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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.
411

Hematopoietic Serine Proteases from the Mast Cell Chymase and Tryptase Loci - a Functional and Evolutionary Analysis

Reimer, Jenny January 2008 (has links)
<p>Mast cells are key effector cells in allergic and inflammatory diseases. However, their primary role is most likely in host defence against parasitic and bacterial infections. Mast cells are a particularly rich source of serine proteases. These proteases belong to the chymase or the tryptase family, which are encoded from the mast cell chymase and the multigene tryptase loci, respectively. To better understand the biological functions and the molecular evolution of these enzymes we have studied the organisation of these two loci in species ranging from fish to human. We show that the mast cell chymase locus has evolved from a single founder gene to a complex locus during the past 200 Myr of mammalian evolution. Forty-five fish candidate genes for hematopoietic serine proteases were also identified. However, in phylogenetic analyses none of them grouped with individual branches holding mammalian mast cell chymase locus genes, indicating an independent parallel evolution in fish. </p><p>Studies of the evolution of the multigene tryptase locus showed that this locus has been highly conserved between marsupials and eutherians. However, no genes belonging to the individual subfamilies identified in eutherians could be identified in fish, amphibians or in birds, which also here indicates parallel evolution.</p><p>To study the evolution of specific cleavage specificities associated with these proteases, the extended cleavage specificity of opossum α-chymase was determined and found to be nearly identical to human mast cell chymase and the major mouse mast cell chymase mMCP-4. This indicates a strong pressure to maintain this specificity during mammalian evolution.</p><p>Basophils are rare blood cells with functions similar to mast cells that when mature almost completely lack mRNA. To study the proteome and to primarily characterize the granule protein content of basophils, an <i>in vitro</i> purification protocol was developed to obtain transcriptionally active umbilical cord blood-derived basophil precursors.</p>
412

The Effect of Hypothalamic Stimulation on the Phagocytic Activity of the Reticuloendothelial System

Lambert, Paul Louis 12 1900 (has links)
Although research has linked the central nervous system with changes in immunoresponsivity, research on the possible role of the central nervous system in altering reticuloendothelial activity is lacking. This study investigated the possible relationship between hypothalamic structures and changes in responsivity of the reticuloendothelial system. Eight male albino rats received bilateral electrode implants in the ventromedial area of the hypothalamus and, following brain stimulation, reticuloendothelial activity was assessed 3, 6, 12, 24, and 96 hours after stimulation. Brain stimulation decreased phagocytic activity of the reticuloendothelial system. These findings may increase our understanding of a possible neural mechanism underlying relationships between stress and resistance to disease states.
413

The mechanism of T cell dysfunction induced by Diethylstilbestrol

Brown, Nicole Chantae 01 January 2005 (has links)
Estrogens have the ability to alter the immune system. Diethylstilbestrol (DES), asynthetic estrogen, is known to have estrogenic activity and induce thymic alterations.We investigated the mechanism by which DES is able to alter T cells and thus theimmune system. First, we studied the effect of DES on mature T cells by using the T cellleukemia cell line, Jurkat. We found that DES treatment reduced cell viability andincreased apoptosis. Additionally, apoptosis was found to involve both death receptorand mitochondria1 pathways. Furthermore, estrogen receptor beta was found to beexpressed in these cells and increased following DES treatment. Secondly, we studiedthe effect of DES on developing T cells using two different mouse models, timed pregnant and HY-TCR transgenic. The pregnant mouse model showed that DESexposure in utero reduced thymic cell viability and induced apoptosis at gestational day(gd)-17. Apoptosis was found to involve the death receptor pathway. Additionally,alterations in T cell subsets was most pronounced at gd-17 as well. The HY-TCR tgmouse model showed that DES exposure altered both positive and negative selection of Tcells. Furthermore, DES was found to alter the ability of T cells to proliferate during animmune response. Finally, we studied the intrathymic interaction between thymicstromal cells and thymic T cells. We found that cel1:cell interaction was important forinducing T cell apoptosis in the thymus. Additionally, FasL expression was increased onthymic stromal cells following DES exposure. Furthermore, the presence of both FasL onstromal cells and Fas on T cells was important for inducing T cell apoptosis in thethymus.
414

