Life Sciences Commons^™

Thinking Beyond The Fried Egg Model: How Accurately Do Students Perceive Cells In A Living Context?, Milissa Knox

Electronic Theses and Dissertations

This exploratory study investigated three aspects of introductory undergraduate biology students’ understanding about cells. The study, which took place at the University of Maine with voluntary students in Basic Biology (“BIO100”) in the summer and fall of 2009, examined (1) students’ pre-course perceptions of cells as they exist in a living context and (2) gains in students’ perception and knowledge about cells after completing the one-semester course (BIO100). Results are based on lecture exam scores, pre-post surveys developed as a part of this thesis, and interviews with two groups of biology students. A total of 498 students participated in the …

The Role Of Tumor Suppressor Co-Chaperone Chip/Stub1 In Erbb2-Mediated Oncogenesis, Haitao Luan

Theses & Dissertations

The epidermal growth factor receptor (EGFR) family member ErbB2 (Her2) is overexpressed in 20 -30% of invasive breast cancers and this overexpression correlates with poor prognosis and shorter overall as well as disease-free survival. Aberrant expression of ErbB2 through gene amplification, transcriptional deregulation and/or altered endocytic trafficking results in overexpression of ErbB2 at the plasma membrane and biases ErbB2 from primarily ligand-driven hetero-dimerization under normal expression conditions to increased ligand-independent homo-dimer and hetero-dimer formation and consequent activation. C-terminus of HSC70-Inteeracting protein (CHIP)/STIP1-homologous U-Box containing protein 1 (STUB1) is an HSP90/HSC70 interacting negative co-chaperone known to promote ubiquitination and degradation of …

Acute Methamphetamine Exposure Affects Histone Modifying Enzymes And Cytokine Production In Macrophages, Ariel Burns

Theses & Dissertations

The effects of methamphetamine (Meth) in the periphery are not well studied and a comprehensive investigation on the effects and molecular mechanism will give insight into why Meth users are at an increased risk of infections. For this reason, we use macrophages as a model for the immune system dysregulation seen in Meth abusers and also because macrophages are a long-lived cell that HIV infects and persists in. We aimed to determine the effects of Meth on the cytokine production, histone modifying enzymes and the corresponding histone post-translational modifications, and the molecular mechanism in HIV-infected human macrophages treated with combination …

The Role Of Cxcr2 In Pancreatic Cancer Development And Progression, Abhilasha Purohit

Theses & Dissertations

This dissertation examines the role of CXCR2, a seven transmembrane G- protein coupled receptor, in mediating autocrine as well as paracrine mechanisms during pancreatic cancer progression. Data presented in the initial section demonstrates the aberrant expression of the CXCR2 biological axis in human pancreatic cancer tissue specimens. A study performed within the first section of this dissertation investigates the contribution of CXCR2 signaling in pancreatic cancer initiation. These studies have identified a novel role of CXCR2 in mediating KRAS^(G12D) -induced autocrine growth transformation of pancreatic cancer cells. The upregulation of the CXCR2 biological axis was found to be directly …

Atypical Protein Kinase C Dependent Polarized Cell Division Is Required For Myocardial Trabeculation, Derek L. Passer

Theses & Dissertations

A hallmark of cardiac development is the formation of myocardial trabeculations exclusively from the luminal surface of the primitive heart tube. Although a number of genetic defects in the endocardium (Grego-Bessa et al., 2007; Liu et al., 2010) and cardiac jelly (Camenisch et al., 2000) disrupt myocardial trabeculation, the role of cell polarity machinery in driving this process remains unclear. Herein, we demonstrate that atypical protein kinase C iota (Prkci) and its interacting partners of Par polarity complex are localized to the luminal side of luminal myocardial cells. Remarkably, a subset of these cells undergoes polarized cell division with the …

A Role For Ehd Family Endocytic Regulators In Endothelial Biology, Alexandra E. J. Moffitt

Theses & Dissertations

Endocytic trafficking is an essential process in eukaryotic cells, specifically for the transport of nutrients, membrane components, and receptors. Cargo destined for endocytic traffic is internalized at the cell surface via clathrin-dependent and clathrin-independent pathways, and brought to the early or sorting endosomes. From there, cargo is further trafficked to lysosomes for degradation, trafficked to other compartments in the cell, or recycled back to the cell surface (either directly or via the endocytic recycling compartment).

