Dissertationen zum Thema „Protozoan diseases“
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Menon, Kathleen I. „Assessment of the antiprotozoal activity of some tubulin inhibitors following cyclodextrin complexation“. Thesis, Menon, Kathleen I. (2002) Assessment of the antiprotozoal activity of some tubulin inhibitors following cyclodextrin complexation. PhD thesis, Murdoch University, 2002. https://researchrepository.murdoch.edu.au/id/eprint/201/.
Der volle Inhalt der QuelleMenon, Kathleen I. „Assessment of the antiprotozoal activity of some tubulin inhibitors following cyclodextrin complexation“. Access via Murdoch University Digital Theses Project, 2002. http://wwwlib.murdoch.edu.au/adt/admin/view/adt-MU20040820.133836.
Der volle Inhalt der QuelleMartínez, Flórez Alba. „Drug repurposing of bioenergetic modulators: use in treatment and vaccination of protozoan parasitic diseases“. Doctoral thesis, Universitat Autònoma de Barcelona, 2017. http://hdl.handle.net/10803/458381.
Der volle Inhalt der QuelleLeishmaniases, African and American trypanosomiases and malaria are parasitic diseases that constitute a major global health problem. The increasing number of drug‐resistances to their current treatments, toxicity cases and the health assistance often required for their administration, makes it urgently necessary to develop efficient vaccines for humans and new affordable therapies, easy to apply and resistant to harsh storage conditions. Due to the fact that these diseases share similar metabolic requirements with better studied diseases, we chose drug repurposing as a potentially effective approach against them. With this purpose, six different compounds used in anti‐cancer research —dichloroacetate (DCA), 3‐bromopyruvate (3BP), 2‐deoxy‐D‐glucose (2DG), lonidamine (LND), metformin (MET), and sirolimus (SIR)— were selected according to their ability to modulate energy production and proliferation related metabolic pathways. The aim of this study was to validate the suitability of these bioenergetics modulators for the management of visceral leishmaniasis, malaria and African and American trypanosomiasis as a treatment, or as a preventive tool by enhancing the protective power of a vaccine against L. infantum. The effectiveness of these compounds was first evaluated on in vitro models of each parasite ― Chagas disease (Trypanosoma cruzi), human African trypanosomiasis (Trypanosoma brucei), visceral leishmaniasis (Leishmania infantum) and malaria (Plasmodium falciparum)―. L. infantum promastigotes were not susceptible to these compounds, whereas L. infantum intracellular amastigote growth was dose‐dependently reduced by 3BP (IC50 = 17.19 μM) and DCA (IC50 = 631.5 μM). In the T. brucei in vitro model all the tested compounds, with the exception of 2DG, affected parasite survival with IC50 values of 1.24 mM for DCA, 76.57 μM for 3BP, 26.76 μM for LND, 2.14 μM for SIR, and 17.30 mM for MET. In the case of T. cruzi, DCA, 3BP, 2DG, LND, and MET showed parasite‐killing activity with IC50 values of 27.07 mM, 27.63 μM, 7.27 mM, 78.37 μM, and 18.48 mM, respectively. For P. falciparum DCA (IC50 = 5.39 mM), 2DG (IC50 = 4.19 mM), LND (IC50 = 209.13 μM), MET (IC50 = 1.32 mM), and SIR (IC50 = 2.50 μM), showed antiplasmodial activity. These results reinforce the hypothesis that drugs with proven efficacy in the treatment of cancer by interfering with energy production might be useful in treating threatening parasitic diseases and provide new opportunities for their repurposing. However, when compounds that were effective in the in vitro approach were administered to the in vivo rodent models of these diseases, none of them contributed to disease management or parasite load control. Immunological analysis in the VL hamster model revealed a significant downregulation of immune‐activation in infected animals treated with DCA and 3BP, which may also contribute to treatment failure. In the last chapter of this work, the suitability of sirolimus as an immunomodulatory compound to boost the activity of a preventive vaccine against VL was analyzed. Sirolimus is an already marketed compound that has been described to boost immune protection against different disease models. In our study, Syrian hamsters were treated with sirolimus concomitantly with the administration of a plasmid DNA vaccine carrying the Leishmania genes LACK, TRYP, PAPLE22 and KMPII, and the subsequent response towards a L. infantum challenge was studied. Our results show that the DNA vaccine itself efficiently reduced the burden of parasites in skin (P = 0.0004) and lymph nodes (P = 0.0452), which was potentiated by SIR administration by also inducing parasitological protection in the spleen (P = 0.0004). The study of immune markers in spleen suggests that lower production of IFN‐γ and the concurrent increase of FoxP3+ expression may be responsible for the protection mediated by the DNA vaccine that was potentiated by sirolimus.
Saville, William James Allan. „The epidemiology of equine protozoal myeloencephalitis (EPM)“. Connect to resource, 1998. http://rave.ohiolink.edu/etdc/view.cgi?acc%5Fnum=osu1243352811.
Der volle Inhalt der QuelleUlrich, Paul N. „Sensitivity of molluscs to temperature, osmotic shock, and infection by protozoa implications for temperate and polar bivalves /“. Access to citation, abstract and download form provided by ProQuest Information and Learning Company; downloadable PDF file, 267 p, 2007. http://proquest.umi.com/pqdlink?did=1251900721&Fmt=7&clientId=79356&RQT=309&VName=PQD.
Der volle Inhalt der QuelleYichoy, Mayte. „Lipid uptake and metabolism in the parasitic protozoan giardia lamblia“. To access this resource online via ProQuest Dissertations and Theses @ UTEP, 2009. http://0-proquest.umi.com.lib.utep.edu/login?COPT=REJTPTU0YmImSU5UPTAmVkVSPTI=&clientId=2515.
Der volle Inhalt der QuelleMoyo, Sipho Dugunye. „Comparative study of clan CA cysteine proteases: an insight into the protozoan parasites“. Thesis, Rhodes University, 2015. http://hdl.handle.net/10962/d1020309.
Der volle Inhalt der QuelleAl-Dahwi, Zaineb. „Impairment of protective immunity to intestinal helminthiases“. To access this resource online via ProQuest Dissertations and Theses @ UTEP, 2007. http://0-proquest.umi.com.lib.utep.edu/login?COPT=REJTPTU0YmImSU5UPTAmVkVSPTI=&clientId=2515.
Der volle Inhalt der QuelleArrowood, Michael James. „Cryptosporidium: Oocyst production and hybridoma generation for examining colostrum and monoclonal antibody roles in cryptosporidial infections“. Diss., The University of Arizona, 1988. http://hdl.handle.net/10150/184335.
Der volle Inhalt der QuelleHeskett, Katherine A. „Investigation of a method to reduce false-positive equine protozoal myeloencephalitis test results title“. [Gainesville, Fla.] : University of Florida, 2004. http://purl.fcla.edu/fcla/etd/UFE0005184.
Der volle Inhalt der QuelleTypescript. Title from title page of source document. Document formatted into pages; contains 79 pages. Includes Vita. Includes bibliographical references.
Oliver, Jacques L. „Protease Inhibitors of the Eastern Oyster, Crassostrea virginica, and their Relationship to the Protozoan Pathogen, Perkinsus marinus“. W&M ScholarWorks, 1999. https://scholarworks.wm.edu/etd/1539617747.
Der volle Inhalt der QuelleChakaingesu, Chikomborero. „Synthesis and structure-activity relationship studies of 1,4-naphthoquinone derivatives as potential anti-trypanosomal agents“. Thesis, Rhodes University, 2014. http://hdl.handle.net/10962/d1020959.
Der volle Inhalt der QuelleRayo, Camacho Corona Maria del. „Natural products against protozoal diseases“. Thesis, University College London (University of London), 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.301221.
Der volle Inhalt der QuelleAngwin, Catherine-Jane. „ANALYSIS OF HUMORAL IMMUNE RESPONSES IN HORSES WITH EQUINE PROTOZOAL MYELOENCEPHALITIS“. UKnowledge, 2017. http://uknowledge.uky.edu/gluck_etds/30.
Der volle Inhalt der QuelleTownley, David. „Control of brassica clubroot disease using modern anti-protozoal fungicides“. Thesis, University of Reading, 2005. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.415514.
Der volle Inhalt der QuelleDavutluoglu, Ayten. „Detection Of Helminth Eggs And Protozoan Cysts In Wastewaters“. Master's thesis, METU, 2005. http://etd.lib.metu.edu.tr/upload/12605921/index.pdf.
Der volle Inhalt der Quelles method, which published in the &ldquo
WHO Laboratory Manual of Parasitological and Bacteriological Techniques&rdquo
and &ldquo
U.S.EPA ICR Microbial Laboratory Manual&rdquo
were used in developing the specific methods used in this study.
