National Repository of Grey Literature 10 records found  Search took 0.00 seconds. 
The use of comet assay for measurement of DNA integrity in clinical and applied research
Bagryantseva, Yana ; Novotná, Božena (advisor) ; Rubeš, Jiří (referee) ; Štětina, Rudolf (referee)
Single cell gel electrophoresis or comet assay combined with enzymes of excision repair is a method for measuring DNA strand breaks and oxidative damage. Using this approach we analysed ineffective hematopoiesis in patients with low-risk MDS. Refractory anemia (RA) exhibited a higher DNA instability in bone marrow cells when compared to controls and the extent of DNA fragmentation correlated with cytopenia. No similar relationship was observed in RA with ring sideroblasts (RARS), although the levels of DNA breaks markedly exceeded even the values detected in RA. Both groups of patients also showed high levels of oxidative damage to DNA. However, there was no clear relationship to the levels of serum ferritin, cytopenia or associated inflammation. This suggested that the oxidative DNA damage per se is not responsible for extensive apoptosis in low-risk MDS. In any case, it undoubtedly contributes to genome instability and disease progression. The second part of thesis was aimed to the impact of air pollution and genetic polymorphisms on oxidative damage to DNA, lipids and proteins of city bus drivers and garagemen. Both groups exhibited a higher level of DNA breaks and oxidative damage to proteins than the controls, while an increased level of lipid peroxidation was detected only in bus drivers. The...
Bioindikátory zánětu, oxidačního a nitračního stresu u potkana kmene Wistar po celotělovém a lokálním ozáření plic
Nagy, Andrea ; Chládek, Jaroslav (advisor) ; Hofer, Michal (referee) ; Štětina, Rudolf (referee)
6 3 SUMMARY Bioindicators of inflammation, oxidative and nitrossative stress in Wistar rats after whole-body and lung irradiation Introduction Radiation pneumonitis and fibrosis limitthe intensity of radiotherapy,increase morbidity and worsen quality of life of patients with lung and breast cancer or Hodgkin's disease. Radiation pneumonitis is an acute inflammatory reaction that resolves either spontaneously or after treatment with corticosteroids. Free radicals play an important role in its etiology. They cause dose-dependent induction of lipoperoxidation, DNA damage, activation of proapoptotic events and changes in activity of enzymes. The inflammatory reaction initiated by free radicals affects primarily epithelial and inflammatory cells, which release a number of cytokines (TNF-α, IL-1, IL-6, TGF-β, etc.). Radiation fibrosis of lungdevelops as a late consequence of radiotherapy (> 3 months). It can lead to chronic respiratory failureand death. Macroscopic findingsincludefibroblastproliferation,collagen deposition and destruction of lung parenchyma. Aims and methodology This work was focused on the changes in the arginine-nitric oxide metabolic pathway induced in the airways, lung and other parts of the body by ionizing gamma radiation in the early phase (within 72 h) as well as in the phase of radiation...
Possibilities of flow cytometry in analysis of cellular response to genotoxic stress
Havelek, Radim ; Řezáčová, Martina (advisor) ; Bílková, Zuzana (referee) ; Štětina, Rudolf (referee)
Possibilities of flow cytometry in analysis of cellular response to genotoxic stress Flow cytometry is a modern tool for interrogating the immunophenotype and functional characteristics of cells. It is a technique of quantitative single cell analysis that works by sensing optical properties of cells in a flow stream with laser beam. Analysis and differentiation of the cells is based on size, granularity, and whether the cell is carrying fluorescent molecules in the form of either conjugated antibodies or dyes. The cells may be stained with fluorescent dyes, incubated with fluorogenic substrate or labelled with fluorochrome-linked antibodies specific for molecules either on the surface or in the intracellular components of the cell. Flow cytometers are multiparameter, recording several measurements on each cell. Therefore, it is possible to identify a homogeneous subpopulation within a heterogeneous population of cells. When cells are exposed to genotoxic agent, they respond quantitatively and qualitatively according to the absorbed dose and the cell type. To cope with the resulting damage to cellular DNA, the temporary cell-cycle checkpoints and DNA damage response mechanisms are activated to allow more time for effective repair. However, if these mechanisms fail or the damage is irreparable, then...
