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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Congenital toxoplasmosis

Beltrán Flores, Santiago, Flores Arriaga, Joel, Lema Correa, Mauricio 13 August 2015 (has links)
Introducción: La toxoplasmosis causada por el Toxoplasma gondii se transmite a los humanos de manera transplacentaria, entre otras. Se estima que infecta a un tercio de la población mundial y está asociado con infección congénita y abortos. Solo son sintomáticos del 10 al 20% de los casos. Caso clínico: Se presenta el caso de un recién nacido pretérmino referido a un hospital de mayor complejidad. Durante la hospitalización se realiza el diagnóstico de toxoplasmosis congénita con diversas manifestaciones sistémicas. Conclusiones: La mayor parte de los casos de toxoplasmosis congénita suelen ser asintomáticos. Es necesario realizar pruebas diagnósticas y un examen físico completo ante la sospecha de la infección para detectar tempranamente todas las manifestaciones posibles. / Background: Toxoplasmosis, caused by Toxoplasma gondii, is transmitted to humans in several ways, such as transplacental spread. It is estimated that this parasite infects a third of the world population and it is associated with congenital infection and fetal loss. Only 10 to 20% of the cases are symptomatic. Case report: We present the case of a pre-term newborn that had been referred to a tertiary care center. During the in-hospital period, diagnosis of congenital toxoplasmosis with many systemic manifestations was performed. Conclusions: Most cases of congenital toxoplasmosis are asymptomatic. Diagnosis tests and a complete physical examination should be performed on all newborns with suspicion of infection to detect all possible manifestations as in the case reported. © 2014 Hospital Infantil de México Federico Gómez. Published by Masson Doyma México S.A. All rights reserved.
2

Cuantificación de cerdos reactores a Toxoplasma gondii provenientes de granjas no tecnificados destinados a consumo humano

Islachin Huayra, Jhon Paul January 2015 (has links)
El objetivo del presente trabajo fue determinar la frecuencia de anticuerpos anti-Toxoplasma gondii en cerdos procedentes de crianza no tecnificada y evaluar la variable sexo como factor de riesgo, para lo cual se analizaron 240 muestras de suero de cerdos de un camal de Lima, con igual número de animales por sexo. Se evaluó mediante la prueba diagnóstica de Inmunofluoresencia Indirecta (IFI). La frecuencia de anticuerpos antiToxoplasma gondii obtenida fue de 26.25%, con intervalo de confianza de 95% entre 20.68% y 31.82%. Al analizar la variable sexo, se encontró 30.83% de machos reactores con intervalo de confianza del 95% entre 22.57% y 39.09%, mientras que en las hembras se encontró 21.67% de positivas con intervalo de confianza del 95% entre 14.30% y 29.04%. La magnitud de la posible asociación del sexo como factor de riesgo fue determinada por el Odds Ratio, obteniéndose un valor de OR = 1.61, con intervalo de confianza de 95% entre 0.90 y 2.88, indicando que le sexo no constituye factor de riesgo para la adquisición de la toxoplasmosis. Palabras claves: Cerdos, no tecnificadas, oxoplasmosis, IFI, Lima. / --- The aim of this study was to determine the frequency of anti-Toxoplasma gondii in pigs from non-tech breeding and assess the gender variable as a risk factor, for which 240 serum samples from pigs of a slaughterhouse in Lima were analyzed, with equal number of animals per sex. It was assessed using the diagnostic test of Immunofluorescence Indirect (IFI). The frequency of antiToxoplasma gondii obtained was 26.25%, with a confidence interval of 95% from 20.68% and 31.82%. In analyzing the variable gender, 30.83% of males reactors met confidence interval of 95% between 22.57% and 39.09%, while in females 21.67% positive he found confidence interval of 95% from 14.30% and 29.04 %. The magnitude of the possible association of sex as a risk factor was determined by the odds ratio, obtaining a value of OR = 1.61, with a confidence interval of 95% between 0.90 and 2.88, indicating that sex is not risk factor for acquiring toxoplasmosis. Keywords: Pigs, Nontechnical, toxoplasmosis, IFI, Lima.
3

Frecuencia de toxoplasmosis en cerdos provenientes de granjas tecnificadas y factores de riesgo asociados a su presentación

