• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 32
  • 21
  • 4
  • 1
  • 1
  • 1
  • 1
  • Tagged with
  • 66
  • 12
  • 12
  • 7
  • 7
  • 7
  • 7
  • 6
  • 5
  • 5
  • 5
  • 5
  • 5
  • 5
  • 5
  • 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.
31

Avaliação imunodiagnóstica de antígenos excretados-secretados de L. (L.) amazonensis, L. (V.) braziliensis e L.(L.) chagasi na Leishmaniose visceral humana e canina. / Evaluation of excreted-secreted antigens of L. (L.) amazonensis, L. (V.) braziliensis and L. (L.) chagasi in immunodiagnosis of human and dog Visceral leishmaniasis.

Cancino, Viviana Vanessa Pinedo 20 August 2009 (has links)
A Leishmaniose visceral é um problema que cresce no Estado de São Paulo afetando o homem e o cão. Os exoantígenos da membrana das leishmanias são liberados no meio de cultura. Os exoantígenos são importantes na indução da imunidade mediada pelas células T e B estimulando a produção elevada de anticorpos. Realizamos uma avaliação comparativa por ELISA e Immunoblotting de exoantígenos e antígenos totais de L. (L.) amazonensis, L. (V.) braziliensis e L. (L.) chagasi, no diagnóstico da leishmaniose visceral humana e canina. Obteve-se por ELISA sensibilidade de 100% para ambos os preparados antigênicos independente da espécie de Leishmania. A melhor especificidade em humanos e cães foi com os exoantígenos. O exoantígeno da L. (L.) chagasi teve a melhor especificidade e média de absorbâncias comparadas aos das outras espécies (p<0.005). Para o hospedeiro humano o ELISA com exoantígenos, não discriminou pacientes com leishmaniose cutânea e ou mucocutânea. O Immublotting dos exoantígenos de L. (L.) chagasi (IBleish) apresentou 100% de sensibilidade e especificidade para os cães. Os dados do IBleish-L. (L.) chagasi demonstraram a possibilidade de sua utilização como método confiável para a confirmação do diagnóstico da leishmaniose canina. / The visceral leishmaniasis is a new problem that grows in the State of São Paulo, affecting men and dogs. The exoantigens from the membrane of the Leishmania, are released out of culture medium. The exoantigens are important in the induction of immunity mediated by T and B cells, stimulating the production of antibodies. This work was carried out an evaluation of ELISA and Immunoblotting using comparatively exoantigens and total antigens of L. (L.) amazonensis, L. (V.) braziliensis and L. (L.) chagasi for the diagnosis of canine and human visceral leishmaniasis. ELISA sensitivity was 100% for all different antigens, independent of the species of Leishmania employed. The best specificity for both human and dogs were obtained with exoantigens. Exoantigen from L. (L.) chagasi was what showed the best specificity and mean absorbance compared to those of other species (p<0.05). The ELISA with exoantigens for the human host not discriminate individuals with leishmaniasis cutaneous or mucocutaneous. The Immunoblotting that used the exoantigens of L. (L.) chagasi (IBleish) showed 100% sensitivity and specificity for the dogs. The IBleish-L. (L.) chagasi showed the possibility of its use as a reliable method to confirm the diagnosis of canine leishmaniasis.
32

Avaliação imunodiagnóstica de antígenos excretados-secretados de L. (L.) amazonensis, L. (V.) braziliensis e L.(L.) chagasi na Leishmaniose visceral humana e canina. / Evaluation of excreted-secreted antigens of L. (L.) amazonensis, L. (V.) braziliensis and L. (L.) chagasi in immunodiagnosis of human and dog Visceral leishmaniasis.

