9 resultados para VACCINE CANDIDATES
em Brock University, Canada
Resumo:
Hepatocellular Carcinoma (HCC) is a major healthcare problem, representing the third most common cause of cancer-related mortality worldwide. Chronic infections with Hepatitis B virus (HBV) and/or Hepatitis C virus (HCV) are the major risk factors for the development of HCC. The incidence of HBV -associated HCC is in decline as a result of an effective HBV vaccine; however, since an equally effective HCV vaccine has not yet been developed, there are 130 million HCV infected patients worldwide who are at a high-risk for developing HCC. Because reliable parameters and/or tools for the early detection of HCC among high-risk individuals are severely lacking, HCC patients are always diagnosed at a late stage where surgical solutions or effective treatment are not possible. Using urine as a non-invasive sample source, two different approaches (proteomic-based and genomic-based approaches) were pursued with the common goal of discovering potential biomarker candidates for the early detection of HCC among high-risk chronic HCV infected patients. Urine was collected from 106 HCV infected Egyptian patients, 32 of whom had already developed HCC and 74 patients who were diagnosed as HCC-free at the time of initial sample collection. In addition to these patients, urine samples were also collected from 12 healthy control individuals. Total urinary proteins, Trans-renal nucleic acid (Tr-NA) and microRNA (miRNA) were isolated from urine using novel methodologies and silicon carbide-loaded spin columns. In the first, "proteomic-based", approach, liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS) was used to identify potential candidates from pooled urine samples. This was followed by validating relative expression levels of proteins present in urine among all the patients using quantitative real time-PCR (qRT-PCR). This approach revealed that significant over-expression of three proteins: DJ-1, Chromatin Assembly Factor-1 (CAF-1) and 11 Moemen Abdalla HCC Biomarkers Heat Shock Protein 60 (HSP60), were characteristic events among HCC-post HCV infected patients. As a single-based HCC biomarker, CAF-1 over-expression identified HCC among HCV infected patients with a specificity of 90%, sensitivity of 66% and with an overall diagnostic accuracy of 78%. Moreover, the CAF-lIHSP60 tandem identified HCC among HCV infected patients with a specificity of 92%, sensitivity of 61 % and with an overall diagnostic accuracy of 77%. In the second genomic-based approach, two different approaches were processed. The first approach was the miRNA-based approach. The expression levels of miRNAs isolated from urine were studied using the Illumina MicroRNA Expression Profiling Assay. This was followed by qRT-PCR-based validation of deregulated expression of identified miRNA candidates among all the patients. This approach shed the light on the deregulated expression of a number of miRNAs, which may have a role in either the development of HCC among HCV infected patients (i.e. miR-640, miR-765, miR-200a, miR-521 and miR-520) or may allow for a better understanding of the viral-host interaction (miR-152, miR-486, miR-219, miR452, miR-425, miR-154 and miR-31). Moreover, the deregulated expression of both miR-618 and miR-650 appeared to be a common event among HCC-post HCV infected patients. The results of the search for putative targets of these two miRNA suggested that miR-618 may be a potent oncogene, as it targets the tumor-suppressor gene Low density lipoprotein-related protein 12 (LPR12), while miR-650 may be a potent tumor-suppressor gene, as it is supposed to downregulate the TNF receptor-associated factor-4 (TRAF4) oncogene. The specificity of miR-618 and miR-650 deregulated expression patterns for the early detection of HCC among HCV infected patients was 68% and 58%, respectively, whereas the sensitivity was 64% and 72%, respectively. When the deregulated expression of both miRNAs was combined as a tandem biomarker, the specificity and the sensitivity were 75% and 58% respectively. 111 Moemen Abdalla HCC Biomarkers In the second, "Trans-renal nucleic acid-based", approach, the urinary apoptotic nucleic acid (uaNA) levels of 70ng/mL or more were found to be a good predictor of HCC among chronic HCV infected patients. The specificity and the sensitivity of this diagnostic approach were 76% and 86%, respectively, with an overall diagnostic value of 81 %. The uaNA levels positively correlated to HCC disease progression as monitored by epigenetic changes of a panel of eight tumor-suppressor genes (TSGs) using methylation-sensitive PCR. Moreover, the pairing of high uaNA levels (:::: 70 ng/mL) and CAF-1 over-expreSSIOn produced a highly specific (l 00%) multiple-based HCC biomarker with an acceptable sensitivity of 64%, and with a diagnostic accuracy of 82%. In comparison to the previous pairing, the uaNA levels (:::: 70 ng/mL) in tandem with HSP60 over-expression was less specific (89%) but highly sensitive (72%), resulting in a diagnostic accuracy of 64%. The specificities of miR-650 deregulated expression in combination with either high uaNA content or HSP 60 over-expression were 82% and 79%, respectively, whereas, the sensitivities of these combinations were 64% and 58%, respectively. The potential biomarkers identified in this study compare favorably with the diagnostic accuracy of the a-fetoprotein levels test, which has a specificity of 75%, sensitivity of 68% and an overall diagnostic accuracy of 70%. Here we present an intriguing study which shows the significance of using urine as a noninvasive sample source for the identification of promising HCC biomarkers. We have also introduced new techniques for the isolation of different urinary macromolecules, especially miRNA, from urine. Furthermore, we strongly recommend the potential biomarkers indentified in this study as focal points of any future research on HCC diagnosis. A larger testing pool will determine if their use is practical for mass population screening. This explorative study identified potential targets that merit further investigation for the development of diagnostically accurate biomarkers isolated from 1-2 mL urine samples that were acquired in a non-invasive manner.