Carranza Champac, Fernando André January 2015 (has links)
La toxoplasmosis constituye una de las principales zoonosis a nivel mundial debido a su distribución cosmopolita y sus elevadas frecuencias en especies de sangre caliente como el cerdo, el cual puede transmitir la enfermedad a través del consumo de su carne cruda o mal cocinada. El objetivo del presente estudio fue estimar la frecuencia de cerdos provenientes de crianza tecnificada reactores a toxoplasmosis. Asimismo se pretendió establecer la posible asociación del sexo con la positividad a toxoplasmosis. Se tomaron 240 muestras de sangre de cerdo provenientes de granjas tecnificadas durante los meses de Noviembre y Diciembre del 2012 en el camal Conchucos, ubicado en el distrito de El Agustino, Lima; durante el proceso de sacrificio. Dichas muestras fueron llevadas al Laboratorio de Parasitología de la Universidad Nacional Mayor de San Marcos, ubicado en el distrito de San Borja, Lima para su procesamiento y evaluación mediante el método de Inmunofluorescencia Indirecta (IFI) debido a sus altas sensibilidad y especificidad. Se obtuvo una frecuencia total de 21.67% de cerdos positivos a toxoplasmosis. Se evalúo el riesgo de la presentación de toxoplasmosis en relación al sexo mediante la medida de asociación llamada Odds Ratio (OR), obteniéndose una asociación de 1.64 con intervalo de confianza de 0.88-3.06, demostrando que no hay asociación estadísticamente significativa. Se concluye que hay una frecuencia significativa de cerdos provenientes de granjas tecnificadas positivos a toxoplasmosis y que el sexo no influye en la presencia de esta enfermedad. Palabras clave: Toxoplasma gondii, toxoplasmosis, cerdo, inmunofluorescencia indirecta / --- Toxoplasmosis is considered as one of the most important zoonosis in the world because of it worldwide distribution and high frequencies in warm-blooded species like pigs, who can transmit the disease through it raw or half-cooked meat. The aim of the current study was to rate the frequency of tech-farms pigs which are positive to test. Also it was pretended to establish if there is any relationship between positive reaction and sex of the animal. It was taken 240 samples of techfarm pig blood between November and Decembre of 2012 in "Conchucos" slaughterhouse, located in El Agustino, Lima; during the bloodshed. Those samples were transported to Parasitology Laboratory in San Marcos University, located in San Borja, Lima to it process and evaluation using the Indirect Inmunofluoresce Assay (IFA) which is well-known as it highly sensitive and specificity. It was found a frequency of 21.67% of positive reactions. The presentation of the disease related to positive reactions and sex was evaluated by the measure of association called Odds Ratio (OR), obtaining a result of 1.64 with confidence interval of 0.88-3.06, establishing there is no significative association. It was concluded there are a significant frequency of reactant pig to toxoplasmosis and sex has no influence in the presentation of this disease. Key words: Toxoplasma gondii, toxoplasmosis, pig, Indirect Inmunofluorescence Assay
4

Toxoplasmosis en alpacas hembras de la Unidad de Producción de Cuyo de la SAIS Pachacútec

De la Cruz Chumpitaz, Hernán Iván January 2009 (has links)
Toxoplasma gondii es un patógeno intracelular obligatorio dentro del Phylum Apicomplexa, con un amplio rango de hospederos incluyendo muchas aves y mamíferos en el mundo. El objetivo del estudio fue determinar la seroprevalencia de anticuerpos anti-Toxoplasma gondii en alpacas de la Unidad de Producción de Cuyo de la SAIS Pachacútec, ubicada en el distrito de Marcapomacocha, Provincia de Yauli, Departamento de Junín. Para tal fin se recolectaron en el mes de enero del 2003, sueros sanguíneos de 258 alpacas hembras para la detección de anticuerpos de Toxoplasma gondii; mediante la técnica de Inmunofluorescencia Indirecta (IFI), encontrándose que el 8.53±3.41% (22/258) de las muestras, presentaban anticuerpos contra el parásito; siendo estos menores en proporción con los hallados en alpacas de otras zonas ganaderas del país, por lo tanto se hace necesario la continuar con estudios similares a fin de determinar el verdadero rol de este parásito con los problemas reproductivos en alpacas. / --- Toxoplasma gondii is an obligate intracellular pathogen within the phylum Apicomplexa, with a broad host range including many birds and mammals in the world. The objective of this study was determine the seroprevalence of antibodies against Toxoplasma gondii in alpacas in the United of Production of Cuyo at the SAIS Pachacutec, located in the district of Marcapomacocha, Province of Yauli, Departament of Junin. In order to do this, 258 sera from female alpacas were collected in the month of January of 2003. Sera was tested against Toxoplasma gondii antibodies using Indirect Immunoflorescence (IFI), being that 8.53±3.41% (22/258) of the samples showed antibodies against the parasite. These results show a lower proportion compared to those findings in alpacas from other zones of the country; therefore, it is necessary to continue with similar studies, which will determine the real pathological role of this parasite in alpacas.
5

