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

Medicine and Health Sciences Commons

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

Articles 1 - 10 of 10

Full-Text Articles in Medicine and Health Sciences

Identification Of The Human Erythrocyte Glucose Transporter (Glut1) Atp Binding Domain: A Dissertation, Kara B. Levine Dec 1999

Identification Of The Human Erythrocyte Glucose Transporter (Glut1) Atp Binding Domain: A Dissertation, Kara B. Levine

GSBS Dissertations and Theses

The human erythrocyte glucose transport protein (GLUT1) interacts with, and is regulated by, cytosolic ATP. This study asks the following questions concerning ATP modulation of GLUT1 mediated sugar transport. 1) Which region(s) of GLUT1 form the adenine nucleotide-binding domain? 2) What factors influence ATP modulation of sugar transport? 3) Is ATP interaction with GLUT1 sufficient for sugar transport regulation?

The first question was addressed through peptide mapping, n-terminal sequencing, and alanine scanning mutagenesis of GLUT1 using [32P]-azidoATP, a photoactivatable ATP analog. We then used a combination of transport measurements and photolabeling strategies to examine how glycolytic intermediates ...


Analysis Of Cell Polarity Signaling In C. Elegans: A Dissertation, Christian Ernest Rocheleau Dec 1999

Analysis Of Cell Polarity Signaling In C. Elegans: A Dissertation, Christian Ernest Rocheleau

GSBS Dissertations and Theses

During embryonic development of the nematode Caenorhabditis elegans, cell fates are specified by asymmetric segregation of cell fate determinants and via cell-cell signaling events. Specification of the eight-cell stage blastomere E, the endoderm progenitor cell, requires both cell signaling and asymmetric cell division. At the four-cell stage, a polarity-inducing signal from the P2 cell is required for the EMS cell to divide asymmetrically to produce an anterior daughter MS, and posterior daughter E. In the absence of signal, the EMS cell divides symmetrically to produce two daughters that adopt the MS fate. This thesis describes the identification and analyses ...


Mechanisms Of Newcastle Disease Virus-Mediated Membrane Fusion: A Dissertation, Judith Stone-Hulslander Nov 1999

Mechanisms Of Newcastle Disease Virus-Mediated Membrane Fusion: A Dissertation, Judith Stone-Hulslander

GSBS Dissertations and Theses

For many paramyxoviruses, including Newcastle disease virus (NDV), syncytia formation requires the expression of both surface glycoproteins (HN and F) in the same cell, and evidence suggests that fusion involves a specific interaction between the HN and F proteins (23, 73). Because a potential interaction in paramyxovirus infected cells has never been clearly demonstrated, such an interaction was explored in Chapter 2 using coimmunoprecipitation and crosslinking. Both HN and F proteins could be precipitated with heterologous antisera after a five minute radioactive pulse as well as after a two hour chase in non-radioactive media, but at low levels. Chemical crosslinking ...


The Ctl Memory Responses To Influenza A Viruses In Humans: A Dissertation, Julie Marie Jameson Nov 1999

The Ctl Memory Responses To Influenza A Viruses In Humans: A Dissertation, Julie Marie Jameson

GSBS Dissertations and Theses

Influenza A virus infections are a major cause of morbidity and mortality in the United States and throughout the world. The current vaccine elicits primarily a humoral response that is specific for the external glycoproteins hemagglutinin (HA) and neuraminidase (NA). However, these are the viral proteins that are most susceptible to antigenic shift and drift, and can evade the humoral response. Cytotoxic T lymphocytes (CTL) recognize and lyse virus-infected cells and are important in clearing influenza A virus infections. CTL can recognize epitopes on both the external glycoproteins and the more conserved internal viral proteins. This thesis investigates the hypothesis ...


Characterization Of The Molecular Mechanisms Regulating The Agrin Signaling Pathway: A Dissertation, Laura Jalso Megeath Oct 1999

Characterization Of The Molecular Mechanisms Regulating The Agrin Signaling Pathway: A Dissertation, Laura Jalso Megeath

GSBS Dissertations and Theses

The nervous system requires rapid, efficient, and accurate transmission between cells for proper functioning. Synapses are the predominant structures through which such vital communication occurs. How synapses are formed, maintained, and eliminated are questions of fundamental importance.

At the nerve-muscle synapse, formation of the postsynaptic apparatus is directed by agrin. The hallmark activity of agrin is the aggregation of acetylcholine receptors (AChRs) into dense clusters opposite the presynaptic nerve terminal. Early events in the agrin signal transduction cascade include activation of the receptor tyrosine kinase MuSK and tyrosine phosphorylation of AChRs, but how these events lead to AChR cluster formation ...


