• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 20
  • 19
  • 5
  • 4
  • 3
  • 3
  • 2
  • 2
  • 1
  • 1
  • Tagged with
  • 78
  • 58
  • 50
  • 28
  • 26
  • 22
  • 22
  • 10
  • 8
  • 8
  • 8
  • 7
  • 7
  • 7
  • 7
  • 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.
51

Kunskap och inställning till HPV och HPV-vaccination bland ungdomar som läser omvårdnadsprogrammet på gymnasiet.

Reimers, Jenny, Brunn, Johanna January 2013 (has links)
Bakgrund    HPV, humant papillomvirus, är den vanligast sexuellt överförbara sjukdomen i världen. HPV kan orsaka kondylom, vilket innebär könsvårtor, men det kan även ge gynekologiska cellförändringar som kan leda till livmoderhalscancer. Syfte            Syftet var att undersöka vilken kunskap och inställning gymnasieelever, som inte ingår i vaccinationsåldern, hade till HPV och HPV-vaccination samt om det fanns några könsskillnader. Metod   En kvantitativ enkätstudie genomfördes på en gymnasieskola i Uppsala, Sverige. Enkätdistribueringen skedde vid två tillfällen och 58 (98,3 %) ifyllda enkäter kunde inhämtas, varav 38 var flickor och 20 var pojkar. Resultat    Flickorna på skolan hade en generellt högre andel rätt svar på enkäten, och totalt var det 21 (55,2 %) av flickorna som var vaccinerade medan endast 1 (5 %) av pojkarna. Av samtliga elever var det 22 (37,9 %) som kunde besvara frågan rätt angående hur många typer av HPV-virus det finns, dock kunde 51 (87,9 %) besvara frågan rätt om hur man skyddar sig mot HPV-viruset. Signifikant könsskillnad hittades i kunskapsfrågan gällande om HPV kan orsaka livmoderhalscancer (p<0,045) där flickorna hade flest rätt svar på frågan. Det var fler vaccinerade flickor jämfört med pojkar (p<0,001) och signifikant fler pojkar som kunde tänka sig att vaccineras (p<0,019). Majoriteten, 68 %, av eleverna var positiva till den befintliga HPV-vaccinationen. Slutsats     Eleverna hade generellt sett en låg kunskapsnivå gällande HPV men trots det var det ändå mer än hälften av flickorna som var vaccinerade. Behov av ytterligare kunskap om HPV och HPV-vaccination till befolkningen behövs. / Background HPV, human papilloma virus, is the most common sexually transmitted disease in the world. HPV can cause genital warts and gynaecological dysplasia, which can lead to cervical cancer. Objective The objective was to describe the amount of knowledge the students had regarding HPV and the HPV-vaccination. Another objective was to describe how many of the students who were vaccinated and to study the existing attitudes towards HPV and the HPV-vaccination. The last objective was to compare whether there was any gender differences. Methods  A quantitative survey study was conduced at an upper secondary school in Uppsala, Sweden. The distribution of the surveys occurred on two occasions and 58 (98,3 %) completed surveys were collected. Results The girls had a generally higher percentage of correct answers on the survey. About 55 % (n=21) of the girls were vaccinated but only 5 %(n=1) of the boys. Regarding how many types of HPV there are 22(37,9 %) of the students answered correctly, although 51 (87,9 %) knew how to protect themselves against a possible infection. Significant differences in gender were found in the question whether HPV can cause cervical cancer or not (p=0,045) and whether the students would be willing to take the vaccine or not (p=0,019). The majority of the students, 68 %, were in favour of the existing HPV vaccination. Conclusion Although the students generally had poor knowledge regarding HPV the majority of the girls had taken the vaccine. The need of further knowledge is vast.
52

Awareness, Knowledge and Attitudes about Human Papilloma Virus among Female tertiary students in South Africa

Admire Takuranenhamo Chikandiwa January 2010 (has links)
<p>The study aimed to describe the knowledge and awareness of HPV infection and vaccine of female university students and to determine the predictors of vaccine acceptability.&nbsp / The study found that 70% of the participants were sexually active. Awareness and knowledge on HPV/vaccine were poor / with only 22% being aware of HPV and that a HPV vaccine was available in South Africa. A greater proportion (80%) reported willingness to be vaccinated. Being aware of the existence of a pap smear, higher knowledge about HPV, higher perceived vaccine effectiveness and higher perceived severity of HPV infection were significantly associated with increased willingness to be vaccinated.</p>
53

