared and a good correlation with the in vitro measurements was found out. The measured values were then analysed. The interdependence was studied in the measured densities and age, density changes measured on the hiatus level and on the bifurcation level for the individual contrast agents. The interdependence of the blood density on the AP dimension of the patients was also studied due to its practical use and it was documented that there is a good correlation of the decreasing density with the AP dimension as a simple parameter used instead of finding out patients{\crq} weights.
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Residual Strains of Arteries as Forensic Index
Adámek, T. ; Horný, L. ; Chlup, Hynek ; Žitný, R.
It has been known for long time that arteries are pre-strained in situ. These residual strains play crucial role in arterial load-bearing capacity. However, to the best of authors’ knowledge they have never been considered from forensics point of view. This paper concerns a possibility of employing the longitudinal pre-strain of human aortas as an indicator of human subject age. Lengths of abdominal aorta were measured within autopsies before and after segment resection. Longitudinal stretch ratio was calculated for 45 male and 12 female cadavers. It was found that both male and female data samples give approximately the same mean of the stretch ratio = 1.2. The correlation coefficients between the pre-strain and age were R=-0.7926, R=-0.8684 in male and female samples, respectively. Linear regression equation with confidence intervals was employed. The correlation between pre-strain and age seems to be suitable statistics to be used in forensic sciences.
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