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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.
171

Imunoproteômica aplicada ao aprimoramento do diagnóstico sorológico da estrongiloidíase humana / Immunoproteomics applied to the improvement of serologic diagnosis of human strongyloidiasis

Corral, Marcelo Andreetta 18 January 2019 (has links)
Estrongiloidíase é a infecção parasitária causada pelo nematódeo Strongyloides stercoralis. Em indivíduos imunocompetentes cursa de forma crônica e assintomática na maioria dos casos; entretanto em imunocomprometidos pode assumir as formas graves como a hiperinfecção e/ou estrongiloidíase disseminada. Diante da baixa sensibilidade do diagnóstico parasitológico, vêm sendo realizadas pesquisas envolvendo o imunodiagnóstico, sobretudo voltadas para variações na obtenção das frações antigênicas heterólogas utilizando Strongyloides venezulensis como fonte de antígeno. O presente trabalho teve como objetivo aprimorar o diagnóstico sorológico da estrongiloidíase humana utilizando técnicas imunoproteômicas. Foram utilizadas amostras de fezes e soro de indivíduos imunocompetentes, divididos em três grupos de acordo com o resultado do exame parasitológico (P: positivos para S. stercoralis; OP: com outras parasitoses; N: negativos para quaisquer parasitos ou comensais) e imunocomprometidos divididos em dois grupos de acordo com o resultado do exame parasitológico (S+ID: positivos para S. stercoralis e S-ID: negativos para S. stercoralis ou qualquer parasito). As amostras de soro dos cinco grupos de pacientes foram submetidas a testes sorológicos a partir das frações antigênicas heterólogas de S. venezuelensis solúvel (TS) e de membrana (TM) utilizando as técnicas ELISA, DOT ELISA e Western-blotting. O ELISA apresentou 95% de sensibilidade em ambas frações antigênicas e 91,8% e 93,8% de especificidade para TS e TM, respectivamente. A técnica foi capaz de detectar anticorpos anti-Strongyloides em 34,4% e 28,1% em pacientes do grupo S+ID utilizando os antígenos TS e TM, respectivamente. O DOT ELISA foi executado somente com a fração TM e apresentou 95% de sensibilidade e 85,7% de especificidade detectando 28,1% de positividade no grupo S+ID. A banda de 40-35 KDa foi a única frequente em todos indivíduos do grupo P e a mais frequente em pacientes S+ID (62,5% para TS e 53,1% para TM). Géis réplicas foram realizados, excisados nas regiões de identificação proteica e submetidos a identificação de proteínas por espectrometria de massas. As proteínas mais abundantes nas frações antigênicas TS e TM foram actina e galectina. A fração TS foi purificada em coluna de afinidade para galectina, dada sua capacidade de modulação do sistema imunológico. As frações não ligada (NL) e galectina (Gal) foram utilizadas como antígenos na técnica ELISA apresentando 90% de sensibilidade e 89,8 e 75% de especificidade para NL e Gal, respectivamente. Foram positivos no ELISA 34,4% e 18,1% das amostras do grupo S+ID utilizando as frações NL e Gal, respectivamente. As técnicas sorológicas utilizando variações antigênicas constituem ferramentas alternativas importantes de diagnósticos que podem ser aplicadas à estrongiloidíase humana, sobretudo na população imunocomprometida / Strongyloidiasis is a parasitic infection caused by nematode Strongyloides stercoralis. In immunocompetent patients, it is chronic and asymptomatic in the most of cases. However, in immunocompromised patients, it can take on severe forms such as hyperinfection and / or disseminated strongyloidiasis. Due to the parasitological diagnosis\'s low sensitivity, research involving the immunoassay has been carried out, primarily focused on changes in the heterologous antigenic fractions using Strongyloides venezulensis as a source of antigen. The present work aimed to improve the serological diagnosis of human strongyloidiasis using immunoproteomic techniques. Feces and sera samples from immunocompetent patients were used and divided into three groups according to parasitological examination result (P: positive for S. stercoralis, OP: with other parasites, N: negative for any parasites or commensal). Samples from immunocompromised patients were divided into two groups according to the parasitological examination result (S+ID: positive for S. stercoralis and S-ID: negative for S. stercoralis or any parasite). Serum samples from the five groups of patients were submitted to serological tests by S. venezuelensis soluble (TS) and from membrane (TM) heterologous antigenic fractions by ELISA, DOT ELISA and Western blotting techniques. The ELISA test showed 95% sensitivity in both antigenic fractions and 91.8% and 93.8% specificity for TS and TM, respectively. This technique was able to detect anti-Strongyloides antibodies in 34.4% and 28.1% in S+ID group by using the TS and TM antigens, respectively. DOT ELISA was performed only with the TM fraction and showed 95% sensitivity and 85.7% specificity, detecting 28.1% positivity in S+ID group. The 40-35 KDa band was the only present in all P group individuals and the most frequent in S+ID patients (62.5% for TS and 53.1% for TM). Replicate gels were made, excised in the protein identification regions and submitted to protein identification by mass spectrometry. The most abundant proteins in TS and TM antigenic fractions were actin and galectin. TS antigen was purified on a galectin affinity column, due the immune modulation ability. The non-bound (NL) and galectin (Gal) fractions were used as antigens in the ELISA technique with 90% of sensitivity and 89.8 and 75% of specificity for NL and Gal, respectively. 34.4% and 18.1% of S+ID group were positive in the ELISA by NL and Gal fractions, respectively. Serological techniques using antigenic variations are an important alternative diagnostic tool and can be applied to human strongyloidiasis, especially in the immunocompromised population
172