Resumo:
In this study, teacher candidates’ experiences, perceptions, and knowledge of multicultural education at 2 Ontario universities were used determine to the effectiveness of their teacher education programs in preparing them to teach in multicultural classrooms. The research also strived to highlight the most effective practices in these programs that contributed to the preparation of teacher candidates for employment in culturally, racially, and ethnically diverse classrooms in Ontario. A questionnaire and interviews were used to determine the effectiveness of the program in preparing them to teach in diverse classrooms. The findings revealed the need for a greater emphasis of multicultural education in teacher education programs at these universities. The data showed that teacher candidates were most critical of the courses and the delivery of the curriculum in relation to multicultural education. Teacher candidates were also concerned with the lack of multicultural education in their practicum placements. In addition, teacher candidates indicated in the questionnaire that they felt competent adapting instruction to the needs of students in multicultural classrooms. However, the results obtained from the interviews were more varied. The interviews highlighted that teacher candidates were hesitant about teaching in culturally diverse classrooms and less likely to state that they were prepared for these teaching environments. As well, many teacher candidates believed their peers were not prepared for multicultural issues. Teacher candidates believed the program could be improved in many ways including specific instruction across all classes, more diverse practicum experiences, guest speakers, case studies, and the creation of new courses that specifically address multicultural education.
Resumo:
The poverty rate in Ontario affects approximately 1 in 6 children. Consequently, many classrooms in the province include students who come from poverty, and teachers are faced with the challenge of providing an equitable education to students who come from economically diverse backgrounds. Because student poverty in our education system is so prevalent, this challenge exists also for teacher candidates who enter the education system and complete their practicums in classrooms that often include students from impoverished backgrounds. This project examined issues of poverty and education and developed a workshop to assist teacher candidates to develop knowledge in this area. The project combined existing pedagogical approaches with participants’ recommendations and developed a workshop that could be delivered to Faculty of Education students. The workshop addresses poverty, the relationship between poverty and education, student academic achievement and well-being, and the relationship between school and home. The goal and hope of the workshop is that teacher candidates will be better prepared when working in economically diverse school environments.
Resumo:
This study used narrative inquiry to shed light on the identity development of teacher candidates who experienced mental health issues during teacher education programs. The study sought to examine (a) stories that teacher candidates tell about being in a teacher education program while experiencing mental health issues; (b) identity development of teachers who have experienced mental health issues; and (c) how narratives of teacher candidates and beginning teachers challenge stereotyping and stigmatization. Through discussion and letter correspondence, the participants and I shared stories that represented our lived experiences. The study explored our stories using the 3 commonplaces of temporality, sociality, and place from a theoretical framework of narrative inquiry. Four themes emerged from the data analysis: the stigmatization of mental health issues; dealing with conflict; the need for a safe and supportive environment; and the complexity of mental health issues. This study contributes to the literature by exploring the lived experiences of teacher candidates and beginning teachers with mental health issues. The narratives inform teacher education programs, the teaching profession, and the mental health field.
Resumo:
The aim of this thesis is to explore the relationship between imagery, technology, and remote adult Aboriginal teacher candidates through the computer software Elluminate Live. It focuses on the implications that the role imagery plays in third generation distance education with these learners and the new media associated therein. The thesis honours the Medicine Wheel teachings and is presented within this cyclical framework that reflects Indigenous philosophies and belief systems. In accordance, Sharing Circle as methodology is used to keep the research culturally grounded, and tenets of narrative inquiry further support the study. Results indicate there are strong connections to curricula enhanced with imagery—most notably a spiritual connection. Findings also reveal that identity associated to geographical location is significant, as are supportive networks. Third generation distance education, such as Elluminate Live, needs to be addressed before Aboriginal communities open the doors to all it encompasses, and although previous literature peers into various elements, this study delves into why the graphical interface resonates with members of these communities. Of utmost importance is the insight this thesis lends to the pedagogy that may possibly evoke a transformative learning process contributing to the success rate of Aboriginal learners and benefit Aboriginal communities as a whole.
