Made available in DSpace on 2014-06-11T19:33:25Z (GMT). No. of bitstreams: 0 Previous issue date: 2012-02-03Bitstream added on 2014-06-13T20:44:54Z : No. of bitstreams: 1 santos_tr_dr_jabo.pdf: 1631121 bytes, checksum: 83d3eb022abd9957f44b31612df7222f (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / O elevado índice de ovinos naturalmente infectados por Toxoplasma gondii, a grande possibilidade destes animais se reinfectarem com este protozoário e a inexistência de dados sobre a transmissão congênita em uma reinfecção, motivaram a realização deste projeto de pesquisa. O objetivo deste experimento foi estudar a transmissão congênita em ovelhas, infectadas e reinfectadas experimentalmente com oocistos de T. gondii, em três fases gestacionais. Vinte ovelhas em idade reprodutiva, sorologicamente negativas para T. gondii (RIFI-IgG), foram selecionadas e primoinfectadas experimentalmente com a cepa ME49 (Dia zero). Três carneiros, sorologicamente negativos para toxoplasmose, neosporose, leptospirose e brucelose, foram utilizados para monta natural (RIFI≤512). Posteriormente ao diagnóstico de gestação, estas ovelhas foram distribuídas em quatro grupos experimentais: GI - cinco ovelhas reinfectadas com T. gondii no 40º dia de gestação (DG), GII - cinco no 80º DG, GIII - cinco no 120º DG e GIV - cinco receberam solução salina no 120º DG (controle não reinfectado). Cinco fêmeas sorologicamente negativas (RIFI<64) para infecção toxoplásmica foram mantidas como controle negativo (não infectado) - GV. Sete dias antes da primoinfecção, imediatamente antes da inoculação, a cada três dias até o 30º dias pós-inoculação e a cada sete dias até o término da gestação, exames clínicos e pesquisa de anticorpos (RIFI-IgG) contra T. gondi foram realizados nas 25 ovelhas. Exames ultrassonográficos foram efetuados para diagnóstico de gestação, posteriormente à reinoculação, a periodicidade deste exame foi quinzenal. Amostras de sangue (soro), de todos os cordeiros provenientes das ovelhas experimentais foram obtidas, imediatamente após o nascimento, no 3º e 14º dia de idade, para... / The high occurrence of naturally infected sheep with Toxoplasma gondii, the great possibility of reinfection and the lack of data on congenital transmission in a reinfection were the motivation of this research project. The aim this study was evaluate the congenital transmission in experimentally reinfected and infected ewes, by oocysts T. gondii, in three pregnancies phases. Twenty ewes, negative serologically for T. gondii (indirect fluorescent antibody test-IgG), were selected and experimentally infected with ME49 strain (Day0). Three ram, negative serologically for toxoplasmosis, neosporosis, leptospirosis and brucellosis were used for natural mating (IFAT≤512). After the diagnosis of pregnancy, these ewes were distributed in four experimental groups: GI - five ewes reinfected with T. gondii on the 40th day of gestation (DG), GII - five in the 80th DG, GIII - DG 120th in five and GIV - five received saline solution in 120th DG (unreinfected). Five ewes, negative serologically (IFA <64) for T. gondii infection were kept as negative control (uninfected) - GV. Seven days before the first infection, immediately prior to inoculation, every three days until the 30th day after inoculation and every seven days until the end of pregnancy, clinical examinations and blood samples (IFAT-IgG against T. gondii) were performed in 25 ewes. Ultrasonographic examinations were performed in the diagnosis of pregnancy and fortnightly after reinfection. Serum samples, from all the lambs were obtained immediately after birth (pre-colostral), at 3 and 14 days of life, for T. gondii (IFAT-IgG). Parasitism by T. gondii was investigated (histopathology, mouse inoculation and PCR) in tissue fragments of female and fetuses, stillbirths and/or dead lambs after birth. Twenty ewes showed T. gondii antibodies specific on post-inoculation day (PID) 11. The most serological title... (Complete abstract click electronic access below)

