National Repository of Grey Literature 15 records found  1 - 10next  jump to record: Search took 0.01 seconds. 
Microscopic Structure of Intestinal Anastomoses and the Use of Animal Models in Experimental Intestinal Surgery
Kural, Tomáš ; Tonar, Zbyněk (advisor) ; Kachlík, David (referee) ; Kocián, Petr (referee)
Despite extensive research and the implementation of modern surgical methods, the incidence of anastomotic leaks remains high. The exact pathophysiological mechanisms responsible for these leaks are still unknown, making prevention a challenge. The use of animal models is extensive in the research of intestinal anastomotic leakage. The literature review of this thesis, therefore, presents a brief history of the usage of experimental animals as well as major differences in terms of anatomy and histology between humans and the experimental mammals utilized in intestinal healing studies. The thesis is based on four studies describing the possibilities of using quantitative histological methods in different applications, animal models, and experimental surgical techniques in the research of intestinal anastomotic healing. The conclusions of these four studies can be summarized as follows: Conclusion 1: TeIGen software is readily accessible to scientists researching fibrous and porous materials using micro-CT analysis. This software aids in producing virtual image sets with defined morphometric attributes, and it can also help with fine-tuning of quantification tools required to examine micro-CT scans. The software also enables the identification of material morphological properties and image...
Histological Evaluation of Experimental Models of Liver Diseases
Malečková, Anna ; Tonar, Zbyněk (advisor) ; Kachlík, David (referee) ; Čížková, Dana (referee)
Animal models are widely used for research of liver diseases pathogenesis and progression and for development of new treatment strategies in hepatology. The dissertation thesis focuses on large animal model, specifically swine. The use of animals, which are anatomically and physiologically close to humans, allows us to bridge the gap between the experimental and human medicine. Histopathological analysis of the liver biopsies is still a fundamental part of liver disease diagnosis and therefore, it is also a part of the experimental design of the studies using the porcine liver. Our aim was to apply qualitative and quantitative histological methods of evaluation on porcine liver and to assess their usability in experimental medicine. The quantitative methods included automated image analysis as well as stereological methods, which guaranteed high reproducibility and comparability of the experimental results. The dissertation thesis is based on 10 manuscripts. Three of them are published reviews associated with the main topic of the thesis. Seven original manuscripts resulted from six experimental studies - their six conclusions are listed bellow: Conclusion 1: We developed an open-source software QuantAn for quantification of microvessels visualized by 3D imaging methods, such as computed tomography...
Histological Evaluation of Surgical Experiments in Animal Models
Grajciarová, Martina ; Tonar, Zbyněk (advisor) ; Petr, Jaroslav (referee) ; Varga, Ivan (referee)
Introduction: The dissertation is based on six studies that focus on the application of quantitative histology in animal model experiments. It includes a presentation of virtual microscopy procedures and image field sampling strategies, mapping changes in the microscopic structure of ovine and porcine carotid segments and their comparison with human coronary arteries and internal thoracic arteries, vascularization assessment in a mouse model of lymphoma xenografts (PDX), the effect of hyperbaric oxygen therapy on type III collagen production and on vascularization in a skin wound in a Zucker Diabetic Fatty rat. Methods: The review article about virtual microscopy was focused on an example of sampling images from various areas of quantitative histology. In other studies, histologically processed sections were stained with a variety of methods for vascular wall construction, cell infiltration (orcein, picrosirius red, Verhoeff's hematoxylin and green trichrome, Gill's hematoxylin, alcian blue) and immunohistochemical antigen detection (α-smooth muscle actin, neurofilament protein, CD-31, von Willebrand factor). Using unbiased sampling and stereological methods, we quantified the area fraction of components (elastin, collagen, smooth muscle actin and chondroitin sulfate) using a stereological grid...
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...
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...
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...
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...
Histological Quantification of MicrovesselsStereology of Vasa Vasorum and Brain Microvessels
Tomášek, Petr ; Tonar, Zbyněk (advisor) ; Skálová, Alena (referee) ; Kachlík, David (referee)
Considering the current knowledge on histology of microvessels suggested that quantification of the tissue microvessels itself should be accompanied by a description of the surrounding tissue components supplied by these microvessels. However, the microscopic anatomy of this tissue context can vary considerably on the scale of large-sized organs, such as the aorta of large mammals or the human brain. Given that the present knowledge on the variability of densities, spatial arrangement, and orientation of microvessels is usually limited to macroscopically small areas of these large organs, we consider mapping of the microvessels on a large macroscopic scale to be a matter of great importance. This became the unifying element of this thesis. The main findings based on six studies presented in the thesis were as follows: Finding #1: The density and the penetration depth of the vasa vasorum has a considerable segmental variability in the porcine aorta. The density of the vasa vasorum was greatest in thoracic aortic segments, as was the depth of penetration into the tunica media, which exceeded previously published findings. The vasa vasorum density declined with age, but the relative depth of their penetration did not. The individual segments of the porcine aorta were not interchangeable for being used...
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...

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