Imunodiagnóstico da estrongiloidíase humana frente a diferentes frações antigênicas de Strongyloides venezuelensis / Immunodiagnosis of human strongyloidiasis by different antigenic fractions of Strongyloides venezuelensis

Marcelo Andreetta Corral 21 May 2014 (has links)
A estrongiloidíase é a infecção parasitária causada pelo nematódeo Strongyloides stercoralis. O diagnóstico definitivo é realizado pela visualização de larvas, principalmente nas fezes. Porém as técnicas parasitológicas têm baixa sensibilidade. As técnicas sorológicas apresentam-se como importante alternativa diagnóstica. Pesquisas apontam para a utilização de antígenos heterólogos solúveis, principalmente de Strongyloides venezuelensis. A identificação e caracterização dos antígenos de membrana podem fornecer fonte alternativa de antígenos e assim auxiliar o desenvolvimento das técnicas imunológicas. O presente trabalho teve como objetivo a avaliação das técnicas ELISA e WB frente a diferentes frações antigênicas de larvas filarioides de S. venezuelensis. Foram utilizadas amostras de sangue e fezes de 92 indivíduos, 20 indivíduos com estrongiloidíase (grupo I), 32 indivíduos com outras parasitoses (grupo II) e 40 indivíduos negativos (grupo III) pelos métodos de Lutz, cultura em placa de ágar e Rugai. Para preparação dos antígenos foram utilizadas larvas infectantes obtidas a partir de ratos infectados experimentalmente com S. venezuelensis. Seis frações antigênicas foram preparadas: frações salinas solúveis e de membrana (PBS 0,01M pH 7,2 e SDS 1%, SS e MS; Tris-HCl 25mM pH 7,5 e CHAPS 1%, ST e MT, respectivamente) e frações alcalinas solúvel e de membrana (NaOH 0,15M e SDS 1%, SA e MA, respectivamente). Para a técnica ELISA foram utilizadas placas sensibilizadas com 10ug/mL de antígeno, soro dos indivíduos diluídos 1:200 em PBS 0,05% Tween 3% de leite (PBSTM) e o conjugado (anti IgG-humana peroxidase) em PBSTM. As amostras foram consideradas positivas quando o Índice ELISA foi maior que 1. Para a técnica de WB os soros foram diluídos 1:100 em Tris-HCl 5% de leite (TM) e o conjugado (anti IgG-humana peroxidase) em TM. Após as técnicas sorológicas foram determinadas os parâmetros de diagnóstico pela curva ROC como sensibilidade (SE), especificidade (ES), Likelihood ratio (LR) além da determinação da acurácia diagnóstica (AC) e do índice Kappa (k). A técnica ELISA destacou as frações de membrana com melhor desempenho em relação aos parêmetros diagnósticos estudados (SE 95%, ES 94,4%, AC 94,8%, LR 17,1, k 0,848). O WB revelou componentes antigênicos imunodominantes variando de 260-10kDa, mas destacam-se as frações de 40-35kDa mais frequentes em todas frações antigênicas. Pela técnica de WB, a fração ST apresentou melhor desempenho em relação aos parêmetros diagnósticos estudados (SE 100%, ES 93,1%, AC 94,5, LR 14,4,k 0,854). A utilização das frações de membrana no imunodiagnóstico da estrongiloidíase humana torna-se fonte acessível e eficaz em relação às frações purificadas, não necessitando de gastos complementares para sua obtenção / Strongyloidiasis is a parasitic infection caused by a nematode Strongyloides stercoralis. The definitive diagnosis is made by the larvae visualization in stool samples. However parasitological techniques have low sensitivity. Serological techniques became as suitable diagnostic alternative. Research indicates for the soluble heterologous antigen utilization, mainly Strongyloides venezuelensis. Identification and characterization of membrane antigen may constitute an alternative source of antigen and then assist the development of serological techniques. The aim of this study was evaluate ELISA and WB techniques behind different antigenic fractions of S. venezuelensis´ infective larvae. A total of 92 serum and stool samples was analyzed, 20 from individuals with strongyloidisis (group 1), 32 with other parasitic diseases (group 2) and 40 from individuals with negative coproparasitology (group 3) using Lutz, agar plate culture and Rugai methods. For the antigen preparation infective larvae of S. venezuelensis from experimental infected rats were employed. Six antigenic fractions were prepareted: saline soluble and from membrane fractions (0.01M PBS pH 7.2, and 1% SDS, SS and MS; 25mM Tris-HCl pH 7.5, 1% CHAPS, MT and ST, respectively) and alkaline soluble and membrane fractions (0.15 M NaOH and 1% SDS, SA and MA, respectively). For ELISA technique, plates were sensitized with 10 ug/mL of antigen, serum samples were diluted 1:200 in 0.05% Tween in PBS 3% milk (PBSTM) and conjugate (anti-human IgG peroxidase) in PBSTM. Positive samples were considered when ELISA index was greater than 1. To WB technique, serum samples were diluted 1:100 in Tris-HCl 5% milk (TM) and conjugate (anti-human IgG peroxidase) in the TM. After serological techniques diagnostics parameters were determined by ROC curve how sensitivity (SE), specificity (ES), Likelihood ratio (LR) and determination of diagnostic accuracy (AC) and Kappa (k) index. ELISA technique highlighted the membrane fractions with better performance compared to parameters diagnoses studied (95% SE, 94.4% ES, 94.8% AC, 17.1 LR, 0.848 k). The WB revealed immunodominant antigenic components ranging from 260-10kDa, but there are the fractions of 40-35kDa more frequent in all antigenic fractions. WB technique showed ST fraction better performance in relation to the diagnostic parameters (100% SE, 93.1% ES, 94.5% AC, 14.4 LR, 0.854 k). Membrane fractions in the immunodiagnosis of human strongyloidiasis become an accessible and effective source of antigens in relation to the purified fractions, requiring no additional expense to obtain it
173