Detecção, tipificação e filogenia molecular de Papilomavírus bovino em bovinos leiteiros / Detection, typing and molecular phylogeny of Bovine Papillomavirus in dairy cattle

Albuquerque, Winnie Castro Amorim e 31 March 2017 (has links)
Submitted by Erika Demachki (erikademachki@gmail.com) on 2017-05-05T19:00:03Z No. of bitstreams: 2 Dissertação - Winnie Castro Amorim e Albuquerque - 2017.pdf: 2279498 bytes, checksum: 160e4a276e405c6393dd5bb7742b106b (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Approved for entry into archive by Luciana Ferreira (lucgeral@gmail.com) on 2017-05-10T13:37:01Z (GMT) No. of bitstreams: 2 Dissertação - Winnie Castro Amorim e Albuquerque - 2017.pdf: 2279498 bytes, checksum: 160e4a276e405c6393dd5bb7742b106b (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Made available in DSpace on 2017-05-10T13:37:01Z (GMT). No. of bitstreams: 2 Dissertação - Winnie Castro Amorim e Albuquerque - 2017.pdf: 2279498 bytes, checksum: 160e4a276e405c6393dd5bb7742b106b (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Previous issue date: 2017-03-31 / Outro / Bovine papillomavirus is the etiological agent of bovine papillomatosis, a disease that triggers warts throughout the skin, udder, roofs, genitalia and in more severe cases can develop extensive papillomas, cause neoplasia in the digestive tract and bladder, weaken the animal's health and cause losses in the Productivity and losses for livestock. The present study aims to detect and typify bovine Papillomavirus present in bovine tissue and blood samples with papillomatosis, to sequence the isolated viral types, to analyze the nucleotide sequences and the phylogeny of the detected viral types. As a result, amplification was obtained in five tissue samples (papilloma) from different bovines, not being successful in the amplification of blood samples. PCR reactions revealed the presence of BPV-1 in 60%, BPV-5 in 40%, BPV-9, BPV-10, BPV-13 and BPV-14 in 20% and BPV-12 in 40% of the analyzed samples. The presence of coinfection was verified in 60% of the lesions analyzed, with up to four viral types infecting the same sample. Alignments of viral type sequences 1, 5 and 14 were validated with identity ranging from 74% to 95%. The phylogenetic diagram showed a genetic approximation between viral types 1 and 14, both belonging to the genus Deltapapillomavirus, and distancing between nucleotide sequences of viral types 5, 9 and 14. Papillomaviruses of types 5 and 9 belong to different genera, Epsilonpapillomavirus and Xipapillomavirus, Respectively, the phylogenetic distance between these viral types, verified in the diagram, is justified. / Papilomavírus bovino é o agente etiológico da papilomatose bovina, doença que desencadeia verrugas por toda pele, úbere, tetos, genitália e em casos mais graves pode desenvolver papilomas extensivos, causar neoplasia no trato digestivo e bexiga, debilitar a saúde do animal e provocar perdas na produtividade e prejuízos para a pecuária. O presente estudo possui como objetivo detectar e tipificar Papilomavírus bovino presentes em amostras de tecido e sangue de bovinos com papilomatose, sequenciar os tipos virais isolados, analisar as sequências nucleotídicas e a filogenia dos tipos virais detectados. Como resultado, obteve-se amplificação em cinco amostras de tecido (papiloma) de diferentes bovinos, não obtendo sucesso na amplificação das amostras de sangue. As reações de PCR revelam a presença do BPV-1 em 60%, BPV-5 em 40%, BPV-9, BPV-10, BPV-13 e BPV-14 em 20% e BPV-12 em 40% das amostras analisadas. A presença de coinfecção foi verificada em 60% das lesões analisadas, com até quatro tipos virais infectando a mesma amostra. Os alinhamentos das sequencias do tipo viral 1, 5 e 14 foram validados com identidade variando de 74% a 95%. O diagrama filogenético demonstrou aproximação genética entre os tipos virais 1 e 14, ambos pertencentes ao gênero Deltapapillomavirus, e distanciamento entre as sequências nucleotídicas dos tipos virais 5, 9 e 14. Os papilomavírus dos tipos 5 e 9 pertencem a gêneros diferentes, Epsilonpapillomavirus e Xipapillomavirus, respectivamente, justifica-se dessa forma, a distância filogenética entre esses tipos virais, verificada no diagrama.
54

