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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.
281

Ocorrência da infecção oculta pelo vírus da hepatite B (VHB) em pacientes com cirrose hepática pelo vírus da hepatite C (VHC) com ou sem carcinoma hepatocelular (CHC) / Occurrence of occult hepatitis B virus infection (HBV) in patients with liver cirrhosis due to hepatitis C virus (HCV) with or without hepatocellular carcinoma

Alencar, Regiane Saraiva de Souza Melo 30 March 2006 (has links)
O presente estudo avaliou materiais de 50 pacientes com cirrose hepática pelo vírus da hepatite C (VHC) que foram submetidos ao transplante hepático no Hospital das Clínicas da Faculdade de Medicina de São Paulo no período de 1993 a 2004, sendo divididos em dois grupos: Grupo 1 (33 pacientes com cirrose pelo VHC) e Grupo 2 (17 pacientes com cirrose pelo VHC com carcinoma hepatocelular). Nosso objetivo foi estudar a ocorrência da infecção oculta pelo VHB em pacientes com cirrose pelo VHC com ou sem CHC através do estudo molecular do genoma viral (DNA do VHB) no soro, tecido hepático tumoral e não tumoral pela utilização da técnica de Reação em Cadeia da Polimerase (PCR), pelos métodos in house e em tempo real. Todos os pacientes eram HBsAg negativos, possuíam soroteca e bloco de explante hepático em parafina, não apresentando concomitância com doenças hepáticas colestáticas, metabólicas e autoimunes. Foram avaliados os prontuários por um único pesquisador no sentido de coletar informações tais como: sexo, idade, dados de exames laboratoriais bioquímicos, sorológicos, ?fetoproteína e coagulação; além de dados clínicos tais como ascite e encefalopatia hepática para cálculos de índices prognósticos da cirrose (Child e MELD). Todo o material de explante hepático teve o Escore de Ishak e a Classificação das Sociedades Brasileiras de Patologia e Hepatologia para hepatites crônicas avaliados, assim como a Classificação de Edmondson e Steiner para os que apresentassem CHC. A técnica de PCR in house para detecção do DNA do VHB no soro e em tecido hepático tumoral e não tumoral apresentou negatividade em todas as amostras. Na técnica de PCR em tempo real apenas um caso do grupo 2 foi positivo no soro (sexo masculino, 66 anos, Anti-HBC total isolado e CHC); no tecido hepático tumoral no grupo 2 tivemos dois casos com resultados indeterminados e no tecido hepático não tumoral também do grupo 2, tivemos dois casos indeterminados. O grupo 1 não apresentou positividade para nenhuma das técnicas utilizadas. Concluímos que entre nossos pacientes com ou sem carcinoma hepatocelular associados à cirrose hepática pelo VHC, a infecção oculta pelo VHB foi muito baixa, provavelmente devido à baixa prevalência da infecção pelo VHB na nossa população / This study evaluated serum and liver tissue samples from 50 patients with liver cirrhosis due to hepatitis C virus (HVC) that underwent liver transplant at the Hospital das Clínicas - University of São Paulo School of Medicine during the period of 1993 to 2004, divided into two groups: Group 1 (33 cirrhotic patients due to HCV) and Group 2 (17 cirrhotic patients due to HCV with hepatocellular carcinoma - HCC). Our aim was to study the occurrence of occult HBV0 infection in cirrhotic patients due to HCV with or without HCC through the molecular study of HBV DNA in the serum, tumoral liver tissue and non tumoral liver tissue by the polymerase chain reaction (PCR) techniques using in house and real time PCR. All the patients were HBsAg negative, having previous serum samples frozen at -20ºC and liver tissue explanted in paraffin, without presenting concomitant cholestatic, metabolic and autoimmune liver diseases. The following variables were collected: gender, age, biochemical and coagulation laboratory tests and HBV serology (HBsAg, anti-HBc total, anti-HBs). Among the clinical data, ascites and encephalopathy were collected for the Child and MELD prognostic indexes. In the explanted liver tissue the Ishak\'s Score, The Brazilian Society of Pathology and Hepatology Classification for chronic hepatitis, and Edmondson and Steiner Classification for HCC were applied in the liver tissue. All samples with or without tumoral liver tissue and serum were negative for HBV DNA using in house PCR technique. By the real time PCR technique only one case from Group 2 was HBV DNA positive in serum (male, 66, isolated anti-HBc total positive and HCC). In the tumoral and non-tumoral liver tissues there were two indeterminated HBV DNA cases among Group 2 patients. All samples for Group 1 patients were negative for HBV DNA using both techniques. In conclusion, our study has shown the extremely low occult hepatitis B virus infection among the HCV cirrhotic patients with or without HCC, maybe due to the low HBV past infection among the Southeastern Brazilian population
282

Avaliação de marcadores sorológicos de proteção e infecção pelo vírus da hepatite B em pessoas vivendo com HIV/Aids, vacinadas previamente para hepatite B / Evaluation of serological markers of infection and protection from hepatitis B virus in people living with HIV previously vaccinated for hepatitis B