Mammalian C-terminal Eps15 homology domain-containing proteins, or EHD proteins (EHD1 to 4), are a family of highly conserved ATPases that function as key regulators of …

The Role Of Bone Sialoprotein In Periodontal Tissue Development And Bone Repair, Yohannes Soenjaya

Electronic Thesis and Dissertation Repository

Bone development and repair involve complex processes that include interaction between cells and their surrounding matrix. In the body, bone sialoprotein (BSP) expression is up-regulated at the onset of mineralization. BSP is a multifunctional acidic phosphoprotein with collagen-binding, hydroxyapatite nucleating, and integrin recognition (RGD sequence, which is important for cell-attachment and signaling) regions. Mice lacking BSP expression (Bsp^-/-), exhibit a bone phenotype with reductions in bone mineral density, bone length, osteoclast activation, and impaired bone healing. This thesis examined the role of BSP in tooth development and also its potential use as a therapeutic reagent for bone …

Investigation Of Cell-Penetrating Peptide Transformation In Two Regenerable Tissue Culture Systems, Atiyyah S. Ferouz

Electronic Thesis and Dissertation Repository

The genetic engineering of plants allows for the modification of plant genomes, subsequently improving plant traits. There are, however, plants recalcitrant to established transformation methods, requiring the implementation of novel techniques. This study investigates the viability of cell-penetrating peptide (CPP) transformation using Tat₂, a CPP with demonstrated transformation efficiency in plant and animal systems, in two regenerable tissue culture systems, soybean somatic embryos and Arabidopsis protoplasts. Assessments of complex formation, Tat₂ cellular translocation, complex uptake, and CPP-mediated transformation were carried out. The results show the formation of a Tat₂-plasmid complex and the uptake of Tat …

Hd2d Is A Regulator Of Abscisic Acid Responses In Arabidopsis, Joshua A. Farhi

Electronic Thesis and Dissertation Repository

Histone deacetylases have important roles in development and stress response in plants. To further investigate their function, the HD2D gene, of the plant specific HD2 family, was studied. An hd2d-1 mutant and two HD2D overexpression lines were used in this study. Germination was delayed in hd2d-1 and HD2D overexpression seeds only in the presence of ABA. HD2D was found to positively regulate the expression of members of the ABA-response pathway (ABI1, ABI5, and RD29A) leading to increased resistance to drought and salinity treatments. Furthermore, HD2D expression delayed flowering by positively regulating FLC expression. Using bimolecular fluorescence complementation, the HD2D protein …

Is The Zebrafish Zombie Mutant Caused By A Mutation In Cdc20?, Peyton Johnston

Honors Theses

The zombie mutant was identified as an early arrest mutant, stopping in development around the 10-somite stage (14 hours of development). Further inspection revealed that this mutant was a cell cycle mutant and cells in the mutant arrest during metaphase as early as the 5-somite stage (11.6 hours of development). A similar phenotype is seen in the Drosophila melanogaster cell cycle gene fizzy, known to be to be a homolog of the Saccharomyces cerevisiae gene, cell division cycle 20 (cdc20). CDC20 is an activator protein of the anaphase promoting complex/cyclosome (APC/C), an ubiquitin E3 ligase that is …

Brown And Beige Adipocytes: Effects Of Inflammation And Nutritional Intervention, Jiyoung Bae

Doctoral Dissertations

Recent findings of brown adipocytes and brown-like or beige adipocytes, capable of dissipating energy as heat, in adult humans have promised new hope for obesity treatment and prevention. Understanding of the regulation of brown and beige adipocytes will provide novel strategies to reach the goal. Pattern recognition receptors (PRR) are responsible for inflammation in adipose tissue, which leads to adipose dysfunction and obesity associated chronic diseases. It has been shown that PRR activation induces inflammation, leading to insulin resistance in white adipocytes and white adipose tissue (WAT). However, the roles of PRR activation in brown adipocytes and brown adipose tissue …

The Role Of G-Protein Signaling In Pathogenesis In Cercospora Zeae-Maydis, Brant Smith

Graduate Theses and Dissertations

Gray leaf spot, caused by Cercospora zeae-maydis, is one of the most destructive foliar diseases of maize worldwide. C. zeae-maydis orients hyphal growth towards stomata (stomatal tropism) and forms infectious structures (appressoria) that are necessary for successful infection. Although some genes involved in pathogenesis in C. zeae-maydis have been identified, the molecular mechanisms are not well understood. In fungi, heterotrimeric G-proteins consist of three subunits (α, β, and γ) and mediate responses to environmental stimuli. They regulate diverse functions, including nutrient detection, virulence, fungal development, conidiation, secondary metabolism, and pathogenesis in many plant pathogenic fungi. This research explored the role …