Made available in DSpace on 2014-06-11T19:27:17Z (GMT). No. of bitstreams: 0 Previous issue date: 2006-08-25Bitstream added on 2014-06-13T20:35:35Z : No. of bitstreams: 1 oliveira_kr_me_botfmvz.pdf: 157744 bytes, checksum: f115a70ad010444fe6ca9960d82e76d8 (MD5) / A toxoplasmose é uma das mais freqüentes zoonoses parasitárias, de distribuição mundial, cujo agente etiológico é o Toxoplasma gondii. A infecção em suínos tem sido descrita em diversos países, demonstrando seu caráter cosmopolita e a susceptibilidade desta espécie. O T.gondii pode ser transmitido sob várias formas, e com relação à espécie suína, a ingestão de carne crua ou mal cozida e seus derivados são importantes vias de transmissão para o homem. Estudou-se a prevalência de anticorpos anti-Toxoplasma gondii em 550 amostras de soros de suínos de criações de fundo de quintal na microrregião de Registro - SP, utilizando como prova sorológica o método de aglutinação direta (MAD). Este mostrou-se uma ferramenta diagnóstica de fácil realização, baixo custo, não necessitando de equipamentos especiais para a leitura e interpretação dos resultados. Das 550 amostras de soro, 111(20,18%) reagiram positivamente com os títulos 64 (15,32%), 256 (27,93%), 1024 (39,64%), 4096 (10,81%), 16384 (4,50%) e 65536 (1,80%). Concluí-se que os resultados obtidos indicam alta prevalência desta enfermidade nas condições e região de origem dos animais. À medida que foram obtidos títulos altos de anticorpos contra o agente, pode-se concluir também que há risco potencial de transmissão da toxoplasmose para o homem, sugerindo que muitos desses animais poderiam apresentar bradizoítos em sua musculatura. / Toxoplasmosis is one of the most frequent parasitic zoonosis with worldwide distribution whose etiological agent is Toxoplasma gondii. The infection in swine has been described in many countries, showing the cosmopolitan character and susceptibility of this specie. T.gondii can be transmitted by many ways. The ingestion of swine raw or badly cocked meat and derivatives are important pathways of transmission to man. The anti-T.gondii antibodies prevalence was studied in 550 serum samples of swine under rustic condition (animals with no breed, popular named as backyard breeding) in Registro-SP, using the modified agglutination test (MAT). Such method is verified as an easy-appliance tool, with low costs and non necessity of special equipment in order to achieve interpretation of results. In 550 samples of serum, 111 (20.18%) were positive with titles of 64 (15.32%), 256 (27.93%), 1024 (39.64:%), 4096 (10.81%), 16384 (4.50%), 65536 (1.80%). These results achieved indicate a high prevalence of the disease on the region studied and under the specific conditions described. The high rate obtained as result also leads to the conclusion that there is potential risk of toxoplasmosis transmission to man due to the possibility of the animals to have bradyzoits in their musculature.

El texto completo de este trabajo no está disponible en el Repositorio Académico UPC por restricciones de la casa editorial donde ha sido publicado. / OBJECTIVES: The objective of this study was to perform a systematic review and meta-analysis of the literature to evaluate the efficacy and safety of therapies for cerebral toxoplasmosis in HIV-infected adults. The pyrimethamine plus sulfadiazine (P-S) combination is considered the mainstay therapy for cerebral toxoplasmosis and pyrimethamine plus clindamycin (P-C) is the most common alternative treatment. Although trimethoprim-sulfamethoxazole (TMP-SMX) has potential advantages, its use is infrequent. METHODS: We searched PubMed and four other databases to identify randomized controlled trials (RCTs) and cohort studies. Two independent reviewers searched the databases, identified studies and extracted data. Risk ratios (RRs) were pooled across studies using random-effects models. RESULTS: Nine studies were included (five RCTs, three retrospective cohort studies and one prospective cohort study). In comparison to P-S, treatment with P-C or TMP-SMX was associated with similar rates of partial or complete clinical response [P-C: RR 0.87; 95% confidence interval (CI) 0.70-1.08; TMP-SMX: RR 0.97; 95% CI 0.78-1.21], radiological response (P-C: RR 0.92; 95% CI 0.82-1.03), skin rash (P-C: RR 0.81; 95% CI 0.56-1.17; TMP-SMX: RR 0.17; 95% CI 0.02-1.29), gastrointestinal impairment (P-C: RR 5.16; 95% CI 0.66-40.11), and drug discontinuation because of adverse events (P-C: RR 0.32; 95% CI 0.07-1.47). Liver impairment was more frequent with P-S than P-C (P-C vs. P-S: RR 0.48; 95% CI 0.24-0.97). CONCLUSIONS: The current evidence fails to identify a superior regimen in terms of relative efficacy or safety for the treatment of HIV-associated cerebral toxoplasmosis. Use of TMP-SMX as preferred treatment may be consistent with the available evidence and other real-world considerations. Larger comparative studies are needed. / Revisión por pares

