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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 …
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 …
Effects Of Industrial Effluents On Populations Of The Freshwater Mussel Lampsilis Radiata In The St Lawrence River, Lee Curtis Grapentine
Effects Of Industrial Effluents On Populations Of The Freshwater Mussel Lampsilis Radiata In The St Lawrence River, Lee Curtis Grapentine
Digitized Theses
The objective of this study was to assess the effects of industrial discharges, contaminated primarily with trace metals, on populations of Lampsilis radiata (Bivalvia: Unionidae) in the upper St. Lawrence River. Effects on shell growth were examined by (a) comparing growth curves derived from analyses of external annual rings of clams sampled from sites located upstream and downstream of four localized sources of discharges, and (b) measuring shell growth for one year from clams that were transplanted into contaminated and uncontaminated sites. Allozyme frequencies in clams from above and below discharges were determined for glucose-phosphate isomerase (GPI) and phosphoglucomutase (PGM), …
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 …
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 …
The Cytoskeleton In The Syncytial Epithelium Of Adult Schistosoma Mansoni, You Zhou
The Cytoskeleton In The Syncytial Epithelium Of Adult Schistosoma Mansoni, You Zhou
Digitized Theses
The surface layer of Schistosoma mansoni is an anucleated syncytium, covered by an apical plasma membrane (APM) and an overlying envelope (En), and is connected with the subsyncytial cell bodies via the membrane-bound cytoplasmic connections (MCC). This syncytium is considered as an adaptation for rapid and synchronous renewal of the surface membranes which play an important role in evasion of the host's immune system.;The present studies demonstrated the effects of the third complement component (C{dollar}\sb3{dollar}) and serotonin (5HT) on the synthesis of the discoid bodies (DBs) and multilamellar bodies (MLBs), and major syncytial inclusion bodies in vitro. With short-time incubations …
31-Phosphorous, Nuclear Magnetic Resonance Spectroscopy Studies Of Exercising Human Muscle, Gregory D. Marsh
31-Phosphorous, Nuclear Magnetic Resonance Spectroscopy Studies Of Exercising Human Muscle, Gregory D. Marsh
Digitized Theses
Phosphorous 31, nuclear magnetic resonance spectroscopy {dollar}(\sp{lcub}31{rcub}{dollar}P NMRS) was used as a non-invasive probe of forearm muscle metabolism in three studies of healthy men and women. Specific objectives of the studies were to: (1) observe the changes in high energy phosphates and intracellular pH in muscle, during a ramp exercise protocol, (2) study the effect of endurance training on muscle metabolism and evaluate the utility of the forearm ramp test as a means to assess muscle oxidative capacity, and (3) describe the kinetics of phosphocreatine (PCr) and inorganic phosphate (Pi) metabolism during the on and off transient response to moderate …
Structure/Function Studies Of Trypanosome Variant Surface Glycoproteins, Vern Bruce Carruthers
Structure/Function Studies Of Trypanosome Variant Surface Glycoproteins, Vern Bruce Carruthers
Digitized Theses
Antigenic variation is manifested by many prominent infectious organisms in adaptive response to host immunity. However, polymorphism in antigenic structure is often limited by the necessity to maintain functionality of the antigen. It follows that it may be possible to design molecularly defined vaccines capable of accounting for variable antigenic phenotype. For this reason, the focus of the present thesis was to develop a model system using trypanosome variant surface glycoprotein (VSG) for examining the effects of amino acid sequence variation on the specificity of antigenic determinants.;In order to assess the suitability for a model system of four VSGs (isoVAT …
Methodologies Of Predicting Vegetation Response To The Environment And To Perturbation On A Regional Level: A Thesis In Three Parts Treating Temporal And Time Static Models, Peter Humphreys Fewster
Methodologies Of Predicting Vegetation Response To The Environment And To Perturbation On A Regional Level: A Thesis In Three Parts Treating Temporal And Time Static Models, Peter Humphreys Fewster
Digitized Theses
The reader of this thesis is presented with a view of Vegetation Science as a dynamic, developing field. Changes are seen as producing increased complexity in the methodology and increased emphasis on prediction. As pointed out in the text, early work has mainly been descriptive and the methods of analysis used were not so much prediction oriented as they were a vehicle for presenting current descriptions of vegetation structure and function. Method development is traced from the early descriptive schemes through more evolved ones which have reflected different and often opposing concepts of what vegetation is. The most noted are …
Spatial Processes In The Analysis Of Vegetation, Janos Podani
Spatial Processes In The Analysis Of Vegetation, Janos Podani
Digitized Theses
Vegetation Science often relies on methods whose principal strategy involves the change of some parameters of sampling. There is, in fact, a time-static spatial dynamism in the analysis of vegetation, and most changes can be ordered into a sequence, whereby spatial processes are defined. The objective of the present thesis is to create a theoretical framework for the discussion and review of time-static spatial processes, to give a methodological basis for their analysis, and to illustrate some possibilities through real and simulated examples.;Two basic types of processes are distinguished: (1) the primary processes defined by the investigator, and (2) the …