Made available in DSpace on 2014-06-11T19:27:20Z (GMT). No. of bitstreams: 0 Previous issue date: 2009-12-10Bitstream added on 2014-06-13T20:56:15Z : No. of bitstreams: 1 herter_drc_me_sjrp.pdf: 754038 bytes, checksum: 1546a0d9c3ae0583356f9052fe2fb9e8 (MD5) / Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) / O presente estudo avaliou a relação entre a resposta de anticorpos contra AMA-1 das variantes de P. vivax (VK210, VK247 e P. vivax-like) e os polimorfismos do gene HLA-DRB1 em populações endêmicas da Amazônia brasileira, para melhor entendimento dos mecanismos que modulam a resposta imune contra a malária. A resposta sorológica foi analisada em indivíduos maláricos e não-maláricos por testes de ELISA para AMA-1. Um subgrupo de amostras foi utilizado para genotipagem do gene HLA-DRB1 por PCR-SSP. Foram detectados 13 alelos diferentes do gene HLA- DRB1, sendo o alelo HLA-DRB1*04 o prevalente na população estudada. Foi detectada uma alta freqüência de respondedores para o antígeno AMA-1, com níveis crescentes de acordo com exposição prévia a malária. Nenhuma associação significativa foi observada entre as variantes da CSP do P.vivax e a resposta a AMA- 1, bem como aos polimorfismos do HLA-DRB1. O HLA-DRB1 apresenta uma distribuição heterogênea na população estudada, evidenciando uma contribuição característica de descendência ameríndia. A resposta de anticorpos contra o antígeno AMA-1 parece não influenciar na epidemiologia das variantes da CSP de P. vivax. Os polimorfismos do gene HLA-DRB1 não influenciam no desenvolvimento de reposta de anticorpos contra o AMA-1 na malária vivax na Amazônia brasileira / To better understand the mechanisms of the immune response modulation against malaria, this study evaluated the relationship among the antibody response to AMA-1 and variants of the circumsporozoite protein (CSP) of the P. vivax (VK210, VK247 and P. vivax-like) and the polymorphisms of HLA-DRB1 gene in populations endemic from the Brazilian Amazon. The antibody response was analyzed in malarial and non-malarial individuals by AMA-1ELISA test. A subset of samples was genotyping of HLA-DRB1 by PCR-SSP. We detected 13 different alleles of HLA-DRB gene, where the HLA-DRB1*04 was the commonest allele. A high frequency of responders to the antigen AMA-1 was detected, with increasing levels according to previous malaria experience. No significant association was observed among the response to P. vivax AMA-1 and, the variants of the CSP and the polymorphisms of HLA-DRB gene. The HLA-DRB1 has a heterogeneous distribution in the population studied, showing an effective contribution of Amerindian groups. The antibody response against the antigen AMA-1 does not influence the epidemiology of variants of the CSP of P. vivax. The polymorphisms of HLA-DRB1 gene do not influence the development of antibody response against AMA-1 in vivax malaria around the Brazilian Amazon region

Orientador: Ricardo Luiz Dantas Machado / Banca: Paula Rahal / Banca: Carlos Eugênio Cavasini / Resumo: O presente estudo avaliou a relação entre a resposta de anticorpos contra AMA-1 das variantes de P. vivax (VK210, VK247 e P. vivax-like) e os polimorfismos do gene HLA-DRB1 em populações endêmicas da Amazônia brasileira, para melhor entendimento dos mecanismos que modulam a resposta imune contra a malária. A resposta sorológica foi analisada em indivíduos maláricos e não-maláricos por testes de ELISA para AMA-1. Um subgrupo de amostras foi utilizado para genotipagem do gene HLA-DRB1 por PCR-SSP. Foram detectados 13 alelos diferentes do gene HLA- DRB1, sendo o alelo HLA-DRB1*04 o prevalente na população estudada. Foi detectada uma alta freqüência de respondedores para o antígeno AMA-1, com níveis crescentes de acordo com exposição prévia a malária. Nenhuma associação significativa foi observada entre as variantes da CSP do P.vivax e a resposta a AMA- 1, bem como aos polimorfismos do HLA-DRB1. O HLA-DRB1 apresenta uma distribuição heterogênea na população estudada, evidenciando uma contribuição característica de descendência ameríndia. A resposta de anticorpos contra o antígeno AMA-1 parece não influenciar na epidemiologia das variantes da CSP de P. vivax. Os polimorfismos