Medicine and Health Sciences Commons^™

Inference And Analysis Of Multilayered Mirna-Mediated Networks In Cancer, Duc Do

Dissertations (1934 -)

MicroRNAs (miRNAs) are small noncoding transcripts that can regulate gene expression, thereby controlling diverse biological processes. Aberrant disruptions of miRNA expression and their interactions with other biological agents (e.g., coding and noncoding transcripts) have been associated with several types of cancer. The goal of this dissertation is to use multidimensional genomic data to model two different gene regulation mechanisms by miRNAs in cancer. This dissertation results from two research projects. The first project investigates a miRNA-mediated gene regulation mechanism called competing endogenous RNA (ceRNA) interactions, which suggests that some transcripts can indirectly regulate one another's activity through their interactions with …

Rediscovery Of The Microtubule System In Chlamydomonas, Yi Liu

Dissertations (1934 -)

Extensive studies have revealed the complex mechanisms underlying the roles of the microtubule system in fundamental cellular processes, the severe consequences in development and health resulted from its anomaly, and the irreplaceable therapeutic agents that perturbs this vital yet inherently unstable cytoskeletal system. Most of the concepts derived from a handful of model organisms become dogma of the field despite contrary observations. By overcoming a major limitation of biflagellate green alga Chlamydomonas - the intense autofluorescence common to photosynthetic cells - this dissertation discovered new phenomena of the microtubule system and conceived an invention. The microtubule system of the green …

The Noncanonical Roles Of Two Primordial Molecules In Flagella, Xiaoyan Zhu

Dissertations (1934 -)

Motile cilia and flagella are ancient organelles that eukaryotic organisms today still rely on to thrive in their natural environment. Not surprisingly, accumulated evidence has shown that the intricate motility machinery, the microtubule-based axoneme, is evolutionarily conserved down to the molecular level. This notion is epitomized by the signature axonemal complex, the radial spoke (RS). The RS is part of a control center conferring the high frequency and tightly regulated movement. Key RS proteins discovered in biflagellate green alga, Chlamydomonas reinhardtii, are also generated by nearly all ciliated organisms, including Homo sapiens. Among them are two subunits from primordial protein …

Reinforcement Learning, Error-Related Negativity, And Genetic Risk For Alzheimer's Disease, Christina Marie Figueroa

Dissertations (1934 -)

Reinforcement learning (RL) has been widely used as a model of animal and human learning and decision-making. The neural networks underlying RL involve many of the same structures primarily affected by Alzheimer’s disease (AD) such as the hippocampus. Yet, RL and non-invasive evaluation of its neural underpinnings have been underutilized as a framework for understanding disease pathology and its pre-clinical states. This study aimed to provide a novel approach for assessing subtle changes in asymptomatic apolipoprotein-E (APOE) carriers and non-carriers. Electroencephalography was collected from forty APOE genotyped older adults (Male n = 11; Mage = 79.30; Meducation = 14.88 years) …

Mechanisms Of Neuronal Death Induced By Environmental Toxicants In Murine Cortical Culture, Travis Rush

Dissertations (1934 -)

This study was directed at examining the neurotoxic mechanisms of several classes of environmental toxicants implicated in neurodegenerative disease. Primary cortical cultures were exposed to organophosphorus pesticides, heavy metals and the cyanobacterial toxin, beta-N-methylamino-L-alanine (BMAA). Several components relating to neuronal injury were assessed in each study and novel aspects are described.

The main action of organophosphorous insecticides is generally believed to be the inhibition of acetylcholinesterase. However, these compounds are now recognized to inhibit many other enzymes and cause neuronal death through a variety of mechanisms. I found that exposure to chlorpyrifos or diazinon caused concentration-dependent neurotoxicity that could not …