Alta eficiência diagnóstica do teste IgM-ELISA utilizando múltiplos antígenos peptídicos (MAPs) de T. gondii  (ESA SAG-1, GRA-1 e GRA-7) na diferenciação de formas clínicas da toxoplasmose / High diagnostic efficiency of IgM-ELISA with the use of multiple antigen peptides (MAPS) from T. gondii  ESA (SAG-1, GRA-1 AND GRA-7 in acute toxoplasmosis

Araújo, Patricia Regina Barboza 28 November 2011 (has links)
Os principais marcadores sorológicos para o diagnóstico da toxoplasmose aguda ou recente são os anticorpos IgM específicos e anticorpos IgG de baixa avidez. Entretanto em alguns pacientes, anticorpos IgM e baixa avidez de anticorpos IgG podem persistir, ultrapassando o período da fase recente aguda contribuindo para erros de interpretação diagnóstica. No presente estudo, a eficiência diagnóstica do ensaio imunoenzimático foi avaliada, com o uso de frações antigênicas ou peptídeos sintéticos originados do antígeno ESA de T.gondii, denominados de SAG-1, GRA-1 e GRA-7. Foram estudadas frações isoladas e combinadas em múltiplos peptídeos antigênicos (MAP), visando estabelecer um perfil confiável para definição sorológica de toxoplasmose recente aguda em amostra única de soro. A melhor eficiência diagnóstica do ensaio foi encontrada com o uso da combinação de peptídeos SAG- 1,GRA-1 e GRA-7, denominada MAP1. A detecção de anticorpos IgG e IgM anti- MAP1 apresentou a melhor definição entre a fase recente aguda da fase recente não aguda na toxoplasmose. Nossos resultados mostraram que IgM anti-MAP1 poderá se constituir um marcador sorológico importante no aumento da eficiência diagnóstica da toxoplasmose recente aguda / The main serological marker for the diagnosis of recent toxoplasmosis is the specific IgM antibody, along with IgG antibodies of low avidity. However, in some patients these antibodies may persist long after the acute/recent phase, contributing to misdiagnosis in suspected cases of toxoplasmosis. In the present study, the diagnostic efficiency of ELISA was evaluated, with the use of peptides derived from T. gondii ESA antigens, named SAG-1, GRA-1 and GRA-7. In the assay referred to, we studied each of these peptides individually, as well as in four different combinations, as Multiple Antigen Peptides (MAP), aiming to establish a reliable profile for the acute/recent toxoplasmosis with only one patient serum sample. The diagnostic performance of the assay using MAP1, with the combination of SAG-1, GRA-1 and GRA-7 peptides, demonstrated better discrimination of the acute/recent phase from non acute/recent phase of toxoplasmosis. Our results show that IgM antibodies to MAP1 may be useful as a serological marker, enhancing the diagnostic efficiency of the assay for acute/recent phase of toxoplasmosis
174

Fenômeno de epitope spreading: caracterização clínico imunológica em pacientes portadores de dermatoses bolhosas autoimunes / Epitope spreading\" phenomena: clínical and immunopathological characterization in patients with bullous dermatosis