Resumo:
In this study, teacher candidates’ perception of their concurrent education program at two Ontario universities were examined, with specific emphasis on how the programs utilized practicum placements, to determine the effectiveness in preparing teacher candidates to teach. This research also strived to uncover the best ways to optimize concurrent teacher education through practicum placements. A questionnaire and interviews were used to uncover teacher candidates’ perceptions at one teacher education program that used full integration of practicum and one that used minimal integration of practicum. The findings revealed that teacher candidates were generally more satisfied with the overall program when there was full integration of practicum. There were statistically significant differences found between the two concurrent programs with regard to practicum time and preparedness and context of the practicum and a highly significant difference found for theory-practice divide. There was also a statistically significant difference (p < .05) observed between the teacher candidates at each university in terms of their beliefs about the need for improvement of their program. Some of the improvements that participants believed could be made to their respective programs included having (a) exceptional mentor teachers and teacher educators, (b) longer placements with a balance of observation and practicum teaching, (c) clear expectations and evaluations of practicum placement, and (d) more distinct connections between theory and practice made within the programs.
Resumo:
This qualitative research project explores the insights of Muslim women as teacher candidates completing pre-service programs in Ontario. Ontario schools cater to students from many ethnic, cultural and religious groups, including a sizable Muslim population. Muslims make up 4.6% of Ontario’s population with the highest concentration of Muslims in the GTA (Statistics Canada, 2011). The Muslim population in Ontario is of a significant enough number that, in a post 9/11 world, it has prompted discussion of how to integrate Muslim populations in Canada. In this research, I explore how Islamophobic sentiment is experienced in Ontario-based teacher education programs. I use Critical Race Theory (CRT) and Critical Race Feminism (CRF) to analyse and deconstruct experiences of female Muslim teacher candidates in pre-service programs. I discuss how Muslims are a racialized group that experience racism as discussed by critical race literature; however, there is a marked difference between how Muslim men and women experience gendered Islamophobia. By using in-depth research-based interviews, I explore how Muslim women perceived diversity, education, accommodations and Islamophobia in pre-service programs. This study adds to the current literature on critical race theory and anti-racist practices in education. Furthermore, this study adds to the voice of Muslim women in the discussion of diversity and inclusivity in educational institutions.
Resumo:
Globally, Prostate cancer (PCa) is the most frequently occurring non-cutaneous cancer, and is the second highest cause of cancer mortality in men. Serum prostate specific antigen (PSA) has been the standard in PCa screening since its approval by the American Food & Drug Administration (FDA) in 1994. Currently, PSA is used as an indicator for PCa - patients with a serum PSA level above 4ng/mL will often undergo prostate biopsy to confirm cancer. Unfortunately fewer than similar to 30% of these men will biopsy positive for cancer, meaning that the majority of men undergo invasive biopsy with little benefit. Despite PSA's notoriously poor specificity (33%), there is still a significant lack of credible alternatives. Therefore an ideal biomarker that can specifically detect PCa at an early stage is urgently required. The aim of this study was to investigate the potential of using deregulation of urinary proteins in order to detect Prostate Cancer (PCa) among Benign Prostatic Hyperplasia (BPH). To identify the protein signatures specific for PCa, protein expression profiling of 8 PCa patients, 12 BPH patients and 10 healthy males was carried out using LC-MS/MS. This was followed by validating relative expression levels of proteins present in urine among all the patients using quantitative real time-PCR. This was followed by validating relative expression levels of proteins present in urine among all the patients using quantitative real time-PCR. This approach revealed that significant the down-regulation of Fibronectin and TP53INP2 was a characteristic event among PCa patients. Fibronectin mRNA down-regulation, was identified as offering improved specificity (50%) over PSA, albeit with a slightly lower although still acceptable sensitivity (75%) for detecting PCa. As for TP53INP2 on the other hand, its down-regulation was moderately sensitive (75%), identifying many patients with PCa, but was entirely non-specific (7%), designating many of the benign samples as malignant and being unable to accurately identify more than one negative.
Resumo:
MicroRNAs (miRNAs) are a class of short (similar to 22nt), single stranded RNA molecules that function as post-transcriptional regulators of gene expression. MiRNAs can regulate a variety of important biological pathways, including: cellular proliferation, differentiation and apoptosis. Profiling of miRNA expression patterns was shown to be more useful than the equivalent mRNA profiles for characterizing poorly differentiated tumours. As such, miRNA expression "signatures" are expected to offer serious potential for diagnosing and prognosing cancers of any provenance. The aim of this study was to investigate the potential of using deregulation of urinary miRNAs in order to detect Prostate Cancer (PCa) among Benign Prostatic Hyperplasia (BPH). To identify the miRNA signatures specific for PCa, miRNA expression profiling of 8 PCa patients, 12 BPH patients and 10 healthy males was carried out using whole genome expression profiling. Differential expression of two individual miRNAs between healthy males and BPH patients was detected and found to possibly target genes related to PCa development and progression. The sensitivity and specificity of miR-1825 for detecting PCa among BPH individuals was found to be 60% and 69%, respectively. Whereas, the sensitivity and specificity of miR-484 were 80% and 19%, respectively. Additionally, the sensitivity and specificity for miR-1825/484 in tandem were 45% and 75%, respectively. The proposed PCa miRNA signatures may therefore be of great value for the accurate diagnosis of PCa and BPH. This exploratory study has identified several possible targets that merit further investigation towards the development and validation of diagnostically useful, non-invasive, urine-based tests that might not only help diagnose PCa but also possibly help differentiate it from BPH.