Thesis (M.Sc.)--York University, 2004. Graduate Programme in Biology. / Typescript. Includes bibliographical references (leaves 59-66). Also available on the Internet. MODE OF ACCESS via web browser by entering the following URL: http://gateway.proquest.com/openurl?url%5Fver=Z39.88-2004&res%5Fdat=xri:pqdiss &rft_val_fmt=info:ofi/fmt:kev:mtx:dissertation&rft_dat=xri:pqdiss:MR11754

Charles University Faculty of Pharmacy in Hradec Králové Department of Pharmacology & Toxicology Student: Andrea Krejzová Supervisor: PharmDr. Ivan Vokřál, Ph.D. Title of diploma thesis: Effect of albendazole on the activity of selected enzymes in tapeworm Hymenolepis diminuta The efficacy of anthelmintics used to treat diseases caused by helminths is not always sufficient, and in some cases, we are directly facing resistance to these drugs. Helminths, including tapeworms, are able to defend against the toxic effect of anthelmintics using several mechanisms. Xenobiotic metabolizing enzymes and transport proteins belong to these mechanisms. When xenobiotic metabolizing enzymes are induced, the efficacy of therapy may be significantly reduced. The effect of xenobiotic metabolizing enzymes on the drug resistance development has been already described in number of helminths. In tapeworms this information is still missing. Main aim of this study was to determine effect of drug albendazole on the activity of selected xenobiotic metabolizing enzymes in rat tapeworm (Hymenolepis diminuta). Tapeworms were incubated with albendazole (1 μM and 10 μM) for 24 hours. Then activities of selected enzymes in cytosol-like, microsome-like and mitochondria-like fractions were determined. This study is focused on...

Charles University Faculty of Pharmacy in Hradec Králové Department of Pharmacology & Toxicology Student: Karolína Lukačiková Supervisor: PharmDr. Ivan Vokřál, Ph.D. Title of diploma thesis: Effect of mebendazole on the activity of selected enzymes in tapeworm Hymenolepis diminuta The resistance of parasitic helminths to anthelmintic drugs is a growing worldwide phenomenon and a concerning issue. Xenobiotic metabolizing enzymes play an important role in drug resistance development as they can lower the concentration of the anthelmintics in the parasite's body and therefore protect the parasite from the anthelmintic effect. The role of drug metabolizing enzymes in drug resistance development has been already described in the group of roundworms and flukes. Limited information is available about this topic in tapeworms. In our study we decided to test the possibility of the anthelmintic mebendazole to affect the activity of these enzymes and possibly to influence the drug resistance development in rat tapeworm (Hymenolepis diminuta). Our first goal was the isolation of adult tapeworms from the definitive host (rat, Rattus norvegicus). We used mealworm beetle (Tenebrio molitor) as an intermediate host. After the successful isolation, adult tapeworms were incubated with the mebendazole (1 and 10µM) in...

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.

A balance of iodine within the rats is important for the maintenance of normal thyroid function. Because of Hymenolepis d[imi]nuta's affinity for certain nutrients, it may upset norma[l] iodine balance in the rat. To determine this, tapeworm-infected and non-infected rats were given 125Iodide orally and the percent uptake of iodide by the thyroid and the amount of radioac[tiv]ity in the tapeworms was determined. The percent distribution of the radio-iodinated compounds in the thyroid, tapeworms and feces was also determined. These procedures were repeated except 125Thyroxine was administered orally. There was a decrease in percent iod[id]e uptake by thyroids of tapeworm-infected rats receiving 125I; however, there was no indication of a hypothyroid condition. Iodide, T4, and T3 were present in the worms, but not enough to account for the decrease in thyroid uptake. The more tapeworms present in the rat, the greater fecal excretion of iodide and T4. Due to this, tapeworms may cause a hypothyroid condition over a longer period of time than this study. The data indicated that T4 was metabolized by the tapeworms.

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Coyotes (Canis latrans) have inhabited Florida (USA) since the 1960s and are currently found throughout the state. The purpose of the present study was to obtain information on enteric parasites and diet of Florida coyotes from two different habitat types. Seasonal variation in diet was also examined. Fresh coyote fecal samples were collected from protected and urban habitats in Pinellas County, Florida (USA; 27°54' n, 82°41'w) from may 2005 to march 2007. A standard fecal flotation examination and formalin-ethyl acetate sedimentation were utilized on fecal samples collected from the protected (n=40) and urban (n=50) habitats. Five novel (newly documented) parasites of coyotes were discovered; one cestode (Hymenolepis spp.), one nematode (Ascaris spp.), and three protozoa (Balantidium coli, Blastocystis spp., and Entamoeba histolytica). Novel parasites of Florida coyotes were also discovered two cestodes (diphyllobothrium latum and dipylidium caninum), two nematodes (toxocara canis and uncinaria stenocephala), one trematode (paragonimus spp.), and four protozoa (cryptosporidium spp., giardia canis, isospora spp., and sarcocystis cruzi). One cestode (Taenia spp.), three nematodes (Ancylostoma caninum, Physaloptera spp., and Trichurus vulpis), and one trematode (Alaria spp.) were also recovered, all of which have previously been documented in Florida coyotes. Diet items were identified to the lowest possible taxonomic level by gross morphological characteristics and medullary configurations of dorsal guard hairs. A poisson regression was utilized to determine the relation between diet items and habitat, season, and interaction. In the protected habitat (n=49), vegetative matter (96%), Insecta (53%), and Rodentia (45%) were recovered most often, as opposed to berries (56%) and Lagomorpha (32%) in the urban habitats (n=71). Overall, vegetative matter, berries, and Lagomorpha were recovered most often from Florida coyote fecal samples. Odocoileus virginianus, Lagomorpha, and berries varied the most between wet and dry seasons. It is suggested that Florida coyotes are more susceptible to reinfection by novel parasites because of their rapid range expansion and lack of acquired immunity. Rapid habitat loss in Florida (i.e., urbanization) lowers survival of adult coyotes, increases the probability of transmission of disease between wild and domestic canids, and alters the diet of coyotes by lowering biological diversity of available prey items.

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In this study, we examined the immunomodulatory effect of excretory/secretory products, crude adult extracts and crude larvae extracts from Hymenolepis diminuta on the intestinal epithelilal cell line from a rat. For determination of the immunomodulation effect of all H. diminuta extracts was used relative gene expression of TNFa, IL-17re and IL-33 from epithelial cells and it was tested using real-time PCR. Our result showed that excretory/secretory products had the strongest antiinflammatory effect on the epithelial cells. We assume that crude adult extracts play an important role in increase of gene expression of IL-33 and also in the immunomodulatory ability of H. diminuta in the host organism.