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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.
31

Influência da infecção pelo vírus linfotrópico humano tipo 1 (HTLV-1) em parâmetros laboratoriais de pacientes com hepatite C crônica / HCV viral load evaluation in patients with HTLV-1 co-infection

Daniela Fernandes Cardoso 18 March 2009 (has links)
INTRODUÇÃO: O vírus da hepatite C (HCV) e o vírus linfotrópico humano tipo 1 (HTLV-1) têm modos de transmissão semelhantes e por esse motivo alguns indivíduos apresentam co-infecção. Sabe-se que o HTLV-1 pode causar uma diminuição da resposta imune celular nos indivíduos infectados, e por esse motivo pode-se esperar uma possível influência na infecção causada pelo HCV. Embora alguns trabalhos apontem para um pior prognóstico da hepatite C em pacientes co-infectados com o HTLV-1, a interação entre essas duas infecções ainda é pouco compreendida. Por este motivo, este estudo buscou avaliar a influência da infecção pelo HTLV-1 em parâmetros laboratoriais de pacientes com infecção crônica pelo HCV. MÉTODOS: Foram selecionados pacientes com infecção crônica pelo HCV e atendidos no Ambulatório de Hepatologia, do IIER, entre julho e novembro de 2007. Os pacientes co-infectados com o HTLV-1 foram selecionados a partir de um banco de dados composto por pacientes provenientes do Ambulatório de HTLV, também do IIER. Foram excluídos os pacientes que já haviam sido tratados para hepatite C, ou que apresentavam infecção por HBV ou HIV. Doze pacientes co-infectados com o HTLV-1 foram comparados a vinte e três pacientes somente com infecção crônica pelo HCV, no que diz respeito a dados demográficos, epidemiológicos, histológicos e testes bioquímicos de função hepática. Amostras de sangue periférico foram coletadas para contagem de linfócitos TCD4+ e TCD8+ por citometria de fluxo. RESULTADOS: Não houve diferença significativa em relação à idade, sexo, consumo de álcool, tabagismo, tempo de diagnóstico de hepatite C e genótipo do HCV. O uso de drogas endovenosas foi o fator de risco mais comum entre os indivíduos co-infectados com o HTLV-1, sugerindo que possivelmente tal prática possa estar relacionada com a coinfecção com o HCV. Os indivíduos co-infectados com o HTLV-1 apresentaram contagem de linfócitos T CD8+ mais elevada do que os pacientes infectados somente pelo HCV, e valores medianos significativamente mais baixos de AST e ALT (p=0,0437 e 0,0159, respectivamente). Além disso, uma porcentagem significativamente menor de pacientes co-infectados com o HTLV-1 possuiam valores de enzimas hepáticas AST, ALT e GGT dentro da normalidade (p= 0,005, 0,008 e 0,04, respectivamente). Apesar de não haver uma diferença estatisticamente significativa, observou-se também uma ocorrência menor de cirrose hepática entre os indivíduos co-infectados com o HTLV-1. CONCLUSÕES: Esses achados sugerem que a infecção pelo HTLV-1 diminuiria a lesão hepática imunomediada, podendo influenciar na história natural da infecção crônica pelo HCV / BACKGROUND: Hepatitis C virus (HCV) and human T-cell lymphotropic virus type 1 (HTLV-1) share similar routes of transmission and some individuals have dual infection. Since HTLV-1 can cause a functional impairment of cellular immune response among carriers, we can expect that the coinfection can modify the outcome of liver disease. Although some studies point to a worse prognosis of hepatitis C in patients co-infected with HTLV-1, the interaction between these two infections is still poorly understood. Therefore, this study was to evaluate the influence of HTLV-1 in laboratory parameters of patients with chronic HCV infection. The aim of this study was to evaluate the influence of HTLV-1 infection on some laboratory parameters in chronic HCV patients. METHODS: There were selected patients with chronic HCV infection followed at Hepatology Outpatient Clinic, in IIER, between July and November 2007. Patients co-infected with HTLV-1 were selected from a database composed of patients from the HTLV Clinic, also in IIER. We excluded patients who had already been treated for hepatitis C or who had HBV or HIV infection. Twelve patients co-infected with HTLV-1 were compared to only twenty-three patients with chronic HCV infection, with respect to demographics, epidemiological, histological and biochemical tests of liver function. Peripheral blood samples were collected for TCD8+ and TCD4+ counts by flow cytometry.RESULTS: There was no significant difference regarding to age, sex, alcohol consumption, smoking, time of diagnosis of hepatitis C and HCV genotype. Intravenous drug use was the most common risk factor among individuals co-infected with HTLV-1, suggesting that such a practice could possibly be related to the co-infection with HCV. Individuals co-infected with HTLV-1 showed higher TCD8+ counts than patients infected by HCV only, and significantly lower median values of AST and ALT (p = 0.0437 and 0.0159, respectively) . Moreover, a significantly lower percentage of patients co-infected with HTLV-1 have values of liver enzymes AST, ALT and GGT within the normal range (p = 0005, 0008 and 0.04, respectively). Although there is no statistically significant difference, there is also a lower incidence of liver cirrhosis among individuals co-infected with HTLV-1.CONCLUSIONS: Subjects coinfected HCV/HTLV-1 had lower plasmatic transaminase levels than HCV infected subjects, mostly into normal ranges. This finding may suggest that the interaction with HTLV-1 can reduce the liver injury during chronic phase of HCV infection
32

