• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 126
  • 97
  • 15
  • 6
  • 6
  • 5
  • 5
  • 4
  • 2
  • 2
  • 1
  • 1
  • 1
  • 1
  • 1
  • Tagged with
  • 320
  • 320
  • 118
  • 106
  • 97
  • 82
  • 58
  • 51
  • 46
  • 30
  • 28
  • 27
  • 27
  • 26
  • 26
  • 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.
231

Vorklinische Untersuchungen zur Wirkung einer Tumorvakzine in der Therapie Human Papillomvirus-assoziierter Tumorerkrankungen

Hoffmann, Corinna 02 August 2012 (has links)
Neuartige Vakzinierungsstrategien zur Aktivierung einer Tumor-spezifischen zellulären Immunantwort sind vielversprechende Ansätze zur Therapie von Tumoren, insbesondere Human Papillomvirus (HPV)-assoziierte Tumore. Bisherige HPV-Impfstudien zeigen zwar die Aktivierung einer spezifischen zellulären Immunantwort, eine Tumorreduktion bleibt jedoch aus. Um diesen Effekt auf Immunzellebene zu definieren, wurde die Wirkung der HPV-Vakzine Ad p14 im Mausmodell und an Untersuchungsmaterial humaner Tumore analysiert. In Mäusen bildeten sich HPV+ TC1-Tumore einer frühen Entwicklungsphase nach Vakzinierung zurück. Tumore einer späten Entwicklungsphase wuchsen dagegen in zwei Intervallen aus. Immunologische Eigenschaften der Tumorzellen blieben dabei unverändert. Unterschiede zeigten sich in den Frequenzen Tumor-infiltrierender Lymphozyten; in progressiven Phasen wurden nur CD4+ T Zellen nachgewiesen, in Regressionsphasen zusätzlich zytotoxische CD8+ T Zellen. Immunmodulatoren, wie Interferon alpha oder DTA-1, einem Antikörper für den Glucocorticoid-induzierten Tumornekrosefaktor-Rezeptor, unterstützten die Wirkung der Vakzine; letzterer erhöhte die Anzahl zytotoxischer CD8+ T Zellen und führte zur Abstoßung der TC1-Tumore. HPV+ Tumorgewebe des Menschen, wie auch ihre Vorstufen, zeigten im Vergleich zu anderen Tumoren, wie Bronchial oder Kolonkarzinomen einen signifikant höheren Anteil an CD4+ und CD8+ T Zellen und an Forkhead Box P3+ regulatorischen T Zellen. Die Ergebnisse deuten darauf hin, dass die immunologischen Abläufe bei der Entwicklung HPV-assoziierter Tumore mit denen vorangeschrittener chronischer Erkrankungen vergleichbar sind, in denen sich CD4+ und CD8+ T Zellantworten erschöpfen während sich gleichzeitig immunsuppressive Mechanismen verstärken. Um die Entwicklung von Impfstoffen zur Therapie HPV-assoziierter Tumore zu verbessern sollten diese Mechanismen ausführlicher betrachtet werden. / Novel vaccination strategies, activating cellular tumour specific immune responses represent a promising approach for the treatment of cancer. Especially featured for these treatments are tumours evolving from chronic human papillomavirus (HPV) infections. But current strategies have not yet proved efficacious for complete tumour regression. Addressing cellular immunological aspects of tumour vaccination, this work focused on effects of HPV vaccine Ad p14 in mice and in samples of human tumours. In mice vaccination resulted in complete regression of early stage murine HPV+ TC1 tumours. Late stage TC1 tumours increased discontinuously. During that process, TC1 cells preserved their immunological characteristics. But frequencies of tumour-infiltrating lymphocytes varied; in progressing tumours only CD4+ T cells occurred, in temporary regressing tumours also CD8+ T cells were detected. Immune modulators, like interferon alpha or glucocorticoid-induced tumour necrosis factor receptor targeting antibody DTA-1 aggravated the effects of vaccination; latter raised cytotoxic CD8+ T cell numbers and resulted in complete tumour regression. Human HPV+ tumours as well as HPV+ precancerous stages revealed numbers of CD4+ and CD8+ T cells and especially of forkhead box P3+ regulatory T cells that were significantly increased compared to melanoma, bronchial or colon carcinoma. To assist further analysis of human HPV-associated cervical cancer and facilitate studies on therapeutic approaches, a humanized mouse model was established. The present work points to immunological exhaustion in the development of HPV-related tumours comparable to chronic diseases where CD4+ and CD8+ T cells exhaust and immunosuppression by regulatory T cells increases at the same time. For the development of appropriate strategies to enhance efficacy in HPV-associated tumour therapy, further knowledge of mechanisms involved in specific T cell activation, T cell exhaustion and immunosuppression is necessary.
232

Caracterização do infiltrado inflamatório no carcinoma cervical e em suas lesões precursoras. / Characterization of the inflammatory infiltrate in cervical cancer and precursor lesions.

