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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.
21

Avaliação da frequência do polimorfismo nos genes que codificam a lecitina ligadora da manose (MBL) e o antagonista do receptor da interleucina-1 (IL1-Ra) em mulheres portadoras de candidíase vulvovaginal recorrente / Frequency of polymorphisms in the genes coding for mannose binding ligation (MBL) and Interleukin-1 receptor antagonist (IL1- Ra) in women with recurrent vulvovaginal candidiasis

Wojitani, Maria Dulce Caoro Horie 31 May 2011 (has links)
A candidíase vulvovaginal corresponde a uma das mais frequentes infecções do trato reprodutivo. Estima-se que 75% das mulheres na idade reprodutiva experimentarão pelo menos um episódio de candidíase vulvovaginal durante suas vidas, a maioria evoluirá com episódios infrequentes, entretanto, 5% sofrerão recorrência, ou seja, quatro ou mais episódios de candidíase vulvovaginal comprovadas clínica e laboratorialmente no período de 1ano. Os mecanismos pelos quais as recorrências ocorrem ainda são pouco conhecidos, estando provavelmente relacionados à alterações na imunidade local. O presente estudo teve como objetivo avaliar as associações entre os polimorfismos nos genes que codificam a lecitina ligadora de manose (MBL) e do antagonista do receptor da interleucina 1 (IL1-Ra) com a candidíase vulvovaginal recorrente (CVVR) em mulheres brasileiras. Foram estudadas 100 mulheres portadoras de CVVR atendidas no Serviço de Imunologia Genética e Infecções do Trato Reprodutivo da Disciplina de Ginecologia da Faculdade de Medicina da Universidade de São Paulo. Para a análise dos polimorfismos nos genes que codificam para a MBL e o IL1-Ra realizou-se coleta de células bucais que foram enviadas para Division of Immunology and Infectious Diseases of Weill Medical College of Cornell University Resultados: Mulheres com candidíase vulvovaginal recorrente apresentaram maior frequência de polimorfismo no códon 54 do gene que codifica a MBL quando comparadas a mulheres saudáveis. Não foram observadas diferenças estatisticamente significativas na frequência do polimorfismo do gene que codifica o IL1-Ra entre os grupos estudados / Vulvovaginal candidiasis is the most common genital infection in women during their childbearing years. About 75% of women suffer at least one syntomatic episode during their lives. Most of them will have infrequent episodes, but 5% will suffer recurrent episode of vulvovaginal candidiasis. The mechanisms responsible for recurrent vulvovaginal candidiasis (RVCC) remain a matter of speculation, although an alteration in local immunity appears to be a major factor. The aim of this study was to assess the correlation between polymorphisms in the genes coding for mannose-binding lectin (MBL) and interleukin-1 receptor antagonist (IL1-Ra) and RVCC in women from São Paulo, Brazil. The study population consisted of 100 women with RVCC, who were seen at Serviço de Infecções do Trato Reprodutivo da Disciplina de Ginecologia da Faculdade de Medicina da Universidade de São Paulo. To analyse for the MBL códon 54 gene polymorphism and for IL1-Ra, buccal cells were obtained with a cotton swabs and shipped to New York at ambient temperature. The polymorphisms were identified in the Division of Immunology and Infectious Diseases of Weill Medical College of Cornell University. Results: Women with RVVC present a high frequency of polymorphisms at codon 54 in the gene coding for MBL; on the other hand there were no differences in polymorphism frequency in the gene coding for IL1-Ra when compared to control women
22

Avaliação da frequência do polimorfismo nos genes que codificam a lecitina ligadora da manose (MBL) e o antagonista do receptor da interleucina-1 (IL1-Ra) em mulheres portadoras de candidíase vulvovaginal recorrente / Frequency of polymorphisms in the genes coding for mannose binding ligation (MBL) and Interleukin-1 receptor antagonist (IL1- Ra) in women with recurrent vulvovaginal candidiasis