Obesity and Asthma: Adiponectin Receptor 1 (Adipo R1) and Adiponectin Receptor 2 (Adipo R2) are expressed by normal human bronchial epithelial (NHBE) cells at air-liquid interface (ALI) and expression changes with IL-13 stimulation

Bradley, Jennifer L 01 January 2016 (has links)
Obesity is recognized as an important risk factor for the development of many chronic diseases such as hypertension, Type 2 diabetes mellitus (T2DM) cardiovascular disease, cancer, renal disease, neurologic dysfunction, metabolic syndrome and asthma (3, 4). Circulating serum adiponectin levels in obese asthmatics have been reported to be low. Therefore, we aimed to investigate the role of adiponectin in a mucus hypersecretion model and hypothesized that adiponectin would decrease IL-13 induced MUC5AC expression from differentiated NHBE cells and that increasing concentrations of IL-13 would cause a decrease in Adipo R1 and Adipo R2 expression. MUC5AC expression with exposure to adiponectin was not significant. However, mRNA expression of Adipo R1 and Adipo R2 was significantly decreased by stimulation of IL-13 for acute (24 hours) and chronic (14 days) exposure. Therefore, the obese state and specifically IL-13 concentration could play a role in Adipo R1 and Adipo R2 expression within NHBE cells.
415

Eventos adversos pós- vacinação contra Influenza em idosos de Minas Gerais / Adverse events after vaccination against Influenza in the elderly in Minas Gerais

