Matching Items (155)
Description
Osteocalcin (Oc) is the most abundant non-collagen protein found in the bone, but its precise function is still not completely understood. Three glutamic acid (Glu) residues within its sequence are sites for vitamin K-dependent post-translational modification, replacing a hydrogen with a carboxylate located at the γ-carbon position, converting these to γ-carboxyglutamic acid (Gla) residues. This modification confers increased binding of Oc to Ca2+ and hydroxyapatite matrix. Presented here, novel metal binding partners Mn2+, Fe3+, and Cr3+ of human Oc were determined, while the previously identified binders to (generally) non-human Oc, Ca2+, Mg2+, Pb2+ and Al3+ were validated as binders to human Oc by direct infusion mass spectrometry with all metals binding with higher affinity to the post-translationally modified form (Gla-Oc) compared to the unmodified form (Glu-Oc). Oc was also found to form pentamer (Gla-Oc) and pentamer and tetramer (Glu-Oc) homomeric self-assemblies in the absence of NaCl, which disassembled to monomers in the presence of near physiological Na+ concentrations. Additionally, Oc was found to form filamentous structures in vitro by negative stain TEM in the presence of increased Ca2+ titrations in a Gla- and pH-dependent manner. Finally, by combining circular dichroism spectroscopy to determine the fraction of Gla-Oc bound, and inductively-coupled plasma mass spectrometry to quantify total Al concentrations, the data were fit to a single-site binding model and the equilibrium dissociation constant for Al3+ binding to human Gla-Oc was determined (Kd = 1.0 ± 0.12 nM). Including citrate, a known competitive binder of Al3+, maintained Al in solution and enabled calculation of free Al3+ concentrations using a Matlab script to solve the complex set of linear equations. To further improve Al solubility limits, the pH of the system was lowered to 4.5, the pH during bone resorption. Complementary binding experiments with Glu-Oc were not possible due to the observed precipitation of Glu-Oc at pH 4.5, although qualitatively if Glu-Oc binds Al3+, it is with much lower affinity compared to Gla-Oc. Taken together, the results presented here further support the importance of post-translational modification, and thus adequate nutritional intake of vitamin K, on the binding and self-assembly properties of human Oc.
ContributorsThibert, Stephanie (Author) / Borges, Chad R (Thesis advisor) / LaBaer, Joshua (Committee member) / Chiu, Po-Lin (Committee member) / Arizona State University (Publisher)
Created2021
Description
The 5-year survival rate for late-stage metastatic melanoma is only ~30%. A major reason for this low survival rate is that one of the most commonly mutated genes in melanoma, NRAS, has no FDA-approved targeted therapies. Because the RAS protein does not have any targeted therapies, patients with RAS mutant tumors have an ongoing need for treatments that indirectly target RAS. This thesis project aims to identify expression and phosphorylation levels of proteins downstream of RAS in melanoma cell lines with the most common driver mutations. By analyzing the protein-level differences between these genetic mutants, we hope to identify additional indirect RAS protein targets for the treatment of NRAS mutant melanoma. RAS has several downstream effector proteins involved in oncogenic signaling pathways including FAK, Paxillin, AKT, and ERK. 5 melanoma cell lines (2 BRAF mutant, 2 NRAS mutant, and 1 designated wildtype) were analyzed using western bloting for FAK, Paxillin, AKT, and ERK phosphorylation and total expression levels. The results of western blot analysis showed that NRAS mutant cell lines had increased expression of phosphorylated Paxillin. Increased Paxillin phosphorylation corresponds to increased Paxillin binding at the FAT domain of FAK. Therefore, cell lines with increased FAK FAT – Paxillin interaction would be more sensitive to FAK FAT domain inhibition. The data presented provide an an explanation for the reduction in cell viability in NRAS mutant cell lines infected with Ad-FRNK. This information also has significant clinical relevance as researchers work to develop synthetic FAK FAT domain inhibitors, such as cyclic peptides. Additionally, cell lines with high levels of phosphorylated AKT showed a significant reduction in the amount of phosphorylated ERK. The identification of this inverse relationship may help to explain why BRAF and NRAS mutations are mutually exclusive. To conclude, NRAS mutant cell lines have increased expression of phosphorylated Paxillin and AKT which may explain why NRAS mutant cell lines are more sensitive to FAK FAT domain inhibition.