Maria Dulce Caoro Horie Wojitani 31 May 2011 (has links)
A candidíase vulvovaginal corresponde a uma das mais frequentes infecções do trato reprodutivo. Estima-se que 75% das mulheres na idade reprodutiva experimentarão pelo menos um episódio de candidíase vulvovaginal durante suas vidas, a maioria evoluirá com episódios infrequentes, entretanto, 5% sofrerão recorrência, ou seja, quatro ou mais episódios de candidíase vulvovaginal comprovadas clínica e laboratorialmente no período de 1ano. Os mecanismos pelos quais as recorrências ocorrem ainda são pouco conhecidos, estando provavelmente relacionados à alterações na imunidade local. O presente estudo teve como objetivo avaliar as associações entre os polimorfismos nos genes que codificam a lecitina ligadora de manose (MBL) e do antagonista do receptor da interleucina 1 (IL1-Ra) com a candidíase vulvovaginal recorrente (CVVR) em mulheres brasileiras. Foram estudadas 100 mulheres portadoras de CVVR atendidas no Serviço de Imunologia Genética e Infecções do Trato Reprodutivo da Disciplina de Ginecologia da Faculdade de Medicina da Universidade de São Paulo. Para a análise dos polimorfismos nos genes que codificam para a MBL e o IL1-Ra realizou-se coleta de células bucais que foram enviadas para Division of Immunology and Infectious Diseases of Weill Medical College of Cornell University Resultados: Mulheres com candidíase vulvovaginal recorrente apresentaram maior frequência de polimorfismo no códon 54 do gene que codifica a MBL quando comparadas a mulheres saudáveis. Não foram observadas diferenças estatisticamente significativas na frequência do polimorfismo do gene que codifica o IL1-Ra entre os grupos estudados / Vulvovaginal candidiasis is the most common genital infection in women during their childbearing years. About 75% of women suffer at least one syntomatic episode during their lives. Most of them will have infrequent episodes, but 5% will suffer recurrent episode of vulvovaginal candidiasis. The mechanisms responsible for recurrent vulvovaginal candidiasis (RVCC) remain a matter of speculation, although an alteration in local immunity appears to be a major factor. The aim of this study was to assess the correlation between polymorphisms in the genes coding for mannose-binding lectin (MBL) and interleukin-1 receptor antagonist (IL1-Ra) and RVCC in women from São Paulo, Brazil. The study population consisted of 100 women with RVCC, who were seen at Serviço de Infecções do Trato Reprodutivo da Disciplina de Ginecologia da Faculdade de Medicina da Universidade de São Paulo. To analyse for the MBL códon 54 gene polymorphism and for IL1-Ra, buccal cells were obtained with a cotton swabs and shipped to New York at ambient temperature. The polymorphisms were identified in the Division of Immunology and Infectious Diseases of Weill Medical College of Cornell University. Results: Women with RVVC present a high frequency of polymorphisms at codon 54 in the gene coding for MBL; on the other hand there were no differences in polymorphism frequency in the gene coding for IL1-Ra when compared to control women
23

Influência de variantes de receptores de reconhecimento padrão na suscetibilidade à malária / Influence of point variants of pattern recognition receptors in the susceptibility to human malaria

Leoratti, Fabiana Maria de Souza 11 September 2008 (has links)
Malária é uma das principais causas de doença e morte no mundo, principalmente de crianças. É considerada a força de seleção evolucionária mais forte que se conhece na história recente do genoma humano. Além dos fatores ambientais e do próprio parasito, fatores genéticos do hospedeiro têm um papel fundamental tanto na suscetibilidade como na evolução clínica da infecção. O sistema imune inato reconhece os plasmódios através de um número limitado de receptores de reconhecimento padrão (PRRs) e inicia vários mecanismos de defesa que resultam no desenvolvimento de inflamação e resistência do hospedeiro à infecção. Mas, a eliminação completa do parasito requer respostas imunes adaptativas que são amplificadas pela ativação do sistema imune inato. As manifestações clínicas de malária são dependentes dos níveis de citocinas próinflamatórias circulantes produzidas, as quais em níveis altos contribuem para a imunopatologia da doença. O balanço entre respostas pró e antiinflamatórias dirigidas contra o parasito é considerado crítico para a proteção clínica, assim a resposta imune inata pode contribuir tanto para proteção da malária como para modular a resposta imune adaptativa. Neste estudo, nós investigamos polimorfismos de um único nucleotídeo (SNP) dos genes de três PRRs: TLR, MBL e CR1 de indivíduos infectados por Plasmodium e residentes em áreas endêmicas de malária no Brasil. Os SNPs TLR1 (I602S), TLR4 (D229G), TLR6 (S249P), TLR9 (T-1237C/ -1486C), MBL [exon 1 nos códons 52, 54, e 57 (MBL2*A ou D, A ou B e A ou C, respectivamente); na região do promotor na posição -221 (*X ou *Y); e na posição +4 da região não traduzida (*P ou *Q)] e CR-1(C5507G) foram determinados por PCR-RFLP. Nós observamos associações entre os polimorfismos TLR1 I602S, TLR6 S249P e da região não traduzida +4 (*Q) e manifestações clínicas de malária e entre os polimorfismos TLR9 T-1486C, TLR T-1237C, MBL*D (códon 52) e do diplótipo de produção insuficiente de MBL (XA+O/O) e parasitemias mais altas. Nenhuma associação foi observada entre o polimorfismo CR-1 C5507G e manifestações clínicas de malária ou com parasitemia. Ao analisarmos juntos os polimorfismos de MBL e TLR, observamos que indivíduos com diplótipo de produção suficiente de MBL (YA/YA+YA/XA+YA/O+XA/XA) TLR1 I602S tinham menos manifestações clínicas de malária e indivíduos com diplótipo de produção suficiente de MBL e não carreadores do alelo TLR9 -1486C tinham parasitemias mais baixas do que os indivíduos com diplótipo de produção insuficiente de MBL e carreadores dos alelos variantes de TLR1 I602S e TLR9 -1486C, respectivamente. Juntos, nossos dados indicam que polimorfismos do promotor de TLR-9 e os diplótipos de produção insuficiente de MBL (XA+O/O) devem de algum modo controlar o nível de parasitemia por plasmódios enquanto a deficiência de TLR1 parece predispor para a presença de manifestações clínicas de malária. Também, podemos sugerir que existe uma cooperação entre TLR1, TLR9 e MBL na ativação da resposta imune inata na malária. Estes achados genéticos devem contribuir para o entendimento da patogênese da malária e levantar uma questão potencialmente interessante que é digna de investigações posteriores em outras populações a fim de validar a contribuição genética destes loci na patogênese da malária / Malaria is one of the major causes of disease and death worldwide, mainly of children. It is also the strongest known force for evolutionary selection in the recent history of the human genome. Besides environmental and parasite factors, host genetic factors play a major role in determining both susceptibility to malaria and the course of infection. Innate immune mechanisms directed against Plasmodium parasites both contribute to protection from malaria and modulate adaptive immune responses. The innate immune system recognizes Plasmodium via a limited number of pattern-recognition receptors (PRRs) and initiates a broad spectrum of defense mechanisms that result in the development of inflammation and host resistance to infection. But, the complete control of the infection requires adaptive immune responses; and the innate immune system is also very efficient in instructing the cellular mediators of adaptive immunity to lead a powerful additional strike force against the parasite. Clinical malaria is characterized by high levels of circulating proinflammatory cytokines, which are thought to contribute to the immunopathology of the disease. The balance between pro- and anti-inflammatory responses toward the parasite is considered critical for clinical protection. The innate immune system initiates and thus sets the threshold of immune responses. In this study, we investigated single nucleotide polymorphisms (SNP) in the genes of three PRRs: TLR, MBL and CR1 in Plasmodium-infected individuals living in endemic areas of Brazil. The SNPs TLR1 (I602S), TLR4 (D229G), TLR6 (S249P), TLR9 (T-1237C/ -1486C), MBL [in the coding sequence of exon 1 at codons 52, 54, and 57 (MBL2*A or D, A or B, and A or C, respectively); in the promoter region at position -221 (*X or *Y); and in the untranslated sequence at position +4 (*P or *Q)] and CR-1(C5507G) were determined by PCR-RFLP. We observed associations of the TLR1 I602S, TLR6 S249P and untranslated sequence at position +4 MBL (*Q) variants with clinical manifestations of malaria and of the TLR9 T-1486C, TLR9 T-1237C, MBL2*D and MBL-insufficient diplotype (XA+O/O) with higher parasitemias. No association was observed to the CR-1 C5507G ) and clinical manifestations of malaria or parasitemia. Also, we observed that individuals with MBLsufficient haplotype (YA/YA+YA/XA+YA/O+XA/XA) and not bearing the allele TLR1 I602S had less clinical manifestations of malaria and individuals with MBL-sufficient haplotype and not bearing TLR9 -1486C had lower parasitemias when compared to individuals with MBL-insufficient diplotype and bearing the variant alleles TLR1 I602S and TLR9 -1486C, respectively. Altogether, our data indicate that TLR-9 promoter and MBL-insufficient haplotype (XA+O/O) polymorphisms to some extent may control the level of Plasmodium parasitemia while TLR1 deficiency seems to predispose to mild malaria. Also, they could suggest cooperation among TLR1, TLR9 and MBL in the immune response against malaria. These genetic findings may contribute to the understanding of the pathogenesis of malaria and raise a potentially interesting issue that is worthy of further investigation in other population in order to validate the genetics contribution of these loci to the pathogenesis of malaria
24