Fernández, Karla Lucía Alvarez 04 May 2016 (has links)
A história natural do câncer cervical invasivo começa com uma infecção produtiva pelo Papiloma vírus humana (HPV) na camada basal do epitélio. Infecções persistentes por vírus de HPVs de alto risco poderão provocar lesões que eventualmente darão origem ao carcinoma invasivo. Sabe-se que o infiltrado inflamatório pode ter um papel importante na evolução da doença. Neste trabalho, quantificamos e caracterizamos fenotipicamente linfócitos T, macrófagos e neutrófilos nas lesões precursoras assim como no carcinoma invasivo. Além disso, para determinar se existia alguma relação entre as populações foi realizada uma análise de correlação entres as populações descritas. Por outro lado, tentando determinar o efeito sistêmico do tumor avaliou-se a frequência de subtipos de monócitos circulantes e através de ensaios alogênicos foi avaliada a capacidade estimuladora das células dendríticas diferenciadas de monócitos circulantes. Os dados apresentados ajudarão a entender o papel que as células do sistema imune podem ter sobre a progressão da doença. / The natural history of cervical cancer begins with a human papilloma virus (HPV) infection of the cells of the basal layer of the epithelium. Persistent infection by high risk HPVs can originate precancerous lesions that may progress to invasive cancer. It has been established the role of the infiltrated inflammatory cells on the progression of the disease. In this work, the phenotype and the frequency of T lymphocytes, macrophages and neutrophils were characterized both in precursor lesions as in invasive carcinoma. In order to stablish a possible relation between the characterized cells, we made a correlation analysis. On the other hand, trying to determine the systemic effect of the tumor we evaluated the frequency of circulating monocyte subtypes and the capacity of dendritic cells to stimulate allogeneic T cells. The data presented will help to understand the role of the immune system cells on the progression of the disease.
233

DETECÇÃO E GENOTIPAGEM DE MÚLTIPLOS TIPOS DO PAPILOMAVÍRUS HUMANO (HPV) EM MULHERES HIV-POSITIVAS E HIV-NEGATIVAS EM GOIÂNIA-GO

Rodrigues, Michelle Christine Carlos 16 September 2011 (has links)
Made available in DSpace on 2016-08-10T10:38:31Z (GMT). No. of bitstreams: 1 MICHELLE CHRISTINE CARLOS RODRIGUES.pdf: 555304 bytes, checksum: 013acceaa7a318df34a1985d5405b098 (MD5) Previous issue date: 2011-09-16 / HIV-infected women are more likely to be infected with high-risk HPV genotypes that have the potential for progressing to cervical cancer. To Know the prevalence of type-specific human papillomavirus (HPV) infections in HIV-infected women is necessary in order to plan effective screening and preventive strategies in such population. Here, we compare the prevalence of infections with multiple HPV types and cytological abnormalities in two groups of women, HIV-positive and HIVnegative, in the city of Goiânia-GO, Brazil. Cervical smears obtained from 57 HIVpositive and 57 HIV-negative women were collected in a preservative medium and submitted to DNA extraction. HPV-DNA detection and genotyping were performed by using the Linear Array HPV Genotyping Test according to the manual provided by the manufacturer. Both groups were similar in regard to social aspects, demographics and behavioral characteristics. HPV DNA was significantly more prevalent in HIV-positive women, compared to HIV-negative women (56.7% vs. 28.3%, p = 0.003). Coinfections with HPV multiple genotypes was also more prevalent in the HIV-positive group (88.2% vs. 58.8%, p = 0.028). HPV16 was the most prevalent in both groups. Cytological abnormalities were observed in 5.3% of HIV-negative women and in 29.8% HIV-positive women. The presence of HPV was significantly associated with cytological abnormalities only in HIV-negative women. Our results demonstrated a greater prevalence of HPV infection in the HIV-positive group of women, with a greater prevalence of infection with multiple genotypes. We here emphasize the need of frequent monitoring of HIV-infected women, in order to allow early detection and efficient treatment for cervical intraepithelial neoplasia (CIN) in this high-risk group. / Mulheres infectadas pelo HIV são mais susceptíveis à infecção por HPVs de alto risco oncogênico, que apresentam um potencial para a progressão para o câncer cervical. Conhecer a prevalência dos tipos específicos do papilomavirus humano nas mulheres HIV infectadas é necessário para planejar um rastreamento eficaz e estabelecer estratégias preventivas em tal população. Aqui, pudemos comparar a prevalência de infecções por múltiplos genótipos de HPV e de alterações citológicas em dois grupos de mulheres, HIV-positivas e HIV-negativas, da cidade de Goiânia- GO, Brasil. Esfregaços cervicais obtidos de 57 mulheres HIV-positivas e 57 mulheres HIV-negativas foram colhidos em meio conservante e enviadas para extração de DNA. A detecção de DNA e genotipagem do HPV foram realizadas usando o Kit Linear Array HPV Genotyping Test, de acordo com o manual fornecido pelo fabricante. Ambos os grupos foram semelhantes no que diz respeito à demografia, aos aspectos sociais e comportamentais. A detecção do DNA de HPV foi significativamente mais prevalente em mulheres HIV positivas, em comparação com as mulheres HIV-negativas (56,7% vs. 28,3%, p = 0,003). Coinfecção por vários genótipos de HPV também foi mais prevalente no grupo de HIV-positivas (88,2% vs. 58,8%, p = 0,028). O HPV16 foi o genótipo mais prevalente em ambos. Anormalidades citológicas foram observadas em 5,3% das mulheres HIV-negativas e 29,8% das mulheres HIV-positivas. A presença de HPV foi significativamente associada com anormalidades citológicas somente nas mulheres HIV-negativas Nossos resultados demonstraram uma maior prevalência de infecção por HPV no grupo de mulheres HIV-positivas, com um elevado número de casos de infecção por vários genótipos. Enfatizamos aqui a necessidade de monitoramento frequente de mulheres infectadas pelo HIV, de modo a permitir o diagnóstico precoce e tratamento eficaz para neoplasia intra-epitelial cervical (NIC) neste grupo de alto risco.
234