Characterization, Mechanisms And Modulation Of Calcium Signals In Glia: A Dissertation, Andreja Strahonja Jun 1999

Characterization, Mechanisms And Modulation Of Calcium Signals In Glia: A Dissertation, Andreja Strahonja

GSBS Dissertations and Theses

Glia are non-excitable cells found in nervous tissue, and have an important role in synaptic plasticity and the maintenance of neuronal environment, as well as the activity, development, degeneration, and repair of neurons. Glial cells are interconnected via gap junctions to form a multicellular syncytium and utilize intercellular and intracellular Ca2+signals to regulate their functions.

Glial Ca2+ signals regulate important cell functions that include gene expression, cell proliferation, metabolism, ion transport systems, release of cell products, and cell death. Consequently, significant alterations of glial Ca2+ signals are associated with pathological processes such as epilepsy, Alzheimer's ...


Structural And Signaling Proteins At The Synapse: Dystroglycan & Insulin Receptor Tyrosine Kinase Substrate P58/53: A Dissertation, Mary-Alice Abbott Apr 1999

Structural And Signaling Proteins At The Synapse: Dystroglycan & Insulin Receptor Tyrosine Kinase Substrate P58/53: A Dissertation, Mary-Alice Abbott

GSBS Dissertations and Theses

The synapse is the primary locus of cell-cell communication in the nervous system. The elaboration of a functional synapse requires both a specialized structure and an efficient communication system. For my thesis work, I studied proteins implicated in each of these functions: the structural molecules dystroglycan and dystrophin, and the signaling elements Insulin Receptor Substrate p58/53 and insulin receptor.

The α/β-dystroglycan complex, believed to be the heart of cellmatrix adhesion in muscle and other tissues, provides a link between dystrophin, a cytoskeletal protein at the base of the muscle cell's Dystrophin Associated Protein Complex, and the extracellular ...


Human T Cell Responses To Dengue Virus Infections: Cd8+Ctl And Acute Immunosuppression: A Dissertation, Anuja Mathew Jan 1999

Human T Cell Responses To Dengue Virus Infections: Cd8+Ctl And Acute Immunosuppression: A Dissertation, Anuja Mathew

GSBS Dissertations and Theses

There are four serotypes of dengue virus designated dengue 1, 2, 3 and 4 (D1, D2, D3 and D4) and epidemiological studies indicate that a severe complication of dengue virus infection - dengue hemorrhagic fever (DHF) is more likely to occur following a secondary infection. DHF is hypothesized to be immunologically mediated and may be triggered by virus-specific T cells. It is also likely that dengue virus-specific cytotoxic T lymphocytes (CTLs) are important for recovery from dengue virus infections. An analysis of the immune response during acute illness and when the patient has recovered from the infection (immune state) is therefore ...


Mrna Poly(A) Tail: A 3' Enhancer Of Translational Initiation: A Thesis, David Munroe Jan 1999

Mrna Poly(A) Tail: A 3' Enhancer Of Translational Initiation: A Thesis, David Munroe

GSBS Dissertations and Theses

Most eukaryotic mRNAs have a sequence of polyadenylic acid [poly(A)] at their 3'-termini. Although it has been almost two decades since the discovery of these poly(A) tracts, their function(s) have yet to be clarified. Earlier results from our laboratory led us to propose that poly(A) has a role in translation. More specifically, we proposed that an interaction of the cytoplasmic poly(A)-binding protein (PABP) with a critical minimum length of poly(A) facilitates the initiation of translation of poly(A)+, but not poly(A)-, mRNAs. The results of several different experimental approaches have provided ...


The Virus-Specific Cd4+ T Cell Response During Acute Lymphocytic Choriomeningitis Virus Infection And Into Long Term Memory: A Dissertation, Steven Michael Varga Jan 1999

The Virus-Specific Cd4+ T Cell Response During Acute Lymphocytic Choriomeningitis Virus Infection And Into Long Term Memory: A Dissertation, Steven Michael Varga

GSBS Dissertations and Theses

CD4+ T cells play a central role in immunity. During virus infections, CD4+ T cells provide the necessary help for B cells to secrete anti-viral antibody and may act as effector cells themselves through the secretion of anti-viral cytokines such as IFN-γ and TNF-α. Recent studies in the lymphocytic choriomeningitis virus (LCMV) system have shown that CD4+ T cells are required to maintain the clearance of persistent viral infections as well as maintain virus-specific memory CD8+ cytotoxic T lymphocytes (CTL). Despite these important functions, surprisingly little information exists concerning the longevity, magnitude, and stability of the CD4+ T cell response ...