Candidate genes other than the CFTR gene as possible modifiers of pulmonary disease severity in cystic fibrosis

Frangolias, Despina Daisy 05 1900 (has links)
Cystic fibrosis (CF) is a single gene Mendelian disorder characterized by pulmonary disease and pancreatic insufficiency. Pulmonary disease is the major cause of death in CF patients. Although some cystic fibrosis transmembrane conductance regulator (CFTR) genotypes are associated with less severe disease, patients possessing the same genotype show great variation in pulmonary disease severity and progression. Genes involved in modulating the inflammatory response and genes increasing susceptibility to infection are proposed as modifiers of pulmonary disease severity. Polymorphisms selected for based on evidence that they affect the function of the gene and prevalence of the putative risk allele: 1) antiprotease gene alpha-1-antitrypsin (alpha-1-AT), 2) innate immunity genes: mannose binding lectin (MBL2) (promoter [G→C] at -221 and codon 52 (Arg52Cys, D allele), 54 (Gly54Asp, B allele), and 57 (Gly57Glu, C allele), and pulmonary surfactant genes SPA-1 (Arg219Trp), SPA-2 (Thr9Asn, Lys223Gln) and SPD (Thr11Met), 3) antioxidant genes GSTM1 and T1 (gene deletion polymorphisms), GSTP1 (Ile105Val) and GCLC repeats, 4) mucin genes (MUC2 and MUC5B). Pulmonary disease progression and survival in patients with chronic Burkholderia cepacia complex (BCC) infection were also investigated controlling for genomovar and RAPD type of the organism. BCC infection was associated with more severe pulmonary disease progression and worse survival. Alpha-1-AT genotype was not a major contributor to variability of pulmonary disease severity, but the results suggest that alpha-1-AT plasma levels during pulmonary infections may be affected by poor nutritional status. We showed similar pulmonary disease progression and MBL2 genotype. Contrary to the previous literature, wild-type MBL2 genotype was associated with steeper decline in pulmonary disease over time following chronic infection with BCC, but genotype was not associated with increased susceptibility to BCC infection. We showed inconsistant results for the pulmonary surfactant gene polymorphisms, GSTM1, T1 and GSTP1 polymorphisms, and number of repeats for GCLC and MUC5B depending on the phenotype investigated. We conclude that some of the variability in pulmonary disease severity and progression in CF is explained by polymorphisms in secondary genes.
25

Candidate genes other than the CFTR gene as possible modifiers of pulmonary disease severity in cystic fibrosis