Rodrigues, Damiana 21 March 2019 (has links)
É de grande relevância o conhecimento dos eventos adversos ocorridos após aplicação da vacina contra Influenza em idosos, visando sua identificação e possíveis intervenções preventivas. Considera-se que os idosos são assistidos por equipe de enfermagem que atua em hospitais, Unidades Básicas de Saúde, em domicílios ou em Instituições de Longa Permanência. Eventos adversos ocorridos após aplicação da vacina contra Influenza em idosos institucionalizados foram os motivadores para o desenvolvimento do presente estudo. Objetivos: Identificar e analisar a ocorrência de eventos adversos após vacinação contra Influenza em idosos de Minas Gerais, caracterizar os dados sócio demográficos e suas associações; confeccionar material educativo direcionado aos enfermeiros que atuam no cuidado aos idosos. Método: Pesquisa descritiva-analítica, retrospectiva e quantitativa; a amostra foi composta por 98 idosos de ambos os sexos, que corresponderam a 12,9% da população inicial, identificados por meio das Fichas de Notificação de Eventos Adversos Pós Vacinação, disponibilizados pelo Sistema de Informação de Eventos Adversos Pós Vacinação de Minas Gerias - BR, entre 2014 e 2016. Os dados foram duplamente digitados e transportados para o programa Ri386 versão 3.4.3 3 IBM SPSS Statics versão 25. Realizou-se estatísticas descritivas, frequência e percentual para as variáveis qualitativas e medidas de tendência central (média e mediana) e dispersão (desvio padrão) para as variáveis numéricas. Para verificar a associação entre os tipos de eventos (não grave, grave e erro de imunização) e as manifestações sistêmicas com as variáveis de caracterização dos idosos e das vacinas, utilizou-se o teste Exato de Fisher e Qui-quadrado; o nível de significância utilizado foi p < 0,05. Após a análise e discussão dos dados procedeu-se a confecção do material educativo. Resultados: Os eventos adversos não graves representaram 84,7% das notificações obtidas, eventos adversos graves, 5,1% e erros de imunização, 10,2%. Os testes revelaram significância estatística para eventos adversos não graves e a variável sexo (p=0,042) mais entre as mulheres que apresentaram manifestações locais, ou seja, 70,3% e entre os homens que apresentaram manifestações clínicas sistêmicas (p=0,021) - 45,8%, as quais foram caracterizadas por sintomas neurológicos. Erro de imunização se caracterizou por aplicações duplas do mesmo imunobiológico por falta de informação ou esquecimento do cartão de vacinas. Conclusão: O conhecimento do enfermeiro sobre a temática em estudo é de fundamental importância para um atendimento adequado livre de danos ao idoso para que não incorra em eventos adversos evitáveis. O material educativo se apresenta como ferramenta para orientar o enfermeiro que assiste o idoso seja em uma Instituição de Longa Permanência, seja numa Unidade de Saúde da Família, Unidades Básicas de Saúde, hospitais ou em domicílio. Espera-se que este estudo desperte interesse para futuras pesquisas relacionadas à compreensão do surgimento dos eventos adversos pós vacinação contra Influenza em idosos, visando a prevenção de tais eventos e suas consequências, assim como estimule a adesão às campanhas vacinais / It is highly important to be aware of the adverse events that occur after the elderly are vaccinated against influenza in order to identify them, therefore making preventive measures possible. It is considerable that the elderly are cared for by nursing teams who work in hospitals, Basic Healthcare Units, residences or in Long Stay Institutions. The adverse events in elderly after they were vaccinated against influenza were the motivators so this study could be developed. Objectives: Identify and analyze the occurrence of the adverse events after the elderly from Minas Gerais are vaccinated against influenza, characterize the socio demographic data and their associations, prepare socio educative material addressed to nurses who work in caring for the elderly. Method: Quantitative, retrospective and descriptiveanalytical study. The sample was composed for 98 seniors both sexes, men and women, covering a rate of 12,9% of the initial population, identified from Notification Sheets of Post-Vaccination Adverse Events, available in the Information of Post-Vaccination Adverse Events System from Minas Gerais - Br, between 2016 and 2016. The data were doubleentered and carried foward for the Program Ri386 version 3.4.3 3 IBM SPSS Statics version 25. Percentage, frequency and descriptive statistics were performed for qualitative variables and central tendency measures (mean and median), and dispersion (standard deviation) for numerical variables. In order to make the association among events possible (severe, nonsevere and immunization error) and the systemic manifestations with the elderly and vaccines variable of characterization, the Fisher\'s Exact and Qui-square tests were used and the significance level that was used was p < 0,05. After the analysis and the discussion of the data, the educative material was prepared. Results: The non-severe adverse events accounted for 84,7% of the obtained notifications, the severe adverse events, 5,1% and the immunization, 10,2%. The tests revealed statistical significance for the non-severe adverse events and the sex variation (p=0,042) better among women who presented local manifestations, that is to say 70,3% and, among men who presented systemic clinical manifestations (p=0,21) - 45,8%, which were characterized by neurological symptoms. The immunization error was characterized by double applications of the same immunobiological, either because of lack of information or vaccination card oversight. Conclusion: The nurse\'s expertise on the thematic being studied is really important for an appropriate caring free from damage to the elderly just so preventable adverse events can be avoided. The educative material is presented like a tool to guide the nurse who cares for the elderly in a Long-Stay Institution, in a Family Health-Care Unit, in Basic Health-Care Units, in hospitals or in residences. It is expected that this study motivates interest for future studies regarding the understanding of the development of different post-vaccination adverse events against influenza in elderly people, aiming the prevention of such events and their consequences. It is also expected that it motivates the accession to vaccination campaigns
416

Direcionando as proteínas MSP-119 de Plasmodium vivax e Plasmodium yoelii para células dendríticas in vivo: análise das respostas imunes celular humoral. / Targeting Plasmodium vivax and Plasmodium yoelii MSP-119 proteins to dendritic cells in vivo: analysis of cellular and humoral immune responses.

