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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.
151

The role of high-risk human papillomavirus in periocular cancers

Afrogheh, Amir H. January 2018 (has links)
Philosophiae Doctor - PhD / Purpose: High risk human papillomavirus (HR-HPV) is well established as a causative agent of squamous cell carcinoma (SCC) of the orophaynx. HR-HPV has also been reported in periocular cancers and precancers, but controversy exists about its overall incidence and clinicopathologic profile. The purpose of this study is to evaluate the role of HR-HPV infection in periocular cancers and precancers, using multiple methods of detection. Design: Retrospective observational case series with laboratory investigations. Methods: Sequential surgical samples of 87 carcinomas (invasive SCC, SCC in situ and sebaceous carcinoma) from three different periocular sites (conjunctiva, lacrimal sac and the eyelid) diagnosed over a 15-year period (2000-2015) were selected for evaluation. Unstained paraffin sections of 87 cases of periocular carcinomas were analyzed with immunohistochemistry (IHC) for p16 as a screening test. p16 positive conjunctival- and lacrimal sac SCC were further evaluated for HR-HPV using DNA in situ hybridization (DNA ISH), and a subset was also analyzed by DNA Polymerase Chain Reaction (DNA PCR). p16 positive periocular sebaceous carcinomas (SC) were analyzed with PCR, and a subset of 18cases was further studied with a novel method of mRNA ISH, an advanced technique with an enhanced sensitivity and specificity. Relevant patient clinical information was obtained from review of the electronic medical records.
152

The role of high-risk human papillomavirus in periocular cancers

Afrogheh, Amir January 2018 (has links)
Philosophiae Doctor - PhD / PURPOSE: High risk human papillomavirus (HR-HPV) is well established as a causative agent of squamous cell carcinoma (SCC) of the orophaynx. HR-HPV has also been reported in periocular cancers and precancers, but controversy exists about its overall incidence and clinicopathologic profile. The purpose of this study is to evaluate the role of HR-HPV infection in periocular cancers and precancers, using multiple methods of detection. DESIGN: Retrospective observational case series with laboratory investigations. METHODS: Sequential surgical samples of 87 carcinomas (invasive SCC, SCC in situ and sebaceous carcinoma) from three different periocular sites (conjunctiva, lacrimal sac and the eyelid) diagnosed over a 15-year period (2000-2015) were selected for evaluation. Unstained paraffin sections of 87 cases of periocular carcinomas were analyzed with immunohistochemistry (IHC) for p16 as a screening test. p16 positive conjunctival- and lacrimal sac SCC were further evaluated for HR-HPV using DNA in situ hybridization (DNA ISH), and a subset was also analyzed by DNA Polymerase Chain Reaction (DNA PCR). p16 positive periocular sebaceous carcinomas (SC) were analyzed with PCR, and a subset of 18cases was further studied with a novel method of mRNA ISH, an advanced technique with an enhanced sensitivity and specificity. Relevant patient clinical information was obtained from review of the electronic medical records.
153

The Cost of Treating Human Papillomavirus-Related Oropharyngeal Cancer

Houston, Karla Smalley 01 January 2019 (has links)
Human papillomavirus (HPV) is a sexually transmitted infection contributing to 70% of oropharyngeal cancers in the United States. The incidence of HPV-related oropharyngeal cancers is greater in Kentucky's population than in any other state. Research has demonstrated the cost of treating oropharyngeal cancer on a national level, but little information exists as to state-specific costs. The purpose of this quantitative study was to examine radiation therapy costs for treating HPV-related oropharyngeal cancer in Kentucky in relation to age, gender, race, and insurance. A theory by Aday and Andersen was applied to explain the relationship between the independent and dependent variables. Cluster sampling was used to randomly select 130 de-identified men and women age 40-65 years who had been diagnosed with oropharyngeal cancer. The data were collected from an existing database. The study used descriptive analysis with correlational, longitudinal data to examine the relationship of categorical and continuous variables. The mean cost for radiation therapy treatment was $123,629.14 (SD= $58,697.36). The multiple regression indicated that the null hypothesis was accepted showing that the independent variables were not statistically significant predictors of the z Score of Cost Difference [F (4,122) = 0.972, p = 0.425]. The results showed no significant independent predictor variables (p > 0.05); gender [t (127) = -0.943, p = 0.348], race [t (127) = 1.378, p = 0.171], insurance type [t (127) = -1.512, p = 0.133], and age group [t (127) = -0.230, p = 0.818]). The results may contribute to positive social change in the development of cancer prevention strategies and policies.
154

