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Theses and Dissertations

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Articles 421 - 438 of 438

Full-Text Articles in Medical Sciences

Pathological Upregulation Of A Calcium-Stimulated Phosphatase, Calcineurin, In Two Models Of Neuronal Injury, Jonathan Elledge Kurz Jan 2006

Pathological Upregulation Of A Calcium-Stimulated Phosphatase, Calcineurin, In Two Models Of Neuronal Injury, Jonathan Elledge Kurz

Theses and Dissertations

Excitotoxic calcium influx and activation of calcium-regulated systems is a common event in several types of neuronal injury. This mechanism has been the focus of intense research, with the hope that a more complete understanding of how neuronal injury affects calcium-regulated systems will provide effective treatment options. This study examines one such calcium-stimulated enzyme, calcineurin, in the context of two common neurological pathologies, status epilepticus and traumatic brain injury.Status epilepticus was induced by pilocarpine injection. NMDA-dependent increases in calcineurin activity were observed in cortical and hippocampal homogenates. Upon closer examination, the most profound increases in activity were found to be …


Characterization Of The Tcof1 Gene Using A Neuroblastoma Cell Line And A Mouse Model, Lin Li Jan 2006

Characterization Of The Tcof1 Gene Using A Neuroblastoma Cell Line And A Mouse Model, Lin Li

Theses and Dissertations

Treacher Collins syndrome (TCS) is an autosomal dominant craniofacial development disorder and is caused by mutations in the TCOF1 gene. The TCOFl protein treacle is a nucleolar protein and may function in ribosome biogenesis.Previously, we identified downstream candidate genes using microarray analysis after manipulating Tcofl levels in a murine neuroblastoma (NB) cell line. The list of genes includes cell cycle genes as well as the transcription factors Cnbp and Tbx2, which are known to affect the cell cycle through the c-myc and p19-Mdm2-p53-p21 pathways respectively. To further characterize the cellular effects of Tcofl, stably transfected NB cell lines with overexpression …


The Role Of Gonadal Hormones On Opioid Receptor Protein Density In Arthritic Rats, Matthew Kren Jan 2006

The Role Of Gonadal Hormones On Opioid Receptor Protein Density In Arthritic Rats, Matthew Kren

Theses and Dissertations

The majority of research on the endogenous opioid system has focused on various pain assays and the efficacy of different opioid agonists. However, minimal attention has been focused on the effects of gonadal hormones and their impact on the opioid peptide system. The present study was designed to determine the effects of modulation of gonadal hormones on the opioid receptor protein levels in Complete Freund's Adjuvant (CFA)-treated arthritic and non-arthritic male and female Lewis rats. Midbrain and spinal cord tissues were collected for comparison of the μ, δ, and κ receptor protein levels in arthritic and non-arthritic animals. Male gonadectomy …


A Twin Study Of Antisocial Behavior And Depression: Methodology, Etiology, And Comorbidity, Kelly A. Tracy Jan 2006

A Twin Study Of Antisocial Behavior And Depression: Methodology, Etiology, And Comorbidity, Kelly A. Tracy

Theses and Dissertations

The etiological connection between internalizing and externalizing disorders is poorly understood. This manuscript aims to investigate the roles of genes and then environment in the development of Major Depressive Disorder (MDD) and Antisocial Personality Disorder (ASPD) and the nature of their comorbidity in young adults. Data from a sample of 2,291 young adult male and female twins from the Young Adult Follow Up Study (YAFU) of the Virginia Twin Study of Adolescent Behavioral Development (VTSABD) were used to estimate the proportion of variation in these traits that can be accounted for by additive genetic, shared environmental, and unique environmental factors. …


Glutamate Excitotoxicty Activates A Novel Calcium Permeable Ion Channel In Cultured Hippocampal Neurons, Laxmikant Sudhir Deshpande Jan 2006

Glutamate Excitotoxicty Activates A Novel Calcium Permeable Ion Channel In Cultured Hippocampal Neurons, Laxmikant Sudhir Deshpande