Expressão de microRNAs em indivíduos com infecção assintomática e com mielopatia associada ao HTLV-1/paraparesia espástica tropical (HAM/TSP) / MicroRNA expression in HTLV-1 asymptomatic carriers and in patients with HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP)

Costa, Emanuela Avelar Silva 20 October 2016 (has links)
Embora o vírus linfotrópico de células T humanas do tipo 1 (HTLV-1) seja reconhecido como o agente etiológico da leucemia/linfoma de células T do adulto (ATL) e da paraparesia espástica tropical/mielopatia associada ao HTLV-1 (HAM/TSP), cerca de 90% dos indivíduos infectados permanecem assintomáticos por toda a vida. Até o presente momento, os fatores associados ao desenvolvimento de doença relacionada ao HTLV-1 não foram totalmente elucidados. Sabe-se que o aumento da carga proviral e a expressão de genes virais estão envolvidos no desenvolvimento/progressão de doenças associadas ao HTLV-1. Assim, por exemplo, a proteína Tax modula genes envolvidos na patogênese da HAM/TSP e genes regulados por HBZ estimulam a proliferação de linfócitos T, induzindo a ATL. Desde a última década, diversos estudos têm demonstrado que células transformadas pelo HTLV-1 apresentam microRNAs do hospedeiro desregulados, o que poderia promover alteração na expressão de genes virais (tax e HBZ), com possível contribuição para o desenvolvimento de HAM/TSP e ATL. Diante desses indícios, o presente estudo teve como objetivos: i) quantificar a expressão de miRNAs humanos conhecidos em células T CD4+ e T CD8+ do sangue periférico de indivíduos assintomáticos infectados por HTLV-1 e de pacientes com HAM/TSP; ii) identificar padrões diferenciais de expressão de miRNAs desregulados que pudessem caracterizar os grupos de pacientes de acordo com sua condição clínica; iii) investigar associações dos padrões diferenciais de expressão de miRNAs com a carga proviral e com a expressão dos genes tax e HBZ de HTLV-1. Analisou-se o perfil de expressão de 754 miRNAs em células T CD4+ e TCD8+ infectadas por HTLV-1 em 19 indivíduos assintomáticos, 17 pacientes com HAM/TSP e 14 controles não infectados. Foram detectados 10 miRNAs diferencialmente expressos no grupo HAM, quando comparados ao grupo ASS (super-expressos: hsa-miR-133a, -148a, -211, -330, -369-5p, -486 e -889 e sub-expressos: hsa-miR-520b, -520e e -566). A expressão alterada dos hsa-miR-133a, -148a, -211, e -889 (super-expressos) e do hsa-miR-520b (sub-expresso) foi correlacionada à carga proviral e a do hsa-miR-211 (super-expresso) à expressão de tax. Além disso, ao analisar as vias canônicas geradas no estudo, identificaram-se as moléculas IL6ST, PTPN11, MAP2K5, ELK4, AKT1, BAD, FOSL1, IRAK 3, CDC42, STAT3 e CREB A como potencialmente afetadas pela expressão alterada de miRNAs no grupo HAM, quando comparado com o grupo ASS. Tais achados mostram-se úteis para o delineamento futuro de estudos longitudinais com indivíduos infectados por HTLV-1, com vistas à identificação de biomarcadores prognósticos de risco para o desenvolvimento de HAM/TSP. / Even though human lymphotropic virus type 1 (HTLV-1) is etiologically linked to adult T-cell leukemia (ATL) and to HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP), about 90% of infected individuals remain asymptomatic lifelong. So far, factors that are associated with development of HTLV-1-related disease have not been totally clarified. Increase in proviral load and expression of viral genes are recognized as involved in disease development and progression. For instance, the Tax protein is known to modulate genes that are involved in HAM/TSP pathogenesis and HBZ-regulated genes account for T lymphocyte proliferation that leads to ATL. In the last decade, several studies have shown that HTLV-1-transformed cells exhibit dysregulated human microRNA expression, which could result in altered viral gene expression (tax and HBZ), contributing to the development of HAM/TSP and ATL. Based on this evidence, our study aimed at: i) quantifying known human miRNA expression in CD4+ and CD8+ peripheral blood T-cells from HTLV-1 asymptomatic carriers and patients with HAM/TSP; ii) identifying distinctive dysregulated miRNA expression profiles that could distinguish patients according to their clinical status; iii) investigating associations between differential miRNA expression profiles with proviral load and with HTLV-1 tax and HBZ gene expression. We analysed the expression profile of 754 miRNAs in CD4+ e CD8+ peripheral blood T cells from 19 HTLV-1 asymptomatic carriers (AC), 17 patients with HAM/TSP (HAM) and in 14 non-infected controls. Ten differentially expressed miRNAs were found in HAM, as compared with AC (overexpressed: hsa-miR-133a, -148a, -211, -330, -369-5p, -486 and -889; and underexpressed: hsa-miR-520b, -520e and -566). Altered expression of hsa-miR-133a, -148a, -211, and -889 (overexpressed) and of hsa-miR-520b (underexpressed) was shown to be correlated with proviral load and that of hsa-miR-211 (overexpressed) with tax expression. Moreover, analysing the miRNA canonical pathways generated in this study, we identified IL6ST, PTPN11, MAP2K5, ELK4, AKT1, BAD, FOSL1, IRAK 3, CDC42, STAT3 and CREB A as molecules that are potentially affected by altered miRNA expression in HAM, as compared to AC. Our findings are useful for the future design of longitudinal studies of HTLV-1 infected cohorts, aiming at the recognition of prognostic biomarkers of risk for the development of HAM/TSP
33