Prognostic markers in oropharyngeal cancers

Oguejiofor, Kenneth Kenechukwu January 2016 (has links)
Introduction: Human papillomavirus (HPV) is changing the prevalence, survival and treatment paradigms in oropharyngeal squamous cell carcinoma (OPSCC). Improved survival of patients with HPV positive compared to HPV negative OPSCC has led to trials of treatment de-escalation. Current HPV detection methods are imprecise, therefore standardised assessment of transcriptionally active HPV in OPSCC is required. Furthermore, the differences in immune characteristics and/or the hypoxia response/effects could explain observed differences in prognosis between HPV positive and negative OPSCC. Rigorous HPV detection and subsequent biomarker evaluation should provide additional information required before introduction of treatment de-escalation in broad patient groupings. Methods: The study cohort was 218 patients with OPSCC who received radiotherapy with curative intent. HPV status was determined on pre-treatment, formalin-fixed paraffin-embedded blocks using: 1) polymerase chain reaction (PCR); 2) in-situ hybridisation (ISH) and 3) immuno-histochemistry (IHC). QuantiGene multiplex assay was designed to detect mRNA of reference sequences of the common high-risk HPV types (16, 18, 33, 35, 45, 52 and 58). HPV detection methods were compared with mRNA quantification. Multimarker IHC of immune cell markers using chromogenic and fluorescent staining was performed, analysed and compared with single marker IHC using automated multispectral image analysis. A validated multiplex IHC method was used for a) chromogenic (CD3, CD4, CD8, and FoxP3) and b) fluorescent (CD8, CD68 and PD1/PD-L1) evaluation in tumour and stroma compartments. Single marker IHC was used to investigate tumour hypoxia markers (HIF-1α and CA-IX) in HPV positive and negative OPSCC. Results: p16 IHC and ISH were the most sensitive and specific, respectively, for classifying HPV status. The combination of the three tests had the highest positive/negative predictive values compared with QuantiGene mRNA detection. Multiplex validation showed that, for serial sections up to 6 μm apart, there were highly significant correlations (P<0.0001) between single and multiplex counts for both chromogenic and fluorescent IHC. Overall there was less variation in cell counts with fluorescent staining when compared to chromogenic staining. Multiplex IHC of TILs in HPV positive and negative OPSCC showed higher infiltration in both tumour and stromal areas of CD3+CD4+ and CD3+CD8+ T cells but not CD4+FoxP3 Tregs in HPV positive compared with HPV negative OPSCC. Only CD3+CD8+ stromal and not tumour area infiltration was associated with increased survival (P=0.02). PD-L1 expression was higher in HPV negative OPSCC and this was related to macrophage (CD68) expression of PD-L1. In HPV negative tumours infiltration with CD68+PD-L1 was associated with a good prognosis. HPV negative patients had higher expression of HIF-1α but not CA-IX. High expression of both markers was associated with a poor prognosis irrespective of HPV status. Conclusions: There are other prognostic factors operating in the larger subdivision of HPV positive and negative OPSCC. Precise HPV detection and inclusion of other prognostic factors is required before treatment de-escalation is used. Expression of immune inhibitory factors (PD1/PD-L1) alone without contextualisation with immune cell density is insufficient for patient prognostication and potential selection for therapy using immune checkpoint inhibitors. Hypoxia modification of radiotherapy should be explored in both HPV positive and negative OPSCC.
55

Ett brev och många frågor. En kvalitativ studie med receptionsteoretisk analys av kvinnors upplevelser vid mottagandet av HPV-positivt skriftligt resultat från screeningen för livmoderhalscancer.