Delgado, Livia 05 May 2016 (has links)
INTRODUÇÃO: As dermatoses bolhosas autoimunes são um grupo heterogêneo de afecções da pele e/ou mucosas associadas à produção de autoanticorpos dirigidos às moléculas de adesão epitelial. Podem ser classificadas em dermatoses bolhosas intraepidérmicas (pênfigos) ou subepidérmicas (penfigóides, epidermólise bolhosa adquirida). Nos últimos anos, a transição entre dermatoses bolhosas autoimunes ou coexistência de autoanticorpos de diferentes dermatoses têm sido relatadas em alguns pacientes e atribuída ao fenômeno de epitope spreading (ES): a diversificação de epítopos reconhecidos pelo sistema imune evocaria uma reação secundária a antígenos distintos e não relacionados aos da doença primária. Neste trabalho avaliamos a ocorrência de fenômenos de ES em pacientes portadores de pênfigo. CASUÍSTICA E MÉTODOS: Inicialmente, foi realizada análise de dados clínicos e laboratoriais (exame histopatológico, de imunofluorescência direta-IFD, indireta IFI e ELISA) de 351 pacientes portadores de pênfigos acompanhados no Ambulatório de dermatoses bolhosas autoimunes do Departamento de Dermatologia da Faculdade de Medicina da Universidade de São Paulo no período de dezembro de 2002 a dezembro de 2012. Foram selecionados pacientes com quadro sugestivo de conversão à dermatose bolhosa distinta da doença primária. RESULTADOS: Nove pacientes apresentaram sinais sugestivos de fenômeno de ES e foram incluídos no estudo: 8 com a conversão de Pênfigo vulgar (PV) a foliáceo (PF) 2,3% (grupo1) e um de PF a Epidermólise bolhosa adquirida (EBA) 0,3% (grupo 2). No grupo 1 o intervalo mediano para a conversão foi de 3,5 anos. Cinco pacientes apresentaram modificação histopatológica de clivagem intraepidérmica na camada suprabasal para clivagem na camada subcórnea durante a suspeita de ES; 2 apresentaram clivagem na camada epidérmica média durante a transição e um manteve clivagem suprabasal, apesar de quadro clínico sugestivo de PF. Todos os pacientes apresentavam depósitos intercelulares de IgG e/ou C3 durante o diagnóstico de PV e PF à IFD. Títulos de IFI variaram de 1:160 a 1:5120. Os valores de ELISA para Dsg1 variaram de 22 a 319; e para Dsg3 de 0.4 a 224 (positivo se > 20). A relação Dsg1/Dsg3 correspondeu à mudança PV-PF. No grupo 2, o ES para EBA ocorreu sete anos após o diagnóstico de inicial de PF. No momento da suspeita de ES o paciente apresentava-se em remissão clínica do quadro de pênfigo folíaceo. A avaliação laboratorial mostrou clivagem subepidérmica neutrofílica, IFD com IgG intercelular intraepidérmica e depósitos de IgM, IgA, IgG e C3 na zona da membrana basal. IFI com técnica de salt split skin revelou depósitos de IgG do lado dérmico. Ao immunobloting houve reconhecimento de colágeno VII e ELISA para Dsg1 foi positivo. CONCLUSÃO: A frequência de ES em pacientes portadores de pênfigo foi de 2,6%. Estudos serão necessários para elucidar a patogênese deste evento e sua importância na progressão dos pênfigos / BACKGROUND: Autoimmune bullous skin diseases represent a heterogeneous group of disorders of skin and mucosa associated with autoantibodies against distinct adhesion molecules. They can be classified, based on the level of loss of adhesion in intraepidermal and sub epidermal dermatosis. The shift from an autoimmune blistering disease to another has been recently described and attributed to the \"epitope spreading\" (ES) phenomena. It occurs when a primary inflammatory/autoimmune process releases \"hidden\" epitopes which are recognized by the lymphocytes and evoke a secondary reaction to antigens distinct from, and non-cross-reactive, with the disease causing-epitope. This study attempted to characterize the occurrence of ES in pemphigus patients. METHODS: We analyzed data from 351 pemphigus patients treated ambulatorially at the Department of Dermatology, Faculty of Medicine, University of São Paulo, from December 2002 to December 2012. A careful search for clinical and laboratorial (histopathology, direct-DIF and indirect-IIF immunofluorescence, ELISA) changes suggestive of shift to a secondary bullous disease was performed. RESULTS: Nine out of 351 patients presented clínical shift and were included in the study: eight from pemphigus vulgaris (PV) to foliaceus (PF) 2.3% (group 1) and one from PF to epidermolysis bullosa acquisita (EBA) 0.3% (group 2). In group 1, median interval of disease shift was 3.5 years. Of 8 patients with clinical PF, five showed change of histopathology pattern from suprabasilar cleavage to subcorneal acantholysis, two had cleavage within the middle epidermal layer, and one sustained the suprabasilar acantholysis. One shifted back to PV after clinical and histopatological changes of PF. All patients showed intercellular IgG and/or C3 deposits during PV and PF diagnosis by DIF. IIF titers varied from 1:160 to 1:5120. ELISA index for Dsg1 varied from 22 to 319; and for Dsg3 from 0.4 to 224 (positive if > 20). Dsg1/Dsg3 indexes corresponded to the clinical PV-PF changes. In group 2, onset of PF occurred at the age of 25, and ES to EBA 7 years later in the absence of PF lesions. Laboratory evaluation showed sub epidermal cleavage with neutrophils, IgG intercellular staining in the epidermis and IgM, IgA, IgG and C3 deposits at BMZ by DIF, IgG deposits by indirect salt-split, recognition of collagen VII by immunoblotting, and positive ELISA for Dsg1. CONCLUSIONS: Intermolecular ES occurred in 2.6% (9/351) of pemphigus patients. Futures studies will be necessary to elucidate the pathogenesis of this event and its significance in pemphigus progression
175