Toxoplasmosis en alpacas hembras de la Unidad de Producción de Cuyo de la SAIS Pachacútec

De la Cruz Chumpitaz, Hernán Iván January 2009 (has links)
Toxoplasma gondii es un patógeno intracelular obligatorio dentro del Phylum Apicomplexa, con un amplio rango de hospederos incluyendo muchas aves y mamíferos en el mundo. El objetivo del estudio fue determinar la seroprevalencia de anticuerpos anti-Toxoplasma gondii en alpacas de la Unidad de Producción de Cuyo de la SAIS Pachacútec, ubicada en el distrito de Marcapomacocha, Provincia de Yauli, Departamento de Junín. Para tal fin se recolectaron en el mes de enero del 2003, sueros sanguíneos de 258 alpacas hembras para la detección de anticuerpos de Toxoplasma gondii; mediante la técnica de Inmunofluorescencia Indirecta (IFI), encontrándose que el 8.53±3.41% (22/258) de las muestras, presentaban anticuerpos contra el parásito; siendo estos menores en proporción con los hallados en alpacas de otras zonas ganaderas del país, por lo tanto se hace necesario la continuar con estudios similares a fin de determinar el verdadero rol de este parásito con los problemas reproductivos en alpacas. / Toxoplasma gondii is an obligate intracellular pathogen within the phylum Apicomplexa, with a broad host range including many birds and mammals in the world. The objective of this study was determine the seroprevalence of antibodies against Toxoplasma gondii in alpacas in the United of Production of Cuyo at the SAIS Pachacutec, located in the district of Marcapomacocha, Province of Yauli, Departament of Junin. In order to do this, 258 sera from female alpacas were collected in the month of January of 2003. Sera was tested against Toxoplasma gondii antibodies using Indirect Immunoflorescence (IFI), being that 8.53±3.41% (22/258) of the samples showed antibodies against the parasite. These results show a lower proportion compared to those findings in alpacas from other zones of the country; therefore, it is necessary to continue with similar studies, which will determine the real pathological role of this parasite in alpacas.
6

Molecular studies on Toxoplasma gondii

Bhalla, Mayank January 2000 (has links)
No description available.
7

La sortiline et les voies endosomales apparentées sont les éléments clefs pour la biogenèse des organites apicaux et la virulence chez Toxoplasma gondii / A Sortilin-like receptor and endolysosomal related pathways are essentiel for intracellular trafficking, apical organelle biogenesis and virulence in Toxoplasma gondii

