No description available.

Micturition requires the precise reciprocal function of the urinary bladder and urethral outlet. Perhaps due to this degree of precision, micturition is prone to dysfunction with injury or disease. One such disease, interstitial cystitis (IC)/painful bladder syndrome (PBS), is characterized by urinary urgency, frequency and pelvic pain. Inflammation has been implicated as a factor in IC/PBS. The overall hypothesis of this project is that urinary bladder inflammation induces expression of inflammatory mediators and changes neurotrophin receptor expression that contribute to functional changes in the urinary bladder. Using a well-characterized rat model of cyclophosphamide (CYP)-induced urinary bladder inflammation, the expression and function of cyclooxygenase-2 (COX-2), a known inflammatory enzyme, and the p75 neurotrophin receptor (p75NTR), involved in neurotrophin signaling, were examined in micturition reflex pathways using neuroanatomical, biochemical, molecular and physiological techniques. Although COX-2 expression is increased in urinary bladder and involved in bladder hyperreflexia after CYP-induced cystitis, the localization and time course of upregulation was not known. We hypothesized increased COX-2 expression in specific tissue compartments (urothelium or smooth muscle) of the urinary bladder with CYPinduced inflammation. Western blotting for COX-2 showed a significant increase in COX-2 expression in both detrusor and urothelium/suburothelium, with the greatest increase in the urothelium/suburothelium. Immunostaining showed increased COX-2 staining in suburothelium with cystitis, co-localized with CD86, a marker for dendritic cells and macrophages. Nerve growth factor (NGF) has been implicated in inflammation, increased voiding frequency and altered sensation in urinary bladder. The specific NGF tyrosine kinase receptor, TrkA, is increased in bladder afferent cells with CYP. NGF also binds p75NTR. The second goals were to examine the expression and functional role of p75NTR in urinary bladder pathways in control and CYP-treated rats. We hypothesized that p75NTR is constitutively expressed in micturition pathways and upregulated with cystitis. With cystitis, p75NTR expression was increased in lumbosacral spinal cord and in bladder afferent cells in dorsal root ganglia. Western blotting for p75NTR showed increased expression in whole urinary bladder with cystitis. Based on bladder function effects of TrkA blockade with cystitis, we hypothesized that p75NTR blockade in the urinary bladder would also decrease bladder hyperreflexia with cystitis. The functional role of p75NTR was studied by intravesical blockade by immunoneutralization with a monoclonal antibody to p75NTR and by PD90780, known to block NGF-p75NTR binding. Both forms of p75NTR blockade significantly decreased bladder capacity in control and CYP-treated rats. Changes in micturition and threshold pressure, and non-voiding contractions were also demonstrated. In conclusion, these dissertation studies demonstrate that CYP-induced bladder inflammation alters expression of inflammatory mediators and neurotrophin receptors in micturition pathways. This altered expression can affect overall urinary bladder function.

