Laboratory and Basic Science Research Commons^™

The Role Of Coagulase-Negative Staphylococcal Secreted Products On Staphylococcus Aureus And Staphylococcus Lugdunensis Infections, Denny Chin

Electronic Thesis and Dissertation Repository

The Staphylococcus genus is comprised of over 40 bacterial species. The most well-studied species in this genus is the notorious human pathogen Staphylococcus aureus, a bacterium that produces coagulase among many other virulence factors. Since S. aureus is a major health burden and causes a plethora of diseases in humans, it has received significant attention and much research has been done to understand its biology to treat diseases caused by this pathogen. However, the coagulase-negative staphylococci (CoNS) make up most of the staphylococcal species and have received less attention since they are thought to have a lesser impact on …

Exogenous Surfactant As A Delivery Vehicle For Intrapulmonary Therapeutics, Brandon J. Baer

Electronic Thesis and Dissertation Repository

As an organ system, the lung has unique advantages and disadvantages for direct drug delivery. Its contact with the external environment allows for the airways to be easily accessible to intrapulmonary delivery. However, its complex structure, which divides into more narrow airways with each branch, can make direct delivery to the remote alveoli challenging. The objective of this thesis was to overcome this issue by using exogenous surfactant, a lipoprotein complex used to treat neonatal respiratory distress syndrome, as a carrier for pulmonary therapeutics. It was hypothesized that therapeutics administered with a surfactant vehicle would display enhanced delivery to the …

Differential Effects Of Kim-1 In Subcutaneous And Orthotopic Renca Models Of Kidney Cancer, Demitra M. Yotis Dy

Electronic Thesis and Dissertation Repository

Renal Cell Carcinoma (RCC) is the most common and fatal type of kidney cancer. Over 30% of patients that are diagnosed with RCC exhibit metastases. Almost 88% of patients with distant metastases succumb to the disease within 5 years of diagnosis. Kidney Injury Molecule-1 (KIM-1) is a cell surface glycoprotein that is not expressed in a healthy kidney but becomes highly expressed on proximal tubular epithelial cells (PTECs) following injury. Data from the Cancer Genome Atlas (TCGA) reveals that >90% of RCC tumours express KIM-1 mRNA and that higher expression levels correlate with increased overall survival rates of patients. The …

An Approach For The In-Vivo Characterization Of Brain And Heart Inflammation In Duchenne Muscular Dystrophy, Joanne Tang

Electronic Thesis and Dissertation Repository

Duchenne muscular dystrophy (DMD) is a neuromuscular disorder caused by dystrophin loss—notably within muscles and CNS neurons. DMD presents as cognitive weakness, progressive skeletal and cardiac muscle degeneration until pre-mature death from cardiac or respiratory failure. Innovative therapies improved life expectancy, but this is accompanied by increased late-onset heart failure and emergent cognitive degeneration. Thus, there is an increasing need to both better understand and track disease pathophysiology in the dystrophic heart and brain prior to onset of severe degenerative symptoms. Chronic inflammation is strongly associated with skeletal and cardiac muscle degeneration, however chronic neuroinflammation’s role is largely unknown in …

Effects Of Increased Sulfatide In Schwann And Mesenchymal Stromal Cells In Metachromatic Leukodystrophy, Srinitya Gannavarapu

Electronic Thesis and Dissertation Repository

Metachromatic leukodystrophy (MLD) is an inherited lysosomal storage disease caused by deficient arylsulfatase A (ARSA) activity, resulting in intra-lysosomal accumulation of sulfatide. Sulfatide is integral for proper maintenance of myelin in the central and peripheral nervous systems. This study characterized mitochondrial morphology, cytokine secretion and phagocytic activity in Schwann and mesenchymal cells isolated from ARSA^-/- mice. Cells were treated with different, increasing concentrations of sulfatide for a period of 24 hours. ARSA^-/- cells presented with persistent, increased fragmented mitochondrial structures suggestive of prolonged mitochondrial fission. Sulfatide treatments increased secretion of pro-inflammatory cytokines TNF-α and IL-1β in ARSA^{-/- …}

Hiv-1 Group M Subtype Fitness, Disease Progression, And Entry Efficiency, Colin M. Venner

Electronic Thesis and Dissertation Repository

Human immunodeficiency virus type 1 (HIV-1) emerged in the human population shortly after the turn of the 19th century. Distribution of HIV-1 across the globe over the past 30–35 years can be traced to founder events with primordial HIV strains from sub-Saharan Africa. Even considering the burden of HIV in Africa, our knowledge of HIV-1 disease is still largely limited to subtype B HIV-1, a strain responsible for 3 million infections in North America and Europe as compared to the 33 million that are infected with HIV-1 subtypes A, C, D, and circulating and unique recombinant forms.

