Dissertations / Theses on the topic 'Hymenolepis'

Hymenolepis nana is a ubiquitous parasite, found throughout many developing and developed countries. Globally, the prevalence of H. nana is alarmingly high, with estimates of up to 75 million people infected. In Australia, the rates of infection have increased substantially in the last decade, from less than 20% in the early 1990’s to 55 - 60% in these same communities today. Our knowledge of the epidemiology of infection of H. nana is hampered by the confusion surrounding the host specificity and taxonomy of this parasite. The suggestion of the existence of two separate species, Hymenolepis nana von Siebold 1852 and Hymenolepis fraterna Stiles 1906, was first proposed at the beginning of the 20th century. Despite ongoing discussions in the subsequent years it remained unclear, some 90 years later, whether there were two distinct species, that are highly host specific, or whether they were simply the same species present in both rodent and human hosts. The ongoing controversy surrounding the taxonomy of H. nana has not yet been resolved and remains a point of difference between the taxonomic and medical literature. The epidemiology of infection with H. nana in Australian communities is not well understood as the species present in these communities has never been identified with certainty. It is not clear which form of transmission commonly occurs in Australia, whether the H. nana ‘strain/species’ present in the north-west of Western Australia is present in human and rodent hosts, or whether humans harbour their own ‘strain/sub-species’ of Hymenolepis. Furthermore, it is not known whether mice are a potential zoonotic source for transmission of Hymenolepis to human hosts. In this study, 51 human isolates of H. nana were inoculated into highly susceptible laboratory rodent species. However, these failed to develop into adult worms in all instances, including when rodent species were chemically and genetically immunosuppressed.In addition, 24 of these human isolates were also cross-tested in the flour beetle intermediate host, Tribolium confusum. Of these, only one isolate developed to the cysticercoid stage in beetles, yet when inoculated into laboratory rodents, the cysticercoids also failed to develop into adult stage. Since isolates of H. nana infecting humans and rodents are morphologically indistinguishable, the only way they can be reliably identified is by comparing the parasite in each host using molecular criteria. In the current study, three regions of ribosomal DNA, the small subunit (18S), the first internal transcribed spacer (ITS1) and the intergenic spacer (IGS) were chosen for genetic characterisation of Hymenolepis spp. from rodent and human hosts from a broad geographic range. In addition, a mitochondrial gene, the cytochrome c oxidase subunit 1 (C01) gene and a non-ribosomal nuclear gene, paramyosin, were characterised in a number of Hymenolepis isolates from different hosts. A small PCR fragment of 369 bp, plus a larger fragment of 1223 bp, were sequenced from the 18S gene of reference isolates of H. nana and the rat tapeworm H. diminuta. Minimal sequence variation was found in the two regions of the 18S between these two morphologically distinct, phylogenetically recognised species, H. nana and H. diminuta, and this indicated that the 18S gene was too conserved for further genetic characterisation of isolates of H. nana from different hosts. A large number of human isolates of H. nana (104) were characterised at the ITS1 using PCRrestriction length fragment polymorphism (PCR-RFLP). The profiles obtained were highly variable and often exceeded the original size of the uncut fragment. This was highly suggestive of the existence of ribosomal spacers that, whilst identical in length, were highly variable in sequence. To overcome the problems of the variable PCR-RFLP profiles, further characterisation of the ITS1, by cloning and sequencing 23 isolates of H. nana, was conducted and this confirmed the existence of spacers which, although similar in length (approximately 646 bp), differed in their primary sequences. The sequence differences led to the separation of the isolates into two clusters when analysed phylogenetically. This sequence variation was not, however, related to the host of origin of the isolate, thus was not a marker of genetic distinction between H. nana from rodents and humans. Indeed, the levels of variability were often higher within an individual isolate than between isolates, regardless of whether they were collected from human or mice hosts, which was problematic for phylogenetic analysis. In addition, mixed parasite infections of H. nana and the rodent tapeworm H. microstoma were identified in four humans in this study, which was unexpected and surprising, as there have been no previous reports in the literature documenting humans as definitive hosts for this parasite. Further studies are required, however, to determine if the detection of H. microstoma in humans reflects a genuine, patent infection or an atypical, accidental occurrence. Sequencing of the mitochondrial cytochrome c oxidase 1 gene (C01) in a number of isolates of Hymenolepis nana from rodents and humans identified a phylogenetically supported genetic divergence of approximately 5% between some mouse isolates compared to isolates of H. nana from humans. This provided evidence that the mitochondrial C01 gene was useful for identifying genetic divergences in H. nana that were not resolvable using nuclear loci. Despite a morphological identity between isolates of H. nana from rodent and human hosts, the genetic divergence observed between isolates at the mitochondrial locus was highly suggestive that H. nana is a species complex, or “cryptic” species (= morphologically identical yet genetically distinct). In addition, whilst not supported by high bootstrap values, a clustering of the Australian human isolates into one uniform genetic group that was phylogenetically separated from all the mouse isolates was well supported by biological data obtained in this study. To confirm the phylogeny of the C01 tree a small segment of the nuclear gene, paramyosin, was sequenced in a number of isolates from humans and rodents. However, this gene did not provide the level of heterogeneity required to distinguish between isolates from rodent and human hosts. The high sequence conservation of the paramyosin gene characterised in this study did not refute the finding that H. nana may be a cryptic species that is becoming host adapted. It simply did not provide additional data to that already obtained. A DNA fingerprinting tool, PCR-RFLP, of the ribosomal intergenic spacer (IGS), was developed in this study in order to evaluate its usefulness in tracing particular genotypes within a community, thus determining transmission patterns of H. nana between rodent and human hosts. Analysis of the IGS of numerous H. nana isolates by PCR-RFLP identified the presence of copies of the IGS that, whilst similar in length, differed in their sequence. Similar to that observed in the ITS1, the existence of different IGS copies was found in both rodent and human isolates of H. nana, thus the variability was not evidence of the existence of a rodent- or humanspecific genotype. Evaluation of the intergenic spacer (IGS) as a fingerprinting tool suggests that this region of DNA is too variable within individuals and thus, cannot be effectively used for the study of transmission patterns of the tapeworm H. nana between different hosts. In summary, it appears that the life cycle of H. nana that exists in remote communities in the north-west of Western Australia is likely to involve mainly ‘human to human’ transmission. This is supported by both the biological and genetic data obtained for the mitochondrial locus in this study. The role of the intermediate hosts, such as Tribolium spp., in the Hymenolepis life cycle is still unclear, however it would appear that it may be greatly reduced in the transmission of this parasite in remote Australian communities. In the future, it is recommended that further genetic characterisation of faster evolving mitochondrial genes, and/or suitable nuclear genes be characterised in a larger number of isolates of H. nana. The use of techniques which can combine the characterisation of genotype and phenotype, such as proteomics, may also be highly valuable for studies on H. nana from different hosts.