DETECÇÃO E GENOTIPAGEM DE HPV EM CARCINOMAS DE CAVIDADE ORAL E OROFARINGE.

Petito, Guilherme 25 June 2014 (has links)
Made available in DSpace on 2016-08-10T10:38:56Z (GMT). No. of bitstreams: 1 GUILHERME PETITO.pdf: 1076353 bytes, checksum: 35ed726e32ffa4f2f32eee9bafc7c8a7 (MD5) Previous issue date: 2014-06-25 / The human papillomavirus (HPV) has been associated with the risk and prognosis of oral cavity and oropharynx carcinomas. This study aimed to estimate the prevalence and genotype distribution of HPV 16 and 18 in oral cavity and oropharyngeal carcinomas, as well as their associations with clinical and histopathological factors of tumors. It is a retrospective descriptive study, with gathered data analysis of 82 medical records and paraffin blocks containing specimens of oral cavity carcinomas and oropharynx diagnosed at the Hospital Araújo Jorge (HAJ), in Goiânia-GO, between 2005 and 2007. The chain reaction polymerase (PCR) was used for HPV detection and genotyping. Among the 82 evaluated patients, 78% were male. The average age of patients was 58 years. Risk factors, like smoking (78 %) and ethylism (70.8 %), were registered in the studied group. HPV DNA was detected in 21 cases (25.6%; 95% CI: 16.9 to 36.6) of which 33.3% were HPV 16 and 14.3% HPV 18. The presence of metastases lymph node and deaths were less common in tumors with HPV, suggesting a better prognosis for these cases, however, the differences between the groups were not statistically significant. The data described in the present study, regarding the presence of the HPV genome, and the high risk oncogenic genotypes, HPV16 and HPV18, in oral cavity and oropharynx carcinomas highlights the importance of vaccination against HPV in such tumours. / O Papilomavírus humano (HPV), tem sido associado com o risco e o prognóstico dos carcinomas da cavidade oral e orofaringe. Este estudo teve como objetivo estimar a prevalência e a distribuição genotípica do HPV 16 e 18 em carcinomas de cavidade oral e orofaringe, bem como suas associações aos fatores clínicos e histopatológicos dos tumores. É um estudo retrospectivo descritivo, com dados coletados análise de 82 prontuários e de blocos de parafina contendo espécimes de carcinomas de cavidade oral e orofaringe diagnosticados no Hospital Araújo Jorge (HAJ), em Goiânia-GO, entre 2005 e 2007. A reação em cadeia da polimerase (PCR) foi usada para detecção e genotipagem do HPV. Dentre os 82 pacientes avaliados, 78% eram do sexo masculino. A média de idade dos pacientes foi de 58 anos. Fatores de risco, como tabagismo (78%) e etilismo (70,8%) foram registrados no grupo estudado. O DNA do HPV foi detectado em 21 casos (25,6%; IC 95%: 16,9 36,6) dos quais 33,3% eram o HPV 16 e 14,3% o HPV 18. A presença de metástases linfonodais e os óbitos foram menos frequentes nos tumores que apresentaram HPV, sugerindo um melhor prognóstico para esses casos, porém, as diferenças entre os grupos não foram estatisticamente significativas. Os dados descritos no presente estudo, com relação à presença do genoma do HPV, incluindo os genótipos de alto risco, HPV16 e HPV18, destacam a importância de vacinação contra o HPV no controle dos carcinomas de cavidade oral e orofaringe.
235

Estudo clínico, citológico e de prevalência do papilomavírus humano em mucosa oral na Anemia de Fanconi / Clinical and cytological assessment and HPV prevalence in oral mucosal cells in Fanconis Anemia

