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The development of nuclear weapons and their proliferation: A comparison of Iran and North Korea
Marek, Martin ; Střítecký, Vít (advisor) ; Smetana, Michal (referee)
The development of nuclear weapons and their proliferation: A comparison of Iran and North Korea Master Thesis Author: Martin Marek Supervisor: PhDr. Vít Střítecký, M.Phil., Ph.D. Year: 2016 Abstract The text deals with nuclear proliferation in the cases of Iran and North Korea. The motives of nuclear ambitions are examined using models of Scott D. Sagan and other selected theoretical concepts. Gradual analysis of exposed states in the perspective of historical development, national security, domestic politics and norms forms the basis for understanding the perception of nuclear weapons by these states and approach to them as to a mean to accomplish certain objectives. Subsequent comparison reveals both similarities and difference between examined states in the perspective of motives of nuclear proliferation and shows explanatory potential of each model, which is various, in given cases. The effort of ensuring national security seems to be the strongest motive in both examined cases. It is followed by domestic influences, whereas norms stand rather for additional factor. Nevertheless, variety in explanatory power of the models is apparent in the cases of Iran and North Korea, notably in relation with their limitations. Other factors, such as regime type or parallel development of other type of weapons of...
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START Treaties: Really so Necessary? (1982/91-2010)
Dobeš, Vojtěch Sebastian ; Koura, Jan (advisor) ; Kovář, Martin (referee)
The presented bachelor thesis deals with the issues of American-Soviet (Russian) weapons reduction treaties START, i.e. since the early preparations of the first treaty to the ratification of the third treaty. The goal of this thesis is especially to analyze the texts of the treaties and show their impact on the nuclear arsenals of both countries. Besides the analysis of the treaties, author will also show the reflection and the impact of the treaties on the other countries and other non-proliferation processes. Keywords: START, weapons of mass reduction disarmament, disarmament treaties, analysis, Cold War, USA, USSR, Russian federation, nuclear weapons, proliferation
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Differentiation potential of polydendrocytes in pathological states of central nervous system
Pavlištová, Tereza ; Anděrová, Miroslava (advisor) ; Smejkalová, Terézia (referee)
NG2 cells also called polydendrocytes or oligodendrocyte progenitors comprise fourth type of glial cells in the brain. Ng2 glia express distinct markers on their cell surface, which can be used for their identification. Particularly, NG2 proteoglycan chondroitin sulphate and receptors for platelet-derived growth factor belong to the main markers. Polydendrocytes arise in two canals of spinal cord and also in the ventral part of frontal brain, telencephalon and diencephalon. Population of NG2 cells is heterogeneous because they differ morphologically, by their electrophysiological properties and distinct differentiation potential depending on localization in brain. In conditions in vitro, polydendrocytes can differentiate into oligodendrocytes, protoplasmic astrocytes or neurons. In early postnatal brain, NG2 glia give rise to astrocytes, but most of these cells remain in the mature state or change themselves to oligodendrocytes. Pathological states of the central nervous system cause an activation of polydendrocytes, they start to be hypertrophied and increase expression of NG2 proteoglycan. Reaction of these cells is influenced by environment and chemical factors, for example growth factors, morphogens and cytokines. Depending on the type of CNS disorder the differentiation potential of NG2 glia...
