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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 malariaLeoratti, 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
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Candidate genes other than the CFTR gene as possible modifiers of pulmonary disease severity in cystic fibrosisFrangolias, 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.
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Candidate genes other than the CFTR gene as possible modifiers of pulmonary disease severity in cystic fibrosisFrangolias, 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.
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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 TRibeiro, 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
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Polimorfismos do gene MBL2 e percentual de IgG4 sérica em glomerulopatia membranosaCOSTA, Denise Maria do Nascimento 21 July 2016 (has links)
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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.
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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 malariaFabiana 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 conscriptsJounio, 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 fibrosisFrangolias, 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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Susceptibility to respiratory tract infections in young men: the role of inflammation, mannose-binding lectin, interleukin-6 and their genetic polymorphismsRantala, A. (Aino) 12 October 2010 (has links)
Abstract
Respiratory tract infections are the most common acute illnesses, and innate immunity and inflammation are important in defence against these infections. Mannose-binding lectin (MBL) mediates innate immune defences by recognising microbial structures. MBL deficiency caused by polymorphisms in the MBL2 gene has been associated with susceptibility to recurrent infections. Interleukin-6 (IL-6) is a mediator of inflammatory response. Polymorphisms in the IL-6 and IL-6 receptor (IL-6R) genes have been previously associated mainly with metabolic disorders and cardiovascular diseases. Chlamydia pneumoniae is a common pathogen in acute respiratory tract infections, but it also has a tendency to cause persistent infections, which have been associated with cardiovascular diseases and its risk factors, such as obesity.
The aims of this study were to investigate if selected polymorphisms of the MBL2, IL-6 and IL-6R genes are associated with respiratory tract infections and markers of C. pneumoniae infection, and to study if persistent C. pneumoniae infection is connected with an elevated body mass index (BMI) in 893 Finnish male military conscripts. Respiratory tract infections were followed during their military service and serum samples were collected at the beginning and end of their service and during each infectious episode.
A variation in serum MBL levels between different MBL2 genotypes and a MBL deficiency in homozygous exon 1 variant genotypes (at codons 52, 54 and 57) were observed. Low MBL levels and MBL2 polymorphisms in exon 1 and promoter region were found to be risk factors for susceptibility to respiratory tract infections as well as for positivity and a rise in C. pneumoniae antibodies during military service.
Associations between IL-6R gene polymorphisms in the promoter region (-183G/A) and in intron 1 and respiratory tract infections were found. In addition, the IL-6 -174G/C polymorphism was associated with persistently elevated C. pneumoniae antibodies and with slightly elevated serum C-reactive protein (CRP) levels, pointing to chronic C. pneumoniae infection.
Furthermore, persistent C. pneumoniae antibodies as a suggestive marker of chronic infection, and elevated serum CRP levels as a marker of systemic inflammation, were associated with an elevated BMI.
In conclusion, the findings support the role for MBL in susceptibility to infections and provide new information about the association between MBL and common respiratory tract infections. The results also suggest that the 5’ area of the IL-6R gene may be a possible candidate region for respiratory tract infection susceptibility, and that IL-6 genetics may be associated with C. pneumoniae infection. The study also provides new information about the role of possible chronic C. pneumoniae infection in obesity. / Tiivistelmä
Hengitystieinfektiot ovat yleisimpiä äkillisiä sairauksia, ja synnynnäisellä immuunivasteella ja tulehduksella on tärkeä rooli puolustuksessa näitä infektioita vastaan. Synnynnäiseen immuniteettiin kuuluva mannoosia sitova lektiini (MBL) tunnistaa infektioita aiheuttavien mikrobien rakenteita. MBL2-geenin polymorfismien aiheuttaman MBL-proteiinin puutteen on todettu altistavan toistuville infektioille. Interleukiini-6 (IL-6) on tulehduksen välittäjänä toimiva sytokiini. IL-6- ja IL-6-reseptori (IL-6R) -geenien polymorfismit on aikaisemmin yhdistetty lähinnä metabolisiin häiriöihin sekä sydän- ja verisuonitauteihin. Chlamydia pneumoniae eli keuhkoklamydia on yleinen hengitystieinfektioiden aiheuttaja, mutta se voi myös aiheuttaa kroonisia infektioita, jotka on yhdistetty sydän- ja verisuonitauteihin sekä niiden riskitekijöihin kuten lihavuuteen.
Työn tarkoituksena oli tutkia tiettyjen MBL2-, IL-6- ja IL-6R-geenien polymorfismien yhteyttä hengitystieinfektiohin ja keuhkoklamydiavasta-ainetasoihin sekä keuhkoklamydiainfektion yhteyttä painoindeksiin 893 suomalaisella varusmiehellä. Hengitystieinfektioita seurattiin palveluksen aikana, ja seeruminäytteet kerättiin palveluksen alussa, lopussa ja jokaisen infektion aikana.
