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Improving Dose Calculations In Electron-Beam Radiation Therapy, John Mclellan
Improving Dose Calculations In Electron-Beam Radiation Therapy, John Mclellan
Digitized Theses
The finite range of electrons in tissue makes electron beams a useful radiation treatment modality for many tumour sites. However, the simplistic methods of dose calculation in current clinical use lack sufficient accuracy in many situations of clinical importance. This thesis rests on the premise that a more accurate dose calculation method must incorporate all the major physical processes which shape the dose distribution.;The thesis unites the important transport processes of electron energy loss and angular scattering in a single mathematical model known as the compound Poisson process (CPP). CPP-based calculations of energy-loss spectra for 10, 20 and 30 MeV …
Human Placental Trophoblast As A Model For Tumor Progression, Nelson K. Khoo
Human Placental Trophoblast As A Model For Tumor Progression, Nelson K. Khoo
Digitized Theses
The human placenta is comprised of extravillous trophoblast (EVT) cells which invade the uterus and its vasculature establishing maternal-fetal exchange of key molecules. The mechanisms of in vitro EVT cell invasiveness are similar to those of malignant tumor cells but are regulated in situ by locally derived factors. This invasiveness is insufficient for malignancy. The goal of this laboratory is to transform normal EVT cells and induce premalignant, malignant and/or metastatic phenotypes to identify genetic changes relevant to tumor progression.;Two SV40 T antigen (Tag) transformed cell lines (long lived RSVT-2; immortal RSVT2/C) derived from the invasive first trimester EVT cell …
Effects Of Aging And Strength Training On Shortening And Lengthening Muscle Actions In Women, Michelle Marie Porter
Effects Of Aging And Strength Training On Shortening And Lengthening Muscle Actions In Women, Michelle Marie Porter
Digitized Theses
There has been much research on strength changes with aging and the consequent effects of resistance training, however, relatively little is known about lengthening (eccentric; ECC) muscle actions. The purposes of these studies were to develop a method of testing and training plantar (PF) and dorsiflexion (DF) of the ankle in a standing position in order to investigate age-related and training effects on shortening (concentric; CONC) and ECC peak torque (PT) in women.;All subjects were healthy and physically active, and performed all testing and training on an isokinetic dynamometer. Strength testing was performed in both standing and supine positions at …
Neurochemical Changes Following Stroke: Role In Neuroprotection And Cardiac Susceptibility, Raymond Tak Cheung
Neurochemical Changes Following Stroke: Role In Neuroprotection And Cardiac Susceptibility, Raymond Tak Cheung
Digitized Theses
The mechanisms mediating neuronal recovery and cardiovascular complications after ischemic stroke are not completely known. In these investigations, I examined changes in neuropeptides and a catecholamine synthesizing enzyme, tyrosine hydroxylase (TH), following middle cerebral artery occlusion (MCAO) in adult male Wistar rats.;Five days following MCAO, the immunoreactivity for TH and neuropeptide Y (NPY) increased in the insular cortex (IC) within the peri-infarct zone. NPY also increased ipsilaterally in the basolateral nucleus of the amygdala, whereas leucine-enkephalin, dynorphin and neurotensin increased ipsilaterally in the central nucleus of the amygdala. Sham MCAO was ineffective.;Neurochemical changes were assessed 5 days after localized excitotoxic …
Expression Of Sodium Pump Subunit Genes During Mouse Preimplantation Development, Daniel James Macphee
Expression Of Sodium Pump Subunit Genes During Mouse Preimplantation Development, Daniel James Macphee
Digitized Theses
The Na,K-ATPase or sodium pump is an enzyme that is found in most animal cells. The enzyme pumps sodium and potassium ions against their concentration gradients and is hypothesized to be a mediator of fluid accumulation during mouse preimplantation development. The purpose of the present study was to determine, using reverse transcriptase-polymerase chain reaction (RT-PCR), whether all {dollar}\alpha\ (\alpha1,\ \alpha2,\ \alpha3,\ \alpha4{dollar}) and {dollar}\beta\ (\beta1{dollar} and {dollar}\beta{dollar}2) isoforms of the sodium pump were expressed during preimplantation development. Previous work by Watson and Kidder (1988) had shown that the {dollar}\alpha{dollar} subunit was localized to the basolateral domains of mural trophectoderm surrounding …