Frangolias, Despina Daisy 05 1900 (has links)
Cystic fibrosis (CF) is a single gene Mendelian disorder characterized by pulmonary disease and pancreatic insufficiency. Pulmonary disease is the major cause of death in CF patients. Although some cystic fibrosis transmembrane conductance regulator (CFTR) genotypes are associated with less severe disease, patients possessing the same genotype show great variation in pulmonary disease severity and progression. Genes involved in modulating the inflammatory response and genes increasing susceptibility to infection are proposed as modifiers of pulmonary disease severity. Polymorphisms selected for based on evidence that they affect the function of the gene and prevalence of the putative risk allele: 1) antiprotease gene alpha-1-antitrypsin (alpha-1-AT), 2) innate immunity genes: mannose binding lectin (MBL2) (promoter [G→C] at -221 and codon 52 (Arg52Cys, D allele), 54 (Gly54Asp, B allele), and 57 (Gly57Glu, C allele), and pulmonary surfactant genes SPA-1 (Arg219Trp), SPA-2 (Thr9Asn, Lys223Gln) and SPD (Thr11Met), 3) antioxidant genes GSTM1 and T1 (gene deletion polymorphisms), GSTP1 (Ile105Val) and GCLC repeats, 4) mucin genes (MUC2 and MUC5B). Pulmonary disease progression and survival in patients with chronic Burkholderia cepacia complex (BCC) infection were also investigated controlling for genomovar and RAPD type of the organism. BCC infection was associated with more severe pulmonary disease progression and worse survival. Alpha-1-AT genotype was not a major contributor to variability of pulmonary disease severity, but the results suggest that alpha-1-AT plasma levels during pulmonary infections may be affected by poor nutritional status. We showed similar pulmonary disease progression and MBL2 genotype. Contrary to the previous literature, wild-type MBL2 genotype was associated with steeper decline in pulmonary disease over time following chronic infection with BCC, but genotype was not associated with increased susceptibility to BCC infection. We showed inconsistant results for the pulmonary surfactant gene polymorphisms, GSTM1, T1 and GSTP1 polymorphisms, and number of repeats for GCLC and MUC5B depending on the phenotype investigated. We conclude that some of the variability in pulmonary disease severity and progression in CF is explained by polymorphisms in secondary genes.
26

Baixos níveis de lectina ligante de manose podem estar associados a uma maior predisposição à doença pelo vírus respiratório sincicial sem interferir na ativação de linfócitos T

Ribeiro, Lucas Zimon Giacomini 16 February 2007 (has links)
Respiratory syncytial virus (RSV) is a major cause of serious lower respiratory tract disease among infants and young children worldwide, and understanding the immune response to its infection is essential for intervention strategies. The innate-response serum mannose-binding lectin (MBL), which recognizes a broad range of pathogens and subsequently activates the complement system, has an essential role in the early phase of infection contributing to the development of an acquired immune response. In this study, 82 children <5 years old with confirmed acute RSV infection and 70 controls had MBL levels measured by an indirect ELISA and PBMC phenotypes characterized by flow cytometry. Samples were distributed in four groups: serum/case (81), serum/control (40), PBMC/case (33), PBMC/control (58). Thirty eight cases were <6 months old and most of them had been interned (33/38). The MBL concentrations from all children presented a wide range of values, however, the greater percentage of cases, i.e. 67.9% (55/81) had <500 ng/mL (low/intermediate) MBL levels compared to 40% (16/40) for control subjects. Case and control MBL levels from children <1 month old were not statistically different, but were substantially lower in cases >24 months old (p=0.034). The CD4+ T cells percentage was lower (p<0.001) in children >6 months old compared to controls, while, the CD8+ T cells percentage in cases and controls was similar except for lower frequency in the 6 12 months old cases (p=0,003). T cell activation (CD3+HLA-II+) was significantly higher in cases compared to controls (p<0,001), in contrast to natural killer cells which were generally decreased (p<0,001). These results suggest that acute RSV infection in these children seems to be associated with low MBL levels, but not interfering in T cell activation. / O virus respiratório sincicial (VRS) é a principal causa de doença do trato respiratório inferior em crianças no mundo todo, principalmente nas menores de seis meses de idade e, compreender a resposta imune contra ele é essencial para desenvolver estratégias de intervenção. A lectina ligante de manose (LLM) do presente no soro, relacionada à resposta imune inata, reconhece uma gama de patógenos, ativa o sistema complemento e tem um papel essencial na fase inicial da infecção, contribuindo para o desenvolvimento de uma resposta adaptativa. Neste estudo, 82 crianças <5 anos de idade com infecção pelo VRS confirmada e 70 controles tiveram os níveis de LLM no soro medidos por um ensaio imuno enzimático indireto e também fenótipos das células mononucleares do sangue periférico (CMSP) caracterizado por citometria de fluxo. As amostras foram distribuidas em quatro grupos: soro/caso (81), soro/controle (40), CMSP/caso (33), CMSP/controle (58). Trinta e oito casos eram <6 meses de idade sendo que a maioria deles foi internada (33/38). As concentrações de LLM em todas as idades tiveram uma ampla distribuição, porém, uma grande porcentagem dos casos, isto é, 67,9% (55/81) tiveram níveis de LLM <500 ng/mL (baixo/intermediário), comparado com 40% (16/40) dos controles. Os nívels de LLM dos casos e controles <1 mês de idade não foram diferentes, mas para as crianças >24 meses de idade, os níveis dos casos foram menores (p=0,034). A porcentagem de células T CD4+ dos casos >6 meses de idade foi menor (p<0.001) do que a dos controles. Ainda, não houve diferença entre casos e controles para as células T CD8+, com excessão da faixa de idade entre 6-12 meses em que os casos apresentaram uma menor freqüência (p=0,003). A ativação de células T (CD3+HLA-II+) foi significativamente maior nos casos do que nos controles (p<0,001), em contraste com as células natural killer que geralmente estiveram diminuidas nos casos (p<0,001). Estes resultados sugerem que a infecção aguda por VRS nessas crianças parece estar associada com baixos nívels de LLM, porém não interferindo na ativação de linfócitos. / Mestre em Imunologia e Parasitologia Aplicada
27