Theses and Dissertations

Glutamate excitotoxicity is the predominant mechanism implicated in neuronal cell death associated with neurological disorders such as stroke, epilepsy, traumatic brain injury and ALS. Excessive stimulation of NMDA subtypes of glutamate receptors leads to protracted intracellular calcium elevations triggering calcium mediated neurotoxic mechanisms culminating in delayed neuronal cell death. In addition, glutamate excitotoxicity induces a NMDA dependent extended neuronal depolarization mediated by continuous calcium influx that correlates with delayed neuronal death. Attempts to prevent neuronal death by blocking calcium entry into the neurons using calcium channel blockers or NMDA receptor antagonists have failed to provide any beneficial effects in clinical …


Immunotoxicological Evaluation Of Critical Windows Of Development Following Exposure To 1,2:5,6 Dibenzanthracene In B6c3f1 Mice, Denise Marie Hernandez Jan 2006

Immunotoxicological Evaluation Of Critical Windows Of Development Following Exposure To 1,2:5,6 Dibenzanthracene In B6c3f1 Mice, Denise Marie Hernandez

Theses and Dissertations

Numerous findings have suggested that the increased prevalence of childhood illnesses such as cancer, infection, and allergy may be due to environmental exposures. One such cause may be maternal smoking or passive smoke exposure. Known immunotoxicants in cigarette smoke and environmental pollution include polycyclic aromatic hydrocarbons such as 1,2:5,6 Dibenzanthracene (DBA). The objective of these studies was to evaluate the immunosuppressive effects of DBA on various stages of immune system development. Adult mice were administered DBA daily in corn oil at dose levels of 158, 500, 1580, and 5000 µglkg S.C. for 28 days. Immunosuppression was not observed at levels …


An Analysis Of Biometric Technology As An Enabler To Information Assurance, Darren A. Deschaine Mar 2005

An Analysis Of Biometric Technology As An Enabler To Information Assurance, Darren A. Deschaine

Theses and Dissertations

The use of and dependence on, Information technology (IT) has grown tremendously in the last two decades. Still, some believe the United States is only in the infancy of this growth. This explosive growth has opened the door to capabilities that were only dreamed of in the past. As easy as it is to see how advantageous this technology is, it also is clear that with its advantages come distinct responsibilities and new problems that must be addressed. For instance, the minute one begins using information processing systems, the world of information assurance (IA) becomes far more complex. As a …


The Study Of The Effect Of Drugs Of Abuse On Protein Kinase A Activity In Mouse Brain And Spinal Cord, George D. Dalton Jan 2005

The Study Of The Effect Of Drugs Of Abuse On Protein Kinase A Activity In Mouse Brain And Spinal Cord, George D. Dalton

Theses and Dissertations

Morphine and Δ9-THC are drugs that produce analgesia and rewarding effects. However, chronic treatment with morphine and Δ9-THC produces problematic side-effects including tolerance and physical dependence. The cellular mechanisms underlying opioid and cannabinoid antinociceptive tolerance have been studied for years. Research has demonstrated that the expression of morphine and Δ9-THC antinociceptive tolerance may be mediated through intracellular signaling pathways, such as the adenylyl cyclase /Protein Kinase A (PKA) cascade. The present study investigated the role of PKA in the expression of morphine and Δ9-THC antinociceptive tolerance. Male Swiss Webster mice were treated chronically with morphine or Δ9-THC and the warm-water …


The Effects Of Footshock On The Reinforcing Efficacy Of Cocaine In Male Long-Evans Rats, Elizabeth S. Hendrick Jan 2005

The Effects Of Footshock On The Reinforcing Efficacy Of Cocaine In Male Long-Evans Rats, Elizabeth S. Hendrick

Theses and Dissertations

Many links exist between cocaine abuse and stress. The literature and laboratory studies in rats suggest that this could be because stress increases the reinforcing efficacy of cocaine. Using male Long-Evans rats, experiments in this thesis tested effects of footshock on the reinforcing efficacy of cocaine using a progressive ratio schedule of reinforcement. They also examined effects of footshock on the reinforcing efficacy of a half-maximal dose of cocaine. Finally, they tested the effects of footshock on cocaine self-administration in rats initially resistant to acquisition of cocaine self-administration. Footshock did not increase reinforcing efficacy of cocaine on a PR schedule …