Viviana Vanessa Pinedo Cancino 20 August 2009 (has links)
A Leishmaniose visceral é um problema que cresce no Estado de São Paulo afetando o homem e o cão. Os exoantígenos da membrana das leishmanias são liberados no meio de cultura. Os exoantígenos são importantes na indução da imunidade mediada pelas células T e B estimulando a produção elevada de anticorpos. Realizamos uma avaliação comparativa por ELISA e Immunoblotting de exoantígenos e antígenos totais de L. (L.) amazonensis, L. (V.) braziliensis e L. (L.) chagasi, no diagnóstico da leishmaniose visceral humana e canina. Obteve-se por ELISA sensibilidade de 100% para ambos os preparados antigênicos independente da espécie de Leishmania. A melhor especificidade em humanos e cães foi com os exoantígenos. O exoantígeno da L. (L.) chagasi teve a melhor especificidade e média de absorbâncias comparadas aos das outras espécies (p<0.005). Para o hospedeiro humano o ELISA com exoantígenos, não discriminou pacientes com leishmaniose cutânea e ou mucocutânea. O Immublotting dos exoantígenos de L. (L.) chagasi (IBleish) apresentou 100% de sensibilidade e especificidade para os cães. Os dados do IBleish-L. (L.) chagasi demonstraram a possibilidade de sua utilização como método confiável para a confirmação do diagnóstico da leishmaniose canina. / The visceral leishmaniasis is a new problem that grows in the State of São Paulo, affecting men and dogs. The exoantigens from the membrane of the Leishmania, are released out of culture medium. The exoantigens are important in the induction of immunity mediated by T and B cells, stimulating the production of antibodies. This work was carried out an evaluation of ELISA and Immunoblotting using comparatively exoantigens and total antigens of L. (L.) amazonensis, L. (V.) braziliensis and L. (L.) chagasi for the diagnosis of canine and human visceral leishmaniasis. ELISA sensitivity was 100% for all different antigens, independent of the species of Leishmania employed. The best specificity for both human and dogs were obtained with exoantigens. Exoantigen from L. (L.) chagasi was what showed the best specificity and mean absorbance compared to those of other species (p<0.05). The ELISA with exoantigens for the human host not discriminate individuals with leishmaniasis cutaneous or mucocutaneous. The Immunoblotting that used the exoantigens of L. (L.) chagasi (IBleish) showed 100% sensitivity and specificity for the dogs. The IBleish-L. (L.) chagasi showed the possibility of its use as a reliable method to confirm the diagnosis of canine leishmaniasis.
33

Avaliação da ação neutralizante e da reatividade de anticorpos anti-rotavírus G3P[2] e G9P[8] em amostras de leite e colostro humanos. / Evaluation of neutralizing activity and antibodies reactivity anti-rotavirus G3P[2] and G9P[8] in human milk and colostrum samples.

Simone Macedo Ribeiro dos Santos 18 May 2010 (has links)
A diarréia por rotavírus tem sido umas das principais causas de mortalidade infantil. Pesquisas, que relatam a presença de IgA no leite e colostro humanos reativos com o rotavírus. Nosso objetivo foi avaliar a presença de anticorpos IgA anti-G3P[2] em amostras de leite e colostro e anti-G9P[8] em amostras de leite pela técnica de ELISA, verificar sua capacidade neutralizante e analisar a reatividade pelo Immunoblotting. Todas as amostras apresentaram anticorpos detectados pelo ELISA e neutralização do vírus G3P[2] e G9P[8]. Não foi observada correlação entre os títulos de ELISA e os neutralizantes para G3P[2], mas para o sorotipo G9P[8] foi possível estabelecer uma correlação significante. As amostras reconheceram frações do antígeno viral no ensaio de Immunoblotting, mas não foi possível estabelecer uma correlação entre altos títulos e alguma fração antigênica específica. Este trabalho fornece subsídios para avaliações das estratégias de vacinação. / The rotavirus diarrhea is one of the main causes of infant mortality. Studies have shown the presence of IgA in milk and colostrum reactive with human rotavirus. Our aim was to evaluate the presence of IgA anti-G3P[2] in milk and colostrum samples and anti-G9P[8] in milk ones, evaluate the IgA reactivity by ELISA and evaluate the IgA reactivity by immunoblotting. In addition, this work aimed to verify the neutralizing all titles of the samples. All of them had antibodies reactive with G3P[2] and G9P[8] and showed varied neutralization titles. There was a significant correlation between anti-G9P[8] IgA titers and the neutralizing ones, but the same was not observed for serotype G3P[2]. All samples recognized some viral antigenic fraction in immunoblotting test, but it was not possible establish a correlation between high antibodies levels and some specific antigenic fraction. This approach may be important for studies concerning vaccination strategies.
34

