A neurocisticercose é a forma mais severa relacionada ao complexo teníase-cisticercose, causada pela Taenia solium. Diversas medidas de controle já foram propostas, ressaltando a profilaxia via hospedeiro intermediário com o desenvolvimento de vacinas contra a cisticercose suína, que podem ser previamente avaliadas em um modelo experimental intraperitoneal com cisticercos de Taenia crassiceps, em camundongos Balb/c, constituindo a cisticercose murina. No presente trabalho foram avaliados: a resposta imune humoral pela pesquisa de anticorpos IgG anti-T. crassiceps por teste ELISA e Imunoblot, relação IgG1/IgG2a e, análise dos índices de avidez; a resposta imune celular, de acordo com os resultados de proliferação celular, dosagem de citocinas e teste de hipersensibilidade tardia (HTT) e; o índice de proteção (IP) induzido por antígeno bruto (LV-total) e purificado (18/14) de T. crassiceps, com ou sem o auxílio de adjuvantes, sob protocolos de imunização ativa por via subcutânea e oral. Paralelamente à análise de imunização ativa, houve avaliação do protocolo de imunização passiva com anticorpos monoclonais (AcMo) anti-T. crassiceps. Foram analisados 19 grupos experimentais divididos em três protocolos de imunização ativa por via subcutânea. No protocolo I foram avaliados três grupos experimentais imunizados com 10&#181;g de 18/14, uma dose, e auxílio dos adjuvantes PSS/DDA, Al(OH)3 ou sem o auxílio destes. Os grupos apresentaram IP entre 24,9% e 51,8%. No protocolo II foram analisados nove grupos imunizados com 5, 10 ou 20&#181;g de 18/14 e diferentes esquemas de adjuvantes: DODAB (IP entre 90,3% e 100,0%), PSS/DDA (IP entre 63,6% e 70,1%) ou Al(OH)3 (IP entre 60,7% e 100,0%). Comparando as concentrações antigênicas, os grupos apresentaram maiores IP quando imunizados com 5 ou 10&#181;g de 18/14. No protocolo III foram analisados sete grupos imunizados com 20, 40 e/ou 60&#181;g de 18/14, com duas ou três doses, em diferentes esquemas de adjuvantes: PSS/DDA e Al(OH)3 ou sem adjuvantes, com IP entre 63,5% e 100,0%. A avaliação da resposta imune humoral dos grupos imunizados por via subcutânea demonstraram a presença de anticorpos IgG por teste ELISA em todos os grupos imunizados, sem correlação dos índices de reatividade (IR) com os IP. Por imunoblot, foram reconhecidas, pelo menos, as proteínas de 14 e 18 kDa após 15 (T15), 30 (T30) e/ou 60 (T60) dias contados a partir da 1ª dose de imunização. Os grupos imunizados por via subcutânea que apresentaram IP> 90,0% tiveram relação IgG1/IgG2a >1,0 no T30 e <1,0 no T60. Quanto à avaliação da resposta imune celular, 10 dos 12 grupos avaliados por ensaios de proliferação de células obtidas de linfonodos induzidas por 18/14 apresentaram índices de estimulação (IE) positivos, enquanto que o antígeno L-Vtotal demonstrou-se imunossupressor nestes experimentos. A análise de dois grupos imunizados de forma ativa, por via subcutânea, com IP=100%, mostrou o predomínio de citocinas com polarização Th1 (IFN-&#947;) no T60 e Th2 (IL-4) no T120. Não houve correlação dos IP com os resultados obtidos com HTT, porém, os resultados foram variáveis de acordo com o perfil antigênico e o adjuvante utilizado pela via subcutânea. Sequencialmente foram analisados seis grupos imunizados de forma ativa, por via oral, com 10, 20 ou 30&#181;g de LV-total, uma ou duas doses, com o auxílio de Al(OH)3 que apresentaram IP entre 48,3% e 100,0%, sem diferença significativa entre os grupos, exceto com o grupo imunizado com duas doses de 30&#181;g, o qual apresentou 100,0% de IP. No T15 e T30 os IR obtidos em teste ELISA para pesquisa de anticorpos IgG anti-T. crassiceps foram entre 0,9 e 2,4, enquanto que no T60 entre 2,6 e 5,1. Por Imunoblot, foram reconhecidas as proteínas de 14, 18, 30 e >40kDa no T60. A relação IgG1/IgG2a foi <1,0 no T30 e no T60, enquanto que HTT foi apresentado <40,0% no T30 e T60. Adicionalmente aos ensaios de imunização ativa, seis grupos de camundongos Balb/c imunizados de forma passiva com anticorpos monoclonais anti-T. crassiceps apresentaram IP até 93,0%. De acordo com os resultados obtidos, antígenos bruto e purificado de T. crassiceps foram considerados promissores para imunização murina, principalmente o 18/14 quando utilizado com DODAB ou hidróxido de alumínio pela via subcutânea. Os mecanismos protetores não foram totalmente elucidados, porém, demonstram polarização para resposta Th1 e proteção parcial dependente de IgG, demonstrada pelos ensaios de imunização