Arthritis includes many conditions of the joints characterized by inflammation, pain, and loss of joint function that affect 66 million people in the U.S. alone. During arthritic degeneration, chondrocytes exhibit downregulated synthesis of extracellular matrix molecules and upregulation of proteolytic enzymes. Fibrochondrocytes, found in meniscal fibrocartilage, appear to behave in a similar way. Metalloproteinases, including matrix metalloproteinases (MMP) and a disintegrin and metollproteinase with thrombospondin motif (ADAMTS) class enzymes have demonstrated efficient, distinct aggrecan degradation in models of arthritis. ADAMTS-4 and ADAMTS-5 are thought to be primary mediators of pathologic aggrecan catabolism, while MMP-17 may be involved in ADAMTS activation. There is also growing evidence of metalloproteinase-independent mechanisms in aggrecan catabolism. The cysteine endopeptidase m-calpain has been detected in cartilage from arthritic joints, and chondrocytes can secrete this protease. The overall objective of this work was to investigate metalloproteinases and m-calpain as comediators of aggrecan turnover in articular cartilage and meniscal fibrocartilage. The central hypothesis was that metalloproteinases cooperate with m-calpain to mediate cytokine-induced aggrecan turnover and associated changes in tissue mechanics. Experiments involved using inhibitors to perturb protease systems, antibodies targeting aggrecan neoepitopes to characterize enzyme activity, and established methods of evaluating tissue compressive and shear properties. Models of degradation and de novo tissue assembly were used to investigate tissue-specific differences in aggrecan turnover. The results of this work demonstrate tissue-specific differences in the abundance and structure of aggrecan, and indicate that the mechanisms and extent of aggrecan processing in the meniscus is dependent on location within the tissue. The relationships between aggrecan structure and tissue material properties are discussed, along with implications for development, disease, and repair.

The incidence rate of chronic hepatopathy in Taiwan is high, which afflicts the patients by progressively developing irreversible cirrhosis. Hepatic fibrosis is the intermediate and crucial stage of this process, characterized by reversibility. If treated properly in this stage, cirrhosis can be successfully prevented. In the liver, activated stellate cells are the key mediators of fibrosis. Transforming growth factor-

La Fibrose Kystique, causée par des mutations du canal CFTR, mène à la dysfonction du transport des fluides et des ions causant la déshydratation du liquide de surface des voies aériennes et ainsi une défaillance de la clairance mucocilliaire. Ce défaut entraine l’accumulation et l’épaississement du mucus au niveau des bronches qui devient alors un environnement idéal pour le développement d’infections chroniques et d’inflammation qui sont associées à la destruction progressive de l’épithélium chez les patients Fibrose Kystique. Même si leur rôle dans les processus lésionnels est très bien connu, l’impact de médiateurs inflammatoires sur la capacité de réparation ne l’est cependant pas. L’objectif de ma maitrise était donc d’étudier la régulation des mécanismes de réparation de l’épithélium bronchique sain et Fibrose Kystique par le facteur de nécrose tumoral (TNF)-alpha, une cytokine pro-inflammatoire cruciale dans l’initiation et la propagation de la réponse inflammatoire chez les patients FK. À l’aide d’un modèle de plaies mécaniques, nous avons montré que le TNF-alpha stimule la réparation de l’épithélium bronchique sain (NuLi-1) et Fibrose Kystique (CuFi-1). De façon surprenante, l’exposition chronique au TNF-alpha augmente cette stimulation tout comme le taux de migration cellulaire pendant la réparation. Cette augmentation de réparation semble être médiée par l’activation de la métalloprotéinase MMP-9, la relâche d’EGF par les cellules épithéliales et ainsi l’activation de la voie d’EGFR. De plus, l’activation de la réparation par le TNF-alpha semble aussi impliquer l’activation des canaux K+, dont nous avons démontré le rôle important dans la réparation. Contrairement à son effet sur la migration cellulaire et sur la réparation, le TNF-alpha diminue la prolifération cellulaire. En somme, en plus de son rôle dans les processus lésionnels, le TNF-alpha semble avoir un rôle complexe dans les processus de réparation puisqu’il stimule la migration et ralentit la prolifération cellulaire. / Cystic fibrosis (CF) pathology, caused by mutations of cftr gene, leads to ion and fluid transport dysfunction that results in mucus thickening and accumulation in the airways. This mucus accumulation promotes bacterial infection and airway inflammation associated with progressive airway epithelial damage in CF patients, unfortunately leading to respiratory failure. However, the effect of inflammatory products on the repair capacity of respiratory epithelia is unclear. Thus, the objective of my project was to study the regulation of normal and CF bronchial epithelial repair mechanisms by tumor necrosis factor-alpha (TNF)-alpha, a major component of inflammation initiation and propagation in CF. With a wound healing model, we observed that TNF-alpha stimulated the non-CF (NuLi-1) and CF (CuFi-1) bronchial wound healing rate. Surprisingly, chronic exposure to TNF-alpha enhanced this stimulation as well as the migration rate during repair. This wound healing rate stimulation by TNF-alpha seems to be due to metalloproteinase MMP-9 activation, EGF shedding by epithelial cells and subsequent EGFR transactivation. Furthermore, we recently reported a crucial relationship between the EGF response and K+ channel function, both controlling bronchial repair. We now show that TNF-alpha wound healing stimulation also implicated KvLQT1 and KATP currents activation. In contrast to its effect on cell migration, TNF-alpha downregulate cell proliferation. Thus, in addition to its recognized role in the inflammatory response leading to epithelial injury, TNF-a could exert complex actions on repair mechanisms of CF airway epithelia by upregulating cell migration while downregulating proliferation.