Post-Juvenile Brain Development Modulates Seizure Characteristics And Diazepam Efficacy In The Rat Pilocarpine-Se Model, William H. Holbert Ii Jan 2005

Post-Juvenile Brain Development Modulates Seizure Characteristics And Diazepam Efficacy In The Rat Pilocarpine-Se Model, William H. Holbert Ii

Theses and Dissertations

These studies were completed to examine how status epilpeticus seizure characteristics are modulated during post-juvenile brain development. This may determine if postnatal age in rats is a better identifier of stages of post-juvenile brain development. The first study fully detailed the acute discrete seizure phase of the rat pilocarpine-SE model. Results for this study showed that Racine behavioral severity score, spike frequency, and seizure severity during the acute discrete seizure phase change in relation to post-juvenile brain developmental stages. The second study fully detailed early and late patterns of status epilepticus. Results for this study displayed modulation of time in …


Multi-Channel Fetal Magnetocardiographic Signal Seperation For Analysis Of Heart Rate Variability, Joshua Quaid Campbell Jan 2004

Multi-Channel Fetal Magnetocardiographic Signal Seperation For Analysis Of Heart Rate Variability, Joshua Quaid Campbell

Theses and Dissertations

Objective: The objectives were to implement signal-processing techniques to separate the fetal magnetocardiogram (FMCG), as collected by SQUID (Superconducting QUantum Interference Device) gradiometers, from mixtures of maternal and fetal biomagnetic signals recorded during the antepartum period and to develop a database of normal FMCG values of the fetal cardiac time intervals and heart rate variability measures. Materials and Methods: The research was performed in three phases: 1) Independent component analysis (ICA), nonlinear filtering techniques, and orthogonal projection methods were optimized enabling the FMCG to be processed using traditional signal analysis techniques; 2) The cardiac time intervals and heart rate variability …


Post-Processing Of Low Dose Mammography Images, Jesung Kim May 2002

Post-Processing Of Low Dose Mammography Images, Jesung Kim

Theses and Dissertations

In mammography, X-ray radiation is used in sufficient doses to be captured on film for cancer diagnosis. A problem lies in the inherent nature of X-rays to cause cancer. The resolution of the images obtained on film is directly related to the radiation dosage. Thus, a trade-off between image quality and radiation exposure is necessary to ensure proper diagnosis without causing cancer. A possible solution is to decrease the dosage of radiation and improve the image quality of mammograms using post- processing methods applied to digitized film images. Image processing techniques that may improve the resolution of images captured at …


Genetic Dissection Of Behavioral And Neurogenomic Responses To Acute Ethanol, Aaron Wolen Dec 2001

Genetic Dissection Of Behavioral And Neurogenomic Responses To Acute Ethanol, Aaron Wolen

Theses and Dissertations

Individual differences in initial sensitivity to ethanol are strongly related to the heritable risk of alcoholism in humans. To elucidate key molecular networks that modulate ethanol sensitivity we performed a systems genetics analysis of ethanol-responsive gene expression in brain regions of the mesocorticolimbic reward circuit (prefrontal cortex, nucleus accumbens and ventral midbrain) across the BXD RI panel, a highly diverse family of isogenic mouse strains before and after treatment with ethanol. Acute ethanol altered the expression of ~2,750 genes in one or more regions and 400 transcripts were jointly modulated in all three. Ethanol-responsive gene networks were extracted with a …


Titrating And Evaluating Multiple Drug Regimens Within Subjects, Margaret Shih Jan 2001

Titrating And Evaluating Multiple Drug Regimens Within Subjects, Margaret Shih

Theses and Dissertations

The dosing of combination therapies is commonly undertaken empirically by practicing physicians, and there is a lack of a coherent algorithm to approach the problem of combination dosing. Current methods of evaluating multiple drug combinations in clinical trials generally do not provide information regarding the location of more effective dosages when the combination is not found to differ from the standard, even though the absence of a difference does not necessarily mean the new combination is ineffective. Additionally, if a new combination is found to be more effective, often a large proportion of the subjects has not benefited from the …