Liebau, Cornelia January 2019 (has links)
Denna studie undersökte kvinnors upplevelser när de fick ett HPV-positivt screeningresultat brevledes. Den svenska screeningen för förebyggande av livmoderhalscancer meddelar resultatet i ett kort, standardiserat brev. Efter att ha inkluderat humant papillomvirus (HPV) i analysen år 2014 verkade kvinnor bli mer oroliga för resultatet som kunde meddela en sexuellt överförd infektion (STI).En intervjustudie genomfördes med åtta kvinnor och empiriska data analyserades med receptionsteori. Resultaten visade vilka känslor kvinnor kämpade med, om de upplevde en negativ inverkan på deras sexualitet och om de var nöjda med ett brev som kommunikationssätt.Okunnighet om HPV och rädsla för cancer var centrala resultat. Kvinnor beskrev till och med en förändring i attityd till andra sexuella praktiker än vaginalt samlag. Resultatbrevet ansågs vara för kort och inte så informativt som nödvändigt. Detta fick samtliga kvinnor att söka efter mer information främst på internet för att hitta svar på deras frågor.Sammanfattningsvis finns det ett behov av grundlig och strukturerad information relaterad till HPV och påverkan på livmoderhalsen. Personal inom hälso- och sjukvårdssystemet bör vara lyhörda för kvinnors oro över deras screeningresultat. / This study explores women´s experiences when receiving their HPV-positive pap smear result as a letter. The Swedish screening programme for the prevention of cervical cancer notifies of the result in a short, standardised letter. After including human papilloma virus (HPV) in the analysis in 2014 women appeared to become more worried about the result showing a sexually transmitted infection (STI). An interview study was performed with eight women and the empirical data was analysed with reception theory. The study-results show which feelings women struggled with, whether they experienced a negative impact on their sexuality, and whether they were content with a letter as communication method for their results. Ignorance of HPV and fear of cancer were central findings. Women even described a change in attitude towards sexual practices other than vaginal intercourse. The result letter was considered to be too short and not as informative as needed. This caused all the women to look for more information foremost on the internet in order to find answers to their questions.In conclusion there is a need for thorough and structured information related to HPV and impact on the cervix. Healthcare system personnel should have a sensitive ear for women´s concerns about their pap smear results.
56

Optimisation d'un vaccin thérapeutique dans les tumeurs des voies aérodigestives supérieures associées aux papillomavirus : rôle de l'induction d'une immunité muqueuse et de la combinaison à la radiothérapie / Therapeutic vaccine optimisation in human papilloma virus associated head and neck cancer : mucosal immunity induction and radiotherapy combination as new players

Nizard, Mevyn 02 July 2015 (has links)
Le cancer est la seconde cause de mortalité dans le monde et les cancers de localisation muqueuse (poumon, estomac, colorectal, du col de l’utérus, …) représentent la première cause de mortalité due au cancer dans le monde. La majorité des vaccins contre les cancers muqueux n’ont à ce jour, pas montré de résultats cliniques significatifs. Au cours de ce travail, nous avons développé une immunothérapie efficace basée sur la sous-unité B non toxique de la toxine de Shiga et montré pour la première fois dans le domaine de la cancérologie que la localisation de l’immunisation était cruciale pour induire des réponses immunitaires anti-tumorales. En effet, dans un modèle préclinique, une immunisation systémique intramusculaire n’a pas permis d’induire de protection thérapeutique efficace contre le développement de tumeurs muqueuses de la langue, alors que la voie d’immunisation intranasale a induit une réponse clinique complète. Nous avons identifié les lymphocytes T CD8+ comme les cellules nécessaires à cette protection et plus précisément la population de lymphocytes T résidents mémoires (Trm). Ces Trm présentent le phénotype classique CD103+ mais expriment également l’intégrine CD49a qui joue un rôle dans la migration/rétention au sein des tumeurs mais également dans la survie à long terme des Trm. Par ailleurs nous avons montré que les cellules dendritiques muqueuses pulmonaires permettaient d’induire ce phénotype CD49a sur les lymphocytes T CD8+ alors que les cellules dendritiques de la rate non. Notre travail montre que l’aspect quantitatif de ces Trm joue un rôle dans la protection anti-tumorale, en effet nous avons pu pour la première fois moduler in vivo le nombre de Trm en traitant les souris par un anticorps anti-TGF-β. La diminution du nombre des Trm est corrélée à la diminution de la protection anti-tumorale. Les patients atteints de cancers des voies aérodigestives supérieures sont majoritairement traités par radiothérapie. Dans l’optique d’essais cliniques à court terme, nous avons montré que la radiothérapie localisée associée à notre immunothérapie permet une protection plus efficace que le traitement seul de l’un ou de l’autre notamment en provoquant un remodelage du microenvironnement tumoral associé à une normalisation vasculaire. Nos résultats ouvrent de nouvelles perspectives dans le développement d’immunothérapies thérapeutiques efficaces contre les cancers muqueux et pourront mener rapidement à des essais cliniques. / Cancer is the second mortality cause worldwide while mucosal cancers (lung, stomac, …) is the first mortality cause from. The majority of cancer vaccines against mucosal tumors have not given rise yet to significant clinical results. In this work we developed a strong immunotherapy based on the nontoxic subunit B from shiga toxin and showed for the first time that the localization of the immunization is crucial to induce potent and effective anti-tumoral responses. In a preclinical model a systemic immunization failed to induce a therapeutical protection against mucosal tumor challenge while intranasal immunization completely succeed. We identified a CD8 T lymphocyte population as a required cells in this protection and more precisely the T resident memory (Trm) cells. This Trm showed the classical CD103 phenotype as well as the CD49a which can play a specific role in the retention or the migration of this cells in the tumor tissue and might play a role in the survival. We also demonstrate that dendritic cells from the mucosal parenchyma was required to induce the CD49a expression on CD8 T cells while dendritic cells from the spleen was not. Our work shows that the Trm number as an impact in the anti-tumoral protection. We were able to reduce the Trm number in vivo using an anti-TGF-β antibody. This number diminution was correlated with a less efficient anti-tumoral protection. Patients with head and neck cancers are treated with radiotherapy. In this situation we showed that the combination of radiotherapy and our immunotherapy was associated with a better protection than radiotherapy alone or immunotherapy alone thanks to a vascular normalization. These results might rapidly lead to clinical trials and might open new ways to work with immunotherapies.
57