Evidence for Absence of Latchbridge Formation in Phasic Saphenous Artery

Han, Shaojie 01 January 2005 (has links)
Tonic arterial smooth muscle can produce strong contractions indefinitely by formation of slowly cycling crossbridges (latchbridges) that maintain force at a high energy economy. To fully understand the uniqueness of mechanisms regulating tonic arterial contraction, comparisons have been made to phasic visceral smooth muscles that do not sustain high forces. This study explored mechanisms of force maintenance in a phasic artery by comparing KCl-induced contractions in the tonic, femoral artery (FA) and its primary branch, the phasic saphenous artery (SA). KCl rapidly (5 N/m2) and [ca2+]i (250 nM) in FA and SA. By 10 min, [ca2+]i declined to 175 nM in both tissues but stress was sustained in FA (1.3 x 105N/m2) and reduced by 40% in SA (0.8 x l05 N/m2). Reduced tonic stress correlated with reduced myosin light chain (MLC) phosphorylation in SA (28% vs. 42% in FA). SA expressed more MLC phosphatase than FA, and permeabilized (β-escin) SA relaxed more rapidly than FA in the presence of MLC kinase blockade, suggesting that MLC phosphatase activity in SA was greater than that in FA. The reduction in MLC phosphorylation in SA was insufficient to account for reduced tonic force (latchbridge model), and SA expressed more "fast" myosin isoforms than did FA. Cytochalasin-D reduced force-maintenance more in FA than SA. These data support the hypothesis that strong force-maintenance is absent in SA because expressed motor proteins do not support latchbridge formation, and because actin polymerization is not stimulated.
35

Obtenção de proteína recombinante baseada em antígenos do líquido vesicular de Taenia crassiceps: aplicação no imunodiagnóstico da neurocisticercose / Recombinant protein obtainment based on antigens from Taenia crassiceps vesicular fluid: application on immunodiagnostics of neurocisticercosis

