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Full-Text Articles in Medicine and Health Sciences

The Effects Of Age And Heterochromatin On Frequencies Of Acquired Chromosomal Aneuploidy In Uncultured Human Leukocytes, Noran Aboalela Dec 2010

The Effects Of Age And Heterochromatin On Frequencies Of Acquired Chromosomal Aneuploidy In Uncultured Human Leukocytes, Noran Aboalela

Theses and Dissertations

While age-related sex chromosomal aneuploidy is a well-characterized phenomenon, the relationship between autosomal loss and age remains unclear. The emergence of the specific and highly sensitive fluorescence in situ hybridization (FISH) technology has enabled investigators to study interphase cells, thereby overcoming problems inherent with the study of metaphase spreads for acquired aneuploidy assessment. Despite all the advantages of this technique, there are some limitations that could be misleading when scoring interphase autosomal aneuploidy. In this study we show that sex chromosomal hypoploidy is correlated with age. By using a twin study design, we evaluated Y chromosome hypoploidy frequencies and found …


Haploinsufficiency Of Rai1 And Its Effect On Bdnf Expression, Sun Kim Dec 2010

Haploinsufficiency Of Rai1 And Its Effect On Bdnf Expression, Sun Kim

Theses and Dissertations

Smith-Magenis Syndrome (SMS) [OMIM, #182290] is a congenital anomaly and mental retardation (MCA/MR) syndrome associated with deletion of chromosome17p11.2 [1]. The clinical phenotype has been well described and includes minor craniofacial anomalies, self-injurious behaviors as well as sleep disturbances, speech delays, and obesity [1,2,3]. The incidence of SMS is estimated to be ~ 1:15,000 - 25,000 births [2,6]. Among SMS patients, ~90% are comprised of 17p11.2 deletions, while ~10% have RAI1 mutations [8]. All 17p11.2 deletions associated with SMS include RAI1 deletion [10]. RAI1 is thought to function as a transcriptional factor although its cellular role is still unclear. First, …


Characterization And Development Of A Stroke-Induced Model Of Acquired Epilepsy In Organotypic Hippocampal Slice Cultures: Role Of The Cannabinoid Cb1 Receptors In Modulation Of Neuronal Excitation And Inhibition, Julie Ziobro Nov 2010

Characterization And Development Of A Stroke-Induced Model Of Acquired Epilepsy In Organotypic Hippocampal Slice Cultures: Role Of The Cannabinoid Cb1 Receptors In Modulation Of Neuronal Excitation And Inhibition, Julie Ziobro

Theses and Dissertations

Stroke is the most common cause of acquired epilepsy in persons 35 and older. The massive increase in extracellular glutamate during stroke causes a cascade of intracellular events that can lead to cell death or the molecular changes that initiate the development of epilepsy. In addition, many studies point to a modulatory role of the endocannabinoid system in controlling seizures. Animal models of stroke induced acquired epilepsy have been difficult to develop. Therefore, this dissertation was initiated to develop an organotypic hippocampal slice culture model of acquired epilepsy and examine the changes in distribution and function of the endogenous CB1 …


Antifolate Modulators Of Amp-Activated Protein Kinase Signaling As Cancer Therapeutics, Scott Rothbart Sep 2010

Antifolate Modulators Of Amp-Activated Protein Kinase Signaling As Cancer Therapeutics, Scott Rothbart

Theses and Dissertations

Since its discovery, it was appreciated that the antifolate pemetrexed had multiple targets within folate metabolism. This laboratory was instrumental in showing that pemetrexed elicited its primary action as a thymidylate synthase inhibitor. Unusual for an antifolate, pemetrexed showed significant clinical activity against malignant pleural mesothelioma and non-small cell lung cancer. Accordingly, the FDA recently issued first-line approvals for pemetrexed in these diseases, leading us to question whether the effects of pemetrexed on other folate-dependent targets could explain this atypical clinical activity of the drug. Studies in this dissertation showed that in addition to thymidylate synthase inhibition, pemetrexed was also …


Cannabinoid Receptors In The 3d Reconstructed Mouse Brain: Function And Regulation, Peter Nguyen Aug 2010

Cannabinoid Receptors In The 3d Reconstructed Mouse Brain: Function And Regulation, Peter Nguyen

Theses and Dissertations

CB1 receptors (CB1R) mediate the psychoactive and therapeutic effects of cannabinoids including ∆9-tetrahydrocannabinol (THC), the main psychoactive constituent in marijuana. However, therapeutic use is limited by side effects and tolerance and dependence with chronic administration. Tolerance to cannabinoid-mediated effects is associated with CB1R adaptations, including desensitization (receptor-G-protein uncoupling) and downregulation (receptor degradation). The objectives of this thesis are to investigate the regional-specificity in CB1R function and regulation. Previous studies have investigated CB1Rs in a subset of regions involved in cannabinoid effects, but an inclusive regional comparison of the relative efficacies of different classes of cannabinoids to activate G-proteins has not …