Lara, Amanda Nazareth 29 May 2017 (has links)
INTRODUÇÃO: A infecção pelo vírus da hepatite B (VHB) é responsável por grande parte das doenças hepáticas crônicas em todo o mundo. Em pessoas vivendo com HIV/Aids (PVHA) a infecção pelo VHB tem maior risco de evolução para cirrose e carcinoma hepatocelular. A vacina da hepatite B é importante na prevenção de doença potencialmente grave, particularmente em PVHA, já que ambos os vírus têm as mesmas vias de transmissão e a coinfecção tem uma alta morbidade. Indivíduos imunocompetentes têm uma boa resposta humoral após uma primeira série de vacina da hepatite B e não há recomendações de rotina para doses de reforço. PVHA podem ter uma pior resposta à vacina da hepatite B, quando comparada à resposta em indivíduos imunocompetentes e a duração da imunidade nesses pacientes é desconhecida. OBJETIVOS: Geral: Avaliar os marcadores sorológicos de proteção e infecção pelo VHB em pacientes adultos vivendo com HIV/Aids, vacinados previamente para hepatite B. Específicos: Avaliar a persistência dos anticorpos anti-HBs em PVHA vacinadas previamente para hepatite B e que apresentaram resposta humoral protetora inicial; avaliar a resposta sorológica à revacinação para hepatite B nos pacientes vacinados previamente e que não apresentaram resposta humoral protetora inicial; investigar a presença de marcadores sorológicos de infecção pelo VHB em PVHA vacinadas previamente para hepatite B. MÉTODOS: Estudo observacional de coorte retrospectiva de PVHA vacinadas primariamente para hepatite B entre 2001 e 2002. Marcadores sorológicos de infecção e proteção para o vírus da hepatite B foram investigados nesses pacientes que ainda estavam em acompanhamento no Serviço de Extensão ao Atendimento de Pacientes HIV/Aids (SEAP), da divisão de Clínica de Moléstias Infecciosas e Parasitárias do Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo entre 2012 e 2014. RESULTADOS: Uma coorte de 121 PVHA foi analisada quanto à soroconversão e persistência do anti-HBs. A maioria era do sexo feminino (54,5%) com média de idade de 50,1 anos. Destes pacientes, 58 (grupo 1) eram inicialmente respondedores à primeira série da vacina (anti- HBs >=10 mUI/mL) e 63 (grupo 2) eram não respondedores. Após um período mediano de avaliação de 11 anos, nenhum dos pacientes teve evidência sorológica de infecção pelo VHB e 41/58 (70.7%) dos inicialmente respondedores mantinham anti-HBs >= 10 mUI/mL. Maior contagem de células T CD4+ e anti-HBs >= 100 mUI/mL, no momento da primeira série vacinal, estiveram associados à persistência de anti-HBs. Durante o período avaliado, 35/63 (55.6%) dos pacientes inicialmente não respondedores (grupo 2) soroconverteram com sucesso (anti-HBs >= 10 mUI/mL) em resposta a uma ou mais doses de reforço vacinal. Foi associado à soroconversão do anti-HBs o número de doses de reforço recebidas. A partir do momento da soroconversão (anti-HBs >=10 mUI/mL), 70 pacientes não receberam nenhuma dose adicional de vacina de hepatite B (grupo 3). Após um período mediano de 10 anos, 54/70 (77,1%) destes indivíduos mantinham anti- HBs >= 10 mUI/mL. CONCLUSÕES: A avaliação dos marcadores sorológicos para VHB em PVHA vacinadas previamente para hepatite B evidenciou: alta persistência de anti-HBs após um período de 10 a 11 anos; doses adicionais de vacina foram capazes de induzir resposta humoral em indivíduos inicialmente não respondedores; não foram detectados marcadores sorológicos de infecção (HbsAg ou Anti-HBc) após 11 anos da vacinação inicial / BACKGROUND: Hepatitis B Virus (HBV) infection is responsible for great part of chronic hepatic diseases worldwide. In people living with HIV (PLHIV), HBV infection has more risk of progressing to cirrhosis and hepatocarcinoma. Hepatitis B vaccine is important in the prevention of a potentially severe disease, particularly in PLHIV, since both viruses have the same routes of transmission and co-infection has greater morbidity. Immunocompetent individuals have a good humoral response after the first hepatitis B vaccine series and no recommendation is made regarding booster doses. PLHIV may have a poor hepatitis B vaccine response, when compared to immunocompetent and the duration of immunity in these patients is unknown. OBJECTIVES: General: Evaluate serological markers of infection and protection from HBV in PLHIV previously vaccinated for hepatitis B. Specific: Evaluate anti-HBs persistence in PLHIV previously vaccinated for HBV who responded to a primary vaccine series; evaluate response to revaccination for hepatitis B in patients who did not respond to first vaccine series; investigate serological markers of infection from HBV in PLHIV previously vaccinated for hepatitis B. METHODS: Observational retrospective study of a PLHIV cohort primarily vaccinated between 2001 and 2002 for hepatitis B. Serological markers of infection and protection from HBV were investigated in those patients who were still attending the HIV/AIDS Patient Care Extension Service at the Clinical Division of Infectious and Parasitic Diseases attached to Hospital das Clínicas at Faculdade de Medicina at Universidade de São Paulo between 2012 and 2014. RESULTS: A cohort of 121 PLHIV was analyzed for seroconversion and persistence of anti-HBs. The majority were female (54.5%) and mean age 50.1 years. From these patients, 58 (group 1) were initially responders to the first vaccine series (anti- HBs >=10 mIU/mL) and 63 (group 2) were non- responders. After a median period of 11 years, none of the patients had serologic evidence of HBV infection and 41/58 (70.7%) of the initially responders had maintained anti-HBs >=10 mIU/mL. Greater CD4+ cell counts and anti- HBs>= 100mIU/mL at the time of first vaccine series were associated with persistence of anti-HBs. During evaluation period, 35/63 (55.6%) of the initially non-responders (group 2) successfully seroconverted (anti-HBs >=10 mIU/mL) in response to one or more booster doses. Booster doses may be effective in PLHIV. Number of booster doses were associated to seroconversion. Seventy of the 121 patients did not receive any further booster doses of hepatitis B vaccine from the time of their seroconversion (anti-HBs >=10 mIU/mL) (group 3). After 10 years of the seroconversion, 54/70 (77,1%) of these individuals has maintained anti- HBs >= 10 mIU/mL. CONCLUSIONS: Evaluation of serological markers for HBV in PLHIV previously vaccinated for hepatitis B showed: strong persistence of anti-HBs after a period of 10 to 11 years; additional vaccine doses elicited humoral response in initially non-responders; there was no serologic evidence of HBV infection (HbsAg ou Anti-HBc) about 11 years after initial vaccination
283

Relationship between hepatitis B virus X protein and hypoxia-inducible factors and the therapeutic targets of sorafenib. / CUHK electronic theses & dissertations collection