Polimorfismos do gene MBL2 e percentual de IgG4 sérica em glomerulopatia membranosa

COSTA, Denise Maria do Nascimento 21 July 2016 (has links)
Submitted by Irene Nascimento (irene.kessia@ufpe.br) on 2016-10-06T17:20:04Z No. of bitstreams: 2 license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) Dissertação Denise Maria do Nascimento Costa.pdf: 2568349 bytes, checksum: 97687424c47175731885cd254c815ad4 (MD5) / Made available in DSpace on 2016-10-06T17:20:04Z (GMT). No. of bitstreams: 2 license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) Dissertação Denise Maria do Nascimento Costa.pdf: 2568349 bytes, checksum: 97687424c47175731885cd254c815ad4 (MD5) Previous issue date: 2016-07-21 / Introdução: Glomerulopatia membranosa (GM) é uma causa de síndrome nefrótica cuja etiologia pode ser primária (GMP) ou secundária, dentre estas é frequente o Lúpus eritematoso sistêmico (LES). Trata-se de uma doença imunologicamente mediada, caracterizada pela deposição de imunocomplexos no espaço subepitelial glomerular. A maioria dos antígenos envolvidos identificados são alvos da imunoglobulina G4 (IgG4), subclasse predominante em imunofluorescências renais na GMP, em contraste com a GM secundária a LES (GMS) na qual IgG1, IgG2 e IgG3 prevalecem. Apesar da IgG4 ser um subtipo de imunoglobulina com baixa capacidade de ativação do complemento, há várias evidências deste envolvimento na GMP. Esses dados, em conjunto com achados de depósitos glomerulares de lectina ligadora de manose (MBL), um dos principais componentes da via das lectinas do complemento, podem sugerir que tanto a via da lectina como a IgG4 estão envolvidas nesta patologia. Sabe-se ainda que o desenvolvimento de GMP também está associado a alterações genéticas. Entretanto, a etiopatogenia da GMP ainda não é totalmente conhecida e estudos para avaliação gênica do MBL2 e dosagem sérica de IgG em GM são escassos. Assim, foi realizado este estudo com o objetivo de avaliar a frequência de polimorfismos do gene MBL2 em portadores de GM, comparados a indivíduos saudáveis. Um segundo objetivo foi comparar pacientes com GMP e GMS quanto a diferenças do percentual de IgG4 sérico em relação a IgG (%IgG4) e da frequência de polimorfismos do MBL2. Métodos: Estudo realizado entre 2014 e 2015, em Pernambuco - Brasil. A amostra incluiu 60 pacientes adultos com diagnóstico histopatológico de GMP ou GMS. Outras causas de GM secundárias foram excluídas. Foram avaliados 35 pacientes com GMP e 24 com GMS, e um grupo controle (GC), formado por 101 indivíduos saudáveis. Resultados: O alelo mutante O do gene MBL2 foi mais frequente no grupo com GM comparados aos GC (42% x 22%; p < 0,001). A heterozigose A/O, em relação ao genótipo A/A, predominou entre os pacientes comparados ao GC, associando-se a GM com OR = 11,16 (95% IC = 4,77 - 28,41). À análise comparativa entre os pacientes com GMP e GMS, não houve diferença das frequências dos polimorfismos genéticos entre os grupos. O grupo GMP apresentou menor mediana de IgG sérica total (p = 0,008) e maior %IgG4 (p = 0,016), comparado ao grupo GMS. Nível sérico de IgG4 não diferiu significativamente entre os grupos GMP e GMS (p = 0,289). Conclusão: O polimorfismo do éxon 1 do gene MBL2 associou-se à GM, comparado a indivíduos saudáveis, porém sem diferença entre as etiologias avaliadas. Já o %IgG4 sérico foi maior na GMP em relação a GMS. Estes resultados sugerem que esta mutação genética possa conferir maior vulnerabilidade a GMP e que o %IgG4 sérico possa ser utilizado como marcador adicional para diagnóstico diferencial entre as duas etiologias da GM. / Introduction: Membranous glomerulopathy (MG) is a cause of nephrotic syndrome whose etiology may be primary (PMG) or secondary, wich is frequent systemic lupus erythematosus (SLE). It is an immune-mediated disease characterized by the deposition of immune complexes in the glomerular subepithelial space. Most of the identified antigens are targets to immunoglobulin IgG4, most common subclass in renal immunofluorescence in GMP, in contrast to the SLE secondary MG (SMG) in which IgG1, IgG2 and IgG3 prevail. Although IgG4 is a immunoglobulin subtype with low complement activation capacity, there is abundant evidence of this involvement in PMG. These data, together with glomerular deposits of mannose-binding lectin (MBL), a major component of the lectin pathway of complement, may suggest that both the lectin pathway and IgG4 are involved in this pathology. It is also known that the development of PMG is associated with genetic alterations. As the pathogenesis of PMG is not yet fully known, and studies for genetic evaluation of MBL2 and serum IgG in MG are scarce, this study was conducted to evaluate the frequency of MBL2 gene polymorphisms in patients with MG, compared to healthy subjects. A second objective was to compare patients with PMG and SMG with respect to the percentage of serum IgG4 (IgG4%) and frequency MBL2 polymorphisms. Methods: This study was conducted between 2014 and 2015 in Pernambuco - Brazil. The sample included 60 adult patients with histopathologic diagnosis of PMG or SMG. Other causes of secondary MG were excluded. Thity five patients with PMG and 24 with SMG were evaluated, compared to a control group (CG) of 101 healthy subjects. Results: The mutant allele O was more frequent in the MG population compared to CG (42% vs. 22%; p <0.001). The heterozygous A/O, compared to genotype A/A, predominated among patients compared to the control group, and was associated with MG (OR = 11.16; 95% CI = 4.77 to 28.41). In the comparative analysis between patients with PMG and SMG, there was no difference in the frequency of genetic polymorphisms between groups. The PMG group had lower median total serum IgG (p = 0.008) and higher IgG4% (p = 0.016) compared to the SMG group. Serum IgG4 did not differ significantly between the groups PMG and SMG (p = 0,289). Conclusion: The polymorphism of exon 1 MBL2 gene was associated with MG, compared to healthy subjects, but no difference between the assessed etiologies. Serum IgG4% was higher in PMG relative to SMG. These results suggest that this gene mutation can confer increased vulnerability to PMG and the serum IgG4% may be used as an additional marker for the differential diagnosis between the two etiologies MG.
28