passiva. / Neurocysticercosis is the most severe form of infection related to the complex taeniasis-cysticercosis, caused by Taenia solium. Several control measures have been proposed, emphasizing the prophylaxis via intermediate host through the development of vaccines against porcine cysticercosis, which may be previously evaluated in an intraperitoneal experimental model using cysticercus of Taenia crassiceps, in Balb/c mice, constituting the murine cysticercosis. In this study were evaluated: the humoral immune response by search of anti-T. crassiceps IgG antibody by ELISA and Immunoblot assays, IgG1/IgG2a ratio and, analysis of avidity indices; the cellular immune response by proliferation assay, cytokine maeasurements and delayed hypersensitivity assay (DHA) and; protection index (PI) induced by crude antigen (total-VF) and purified (18/14) of T. crassiceps, with or without adjuvants, through active immunization protocols by subcutaneous and oral administration. In parallel to the active immunization was performed the evaluation of passive immunization protocol with anti-T. crassiceps monoclonal antibodies (AcMo). Were analyzed 19 experimental groups, divided into three active immunization protocols by subcutaneous via. In I Protocol were evaluated three experimental groups which were immunized with 10&#181;g of 18/14 antigen, one dose, with or without PSS/DDA, Al(OH)3 adjuvants. These groups showed PI between 24,9% and 51,8%. In II Protocol were evaluated nine experimental groups which were immunized with 5, 10 or 20&#181;g of 18/14 antigen, using different schemes of adjuvants: DODAB (PI between 90,3% and 100,0%), PSS/DDA (PI between 63,6% and 70,1%) or Al(OH)3 (PI between 60,7% and 100,0%). Comparing the concentrations antigenic, groups had higher IP when immunized with 5 or 10&#181;g of 18/14 antigen. In III Protocol were evaluated seven groups immunized with 20, 40 and/or 60&#181;g of 18/14 antigen, with two or three doses, using also different schemes of adjuvants: PSS/DDA and Al(OH)3 adjuvants or without them, showing PI between 63,5% and 100,0%. The evaluation of humoral immune response of all subcutaneous immunizated groups demonstrated the presence of IgG antibodies by ELISA in all immunized groups, without correlation between reactivity indices (RI) and PI. By immunoblot, were recognized at least the 14 and 18 kDa proteins after 15 (T15), 30 (T30) and/or 60 (T60) days from the first dose immunization. The groups immunized subcutaneously that showed PI > 90,0% had IgG1/IgG2a ratio >1,0 in T30 and <1,0 at T60. About the cellular immune response evaluation, 10 among 12 groups evaluated by proliferation assays using lymphonodes stimulated with 18/14 antigen showed indices of stimulation (IS) positive, while the VF-total antigen was shown immunosuppressive in these experiments. The analysis of two groups actively immunized subcutaneously with PI equal to 100%, showed predominance of cytokines tending to Th1 (IFN-&#947;) in T60 time and Th2 (IL-4) in T120 time. There was no correlation between PI indices and the results obtained from the DHA, however, the results varied according to the antigenic profile and the adjuvant subcutaneously used. Sequentially were analyzed six groups actively immunized by oral via, with 10, 20 or 30&#181;g of LV-total, one or two doses, supported by Al(OH)3 adjuvant which showed PI between 48,3% and 100,0%, with no significant difference between the groups, except the group immunized with two doses of 30&#181;g, which had PI of 100,0%. In T15 and T30 times the reactivity indices obtained by ELISA test for the detection of IgG anti-T. crassiceps antibodies were between 0,9 and 2,4, while in T60 time they were between 2,6 and 5,1. By Immunoblot, were recognized the 14, 18, 30 and > 40kDa proteins in T60 time. The IgG1/IgG2a ratio was <1,0 in T30 and T60 time, while DHA was presented <40,0% in T30 and T60. In addition to the active immunization assays, groups of six Balb/c mice were passively immunized with anti-T. crassiceps monoclonal antibodies and they showed PI up to 93,0%. According to the obtained results, crude and purified antigens of T. crassiceps were considered promising for murine immunization, especially when 18/14 antigen was used together with DODAB or aluminum hydroxide subcutaneously. The protective mechanisms have not been fully elucidated, however, showed trend towards Th1 response and dependent partial protection of IgG, as demonstrated by passive immunization assays.