do gene HLA-DRB1 não influenciam no desenvolvimento de reposta de anticorpos contra o AMA-1 na malária vivax na Amazônia brasileira / Abstract: To better understand the mechanisms of the immune response modulation against malaria, this study evaluated the relationship among the antibody response to AMA-1 and variants of the circumsporozoite protein (CSP) of the P. vivax (VK210, VK247 and P. vivax-like) and the polymorphisms of HLA-DRB1 gene in populations endemic from the Brazilian Amazon. The antibody response was analyzed in malarial and non-malarial individuals by AMA-1ELISA test. A subset of samples was genotyping of HLA-DRB1 by PCR-SSP. We detected 13 different alleles of HLA-DRB gene, where the HLA-DRB1*04 was the commonest allele. A high frequency of responders to the antigen AMA-1 was detected, with increasing levels according to previous malaria experience. No significant association was observed among the response to P. vivax AMA-1 and, the variants of the CSP and the polymorphisms of HLA-DRB gene. The HLA-DRB1 has a heterogeneous distribution in the population studied, showing an effective contribution of Amerindian groups. The antibody response against the antigen AMA-1 does not influence the epidemiology of variants of the CSP of P. vivax. The polymorphisms of HLA-DRB1 gene do not influence the development of antibody response against AMA-1 in vivax malaria around the Brazilian Amazon region / Mestre

Orientador: Lilian Maria de Castilho / Dissertação (mestrado) - Universidade Estadual de Campinas, Faucldade de Ciencias Medicas / Made available in DSpace on 2018-08-12T08:43:08Z (GMT). No. of bitstreams: 1 Omoto_Ricardo_M.pdf: 806455 bytes, checksum: 919c6c6ffefecaf298fe52f6907eabfc (MD5) Previous issue date: 2008 / Resumo: Introdução: As bases moleculares responsáveis pelas variantes do gene GYPB ainda não estão estabelecidas para a população de Brasileiros descendentes de Africanos. O presente estudo foi realizado para analisar os mecanismos moleculares que originam o fenótipo S-s- e determinar a frequência do gene GYPB*S silencioso no fenótipo S-s+, em uma população de doadores de sangue descendentes de Africanos. Materiais e Métodos: Foram selecionadas 165 amostras de sangue de Brasileiros descendentes de Africanos (Nordeste do Brasil) fenotipados como S-s- (n=17) e S-s+ (n=148) por hemaglutinação. Com a finalidade de identificar as formas variantes do gene GYPB, realizamos a genotipagem dessas amostras pelas técnicas de PCR Alelo-específico (AS-PCR) e PCR-RFLP. Resultados: Em 13 das 17 amostras S-s- (76,5%) ambos os alelos GYPB*S e GYPB*s estavam deletados. Em 137 das 148 amostras fenotipadas como S-s+ (92,6%), o resultado da genotipagem pela técnica AS-PCR foi consistente com o fenótipo S-s+. Em 4 das amostras S-s- (23,5%) e em 11 das amostras S-s+ (7,4%) foi identificada a presença do alelo GYPB*S associado com o silenciamento do antígeno S. Das amostras de DNA de doadores com o fenótipo S-s- que demonstraram a presença do alelo GYPB*S, 2 apresentaram a variante GYP(P2), 1 a variante GYP(NY) e, em 1 amostra encontramos ambas as formas variantes de GYPB: GYP(P2) e GYP(NY) Em 11 doadores com o fenótipo S-s+ houve heterozigosidade para o alelo GYP(P2) (n=8) e heterozigosidade para o alelo GYP(NY) (n=3). Conclusão: Esse estudo relata pela primeira vez os mecanismos moleculares responsáveis pelo fenótipo S-s- em uma população de Brasileiros descendentes de Africanos e promove o conhecimento de uma nova informação sobre a frequência (7,4%) e as bases moleculares do gene GYPB*S silencioso nesta população. / Abstract: Background: The molecular background of variant forms of GYPB is not well studied in Brazilians of African descent. The present study was carried out to determine the molecular bases of the S-s- phenotype and the frequency of GYPB*S silent gene for the S-s+ phenotype in a blood donor population of African Brazilians. Methods: We selected 165 blood samples from African Brazilians (Northeastern Brazil) who phenotyped as S-s- (17) and S-s+ (148) by hemagglutination. AS-PCR and PCR-RFLP were used to identify the variant forms of GYPB. Results: In 13 of 17 S-s- samples (76.5%) both GYPB were deleted. In 137 