Influência de variantes de receptores de reconhecimento padrão na suscetibilidade à malária / Influence of point variants of pattern recognition receptors in the susceptibility to human malaria

Fabiana Maria de Souza Leoratti 11 September 2008 (has links)
Malária é uma das principais causas de doença e morte no mundo, principalmente de crianças. É considerada a força de seleção evolucionária mais forte que se conhece na história recente do genoma humano. Além dos fatores ambientais e do próprio parasito, fatores genéticos do hospedeiro têm um papel fundamental tanto na suscetibilidade como na evolução clínica da infecção. O sistema imune inato reconhece os plasmódios através de um número limitado de receptores de reconhecimento padrão (PRRs) e inicia vários mecanismos de defesa que resultam no desenvolvimento de inflamação e resistência do hospedeiro à infecção. Mas, a eliminação completa do parasito requer respostas imunes adaptativas que são amplificadas pela ativação do sistema imune inato. As manifestações clínicas de malária são dependentes dos níveis de citocinas próinflamatórias circulantes produzidas, as quais em níveis altos contribuem para a imunopatologia da doença. O balanço entre respostas pró e antiinflamatórias dirigidas contra o parasito é considerado crítico para a proteção clínica, assim a resposta imune inata pode contribuir tanto para proteção da malária como para modular a resposta imune adaptativa. Neste estudo, nós investigamos polimorfismos de um único nucleotídeo (SNP) dos genes de três PRRs: TLR, MBL e CR1 de indivíduos infectados por Plasmodium e residentes em áreas endêmicas de malária no Brasil. Os SNPs TLR1 (I602S), TLR4 (D229G), TLR6 (S249P), TLR9 (T-1237C/ -1486C), MBL [exon 1 nos códons 52, 54, e 57 (MBL2*A ou D, A ou B e A ou C, respectivamente); na região do promotor na posição -221 (*X ou *Y); e na posição +4 da região não traduzida (*P ou *Q)] e CR-1(C5507G) foram determinados por PCR-RFLP. Nós observamos associações entre os polimorfismos TLR1 I602S, TLR6 S249P e da região não traduzida +4 (*Q) e manifestações clínicas de malária e entre os polimorfismos TLR9 T-1486C, TLR T-1237C, MBL*D (códon 52) e do diplótipo de produção insuficiente de MBL (XA+O/O) e parasitemias mais altas. Nenhuma associação foi observada entre o polimorfismo CR-1 C5507G e manifestações clínicas de malária ou com parasitemia. Ao analisarmos juntos os polimorfismos de MBL e TLR, observamos que indivíduos com diplótipo de produção suficiente de MBL (YA/YA+YA/XA+YA/O+XA/XA) TLR1 I602S tinham menos manifestações clínicas de malária e indivíduos com diplótipo de produção suficiente de MBL e não carreadores do alelo TLR9 -1486C tinham parasitemias mais baixas do que os indivíduos com diplótipo de produção insuficiente de MBL e carreadores dos alelos variantes de TLR1 I602S e TLR9 -1486C, respectivamente. Juntos, nossos dados indicam que polimorfismos do promotor de TLR-9 e os diplótipos de produção insuficiente de MBL (XA+O/O) devem de algum modo controlar o nível de parasitemia por plasmódios enquanto a deficiência de TLR1 parece predispor para a presença de manifestações clínicas de malária. Também, podemos sugerir que existe uma cooperação entre TLR1, TLR9 e MBL na ativação da resposta imune inata na malária. Estes achados genéticos devem contribuir para o entendimento da patogênese da malária e levantar uma questão potencialmente interessante que é digna de investigações posteriores em outras populações a fim de validar a contribuição genética destes loci na patogênese da malária / Malaria is one of the major causes of disease and death worldwide, mainly of children. It is also the strongest known force for evolutionary selection in the recent history of the human genome. Besides environmental and parasite factors, host genetic factors play a major role in determining both susceptibility to malaria and the course of infection. Innate immune mechanisms directed against Plasmodium parasites both contribute to protection from malaria and modulate adaptive immune responses. The innate immune system recognizes Plasmodium via a limited number of pattern-recognition receptors (PRRs) and initiates a broad spectrum of defense mechanisms that result in the development of inflammation and host resistance to infection. But, the complete control of the infection requires adaptive immune responses; and the innate immune system is also very efficient in instructing the cellular mediators of adaptive immunity to lead a powerful additional strike force against the parasite. Clinical malaria is characterized by high levels of circulating proinflammatory cytokines, which are thought to contribute to the immunopathology of the disease. The balance between pro- and anti-inflammatory responses toward the parasite is considered critical for clinical protection. The innate immune system initiates and thus sets the threshold of immune responses. In this study, we investigated single nucleotide polymorphisms (SNP) in the genes of three PRRs: TLR, MBL and CR1 in Plasmodium-infected individuals living in endemic areas of Brazil. The SNPs TLR1 (I602S), TLR4 (D229G), TLR6 (S249P), TLR9 (T-1237C/ -1486C), MBL [in the coding sequence of exon 1 at codons 52, 54, and 57 (MBL2*A or D, A or B, and A or C, respectively); in the promoter region at position -221 (*X or *Y); and in the untranslated sequence at position +4 (*P or *Q)] and CR-1(C5507G) were determined by PCR-RFLP. We observed associations of the TLR1 I602S, TLR6 S249P and untranslated sequence at position +4 MBL (*Q) variants with clinical manifestations of malaria and of the TLR9 T-1486C, TLR9 T-1237C, MBL2*D and MBL-insufficient diplotype (XA+O/O) with higher parasitemias. No association was observed to the CR-1 C5507G ) and clinical manifestations of malaria or parasitemia. Also, we observed that individuals with MBLsufficient haplotype (YA/YA+YA/XA+YA/O+XA/XA) and not bearing the allele TLR1 I602S had less clinical manifestations of malaria and individuals with MBL-sufficient haplotype and not bearing TLR9 -1486C had lower parasitemias when compared to individuals with MBL-insufficient diplotype and bearing the variant alleles TLR1 I602S and TLR9 -1486C, respectively. Altogether, our data indicate that TLR-9 promoter and MBL-insufficient haplotype (XA+O/O) polymorphisms to some extent may control the level of Plasmodium parasitemia while TLR1 deficiency seems to predispose to mild malaria. Also, they could suggest cooperation among TLR1, TLR9 and MBL in the immune response against malaria. These genetic findings may contribute to the understanding of the pathogenesis of malaria and raise a potentially interesting issue that is worthy of further investigation in other population in order to validate the genetics contribution of these loci to the pathogenesis of malaria
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Oropharyngeal carriage of respiratory bacteria among military conscripts