Hymenolepis nana is a ubiquitous parasite, found throughout many developing and developed countries. Globally, the prevalence of H. nana is alarmingly high, with estimates of up to 75 million people infected. In Australia, the rates of infection have increased substantially in the last decade, from less than 20% in the early 1990's to 55 - 60% in these same communities today. Our knowledge of the epidemiology of infection of H. nana is hampered by the confusion surrounding the host specificity and taxonomy of this parasite. The suggestion of the existence of two separate species, Hymenolepis nana von Siebold 1852 and Hymenolepis fraterna Stiles 1906, was first proposed at the beginning of the 20th century. Despite ongoing discussions in the subsequent years it remained unclear, some 90 years later, whether there were two distinct species, that are highly host specific, or whether they were simply the same species present in both rodent and human hosts. The ongoing controversy surrounding the taxonomy of H. nana has not yet been resolved and remains a point of difference between the taxonomic and medical literature. The epidemiology of infection with H. nana in Australian communities is not well understood as the species present in these communities has never been identified with certainty. It is not clear which form of transmission commonly occurs in Australia, whether the H. nana 'strain/species' present in the north-west of Western Australia is present in human and rodent hosts, or whether humans harbour their own 'strain/sub-species' of Hymenolepis. Furthermore, it is not known whether mice are a potential zoonotic source for transmission of Hymenolepis to human hosts. In this study, 51 human isolates of H. nana were inoculated into highly susceptible laboratory rodent species. However, these failed to develop into adult worms in all instances, including when rodent species were chemically and genetically immunosuppressed. In addition, 24 of these human isolates were also cross-tested in the flour beetle intermediate host, Tribolium confusum. Of these, only one isolate developed to the cysticercoid stage in beetles, yet when inoculated into laboratory rodents, the cysticercoids also failed to develop into adult stage. Since isolates of H. nana infecting humans and rodents are morphologically indistinguishable, the only way they can be reliably identified is by comparing the parasite in each host using molecular criteria. In the current study, three regions of ribosomal DNA, the small subunit (18S), the first internal transcribed spacer (ITS1) and the intergenic spacer (IGS) were chosen for genetic characterisation of Hymenolepis spp. from rodent and human hosts from a broad geographic range. In addition, a mitochondrial gene, the cytochrome c oxidase subunit 1 (C01) gene and a non-ribosomal nuclear gene, paramyosin, were characterised in a number of Hymenolepis isolates from different hosts. A small PCR fragment of 369 bp, plus a larger fragment of 1223 bp, were sequenced from the 18S gene of reference isolates of H. nana and the rat tapeworm H. diminuta. Minimal sequence variation was found in the two regions of the 18S between these two morphologically distinct, phylogenetically recognised species, H. nana and H. diminuta, and this indicated that the 18S gene was too conserved for further genetic characterisation of isolates of H. nana from different hosts. A large number of human isolates of H. nana (104) were characterised at the ITS1 using PCRrestriction length fragment polymorphism (PCR-RFLP). The profiles obtained were highly variable and often exceeded the original size of the uncut fragment. This was highly suggestive of the existence of ribosomal spacers that, whilst identical in length, were highly variable in sequence. To overcome the problems of the variable PCR-RFLP profiles, further characterisation of the ITS1, by cloning and sequencing 23 isolates of H. nana, was conducted and this confirmed the existence of spacers which, although similar in length (approximately 646 bp), differed in their primary sequences. The sequence differences led to the separation of the isolates into two clusters when analysed phylogenetically. This sequence variation was not, however, related to the host of origin of the isolate, thus was not a marker of genetic distinction between H. nana from rodents and humans. Indeed, the levels of variability were often higher within an individual isolate than between isolates, regardless of whether they were collected from human or mice hosts, which was problematic for phylogenetic analysis. In addition, mixed parasite infections of H. nana and the rodent tapeworm H. microstoma were identified in four humans in this study, which was unexpected and surprising, as there have been no previous reports in the literature documenting humans as definitive hosts for this parasite. Further studies are required, however, to determine if the detection of H. microstoma in humans reflects a genuine, patent infection or an atypical, accidental occurrence. Sequencing of the mitochondrial cytochrome c oxidase 1 gene (C01) in a number of isolates of Hymenolepis nana from rodents and humans identified a phylogenetically supported genetic divergence of approximately 5% between some mouse isolates compared to isolates of H. nana from humans. This provided evidence that the mitochondrial C01 gene was useful for identifying genetic divergences in H. nana that were not resolvable using nuclear loci. Despite a morphological identity between isolates of H. nana from rodent and human hosts, the genetic divergence observed between isolates at the mitochondrial locus was highly suggestive that H. nana is a species complex, or 'cryptic' species (= morphologically identical yet genetically distinct). In addition, whilst not supported by high bootstrap values, a clustering of the Australian human isolates into one uniform genetic group that was phylogenetically separated from all the mouse isolates was well supported by biological data obtained in this study. To confirm the phylogeny of the C01 tree a small segment of the nuclear gene, paramyosin, was sequenced in a number of isolates from humans and rodents. However, this gene did not provide the level of heterogeneity required to distinguish between isolates from rodent and human hosts. The high sequence conservation of the paramyosin gene characterised in this study did not refute the finding that H. nana may be a cryptic species that is becoming host adapted. It simply did not provide additional data to that already obtained. A DNA fingerprinting tool, PCR-RFLP, of the ribosomal intergenic spacer (IGS), was developed in this study in order to evaluate its usefulness in tracing particular genotypes within a community, thus determining transmission patterns of H. nana between rodent and human hosts. Analysis of the IGS of numerous H. nana isolates by PCR-RFLP identified the presence of copies of the IGS that, whilst similar in length, differed in their sequence. Similar to that observed in the ITS1, the existence of different IGS copies was found in both rodent and human isolates of H. nana, thus the variability was not evidence of the existence of a rodent- or humanspecific genotype. Evaluation of the intergenic spacer (IGS) as a fingerprinting tool suggests that this region of DNA is too variable within individuals and thus, cannot be effectively used for the study of transmission patterns of the tapeworm H. nana between different hosts. In summary, it appears that the life cycle of H. nana that exists in remote communities in the north-west of Western Australia is likely to involve mainly 'human to human' transmission. This is supported by both the biological and genetic data obtained for the mitochondrial locus in this study. The role of the intermediate hosts, such as Tribolium spp., in the Hymenolepis life cycle is still unclear, however it would appear that it may be greatly reduced in the transmission of this parasite in remote Australian communities. In the future, it is recommended that further genetic characterisation of faster evolving mitochondrial genes, and/or suitable nuclear genes be characterised in a larger number of isolates of H. nana. The use of techniques which can combine the characterisation of genotype and phenotype, such as proteomics, may also be highly valuable for studies on H. nana from different hosts.