Barbosa, Icaro Matioli 15 December 2011 (has links)
Células dendríticas (DCs) são células do sistema imunológico muito importantes no processo de indução de imunidade, capazes de conectar respostas imunes inata e adquirida e levar à ativação de células T e B. Recentemente demonstrou-se que é possível direcionar antígenos diretamente para as DCs in vivo através da administração de baixas doses de uma proteína recombinante híbrida fusionada a um anticorpo monoclonal específico para receptores presentes na superfície destas células. Dois dos anticorpos monoclonais utilizados tem a capacidade de ligar-se aos receptores endocíticos DEC205 e DCIR2 presentes na superfície de duas sub-populações distintas de DCs.Construiu-se anticorpos híbridos em fusão com os genes que codificam a proteína MSP-119 presente na superfície das formas merozoítas de P.yoelii e P.vivax. Ensaios de imunização mostraram que o anticorpo anti-DEC fusionado a qualquer das duas proteínas foi capaz de induzir principalmente uma resposta imune celular quando administrado na presença de diferentes adjuvantes. Já a resposta imune humoral foi modulada dependendo de várias combinações. / Dendritic cells (DCs) are cells of the immune system very important in the process of induction of immunity. They are able to connect innate and acquired immune responses and lead to activation of T and B cells. Recently it was shown that it is possible to target antigens directly to DCs in vivo by the administration of low doses of a recombinant hybrid protein consisting of a monoclonal antibody specific for receptors present on the surface of these cells fused with the antigen of interest. When these hybrid antibodies were injected in animals in the presence of a DC maturation stimulus, strong immune response against different antigens was obtained. Two of the monoclonal antibodies used have the ability to bind to either the DEC205 or the DCIR2 endocytic receptors present on the surface of two distinct DC sub-populations. In this work, we constructed hybrid antibodies fused with the sequence encoding the MSP-119 protein present on the surface P. yoelii and P. vivax merozoites. Most antibodies were successfully produced and maintained their ability to bind to their respective receptors. Immunization trials showed that the anti-DEC antibody fused to any of the two proteins was able to induce mainly a cellular immune response when administered in the presence of adjuvants. On the other hand, the humoral immune response depends of some combinations.
417

Isolamento e caracterização de peptídeos antimicrobianos derivados da digestão da hemoglobina em Rhipicephalus (Boophilus microplus) / Isolation and characterization of antimicrobial peptides produced during hemoglobin digestion on Rhipicephalus (Boophilus) microplus.

Silva, Rodrigo Caetano Belmonte da 05 February 2010 (has links)
A hemoglobina possuí um grande potencial antimicrobiano, sendo os peptídeos antimicrobianos (AMPs) derivados de proteínas contêm o grupamento heme denominados hemocidinas. O carrapato bovino Rhipicephalus (Boophilus) microplus é capaz de adquirir e processar grandes quantidades de sangue para seu metabolismo. Neste trabalho, purificamos hemocidinas produzidas no tubo digestório do carrapato. Identificamos 10 fragmentos da hemoglobina bovina que possuem atividade contra Candida albicans (Hb 1-94, 3-94, 1-87, 93-141, 102-141, 103-141, 107-141, 104-141 e 98-114 e Hb\"beta\" 127-145). Determinamos que todos os peptídeos apresentam um alto conteúdo de aminoácidos básicos, além de uma estrutura secundária em \"alfa\"-hélice, características encontradas em outros AMPs. Verificamos também que as duas principais proteases que atuam na produção das hemocidinas são uma cisteíno- e uma aspártico-proteinase. A identificação de diversas hemocidinas, no tubo digestório de R. (Boophilus) microplus, indica uma possível participação das hemocidinas na proteção contra microorganismos / The hemoglobin posses a great potential as an antimicrobial, being denominated hemocidins the antimicrobial peptides (AMPs) derived from heme containing proteins. The cattle tick Rhipicephalus (Boophilus) microplus is capable of processing large amounts of blood to its own metabolism. In this work we purified the hemocidins that are produced in the tick gut. We identified 10 fragments from bovine hemoglobin that presents activity towards Candida albicans (Hb 1-94, 3-94, 1-87, 93-141, 102-141, 103-141, 107-141, 104-141 e 98-114 e Hb\"beta\" 127-145). We determined that all the peptides presents a high content of basic amino acids, besides a secondary structure in \"alfa\"-helix conformation, characteristics found in other AMPs. We also verified that a cistein- and an aspartic-protease are the two main proteases involved on the production of these hemocids. The identification of several hemocidins in the gut of R. (Boophilus) microplus, suggests that these AMPs may play a role in the defense of the tick against microorganisms
418