In 2005 Prince Edward Island’s plebiscite on replacing the single member plurality (SMP) voting system with a mixed member proportional (MMP) voting system was defeated. In New Brunswick a similar referendum, recommended by the Commission on Legislative Democracy in 2004, was never held. This thesis investigates media coverage of these recent electoral reform initiatives in Prince Edward Island and New Brunswick. Specifically, it examines local newspaper coverage of each province’s electoral reform initiatives and analyses the findings to determine if the newspapers demonstrated any bias for or against the implementation of a new voting system. It concludes that in each province the local newspaper media demonstrated a pro-electoral reform position, though there was considerable variation between the newspapers with respect to the breadth of coverage, the amount of bias and how that bias was articulated to readers. / Graduate

As major effector cells of the innate immune response, macrophages must adeptly migrate from blood to infected tissues. Endothelial transmigration is accomplished by matrix metalloproteinase (MMP)-induced degradation of basement membrane and extracellular matrix components. The classical activation of macrophages with LPS and IFN-γ causes enhanced microtubule stabilization and secretion of MMPs. Macrophages upregulate MMP-9 expression and secretion upon immunological challenge, and require its activity for migration during inflammatory response. However, the dynamics of MMP-9 production and intracellular distribution, as well as the mechanisms responsible for its trafficking, are unknown. Using immunofluorescent imaging, we localized intracellular MMP-9 to small Golgi-derived cytoplasmic vesicles that contain calreticulin and PDI, in activated macrophages. Vesicular organelles of MMP-9 aligned along stable subsets of microtubules and colocalized with the anterograde molecular motor protein, kinesin. We demonstrated a functional contribution of stable MTs in the enhanced trafficking of MMP-9 extracellularly, and showed that heterogeneity exists in macrophage cell populations with respect to MMP-9 production.

Breast cancer is characterized in part by chronic inflammation and tissue remodelling in the mammary gland. Adipocyte enhancer binding protein 1 (AEBP1), a pro-inflammatory protein, is up-regulated in breast cancer and enhances cytokine secretion in the mammary tumour microenvironment. AEBP1 over-expression in cultured macrophages resulted in increased enzymatic activity of MMP-9, a matrix metalloproteinase implicated in processing cytokines and stimulating tumour cell growth and mobility. MMP-9 activates the cytokine tumour necrosis factor-alpha (TNF?), and is required for the transformation of epithelial cells by the cytokine interleukin 6 (IL6). Treatment of epithelial cells with TNF? and IL6, both of which promote tumourigenesis, induced AEBP1 expression. Chromatin immunoprecipitation results suggested AEBP1 induction is directly mediated by pro-inflammatory transcription factors NF-?B and STAT3, downstream effectors of TNF? and IL6, respectively. AEBP1 induction may enhance inflammation, thereby contributing to cell proliferation and survival.

As major effector cells of the innate immune response, macrophages must adeptly migrate from blood to infected tissues. Endothelial transmigration is accomplished by matrix metalloproteinase (MMP)-induced degradation of basement membrane and extracellular matrix components. The classical activation of macrophages with LPS and IFN-γ causes enhanced microtubule stabilization and secretion of MMPs. Macrophages upregulate MMP-9 expression and secretion upon immunological challenge, and require its activity for migration during inflammatory response. However, the dynamics of MMP-9 production and intracellular distribution, as well as the mechanisms responsible for its trafficking, are unknown. Using immunofluorescent imaging, we localized intracellular MMP-9 to small Golgi-derived cytoplasmic vesicles that contain calreticulin and PDI, in activated macrophages. Vesicular organelles of MMP-9 aligned along stable subsets of microtubules and colocalized with the anterograde molecular motor protein, kinesin. We demonstrated a functional contribution of stable MTs in the enhanced trafficking of MMP-9 extracellularly, and showed that heterogeneity exists in macrophage cell populations with respect to MMP-9 production.

This thesis focuses on applying microfluidic techniques to analyze two carbon management methods; underground carbon sequestration and enhanced oil recovery. The small scale nature of microfluidic methods enables direct visualization of relevant pore-scale phenomena, enabling elucidation of parameters such as diffusion coefficients and critical compositions. In this work, a microfluidic platform was developed to control a two-phase carbon dioxide (CO2)-water interface for diffusive quantification with fluorescent techniques. It was found that the diffusion coefficient of CO2 in pure water was constant (1.86 [± 0.26] x10-9 m2/s) over a range of pressures. The effects of salinity on diffusivity were also measured in solutions, it was found that the diffusion coefficient varied up to 3 times. A microfluidic technique able to determine the critical composition of a model ternary mixture was also successfully implemented. Results indicate potential application of this approach to minimum miscibility pressure measurements used in enhanced oil recovery.

No description available.

This study examined the efficacy of continuous nicotinamide (NAM) administration on recovery of function in rats following traumatic brain injury (TBI). TBI was induced via controlled cortical impact (CCI) bilaterally in the prefrontal cortex (+1.5, 0.0 relative to bregma) or sham surgeries were performed. Rats were then treated with either NAM (150 mg/kg/day) or vehicle (saline). Rats were tested behaviorally on the bilateral tactile adhesive removal task, locomotor placing task, novel exploratory behavior and the Morris water maze (MWM). Rats were also assessed histologically by looking at lesion size, GFAP expression (as a measure of active astroctyes) and MMP-9 expression (as a measure of inflammatory response) at time points of 24 and 48 hours and 30 days. The behavioral assessments showed significant improvements in the NAM-treated animals on the bilateral tactile adhesive removal, locomotor placing and MWM. The histological assessments showed significant lesion reduction at 30 days in the NAM-treated group. There were no differences between NAM-treated and vehicle groups on either GFAP or MMP-9 expression. These results indicate that NAM treatment after TBI can significantly improve recovery of function in rats.