Gomes, Andréia Bartachini 10 February 2011 (has links)
A neurocisticercose (NC) é uma doença provocada por larvas de Taenia solium (Tso) no sistema nervoso central. Seu diagnóstico fundamenta-se em critérios clínicos, epidemiológicos e laboratoriais. A utilização de antígenos parasitários no imunodiagnóstico apresenta desvantagens como: necessidade de animais, ausência de homogeneidade entre lotes, baixo rendimento, e contaminação com proteínas suínas. Assim, os antígenos recombinantes podem otimizar o imunodiagnóstico da NC, pois são reagentes simples e reprodutíveis, sem requerer animais. Este estudo teve como objetivo a obtenção, caracterização e análise da reatividade de proteína recombinante baseada em antígenos de líquido vesicular de Taenia crassiceps (Tcra). Assim, o cDNA foi obtido por amplificação a partir de RNAm de cisticercos de Tcra. A proteína recombinante Tc14 foi produzida em Escherichia coli (DE3) BL21 utilizando-se o vetor de expressão pET-22b e purificada por cromatografia de afinidade. A caracterização antigênica deu-se por Imunoblot (IB) utilizando anticorpos monoclonais (AcMo). Houve reatividade com todos os AcMo utilizados (AcMo anti-antígeno de excreção/secreção de Tcra, AcMo anti-líquido vesicular de Tcra, AcMo antilíquido vesicular de Tso e AcMo anti-antígeno total de Tso), exceto com o AcMo anti-antígeno de escólex de Tso. Utilizando-se 22 amostras de soro e 19 de líquor (LCR) de pacientes com NC, 48 soros e 28 LCR do grupo controle negativo (GCN) e 17 soros de hidatidose do grupo outras parasitoses (OP) em Imunoblot foi observada reatividade na região de 14kDa, correspondente a Tc14, em todas as amostras NC, mas não nos GCN e OP. Em ELISA com Tc14 obteve-se sensibilidade (S) e especificidade (E) de 100% com LCR (29 amostras de NC e 35 do GCN) e S de 95,1% e E de 100% com soro (41 amostras de NC, 52 do GCN). Dentre 51 soros de OP, mostraram-se reagentes um de hidatidose e outro de estrongiloidíase. A análise comparativa entre diferentes antígenos e testes sorológicos apresentou índice de positividade de 100% em IB utilizando os antígenos Tc14 ou LLG (antígeno purificado de Tso com lentil-lectina); já em ELISA, os índices foram de 83,4% para Tc14 e 91,6% para 18/14 (antígeno purificado de líquido vesicular de Tcra com AcMo). Em ensaios de linfoproliferação a porcentagem de respondedores no grupo NC foi de 16,6% (com 0,05 e 0,6 &#181;g de Tc14/poço), 50% (com 0,4 &#181;g de Tc14/poço), 44,4% (com 1,0 &#181;g de Tc14/poço) e 20% (com 2,0 &#181;g de Tc14/poço). Não houve proliferação no GCN. A dosagem de citocinas em sobrenadante de cultura apresentou reatividade diferenciada entre o GCN e NC para IL-10, sendo uma amostra do GCN reagente e duas amostras de NC não reagentes. Não foi possível detectar IFN-&#947;. Em ELISA para IgG total 91,7% dos plasmas do grupo NC apresentaram reatividade, sendo a positividade para os isótipos IgG1, IgG2, IgG3 e IgG4 respectivamente, de 75; 33,3; 50 e 25%. O antígeno recombinante mostrou-se como ferramenta promissora para imunoensaios na NC, abrindo nova perspectiva envolvendo estudos a serem realizados sobre diferentes sistemas de expressão e antigenicidade frente a um número maior de amostras. / The neurocisticercosis (NC) disease is caused by the presence of Taenia solium (Tso) larvae in the central nervous system. Its diagnosis is based on clinical criteria, epidemiological studies and laboratorial exams. Nevertheless, the use of parasite antigenic extracts into the immunodiagnosis presents some disadvantages: it requires animals, lacks of homogeneity between lots, low yield and may become contaminated with swine proteins. Consequently, the utilization of recombinant antigens could optimize the immunodiagnostic of NC, as they are simple and reproducible reagents that do not require animals. This study aimed the capture, characterization and reactivity analysis of the recombinant protein based on antigens of the vesicular fluid of Taenia crassiceps (Tcra). In order to do so, the cDNA was obtained through the amplification deriving from RNAm of cysticerci of Tcra. The recombinant protein Tc14 was produced in Escherichia coli (DE3) BL21 using the expression vector pET-22b and purified by affinity chromatography (nickel resin). The antigenic characterization was performed by immunoblotting (IB) using monoclonal antibodies (MoAb). The recombinant protein presented reactivity with all the MoAb used (Anti-secretion/excretion antigens from Tcra MoAb, anti-vesicular fluid from Tcra MoAb, anti-vesicular fluid from Tso MoAb and anti- total antigen from Tso MoAb), except with the anti-antigen from Tso scolex MoAb. The immunoblot was performed using 22 serum samples and 19 cerebrospinal fluid (CSF) from patients with NC, 48 serum and 28 CSF from the negative control group (GCN) and 17 hydatidosis serum from other parasitosis\' group (OP). It showed reactivity in the 14kDa region, correlated to Tc14, in all NC samples, but not presented on GCN and OP. In ELISA with Tc14, the sensibility (S) and specificity (E) of 100% was obtained with CSF (29 NC samples and 35 GCN samples) and 95.1% of S and 100% of E with serum (41 NC samples, 52 GCN samples). Among 51 OP serums, one from hydatidosis and one from strongyloidiasis demonstrated reactivity. The comparative analysis amongst different antigens and serological tests demonstrated positivity of 100% in IB when using the Tc14 antigens or LLG (purified antigen of Tso with lentil lectin). In ELISA, the positivity indicated was of 83.4% for Tc14 and 91.6% for 18/14 (vesicular fluid purified antigen with MoAb from Tcra). In lymphoproliferation tests, the percentage of responders in NC group was of 16.6% (with .0.5 and 6 &#181;g of Tc14/well), 50% (with 0.4 &#181;g of Tc14/well). No proliferation occurred in GCN. The dosage of cytokines in culture supernatants presented different reactivity amongst GCN and NC for IL-10, as one sample of GCN reacted and two NC samples did not. It was not possible to detect IFN-&#947;. In ELISA for total lgG, 91.7 % of plasmas from NC group presented reactivity, with positivity for the isotypes lgG1, lgG2, lgG3 and lgG4, 75 %, 33.3 %, 50 % and 25 %, respectively. The recombinant antigen prevails as a promising tool for immunoassays in NC, opening a new perspective involving studies to be performed concerning different expression and antigenicity ahead of a larger number of samples.
36

