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Ideas of lower secondary pupils related to the content of the curriculum focused on viruses and the ways of their transmission, expressed through a verbal description and drawing
ZÍKOVÁ, Eva
The aim of this thesis was to investigate the perceptions of primary school pupils about viruses and viral infection, both through verbal description and the use of drawings. A part of the thesis was to create a teaching unit based on critical thinking and working with text to develop pupils' constructs about viral issues. The review of the literature focuses on the definition of viruses and viral infection, and the topic of viruses in curriculum documents is introduced, complemented by an analysis of selected science textbooks. Part of the literature review is devoted to teaching methods, with an emphasis on working with text, as this method was used in the research investigation. The research itself was carried out in two primary schools through a questionnaire survey (in the form of a pretest and a posttest) combined with the implementation of the designed teaching unit. The results were then extended with information obtained from interviews with selected pupils. The results of the questionnaire survey showed that the pupils in the study sample had only a rough idea mainly about viruses and had significant difficulties in describing viral infection. After the implementation of the teaching unit, the pupils achieved better results. The teaching unit helped them better express the characteristics of the virus and the viral infection. Interviews with selected pupils confirmed these results, as it appeared that pupils were already able to describe the course of the viral infection in their own words.
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Use of biochemical methods in the study of plant metabolism with emphasis on the defense system
Bělonožníková, Kateřina ; Ryšlavá, Helena (advisor) ; Luhová, Lenka (referee) ; Plchová, Helena (referee)
As sessile organisms, plants cannot avoid being exposed to various biotic and abiotic stress factors. To defend themselves plants have developed complex and sophisticated defense mechanisms. In agriculture, pesticides are used for plant protection, but they can have undesirable side effects, and therefore attention is being paid to biological control agents. One such agent is Pythium oligandrum, a soil oomycete that has a positive effect on plants at several levels. On the one hand, it secretes elicitins, which stimulate defensive responses and prepare the plant for possible infection (i.e., priming effect), and on the other hand, it produces tryptamine, a precursor of auxin, thus supporting the plant's growth. Furthermore, P. oligandrum directly acts as pathogen mycoparasite or evokes antibiosis, or competition for nutrients and space with other microorganisms. The key research topic of this thesis was the analysis of the biochemical properties of eleven Pythium strains and their impact on plant metabolism. Our results showed that even closely related P. oligandrum strains significantly differ in the content of compounds secreted into the medium, including proteins, amino acids, tryptamine, and hydrolytic enzymes capable of degrading cell walls (endo-β-1,3-glucanase, chitinase, and cellulase),...
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Exosomes in viral infection and cancer
Sekavová, Alžběta ; Španielová, Hana (advisor) ; Hirsch, Ivan (referee)
Exosomes facilitate intercellular communication and transport of cellular cargo. Understanding the mechanisms underlying the cargo sorting to exosomes and the transport itself is crucial for vaccine development and diagnostic research. Exosome-mediated transfer contributes to immune response as well as progression of several diseases, including cancer and viral infections. Research on exosomes and their role in life cycles of tumorigenic viruses links already known mechanisms of viral carcinogenesis to the transport mechanisms of both cellular and viral proteins and nucleic acids. Epstein-Barr virus employs exosomes for transmission of the LMP1 oncoprotein and regulatory RNAs, whereas human immunodeficiency virus exploits cellular exosomal pathway for hijacking its membrane during budding, which helps it evade the immune system. It has been discovered that hepatitis C virus transfers its infectious virions between cells in exosomes. Exosomes containing oncoproteins and viral RNAs are also released from cells infected with other human tumorigenic viruses. However, mechanisms and implications of such events remain to be discovered. Keywords: exosome, cancer, viral infection, tumorigenic viruses, immunity, in- tercellular communication, hepatitis C virus, Epstein-Barr virus, human immuno- deficiency virus
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Use of biochemical methods in the study of plant metabolism with emphasis on the defense system
Bělonožníková, Kateřina
As sessile organisms, plants cannot avoid being exposed to various biotic and abiotic stress factors. To defend themselves plants have developed complex and sophisticated defense mechanisms. In agriculture, pesticides are used for plant protection, but they can have undesirable side effects, and therefore attention is being paid to biological control agents. One such agent is Pythium oligandrum, a soil oomycete that has a positive effect on plants at several levels. On the one hand, it secretes elicitins, which stimulate defensive responses and prepare the plant for possible infection (i.e., priming effect), and on the other hand, it produces tryptamine, a precursor of auxin, thus supporting the plant's growth. Furthermore, P. oligandrum directly acts as pathogen mycoparasite or evokes antibiosis, or competition for nutrients and space with other microorganisms. The key research topic of this thesis was the analysis of the biochemical properties of eleven Pythium strains and their impact on plant metabolism. Our results showed that even closely related P. oligandrum strains significantly differ in the content of compounds secreted into the medium, including proteins, amino acids, tryptamine, and hydrolytic enzymes capable of degrading cell walls (endo-β-1,3-glucanase, chitinase, and cellulase),...