Helicobacter pylori (H. pylori) infection causes achlorydria, depressed gastric acid barrier, impaired immune response and is suspected in bacterial overgrowth and diarrhoea. These features of the infection are known to cause significant malabsorption of nutrients and impairment of linear growth in children. The prevalence of H. pylori infection in children is known to be much higher in developing countries, especially among the lower socio-economic groups. The true prevalence of infection in urban children in Mexico and its impact on their growth are largely unknown. This study examined the prevalence of H. pylori infection in school children from an urban area in Northwest Mexico and attempted to identify the risk factors that predispose individuals to infection in childhood; as well as to relate the presence of this infection to growth of children. The cross-sectional study was conducted in 1997/98 in the poorest socio-economic sectors of the city of Hermosillo, Sonora, among 178 children aged 9 and 10 years. H. pylori status was determined in children by the 13C-urea breath test. Anthropometric (weight and height) and haemoglobin measurements along with analysis of faecal samples and a 24-hour dietary recall were carried out in each child. Family sociodemographic/socio-economic status and living conditions data were elicited from parents by interview via structured questionnaires. The overall prevalence rate of H. pylori infection for the children in Hermosillo as determined by this study was 47.1%. The findings indicate that rural-born father, number of siblings, the type of main water supply (one tap in the yard) and the sharing of bed by the study child are important risk factors for acquiring the H. pylori infection. A borderline significant but small effect of H. pylori infection on height for-age was observed in this study. H. pylori infection was found to be positively highly associated with Hymenolepis nana. No differences in mean energy, protein and iron intakes between H. pylori positive and negative children were observed. However, significant differences in the mean energy, protein and iron intakes were observed between boys and girls. H. pylori infection and enteric parasites were not significantly correlated with the presence of anaemia.