Tutkimuksessa havaittiin vaihtelua seerumin MBL-pitoisuudessa eri MBL2-genotyyppien välillä sekä MBL:n puute homotsygooteissa eksoni 1 -alueen varianttigenotyypeissä (kodoneissa 52, 54 ja 57). Alhaiset MBL-tasot sekä MBL2-geenin polymorfismit eksoni 1 -alueella ja säätelyalueella olivat riskitekijöitä hengitystieinfektioalttiudelle sekä keuhkoklamydiavasta-aineiden esiintymiselle ja vasta-aineiden nousulle palveluksen aikana.
IL-6R-geenin polymorfismit säätelyalueella (-183G/A) ja introni 1 -alueella liittyivät hengitystieinfektioihin. Lisäksi IL-6-geenin -174G/C polymorfismi oli yhteydessä jatkuvasti kohonneisiin keuhkoklamydiavasta-aineisiin sekä seerumin C-reaktiivisen proteiinin (CRP) tasoihin, jotka mahdollisesti osoittaisivat kroonista keuhkoklamydiainfektiota. Lisäksi krooniseen keuhkoklamydia-infektioon viittaavat vasta-ainetasot sekä tulehdukseen liittyvä kohonnut CRP-pitoisuus olivat yhteydessä ylipainoon.
Tutkimuksen tulokset tukevat aikaisemmin havaittua MBL:n vaikutusta infektioalttiuteen ja lisäksi antavat uutta tietoa MBL:n yhteydestä tavallisiin hengitystieinfektioihin. Tulokset viittaavat myös siihen, että IL-6R-geenin 5’-alueella voi olla yhteyttä hengitystieinfektioalttiuteen ja että IL-6-polymorfismi olisi yhteydessä keuhkoklamydiainfektioon. Tutkimus antaa myös uutta tietoa mahdollisen kroonisen keuhkoklamydiainfektion liittymisestä ylipainoon.
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Molecular cloning and expression of mannose-binding lectin from Chinese herb, yu chu (Polygonatum odoratum) in rice. / Molecular cloning & expression of mannose-binding lectin from Chinese herb, yu chu (Polygonatum odoratum) in riceJanuary 2005 (has links)
by Wai Ching Man. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2005. / Includes bibliographical references (leaves 154-159). / Abstracts in English and Chinese. / Statement --- p.ii / Acknowledgements --- p.iii / Abstract --- p.v / 摘要 --- p.vii / List of Abbreviations --- p.viii / Table of contents --- p.x / List of Tables --- p.xiv / List of Figures --- p.xv / Chapter Chapter 1 --- Introduction --- p.1 / Chapter Chapter 2 --- Literature review --- p.4 / Chapter 2.1 --- Plant lectins --- p.4 / Chapter 2.1.1 --- Introduction --- p.4 / Chapter 2.1.2 --- Definition and subdivision of plant lectins --- p.4 / Chapter 2.2 --- Monocot mannose-binding lectins --- p.6 / Chapter 2.2.1 --- Occurrence and carbohydrate binding specificity --- p.6 / Chapter 2.2.2 --- Molecular structure and amino acid sequence --- p.7 / Chapter 2.2.3 --- "Molecular cloning, biosynthesis and post-translational modification" --- p.10 / Chapter 2.2.4 --- Mannose-binding lectins of Family Liliaceae --- p.11 / Chapter 2.2.4.1 --- Tulipa gesneriana lectins (TGL) --- p.12 / Chapter 2.2.4.2 --- Aloe arborescens lectins (AAL) --- p.13 / Chapter 2.2.4.3 --- Polygonatum multiflorum agglutinin (PMA) and lectin-related protein --- p.14 / Chapter 2.3 --- Polygonatum odoratum lectins (POL) --- p.15 / Chapter 2.3.1 --- Isolation and purification of POL from Yu Chu --- p.15 / Chapter 2.3.2 --- Agglutinating activity and anti-viral activities of POL --- p.17 / Chapter 2.3.3 --- Bacterial expression of POL in Escherichia coli --- p.18 / Chapter 2.4 --- Plant-based production of recombinant proteins --- p.20 / Chapter 2.4.1 --- Advantages of using plants as expression system --- p.20 / Chapter 2.4.2 --- Plant-derived recombinant proteins --- p.22 / Chapter 2.5 --- Expression of heterologous proteins in rice --- p.24 / Chapter 2.5.1 --- The facts of rice --- p.24 / Chapter 2.5.2 --- Rice storage proteins --- p.25 / Chapter 2.5.2 --- Expression of lysine-rich protein (LRP)/glutelin fusion proteinin rice seeds --- p.28 / Chapter 2.5.3 --- Expression of Galanthus nivalis agglutinin in rice --- p.29 / Chapter 2.6 --- Protein trafficking in plants --- p.30 / Chapter 2.6.1 --- Golgi-dependent pathways --- p.30 / Chapter 2.6.2 --- Golgi-independent pathway --- p.32 / Chapter 2.6.3 --- Expression of protein targeting determinants in tobacco