of the 148 S-s+ samples (92.6%), the AS-PCR was consistent with the S-s+, phenotype. In 4 of the S-s- samples (23.5%) and 11 of the S-s+ samples (7.4%) showed the presence of the GYPB*S allele associated with silencing of the S antigen. In the 4 donors with the S-s- phenotype there was homozygosity (or hemizygosity) for the GYP(P2) allele (n=2), homozygosity (or hemizygosity) for the GYP(NY) allele (n=1) and heterozygosity for the GYP(P2) and GYP(NY) alleles (n=1). In the 11 donors with the S-s+ phenotype there was heterozygosity for GYP(P2) allele (n=8) and heterozygosity for GYP(NY) allele (n=3). Conclusion: This study reports for the first time the molecular mechanisms responsible for the S-s- phenotype in a population of African Brazilians and provides a new information about the frequency and molecular bases of GYPB*S silent gene (7.4%) in this population. / Mestrado / Clinica Medica / Mestre em Clinica Medica

Orientadores: Luiz Paulo Kowalski, Oslei Paes de Almeida / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Odontologia de Piracicaba. / Made available in DSpace on 2018-08-20T00:22:19Z (GMT). No. of bitstreams: 1 Mariano_FernandaViviane_D.pdf: 3892005 bytes, checksum: a69171d91fdd09d696a1fb4a7bc5acc0 (MD5) Previous issue date: 2009 / Resumo: O Carcinoma ex-adenoma pleomorfo (CXAP) é uma neoplasia indolente, cuja patogênese ainda não está esclarecida, embora se acredite que resulte do acúmulo de alterações genéticas em adenoma pleomorfo (AP) de longa permanência. No presente estudo, avaliamos os fatores clincopatológicos em uma série de 38 casos de CXAP provenientes de três instituições do estado de São Paulo, Brasil. Analisamos também, o índice de proliferação celular, através da imunomarcação de Ki-67 em 36 APs, 22 APs provenientes de CXAP e 36 CXAPs nas diferentes fases de progressão maligna (precoces e francamente invasivos), subdivididos quanto aos tipos histológicos, a fim de determinar uma possível ferramenta de auxílio diagnóstico. Com estes mesmos grupos de tumores, estudamos o perfil genético de ganho e perda de número de cópias e metilação de genes supressores de tumor, através da técnica de Multiplex Ligation Probe-Dependent Amplification (MLPA). Os resultados mostraram características clinicopatológicas semelhantes às descritas em grandes séries da literatura. Observamos que a marcação de Ki-67 pode ser uma útil ferramenta na distinção entre AP e CXAP, mesmo em fases precoces de transformação maligna. Este índice mostrou não ser importante para distinção dos subtipos histopatológicos. Além disso, encontramos várias alterações em genes supressores de tumor presentes durante a tumorigênese do AP e carcinogênese do CXAP, e observamos um aumento cumulativo de alterações genômicas, sendo algumas delas, específicas para cada fase / Abstract: Carcinoma ex pleomorphic adenoma (CXPA) is an aggressive neoplasm, and its pathogenesis is still unclear, although it is believed to result from the accumulation of genetic alterations in pleomorphic adenomas (PAs) with long duration. In the present study, we evaluated the clinicopathological features in a series of 38 cases of CXPA from three institutions of the state of Sao Paulo, Brazil. We also analyzed the index of cell proliferation by labeling of Ki-67 in 36 PA, 22 PA from CXPA, and 36 CXPA in different stages of malignant progression (early and frankly invasive) subdivided in histolopathological types, to determine a possible tool to aid the diagnosis. With the same groups of tumors, it was studied also the genomic profile of gain and loss of copy number and methylation of tumor suppressor genes across Multiplex Ligation-Dependent Probe Amplification (MLPA). The results showed similar clinicopathological features to those described in large published series. We observed that Ki-67 is a useful tool in distinguishing between PA and CXPA, even in the early stages of malignant transformation. This index showed no importance for distinction among the several histological subtypes of CXPA. Furthermore, we find that various tumor suppressor genes are altered during PA tumorigenesis and CXPA carcinogenesis, and there is an accumulative increase of genomic alterations that seems to be specific for each phase / Doutorado / Patologia / Doutor em Estomatopatologia

