Open Access. Powered by Scholars. Published by Universities.®

Medicine and Health Sciences Commons™

Open Access. Powered by Scholars. Published by Universities.®

Theses and Dissertations

Discipline
Institution
Keyword
Publication Year
File Type

Articles 3241 - 3270 of 4193

Full-Text Articles in Medicine and Health Sciences

Rural Hospital System Affiliations And Their Effects On Hospital Economic Performance, 2004-2008, Mark Swofford Jun 2011

Rural Hospital System Affiliations And Their Effects On Hospital Economic Performance, 2004-2008, Mark Swofford

Theses and Dissertations

The formation of multi-hospital systems represents one of the largest structural changes in the hospital industry. As of 2008, system affiliated hospitals outnumbered stand alone hospitals 2511 to 2167 and the percentage of system affiliated rural hospitals has increased dramatically from 24.8% in 1983 to 42.2% in 2008 (based on AHA data for non-federal acute care general hospitals). The effects of system membership on hospital performance have been of great interest to health care researchers, but the majority of research on multi-hospital systems has either focused exclusively on urban facilities or pooled urban and rural facilities in the same sample, …


The Relationship Between Physicians‘ Ownership Of Physical Therapy Services And Referral Patterns To Hospital-Based Outpatient Rehabilitation Centers, Joy Bruce Jun 2011

The Relationship Between Physicians‘ Ownership Of Physical Therapy Services And Referral Patterns To Hospital-Based Outpatient Rehabilitation Centers, Joy Bruce

Theses and Dissertations

Background and Purpose A debate over the practice of physician self-referral has been ongoing in health care since the 1980s. At issue is the practice of physicians who refer patients to facilities in which they share a financial interest, a phenomenon known as referral for profit. Physician investment or ownership interest in ancillary (e.g., physical therapy) services has been shown to have an impact on utilization rates, costs, access to care, and quality of care. What has not been identified in previous research is the influence of physicians‘ selective referral on competing clinics, particularly the hospital-based outpatient centers that share …


Differential Glial Cell Responses In The Dentate Gyrus In Young Adult And Aged Brains Following Traumatic Brain Injury, Christoher Shin Jun 2011

Differential Glial Cell Responses In The Dentate Gyrus In Young Adult And Aged Brains Following Traumatic Brain Injury, Christoher Shin

Theses and Dissertations

Traumatic brain injury (TBI) affects 3 out of every 1000 Americans each year, and is the leading cause of morbidity and mortality after trauma, accounting for as many as 56,000 deaths per year (Dutton and McCunn, 2003). The Centers for Disease and Control and Prevention found that TBI most commonly occurs in adolescents and young adults aged from 15 to 24 years and in the elderly (75 years and older). Following injury, the secondary injury begins almost immediately after the primary injury and is the result of a number of cascades where once activated, exacerbate the already altered homeostasis of …


Cis 3,4', 5-Trimethoxy-3'-Aminostilbene (Stilbene 5c) Induces Apoptosis And Protective Autophagy In B16f10 Melanoma Cells, Betelehem Asnake Jun 2011

Cis 3,4', 5-Trimethoxy-3'-Aminostilbene (Stilbene 5c) Induces Apoptosis And Protective Autophagy In B16f10 Melanoma Cells, Betelehem Asnake

Theses and Dissertations

The weak selectivity of chemotherapeutic drugs against tumors has sustained efforts to develop better chemotherapeutic agents that are more potent and selective at destroying tumor cell populations versus normal tissues. This project focuses on evaluating the cell killing effects of the microtubule inhibitor, stilbene 5c, against melanoma cancer. We utilized an in vitro murine melanoma model to study the effects of stilbene 5c on tumor proliferation and survival, as well as growth arrest and cell death. Our findings indicate that stilbene 5c promotes dose dependent cell death in melanomas with the induction of apoptosis and autophagy. The role of autophagy …


Three-Dimensional Photographic Evaluation Of Immediate Soft Tissue Changes Following Rapid Maxillary Expansion, Nathan Granillo Jun 2011