This dissertation analyzes …

Effect Of Estrogen And Glucocorticoid Signaling On Th2 Cells – Implications For Severe Asthma, Meerah Vijeyakumaran

Electronic Thesis and Dissertation Repository

T helper (Th2) cells are increased in asthma and mediate allergic inflammation through production of type 2 cytokines (interleukin-4, -5 and -13). One pathway to activate Th2 cells is through chemoattractant-homologous receptor expressed on Th2 cells (CRTh2), a receptor for prostaglandin D₂ (PGD₂). Glucocorticoids (GCs) are the main treatment for allergic disease, due to their ability to suppress type 2 cytokine production and induce apoptosis. Incidence and severity of asthma is greater in women than men, which may be related to sex-specific efficacy of GCs. Recently, our laboratory found that severe asthmatic women had more circulating Th2 …

The Effect Of Insulin Treatment And Exercise Modality On Skeletal Muscle Fiber Size In Streptozotocin-Induced Type 1 Diabetic Rats, John Z. Nickels

Electronic Thesis and Dissertation Repository

Severe Type 1 Diabetes Mellitus (T1DM) is known to have several negative effects on skeletal muscle mass, a condition known as diabetic myopathy. One of these effects is the atrophy of the glycolytic muscle fibers. However, the role of intensity of insulin treatment and exercise modality in attenuating this loss in fiber cross-sectional area (CSA) specifically has yet to be determined. The purpose of this investigation was to determine the effects of 12 weeks of differing intensity of insulin therapy and exercise modality on the CSA of plantaris muscle fibers, identified by myosin heavy chain (MHC) of STZ-induced T1DM rats. …

Regulation Of Phosphatase And Tensin Homolog Expression And Activity By Transforming Growth-Factor Beta In The Trabecular Meshwork Cells: Implications For Primary Open Angle Glaucoma, Nikoleta Tellios

Electronic Thesis and Dissertation Repository

Glaucoma is a multifactorial condition caused, in part, by fibrosis of the sieve-like trabecular meshwork (TM) tissue, which impedes drainage of aqueous humor (AH), leading to increased intraocular pressure and associated optic nerve damage and blindness. Fibrosis of the TM is mainly caused by the increased levels of active transforming growth factor-β 2 (TGFβ2) in the AH of glaucoma patients.

Previous reports have shown that TGFβ decreases the expression of Phosphatase and Tensin Homolog (PTEN) gene and that PTEN is a major regulator of ECM deposition. In this study we investigate the regulation of PTEN protein expression and …

Characterization Of The Nicotine-Induced Endoplasmic Reticulum Stress Response In The Rat Placenta In Vivo And In Vitro, Michael Ka Chun Wong

Electronic Thesis and Dissertation Repository

Nicotine exposure during pregnancy leads to adverse health outcomes, including compromised placental development. Although the molecular mechanisms remain elusive, recent studies identified that endoplasmic reticulum (ER) stress may underlie poor placentation. Therefore, we were interested in investigating the effects of nicotine exposure on the ER stress response in the placenta. A well-established maternal nicotine exposure rat model and Rcho-1 trophoblast giant cell model were utilized to address the research questions. Maternal nicotine exposure in vivo led to elevated ER stress in association with impaired disulfide bond formation and hypoxia. Nicotine exposure in vitro further differentiated that ER stress may be …

The Effect Of A Multiple Modality Mind-Motor Exercise Intervention On Single And Dual-Task Gait, Balance, And Executive Function, In Community Dwelling Older Adults With A Subjective Cognitive Complaint: A Randomized Controlled Trial., John P. Bocti

Electronic Thesis and Dissertation Repository

Cognitive decline disorders are becoming increasingly prevalent, with older adults at increased risk. Combined exercise has been recently explored as an intervention to help to prevent the decline, however cognitive activation in combination with physical activity has yet to be explored. Therefore, the purpose of the study is to determine the effects of multiple modality exercise programs in combination with a mind-motor task and their effects on mobility and cognitive variables. A total of (n=89) older adults (55+ yrs), with subjective cognitive complaints participated in a multiple modality exercise class, three days a week over six months, with the intervention …

Molecular Mechanisms Linking Amino Acid (Leucine) Deprivation To Igfbp-1 Hyperphosphorylation In Fetal Growth Restriction, Niyati M. Malkani

Electronic Thesis and Dissertation Repository

In this study, we explore the molecular mechanisms linking amino acid (leucine) deprivation to IGFBP-1 hyperphosphorylation in vitro. During pregnancy, a maladaptive fetal response to in utero amino acid deprivation leads to Fetal Growth Restriction (FGR). FGR infants display elevated phosphorylated IGFBP-1, which is associated with decreased IGF-I bioavailability. Leucine deprivation inhibits mechanistic target of rapamycin (mTOR) signaling and stimulates the amino acid response (AAR). Using HepG2 cells, a model for fetal hepatocytes, we demonstrate that in leucine deprivation, the AAR modulates total and phosphorylated IGFBP-1 while mTOR mediates total IGFBP-1 secretion only. We also reveal that protein kinases …

Identification And Characterization Of Cysteine Protease Genes In Tobacco For Use In Recombinant Protein Production, Kishor Duwadi

Electronic Thesis and Dissertation Repository

Plants are an attractive host system for pharmaceutical protein production. Many therapeutic proteins have been produced and scaled up in plants at a low cost compared to the conventional microbial and animal based systems. The main technical challenge during this process is to produce sufficient level of proteins in plants. Low yield is generally caused by proteolytic degradation during expression and downstream processing of recombinant proteins. The yield of a human therapeutic protein interleukin (IL) -10 produced in transgenic tobacco leaves was found to be below the critical level, and is potentially due to degradation by tobacco cysteine proteases (CysPs). …