Sloves, Pierre-Julien 29 October 2012 (has links)
Toxoplasma gondii, l'agent de la toxoplasmose, représente un modèle appartenant aux parasites Apicomplexa, phylum dans lequel on retrouve Plasmodium falciparum, l'agent causal du paludisme, et de nombreux agents opportunistes dangereux. Les parasites de ce phylum possèdent la même organisation avec des organites situés à l'apex, spécialisés dans l'interaction hôte-pathogène et qui sont cruciaux pour permettre l'infection de l'hôte: les rhoptries et micronèmes. Les protéines contenues dans ces organites sécrétoires sont acheminées via le système de type endolysosomal. Toutefois, les récepteurs qui jouent un rôle clé dans le tri des protéines et la biogenèse des organites apicaux restaient à identifier. La sortiline est un récepteur transmembranaire de type I, plus connu chez l'Homme dans le tri, le transport des protéines et ses rôles dans la maladie de Parkinson, d'Alzheimer ou du diabète ont largement été décrits. Nous avons déterminé que l'homologue de la sortiline chez Toxoplasma TgSORTLR pour «Toxoplasma gondii Sortiline Like Receptor» est localisé au niveau de l'appareil de Golgi et du réseau post-Golgien. TgSORTLR se lie spécifiquement aux protéines de rhoptries et de micronèmes à l’aide du domaine N-terminus, probablement au niveau de l'appareil de Golgi. Nous avons montré que le domaine C-terminus est déterminant pour la localisation de TgSORTLR et que l'expression d'une version tronquée de la protéine dépourvue du domaine C-terminus induit la complète délocalisation des protéines de rhoptries et de micronèmes. Nous avons également identifié les protéines cytosoliques qui interagissent avec le domaine C-terminus de TgSORTLR et démontré que ces protéines cytoplasmiques sont pour la plupart connues pour leurs rôles importants dans le transport antérograde ou rétrograde des vésicules du trafic intracellulaire. L’absence de TgSORTLR obtenue grâce à une stratégie de «knock-out » conditionnel entraîne non seulement une totale délocalisation des protéines de rhoptries et de micronèmes mais aussi à une disparition des organites apicaux, ce qui conduit à la forte atténuation de la virulence du parasite chez la souris et surtout à l'absence complète de symptômes toxoplasmiques. Des expériences de complémentations réalisées dans la souche dépourvue de TgSORTLR ont montré que l’extrémité N-terminus (acides aminés 39 à 202) de TgSORTLR est également nécessaire pour sa localisation correcte et pour ses fonctions de récepteur intracellulaire chez T. gondii. Enfin, nous avons caractérisé, par des techniques de « knock in » ou remplacement du gène endogène par une copie étiqueté avec l’épitope HA, puis montré que des protéines homologues de μ1-adaptine, Sec23, Vps9, Vps26 et Vps35 de T. gondii co-localisent et se fixent spécifiquement à TgSORTLR. Ces résultats récents confirment que l'extrémité C- terminus et cytoplasmique du récepteur TgSORTLR se comporte d'une manière similaire aux sortilines des cellules de mammifère. L’étude de ces partenaires de TgSORTLR nous permet de mieux comprendre le trafic de TgSORTLR, de reconstituer en partie le système endolysosomal et son rôle dans le transport et la biogenèse des organites vitaux de T. gondii. / Toxoplasma gondii, the causative agent of toxoplasmosis belongs to the phylum named Apicomplexa that also contains Plasmodium falciparum, the causative agent of malaria and others parasites such as Cryptosporidium or Eimeria. Apicomplexan parasites are uniquely characterized by specific organelles, rhoptries and micronemes, which are located at the apical end of the parasite. These organelles are involved in the control of host-pathogen interactions. The proteins in these secretory organelles are trafficked through the endolysosomal system. However, the receptors that play key roles in protein sorting and biogenesis of these apical organelles remain to be identified. Sortilin is a type I transmembrane receptor known in humans for protein sorting and trafficking. Here, we report that the homologue of sortilin in T. gondii designated TgSORTLR for “Toxoplasma gondii SORTilin Like Receptor” is localized to Golgi and post-Golgi compartments and transports proteins into rhoptries and micronemes via their specific interactions with its luminal domain. We demonstrate that the C-terminus of TgSORTLR is also important for its subcellular localization through binding to cytosolic components of vesicular trafficking proteins known to be involved in anterograde and retrograde transports. The depletion of TgSORTLR using conditional knock-out strategy causes a complete rmis-localization of proteins of both rhoptries and micronemes, leading to the loss of these apical organelles. These mutants display a strong attenuation of the parasite virulence in mice with the absence of acute toxoplasmosis symptoms. Complementation of the strain lacking TgSORTLR showed that N-terminal region between 39-202 amino acids indicated that the N-terminus, similarly to the C-terminus is essential for its correct localization. We conclude that the full-length TgSORTLR protein is required for its biological functions as intracellular sorting receptor in T. gondii.
8

Studies on the epidemiology of toxoplasmosis in South Africa

Kistiah, Kesenthri 16 September 2009 (has links)
M.Sc.(Med.), Faculty of Health Sciences, University of the Witwatersrand / Toxoplasmosis is an infection of vertebrates caused by the obligate intracellular protozoan parasite, Toxoplasma gondii. It is one of the most common parasitic diseases of humans, infecting approximately one third of the world’s population. It is a significant cause of congenital disease and an important opportunistic pathogen which has become an increasing problem worldwide due to the AIDS epidemic. There is limited historical information about the disease in South Africa. More knowledge is needed at a regional level to properly consider solutions aimed at reducing the risk for this disease. The seroprevalence of T. gondii in samples of selected populations at risk, namely HIV-positive individuals and a more general population sample biased towards pregnant women, was therefore investigated and found to be 9.8% (37/376) and 6.4% (32/497) in the respective samples. The Pastorex Toxo latex agglutination test was evaluated and found to be a cheap, reliable method to screen for T. gondii exposure. PCR-based diagnostics were developed for direct diagnosis on tissue samples. Rodent T. gondii infection prevalence was investigated, but did not yield any positive results. This study helped to answer questions relating to the seroprevalence and diagnosis of T. gondii in South Africa. Many questions still remain to be answered, however to fully understand the impact of this parasite in our country.
9

