Medicine and Health Sciences Commons^™

Hematopoietic Stem Cell Threshold Sensing Controls Regulatory Pathways Facilitating Clinically Relevant Ex Vivo Expansion For Stem Cell Transplantation, Andrew D. Lasiter

Theses and Dissertations (ETD)

The ex vivo expansion of hematopoietic stem cells (HSCs) for transplantation has threefold importance: 1.) First, because of the rarity of stem cells there often isn’t a sufficient supply obtainable from common sources for larger children and adults. 2.) Secondly, patient morbidity and time to hematopoietic reconstitution following myeloablative preconditioning is improved by administering a larger pool of HSCs. 3.) Lastly, gene therapies for hematological diseases still require a robust supply of HSCs to offset varying degrees of inefficiency in vector mediated transfection protocols. These reasons, and others, have been an impetus for many discoveries made within four primary subdivisions …

The Role Of Bip Nucleotide Exchange Factor Sil1 In Immunoglobulin Biosynthesis, Tyler Sanford

Theses and Dissertations (ETD)

BiP is an essential endoplasmic reticulum resident molecular chaperone of the HSP70 family that binds exposed hydrophobic regions of unfolded proteins. Substrates bound by BiP are protected from dangerous non-specific interaction with other unfolded proteins via their aggregation prone exposed hydrophobic regions, which are normally buried in the native state, and act as BiP binding targets. For these substrates to mature into the native state, BiP must be released. Like all HSP70 family members, cycles of BiP binding and release are nucleotide dependent and facilitated by two genres of cochaperones, HSP40s, and nucleotide exchange factors (NEFs). HSP40s function in stimulating …

Metabotropic Glutamate Receptor 5 In The Medial Prefrontal Cortex: Role In Cocaine Sensitization And Addiction, Kristin Marie Timmer

Theses and Dissertations (ETD)

Cocaine sensitization is associated with cocaine-induced hyperexcitability of pyramidal projection neurons within the medial prefrontal cortex (mPFC). Such hyperexcitability presumably results in increased glutamatergic input to reward-affiliated brain regions such as the ventral tegemental area (VTA) and nucleus accumbens (NAc), consequently facilitating drugseeking behavior. Metabotropic glutamate receptor 5 (mGluR5) has been implicated in cocaine addiction and demonstrated to increase neuronal excitability, therefore, the aim of the present study was to investigate the effect of intra-mPFC mGluR5 manipulation on behavioral and neurochemical sensitization and drug-seeking. Bilateral cannulae were implanted into the mPFC of male Sprague-Dawley rats and mGluR5 antagonist MTEP (15 …

N200 And P300 Evoked By Stimuli Straddling Category Boundary In Lexical Context, Ji Young Lee

Theses and Dissertations (ETD)

Background and Objectives: Event-related potentials (ERPs) like N200 and P300 have been reported to reflect the categorical perception of speech. The purpose of the present study is to explore whether these ERP components reflect the influence of lexical context on categorical perception. Findings may provide evidence for bottom-up or top-down processing of speech. Methods: On a seven step series of the /bi/-/pi/ continuum, a two-forced choice labeling test was administered in two conditions: /bi/ context (e.g. bee sting) and /pi/ context (e.g. pea soup). From the labeling results, Stimulus 1which is a prototypical /bi/ was selected for standard stimuli, and …

Mrp4 Is A Crucial Regulator Of Testosterone Biosynthesis, Jessica Ann Morgan

Theses and Dissertations (ETD)

The physiological role of multidrug resistance protein 4 (Mrp4) in the testes is unknown. It was discovered that Mrp4 is expressed primarily in mouse and human Leydig cells; however, there is no current evidence that Mrp4 regulates testosterone biosynthesis. The role of Mrp4 was investigated in Leydig cells where testosterone production is regulated by cAMP, an intracellular second messenger formed when the luteinizing hormone (LH) receptor (Lhr) is activated. As Mrp4 regulates cAMP, we compared testosterone levels in our Mrp4 WT and KO mice. Prepubertal KO mice had significantly reduced testicular testosterone, impaired gametogenesis, and disrupted cAMP homeostasis, resulting in …

Anti-Apoptotic Mcl-1 Localizes To The Mitochondrial Matrix And Couples Mitochondrial Fusion To Respiration, Rhonda Perciavalle

Theses and Dissertations (ETD)

MCL-1, an anti-apoptotic BCL-2 family member that is essential for the survival of multiple cell lineages, is also among the most highly amplified genes in cancer. Although MCL-1 is known to oppose cell death, precisely how it functions to promote survival of normal and malignant cells is poorly understood. Here, I report that different forms of MCL-1 reside in distinct mitochondrial locations and exhibit separable functions. On the outer mitochondrial membrane, a MCL-1 isoform acts like other anti-apoptotic BCL-2 molecules to antagonize apoptosis, whereas an amino-terminally truncated isoform of MCL-1 that is imported into the mitochondrial matrix is necessary to …

Discovery Of Dihydroartemisinin And Dasatinib Drug Combination To Cure Pooroutcome Bcr-Abl+ Acute Lymphoblastic Leukemia, Harpreet Singh

Theses and Dissertations (ETD)

Oncogenic signaling by the Philadelphia chromosome-encoded BCR-ABL fusion kinase initiates and drives both Philadelphia chromosome-positive acute lymphoblastic leukemia (Ph+ ALL) and chronic myelogenous leukemia (CML). Food and Drug Administration (FDA)- approved BCR-ABL-specific kinase inhibitors (BCR-ABL–KIs) imatinib, dasatinib and nilotinib induce prolonged remissions in CML but poor leukemia-reduction and relapse-control in Ph+ ALL. The relative primary BCR-ABL–KI-resistance in Ph+ ALL patients carrying predominantly BCR-ABLWT disease cannot be attributed to drug-resistant BCR-ABL mutations (BCR-ABLMUTANTS), and remains poorly understood.

