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Characterization Of A Small Animal Spect Platform For Use In Preclinical Translational Research, Dustin Ryan Osborne

Doctoral Dissertations

Imaging Iodine-125 requires an increased focus on developing an understanding of how fundamental processes used by imaging systems work to provide quantitative output for the imaging system. Isotopes like I-125 pose specific imaging problems that are a result of low energy emissions as well as how closely spaced those emissions are in the spectrum. This work seeks to characterize the performance of a small animal SPECT-CT imaging system with respect to imaging I-125 for use in a preclinical translational research environment and to understand how the performance of this system relates to critical applications such as attenuation and scatter correction. …

Optimizing Heart Dose Reduction For Deep Inspiration Left Breast Radiotherapy, Ronald James Harder

UNLV Theses, Dissertations, Professional Papers, and Capstones

Multiple studies have shown that an increased risk of late injury cardiac abnormalities including congestive heart failure (CHF), ischemia, and coronary artery disease (CAD) can be associated with common left breast radiation therapy (RT) techniques. Many radiation therapy clinics have adopted the Deep Inspiration Breath Hold (DIBH) technique for the treatment of the left breast with external beam therapy based on studies showing a decrease in the dose received by the heart. A common technology used to monitor inhalation during DIBH is the Real-Time Position Management (RPM) system (Varian Medical Systems, Palo Alto, CA). This study analyzes if there is …

Contribution Of Ectodomain Mutations In Epidermal Growth Factor Receptor To Signaling In Glioblastoma Multiforme, Marta L. Rojas

Dissertations & Theses (Open Access)

CONTRIBUTION OF ECTODOMAIN MUTATIONS IN EPIDERMAL GROWTH FACTOR RECEPTOR TO SIGNALING IN GLIOBLASTOMA MULTIFORME

Publication No._________

Marta Rojas, M.S.

Supervisory Professor: Oliver Bögler, Ph.D.

The Cancer Genome Atlas (TCGA) has conducted a comprehensive analysis of a large tumor cohort and has cataloged genetic alterations involving primary sequence variations and copy number aberrations of genes involved in key signaling pathways in glioblastoma (GBM). This dataset revealed missense ectodomain point mutations in epidermal growth factor receptor (EGFR), but the biological and clinical significance of these mutations is not well defined in the context of gliomas.

In our study, we focused on understanding …

Novel Amino Acid Transporter-Targeted Radiotracers For Breast Cancer Imaging, Fanlin Kong

Dissertations & Theses (Open Access)

Breast cancer is the most common malignancy among women in the world. Its 5-year survival rate ranges from 23.4% in patients with stage IV to 98% in stage I disease, highlighting the importance of early detection and diagnosis. ¹⁸F-2-Fluoro-2-deoxy-glucose (¹⁸F-FDG), using positron emission tomography (PET), is the most common functional imaging tool for breast cancer diagnosis currently. Unfortunately, ¹⁸F-FDG-PET has several limitations such as poorly differentiating tumor tissues from inflammatory and normal brain tissues. Therefore, ¹⁸F-labeled amino acid-based radiotracers have been reported as an alternative, which is based on the fact that tumor cells uptake …

Adaptive Intensity Modulated Radiation Therapy Planning Optimization With Changing Tumor Geometry And Biology Enforcing Both Cumulative And Fraction Size Dose Constraints, Behlul Saka

Graduate Theses and Dissertations

Intensity Modulated Radiation Therapy (IMRT) is a modern technique of delivering radiation treatments to cancer patients. In IMRT technology, intensities must be chosen for the many small unit grids into which the beams are divided to produce a desired distribution of dose at points throughout the body with the goal of maximizing dose delivered to the tumor while sparing healthy tissues from excessive radiation and keeping dose homogeneous across the tumor. Although IMRT plans are optimized as a single overall treatment plan, they are delivered over 30-50 treatment sessions (fractions) and both cumulative and per-fraction dose constraints apply. The extended …