Artificial reefs were installed in Smith Mountain Lake, Virginia, during the summer and fall of 1973 to evaluate the biological effects on the aquatic ecosystem. Virtually all sport fishes were attracted to the reef areas. The frequency of sport fish on the reefs generally coincided with their overall abundance in the reservoir. Sunfishes (Lepomis spp.) and white catfish were the most common. Centrarchid basses were also well represented in the reef sport fish community. Sport fishes were significantly more abundant on the experimental reef sites during both years after reef construction than prior to reef installation. Fishes colonized the reef area on a seasonal basis. Fishes moved onto the reefs in the spring as water warmed and off reefs as temperature cooled in late fall. Centrarchid sunfishes preferred low profile reef units in shallow water (1.5 m) while centrarchid basses preferred high profile reef units in deeper water (4.6-6.1 m). Nest building centrarchid basses spawned adjacent to the reef units while centrarchid sunfishes spawned inshore of the shallowest reef units. Cavern seeking ictalurids were the only sport fish to utilize the reef substrate directly for spawning. They deposited their eggs between the sidewalls of the tire units. The tire reef units resulted in increased primary productivity and nutrient levels of the tire reef periphyton community as compared to the primary productivity and nutrient concentration of the littoral phytoplankton. Periphyton communities attached to the tire reefs were the major food and ultimate source of energy of the reef sport fish community. Installation of artificial tire reefs altered the availability of food to reef fishes and subsequently modified the typical lentic food web in isolated areas of the impoundment. Reef sport fishes utilized the tire reefs extensively as a feeding station during the growing season. Sunfishes converted periphyton and other reef associated food into increased body condition and growth (weight) when compared to fishes from other natural structure types in the reservoir. Therefore, artificial tire reefs in Smith Mountain Lake showed a potential for increasing fish production. Most Peterson disc tagged fishes indicated a strong home range tendency to specific parts (site of original capture) of the multi-component reef. Entanglement of Peterson discs in monofilament fishing line on the bottom of the reservoir caused an important source of tag loss. Seasonal climatic changes in temperature and morphometric features of the basin of Smith Mountain Lake influenced the movement of telemetry equipped largemouth bass. Non-reef largemouth bass showed increased summer movement and utilized uncleared offshore areas of the reservoir while reef bass were more sedentary confining the majority of their summer movement to littoral reef areas. After thermal destratification, behavior of reef and non-reef bass were essentially the same. Both groups of fish moved offshore into deeper water away from the reefs during winter. Underwater biotelemetry techniques were developed to successfully monitor the movement of bluegill for periods up to 30 days or more. Changes in water temperature and to a lesser extent morphometric features of the reservoir influenced bluegill movement. Non-reef bluegill showed increased summer activity and utilized offshore areas while reef bluegill were more sedentary on the reefs during the summer. After thermal destratification bluegill moved to offshore areas. Bass and bluegill moved primarily during daylight hours where periods of peak activity were likely associated with feeding. Internal implantation of transmitters into bass did not appear to affect bass behavior. Surgical effects of transmitter implantation on bluegill apparently had a minimal effect on bluegill behavior. The results of this study show a net beneficial biological effect of artificial reefs on the aquatic ecosystem of Smith Mountain Lake, Virginia, and indicate that artificial reefs placed in structure deficient freshwater lentic environments are a viable fisheries management tool. / Ph. D.

This study examined project stakeholders‘ expectations of a funded enterprise coaching project designed to alleviate symptoms of deprivation in Corby. A mixed method approach of Q study and semi-structured interviews was used to reveal the expectations, behaviours and evaluation of four main groups of stakeholders - the project clients (13); the project delivery team (6); Corby Borough Council (3); and the project funder (1) - a total of 23 participants. Results of the Q study analysis revealed three factors, indicating that stakeholders have different expectations about the project. The semi-structured interviews demonstrated that although stakeholders tried to promote their expectations, their influences were significantly limited by their power to influence decision making. Apart from the dominant project funder, there was no rigorous connection between stakeholders‘ expectations and the project evaluation criteria (time, cost and quality). Triangulated results led to the development of a unique model that incorporates broader stakeholder expectations and promotes distributed power and communication in the decision making process. This model further assists in drawing attention to emerging conflicts and problems as a constant process is developed for future project management.

In these experiments, we primarily investigate the role and source of nerve growth factor (NGF) in peripheral tissues undergoing chronic inflammation. It has been previously determined that there is a significant increase in the levels of NGF following prolonged inflammation of the urinary bladder or the colon, and the first of two projects discussed here mimics this increase with transgenic mice which ectopically produce NGF under control of the smooth muscle alpha-actin promoter. It was determined by this increase that a p75-sensitive increase in sympathetic innervation occurs when an abundance of NGF is produced locally in the descending colon. Sensory innervation in the colon was found to come from two unique populations, one of which increased following heightened NGF levels. The urinary bladders of NGF overexpressing mice were determined to have an increase in sensory axonal density. The second project described here features chemically induced colonic inflammation and observes the nervous and growth factor changes as a response. Transgenic reporter mice are used to observe the cellular source of NGF in the descending colon, which unexpectedly was determined to be Dogiel type II (DgII neurons) based on morphological and chemical characteristics. We report the increase in NGF mRNA and protein observed following a brief 5-day colonic inflammation, and note that there is no increase in axonal density observed. The chemical inflammation did, however, induce an increase in axonal varicosities, used as a measure of axon damage. Finally, a heterozygous null-mutation of NGF was made in a line of transgenic mice to observe changes in local sensory neurons, sympathetic innervation or NGF protein production, but no differences between the heterozygous null mutants and age-matched wild-type siblings were observed. / Thesis (Master, Neuroscience Studies) -- Queen's University, 2013-09-05 12:08:44.326

No description available.