Added t.p. with thesis statement inserted. / Bibliography: leaves 25-28.

Orientador: Cáris Maroni Nunes / Resumo: O complexo teníase-cisticercose é causado pelos cestódeos Taenia saginata e Taenia solium, que têm o homem como hospedeiro definitivo e obrigatório e os bovinos e os suínos, respectivamente, como hospedeiros intermediários. A presença da forma adulta destes cestódeos no intestino delgado causa pequenos danos ao homem, enquanto a presença das formas larvárias nos tecidos e órgãos causam lesões nos hospedeiros intermediários, resultando na cisticercose. O homem pode também ser hospedeiro ocasional da T. solium e desenvolver a cisticercose, quando da ingestão acidental de seus ovos. Uma das medidas de controle desta zoonose é a inspeção sanitária de bovinos e suínos ao abate, evitando assim que os parasitas completem seu ciclo biológico. Assim, o complexo teníase-cisticercose, além de ser um grave problema de saúde pública, é também um problema econômico na agropecuária, visto que as carcaças podem ser condenadas quando da presença de formas larvares ou terem seu valor reduzido. A neurocisticercose é a forma mais grave desta zoonose no homem e seu diagnóstico é realizado por meios imunológicos e/ou por exames de imagens, que permitem a visualização dos das lesões no sistema nervoso central. Já a teníase é diagnosticada por meio da pesquisa de proglotes ou de ovos das tênias nas fezes, os quais são indistinguíveis morfologicamente. O objetivo do presente estudo foi avaliar a ocorrência de teníase humana por meio da análise dos resultados de exames coproparasitológicos rotineirame... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: The taeniasis-cysticercosis complex is caused by the cestodes Taenia saginata and Taenia solium, which have man as their definitive and mandatory host and cattle and swine, respectively, as intermediate hosts. The presence of the adult form of these cestodes in the small intestine causes minor damage to humans, while the presence of the larval forms in tissues/organs causes damage to the intermediate hosts, resulting in cysticercosis. Man can also be an occasional host of T. solium and develop cysticercosis when ingesting its eggs. One of the measures to control this zoonosis is sanitary inspection of cattle and pigs at slaughter in order to prevent the parasites from completing their biological cycle. Thus, in addition of being a serious public health problem the taeniasiscysticercosis complex is also an economic problem once the carcasses with the larval forms can be condemned or have a reduced value. Neurocysticercosis is the most severe form of this zoonosis in man and its diagnosis is done by immunological method and/or by imaging exams, which allow the visualization of the lesions in the central nervous system. Taeniasis is diagnosed by searching for proglottids and/or tapeworm eggs in feces, which are morphologically indistinguishable. The objective of the present study was to evaluate the occurrence of human taeniasis by analyzing the results of the coproparasitological exams routinely performed in a private clinical analysis laboratory at a city in São Paulo state, B... (Complete abstract click electronic access below) / Mestre

Made available in DSpace on 2015-03-26T13:46:43Z (GMT). No. of bitstreams: 1 texto completo.pdf: 1492276 bytes, checksum: 4d382ffe8ee028de0569c86987765f6b (MD5) Previous issue date: 2004-12-14 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / This study was carried out with the purpose to develop an serological diagnosis protocol of bovine cysticercosis for the ELISA test using two metacestodes antigens of Taenia crassiceps and three of Taenia solium. There were used 20 sera of experimentally infected cattle with T. saginata eggs, 60 of cattle with natural infection, diagnosed at slaughterhouses, five of cattle negative for cisticercose, reared in isolation, 55 of negative bovine in slaughterhouses and 10 of bovine with actinomicosis (n=2), actinobacilosis (n=1), fasciolosis (n=1) diagnosed at slaughterhouse and of experimentally infected cattle with Anaplasma marginale (n=3), Babesia sp. (n=2) and