Osteopontin (Opn): Structural Analysis Of The Mouse Opn Gene And Functional Analysis Of The Opn Protein In Malignancy, Elke Ingeborg Behrend
Osteopontin (Opn): Structural Analysis Of The Mouse Opn Gene And Functional Analysis Of The Opn Protein In Malignancy, Elke Ingeborg Behrend
Digitized Theses
Osteopontin (OPN) is an integrin-binding cell adhesion protein, that is expressed in many normal cells and tissues, and that is associated with a number of pathological conditions, including cancer. The work presented in this thesis addresses both structural studies of the opn gene, and functional studies of the OPN protein, in an attempt to improve our understanding of OPN.;Two conflicting gene structures of the mouse opn gene had been reported that put into question the location of the promoter, the transcriptional start site, and exon 1 of the mouse opn gene. Analysis of the expressed messages predicted by the two …
Neurophysiology Of Spared Motor Tracts In Spinal Cord Injury, Dalton Louis Wolfe
Neurophysiology Of Spared Motor Tracts In Spinal Cord Injury, Dalton Louis Wolfe
Digitized Theses
Recent experimental and therapeutic initiatives have been directed towards enhancing the survival and function of preserved central axons following spinal cord injury (SCI). The continued development of these initiatives depends largely on the sensitivity of techniques to detect the presence of residual innervation in descending motor tracts. Detection of preserved innervation in SCI patients provided the focus of the present thesis.;Preserved motor innervation was investigated in patients with established SCI using transcranial magnetic stimulation of the motor cortex to elicit motor evoked potentials (MEPs) in muscles innervated below the level of the lesion. In particular, a set of experiments was …
Role Of Nitric Oxide In Interleukin-2 Therapy-Induced Capillary Leak Syndrome, Amila Orucevic
Role Of Nitric Oxide In Interleukin-2 Therapy-Induced Capillary Leak Syndrome, Amila Orucevic
Digitized Theses
Systemic interleukin-2 (IL-2) therapy has been limited by a major side effect known as "capillary leak syndrome", characterized by retention of extravascular fluid, severe hypotension, and multiple organ system dysfunction. The present study tested the hypothesis that an overproduction of nitric oxide (NO) induced by IL-2 therapy was, at least in part, responsible for this syndrome. Studies were undertaken in healthy or C3-L5 mammary adenocarcinoma bearing C3H/HeJ mice to evaluate whether treatment with inhibitors of NO synthesis (N{dollar}\rm\sp{lcub}G{rcub}{dollar}-Methyl-L-Arginine, NMMA and N{dollar}\rm\sp{lcub}G{rcub}{dollar}-Nitro-L-Arginine methyl ester, L-NAME) can prevent IL-2 induced capillary leakage without compromising the therapeutic benefit of IL-2. Intraperitoneal IL-2 therapy …
Detection And Estimation Of Boundaries In Spatial Data, Lei Xie
Detection And Estimation Of Boundaries In Spatial Data, Lei Xie
Digitized Theses
The objective of this thesis is to develop methodology for detecting and estimating parameter changes at unknown boundaries for regression models of spatial data. This methodology has many applications including quality control, epidemiology, pharmacology, agriculture, meteorology and geology.;Statistics are derived for testing a spatial array of observations from a regression model for no change in parameters against possible alternatives involving change of parameters at unknown boundaries based on a Bayes-type approach and a locally optimal framework. These test statistics are defined in terms of set indexed partial sums of regression residuals. Limit processes are obtained for set indexed partial sums …
P53-Dependent Tumorigenesis And Gene Expression In Mammalian Brain, Meyel Donald Van
P53-Dependent Tumorigenesis And Gene Expression In Mammalian Brain, Meyel Donald Van
Digitized Theses
Astrocytic gliomas are the most common brain cancers of adults. The goal of this research was to examine the molecular genetic determinants of gliomas, with particular emphasis on the tumor suppressor gene P53. First, I studied the frequency, nature and timing of P53 mutations in human gliomas. I observed that glioma-prone families do not have inherited mutations of P53, nor of the Nf1-GRD, Nf2, MTS1, MTS2, or CDK4 genes. However, a high frequency of loss of heterozygosity at chromosome 9p was noted in gliomas that cluster in families. In a second study of low-grade gliomas that progressed to higher grade …
Visualization And Analysis Of Multiple Sclerosis Lesions In Magnetic Resonance Images, J Ross Mitchell