The Impact Of Adolescent Nicotine Exposure On Drug Dependence In Adulthood, Mai Alajaji Jul 2010

The Impact Of Adolescent Nicotine Exposure On Drug Dependence In Adulthood, Mai Alajaji

Theses and Dissertations

Nicotine is one of the first and most commonly abused drugs in adolescence. According to The Center for Disease Control, every day more than 6000 adolescents try their first cigarette and over 3000 of them become daily smokers. Smoking among adolescents is a strong predictor of future drug abuse and dependence in adulthood. A number of studies has suggests that adolescents pre-exposed to nicotine may suffer permanent disruption of the brain’s reward systems through changes in dopamine receptor function. We hypothesize that nicotine exposure during adolescence causes long lasting neurobiological alterations that increase the likelihood of cocaine use in adulthood. …


The Mechanism Of Obesity In Rai1+/- Mice, Kristie Schmidt Jul 2010

The Mechanism Of Obesity In Rai1+/- Mice, Kristie Schmidt

Theses and Dissertations

Smith-Magenis syndrome (SMS) is a genetic disorder caused by a deletion or mutation of the retinoic acid induced 1 (RAI1) gene on chromosome 17p11.2 that results in haploinsufficiency. SMS patients with a deletion account for 90% of the cases, while the other 10% have a mutation in RAI1. The syndrome is characterized by cognitive impairment, craniofacial abnormalities, sleep disturbances, developmental delay, obesity, and behavioral phenotypes. SMS is thought to affect 1:25,000 live births, although due to similar infantile phenotypes with Down syndrome and Prader-Willi syndrome, SMS may be mis- or under-diagnosed. In a study of 54 children, it was shown …


Cell Death And Sustained Senescence Arrest In Colon Carcinoma And Melanoma Tumor Cells In Response To The Novel Microtubule Poison, Jg-03-14, Jonathan Biggers Jul 2010

Cell Death And Sustained Senescence Arrest In Colon Carcinoma And Melanoma Tumor Cells In Response To The Novel Microtubule Poison, Jg-03-14, Jonathan Biggers

Theses and Dissertations

Previous studies from this and other laboratories have shown that the novel microtubule poison, JG-03-14, which binds to the colchicine binding site of tubulin, has the capacity to promote both autophagy and apoptosis in breast tumor cells, as well as interfering with endothelial cell function and potentially disrupting tumor vasculature. The current work was designed to investigate the interaction between JG-03-14 and cell culture models of colon carcinoma and melanoma, specifically HCT116 human colon carcinoma cells and B16F10 murine melanoma cells. In both cases, JG-03-14 promoted death in the bulk of the treated population. FACS analysis, DAPI and TUNEL staining …


Identification And Characterization Of A Second Wolfram Syndrome Gene, Sami Amr May 2010

Identification And Characterization Of A Second Wolfram Syndrome Gene, Sami Amr

Theses and Dissertations

Wolfram Syndrome (WFS) is a debilitating autosomal recessive neurodegenerative disorder characterized by juvenile onset insulin dependent diabetes mellitus (DM) and optic atrophy (OA) as well as a number of neurological and endocrine complications that result in early death due to respiratory complications. Previous research has mapped Wolfram syndrome to chromosome 4p16.1 and the disease has been attributed to mutations in the WFS1 gene affecting the WFS1 protein (wolframin), an ER membrane glycoprotein that plays an important role in the unfolded protein response (UPR) and in intracellular Ca2+ homeostasis. An additional locus for WFS on chromosome 4q22-24 was identified by linkage …


The Mechanism Of Mitochondrial Folate Transport By The Mitochondrial Folate Transporter, Scott Alan Lawrence Apr 2010

The Mechanism Of Mitochondrial Folate Transport By The Mitochondrial Folate Transporter, Scott Alan Lawrence

Theses and Dissertations

The mitochondrial folate transport protein (MFT) functions to transport folates into the mitochondrial matrix. The MFT is a member of a mitochondrial carrier family (MCF) of proteins that have a high degree of sequence and structural similarities, yet they transport vastly different substrates at high specificities. In this dissertation research, the folate-specific transport mechanism of the MFT was explored using experimental and computational techniques. MFT residues that differed from MCF consensus residues in conserved PxD/ExxK/R motifs and at a predicted substrate-binding site common to all MCF proteins were investigated. Site-directed mutagenesis of these anomalous residues in the MFT revealed that …