concomitant infection for Anaplasma marginale and Babesia bovis (n=1). There were used the total and fluid cistic antigens of T. Crassiceps metacestodes and escólex and membrane antigens of T. solium metacestodes in ELISA test, after previous characterization in polyacrylamide gel electrophoresis (PAGE) in gradient 5 to 20%. The better antigen concentration was 1 µg and the better sera and conjugated dilutions were 1:25 and 1:5.000, respectively. Although the T. solium antigens have provided the most sensibility values, the T. crassiceps antigens also showed good performance to the bovine cysticercosis diagnosis. Different control serum groups employed for the cut-off calculation had changed the ELISA test results. We can concluded that the ELISA test for antibodies detection presents deficiencies in the diagnosis of naturally infected animals that showed low sensibility (5 to 32%) for different antigens. However, for experimentally infected cattle, the sensibility was high, 75 to 90% for different antigens. The test could still be considered useful in the differentiation between the cisticercose and other diseases, due to its high specificity rates (81 to 100%). / A cisticercose bovina é uma zoonose que tem o ser humano como único hospedeiro definitivo. Além de sua importância para a Saúde Pública, esta parasitose acarreta prejuízos econômicos em matadouros, ao levar as carcaças acometidas a julgamento. Este trabalho teve como objetivo o desenvolvimento de um teste de diagnóstico sorológico da cisticercose bovina pelo teste ELISA empregando dois antígenos de larvas de Taenia crassiceps e três de Taenia solium. Foram utilizados 20 soros de bovinos infectados experimentalmente com ovos de T. saginata, 60 de bovinos com infecção natural, diagnosticados em matadouros, cinco de bovinos negativos para cisticercose, criados sob isolamento, 55 de bovinos considerados negativos em matadouros e 10 de bovinos portadores de actinomicose (n=2), actinobacilose (n=1), fasciolose (n=1) diagnosticados em matadouro e de bovinos infectados experimentalmente com Anaplasma marginale (n=3), Babesia sp. (n=2) e infecção mista por Anaplasma marginale e Babesia bovis (n=1). Foram empregados os antígenos total e vesicular de larva de Taenia crassiceps e total, de escólex e de membrana de larva de Taenia solium no teste ELISA, após prévia caracterização em eletroforese em gel de poliacrilamida (SDS-PAGE) sob gradiente 5 a 20%. Após a realização de ensaios de avaliação do desempenho do teste em duas etapas, sempre considerando o critério da amplitude da diferença entre densidades ópticas de soros-controle positivos e negativos, foram obtidos os resultados que se seguem. A concentração de 1 µg de antígeno por orifício foi a que proporcionou, na maioria das vezes, a maior diferenciação entre soros positivos e negativos com todos os cinco antígenos estudados. As diluições 1:25 de soros e 1: 5.000 de conjugado também foram as que se destacaram, à exceção do antígeno de líquido vesicular de larva de T. crassiceps, que teve melhor desempenho quando o conjugado foi diluído a 1:2.500 vezes. O leite desnatado foi a melhor substância bloqueadora dos sítios reativos remanescentes da placa. Embora os antígenos de larva de T. solium tenham proporcionado valores mais elevados de sensibilidade, os antígenos de larva de T. crassiceps também mostraram bom desempenho no diagnóstico de cisticercose bovina. A escolha de diferentes grupos de soroscontrole para o cálculo do ponto de corte interferiu de forma expressiva no desempenho do teste ELISA. Pode-se concluir que o teste ELISA para detecção de anticorpos apresenta deficiências no diagnóstico de animais destinados ao abate, em virtude de sua baixa sensibilidade (5 a 32%) para diferentes antígenos, quando se consideram soros de animais com infecção natural, geralmente discreta. No entanto, no caso de animais infectados experimentalmente, a sensibilidade se mostrou elevada, 75 a 90%, para diferentes antígenos. O teste ainda pode ser considerado útil na diferenciação entre a cisticercose e outras doenças, devido às suas elevadas taxas de especificidade (81 a 100%).