Three-Dimensional Photographic Evaluation Of Immediate Soft Tissue Changes Following Rapid Maxillary Expansion, Nathan Granillo

Theses and Dissertations

The skeletal and dental changes associated with rapid maxillary expansion (RME) are well documented. Effects on the soft tissues and the potential impact on facial esthetics have not been well researched. The purpose of this study was to evaluate immediate changes in facial soft tissues as a result of RME by comparing threedimensional digital photogrammetric images before and after RME treatment. The 3dMDface System was used to obtain photographic images of 21 patients (mean age = 11.8 years) before and after RME treatment for transverse maxillary deficiency. A control group of 13 patients (mean age = 12.7 years) also had …


Self-Perception Of Smile Aesthetics And Self-Esteem, Larry Scarborough Jun 2011

Self-Perception Of Smile Aesthetics And Self-Esteem, Larry Scarborough

Theses and Dissertations

Introduction: Self-perception of smile aesthetics has been suggested as the most common reason for seeking orthodontic treatment. A recent study concluded that an improvement of dental attractiveness at the end of orthodontic treatment had positive effects on self-esteem. The purpose of this study was to determine if a relationship exists between one’s self-perceived smile aesthetics and their self-esteem. Methods: A survey was conducted where each subject completed an evaluation of their smile aesthetics and a Rosenberg Self-esteem Test (RST). A smiling photograph of each subject was evaluated by dental professionals for dental aesthetics and straightness. Results: Female students rated their …


Cmv Vaccine Development Based On Epithelial Entry Mediators Ul128, Ul130, Ul131, Frances Saccoccio Jun 2011

Cmv Vaccine Development Based On Epithelial Entry Mediators Ul128, Ul130, Ul131, Frances Saccoccio

Theses and Dissertations

Congenital cytomegalovirus infection is the leading cause of sensorineural hearing loss in the U.S. CMV vaccines developed to date do not protect the majority of women of childbearing age from primary CMV infection. Insufficient vaccine-induced epithelial entry neutralizing activity may be the reason for poor performance of these vaccines. CMV entry into endothelial and epithelial but not fibroblast cells requires the virion envelope complex gH/gL/UL128-131. Since current vaccines do not target this complex, epithelial entry mediators UL128-131 are attractive subunit CMV vaccine candidates, since they should target mucosal immunity. The mucosal immune response, specifically salivary epithelial entry neutralizing activity, has …


Heat Shock Proteins As Novel Cancer Therapeutics: Targeting The Hallmarks Of Cancer, Chao Li Jun 2011

Heat Shock Proteins As Novel Cancer Therapeutics: Targeting The Hallmarks Of Cancer, Chao Li

Theses and Dissertations

Molecular chaperones, commonly known as heat shock proteins (HSPs), are essential for mammalian cells to maintain homeostasis, and HSPs function by inducing an ATPase-coupled structural change, followed by interactions with diverse co-chaperones and over 200 client proteins implicated in many critical signaling networks. These highly expressed HSPs participate in the onset and progression of several human diseases including cancer, and their connection with tumorigenesis has facilitated research and clinical trials related to targeting HSPs as a novel anti-tumor therapy. The predominant mechanism of chaperone inhibition is through either disruption of the HSP association with client protein or an altered binding …


Statistical Image Reconstruction For Quantitative Computed Tomography, Joshua Evans May 2011

Statistical Image Reconstruction For Quantitative Computed Tomography, Joshua Evans

Theses and Dissertations

Statistical iterative reconstruction (SIR) algorithms for x-ray computed tomography (CT) have the potential to reconstruct images with less noise and systematic error than the conventional filtered backprojection (FBP) algorithm. More accurate reconstruction algorithms are important for reducing imaging dose and for a wide range of quantitative CT applications. The work presented herein investigates some potential advantages of one such statistically motivated algorithm called Alternating Minimization (AM). A simulation study is used to compare the tradeoff between noise and resolution in images reconstructed with the AM and FBP algorithms. The AM algorithm is employed with an edge-preserving penalty function, which is …


Impact Of Medicare Part D Coverage Gap On Beneficiaries' Adherence To Prescription Medications, Urvi Desai May 2011