This research investigates the ability of rat tapeworm (Hymenolepis diminuta) to accumulate zinc in tissue and the influence of its intake and excretion by its host (laboratory rat). The host was fed by food with zinc in two forms: 1) a mixture of standard food ST1 with hyperaccumulator plant Arabidopsis halleri, 2) ST1 mixture with zinc lactate, which is ordinarily used as a feed supplement for increasing zinc content and it is often included in human diet supplements. Rat control group fed by ST1 only was included in the experiment for verification of the difference. Rats were divided to six groups (OO, OT, RT, RO, MO a MT). Three rat groups were infected by rat tapeworm (OT, RT, MT) and three rat groups were not infected (OO, RO, MO). The control groups OO and OT were fed by ST1 only. RO and RT groups were fed by ST1 with admixture of Arabidopsis halleri and groups MO and MT were fed by ST1 with zinc lactate. Urine and excrements of the rats were collected twice a week during the experiment and their amounts were measured every day. The rats were weighted every week. At the end of the balance phase of the experiment rats were euthanized and seven selected tissues were removed (liver, kidney, spleen, small intestine, testis, muscle and bone). Rat tapeworm was removed from the infected rats. Blood was drawn from the rats. The results show that rat groups infected by the rat tapeworm had lower concentration of zinc in almost all analyzed tissues except for spleen, where the concentration of zinc was the same as in groups without the rat tapeworm. Based on the results the rat tapeworm also has an influence on the excretion of feces and urine.

