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Oocyte meiotic maturation is a process of a transformation of the oocyte at the germinal vesicle stage to the oocyte at the stage of second meiotic metaphase. The process called oocyte aging occurs when oocytes are exposed after the completion of meiotic maturation to the prolonged cultivation. This process is characterized by a decrease in oocyte quality. The addition of suitable compounds into the cultivation medium could improve the quality of maturing and aging oocytes. Hydrogen sulfide is a gaseous molecule that is endogenously produced and fulfills signal function in organisms. Alliin and S-allyl cysteine are garlic derivatives that exhibit many positive effects on organisms. Many of them are mediated by their ability of releasing hydrogen sulfide. We hypothesize that the quality of oocytes in the in vitro cultivation system can be improved by the addition of the hydrogen sulfide donor and garlic derivatives into the cultivation medium. The aim of the study was to evaluate the effects of hydrogen sulfide and garlic derivatives on the meiotic maturation of oocytes, the effects of hydrogen sulfide on oocyte aging and the effects of cultivation with hydrogen sulfide and garlic derivatives on early embryonic development. It was found out that hydrogen sulfide donor accelerates oocyte nuclear maturation and causes an earlier increase of MPF and MAPK activities. Hydrogen sulfide donor improves activating potential of oocytes. It was found out that endogenous hydrogen sulfide production occurs during aging of procine oocytes and that the hydrogen sulfide production decreases after first 24 hours of prolonged cultivation. The inhibitors of hydrogen sulfide releasing enzymes impaired the quality of aged oocytes. Hydrogen sulfide donor completely suppressed fragmentation of oocytes exposed to prolonged cultivation and improved the quality of aged oocytes treated simultaneously with the inhibitors of hydrogen sulfide releasing enzymes. The presence of hydrogen sulfide donor during the prolonged cultivation of oocytes improved early embryonic development after parthenogenetic activation. It was found out that whereas alliin disrupts meiotic maturation of oocytes, S-allyl cystein has not influenced this process. S-allyl cysteine accelerated the onset of embryo cleavage and reduced ROS levels in maturing and parthenogenetically activated oocytes.

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Charles University in Prague Faculty of Pharmacy in Hradec Králové Department of Pharmacology & Toxicology Student: Dominik Jandura Supervisor: PharmDr. Ivan Vokřál, Ph.D. Title of diploma thesis: In vitro cultivation of tapeworm Hymenolepis diminuta - 2 Aim of this diploma thesis was to obtain cycticercoids of the rat tapeworm (Hymenolepis diminuta), excyst them and find out the conditions for the maximal in vitro incubation period. As the intermediate host mealworm beetle (Tenebrio molitor) infected by the rat feces containing tapeworm eggs was used. Excystment was done using L-cystein and sodium tauroglycocholate. Excysted larvae were cultured in vitro (37 řC, 5 % CO2) in RPMI 1640 medium enriched with other substances chosen according previously published methods. Mainly sheep, mouse or rat liver extracts eventually in combination with yeast extract and sheep bile were used. The effect of tested substances on the cultivation was evaluated by measuring of the tapeworm's growth. The best effect on the grow of the tapeworms was observed using medium containing serum, yeast extract and sheep liver extract where tapeworms achieved length of 1561 µm after 16 days of incubation. The further growth was limited by appearance of pathologic formations.

The presented diploma thesis deals with the analysis and production of selected microbial metabolites of the yeast Rhodotorula kratochvilovae in comparison to various species of microalgae. The theoretical part summarizes the knowledge about the conditions for optimal growth and production of secondary metabolites. Analytical methods, by which metabolites were quantified and evaluated, were also described. In the experimental part of this thesis, the amount of accumulated biomass, exoglycolipids, intracellular lipids, phycobiliproteins and carotenoids according to various nutrient sources in the culture medium was studied. Specifically, the yields of these metabolites were investigated in the utilization of various sources of nitrogen (yeast extract, urea, ammonium sulfate, ammonium chloride and potassium nitrate), carbon (glucose, mannose, xylose, glycerol and lactose) and at variable C / N ratios (20; 40; 70; 100 and 120: 1) ideally selected sources of observed nutrients in partial experiments. The last part of the experiment was focused on comparison of the analysis of metabolites of autotrophic algae (chlorophylls, phycobiliproteins and lipids).