Life Cycle and Transmission Toxoplasmosis is a disease produced by infection with the protozoan Toxoplasma gondii, an intracellular parasite which was first isolated from the North African rodent, Cyterodactylus gondii, in 1908. Since that time, this organism has been shown to have worldwide distribution and is probably the most common parasite of mammals, birds and reptiles (Remington., 1960). In 1965, Hutchinson described toxoplasma oocysts in cat feces, but it was not until 1970 that the life cycle of the organism was disclosed. The felidae represent the primary host for toxoplasma and are the only animals known to harbor the intestinal form (Frenkel., 1973). The oocysts are shed by the cat within 3 to 5 days after infection and sporulate within the feces in another 3 to 4 days. This oocyst is fairly resistant to drying and disinfectants and may remain infective in fairly moist soil for up to several years (Jacobs.. 1974). (Figure 1)

No description available.

Diss. (sammanfattning) Stockholm : Karol. inst., 2005. / Härtill 8 uppsatser.

Diss. (sammanfattning) Stockholm : Karolinska institutet, 2002. / Härtill 6 uppsatser.

Schizophrenia is a devastating mental disorder that affects around 1% of the world’s population, characterized by the presence of positive symptoms including hallucinations and delusions, negative symptoms including depression and anxiety, and cognitive impairment including deficits in speech and memory. The complete etiology of schizophrenia is not yet understood, though it is known that both genetics and environmental factors play a role. One environmental factor, a chronic cerebral infection by the parasite Toxoplasma gondii, has one of the highest correlations with schizophrenia of any environmental factor, and may play a role in the pathology of the disease. This is especially true in the case of Type I toxoplasma, which is the most virulent of the three common strains of the parasite. Toxoplasmosis causes an increase in dopamine levels in the striatum and substantia nigra through the production of two enzymes that mimic the rate limiting enzyme in dopamine synthesis, tyrosine hydroxylase. Increased dopamine concentrations in these areas are experimentally correlated with positive schizophrenia symptoms. In addition, toxoplasmosis causes chronic upregulation of the kynurenine pathway via INF- release, leading to chronically elevated kynurenic acid levels. This leads to dysfunction of the glutamatergic system via (1) the binding and inhibition ofα7- nicotinic receptors, leading to decreased GABAergic inhibitory activity in the hippocampus and decreased glutamate release in the prefrontal cortex, and (2) NMDA and AMPA receptor hypofunction, causing decreased inhibitory signaling by GABAergic neurons leaving glutamatergic neurons in a hyper-excitable state. These mechanisms, compounded by commonly identified mutations in the genes of schizophrenic individuals affecting the dopaminergic system, the kynurenine pathway,α7-nicotinic receptors, and the glutamatergic system, create a viable theory as to how the interplay between genetics and toxoplasmosis could cause schizophrenia.