Studies on molecular mechanisms of transformation by human papillomavirus : the role of E6 and E5 oncogenes

Gu, Zhengming January 1996 (has links)
No description available.
155

The use of Human Papillomavirus promoters to target Cervical Cancer cells

Lung, Mandy Siu Yu, Biotechnology & Biomolecular Sciences, Faculty of Science, UNSW January 2008 (has links)
Human Papillomavirus (HPV) is one of the most common causes of sexually transmitted disease worldwide. Infections by high-risk HPVs, such as HPV-18, have been associated etiologically with cervical cancer. The successful development of HPV vaccines may be beneficial to the HPV-na??ve population, but women that have already been exposed to the virus are still at risk of developing HPV-associated malignancies. A need for a systemic cure for HPV-infection therefore still exists. Gene therapies using tissue-specific promoters have been reported to be a promising tool for treating cancers; however, few studies have explored this possibility for cervical cancer. The aim of this project is to construct a gene expression vector that can specifically target HPV-infected cervical cancer cells, by making use of the activity and selectivity of the P105 promoter which is determined by transcription control elements within the HPV-18 long control region (LCR). The first part of this study involved the construction of LCR deletion plasmids, and examining the subsequent level of gene expression induced within different mammalian cell lines. The results suggest the LCR to be capable in achieving cervical cancer-specific gene expression. The 3′-end of the viral L1 gene upstream of the LCR appeared to have a repressive effect on the promoter and therefore should be excluded for maximum LCR promoter activity. The second part of the project involved site-directed mutagenesis studies performed on selected transcription factor binding sites with an attempt to further increase the level of LCR promoter activity and specificity towards HPV-infected cervical cancer cells. The results suggest that a GRE/YY1 mutation may significantly enhance promoter activity. In terms of promoter regulation, the E2BSs appeared to be responsible for promoter activation in the absence of viral E2 proteins. The findings of this study suggest a possible gene therapy approach towards the treatment of cervical cancer. By making use of the activity and specificity of the HPV-18 P105 promoter to induce cervical carcinoma-specific expression of appropriate therapeutic genes, suicidal phenotypes can be introduced selectively within HPV-positive cervical cancer cells while normal HPV-negative cells are unaffected.
156

Human papillomavirus prevalence and expression in trophoblastic and cervical cells/Prévalence et expression des papillomavirus humains dans les cellules trophoblastiques et cervicales