Cotterell, Sarah Elizabeth Jane. „The production and recruitment of leukocytes during murine visceral leishmaniasis“. Thesis, London School of Hygiene and Tropical Medicine (University of London), 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.321966.
Der volle Inhalt der QuelleBromley, Elizabeth Verity. „Characterisation of a novel protein belonging to the WD repeat family in the protozoan parasite Trypanosoma cruzi“. Thesis, London School of Hygiene and Tropical Medicine (University of London), 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.289740.
Der volle Inhalt der QuelleJoyce-Menekse, Miranda Elizabeth. „Synthesis of novel azasteroids and azastilbenes as potential inhibitors of 24-methyltransferase“. Thesis, Cardiff University, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.344021.
Der volle Inhalt der QuelleHay, Alayna Nicole. „Equine Protozoal Myeloencephalitis: investigating immunopathogenesis and treatment efficacy in mouse models and clinically affected horses“. Diss., Virginia Tech, 2020. http://hdl.handle.net/10919/96373.
Der volle Inhalt der QuelleDoctor of Philosophy
Horses are susceptible to the neurologic disease Equine Protozoal Myeloencephalitis, more commonly referred to as EPM by equine enthusiasts. The disease results from ingestion of the parasite, Saracocystis neurona, which contaminates the horse's natural environment; therefore, horses are likely to come in contact with the parasite while eating or drinking. Not all horses that encounter S. neurona develop neurologic disease, some will be protected by their immune system with the only evidence of exposure being serological antibodies. In efforts to not experimentally induce EPM in horses, an immunocompromised mouse model is often used instead. Through the use of the immunocompromised mouse model, researchers have discovered that the immune cell, T lymphocytes, and signaling molecule, interferon gamma, are important for protection against S. neurona infection. In one study conducted for this dissertation it was found that T lymphocytes need to be able to produce interferon gamma in order to provide protection. Another issue that the immunocompromised mouse model has helped address, is EPM treatment efficacy. The inability of antiprotozoal drugs that are utilized for EPM treatment to fully eliminate the parasite from the horse's body is thought to cause reoccurring disease in some horses. One non-FDA approved treatment was evaluated here and determined not to be effective in the immunocompromised mouse model. One FDA approved treatment option, which is commonly used to treat EPM, was evaluated as well. This drug was proven to be effective at preventing disease while mice were being treated but termination of treatment led to development of neurologic disease, exemplifying treatment failure. One final study was conducted to examine the different types of immune cells and signaling molecules in spinal cord tissue samples collected, from horses which had to be euthanized due to poor prognosis related to EPM. In this study a novel experimental technique was successfully used which will help progress EPM research. Overall results of these studies offered more explanation on the immune response that protects against neurologic disease from S. neurona infection and demonstrated that not all treatments are effective and reoccurring disease may be a result of treatment failure.
Ben, Younes Chennoufi Amena. „Etude immunopathologique des lésions neuromusculaires de la maladie de Chagas expérimentale de la souris“. Paris 6, 1986. http://www.theses.fr/1986PA066216.
Der volle Inhalt der QuelleRodrigues, Daniela Almeida. „MÉTODO PARA ENUMERAÇÃO DE OVOS DE HELMINTOS E OOCISTOS DE PROTOZOÁRIOS NA RIZOSFERA DE UMA MACRÓFITA“. Universidade Federal de Santa Maria, 2015. http://repositorio.ufsm.br/handle/1/7648.
Der volle Inhalt der QuelleBrazil has a sanitation service with greater deficit coverage, this factor, related to water pollution that receives the discharge of effluents untreated, mainly from domestic sources, as the collection and treatment do not exist or are inadequate. Discharging effluents directly into the ground without proper treatment can lead to contamination of water resources, soil and groundwater, according to local characteristics. Amid this reality, the degradation of natural resources on the campus of UFSM, due to increased academic population, has drawn attention of researchers and managers of the institution. There is a considerable extension of plants as weeds very close to launch domestic Campus of the University, such as Typha domingensis, which are responsible for much of retention of microorganisms in waste water releases and the study location does not exist until the when a microbiological control. This work is justified by the importance of analysis of environmental samples such releases and advocate methodologies for proving the presence of helminth eggs and oocysts of protozoa present in the rhizome of these plants. This factor becomes important by the fact that helminths and protozoa are great cause of gastrointestinal diseases and may, depending on habitat conditions, health and age, cause the individual to death. The study area was next to two buildings in the student's home with release of wastewater. The aim of this study was to develop a methodology to verify the presence of helminth eggs and oocysts of protozoa in the rhizosphere of weeds in natural environment, with release of sewage. The study was conducted in two phases, with the first phase analysis of helminth eggs and oocysts of protozoa present in twelve samples of waste water releases through Bailenger method that occurred during a period of three months, with analysis performed weekly. The second phase was to detect the presence of helminth eggs and oocysts of protozoa with a modified methodology in this paper, called Roberts & Wolff, for analysis of the rhizosphere of the rhizome of macrophyte Typha domingensis in 10 specimens of the plant, also with an approximate time of analysis of three months. The results of the first stage coincide with the data of some studies with wastewater. The results of the second phase even being positive for the presence of helminth eggs and oocysts of protozoa do not make it possible to compare, since there is the analysis results literature helminth eggs and oocysts of protozoa present in the rhizosphere of macrophyte Typha domingensis. As a result of the analysis of the first phase gave an average value of the presence of helminth eggs 112.4 eggs/ L FP35 and 113.5 eggs/ L FP50. Samples of Cryptosporidium sp all samples tested positive for the presence of oocysts and Giardia sp all were negative. In the second phase, we obtained a greater number of eggs found in a sample of one of the analyzed samples and other samples remained very close values of helminth eggs. In Cryptosporidium sp samples only the last three specimens was negative and Giardia sp only a sample of a specimen was positive.
O Brasil possui um serviço de saneamento com maior déficit de cobertura, fator esse, relacionado a poluição das águas que recebe o lançamento de efluentes sem tratamento, principalmente os de origem doméstica, uma vez que a coleta e o tratamento não existe ou é inadequado. O lançamento de efluentes diretamente no solo, sem tratamento adequado pode acarretar a contaminação dos cursos hídricos, do solo e da água subterrânea, de acordo com as características do local. Em meio a essa realidade, a degradação de recursos naturais no Campus da UFSM, devido ao aumento da população acadêmica, tem chamado atenção de pesquisadores e gestores da instituição. Há uma considerável extensão de plantas como macrófitas muito próximas aos lançamentos domésticos no Campus da Universidade, tais como a Typha domingensis, que são responsáveis por uma boa parte de retenção de microrganismos presentes em lançamentos de águas residuais e que no local estudado não existe até o momento um controle microbiológico. O presente trabalho justifica-se pela importância de análises de amostras ambientais desses lançamentos e de preconizar metodologias que possibilitem comprovar a presença de ovos de helmintos e oocistos de protozoários presentes no rizoma dessas plantas. Esse fator torna-se importante pelo fato que helmintos e protozoários são grande causadores de doenças gastrointestinais, podendo, em função das condições de habitat, saúde e idade, levar o indivíduo a morte. A área estudada foi próxima a dois prédios da casa do estudante com lançamento de águas residuais. O objetivo geral desse trabalho foi desenvolver metodologia para verificar a presença de ovos de helmintos e oocistos de protozoários na rizosfera de macrófitas em ambiente natural, com lançamento de efluentes sanitários. O estudo foi desenvolvido em duas fases, tendo como primeira fase a análise de ovos de helmintos e oocistos de protozoários presentes em doze amostras de lançamentos de águas residuais através do método de Bailenger que ocorreu durante um período de três meses, com análise realizadas semanalmente. A segunda fase foi detectar a presença de ovos de helmintos e oocistos de protozoários com uma metodologia modificada neste trabalho, denominada de Rodrigues & Wolff, para análise da rizosfera do rizoma da macrófita Typha domingensis em 10 exemplares da planta, também com um tempo aproximado de análise de três meses. Os resultados da primeira fase coincidem com dados de alguns estudos realizados com águas residuais. Os resultados da segunda fase, mesmo sendo positivos para a presença de ovos de helmintos e oocistos de protozoários não tornam possível a comparação, visto que não existe na literatura resultados de análise de ovos de helmintos e oocistos de protozoários presente na rizosfera da macrófita Typha domingensis. Como resultado das análises da primeira fase obteve-se um valor médio da presença de ovos de helmintos de 112,4 ovos/L na FP35 e 113,5 ovos/L na FP50. Nas amostras de Cryptosporidium sp todas as amostras deram positivas para a presença desse oocisto e Giardia sp todas deram negativas. Na segunda fase, obteve-se um maior número de ovos encontrados em uma das amostras de um dos exemplares analisados e as demais amostras mantiveram valores muito próximos de ovos de helmintos. Nas amostras de Cryptosporidium sp somente as dos últimos três exemplares deu negativo e Giardia sp somente em uma amostra de um exemplar deu positivo.