A infecção murina pelo Trypanosoma cruzi clone Sylvio X10/4: envolvimento do sistema imune no controle da parasitemia. / The murine infection by Trypanosoma cruzi clone Sylvio X10/4: immune system involvement in parasitemia control.

Giacomini, Giovana 05 February 2013 (has links)
O Trypanosoma cruzi, parasita causador da doença de Chagas, apresenta isolados virulentos e de baixa virulência. Exploramos o envolvimento do sistema imune nos baixos níveis de parasitemia de camundongos infectados com parasitas de baixa virulência Sylvio X10/4. Camundongos C57Bl/6 WT não apresentam parasitemia patente após 24 horas da infecção, e a análise da carga parasitária revelou que a maioria dos parasitas vão para o fígado e baço. O envolvimento dos anticorpos naturais foi descartado, e uma pequena participação do sistema complemento sugerida. Já camundongos IFN-<font face=\"Symbol\">gKO infectados apresentaram parasitemia intermitente nas primeiras semanas, e isto não pôde ser atribuído à deficiência na produção de proteínas de fase aguda. Anticorpos específicos parecem cruciais para o controle do parasita; além disso, animais que apresentam apenas IgM são resistentes à infecção. Assim, sugerimos que a rápida saída que segue a inoculação do Sylvio X10/4 é um processo de remoção ativa e, em longo prazo, não somente a IgG, mas a IgM tem um papel importante na proteção. / Trypanosoma cruzi, the parasite responsible for Chagas´ disease, displays virulent isolates and low-virulence ones. We explored the involvement of the immune system in the low level parasitemia of mice infected with low-virulence Sylvio X10/4 parasites. C57BL/6 WT mice do not show patent parasitemias after 24 hours after infection and the parasite load revealed that most parasites go to the liver and spleen. The involvement of natural antibodies was discarded and a small participation of the complement system was suggested. However, infected IFN-<font face=\"Symbol\">gKO mice showed intermittent patent parasitemias in the first weeks of infection and this can not be attributed to deficiency in the production of acute phase proteins. Parasite-specific antibodies seem crucial for parasite control, in addition, animals that have only IgM are resistant to infection. Thus, we suggest that the rapid clearance that follows Sylvio X10/4 inoculation is an active removal process and, at the long run, not only IgG, but also IgM play an important role in protection.
419

Efeito da prostaglandina E2 na expressão de ligantes de receptores de morte e na morte celular induzida por ativação em subpopulações de linfócitos T CD4+. / Effect of prostaglandin E2 on the expression of death receptors ligands and activation-induced cell death in CD4+ T cells subsets.