Orientador: Marco Antônio Zanini / Resumo: A hidrocefalia é uma das complicações mais frequentes da neurocisticercose extraparenquimatosa, combinando mecanismos obstrutivos e inflamatórios que causam prejuízos à circulação de líquor. Modelos experimentais podem auxiliar na compreensão de mecanismos fisiopatológicos da doença. Estudamos alterações comportamentais, radiológicas e morfológicas de ratos num modelo experimental de hidrocefalia induzida por neurocisticercose através da inoculação cisternal de cistos e antígenos de Taenia crassiceps comparando-o com o modelo clássico de hidrocefalia experimental induzida por caulim. Foram utilizados 52 animais divididos em quatro grupos: cistos, antígenos, caulim e controle. Para avaliação comportamental foi utilizado teste de campo aberto; para avaliação radiológica foram adquiridas imagens de ressonância magnética com estudo de volume ventricular; e para avaliação morfológica foram analisadas figuras de inflamação e expressão imunoistoquímica de proteína ácida fibrilar glial (GFAP) e aquaporina-4 (AQP-4). Diferentemente do que ocorre na hidrocefalia por caulim, o comportamento dos animais com hidrocefalia por neurocisticercose não foi alterado precocemente (p = 0,02). O volume ventricular da hidrocefalia induzida por neurocisticercose experimental teve evolução progressiva e as alterações de ressonância magnética foram semelhantes às observadas em humanos. A hidrocefalia induzida por neurocisticercose experimental induz reações inflamatórias e astrocitária periventriculare... (Resumo completo, clicar acesso eletrônico abaixo) / Doutor

Bovine cysticercosis is a zoonotic disease for which cattle are the intermediate hosts of the human tapeworm <i>Taenia saginata</i>. Routine inspection measures are implemented in Canada by the Canadian Food Inspection Agency (CFIA), and similarly elsewhere, for the postmortem detection of larval parasite cysts (cysticerci) in beef destined for human consumption. Detection is based on the gross examination of traditional carcass predilection sites, although it is recognized that the parasite has no true predilection for a particular tissue or site. In order to evaluate the efficacy of the inspection protocol currently implemented in Canada, a study was undertaken to determine the distribution of <i>T. saginata</i> cysticerci in tissues of experimentally infected cattle. Forty-two cross-bred beef cattle were divided into five groups of 5-12 animals each and inoculated orally with either 10000, 5000, 1000, 100 or 10 <i>T. saginata</i> eggs obtained from cases of human taeniosis in Thailand. From 47 to 376 days post-inoculation (DPI), ten animals inoculated with 5000 eggs were killed and the carcasses partitioned into 31 tissue sites. These consisted of the traditionally inspected tissue sites of heart, masseter and pterygoid muscles, tongue, oesophagus, and diaphragm (membranous and crura); as well as non-traditional sites of lung, liver and 20 additional muscles or muscle groups. After the routine inspection for cysticerci of traditional tissue sites, tissues from all sites were each cut into approximately 0.5 cm thick slices and the total number of parasitic cysts and cyst density (cysts/g of tissue) were determined for each site. Traditional sites were similarly evaluated for the remaining 32 animals that were killed between 117 and 466 DPI. Sites were ranked based on cyst density. In the animals for which non-traditional sites were also evaluated, no sites had higher cyst densities than those traditionally inspected. When only traditional sites for all animals were compared, the heart ranked highest overall, although not significantly different from masseter, and was the most frequently affected site. The traditional site of oesophagus was among the poorest of all sites for detection of cysticerci. The heart was confirmed as the site of choice for detection of bovine cysticercosis based on high cyst density and frequency of infection. There was also enhanced visibility of parasite lesions in the heart due to the relatively early degeneration and resultant gross pathology that occurs in cardiac muscle. More thorough examination of the heart is recommended during post-mortem inspection for this parasite, particularly when examining animals from an infected herd. <p>Currently, confirmation by CFIA of suspect cysticerci recovered during meat inspection relies on gross, stereomicroscopic, or standard histological examination. Although degenerating cysticerci are more likely to be detected and submitted for diagnosis, they often cannot be definitively identified by these methods. A recently developed monoclonal antibody-based immunohistochemical (IHC) assay for post-mortem diagnosis of this parasite was optimized and standardized. The IHC method was compared to the currently used histological assay using 169 degenerated known-positive <i>T. saginata</i> cysticerci collected from the experimental infections in the first study and from field submissions, and known-negative specimens and lesions of various etiologies from non-infected cattle. The use of the IHC assay identified significantly more known-positive bovine cysticerci (91.7%) than the histological method (38.5%), and non-specifically reacted only with the other cestode species examined. Since <i>T. saginata</i> is the only larval cestode typically found in the muscle of cattle, this cross-reactivity is not significant and the IHC assay will be a useful tool for the identification of lesions caused by degenerated bovine cysticerci.<p>This research provided evidence to support changes to the current post-mortem inspection, detection and diagnostic procedures and will contribute to more effective and efficient control of bovine cysticercosis.