Weyn, Christine 08 November 2010 (has links)
Human papillomavirus (HPV) is a double-stranded DNA virus, typically infecting mucosal or cutaneous epithelial keratinocytes. Today, more than 118 different HPV types have been formally described. Sexual transmission of mucosal HPVs is very common and generally asymptomatic, but HPV infection can be associated with benign lesions such as condylomata acuminata or, in rare cases, with malignant lesions such as cervical cancer. Two prophylactic vaccines are currently available in Europe, protecting against HPV-16 and HPV-18 (Cervarix) or against HPV-6, HPV-11, HPV-16 and HPV-18 (Gardasil). In order to assess the impact of the vaccination program, it is mandatory to obtain geographically widespread date on the baseline HPV prevalence and type distribution in cervical samples from women, presenting or not, normal or abnormal cytologic or histologic results. We undertook an epidemiological study in the Capital Region of Brussels to determine the HPV prevalence and type-distribution in 1526 cervical samples of women presenting a cytology within normal limits (WINL), atypical squamous cells of undetermined significance (ASC-US), low-grade squamous intra-epithelial lesions (LSIL), high-grade squamous intra-epithelial lesions (HSIL) or invasive cervical cancer (ICC). The HPV prevalence was 10.8% (95%CI: 8.8-12.8) for NILM, 34.5% (95%CI: 28.3-40.8) for ASC-US, 54.0% (95%CI: 47.4-60.6) for LSIL and 100% for HSIL and ICC. With an HPV-16 and HPV-18 prevalence of 63.3% (95%CI: 44.1-67.7) and 73.5% (95%CI: 63.0-84.0) in mono-infected HSIL and ICC, respectively, HPV 16/18 L1 VLP vaccines would be expected to significantly reduce the management and treatment of women suffering from HSIL and ICC in the Capital Region of Brussels. We also detected HPV-30, HPV-53, HPV-66 and HPV-68 in mono-infected HSIL and ICC samples, possibly providing arguments for the reconsideration of the carcinogenicity of these types. Vertical transmission of HPV was also previously reported, but in most cases one could not exclude a placental contamination by HPV positive cells from an infected birth canal. In order to confirm that the placenta can be infected with HPV, we analysed residual cells from 35 transabdominally obtained placental samples from pregnant women undergoing chorionic villous sampling for screening of suspected foetal abnormalities and found that two samples were positive for HPV-16 and HPV-62, respectively. The clinical importance of these results remains to be elucidated, but the previously observed association between placental HPV infection and pregnancy loss might gain further in importance. HPV gene regulation in placental trophoblastic cells has not been studied so far. We studied the HPV-16 early gene expression regulation in transiently transfected monolayer cultured trophoblastic cells with an HPV-16 long control region (LCR) driven reporter plasmid. We observed important differences in constitutive HPV-16 LCR activities between trophoblastic cell lines and could identify progesterone as an important inducer of HPV-16 early gene expression. Steroid hormones are induced during pregnancy and could therefore lead to an enhanced expression of the E5, E6 and E7 proteins upon placental HPV infection. Since these proteins were previously shown to affect trophoblast adhesion, survival, migration and invasion, their enhanced expression might eventually contribute to pregnancy loss. We furthermore found that the transcription of episomally maintained HPV-16 is not regulated by E2 or E1, but by E5, E6 and/or E7.
157

Normalization and Informed Decision-making in Public Health Programs: A Case Study of HPV Vaccination in Canada

Navaneelan, Tanya 19 November 2012 (has links)
This thesis examined the evidence, policy decision-making, and implementation of HPV vaccination in Canada as a case study to explore normalization versus individualized decision making in public health programs. Mixed methods were used: a systematic review, content analyses and policy document analysis. Overall, the scientific evidence supported an effect of vaccination against HPV infection and precancerous cervical lesions, but evidence regarding cervical cancer incidence or mortality is lacking. Scientific and medical communities appeared optimistic about the vaccine, but cautious about its readiness for routine implementation. Policy decision-making was initially cautious, but shifted towards active program implementation, possibly related to the availability of federal funding. The educational materials and media coverage both sent clearly normalizing messages about HPV vaccination. The discussion suggests that HPV vaccination might be more suited to an individualized than population approach, but many factors coincided to promote its implementation, in Canada, within a traditional public health model.
158