Nascimento, Inaê Santiago do 07 February 2013 (has links)
Linfócitos T CD4+ tem a capacidade de diferenciação em várias subpopulações, como Th1, com habilidades distintas para o combate das infecções. Uma vez que estas células exerceram suas funções efetoras, é necessária a retração das populações para restauração da homeostase do sistema imunológico, o que pode acorrer por morte celular induzida por ativação (AICD). Baseado em dados obtidos anteriormente por nosso grupo de pesquisa, o presente estudo buscou investigar se a PGE2 protegeria linfócitos T CD4+ diferenciados in vitro, da mesma forma que protegeu hibridomas DO11.10 da AICD. Para isso, utilizamos linfócitos T CD4+ de baço total ou purificados de camundongo C57Bl/6 selvagem e polarizados para Th1, na presença de anti-CD3, anti-CD28 e citocina IL-12 por 4 dias. Observamos que, tanto em células CD4+ purificadas quanto CD4+ de baço total, as células Th1 não foram protegidas do processo de AICD pela PGE2, sugerindo que uma proteção não seja vantajosa quando a célula já se encontra em estágios avançados de seu ciclo, evitando o desenvolvimento de autoimunidades. / CD4+ T cells have the ability to differentiate into several subsets, such as Th1, with distinct abilities to fight infections. Once these cells exerted their effector functions, their elimination is necessary to restore the immune system homeostasis, which may occur by activation-induced cell death (AICD). Based on data previously obtained by our research group, this study aimed to investigate whether PGE2 protects in vitro differentiated CD4+ T cells, the same way that it protected DO11.10 hybridomas from AICD. To assess this, we used CD4+ T cells from total splenocytes or purified CD4+ T lymphocytes from C57Bl/ 6 wildtype mice, polarized to Th1 in the presence of anti-CD3, anti-CD28 and IL-12 for 4 days. We observed that the generated Th1 cells, in both conditions of purified CD4+ T cells or the ones from total splenocytes, were not protected from the process of AICD by PGE2, suggesting that this protection is not advantageous when these cells are already in advanced stages of their life cycle, thus avoiding the development of autoimmune diseases.
420

Imunomodulação por tumores associados ao papilomavírus humano. / Immunomodulation by human papillomavirus associated tumors.

Stone, Simone Cardozo 13 March 2013 (has links)
O câncer cervical é o segundo mais comum em mulheres em países em desenvolvimento, sendo causado por infecção persistente por Papilomavírus Humano (HPV). Quando esta persistência ocorre, entre outros fatores, está relacionada a mecanismos de evasão do sistema imune apresentados pelo vírus. A frequência de macrófagos aumenta com a progressão da lesão cervical e há aumento de células mielóides no baço de camundongos com tumor. Este trabalho tem como objetivo observar os efeitos sistêmicos de tumores associados ao HPV sobre a proliferação e recrutamento de células do sistema imune e identificar fatores que tenham papel nesses mecanismos. Utilizando modelos de tumor in vivo, observou-se que tumores associados ao HPV recrutam mais células para o tumor e induzem maior proliferação celular. Também avaliamos o perfil de expressão de citocinas nas linhagens tumorais e o perfil geral de expressão de proteínas através de eletroforese 2D. Com isto, demonstramos que linhagens tumorais positivas para HPV apresentam maior expressão de IL-6, IL-8, CXCL1, sICAM e Serpina E1. / Cervical cancer is the second most common type of cancer in women in developing countries. Its main etiologic factor is persistent infection with high risk human papillomavirus (HPV). This persistence occurs only in some cases and, among other factors, is related to mechanisms of immune evasion displayed by the virus. There is an increase in the frequency of macrophages proportional to cervical intraepithelial lesion grade and an increase of myeloid cells in the spleen of tumor bearing mice. This work aims to observe the systemic effects of HPV associated tumors on the proliferation and recruitment of immune cells, and identify factors that have a role in these mechanisms. Using in vivo tumor models, we found that HPV positive tumors recruit a higher percentage of cells and induce cellular proliferation. We also studied cytokine expression profiles of tumor cell lines, and performed proteomic assay with tumor cells transduced with HPV oncogenes. Our data shows that HPV associated tumor cell lines display higher expression of IL-6, IL-8, CXCL1, sICAM and Serpin E1.

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