Thesis (Ph. D.)--Ohio State University, 2003.
Title from first page of PDF file. Document formatted into pages; contains xii, 137 p.; also includes graphics. Includes abstract and vita. Advisors: Jerry F. Downhower and Peter W. Pappas, Dept. of Evolution, Ecology, and Organismal Biology. Includes bibliographical references (p. 128-137).

Chapter 2 Natural concurrent infections of rats with H. diminuta and M. moniliformis may increase the chances of individual insects being infected by both parasites simultaneously. Although previous work has shown H. diminuta and M. moniliformis can co-exist in the small intestine of the rat, it was considered important to determine the length of time the two species would be simultaneously patent. This time period would occur during maximum rate of egg production by both parasite species, determined from numbers of eggs found the rat's faeces. It was concluded that although eggs of both species were found in the faeces for proximity 11 weeks post-infection, the chances of an insect acquiring an infection would be highest at the time of peak egg production. This was approximately 6 weeks in the mid-patent period of M. moniliformis. Chapter 3 The initial process leading to an infection of the intermediate host by H. diminuta and M. moniliformis were examined; i.e. egg ingestion, hatching, passage along the insect gut and penetration of the midgut wall. Adaptations by the larvae of both species of parasite to infect the intermediate host were shown to influence host-specificity. H. diminuta and M. moniliformis hatched in the guts of a wide variety of insect species, but only M. moniliformis acanthors penetrated the gut wall of P. americana. H. diminuta oncospheres only penetrated the gut walls of the locusts, Schistocerca gregaria and their natural hosts, the flour beetles Tribolium confusum and Tenebrio molitor. Transit time for food material passing along the gut was found to be important in the synchronisation of parasite hatching with arrival at the site of gut penetration. P. americana holds food items and parasites in the foregut (crop) until partially digested before allowing them into the midgut. Thus any H. diminuta oncospheres stimulated to hatch by the insect's mouthparts only progressed as far as the crop until initial digestion was completed; the time taken for crop contents to be passed in to the midgut tended to exceed the time larvae remained active and capable of gut penetration. In contrast, M. moniliformis acanthors hatch over a longer time period and therefore enter the midgut in a state capable of gut penetration. The abilities of the two species of parasite to tunnel through the midguts of different insect species was compared in vitro using a qualitative assay technique. H. diminuta oncospheres were unable to penetrate the tissues of P. americana midgut. Chapter 4 Eggs from both species of parasite were fed simultaneously to insects. It was initially proposed that oral infections of cockroaches with M.moniliformis might facilitate penetration of the cockroach gut by H. diminuta oncospheres, if the gut tissues were sufficiently disrupted by the former parasite. However, only locusts could be simultaneously infected with both species orally, infected, and viable H. diminuta oncospheres fed to cockroaches were found to adversely affect the success of a simultaneously offered dose of M. moniliformis eggs (acanthors). A hypothesis was put forward to explain this result; that H. diminuta oncospheres perturbed the midgut tissues in their unsuccessful attempt to burrow through the gut wall, thus initiating a wound-healing response by the hosts immune system. This resulted in gut-penetrant M. moniliformis larvae being killed by a melanotic encapsulation reaction. Unfortunately, light and electron microscopy has revealed little evidence of such a wounding in the gut which might have initiated such an immune response. Chapter 5 H. diminuta oncospheres were injected directly into the cockroach haemocoele, as it has been previously shown that a small number of parasites survive. By repeatedly passaging the few surviving cysticercoids from each infection through the rat/cockroach system it was hoped to raise a cockroach-infective strain of H. diminuta. However, their infectivity to cockroaches did not increase in successive generations; several explanations for the possible failure of this selection programme have been put forward. Intrahaemocoelic injections of pre-hatched H. diminuta oncospheres or M. moniliformis acanthellae into the host made it possible to by-pass the gut and thus investigate concurrent haemocoelic infections of cockroaches with both species of parasite. When H. diminuta was injected into M. moniliformis-infected cockroaches, prevalence and intensity of the former were significantly elevated compared to naive controls, indicating that a putative immunosuppressive action from M. moniliformis facilitated H. diminuta development. In some instances, H. diminuta was found to have burrowed through the envelope surrounding M. moniliformis and continued normal development within, unmolested by the host's haemocytes. This was considered as further evidence for the protective nature of the acanthocephalan envelope. Chapter 6 In Chapter 6, assays for aspects of haemocyte behaviour was performed on insects (in particular, P. americana) experimentally infected with either M. moniliformis or H. diminuta. It was found that the phenomenon seen in Chapter 4, whereby H. diminuta adversely affected the success of M. moniliformis when fed simultaneously to cockroaches, appears to be a direct consequence of the stimulatory effect of H. diminuta on the immune system. Conversely, the developing larvae of M. moniliformis were shown to depress haemocytic activity; possibly explaining why elevated numbers of injected H. diminuta survive in M. moniliformis-infected cockroaches. To investigate the affects of immune stimulation on the survival of parasites, locusts were injected with Zymosan, a derivative of yeast cell walls containing 1,3-glucans. H. diminuta oncospheres, injected into Zymosan-stimulated locusts appeared to be partially encapsulated, resulting in a temporary arrest in their development when compared to controls. An assay was devised to observe the encapsulation of materials in vitro by the haemocytes of P. americana. This method was used to show differences in the haemocytic encapsulation reaction to the different larval stages of M. moniliformis and H. diminuta. Both the gut-penetrant stages of each parasite (i.e. oncospheres and acanthors) were encapsulated, whereas the haemocoelic stages (i.e. cysticercoids and acanthellae to cystacanths) remained free of haemocytes. Chapter 7 Finally, in Chapter 7, a model for the alternative pathways leading to success or failure of parasitism by H. diminuta and M. moniliformis in the insect host has been discussed. The results presented here contribute to the fuller understanding of how immune stimulation and immunosuppression affect the survival of helminth parasites, particularly in the cockroach host. These two phenomena have also been shown to be effected by the parasites themselves.

