El documento digital no refiere asesor / Estudia y cuantifica la infección de Toxoplasma gondii en felinos domésticos asociado al tipo de crianza, controlada (sin acceso a la calle) y no controlada (con acceso libre a la calle). Se trabajo con 106 muestras de sangre procedente de diferentes distritos de Lima, que se analizaron con la prueba de Hemaglutinación indirecta. Se encontró que el 17.9 % (19/106) presentaron anticuerpos contra T. gondii; siendo de 16% (8/50) y 19.6% (11/56) de animales positivos en los grupos de crianza controlada y no controlada respectivamente, y un Odds Ratio de 1.2 (0.5 – 2.6). No se encontró asociación significativa entre la frecuencia de infección y el tipo de crianza. Sin embargo las variables sexo y dieta resultaron asociadas significativamente, al ser evaluadas mediante la prueba de Chi-cuadrado. El estudio demuestra que las infecciones por T. gondii en felinos domésticos no pueden ser atribuidas exclusivamente al tipo de crianza, sino que existen otras fuentes de infección que deben de tenerse en cuenta para evitar el riesgo de infección de estos animales y potencialmente el hombre. / Tesis

Analiza el sistema disciplinatorio de los miembros de Sendero Luminoso en la cárcel, ya que la disciplina que ejerció esta agrupación dentro de las cárceles limeñas siempre fue tomada desde un aspecto muy tangencial, sin tener en cuenta lo importante que es entender sus funciones y sus partes. Así como también observar a través de la cotidianidad carcelaria senderista, disciplinada y políticamente dogmática, qué hubiera pasado si Sendero Luminoso hubiera tomado el poder, teniendo como herramienta las diferentes perspectivas de los que vivieron en los pabellones dominados por esta agrupación. El presente estudio tiene como espacio definido el sistema penitenciario peruano, en especial el penal de máxima seguridad Miguel Castro Castro y las diferentes cárceles limeñas, como las de Lurigancho y Santa Mónica, en donde se encontraron los pabellones dominados por Sendero Luminoso en los años que van desde 1980 a 1992. En este periodo, denominado “Régimen Abierto”, hubo pocas restricciones de seguridad, y se diferencia mucho del periodo que va del año de 1992 a 1997, denominado “Régimen Cerrado”. / Tesis

La toxoplasmosis es una zoonosis de amplia distribución mundial, causante de problemas de abortos y reabsorción embrionaria. En las explotaciones ovinas es importante desde el punto de vista económico, por las pérdidas que conlleva, tiene manifestaciones clínicas diversas e inespecíficas, por lo tanto es difícil poder precisar el diagnóstico con certeza, el diagnóstico debe contar con el apoyo de las pruebas inmunológicas adecuadas, actualmente existen dos pruebas la hemaglutinación indirecta (HAI) y la inmunofluorescencia indirecta (IFI) utilizadas con frecuencia. Es por esto que el objetivo del presente estudio fue medir el grado de concordancia entre las técnicas de HAI e IFI para la detección del Toxoplasma gondii en ovinos. Se colectaron 310 sueros de ovinos hembras de diferentes edades del Fundo Santa María, Distrito de Nuñoa, Provincia de Melgar, Departamento de Puno, los cuales fueron almacenados a -20° C para su posterior análisis serológico. La muestras fueron analizadas en el Laboratorio de Parasitología de la Facultad de Medicina Veterinaria de la Universidad Nacional Mayor de San Marcos. Al evaluar el grado de concordancia entre ambas tecnicas se halló un valor de Kappa (K) igual a 24% indicando que el grado de asociación entre ambas tecnicas fue del tipo regular y mediante la prueba de Mc Nemar se encontró que existen diferencias significativas entre ambas, no siendo reemplazable una por la otra. Adicionalmente se halló una seroprevalencia para Toxoplasma gondii de 50.3 ± 5.56 % por el método de HAI y 88.1 ± 3.6 % por el método de IFI. La frecuencia por edades en animales menores de 1 año, mayores de 1 año y menores de 2 años, mayores de 2 años y menores de 3 años y mayores de 3 años fue de 23.2 %, 33.3 %, 52.1 % y 58.7 % respectivamente por el método de HAI y de 72.01 %, 90,0 %, 91.2 % y 90.5 % por el método de IFI. Estos resultados confirmarían que la concordancia entre las pruebas de HAI e IFI en el diagnóstico de la toxoplasmosis ovina fue de tipo regular no siendo reemplazables entre ellas. / The toxoplasmosis is a zoonosis of worldwide distribution, which causes problems as abortions and embryonic reabsorption. In the sheep developments, it is very important from the economic point of view for the losses that it bears. The Toxoplasma gondii infection has clinical diverse and unspecific declarations, therefore it is hard to certainly precise the diagnosis, that's why the diagnosis must count on the support of the suitable immunological tests, at the moment two test exist indirect hemagglutination (HAI) and indirect inmunofluorescencia (IFI) wich are used frequently. The present work takes as a target measuring the grade of congruity between the skills of immunofluorescence innuendo and hemagglutination innuendo for the detection of the Toxoplasma gondii in sheep. For the study there were collected 310 wheys of sheep females of different ages from the farm Santa Maria, District of Nuñoa, County of Melgar, and Department of Puno. After collected the wheys were stored to 20° C for his later serologic analysis. The samples were analyzed in the laboratory of parasitology of the faculty of veterinary medicine of the University of San Marcos. The results were submitted to statistical analysis, being a grade of congruity between these two tests determined by the value of Kappa (K) equal to 0.24 what corresponds to a grade of affiliation of regular type and by means of the test of Mc Nemar it was found that significant differences between both exist not being replaceable one for other one, also the study found a seroprevalence for Toxoplasma gondii of 50.3±5.6% for the method of HAI and 88.1±3.6% for the method of IFI. The seroprevalence for ages which was categorized for practical ends in animals of until one year, up to two, up to three and bigger than 3, it was of 23.3, 33.3, 52.1 and 58.7 respectively for the method of HAI and of 72.1, 90,1, 91.7 and 90.5 for the method of IFI. These results confirm that the congruity between the tests of HAI and IFI in the diagnosis of the sheep toxoplasmosis is of regular type and both tests are not replaceable.