Jounio, U. (Ulla) 02 October 2012 (has links)
Abstract The aims of this work were to study the carriage of respiratory bacteria and to identify risk factors affecting pharyngeal colonisation by these pathogens among young Finnish men during military service, and also to investigate the role of mannose-binding lectin (MBL) concentrations and MBL2 gene polymorphisms in the carriage of respiratory bacteria. A total of 892 military recruits entering the Kainuu Brigade, including 224 men with asthma, were followed up prospectively to the end of their military service. Carriage of Streptococcus pneumoniae, Neisseria meningitidis and beta-haemolytic streptococci appeared to be higher during and at the end of military service than at the beginning. Smoking was found to be a significant risk factor for colonisation by these bacteria. S.pneumoniae was more common in the asthmatic than military conscripts in the non-asthmatic ones at the beginning of military service. A low MBL level increased the risk of carrying N. meningitidis and beta-haemolytic streptococci during military service among non-smokers but not among smokers. Low MBL levels producing MBL2 haplotypes seemed to be associated with the carriage of N. meningitidis and S. pneumoniae. Characterisation of all the oropharyngeal N.meningitidis isolates obtained (n=215) by phenotypic and genotypic methods showed that most of them belonged to the carriage-associated ST-60 clonal complex. Clonal complexes ST-41/44, ST-32, and ST-23, which have previously been associated with disease, also accounted for a third of the carriage strains. Furthermore, a significant association was indicated between an acute upper respiratory infection and oropharyngeal carriage of the virulent meningococcal ST-23 clone. In conclusion, the results reported here show a significant increase in bacterial carriage during military service and provide new information on the association between MBL and carriage of respiratory bacteria. These findings also highlight the importance of smoking cessation, especially among military conscripts, who have been found to be a risk group for invasive bacterial diseases, and they also point to the importance of meningococcal vaccination for military recruits and the need for an efficacious vaccine against serogroup B meningococci. / Tiivistelmä Hengitystieinfektiot ovat yleisiä varusmiespalvelun aikana. Myös oireeton bakteerien nielukantajuus on lisääntynyt. Useimmiten infektiot ovat lieviä virusinfektioita, mutta bakteerien nielukantajuus voi johtaa myös vaikeisiin bakteeritulehduksiin. Tämän väitöskirjatyön tarkoituksena oli tutkia bakteerien nielukantajuutta varusmiespalveluksen alkaessa ja päättyessä sekä mahdollisten hengitystieinfektioiden aikana ja näin saada uutta tietoa bakteerien nielukantajuuteen vaikuttavista tekijöistä. Lisäksi tavoitteena oli selvittää mannoosia sitovan lektiinin (MBL) sekä MBL2-geenin polymorfismien yhteyttä bakteerien nielukantajuuteen. Työn tarkoituksena oli myös feno- ja genotyypittää varusmiehiltä palveluksen aikana eristetyt meningokokkikannat ja verrata niitä vastaavana ajankohtana invasiivista tautia sairastaneista henkilöistä eristettyihin meningokokkikantoihin. Tutkimuksessa seurattiin prospektiivisesti 892 varusmiestä, jotka suorittivat asepalveluksen Kainuun Prikaatissa vuosina 2004–2006. Tutkimukseen osallistuneista varusmiehistä 224:llä oli astma. Tutkimuksessa havaittiin, että oireeton bakteerien nielukantajuus lisääntyy merkitsevästi varusmiespalveluksen aikana. Lisäksi havaittiin, että tupakointi oli merkittävä itsenäinen riskitekijä pneumokokin, meningokokin sekä beta-hemolyyttisten streptokokkien nielukantajuudelle varusmiespalveluksen aikana. Astmaatikkojen pneumokokin nielukantajuus varusmiespalveluksen alussa oli yleisempi kuin terveiden varusmiesten. Tutkimuksessa osoitettiin myös pienen seerumin MBL-pitoisuuden sekä MBL2-geenin polymorfismin eksoni 1:n alueella ja geenin säätelyalueella olevan riskitekijöitä meningokokin, pneumokokin sekä beta-hemolyyttisten streptokokkien nielukantajuudelle tupakoimattomilla varusmiehillä. Meningokokin nielukannoista jopa kolmasosa kuului genotyyppiryhmään, jonka on aiemmissa tutkimuksissa havaittu liittyvän invasiiviseen tautiin. Tutkimuksessa osoitettiin myös tietyn hyperinvasiivisen meningokokin genotyypin (ST-23) liittyvän hengitystieinfektioepisodeihin. Tässä väitöskirjatyössä osoitettiin, että bakteerien nielukantajuus lisääntyy merkitsevästi varusmiespalveluksen aikana ja että oireettomilla varusmiehillä tavataan myös hyperinvasiivisia meningokokkikantoja. Tutkimus antoi myös uutta tietoa hyperinvasiivisten meningokokin genotyyppien liittymisestä hengitystieinfektioihin sekä MBL:n vaikutuksesta bakteerien nielukantajuuteen. Tutkimushavainnot tukevat tupakoimattomuuden edistämisen tärkeyttä myös varusmiespalveluksen aikana.
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Candidate genes other than the CFTR gene as possible modifiers of pulmonary disease severity in cystic fibrosis

