Medicine and Health Sciences Commons^™

The Effect Of Mtad On Eight Strains Of E. Faecalis In Contaminated Root Canals, Bradley M. Newberry

Loma Linda University Electronic Theses, Dissertations & Projects

The purpose of this investigation was to determine the antimicrobial effect of Biopure MTAD (a mixture of a tetracycline isomer, an acid, and a detergent) as a final irrigant on eight strains of Enterococcus faecalis (E. faecalis) in contaminated root canals of extracted human teeth. In addition, the Minimum Inhibitory Concentration (MIC) and Minimum Lethal Concentration (MLC) of MTAD were also measured on the same strains of bacteria. Two-hundred and forty extracted human teeth were instrumented using 1.3% NaOCl followed by 17% EDTA to remove the smear layer. The teeth were randomly contaminated with one of eight strains of E. …

The Role Of Nogo-A During Development Of The Chick Central Nervous System, Shelly A. Caltharp

Loma Linda University Electronic Theses, Dissertations & Projects

Nogo-A is a potent inhibitor of axon regeneration that is expressed by myelin forming oligodendrocytes of the adult central nervous system (CNS). However, neuronal expression of Nogo-A during development suggests an additional role. Little is known about the putative functions of Nogo-A during embryonic development. To examine its potential role we isolated and analyzed the Nogo-A sequence in the chick, we localized its mRNA expression pattern and cell-specific distribution during key phases of cortical development, and studied regulation of its expression during phases that showed promise of function based on expression patterns.

Our results revealed five previously undescribed Nogo-A specific …

Electromagnetic Differences In The Brain During Memory Retrieval, Warren Scott Merrifield

Loma Linda University Electronic Theses, Dissertations & Projects

The primary objectives for this experiment were to analyze the neuroanatomical correlates of autobiographical, episodic and semantic memory, use a different paradigm to promote episodic memory retrieval, and employ a different analysis technique to understand retrieval processes. Autobiographical and episodic memories are personal memories from the past. Autobiographical is more general (e.g. a street name of a house growing up) and episodic is more specific to time (e.g. 13th birthday party that took place on a street). For autobiographical and episodic memory retrieval operations, there is no general consensus as to the localization of function, but bilateral activation of the …

Biochemical Characteristics Of Inconsistent Free T₄ Assays, Kristofer S. Fritz

Loma Linda University Electronic Theses, Dissertations & Projects

Serum levels of free thyroxine (T₄) are helpful in the clinical evaluation of patients who are suspected of having thyroid disease, since free T₄ (unbound) is known to closely relate to hyper, eu and hypothyroidism. There are documented inconsistencies among commercially available direct free thyroxine immunoassays. The biochemical basis for these inconsistencies is not understood and has not been characterized. Direct free T₄ measurements have been linked to both T₄-binding serum protein concentrations and protein-bound T₄ concentrations. A free T₄ reference method using direct equilibrium dialysis radioimmunoassay has been well characterized. New …

Maturational Changes In Cerebrovascular Thick- And Thin-Filament Regulation, Renan Joel Sandoval

Loma Linda University Electronic Theses, Dissertations & Projects

The present study focused on the main hypothesis that age-related changes in myofilament Ca²⁺ sensitivity involve simultaneous changes in the relations between cytosolic Ca²⁺ transients, myosin phosphorylation, and force development. To define the effects of late fetal and early postnatal maturation, parallel experiments were carried out using cerebral arteries from both term lamb fetuses (140-141 days of gestation) and nonpregnant adult sheep. Fetal and adult cerebral arteries were stimulated by either mechanically, electromechanically, and/or pharmacomechanically-induced contractions, and the relations of cytosolic Ca²⁺, MLC phosphorylation, and contractile tensions were measured. These measurements allowed for stimulus and age-dependent …