Effects Of Bone Morphogenetic Protein-2 And Parathyroid Hormone-Related Peptide On Collagen Xi During Skeletal Development, Neda Shefa

Boise State University Theses and Dissertations

Long bones develop via endochondral ossification, a process in which cartilage precedes bone. During endochondral ossification prechondrogenic cells undergo proliferation and apoptose as cells of the periosteum differentiate into bone. The process of endochondral ossification is regulated by a group of endocrine as well as paracrine molecules that includes bone morphogenetic protein-2 (BMP-2) and parathyroid hormone-related peptide (PTHrP). Collagens are extracellular matrix molecules that are present in a spatiotemporal manner during endochondral ossification. Collagen XI alpha 1 (Col11a1) is a minor fibrillar collagen that is alternatively spliced during development and can result in up to eight different spliceforms. During endochondral …

Eicosapentaenoic Acid (Epa) From Porphyridium Cruentum: Increasing Growth And Productivity Of The Microalgae For Pharmaceutical Products, Maryam Asgharpour

Graduate Theses and Dissertations

One of the major nutritional requirements in our diet is an adequate intake of omega-3 specially eicosapentaenoic acid (EPA). In the present study, the effects of two temperatures (16°C & 20˚C) and light intensities (140 & 180µE/M2.S) and four nitrate levels (0.075, 0.3, 0.5 and 0.7g/L) on the cell growth and lipid productivity of Porphyridium cruentum, one of the most promising oil-rich species of microalgae, were investigated. A growth comparison was carried out using pure CO2 and 5% CO2/air. Additionally, the ratio of the fatty acids with omega-3 and omega-6 groups at various growth conditions were compared, since an appropriate …

Response Of Bacterial Cells To Fluctuating Environment, Sudip Nepal

Graduate Theses and Dissertations

We have studied morphological and genomic variations occurring in a mesophilic bacterium Escherichia coli (E. coli) in a wide range of continuous and fluctuating hydrostatic pressures. For all the studies here the temperature is maintained at 37◦C, the optimal growth tem- perature of E. coli at atmospheric pressure. Cell division is inhibited at high hydrostatic pressures resulting in an increase of cell length. The increase of cell-length depends on the extent and duration of the stress applied on bacterial cells. We have studied the effect of high pressure stress in three different conditions – (i) Wild-type cells (almost no genetic …

Effects Of Global Dna Methylation Changes On Neurobehavior In Zebrafish, Matthew Christopher Pickens

Theses and Dissertations

A number of environmental neurotoxicants modulate DNA methylation, but its influence on neurobehavior remains unclear. The laboratory has established that low-level developmental methylmercury exposure induces neurobehavioral deficits; the current results demonstrate that it also induces global DNA hypomethylation. DNA methyltransferase 1-mutant zebrafish (exhibit ~70% reduction in enzymatic activity) were used to assess the role of DNA hypomethylation on behavior. Several neurobehavioral assays including the C-start escape, circadian rhythm, basic locomotion and visual-motor response (VMR) were also performed. There was a significant difference in VMR between the wild type and mutant animals. Other behavior assays revealed no significant difference, primarily due …

Mobilization Of Adipose Stromal Cells In Obesity And Cancer By Sparc And Its Proteolytic Isoforms, Chieh Tseng

Dissertations & Theses (Open Access)

Obesity increases cancer risk and progression as shown by epidemiologic studies. However, the underlying pathophysiology remained unclear. Adipose stromal cells (ASC) are adipose tissue-derived mesenchymal progenitors, abundant in white adipose tissue (WAT). In this study, we show that the ASC pool is expanded in obesity and is associated with promoted tumor growth. Next, by using a chimeric GFP-RFP bone marrow transplant model, we observed higher tumor infiltrating cells with ASC phenotype in obese mice compared to lean. Consistently, systemic circulating ASC frequency is six fold higher in tumor-bearing obese mice compared to lean. The tumor infiltrating cells with ASC phenotype …

Defining The Molecular Networks Necessary For Thymus Fate And Organogenesis, Kaitlin A. Reeh

Dissertations & Theses (Open Access)

The thymus and parathyroid (PT) glands originate from endodermal progenitors in the bilateral third pharyngeal pouches (3^rd pps). By E11.5 during mouse development, cells committed to the thymus lineage express Foxn1 whereas PT-fated cells express Gcm2. While these transcription factors are required for organ-specific differentiation, the exact molecular mechanisms that specify endodermal progenitors to either the thymus or parathyroid lineage are not well defined. Tbx1 is initially expressed throughout the 3^rd pp endoderm, as it is required for segmentation of the pharyngeal apparatus, but is downregulated in the thymus-fated domain by E10.5. Despite the widely held notion …