January 2012 (has links)
慢性乙型肝炎病毒(HBV)感染是肝癌發生的重要因素,其中乙肝病毒X蛋白(HBx)在這一過程起著關鍵作用。研究發現,一些HBV變體和HBx突變具有更高致癌風險,而且這些變體和突變存在地區差異。香港是HBV感染高發地帶,因此本研究目的是從這一地區120個肝癌組織標本中篩查出HBx突變位點。我們用巢式PCR從84.16% (101/120)的標本中提取和擴增了HBx,並進行基因測序。三種HBx突變被檢測出,包括點突變,遠端羧基端截斷和缺失突變。其中點突變位點有39個,特別的是在50%的標本中檢測出A1630G/G1721A 和 A1762T/G1764A雙突變。在31.68% (32/101)的標本中發現遠端羧基端截斷,以及在2.97% (3/101)的標本中檢測出缺失突變。總之,大多數突變集中在HBx轉錄啟動域,表明這些突變在肝癌發生中可能起著重要作用。 / 缺氧誘導因數-1α(HIF-1α)在肝癌的發生和發展中也起著重要作用。研究發現,野生型HBx可以啟動HIF-1α,但是變異型HBx和HIF-1α的關係還沒有研究清楚。我們研究表明HBx轉錄啟動域是必需而且足夠啟動HIF-1α的。在這個區域的突變中,雙突變K130M/V131Z增強HBx對HIF-1α的活性,但遠端羧基端截斷和缺失突變削弱其功能。進一步研究發現,羧基端特別是119-140氨基酸對HBx的穩定和功能非常重要。肝癌標本中,我們也發現HBx和HIF-1α的表達呈正相關。因此,雖然不同的突變對於HBx的功能有不同的影響,但總的來說這些突變可以促進HIF-1α的表達和啟動,進而導致肝癌患者的預後不良。 / 靶向治療在肝癌綜合治療中扮演重要角色。索拉菲尼(Sorafenib)是一種多激酶抑制劑,臨床實驗發現它對晚期肝癌治療有效,但其抑制腫瘤血管生成機制還不完全清楚。我們研究發現Sorafenib明顯而且劑量依賴性地降低HIF-1α的表達和活化,進而抑制血管內皮生長因數(VEGF)的表達。Sorafenib抑制mTOR, ERK, p70S6K, RP-S6, eIF4E和4E-BP1等翻譯起始因數的磷酸化,從而抑制HIF-1α的合成而不影響其降解。體外實驗進一步發現Sorafenib降低HIF-1α和VEGF的表達,從而抑制腫瘤的血管形成和生長。總之,我們的研究表明sorafenib可能通過阻斷mTOR/p70S6K/4E-BP1 和 ERK 信號通路來抑制HIF-1α的合成,從而發揮其抗腫瘤血管生成作用。 / Chronic HBV infection is the leading cause of hepatocellular carcinoma (HCC) and HBx plays a crucial role in the molecular pathogenesis of HBV-related HCC. Previous investigations have indicated that some variations of HBV or mutations of HBx are associated with higher risk of HCC development, whereas the mutations profiles may be disparate in different regions. In the present studies, we thus aim to screen and identify the HBx mutation hotspots in 120 HCC tissues from Hong Kong, a region with HBV hyper-endemic. HBV DNAs were successfully isolated and amplified in 84.16% (101/120) HCC specimens via nest-PCR, and then subjected to gene sequencing. Three types of HBx mutations, including point mutations, distal carboxyl-terminal truncations and deletion mutations, were discovered. Among the point mutations, 39 mutation hotspots were indentified, with two double mutations (A1630G/G1721A and A1762T/G1764A) occurring in approximate 50% of 101 HCC cases. Distal C-terminal truncated mutations were discovered in 31.68% (32/101) of HCC cases, whereas deletion mutations were detected in 2.97% (3/101) of them. Overall, majority of identified mutations were located at the transactivation domain of HBx, suggesting the crucial roles of these mutations in HCC development. / Hypoxia-inducible factor-1α (HIF-1α) also closely involves in the development and progression of HCC. Wild-type HBx has been shown to activate HIF-1α. But the relationship between HBx mutants and activation of HIF-1α has not been fully elucidated. We here revealed that the transactivaiton domain of HBx was necessary and sufficient to activate HIF-1α. Double mutations K130M/V131Z in this domain enhanced the functionality of HBx in upregulating the expression and the activation of HIF-1α, whereas C-terminal truncations and deletion mutations weakened this prosperity of HBx. We further uncovered that the C-terminus, especially the region of amino acids 119-140, was essential for the stability and transactivation of HBx. The positive association between the HBx mutants and HIF-1α was found in the HCC tissue samples. Therefore, although mutations exerted different effects on the functionality of HBx, the overall activity of HBx mutants was suggested to upregulate HIF-1α, whose level is related to poor prognosis of HCC patients. / The therapy targeting a critical molecule in the development of HCC such as HIF-1α may be a potential and effective treatment regimen for HCC patients. Sorafenib, a multikinase inhibitor, has demonstrated promising results for the treatment of advanced HCC in clinical trials, but the mechanism that accounts for the anti-angiogenic efficiency of this agent has not been fully elucidated. We here revealed that sorafenib remarkably and dose-dependently decreased the expression and the transcriptional activity of HIF-1α, and its target gene, vascular endothelial grow factor (VEGF). Further analysis revealed that this reduction of HIF-1α by sorafenib was caused by the inhibition of HIF-1α protein synthesis rather than by the promotion of HIF-1α protein degradation. Moreover, the phosphorylated levels of mTOR, ERK, p70S6K, RP-S6, eIF4E and 4E-BP1 were significantly suppressed by sorafenib. In vivo studies further confirmed the inhibitory effect of sorafenib on the expression of HIF-1α and VEGF proteins, leading to a decrease of tumor vascularisation and growth. Collectively, our data suggest that sorafenib may exhibit anti-angiogenic activity by inhibiting HIF-1α synthesis, which is likely to be achieved through suppressing the phosphorylation of mTOR/p70S6K/4E-BP1 and ERK. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Liu, Liping. / Thesis (Ph.D.)--Chinese University of Hong Kong, 2012. / Includes bibliographical references (leaves 133-154). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstract also in Chinese. / Abstract --- p.I / 摘要 --- p.IV / Publications --- p.VI / Acknowledgements --- p.VII / Abbreviations --- p.IX / List of Figures --- p.XI / List of Tables --- p.XIII / Table of Contents --- p.XIV / Chapter Chapter I --- General Introduction --- p.1 / Chapter 1.1 --- Overview of Hepatocellular Carcinoma --- p.1 / Chapter 1.2 --- HBV Infection and HCC Development --- p.6 / Chapter 1.3 --- Overview on Hepatitis B virus X Protein --- p.10 / Chapter 1.4 --- Roles of Hypoxia-inducible Factors in HCC --- p.17 / Chapter 1.5 --- Targeted Therapies and Sorafenib --- p.27 / Chapter Chapter II --- Identification of HBx Mutation Hotspots in HCC Tissues --- p.31 / Chapter 2.1 --- Abstract --- p.31 / Chapter 2.2 --- Introduction --- p.32 / Chapter 2.3 --- Materials and Methods --- p.35 / Chapter 2.4 --- Results --- p.40 / Chapter 2.5 --- Discussion --- p.53 / Chapter Chapter III --- The Relationship between HBx Mutants and HIF-1α --- p.59 / Chapter 3.1 --- Abstract --- p.59 / Chapter 3.2 --- Introduction --- p.60 / Chapter 3.3 --- Materials and Methods --- p.63 / Chapter 3.4 --- Results --- p.70 / Chapter 3.5 --- Discussion --- p.91 / Chapter Chapter IV --- The Effects of Sorafenib on Hypoxia-inducible Factor-1α --- p.96 / Chapter 4.1 --- Abstract --- p.96 / Chapter 4.2 --- Introduction --- p.98 / Chapter 4.3 --- Materials and Methods --- p.101 / Chapter 4.4 --- Results --- p.108 / Chapter 4.5 --- Discussion --- p.124 / Chapter Chapter V --- Conclusion and Future Plans --- p.129 / Chapter 5.1 --- Conclusion --- p.129 / Chapter 5.2 --- Future Plans --- p.131 / References --- p.133
284

