Thesis (MA (Criminology))--University of Pretoria, 2006. / Includes bibliographical references. Available on the Internet via the World Wide Web.

Les virus zoonotiques sont une menace pour les humains à cause de leur capacité à passer des réservoirs animaux à l'homme. La rage est provoquée par un virus zoonotique (Virus de la Rage) qui a de multiples réservoirs animaux. La rage est contractée lors de la morsure par un animal infecté et est incurable et létale après l'apparition des premiers symptômes. Un défi visant à éradiquer la rage chez les chiens à l'horizon 2030 a été proposé. Il imposera de stopper la transmission du virus aux populations de chiens à partir des autres réservoirs animaux. Pour cela, il est essentiel de comprendre les mécanismes de transmission entre hôtes potentiels du virus. Dans notre thèse, nous faisons l'hypothèse que le passage d'un hôte à un autre est lié à la diversité des populations virales chez un hôte donné, appelée "hétérogénéité virale".Pour étudier cette hétérogénéité virale, des méthodes de séquençage des populations virales ont été développées. La transmission du virus de la rage entre chiens a été analysée et un évènement de transmission entre chien et renard a été étudié. Une plus importante hétérogénéité virale a été observée chez le renard après sa contamination par le chien en comparaison avec d'autres renards infectés par des congénères de la même espèce. Ceci suggère que l'hétérogénéité virale est importante dans le phénomène de transmission inter-espèce. Ces résultats sont importants pour améliorer notre compréhension de l'évolution du virus de la rage chez un nouvel hôte et pourront aider les efforts d'éradication de la maladie. / Zoonotic viruses are a threat to humans, jumping from animal reservoirs into humans. Rabies is caused by rabies virus (RABV), a zoonotic virus, with many animal reservoirs. Rabies is contracted from a bite of infected animal and once symptoms appear, death is inevitable. A challenging target date of 2030 to eliminate rabies in dogs has been set. One challenge will be stopping RABV re-entering the dog population from other animal reservoirs. Understanding how RABV switches hosts is important to prevent it happening. In this thesis, I hypothesise that successful host switching is due to the diverse population of viruses within the host termed ‘viral heterogeneity’. To investigate viral heterogeneity, methods to sequence the virus populations within clinical samples were developed. Transmission of RABV within dogs was analysed and a host shift event from dogs to foxes was investigated. High viral heterogeneity was seen in foxes after the host shift than in other foxes, suggesting it is important for a successful host shift. These data will be important to improve our understanding of how viruses evolve in new hosts, helping governments to eradicate disease.

Expression of the Receptor for Advanced Glycation End Products (RAGE) and is upregulated in a several cancers. Based on published studies, we hypothesized that RAGE, when overexpressed in pancreatic cancer cells, will promote cell proliferation and migration. To study the role of RAGE in pancreatic cancer, we selected the human pancreatic cancer cell-line PANC-1, and stably transfected the cells with full length RAGE to generate model cell-lines that overexpress RAGE. We obtained two cell-lines PANC-1 FLR2 and PANC-1 FLR3 and examined the influence of RAGE on cellular properties. A significant increase in proliferation but a reduction in migratory abilities of PANC-1 FLR2 and PANC-1 FLR3 cells was observed. The increase in proliferation and reduction in migration was reverted upon knockdown of RAGE in PANC-1 FLR2 cells with siRNA specific for RAGE. The reduction in migration was supported by the reduced levels of vimentin and several integrins in RAGE transfected cells. Furthermore, we observed a downregulation in FAK, AKT, ERK1/2 and NF-κB activity. Growing evidence supports that RAGE is essential for pancreatic cancer progression. It has also been shown that RAGE facilitates pancreatic tumor cell survival by enhancing autophagy and inhibiting apoptosis. The goal of our study was to determine the effect of RAGE inhibition during gemcitabine chemotherapy on the growth of pancreatic tumor. Hence, we investigated the effect of RAGE inhibitors and their combination with gemcitabine in an orthotopic mouse model of pancreatic cancer using mouse pancreatic cancer cell-line KPC 5508. We used two RAGE inhibitors, an anti-RAGE monoclonal antibody (IgG2A11) and a small molecule RAGE inhibitor (FPS-ZM1). We observed a significant reduction in tumor weights of the mice treated with the combination of IgG2A11 and gemcitabine as compared to gemcitabine alone treated mice. The reduction in tumor growth was accompanied with increase in p62 levels (marker of autophagy) and increase in levels of cleaved PARP (marker of apoptosis). We also observed reduction in HMGB1 and phosphorylation levels of ERK1/2 in tumors from the group treated with the combination as compared to the gemcitabine alone treated group. / North Dakota State University. College of Health Professions / NIH Grant # P20 GM109024 from the National Institute of General Medicine