Araujo, Melissa Rodrigues de 26 September 2008 (has links)
A Anemia de Fanconi (AF) é uma doença genética rara de herança recessiva caracterizada por insuficiência da medula óssea, anormalidades de desenvolvimento malformações congênitas. A doença evolui para anemia aplástica grave em decorrência da falência progressiva da medula óssea e neoplasias malignas, principalmente a leucemia mielóide aguda e os carcinomas espinocelulares em região de cabeça e pescoço. O risco de desenvolvimento de neoplasias malignas aumenta após o transplante de medula óssea TMO), e recentemente foi proposta a participação do papilomavírus humano (HPV) na carcinogênese na AF. Neste estudo foram realizados exame físico da boca, coleta de amostras de esfregaços de células epiteliais orais por meio da citologia em base líquida, avaliação quanto à presença de atipias de acordo com a classificação de Papanicolaou, análise citomorfométrica das células epiteliais orais, detecção do HPV por meio de técnicas de PCR e tipificação das amostras positivas por meio de hibridização reversa. A amostra foi dividida em 4 grupos: pacientes com AF transplantados (I) e não transplantados de medula óssea (II), pacientes com Anemia aplástica severa (AAS) transplantados (III) e um grupo de indivíduos saudáveis (controle) (IV). Ao exame físico não foram detectadas lesões malignas. Os resultados mostraram que, em comparação ao grupo controle: a) houve aumento da área do núcleo (NA) das células epiteliais orais na AF e na AAS (p<0,05); b) houve aumento da área do citoplasma (CA) na AF (p<0,05); c) houve diminuição da razão NA/CA na AF em pacientes transplantados (p<0,05), aumento desta na AAS (p<0,05) e ausência de alterações nos pacientes com AF não transplantados de medula óssea; d) foi encontrada alta prevalência do HPV nos pacientes tranplantantados de medula óssea para AF (35%, p<0,05) e AAS (38%, p<0,05), enquanto que nos pacientes com AF não transplantados 27,27%) não houve diferença estatisticamente significativa em relação ao grupo controle 6,25%) e e) o HPV-16, de alto risco para transformação maligna, foi o genótipo mais freqüente (grupo I 71,42%, grupo II 33,33%, grupo III 28,57%, grupo IV 0%). O risco relativo em apresentar a infecção pelo HPV foi maior nos pacientes transplantados, tendo sido influenciado pela idade e pelo tempo de TMO. Em conclusão, estes resultados demonstraram que existem alterações na morfometria das células epiteliais orais na AF e há alta prevalência de HPVs, especialmente HPV-16, na boca de pacientes sem lesões orais malignas. / Fanconis anemia (FA) is a rare recessive genetic disorder characterized by boné marrow failure, developmental malformations and congenital abnormalities. FA progressive bone marrow failure usually evolves to aplastic anemia and malignant neoplasias, especially acute myeloid leukemia and head and neck squamous cell carcinomas. The risk of malignancies is increased after bone marrow transplantation (BMT), and recently the role of human papillomavirus (HPV) in FA carcinogenesis was proposed. We performed an oral examination, liquid based cytology sampling of oral epithelial cells, assessment of atypias according to Papanicolaou classification, cytomorphometric analysis of oral epithelial cells, HPV screening by PCR and genotyping by reverse hybridization. Sample subjects were divided into 4 groups: BMT FA patients (I), not BMT FA patients (II), BMT severe aplastic anemia patients (SAA) and a healthy control group (IV). No malignant lesions were detected on oral examination. In comparison with the control group the results showed: a) an increase in the nuclear area (NA) in oral epithelial cells in FA and SAA (p<0.05); b) an increase in the cytoplasmic area (CA) in FA (p<0.05); c) a decrease in the NA/CA ratio in BMT FA patients (p<0.05), an increase of it in SAA (p<0.05) and no alterations in not BMT FA patients; d) a high HPV prevalence was detected in BMT FA (35%, p<0.05) and SAA patients (38%, p<0.05), whereas in not BMT FA patients (27.27%) there was not a significant statistical difference in comparison with the control group (6.25%) and e) the high risk, HPV-16, was the most frequent genotype (group I 71.42%, group II 33.33%, group III 28.57%, group IV 0%). HPV infection odds ratio adjusted for age and years of BMT showed an increase in HPV infection for both factors. In conclusion, results demonstrated that there were morphometric alterations in oral epithelial cells in FA and a high prevalence of oral HPV, especially HPV-16, in these patients without malignant lesions.
236

Avaliação de citocinas na secreção endocervico-vaginal de pacientes com vaginose bacteriana e papilomavírus humano / Evaluation of cytokines in endocervical-vaginal secretion of patients with bacterial vaginosis