Chromosomal damage and DNA repair capacity in blood lymphocytes as transient markers in carcinogenesis.
Kroupa, Michal ; Vodička, Pavel (advisor) ; Štětina, Rudolf (referee)
Recent knowledge suggests that the onset of cancer is modulated by the interplay of internal and external environmental factors along with numerous gene variants. Structural chromsomal aberrations in peripheral blood lymphocytes are considered as biomarkers of effect of genotoxic carcinogens and reflect elevated risk of cancer. Incomplete or deficient repair of double-strand breaks in DNA underlie chromosomal aberrations and the measurement of cytogenetic alterations may reflect interindividual differences in the response towards the mutagen. In this study the expected deficiences in the DNA repair capacity have been determined in incident oncological patients with breast, colorectal and urogenital cancers. The determination of chromosomal aberrations have been supplemented by the measurement of variants in genes involved in double-strand breaks repair (XRCC3, rs861539; RAD54L, rs1048771). Methodologically, we employed conventional cytogenetic analysis, cytogenetic analysis following the induction of chromocomal damage by bleomycin ("Challenge assay"), TaqMan discrimination analysis for the detection of allelic variants and statistical analyses. By using these methods we did not observe statistically signifiant differences either in chromosomal breaks (p=0,354) or in a percentage of cells with...
Possibilities of flow cytometry in analysis of cellular response to genotoxic stress
Havelek, Radim ; Řezáčová, Martina (advisor) ; Bílková, Zuzana (referee) ; Štětina, Rudolf (referee)
Possibilities of flow cytometry in analysis of cellular response to genotoxic stress Flow cytometry is a modern tool for interrogating the immunophenotype and functional characteristics of cells. It is a technique of quantitative single cell analysis that works by sensing optical properties of cells in a flow stream with laser beam. Analysis and differentiation of the cells is based on size, granularity, and whether the cell is carrying fluorescent molecules in the form of either conjugated antibodies or dyes. The cells may be stained with fluorescent dyes, incubated with fluorogenic substrate or labelled with fluorochrome-linked antibodies specific for molecules either on the surface or in the intracellular components of the cell. Flow cytometers are multiparameter, recording several measurements on each cell. Therefore, it is possible to identify a homogeneous subpopulation within a heterogeneous population of cells. When cells are exposed to genotoxic agent, they respond quantitatively and qualitatively according to the absorbed dose and the cell type. To cope with the resulting damage to cellular DNA, the temporary cell-cycle checkpoints and DNA damage response mechanisms are activated to allow more time for effective repair. However, if these mechanisms fail or the damage is irreparable, then...
The Study of Receptor-specific Radiopharmaceuticals Interactions with Biological Systems at the Cellular Level
Bárta, Pavel ; Lázníček, Milan (advisor) ; Nachtigal, Petr (referee) ; Štětina, Rudolf (referee)
Charles University in Prague, Faculty of Pharmacy in Hradec Králové Department of Pharmacology and Toxicology Candidate Mgr. Pavel Bárta Supervisor Prof. PharmDr. Ing Milan Lázníček, CSc. Title of Doctoral Thesis The study of receptor-specific radiopharmaceuticals interactions with biological systems at the cellular level The targeting of receptor specific peptides or antibodies is one important diagnostic and therapeutic tool in the fight against cancer diseases. Receptor specific peptides often have their origin from the human natural peptide hormones; hence they are commonly marked as peptide analogues. The peptide analogues contain in their amino acids sequence the binding site identical with the site of natural peptides, which they are originated from. This binding site is responsible for the interaction with the targeted receptor. The peptide analogues are employed instead of the natural peptides because their biological properties can be improved, for example facilitating distribution in the organism to their place of action, or protection from biological degradation. The peptide ligand binding itself on targeted receptors and its internalization into cells typically does not trigger a therapeutic effect. From this reason, peptide analogues carry active substances like cytotoxine or...

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