plants and suspension cells --- p.33 / Chapter Chapter 3 --- Materials and Methods --- p.35 / Chapter 3.1 --- Introduction --- p.35 / Chapter 3.2 --- Chemcials --- p.35 / Chapter 3.3 --- Bacterial strains --- p.35 / Chapter 3.4 --- Cloning of POL cDNA --- p.36 / Chapter 3.4.1 --- Plant materials --- p.36 / Chapter 3.4.2 --- RNA extraction --- p.36 / Chapter 3.4.3 --- RT-PCR amplification of POL cDNA --- p.36 / Chapter 3.4.4 --- 5'RACE and 3'RACE --- p.38 / Chapter 3.4.5 --- Sequencing of POL cDNA --- p.39 / Chapter 3.5 --- Analysis of POL protein --- p.40 / Chapter 3.5.1 --- Protein extraction and Tricine-SDS PAGE --- p.40 / Chapter 3.5.2 --- Western blot analysis --- p.41 / Chapter 3.6 --- Chimeric gene construction --- p.42 / Chapter 3.6.1 --- Construction of the Cauliflower mosaic virus (CaMV)35S promoter/POL constructs --- p.44 / Chapter 3.6.2 --- Construction of the glutelin-1 promoter/POL constructs --- p.48 / Chapter 3.6.3 --- Sequence fidelity of chimeric genes --- p.55 / Chapter 3.7 --- Expression of transgenes in rice --- p.55 / Chapter 3.7.1 --- Plant materials --- p.55 / Chapter 3.7.2 --- Agrobacterium transformation --- p.55 / Chapter 3.7.3 --- Callus induction --- p.56 / Chapter 3.7.4 --- Agrobacterium culture and rice transformation --- p.56 / Chapter 3.7.5 --- Selection and regeneration of rice callus --- p.56 / Chapter 3.7.6 --- Isolation of genomic DNA --- p.58 / Chapter 3.7.7 --- Southern blot analysis --- p.58 / Chapter 3.7.8 --- Extraction of leaf total RNA --- p.59 / Chapter 3.7.9 --- Extraction of seed total RNA --- p.59 / Chapter 3.7.10 --- Northern blot analysis --- p.60 / Chapter 3.7.11 --- Protein extraction and Tricine SDS-PAGE --- p.60 / Chapter 3.7.12 --- Western blot analysis --- p.61 / Chapter 3.8 --- Cytopathic effect (CPE) reduction assay --- p.61 / Chapter 3.8.1 --- Protein extraction --- p.61 / Chapter 3.8.2 --- CPE reduction assay --- p.62 / Chapter 3.9 --- Confocal immunofluorescence --- p.63 / Chapter 3.9.1 --- Preparation of sections --- p.63 / Chapter 3.9.2 --- Labelling of fluorescence probes --- p.63 / Chapter 3.9.3 --- Image collection --- p.64 / Chapter Chapter 4 --- Results --- p.65 / Chapter 4.1 --- Cloning of POL cDNA from Yu Chu --- p.65 / Chapter 4.1.1 --- RNA extraction and partial POL cDNA amplification --- p.65 / Chapter 4.1.2 --- 5'RACE and 3'RACE --- p.67 / Chapter 4.1.3 --- Sequencing of POL cDNA --- p.68 / Chapter 4.1.4 --- Sequences comparison of POL and Liliaceae lectins --- p.75 / Chapter 4.2 --- Occurence of POL protein in Yu Chu plant --- p.77 / Chapter 4.3 --- Constitutional expression of POL in rice --- p.79 / Chapter 4.3.1 --- Construction of Cauliflower mosaic virus 35S promoter constructs --- p.80 / Chapter 4.3.2 --- Southern blot analysis --- p.82 / Chapter 4.3.3 --- Northern blot analysis --- p.84 / Chapter 4.3.4 --- Western blot analysis --- p.85 / Chapter 4.3.5 --- Western blot analysis of 35S/POL T1 plant --- p.87 / Chapter 4.4 --- Seed-specific expression of POL in rice --- p.88 / Chapter 4.4.1 --- Construction of the glutelin-1 promoter constructs --- p.89 / Chapter 4.4.2 --- Southern blot analysis --- p.92 / Chapter 4.4.3 --- Northern blot analysis --- p.96 / Chapter 4.4.4 --- Western blot analysis --- p.101 / Chapter 4.4.5 --- Western blot analysis of POL-BP-8O and POL-α-TIP T1 transgenic plants --- p.117 / Chapter 4.5 --- Cytopathic effect (CPE) reduction assay --- p.122 / Chapter 4.6 --- Confocal immunofluorescence studies --- p.125 / Chapter Chapter 5 --- Discussion --- p.134 / Chapter 5.1 --- Cloning of POL cDNA --- p.134 / Chapter 5.2 --- Analysis of constitutional expression of POL in rice --- p.136 / Chapter 5.3 --- Analysis of seed-specific expression of POL in rice --- p.138 / Chapter 5.4 --- Localization of POL in POL-BP-8O and POL-α-TIP transgenic rice seeds --- p.146 / Chapter 5.5 --- Cytopathic effect (CPE) reduction assay --- p.148 / Chapter 5.6 --- Future prospects --- p.151 / Chapter Chapter 6 --- Conclusion --- p.153
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