Bovine cysticercosis is a zoonotic disease for which cattle are the intermediate hosts of the human tapeworm <i>Taenia saginata</i>. Routine inspection measures are implemented in Canada by the Canadian Food Inspection Agency (CFIA), and similarly elsewhere, for the postmortem detection of larval parasite cysts (cysticerci) in beef destined for human consumption. Detection is based on the gross examination of traditional carcass predilection sites, although it is recognized that the parasite has no true predilection for a particular tissue or site. In order to evaluate the efficacy of the inspection protocol currently implemented in Canada, a study was undertaken to determine the distribution of <i>T. saginata</i> cysticerci in tissues of experimentally infected cattle. Forty-two cross-bred beef cattle were divided into five groups of 5-12 animals each and inoculated orally with either 10000, 5000, 1000, 100 or 10 <i>T. saginata</i> eggs obtained from cases of human taeniosis in Thailand. From 47 to 376 days post-inoculation (DPI), ten animals inoculated with 5000 eggs were killed and the carcasses partitioned into 31 tissue sites. These consisted of the traditionally inspected tissue sites of heart, masseter and pterygoid muscles, tongue, oesophagus, and diaphragm (membranous and crura); as well as non-traditional sites of lung, liver and 20 additional muscles or muscle groups. After the routine inspection for cysticerci of traditional tissue sites, tissues from all sites were each cut into approximately 0.5 cm thick slices and the total number of parasitic cysts and cyst density (cysts/g of tissue) were determined for each site. Traditional sites were similarly evaluated for the remaining 32 animals that were killed between 117 and 466 DPI. Sites were ranked based on cyst density. In the animals for which non-traditional sites were also evaluated, no sites had higher cyst densities than those traditionally inspected. When only traditional sites for all animals were compared, the heart ranked highest overall, although not significantly different from masseter, and was the most frequently affected site. The traditional site of oesophagus was among the poorest of all sites for detection of cysticerci. The heart was confirmed as the site of choice for detection of bovine cysticercosis based on high cyst density and frequency of infection. There was also enhanced visibility of parasite lesions in the heart due to the relatively early degeneration and resultant gross pathology that occurs in cardiac muscle. More thorough examination of the heart is recommended during post-mortem inspection for this parasite, particularly when examining animals from an infected herd. <p>Currently, confirmation by CFIA of suspect cysticerci recovered during meat inspection relies on gross, stereomicroscopic, or standard histological examination. Although degenerating cysticerci are more likely to be detected and submitted for diagnosis, they often cannot be definitively identified by these methods. A recently developed monoclonal antibody-based immunohistochemical (IHC) assay for post-mortem diagnosis of this parasite was optimized and standardized. The IHC method was compared to the currently used histological assay using 169 degenerated known-positive <i>T. saginata</i> cysticerci collected from the experimental infections in the first study and from field submissions, and known-negative specimens and lesions of various etiologies from non-infected cattle. The use of the IHC assay identified significantly more known-positive bovine cysticerci (91.7%) than the histological method (38.5%), and non-specifically reacted only with the other cestode species examined. Since <i>T. saginata</i> is the only larval cestode typically found in the muscle of cattle, this cross-reactivity is not significant and the IHC assay will be a useful tool for the identification of lesions caused by degenerated bovine cysticerci.<p>This research provided evidence to support changes to the current post-mortem inspection, detection and diagnostic procedures and will contribute to more effective and efficient control of bovine cysticercosis.

This item was digitized as part of the Million Books Project led by Carnegie Mellon University and supported by grants from the National Science Foundation (NSF). Cornell University coordinated the participation of land-grant and agricultural libraries in providing historical agricultural information for the digitization project; the University of Arizona Libraries, the College of Agriculture and Life Sciences, and the Office of Arid Lands Studies collaborated in the selection and provision of material for the digitization project.