Metacestodes of Hymenolepis dirninuta cause a reduction in the reproductive success of Tenebrio rno/itor by interfering with the process of vitellogenesis. The parasite produces a molecule that causes a decrease in the synthesis of vitellogenin (Vg) in the beetle host. This thesis provides an account of the progress towards the isolation of this molecule and attempts to determine its mode of action. The parasite molecule is a small peptide, as determined by its chemical nature. It is pronase sensitive and heat insensitive, has a strong absorbance at 215nm and is blocked at both the NH2- and COOH-terminals. Two putative modes of action of the parasite manipulator molecule have been explored, namely induction of apoptosis of fat body cells or alteration of Vg mRNA abundance. The levels of chromatin condensation and DNA fragmentation in fat body nuclei are significantly elevated upon infection in vivo, indicating increased apoptosis. However, fat body tissue from non-infected females cultured with live parasites did not exhibit an increase in the levels of apoptosis. This suggests that apoptosis is not induced by the parasite molecule. Follicle resorption in the ovaries was also examined. Although there is a significant increase in the number of ovarioles undergoing resorption in H dirninutainfected T. molitor, the cause is not follicle cell apoptosis.

Hymenolepis microstoma and H.diminuta were explored as models to elucidate further the mechanism and target of cyclosporin A (CsA) action in helminths. It was established that the mode of action against H.microstoma was direct and not mediated via the host immune response. Supporting evidence includes: (1) the weakly immunosuppressive derivative of CsA, B-5-49 showed similar anthelmintic action to that of CsA against H.microstoma in vivo. When administered around the time of infection, B-5-49 was marginally more effective than CsA in reducing the survival of juvenile worms, reversibly inhibiting worm growth and delaying the anterior migration of the worms to the bile duct. B-5-49 showed activity equal to that of CsA when administered to adult (19 day-old) H.microstoma reducing the numbers and weights of worms in a dose-dependent manner, causing destrobilation and ceasing worm oncosphere production. When administered subcutaneously prior to infection with H.microstoma, B-5-49 reduced worm weight although to a lesser extent than CsA. These reductions were dependent on dose and on route of administration; drug activity was considerably diminished when delivered orally rather than subcutaneously or intraperitoneally; (2) physiologically attainable concentrations of both CsA and B-5-49 were active against H.microstoma in vitro in a dose-dependent manner. Juvenile worms were more susceptible to drug action than adults; and (3) in vivo administration of B-5-49 resulted in morphological damage to the surface of H.microstoma identical to that caused by CsA. Similar morphological changes were also demonstrated when worms were exposed to either drug in vitro. Damage was both dose- and age-dependent and was characterised by proglottis swelling accompanied by apparent fluid accumulation and the formation of protuberances extending from the worm surface.