ContributorsSherwood, Nicole (Author) / Gould, Ian (Thesis director) / LaBaer, Joshua (Committee member) / Marlowe, Timothy (Committee member) / Barrett, The Honors College (Contributor) / School of Life Sciences (Contributor)
Created2022-05
Description
Emerging pathogens present several challenges to medical diagnostics. Primarily, the exponential spread of a novel pathogen through naïve populations require a rapid and overwhelming diagnostic response at the site of outbreak. While point-of-care (PoC) platforms have been developed for detection of antigens, serologic responses, and pathogenic genomes, only nucleic acid diagnostics currently have the potential to be developed and manufactured within weeks of an outbreak owing to the speed of next-generation sequencing and custom DNA synthesis. Among nucleic acid diagnostics, isothermal amplification strategies are uniquely suited for PoC implementation due to their simple instrumentation and lack of thermocycling requirement. Unfortunately, isothermal strategies are currently prone to spurious nonspecific amplification, hindering their specificity and necessitating extensive empirical design pipelines that are both time and resource intensive. In this work, isothermal amplification strategies are extensively compared for their feasibility of implementation in outbreak response scenarios. One such technology, Loop-mediated Amplification (LAMP), is identified as having high-potential for rapid development and PoC deployment. Various approaches to abrogating nonspecific amplification are described including a novel in silico design tool based on coarse-grained simulation of interactions between thermophilic DNA polymerase and DNA strands in isothermal reaction conditions. Nonspecific amplification is shown to be due to stabilization of primer secondary structures by high concentrations of Bst DNA polymerase and a mechanism of micro-complement-mediated cross-priming is demonstrated as causal via nanopore sequencing of nonspecific reaction products. The resulting computational model predicts primer set background in 64% of 67 test assays and its usefulness is illustrated further by determining problematic primers in a West Nile Virus-specific LAMP primer set and optimizing primer 3’ nucleotides to eliminate micro-complements within the reaction, resulting in inhibition of background accumulation. Finally, the emergence of Orthopox monkeypox (MPXV) as a recurring threat is discussed and SimCycle is utilized to develop a novel technique for clade-specific discrimination of MPXV based on bridging viral genomic rearrangements (Bridging LAMP). Bridging LAMP is implemented in a 4-plex microfluidic format and demonstrates 100% sensitivity in detection of 100 copies of viral lysates and 45 crude MPXV-positive patient samples collected during the 2022 Clade IIb outbreak.
ContributorsKnappenberger, Mark Daniel (Author) / Anderson, Karen S (Thesis advisor) / LaBaer, Joshua (Committee member) / Roberson, Robert (Committee member) / Lindsay, Stuart (Committee member) / Arizona State University (Publisher)
Created2023
Description
MicroRNAs (miRNAs) are 17-22 nucleotide non-coding RNAs that regulate gene expression by targeting non-complementary elements in the 3’ untranslated regions (3’UTRs) of mRNAs. miRNAs, which form complex networks of interaction that differ by tissue and developmental stage, display conservation in their function across metazoan species. Yet much remains unknown regarding their biogenesis, localization, strand selection, and their absolute abundance due to the difficulty of detecting and amplifying such small molecules. Here, I used an updated HT qPCR-based methodology to follow miRNA expression of 5p and 3p strands for all 190 C. elegans miRNAs described in miRBase throughout all six developmental stages in triplicates (total of 9,708 experiments), and studied their expression levels, tissue localization, and the rules underlying miRNA strand selection. My study validated previous findings and identified novel, conserved patterns of miRNA strand expression throughout C. elegans development, which at times correlate with previously observed developmental phenotypes. Additionally, my results highlighted novel structural principles underlying strand selection, which can be applied to higher metazoans.