Reproduction de : Thèse doctorat : Médecine. Immunologie et biologie parasitaire : Reims : 2005. / Titre provenant de l'écran-titre. Bibliogr. p.121-141.

Reproduction de : Thèse d'exercice : Médecine : Nancy 1 : 2003. / Thèse : 2003NAN1102. Titre provenant de l'écran-titre.

The occurrence and ecology of the apicomplexan parasite Toxoplasma gondii in arctic wildlife is not well understood. Transmission cycles, especially in terrestrial systems, are enigmatic because environmentally resistant oocysts, shed by felid definitive hosts, might be less responsible for transmission in the Arctic than in more southern latitudes. Toxoplasma gondii can also be transmitted through the food web by carnivory, and by transmission from mother to fetus during gestation, and these routes are thought to play a large role in the ecology of T. gondii in the Arctic. In this thesis, I examine T. gondii in a well-described part of the food web at Karrak Lake, Nunavut, in the central Canadian Arctic and through experimental infections of domestic waterfowl. In the field over 3 years, I sampled generalist carnovires (arctic foxes), migratory herbivores (Ross’s Geese and Lesser Snow Geese), and resident herbivores (lemmings). Using an occupancy modeling approach that accounted for imperfect detection, I compared commonly used serological assays to estimate prevalence of T. gondii antibodies in sera from arctic foxes and eluted blood on filter paper from Ross’s geese and Lesser Snow Geese and compared commonly used serological assays. I also used a naïve estimator to determine prevalence of T. gondii antibodies in sera from Ross’s Geese and Lesser Snow Geese, and blood on filter paper from lemmings. I detected antibodies against T. gondii in sera from arctic foxes (47-60%, depending on age category), Ross’s Geese (32%) and Lesser Snow Geese (28%). I also detected antibodies in blood on filter paper from Ross’s Geese (39% seropositive) and Lesser Snow Geese (36% seropositive) but not in lemmings. These findings suggest that light geese might introduce T. gondii to the Karrak Lake ecosystem with the annual spring migration and that oocyst transmission might not occur in the terrestrial system, because the parasite was not detected in resident rodents. For the in vivo experimental infections, we used a novel application of a multi-scale occupancy framework to determine within-host detection probability of T. gondii in experimentally inoculated domestic geese and then used those results to guide tissue sampling in wild Ross’s Geese and Lesser Snow Geese. In the experimental inoculation trial, the heart and brain had the highest detection probability for T. gondii through a real-time PCR with melt-curve analysis. Toxoplasma gondii DNA was not detected in tissues from wild geese, suggesting that the parasite was either not present, or methodological difficulties prevented its detection. The research presented in this thesis forms the groundwork for further T. gondii studies in this region.

Thesis (Ph.D.) - University of St Andrews, June 2007. / Restricted until 20th June 2009.

Thèse (M.Sc.) -- Université Laval, 1997. / Bibliogr.: f. 56-65. Publié aussi en version électronique.