Avaliação da biocompatibilidade e citotoxicidade dos cimentos : Endo-CPM-Sealer, Sealapex e Ângelus MTA /

Watanabe, Simone. January 2008 (has links)
Orientador: João Eduardo Gomes Filho / Banca: Célio Percinoto / Banca: Elisa Maria Aparecida Giro / Resumo: A necessidade de melhorar a qualidade dos materiais utilizados no tratamento endodôntico tem estimulado o estudo de vários materiais, buscando melhores condições de trabalho, biocompatibilidade e propriedade de estimular a ocorrência do selamento biológico. Este trabalho teve a finalidade de avaliar quantitativamente e qualitativamente a resposta tecidual frente ao implante de tubos de polietileno preenchidos pelos cimentos Endo-CPM-Sealer®, Sealapex® e Ângelus MTA® em tecido subcutâneo de ratos e a citotoxicidade e a produção de citocinas (IL-1β e IL-6) por fibroblastos de camundongos estimulados por estes cimentos. Para os testes de biocompatibilidade foram utilizados 30 ratos, os quais receberam individualmente três implantes de tubos de polietileno contendo os cimentos a serem testados e mais um tubo vazio como controle. Após 7, 15, 30, 60 e 90 dias do período de implantação, os animais foram sacrificados e os tubos de polietileno juntamente com o tecido que o circunda foram removidos, fixados e processados para análise em microscopia de luz. Após inclusão em glicol metacrilato, foram realizados cortes seriados de 3mm, corados com hematoxilina-eosina e cortes de 10mm, corados com Von Kossa e sem coloração para serem analisados sob luz polarizada. Os resultados foram analisados estatisticamente pelo teste de Kruskal Wallis. Os materiais Endo-CPM-Sealer®, Sealapex® e Ângelus MTA® causaram reações moderada no tempo experimental de 7 dias que diminuiu com o tempo. A resposta foi similar entre os grupos Controle, Endo- CPM-Sealer® e Ângelus MTA® no tempo experimental de 30 dias. Aos 60 dias todos os grupos foram semelhantes ao Controle. Mineralizações e granulações birrefringentes à luz polarizada foram observadas com todos os materiais. Foi possível concluir que o Endo-CPM-Sealer® foi biocompatível e estimulou a mineralização. Para o teste... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: The need of improving the quality of materials used in endodontic treatment has stimulated the study of various materials seeking better working conditions, biocompatibility and property to stimulate the occurrence of biological sealing. The aim of this study was to evaluate quantitatively and qualitatively the tissue response to the implantation of polyethylene tubes filled with Endo-CPM-Sealer®, Sealapex® and Ângelus MTA® in subcutaneous tissue of rats and cytotoxicity and production of cytokines (IL-1β and IL-6) by mouse fibroblasts stimulated by these sealers. Thirty rats were used for the biocompatibility tests. Each animal received three implants of polyethylene tubes containing the cement to be tested and one empty polyethylene tube was used as control. After 7, 15, 30, 60 and 90 days from the implantation time, the animals were killed and the tubes with surrounding tissues were removed, fixed and processed for analysis using a light microscope. After inclusion in glycol methacrylate, they were serially sectioned into 3 μm or 10 μm cuts and stained with hematoxylineosin, Von Kossa or remained without staining to be observed under polarized light. The results were statistically analyzed by Kruskal Wallis test. The materials Endo- CPM-Sealer®, Sealapex® and Ângelus MTA® caused moderate reactions at 7 days which decreased with time. The response was similar among the control group, Endo- CPM-Sealer® and Ângelus MTA® at the 30th day. At 60th day all groups were similar to control group. Mineralization and granulations birefringent to the polarized light were observed with all materials. It was possible to conclude that Endo-CPM-Sealer® was biocompatible and stimulated mineralization. To test the cytotoxicity of mouse fibroblast (L929) were incubated in plate of 24 wells and stimulated with the sealers tested. Cell culture... (Complete abstract click electronic access below) / Mestre
176

Alta eficiência diagnóstica do teste IgM-ELISA utilizando múltiplos antígenos peptídicos (MAPs) de T. gondii  (ESA SAG-1, GRA-1 e GRA-7) na diferenciação de formas clínicas da toxoplasmose / High diagnostic efficiency of IgM-ELISA with the use of multiple antigen peptides (MAPS) from T. gondii  ESA (SAG-1, GRA-1 AND GRA-7 in acute toxoplasmosis