Memoria para optar al Título Profesional de Médico Veterinario / La cisticercosis muscular bovina (Cysticercus bovis) es una zoonosis con importancia económica y para la salud pública. En el presente estudio se dan a conocer antecedentes sobre la presencia de C. bovis en predios de las regiones de Coquimbo, Valparaíso y Metropolitana y su relación espacial con asentamientos humanos y cursos de agua superficiales que actuarían como factores de riesgo. Para esto se realizó un seguimiento a 457 bovinos diagnosticados post-mortem con cisticercosis muscular, beneficiados durante el año 2010 en dos plantas faenadoras que cuentan con inspección veterinaria oficial del Servicio Agrícola y Ganadero en la Región de Valparaíso. Del total indicado, 424 casos correspondieron a cisticercosis leve (92,78%) y 33 casos a cisticercosis masiva (7,22%). De los 26.167 bovinos beneficiados en la región, por categoría, las vacas fueron las que presentaron un mayor porcentaje de hallazgos de C. bovis (2,38%) diferencia estadísticamente significativa (α=0,05), comparado con novillos, bueyes, toros, vaquillas y terneros. Según la distribución mensual, se observó una mayor proporción de casos en los meses de verano, también diferente significativamente comparado con las otras tres estaciones (α=0,05). Se descartaron 48 animales de procedencia distinta a las regiones objetivo y 113 animales (24,7%), que no presentaban todos los antecedentes necesarios para determinar su predio de origen. De esta manera, se obtuvo un grupo de 296 bovinos, pertenecientes a 112 predios, de los cuales 12 se encontraron en la Región de Coquimbo, 78 en la Región de Valparaíso y 22 en la Región Metropolitana.. Estos predios se georreferenciaron y situaron en un mapa digital donde se registró la distancia que presentaban con asentamientos humanos y cursos de agua superficiales, obteniéndose en ambos casos, que la mayor cantidad de predios positivos a esta parasitosis, se ubicaban en áreas cercanas (menos de 300 metros) de dichos factores de riesgo

Neurocysticercosis is a disease in which larvae of the tapeworm, Taenia solium, infect the central nervous system of humans. Seizures are the most common symptom of NCC, occurring in between 70 % and 90 % of all symptomatic NCC cases. Neurocysticercosis impacts heavily on the quality of life of patients, and further presents a significant drain on the economic resources of endemic countries. Despite its considerable global impact, the molecular and cellular mechanisms underlying seizures in neurocysticercosis remain largely unknown. In this thesis I have explored novel models for neurocysticercosis by combining mouse hippocampal organotypic brain slice cultures with various preparations of a model parasite, Taenia crassiceps. Utilising these models, I first explored, using patch clamp and local field potential electrophysiology, how Taenia larval extracts directly affect neuronal excitability. I report that extracts of Taenia crassiceps resulted in a significant acute excitation of neurons and triggered seizure-like events in brain slices. Further investigation revealed that this excitation was mediated by the activation of glutamate receptors and that, indeed, the larvae of both Taenia crassiceps and Taenia solium contain and produce levels of glutamate sufficient to explain this effect. Chronic exposure of brain slices to intact, living, larvae did not, however, result in any changes in network excitability. Next, I investigate whether Taenia larvae produce acetylcholinesterases, as these enzymes have the potential to affect neuronal signaling by digesting the neurotransmitter acetylcholine. Ellman's assays, in situ acetylcholinesterase activity assays, and patch clamp electrophysiology reveal that both Taenia crassiceps and Taenia solium larvae produce acetylcholinesterases and that the activity of Taenia acetylcholinesterases is sufficient to digest acetylcholine at a concentration that alters neuronal signaling. Finally, I explore the effect that Taenia larval extracts have on the innate immune cells of the brain, as the responses of these cells can also alter neuronal excitability. Through the measurement of brain slice cytokine release using enzyme-linked immunosorbent assays, I discover that Taenia crassiceps extracts have robust antiinflammatory effects, which involve lipid, protein, and glycan elements. This thesis presents novel findings that reveal ways in which Taenia larvae interact with both neuronal and nonneuronal resident brain cells. It further delves into how these interactions could contribute to seizure generation in neurocysticercosis and proposes some potential new therapeutic approaches to treat seizures in neurocysticercosis.