Charles University in Prague Faculty of Pharmacy in Hradec Králové Department of Biochemical Sciences Candidate: Jana Firbasová Supervisor: Doc. Ing. Barbora Szotáková, Ph.D. Title of diploma thesis: Biotransformation of selected anthelmintics in tapeworm Hymenolepis diminuta Biotransformation enzymes of parasitic helminths are recently studied in the context of the increasing resistance of helminths to anthelmintics. Knowledge of parasite detoxification system may help to increase the success of helminthoses therapy. This thesis focuses on xenobiotic metabolism in the rat tapeworm (Hymenolepis diminuta). Infection of intermediate hosts - red flour beetle (Tribolium castaneum) and mealworm beetle (Tenebrio molitor), a choice of more appropriate intermediate host, infection of definitive host (rat) and isolation of tapeworms from its intestine, was also the part of the thesis. The main task was to study the biotransformation of anthelmintics and activity of oxidation, reduction and conjugation enzymes. The results of this study show that H. diminuta is able to reduce flubendazole and mebendazol, oxidation of albendazole was not proven ex vivo. H. diminuta is equipped with oxidative enzymes (superoxide dismutase, peroxidase, catalase), which protects it from exposure to the oxidants produced by the...

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.

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...

Thesis (M. Sc.)--York University, 2002. Graduate Programme in Biology.
Title on thesis acceptance page : Molecular cloning of an [alpha]-tubulin from the Cestode, Hymenolepis, diminuta. Includes bibliographical references (leaves 110-125). Also available on the Internet. MODE OF ACCESS via web browser by entering the following URL: http://wwwlib.umi.com/cr/yorku/fullcit?pMQ71611.

It was the purpose of this investigation to determine the origin(s) of 5-hydroxytryptamine (5HT) in the rat tapeworm, Hymenolepis diminuta, where 5HT has been identified as a major neurotransmitter. Three questions were addressed in this study relative to the source(s) of 5HT in these helminths: (1) the ability or inability of these worms to synthesize 5HT via its precursors, i.e., tryptophan; and 5-hydroxytryptophan; (2) to establish whether or not 5HT is acquired directly from the host, i.e., uptake capability; (3) to establish the presence or absence of a 5HT carrier-mediated transport mechanism for 5HT absorption by these worms It was found that, in vitro, H. diminuta were severely limited in their ability to hydroxylate the indole ring of tryptophan. The majority of the exogenous tryptophan absorbed by these worms went directly into polypeptides and/or proteins. However, incubations of these helminths in 5-hydroxytryptophan (50HT) indicated that these worms are capable of decarboxylating 50HT, thereby producing an increase in 5HT These worms in vitro, after 30 minutes incubation, evidence an efficient absorption of 5HT at physiological ambient concentrations that correspond to and in some cases exceed the circadian variation of the amine in vivo. Tissue section autoradiography for ('3)H-5HT absorbed by H. diminuta indicated that there were significant concentrations of 5HT absorbed within the worm internal tissues Five-hydroxytryptamine uptake by these worms, in vitro, was significantly inhibited by its structural analogues, imipramine, tryptophan, 5-hydroxyindole acetic acid and tryptamine. However, 5HT uptake inhibition by its precursor, 5-hydroxytryptophan, was determined not significant. Further, it was found that radiolabeled 5HT uptake is inhibited by chemical 5HT yielding a histogram which suggests a carrier-mediated transport mechanism which seems to operate at the extremely low molar range In summary, it is suggested tht 5HT in H. diminuta is supplied by the host; that the parasite, incapable of manufacturing this compound (5HT) through limitations of its environment (anaerobiasis) and biochemistry, otherwise has developed absorptive mechanisms to acquire this needed compound, synthesized in the intestine by its host
acase@tulane.edu