Though optimized for use in C. elegans, this method can be easily adapted to other eukaryotic systems, allowing for more scalable quantitative investigation of miRNA biology and/or miRNA diagnostics.
ContributorsMeadows, Dalton Alexander (Author) / Mangone, Marco (Thesis advisor) / LaBaer, Joshua (Committee member) / Murugan, Vel (Committee member) / Wilson-Rawls, Jeanne (Committee member) / Arizona State University (Publisher)
Created2023
Description
Under the direction of Dr. Carolyn Compton, a group of seven Barrett honors students have embarked on a truly unique team thesis project to create a documentary on the process of creating a COVID-19 testing laboratory. This documentary tells the story of the ASU Biodesign Clinical Testing Laboratory (ABCTL), the first lab in the western United States to offer public saliva testing to identify the presence of COVID-19.
ContributorsCura, Joriel (Director, Photographer) / Foote, Hannah (Producer, Sound designer) / Raymond, Julia (Production personnel) / Bardfeld, Sierra (Narrator, Editor) / Dholaria, Nikhil (Writer of added commentary) / Liu, Tara (Writer of added commentary) / Varghese, Mahima (Writer of added commentary) / Compton, Carolyn C. (Interviewee, Project director) / Harris, Valerie (Interviewee) / LaBaer, Joshua (Interviewee) / Miceli, Joseph (Interviewee) / Nelson, Megan (Interviewee) / Ungaro, Brianna (Interviewee)
Created2021
Description
Breast cancer is one of the leading causes of cancer-related deaths among women in the United States. Uninsured women are less likely to receive breast cancer screenings, more likely to be diagnosed at an advanced stage, and more likely to have poorer outcomes following a breast cancer diagnosis (Abdelsattar et al., 2016; Akinlotan et al., 2021; Ko et al., 2020; & Ntiri et al., 2018). Women in underserved communities often experience socioeconomic barriers which impact obtaining preventative screenings, such as mammograms. Lack of patient navigation, transportation, and financial concerns interfere with obtaining breast cancer screening (Akinlotan et al., 2021 & Miller et al., 2019). Through the intervention of mobile mammography, uninsured women in underserved communities can be reached and access to screening mammograms can be achieved (Stanley et al., 2017 & Vang et al., 2018). Two mobile mammography events were hosted at the project site which provided 35 women with screening mammograms. All scheduled mammogram time slots at the events were filled and completed. Offering mobile mammography to this population has the potential to increase breast cancer surveillance.
ContributorsGlessner-Vallee, Paula (Author) / Santerre, Jennifer (Thesis advisor) / College of Nursing and Health Innovation (Contributor)
Created2023-04-26
Description
Introduction: The objective of this study is to emphasize the significance of exclusive breastfeeding (EB) and investigate methods to encourage and sustain it within a hospital environment. Using the self-efficacy theory, the study seeks to improve the current support system for breastfeeding mothers and their families. Methods: The project was approved by the university IRB and facility IRB; guidelines were maintained. The project takes place in a non-profit organization in the southwestern United States. Education was conducted at a required staff meeting for Women and Infant Services (WIS) floor about supporting breastfeeding mothers. A pre- and post-education Breastfeeding Knowledge Scale (BKS) survey was performed, effectiveness was measured using a two-tailed t-test. The reliability of the BKS scale is 0.83 and the validity of the scale is reported to be strong. The hospital measures the EB rates of patients that are greater than 37 weeks gestation without need for neonatal intensive unit care and the mom requests to breastfeed. Results: The goal was 42% rate of EB in the first 48 hours after birth. After education the average rate of EB was 39.6%, lower than the goal but higher than the 33.7% rate before education. A two-tailed paired sample t-test (n=27) was used for BKS and the results were significant based on an alpha value; thus, showing significant knowledge gain. Conclusion: Consistent staff education improves breastfeeding support for moms in the hospital, leading to successful exclusive breastfeeding. This project benefits various settings, such as pediatric, postpartum, labor and delivery, and pediatric offices.