Expressão de microRNAs em indivíduos com infecção assintomática e com mielopatia associada ao HTLV-1/paraparesia espástica tropical (HAM/TSP) / MicroRNA expression in HTLV-1 asymptomatic carriers and in patients with HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP)

Emanuela Avelar Silva Costa 20 October 2016 (has links)
Embora o vírus linfotrópico de células T humanas do tipo 1 (HTLV-1) seja reconhecido como o agente etiológico da leucemia/linfoma de células T do adulto (ATL) e da paraparesia espástica tropical/mielopatia associada ao HTLV-1 (HAM/TSP), cerca de 90% dos indivíduos infectados permanecem assintomáticos por toda a vida. Até o presente momento, os fatores associados ao desenvolvimento de doença relacionada ao HTLV-1 não foram totalmente elucidados. Sabe-se que o aumento da carga proviral e a expressão de genes virais estão envolvidos no desenvolvimento/progressão de doenças associadas ao HTLV-1. Assim, por exemplo, a proteína Tax modula genes envolvidos na patogênese da HAM/TSP e genes regulados por HBZ estimulam a proliferação de linfócitos T, induzindo a ATL. Desde a última década, diversos estudos têm demonstrado que células transformadas pelo HTLV-1 apresentam microRNAs do hospedeiro desregulados, o que poderia promover alteração na expressão de genes virais (tax e HBZ), com possível contribuição para o desenvolvimento de HAM/TSP e ATL. Diante desses indícios, o presente estudo teve como objetivos: i) quantificar a expressão de miRNAs humanos conhecidos em células T CD4+ e T CD8+ do sangue periférico de indivíduos assintomáticos infectados por HTLV-1 e de pacientes com HAM/TSP; ii) identificar padrões diferenciais de expressão de miRNAs desregulados que pudessem caracterizar os grupos de pacientes de acordo com sua condição clínica; iii) investigar associações dos padrões diferenciais de expressão de miRNAs com a carga proviral e com a expressão dos genes tax e HBZ de HTLV-1. Analisou-se o perfil de expressão de 754 miRNAs em células T CD4+ e TCD8+ infectadas por HTLV-1 em 19 indivíduos assintomáticos, 17 pacientes com HAM/TSP e 14 controles não infectados. Foram detectados 10 miRNAs diferencialmente expressos no grupo HAM, quando comparados ao grupo ASS (super-expressos: hsa-miR-133a, -148a, -211, -330, -369-5p, -486 e -889 e sub-expressos: hsa-miR-520b, -520e e -566). A expressão alterada dos hsa-miR-133a, -148a, -211, e -889 (super-expressos) e do hsa-miR-520b (sub-expresso) foi correlacionada à carga proviral e a do hsa-miR-211 (super-expresso) à expressão de tax. Além disso, ao analisar as vias canônicas geradas no estudo, identificaram-se as moléculas IL6ST, PTPN11, MAP2K5, ELK4, AKT1, BAD, FOSL1, IRAK 3, CDC42, STAT3 e CREB A como potencialmente afetadas pela expressão alterada de miRNAs no grupo HAM, quando comparado com o grupo ASS. Tais achados mostram-se úteis para o delineamento futuro de estudos longitudinais com indivíduos infectados por HTLV-1, com vistas à identificação de biomarcadores prognósticos de risco para o desenvolvimento de HAM/TSP. / Even though human lymphotropic virus type 1 (HTLV-1) is etiologically linked to adult T-cell leukemia (ATL) and to HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP), about 90% of infected individuals remain asymptomatic lifelong. So far, factors that are associated with development of HTLV-1-related disease have not been totally clarified. Increase in proviral load and expression of viral genes are recognized as involved in disease development and progression. For instance, the Tax protein is known to modulate genes that are involved in HAM/TSP pathogenesis and HBZ-regulated genes account for T lymphocyte proliferation that leads to ATL. In the last decade, several