Prevalência de resistência primária aos antivirais utilizados no tratamento da hepatite B entre pacientes com infecção crônica pelo vírus da hepatite B não submetidos a tratamento / Prevalence of primary resistance to antivirals used in the treatment of hepatitis B among treatment-naïve patients with chronic hepatitis B

Gouvêa, Michele Soares Gomes 27 June 2014 (has links)
O objetivo principal deste estudo foi avaliar a frequência de cepas do HBV com mutações de resistência aos análogos nucleos(t)ídeos (AN) utilizados no tratamento da hepatite B entre indivíduos cronicamente infectados, não submetidos a tratamento, procedentes de diferentes regiões do Brasil. Além disso, foram avaliadas a presença de mutações que alteram a antigenicidade do HBsAg promovendo escape dos anticorpos anti-HBs; mutações nos genes pré-core/core e a associação dos diferentes subgenótipos com as mutações encontradas e características demográficas e laboratoriais dos pacientes. Foram incluídas 779 amostras de soro de pacientes com infecção crônica pelo HBV e virgens de tratamento com AN ou interferon, as quais foram coletadas no período de 2006 a 2011. Os pacientes eram procedentes dos seguintes estados brasileiros: Pará, Maranhão, Bahia, Minas Gerais, São Paulo, Paraná e Rio Grande do Sul. O DNA do HBV foi extraído das amostras de soro utilizando o Kit QIAamp DNA Blood Mini Kit (Qiagen) e posteriormente foi realizada a amplificação das regiões S/polimerase (S/P) e pré-core/core (PCC) do genoma viral por nested PCR. O fragmento amplificado foi submetido a sequenciamento direto em sequenciador automático de DNA (ABI 3500) e as sequências obtidas foram analisadas para identificação dos genótipos e subgenótipos do HBV, pesquisa de mutações na polimerase, no HBsAg e nos genes pré-core/core. A região S/Pol foi amplificada e sequenciada com sucesso em 702 amostras, as quais foram incluídas para atender aos objetivos deste estudo. Entre as 702 amostras analisadas sete genótipos e 12 subgenótipos do HBV foram identificados. O subgenótipo A1 foi o mais frequente (63,7%, 447/702), seguido pelo HBV/D3 (14,5%, 102/702). Os demais genótipos e subgenótipos encontrados e suas frequências foram as seguintes: A2 (3,3%, 23/702), A3 (0,1%, 1/702), B1 (0,1%, 1/702), B2 (0,1%, 1/702), C2 (0,9%, 6/702), D1 (0,9%, 6/702), D2 (4,6%, 32/702), D4 (5,1%, 36/702), D com subgenótipo não identificado (0,7%, 5/702), E (0,6%, 4/702), F2a (4,6%, 32/702), F4 (0,4%, 3/702), e G (0,4%, 3/702). Cepas do HBV com mutações de resistência (rtS202G, rtM204V/I, rtA194T, rtM250I, rtA181T/S, rtT184S) associadas ou não a mutações compensatórias (rtL80I, rtV173L, rtL180M, rtV207I) foram identificadas em 1,6% (11/702) das amostras analisadas. Cepas com mutações potencialmente associadas com resistência ao adefovir (rtS85A, rtL217R, rtI233V, rtN238T, rtN238D, rtN248H, rtV214A,e rtQ215S) ou ao entecavir (rtS219A) foram identificadas em 7,7% (54/702) e 2,6% (16/702) dos pacientes, respectivamente. Cinquenta e sete (8,5%) amostras apresentaram cepas do HBV com mutações na principal região hidrofílica do HBsAg previamente relacionadas com escape dos anticorpos anti-HBs ou com prejuízo na secreção do HBsAg. Foram feitas análises estatísticas para avaliar a correlação entre os subgenótipos do HBV mais frequentes na casuística (A1, A2, D1, D2, D3, D4 e F2a) e a presença de mutações nos genes PCC. Dentre as mutações nos genes PCC associadas com redução ou falha na expressão do HBeAg, as mutações A1762T/T1764A estiveram associadas aos subgenótipos A1 e F2a; G1862T e mutações nas posições 1809-1812 ao subgenótipo A1; G1896A e/ou G1899A aos subgenótipos D2, D3 e D4. Mutações associadas com evolução da doença foram detectadas e entre essas as mutações C1766T e T1768A estiveram associadas aos subgenótipos A1 e F2a, e a mutação G1888A foi associada ao subgenótipo A1. As cepas do HBV que circulam nas diferentes regiões brasileiras estudadas apresentam grande variabilidade genética e a distribuição dos genótipos e subgenótipos reflete a formação histórica de cada região e do fluxo migratório mais recente. A frequência de cepas do HBV com mutações de resistência aos AN circulando entre pacientes virgens de tratamento com esses medicamentos nas diferentes regiões do Brasil estudadas é baixa, sendo que o perfil de mutações que confere resistência total à lamivudina e parcial ao entecavir parece ser o mais disseminado. Embora tenham sido detectados casos de infecção com cepas do HBV portando mutações com grande impacto na antigenicidade dessa proteína todas as amostras apresentaram HBsAg detectável. Pacientes com