Iron Dysregulation And Inflammation In Alzheimer’S Disease, Shino D. Magaki

Loma Linda University Electronic Theses, Dissertations & Projects

Alzheimer’s disease (AD) is the most common form of senile dementia in the US and worldwide but the causes of its pathogenesis are currently unknown. In this study, we examined two processes that have been implicated in the early stages of AD and other forms of neurodegeneration, iron dysregulation and inflammation, both of which can promote the increased production of amyloid precursor protein (APP). We have measured different pools of brain iron in transgenic iron regulatory protein 2 knockout (IRP2-/-) mice in the early stages of neurodegeneration and in affected brain regions from AD patients at different stages of the …

Regulation Of Alpha-1-Adrenoceptor-Mediated Contractions Of The Uterine Artery By Pkc, Hongying Zhang

Loma Linda University Electronic Theses, Dissertations & Projects

Pregnancy is associated with a significant decrease in uterine vascular tone and a striking increase in uterine blood flow, which ensures normal fetal development. Multiple mechanisms are involved in the adaptation of uterine artery contractility during pregnancy. Both protein kinase C (PKC) and activation of ai-adrenoceptors play important roles in the regulation of uterine artery contractility. In addition, PKC mediates the pregnancyassociated decrease in myogenic tone of the uterine artery, and interacts with ajadrenoceptors leading to modulation of ai-adrenoceptor-mediated contractions of vascular smooth muscle. Yet, whether or to what extent PKC regulates ai-adrenoceptormediated contractions of the uterine artery and their …

Radiation-Induced Increases In Pkc Modulate Integrin Expression And Contribute To Fibrotic Changes, Pinal Rushikesh Pandya

Loma Linda University Electronic Theses, Dissertations & Projects

The sequences of events in fibrosis are similar to those in wound healing; however, the normal termination and resolution stages do not take place. The initial cellular response following ionizing radiation involves accumulation of the ECM (extracellular matrix) including collagen, fibronectin and the interaction of many growth factors (cytokines) with their receptors. There are a number of unanswered questions regarding many aspects of radiation-induced fibrosis, including the initial triggers and physical changes that initiate the process. We have confirmed that elevated pKC and other cellular changes following radiation are similar to those found at sites of inflammation. This information leads …

The Effect Of Radiation And Repeated Sub-Culturing On Tgf-Β1 Signaling In Frtl-5 Cells, Cheryl G. Burrell

Loma Linda University Electronic Theses, Dissertations & Projects

From our ongoing in vitro studies using the Fisher Rat Thyroid cell line-5 (FRTL-5) we recorded accelerated growth, reduced follicularization and reduction in thyroxin release that occurred as the cells were repeatedly sub-cultured. We also recorded that these changes occurred earlier and more rapidly following radiation exposure. We determined that TGF-β1 production increased under both conditions. We hypothesized that alteration in the TGF-β1 signaling pathway contributed to the changes observed in the cellular properties of FRTL-5 cells. Our objective was to examine some of the players in the TGF-β1 signaling pathway to determine whether radiation and/or repeated subculturing promoted changes …

The Effect Of Walnuts Compared To Fatty Fish On Plasma And Erythrocyte Fatty Acid Composition, Lymphocyte Subsets And Inflammatory Mediators, Yu-Lan Ching

Loma Linda University Electronic Theses, Dissertations & Projects

The purpose of this study was to compare the effects of walnuts vs. fatty fish on circulating inflammatory markers, on lymphocyte subsets, on plasma concentrations of eicosanoids precursor polyunsaturated fatty acid and on erythrocyte membrane fatty acid composition. Under controlled metabolic feeding conditions and randomized crossover (3x3 Latin-square) design, 27 subjects alternately consumed a control diet, a walnut diet (1.5 oz (42.5g) /day of walnuts, 6 times/week) or a fish diet (8 oz (226g) /week of salmon) for 4 weeks each. Consumption of the walnut diet (ALA 5.43 g/day) compared to the fish diet (EPA 170 mg/day and DHA 590 …