Optimisation d'un vaccin thérapeutique dans les tumeurs des voies aérodigestives supérieures associées aux papillomavirus : rôle de l'induction d'une immunité muqueuse et de la combinaison à la radiothérapie / Therapeutic vaccine optimisation in human papilloma virus associated head and neck cancer : mucosal immunity induction and radiotherapy combination as new players

Nizard, Mevyn 02 July 2015 (has links)
Le cancer est la seconde cause de mortalité dans le monde et les cancers de localisation muqueuse (poumon, estomac, colorectal, du col de l’utérus, …) représentent la première cause de mortalité due au cancer dans le monde. La majorité des vaccins contre les cancers muqueux n’ont à ce jour, pas montré de résultats cliniques significatifs. Au cours de ce travail, nous avons développé une immunothérapie efficace basée sur la sous-unité B non toxique de la toxine de Shiga et montré pour la première fois dans le domaine de la cancérologie que la localisation de l’immunisation était cruciale pour induire des réponses immunitaires anti-tumorales. En effet, dans un modèle préclinique, une immunisation systémique intramusculaire n’a pas permis d’induire de protection thérapeutique efficace contre le développement de tumeurs muqueuses de la langue, alors que la voie d’immunisation intranasale a induit une réponse clinique complète. Nous avons identifié les lymphocytes T CD8+ comme les cellules nécessaires à cette protection et plus précisément la population de lymphocytes T résidents mémoires (Trm). Ces Trm présentent le phénotype classique CD103+ mais expriment également l’intégrine CD49a qui joue un rôle dans la migration/rétention au sein des tumeurs mais également dans la survie à long terme des Trm. Par ailleurs nous avons montré que les cellules dendritiques muqueuses pulmonaires permettaient d’induire ce phénotype CD49a sur les lymphocytes T CD8+ alors que les cellules dendritiques de la rate non. Notre travail montre que l’aspect quantitatif de ces Trm joue un rôle dans la protection anti-tumorale, en effet nous avons pu pour la première fois moduler in vivo le nombre de Trm en traitant les souris par un anticorps anti-TGF-β. La diminution du nombre des Trm est corrélée à la diminution de la protection anti-tumorale. Les patients atteints de cancers des voies aérodigestives supérieures sont majoritairement traités par radiothérapie. Dans l’optique d’essais cliniques à court terme, nous avons montré que la radiothérapie localisée associée à notre immunothérapie permet une protection plus efficace que le traitement seul de l’un ou de l’autre notamment en provoquant un remodelage du microenvironnement tumoral associé à une normalisation vasculaire. Nos résultats ouvrent de nouvelles perspectives dans le développement d’immunothérapies thérapeutiques efficaces contre les cancers muqueux et pourront mener rapidement à des essais cliniques. / Cancer is the second mortality cause worldwide while mucosal cancers (lung, stomac, …) is the first mortality cause from. The majority of cancer vaccines against mucosal tumors have not given rise yet to significant clinical results. In this work we developed a strong immunotherapy based on the nontoxic subunit B from shiga toxin and showed for the first time that the localization of the immunization is crucial to induce potent and effective anti-tumoral responses. In a preclinical model a systemic immunization failed to induce a therapeutical protection against mucosal tumor challenge while intranasal immunization completely succeed. We identified a CD8 T lymphocyte population as a required cells in this protection and more precisely the T resident memory (Trm) cells. This Trm showed the classical CD103 phenotype as well as the CD49a which can play a specific role in the retention or the migration of this cells in the tumor tissue and might play a role in the survival. We also demonstrate that dendritic cells from the mucosal parenchyma was required to induce the CD49a expression on CD8 T cells while dendritic cells from the spleen was not. Our work shows that the Trm number as an impact in the anti-tumoral protection. We were able to reduce the Trm number in vivo using an anti-TGF-β antibody. This number diminution was correlated with a less efficient anti-tumoral protection. Patients with head and neck cancers are treated with radiotherapy. In this situation we showed that the combination of radiotherapy and our immunotherapy was associated with a better protection than radiotherapy alone or immunotherapy alone thanks to a vascular normalization. These results might rapidly lead to clinical trials and might open new ways to work with immunotherapies.
58