A hipótese de \"manipulação comportamental\" supõe que um parasito pode alterar o comportamento de seu hospedeiro visando aumentar a probabilidade de completar seu ciclo evolutivo. Tais alterações aumentariam a taxa de transmissão hospedeirohospedeiro, assegurando ao parasito ou a seus propágulos o encontro de novo hospedeiro. A possibilidade de infecções parasitárias provocarem mudanças comportamentais em seus hospedeiros e a elevada frequência com que o acometimento de seres humanos por larvas de Toxocara e cistos de Toxoplasma ocorre, têm chamado à atenção de pesquisadores interessados no estudo das relações hospedeiro-parasita. Na infecção por Toxoplasma gondii e Toxocara canis, cistos e larvas estão presentes em diversos locais anatômicos incluindo musculatura, coração, pulmões, olhos e cérebro. A presença de parasitos no cérebro dá oportunidade de manipulação do comportamento do hospedeiro. Entretanto, não se sabe qual ou quais mecanismos estão envolvidos no processo de manipulação do comportamento. Os objetivos do presente estudo foram verificar alterações na ansiedade, medo, memória e aprendizagem de Rattus norvegicus experimentalmente infectados por Toxocara canis e/ou Toxoplasma gondii em dois períodos após infecção, bem como a localização das larvas e cistos e presença de placas beta amiloide ( A) na região do hipocampo no tecido cerebral desses roedores corado pela técnica de Hematoxilina e Eosina (HE), e Vermelho de Congo, respectivamente. Foram utilizadas 40 exemplares fêmeas da espécie Rattus norvegicus, com seis a oito semanas. Os animais foram divididos em quatro grupos: Toxocara - 10 ratos infectados com 300 ovos de Toxocara canis, Toxoplasma -10 ratos infectados com 10 cistos de Toxoplasma gondii, Infecção dupla - 10 ratos infectados com 300 ovos de Toxocara canis e 10 cistos de Toxoplasma gondii, e controle - 10 ratos sem infecção. Nos dias 40, 41, 70 e 71 após a infecção, os animais dos grupos infectados e controle foram submetidos à avaliação no Labirinto em Cruz Elevado e Campo aberto. Aos 120 após infecção foi feita avaliação da memória, aprendizado e aversão a urina de gato dos animais no Labirinto de Barnes. No final das análises comportamentais os animais foram levados a eutanásia para retirada do cérebro e confecção dos cortes histológicos preparados em HE e Vermelho de Congo. Os resultados mostraram efeito ansiolítico para ambas as infecções, principalmente para Toxoplasma gondii. Não houve comprometimento da memória e aprendizado no LB, porém os animais infectados por Toxocara canis ou Toxoplasma gondii apresentaram menor tempo para encontrar a toca com urina e entrar nela. A leitura dos cortes histológicos corados com HE mostraram larvas de Toxocara canis e cistos de Toxoplasma gondii em regiões do sistema nervoso central dos animais relacionadas com memória e aprendizado. As lâminas coradas com Vermelho de Congo apresentaram placas beta amiloides ( A) em metade dos animais infectados por Toxoplasma gondii. Conclui-se que a infecção por ambos os parasitos apresenta efeito ansiolítico quando ocorre infecção única. Quando a Infecção ocorre concomitantemente há modulação no comportamento. Além disso, ratas infectadas com infecção única apresentam-se menos aversivas à urina de gatos. / The hypothesis of \"behavioral manipulation\" states that a parasite can change the behavior of its host specifically to improve the chances of completing its life cycle. It means the increase of transmission host to host and ensures that the parasite or their propagules are released in appropriate place increasing their survival . The possibility of parasitic infections to cause behavioral changes in their hosts and the high frequency which the involvement of humans by larvae of Toxocara and Toxoplasma cysts occur , have called the attention of researchers interested in the study of host/parasite relationships. In human beings Toxoplasma gondii cysts and Toxocara canis larvae infections are present in various anatomical sites including muscles, heart, lungs, eyes and brain. The presence of parasites in brain gives opportunity of manipulation of the host behavior. However, the mechanisms involved in the behavior changes are still unclear. The aims of this study were to assess changes in anxiety, fear, memory and learning, as well as the larvae, cysts and the presence of beta amyloid plaques (A) in the hippocampus region of the brain tissue of the Rattus norvegicus exper imentally infected with Toxocara canis and/or Toxoplasma gondii, in two stages of infection, satained with hematoxyl in/eosin (HE) and Red Congo techniques, respectively. Eighty female Rattus norvegicus species, aged six to eight weeks-old were used. The animals were divided into four groups: Toxocara - 10 rats infected with 300 Toxocara canis eggs, Toxoplasma - 10 rats infected with 10 cysts of Toxoplasma gondii, double infection - 10 mice infected with 300 Toxocara canis eggs and 10 Toxoplasma gondii cysts, and control - 10 rats without infection. In the days 40, 41, 70 and 71 after infection, the infected animals and that belonging to the control group were evaluated in the Elevated plus-maze (EPM) and Open- field (OF). At 120 days after infection the memory and learning evaluation and aversion to cat urine by the rats were assessed in the Barnes maze. At the end of the behavioral analysis the animals were euthanized to remove the brain and preparation of histological sect ions stained by Hematox yl in/Eosin (HE) and Congo Red. The results showed anxiolytic effect for both infections, especially for Toxoplasma gondii. There was no impairment of memory and learning in LB, but the animals infected by Toxocara canis or Toxoplasma gondii spentless time to find the bur row with urine and entering it. The reading of the histological sections stained with HE showed larvae of Toxocara canis and Toxoplasma gondii cysts in regions of the central nervous system of animals related to memory and learning. The slides stained with Congo Red showed A-plate for the majority of animals infected by Toxoplasma gondii. It is concluded in the single infection, to both parasites, produced anxiolytic effect. When infections occur concomitantly there was a modulating effect in rats\' behavior. In addition, rats infected with single infection presents less aversive urine cats.