Patricia Regina Barboza Araújo 28 November 2011 (has links)
Os principais marcadores sorológicos para o diagnóstico da toxoplasmose aguda ou recente são os anticorpos IgM específicos e anticorpos IgG de baixa avidez. Entretanto em alguns pacientes, anticorpos IgM e baixa avidez de anticorpos IgG podem persistir, ultrapassando o período da fase recente aguda contribuindo para erros de interpretação diagnóstica. No presente estudo, a eficiência diagnóstica do ensaio imunoenzimático foi avaliada, com o uso de frações antigênicas ou peptídeos sintéticos originados do antígeno ESA de T.gondii, denominados de SAG-1, GRA-1 e GRA-7. Foram estudadas frações isoladas e combinadas em múltiplos peptídeos antigênicos (MAP), visando estabelecer um perfil confiável para definição sorológica de toxoplasmose recente aguda em amostra única de soro. A melhor eficiência diagnóstica do ensaio foi encontrada com o uso da combinação de peptídeos SAG- 1,GRA-1 e GRA-7, denominada MAP1. A detecção de anticorpos IgG e IgM anti- MAP1 apresentou a melhor definição entre a fase recente aguda da fase recente não aguda na toxoplasmose. Nossos resultados mostraram que IgM anti-MAP1 poderá se constituir um marcador sorológico importante no aumento da eficiência diagnóstica da toxoplasmose recente aguda / The main serological marker for the diagnosis of recent toxoplasmosis is the specific IgM antibody, along with IgG antibodies of low avidity. However, in some patients these antibodies may persist long after the acute/recent phase, contributing to misdiagnosis in suspected cases of toxoplasmosis. In the present study, the diagnostic efficiency of ELISA was evaluated, with the use of peptides derived from T. gondii ESA antigens, named SAG-1, GRA-1 and GRA-7. In the assay referred to, we studied each of these peptides individually, as well as in four different combinations, as Multiple Antigen Peptides (MAP), aiming to establish a reliable profile for the acute/recent toxoplasmosis with only one patient serum sample. The diagnostic performance of the assay using MAP1, with the combination of SAG-1, GRA-1 and GRA-7 peptides, demonstrated better discrimination of the acute/recent phase from non acute/recent phase of toxoplasmosis. Our results show that IgM antibodies to MAP1 may be useful as a serological marker, enhancing the diagnostic efficiency of the assay for acute/recent phase of toxoplasmosis
177

Toxocaríase murina experimental: diagnóstico por PCR e comparação com técnicas imunológicas / Experimental murine toxocariasis: PCR diagnosis and its comparison with immunological techniques

Gabriela Rodrigues e Fonseca 03 July 2018 (has links)
A toxocaríase é considerada uma das cinco parasitoses negligenciadas pelo Centers for Disease Control and Prevention e recebe ainda pouca atenção. As metodologias diagnósticas conhecidas são bem estabelecidas, apresentando, porém, limitações caracterizadas, sobretudo, pela ocorrência de reações-cruzadas. A biologia molecular mostra grandes avanços para o diagnóstico eficaz de diversas parasitoses, mas ainda carece de estudos em amostras de fácil obtenção para o diagnóstico da toxocaríase. Para aprimorar o conhecimento sobre a importância da técnica da Reação em Cadeia da Polimerase Convencional (PCR) e sua relação com técnicas diagnósticas já conhecidas, foram utilizados 42 camundongos BALB/c, machos, entre 6 a 8 semanas de vida, divididos em três grupos, inoculados com 5, 50 ou 500 ovos larvados e sangrados pelo plexo orbital aos 15, 30, 60 e 90 dias pós infecção. Ainda, do total, 24 camundongos foram sangrados aos 120 dias pós infecção. Ao final do experimento, foi realizada a recuperação de larvas e a PCR de tecido hepático, cérebro e carcaça de camundongos dos grupos infectados. As amostras de soro foram processadas pelas técnicas de ELISA, Western-blotting e PCR. O ELISA e o Western-blotting mostraram resultados reagentes em todas as datas para a maioria dos inóculos de ovos, com relação diretamente proporcional entre a detecção de anticorpos e a carga parasitária. Durante o período da infecção, a detecção de IgG foi mais intensa próxima aos 60 dias pós-infecção para a maioria dos inóculos de ovos, por ambos os métodos imunológicos. Apesar de identificar DNA de larvas e vermes adultos, a PCR não foi capaz de detectar DNA do parasito em amostras de soro em todos os grupos e datas pós-infecção. Em contrapartida, foi detectado DNA do parasito em todos os órgãos com ao menos um dos primers utilizados. Foram recuperadas larvas na maioria dos órgãos com maior porcentagem de recuperação relatada nos animais inoculados com 50 ovos larvados. O diagnóstico molecular, utilizando sangue do paciente, ainda não pode ser considerado uma ferramenta para o diagnóstico dessa infecção / Toxocariasis is considered by the Centers for Disease Control and Prevention one of the five neglected diseases and still receives little attention. The diagnostic methods are well established, presenting, however, limitations characterized mainly by the occurrence of cross-reactions. Molecular biology shows great advance for the effective diagnosis of several parasitic infections, but still lacks studies using samples that are easily obtained for the diagnosis of toxocariasis. In order to refine the knowledge about the importance of Conventional Polymerase Chain Reaction (PCR) and its relation with known techniques, 42 BALB/c male mice, between 6-8 weeks of age were inoculated with 5, 50 and 500 embryonated eggs respectively and bled by the orbital plexus at 15, 30, 60 and 90 days post infection. Also, 24 of 42 animals were bled the same way at 120 days post-infection. At the end of the experiment, larval recovery and conventional PCR were performed in liver, brain and carcass of mice of the infected groups. Serum samples were processed by ELISA, Western-blotting and PCR. The ELISA and Western-blotting techniques showed positive results in all days post infection for most eggs inocula and showed a directly proportional dependence between the infective dose and the level of antibodies. During the course of the infection, IgG detection was most intense near 60 days post infection for most eggs inocula, for both diagnostic methods. Despite positive DNA identification in larvae and adult worms, PCR wasn\'t able to detect parasite DNA in serum samples in all infected groups and days post infection. In contrast, parasite DNA was detected in all organs with at least one of the primers. Larvae were recovered from most organs, and animals inoculated with 50 embryonated eggs showed the highest percentage of larval recovery. Molecular diagnosis using patient\'s blood is not the best tool for toxocariasis diagnosis so far
178