RIBEIRO, ROSANGELA do S. P. „Incidencia e epidemiologia da Leishmaniose visceral no norte do Tocantins“. reponame:Repositório Institucional do IPEN, 2010. http://repositorio.ipen.br:8080/xmlui/handle/123456789/9611.
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Dissertacao (Mestrado)
IPEN/D
Instituto de Pesquisas Energeticas e Nucleares - IPEN-CNEN/SP
PARTATA, ANETTE K. „Epidemiologia da Leishmaniose visceral humana em Araguaia (TO) e o diagnostico sorologico da doenca“. reponame:Repositório Institucional do IPEN, 2010. http://repositorio.ipen.br:8080/xmlui/handle/123456789/11532.
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Tese (Doutoramento)
IPEN/T
Instituto de Pesquisas Energeticas e Nucleares - IPEN-CNEN/SP
BORBOREMA, SAMANTA E. T. „Desenvolvimento e farmacocinetica de antimonio encapsulado em lipossomas de fostatidilserina utilizando radioisotopos em leishmaniose experimental“. reponame:Repositório Institucional do IPEN, 2010. http://repositorio.ipen.br:8080/xmlui/handle/123456789/9537.
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Tese (Doutoramento)
IPEN/T
Instituto de Pesquisas Energeticas e Nucleares - IPEN-CNEN/SP
Pardini, Anne Dale. „The pathology and pathogenesis of canine cerebral babesiosis“. Diss., University of Pretoria, 2000. http://hdl.handle.net/2263/27842.
Der volle Inhalt der QuelleDie patologie van die serebrale vorm van bosluiskoors in honde is ondersoek. Die letsels is makroskopies, histologies en elektronmikroskopies beskryf. Letsels kon makroskopies in twee groepe verdeel word: Globale letsels en gelokaliseerde letsels. Kongestiewe brein swelling, diffuse serebrale kongestie en serebrale anemie kom voor as globale letsels in serebrale babesiose. Multifokale bloeding en nekrose kom voor as gelokaliseerde letsels. Edeem was nie konsekwent teenwoordig nie, en was algemeen of verspreid. Die meeste algemene histologiese veranderinge was in beide serebrale en kontrole gevalle teenwoordig. Gelokaliseerde letsels waarin spesifieke hisotpatologiese veranderinge voorgekom het, was kenmerkend van serebrale babesiose. Die primere letsel is hoogs gelokaliseerde beskadiging van endoteelselle. Beskadiging van die kapillere bloedvate ontstaan vroeg in die ontwikkeling van letsels. Verdere ontwikkeling van die letsel word gekenmerk deur peri-vaskulere bloeding en neutrofiel infiltrasie wat aanduidend is van reperfusie beskadiging. Volontwikkelde letsels is plaaslik-ekstensief en het die voorkoms van hemoragiese infarkte Dit is waarskynlik dat mikrovaskulere infarksie 'n rol speel in die patogenese van die letsels, aangesien veneuse trombose nie ontstaan nie. Noue kontak tussen rooibloedselle en kapillere endoteel is elektronmikroskopies bevestig. Endoteelselnekrose ontstaan voordat tekens van beskadiging geidentifiseer kan word in neurone of gliaselle. Dit blyk dat kapillere endoteelselbeskadiging die primere letsel by die ontstaan van gelokaliseerde lese Is is, en dat sekondere lesels ontwikkel as gevolg van mikrovaskulere infarksie.
Dissertation (MSc)--University of Pretoria, 2000.
Paraclinical Sciences
Unrestricted
GALISTEO, JUNIOR ANDRES J. „Toxoplasma gondii vs radiacao ionizante: estudo da imunidade intestinal em camundongos C57Bl/6j experimentalmente vacinados com taquizoitos irradiados“. reponame:Repositório Institucional do IPEN, 2004. http://repositorio.ipen.br:8080/xmlui/handle/123456789/11255.
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Dissertacao (Mestrado)
IPEN/D
Instituto de Pesquisas Energeticas e Nucleares - IPEN/CNEN-SP
Ochaya, Stephen O. „Mapping the genome and characterization of an acetyltransferase of Trypanosoma cruzi /“. Stockholm, 2006. http://diss.kib.ki.se/20060523/ocha/.
Der volle Inhalt der QuelleSILVA, ANDREIA dos S. „Investigação de interações hiperfinas em DNA e anticorpos de diferentes linhagens de camundongos frente à infecção por T. cruzi pela epectroscopia de correlação angular gama-gama perturbada“. reponame:Repositório Institucional do IPEN, 2012. http://repositorio.ipen.br:8080/xmlui/handle/123456789/10117.
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
Tese (Doutoramento)
IPEN/T
Instituto de Pesquisas Energeticas e Nucleares - IPEN-CNEN/SP
FAPESP:08/00844-6
Gautam, Ablesh. „EXAMINATION OF THE SNSAG SURFACE ANTIGEN GENE FAMILY IN SARCOCYSTIS NEURONA“. UKnowledge, 2014. http://uknowledge.uky.edu/gluck_etds/20.
Der volle Inhalt der QuelleLobato, J?nior Wellington Sena. „Protozo?rios de vida livre em dois trechos da bacia hidrogr?fica do Rio Pirangi (RN): rela??es com a educa??o em ci?ncias e preserva??o“. Universidade Federal do Rio Grande do Norte, 2013. http://repositorio.ufrn.br:8080/jspui/handle/123456789/18238.
Der volle Inhalt der QuelleCoordena??o de Aperfei?oamento de Pessoal de N?vel Superior
The vast hidric wealth of Brazil gets its watersheds more susceptible to impacts that compromise the water quality, affecting the ecosystem stability of aquatic environments. The decrease in the quality of water resources also results in a decrease of its multiple uses, especially in tourist areas of the coast, where the continuous flow of people to these sites increases even further the probability of inappropriate behavior of both tourists and local residents. Studies regarding the microbiological communities are still scarce, especially on the free-living protozoa that play unique roles in the food chain of aquatic ecosystems. Due to the large role played by this group of microorganisms in aquatic environments, the present study aimed at identifying the genus and species of free-living protozoa present in two sections of the Pium River, east coast of Rio Grande do Norte, making an association between the its occurrence and trophic conditions of the environment in which they are, also checking the bioindicator capacity of these organisms in water quality. It also aimed to conduct a survey with students to identify the main difficulties regarding the knowledge of free-living protozoa and hydric transmission diseases in two public schools near the river studied in the Pium district, county of Parnamirim. The survey was analyzed by means of questionnaires at both schools. Students identified several activities developed Pium river, highlighting its multifunctionality and importance to the region. A total of 76 taxa of free-living protozoa was recorded, of these, 33 were ciliates, 19 flagellates and 24 sarcodia. The spatial and temporal patterns of these organisms to both points studied revealed the bioindicator potentiality of some effective species identified. However, knowledge about the free-living protozoa proved quite lagged, presenting misconceptions that show them as pathogenic organisms exclusively, totally disregarding their ecological role. In order to remedy the flaws existing in students in relation to the functional role of protozoa, workshops were planned on these microorganisms while also addressing issues related to hydric transmission diseases through lectures, recreational activities and interactive presentations. These practical activities of Science Education had the goal of bringing students the context of local water resources, aiming to promote a greater clarification regarding of the functional role of free-living protozoa in aquatic environments
A vasta riqueza h?drica do Brasil deixa suas bacias hidrogr?ficas mais suscet?veis a impactos que comprometam a qualidade da ?gua, afetando a estabilidade ecossist?mica dos ambientes aqu?ticos. A diminui??o da qualidade dos recursos h?dricos resulta tamb?m na diminui??o dos seus usos m?ltiplos, principalmente em regi?es tur?sticas do litoral, onde o fluxo cont?nuo de pessoas a esses locais aumenta ainda mais a probabilidade de comportamentos inadequados tanto dos turistas quanto dos residentes locais. Os estudos a respeito das comunidades microbiol?gicas ainda s?o escassos, principalmente as de protozo?rios de vida livre, que desempenham fun??es singulares dentro da cadeia alimentar dos ecossistemas aqu?ticos. Devido ao grande papel desempenhado por este grupo de microrganismos nos ambientes aqu?ticos, o presente estudo teve por objetivo identificar os protozo?rios de vida livre, em g?nero e esp?cie, presentes em dois trechos do Rio Pium, litoral leste do Rio Grande do Norte, fazendo uma rela??o entre a ocorr?ncia e as condi??es tr?ficas do ambiente em que se encontram. Tamb?m se objetivou realizar uma sondagem junto aos alunos para identificar as principais dificuldades quanto ao conhecimento dos protozo?rios de vida livre e doen?as de veicula??o h?drica em duas escolas p?blicas pr?ximas ao rio estudado, no distrito de Pium, munic?pio de Parnamirim. A sondagem foi analisada por meio de question?rios aplicados em ambas as escolas. Foi registrado um total de 76 t?xons de protozo?rios de vida livre, destes, sendo 33 ciliados, 19 flagelados e 24 sarcod?neos. Os padr?es espaciais e temporais desses organismos nos dois pontos estudados revelaram a potencialidade bioindicadora eficaz de algumas esp?cies identificadas. Os alunos identificaram diversas atividades desenvolvidas no Rio Pium, destacando sua multifuncionalidade e import?ncia para a regi?o. Por?m, o conhecimento sobre os protozo?rios de vida livre mostrou-se bastante defasado, apresentando concep??es alternativas que os evidenciam como organismos exclusivamente patog?nicos, desconsiderando totalmente seu papel ecol?gico primordial. Com o prop?sito de minimizar os poss?veis equ?vocos existentes nos alunos em rela??o ao papel funcional dos protozo?rios, foram planejadas oficinas did?ticas sobre estes microrganismos, abordando tamb?m temas relacionados a doen?as de veicula??o h?drica por meio de palestras, atividades l?dicas e apresenta??es interativas. Estas atividades pr?ticas de Educa??o em Ci?ncias tiveram o intuito de aproximar os alunos do contexto dos recursos h?dricos locais, almejando-se promover um maior esclarecimento sobre o papel funcional dos protozo?rios de vida livre nos ambientes aqu?ticos
Molina, Julia Pereira 1985. „Caracterização da infecção por tripanossomatídeos (Protozoa: Kinetoplastida) presentes em três espécies de cascudo (Pisces: Loricariidae) do Rio Mogi-Guaçu, SP“. [s.n.], 2010. http://repositorio.unicamp.br/jspui/handle/REPOSIP/315169.