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Role of intestinal circadian clock in epithelial transport, proliferation, and tumourigenesis
Soták, Matúš ; Pácha, Jiří (advisor) ; Bendová, Zdeňka (referee) ; Herichová, Iveta (referee)
AABBSSTTRRAACCTT The molecular circadian clock enables anticipation of environmental changes. In mammals, clocks are ubiquitously present in almost all tissues and they are comprised of transcriptional-translational feedback loops of the so-called clock genes. The central clock represents the intrinsic pacemaker which is located in suprachiasmatic nuclei (SCN) of hypothalamus and synchronizes peripheral clocks. Clockwork system in alimentary tract and its regulatory link to intestinal functions are poorly understood. Therefore the objective of the thesis was to characterize molecular clock in particular parts of the rat intestine and to elucidate its link to the intestinal transport, regulation of cell cycle and neoplastic transformation in colonic tissue. We used quantitative RT-PCR (qPCR) to determine circadian profiles of mRNA expression of clock genes in the epithelium of duodenum, jejunum, ileum, and colon of rat. Furthermore, we analysed the expression of genes coding sodium chloride transporters and channels as well as cell cycle regulators in colon. To focus more precisely on different structures of intestinal epithelia we used laser capture microdissection. In addition, we performed Ussing chamber measurements to determine the colonic electrogenic transport. To study the contribution of circadian...
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The effect of endothelial cell proliferation on susceptibility to mitochondrially controlled apoptosis and oxidative stress.
Blecha, Jan ; Novák, Petr (advisor) ; Plecitá, Lydie (referee)
Mitochondria are multifunctional organelles playing a key role in energy metabolism and cell death induction. Mitochondria, and specifically their respiratory chain, are also the main producers of reactive oxygen species (ROS) in cells. Metabolism can be affected by the state of cellular proliferation and certain ROS-inducing agents have an antiangiogenic effect based on the preferential elimination of proliferating endothelial cells (EC). Therefore, in this work we investigated, whether mitochondria could be responsible for different sensitivity of proliferation and confluent EC to cell death. We mainly focused on systems that regulate ROS level and apoptosis: respiratory chain (ROS production), antioxidant defense (ROS detoxification) and Bcl-2 family of proteins (apoptosis regulation). First, we treated EC with functional and nonfunctional respiratory chain with various oxidative stress- and apoptosis-inducing agents and determined ROS production and susceptibility to apoptosis in proliferating and confluent cells. Our results show that functional respiratory chain greatly increases the susceptibility of proliferating cells to ROS induction and apoptosis, whereas in qiescent cells it protects against cell death. Given these findings, we assessed the activity of respiratory chain in proliferating...
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Mechanisms of growth of the cardiac conduction system
Skuhrová, Kristýna ; Sedmera, David (advisor) ; Elsnicová, Barbara (referee)
The ability to produce regular rhythm and independence of nervous system and are some of the features of the cardiac conduction system. The conduction system comprises the sinoatrial node, internodal tracts, the atrioventricular node, the atrioventricular (His) bundle, its right and left branches, and the terminal network of Purkinje fibers. However, this system is frequently the cause of the cardiac rhythm disorders, i.e., arrhythmias. There are many unanswered questions about the conduction system, even though its development is closely connected to the growth of the whole heart. The heart undergoes many dramatic changes during its development, such as modification of linear heart tube into the mature four-chamber organ. Looping and forming chambers cause change of localization first "pacemaker" from the caudal end of the heart tube to the area of the right atrium. Prenatal growth of the heart is based upon cell proliferation or hyperplasia. The cell divisions are rapidly stopped soon after birth and the cells start to grow by increase in volume, i.e., hypertrophy. The cells of some species can expand hyperplasia or hypertrophy in early postnatal period. The mouse is one of the organisms with the cell expansion provided by combination of proliferation and hypertrophy. Most of the adult...
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Role of prion proteins at differentiating cells
Kučerová, Johanka ; Holada, Karel (advisor) ; Drbal, Karel (referee)
Cellular prion protein (PrPC) is well known for its pathological isoform PrPSc, widely believed to be the infectious agent of the prion diseases, which include Bovine spongiform encephalopathy (BSE), scrapie and Creutzfeldt-Jakob disease. The physiological role of PrPC is poorly understood, but its involvement in the regulation of apoptosis, adhesion molecules, antioxidant, or signal molecules, has been described. Despite of these findings, it hasn't been proven, that the protein is necessary for normal development of mice. However, the protein was shown to be essential for regeneration of hematopoietic stem cells after exposure to lethal stress conditions. Expression of PrPC may have an effect on the proliferation and differentiation of cells by helping them keep the proliferative activity, or slow spontaneous differentiation. The quantity of the protein correlates positively or negatively with expression of transcription factors such as Oct4/Nestin, which are essential for development in embryogenesis. Its expression also regulates transition of cells from G1 phase to S phase of the cell cycle. This bachelor thesis is focused on published results describing the influence of PrPC on cellular proliferation and differentiation.