Insulin-Like Growth Factor Binding Protein-3 (Igfbp-3) Plays An Essential Role In Cellular Senescence: Molecular And Clinical Implications., Amanda Garza Apr 2010

Insulin-Like Growth Factor Binding Protein-3 (Igfbp-3) Plays An Essential Role In Cellular Senescence: Molecular And Clinical Implications., Amanda Garza

Theses and Dissertations

Normal somatic cells have a limited proliferative capacity in vivo and in vitro, termed senescence and later, thought to contribute to molecular and cellular organismal aging. There are several studies that demonstrate the importance of the GH/IGF axis in longevity, aging and cellular senescence. One primary component of the IGF signaling involves IGFBP-3. It is well documented that IGFBP-3 levels are significantly increased in senescent human diploid fibroblasts however IGFBP-3 function is not known in this system. Interestingly, Werner syndrome fibroblasts, commonly used as a model of cellular aging, have upregulated IGFBP-3 levels in young and late passage cells compared …


Mechanisms Associated With Aging And Age-Related Disease In Drosophila, Melanie Jones Apr 2010

Mechanisms Associated With Aging And Age-Related Disease In Drosophila, Melanie Jones

Theses and Dissertations

Aging is an intrinsic process that is independent of obvious disease. In contrast to normal aging, age-related diseases are conditions that typically manifest at advanced ages, are associated with explicit pathology and cause disability and premature death. We used Drosophila as a model to investigate the molecular-genetic mechanisms associated with aging and age-related disease. Age-related locomotor impairment (ARLI) is a serious condition for the elderly and greatly impacts their quality of life. Toward identifying genes and mechanisms that influence ARLI, we performed a forward genetic screen using Drosophila mutants. This screen identified a loss of function mutant in PDK1, a …


Identification Of Loci Contributing To The Smith-Magenis Syndrome-Like Phenotype And Molecular Evaluation Of The Retinoic Acid Induced 1 Gene, Stephen Williams Apr 2010

Identification Of Loci Contributing To The Smith-Magenis Syndrome-Like Phenotype And Molecular Evaluation Of The Retinoic Acid Induced 1 Gene, Stephen Williams

Theses and Dissertations

Smith-Magenis syndrome (SMS) is a multiple congenital abnormalities intellectual disability syndrome that results from a deletion of chromosome 17p11.2 or mutation of the retinoic acid inducted one gene (RAI1). SMS is characterized by a multitude of phenotypic features including craniofacial defects, short stature, obesity, intellectual disability, self-abusive behavior, sleep disturbance and behavioral abnormalities. Interestingly, although SMS is a clearly defined syndrome with a known molecular change at its foundation, ~40% of all candidate cases sent to the Elsea lab for evaluation do not have a mutation or deletion of RAI1. We hypothesize that at least one other locus must be …


Differential Roles Of The Two Major Endocannabinoid Hydrolyzing Enzymes In Cannabinoid Receptor Tolerance And Somatic Withdrawal, Joel Schlosburg Apr 2010

Differential Roles Of The Two Major Endocannabinoid Hydrolyzing Enzymes In Cannabinoid Receptor Tolerance And Somatic Withdrawal, Joel Schlosburg

Theses and Dissertations

While there is currently active debate over possible therapeutic applications of marijuana and cannabis-based compounds, consistently their primary drawbacks have been the psychoactive properties, dependence, and abuse potential. Prolonged administration of ∆9-tetrahydrocannabinol (THC), the primary psychoactive constituent in marijuana, demonstrates both tolerance and physical withdrawal in both preclinical and clinical studies. Repeated THC administration also produces CB1 receptor adaptations in the form of reduced activation of receptors, along with a downregulation of membrane surface receptors, in many brain regions involved in THC-associated behaviors. The increased need for drug to maintain therapeutic effects, and a withdrawal syndrome following discontinuation of use, …


Modulation Of Cocaine-Like Behavioural Activity By Serotonin Uptake Inhibition Relative To The Effects Of The Novel And Selective Dopamine Transporter Inhibitor, D-84, Angela Batman Apr 2010

Modulation Of Cocaine-Like Behavioural Activity By Serotonin Uptake Inhibition Relative To The Effects Of The Novel And Selective Dopamine Transporter Inhibitor, D-84, Angela Batman

Theses and Dissertations

Cocaine dependence is a major health concern worldwide, but despite this high rate of abuse there are currently no approved therapies for cocaine dependence. Replacement pharmacotherapies are one possible approach for treating cocaine dependence, and identification of such therapeutics for cocaine abuse is the long-term goal of this research. Cocaine binds to, and inhibits uptake at the dopamine (DAT), serotonergic (SERT) and noradrenaline (NET) uptake transporters, but studies have shown that cocaine produces its strong behavioural and positive reinforcing effects through inhibition of the DAT. To this end a great number of diverse, non-selective DAT-inhibiting compounds have been investigated as …