CAMPOS, Ana Claudia Camargo 09 March 2011 (has links)
Made available in DSpace on 2014-07-29T15:25:14Z (GMT). No. of bitstreams: 1 Tese Ana Claudia Camargo Campos.pdf: 1642230 bytes, checksum: 4133de8b8f584001e502d94d537e3e82 (MD5) Previous issue date: 2011-03-09 / The vagina and the cervix are the first immune and physical line of defense against sexually transmitted pathogens. However infectious process in the vagina, caused by potentially pathogenic microorganism such as bacterial vaginosis (BV), are very often. This may be associated with a morbid entity as Human Papillomavirus (HPV). It was evaluated the association between the presence of BV and HPV in the lower female genital tract, identifying the clinical and lab aspects in women who received medical attention at emergency rooms in the city of Goiânia-GO and observed the production of cytokines in endocervical secretions in cases with VB associated with HPV. This study included 173 sexually active women, between 16 and 48 years old, divided into groups: control, with BV and with high and low risk of HPV. A survey was conducted to collect the intrinsic and extrinsic factors associated with the patients. Microbial cultures, vaginal pH, identification of high and low risk of HPV by PCR, and the concentration of cytokines were performed. The result of the research data was submitted to a statistical analysis, calculating the oods ratio, confidence intervals and p of 0,05. Forty seven cases of BV were diagnosed. Besides, the presence of a vaginal pH > 4.5, showed a result statistically significant for the presence of HPV, p = 0.001 was also observed. When analyzing the multivariate logistic regression, the independent risk factors for the presence of VB were: having more than one sexual partner in the last 5 years p<0,001 and have more than 3 sexual intercourses per week p=0,002. But in HPV infection the independent risk factors were: being married p=0,029 and pH &#8804; 4.5 p<0,001 and in the case of high-risk HPV the only independent factor considered was the pH &#8804; 4.5 p= 0,006. Relating HPV infections with high and low risk and the presence of VB with some immune factors by the strength of local cytokines, it was found that, IL-2 and IL-12 were significantly elevated in cases of BV and HPV. The IL-6 was high only for HPV, followed by IFN-gamma and IL-10 although the last two showed a trend towards statistical significance in HPV cases. It was concluded through the univariate analysis that the factors, having more than one sexual partner in the last 5 years, a failure in the use of condoms and the presence of leucorrhoea and dyspaurenia were related to the presence of BV and level of alkaline in the vagina which could possibly predispose to infections HPV, and the immune response Th1-type cytokines in vaginal secretions in the presence of BV and/or HPV may also be similar. / A vagina e a cérvice são as primeiras linhas de defesa física e imunológica contra patógenos sexualmente transmissíveis. No entanto, os processos infecciosos na vagina causados por micro-organismos potencialmente patogênicos como nas vaginoses bacterianas (VB) são muito comuns. Podendo estar associados a uma entidade mórbida como o papilomavírus humano (HPV). Avaliou-se a relação existente entre a presença de VB e o HPV no trato genital inferior, dentificando os aspectos clínicos e laboratoriais das mulheres atendidas em um hospital e em 5 unidades básicas de saúde da cidade de Goiânia-GO e verificou-se a concentração de citocinas na secreção endocervical nos casos com VB e HPV. O estudo incluiu 173 mulheres sexualmente ativas entre 16 e 48 anos de idade, divididas em grupos: controle, com VB e com HPV de alto e baixo riscos. Aplicou-se um questionário onde foram analisados os fatores de riscos extrínsecos e intrínsecos destas pacientes. Realizou-se exames de cultura e identificação microbiana, verificando o pH vaginal, seguido da identificação do HPV de alto e baixo riscos pelo PCR e dosagem de citocinas. Os dados obtidos foram submetidos à análise estatística, com cálculos do odds ratio, intervalo de confiança e p de 0,05. Foram identificados 47 casos de VB. A presença de pH vaginal > 4,5 mostrou resultado estatisticamente significativo ao aparecimento de HPV, p=0,001. Ao se analisar a regressão logística multivariada, os fatores de risco independentes para a presença de VB foram: ter mais de um parceiro sexual nos últimos 5 anos p<0,001 e ter mais de 3 relações sexuais por semana p=0,002. Já na presença de HPV os fatores independentes foram: estado civil casado p=0,029 e pH &#8804; 4,5 p< 0,001 e no caso de ser HPV de alto risco o único fator considerado independente foi o pH &#8804; 4,5 p= 0,006. Ao se relacionar as infecções pelo HPV de alto e baixo risco e pela presença de VB com alguns fatores imunológicos, através da dosagem das citocinas locais, verificou-se que as IL-2 e IL-12 mostraram maior concentração nos casos de VB e HPV se comparadas ao controle. A IL-6 mostrou-se elevada somente para HPV, seguidos pelo IFN-gama e a IL-10 embora estas duas últimas próximas ao estatisticamente significativo. Concluiu-se que na análise univariada que ter mais de um parceiro sexual nos últimos 5 anos e realizar mais de 3 relações sexuais por semana são fatores independentes associados à VB e a alcalinização da vagina provavelmente seja um fator predisponente às infecções pelo HPV e a resposta imune, através das citocinas tipo Th1 da secreção vaginal na presença de VB e/ou HPV, possivelmente seja semelhante.
237

Seleção de motivos semelhantes a  Papilomavírus, a partir de bibliotecas de phage display, que apresentem potencial aplicação translacional / Search for Papillomavirus-like motif with Potential Translational Application Selected by Phage Display