Investigations of equine sarcoids and bovine papillomavirus in Western Canada

Wobeser, Bruce 25 February 2011
Equine sarcoids are the most common skin tumors of horses. Despite being such a common entity, relatively little is known about many features of sarcoid epidemiology or growth. In addition, due to the detection of Bovine Papillomavirus (BPV) DNA of 2 different types, BPV type 1 (BPV1) and BPV type 2 (BPV2), in equine sarcoids BPV has been suggested as the causative agent of sarcoid development. Recently, however, BPV DNA has also been detected in other skin conditions of horses; the significance of this is unclear. Multiple studies to learn more about sarcoids were undertaken.<p> To investigate the epidemiology of sarcoids in horses in Western Canada the records of five veterinary diagnostic laboratories were searched to identify submissions of sarcoids from horses. The submission record and diagnostic reports of 802 separate submissions of equine sarcoids were reviewed for age, breed, and gender of the horse and the number, location and clinical type of sarcoid. Based on these submissions, horses of a wide variety of ages and 23 different equine breeds were affected, within these breeds, Donkeys were overrepresented.<p> The presence of BPV was determined by Polymerase Chain Reaction (PCR). BPV was found in 74 of 96 (77.1%) samples, and using Restriction Fragment Length Polymorphism, BPV1 and BPV2 were identified in these samples. BPV2 was present in 59 (79.7%) of these. Unlike other areas in the world, in Western Canada, equine sarcoids are most commonly associated with BPV2.<p> A second study examined different clinical types of sarcoids to determine if there was differential expression of immunohistochemical markers associated with apoptosis, Cleaved Caspase 3(ClC3), and antiapoptotic factors, B-Cell Lymphoma 2 (Bcl-2) and Survivin. No differences in the expression of any of these markers regardless of BPV type were noted. Survivin was expressed in equine sarcoids of all types and increased levels of expression are associated with more aggressive clinical behaviour.<p> Finally, the location of BPV DNA was determined in both sarcoids and a variety of non-sarcoid inflammatory skin conditions of horses, as well as, normal skin. PCR for BPV DNA was performed on 86 skin biopsies from horses with non-sarcoid skin conditions, as well as, normal skin. BPV DNA was present in 41 of 86 biopsies. These positive samples, in addition to BPV positive sarcoid samples from the earlier study, were dissected into tissue compartments using laser microdissection followed by 2 forms of BPV DNA amplification, PCR and isothermal loop mediated amplification. BPV DNA was more often located in the epidermis of non-sarcoid skin conditions than in sarcoids. In addition, areas of inflammation within the dermis and epidermis were more likely to contain BPV DNA than non-inflamed areas. These results suggest that while BPV is commonly found in equine skin, the location where it is found differs between sarcoids and non-sarcoid samples. When BPV DNA was found in non-sarcoid samples, it was commonly associated with inflammation suggesting that microscopic damage to the epidermal barrier of the skin maybe an adequate predisposing factor to the development of sarcoids.
159

Des algorithmes bioinformatiques pour la recherche des régions génomiques responsables d'une maladie

Badescu, Dunarel January 2009 (has links) (PDF)
L'évolution des espèces est régie par les modifications stochastiques qui ont eu lieu au niveau du code génétique -l'ADN -composé d'une suite de petites molécules (les nucléotides). Selon l'ampleur de ces évènements, il y a d'abord des modifications à petite échelle, impliquant quelques nucléotides -les insertions, délétions et substitutions. Due à l'impossibilité actuelle de différencier les insertions des délétions, on les appelle communément indels. D'un autre coté, il ya des modifications à grande échelle -impliquant parfois des grandes régions génomiques ou des chromosomes. Les modifications à grande échelle les plus fréquentes sont: les duplications, translocations, inversions et délétions. Au cours de ce projet, nous avons développé une méthode de génomique comparée, capable de relier l'information épidémiologique, comme la carcinogenicité et l'invasivité des souches, aux séquences génomiques. Cette méthode permet de détecter des régions statistiquement significatives à analyser plus en détail par des biologistes, tout en étant capable de discriminer ce seuil à l'aide du calcul des p-values. Nous avons utilisé cette méthode dans l'étude du virus du papillome humain et de la bactérie Neisseria Meningitidis, bactérie responsable de la méningite. Pour le virus du papillome humain, notre méthode a été capable de détecter le domaine PDZ, une région du gène E6, qui est une condition sine qua non de la carcinogenicité du produit de ce gène. Au cours des analyses phylogénétiques de cette famille nous avons trouvé une corrélation statistiquement significative entre les événements à petite échelle et les données épidémiologiques. Par la suite nous avons proposé une séquence de tests pour orienter l'analyse statistique de cette corrélation. Nous avons également remarqué que la carcinogenicité est généralement monophylétique, donc issue d'un ancêtre commun. L'arbre phylogénétique inféré est le premier basé sur les génomes entiers, ce qui a permis d'étudier la variabilité des topologies de gènes par rapport à celle du génome. Pour la bactérie Neisseria Meningitidis nous avons montré qu'il est possible de syntoniser les fonctions de discrimination, pour établir la différence entre les régions responsables du maximum d'invasivité et celles qui ont un rôle structural dans ce processus, détection des structures moléculaires connues (i.e. les anses extra cellulaires, dans notre cas). Les résultats de nos travaux ont permis la mise à la disposition de la communauté internationale de deux bases de données, pour le VPH et le Neisseria, respectivement. Ces bases contiennent des régions candidates à être analysées en laboratoire par des biologistes. ______________________________________________________________________________ MOTS-CLÉS DE L’AUTEUR : Algorithme pour la détection des régions carcinogènes, Événements évolutionnaires, Analyse de redondance, Arbre phylogénétique, Conception de vaccin, Mutations, Invasivité, Neisseria Meningitidis, Virus du papillome humain.
160

