National Repository of Grey Literature 6 records found  Search took 0.01 seconds. 
Morphological changes of cardiopulmonary vascular bed under experimental conditions
Novotný, Tomáš ; Vajner, Luděk (advisor) ; Mazurová, Yvona (referee) ; Tonar, Zbyněk (referee)
In rats, the environment with low content of oxygen induces the development of hypoxic pulmonary hypertension based also on remodeling of pulmonary resistance arteries. This process is particularly triggered by the mast cell degranulation products, especially rodent-like interstitial collagenase (matrix metalloproteinase 13). Sodium cromoglycate administration leads to an effective stabilization of the mast cell granules and thus to the modified remodeling process. During 4-day and 21-day hypoxia, we treated Wistar Han rats with sodium cromoglycate in case control study. We assessed pulmonary vascular remodeling morphology using conventional histological techniques and immunohistochemistry. Then we assessed counts of pulmonary mast cells, both total and MMP-13 positive ones, around pulmonary arteries. Hypoxia induced remodeling of all categories of pulmonary arteries. Sodium cromoglycate treatment in first four days of hypoxia modified and reduced these changes. Treatment in last four days of 21-days hypoxia experiment has only negligible effect. Hypoxia led to changes in collagen VI amount and distribution as well as decrease in number of toluidine blue detectable mast cell as well as MMP13 positive mast cells in the wall of pulmonary arteries. Hypoxia led to significant remodeling of all...
Microscopic structura and mechanical properties of aorta and pulmonary artery
Kubíková, Tereza ; Tonar, Zbyněk (advisor) ; Kučera, Tomáš (referee) ; Horný, Lukáš (referee)
Introduction: This dissertation thesis consists of seven studies, the common aim of which was to describe the functional histology of the aorta and some of its branches, as well as the pulmonary artery. The thesis focuses on analysis of the microscopic composition of various segments of the porcine aorta during ontogenesis as an experimental model, as well as cryopreserved samples of human aorta, pulmonary artery and their valves. Further it assesses damage to the renal artery during its denervation, and evaluates cell colonization of synthetic vascular substitutes after their implantation into the abdominal aortas of mice. The introduction gives an overview of the structure of the aorta and pulmonary artery and their valves, selected diseases affecting large vessels, and histological and biomechanical methods used for their characterization. Methods: We used the paraffin section method with basic and advanced stains, immunohistochemical detection of antigens (α-smooth muscular actin, desmin, vimentin, chondroitin sulfate, von Willebrand factor, neurofilament protein, tyrosine hydroxylase) and biomechanical tests (uniaxial tensile tests) for determination of ultimate strain, ultimate stress and Young's modulus of elasticity. We used stereological methods based on the interaction of test grids of...
Alternative autologous vascular grafts in cardiovascular surgery
Loskot, Petr ; Tonar, Zbyněk (advisor) ; Stingl, Josef (referee) ; Šebesta, Pavel (referee)
Introduction: Cardiovascular surgery is a relatively young but progressively evolving field in medicine. More specifically, in the past decades, cardiac surgery achieved significant advances in understanding the causes, progression and treatments of ischemic heart disease (IHD). The IHD is the most common coronary disease, and it ranks first in morbidity and mortality in the developed world. It justifies the need for significant fundamental research as well as its study in clinical practice. It now includes specialized cardiovascular centres with the complex specialized treatments. A group of interventional cardiologists capable of performing routine examinations of the coronary veins using selective angiography has been established. They can eventually also perform percutaneous coronary interventions with direct stent implants. Thus the advances have been made in comprehensive indication of the patients towards their optimal treatments under the regime of a cardio-team. Such team comprises of a cardio-surgeon, interventional cardiologist, echocardiography specialist and the attending physician who is usually the cardiologist. The IHD treatments involve preventive cardiology with the regime measures and checks, pharmacotherapy, interventional cardiology and cardiac surgery to spa treatment and...