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

碩士
國立陽明大學
寄生蟲學研究所
90
Vampiorlepis nana（＝Hymenolepis nana）constitutes the phylum of platyhelminthes , class of cestoda ,order of cyclophyllidea. H.nana is generally found in the intestine of rodents and the children are more easily infected by its egg. In this experiment, we used on antigen of oncosphere and used ELISA and western blot analysis, used Balb/c as model, study immunized by oncosphere （A:1×104oncosphere of H.nana、 B:100 oncosphere of H. nana、 C:1×104oncosphere of H.microstoma and D:1×104oncosphere of H.diminuta）and on the fourth day challenged with egg ,further , evaluate molecular weight and protection of oncosphere Ag ? The result of this experiment shows that titre of IgG in A and C group has not only significantly increased but also maintain. The titre of IgM in B and D group has significantly increased during the early phase but decreased to normal in the letter phase ; the titre of IgA in Band D group has significantly increased during the early thirtieth days but after that, if progressively decreased to normal . However, the reduction rate of the protection immunity of this Ag in A and C group were 87.7﹪and 80.9﹪,respectively. Therefore , the protection immunity of A and C group were comparatively better. The result of western blot analysis showed that among antigen extracted from oncosphere ,IgG、IgM and IgA responses were positive in sera. Most of the hydrophobic Ag appeared to have reaction in a range of 14kDa~54kDa.We hypothesis that the antigens in the range of 14kDa~54kDa may be related to host humoral responses. Further researches will be required to understand function and characterization of this protein.

碩士
高雄醫學大學
醫學研究所
100
Introduction: Hymenolepis nana is a kind of world wild spread Zoonosis disease, is usually found on children of immune suppress patient. Hymenolepis nana can be spread by eggs or from intermediate host such as beetles or flea. Zingiber officinale Roscoe is a kind of plant often use for cooking of traditional medical using. Ginger’s medical application is good for against vommit, asthma, dierrea, anti-inflammantary and treating GI or breath system decease. Method: In this research we use CH2Cl2-methanol-hexane-acetone system to separate pure compound and use to treating Hymenolepis nana in vitro, and use the more pure extraction R2 to treatment the BALB/c mice which was confirm infected by Hymenolepis nana. Then dissect the mice after treatment for ten days and examine the immune system’s variation and some marker about treating assessment. Result: 10-Shagaol and 10-Ginerol in 200 μM treating to worms was found cause the worm death at 6 hour and 12 hours. In 100 μM treating was found effect at 12 hour and 24 hours. In morphology observation find the significant injure on scolex and other segment. The EPG was found has two high peak in infected, R2 and high infected group, and the second peak of high infected group is late two days than infected group and R2 group. Weight of R2 group is less than other groups. There is no significant in worm’s number between each group but male BALB/c mice have more worms than female. Interleukin-5 and Murine KC in R2 groups is significant high than other group, but interleukin-12 has no significant in each groups. Conclusion: The extraction (R2) of Zingiber officinale Roscoe seems doesn’t show extremely effects on Hymenolepis nana infection but has the significant effects in Th2 pathway.

碩士
高雄醫學院
醫學研究所
86
Effect of saikosaponin-d, which was extracted from the root of Bupleurum kaoi, upon the immune responses against the infection of Hymenolepis nana in BALB/cmice was investigated. This Chinese medicine is famous for its reputed anti-inflammatory, anti-tumor and other biological activities. In this present study,mice were periodically treated with saikosaponin-d by intraperitoneal injectionand then infected ith Hymenolepis nana. We examined the eggs' number of per gram faece from 0 to 30 day post infection and calculated recovery number of scolice. On the other hand, we used ELISA to examin the concentration of cytokines(including interleukin-2, interleukin-4, interleukin-5 and interferon- gamma) inspleen cell culture on 30 day post infection. Compared to mice treated with phosphate buffer saline and intreated mice, longer prepatent period, less number of worms, higher levels of interleukin-2 and interferon-gamma and lower interleukin-4 and interleukin-5 were found in mice treated with saikosaponin-d.These data showed that in mice, immunity is generated against Hymenolepis nanain the injection of saikosaponin-d. These data also suggested that there is a TH1 polarization occurs during the infection of Hymneolepis nana. The possible mechanism of effect against immunocompetent cells is discussed.

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.