Diss. (sammanfattning) Uppsala : Sveriges lantbruksuniv. / Härtill 6 uppsatser.

Diss. (sammanfattning) Uppsala : Sveriges lantbruksuniv., 2004. / Härtill 4 uppsatser.

Diss. (sammanfattning) Uppsala, Sweden : Sveriges lantbruksuniv., 2006. / Härtill 4 uppsatser.

Thèse (M.Sc.) -- Université Laval, 1997. / Bibliogr.: f. 104-125. Publié aussi en version électronique.

Mestre -- Instituto Nacional de Controle de Qualidade em Saude, Rio de Janeiro, 2003.

Soluble amyloid-beta (Aβ) aggregates, including Aβ protofibrils, play a central role in Alzheimer’s disease (AD) and constitute a potential diagnostic biomarker and a therapeutic target. Aβ protofibrils promote synapse dysfunction and neurodegeneration, but the mechanisms behind these effects remain unclear. The aim of this thesis was to increase the knowledge of Aβ protofibrils in AD pathology. When measuring low abundant antigens, such as soluble Aβ aggregates, in plasma and CSF by immunoassays, there is a possibility of interference by heterophilic antibodies (HA). In paper I, we show that HA generate false positive signals, by cross-binding the assay antibodies, when plasma and CSF from AD patients and healthy controls were analyzed for soluble Aβ aggregates, using sandwich ELISAs. Natural anti-Aβ antibodies exist in AD patients and healthy individuals. Circulating Aβ and anti-Aβ antibodies may form immune complexes, masking epitopes on the anti-Aβ antibody, which makes the anti-Aβ antibody concentration difficult to measure. In paper II, the ELISpot technique enabled us to successfully measure B cell production of anti-Aβ antibodies. Our results show that anti-Aβ protofibril antibody production is present in both AD patients and healthy individuals, but is significantly higher in AD patients, indicating that the immune system attempt to eliminate the toxic Aβ species. Insufficient lysosomal degradation is proposed to cause sporadic AD. In paper III, we used a co-culture system of astrocytes, neurons and oligodendrocytes, to clarify the role of astrocytes in Aβ protofibril clearance. Astrocytes are the most prominent glial cell type in the brain, but their role in AD remains elusive. We found that astrocytes effectively engulf, but inefficiently degrade Aβprotofibrils. This result in a high intracellular load of toxic, partly N-terminally truncated Aβ and lysosomal dysfunction. Moreover, we found that secretion of microvesicles, containing N-terminally truncated Aβ, induce neuronal apoptosis. In paper IV, we show that treatment with the protofibril selective antibody mAb158 lead to enhanced Aβ clearance and thereby prevent Aβ neurotoxicity. Taken together, this thesis contributes with important knowledge on the role of Aβ protofibrils in AD pathogenesis and technical aspects that should be considered when measuring Aβ in human tissues.

Hanseníase é uma das mais antigas e instigantes doenças que acometem o ser humano. Ferramentas moleculares e imunológicas são avaliadas em diversos estudos epidemiológicos, porém com resultados controversos devido à alta complexidade da doença e metodologias utilizadas. Este estudo descreve o uso da sorologia anti PGL-I e da detecção de DNA em swab nasal para caracterizar a epidemiologia molecular do Mycobacterium leprae em pacientes e contatos domiciliares de pacientes com hanseníase. Em pacientes com hanseníase a positividade nos testes ELISA anti PGL-I e PCR para a detecção do DNA de M. leprae em swab nasal são inversamente associadas ao teste de Mitsuda e são diretamente associadas com o índice baciloscópico e as formas clínicas no espectro da doença, aumentando em direção às formas bacilíferas. As porcentagens gerais de positividade em pacientes foram 63,3% para o ELISA anti PGL-I e 34,2% para a PCR para detecção do DNA de M. leprae em swab nasal. Nos contatos domiciliares de pacientes com hanseníase as porcentagens gerais para o ELISA anti PGL-I e para a PCR para detecção do DNA de M. leprae em swab nasal foram 13,3% e 4,7% respectivamente. Os contatos com resultados positivos nestas metodologias representam portadores sadios ou com infecção subclínica e podem participar na transmissão e manutenção do M. leprae na comunidade, mesmo que os mesmos não venham a adoecer. É imperativo para o controle da hanseníase o monitoramento de contatos domiciliares em regiões endêmicas para detecção precoce de novos casos e a quimioprofilaxia deve ser utilizada como prevenção para o desenvolvimento da doença e interrupção da transmissão. / Leprosy is one of the oldest and most instigating diseases to affect humans. Molecular and immunological tools are evaluated in epidemiological studies; however, the results present controversies mainly due to disease complexity and methodologies. This study describes the application of anti PGL-I serology and nasal swab DNA detection to characterize Mycobacterium leprae molecular epidemiology in patients and household contacts of leprosy patients. Among leprosy patients the positivity to the anti PGL-I ELISA and the PCR for the detection of M. leprae DNA in nasal swabs are inversely associated to the lepromin test and arte directly associated to the bacillary index and the clinical forms in the disease spectrum, increasing towards baciliferous forms. The overall positivity percentages were 63.3% for the anti PGL-I ELISA and 34.2% for the PCR for the detection ofM. leprae DNA in nasal swabs. Among household contacts of leprosy patients the overall percentages for the anti PGL-I ELISA and for the PCR for the detection of M. leprae DNA in nasal swabs were 13.3% e 4.7% respectively. Among leprosy patients, assays positivity is associated with the clinical presentation of the disease, increasing towards bacilliferous subtypes. Positive results in contacts represent healthy carriers and subclinical infection and these individuals can participate in transmission and spread of M. leprae in the community, even though they may not develop the disease. In endemic regions, contact monitoring is imperative in leprosy control for early case detection and chemoprophylaxis must be applied as prevention to disease development and disruption of transmission. / Dissertação (Mestrado)

