Medicine and Health Sciences Commons^™

Activation Of Ca2+-Activated K+ Channels And Cell Migration By Hepatocyte Growth Factor/Scatter Factor In Madin-Darby Canine Kidney Cells., Min Jin

Electronic Theses and Dissertations

Hepatocyte Growth Factor/Scatter Factor (HGF/SF) stimulates migration of various cells and has been linked via Met tyrosine kinase signaling to transformation and the metastatic phenotype. HGF/SF-Met signaling also plays a role in malignancy. Migration of transformed MDCK-F cells depends on activation of a charybdotoxin (ChTX)-sensitive, volume-activated membrane K⁺ current. Patch-clamp electrophysiology and transwell migration assays were used to study the effects of HGF/SF on membrane K⁺ currents and cell migration in MDCK II cells. HGF/SF activated membrane K⁺ currents that increased over 24 hr, and these could be modulated by altering intracellular free calcium concentration [Ca^{2+ …}

Dose-Response Effects Of Lithium On Spatial Memory In The Black Molly Fish., Thomas Kyle Creson

Electronic Theses and Dissertations

Lithium continues to be widely prescribed for the management of bipolar disease, yet cognitive impairment-related side effects promote noncompliance of the treatment regimen. We have introduced a novel animal model, the black molly fish, to study dose-response effects of lithium on short-term (STM) and long-term (LTM) memories. We developed a method utilizing capillary ion analysis (CIA), to measure plasma and brain lithium levels employed in our behavioral studies. We then developed an appropriate testing environment to ascertain learning capacities of these fish. We established that black mollies could adequately perform a forced-choice spontaneous alternation (SA) task used extensively in rodents …

Isolation And Investigation Of The Exopolysaccharide From Thauera Sp. Mz1t, Michael S. Allen

Doctoral Dissertations

Thauera sp. strain MZ1T is a floc-forming bacterium isolated from the wastewater treatment plant of Eastman Chemical Company. Its overabundance in that system in the form of zoogloeal clusters was positively correlated to episodes of poor dewatering of activated sludge (Lajoie 2000). The specific cause of this problem was thought to be due to the production of large quantities of hydrophilic exopolysaccharide (EPS) by MZ1T, which entraps water in the form of a hydrated gel, and results in a sludge that is resistant to mechanical dewatering.

A method for the reproducible extraction of EPS from pure cultures of MZ1T was …

Evolution Of Lake Malawi Cichlid Fishes (Perciformes: Teleostei), Peter F. Smith

Electronic Theses and Dissertations

The cichlid fish species flocks of East Africa provide a compelling model system in which to study the process of speciation. In Lake Malawi, greater than 1000 species of cichlids have emerged since the filling of the lake basin about 1 million years ago. Over 99% of the Lake Malawi haplochromine cichlids are endemic, suggesting that most of this diversification has taken place within the temporal and spatial boundaries set by the Lake's shores. Moreover, many of these species are endemic to small areas within the lake, indicating that speciation has occurred very recently or perhaps is in progress in …

A New Immunoassay For Quantification Of A Novel Cancer Antigen In Serum And Immunostaining Of Carcinoma Tissues And Cultured Cells Revealing The Antigenic Cellular Location., Emily Christine Mcduffee

Electronic Theses and Dissertations

The purpose of this study is 1) to examine the presence of the antigen in serum by employing a newly developed ELISA immunoassay that quantifies the total antigen and bound antigen (antigen-antibody complex) using polyclonal chicken antibodies directed against an IgM-binding epitope of the new antigen, and 2) to determine the location of the antigen in carcinoma and normal cells. Sera from healthy volunteers (n = 147) and cancer patients (n = 26) were compared for both bound and total antigen concentrations using the new ELISA. Healthy volunteers were subdivided into three groups: those with a personal history of cancer …

Roles And Regulation Of Nf-Xb In Platelet-Derived Growth Factor Transformed Cells, Takeshi Shimamura

Dissertations

Platelet-derived growth factor (PDGF) is overexpressed in various cancer cells and the overexpression may be correlated with the prognosis of several types of cancers. Binding of PDGF to its receptors induces receptor dimerization and subsequent autophosphorylation of tyrosine residues in the receptor’s cytoplasmic domains. The phosphorylated tyrosine residues interact with the secondary signaling molecules to initiate signaling cascades that trigger cellular changes by affecting downstream effectors. In our recent publication, we have shown that a NF-icB mediates the transformation of mouse fibroblast cells overexpressing PDGF B chain. Though there is a significant correlation between PDGF stimulation and N F-kB activity, …

The Influence Of Warning Label Presentation In Memory Recognition Of Aging Adults, Brian J. Call