The aim of this study is to further establish the validity and reliability of the Dula Dangerous Driving Index (DDDI). The reliability and validity of the instrument was investigated by comparing data from a US university sample, a US community sample, and a sample of Belgian traffic offenders. Exploratory and confirmatory factor analysis supported the presence of a four-factor structure with items for Drunk Driving forming a separate scale apart from items for Risky Driving, Negative Cognitive/Emotional Driving and Aggressive Driving. A multi-group confirmatory factor analysis with model constraints supported the validity of the DDDI. Inter-correlations revealed that the DDDI subscales are closely interrelated and uni-dimensionality of the measure was found in all three samples. This suggests the DDDI Total score can be used as a composite measure for dangerous driving. However, the validity of the subscales was demonstrated in the Belgian sample, as specific traffic offender groups (convicted for drunk driving, aggressive driving, speeding) scored higher on corresponding scales (Drunk Driving, Aggressive Driving, and Risky Driving, respectively), indicating that it is clinically meaningful to differentiate the subscales.

No description available.

Receptors for advanced glycation end-products (RAGE) are multi-ligand cell surface receptors highly expressed in the lung that modulate pulmonary inflammation during disease. However, the contributions of RAGE signaling are unknown during pulmonary organogenesis. In order to test the hypothesis that RAGE misexpression adversely affects lung morphogenesis, conditional transgenic mice were generated that over-express RAGE in alveolar type II cells of the lung. When RAGE is over-expressed throughout embryogenesis, severe lung hypoplasia ensues, culminating in perinatal lethality. Flow cytometry and immunohistochemistry employing cell-specific markers for various distal cell types demonstrated anomalies in key epithelial cell populations resulting from RAGE up-regulation through embryonic (E) 18.5. Electron microscopy also identified significant morphological disturbances to distal cell types including separation from the basement membrane. Possible mechanisms leading to the disappearance of pulmonary tissue by increased RAGE expression were then evaluated. A time course of lung organogenesis commencing at E12.5 demonstrated that increased RAGE expression primarily alters lung morphogenesis beginning at E16.5. TUNEL immunohistochemistry and immunoblotting for active caspase-3 confirm a shift toward apoptosis in lungs from RAGE over-expressing mice when compared to wild type controls. Assaying for NF-κB also revealed elevated nuclear translocation in lungs from transgenic mice compared to controls. An RT-PCR assessment of genes regulated by NF-κB demonstrated elevated expression of Fas ligand, suggesting increased activity of the Fas-mediated signal transduction pathway in which ligand-receptor interaction triggers cell death. These data provide evidence that RAGE expression must be tightly regulated during organogenesis. Furthermore, additional elucidation of RAGE signaling potentially involved in branching morphogenesis and cell cycle abnormalities may provide insight into the progression of RAGE-mediated lung diseases.