Impact Of Medicare Part D Coverage Gap On Beneficiaries' Adherence To Prescription Medications, Urvi Desai

Theses and Dissertations

INTRODUCTION: Medicare Part D provides prescription drug coverage to seniors through a benefit plan with a major deductible inserted in the middle. It is important to study the extent to which this structure affects seniors’ adherence to prescription medications. Therefore, this study had the following objectives: (1) To identify characteristics of beneficiaries reaching and not reaching the coverage gap, (2) To study the entry and exit times from the coverage gap, (3) To study the impact of a complete gap in coverage on beneficiaries’ adherence to prescription medications, (4) To study the impact of a partial gap in coverage on …


Application Of Pharmacometric Methods To Improve Pediatric Drug Development, Mallika Lala May 2011

Application Of Pharmacometric Methods To Improve Pediatric Drug Development, Mallika Lala

Theses and Dissertations

Pharmacometrics is a quantitative science that is rapidly changing the landscape of drug development, and particularly so for the pediatric population. The motivation behind the research underlying this dissertation is to contribute towards the improvement of pediatric drug development by the astute application of pharmacometric methods. Two distinct research areas have been focused upon: 1- improving pediatric pharmacokinetic (PK) trial design and 2- improving pediatric dosing of warfarin by using a genetics-based dosing regimen. The first project examined in detail the feasibility of and simulation-based methodology for implementing a recent regulatory PK quality standard. The focus was on designing pediatric …


Prenatal Alcohol Exposure Reduces Dendritic Spine Density Across Sensory Cortices, Francis Oppong May 2011

Prenatal Alcohol Exposure Reduces Dendritic Spine Density Across Sensory Cortices, Francis Oppong

Theses and Dissertations

Dendritic spines are the major site of excitatory synapses in cortex, and factors that reduce dendritic spine numbers will produce serious cortical processing deficits, such as has been demonstrated for mental retardation and other psychiatric disorders. Prenatal alcohol exposure also has detrimental effects on brain development that lead to Fetal Alcohol Spectrum Disorder (FASD), which results in reduction of dendritic spine numbers in the hippocampus, prefrontal cortex and somatosensory cortex. FASD also is associated with temporal processing disorders involving sequential auditory stimuli that would be processed in auditory cortical areas. However, it is unknown if the reduction of spine density …


Comparison Of Adhesion Of Gutta Percha/Ah Plus® And Resilon/Epiphany® Se™ After A Final Rinse With Different Concentrations Of Ethanol, Suren Paravyan May 2011

Comparison Of Adhesion Of Gutta Percha/Ah Plus® And Resilon/Epiphany® Se™ After A Final Rinse With Different Concentrations Of Ethanol, Suren Paravyan

Theses and Dissertations

The purpose of this study was to evaluate effect of final rinse of ethanol on bond strength in teeth obturated with Gutta Percha (GP)/AH Plus® or Resilon/Epiphany®SE™. Thirty-two extracted human anterior teeth were shaped to size 30, 0.06 taper and subjected to an identical irrigation protocol. Specimens were randomly divided into eight groups according to final irrigating solution (saline, 70%, 95%, 100% ethanol) and obturation material. Two millimeter thick slices were obtained by sectioning each obturated root. Bond strength was determined using micropush-out assay. Data was analyzed using Student’s t-test. Obturation with GP/AH Plus® formed a statistically significant stronger bond …


The Effect Of Insulating K-Type Files On Accuracy And Reliability As Used In Two Electronic Apex Locators, Timothy Finkler May 2011

The Effect Of Insulating K-Type Files On Accuracy And Reliability As Used In Two Electronic Apex Locators, Timothy Finkler

Theses and Dissertations

The purpose of this in-vitro study is to compare the accuracy and reliability of a 3rd and 4th generation electronic apex locator (EAL) in locating the apical foramen when using insulated and non-insulated K files. Forty extracted human adult single-rooted teeth were coronally sectioned and placed in agar. EAL determined tooth length measurements were compared to actual tooth measurements. Comparisons to the standard measures used correlation and paired t-test. Preliminary comparisons of the groups used ANOVA to compare the means and the Brown-Forsythe test to compare variance. In the final analyses, the measurements were compared using a repeated-measures mixed-model multiway …


