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Selective screening of antiparasitic substances
Wernerová, Klára ; Mach, Jan (advisor) ; Kovářová, Julie (referee)
The mitochondrion is the key organelle of the cell. It is involved in energy metabolism, the Krebs cycle, the respiratory chain, and the formation of Fe-S clusters, which form the structure of many proteins. Therefore, disruption of the mitochondria is usually fatal to the cell, especially if it contains only one mitochondrion, as is the case in Trypanosoma brucei brucei. The T. b. brucei parasite has become the primary model organism for our study because its basic biochemical processes are already well described, including mitochondrial metabolism, and it is also easy to cultivate in the laboratory. Other model organisms we used in this study were Leishmania mexicana, Cryptococcus neoformans and Candida albicans. All these organisms are causative agents of serious diseases, and although there are drugs against them, new drugs need to be developed due to the frequent emergence of resistances. Mitochondria-targeting drugs are promising for the pharmaceutical industry. In this work, we investigate the efficacy of compounds whose structure is composed of a mitochondrial phosphonium anchor linked to a carbon chain. These substances are capable of incorporation into the mitochondrial membranes. The work not only focuses on comparing the potency of the tested substances in selected model organisms, but...
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Iron metabolism of parasitic amoeba Acanthamoeba castellanii
Krejbichová, Lucie ; Mach, Jan (advisor) ; Horáková, Eva (referee)
Acanthamoeba castellanii, an opportunistic parasitic amoeba, rarely causes infection in humans. Yet, the treatment and diagnosis is often complicated. It causes two diseases: granulomatous encephalitis and acanthamoeba keratitis (inflammation of the cornea of the eye). There is a modern way to deal with parasitic protists and other infectious diseases - interference with iron metabolism. Iron is a crucial element for living organisms; it is involved in many metabolic processes. However, it is also toxic for the organisms and therefore, its uptake, storage and homeostasis in the cell is a strictly controlled process. Ferric reductase takes part in iron homeostasis inside the acanthamoeba cell. Fluorescent microscopy has shown that ferric reductase is located in the vacuole membranes and its activity increases when iron availability decreases. This protein probably mediates the reduction of iron ions that are used in other cellular processes, especially for the transport of iron across membranes. Interestingly, the reduced availability of iron doesn't affect the mitochondrial Fe-S cluster pathway as we proved by fluorescent microscopy with an antibody against one of the proteins of this pathway (IscU). Iron deficiency doesn't affect respiration but alternative oxidase activity is reduced. Moreover, deprived...
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Advances in treatment of human trypanosomiasis
Novotná, Kristýna Klára ; Mach, Jan (advisor) ; Grekov, Igor (referee)
Sleeping sickness is a human disease found in sub-saharan Africa, and is caused by a parasitic protozoan Trypanosoma brucei. Trypanosoma brucei species infects various mammals, however, only Trypanosoma brucei gambiense and Trypanosoma brucei rhodesiense subspecies are resistant to trypanolytic factors found in human blood serum. This work briefly summarizes known operating mechanisms of trypanolytic factors and resistance mechanisms of trypanosomes to these factors. The work covers mainly description and summarization of current diagnostic methods of sleeping sickness and used trypanocidal drugs. Majority of introduced methods shows high levels of sensitivity and specificity, however, for poor, disease affected areas they are often way too expensive. Prescribed drugs are expensive as well, and what's more, they are often ineffective against both subspecies and have severe side effects. Last part of the work is dedicated to potential development of new medicaments.
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Naegleria: from free-living protist to brain eating deadly pathogen
Matějková, Magdalena ; Mach, Jan (advisor) ; Marková, Lenka (referee)
N. fowleri is mostly a free-living amoeboflagellate which, in favorable conditions, can occasionally adopt a parasitic lifestyle. In such cases, the amoeba becomes causative agent of primary amoebic meningoencephalitis, a severe and largely fatal disease occurring in several mammals including humans. The treatment of this disease is complicated by many unwanted side-effects of available drugs and a lack of prompt diagnostic methods. Within the Naegleria genus, N. fowleri is the only human pathogen. According to up-to-date knowledge, the pathogenicity of this species is due to its metabolic properties as well as to a particular set of proteins expressed by this protist. Besides a wide scale of enzymes, some of these proteins participate in the formation of cellular structures which are crucial for the pathogenesis. All these particularities should be targeted in a search for a better treatment. The thesis is focusing on a comparison of N. fowleri with related species N. gruberi and N. lovaniensis, stressing out the differences of N. fowleri from these non-pathogenic species. Key words: Naegleria fowleri, primary amoebic meningoencephalitis, immune response, pathogenesis, facultative parasitism
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Current options of treatment for parasitic kinetoplastids
Čadková, Aneta ; Mach, Jan (advisor) ; Richterová, Lenka (referee)
Chagas disease, sleeping sickness and leishmaniasis are diseases occurring mainly in developing areas of Africa, America and Asia. They are caused by parasitic kinetoplastids from the genus Trypanosoma and Leishmania. These protozoans undergo morphologic transformations during their development leading to changes of their properties. They are characterized by complex mechanisms that allow them to evade the host's immunity. At the same time, because of these mechanisms and selection pressures, they are able to subsequently develop resistance to used drugs. The diseases caused by protozoa are classified as "neglected tropical diseases". The research and development of drugs against them is heavily underfunded. Currently used drugs are expensive, have a number of side effects, and due to lack of usage regulation develop resistance. The work first generally presents human parasites of the class Kinetoplastida. It further describes the treatment of diseases caused by the characterized species and focuses on a summary of currently used drugs, their mechanism, resistance and potential new drugs in clinical phases. Key words: kinetoplastids, Trypanosoma, Leishmania, treatment, disease, mechanism of action, resistance, nitroreductase