>Magister Scientiae - MSc / Prostate Cancer is the leading cause of cancer-related death in males in the Western world. It is a common biological disease originating from the reproductive system of the male namely, the prostate gland, usually in older patients (over the age of 50) and with a family history of this disease. The disease shows clinical aggressiveness due to genetic alterations of gene expression in prostate epithelial cells. Prostate cancer is currently diagnosed by biopsy and prostate cancer screening via the Prostate-Specific Antigen (PSA) blood test. Early detection is critical and although PSA was discovered to aid in the diagnoses of this cancer at its early stages, it has a disadvantage due to its low specificity thus causing unnecessary biopsies of healthy individuals and overtreatment of patients. Although various studies and efforts have been made to identify the ideal biomarker for prostate cancer and many even being applied to clinical use, it is still challenging and has not replaced the best-known biomarker PSA. PSA test has minimal invasive characteristics, at relatively low cost together with high sensitivity but low specificity. Biomarker discovery is a challenging process and a good biomarker has to be sensitive, specific and its test highly standardized and reproducible as well as identify risk for or diagnose a disease, assess disease severity or progression, predict prognosis or guide treatment. Computational biology plays a significant role in the discovery of new biomarkers, the analyses of disease states and the validation of potential biomarkers. Bioinformatic approaches are effective for the detection of potential micro ribonucleic acid (miRNA) in cancer. Altered miRNA expression may serve as a biomarker for cancer diagnosis and treatment. Small non-protein coding RNA, miRNA are small regulatory RNA molecules that modulate the expression of their target genes. miRNAs influence numerous cancer-relevant processes such as proliferation, cell cycle control, apoptosis, differentiation, migration and metabolism. Discovery and existence of extracellular miRNAs that circulate in the blood of cancer patients has raised the possibility that miRNAs may serve as novel diagnostic markers. Since a single miRNA is said to be able to target several mRNAs, aberrant miRNA expression is capable of disrupting the expression of several mRNAs and proteins. Biomarker discovery for prostate cancer of mRNA and miRNA expression are strongly needed to enable more accurate detection of prostate cancer, improve prediction of tumour aggressiveness and facilitate diagnosis. The aim of this project was to focus on functional analyses of genes and their protein products regulated by previously identified miRNA in prostate cancer using bioinformatics as a tool. Most proteins function in collaboration with other proteins and therefore this study further aims to identify these protein-protein interactions and the biological relevance of these interactions as it relates to Prostate cancer. Various computational databases were used such as STRING, DAVID and GeneHub-GEPIS for functional analyses of these miRNA regulated genes. The main focus was on the 21 genes regulated by several miRNAs identified in a previous study. Results from this study identified six genes; ERP44, GP1BA, IFNG, SEPT2, TNFRSF13C and TNFSF4, as possible diagnostic biomarkers for prostate cancer. These results are promising, since the targeted biomarkers would be easily detectable in bodily fluids with the Gene Ontology (GO) analysis of these gene products showing enrichment for cell surface expression. The six genes identified in silico were associated to transcription factors (TFs) to confirm regulatory control of these TFs in cancer promoting processes and more specifically prostate cancer. The CREB, E2F, Nkx3-1 and p53 TFs were discovered to be linked to the genes IFNG, GP1BA, SEPT2 and TNFRSF13C respectively. The expression of these TFs show strong association with cancer and cancer related pathways specifically prostate cancer and thus demonstrates that these genes can be