A toxoplasmose é causada pelo protozoário coccídio Toxoplasma gondii e consiste em um dos processos parasitários mais comuns entre os animais endotérmicos. A presença desse protozoário em cetáceos pode estar associada à exposição dos animais aos oocistos de T. gondii eliminados pelas fezes de felídeos e/ou contato com solo contaminado com o parasita, que tenham comprometido a água do mar a partir de drenagens fluviais e fluentes ou ainda pelo escoamento de água de navios. O objetivo desse trabalho foi investigar a ocorrência de T. gondii em cetáceos encalhados, ou provenientes de captura acidental, ou que vieram a óbito durante o processo de reabilitação ou cativeiro, ao longo da costa brasileira, valendo-se para tanto de avaliações histopatológicas e de técnicas imuno-histoquímicas (IHQ). Os principais órgãos examinados foram fígado, pulmão, linfonodos, baço e cérebro. Esse estudo avaliou tecidos de 186 exemplares de 21 espécies diferentes de cetáceos da costa brasileira entre 1988 e 2014, cujas amostras foram encaminhadas e encontram-se depositadas no Banco de Tecidos de Mamíferos Marinhos, do Laboratório de Patologia Comparada dos Animais Selvagens (LAPCOM) do Departamento de Patologia, FMVZ-USP. Dos mamíferos marinhos analisados, a ocorrência de T. gondii foi confirmada em 1,1% (2/186), justificada pela presença de pelo menos um cisto em pulmão e/ou fígado. Os animais positivos pertenciam a duas espécies diferentes, provenientes do sudeste do Brasil; um golfinho nariz-de-garrafa (Tursiops truncatus) encalhado vivo no Rio de Janeiro - RJ, e uma orca (Orcinus orca) proveniente de cativeiro. As principais observações histopatológicas encontradas foram hepatite necrotizante, broncopneumonia fibrinosa supurativa com presença de cistos compatíveis com T. gondii, pneumonia broncointersticial fibrinosa com carneificação, glomérulonefrite membranosa e linfadenite necrótica. Devido à severidade das lesões suspeita-se que esse protozoário teve um importante papel no encalhe/óbito desses dois indivíduos. Esse estudo acrescentou duas novas espécies de cetáceos àquelas já reportadas como suscetíveis à infecção pelo protozoário, mas nunca antes descritos no Brasil. Os resultados ratificaram a ocorrência da infecção por T. gondii em cetáceos da costa brasileira e a sua importância em mamíferos marinhos em cativeiro e de vida livre / Toxoplasmosis is caused by the coccidian Toxoplasma gondii - phylum Apicomplexa, which is one of the most common parasites affecting endothermic animals. The presence of T. gondii in cetaceans may be associated with feline feces and/or soil contaminated with the parasite, which may reach water bodies through run-off. This study investigated the occurrence of T. gondii in cetaceans along the Brazilian coast. Tissue samples of 186 individuals stranded along the Brazilian coast between 1988 and 2014, belonging to 21 species of cetaceans and currently part of the Marine Mammal Tissue Bank of the Laboratory of Comparative Pathology, Pathology Department, School of Veterinary Medicine and Animal Sciences, University of São Paulo. Immunohistochemistry (IHC) for T. gondii was performed using formalin-fixed, paraffin embedded tissue sections of liver, lung, lymph nodes, spleen and brain. Infected tissues of a Guiana dolphin (Sotalia guianensis) were used as positive controls. A total of 1.1 % (2/186) of the animals evaluated were positive, which was justified by the presence of least one cyst in one of the evaluated organs/tissues. These specimens belong to two different species of cetaceans: Killer whale (Orcinus orca) and bottlenose dolphin (Tursiops truncatus), both from southeastern Brazil. One individual stranded alive in Rio de Janeiro (T. truncatus); and one was kept in captivity (O. orca) in São Paulo state. The most noteworthy lesions observed through microscopy included necrotizing hepatitis, fibrinous suppurative bronchopneumonia with cysts compatible with T. gondii, bronchointersticial fibrinous pneumonia, membranous glomerulonephritis and necrotizing lymphadenitis. Due to the severity of lesions protozoan was suspected to have an important role in the stranding/death of the two wild individuals. This study added two new species of cetaceans to those already reported as susceptible to infection by T. gondii, never before described in Brazil. These results confirm the occurrence of T. gondii infection in cetaceans from the Brazilian coast and the importance of this parasite to marine mammals kept in captivity and free ranging dolphins