Development of immunological methods and Real-Time PCR for detection of Macadamia nut (Macadamia spp.)

Eliasson, Hanna January 2005 (has links)
<p>A new European labeling directive (2003/89/EC) states that certain foods and products derived thereof must always be declared. Among the tree nuts specified is Macadamia nut (Macadamia spp.). During the last few years, cases of IgE-allergic reactions, even severe anaphylaxes, have been reported. Reliable methods for the detection of this nut are needed.</p><p>Protein from Macadamia nuts was isolated. Polyacrylamide gel electrophoresis in SDS revealed two main protein bands of about 20 and 50kDa. These protein bands were cut and extracted from the gel and rabbits were immunized with each protein.</p><p>Immunoblotting showed dominant reactivity with the respective antigens. The antisera were further tested for specificity in immunodiffusion and in rocket immunoelectrophoresis.</p><p>In addition, a specific DNA-method was developed, based on Real-Time PCR using Macadamia vicilin as target sequence. Two different primer pairs were tested. Specificity was tested against potentially related nuts. Optimisation of primer and probe concentrations was performed. The limit of detection was 2-4 pg DNA, corresponding to a macadamia nut concentration of 50 to 100 μg per g. In a background of soybean DNA, down to 0,01 % macadamia DNA could be detected.</p>
37

Development of immunological methods and Real-Time PCR for detection of Macadamia nut (Macadamia spp.)

Eliasson, Hanna January 2005 (has links)
A new European labeling directive (2003/89/EC) states that certain foods and products derived thereof must always be declared. Among the tree nuts specified is Macadamia nut (Macadamia spp.). During the last few years, cases of IgE-allergic reactions, even severe anaphylaxes, have been reported. Reliable methods for the detection of this nut are needed. Protein from Macadamia nuts was isolated. Polyacrylamide gel electrophoresis in SDS revealed two main protein bands of about 20 and 50kDa. These protein bands were cut and extracted from the gel and rabbits were immunized with each protein. Immunoblotting showed dominant reactivity with the respective antigens. The antisera were further tested for specificity in immunodiffusion and in rocket immunoelectrophoresis. In addition, a specific DNA-method was developed, based on Real-Time PCR using Macadamia vicilin as target sequence. Two different primer pairs were tested. Specificity was tested against potentially related nuts. Optimisation of primer and probe concentrations was performed. The limit of detection was 2-4 pg DNA, corresponding to a macadamia nut concentration of 50 to 100 μg per g. In a background of soybean DNA, down to 0,01 % macadamia DNA could be detected.
38