Development of molecular markers for the typing and genetic analysis of Toxoplasma gondii

Fazaeli, Asghar January 2000 (has links)
To develop robust and reproducible methods for molecular typing of <I>Toxoplasma </I>strains, the DNA regions of 5<I>S</I> rDNA, 28S-18S rDNA <I>IGS SAG2</I>, and <I>GRA6</I> loci were examined. The 5<I>S</I> sequences were identical among 24 different strains; sequencing of the <I>IGS</I> region showed a few polymorphisms (0.66%) distinguishing virulence types. The IGS PCR-RFLP methods were developed and used to examine 29 strains of different virulence types. Sequence analysis of the IGS 5'-end showed great diversity between <I>Neospora caninum </I>and <I>T. gondii. </I>The IGS-RFLPs also clearly distinguished between those two closely related species. Nucleotide sequencing of the <I>SAG2</I> locus (a surface antigen coding gene) showed 1.37% polymorphisms among 24 strains. Apart from a single nucleotide change at the 5'-flanking region, the type III and type I strains were identical. However, three new alleles of this locus were identified in minor variants of the strains. Analysis of the coding region of the <I>GRA6</I> locus (a dense granule antigen coding gene) revealed a great degree of polymorphisms (3.24%) among 33 strains. Nine different alleles, representing the three current types and the minor variants of strains were characterised at this locus. A PCR-RFLP based on <I>GRA6</I> polymorphisms was developed which could distinguish the three major types of <I>T. gondii</I>. This marker proved to be a suitable tool for a population study of the <I>Toxoplasma </I>parasite. The predominance of non-synonymous nucleotide substitutions in <I>SAG2</I> and <I>GRA6</I> genes confirmed positive selection in these loci, suggesting they play an important role in the parasite virulence. Phylogenetic analysis based on the multi-locus sequence alignment showed the existence of more than three lineages in <I>Toxoplasma </I>populations.
10

A systematic review of the relative efficacy and toxicity of treatment regimens for HIV-associated cerebral toxoplasmosis: is trimephoprim-sulfamethaxozole a real option?

Universidad Peruana de Ciencias Aplicadas (UPC), Thota, P., Pellegrino, D., Pasupuleti, V., Benítes-Zapata, Vicente A., Vidal, J., Hernández, Adrian V., Deshpande, Abhishek 15 October 2015 (has links)
Background: Pyrimethamine and sulfadiazine (P-S) combination is effective and considered the mainstay therapy for cerebral toxoplasmosis (CT). Alternative treatment regimens are available, but their relative efficacy and tolerability are not well known. Particularly, trimephoprim-sulfamethaxozole (TMP-SMX) shows potential advantages (i.e., tolerability, posology, parenteral formulation, cost, and accessibility) but its use is infrequent when P-S is available. Methods: We searched PubMed and 4 other databases to identify randomized controlled trials (RCTs) and cohort studies comparing different regimens for the treatment of HIV-associated CT. Two independent reviewers searched and identified studies and extracted data. Risk ratios (RRs) were pooled across studies using random-effects models. Results: Nine studies were included (5 RCTs, 3 retrospective cohorts, 1 prospective cohort). Treatment with P-S has the same or better clinical efficacy than P-C or TMP-SMX in terms of partial or complete response clinical response (P-C vs P-S: RR 0.87, 95%CI 0.70-1.08; TMP-SMX vs P-S: RR 0.97, 95%CI 0.78-1.21) and radiological response (P-C vs P-S: RR 0.92, 95%CI 0.82-1.03). Safety profile in terms of skin rash (P-C vs P-S: RR 0.81, 95%CI 0.56-1.17; TMP-SMX vs P-S: RR 0.17, 95%CI 0.02-1.29), liver impairment (P-C vs P-S: RR 0.48, 95%CI 0.24-0.97) and drug discontinuation due to adverse events (P-C vs P-S: RR 0.32, 95%CI 0.07-1.47) were worse with P-S regimen. Conclusion: The available evidence fails to identify any one superior regimen for the treatment of CT. However, P-S regimen has worse safety profile than P-C or TMP-SMX. Although current evidence does not allow a definitive recommendation, use of TMP-SMX for treatment of HIV-associated CT is consistent with the available data. More large studies comparing alternative therapies are needed. / IDWeek, Evento que se llevó a cabo del 7 -11 de Octubre de 2015, en la ciudad de San Diego, CA, EE.UU. Evento Sesión HIV: Other Opportunistic Infections in HIV. Saturday, October 10, 2015. Room: Poster Hall

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