Visualization And Analysis Of Multiple Sclerosis Lesions In Magnetic Resonance Images, J Ross Mitchell
Digitized Theses
Magnetic Resonance Imaging (MRI) provides very sensitive indication of the presence and extent of the lesions of Multiple Sclerosis (MS). As a result, quantifying changes in the number and extent of lesions in MR images has been used to indicate disease activity in clinical trials of new therapies. However, lesion quantification is long, arduous, and subject to variability between and within operators. These factors limit the application of quantitative techniques and increase the duration, and thus cost, of clinical trials which rely on their measurements to assess therapeutic effect.;A computerised system was developed for assisted 3-D quantification and analysis of …
Structural Basis For Human Anti-Dna Antibody Specificity, Mahmoud Mahmoudi
Structural Basis For Human Anti-Dna Antibody Specificity, Mahmoud Mahmoudi
Digitized Theses
Anti-DNA antibodies are hallmarks of SLE both in human and inbred lupus prone mice. The role of these antibodies in disease pathogenesis, particularly in glomerulonephritis has been documented. It is now well accepted that the genetic potential to generate anti-DNA antibodies also exists in the normal B cell immune repertoire. This genetic potential has been revealed by detection of anti-DNA antibodies in serum of normal individuals and by immortalizing DNA reactive B cells as hybridomas and as transformed cell lines. There is growing evidence that anti-DNA antibodies from the normal B cell repertoire and disease-associated anti-DNA antibodies share V region …
Dietary Intake And Health Status Of Immigrants And Non-Immigrants In Ontario And Quebec, Joceline Pomerleau
Dietary Intake And Health Status Of Immigrants And Non-Immigrants In Ontario And Quebec, Joceline Pomerleau
Digitized Theses
Introduction: Dietary intake and health status of immigrants to various countries are often different from those of non-immigrants living in these countries. Because the diversity of the immigrants and ethnic minorities in Canada is increasing, the association of place of birth with nutrition and health among Canadians needs to be investigated.;Methods: Cross-sectional data from the 1990 Ontario Health Survey (OHS) and the 1990 Quebec Heart Health and Nutrition Survey (QHHNS) were used. A selection of nutritional (dietary, anthropometric, knowledge variables) and health (health problems, lipidemia, consultations with health professionals, cut-down/bed-days, self-perceived health) outcomes were examined among adult respondents (OHS: n …
Maternal Depression, Perceptions, Contextual Stress, And Parenting, Christine Marie-Antoinette Wekerle
Maternal Depression, Perceptions, Contextual Stress, And Parenting, Christine Marie-Antoinette Wekerle
Digitized Theses
The relationship between maternal depression and parenting was explored in three distinct ways: (1) the direct effect of maternal depression, as it is measured proximally and distally to parenting, (2) the moderation of proximal and distal maternal depression by contextual stress, and (3) the mediation of proximal and distal maternal depression by maternal perceptions of child problem behaviour. Two aspects of maternal behaviour were examined: aversive parenting (negative control strategies, negative affect, lack of positive control strategies) and positive affect (positive affect and affection).;A community sample of 95 mother-child dyads participated in 12, 1-hr in-home behavioural observations. Also, mothers completed …
Self-Concept Dimensions Associated With Eating Disturbance, Sandra Ann Yuen
Self-Concept Dimensions Associated With Eating Disturbance, Sandra Ann Yuen
Digitized Theses
The present thesis provided a detailed examination of the self-concept variables associated with eating disturbance. Two distinct self-concept variables, namely, the content and evaluative dimensions of self, were evaluated in relation to global measures of bulimia nervosa. These self-concept dimensions were further examined in relation to the eating pathology and general maladjustment features of bulimia, including the behavioural, motivational, and cognitive-affective components of eating disturbance.;Study 1 examined the actual and ideal self-concept content dimensions and the self-certainty and attribute importance evaluative self-dimensions, across the domains of body image, depressive personality, sociability, and social roles. Individuals reporting higher levels of bulimia …
Structural Studies On Silver(I) Metallothionein, Ziqi Gui
Structural Studies On Silver(I) Metallothionein, Ziqi Gui
Digitized Theses