Expression of Human Coronavirus NL63 and SARS-CoV Nucleocapsid Proteins for antibody production

Mnyamana, Yanga E. January 2012 (has links)
<p>Human Coronaviruses (HCoVs) are found within the family Coronaviridae (genus, Coronavirus) and are enveloped, single-stranded, positive-sense RNA viruses. Infections of humans by&nbsp / coronaviruses are not normally associated with severe diseases. However, the identification of the coronavirus responsible for the outbreak of severe acute respiratory syndrome (SARS-CoV)&nbsp / showed that highly pathogenic coronaviruses can enter the human population. The SARS-CoV epidemic resulted in 8 422 cases with 916 deaths globally (case fatality rate: 10.9%). In 2004 a&nbsp / group 1 Coronavirus, designated Human Coronavirus NL63 (HCoV-NL63), was isolated from a 7 month old Dutch child suffering from bronchiolitis. In addition, HCoV-NL63 causes disease in&nbsp / children (detected in approximately 10% of respiratory tract infections), the elderly and the immunocompromised. This study was designed to express the full length nucleocapsid (N) proteins of&nbsp / HCoV-NL63 and SARS-CoV for antibody production in an animal model. The NL63-N/pFN2A and SARSN/ pFN2A plasmid constructs were used for this study. The presence of the insert on the Flexi &reg / vector was confirmed by restriction endonuclease digest and sequence verification. The sequenced chromatographs obtained from Inqaba Biotec were consistent with sequences from&nbsp / the NCBI Gen_Bank. Proteins were expressed in a KRX Escherichia coli bacterial system and analysed using 15% SDS-PAGE and Western Blotting. Thereafter, GST-tagged proteins were purified&nbsp / ith an affinity column purification system. Purified fusion proteins were subsequently cleaved with Pro-TEV Plus protease, separated on 15% SDS-PAGE gel and stained with Coomassie&nbsp / Brilliant Blue R250. The viral fusion proteins were subsequently used to immunize Balbc mice in order to produce polyclonal antibodies. A direct ELISA was used to analyze and validate the&nbsp / production of polyclonal antibodies by the individual mice. This is a preliminary study for development of diagnostic tools for the detection of HCoV-NL63 from patient samples collected in the&nbsp / Western Cape.</p>
179

Expression of Human Coronavirus NL63 and SARS-CoV Nucleocapsid Proteins for antibody production

Mnyamana, Yanga E. January 2012 (has links)
<p>Human Coronaviruses (HCoVs) are found within the family Coronaviridae (genus, Coronavirus) and are enveloped, single-stranded, positive-sense RNA viruses. Infections of humans by&nbsp / coronaviruses are not normally associated with severe diseases. However, the identification of the coronavirus responsible for the outbreak of severe acute respiratory syndrome (SARS-CoV)&nbsp / showed that highly pathogenic coronaviruses can enter the human population. The SARS-CoV epidemic resulted in 8 422 cases with 916 deaths globally (case fatality rate: 10.9%). In 2004 a&nbsp / group 1 Coronavirus, designated Human Coronavirus NL63 (HCoV-NL63), was isolated from a 7 month old Dutch child suffering from bronchiolitis. In addition, HCoV-NL63 causes disease in&nbsp / children (detected in approximately 10% of respiratory tract infections), the elderly and the immunocompromised. This study was designed to express the full length nucleocapsid (N) proteins of&nbsp / HCoV-NL63 and SARS-CoV for antibody production in an animal model. The NL63-N/pFN2A and SARSN/ pFN2A plasmid constructs were used for this study. The presence of the insert on the Flexi &reg / vector was confirmed by restriction endonuclease digest and sequence verification. The sequenced chromatographs obtained from Inqaba Biotec were consistent with sequences from&nbsp / the NCBI Gen_Bank. Proteins were expressed in a KRX Escherichia coli bacterial system and analysed using 15% SDS-PAGE and Western Blotting. Thereafter, GST-tagged proteins were purified&nbsp / ith an affinity column purification system. Purified fusion proteins were subsequently cleaved with Pro-TEV Plus protease, separated on 15% SDS-PAGE gel and stained with Coomassie&nbsp / Brilliant Blue R250. The viral fusion proteins were subsequently used to immunize Balbc mice in order to produce polyclonal antibodies. A direct ELISA was used to analyze and validate the&nbsp / production of polyclonal antibodies by the individual mice. This is a preliminary study for development of diagnostic tools for the detection of HCoV-NL63 from patient samples collected in the&nbsp / Western Cape.</p>
180

Development of an enzyme-linked immunosorbent assay (ELISA) for field detection and discrimination of Fusarium circinatum from Fusarium oxysporum and Diplodia pinea in pine seedlings.