Preventing Thymus Involution In K5.Cyclin D1 Transgenic Mice Sustains The Naïve T Cell Compartment With Age, Michelle L. Bolner

Dissertations & Theses (Open Access)

The thymus maintains T cell receptor (TCR) repertoire diversity through perpetual release of self-MHC restricted naive T cells. However, thymus involution during the aging process reduces naïve T cell output, leading to defective immune responsiveness to newly encountered antigens. We have found that early thymus involution precipitates the age-associated shift favoring memory T cell dominancy in young control mice. Furthermore, we have shown that age-related thymus involution is prevented in mice expressing a keratin 5 promoter-driven Cyclin D1 (K5.D1) transgene in thymic epithelial cells (TECs). Thymopoiesis occurs normally in K5.D1 transgenic thymi and sustains T cell output to prevent the …

Molecular Regulation Of Vascular Calcification In Murine Models Of Atherosclerosis, Shanshan Gao

Dissertations & Theses (Open Access)

Background: Calcification occurs often in the atherosclerotic lesions of patients with coronary heart disease and animals with hypercholesterolemia, such as apolipoprotein-E deficient (ApoE-/-) mice. However, the mechanism(s) underlying the development of calcification in atherosclerosis remains unclear. ApoE acts as a lipid transporter, but also has been recognized as a potential regulator of osteogenesis. Little information is available as to whether ApoE has any direct impact on osteogenesis and calcification in vascular smooth muscle cells (VSMC). Several signal transduction pathways play a role in regulation of calcification, including the Wnt/β-catenin system and potentially GTAP, an ubiquitin-conjugating enzyme responsible for protein …

Leptin Regulates The Expression Of Autophagy-Related Genes In Chickens, Peter Olawale Ishola

Graduate Theses and Dissertations

Autophagy or cellular self-digestion, a lysosomal degradation pathway that is conserved from yeast to human, plays a key role in recycling cellular constituents, including damaged organelles. It also plays a pivotal role in the adaptation of cells to a plethora of distinct stressors including starvation. Autophagy has been extensively studied in mammals and yeast, but little is known in avian species. Thus, the major objective of the present study was to determine the effects of leptin on autophagy-related genes in chicken hypothalamus, muscle and liver. Leptin is an adipocytokine that is mostly produced by white adipose cells in mammals (as …

Transcriptomics Of Chicken Primordial Germ Cells, Nhung Thi Nguyen

Graduate Theses and Dissertations

Chicken primordial germ cells (PGCs) are derived from extraembryonic tissue of the embryo and first appear at stage X of development. They enter the bloodstream and migrate to the genital ridge, unite with somatic tissue to form a developing gonad, and then differentiate to sperm or ova (Fujimoto et al., 1976). Understanding molecular features of both male and female PGCs not only clarify the differentiation mechanism of such cells toward different germ lines, but will also help in selecting for highly productive types of commercial chicken. Most previous studies focused on the location of PGCs (Eyal-Giladi et al., 1981; Swift …

Problem Solving Skill And Obesity In Children, Caitlin R. Spano

The Eleanor Mann School of Nursing Undergraduate Honors Theses

Abstract:

Introduction: Childhood obesity is a problem that leads to many serious health effects including early maturation, decreased quality of life and increased risk for cardiovascular disease. In 2012, over one third of children were considered obese (Childhood Obesity Facts 2015). Efforts have been made to reduce this number but they have not been fully successful (Nutrition Standards for School Meals 2015, Prevalence of Childhood obesity in the United States 2011-2012 2015). What other factors are causing kids to choose foods that lead to weight gain.

Literature Review: In research regarding psychological motivations of overeating, there has been a correlation …

Characterization Of Embryonic Stem Cell-Differentiated Cells As Mesenchymal Stem Cells, Rachael N. Kuehn

Honors Theses

Embryonic stem cells (ESCs), due to their ability to differentiate into different cell types while still maintaining a high proliferation capacity, have been considered as a potential cell source in regenerative medicine. However, current ESC differentiation methods are low yielding and create heterogeneous cell populations. If transplanted in the human body, differentiated ESCs could be rejected by the immune system, form tumors, or may not function normally within the human body. On the other hand, mesenchymal stem cells (MSCs), a type of adult stem cell typically derived from bone marrow, have proved to be excellent candidates in clinical applications due …

The Effect Of Leucine Supplementation On Mitochondrial Biogenesis And Mitochondrial Protein Synthesis In Rats Fed A High-Fat Diet, David M. Skinner