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Nervous tissue regeneration following ischemic injury in adulthood - the role of glial cells
Kamenická, Monika ; Anděrová, Miroslava (advisor) ; Kletečková, Lenka (referee)
Ischemic stroke (ischemia) is one of the most common causes of death in the world. The consequences of this disease are enormous and markedly affect the lives of patients who often are unable to live a full quality of life as before. Therefore, the current research is focused on elucidating new mechanisms that could mitigate the effects of ischemia and better regeneration of nerve tissue. This theses aims to summarize the current knowledge about neurogenesis/gliogenesis in the nerve tissue under physiological conditions, after ischemic injury and subsequent regeneration. The first chapter is focused on neurogenesis in the nervous tissue of adults. The two main neurogenic regions are described, such as subventricular zone and the gyrus dentatus in hippocampus. The following is a brief description of cells that are located in neurogenic regions and their function under physiological conditions. The second chapter focuses on gliogenesis in adult nervous tissue and describes the glial cells responsible for numerous functions in CNS. Furthermore, the functions of individual types of glial cells are listed. The third chapter gives the overview about pathophysiology of ischemia. The author tries to explain what is happening in the brain tissue during and following ischemia, what types of ischemia are...
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The functional in vitro analysis of the BRCA1alternative splicing variants
Ševčík, Jan ; Kleibl, Zdeněk (advisor) ; Stopka, Tomáš (referee) ; Macůrek, Libor (referee)
BACKGROUND: The inactivation of the tumor suppressor gene BRCA1 is a predisposing factor for a breast/ovarian cancer development. Formation of cancer-specific alternative splicing variants with aberrant biological properties can represent additional mechanism decreasing the overall BRCA1 activity in DNA double strand break (DDSB) repair. In this study, we analyzed BRCA1 alternative splicing variants BRCA114-15 and 17-19 ascertained previously during the screening of high-risk breast cancer individuals. METHODS: We established a stable MCF-7 cell line-based model system for an in vitro analysis of BRCA1 variants. Using this system, we analyzed the impact of BRCA114-15 and 17-19 variants on DNA repair kinetics using comet assay and confocal immunomicroscopy. The capacity of DNA repair was assessed directly by an in vitro NHEJ assay and indirectly by a mitomycin C sensitivity test. The proliferation activities were determined by a clonogenic assay and growth curves. RESULTS: Overexpression of BRCA114-15 and 17-19 increases the endogenous level of DNA damage, slows down the DDSB repair, and decelerates the initial phase of radiation-induced foci formation and prolongs their persistence. Moreover, BRCA114-15 and 17-19 differentially influence the activity of HR and NHEJ and sensitivity of MCF-7 cells to ionizing...
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The role of estrogen receptors in prognosis and therapy outcome of breast cancer
Kloudová, Alžběta ; Souček, Pavel (advisor) ; Dračínská, Helena (referee)
Estrogen receptors (ER) are members of nuclear receptor family, which mediate distinct physiological functions after binding a steroid ligand. Apart from that they play a role in many diseases including breast cancer. ER is among proteins routinely evaluated in clinical practice and on the basis of ER expression, patients are treated by endocrine therapy. There are different opinions of the role of ER in cancer cells, but in the future, detection of ER and treatment by ER- and ER-selective ligands could contribute to improvement of cancer therapy. Isoforms, mutations and posttranslational modifications of ER present other important factors, which can influence estrogen signalization and endocrine therapy efficiency and deciphering of their importance for cancer cells could bring better understanding of ER signalization and improvement of the therapy.
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