Made available in DSpace on 2014-06-11T19:32:52Z (GMT). No. of bitstreams: 0 Previous issue date: 2008-06-19Bitstream added on 2014-06-13T18:48:10Z : No. of bitstreams: 1 curci_vclm_dr_jabo.pdf: 208355 bytes, checksum: b31da2026d8809c55818b68c4c8d77b7 (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Foi avaliado pelo teste de ELISA indireto a resposta humoral para as toxinas botulínicas tipos C e D em animais vacinados com quatro diferentes produtos comerciais. Empregou-se duas vacinas bivalentes C e D (vacina 1 e vacina 2) e duas polivalentes contendo ainda os toxóides botulínicos tipos C e D (vacina 3 e vacina 4). Para análise foram realizadas seis colheitas de sangue ao longo do experimento, nos dias 0, 42, 75, 160, 250 e 342 após a vacinação. A imunidade passiva em bezerros até os 90 dias de idade, filhos de mães vacinadas com diferentes toxóides comerciais foram avaliados em 75 bezerros, agrupados de acordo com a vacina utilizada na mãe (B1, B2, B3 e B4). Para análise foram realizadas 3 colheitas de sangue, nos dias 5 (± 2), 45 e 90 dias após o nascimento. A avaliação da resposta humoral de bovinos vacinados em diferentes faixas etárias também foi realizada empregando-se uma vacina antibotulínica bivalente (C e D) comercial. Para análise, 90 bovinos foram divididos em 3 grupos de acordo com a faixa etária; animais com idade inferior a 2 anos, entre 2 e 5 anos e superior a 5 anos. Na avaliação da resposta humoral de animais vacinados com quatro diferentes produtos comerciais, para a toxina tipo C, as vacinas 1, 2, 3 e 4 não apresentaram diferenças significativas aos 42 dias da primeira dose. Aos 75 dias, a vacina 1, foi superior às vacinas 3 e 4, induzindo maior produção de anticorpos nos animais, porém não diferiu da vacina 2. Aos 160 dias houve queda na quantidade de anticorpos em todos os grupos, não havendo mais diferenças significativas entre as quatro vacinas testadas. Para a toxina tipo D, aos 42 dias da vacinação, não houve diferenças significativas entre as vacinas 1, 2 e 4, que apresentaram neste momento, valores superiores a vacina 3. No entanto, quando avaliadas aos 75 dias, a vacina 1 apresentou maior produção de anticorpos, diferindo... / To compare the efficiency of an “in house” ELISA test, standardized to measure antibody C and D from Clostridium botulinum, a survey to analysis four different commercial vaccines was conducted. The vaccines used were two commercial, bivalent botulinum containing subtypes C and D (vaccine 1 and vaccine 2) and other two polyvalent including subtypes C and D. The first trial was blood samples taken at 0, 42, 75, 160, 250 and 342 days after vaccination, whereas the booster was performed at day 42. The second trial, maternal antibodies were also measured taken blood samples from 1-3 months age steers obtained from vaccinated heifers with the same vaccines described above, and divided into four different groups (B1, B2, B3, B4). The blood samples were taken at days 5, 45 and 90 after birth. Third and last trial was humoral response from vaccinated cattle with different age evaluation performed using the commercial Clostridium botulinum vaccine subtype C and D. For this purpose, 90 animals never vaccinated, were divided into 3 groups: 1 - 2 years old; 2 – animals aged between 2 and 5 years old; 3 – animals 5 years old. The blood samples were taken 30 days after vaccination after second dose of the vaccine. From the first trial, no significant difference was observed when subtype C was search in sera from animals at 42 days after vaccination. However, at 75 days after vaccination, vaccine 1 was able to induce higher levels of antibodies when compared to vaccine 3 and 4. The antibody level was declining after 160 days post vaccination. For subtype D antigen, at 42 days after vaccination, no differences could be observed. However, at 75 day after vaccination, higher levels of antibodies were observed from animals vaccinated with vaccine 1. Comparing the bivalent vaccines, these were able to induce higher antibodies levels at 75 days after vaccination (toxoid C). In addition, the same... (Complete abstract click electronic access below)