Master's Theses - Daytona Beach

Research indicates that hundreds of thousands of people are injured each year as a result of poor communication between medical personnel, warning label information, and consumers when taking over the counter or prescription medication. Typically, as adult's age, they are increasingly responsible for remembering the hazards of taking medications. If inadequate information exists in memory in regards to side effects, dosage, and other warnings, the likelihood of improper usage will increase. Because aging adults typically have a reduction in cognitive resources, it was hypothesized that older adults would require the aid of additional warning information to assist in the retrieval …

Hiv Tat Protein Activates Endothelial Cells Through Nfκb And Map Kinase Pathways., Jason L. Henry

Electronic Theses and Dissertations

HIV infection has been shown to predispose patients to accelerated development of heart disease. One mechanism for this pathology may involve endothelial activation either by HIV itself or by its secreted proteins, gp120 (a viral envelope protein) and tat (a protein that upregulates transcription of viral genes). We have studied the effects of gp120 and tat on signaling and production of inflammatory cytokines by Human Pulmonary Artery Endothelial Cells (HPAEC). HPAEC were stimulated at varying time points with combinations of gp120, tat, and monokines (IL-1β and TNFα). Cell lysate fractions were analyzed for MAP Kinase activity and NFκB activation, and …

The Signaling Pathway Of Oxysterol Induced Apoptosis In Chinese Hamster Ovary (Cho)-K1 Cells., Lin Yang

Electronic Theses and Dissertations

Apoptosis, a form of genetically programmed cell death, plays a key role in regulation of cellularity of the arterial wall. During atherogenesis, improper apoptosis may cause abnormalities of arterial morphogenesis, wall structural stability, and metabolisms. It has been well established that vascular cells undergo apoptosis after uptake of oxidized low-density lipoprotein (oxLDL). Thus, an analysis of the signaling pathway of apoptotic induction by oxLDL is of value in understanding the development of atherosclerotic plaque. In order to elucidate the signaling pathway of apoptosis induced by oxLDL, we have used Chinese hamster ovary (CHO)-K1 cells treated with a potent oxysterol, 25-hydroxycholesterol …

30s Ribosomal Subunit Assembly Is A Target For Inhibition By Aminoglycoside Antibiotics In Escherichia Coli., Roopal Manoj Mehta

Electronic Theses and Dissertations

Antibacterial agents specific for the 50S ribosomal subunit not only inhibit translation but also prevent assembly of that subunit. I examined the 30S ribosomal subunit in growing Escherichia coli cells to see if antibiotics specific for that subunit also had a second inhibitory effect. I used the aminoglycoside antibiotics paromomycin and neomycin, which bind specifically to the 30S ribosomal subunit. Both antibiotics inhibited the growth rate, viable cell number, and protein synthesis. I used a ³H-uridine pulse and chase assay to examine the kinetics of ribosome subunit assembly in the presence and absence of each antibiotic. Analysis revealed a …

Analysis Of Aneuploidy During Mouse Spermatogenesis, April D. Pyle

Doctoral Dissertations

Successful transition through meiosis is required for production of chromosomally-balanced gametes. When chromosome segregation goes awry during meiosis, aneuploidy can occur. Unfortunately, the mechanisms behind this nondisjunction are not well understood. Therefore, this dissertation has focused on learning more about the causative factors associated with aneuploidy during spermatogenesis. Are there factors that are always associated with leading to production of aneuploid sperm? One of the main goals of this dissertation is to find mouse models to study what factors may be involved in chromosome malsegregation; such as pairing, recombination, and transition through the division phases of meiosis.

The first part …

Aquaporins And Aquaglyceroporins Of Legume Nodules: Structure, Function, And Regulation, James F. Guenther

Doctoral Dissertations

By isolating RNA from mature nodules of the legume Lotus japonicas and employing an RT-PCR approach, two new cDNAs were characterized whose open reading frames code for members of the MIP (Major Intrinsic Protein) family of membrane proteins. These two genes products were termed (Lotus Intrinsic Membrane Protein 1 and 2) LIMP1 and LIMP2. Both LIMP1 and LIMP2 display all the hallmarks of the MIP protein family including, six putative transmembrane domains based on hydropathy plots, and the invariant NPA (asparagine-proline-alanine) signature motifs located symmetrically on two loops, which connect transmembrane helix 3-4 and transmembrane helix 5-6. Based on sequence …

Bordetella Bronchiseptica: A Candidate Mucosal Vaccine Vector, Sreekumari Rajeev

Doctoral Dissertations

Bordetella bronchiseptica colonizes the upper respiratory tract of a wide variety of mammals and is involved in diseases such as kennel cough in dogs, atrophic rhinitis in pigs and upper respiratory tract infections of laboratory animals. Studies were focused on developing a heterologous antigen expression system in B. bronchiseptica and to evaluate the potential of this organism as a candidate mucosal vaccine vector. Since the role of Bordetella bronchiseptica and Pasteurella multocida toxin (PMT) in the disease atrophic rhinitis of pigs was well documented, this research was focused in the possibility of developing a refined vaccine to control this disease. …