Der volle Inhalt der QuelleDissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Biologia
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Resumo: Os tripanossomas já foram reportados em diversas espécies de peixes de água salgada e doce, sendo a maioria das espécies descritas com base nas características morfológicas. Tripanossomas parasitos de peixes são heteroxenos e são transmitidos por hirudíneos. Este trabalho tem como objetivos caracterizar a prevalência e densidade da infecção por Trypanosoma sp. presentes no sangue de três espécies de cascudos do rio Mogi Guaçu, Cachoeira de Emas, município de Pirassununga, SP e caracterizar morfologicamente e por técnicas moleculares os exemplares de Trypanosoma encontrados no sangue dos cascudos. Entre fevereiro de 2008 e fevereiro de 2009 foram coletados 256 exemplares de cascudos sendo 60 Hypostomus albopunctatus, 100 Hypostomus regani e 96 Hypostomus strigaticeps. O sangue foi coletado por punção cardíaca e alíquotas de 8?l foram retiradas para confecção de esfregaço em camada delgada, que foram fixados em metanol e corados por Giemsa, para a determinação da positividade e densidade dos tripanossomas. Após a biometria e coleta do sangue os peixes foram marcados e metade foi acondicionada em um tanque de criação do CEPTA/ ICMBIO para verificação da manutenção da infecção e o restante foi devolvido ao rio. A prevalência geral de tripanossomas foi de 47,6 % e densidade média geral de 0,75 parasitas/ µl de sangue. A prevalência ao longo do ano apresentou diferenças significativas apenas para Hypostomus regani (p=0,0054) e Hypostomus strigaticeps (p=0,0007). A densidade média de parasitas não apresentou diferenças significativas entre as três espécies de peixes analisados, assim como a variação mensal da densidade por espécie de peixes. Hirudíneos do gênero Placobdella sp. foram coletados da superfície do corpo e da boca de H regani e H. strigaticeps para extração do DNA, os oligonucleotídeos utilizados (S-1842 e S-1843) amplificaram um fragmento de 1000pb do gene 18S rRNA dos tripanossomas isolados de hirudíneos coletados em H regani e H. strigaticeps. Dos 19 peixes recapturados após dois meses apenas três se mantiveram positivos. Foram medidos 255 tripanossomas sendo 66 de H. albopunctatus, 64 de H. regani e 95 de H. strigaticeps e os valores foram comparados com os de outras espécies de tripanossomas encontradas em peixes do gênero Hypostomus. Os parasitas encontrados nas três espécies de peixes apresentaram características morfológicas semelhantes. Foi estabelecida a frequência de ocorrência de acordo com a variação do comprimento do corpo para evidência de pleomorfismo. Os dados morfológicos mostram que Trypanosoma sp.1 e Trypanosoma sp.2 podem ser considerados de espécies diferentes; as análises evidenciaram a presença de pleomorfismo nos tripanossomas encontrados nas três espécies de peixes.
Abstract: Trypanosomes have been reported in several species of fish that inhabit salt and fresh waters. The majority of these protozoan species are described based on morphologic features. The parasites are heteroxenic and are transmitted by leeches. This work aims to characterize the prevalence and density of infection by Trypanosoma sp. present in the blood of three species of armored catfish collected from Mogi Guaçu river (Cachoeira das Emas, Pirassununga city, SP) and characterize morphologically and by molecular techniques the trypanosomes found in the blood of catfish. Between february 2008 and february 2009, 256 specimens of armored catfish were collected, being 60 Hypostomus albopunctatus, 100 Hypostomus regain, and 96 Hypostomus strigaticeps. The blood was collected by cardiac puncture and a sample of 8µl was removed to realize blood smears on microscope slides. The slides were fixed in methanol and stained with giemsa for posterior analysis on light microscopy for determination of positive presence and density of trypanosomas. After biometric analysis and blood collection fish were marked half of the fish marked were maintened in a tank of CEPTA/ ICMBIO for future verification of the infeccion maintence and the other half were retorned to the river. It was found a prevalence of 47,6% and the average density of 0,75 parasitas/µl of blood. The prevalence during the year presented significative differences only for Hypostomus regani (p=0,0054) e Hypostomus strigaticeps (p=0,0007). The average density of parasites showed no significant differences among the three fish species analyzed and the monthly variation of density per species of fish. Also, leeches of the genus Placobdella sp. were collected from the surface of the body and mouth of armored catfish for DNA extraction. The primers used (S-1842 and S- 1843) amplified a 1000bp fragment of the 18S rRNA gene of trypanosomes isolated from leeches collected in H regani and H. strigaticeps. Of the 19 fish recaptured after two months only three remained positive. Therein, 255 trypanosomes were measured being 66 H. albopunctatus, 64 H. regani and 95 H. strigaticeps and values were compared with those of other parasite species found in different species of fish. The parasites found in the three species of fish presented similar morphological characteristics. The frequency of occurrence was established according to the variation in body length as evidence of pleomorphism. Nevertheless morphological data show that Trypanosoma sp.1 and Trypanosoma p.2 can be considered distinct species, the analysis revealed the presence of pleomorphism in trypanosomes found in the three species of fish.
Mestrado
Parasitologia
Mestre em Parasitologia
Branche, Carole. „Genome characterisation and mobility investigation in trypanosomes /“. Stockholm, 2006. http://diss.kib.ki.se/2006/91-7140-682-4/.
Der volle Inhalt der QuellePereira, Mirna Aparecida. „Ocorrencia de Cryptosporidium spp. e Giardia spp. em hortaliças da região metropolitana de Campinas (SP) : sua relação com a comunidade de trabalhadores e com a area agricola“. [s.n.], 2008. http://repositorio.unicamp.br/jspui/handle/REPOSIP/315591.
