National Repository of Grey Literature 55 records found  previous11 - 20nextend  jump to record: Search took 0.01 seconds. 
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
The contribution of myocardial contrast echocardiography in patients with coronary heart disease
Toušek, Petr ; Gregor, Pavel (advisor) ; Chaloupka, Václav (referee) ; Hradec, Jaromír (referee) ; Kittnar, Otomar (referee)
Contrast echocardiography is a new myocardial echocardiographic method that extends the capabilities of conventional echocardiography. In our first two works, we focused on determining the size of infarction in patients after AMI and compared this method with today's most commonly used diagnostic methods. We found good agreement between KEM and SPECT in the evaluation of infarction size and correlation between the extent of oscillations Q on ECG and impaired microvascular perfusion of the myocardium - or the size of infarction. In patients with chronic forms of CHD, we found that the KEM can fairly well predict the kinetics porevaskularizační improvement segments with severely impaired kinetics and in this clinical situation is comparable with Contrast-magnetic resonance imaging. In addition, low variability and low number of investigative areas nehodnotitelných infarction KEM show that it is a simple, easily reproducible and teachable method. Finally, the relatively low cost and wide availability KEM indicate great potential usefulness of this method in clinical practice.
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...
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...
Hemodynamic adaptation mechanisms of heart failure to percutaneous venoarterial extracorporeal circulatory support
Hála, Pavel ; Kittnar, Otomar (advisor) ; Szárszoi, Ondrej (referee) ; Havránek, Štěpán (referee)
Introduction: Venoarterial extracorporeal membrane oxygenation (VA ECMO) is widely used in the treatment of circulatory failure, but repeatedly, its negative effects on the left ventricle (LV) have been observed. The purpose of this study is to assess the influence of ex- tracorporeal blood flow (EBF) on systemic hemodynamic changes and LV performance parameters during VA ECMO therapy of decompensated heart failure. Methods: Porcine models of low-output chronic and acute heart failure were developed by long-term fast cardiac pacing and coronary hypoxemia, respectively. Profound signs of circulatory decompensation were defined by reduced cardiac output and tissue hypoperfusion. Sub- sequently, under total anesthesia and artificial ventilation, VA ECMO was introduced. LV performance and organ specific parameters were recorded at different levels of EBF using an LV pressure-volume loop analysis, arterial flow probes on carotid and subclavian arteries, and transcutaneous probes positioned to measure cerebral and forelimb regional tissue oxygen saturations. Results: Conditions of severely decompensated heart failure led to systemic hypotension, low tissue and mixed venous oxygen saturations, and increase in LV end-diastolic pressure. By increasing the EBF from minimal flow to 5 L/min, we observed a...
Using of non-invasive cardiac imaging for precise evaluation of atrium size and prediction of atrial wall fibrosis in patients with atrial fibrillation
Fingrová, Zdeňka ; Havránek, Štěpán (advisor) ; Kittnar, Otomar (referee) ; Skála, Tomáš (referee)
Atrial fibrillation is the most prevalent arrhythmia worldwide and remains one of the major causes of morbidity and mortality. Atrial fibrillation is an arrhythmia that has a various etiology and takes number of clinical forms. Due to the heterogenity of atrial fibrillation, it is necessary to individualize the optimal treatment strategy, ie conservative pharmacological therapy or interventional therapy as catheter ablation. Inncorrect indication of catheter ablation of atrial fibrillation leads to low success rate of the procedure and increases the risk of the procedure. The success rate of catheter ablation of atrial fibrillation depends on many clinical parameters, including the size and volume of the left atrium and the presence of pathological tissue in the atrial myocardium. In everyday practice, echocardiography (2D-echocardiography) is the most dominant method in estimation of the left atrial parameters, for it's simplicity, non- invasiveness, financial costs and the absence of ionizing radiation. Different methods for assesment of left atrial parameters are cardiac CT, cardiac magnetic resonance imaging and methods of 3-D echocardiography or 3-D angiography. The results of the present studies show that in patients with non-valvular atrial fibrillation who are indicated for catheter...
Biomechanical model of interaction between ventilation and hemodynamics induced by mechanical ventilation
Otáhal, Michal ; Kittnar, Otomar (advisor) ; Maršík, František (referee) ; Dostál, Pavel (referee)
MUDr. Michal Otáhal Biomechanický model interakce oběhu a ventilace za podmínek UPV Abstract: Conventional mechanical ventilation provides gas exchange in conditions of respiratory failure by application positive airway pressure in the respiratory system. Due to the significant change in pressure conditions inside the thorax during conventional artificial ventilation the circulation can be significantly affected. Recruitment maneuver (RM) techniques can be a part of ventilation strategy in patients with the Acute Respiratory Distress Syndrome (ARDS), that are used to re-aerate collapsed parts of the lung parenchyma. During these RMs a significantly higher airway pressure is used than in protective ventilation strategy, which can limit the flow through the lung capillary network and can significantly affect the systemic hemodynamics of the patient. The aim of this work was to develop an optimized animation model of ARDS, then to compare the influence that has the application of different types of recruitment maneuvers on hemodynamics and to create a biomechanical simulation model of interaction and blood circulation and its verification with data obtained during the implementation of different types of RM in the experimental animal ARDS model. Results from the experimental animal model and simulations...

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