Prognostic and predictive biomarkers of glial tumors of the central nervous system in the context of personalized medicine
Polívka, Jiří ; Tonar, Zbyněk (advisor) ; Holubec, Luboš (referee) ; Ehler, Edvard (referee)
The glial tumors, so called gliomas, represent the largest group of the primary central nervous system malignancies. Gliomas remain generally an incurable disease progressing from the lower grades of malignancy to the more aggressive tumors in the course of time. This finally leads to the rapid patient's clinical deterioration and eventually the death. Recently there has been a significant expansion of knowledge in the neuro-oncology domain regarding the onset and development of neoplastic disease at the genetic as well as epigenetic level. Novel prognostic and predictive molecular genetic biomarkers are emerging that can be used for more precise diagnosis, for more accurate assessment of a patients' prognosis, or for better selection of therapy and prediction of therapeutic response. The fundamental view of the histological- based classification of central nervous system tumors is gradually changing and the molecular biomarkers are incorporating in addition to histopathology to refine the diagnoses of many tumor entities at the moment. The recent findings from molecular genetics of gliomas together with the results from clinical trials incorporating the various biomarkers are discussed in this thesis. In the first study the biomarker isocitrate dehydrogenases 1 (IDH1) R132H mutation was examined...
Nanofibrous vascular grafts
Horáková, Jana ; Lonský, Vladimír (referee) ; Tonar, Zbyněk (referee)
There is a pressing need to develop vascular graft since no clinically available appropriate prosthesis with inner diameter less than 6 mm works in a long term after implantation. In the thesis, blood vessel substitutes made from biodegradable polymers were created and characterized as potential candidates for such a medical device. The idea of tissue engineering scaffolds is based on mimicking natural environment - extracellular matrix therefore ideal bypass graft was designed as double layered structure with defined morphology of each layer. The proposed structure was created by electrospinning of polycaprolactone (PCL). The morphology of the resulting fibers resembled inner and medial layer of native arteries suggesting that this similarity will help body to regenerate functional tissue after implantation. Besides PCL, novel polymer from the same group of polyester - copolymer polylactide-polycaprolactone (PLC 70/30) was electrospun into a tubular form. Vascular graft made from copolymer PLC created only single layered prosthesis. Further tests were conducted with both presented electrospun materials in order to compare their bulk and surface properties. Copolymer PLC was slightly more hydrophilic than polycaprolactone. Thermal behavior revealed that copolymer is mostly amorphous with melting...
Quantification in descriptive and experimental study of functional
Tonar, Zbyněk ; Kočová, Jitka (advisor) ; Hach, Petr (referee) ; Míšek, Ivan (referee) ; Křen, Jiří (referee)
Dissertation abstract The dissertation thesis consists of seventeen papers dealing with quantitative histological assessment of vascular wall and with application of morphometry in atherosclerosis research as well as in biomechanics of elastic arteries. History of microscopic morphometry with an emphasis on stereology is reviewed in the Introduction. The principles of mathematical morphology and of stereological estimation of volume, surface, area, length, and numerical density of objects in tissue blocks are explained in the Methods. The key rules of unbiased sampling of histological series and designing morphometric studies are summarized. The distribution of the overall observed variance in biological experiments, its sources and management are discussed. Procedures necessary for three-dimensional reconstructions based on scanned histological series are described. We proved that inflammatory process was significant in patients with ruptured aneurysm of abdominal aorta (AAA). There were more pronounced inflammatory infiltrates in areas of neovascularization in ruptured AAA than in asymptomatic AAA patients. Histological findings were in agreement with higher cytosol cytokine levels (IL-6, IL-8, TNF-α), enhanced collagen III metabolism and degradation in ruptured AAA. We found lower volume fraction of the...

See also: similar author names
1 Tonar, Z.
Interested in being notified about new results for this query?
Subscribe to the RSS feed.