Der volle Inhalt der QuelleTese (doutorado) - Universidade Estadual de Campinas, Instituto de Biologia
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Resumo: Cryptosporidium spp. e Giardia spp. são parasitos causadores de gastroenterites destacando se pela elevada incidência de casos, características de resistência aos tratamentos químicos e capacidade de permanência no meio ambiente. O importante papel desses protozoários em vários surtos epidêmicos de veiculação hídrica e alimentar coloca em evidência as hortaliças que, por serem ingeridas cruas, favorecem a aquisição destas parasitoses. No Brasil, são escassos os dados sobre a ocorrência destes protozoários em vegetais como alface e rúcula, alimentos frescos amplamente consumidos pela população. O propósito deste estudo foi investigar a ocorrência destes parasitos em amostras de hortaliças cultivadas na região agrícola de Campinas (SP), e comercializadas pela Central de Abastecimento de Campinas S.A. CEASA, avaliar a água utilizada na irrigação das mesmas, e as condições higiênico sanitárias das Unidades de Produção Agrícola UPAs estudadas (n=15). Para tanto, a presença de oocistos e cistos foi determinada em amostras de alface (Lactuca saliva) e rúcula (Eruca saliva) e parâmetros fisico químicos foram estabelecidos para a água de irrigação destes vegetais, em diferentes épocas do ano. As coletas foram realizadas durante dois anos consecutivos, nos períodos de maior freqüência d<;ls chuvas e de maior ocorrência (esperada) de casos de criptosporidiose em Campinas (devido à acentuada sazonalidade do protozoário no fim do verão e início do outono) e, em períodos que correspondessem a épocas de maior utilização das águas subsuperficiais na irrigação das hortaliças, devido à escassez de chuvas. As diversas amostras de vegetais, após serem lavadas com 100ml de solução contendo Tween 80 (0,01 %), foram filtradas em membranas de ésteres mistos de celulose (47mm de diâmetro e 3/lm de porosidade nominal), seguida de eluição mediante extração mecânica. Após concentração por centrifugação (1050 x g por 10 minutos), os sedimentos resultantes foram examinados mediante a reação de imunotluorescência direta e teste confirmatório das características morfológicas empregando se o corante tluorogênico DAPI (4',6' diamidino 2 phenylindole). Também se utilizou a técnica de centrífugo tlutuação em sulfato de zinco, com o intuito de comparar a eficiência de detecção destes protozoários nos vegetais. Amostras de água de irrigação (2 litros) foram processadas pela mesma metodologia. A presença de cistos de Giardia spp. ocorreu em 4,1% das 120 amostras de hortaliças examinadas, no primeiro e terceiro períodos de coleta, e não foram encontrados na água de irrigação. Cryptosporidium spp. não foi detectado em nenhum dos períodos investigados, tanto em relação às amostras de hortaliças quanto da água de irrigação. A técnica de centrífugo flutuação em sulfato de zinco mostrou se ineficiente, pois não foi revelada a presença de cistos de protozoários e oocistos de Cryptosporidium spp. nas amostras de hortaliças, quando este método foi empregado. A sensibilidade da técnica de filtração em membranas para os vegetais foi de 2,3 % a 63,1 % para oocistos e, para cistos, 1,1 % a 29,3 %. Em amostras de água de irrigação, a sensibilidade desta metodologia variou de 6,0 % a 15 % para Cryptosporidium spp. e, de 23,6 % a 25,8 % para Giardia spp.. Cistos foram encontrados em 6,6 % das amostras de alface, com densidade de 180 a 230 cistos/50g e, 1,6% das amostras de rúcula, com densidade de 180 cistos/50g de folhas de vegetal o que representa elevada importância em Saúde Pública, dada a possibilidade de aquisição de giardiose. O esclarecimento sobre a dispersão destes protozoários no ambiente e o aperfeiçoamento de procedimentos de detecção dos mesmos, quer em amostras hídricas ou alimentares, são vantajosos para o entendimento da epidemiologia destes patógenos
Abstract: Cryptosporidium spp. and Gim-dia spp. are waterborne parasites that cause gastroenteritis. They are known for the high incidence of cases and the chemical resistance to treatments and capacity to stay intact for a prolonged time in environment. Today, the great influence of protozoa in several waterborne and foodborne outbreaks, becomes evident that vegetables eaten raw are dangerous and favor acquisition of intestinal parasitosis. In Brazil, there is little information on transmission of Cryptosporidium spp. and Giardia spp. in fresh vegetables as lettuce and rucola, largely consumed by population. The objective of this study was to investigate the occurrence of Cryptosporidium and Giardia in vegetable samples from agricultural area in Campinas District (SP, Brazil), and commercialized by Central de Abastecimento de Campinas S.A, CEASA, as well to evaluate the water used in vegetable irrigation, and the health and hygiene related conditions of Unidades de Produção Agrícola - UPAs (n = 15). Therefore, the presence of cysts and oocysts was determined in lettuce (Lactuca saliva) and rucola (Eruca saliva) samples and physico chemical parameters were established for irrigation water of vegetables, in different seasons of the year. Collections were made over two consecutive years, in such a way that chqracterized seasons of higher frequency of rains corresponding to months of higher occurrence of cryptosporidiosis cases in Campinas district (due to accentuated seasonality of protozoa in the end of summer and fhe beginning of autumn) and in per~?ds that corresponded to séasons of high peak utilization of subsurface waters in vegetable irrigation due to lack of rain. After washed with 100 ml of Tween 80 (0,01 %) several vegetable samples were filtered through mixed esters of cellulose membranes (4 7mm diameter and 311m nominal porosity), followed by elution by mechanical extraction. After concentration by centrifugation (1050 x g 10 minutes), the resulting sediments were examined by means of direct immunofluorescence reaction and confirmatory morphological test using the fluorogenic stain DAP1 ( 4', 6' diamidino 2 phenylindole), it was also used zinc sulfate centrifugation flotation method to compare detection efficiency of protozoa in vegetables. Irrigation water samples (2L) were processed by the same methodology. The presence of Giardia spp. cysts occurred in 4,1% of 120 vegetable samples, in the first and third collection periods, cysts were not detected in irrigation water. Cryptosporidium spp. was not detected in either investigated seasons Cin relation to vegetable samples and irrigation water) and the presenee of eysts and ooeysts was not detected through zinc sulfate centrifugation flotation method in either vegetable samples. Sensibility of membrane filtration method for vegetables was 2,3 % to 63,1 % oocysts and 1, I % to 29,3 % eysts, respeetively. In irrigation water samples, the sensibility of methodology varied from 6,0 % to 15 % for Cryptosporidium spp. and from 2.,3 % to 25,8 % for Giardia spp.. Cysts were found in 6,6% of lettuce samples with a density of 180 to 230 cysts/50g, and 1,6 % of rueola samples with a density of 180 eysts/50g found on vegetable leaves. Therefore, it has a high importance for public health due to risk faetor for aequisition of giardiasis. The knowledge on protozoa spreading into environment and the improvement of deteetion process in food or water samples are useful for epidemiological understanding of those parasites
Doutorado
Doutor em Parasitologia
OLIVEIRA, MARIA J. A. de. „Obtenção de membranas de hidrógeis para tratamento alternativo da Leishmaniose tegumentar“. reponame:Repositório Institucional do IPEN, 2013. http://repositorio.ipen.br:8080/xmlui/handle/123456789/10511.
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
Tese (Doutoramento)
IPEN/T
Instituto de Pesquisas Energeticas e Nucleares - IPEN-CNEN/SP
FAPESP:09/50926-1
Millet, Pascal. „Développement, en culture cellulaire, de quelques Coccidiomorphes (Isopora, Plasmodium) : mise au point d'un modèle expérimental pour la chimiothérapie du paludisme“. Paris 6, 1986. http://www.theses.fr/1986PA066272.
Der volle Inhalt der QuelleAndrade, Elisabeth Campos de. „Ensaio clínico randomizado da nitazoxanida no tratamento de poliparasitoses intestinais em municípios da Zona da Mata, Minas Gerais“. Universidade Federal de Juiz de Fora (UFJF), 2009. https://repositorio.ufjf.br/jspui/handle/ufjf/3946.
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FAPEMIG - Fundação de Amparo à Pesquisa do Estado de Minas Gerais
As parasitoses intestinais são um importante problema de saúde pública principalmente nos países subdesenvolvidos ou em desenvolvimento. Embora o parasitismo intestinal seja amplamente reconhecido como relevante no contexto epidemiológico de diversas comunidades, os estudos sobre o assunto são ainda insuficientes, principalmente no Brasil. Em vista da dificuldade de diagnóstico específico das parasitoses, muitas vezes são realizados tratamentos empíricos com mais de uma droga. O objetivo principal do presente estudo foi avaliar a efetividade e segurança do uso de nitazoxanida no tratamento de poliparasitoses comparado à terapêutica tradicional ofertada pelo serviço público. Além deste objetivo, foi possível investigar a prevalência e os fatores associados às parasitoses intestinais na população de Colônia do Paiol, uma comunidade quilombola, na Zona da Mata, Minas Gerais. Na comunidade analisada, procedeuse um estudo transversal por censo, sendo que dos 425 moradores, 391 (92%) foram avaliados através de questionário estruturado e exame coproparasitológico. Os resultados mostraram uma alta positividade (63,8%), sendo as espécies patogênicas mais freqüentes Ascaris lumbricoides (22,4%) e Trichuris trichiura (17,9%). O poliparasitismo ocorreu em 36,5% dos investigados. O ensaio clínico, controlado, duplo cego, randomizado avaliou 65 indivíduos em dois grupos de tratamento. A taxa de cura foi de 32,4% e 38,7% com a nitazoxanida e com o tratamento convencional, respectivamente, mas esta diferença não foi estatisticamente significativa (p=0,599). A ocorrência de vômito (p= 0,031) esteve associada ao tratamento convencional e de urina esverdeada ao uso de nitazoxanida (p=0,002). Os outros efeitos adversos foram independentes da droga. Houve diferença estatisticamente significativa em relação à cor da pele e a taxa de cura para ambos os tratamentos. A menor eficácia efetividade foi apresentada pelos indivíduos de cor preta. São necessários outros estudos para esclarecer a baixa efetividade nos casos de poliparasitismo, assim como, reavaliar as práticas preventivas e terapêuticas, com o uso de novas drogas e de agentes de largo espectro, podendo a nitazoxanida ser uma droga alternativa neste contexto. Agrega-se às novas possibilidades terapêuticas, a necessidade de políticas públicas que garantam qualidade de vida, através de saneamento básico, educação para saúde e acesso ao sistema público de saúde, minimizando as iniqüidades na sociedade.