Lanre Precieux Kabir Sulaiman 16 November 2017 (has links)
O vínculo entre papilomavírus humano de alto risco e câncer cervical está bem estabelecido. Apesar da existência de vacinas profiláticas contra infecções pelos tipos mais comuns de HPV, para infecções e tumores causados por esses vírus as alternativas terapêuticas são restritas. Encontramos alguns motivos com homologias para proteínas do HPV de alto risco durante o imunoscreening de uma biblioteca de phage display com soros de participantes HPV-16-soropositivos da coorte Ludwig-McGill. Após enriquecimento das sequências, os bacteriófagos recombinantes foram purificados e amplificados para uso como imunógenos.Usando uma abordagem profilática, nós vacinamos experimentalmente camundongos imunocompetentes com um dos nossos bacteriófagos recombinantes, usando o bacteriófago sem inserto como controle. Estes camundongos foram então desafiados com células tumorais TC-1 (HPV-16 positivas), tendo-se avaliado as respostas imunes disparadas durante a progressão tumoral. Também usamos uma abordagem terapêutica, aonde os camundongos foram primeiro injetados com as células tumorais e imunizados com o bacteriófago após o estabelecimento do tumor. O crescimento tumoral foi monitorado e os tumores, baço e linfonodos foram avaliados quanto à quantidade e qualidade da resposta imunológica. Os testes de ELISA revelaram que todos os camundongos vacinados responderam à imunização com os diferentes bacteriófagos. O crescimento tumoral foi significativamente reduzido nas imunizações profiláticas e terapêuticas, embora a redução do tumor fosse mínima quando os camundongos foram tratados 9 dias após o enxerto. A redução no crescimento tumoral também se traduziu em uma sobrevivência significativamente maior para os camundongos imunizados. Estudos de infiltração celular não revelaram alterações em diversas sub-populações imunes, mas uma tendência de aumento de linfócitos T citotóxicos foi observada nos camundongos imunizados com PEP1 (bacteriófago contendo inserto). A importância deste aumento de CD8 na redução observada do crescimento tumoral foi confirmada utilizando camundongos CD8-knockout, onde a redução do crescimento tumoral previamente observada foi anulada. Foi observado um aumento de taxa CD8:CD4 nos camundongos imunizados e isto é uma indicação de ambiente tumoral citotóxico. Os ensaios de proliferação celular para testar a especificidade do antígeno dos linfócitos dos camundongos imunizados foram, no entanto, inconclusivos; da mesma forma, não pudemos alterar o padrão observado com o uso de adjuvante CpG. A utilidade da técnica de phage display também foi observada neste trabalho experimental. Trabalhos adicionais para entender o mecanismo de ação desses fagos recombinantes no controle do crescimento de tumores causados por HPV e seu potencial imuno-estimulador são necessários / The link between high-risk human papillomavirus and cervical cancer is well established. Despite the existence of prophylactic vaccines against infections by the most common types of HPV, therapeutic alternatives are limited for infections and tumors caused by these viruses. We found some homology motifs for high-risk HPV proteins during the immune-panning of a phage display library with sera from HPV-16- seropositive participants of the Ludwig-McGill cohort. After enrichment of the sequences, the recombinant bacteriophages were purified and amplified for use as immunogens. Using a prophylactic approach, we vaccinated experimentally immunocompetent mice with one of our recombinant bacteriophages using the insertless bacteriophage as a control. These mice were then challenged with TC-1 tumor cells (HPV-16 positive), and the immune responses triggered during tumor progression were evaluated. We also used a therapeutic approach where mice were first injected with tumor cells and immunized with the bacteriophage after tumor establishment. Tumor growth was monitored and tumors, spleen and lymph nodes were evaluated for the quantity and quality of the immune response. ELISA tests revealed that all vaccinated mice responded to immunization with the different bacteriophages. Tumor growth was significantly reduced in prophylactic and therapeutic immunizations, although tumor reduction was minimal when mice were treated 9 days after TC-1 cells grafting. The reduction in tumor growth also translated into a significantly greater survival for the immunized mice. Cell infiltration studies did not reveal changes in several immune subpopulations, but an upward trend in cytotoxic T lymphocytes was observed in mice immunized with PEP1 (insert-containing bacteriophage). The importance of this increase in CD8 in the observed reduction of tumor growth was confirmed using CD8-knockout mice, where the previously observed reduction of tumor growth was abolished. An increase in CD8:CD4 rate was observed in the immunized mice and this is an indication of a cytotoxic tumor environment. Cell proliferation assays to test the antigen specificity of lymphocytes from immunized mice were, however, inconclusive; likewise, we could not change the pattern observed with the use of CpG adjuvant. The usefulness of the phage display technique was also observed in this experimental work. Additional studies to understand the mechanism of action of these recombinant phages in the control of HPV tumor growth and its immunostimulatory potential are warranted
238

Modeling, Design, Fabrication, and Characterization of a Highly Sensitive Fluorescence-based Detection Platform for Point-of-Care Applications