Metallothioneins (MT) are a class of low molecular weight, cysteine rich proteins in almost all living things. These proteins have been found to bind a wide range of metals both in vivo and in vitro due to the unusually high cysteinyl sulfur content. The metallothioneins are believed to possess the ability to store and transport essential metals, such as Zn(II) and Cu(I), and also to detoxify toxic metals, such as Cd(II) and Hg(II). However, the precise physiological functions of these proteins still remain unclear to date. As silver(I)-metallothioneins have shown different stoichiometric ratios of Ag:MT from Zn(II)- and Cd(II)-metallothioneins in …
Characterization Of Intestinal Epithelial Cells In Acute Intestinal Allograft Rejection, Xian-Chang Li
Characterization Of Intestinal Epithelial Cells In Acute Intestinal Allograft Rejection, Xian-Chang Li
Digitized Theses
Intestinal transplantation (IT) remains highly experimental compared to other solid organ transplants because of poorly defined mechanisms of graft rejection. In this project, the role of luminal bacteria-derived endotoxin and inflammatory cytokines (IL-1, IL-6, TNF-{dollar}\alpha){dollar} in intestinal epithelial damage during acute graft rejection was examined. In a novel mouse model of IT, the acute intestinal rejection was associated with elevated levels of endotoxin, IL-6, and TNF-{dollar}\alpha{dollar} in the peripheral blood. The progressive increase in endotoxin and TNF-{dollar}\alpha{dollar} levels correlated well with the histologic severity of epithelial damage. To further define the role of endotoxin and inflammatory cytokines on intestinal epithelial …
The Contribution Of Outcome Expectancies To Drinking Behaviour, Anne-Marie Wall
The Contribution Of Outcome Expectancies To Drinking Behaviour, Anne-Marie Wall
Digitized Theses
The present dissertation was conducted to gain a better theoretical understanding of the contribution of outcome expectancies to male undergraduate drinking behaviour. Two assumptions important to the construct validity of outcome expectancies were investigated: (1) outcome expectancies are situation-specific and (2) outcome expectancies are different from attitudes toward drinking.;In each of the four studies conducted in the first series of studies, environmental setting (i.e., bar vs. lab) was manipulated and a second variable was manipulated through instructional set. Specifically, expected beverage content (i.e., beer vs. soda pop), social context (i.e., alone, with friends, no explicit instructions), and level of intoxication …
Health Politics And Structural Interests: The Development Of Community Health Centres In Ontario, William John Church
Health Politics And Structural Interests: The Development Of Community Health Centres In Ontario, William John Church
Digitized Theses
Health care politics can be understood as a competition among interests for control and power. Traditionally, the medical profession has dominated the health sector because of its monopoly position as the provider of medical services. In Canada, the entrance of government into the medical market as a monopoly purchaser of medical services has challenged the dominant position of the medical profession.;Since the introduction of publicly financed health insurance, politicians and administrators have been concerned with gaining control over the cost of the health care system. A rethinking of the basic policy assumptions has led to efforts to rationalize the delivery …
Physical Factors Influencing The Quality Of Megavoltage Radiographs, David Anthony Jaffray
Physical Factors Influencing The Quality Of Megavoltage Radiographs, David Anthony Jaffray
Digitized Theses
It has been recognized that improved methods of verifying radiation field placement in external beam radiotherapy are required in order to make frequent checks of field placement feasible. As a result, a large number of electronic portal imaging systems have been developed as possible replacements for film. These developments have produced digital systems with faster acquisition and display (few seconds), but the quality of the images acquired with such systems is still disappointing. The reasons for this are not well known, possibly because relatively few studies of the fundamental physics of imaging at megavoltage energies have been made.;This thesis examines …
Dynamics Of Morbidity And Mortality In Africa And Implications For Health Care Planning, Sulaiman Maladoh Bah
Dynamics Of Morbidity And Mortality In Africa And Implications For Health Care Planning, Sulaiman Maladoh Bah
Digitized Theses