Women's Cognitive Appraisals Of Their Birth Experience As Predictive And Maintaining Factors Of Postpartum Posttraumatic Stress Symptom Severity, Lauren Carr Spooner

Dissertations

Empirical support has accumulated for evidence of posttraumatic stress symptoms following approximately 30% of childbirth experiences (Olde, van der Hart, Kleber, & van Son, 2006). Researchers have suggested that there is a complex relationship among predisposing, precipitating, and maintaining factors that impact postpartum PTSD (Slade, 2006). Anxiety, perception of support, and negative cognitions are such factors that have been shown to significantly correlate with PTSD symptoms (Foa & Rothbaum, 1998; Olde et al., 2006; Soet, Brack, & Dilorio, 2003), but have not been studied together in relation to PTSD associated with traumatic birth. The current study controlled for trait anxiety …

Association Between Childhood Demographics And Blood Lead Screening---Nevada Kindergarten Health Survey 2010, Lina Zhang

UNLV Theses, Dissertations, Professional Papers, and Capstones

Lead, as a toxic substance, invades the human body, and gradually damages the organs. Oftentimes, elevated blood lead levels are not recognized until serious health issues are found. In the United States, approximately 250,000 children aged 1-5 years have elevated blood lead levels greater than 10 micrograms of lead per deciliter of blood (Centers for Disease Control and Prevention, 2004).

However, there is no effective treatment for lead poisoning. Chelation can merely decrease the blood lead levels but cannot reverse the existing damage. To prevent and control childhood lead poisoning, many studies have been conducted to investigate the sources of …

Evaluation Of The Pilot Program, Pediatric Early Warning Sentinel Surveillance Program (Pewss), And Its Efficacy In Monitoring Pediatric Illness In Clark County, Nevada, Michelle Lee Lutman

UNLV Theses, Dissertations, Professional Papers, and Capstones

The influenza outbreak that occurred during 2009 stimulated the formation of several surveillance programs throughout the country. The majority monitor only influenza; however, there are several other circulating respiratory pathogens, especially within the pediatric community. These other respiratory pathogens cause a variety of illnesses, such as bronchitis, pneumonia, croup, etc. Prior research has provided the medical community with valuable information about respiratory illnesses, especially those which afflict pediatric patients. Areas of knowledge including seasonality, demographics, signs and symptoms, prevention measures, and pathogenicity, have been greatly expanded over the years. This information has been of tremendous help to the medical community …

The Role Of Home Environments In Residential Adjustment Decision Making In Later Life, Kimberly Joy Stoeckel

Graduate Doctoral Dissertations

Using the nationally representative Health and Retirement Study, this research explored the multi-faceted influence of the accessibility of housing environments on the occurrence and characteristics of residential adjustments made by older adults aged 70 or older. A range of housing adjustment outcomes were examined, including home modifications and relocation into age-segregated senior housing. Analysis of the accessibility gains following relocation was also included in the empirical analyses.

The Ecological Theory of Aging (Lawton & Nahemow, 1973) provided the conceptual framework for the research. The longitudinal design of the HRS empirically advanced understanding of the key theoretical constructs by sensitizing the …

Wound Healing And The Role Of Biomarkers And Biofilms, Mujtaba Khan

All Capstone Projects

An injury to the skin alters the integrity of underlying tissues and microcirculation and thus certainly culminates in a wound. Wound healing is a highly complex, dynamic, interactive and well regulated physiological process involving blood cells, extracellular matrix, parenchyma cells and soluble mediators. It starts with alteration in integrity of tissues and ends with the formation of scar. The process of wound healing is distinguished into Haemostasis, Inflammation, Proliferation and Remodeling. Various cells like platelets, neutrophils, macrophages, lymphocytes, angiocytes, keratinocytes, fibroblasts and factors like platelet derived growth factor, transforming growth factor, platelet derived epidermal growth factors, fibroblasts growth factor, albumin, …

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 …

An Occupational-Based Experimental Study Of Collective Vs. Personal Efficacy To Encourage Sun Protective Behaviors In Head Start Preschool Teachers, Elizabeth A. Holzhauser