Lyme borreliosis (LB) is caused by spirocheter of Borrelia burgdorferi sensu lato. There are different types of borrelia species and some differ in their ability to survive in the presence of the complement system. B. afzelii is complementresistant while B. garinii is complementsensitive. This is based on the ability to recruit immune regulators, such as factor H to the bacterial surface and prevent activation of the complement system. Some individuals may show anti-Borrelia antibodies without having developed clinical symptoms. This may indicate a more effective immune response against spirochetes. The aim of this study was to investigate differences in complement activation by measuring C3a and sC5b-9 with sandwich ELISA between two previously Borrelia-exposed groups; individuals with previous subclinical Lyme borreliosis (SB) and patients previously diagnosed with neuroborreliosis (NB), and a control group without signs of LB exposure. Samples analyzed in this study consisted of controls (Ctrl, n = 8st), SB (n = 60st) and NB (n = 22st). Plasma from the groups were activated with ACA1 and Lu59. To compare the relative increase between the groups, complement factor C3a and the soluble terminal complement complex, sC5b-9, were analyzed using sandwich-ELISA.The analysis of C3a and sC5b-9 showed higher activation with Lu59 than ACA1, which is consistent with previous studies. According to C3a-analysis, no significant differences were observed between the groups for neither ACA1 nor Lu59. According to sC5b-9-analysis, a significant difference between SB and Ctrl (p= 0,0081) for Lu59 was observed. Conclusion of the studie was that further studies are required to interpret how this complement activation affects LB from a clinical prespective.

Submitted by Hiolanda Rêgo (hiolandarego@gmail.com) on 2016-07-13T17:37:49Z No. of bitstreams: 1 Dissertação_ICS_ Renato Carminati.pdf: 854115 bytes, checksum: 8d88e20d9828adf29e18fda53a89e4b8 (MD5) / Approved for entry into archive by Delba Rosa (delba@ufba.br) on 2016-08-23T15:46:57Z (GMT) No. of bitstreams: 1 Dissertação_ICS_ Renato Carminati.pdf: 854115 bytes, checksum: 8d88e20d9828adf29e18fda53a89e4b8 (MD5) / Made available in DSpace on 2016-08-23T15:46:57Z (GMT). No. of bitstreams: 1 Dissertação_ICS_ Renato Carminati.pdf: 854115 bytes, checksum: 8d88e20d9828adf29e18fda53a89e4b8 (MD5) / A linfadenite caseosa é uma doença crônica que acomete principalmente caprinos e ovinos. O agente etiológico é a bactéria Corynebacterium pseudotuberculosis e a doença caracteriza-se pela formação de granulomas nos linfonodos internos ou superficiais e em outros órgãos. A avaliação da resposta imune humoral é uma importante ferramenta para localização de animais possivelmente infectados, dificultando desta forma a disseminação do agente. O presente estudo avaliou a sensibilidade e especificidade de quatro ensaios imunoenzimáticos (ELISA), tendo como padrão ouro o isolamento microbiológico, confirmado por PCR. Foram utilizados dois antígenos sendo o primeiro o sobrenadante da cultura de C. pseudotuberculosis em caldo BHI e o outro obtido a partir do fracionamento em três fases (TPP) do sobrenadante de cultura de C. pseudotuberculosis, no mesmo meio. Foram usadas 49 amostras de soro de caprinos que apresentavam granulomas superficiais, dos quais isolou-se C. pseudotuberculosis, as bactérias isoladas e identificadas por provas bioquímicas foram submetidas a reação de polimerase em cadeia. Foram usadas 50 amostras de soro de caprinos clinicamente sadios. A sensibilidade e especificidade do ELISA indireto BHI foi de 98% e 98%. Para o ELISA indireto TPP obteve-se uma sensibilidade e especificidade de 100% e 100%. Para o ELISA sanduíche BHI a sensibilidade e especificidade foram, de respectivamente 86% e 84%. A sensibilidade e especificidade para o ELISA sanduíche TPP, foram 74% e 72%. A banda de 815 bp para do fragmento 16S RNA de C. pseudotuberculosis foi amplificada para todas as 49 amostras isoladas.