Potencial oncogênico de variantes naturais de papilomavírus humano / Oncogenic potential of natural variants of human papillomavirus

Sichero, Laura 19 December 2003 (has links)
O principal fator etiológico da neoplasia do colo do útero é a infecção por HPVs (papilomavírus humano) de alto risco oncogênico, principalmente HPVs 16 e 18. A variabilidade intra-típica de ambos tipos virais tem sido extensivamente estudada. A análise da diversidade genética de isolados oriundos de diferentes regiões dos cinco continentes permitiu traçar a origem e filogenia destes vírus, e sugeriu-se que a evolução destes reflete a relação dos mesmos com seu hospedeiro. Considera-se uma variante molecular de um tipo de HPV um genoma que possui 98% ou mais de identidade nos genes Ll , E6 e E7 com um genoma já descrito. Entretanto, variantes moleculares apresentam aproximadamente 5% de diferença na seqüência da LCR (long contral region). Alguns grupos de pesquisa de diferentes partes do mundo relataram a associação epidemiológica entre variantes específicas de HPVs 16 e 18 e o risco aumentado de infecção persistente e de desenvolvimento de lesão do colo uterino de alto grau. No Brasil foi observada a associação positiva entre variantes não-européias de HPVs 16 e 18 e o risco de lesão do colo uterino em um estudo epidemiológico prospectivo que vem sendo conduzido em São Paulo. Neste estudo foi analisada a atividade transcricional dos promotores P97 e P105 de variantes moleculares de HPVs 16 e 18, respectivamente. A variante asiático-americana de HPV-18, B18-3, apresentou a maior atividade transcricional entre todos os isolados testados. Entre as variantes moleculares de HPV-18, o isolado europeu B18-2 foi o menos ativo transcricionalmente. Entre as amostras de HPV-16, a variante européia B-12 foi a que apresentou a maior atividade transcricional. Foi observado, também, que o promotor P105 de HPV-18 é mais ativo transcricionalmente que o promotor P97. Adicionalmente, foi analisada a capacidade de imortalização de queratinócitos humanos primários por E6/E7 de variantes moleculares de HPV-16. Essas variantes não diferiram muito quanto a eficiência de formação de colônias de queratinócitos crescidos em baixa densidade. Entretanto, a variante asiático-americana gerou um maior número de colônias potencialmente imortalizadas. Esses resultados têm implicações importantes na determinação do risco de desenvolvimento de lesões de colo uterino associadas ao HPV. / Infection by high-risk HPV (human papillomavirus) types, especially HPVs 16 and 18, is the major etiological factor of cervical neoplasia. Intratypic nucleotide variability of both HPV types has been extensively studied. Genetic diversity analyses of isolates from different regions of the five continents permitted to reconstruct the origin and phylogeny of this virus, and suggested that viral evolution reflects the relation between the virus and their host. A molecular variant of HPV possess 98% or more identity in L1, E6 and E7 genes with another viral genome. However, molecular variants have approximately 5% differences within the LCR (long control region). Some research groups from different parts of the world have described the epidemiologic association between specific variants of HPVs 16 and 18 and increased risk of persistent infection and development of squamous intraepithelial lesions. In Brazil, we observed a positive association between non-European variants of HPVs 16 and 18 and risk of cervical lesion in a prospective epidemiologic study that is being conducted in São Paulo. In this study we analyzed P97 and P105 transcriptional activity of molecular variants of HPVs 16 and 18, respectively. The Asian-American variant of HPV-18, B18-3, exhibited the highest transcriptional activity among all isolates tested. Among HPV-18 molecular variants, the B 18-2 European isolate was the less transcriptionally active. Among HPV-16 samples, the B-12 European variant exhibited the highest transcriptional activity. We also observed that the HPV-18 P105 promoter was more active than the HPV-16 P97 promoter. Furthermore, we analyzed the capacity of immortalization of primary human keratinocytes by E6/E7 molecular variants of HPV-16. These variants did not differ much in the efficiency of colony formation by low density keratinocyte plating. However, the Asian-American variant yielded a higher number of colonies potentially immortalized. These results have important implications in the determination of risk for development of HPV -associated cervical lesions.
59