assessed as possible biomarkers for prostate cancer. The prognostic and predictive values of the candidate genes were evaluated to assess their relationship to prognosis of this disease by means of several in silico prognostic databases. The results revealed expression differences for the majority of the candidate genes were not significantly sufficient to be distinguished as strong prognostic biomarkers in several prostate cancer populations. Although one marker, GP1BA was supported as having prognostic value for prostate cancer based on it's statistical pvalue in one of the prostate cancer patient datasets used. Another candidate gene SEPT2 showed promise as it has some prognostic value in the early stages of the disease. Although the results yielded, based on the in silico analysis, were not the discovery of an ideal diagnostic marker based on the set criteria in this study, further analysis using a molecular approach qRT-PCR can be considered for a detailed followup study on selected candidate genes to evaluate their roles in disease initiation and progression of prostate cancer using cell lines as well as patient samples. / CSIR

Salmonella enterica serovar Typhimurium (ST) is an intracellular bacterium that resides within the phagosome of infected cells. ST is the causative agent of gastroenteritis in humans and typhoid like disease in mice. ST infects epithelial cells and phagocytic cells such as dendritic cells (DCs), which are immune sentinels that have been regarded as the most critical antigen-presenting cell (APC). I evaluated the role of CD8α DCs, a subset of DCs capable of antigen presentation of phagosomal pathogens to activate CD8+ T cells. Furthermore, I assessed the role of key cytokines such as the group of classical anti-viral cytokines known as Interferon-I (IFN-I), on licensing CD8+ T cells. Interestingly, IFN-I signalling was necessary for production of inflammatory cytokines and induction of cell death, which activated CD8+ T cells and clearance of ST. Lastly, I examined the role of key cell death pathways in innate immune protection against ST. In particular, I addressed how signalling pathways in necroptosis and pyroptosis are critical for the production of IL-1beta and IL-18 which mediate immune protection against ST. Determining the mechanisms of which DCs engage innate and adaptive immune responses against phagosomal bacteria is the central question of my study and is addressed by examining critical roles of DC function, inflammation and cell death.

京都大学 / 0048 / 新制・論文博士 / 博士(農学) / 乙第13344号 / 論農博第2887号 / 新制||農||1079(附属図書館) / 学位論文||R2||N5251(農学部図書室) / (主査)教授 小川 順, 教授 木岡 紀幸, 教授 栗原 達夫 / 学位規則第4条第2項該当 / Doctor of Agricultural Science / Kyoto University / DFAM

The major histocompatibility complex class I (MHC-I) antigen presentation pathway is necessary for the immune system to be able to detect, control, and eliminate cancers. MHC-I binds oligopeptides derived from cellular proteins and presents them on the cell surface to CD8+ T cells. Consequently, the CD8+ T cells can monitor whether any cells are making abnormal proteins and, if so, can destroy those cells. Because MHC-I presentation is not essential for cell viability, immune selection pressure often leads to cancers that are MHC-I low as they can better evade CD8+ T cell recognition. It is, therefore, important to fully understand the mechanisms of MHC-I presentation as this will identify new ways to target and exploit the pathway for cancer therapeutics. Although several components of the MHC-I pathway have already been characterized, some knowledge gaps remain. Unbiased forward genetic screens from our lab identified some novel gene candidates, such as IRF2, which positively regulate MHC-I presentation. In this dissertation, I will reveal which antigen presentation pathway genes are transcriptionally controlled by IRF2 and contribute to the MHC-I presentation deficiency observed in cells lacking IRF2 and I will also show that IRF2 negatively regulates PD-L1 expression. By influencing both MHC-I antigen presentation and PD-L1 expression in this manner, cancers lacking IRF2 (of which there are many) are both harder to see and more difficult to eliminate.