HBeAg negativo foram mais frequentes na casuística estudada, independente do subgenótipo. As mutações encontradas nos genes PCC sugerem que há perfis de mutações diferentes envolvidos na negatividade do HBeAg para cada subgenótipo / The main aim of this study was to evaluate the frequency of HBV strains harboring mutations that confer resistance to nucleos(t)ide analogues (NA) used to hepatitis B treatment among treatment-naïve patients with chronic hepatitis B from different Brazilian region. Furthermore, we evaluated the presence of mutations that alter the antigenicity of HBsAg causing anti-HBs escape; mutations in genes pre-core/core and the association of different subgenotypes with the mutations detected and demographic and laboratory characteristics of the patients. Serum samples from 779 treatment-naïve patients with chronic HBV infection were included in this study. The samples were collected between 2006 to 2011 and the patients were from the following states: Pará, Maranhão, Bahia, Minas Gerais, São Paulo, Paraná and Rio Grande do Sul. HBV DNA was extracted from serum samples using the QIAamp DNA Blood Mini Kit (Qiagen) and amplification of S/polymerase (S/Pol) and pre-core/core (PCC) regions were performed by nested PCR. The amplified PCR products were submitted to sequencing in an automatic DNA sequencer (ABI 3500). The sequences obtained were analyzed to classify HBV genotypes/subgenotypes and to analyze the presence of mutations. S/Pol region was amplified and sequenced successfully from 702 samples, which were included in this study. Among these 702 samples, seven genotypes and 12 subgenotypes have been identified. HBV subgenotype A1 was the most frequent (63.7%, 447/702), followed by HBV/D3 (14.5%; 102/ 702). The remaining genotypes and subgenotypes identified and their frequencies were as follows: A2 (3.3%, 23/702), A3 (0.1%, 1/702), B1 (0.1%, 1/702), B2 (0.1%, 1/702), C2 (0.9%, 6/702), D1 (0.9%, 6/702), D2 (4.6%, 32/702), D4 (5.1%, 36/702), D unclassified subgenotype (0.7%, 5/702), E (0.6%, 4/702), F2a (4.6%, 32/702), F4 (0.4%, 3/702), and G (0.4%, 3/702). HBV strains harboring mutations conferring NA resistance alone (rtS202G, rtM204V/I, rtA194T, rtM250I, rtA181T/S, rtT184S) or combined with compensatory mutations (rtL80I, rtV173L, rtL180M, rtV207I) were identified in 1.6% (11/702) of the patients. Isolates harboring mutations potentially associated with adefovir resistance (rtS85A, rtL217R, rtI233V, rtN238T, rtN238D, rtN248H, rtV214A, and rtQ215S) or entecavir resistance (rtS219A) were identified in 7.7% (54/702) and 2.6% (16/702) of the patients, respectively. HBV with HBsAg mutations previous related with anti-HBs escape or impaired secretion were detected in 8.5% (57/702) of the samples. Statistical analyzes were performed to assess the correlation between the more frequent HBV subgenotypes found in this study (A1, A2, D1, D2, D3, D4 and F2a ) and mutations in PCC genes. Among the mutations found in these genes that were associated with reduction or failure in HBeAg synthesis, A1762T/T1764A mutations were associated to subgenotypes A1 and F2a; G1862T and mutations at positions 1809-1812 to subgenotype A1; G1896A and/or G1899A to subgenotypes D2, D3 and D4. Other mutations associated with disease progression were found: C1766T and T1768A mutations were associated with subgenotypes A1 and F2a, and the G1888A mutation was associated with subgenotype A1. HBV strains circulating in different Brazilian regions studied showed high genetic variability and distribution of genotypes and subgenotypes reflects the population formation history of each region and the occurrence of recent events of migration. The frequency of HBV strains with NA resistance mutations circulating among treatment-naive patients in different regions of Brazil studied is low and the profile of mutations that confer total resistance to lamivudine and partial resistance to entecavir is more widespread. Although some cases of infection have been detected with HBV strains carrying mutations associated with major impact on the antigenicity of this protein, all samples had detectable HBsAg. HBeAg negative cases were more frequent in the studied population, regardless of subgenotype. Different pattern of mutations were found in PCC genes, suggesting that different mechanisms are involved in HBeAg negativity for each subgenotype
285

Influência da infecção pregressa pelo vírus da hepatite B em portadores de hepatite C crônica: análise histológica / Influence of previous HBV infection in patients with chronic hepatitis C: histological assessment