Comparison Of Epiphany® And Ah-Plus® Root Canal Sealer Penetration Of Dentinal Tubules: A Sem Study, Kalisha Jordan May 2011

Comparison Of Epiphany® And Ah-Plus® Root Canal Sealer Penetration Of Dentinal Tubules: A Sem Study, Kalisha Jordan

Theses and Dissertations

The purpose of this study was to evaluate the effect of a final rinse of ethanol on depth of sealer penetration in teeth obturated with Gutta Percha (GP)/AH-Plus® (Dentsply, De Trey GmbH, Konstanz, Germany) or Resilon/Epiphany® SE™ (Pentron Clinical Technologies, LLC, Wallingford, CT). Extracted human anterior teeth (n= 32) were shaped to size 30, 0.06 taper using nickel-titanium rotary files and subjected to an identical irrigation protocol. Specimens were randomly divided into eight groups according to final irrigating solution (saline, 70%, 95%, or 100% ethanol) and obturation material (GP/AH-Plus® or Resilon/EpiphanyÒ SE™). A 2mm thick slice was obtained by sectioning …


The Effects Of A Fluoride Releasing Orthodontic Primer On Demineralization Around Brackets: An In-Vivo Study., Daniel Pennella May 2011

The Effects Of A Fluoride Releasing Orthodontic Primer On Demineralization Around Brackets: An In-Vivo Study., Daniel Pennella

Theses and Dissertations

The purpose of this study was to investigate the effects of a fluoride releasing orthodontic primer on demineralization adjacent to brackets. Twenty-two patients were recruited for this study. One premolar was randomly chosen as the experimental tooth, the contralateral tooth was the control. Teeth were visually analyzed for white spot lesions (WSLs). Knoop microhardness was used to determine hardness. Visual examination results showed no significant difference in the number of WSLs observed between Opal Seal and Transbond XT over the duration of this study. Solid conclusions could not be drawn from the results of microhardness testing. Therefore, it cannot be …


A Novel Bioactive Glass-Enhanced Orthodontic Bonding Resin: A Shear Bond Strength Study, Cole Johnson May 2011

A Novel Bioactive Glass-Enhanced Orthodontic Bonding Resin: A Shear Bond Strength Study, Cole Johnson

Theses and Dissertations

Enamel decalcification caused by poor oral hygiene is a significant problem in orthodontics. Bioactive glass-containing resins have been shown to release Ca2+ ions into surrounding solution. The purpose of this study was to determine the shear bond strength of four different compositions of orthodontic resin prepared with bioactive glass (N=20). Premolars were bonded using one of four BAG-BOND compositions. Brackets were debonded and ARI scores were given. The mean shear bond strength was 7.23 ± 2.47 MPa (62 BAG-BOND), 8.25 ± 2.87 MPa (65 BAG-BOND), 8.78 ± 3.08 MPa (81BAG-BOND) and 5.80 ± 2.27 MPa (85 BAG-BOND). 65 and 81 …


Patient Satisfaction With Sedation For Periodontal Surgery: A Randomized, Cross-Over Clinical Study, Jason Streem May 2011

Patient Satisfaction With Sedation For Periodontal Surgery: A Randomized, Cross-Over Clinical Study, Jason Streem

Theses and Dissertations

PURPOSE: To create a study designed to assess patient satisfaction and preference for oral versus intravenous sedation in conjunction with periodontal surgical procedures. METHODS: Twenty-six patients who required at least two periodontal surgery procedures and requested sedation for treatment, participated in our study at VCU Department of Periodontics. This was a randomized, cross-over design with groups which received an intravenous sedative regimen with or without oral sedation premedication for one surgery and oral sedation medication alone for the other surgery. The primary outcome measurement was the type of sedation preferred by the subject. RESULTS: 14/26 (53.8%) subjects indicated a preference …