In Vivo And In Vitro Nuclear Magnetic Resonance Imaging And Spectroscopy Of Psychoactive Drugs In Rat Brain, Diana M. Lindquist Jan 1998

In Vivo And In Vitro Nuclear Magnetic Resonance Imaging And Spectroscopy Of Psychoactive Drugs In Rat Brain, Diana M. Lindquist

Theses and Dissertations

Four psychoactive drugs were studied using various in vivo nuclear magnetic resonance (NMR) techniques. Trifluoperazine (TFP) was given to several normal rats, whose brains were then studied using in vivo fluorine-19 NMR. Three peaks were detected in the in vivo fluorine spectra: one at -62 ppm, which was due to TFP, and two others at -55 and -75 ppm, which are due to unknown metabolites of TFP. Samples of skin, skull, muscle, and brain were obtained from these rats and extracted for in vitro analysis. The metabolites responsible for the in vivo peak at -75 ppm also appeared in the …


Comparison Of Virulent And Avirulent Legionella Pneumophila And Evaluation Of Fish As A Potential Environmental Reservoir/Experimental Model, Sandra Reading Sommer Jan 1987

Comparison Of Virulent And Avirulent Legionella Pneumophila And Evaluation Of Fish As A Potential Environmental Reservoir/Experimental Model, Sandra Reading Sommer

Theses and Dissertations

Legionella pneumophila was first recognized as a cause of human pneumonia in 1976 . Since then, much has been learned about the microbiology, pathophysiology and epidemiology of this organism. The features which permit one strain but not another to invade human lung tissue and produce disease remain incompletely understood. This study e valuated several attributes of a virulent and an avirulent strain of L. pneumophila in an attempt to identify characteristics which would distinguish the two. Evaluation of a new medium, buffered egg yolk agar, showed that virulence was maintained after 26 passages, which was the same as the buffered …


Nosocomial Respiratory Tract Infections Associated With The Use Of Ventilatory Support Systems: Epidemiological And Bacteriological Study Of The Effect Of Changing Breathing Circuits At 24 Or 48 Hours, Virginia Archer Lamb Jan 1987

Nosocomial Respiratory Tract Infections Associated With The Use Of Ventilatory Support Systems: Epidemiological And Bacteriological Study Of The Effect Of Changing Breathing Circuits At 24 Or 48 Hours, Virginia Archer Lamb

Theses and Dissertations

Nosocomial (hospital-acquired) pneumonia (HAP) continues to be an important cause of morbidity and mortality in the hospital. HAP is the third most common nosocomial infection after urinary tract and surgical wound infections. In addition, HAP is the nosocomial infection with the highest mortality rate. These infections are often difficult to treat, because most are caused by Gram-negative bacilli (GNB) that may be highly resistant to antimicrobial agents. HAPs frequently occur in intensive care patients with underlying lung and/or systemic diseases. Many patients are intubated and are on assisted ventilation. Several sources of infection associated with ventilators or respirators have been …


The Incidence Of Obesity In Lds College Women: The Effect Of Selected Physical Socio-Environmental Variables On Total Percent Body Fat In Two Populations Of Lds Women, Carrie Tanner Summers Jan 1984

The Incidence Of Obesity In Lds College Women: The Effect Of Selected Physical Socio-Environmental Variables On Total Percent Body Fat In Two Populations Of Lds Women, Carrie Tanner Summers

Theses and Dissertations

The purpose of this study was to determine the effect of selected physical socio-environmental variables on total percent body fat. The sample population consisted of single, LDS, white women attending Brigham Young University (BYU) and California State University at Fullerton (CSUF). Significant data as well as trends that appeared were included in this paper.

From the data collected, it was concluded that the sample populations at BYU and CSUF were the same. The incidence of obesity was determined only among individuals attending both universities. The entire sample population mean was 22.19 percent. This percentage did not meet the obesity criteria. …