National Repository of Grey Literature 35 records found  1 - 10nextend  jump to record: Search took 0.01 seconds. 
Regional flow and number of microembolisms in the common carotid artery at different levels of hemodynamics controlled by VA-ECMO.
Janák, David ; Kittnar, Otomar (advisor) ; Danzig, Vilém (referee) ; Bešík, Josef (referee)
Extracorporeal membrane oxygenation (ECMO) is a method that allows extracorporeal life support in potentially reversible life-threatening conditions affecting the heart or lungs which are refractory to conventional treatment. Depending on the parameters of its setting, this method affects the haemodynamics of the cardiovascular system and the perfusion of the target organ. From the point of view of its character, the necessity for invasive application, and the function thereof in the conditions of the cardiovascular system, ECMO is regarded as a risky method accompanied by a number of complications. Among the critical complications are thromboembolic complications affecting the central nervous system (CNS) and haemorrhagic complications. The goal of this paper is to present and verify the prerequisites for the formation of periprocedural embolisms affecting the CNS and to evaluate the regional haemodynamics of the CNS. This is done by analysing the presence of embolisms and by analysing the parameters of blood flow rates in the right common carotid artery (arteria carotis communis-ACC) and the corresponding oxygenation of the brain tissue during various flow rate parameters generated by the ECMO support on induced heart failure in a biological porcine model. In the first section of the paper, 8...
Electrical stability of the heart during hypothermia-induced potassium plasmatic level changes and after modulation of the autonomic nervous system by renal denervation.
Kudlička, Jaroslav ; Kittnar, Otomar (advisor) ; Nováková, Marie (referee) ; Danzig, Vilém (referee)
Malignant ventricular arrhythmias are a common cause of sudden cardiac death. Moderate therapeutic hypothermia (MTH) is routinely used in post-resuscitation care for anticipated neuroprotective effects. However, the safety of MTH in terms of the electrical stability of the heart has not been satisfactorily proved yet. Also, the increased sympathetic tone in patients with heart failure contributes to a higher incidence of malignant ventricular arrhythmias. The aim of this work was to verify the safety of MTH as regards the inducibility of ventricular fibrillation (VF) in the pig biomodel, especially in relation to spontaneous changes in the kalemia and QT interval. Furthermore, we assumed that renal denervation (RDN) could reduce the inducibility of VF. In the first part of the thesis, the extracorporeal cooling was introduced in fully anesthetized swine (n = 6) to provide MTH. Inducibility of VF was studied by programmed ventricular stimulation (8 basic stimuli with up to 4 extrastimuli) three times in each biomodel under the following conditions: during normothermia (NT), after reaching the core temperature 32 řC (HT) and after another 60 minutes of stable hypothermia (HT60). VF inducibility, effective ventricular refractory period (ERP), QTc interval, and potassium plasma level were measured. In...
Changes of the electric field of the heart in disorders of glucose metabolism and ways of influencing them by correction of impaired autonomic nervous regulation
Fialová, Elena ; Kittnar, Otomar (advisor) ; Danzig, Vilém (referee) ; Ošťádal, Petr (referee)
Diabetes mellitus (DM) is not just a simple metabolic disorder, however, it is considered to be a cardiovascular disease of a metabolic origin. This is apparent especially when speaking about type 2 diabetes (DM II). Patients with DM have a high occurrence of vegetative nervous system (VNS) disorders that manifest themselves as an increased activity of the sympathetic nervous system that correlates with peripheral autonomic neuropathy and is considered to be the major pathophysiological mechanism for the development of DM II. The objective of our study was to determine whether a comprehensive spa treatment (ST) may affect the level of the sympathetic tone of patients suffering from DM II. As an indicator of the sympathetic tone, selected electrocardiographic parameters derived from the HRV, microvolt T-wave alternans, and microvolt R-wave alternans were evaluated. The electrophysiological examination of patients was performed before and after a three-week spa treatment using the KARDiVAR system. The method is used to examine the current state of the autonomic nervous system and carry out an analysis of risk factors and adaptive capabilities of the organism. The results showed favorable changes in DM II patients after the ST, primarily in terms of reduced sympathetic adrenal system activity,...
Utilization of GRID technology in processing of medical information
Kulhánek, Tomáš ; Šárek, Milan (advisor) ; Kittnar, Otomar (referee) ; Anjum, Ashiq (referee)
This thesis focuses on selected areas of biomedical research in order to benefit from current computational infrastructures established in scientific community in european and global area. The theory of computation, parallelism and distributed computing, with focus on grid computing and cloud computing, is briefly introduced. Exchange of medical images was studied and a seamless integration of grid-based PACS system was established with the current distributed system in order to share DICOM medical images. Voice science was studied and access to real-time voice analysis application via remote desktop technology was introduced using customized protocol to transfer sound recording. This brings a possibility to access current legacy application remotely by voice specialists. The systems biology approach within domain of human physiology and pathophysiology was studied. Modeling methodology of human physiology was improved in order to build complex models based on acausal and object-oriented modeling techniques. Methods for conducting a parameter study (especially parameter estimation and parameter sweep) were introduced using grid computing and cloud computing technology. The identification of parameters gain substantial speedup by utilizing cloud computing deployment when performed on medium complex models of...