El texto completo de este trabajo no está disponible en el Repositorio Académico UPC por restricciones de la casa editorial donde ha sido publicado. / Background: Carcinoembryonic antigen (CEA) in the pancreatic cystic fluid is the most important biomarker for differentiating mucinous from non-mucinous pancreatic cystic lesions (PCLs). However, recent studies have shown that glucose levels in pancreatic cystic fluid can discriminate mucinous from non-mucinous cysts. Aims: To perform a meta-analysis to determine the utility of intracystic fluid glucose of pancreatic mucinous cysts compared with intracystic CEA. Methods: We conducted a systematic review of the literature in the PubMed, OVID Medline, and Cochrane databases. This meta-analysis considers studies published up to October 2020. Results: Six studies comprising 506 patients were selected; 61.2% of the population was female. Of the 480 PCLs, 287 (59.7%) were mucinous. Pooled sensitivity and specificity of cystic fluid glucose levels for mucinous PCLs were 91% and 85%, respectively. The positive likelihood ratio (PLR) and negative likelihood ratio (NLR) were 6.33 and 0.11, respectively. Pooled diagnostic odds ratio (DOR) was 60.94. The pooled area under the summary receiver operating characteristic (SROC) curve was 0.959. Pooled sensitivity and specificity of pancreatic cystic fluid CEA levels were 61% and 93%. The PLR and NLR were 8.51 and 0.40, respectively. Pooled DOR was 23.52, and the pooled area under the SROC curve was 0.861. Conclusion: Glucose has become a useful method and appears to be better than CEA for differentiating between mucinous PCLs and non-mucinous PCLs. We suggest that the analysis of glucose in PCLs be routinely performed for the differential diagnosis of these lesions. / Revisión por pares

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the novel coronavirus that causes coronavirus disease 2019 (COVID-19) and has escalated, becoming a pandemic in early 2020. Multiple testing modalities have been developed to detect this virus including RT-PCR, antigen, and serology testing. RT-PCR testing is the clinical gold standard and is used for diagnostic purposes of current infections. Antigen testing is rapid and requires significantly less equipment, but lacks the sensitivity of RT-PCR testing. Serology assays detect antibodies raised against SARS-CoV-2, so only detect prior exposure. It is important to note that use of antibody tests may also detect prior asymptomatic infections. For these reasons, it is imperative that all testing modalities be continuously developed and improved to better our understanding of disease transmission, helping to inform and change infection control policies and protecting both employees in the workplace and patients. We aim to quantify the seroprevalence of anti-SARS-CoV-2 IgG in the healthcare workers at Boston Medical Center, including those with asymptomatic infections. Our results show an overall seroprevalence of 5.5% with an asymptomatic seroprevalence of 1.8%. High risk groups include those who are obese, smokers, and Hispanic/LatinX. Experiencing some symptoms was associated with a higher risk of seropositivity, as was lack of social distancing amongst coworkers. In a separate study, we aim to assess the direct antigen rapid tests (DART) created by E25Bio in patients seeking care at Boston Medical Center. This study has been significantly limited by number of participants, as recruitment has been paused during both COVID-19 surges in Boston, MA. The current data shows poor positive agreement between DART and RT-PCR, but acceptable negative agreement. Each testing modality works to fill in the gaps of knowledge that still persist around SARS-CoV-2. Each of these testing types provides a unique piece of information and when used together, will help to inform strategies to overcome the SARS-CoV-2 pandemic.