No description available.

Master of Science

L’intégration de la copie ADN du VIH-1 dans le génome d’une cellule infectée est une étape essentielle du cycle réplicatif de ce rétrovirus. Elle est réalisée par une enzyme virale, l’intégrase, qui constitue une cible privilégiée des stratégies antivirales. Différentes études suggèrent une régulation de la sélectivité d’intégration par la chromatine et la transcription. La protéine cellulaire LEDGF/p75, activateur transcriptionnel, interagissant à la fois avec l’intégrase et la chromatine constitue une parfaite illustration de cette régulation.Mon projet de thèse a été d’étudier les liens entre LEDGF/p75, la chromatine et la transcription au cours de l’intégration du VIH-1.Tout d’abord, mes travaux ont permis de valider in vitro l’interaction entre LEDGF/p75 et son partenaire TOX4, récemment identifié par notre équipe. J’ai également montré que le domaine de TOX4, fixant LEDGF/p75, inhibe in vitro l’intégration sur matrice chromatine en présence de LEDGF/p75, suggérant un rôle inhibiteur de TOX4 à l’étape d’intégration du VIH-1.Ensuite, j’ai mis au point des protocoles in vitro de couplage entre l’intégration et la transcription. L’utilisation d’extraits nucléaires pour transcrire par l’ARN polymérase II n’étant pas compatible avec le processus d’intégration, j’ai utilisé l’ARN polymérase T7 purifiée comme machinerie de transcription et étudié les conséquences sur l’intégration. Bien que l’ARN synthétisé inhibe l’intégration, j’ai pu montrer que le passage d’une ARN polymérase sur la matrice d’intégration n’affecte pas l’efficacité globale d’intégration.Enfin, la transcription modifiant la topologie de l’ADN, mon dernier objectif a été d’étudier in vitro l’effet de ce paramètre sur l’intégration. En utilisant des plasmides de différentes formes topologiques comme substrats accepteurs d’intégration, j’ai montré que l’intégration est favorisée sur les formes surenroulées négativement. J’ai également prouvé que cette sélectivité est indépendante de la présence de LEDGF/p75.Mes travaux constituent une étape dans la connaissance des bases moléculaires et mécanistiques de la sélectivité d’intégration du VIH-1 pouvant déboucher sur l’établissement de nouvelles stratégies antirétrovirales. / The integration of the DNA copy of HIV-1 in an infected cell is an essential step of the replication cycle of the retrovirus. It’s performed by a viral enzyme, called integrase, which constitutes a major target of antiviral strategies. Several studies suggest a regulation of integration selectivity by chromatin and transcription. The cellular protein LEDGF/p75, a transcriptional activator, interacting with both integrase and chromatin perfectly illustrates this regulation. My thesis project was to study the links between LEDGF/p75, chromatin and transcription during HIV-1 integration.First, my work validated in vitro the interaction between LEDGF/p75 and its partner TOX4, recently identified by our team. I have also shown that the TOX4 domain, interacting with LEDGF/p75, inhibits integration in vitro on chromatin templates in the presence of LEDGF/p75, suggesting an inhibitory role of TOX4 during the HIV-1 integration step.Then, I developed several in vitro protocols coupling HIV-1 integration and cellular transcription. As RNA polymerase II transcription machinery from Hela nuclear extracts prevents the integration process, I used purified T7 RNA polymerase to perform transcription and studied its consequences on integration. I could show that the synthetized RNA inhibits integration but that the transcription process per se does not affect global integration efficiency on the transcribed template. Since transcription modifies DNA topology, my last goal was to study the effect of this parameter on integration in vitro. Using plasmids of different topological forms as integration acceptor substrates, I showed that integration is enriched in negative supercoiled plasmids. I also proved that this selectivity is independent of the presence of LEDGF/p75. My work constitutes an initial step in understanding the molecular and mechanistic basis of HIV-1 integration selectivity that can lead to the establishment of new antiretroviral strategies.

Thèse numérisée par la Direction des bibliothèques de l'Université de Montréal.