Optimisation d'un vaccin thérapeutique dans les tumeurs des voies aérodigestives supérieures associées aux papillomavirus : rôle de l'induction d'une immunité muqueuse et de la combinaison à la radiothérapie / Therapeutic vaccine optimisation in human papilloma virus associated head and neck cancer : mucosal immunity induction and radiotherapy combination as new players

Nizard, Mevyn 02 July 2015 (has links)
Le cancer est la seconde cause de mortalité dans le monde et les cancers de localisation muqueuse (poumon, estomac, colorectal, du col de l’utérus, …) représentent la première cause de mortalité due au cancer dans le monde. La majorité des vaccins contre les cancers muqueux n’ont à ce jour, pas montré de résultats cliniques significatifs. Au cours de ce travail, nous avons développé une immunothérapie efficace basée sur la sous-unité B non toxique de la toxine de Shiga et montré pour la première fois dans le domaine de la cancérologie que la localisation de l’immunisation était cruciale pour induire des réponses immunitaires anti-tumorales. En effet, dans un modèle préclinique, une immunisation systémique intramusculaire n’a pas permis d’induire de protection thérapeutique efficace contre le développement de tumeurs muqueuses de la langue, alors que la voie d’immunisation intranasale a induit une réponse clinique complète. Nous avons identifié les lymphocytes T CD8+ comme les cellules nécessaires à cette protection et plus précisément la population de lymphocytes T résidents mémoires (Trm). Ces Trm présentent le phénotype classique CD103+ mais expriment également l’intégrine CD49a qui joue un rôle dans la migration/rétention au sein des tumeurs mais également dans la survie à long terme des Trm. Par ailleurs nous avons montré que les cellules dendritiques muqueuses pulmonaires permettaient d’induire ce phénotype CD49a sur les lymphocytes T CD8+ alors que les cellules dendritiques de la rate non. Notre travail montre que l’aspect quantitatif de ces Trm joue un rôle dans la protection anti-tumorale, en effet nous avons pu pour la première fois moduler in vivo le nombre de Trm en traitant les souris par un anticorps anti-TGF-β. La diminution du nombre des Trm est corrélée à la diminution de la protection anti-tumorale. Les patients atteints de cancers des voies aérodigestives supérieures sont majoritairement traités par radiothérapie. Dans l’optique d’essais cliniques à court terme, nous avons montré que la radiothérapie localisée associée à notre immunothérapie permet une protection plus efficace que le traitement seul de l’un ou de l’autre notamment en provoquant un remodelage du microenvironnement tumoral associé à une normalisation vasculaire. Nos résultats ouvrent de nouvelles perspectives dans le développement d’immunothérapies thérapeutiques efficaces contre les cancers muqueux et pourront mener rapidement à des essais cliniques. / Cancer is the second mortality cause worldwide while mucosal cancers (lung, stomac, …) is the first mortality cause from. The majority of cancer vaccines against mucosal tumors have not given rise yet to significant clinical results. In this work we developed a strong immunotherapy based on the nontoxic subunit B from shiga toxin and showed for the first time that the localization of the immunization is crucial to induce potent and effective anti-tumoral responses. In a preclinical model a systemic immunization failed to induce a therapeutical protection against mucosal tumor challenge while intranasal immunization completely succeed. We identified a CD8 T lymphocyte population as a required cells in this protection and more precisely the T resident memory (Trm) cells. This Trm showed the classical CD103 phenotype as well as the CD49a which can play a specific role in the retention or the migration of this cells in the tumor tissue and might play a role in the survival. We also demonstrate that dendritic cells from the mucosal parenchyma was required to induce the CD49a expression on CD8 T cells while dendritic cells from the spleen was not. Our work shows that the Trm number as an impact in the anti-tumoral protection. We were able to reduce the Trm number in vivo using an anti-TGF-β antibody. This number diminution was correlated with a less efficient anti-tumoral protection. Patients with head and neck cancers are treated with radiotherapy. In this situation we showed that the combination of radiotherapy and our immunotherapy was associated with a better protection than radiotherapy alone or immunotherapy alone thanks to a vascular normalization. These results might rapidly lead to clinical trials and might open new ways to work with immunotherapies.
60