Health, Human Performance and Recreation Undergraduate Honors Theses

This study aims to illuminate interaction between leucine supplementation and mitochondrial proteins concerned with synthesis and biogenesis. We hypothesized that supplementation with leucine will attenuate the weight gain of the high fat diet in comparison with the normal chow group, by enhancing mitochondrial biogenesis and content. We conducted a laboratory experiment using Western Blotting techniques to determine protein expression. Proteins of interest in this study include PGC-1α, COX-IV, TUFM, TFAM, and mtIF2. The findings from the research show a main effect of an increase in the expression of PGC-1 α in high fat diets. There was no difference in the …

Identifying Protein Kinase Tbk1 As A Novel Inhibitor Of Intestinal Tumorigenesis, Amber L. Mathews

Dissertations & Theses (Open Access)

Colorectal cancer (CRC) is the third most common cancer diagnosed in women and men， causing almost 600,000 annual deaths worldwide. There is a clear need to understand how CRC forms and progresses in order to improve the strategies of CRC prevention and therapy. A major factor that drives the development of CRC is genetic mutations that lead to activation of oncogenes and inactivation of tumor suppressor genes in intestinal epithelial cells (IECs). In addition, the initiation and progression of CRC involve environmental and immunological factors. In particular, chronic inflammatory conditions are known as an important risk factor for CRC. Intestinal …

Normal Glycolytic Enzyme Activity Is Critical For Hypoxia Inducible Factor-1a Activity And Provides Novel Targets For Inhibiting Tumor Growth, Geoffrey Grandjean Phd

Dissertations & Theses (Open Access)

Normal Glycolytic Enzyme Activity is Critical for Hypoxia Inducible Factor-1α Activity and Provides Novel Targets for Inhibiting Tumor Growth

By Geoffrey Grandjean

Advisory Professor: Garth Powis, D. Phil

Unique to proliferating cancer cells is the observation that their increased need for energy is provided by a high rate of glycolysis followed by lactic acid fermentation in a process known as the Warburg Effect, a process many times less efficient than oxidative phosphorylation employed by normal cells to satisfy a similar energy demand ^[1]. This high rate of glycolysis occurs regardless of the concentration of oxygen in the cell and …

Compounds Released From Biomass Deconstruction: Understanding Their Effect On Cellulose Enzyme Hydrolysis And Their Biological Activity, Angele Djioleu

Graduate Theses and Dissertations

The effect of compounds produced during biomass pretreatment on cellulolytic enzyme was investigated. Liquid prehydrolyzates were prepared by pretreating switchgrass using 24 combinations of temperature, time, and sulfuric acid concentration based on a full factorial design. Temperature was varied from 140°C to 180°C; time ranged from 10 to 40 min; and the sulfuric acid concentrations were 0.5% or 1% (v/v). Identified products in the prehydrolyzates included xylose, glucose, hydroxymethylfurfural (HMF), furfural, acetic acid, formic acid, and phenolic compounds at concentration ranging from 0 to 21.4 g/L. Pretreatment conditions significantly affected the concentrations of compounds detected in prehydrolyzates. When assayed in …

Regulation Of The Retinoblastoma Tumor Suppressor By The Novel Ras Effector Nore1a., Thibaut François Barnoud

Electronic Theses and Dissertations

Ras is the most frequently mutated oncogene in human cancers. It acts as a critical branch point in signal transduction, regulating numerous downstream effectors involved in cell growth and differentiation. While Ras can activate many growth promoting pathways, it can paradoxically regulate growth inhibitory pathways leading to apoptosis and cell cycle arrest. One of the ways Ras can inhibit the growth of cells is via a family of effectors called the RASSF proteins. RASSF5 (NORE1A) is a tumor suppressor that is frequently inactivated in human tumors by epigenetic mechanisms. NORE1A binds directly to Ras and promotes Ras-induced senescence. We have …

Third Ventricle Width As A Metric For Fast And Efficient Detection Of Atrophy In Traumatic Brain Injury, Christopher Scott Finuf

Theses and Dissertations

In an average year more than 1.7 million people will experience a traumatic brain injury (TBI) in the United States. It is known that atrophy occurs across a spectrum for TBI patients, ranging from mild to severe. Current conventional magnetic resonance imaging (MRI) methods are inconsistent in detecting this atrophy on the milder end of the spectrum. Also more contemporary imaging tools, although efficient, are too time consuming for clinical applicability. It is for these reasons that a quick and efficient measurement for detecting this atrophy is needed by clinicians. The measuring of third ventricle width had the potential to …