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Migration and pathogenicity of neurotropic helminths
Pech, Václav ; Horák, Petr (advisor) ; Chanová, Marta (referee)
A neurotropism of helminths can be observed in their intermediate, paratenic and definitive hosts. Neurotropic helminths migrate through the nervous tissue, where maturation and reproduction can take place. The neurotropic helminths can be found in the family of trematodes (Diplostomum baeri, D. phoxini, Ornithodiplostomum ptychocheilus, Trichobilharzia regenti), cestodes (Taenia multiceps, T. solium) and nematodes (Angiostrongylus cantonensis, Elaphostrongylus cervi, Parelaphostronglus tenuis, Baylisascaris procyonis). Presence of these helminths in the nervous tissue can (usually with contribution of the immune system) lead to neurological or other pathological changes: the infected hosts can even die. Some of the neurotropic helminths (A. cantonensis, B. procyonis, T. solium, T. multiceps) can infect humans as well.
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Differentiation of totipotent germinal cells in larvae of bird schistosomes
Peštová, Jitka ; Horák, Petr (advisor) ; Chanová, Marta (referee)
This thesis aims to explore the larval development of a bird fluke Trichobilharzia regenti in its intermediate hosts, as well as the processes of differentiation of its embryonal cells and the differentiation between sporocystogenesis and cercariogenesis in sporocysts, with the ultimate goal to find out whether it is possible to find multiple generations of daughter sporocysts throughout the development of avian schistosomes in the intermediate hosts, just like in the case of human schistosomes of genus Schistosoma. Five developmental stages of daughter sporocysts, and ten developmental stages of cercariae have been defined. The first developmental stage in both larvae is the germinal cell. It divides and gives rise to a cell agregate. Afterwards an envelope (primitive epithelium) is formed around the embryo and subsequently, the embryo elongates. At this stage, the development of the two larvae undergoes different pathways. We can distinguish daughter sporocyst from cercaria in the phase, when the tegument is completed. The daughter sporocyst acquires characteristic vermiform appearance, and its body cavity contains plenty of germinal cells. For cercariae with an developed tegument, presence of the penetration glands is characteristic. Key words: Trichobilharzia regenti, germinal cells, mother...
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Vliv vybraných látek ovlivňujících centrální nervový systém na kostní metabolismus
Fekete, Soňa ; Živný, Pavel (advisor) ; Horák, Petr (referee) ; Nobilis, Milan (referee)
The increase in life expectancy of the world population is associated with challenges regarding health issues. For instance, osteoporosis is a medical condition mostly observed in elderly people, in which the quality and quantity of the bone are severely affected. Not only for women but also for men, osteoporosis is recognized as an important public health issue. Osteoporosis is a systemic skeletal disorder and is a result of loss of skeletal mass. Osteoporosis is characterized by low bone mass, microarchitectural deterioration of bone tissue and an increase in bone fragility and susceptibility to fracture. Osteoporotic fractures are a significant cause of morbidity and mortality. The longterm use of drugs such as antiepileptics and antidepressants could affect the onset of osteoporosis. The aim of the study was to evaluate the effect of orchidectomy, the effect of newer antiepileptic (levetiracetam, lacosamide, topiramat, lamotrigine) and antidepressive drugs (mirtazapine, venlafaxine and trazodone) on bone metabolism in healthy male Wistar rats. The first specific aim was to determine the effect of orchidectomy on bone metabolism in rats. We found that after 12 weeks post-orchidectomy there was a negative effect on bone metabolism in rats. These results established these animals as suitable models for...
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Do public R&D subsidies boost competitiveness of supported companies in the Czech Republic?
Horák, Petr ; Teplý, Petr (advisor) ; Švarcová, Natálie (referee)
The purpose of this thesis is to investigate the impact of government non-investment and applied R&D subsidies on the firm level competitiveness. According to many literature sources the indicators of competitiveness are assumed to be Return on Assets, Return on Equity, Return on Sales and Asset Turnover ratio. The tool used to test the effect is counterfactual analysis. The subsidized companies are compared to a control group drawn by Propensity Score Matching, the effect is tested by Average Treatment Effect on the Treated and the difference in size of other financials is derived by Difference in Differences. The study focuses on two industries NACE C25 (metallurgy) and C28 (manufacture of machines). The subsidized companies show no added significant growth of competitiveness whatsoever. The financials (Total Assets, Equity, Turnover) grew, compared to the control group, only for industry C25. JEL Classification O31, O38, H21 Keywords R&D, Innovation, non-investment, subsidies, applied R&D, competitiveness Author's e-mail petr.rotr@post.cz Supervisor's e-mail petr.teply@fsv.cuni.cz
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Cathepsins B of the bird schistosome, Trichobilharzia regenti
Dolečková, Kateřina ; Horák, Petr (advisor) ; Grevelding, Christoph (referee) ; Horn, Martin (referee)
1. Overview Schistosomes have achieved first position among parasitic helminths, because some of them are the etiological agents of a serious human parasitic disease, schistosomiasis, which affects over 200 million people in tropical and subtropical countries (WHO, 2001). Other schistosomatids, such as the bird flukes of the genus Trichobilharzia, have also implications for human health. Although they can mature only in specific hosts (birds), their invasive larvae - cercariae - are able to penetrate also human skin due to chemical signals similar to those present on bird skin (Haas and van de Roemer 1998). Repeated infections result in an inflammatory reaction of the skin called cercarial dermatitis. Due to the increasing number of outbreaks all around the world, cercarial dermatitis is cons disease (Kolářová 2007idered as re-emerging ; Larsen et al. 2004). Among schistosomes, Trichobilharzia regenti is the only species described so far having a unique migration route within vertebrate hosts: after penetration of the skin, the invasive larvae enter peripheral nerves and continue via the spinal cord and central nervous system to the nasal cavity of birds, causing neuromotor disorders or paralyses of birds and even experimental mammals (Hrádková...
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