Bladder obstruction (neurogenic or anatomic) induces strain injury in detrusor smooth muscle cells. Signaling via strain injury in other systems has been highly studied, while in bladder obstruction, it has been quite limited to a small number of pathways. In our study we have examined the effects of strain injury using a combination of in vivo, ex vivo and in vitro models, with the aim of understanding disease pathogenesis in the bladder. Using a combination of literature searches, phospho-protein screens and pathway analysis, we uncovered three pathways activated by mechanical strain, ERK, STAT3 and mTOR, with potential for changing not only the way we understand but also the way we treat obstructive myopathies of the bladder. We found that not only were these pathways activated in response to strain and distension injury of BSMC, but they were also responsible for proliferation and sometimes de-differentiation. Included herein are three chapters, published in 2006 and 2010, on the role of ERK, STAT3 and mTOR pathways in bladder smooth muscle cell proliferation and differentiation, 8 Appendices containing the first pages of other papers and reviews published during the course of my studies.

Previous studies reported that matrix protein supplementation (fibronectin/fibrinogen, FN/FG) of agarose gel microcapsules enhances survival and pulmonary retention of syngeneic rat multipotent stromal cells (MSCs). I hypothesized that additional supplementation of microcapsules with osteopontin (OPN) and transglutaminase 2 (TG2) would enhance cell survival, while stabilizing the provisional matrix. Using monomeric OPN or OPN polymerized with TG2, I examined human MSC adhesion, morphology, focal contact formation and apoptosis. Polymeric OPN induced greater adhesion than monomeric OPN (84.5±10.7 vs. 44.3±10.0cells/field), and also significantly enhanced focal contact formation (351.5±21.2 vs. 45.6±17.6 focal contact sites/cell) and cell spreading (2.7x103±0.20x103μm2 vs. 1.2x103±0.26x102μm2) while preserving MSC pluripotency. Microcapsules supplemented with FN/FG, polymeric OPN and TG2 demonstrated significantly less apoptotic cells than FN/FG microcapsules (14.0±2.34% vs. 28.2±3.22%). Reduced apoptosis was attributed to matrix stabilization by TG2 and the synergistic activity of matrix proteins. It is anticipated that this enhanced survival will maximize the therapeutic potential of MSCs.

Ovarian high-grade serous cancer (HGSC) is the most lethal gynecologic malignancy and well-characterized models may improve patient outcomes. Patient-derived xenografts (PDXs) recapitulate disease heterogeneity; however, to be useful in predicting response to novel chemotherapeutics, they must reflect the response of the donor tissue to standard chemotherapy. The objectives of this study were: first, to evaluate the response of PDXs’ to platinum therapy and compare this response to that of the donor; and second, to determine whether treatment with chemotherapy enriches for tumourigenic cells. Eighteen samples formed tumours in the mammary fat pads of NOD-Scid-IL2Rγnull mice and were treated with Carboplatin. There was a 100% concordance between sample status and PDXs response to chemotherapy. HGS histology was confirmed for all cases. A conclusion regarding post-chemotherapy tumourigenicity could not be made due to inadequate statistical power. PDXs represent useful tools for evaluation of novel therapies and identification of patients who are platinum-resistant/sensitive.

The main objective of my dissertation was to evaluate the biomedical and psychosocial factors associated with pain and disability in patients following traumatic upper extremity nerve injuries. This was approached by conducting 3 studies. The first study surveyed peripheral nerve surgeons regarding the assessment of pain in patients with nerve injury. The results showed that only 52% of surgeons always evaluate pain in patients referred for motor/sensory dysfunction. Pain assessment frequently includes verbal response and assessment of psychosocial factors is infrequent. The second study was a retrospective review to assess disability, as measured by the Disabilities of the Arm, Shoulder and Hand (DASH), in patients with chronic nerve injury. Results showed substantial disability (mean DASH 52 + 22) and a significantly lower health status (p < 0.001) compared with well-established norms. In the regression model, the factors associated with the DASH (R2 = 44.5%) were pain, older age and nerve injured. The third study was a cross-sectional evaluation of the biomedical and psychosocial factors associated with pain and disability after upper extremity nerve injury in 158 patients. DASH scores were significantly higher in patients with workers’ compensation or litigation (p = 0.03), brachial plexus injuries (p < 0.001) and unemployed patients (p < 0.001). In the multivariable regression analysis, the final model explained 52.7% of the variance with these predictors; pain intensity (Beta = .230, p = 0.006), nerve injured (Beta = -.220, p = 0.000), time since injury (Beta = -.198, p = 0.002), pain catastrophizing (Beta = .192, p = 0.025), age (Beta = .187, p = 0.002), work status (Beta = .179, p = 0.008), cold sensitivity (Beta = .171, p = 0.015), depression score (Beta = .133, p = 0.066), workers’ compensation/litigation (Beta = .116, p = 0.049) and gender (Beta = -.104, p = 0.09). Future investigation regarding treatments of the factors that are associated with disability and chronic pain will assist to improve health related quality of life in patients with traumatic nerve injury.