January 2018 (has links)
abstract: Over the past several decades, there has been a growing interest in the use of fluorescent probes in low-cost diagnostic devices for resource-limited environments. This dissertation details the design, development, and deployment of an inexpensive, multiplexed, and quantitative, fluorescence-based lateral flow immunoassay platform, in light of the specific constraints associated with resource-limited settings. This effort grew out of the need to develop a highly sensitive, field-deployable platform to be used as a primary screening and early detection tool for serologic biomarkers for the high-risk human papillomavirus (hrHPV) infection. A hrHPV infection is a precursor for developing high-grade cervical intraepithelial neoplasia (CIN 2/3+). Early detection requires high sensitivity and a low limit-of-detection (LOD). To this end, the developed platform (DxArray) takes advantage of the specificity of immunoassays and the selectivity of fluorescence for early disease detection. The long term goal is to improve the quality of life for several hundred million women globally, at risk of being infected with hrHPV. The developed platform uses fluorescent labels over the gold-standard colorimetric labels in a compact, high-sensitivity lateral flow assay configuration. It is also compatible with POC settings as it substitutes expensive and bulky light sources for LEDs, low-light CMOS cameras, and photomultiplier tubes for photodiodes, in a transillumination architecture, and eliminates the need for expensive focusing/transfer optics. The platform uses high-quality interference filters at less than $1 each, enabling a rugged and robust design suitable for field use. The limit of detection (LOD) of the developed platform is within an order of magnitude of centralized laboratory diagnostic instruments. It enhances the LOD of absorbance or reflectometric and visual readout lateral flow assays by 2 - 3 orders of magnitude. This system could be applied toward any chemical or bioanalytical procedure that requires a high performance at low-cost. The knowledge and techniques developed in this effort is relevant to the community of researchers and industry developers looking to deploy inexpensive, quantitative, and highly sensitive diagnostic devices to resource-limited settings. / Dissertation/Thesis / Doctoral Dissertation Electrical Engineering 2018
239

Skolsköterskors agerande när vårdnadshavare tackar nej till HPV-vaccination för flickor i årskurs 5-6 / School nurses reactions to guardians who decline HPV vaccination for girls in grade 5 or 6

Truedsson, Karin January 2018 (has links)
Introduktion: Humant papillomvirus, HPV, är världens vanligaste sexuellt överförbara infektion. De flesta HPV-infektioner läker ut av sig själva men de kan också bli kroniska och på sikt leda till cellförändringar och cancer. Sedan 2012 erbjuds alla flickor i Sverige vaccination mot HPV för att förhindra livmoderhalscancer, som är den vanligaste HPV-relaterade cancerformen. Vaccinationen utförs av skolsköterskor i årskurs 5-6. Vaccinationstäckningen för HPV-vaccination är dock lägre än för övriga vaccinationer i det svenska barnvaccinationsprogrammet. Skolsköterskorna har en viktig roll när det gäller att bemöta tveksamma vårdnadshavare och att få upp vaccinationstäckningen för att på sikt minska antalet cancerfall orsakade av HPV. Syftet med studien var att beskriva hur skolsköterskor i Halland agerar när vårdnadshavare tackar nej till HPV-vaccination för flickor i årskurs 5-6 och vad de upplever är anledningen till nekande. Metoden som valdes var en webbaserad enkätundersökning bland skolsköterskor på mellanstadieskolor i de sex halländska kommunerna. Enkäten skickades ut till 101 respondenter. Svarsfrekvensen var 56 procent och resultatet visade att skolsköterskorna i Halland inte agerar alls när vårdnadshavare tackar nej till HPV-vaccination för flickor i årskurs 5-6. Det främsta motivet till detta är att skolsköterskorna erbjuder nytt vaccinationstillfälle i senare årskurser. Skolsköterskornas uppfattning är att desinformation på internet, rädsla för biverkningar och flickornas ringa ålder utgör de vanligaste anledningarna för vårdnadshavare att tacka nej. Slutsats:Fortsatt arbete för att stärka skolsköterskorna i sin roll som vaccinationsförespråkare är nödvändig för att öka vaccinationstäckningen för HPV. / Introduction: Human papillomavirus, HPV, is the most common sexually transmitted infection. Most HPV infections disappear without intervention but HPV infection can also become chronic and lead to cancer. Since 2012, all girls in Sweden are offered vaccination against HPV to prevent cervical cancer, the most common HPV-related form of cancer. The vaccination is provided by school nurses in grade 5 or 6. HPV vaccination compliance is lower than other vaccinations in the National Vaccine Program for children in Sweden. School nurses play an important role in encouraging guardians to vaccinate their children, especially those who hesitate, to increase the number of girls getting vaccinated. Increasing compliance via school nurses´ actions can reduce the number of HPV related cancers in the long term. The aim of the study was to describe how school nurses in Halland, a province on the southwest coast of Sweden, react to guardians´ rejection of the HPV vaccination for girls in grade 5 or 6. Also queried was what these nurses hear as the reasons for refusal. The assessment method selected was a web-based survey. The survey link was provided to 101 school nurses at schools teaching 5th and 6th grade in the six municipalities of Halland. The response rate was 56 percent and the results show that the school nurses in Halland do not react at all when guardians decline vaccination. The reasons given are that they believe that vaccinations are voluntary and/or that vaccinations are offered again in later grades. School nurses perceive that disinformation on the internet, fear of side effects and the young age of the girls are the main reasons for guardians´ declining HPV vaccination. Conclusion: Further motivation among school nurses in Halland is needed to increase HPV vaccination compliance.
240