Intestinal parasitism is an important public health concern, chiefly in underdeveloped or developing countries. Although widely recognized as a relevant community epidemiological issue, intestinal parasitism has not been sufficiently studied in Brazil. Because specific diagnosis is difficult and generally cumbersome, empiric treatment, sometimes with more than one drug, is frequently employed. The main aim of this study was the assessment of the effectiveness and safety of nitazoxanide for the treatment of intestinal polyparasitism, as compared to traditional therapy provided by the public service. The study also investigated the prevalence of and factors associated with intestinal parasitism in the population of Colônia do Paiol, a quilombola community from the Zona da Mata, Minas Gerais, Brazil. A census-based cross-sectional study used a structured questionnaire and stool examination to assess 391 people (92%) of the 425 inhabitants of the community. The frequency of intestinal parasitism was as high as 63.8%, with predominance of Ascaris lumbricoides (22.4%) and Trichuris trichiura (17.9%). Polyparasitism occurred in 36.5% of those investigated. A double-blind randomized controlled trial assessed 65 individuals in two treatment groups. Cure rates were 32.4% and 38.7% with nitazoxanide and conventional treatment, respectively, but the difference was not statistically significant (p = 0.599). Vomiting (p = 0.031) was associated with conventional treatment and greenish urine with nitazoxanide use (p = 0.002). Other untoward effects were independent of which drug was used. There was a statistically significant difference concerning skin color and cure rates for both treatments. Dark-skinned subjects had lower cure rates. Further studies are necessary to clarify the reasons for the low effectiveness found in these cases of polyparasitism, and to reevaluate preventive and therapeutic approaches with new and broad-spectrum drugs, nitazoxanide being an option in this context. In addition to new therapeutic approaches, there is a clear need to develop public policies that, through the provision of basic sanitation, health education and access to the public health system, assure quality of life and minimize inequity.
LE, COZ SERGE. „La rhizomanie de la betterave sucriere : multiplication du virus et aspects agronomiques de la maladie“. Paris 6, 1986. http://www.theses.fr/1986PA066644.
Der volle Inhalt der QuelleHawkesford, T. „Diagnosis, epidemiology and human immune response to cryptosporidiosis“. Thesis, 1989. https://eprints.utas.edu.au/20297/7/whole_HawkesfordTiina1989.pdf.
Der volle Inhalt der QuelleFerreira, Maryke Louise. „Systematics and ecology of Australian and South African gnathiid isopods, with observations on blood-inhabiting Protozoa found in some of their host fishes“. Thesis, 2011. http://hdl.handle.net/10210/3766.
Der volle Inhalt der QuelleIn this research project, a variety of sites and ecosystems were studied. These ranged from tropical coral reefs (north-eastern Coast of Australia), to warm temperate intertidal pools (South Coast of South Africa, SA) and sub-tropical estuaries (East Coast of SA). The overall aims of the thesis were to examine the haematophagous gnathiid ectoparasites and blood protozoans of some host teleosts found in these systems, and to some extent to investigate the role gnathiids might play as vectors of the protozoans. Gnathiid research in Australia on the Great Barrier Reef (GBR) focuses mainly on gnathiid ecology and not taxonomy. This is not the case in SA, where gnathiid taxonomy is researched more regularly and gnathiid ecology has received little attention. In this thesis, two new gnathiid species, Gnathia aureamaculosa and Gnathia sp. B, were described from a number of teleost fishes of the GBR and several morphological features, including live colouration patterns, were highlighted as useful in future gnathiid identification and discrimination. The feeding ecology of Gnathia africana from SA was also examined and this feeding study was based on similar work done on coral reef gnathiids in Australia. Gnathiids of the GBR are mainly nocturnal due to cleaner fish predation during the day, whereas G. africana was found to have a preference for dawn/early morning/midday feeding on an intertidal teleost, Clinus superciliosus. Gnathia africana‟s behaviour/feeding patterns, especially of its different juvenile stages, are therefore determined by time of day, and likely by locality and predation by other organisms, such as fishes, though probably not by cleaner fish. Gnathiid feeding behaviours/patterns are thus, it seems, determined by environmental and biological factors, and these vary according to the type of ecosystem studied. Several gnathiids and fish blood protozoan species are known from the South Coast of SA, but the East Coast has remained largely unexplored. Sampling along the East Coast yielded the first records of haemogregarines from the blood of fishes in this region, in particular new hosts and locality records probably for both probable Haemogregarina bigemina and a Haemogregarina quadrigemina – like haemogregarine. However, both haemogregarines displayed unusual features compared with the original species descriptions, in size, development patterns, or effect on host cells. Limited data suggested that juveniles of Gnathia pilosus were possible haematophagous vectors of these haemogregarines, but further studies are required to confirm this.
Cloete, Yolandi Clignet. „The characterization of an intracellular protozoan parasite infecting the digestive gland of abalone, Haliotis midae“. Thesis, 2010. http://hdl.handle.net/10210/3210.
Der volle Inhalt der QuelleAbalone are among the world’s leading shellfish consumed by human populations. Harvesting in California began in the late 1800s from intertidal zones and in the early 1900s wild abalone were collected by diving. Popular demand for abalone products in the Far East then led to extensive harvesting of wild abalone and a drastic decline in population numbers. This problem was overcome to a degree by the development of land-based abalone farms. At these farms it was possible to breed abalone on a large scale. Currently twelve abalone farms operate in South Africa and the estimated production for 2006 was 537 tons of meat, worth R 80 mil. Parasites and diseases pose threats to the production of abalone, especially under farmed conditions, and can cause considerable financial loss. Labyrinthuloides haliotidis, Haplosporidium nelsoni and Terebrasabelle heterouncinata are a few parasites that contribute to the above mentioned problems. Lately, a new protozoan parasite was discovered in the digestive glands of Haliotis midae farmed in the Western Cape Province, during routine health assessments. For the purposes of this dissertation it is designated an unidentified digestive gland parasite (UDP). The aims of this study are thus to undertake a comprehensive literature review of parasites infecting wild and farmed abalone, as well other shellfish species, describe and characterise the UDP infecting the digestive gland of Haliotis midae based on its structure and ultrastructure, evaluate the role of this parasite in disease by analysing data from histological studies, provide a preliminary indication of the life cycle of this parasite, attempt analysis of DNA from the UDP, and identify potential areas for further research into control of the parasite. A total of 180 abalone, (Haliotis midae) were collected from three abalone farms in the Western Cape during May 2005, October 2005, January 2006 and January 2007. To establish whether this parasite also occurs in wild abalone, a single sampling (six H. midae and 28 H. spadicea) took place during 2006 in Tsitsikamma National Park. Collected farmed and wild abalone were weighed and measured, removed from their shells and then killed according to accepted methods before their digestive glands were removed.
DI, CHIO Carla. „Design, synthesis and biological evaluation of novel bioactive molecules for the treatment of protozoan and human diseases“. Doctoral thesis, 2021. http://hdl.handle.net/11570/3214296.
Der volle Inhalt der QuelleDESIGN, SYNTHESIS AND BIOLOGICAL EVALUATION OF NOVEL NONPEPTIDE MOLECULES AS ANTILEUKEMIC AGENTS Diarylpentanoids are natural products extracted from several vegetables, fruits, teas and other plants. The chemical structure of these compounds is characterized by two aromatic rings linked by a five carbon (C5) bridge. These compounds could be considered as monocanrbonyl anlogues of curcumin (Figure 45), a natural product isolated from Curcuma Longa L., that has several pharmacological properties. These derivatives are characterized by the replacement of C7 bridge of curcumin with a C5 bridge, for this reason they are also called C5-curcuminoids. The diarylpentanoids are more stable either chemically or metabolically than curcumin, because of the replacement of the unstable β-diketone moiety. Among the various activities of the diarylpentanoids the most important is the antitumor activity. During my PhD work, I synthesized a new series of symmetrical diarylpentanoids 112a-p which were characterized by a dienone moiety and by a different pattern of substitution on the two phenyl rings. In this regard, we investigated the impact on cytotoxicity of electron-donating (methoxy) or electron-withdrawing (halogen) groups, which were introduced in ortho, meta or para position of both the aromatic rings. This choice was based on literature data, which attest that the antitumor activity is generally influenced by the number of substituents on the phenyl rings. In fact, the general cytotoxicity seems to enhance with an increasing number of substituents, while the cytotoxicity decreased, if the number of substituents reached eight. These compounds were tested against human acute lymphocytic CCRF-CEM leukemia cells and CEM/ADR5000 cells, a multidrug-resistant sub-line derived from drug-sensitive, parental CCRF-CEM cells developed in vitro. The results of this investigation will be reported and discussed in the next sections.