Investigations of equine sarcoids and bovine papillomavirus in Western Canada

Wobeser, Bruce 25 February 2011 (has links)
Equine sarcoids are the most common skin tumors of horses. Despite being such a common entity, relatively little is known about many features of sarcoid epidemiology or growth. In addition, due to the detection of Bovine Papillomavirus (BPV) DNA of 2 different types, BPV type 1 (BPV1) and BPV type 2 (BPV2), in equine sarcoids BPV has been suggested as the causative agent of sarcoid development. Recently, however, BPV DNA has also been detected in other skin conditions of horses; the significance of this is unclear. Multiple studies to learn more about sarcoids were undertaken.<p> To investigate the epidemiology of sarcoids in horses in Western Canada the records of five veterinary diagnostic laboratories were searched to identify submissions of sarcoids from horses. The submission record and diagnostic reports of 802 separate submissions of equine sarcoids were reviewed for age, breed, and gender of the horse and the number, location and clinical type of sarcoid. Based on these submissions, horses of a wide variety of ages and 23 different equine breeds were affected, within these breeds, Donkeys were overrepresented.<p> The presence of BPV was determined by Polymerase Chain Reaction (PCR). BPV was found in 74 of 96 (77.1%) samples, and using Restriction Fragment Length Polymorphism, BPV1 and BPV2 were identified in these samples. BPV2 was present in 59 (79.7%) of these. Unlike other areas in the world, in Western Canada, equine sarcoids are most commonly associated with BPV2.<p> A second study examined different clinical types of sarcoids to determine if there was differential expression of immunohistochemical markers associated with apoptosis, Cleaved Caspase 3(ClC3), and antiapoptotic factors, B-Cell Lymphoma 2 (Bcl-2) and Survivin. No differences in the expression of any of these markers regardless of BPV type were noted. Survivin was expressed in equine sarcoids of all types and increased levels of expression are associated with more aggressive clinical behaviour.<p> Finally, the location of BPV DNA was determined in both sarcoids and a variety of non-sarcoid inflammatory skin conditions of horses, as well as, normal skin. PCR for BPV DNA was performed on 86 skin biopsies from horses with non-sarcoid skin conditions, as well as, normal skin. BPV DNA was present in 41 of 86 biopsies. These positive samples, in addition to BPV positive sarcoid samples from the earlier study, were dissected into tissue compartments using laser microdissection followed by 2 forms of BPV DNA amplification, PCR and isothermal loop mediated amplification. BPV DNA was more often located in the epidermis of non-sarcoid skin conditions than in sarcoids. In addition, areas of inflammation within the dermis and epidermis were more likely to contain BPV DNA than non-inflamed areas. These results suggest that while BPV is commonly found in equine skin, the location where it is found differs between sarcoids and non-sarcoid samples. When BPV DNA was found in non-sarcoid samples, it was commonly associated with inflammation suggesting that microscopic damage to the epidermal barrier of the skin maybe an adequate predisposing factor to the development of sarcoids.

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