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Effect of adenosine deaminase acting on RNA on viral infection of eukaryotic cells
Kubů, Martin ; Vopálenský, Václav (advisor) ; Fraiberk, Martin (referee)
Double-stranded RNA is a molecule rarely found in a cell, but it is specific for viral infection. It is also a substrate of ADAR enzymes. These enzymes convert adenosin to inosine, which is recognized as guanosine by cellular machinery. Apart from editing activity, ADAR enzymes interact with cellular proteins, such as Dicer and protein kinase R, which together with editing affects viral replication. In this work, the information about antiviral activity of ADAR enzymes and their impact on infection of selected primarily human viruses is reviewed.
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Mechanisms of superinfection exclusion by animal viruses
Vlachová, Štěpánka ; Horníková, Lenka (advisor) ; Šmahel, Michal (referee)
Viral interference can be found in both homologous and heterologous viruses and may have significant impact on the infection. One of such impacts is superinfection exclusion, which is a defence mechanism used by a wide variety of viruses. The superinfection exclusion may occur in different steps of viral life cycle. Despite being a common viral function, most of the mechanisms of exclusion stay yet undefined, same as proteins, which are taking part in superinfection exclusion. This work is a summary of knowledge in the field of interference between animal viruses, with focus on homologous interference and mechanisms of superinfection exclusion. Research of this phenomenon can bring important information for the development of new antiviral treatment, virus diagnosis and understanding of interactions between viruses. Key words: Viral infection, animal viruses, homologous interference, superinfection exclusion, mechanisms of exclusion
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Endoplasmic reticulum-associated degradation and its role in virus infection
Svobodová, Terezie ; Forstová, Jitka (advisor) ; Mašek, Tomáš (referee)
The endoplasmic reticulum-associated degradation pathway, ERAD, is an important mechanism for maintaining cellular homeostasis. The function of ERAD is degradation of accumulated unfolded proteins in the endoplasmic reticulum. ERAD is carefully regulated by pathway called "Unfold protein response" and by "ERAD tuning" mechanism. Some viruses have adopted the ways how to exploit this system or its factors for their own benefit. These utilizations include targeting of specific host proteins for degradation, transfer of viral products or virions from the endoplasmic reticulum into the cytoplasm, or the use of a membrane platform arising from the cooperation with "ERAD tuning" for viral replication. Role of ERAD in viral infection can manifest itself in different ways, it can contribute to degradation not only of host proteins but also of viral products. In this work I summarize mechanisms of ERAD pathway and their regulatory pathways. Meanwhile, in the specific examples, I present roles of ERAD pathway and associated systems in viral infections.
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Exosomes in viral infection and cancer
Sekavová, Alžběta ; Španielová, Hana (advisor) ; Hirsch, Ivan (referee)
Exosomes facilitate intercellular communication and transport of cellular cargo. Understanding the mechanisms underlying the cargo sorting to exosomes and the transport itself is crucial for vaccine development and diagnostic research. Exosome-mediated transfer contributes to immune response as well as progression of several diseases, including cancer and viral infections. Research on exosomes and their role in life cycles of tumorigenic viruses links already known mechanisms of viral carcinogenesis to the transport mechanisms of both cellular and viral proteins and nucleic acids. Epstein-Barr virus employs exosomes for transmission of the LMP1 oncoprotein and regulatory RNAs, whereas human immunodeficiency virus exploits cellular exosomal pathway for hijacking its membrane during budding, which helps it evade the immune system. It has been discovered that hepatitis C virus transfers its infectious virions between cells in exosomes. Exosomes containing oncoproteins and viral RNAs are also released from cells infected with other human tumorigenic viruses. However, mechanisms and implications of such events remain to be discovered. Keywords: exosome, cancer, viral infection, tumorigenic viruses, immunity, in- tercellular communication, hepatitis C virus, Epstein-Barr virus, human immuno- deficiency virus
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The role of Interferon regulatory factors in virus infections
Suchý, Tomáš ; Forstová, Jitka (advisor) ; Matyska Lišková, Petra (referee)
Viruses are intracellular parasites, which expose their proteins and nucleic acids during their interaction with a cell. Thanks to co-evolution the host immune system developed mechanims how to recognize these components and subsequently activate defensive mechanisms. This work summarizes the knowledge about selected transcription factors with interferon regulatory function. Induction of the antiviral state is complicated and strictly regulated process. Primary function of selected transcription factors is to connect virus detection and synthesis of cellular molecules with antiviral potential. The work includes information about the direct interaction of viral proteins with interferon regulatory factors. These facts enable us insight into the molecular struggle between a host and a virus. As the name of factors suggests, the most important function is to influence the interferon production. Gathering of information about coordination of the immune system is beneficial for humane medicine and future therapeutic purposes. Key words: interferon regulatory factors; viral infection; regulation of innate immunity; interferon; pathogen recognition
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