The Biodiversity of Hydrogenases in Frankia : Characterization, regulation and phylogeny

Leul Zerihun, Melakeselam January 2007 (has links)
All the eighteen Frankia strains isolated from ten different actinorhizal host plants showed uptake hydrogenase activity. The activity of this enzyme is further increased by addition of nickel. Nickel also enhanced the degree of hydrogenase transfer into the membranes of Frankia, indicating the role of this metal in the processing of this enzyme. The uptake hydrogenase of Frankia is most probably a Ni-Fe hydrogenase. Genome characterization revealed the presence of two hydrogenase genes (syntons) in Frankia, which are distinctively separated in all the three available Frankia genomes. Both hydrogenase syntons are also commonly found in other Frankia strains. The structural, regulatory and accessory genes of both hydrogenase synton #1 and #2 are arranged closely together, but in a clearly contrasting organization. Hydrogenase synton #1 and #2 of Frankia are phylogenetically divergent and that hydrogenase synton #1 is probably ancestral among the actinobacteria. Hydrogenase synton #1 (or synton #2) of Frankia sp. CcI3 and F. alni ACN14a are similar in gene arrangement, content and orientation, while the syntons are both reduced and rearranged in Frankia sp. EANpec. The hydrogenases of Frankia sp. CcI3 and F. alni ACN14a are phylogenetically grouped together but never with the Frankia sp. EAN1pec, which is more closely related to the non-Frankia bacteria than Frankia itself. The tree topology is indicative of a probable gene transfer to or from Frankia that occurred before the emergence of Frankia. All of the available evidence points to hydrogenase gene duplication having occurred long before development of the three Frankia lineages. The uptake hydrogenase synton #1 of Frankia is more expressed under free-living conditions whereas hydrogenases synton #2 is mainly involved in symbiotic interactions. The uptake hydrogenase of Frankia can also be manipulated to play a larger role in increasing the efficiency of nitrogen fixation in the root nodules of the host plants, there by minimizing the need for environmentally unfriendly and costly fertilizers. The hydrogen-evolving hydrogenase activity was recorded in only four Frankia strains: F. alni UGL011101, UGL140102, Frankia sp. CcI3 and R43. After addition of 15mM Nicl2, activity was also detected in F. alni UGL011103, Frankia sp. UGL020602, UGL020603 and 013105. Nickel also increased the activity of hydrogen-evolving hydrogenases in Frankia, indicating that Frankia may have different types of hydrogen-evolving hydrogenases, or that the hydrogen-evolving hydrogenases may at least be regulated differently in different Frankia strains. The fact that Frankia can produce hydrogen is reported only recently. The knowledge of the molecular biology of Frankia hydrogenase is, therefore, of a paramount importance to optimize the system in favor of hydrogen production. Frankia is an attractive candidate in search for an organism efficient in biological hydrogen production since it can produce a considerable amount of hydrogen.
39

Methodological aspects on anti-nuclear antibody determination in canine autoimmunity and in vitro studies of antigen-specific cellular responses /

Hansson, Helene, January 1900 (has links) (PDF)
Diss. (sammanfattning) Uppsala : Sveriges lantbruksuniv. / Härtill 4 uppsatser.
40

Development of a monoclonal antibody assay for Infectious Hypodermal and Hematopoietic Necrois Virus (IHHINV) of shrimp /

Bui, Thi Bich Hang, Manop Suphantharika, January 2007 (has links) (PDF)
Thesis (M.Sc. (Biotechnology))--Mahidol University, 2007. / LICL has E-Thesis 0023 ; please contact computer services.

Page generated in 0.0723 seconds