Frangolias, Despina Daisy 05 1900 (has links)
Cystic fibrosis (CF) is a single gene Mendelian disorder characterized by pulmonary disease and pancreatic insufficiency. Pulmonary disease is the major cause of death in CF patients. Although some cystic fibrosis transmembrane conductance regulator (CFTR) genotypes are associated with less severe disease, patients possessing the same genotype show great variation in pulmonary disease severity and progression. Genes involved in modulating the inflammatory response and genes increasing susceptibility to infection are proposed as modifiers of pulmonary disease severity. Polymorphisms selected for based on evidence that they affect the function of the gene and prevalence of the putative risk allele: 1) antiprotease gene alpha-1-antitrypsin (alpha-1-AT), 2) innate immunity genes: mannose binding lectin (MBL2) (promoter [G→C] at -221 and codon 52 (Arg52Cys, D allele), 54 (Gly54Asp, B allele), and 57 (Gly57Glu, C allele), and pulmonary surfactant genes SPA-1 (Arg219Trp), SPA-2 (Thr9Asn, Lys223Gln) and SPD (Thr11Met), 3) antioxidant genes GSTM1 and T1 (gene deletion polymorphisms), GSTP1 (Ile105Val) and GCLC repeats, 4) mucin genes (MUC2 and MUC5B). Pulmonary disease progression and survival in patients with chronic Burkholderia cepacia complex (BCC) infection were also investigated controlling for genomovar and RAPD type of the organism. BCC infection was associated with more severe pulmonary disease progression and worse survival. Alpha-1-AT genotype was not a major contributor to variability of pulmonary disease severity, but the results suggest that alpha-1-AT plasma levels during pulmonary infections may be affected by poor nutritional status. We showed similar pulmonary disease progression and MBL2 genotype. Contrary to the previous literature, wild-type MBL2 genotype was associated with steeper decline in pulmonary disease over time following chronic infection with BCC, but genotype was not associated with increased susceptibility to BCC infection. We showed inconsistant results for the pulmonary surfactant gene polymorphisms, GSTM1, T1 and GSTP1 polymorphisms, and number of repeats for GCLC and MUC5B depending on the phenotype investigated. We conclude that some of the variability in pulmonary disease severity and progression in CF is explained by polymorphisms in secondary genes. / Medicine, Faculty of / Medicine, Department of / Experimental Medicine, Division of / Graduate

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