A Toxoplasmose é uma zoonose cosmopolita que ocorre principalmente em indivíduos imunodeprimidos, gestantes e em pacientes em terapia anti-câncer. Na Medicina Veterinária, animais como ovelhas, cabras e porcos são seriamente afetados podendo ocorrer abortos e com isto perdas significativas em termos econômicos. Atualmente não se dispõem de vacinas contra a toxoplasmose, mas tem-se desenvolvido modelos animais em ratas e camundongos para o ensaio imunológico contra a enfermidade. Os modelos atualmente utilizados, possuem limitações, por exemplo, não é possível ensaiar no modelo rata um imunógeno de Toxoplasma gondii, uma vez que todas as linhagens de ratas disponíveis são resistentes. Portanto não se pode ensaiar desafios vacinais altamente exigentes neste modelo. Por isso é aconselhável contar com experimentos efetuados em diversas espécies animais. Está sendo proposto testar o Hamster (Mesocricetus auratus), com o intuito de estabelecer se é ou não um modelo que se aproxima das respostas esperadas nos humanos.Antes de se comprometer a custos muito elevados com ensaios finais de vacinações, o aconselhável é contar com ensaios em diversas espécies, pois os animais respondem de formas dIferentes aos mesmos imunógenos. Na transmissão congênita crônica dez Hamsters foram inoculados com 40 oocistos por via oral da cepa Me-49 do T.gondii e após sessenta dias foram postas para cruzarem com os machos. Obteve-se resultados promissores uma vez que a transmissão congênita aos seus filhotes nesta fase crônica da infecção foi nula. Na transmissão congênita aguda da infecção, obteve-se 42,9% de taxa de transmissão de T.gondii. Não foi observada a transmissão lactogênica, do toxoplasma, na fase aguda da infecção. / Taxoplasmosis is a cosmopolitan disease that causes a lot of damage to immunocompromised people, pregnant women, patients who have had transplants and people undergoing anticancer therapy. Animals like sheep, goats and pigs are seriously affected causing abortions and consequently significant economic losses. This is why, the importance of studing the transmission, the mechanisms of transmission and the forms of infection. Currently, vaccines against toxoplasmosis are not available, but animals’ models, in rats and mice, have been developed to an immune assay against this disease. These models considered to the study have some limitations, however it is not possible to apply a toxoplasma immune assay on a rat model, because it is a susceptible race and it has already been proven that rats are resistant to toxoplasma. We proposed to test the hamster (Mesocrisetua auratus) with the intention of establishing if it is or not one model that approaches the same results expected on human beings, therefore before compromising high costs with final assays of vaccinations, the advisable thing to do is to turn to assays on diverse species, because animals have different answers to the same immune. We intended to test hamster (Mesocrisetus auratus), with the intention of establishing if it is or no a model that approaches the expected ansewer from diferential ways to the same strains. In the chronic congenital transmit, in Hamsters was obtained promising results because yours creates didn’t present title when their organs (liver and lung), they were bioassayed in mice and twenty five days after they were bled and their serum tested with direct agglutination of Desmonts and Remington (1980), confirming that the passage wasn’t made during the gestation of females infected before the conception. In the sharp congenital transmission of the infection, it was obtained 42,9% that passed to their descendants antibodies of T. gondii. In the lactogenic transmission, wasn’t have title for T.gondii

Infections are a common co-morbidity in Alzheimer's disease (AD), and evidence suggests that infections can exacerbate neuroinflammation and increase cognitive decline in AD patients. In AD, immune changes are observed both in the central nervous system (CNS) and in the rest of the body. However, only a few studies have investigated immune responses to infection in AD. Here, two extensively studied infections, Toxoplasma gondii (T. gondii) and Trichuris muris (T. muris) were used to investigate infection in AD. T. gondii is a protozoan parasite which is common globally, including in the developed world where AD cases are increasing dramatically. Infection with T. gondii starts in the gut, before becoming systemic and then infecting the CNS, where the parasite forms a chronic cyst infection. In contrast, T. muris is a nematode parasite, which remains localised to the gut. Notably, T. gondii is known to alter neuroinflammation and behaviour. T. gondii forms cysts preferentially in the areas of the brain commonly affected by AD, such as the hippocampus, which therefore makes it an interesting model to study co-morbidity. AD is often associated with advanced age. As we age, our immune system declines, and an important unanswered question is whether age impacts on the immune response to infection. This is of particular significance when considering chronic infections such as T. gondii, which require immune surveillance to prevent parasite recrudescence. Therefore, the aim of this thesis was to investigate infection in AD by determining: whether the immune response to an infection is altered in AD; whether the immune response to an infection in AD differs with age; what the effects of infection are on neuroinflammation, pathology and behaviour in AD; what are the effects of chronic infection with T. gondii. Immune responses to infection were altered in both the 3xTg-AD and the APP PS1 mouse models of AD, including increased inflammation and weight loss in AD mice following infection. Although older (eleven to twelve-month-old) 3xTg-AD mice showed some alterations in cytokine responses following infection, overall there were no major difference compared to younger (five to six-month-old) animals. Additionally, infection was found to alter neuroinflammation in both 3xTg-AD and APP PS1 mice, though differently. In 3xTg-AD mice, microglia activation increased following infection with T. gondii and T. muris, showing that infection did not need to be in the brain to alter neuroinflammation. In APP PS1 mice, a decrease in microglia activation occurred after infection with T. gondii, which was accompanied by an increase in IL-1alpha production and increased amyloid beta levels in APP PS1 mice following infection. However, no changes were found in behaviour following infection with T. gondii or T. muris in AD mouse models. Finally, chronic T. gondii infection was investigated in the TgF344-AD rat, which was established as a suitable AD model with both amyloid and tau pathology in which to study chronic infection. This work adds to a growing body of literature to suggest that infections are detrimental to AD patients, and that future measures to decrease morbidity could focus on further study of infections in AD, and the development of strategies to better prevent infections in AD patients.