The Natural Polyphenol Resveratrol Potentiates The Lethality Of Hdac Inhibitors In Acute Myelogenous Leukemia Cells Through Multiple Mechanisms., Alae Abod Yaseen May 2011

The Natural Polyphenol Resveratrol Potentiates The Lethality Of Hdac Inhibitors In Acute Myelogenous Leukemia Cells Through Multiple Mechanisms., Alae Abod Yaseen

Theses and Dissertations

This study examined the mechanisms underlying the interactions between the natural polyphenol Resveratrol and HDAC inhibitors in both U937 myelomonocytic leukemia cell line and blood samples from AML patients and normal cord blood. Simultaneous exposure to Resveratrol and HDAC inhibitors (Vorinostat-SAHA or Panobinostat-LBH589) resulted in potentiating the lethality caused by any single agent of the combination, this interaction found to be synergistic at multiple concentrations. Exposing U937 cells to minimal toxic doses of Resveratrol and HDACIs results in release of mitochondrial pro-apoptotic proteins AIF and cytochrome c, pro-apoptotic caspase activation especially caspase-8, and induction of DNA damage. These events were …


Defining The Bacterial Flora Of Periodontal Pockets In Chronic Periodontitis Patients, Rafael Rodriguez May 2011

Defining The Bacterial Flora Of Periodontal Pockets In Chronic Periodontitis Patients, Rafael Rodriguez

Theses and Dissertations

PURPOSE: The purpose of this study is to describe the subgingival bacterial biodiversity in untreated chronic periodontitis patients through the use of next generation 16S rRNA molecular analysis, and to determine similarities or differences between deep and shallow pockets within the same patients. METHODS: The analysis involved paired subgingival plaque samples from 24 subjects diagnosed with Generalized Moderate to Severe Chronic Periodontitis. One sample was selected from a single site having a probing depth >5 mm (i.e. Deep Site), and the other from a site with a probing depth <3mm (i.e. Shallow Site) within each subject. Bacterial DNA amplification of the V4-V6 region of the 16S rRNA was performed. The amplicons were sequenced via 454 Roche Genome Sequencer FLX System. The identified sequences were evaluated, and then compared to calculated false discovery rates. RESULTS: A total of 119 independent microbial genera were identified within the samples analyzed. Seven genera were identified to be statistically significant (p<0.05) in their association to deep or shallow sites following t-test and boot strap randomization: Actinomyces (p=0.004), Methylobacterium (p=0.028), Veillonella (p=0.028), and Rothia (p=0.038), and Streptococcus (p=0.033) in Shallow sites; while Mycoplasma (p=0.007) and Fusobacterium (p=0.016) were associated with deep sites. However, taking into account the calculated false discovery rates, it is suggested that none of the 119 microbial genera identified in this study were significantly associated with either deep nor shallow sites. CONCLUSION: The microbial genera identified within this study to be associated with deep and shallow sites follows the traditional pattern anticipated from the literature. However, the calculated false discovery rates suggest that these results may have occurred by chance and not due to a true difference.


Distinct T Cell Clones Are Associated With Graft-Versus-Host Disease (Gvhd), And Potentially Graft-Versus-Tumor (Gvt), Responses Following Allogeneic Stem Cell Transplantation, Jennifer Berrie Apr 2011

Distinct T Cell Clones Are Associated With Graft-Versus-Host Disease (Gvhd), And Potentially Graft-Versus-Tumor (Gvt), Responses Following Allogeneic Stem Cell Transplantation, Jennifer Berrie

Theses and Dissertations

In patients undergoing hematopoietic stem cell transplantation (HSCT) with HLA-identical donors, genetic polymorphisms result in a mismatch between donors and recipients in their minor histocompatibility antigens (mHAgs), and tumors may also express tumor-associated antigens (TAA) that may not be abundantly present in the donors. Donor T cells can recognize such mHAgs and TAAs as foreign antigens and generate an objective response against hematologic malignancies in a graft-versus-tumor (GVT) effect. However, a major side effect of HSCT occurs when donor T cells are alloreactive against the recipients’ normal cells, leading to graft-versus-host disease (GVHD). The ability to identify T cell clones …