Lisboa Neto, Gaspar 16 June 2009 (has links)
INTRODUÇÃO: Os vírus das hepatites B (VHB) e C (VHC) são os principais causadores de hepatopatia crônica em todo mundo. Ambos compartilham vias semelhantes de transmissão. Em pacientes portadores crônicos de VHC com sorologia compatível com infecção pregressa pelo VHB (anti-HBcAg[+] e HBsAg [-]), o VHB DNA residual tem sido detectado por técnicas de biologia molecular altamente sensíveis no soro, em células linfomononucleares de sangue periférico e em hepatócitos (como cccDNA), de forma que o anti-HBcAg tem sido associado a pior prognóstico, tanto histológico quanto terapêutico. OBJETIVOS: Analisar a associação entre infecção pregressa pelo VHB nos portadores crônicos do VHC e o dano histológico hepático, além das características epidemiológicas, clínicas e laboratoriais destes pacientes em região de baixa prevalência para o VHB. MÉTODOS: A prevalência do anti-HBcAg foi avaliada em 574 pacientes portadores crônicos de VHC atendidos durante o ano de 2006 no ambulatório de Hepatites Virais do DMIP-HC FMUSP. Deste grupo, foram selecionados 215 pacientes (98 de 112 com anti-HBcAg[+] e 117 de 462 monoinfectados pelo VHC) para análise comparativa. Ainda, 145 indivíduos foram submetidos à análise estatística multivariada, por metodologia de Regressão Logística sequencial, para identificação de possíveis preditores de fibrose avançada. RESULTADOS: Foram avaliados 98 pacientes com marcadores sorológicos de infecção pregressa pelo VHB. Quarenta e seis indivíduos (47%) possuíam o anti-HBcAg de forma isolada. O principal fator de risco relacionado à infecção viral foi hemotransfusão (31,6%). Contudo, a freqüência de UDI foi maior no grupo com infecção pregressa pelo VHB, em relação aos 117 indivíduos monoinfectados pelo VHC (p<0,05). Não houve diferença estatisticamente significativa quanto ao estadiamento (p=0,40) ou à graduação necroinflamatória histológica (APP, p=0,70) entre esses dois grupos. O tempo de infecção e a taxa de progressão de fibrose também foram semelhantes (p=0,99 e p=0,61, respectivamente). A presença do anti-HBcAg não foi considerada preditora de fibrose hepática avançada (p=0,11), porém identificamos como variáveis independentes o tabagismo acentuado (OR 4,40; IC95%: 1,30-14,87), aumento da ALT (OR 1,01; IC95%: 1,00-1,03), de gamagt (OR 1,01; IC95%: 1,00-1,01) e leucopenia (OR 7,75; IC95%: 2,13-28,23). CONCLUSÃO: A prevalência de infecção pregressa pelo VHB em portadores de infecção crônica pelo VHC foi de 20%, sendo este valor compatível com outros estudos realizados em regiões de endemicidade semelhante. A freqüência do marcador anti-HBcAg isolado foi alta neste grupo, refletindo uma possível supressão da imunidade humoral contra o VHB frente a resposta dirigida ao VHC. A infecção pregressa pelo VHB não parece acentuar ou acelerar o dano histológico hepático no nosso meio. / INTRODUCTION: Hepatitis B (HBV) and C (HCV) virus are the main causers of chronic hepatic disease worldwide. Both viruses share similar transmission routes. In chronic HCV infected patients with serological markers of resolved HBV infection (anti-HBcAg [+] and HBsAg [-]), residual HBV-DNA has been detected through highly sensible techniques in serum, PBMC and hepatocytes (as cccDNA). In fact, anti-HBcAg has been associated with worse prognoses, severe histological liver damage and less sustained virological response to HCV treatment. OBJECTIVE: Assess the relationship between previous HBV infection (anti-HBcAg [+]; HBsAg [-]) in patients with chronic hepatitis C (HCV) and histological damage, considering epidemiological, clinical and laboratorial characteristics of this group in a region of low prevalence for HBV. METHODS: Anti-HBcAg prevalence was evaluated in 574 patients seen during a period of one year in a tertiary center (University of Sao Paulo General Hospital, Sao Paulo, Brazil). Of this group, 215 subjects addressed selection criteria and have been selected for evaluation (98 of 112 carriers of anti-HBcAg and 117 of 462 infected only by HCV). 145 individuals have undergone analysis for identification of predictors of advanced fibrosis through univariate and multivariate stepwise logistic regression. RESULTS: Nineteen-eight subjects with serological markers of previous HBV infection were evaluated. Forty-six (47%) patients had anti-HBcAg in isolated form. The main risk factor for infection was blood transfusion (31,6%). However, the IDU frequency was greater in this group (p<0.05). There was no difference regarding histological staging (fibrosis ranging from 0 to 4, p=0.40) or grading (portal inflammation, p=0.70) compared with subjects infected only by HCV with no markers of HBV infection. The rate of fibrosis progression (in units per year) and the infection length was similar in these two groups (p=0,61 and p=0,99, respectively). Anti-HBcAg was not considered a predictor for advanced fibrosis (p=0.11). However, we identified tobacco smoking (OR 4.40; CI 95%: 1.30-14.87), increased ALT (OR 1.01; CI 95%: 1.00-1.03), increased -gt (OR 1.01; CI 95%: 1.00-1.01) and leucopenia (OR 7.75; CI 95%: 2.13-28.23) as independent variables. CONCLUSION: The prevalence of resolved HBV infection in subjects with chronic hepatitis C was 20%. This result was equivalent to other studies carried out in regions of similar endemicity. The frequency of the isolated anti-HBcAg was higher in this group, reflecting a possible suppression of the humoral immunity against HBV caused by an active immune response directed to HCV. Former and resolved HBV infection does not seem to increase or accelerate histological damage in our geographical area.
286

Avaliação de marcadores sorológicos de proteção e infecção pelo vírus da hepatite B em pessoas vivendo com HIV/Aids, vacinadas previamente para hepatite B / Evaluation of serological markers of infection and protection from hepatitis B virus in people living with HIV previously vaccinated for hepatitis B