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Legal regulation of weapons and ammunition in the Czech Republic and implementation of EU regulations
Mach, Jan ; Staša, Josef (advisor) ; Prášková, Helena (referee)
in English The introduction of this thesis explains the basic concepts of the legislative regulation of weapons and ammunition in the Czech Republic and their use in specific cases. This part also briefly presents the legal history of selected institutes of weapons legislation in the Czech Republic with EU law, in particular conditions and possession of weapons, business in the field of weapons and categorization of weapons. The next part analyzes Act No. 288/1995 Coll. again focusing on selected institutes important in the context of the implementation of EU law. The following are comparisons of Council Directive 91/477 / EEC in its original version with Act No. 119/2002 Coll. in the original wording and Council Directive 91/477 / EEC as amended by Directive 2008/51 / EC of the European Parliament and of the Council with Act No. 119/2002 Coll. as amended by Act No. 222/2017 Coll., with an overlap into certain legal regulations. The thesis also describes and analyzes the reasons for the adoption of Directive (EU) 2017/853 of the European Parliament and of the Council, the process of its adoption and the Czech Republic's lawsuit for its invalidity and describes the subsequent proceedings in front of the EU Court of Justice. Due to the lawsuit rejection, Czech Republic was forced to adopt an...
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Biogenesis of mitochondria in parasitic protist Trypanosoma brucei
Mach, Jan
In last decade, investigations of mitochondria including their various reduced forms such as hydrogenosomes and mitosomes revealed unexpected diversity of this indispensable organelle. Interestingly, the single mitochondrion of parasitic protist Trypanosoma brucei is able to undergo remarkable functional and structural changes reflecting available carbon sources. Moreover, it was proposed that trypanosomes belong among the most ancient eukaryotes and as such, their mitochondria raised high attention of biologists. To contribute to the knowledge of mitochondrial biogenesis and function, we focused on studies of two key mitochondrial processes, the processing of preproteins that are imported to the mitochondria, and mechanism of pyruvate transport to these organelles. Moreover, we also investigated uptake of iron by T. brucei. This metal is essential for function of numerous proteins, particularly for iron-sulfur proteins in mitochondria. Evolutionary history of trypanosomes and their mitochondrion is a question of debates. According to some reports, mitochondrion of trypanosomes represent an ancient form of this organelle, which is supported by identification of putative "archaic" translocase of the outer mitochondrial membrane (ATOM) and finding of only a single type of translocation pore in...
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Iron metabolism of parasitic protist Trypanosoma brucei
Krejbichová, Lucie ; Mach, Jan (advisor) ; Pyrih, Jan (referee)
Trypanosoma brucei is a parasite most frequently occurring in Sub-Saharan Africa that causes sleeping sickness in humans and various similar illnesses in animals. The bloodsucking tsetse flies (Glossina) transfer the parasite to humans, their final hosts. Throughout its complex life cycle, Trypanosoma occurs in different environments and undergoes various morphological and metabolic changes. Iron is an important element for all living organisms, including Trypanosoma. The metal plays a crucial role in the host-parasite interaction since trypanosomes are dependent on the iron they acquire from the host or vector. Trypanosomes use iron in metabolic reactions, such as energy metabolism, respiration, nucleic acid synthesis, detoxification, and cellular homeostasis. It is an important element in the synthesis of iron-sulfur clusters which function as cofactors during the above-mentioned reactions. The understanding of iron metabolism in the cell can facilitate the development of new medicaments, an example being iron chelators.
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Temporary agency employment - legal theory and application practice
Mach, Jan ; Pichrt, Jan (advisor) ; Morávek, Jakub (referee)
Temporary agency employment - legal theory and application practice The title of this diploma thesis is "Temporary agency employment - Legal theory and application practice ", where temporary agency employment being is characterized as flexible form or provision of labor force. The main aim of this work is to summarize the regulations of temporary agency employment and to point out problematic its most critical flaws. The thesis additionally highlights the most important differences compared to regulations in force in neighboring countries. The first chapter defines the central attributes of temporary agency employment, including flexibility and secondment. It further formalizes how temporary agency employment differs from similar concept of outsourcing. The main law text sources are subsequently presented and set to the historical law context of the Czech Republic. The third chapter defines the main players partaking in temporary agency employment, with focus on how permissions are obtained, the deposit obligation and the bankruptcy insurance. The fourth chapter deals with interplay of labor and commercial law, including the definition of individual terms of the contract. Next, the liabilities of all parties are explained, with particular focus on regulation of salary and employment terms,...
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