studies have shown that HTLV-1-transformed cells exhibit dysregulated human microRNA expression, which could result in altered viral gene expression (tax and HBZ), contributing to the development of HAM/TSP and ATL. Based on this evidence, our study aimed at: i) quantifying known human miRNA expression in CD4+ and CD8+ peripheral blood T-cells from HTLV-1 asymptomatic carriers and patients with HAM/TSP; ii) identifying distinctive dysregulated miRNA expression profiles that could distinguish patients according to their clinical status; iii) investigating associations between differential miRNA expression profiles with proviral load and with HTLV-1 tax and HBZ gene expression. We analysed the expression profile of 754 miRNAs in CD4+ e CD8+ peripheral blood T cells from 19 HTLV-1 asymptomatic carriers (AC), 17 patients with HAM/TSP (HAM) and in 14 non-infected controls. Ten differentially expressed miRNAs were found in HAM, as compared with AC (overexpressed: hsa-miR-133a, -148a, -211, -330, -369-5p, -486 and -889; and underexpressed: hsa-miR-520b, -520e and -566). Altered expression of hsa-miR-133a, -148a, -211, and -889 (overexpressed) and of hsa-miR-520b (underexpressed) was shown to be correlated with proviral load and that of hsa-miR-211 (overexpressed) with tax expression. Moreover, analysing the miRNA canonical pathways generated in this study, we identified IL6ST, PTPN11, MAP2K5, ELK4, AKT1, BAD, FOSL1, IRAK 3, CDC42, STAT3 and CREB A as molecules that are potentially affected by altered miRNA expression in HAM, as compared to AC. Our findings are useful for the future design of longitudinal studies of HTLV-1 infected cohorts, aiming at the recognition of prognostic biomarkers of risk for the development of HAM/TSP
34

The prevalence of HBV, HTLV, HIV and concurrent infections in blood recipients of the South African National Blood Service (SANBS)

Willemse, Reynier 12 1900 (has links)
M. Tech. (Department of Biotechnology, Faculty of Applied and Computer Sciences), Vaal University of Technology. / Background: Currently, the South African National Blood Services are not testing for HTLV and HTLV screening is not mandated by the WHO or by regulatory standards in South Africa. Looking at the uniquely high prevalence of HIV and HIV / HBV co-infections in the South African population and taking into account the literature that suggests that most of these infected patients will be receiving blood, exposing these patients to an additional burden like HTLV can result in an increased disease progression of HIV to AIDS and a poor prognosis in these infected patients. Study design and methods: A blinded cross-sectional study was performed. 7015 specimens were collected from all blood transfusion laboratories across South Africa excluding the Western Cape Blood Transfusion Service laboratories. The specimens collected were tested using the ABBOTT Alinity S® Immunochemiluminescent autoanalyser. All test results were confirmed with the Roche Cobas® E801 and E411 auto analyser. Results: Over all prevalence for HIV was 39.39% (N=2763), HBV 7.57% (n=531) and HTLV 0.70% (N=49). Concurrent infection for HIV/HBV 4.92% (N=345), HIV/HTLV 0.36% (N=25), HBV/HTLV 0.09% (N=6) and HIV/HBV/HTLV 0.07% (N=5). Conclusion: This study confirmed an overall high prevalence of HIV and HBV infections among patients receiving blood products from the SANBS. Compared to the general population, the HIV prevalence in blood recipients was two-fold higher. Patients receiving a blood transfusion from the SANBS have high rates of HIV, HBV and HTLV which should be taken into consideration when determining donor screening strategies.

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