Recapitulating Osteoblastogenesis With Electrospun Fibrinogen Nanofibers And Adipose Stem Cells And Electrospinning Adipose Tissue-Derived Basement Membrane, Michael Francis Feb 2010

Recapitulating Osteoblastogenesis With Electrospun Fibrinogen Nanofibers And Adipose Stem Cells And Electrospinning Adipose Tissue-Derived Basement Membrane, Michael Francis

Theses and Dissertations

To repair, replace, or regenerate damaged or diseased tissue has been a long-standing, albeit elusive, goal in medical research. Here, we characterize patient-derivable mesenchymal stem cell types, termed adipose-derived stem cells (ASCs). These cells, which can be derived from liposuction fat and lipoaspirate saline, are sources for patient-derivable extracellular matrix (ECM), fibrinogen (Fg) and adipose tissue extracellular matrix, and may prove useful for synthesizing new bone tissue analogues in vitro. Traditionally and rapidly isolated ASCs were thoroughly characterized as multipotent, having osteogenic, adipogenic, and chondrogenic differentiation potential, and they exhibited comparable proliferative lifespans. These ASCs also shared an indistinguishable immunophenotype …


Regulation Of Telomerase Expression In Stem Cell Reprogramming, Patrick Sachs Jan 2010

Regulation Of Telomerase Expression In Stem Cell Reprogramming, Patrick Sachs

Theses and Dissertations

A great need exists for an abundant, easily accessible source of patient-specific cells that will function for use in regenerative medicine. One promising source is the adult stem cell derived from adipose tissue (ASCs). Isolated from waste lipoaspiration, these cells could serve as a readily available source for the regeneration of damaged tissues. To further define the biology of ASCs, we have isolated multiple cell strains from different adipose tissue sources, indicating wide-spread distribution in the body. We find that a widely used set of cell surface markers fail to distinguish ASCs from normal fibroblasts. However, our ASC isolations are …


Autotaxin: A Regulator Of Oligodendrocyte Differentiation, Larra Yuelling Jan 2010

Autotaxin: A Regulator Of Oligodendrocyte Differentiation, Larra Yuelling

Theses and Dissertations

In order for oligodendrocyte progenitor cells (OPCs) to differentiate into fully mature, myelinating oligodendrocytes, they must be specified at the correct times and undergo coordinated changes in both gene expression and morphology. As oligodendrocytes differentiate, they transition from a bipolar morphology into a morphology characterized by a complex network of multiple processes, which will eventually generate membranous structures necessary for myelination of axonal segments. As changes are observed in cellular morphology, oligodendrocytes also undergo changes in their gene expression profile and express genes necessary for both early and later stages of development such as olig1 and myelin basic protein (mbp), …


The Role Of Methyl Cpg Binding Domain Protein 2 (Mbd2) In The Regulation Of Embryonic And Fetal Β-Type Globin Genes, Merlin Nithya Gnanapragasam Jan 2010

The Role Of Methyl Cpg Binding Domain Protein 2 (Mbd2) In The Regulation Of Embryonic And Fetal Β-Type Globin Genes, Merlin Nithya Gnanapragasam

Theses and Dissertations

The reexpression of the fetal γ-globin gene in adult erythrocytes is of therapeutic interest due to its ameliorating effects in β-hemoglobinopathies. We recently showed that Methyl CpG Binding Domain Protein2 (MBD2) contributes to the silencing of the chicken embryonic ρ-globin and human fetal γ-globin genes. We further biochemically characterized an erythroid MeCP1 complex that is recruited by MBD2 to mediate the silencing of these genes. These observations suggest that the disruption of the MeCP1 complex could augment the expression of the fetal/embryonic globin genes. In the studies presented in chapter 2, we have pursued a structural and biophysical analysis of …


The Role Of Synaptically Evoked Plateau Potentials In Retinogeniculate Development, Emily Dilger Jan 2010

The Role Of Synaptically Evoked Plateau Potentials In Retinogeniculate Development, Emily Dilger

Theses and Dissertations

We study the activity-dependent refinement of sensory systems by using the mouse retinogeniculate system as a model. Spontaneous retinal waves lead to robust excitatory post-synaptic activity in developing relay cells in the dorsal lateral geniculate nucleus (dLGN) of the thalamus and are reportedly needed to help guide the segregation of retinal inputs into eye-specific domains as well as for the pruning of extraneous retinal inputs onto single dLGN relay cells. The composition of retinally evoked post-synaptic activity activated by these retinal waves in dLGN is largely unknown, but based on our in vitro recordings, such activity seems well suited to …