Amanda Nazareth Lara 29 May 2017 (has links)
INTRODUÇÃO: A infecção pelo vírus da hepatite B (VHB) é responsável por grande parte das doenças hepáticas crônicas em todo o mundo. Em pessoas vivendo com HIV/Aids (PVHA) a infecção pelo VHB tem maior risco de evolução para cirrose e carcinoma hepatocelular. A vacina da hepatite B é importante na prevenção de doença potencialmente grave, particularmente em PVHA, já que ambos os vírus têm as mesmas vias de transmissão e a coinfecção tem uma alta morbidade. Indivíduos imunocompetentes têm uma boa resposta humoral após uma primeira série de vacina da hepatite B e não há recomendações de rotina para doses de reforço. PVHA podem ter uma pior resposta à vacina da hepatite B, quando comparada à resposta em indivíduos imunocompetentes e a duração da imunidade nesses pacientes é desconhecida. OBJETIVOS: Geral: Avaliar os marcadores sorológicos de proteção e infecção pelo VHB em pacientes adultos vivendo com HIV/Aids, vacinados previamente para hepatite B. Específicos: Avaliar a persistência dos anticorpos anti-HBs em PVHA vacinadas previamente para hepatite B e que apresentaram resposta humoral protetora inicial; avaliar a resposta sorológica à revacinação para hepatite B nos pacientes vacinados previamente e que não apresentaram resposta humoral protetora inicial; investigar a presença de marcadores sorológicos de infecção pelo VHB em PVHA vacinadas previamente para hepatite B. MÉTODOS: Estudo observacional de coorte retrospectiva de PVHA vacinadas primariamente para hepatite B entre 2001 e 2002. Marcadores sorológicos de infecção e proteção para o vírus da hepatite B foram investigados nesses pacientes que ainda estavam em acompanhamento no Serviço de Extensão ao Atendimento de Pacientes HIV/Aids (SEAP), da divisão de Clínica de Moléstias Infecciosas e Parasitárias do Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo entre 2012 e 2014. RESULTADOS: Uma coorte de 121 PVHA foi analisada quanto à soroconversão e persistência do anti-HBs. A maioria era do sexo feminino (54,5%) com média de idade de 50,1 anos. Destes pacientes, 58 (grupo 1) eram inicialmente respondedores à primeira série da vacina (anti- HBs >=10 mUI/mL) e 63 (grupo 2) eram não respondedores. Após um período mediano de avaliação de 11 anos, nenhum dos pacientes teve evidência sorológica de infecção pelo VHB e 41/58 (70.7%) dos inicialmente respondedores mantinham anti-HBs >= 10 mUI/mL. Maior contagem de células T CD4+ e anti-HBs >= 100 mUI/mL, no momento da primeira série vacinal, estiveram associados à persistência de anti-HBs. Durante o período avaliado, 35/63 (55.6%) dos pacientes inicialmente não respondedores (grupo 2) soroconverteram com sucesso (anti-HBs >= 10 mUI/mL) em resposta a uma ou mais doses de reforço vacinal. Foi associado à soroconversão do anti-HBs o número de doses de reforço recebidas. A partir do momento da soroconversão (anti-HBs >=10 mUI/mL), 70 pacientes não receberam nenhuma dose adicional de vacina de hepatite B (grupo 3). Após um período mediano de 10 anos, 54/70 (77,1%) destes indivíduos mantinham anti- HBs >= 10 mUI/mL. CONCLUSÕES: A avaliação dos marcadores sorológicos para VHB em PVHA vacinadas previamente para hepatite B evidenciou: alta persistência de anti-HBs após um período de 10 a 11 anos; doses adicionais de vacina foram capazes de induzir resposta humoral em indivíduos inicialmente não respondedores; não foram detectados marcadores sorológicos de infecção (HbsAg ou Anti-HBc) após 11 anos da vacinação inicial / BACKGROUND: Hepatitis B Virus (HBV) infection is responsible for great part of chronic hepatic diseases worldwide. In people living with HIV (PLHIV), HBV infection has more risk of progressing to cirrhosis and hepatocarcinoma. Hepatitis B vaccine is important in the prevention of a potentially severe disease, particularly in PLHIV, since both viruses have the same routes of transmission and co-infection has greater morbidity. Immunocompetent individuals have a good humoral response after the first hepatitis B vaccine series and no recommendation is made regarding booster doses. PLHIV may have a poor hepatitis B vaccine response, when compared to immunocompetent and the duration of immunity in these patients is unknown. OBJECTIVES: General: Evaluate serological markers of infection and protection from HBV in PLHIV previously vaccinated for hepatitis B. Specific: Evaluate anti-HBs persistence in PLHIV previously vaccinated for HBV who responded to a primary vaccine series; evaluate response to revaccination for hepatitis B in patients who did not respond to first vaccine series; investigate serological markers of infection from HBV in PLHIV previously vaccinated for hepatitis B. METHODS: Observational retrospective study of a PLHIV cohort primarily vaccinated between 2001 and 2002 for hepatitis B. Serological markers of infection and protection from HBV were investigated in those patients who were still attending the HIV/AIDS Patient Care Extension Service at the Clinical Division of Infectious and Parasitic Diseases attached to Hospital das Clínicas at Faculdade de Medicina at Universidade de São Paulo between 2012 and 2014. RESULTS: A cohort of 121 PLHIV was analyzed for seroconversion and persistence of anti-HBs. The majority were female (54.5%) and mean age 50.1 years. From these patients, 58 (group 1) were initially responders to the first vaccine series (anti- HBs >=10 mIU/mL) and 63 (group 2) were non- responders. After a median period of 11 years, none of the patients had serologic evidence of HBV infection and 41/58 (70.7%) of the initially responders had maintained anti-HBs >=10 mIU/mL. Greater CD4+ cell counts and anti- HBs>= 100mIU/mL at the time of first vaccine series were associated with persistence of anti-HBs. During evaluation period, 35/63 (55.6%) of the initially non-responders (group 2) successfully seroconverted (anti-HBs >=10 mIU/mL) in response to one or more booster doses. Booster doses may be effective in PLHIV. Number of booster doses were associated to seroconversion. Seventy of the 121 patients did not receive any further booster doses of hepatitis B vaccine from the time of their seroconversion (anti-HBs >=10 mIU/mL) (group 3). After 10 years of the seroconversion, 54/70 (77,1%) of these individuals has maintained anti- HBs >= 10 mIU/mL. CONCLUSIONS: Evaluation of serological markers for HBV in PLHIV previously vaccinated for hepatitis B showed: strong persistence of anti-HBs after a period of 10 to 11 years; additional vaccine doses elicited humoral response in initially non-responders; there was no serologic evidence of HBV infection (HbsAg ou Anti-HBc) about 11 years after initial vaccination
287

Pathology of hepatitis B-associated chronic liver disease and hepatocellular carcinoma in Hong Kong

Wu, Pui-chee., 胡沛之. January 1984 (has links)
published_or_final_version / Medicine / Master / Doctor of Medicine
288

Sex, drugs and STIs : syphilis infection and hepatitis B vaccine compliance among illicit drug users in Houston /

Sparrow, Passion La Shaunda. Hwang, Lu-Yu. January 2007 (has links)
Thesis (Dr. P.H.)--University of Texas Health Science Center at Houston, School of Public Health, 2007. / "May 2007." Includes bibliographical references.
289