Sulfatide Is Required For Organization Of The Paranode In The Myelinated Axon In The Peripheral Nervous System, Eva Kwong Apr 2011

Sulfatide Is Required For Organization Of The Paranode In The Myelinated Axon In The Peripheral Nervous System, Eva Kwong

Theses and Dissertations

Myelin facilitates the timely, efficient conduction of action potentials along axons. Made by Schwann cells (SCs) in the PNS, myelin is unique in that it is composed of a high percentage of lipids, particularly galactolipids. Sulfatide, one such galactolipid, is made by cerebroside sulfotransferase (CST) and has been shown to play a role in organizing paranodal domains in myelinated axons. However less is known regarding the involvement of sulfatide in the establishment and maintenance of the node, of particular interest as it is responsible for the potentiation of action potentials along the axon. Using immunohistochemical and, to a lesser extent, …


Role Of Two-Component System Response Regulators In Virulence Of Streptococcus Pneumoniae Tigr4 In Infective Endocarditis, My Trinh Apr 2011

Role Of Two-Component System Response Regulators In Virulence Of Streptococcus Pneumoniae Tigr4 In Infective Endocarditis, My Trinh

Theses and Dissertations

Streptococci resident in the oral cavity have been linked to infective endocarditis (IE). While viridans streptococci are commonly studied and associated with IE, less research has been focused on Streptococcus pneumoniae. Two-component systems (TCSs), consisting of a histidine kinase (HK) protein and response regulator (RR) protein, are bacterial signaling systems that may mediate S. pneumoniae TIGR4 strain virulence in IE. To test this hypothesis, TCS RR mutants of TIGR4 were examined in vivo through use of rabbit models. There were 14 RR proteins identified and 13 RR mutants synthesized because SP_1227 was found to be essential. The requirement of the …


Trends In Dental Care For Individuals With Ectodermal Dysplasia, Justin Edwards Apr 2011

Trends In Dental Care For Individuals With Ectodermal Dysplasia, Justin Edwards

Theses and Dissertations

Purpose: The specific aim of this study is to evaluate the trends in dental health care for individuals with ectodermal dysplasia. Methods: This was a cross sectional analysis of subjects recruited through the National Foundation of Ectodermal Dysplasia (NFED). From 1997 to 2000, individuals with ectodermal dysplasia or their caregiver (if the individuals were too young to selfreport) voluntarily completed questionnaires. The questionnaire consisted of 37 items consisting of demographics, ectodermal dysplasia diagnosis, access to dental care, level of dental utilization, and type of dental services received. Descriptive statistics were used in addition to ANOVA analyses to evaluate the changing …


Maternal Influences On The Development Of Infant Oral Biofilm, James Dibelka Apr 2011

Maternal Influences On The Development Of Infant Oral Biofilm, James Dibelka

Theses and Dissertations

Purpose: The purpose was to examine the maternal influences on the development of infant oral biofim and dominant bacterial strains of at risk populations. Methods: The study used a cross-sectional design to examine factors influencing biofilm colonization and the identification of bacterial strains transmitted from mother to child. Participants were enrolled in Children’s Health Involving Parents of Greater Richmond (CHIP). Plaque and saliva samples were collected from mothers and their children ages 6-36 months. The colonized oral bacteria strains of the mother infant dyads were then compared. Oral bacterial strain identification was completed using the HOMIM Forsythe microbe identification array. …


The Role Of The Propeptide And Its Residues In Activation And Secretion Of Elastase, An M4 Metalloprotease Secreted By Pseudomonas Aeruginosa, Emily Boice Apr 2011

The Role Of The Propeptide And Its Residues In Activation And Secretion Of Elastase, An M4 Metalloprotease Secreted By Pseudomonas Aeruginosa, Emily Boice