ContributorsHudson, Jennifer (Author) / Esperas, Amanda (Thesis advisor) / College of Nursing and Health Innovation (Contributor)
Created2023-04-26
Description
Introduction: Depression screening in the pediatric setting is a crucial part of the adolescent's examination. A standardized screening tool and protocol streamlines the process of assessing adolescents and minimizes the chances of serious mental health disorders going undetected and untreated. Evaluation of current evidence demonstrates the use of a standardized tool improves detection, diagnosis, and management of depression and other mental health illnesses.
Method: The Patient Health Questionnaire—modified for adolescents (PHQ9-A) was administered to all eligible adolescents, ages 12-18, during an annual well visit for a period of 6 weeks. Lewin's Change Theory guided a system change in the electronic health record, and the questionnaire results were documented and provided to the pediatric provider at the time of the appointment. A chart review was conducted to determine whether all eligible patients were administered the questionnaire and if a depression diagnosis or mental health referral had been made.
Results: Out of 76 eligible well visits, 65 (86%) patients completed the PHQ9-A. The average score was 5.29 (SD = 6.49) with a maximum score of 25. Out of those that completed screening, 11 (17%) had a positive PHQ9-A score resulting in 8 referrals to mental health services and 2 mental health diagnoses in the clinic.
ContributorsCoomer, Meagan (Author) / Rauton, Monica (Thesis advisor) / College of Nursing and Health Innovation (Contributor)
Created2023-04-27
Description
Background: There is growing evidence that persistent exposure to the adverse effects of stressful work conditions, abuse, and re-traumatization without proper intervention leads to compassion fatigue (CF) and reduced compassion satisfaction (CS). Without appropriate intervention, the outcome of CF affects the patient, staff, and the organization. Despite proposed self-care measures, mental health (MH) workers continue to struggle with CF and lack the resources to combat the issue.
Objectives: Ongoing awareness on the implications of trauma and its impact on one's behavior, supports the use of Trauma-informed care (TIC) skills in creating a conducive work environment. This quality improvement project examines the efficacy of TIC education as an intervention for CF pre/post-one-hour education session among MH workers.
Methods: MH nurses (n=8) from diverse backgrounds in a Phoenix inpatient psychiatric hospital gave consent for the study. Participation was sought via flyers and entailed attending the one-hour education session, filling out a demographic, and pre/post-professional quality of life (ProQol) surveys. The ProQol standardized tool measures CF, CS, and burnout with reliability >0.70. Expected outcomes include a reduction in CF and an improvement in CS. Data analysis using intellectus software involved descriptive analysis and paired t-tests to compare outcomes.
Results: Pre/post data analysis was statistically significant, P = 0.003, which shows a reduction in CF and an improvement in CS.
Conclusion: TIC as an intervention for CF looks promising. MH nurses can manage their stress symptoms and that of their patients using TIC skills.
ContributorsOnyia, Nneka (Author) / Guthery, Ann (Thesis advisor) / College of Nursing and Health Innovation (Contributor)
Created2023-04-29
Description
Substance use disorder has been increasing in the United States year after year. Modern treatments fail as often as they succeed. The current standards of practice fail to provide patients with the ability to harness thoughts and control anxiety. Mindfulness practices are currently being adapted as a therapeutic technique to address some of these concerns. An exhaustive literature review was conducted to investigate how various mindfulness techniques impact substance use disorder. Ten high-quality studies were retained and synthesized to show current understandings of the effectiveness of a mindfulness therapeutic technique. An evidence-based intervention is suggested for implementing mindfulness-based relapse prevention into a residential treatment facility. The intervention created incorporates the self-efficacy theory and an adapted health-belief model. Adults in a residential treatment facility for substance use disorder were given eight mindfulness sessions over the course of four weeks. Participants were given pre- and post-intervention screenings for mindful attention and anxiety. The data analysis after two-tailed paired T-tests showed that anxiety significantly decreased (α=.05, p<.001) and mindful attention increased significantly (α=.05, p=.015). Overall, mindfulness shows promise in its potential to reduce substance abuse.
ContributorsWandler, Ryan (Author) / Nunez, Diane (Thesis advisor) / College of Nursing and Health Innovation (Contributor)
Created2023-04-27