This dissertation uses population-based administrative healthcare data to evaluate the outcomes, processes-of-care and practice variation associated with preoperative medical consultation in Ontario, Canada. First, a multicentre cross-sectional study was conducted to develop a novel algorithm for identifying preoperative medical consultations using administrative data. The optimal claims-based algorithm was a physician service claim for a consultation by a cardiologist, general internist, endocrinologist, geriatrician, or nephrologist within 120 days before the index surgery. This algorithm had a sensitivity of 90% (95% confidence interval [CI], 86 to 93) and specificity of 92% (95% CI, 88 to 95). Second, we conducted a population-based cohort study to evaluate the association of preoperative medical consultation with outcomes and processes-of-care. After adjustment for measured confounders using propensity-score methods, consultation was associated with increased preoperative testing, preoperative pharmacological interventions, 30-day mortality [relative risk (RR) 1.16; 95% CI, 1.07 to 1.25], 1-year mortality (RR 1.08; 95% CI, 1.04 to 1.12), and mean hospital stay (difference 0.67 days; 95% CI, 0.59 to 0.76). These findings were stable across subgroups, as well as sensitivity analyses that tested for unmeasured confounding. Third, temporal trends and practice variation in consultation were evaluated within the population-based cohort. The proportion of patients undergoing consultation remained relatively stable over the study period, at approximately 39%. Although patient-level and surgery-level factors did predict consultation use, they explained only 6.8% of variation in consultation rates. By comparison, inter-hospital differences in rates were substantial (range, 1.9% to 86.8%), were not explained by surgical volume or teaching status, and persisted after adjustment for patient-level and surgery-level factors. Overall, this dissertation highlights the need for research to identify interventions for safely decreasing perioperative risk, define mechanisms by which consultation influences outcomes, examine factors that influence practice variation in medical consultation, and identify patients who benefit most from preoperative medical consultation.

Objectives: 1) Evaluate the risk of atherosclerosis in rheumatic disease compared to healthy controls; 2) Assess the lipid profile of children with systemic lupus erythematosus (SLE) at presentation before treatment with corticosteroids; 3) Compare the lipid profiles of children with juvenile dermatomyositis (JDM), systemic juvenile idiopathic arthritis (SJIA), and SLE; 4) Evaluate the extent of early atherosclerosis in children with JDM, SJIA, and SLE; 5) Investigate the progression of early markers of atherosclerosis in children with SLE. Methods. The methods include a systematic review, a cross sectional study of serum lipid levels of a cohort of children with SLE, an analysis of the first time point of a prospective study of cardiovascular disease risk factors and vascular function measures of a cohort of children with JDM, and SJIA, and SLE and a longitudinal study of vascular function measures of a prospective study of a cohort of children with SLE. Results. Our systematic review demonstrated that carotid intima media thickness (CIMT), a surrogate marker of early atherosclerosis, was significantly increased in rheumatic disease populations. We found that newly diagnosed children with SLE before corticosteroid treatment exhibited a pattern of dyslipoproteinemia of increased triglycerides and depressed HDL-cholesterol. When we measured the lipid profiles in children with the rheumatic diseases of JDM, SJIA, and SLE, one third of children had at least one abnormal lipid value. The most common abnormalities were found for total cholesterol and triglyceride levels and most often in children with JDM. One quarter of all patients were found to have insulin resistance. Lastly, when we considered the effects of treatment in children with SLE, we found that improvement in CIMT was possible and it correlated with a higher cumulative dose of prednisone over the study period. Conclusions. Early markers of atherosclerosis in pediatric rheumatic disease are important for determining the risk of these children in developing heart disease as young adults. Chronic inflammation plays a significant role and should be considered an important predictor of premature atherosclerosis.