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 …

Prevalence Of Various Upper Extremity Disorders In Patients With Carpal Tunnel Syndrome Versus Patients Without Carpal Tunnel Syndrome, Daniel C. Buda

Loma Linda University Electronic Theses, Dissertations & Projects

Background and Purpose: Increasingly larger numbers of patients present with repetitive strain injuries of the upper extremities, especially carpal tunnel syndrome (CTS). A large number of these patients appear to have more than one upper extremity condition. The purpose of this study was to determine the probability that a patient diagnosed with carpal tunnel syndrome will also be diagnosed with other upper extremity and/or cervical spine disorders.

Subjects: A group of 188 subjects diagnosed with carpal tunnel syndrome and a group of 203 subjects without carpal tunnel syndrome were selected through a chart review of patients at Loma Linda …

Pkcα Translocation And Actin Remodeling In Contracting A7r5 Smooth Muscle Cells, Chenwei Li

Theses, Dissertations and Capstones

Recent research indicates that protein kinase C (PKC) plays an important role in smooth muscle contraction. Because PKC activation and specificity of substrate phosphorylation is believed to be associated with the relocalization of the enzyme to specific cell sites, we first investigated the subcellular translocation of PKCα in A7r5 smooth muscle cells by confocal microscopy through use of standard immunohistologic staining and PKCα - enhanced green fluorescent protein (PKCα -EGFP) fusion protein expression. PKCα was diffusely distributed throughout the cytosol in the unstimulated A7r5 cell. Upon stimulation with phorbol 12, 13 dibutyrate (PDBu), PKCα was translocated primarily to either the …

Characterization Of Host-Bacteria Interactions Contributing To Group B Streptococcus Colonization, Jennifer Marie Smith

Theses, Dissertations and Capstones

Group B streptococcus (GBS) is the leading cause of life-threatening bacterial infections during the first three months of life. GBS is also a frequent cause of maternal postpartum infections. Both types of infections stem from maternal vaginal and/or rectal colonization with GBS in the perinatal period. Limited information is available concerning how the colonization process occurs and what role the host immune system may play in the establishment of persistent colonization by GBS. The complex interactions between the immune system and GBS normally should end in clearance of the bacteria. However, since colonization by GBS occurs in a large number …

Gravistimulation Of Pisum Sativum And Expression Of The Cell Membrane Expansin Proteins, Sherrine A. Ibrahim

Theses, Dissertations and Capstones

This thesis research investigates the regulation of gene expression in pea stems (Pisum sativum) after changes in orientation to gravity (gravistimulation). Specifically, this project examines the changes in extracellular soluble proteins due to gravistimulation in pea seedlings. This change in gravity alters the cellular growth pattern, which can be directly linked to enzymatic activity resulting in the expression of cell wall loosening proteins called expansins. This loosening of the cell wall matrix subsequently increases elasticity in growing cells, thus leading to an upward curvature of the stems. These changes in enzymatic activity and gene expression are crucial for …

An Examination Of The Relationship Between Lung Function And Aerobic Capacity In People With Asthma., Pat Flanagan

Theses

The prevalence of asthma is rapidly increasing throughout the world. Many developed countries have reported a greater incidence and severity of asthma in both adults and children (Woolcock and Peat, 1997). Up to 90% of those diagnosed with asthma will experience some asthma symptoms during or after exercise. This condition is known as Exercise-Induced Asthma (EIA). The severity of the bout of EIA depends mainly on the type, intensity and duration of the exercise session. Environmental conditions, medication and possibly the level of fitness of the individual may also influence EIA (Storms and Joyner, 1999; Guill, 1996; Weiler, 1996).

The …

The Effects Of Prostaglandin E2 On The Neurons Of The Ventromedial Preoptic Area Of The Hypothalamus: A Mechanism Of Fever, Heather J. Ranels

Dissertations, Theses, and Masters Projects

No abstract provided.

The Role Of Diet And Physical Activity For Ovarian Cancer Results From The Adventist Health Study, Fatemeh Kiani

Loma Linda University Electronic Theses, Dissertations & Projects

A few aspects of the epidemiology of ovarian cancer are well understood, such as the inverse relationship with parity and oral contraceptive (OC) use. The role of other factors such as the potential influence of diet or physical activity is far from being established. A few studies, however, have been able to identify dietary risk factors for ovarian cancer. In this dissertation, I have conducted two studies that investigate the relationship between dietary factors and physical activity and the three endpoints: 1) nonfatal ovarian cancer (1976-1982; time to diagnosis), 2) fatal ovarian cancer (1976-1988; time to death), and 3) total …