The stress response to cardiac catheterisation. The concentration of stress markers of the hypothalamic-pituitary-adrenal axis
Skarlandtová, Hana ; Kittnar, Otomar (advisor) ; Gregor, Pavel (referee) ; Svoboda, Miroslav (referee)
In our study, we analyzed four stress markers (cortisol, cortisone, DHEA and DHEAS) in blood serum in young sows using minimally invasive heart catheterisation as the stress factor. The marker levels were assessed in four defined periods of the experiment, beginning with the baseline level on the day before intervention (1), the second period was after the introduction of anaesthesia (2), the third was after conducting tissue stimulation or ablation (3), and the final period was after the end of the catheterisation (4). Cortisol and cortisone were detected using HPLC method, DHEA(S) by commercial kits. For statistical analyses non-parametric tests were used (due to non standard Gaussian data distribution). In our study we arranged these experiments: 1. Diurnal variability in these markers concentration during heart catheterisation was tested. 2. Are there differences between stress markers concentration the day before experiment (sampling 1) and in the day of the catheterisation (samplings 2, 3, 4)? 3. Are there differences between these markers concentration during operation (the first sampling was excluded)? 4. The cortisol/cortisone ratio was calculated. We found only minimal statistical differences in studied markers between the morning and afternoon group (p > 0.05) in experiment 1. For tested...
Reunified description of acid-base physiology and chemistry of blood plasma
Matoušek, Stanislav ; Kofránek, Jiří (advisor) ; Wooten, Wrenn (referee) ; Kittnar, Otomar (referee)
This thesis addresses an important problem of biomedical acid-base theory, where there are two apparently contradictory ways of describing the acid-base status of blood plasma, while the underlying physiology and chemistry obviously has to be only one. The two descriptions are called the traditional approach, based mainly on the work of Ole Siggaard-Andersen and the modern approach, based on the work of Peter Stewart and his followers. This work has three starting points. First are generally accepted basic concepts of acid-base chemistry and physiology. Second is an elegant formalism to the description of acid-base phenomena in complex solutions developed by Guenther. First part of this thesis builds on these two starting points, which serve as a basis for a detailed analysis augmented by the use of simple computer modelling. This results in formal description of several more advanced concepts, including the titration curves of proteins, behaviour of bicarbonate and protein buffers in single solution, relationship between strong ion charge and protein buffer charge and fuzzy division between strong ions and buffer ions in physiology. The modeling work then proceeds to comparing various models of albumin, principal protein buffer of blood plasma. Theoretical concepts of this work, such as pH-pKA...
Changes in motor function and seizure susceptibility after photothrombic ischemic stroke in immature rat
Brima, Tufikameni ; Otáhal, Jakub (advisor) ; Kittnar, Otomar (referee) ; Dylevský, Ivan (referee)
i | P a g e ABSTRACT Changes in motor function and seizure susceptibility after photothrombic ischemic stroke in immature rat Perinatal stroke is a common cerebrovascular disorder affecting one in every 4000 births, typically associated with sequelae that include motor and cognitive deficits and long term comorbidities including epilepsy. We sought to determine the effect of perinatal induced stroke on motor function and seizure susceptibility in rats. Photothrombotic model of stroke was used in rat at postnatal day 7. Firstly we induced ischemic lesions of different extends to assess the consequences of stroke on motor function, locomotion and its correlation to morphological changes after stroke. To this end, paradigms sensitive to sensorimotor changes were used; histological changes were also assessed. Secondly, with the use of pure cortical lesions, seizure susceptibility in PTZ elicited models of epileptic seizures was analysed. For seizure occurrence, latency and severity, two different concentrations of PTZ (60 and 100 mg/kg) were administered subcutaneously in two different age groups at P 12 and P 25. In addition, episodes of rhythmic EEG activity were registered at P 25 following successive 20- and 40-mg/kg doses of PTZ administered interperitonealy. Our data depicted two kinds of lesions with...
Optical Signals of Brain
Konopková, Renata ; Otáhal, Jakub (advisor) ; Kittnar, Otomar (referee) ; Valeš, Karel (referee)
Intrinsic optical signals are the signals reflecting changes in transmittance or reflectance of the light illumitating the tissue. Registration of such changes can be applied for the detection of physiological condition in the slices of biological tissues (in vitro) or in the whole animal (in vivo). The aim of this project is to introduce this topic and show different possibilities for the detection of changing optical properties of nervous tissue both in vitro and in vivo. The detection system of both light source and attachment of the optical fibre to the skull of the animal for in vivo experimets have been designed. The proper experimental part of the study have been done in hippocampal tissue slices and shows the correlation of the tissue activity and the optical signal at level of ion channels, glutamatergic synaptic activity, glial component of the signal and mitochondrial signal. We are dealing with the source of the noice that we record while detecting rather subtle changes of optical properties. We are indroducing the software VisionBrain for synchronous detection of both electrical and optical changes. Keywords: Intrinsic optical signals, hippocampus, imaging, biomechanics
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...
The role of intrarenal interaction in the renin-angiotensin system; nitric oxide and oxidative stress in the regulation of renal function and blood pressure in experimental models of hypertension
Kopkan, Libor ; Červenka, Luděk (advisor) ; Štípek, Stanislav (referee) ; Widimský, Jiří (referee) ; Kittnar, Otomar (referee)
The role of intrarenal interaction in the renin-angiotensin system; nitric oxide and oxidative stress in the regulation of renal function and blood pressure in experimental models of hypertension Powered by TCPDF (

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