Estudo clínico, epidemiológico, histológico de papilomas de mucosa oral e sua relação com Papilomavírushumano (HPV) através das técnicas de hibridização in situ e  PCR / Clinic, epidemiologic, histologic study of oral papillomas and its relation to Humanpapillomavirus (HPV) by In Situ Hybridization and PCR

Tancredi, Angelo Rafael Calabria 07 December 2007 (has links)
O Papilomavírushumano (HPV) é um DNA vírus do grupo papovavírus, que é altamente transmissível sexualmente, sendo bastante encontrado na região anogenital e mucosa oral. A sua implantação oral pode ser por auto-inoculação ou pelo contato oro-sexual. As principais manifestações orais associadas ao HPV são: papiloma, condiloma acuminado, verruga vulgar e hiperplasia epitelial focal. O papiloma é uma lesão epitelial associada ao HPV e pode ocorrer em vários locais da mucosa oral. Histopatologicamente, o papiloma oral é caracterizado por coilocitose, disceratose, papilomatose, hiperceratose e acantose. A literatura ressalta a importância do estudo dessas lesões, uma vez que estudos demonstram que mesmo com os achados macroscópicos e histológicos serem compatíveis com a presença do vírus, somente técnicas de detecção podem comprovar a presença viral.O objetivo deste estudo foi verificar a presença do HPV, por meio das técnicas de hibridização in situ e PCR, em lesões diagnosticadas histopatologicamente como papilomas e comparar esses resultados com características clínicas e histológicas. Cinqüenta casos foram selecionados da Disciplina de Patologia Bucal e da Disciplina de Estomatologia Clínica da FOUSP. Esta seleção de 50 casos foi submetida à reação de hibridização in situ, e 10 casos dentre os mesmos por técnica da PCR e 100% casos foram negativos. Nenhuma das características histológicas previamente analisadas puderam formar estreita relação com a hibridização in situ e PCR. Conclui-se que a análise histopatológica ao HE não se correlaciona com os resultados das técnicas de hibridização in situ e PCR, porém importante ressaltar para detecção do HPV nas lesões estudadas é imprescindível o uso de técnicas de Biologia Molecular otimizadas como a hibridização in situ e PCR realizadas nesse estudo. / The Humanpapillomavirus (HPV) is a DNA virus from the group of papovavirus, which is highly sexually transmitted and it can be often found in the anogenital area and in the oral mucosal. The oral implantation can be by self-inoculation or by the oral sexual contact. The main oral appearances associated to HPV are: papilloma, condylomata acuminata, verruca vulgaris and focal epithelial hyperplasia. Papilloma is an epithelial lesion that is associated to HPV and can occurs in many places of the oral mucosal. Histopathologically, the oral papilloma is characterized by koylocitosis, dyskeratosis, papillomatosis, hyperkeratosis and acanthosis. The literature shows the importance of these lesions once studies show that macroscopic and histologic founds suggest the presence of the virus, only detection technics can prove the viral presence. The target of this study is to check the presence of HPV, by means of In situ hybridization and PCR, in lesions diagnosed histopathologically as papillomas and compare these results with clinic and histologic features. Fifty cases were selected from the Discipline of Oral Pathology and the Discipline of Oral Diagnose of FOUSP. This selection of 50 cases were submitted to the reaction of In situ hybridization, and 10 cases among the same by PCR and 100% of the cases were negative. None of the histologic features were previously analyzed could form a narrow relation with the In situ hybridization and PCR. Therefore it is concluded that the histopathologic analysis to HE do not correlate with the results of the In situ hybridization and PCR, however the detection of the HPV in the studied lesions it is absolutely necessary the use of Molecular Biology techniques as the In situ hybridization and PCR done in this study.

Page generated in 0.0297 seconds