Mkhize, Phumzile. 18 September 2014 (has links)
Fusarium circinatum is a fungal pathogen that has had a serious impact on pine production throughout the world. It attacks most Pinus species including Pinus elliottii, Pinus patula and Pinus radiata. Infections in South Africa (SA) are largely on seedlings, and result in fatal seedling wilt. Accurate and quick detection systems suitable for field use are needed to monitor the spread of the disease and optimize fungicide applications. Detection of F. circinatum is currently based on visual observations of typical symptoms. However, symptoms are not unique to the pathogen and can be caused by other biotic and abiotic stress factors. Nucleic acid-based identification techniques using PCR are available for different fungal species. These are sensitive and accurate, but they are expensive and require skilled biotechnologists to conduct the assays. In this study an enzyme-linked immunosorbent assay (ELISA) was developed to identify F. circinatum in infected seedlings. This optimized ELISA is able to discriminate between F. circinatum and two other fungi that frequently affect pine. This method has advantages over other assays because of its ease of operation and sample preparation, sensitivity and the ability to run multiple tests simultaneously. Mycelium-soluble antigens from Diplodia pinea (=Sphaeropsis sapinea), F. circinatum and F. oxysporum were prepared in nutrient broth. Analysis of these antigens on SDS-PAGE indicated the presence of common antigens between the different fungal pathogens. Some antigens were expressed more by some isolates than by others. Separate groups of chickens were immunised with mycelium-soluble antigens from D. pinea, F. circinatum and F. oxysporum and exo-antigen from F. circinatum prepared in nutrient broth. A 34 kDa protein purified from SDS-PAGE specific for D. pinea was also used for immunisation. Five sets of antibodies were obtained including anti-D. pinea, anti-F. circinatum, anti-F. oxysporum, anti-F. circinatumexo and anti-D. pinea 34 kDa antibodies, respectively. Reactivity of these antibodies was evaluated against antigens prepared in nutrient broth using western blotting and ELISA. Western blot analysis indicated that immuno-dominant antigens for F. circinatum were larger than 34 kDa and their reactivity was not the same between different isolates. Each of the antibodies prepared using mycelium-soluble antigens showed increased reactivity when detecting its own specific pathogen, but cross-reactivity was observed. Anti-D.pineaantibodies showed minimal cross-reactivity with antigens from F. circinatum and F. oxysporum. Anti-F. circinatum antibodies cross-reacted with antigens from F. oxysporum but showed little cross-reactivity with D. pinea antigens. Anti-F. oxysporum antibodies showed more cross-reactivity towards antigens from F. circinatum than those from D. pinea. No reactivity was observed when anti-F. circinatum-exo antigen and anti-D. pinea 34 kDa antibodies were used in immuno-blotting analysis. Evaluation of antibody reactivity using indirect ELISA showed patterns similar to those observed on western blotting, where anti-D. pinea, anti-F. circinatum and anti-F. oxysporum antibodies showed the same cross-reactivity relationships. Anti-F. circinatum and anti-F. oxysporumantibodies showed a significant difference when reacting with antigens isolated from other pathogens including D. pinea, F. circinatum, F. oxysporum, F. solani, F. graminearum and F. culmorum (P = 0.001). No significant difference was observed when the antigens were detected with anti-D. pinea antibodies. Reactivity of anti-F. circinatum-exo and anti-D. pinea34 kDa antibodies was mostly similar to that of non-immune antibodies and showed no significant difference between detection of different antigens. Pine seedlings were artificially infected with the three fungal pathogens using a spore concentration of 1 – 1 x 106conidiaml-1.Infection was monitored using scanning electron microscopy. Results showed increased levels of mycelium growth on the stem and roots of the F. circinatum and F. oxysporum infected seedlings and on the leaves and stem in the case of D. pinea infected seedlings. These plant parts were used in ELISA tests for the detection of antigens. Isolation of antigens from the plant materials involved crushing plant parts in buffer and centrifugation of the suspension. The supernatant obtained was directly used in the assay. ELISA tests prepared in this study were sensitive enough to detect infection caused by 1 conidium ml-1at two weeks post inoculation. A positive reaction for detection of F. circinatum and F. oxysporum was indicated by an ELISA reading above an optical density at 405 nm. The plant material used in ELISA tests were further analysed using PCR. Results indicated that there was no cross-infection between seedlings and served as a confirmation of the disease-causing pathogen. This indicated that cross-reactivity observed was due to other factors such as common epitopes on the major antigens. Use of an ELISA dip-stick or ELISA using these antibodies should provide an easy, fast field test to identify infections of pine, discriminating between F. circinatum, F. oxysporum and D. pinea. / M.Sc.Agric. University of KwaZulu-Natal, Pietermaritzburg 2013.

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