Roy, Nainita. „Understanding Heat Shock Protein 90 Biology And Exploring Its Potential As A Target Against Neglected Protozoan Diseases“. Thesis, 2011. https://etd.iisc.ac.in/handle/2005/1965.
Der volle Inhalt der QuelleRoy, Nainita. „Understanding Heat Shock Protein 90 Biology And Exploring Its Potential As A Target Against Neglected Protozoan Diseases“. Thesis, 2011. http://etd.iisc.ernet.in/handle/2005/1965.
Der volle Inhalt der QuelleKwitshana, Zilungile L. „In vitro culture and isoenzyme analysis of giardia lamblia“. Thesis, 1999. http://hdl.handle.net/10413/8226.
Der volle Inhalt der QuelleThesis (M.Med.Sc.)-University of Natal, Durban, 1999.
„Biodiversity and systematics of apicomplexan parasites infecting South African leopard and hinged tortoises“. Thesis, 2010. http://hdl.handle.net/10210/3081.
Der volle Inhalt der QuelleResearch into blood protozoans (haematozoans) infecting African tortoises is scanty with only a few records published, many during the early part of the last century. Little research had been done on the blood parasites of tortoises examined in this study namely, Kinixys lobatsiana, K. belliana belliana, K. natalensis, Geochelone pardalis pardalis, G. pardalis babcocki and Chersina angulata. The study therefore aimed to: 1) examine apicomplexan haematozoan parasites infecting several of South Africa’s indigenous tortoises and compare them with published species descriptions, especially from neighbouring Mozambique; 2) provide host details (identity, ectoparasites, host weight and gender, effects of blood parasites on host cells) and locality records in different seasons for described and new apicomplexan species; 3) describe new and recorded parasites using morphometrics and, if possible, ultrastructural characteristics 4) attempt apicomplexan DNA extraction, amplification and, if feasible, purification; and 5) establish a basis for future research as a result of the acquired knowledge. During the current study, 154 tortoises of six species in three genera, both captive and wild, and from four South African provinces (Gauteng, North West, Kwazulu-Natal and Western Cape) were sampled. Giemsa stained blood smears and use of image analysis enabled morphometric analysis of the apicomplexans and their effects on host cells, while some blood preserved in Karnovsky’s and Todd’s fixatives received detailed examination by transmission electron microscopy. Lastly, blood preserved in lysis buffer during collection, and with the highest parasitaemias, was subjected to parasite DNA extraction and amplification. Comparisons between a published account of apicomplexans recorded from K. b. belliana in Mozambique, and those found in the current study, identified two haemogregarine species. In the present research, Haemogregarina fitzsimonsi Dias, 1953 infected 2/27 (7%) wild North West K. lobatsiana, 2/3 (66%) captive Kwazulu-Natal K. natalensis, 7/14 (50%) captive Kwazulu- Natal K. b. belliana, 3/6 (50%) captive Kwazulu-Natal G. p. pardalis, 2/41 (5%) wild G. p. babcocki and 13/37 (35%) captive Gauteng G. pardalis. In addition, Haemogregarina parvula Dias, 1953, infected 2/14 (14%) captive K. b. belliana and 1/10 (10%) captive G. p. pardalis. An unknown species of haemogregarine, possibly also H. fitzsimonsi occurred in 6/16 (38%) Chersina angulata from the Western Cape. As well as haemogregarines, two haemoproteids were identified: Haemoproteus balazuci Dias, 1953 infected 2/27 (7%) wild North West K. lobatsiana, 2/2 (100%) captive Gauteng K. lobatsiana and 1/41 (2%) wild North West G. p. babcocki; Haemoproteus sp., a likely new species, was found in 1/3 (33%) captive K. natalensis. Infections with Haemogregarina and Haemoproteus were not concurrent in this study, but were found to occur concurrently in Dias (1953) findings, and only the two Haemogregarina spp. occurred together in captive Kwazulu-Natal G. p. pardalis tortoises, which do not occur naturally in the region. Haemogregarina fitzsimonsi did not appear region or host specific, since it infected 5/6 species of tortoises from all provinces sampled. Haemogregarina parvula apparently existed only in tortoises from Kwazulu-Natal. Furthermore, captive Gauteng female tortoises were found to have a higher rate of infection than males and heavier tortoises showed a lower intensity infection than lighter and younger tortoises. On average season appeared to have a slight affect on parasite prevalence, with a higher prevalence during the summer rather than the winter, possibly a result of the activity of the assumed vector, which may be the tick species Amblyomma marmoreum (found on G. pardalis) and/or Amblyomma hebraeum (found on C. angulata). For the new Haemoproteus sp., the small sample size meant that meaningful data on host-specificity and range was not gathered, but Hp. balazuci occurred in K. lobatsiana in the drier regions of the North West and Gauteng. Although DNA extraction was possible for H. fitzsimonsi, the technique requires further refinement and samples with greater parasitemias before it can be used with additional material, and sequencing can be attempted. Thus, new localities, hosts, host data and possible vectors (ticks) were recorded for the apicomplexan species identified by Dias (1953) and they were re-described using modern techniques. Also, possibly new Haemogregarina and Haemoproteus spp. were recorded, but their identity requires confirmation by DNA analysis. It is anticipated that these, and future results, will increase the knowledge of the ecology and biodiversity of apicomplexan haematozoans parasitising chelonian hosts in South Africa, with possible application to the conservation of these and other tortoise species around the world.
Stilger, Krista L. „Identification of TgElp3 as an essential, tail-anchored mitochondrial lysine acetyltransferase in the protozoan pathogen toxoplasma gondii“. Thesis, 2014. http://hdl.handle.net/1805/4660.
Der volle Inhalt der QuelleToxoplasma gondii, a single-celled eukaryotic pathogen, has infected one-third of the world’s population and is the causative agent of toxoplasmosis. The disease primarily affects immunocompromised individuals such as AIDS, cancer, and transplant patients. The parasites can infect any nucleated cell in warm-blooded vertebrates, but because they preferentially target CNS, heart, and ocular tissue, manifestations of infection often include encephalitis, myocarditis, and a host of neurological and ocular disorders. Toxoplasma can also be transmitted congenitally by a mother who becomes infected for the first time during pregnancy, which may result in spontaneous abortion or birth defects in the child. Unfortunately, the therapy currently available for treating toxoplasmosis exhibits serious side effects and can cause severe allergic reactions. Therefore, there is a desperate need to identify novel drug targets for developing more effective, less toxic treatments. The regulation of proteins via lysine acetylation, a reversible post-translational modification, has previously been validated as a promising avenue for drug development. Lysine acetyltransferases (KATs) are responsible for the acetylation of hundreds of proteins throughout prokaryotic and eukaryotic cells. In Toxoplasma, we identified a KAT that exhibits homology to Elongator protein 3 (TgElp3), the catalytic component of a transcriptional elongation complex. TgElp3 contains the highly conserved radical S-adenosylmethionine and KAT domains but also possesses a unique C-terminal transmembrane domain (TMD). Interestingly, we found that the TMD anchors TgElp3 in the outer mitochondrial membrane (OMM) such that the catalytic domains are oriented towards the cytosol. Our results uncovered the first tail-anchored mitochondrial KAT reported for any species to date. We also discovered a shortened form of Elp3 present in mouse mitochondria, suggesting that Elp3 functions beyond transcriptional elongation across eukaryotes. Furthermore, we established that TgElp3 is essential for parasite viability and that its OMM localization is important for its function, highlighting its value as a potential target for future drug development.
Makumire, Stanley. „Investigation of the role of the GGMP motif of Plasmodium falciparum Hsp70-1 on the chaperone function of the protein and its interaction with a co-chaperone, PfHop“. Thesis, 2019. http://hdl.handle.net/11602/1436.