Clonagem, expressão, purificação e caracterização das proteínas do capsídio viral do papilomavírus humano (HPV) / Cloning, expression, purification and characterization of human papillomavirus (HPV) capsid proteins

Chaves, Ágtha de Alencar Muniz 17 December 2012 (has links)
O Câncer Cervical é um importante problema de saúde pública, causando aproximadamente 270 milhões de mortes anuais. Atualmente, esse câncer é o segundo mais comum em mulheres no mundo, com os maiores índices de incidência ocorrendo nos países em desenvolvimento. O Câncer cervical tem como agente etiológico o Papilomavírus Humano (HPV). O vírus possui DNA circular duplo com genes que codificam oito proteínas, E1, E2, E4, E5, E6, E7 (não estruturais), e L1 e L2 (estruturais) que formam o capsídio viral. A proteína L1 quando produzida em sistema heterólgo de expressão tem a capacidade de auto-arranjo em partículas semelhantes ao vírus chamadas de VLPs (\"Vírus like Particles\"), que são a base das vacinas profiláticas disponíveis, Gardasil® e Cervarix®. Neste trabalho, foram produzidas VLPs da proteína L1 do HPV-16 na levedura metilotrófica Pichia pastoris utilizando dois tipos de vetores de expressão para leveduras, um epissomal e outro integrativo, para os trabalhos de purificação. Inicialmente as amostras obtidas ao final da purificação apresentaram degradação e agregação da proteína L1, além de contaminantes. O protocolo de purificação foi modificado e as amostras obtidas no final do processo de purificação não apresentaram degradação e nem agregação da proteína L1, embora ainda tenha sido detectada a presença de contaminantes e, portanto, as amostras obtidas estavam semi-purificadas. Uma segunda abordagem para o desenvolvimento de uma vacina alternativa foi realizada, na qual foram produzidos candidatos vacinais baseados na proteína L2 do Papilomavírus Humano (L2 do HPV-16, L2 do HPV-18 e L2 Multimérica), e também foram expressas proteínas fusionadas ao domínio ZZ de Staphylococcus aureus, utilizado neste caso como adjuvante. Em geral as proteínas de fusão, ainda que apresentando a fusão em sua forma funcional, geraram uma fraca indução de anticorpos IgG e de anticorpos neutralizantes. Pode-se observar uma produção de anticorpos neutralizantes contra pseudovírus homólogos e heterólogos que dependeu da combinação com os adjuvantes utilizados. Numa tentativa de maximizar a eficiência imunológica dos antígenos utilizados, um novo ensaio de imunização foi realizado com uma formulação conjunta contendo três proteínas (L2 do HPV-16, L2 do HPV-18 e L2 Multimérica), sendo também avaliadas as propriedades de três adjuvantes. A combinação da formulação vacinal com os adjuvantes gerou altos níveis de anticorpos L2-específicos, destacando-se as formulações com o hidróxido de alumínio/MPLA e com a vacina celular Pertussis low. Com a utilização desses adjuvantes, os níveis de anticorpos permaneceram elevados a longo termo. Pode-se observar a imunogenicidade de cada um dos antígenos dependeu de sua formulação com os adjuvantes testados. / Cervical cancer is one of the most important problems of public health, causing nearly 270 million deaths annually. Currently, cervical cancer is the second more common type in women worldwide and the highest incidences occuring in developing countries. Human papillomavirus (HPV) are the ethiologic agents of cervical cancer. HPV have a double-stranded circular DNA genome encoding eight viral proteins, E1, E2, E4, E5, E6, E7 (non-structural), and L1, L2 (structural), the last ones forming the viral capsid. L1 protein expressed in heterologous systems self-assembles into VLPs (\"Virus like Particles\"), the base of prophylactic vaccines available commercially, Gardasil and Cervarix. In this work, we produced VLPs of HPV-16 L1 protein in the methylotrophic yeast Pichia pastoris for purification assays. Initially, samples obtained from purification presented degradation and aggregation of L1 protein and also contaminants. The purification protocol was modified and samples obtained in the new process did not present degradation nor aggregation but the presence of some contaminants could still be detected. Therefore, samples obtained were semi-purified. A second approach to the development of an alternative vaccine was performed with the production of vaccine candidates based on the HPV L2 protein (HPV-16 L2, HPV-18 L2 and Multimeric L2) and we also expressed the same proteins fused to Staphyloccocus aureus ZZ domain, using it as an adjuvant. In general, the fused proteins induced low antibodies titer and low neutralizing antibodies titer when compared to other formulations. Neutralizing antibodies elicited against homologous and heterologous pseudovirus depended on the adjuvant used. In another approach, trying to enhance immunologic antigen efficiencies, an immunization assay was performed with a formulation containing L2 HPV- 16, L2 HPV-18 and Multimeric L2 and the properties of three adjuvants were assessed. The vaccine formulations adjuvanted with alum/MPLA and cellular Pertussis low vaccine induced the highest levels of L2-specific antibodies. In addition, the usage of adjuvants maintained the antibody levels in the long term. The immunogenicity of each antigen depends on the adjuvant combination used.

Page generated in 0.0429 seconds