We established a cell-based platform to evaluate the modulation of anti-Ph+ ALL activity of drugs by both tumor-extrinsic cytokines normally present in the leukemia …

Phenotypic And Electrophysiologic Characterization Of A Mouse Model Of Fragile X Syndrome, Snigdha Roy

Theses and Dissertations (ETD)

Fragile X syndrome (FXS) is the most common form of inherited mental retardation. It is caused by a mutation in the fragile X mental retardation (FMR1) gene on the X chromosome. Many children with FXS exhibit autistic behaviors and deficits in motor coordination including speech articulation deficits. The development of the FMR1 knockout (Fmr1 KO) mouse, in which the Fmr1 gene is inactivated, has provided an animal model that can be used to investigate underlying neuro-physiological mechanisms associated with FXS as well as to evaluate potential therapeutic treatments. In this study, quantitative behavioral assays were used, such as long term …

Contribution Of The Unfolded Protein Response To Vegf Expression, Ethel Rose Pereira

Theses and Dissertations (ETD)

Tumor cells experience a limiting microenvironment due to inadequate vascularization that can affect the normal functioning of intracellular organelles. In the case of the endoplasmic reticulum, the limiting environment is further exacerbated by the high metabolic demands of the tumor cells, which together interfere with the proper maturation of nascent proteins synthesized there. The resultant accumulation of unfolded proteins activates a signal transduction pathway known as the Unfolded Protein Response, which serves primarily to protect the cell during stress and helps restore homeostasis to this organelle. As tumors expand resulting in regions that are a greater distance from functional blood …

Cns Penetration Of Tyrosine Kinase Inhibitors In Mouse Models, Mohamed Elmeliegy

Theses and Dissertations (ETD)

For the past three decades, advances in the treatment of central nervous system (CNS) tumors such as malignant glioma have only been modest. One particular challenge facing treatment of brain tumors is the delivery of therapeutically effective concentrations of anti-cancer agents to the target site in the brain. The sanctuary of the brain is protected by several barrier systems such as the blood-brain barrier (BBB) and the blood-cerebrospinal fluid barrier (BCSFB). These barriers restrict the passage of anti-cancer drugs into the brain via several protective mechanisms.

In the present study, we used cerebral microdialysis sampling, a technique for sampling unbound …

Beta-2-Adrenergic Receptor Regulates Insulin Signaling To Reduce Cell Death In Müller Cells, Robert Jason Walker

Theses and Dissertations (ETD)

No abstract provided.

The Molecular Basis Of Fitness And Transmissibility Of Neuraminidase Inhibitor Resistant Influenza A Viruses, Susu Duan

Theses and Dissertations (ETD)

Neuraminidase (NA) inhibitors including oral oseltamivir and inhaled zanamivir are among the first line of defense against influenza virus infection. Development of resistance to NA inhibitors is a huge drawback for limited options for the control of influenza. During the first decade of NA inhibitor use, the detection rates of resistance to both NA inhibitors had remained low in circulating influenza viruses. However, the 2008~2009 season was marked by a radical increase of prevalence of oseltamvir resistance from <1% to >90% in worldwide surveillance in less than a year. The resistance was solely linked to NA H275Y variants of seasonal H1N1 viruses, …

Neocortical Layer 4 To Layer 2/3 Sensory Information Processing Investigated With Digital-Light-Projection Neuronal Photostimulation, Jason Paul Jerome

Theses and Dissertations (ETD)

The mammalian brain forms neuronal networks and microcircuits with cell-type- and anatomical-specific synaptic connections. Despite great advances in elucidating the cellular physiology of the nervous system, little is known about the computational processes occurring at the level of neuronal microcircuits. Much success has been reported in describing the synaptic input patterns of many brain regions and cell types using photostimulation systems; however, these systems are severely limited in their ability to study the integration of synaptic input from multiple synchronous or temporally correlated presynaptic locations. Here we describe a system that allows the generation of arbitrary 2-D stimulus patterns with …

Hp Turns 17: T Helper 17 Cell Response During Hypersensitivity Pneumonitis (Hp) And Factors Controlling It, Hossam Abdelsamed

Theses and Dissertations (ETD)

Hypersensitivity Pneumonitis (HP) is an interstitial lung disease caused by repeated inhalation of a wide range of environmental antigens. It is characterized by alveolitis, granuloma formation, and fibrosis. Since HP is a T cell-mediated disease, it is important to determine the type of T cell response associated with granuloma formation and the factors that control this response. We hypothesized that HP is associated with a predominant Th17 cell response where both T-bet and TLRs 2 and 9 are controlling T cell response during HP. The results demonstrated a predominant Th17 response associated with granuloma formation in the lungs of C57BL/6J …