Parkinson’s disease (PD) and dystonia are movement disorders related to dysfunctions of basal ganglia (BG). Deep brain stimulation (DBS) of the subthalamic nucleus (STN) and internal globus pallidus (GPi) are treatments for PD and dystonia. Previous research indicated that abnormally elevated oscillatory activities at the theta (3-10 Hz) beta frequency bands (11-30 Hz) may be related to parkinsonian and dystonic motor symptoms but their precise roles are not well understood. Recently, DBS of the pedunculopontine nucleus region (PPNR) has been used to treat PD patients with postural and gait dysfunctions, but movement-related PPNR activities had not been explored. We aimed to investigate movement-related local field potentials (LFP) recorded from the BG and PPNR in PD and dystonia patients. We recorded STN LFP from PD patients and subsequently applied the intrinsic STN theta, beta, and gamma (31-100 Hz) frequencies through DBS to study their effects on PD motor signs. We also recorded movement-related PPNR LFP in PD patients and movement-related GPi activities in patients with primary dystonia. Finally, we simultaneously recorded movement-related activities from the GPi and the motor thalamus in a patient with secondary dystonia. We found that DBS at the dopamine-dependent and movement-related intrinsic STN gamma frequencies, were as effective as traditionally used high frequencies (130-185 Hz) in reducing PD motor signs, but theta and beta frequencies did not worsen motor symptoms. Voluntary movements modulated two discrete movement-related frequencies in the theta and beta bands in the PPNR and these two frequencies interacted with the sensorimotor and frontal cortices during movements. We showed that voluntary movements modulated beta and gamma frequencies in the GPi. A resting ~5-18 Hz coherence between the GPi bilaterally was attenuated during movements in patients, which may be related to dystonia because this 5-18Hz coherence was also present between the GPi and motor thalamus in the patient with secondary dystonia. Our findings indicated that intrinsic STN gamma frequency oscillations were likely prokinetic rhythms but theta and beta frequencies may not contribute to PD motor symptoms. Voluntary movements modulated theta and beta frequencies in the PPNR, which may explain why PPNR DBS uses lower frequencies than those of the BG. The 5-18 Hz oscillatory activities in the BG-thalamic circuit may be a feature of dystonia.

Similarities between the peripheral auditory and vestibular systems suggest that children with sensorineural hearing loss (SNHL) may demonstrate vestibular and balance impairments. This hypothesis was studied in 40 children with severe to profound SNHL and unilateral cochlear implants (CI). Vestibular function was assessed with caloric, rotational, and vestibular evoked myogenic potential (VEMP) testing; balance was assessed with standardized static and dynamic tests. Horizontal semicircular canal function was abnormal in 53% (17/32) with caloric, and 39% (14/36) with rotational stimulation. Saccular function was absent bilaterally in 5/26 (19%) and unilaterally in 5/26 (19%) with VEMP. Balance abilities were significantly poorer (μ=12.9±5(SD)) than normal hearing controls (μ=17±5(SD); p=0.0006) and correlated best with horizontal canal function from rotational stimulation (p=0.004;R2=0.24). SNHL from meningitis was associated with worse balance function than other etiologies. Vestibular and balance dysfunction occurred in >1/3 of children with SNHL and CI, and is highly dependent on etiology.

Post-stroke fatigue (PSF) is a common yet under-diagnosed and undertreated phenomenon. The unresolved debate over what is PSF has hampered the ability of clinicians to study and develop treatments for this condition. Patients with stroke (n=70) seeking neurorehabilitation at Toronto Rehabilitation Institute completed self-report ratings of fatigue, depressive and anxiety symptoms, and sleepiness. Data were collected from objective measures of stroke topography, sleep disorders, physical fatigability and comorbid medical conditions. A Principal-Components Analysis was performed. Factor 1, the “Distress” factor, was comprised of the all of the self-reported scales i.e. depression, anxiety, fatigue and sleepiness. Factor 2, the “Physical State” factor, was comprised of a diagnosis of Obstructive Sleep Apnea, stroke territory and total medical burden. Factor 3, the “Performance” factor, was comprised by the 6 Minute Walk Test. An orthogonal rotation was the most parsimonious fit to the data, suggesting that the three factors are uncorrelated to each other.

Background: No spine-specific educational tool has been developed using input from all relevant stakeholders, including patients. Purpose: The objective of this study was to determine the information needs of lumbar microdiscectomy patients. Methods: Qualitative methods with thematic analysis was used. Focus groups were conducted with: 1) preoperative microdiscectomy patients; 2) postoperative microdiscectomy patients; 3) spine surgeons; 4) spine fellows; 5) orthopaedic surgery residents; 6) anesthesiologists; 7) surgeons’ administrative assistants; and, 8) preoperative assessment team. Results: Major information needs were related to: anesthesia, surgical procedure details and postoperative course. Patients desire information on postoperative course much more than surgeons perceive. Desired attributes of information tools as well as patient factors that influence the extent of information shared by surgeons were determined. Information resources should be given to patients as soon as they are deemed surgical candidates. Conclusions: Microdiscectomy patients desire more information than currently provided to them – in particular postoperative-related information.