Vorbeugender Gesundheitsschutz für das Personal vor Infektionen mit übertragbaren Erregern / Preventative and safety measures preventing infectious diseases for healthcare professionals

Reinmuth, Lara 05 March 2018 (has links)
No description available.
290

Influência da infecção pregressa pelo vírus da hepatite B em portadores de hepatite C crônica: análise histológica / Influence of previous HBV infection in patients with chronic hepatitis C: histological assessment

Gaspar Lisboa Neto 16 June 2009 (has links)
INTRODUÇÃO: Os vírus das hepatites B (VHB) e C (VHC) são os principais causadores de hepatopatia crônica em todo mundo. Ambos compartilham vias semelhantes de transmissão. Em pacientes portadores crônicos de VHC com sorologia compatível com infecção pregressa pelo VHB (anti-HBcAg[+] e HBsAg [-]), o VHB DNA residual tem sido detectado por técnicas de biologia molecular altamente sensíveis no soro, em células linfomononucleares de sangue periférico e em hepatócitos (como cccDNA), de forma que o anti-HBcAg tem sido associado a pior prognóstico, tanto histológico quanto terapêutico. OBJETIVOS: Analisar a associação entre infecção pregressa pelo VHB nos portadores crônicos do VHC e o dano histológico hepático, além das características epidemiológicas, clínicas e laboratoriais destes pacientes em região de baixa prevalência para o VHB. MÉTODOS: A prevalência do anti-HBcAg foi avaliada em 574 pacientes portadores crônicos de VHC atendidos durante o ano de 2006 no ambulatório de Hepatites Virais do DMIP-HC FMUSP. Deste grupo, foram selecionados 215 pacientes (98 de 112 com anti-HBcAg[+] e 117 de 462 monoinfectados pelo VHC) para análise comparativa. Ainda, 145 indivíduos foram submetidos à análise estatística multivariada, por metodologia de Regressão Logística sequencial, para identificação de possíveis preditores de fibrose avançada. RESULTADOS: Foram avaliados 98 pacientes com marcadores sorológicos de infecção pregressa pelo VHB. Quarenta e seis indivíduos (47%) possuíam o anti-HBcAg de forma isolada. O principal fator de risco relacionado à infecção viral foi hemotransfusão (31,6%). Contudo, a freqüência de UDI foi maior no grupo com infecção pregressa pelo VHB, em relação aos 117 indivíduos monoinfectados pelo VHC (p<0,05). Não houve diferença estatisticamente significativa quanto ao estadiamento (p=0,40) ou à graduação necroinflamatória histológica (APP, p=0,70) entre esses dois grupos. O tempo de infecção e a taxa de progressão de fibrose também foram semelhantes (p=0,99 e p=0,61, respectivamente). A presença do anti-HBcAg não foi considerada preditora de fibrose hepática avançada (p=0,11), porém identificamos como variáveis independentes o tabagismo acentuado (OR 4,40; IC95%: 1,30-14,87), aumento da ALT (OR 1,01; IC95%: 1,00-1,03), de gamagt (OR 1,01; IC95%: 1,00-1,01) e leucopenia (OR 7,75; IC95%: 2,13-28,23). CONCLUSÃO: A prevalência de infecção pregressa pelo VHB em portadores de infecção crônica pelo VHC foi de 20%, sendo este valor compatível com outros estudos realizados em regiões de endemicidade semelhante. A freqüência do marcador anti-HBcAg isolado foi alta neste grupo, refletindo uma possível supressão da imunidade humoral contra o VHB frente a resposta dirigida ao VHC. A infecção pregressa pelo VHB não parece acentuar ou acelerar o dano histológico hepático no nosso meio. / INTRODUCTION: Hepatitis B (HBV) and C (HCV) virus are the main causers of chronic hepatic disease worldwide. Both viruses share similar transmission routes. In chronic HCV infected patients with serological markers of resolved HBV infection (anti-HBcAg [+] and HBsAg [-]), residual HBV-DNA has been detected through highly sensible techniques in serum, PBMC and hepatocytes (as cccDNA). In fact, anti-HBcAg has been associated with worse prognoses, severe histological liver damage and less sustained virological response to HCV treatment. OBJECTIVE: Assess the relationship between previous HBV infection (anti-HBcAg [+]; HBsAg [-]) in patients with chronic hepatitis C (HCV) and histological damage, considering epidemiological, clinical and laboratorial characteristics of this group in a region of low prevalence for HBV. METHODS: Anti-HBcAg prevalence was evaluated in 574 patients seen during a period of one year in a tertiary center (University of Sao Paulo General Hospital, Sao Paulo, Brazil). Of this group, 215 subjects addressed selection criteria and have been selected for evaluation (98 of 112 carriers of anti-HBcAg and 117 of 462 infected only by HCV). 145 individuals have undergone analysis for identification of predictors of advanced fibrosis through univariate and multivariate stepwise logistic regression. RESULTS: Nineteen-eight subjects with serological markers of previous HBV infection were evaluated. Forty-six (47%) patients had anti-HBcAg in isolated form. The main risk factor for infection was blood transfusion (31,6%). However, the IDU frequency was greater in this group (p<0.05). There was no difference regarding histological staging (fibrosis ranging from 0 to 4, p=0.40) or grading (portal inflammation, p=0.70) compared with subjects infected only by HCV with no markers of HBV infection. The rate of fibrosis progression (in units per year) and the infection length was similar in these two groups (p=0,61 and p=0,99, respectively). Anti-HBcAg was not considered a predictor for advanced fibrosis (p=0.11). However, we identified tobacco smoking (OR 4.40; CI 95%: 1.30-14.87), increased ALT (OR 1.01; CI 95%: 1.00-1.03), increased -gt (OR 1.01; CI 95%: 1.00-1.01) and leucopenia (OR 7.75; CI 95%: 2.13-28.23) as independent variables. CONCLUSION: The prevalence of resolved HBV infection in subjects with chronic hepatitis C was 20%. This result was equivalent to other studies carried out in regions of similar endemicity. The frequency of the isolated anti-HBcAg was higher in this group, reflecting a possible suppression of the humoral immunity against HBV caused by an active immune response directed to HCV. Former and resolved HBV infection does not seem to increase or accelerate histological damage in our geographical area.

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