Theses and Dissertations

Pseudomonas aeruginosa secretes several proteases associated with pathogenesis, but the most abundant and active is elastase (M4 metalloendopeptidase). Elastase (lasB), is first synthesized as a preproenzyme, with a signal peptide, an 18-kDa N-terminal propeptide, and a 33-kDa mature domain. The propeptide functions as an intramolecular chaperone that is required for the folding and secretion of elastase, but ultimately is proteolytically removed and degraded. Previous research has identified the conserved residues in the propeptide of elastase as compared to other M4 protease precursors and showed some among them to be important for the production of active elastase. In this project, the …


Targeting The Endocannabinoid System To Reduce Nociception, Lamont Booker Apr 2011

Targeting The Endocannabinoid System To Reduce Nociception, Lamont Booker

Theses and Dissertations

Pain of various etiologies (e.g., visceral, inflammatory) can be a debilitating disorder that presents a problem of clinical relevance. While it is known that ∆9-tetrahydrocannabinol (THC) the primary psychoactive constituent found in marijuana produces analgesia in various rodent models of pain, its pharmacological properties are overshadowed by its psychomimetic effects. THC is the primary phytocannabinoid found in marijuana though other prevalent constituents such as the phytocannabinoids (e.g., cannabidiol (CBD), cannabinol (CBN), cannabichromene (CBC), tetrahydrocannabivarin (THCV)) may possess antinociceptive actions without the psychomimetic effects associated with THC. Indeed, these phytocannabinoids act upon the endocannabinoid system (ECS) that is comprised of the …


Electrophysiological Characterization Of Enteric Neurons Isolated From The Immortomouse, Edward G. Hawkins Apr 2011

Electrophysiological Characterization Of Enteric Neurons Isolated From The Immortomouse, Edward G. Hawkins

Theses and Dissertations

The availability of murine genetic models is extremely advantageous to studying gastrointestinal function, but the benefits afforded by studying enteric neurons in mice has been hindered by their accessibility. Fetal (E13) and 2 day post-natal (P2) enteric neuron cell lines (IM-FEN and IM-PEN, respectively) were recently developed from the H-2Kb-tsA58 immortomouse. Our goal was to identify the electrophysiological properties of these cell lines and clarify their utility as a model of enteric neurons. IM-PEN cells stained positively for the neuron specific markers βIII-tubulin and PGP9.5 and were negative for the glial cell marker S100. Detection of mRNA for TRPA1, TRPV1, …


Involvement Of P53 In The S-Phase Checkpoint During Nucleotide Deficiencies, Cortney Heyer Apr 2011

Involvement Of P53 In The S-Phase Checkpoint During Nucleotide Deficiencies, Cortney Heyer

Theses and Dissertations

Several classes of antimetabolites have been developed for the treatment of cancer, including numerous inhibitors of nucleotide biosynthesis. N-(phosphonacetyl)-L-aspartate (PALA) and hydroxyurea (HU) are two antimetabolites that inhibit nucleotide biosynthesis; PALA inhibits de novo pyrimidine synthesis and HU inhibits the conversion of ribonucleotide diphosphates to deoxyribonucleotide diphosphates. Due to the similar mechanisms, it was thought that cancer cells would respond similarly to HU and PALA treatment. However, studies in this dissertation revealed strikingly different responses to either HU or PALA treatment in HCT116 cells. A cytoprotective S-phase arrest was activated upon HU treatment while PALA treatment failed to activate the …


Adam10 Exacerbation Of Allergic Disease Is Potentially Explained By Its Role In Cd23 Exosomal Sorting., Joel Mathews Apr 2011

Adam10 Exacerbation Of Allergic Disease Is Potentially Explained By Its Role In Cd23 Exosomal Sorting., Joel Mathews

Theses and Dissertations

CD23, the natural negative regulator of IgE, has been shown to be involved in asthma progression through its regulation of IgE. To investigate if its sheddase, ADAM10, is also involved in asthma progression, three mouse models were utilized; an IgE/mast cell dependent model, an IgE dependent, mast cell independent model and a mast cell and IgE independent model. Experimental asthma was then induced in mice which were selectively deficient for ADAM10 in B cells (ADAM10-/-) and compared to WT controls. The ADAM-/- mice had decreased signs of asthma, including eosinophilia, AHR and IgE synthesis in the IgE dependent model compared …