The dissertation aims to tie together the empirical, theoretical and policy oriented aspects dealing with the dynamics of morbidity and mortality in Africa. On the theoretical aspect, scholars are arguing that the epidemiologic transition theory which provided the framework for understanding African mortality in the past, is actually part of a broader health transition theory which also includes a health care transition. In this theory, the overemphasis on biomedical interventions is down-played. To understand African mortality, it is argued, we have to consider the social and cultural determinants. Also we have to consider morbidity and its relationship to mortality. This …
Drugs In Sport, The Straight Dope: A Philosophical Analysis Of The Justification For Banning Performance-Enhancing Substances And Practices In The Olympic Games, Angela Jo-Anne Schneider
Drugs In Sport, The Straight Dope: A Philosophical Analysis Of The Justification For Banning Performance-Enhancing Substances And Practices In The Olympic Games, Angela Jo-Anne Schneider
Digitized Theses
Many believe that "doping" has no place in sport, especially no place in the Olympic Games. Yet despite, or indeed perhaps because of, this belief remarkably little has been done in the way of attempting to justify those bans.;The arguments that are offered in support of bans fall into four categories: (i) that doping is cheating or unfair, (ii) that it is harmful, (iii) that it perverts the nature of sport, and (iv) that is is dehumanizing or unnatural.;I examine each of these categories of argument in turn. The cheating or unfairness argument is readily dismissed as question-begging. The substances …
The Consequences Of Low Birthweight, Ann L. Robson
The Consequences Of Low Birthweight, Ann L. Robson
Digitized Theses
An extensive literature investigating the consequences of low birthweight for childhood development has focused on group differences and the prediction of global cognitive outcomes. The purpose of this thesis was to identify factors that predict specific childhood outcomes and to consider explanatory models of the role of early medical risk for childhood language, motor and attention outcomes. Ninety low birthweight children participating in a prospective longitudinal study were assessed at {dollar}5{lcub}1\over2{rcub}{dollar} years of age. Although there were no consistent differences between within-sample medical risk subgroups on the childhood outcome measures, regression analyses demonstrated that both early medical risk and environmental …
Host And Viral Determinants Influencing The Pathogenesis Of Coronavirus-Induced Neurological Disease In Rodents, John M. Pasick
Host And Viral Determinants Influencing The Pathogenesis Of Coronavirus-Induced Neurological Disease In Rodents, John M. Pasick
Digitized Theses
Host and viral determinants influencing the outcome of coronavirus JHM infections of the CNS of rodents were investigated using intact animals and primary neural cell cultures. Two problems pertinent to the process of pathogenesis were addressed. The first was concerned with elucidating host factors responsible for controlling the age dependent nature for induction of the demyelinating form of disease in suckling rats. In the second, the basis of the relative resistance exhibited by inbred SJL/J mice to JHMV was examined in relation to both host and viral determinants.;Using primary, dissociated neural cultures from perinatal rats, several interesting aspects of host …
Occupational Exposure To Styrene: Contribution To Hearing Loss, Andrea M. Sass-Kortsak
Occupational Exposure To Styrene: Contribution To Hearing Loss, Andrea M. Sass-Kortsak
Digitized Theses
Prolonged significant noise exposures are well known to result in permanent hearing loss. However, little is known of the contribution of industrial chemical exposures to hearing loss. Information available, both from animal and human studies, raises the possibility that certain aromatic hydrocarbons are ototoxic. The purpose of this study was to assess whether occupational styrene exposure causes hearing loss in a group of workers in the fibre reinforced plastics manufacturing industry. The hearing acuity of 299 subjects was determined, using pure tone screening audiometry, at the beginning of a single workshift and again at the end of the shift. On …
Comparative Studies Of The Effects Of Menogaril And Adriamycin On Cell Morphology And Membrane Function Of Parental And Multidrug Resistant Cells, Stewart E. Daly
Comparative Studies Of The Effects Of Menogaril And Adriamycin On Cell Morphology And Membrane Function Of Parental And Multidrug Resistant Cells, Stewart E. Daly
Digitized Theses