Der volle Inhalt der QuelleDepartment of Biochemistry
The main malaria agent, Plasmodium falciparum expresses an Hsp70 (PfHsp70-1) which plays a significant role in parasite survival. PfHsp70-1 is distinct in that it possesses glycine-glycine-methionine-proline (GGMP) tetrapeptide repeats in its C-terminal domain. To date, the GGMP motif of PfHsp70-1 has not been studied. The motif is positioned within the C-terminal lid segment of PfHsp70-1. The motif is also about seven residues upstream the terminal EEVD residues that are responsible for the interaction of PfHsp70-1 with its functional regulators (co-chaperones). P. falciparum Hsp70/Hsp90 organizing protein (PfHop) constitutes one of the functional regulators of PfHsp70-1. PfHop allows PfHsp70-1 and its chaperone partner, PfHsp90 to form a functional partnership. Given the proximity of the GGMP repeats to the C-terminus of PfHsp70-1, it was postulated in this study that the GGMP repeat residues may regulate attachment of PfHop to PfHsp70-1. Hence, this study hypothesized that the GGMP repeat motif is important for the interaction between PfHop and PfHsp70-1 as well as the chaperone activity of PfHsp70-1. Two variants in which the N-terminal and the C-terminal GGMP repeats were conservatively substituted were generated. E. coli Hsp70 (DnaK) lacks a GGMP motif. Thus, the GGMP motif of PfHsp70-1 was introduced into E. coli DnaK in order to generate a third GGMP variant. Recombinant forms of PfHsp70-1, DnaK, and their GGMP variants were heterologously expressed in E. coli XL1 Blue cells. The proteins were purified to homogeneity by using a combination of Ni-NTA affinity chromatography, ion exchange, and size exclusion chromatography. Purified proteins were then biophysically characterized using CD spectroscopy and tryptophan fluorescence. Findings from this study revealed that there were minimal secondary structural differences between PfHsp70-1, DnaK and their GGMP variants. In order to investigate the chaperone function of PfHsp70-1, DnaK and the GGMP variants, a complementation assay in E. coli dnak756 cells whose Hsp70 is functionally compromised was conducted. The PfHsp70-1 GGMP variants were able to suppress the thermosensitivity of the E. coli cells. However, the Investigation of the role of GGMP motif of Plasmodium falciparum Hsp70-1 on the chaperone function of the protein and its interaction with a co-chaperone, PfHop ii DnaK-G variant failed to confer cytoprotection to the E. coli dnak756 cells. To further validate the findings from the complementation assay, the ability of the recombinant proteins to suppress aggregation of heat stressed Malate dehydrogenase (MDH) was elucidated. PfHsp70-1 had better MDH aggregation suppression capabilities than its GGMP variants. Overall, findings from the MDH aggregation suppression assay suggest that the GGMP repeats may contribute towards substrate binding. Substrate binding might be dependent on the specific positioning of a particular repeat in the GGMP motif of PfHsp70-1. Furthermore, the ATPase activity of PfHsp70-G632 and PfHsp70-G648 was significantly reduced compared to PfHsp70-1 (wild type). However, PfHsp70-G632 had the lowest ATPase activity. Interestingly, the ATPase activity of PfHsp70-G632 was enhanced in the presence of synthetic Hsp70 model peptide substrates. Slot blot and ELISA approaches confirmed that the GGMP mutations partially abrogated the interaction of PfHsp70-1 with PfHop. Altogether, the findings suggest that the GGMP motif of PfHsp70-1 has marginal effects on the structure of PfHsp70-1. In conclusion, this study provides the first direct evidence that the GGMP motif is important for the chaperone function of PfHsp70-1 as well as its interaction with PfHop.
NRF
Lebepe, Charity Mekgwa. „Comparative analysis of a chimeric Hsp70 of E. coli and Plasmodium falciparum origin relative to its wild type forms“. Diss., 2018. http://hdl.handle.net/11602/1360.
Der volle Inhalt der QuelleDepartment of Biochemistry
Sustaining proteostasis is essential for the survival of the cell and altered protein regulation leads to many cellular pathologies. Heat shock proteins (Hsps) are involved in the regulation of the protein quality control. Hsps are a group of molecular chaperones that are upregulated in response to cell stress and some are produced constitutively. The Hsp70 family also known as DnaK in Escherichia coli (E. coli) is the most well-known group of molecular chaperones. Structurally, Hsp70s consist of a nucleotide binding domain (NBD) and a substrate binding domain (SBD) conjugated by a linker sub-domain. ATP binding and hydrolysis is central to the Hsp70 functional cycle. Hsp70s play a role in cytoprotection especially during heat stress in E. coli. Hsp70s from different organisms are thought to exhibit specialized cellular functions. As such E. coli Hsp70 (DnaK) is a molecular chaperone that is central to proteostasis in E. coli. On the other hand, Plasmodium falciparum Hsp70s are structurally amenable to facilitate folding of P. falciparum substrates. The heterologous production of P. falciparum proteins in E. coli towards drug discovery has been a challenge. There is need to develop tools that enhance heterologous expression and proper folding of P. falciparum proteins in an E. coli expression system. To this end, a chimeric Hsp70, KPf consisting of E. coli DnaK NBD and P. falciparum Hsp70-1 (PfHsp70-1) SBD was previously designed. KPf was shown to confer cytoprotection to E. coli DnaK deficient cells that were subjected to heat stress. In this study it was proposed that KPf has an advantage over E. coli DnaK and PfHsp70-1 in its function as a protein folding chaperone. Therefore, the main aim of this study was to characterize the chaperone function of KPf relative to the function of wild type E. coli and P. falciparum Hsp70s. The recombinant forms of KPf, DnaK and PfHsp70-1 proteins were successfully expressed and purified using nickel affinity chromatography. Circular Dichroism (CD) structural study demonstrated that KPf and PfHsp70-1 are predominantly α-helical and are also heat stable. Tertiary structure studies of PfHsp70-1 and KPf using tryptophan fluorescence revealed that both confirmations of recombinant proteins are perturbed by the presence of ATP more than ADP. Interestingly, the substrate binding capabilities of these proteins were comparable both in the absence or presence of nucleotides ATP/ADP. KPf is an independent chaperone, that exhibit nucleotide binding and hydrolysis. The current study has established unique structure-function features of KPf that distinguishes it from its “parental” forms, DnaK and PfHsp70-1.
NRF
Mabate, Blessing. „Exploration of interaction between Plasmodium falciparum Hsp70-x (PfHsp70-x) and human Hsp70-Hsp90 organizing protein (human Hop)“. Diss., 2017. http://hdl.handle.net/11602/934.
Der volle Inhalt der QuelleDepartment of Biochemistry
Malaria is a disease that claims about half a million lives annually, mainly children. There are 5 Plasmodium species that cause malaria; namely, P. falciparum, P. ovale, P. malariae, P. knowlesi and P. vivax. P. falciparum is the most virulent of them all. The parasite upregulates some heat shock proteins (Hsps) in response to stress it encounters during its life cycle. These Hsps play a major role in proteostasis. The drug resistance of P. falciparum to traditionally used remedies has led to a need for the development of novel drugs. Hsps have been implicated as antimalarial drug targets. Hsps act as molecular chaperones and some make complexes, which are important in facilitating protein folding. As an example, heat shock protein 70 (Hsp70) and heat shock protein 90 (Hsp90) form a functional complex through an adaptor protein, Hsp70-Hsp90 organizing protein (Hop). P. falciparum expresses six Hsp70s that are localized in different subcellular compartments. Amongst them, P. falciparum Hsp70-x (PfHsp70-x), is exported to the erythrocyte where it is implicated in host cell remodeling. PfHsp70-x possesses an ATPase domain, substrate binding domain and a C-terminal subdomain. PfHsp70-x possesses an EEVN motif on its C-terminus which is implicated in interactions with co-chaperones amongst them, Hop. Although some of the chaperone functions of PfHsp70-x have been reported, its interaction with human chaperones has not been investigated. The availability of PfHsp70-x in the infected erythrocyte cytosol presents a possibility that this protein may functionally cooperate with human Hsp90 via human Hop (human Hop). This hypothesis that PfHsp70-x interacts with human chaperones is strengthened by the absence of Hsp90 and Hop of parasite origin in the infected erythrocytes. The main aim of this study was to explore the chaperone activity of PfHsp70-x and its functional co-operation with human Hop. Recombinant PfHsp70-x (full length and EEVN deletion mutant) proteins were expressed in E. coli XL1 Blue cells and purified using nickel affinity chromatography. PfHsp70-x was found to be structurally comprised of mostly alpha helices and demonstrated heat stability based on circular dichroism (CD) spectrometry studies. It was established that the EEVN motif may be important for the ATPase activity of PfHsp70-x. However, it was established that the EEVN motif was not important in regulating the holdase chaperone (protein aggregation suppression) function of PfHsp70-x. Furthermore, PfHsp70-x and its mutant preferentially bound to asparagine-rich peptides. Parasite proteins have high asparagine repeat regions as compared to human proteins. In addition, preference for asparagine-rich proteins iii could signify that PfHsp70-x is biased towards binding proteins of parasitic origin. Surface plasmon resonance (SPR) analysis suggested that PfHsp70-x interacts with human Hop with relatively higher affinity compared to its EEVN minus derivative. In conclusion, the removal of the EEVN motif of PfHsp70-x does not affect the chaperone function of PfHsp70-x. However, the EEVN motif is essential for the interaction of PfHsp70-x with human Hop.