Receptors for advanced glycation end-products (RAGE) are multi-ligand cell surface receptors of the immunoglobin family expressed by epithelium and macrophages. RAGE expression increases following ligand binding and when diverse cells are exposed to a variety of insults including cigarette smoke extract (CSE). The current research sought to characterize the pro-inflammatory contributions of RAGE expressed by alveolar macrophages (AMs) following CSE exposure. Acute exposure of mice to CSE via nasal instillation revealed diminished bronchoalveolar lavage (BAL) cellularity and fewer AMs in RAGE null mice compared to controls. Primary AMs were obtained from BAL, exposed to CSE in vitro, and RNA, DNA, and protein were analyzed. CSE significantly increased RAGE expression by wild type AMs. Employing ELISAs, wild type AMs exposed to CSE had increased levels of active Ras, a small GTPase that perpetuates pro-inflammatory signaling. Conversely, RAGE null AMs had less Ras activation compared to wild type AMs after exposure to CSE. In RAGE null AMs, assessment of p38 MAPK and NF-κB, important intracellular signaling intermediates induced during an inflammatory response, revealed CSE-induced inflammation occurs at least in part via RAGE signaling. For example, activated p38 was diminished in RAGE null AMs compared to controls and assessment of phosphorylated NF-κB in CSE exposed RAGE null AMs suggest lessened nuclear translocation of NF-κB compared to wild type AMs exposed to CSE. Importantly, quantitative RT-PCR revealed that mRNA expression of pro-inflammatory cytokines including TNF-α and IL-1β were detectably decreased and analysis of secreted proteins by ELISA displayed diminished IL-1β in RAGE null AMs exposed to CSE compared to CSE-exposed wild type AMs. These results reveal that primary AMs orchestrate CSE-induced inflammation, at least in part, via RAGE-mediated mechanisms.

Receptors for advanced glycation end-products (RAGE) are pattern recognition receptors of the immunoglobulin superfamily highly expressed in the lung. Likely functions include the modulation of pulmonary inflammation during disease. However, the contributions of RAGE in the developing lung in cases where secondhand smoke (SHS) exposure occurs are unknown. In order to test the hypothesis that RAGE misexpression adversely affects lung morphogenesis, we exposed gestating dams to a controlled dose of SHS during the last four critical days of in utero lung morphogenesis. We discovered that both maternal and fetal lungs respond to SHS by up-regulating RAGE. Exposed fetuses were markedly smaller compared to controls and lungs were compromised in terms of apoptotic status, collagen abundance necessary in the derivation of respiratory compartments, and the expression of MMP-9, a protease known to target extracellular matrix. Interestingly, RAGE knock out animals similarly exposed to SHS were protected, in part, from the same SHS-mediated pulmonary abnormalities. We next generated a conditional transgenic mouse that provided an opportunity to genetically augment distal lung RAGE expression in the absence of SHS exposure. Our RAGE transgenic mice (RAGE TG) were severely hypoplastic and ultrastructural analysis demonstrated weakened basement membranes in RAGE TG animals compared to controls. Specific observations in RAGE TG mice included diminished type IV collagen required for basement membrane derivation, augmented MMP-9 expression, and inhibition of pulmonary vasculature visualized by Pecam-1 staining, a marker of vascular endothelial cells. The further observation that FoxM1, a critical transcriptional regulator of endothelial cell differentiation, was inhibited in RAGE TG mice suggested a novel potential mechanism of impaired vascularization mediated by RAGE. These data provide evidence that RAGE expression must be tightly regulated during lung organogenesis. Furthermore, additional research into the nuances of RAGE signaling during development may shed needed light on the pathobiochemistry of adult lung diseases that potentially have in utero origins.

The receptor for advanced glycation end-products (RAGE) has increasingly been demonstrated to be an important modulator of inflammation in cases of pulmonary disease. Published reports involving tobacco smoke exposure have demonstrated increased expression of RAGE, its participation in pro-inflammatory signaling and its role in irreversible pulmonary remodeling. The current research evaluated for the first time the in vivo effects of short-term tobacco smoke exposure in RAGE null and control mice compared to identical animals exposed to room air only. Quantitative real time PCR, immunoblotting, and immunohistochemistry revealed elevated RAGE expression in controls after four weeks of exposure and an anticipated absence of RAGE expression in RAGE null mice regardless of smoke exposure. Inflammatory cell behaviors were confirmed by measuring active Ras, NF-κB, and cytokine synthesis and secretion. Furthermore, bronchoalveolar lavage fluid (BALF) was procured from RAGE null and control animals after exposure for the assessment of total protein in order to indirectly measure vascular permeability, inflammatory cells and chemoattractant molecules involved in the inflammatory response. As a general theme, inflammation induced by tobacco smoke exposure was influenced by the availability of RAGE. These data reveal captivating information suggesting a role for RAGE signaling in lungs exposed to tobacco smoke. Furthermore, research may demonstrate RAGE signaling as an important therapeutic target capable of ameliorating cell level inflammation in those coping with exposure.

Mémoire numérisé par la Direction des bibliothèques de l'Université de Montréal.