This project was initiated to obtain a better understanding of the cellular mode of action of the anthracycline drug menogaril. Comparative experiments demonstrated that menogaril was as cytotoxic as adriamycin against parental AUX B1 Chinese hamster ovary cells (CHO), however, multidrug resistant (MDR) CH{dollar}\sp{lcub}\rm R{rcub}{dollar}C5 CHO cells, which are characterized by the overexpression of P-glycoprotein relative to the parental cells, were less resistant to menogaril. When parental and MDR cells were exposed to equitoxic concentrations of both drugs, menogaril accumulated to a higher level, however, both drugs accumulated to a significantly higher level in the MDR cells. Immediately after exposure …
The Classification Of The Schizophrenias According To Symptomatology: A Two-Factor Model, Ian R. Nicholson
The Classification Of The Schizophrenias According To Symptomatology: A Two-Factor Model, Ian R. Nicholson
Digitized Theses
The purpose of this investigation was to examine a proposed two-factor model of schizophrenic symptomatology (Nicholson & Neufeld, in press). To achieve this aim, a semi-structured interview was administered to one hundred schizophrenic patients and a series of symptomatology scales were rated. Preliminary analysis indicated that these ratings were consistent with previous research in schizophrenia.;The item-level data from the scales was clustered to reduce redundancies in the large amount of data (95 schizophrenia variables) and 26 symptom clusters resulted. These symptom clusters were then rated and subsequently placed into four schizophrenia variable groups (paranoid, nonparanoid, positive, and negative). The four …
Myocardial Electrophysiological Alterations In Pacing-Induced Heart Failure And Defibrillation Shock Delivery, Huagui Li
Digitized Theses
Heart failure patients frequently have ventricular arrhythmias and high incidence of sudden death. Current antiarrhythmic drug therapies have failed to improve the survival of these patients as the arrhythmogenesis is poorly understood. The only effective therapy for lethal arrhythmia, ventricular fibrillation, is electrical shock (defibrillation). Studies on arrhythmogenesis and potential antiarrhythmic therapies in heart failure are needed.;This thesis investigated: (1) cardiac electrophysiological changes and arrhythmogenesis in a heart failure model; (2) cellular electrophysiological effects of defibrillation shocks.;Heart failure was produced by rapid ventricular pacing (240 beats/min, 4-5 weeks) in 35 dogs. Twenty-one operated, non-paced dogs served as control. Increased impulse …
Life Stress, Appraisals Of Diabetes, Coping And Long Term Blood Glucose Control In Adults With Insulin-Dependent Diabetes Mellitus: A Twelve Week Study, Owen Jon Garrett
Life Stress, Appraisals Of Diabetes, Coping And Long Term Blood Glucose Control In Adults With Insulin-Dependent Diabetes Mellitus: A Twelve Week Study, Owen Jon Garrett
Digitized Theses
Although there is a general consensus in the literature of a relationship between stress and blood glucose control in individuals with insulin dependent diabetes mellitus (IDDM), the extent and nature of this relationship is not well understood. The present study addressed several questions and hypotheses regarding proposed relationships between life stress, long term blood glucose control, coping with diabetic problems and cognitive appraisals of diabetes in persons with IDDM. A longitudinal, prospective research design was used in which fifty-seven persons were followed over two consecutive six week periods. A composite measure of life stress was developed and interrelationships among appraisals …
To Advocate, To Diffuse, And To Elevate: The Culture And Context Of Medical Publishing In Canada, 1630 To 1920, Jennifer Jean Connor
To Advocate, To Diffuse, And To Elevate: The Culture And Context Of Medical Publishing In Canada, 1630 To 1920, Jennifer Jean Connor
Digitized Theses
Although medical publications have traditionally provided the primary medium for research, communication and education in medicine, scholars have not yet attempted to analyze them to understand how they varied; how they interacted with authors and publishers; how they were disseminated; how they changed and why; and how they were received (owned, read or used) by the medical profession or the general public. Typically, scholars have provided brief historical surveys of medical literature and have focused mainly on one genre, the medical journal. Even less is known about medical literature in Canada. This thesis therefore examines medical publications and the process …