Loma Linda University Electronic Theses, Dissertations & Projects

Background. Skin cancer is one of the most common types of cancers in the United States. An analysis of literature shows that skin cancer can be partially mitigated through personal behavior changes (Glanz, Buller, & Saraiya; 2007, Canadian Centre of Occupational Health and Safety [CCOHS], 2010). Currently national sun-safety educational campaigns promote sun-protective behaviors to individuals who receive exposure due to their work environment (Task Force on Community Preventive Services, 2004). Preschool teachers employed with San Bernardino County Head Start are inadvertently exposed to sunlight during mandatory recess periods posing risks to their health.

Purpose. This study evaluated two instructional …

Strategies For Reducing The Impact Of Tumour Motion During Helical Tomotherapy, Bryan Kim

Electronic Thesis and Dissertation Repository

Tumour motion presents a significant limitation for effective radiotherapy of lung cancer, and more specifically for helical tomotherapy. The simultaneous and continuous movements of tomotherapy subsystems (gantry, couch, and binary multi-leaf collimator) can lead to inaccurate dose delivery, when combined with tumour motion. In this thesis, we have investigated the impact of tumour motion and strategies to reduce the resulting dose discrepancies for helical tomotherapy, through computer simulations and film measurements performed in a dynamic body phantom. Three distinctively different types of dose discrepancies have been isolated: dose rounding, dose rippling, and the intensity-modulated radiation therapy (IMRT) asynchronization effect. Each …

Brain Activation And Connectivity In Non-Disabled Multiple Sclerosis Patients, Rene A. Colorado

Dissertations & Theses (Open Access)

Multiple sclerosis (MS) is the most common demyelinating disease affecting the central nervous system. There is no cure for MS and current therapies have limited efficacy. While the majority of individuals with MS develop significant clinical disability, a subset experiences a disease course with minimal impairment even in the presence of significant apparent tissue damage on magnetic resonance imaging (MRI). The current studies combined functional MRI and diffusion tensor imaging (DTI) to elucidate brain mechanisms associated with lack of clinical disability in patients with MS. Recent evidence has implicated cortical reorganization as a mechanism to limit the clinical manifestation of …

The Development And Implementation Of An Anthropomorphic Head Phantom For The Assessment Of Proton Therapy Treatment Procedures, Paige A. Summers

Dissertations & Theses (Open Access)

Proton therapy has become an increasingly more common method of radiation therapy, with the dose sparing to distal tissue making it an appealing option, particularly for treatment of brain tumors. This study sought to develop a head phantom for the Radiological Physics Center (RPC), the first to be used for credentialing of institutions wishing to participate in clinical trials involving brain tumor treatment of proton therapy. It was hypothesized that a head phantom could be created for the evaluation of proton therapy treatment procedures (treatment simulation, planning, and delivery) to assure agreement between the measured dose and calculated dose within …

Analysis Of Chlamydia Pneumoniae And Ad-Like Pathology In The Brains Of Balb/C Mice Following Direct Intracranial Infection With Chlamydia Pneumoniae, Jessica Rachel Barton

PCOM Biomedical Studies Student Scholarship

Alzheimer’s disease (AD) is an age-related progressive neurodegenerative disorder and the most common form of dementia. The pathology in the central nervous system (CNS) impairs memory and cognition, hindering the capabilities and the quality of life of the individual. This project continues studying the role of infection and Alzheimer’s disease and contributes to the overall understanding of the possible causes of this disease. In this study, BALB/c mice were infected, via direct intracranial injection, with a respiratory isolate (AR-39) of Chlamydia pneumoniae. Their brains were analyzed at 7 and 14 days post-infection, using immunohistochemistry, for the presence of C. …

The Role Of Acidic Fibroblast Growth Factor And Fibroblast Growth Factor Receptor 4 In High Grade Serous Carcinoma, Tarrik Zaid

Dissertations & Theses (Open Access)

Background: High grade serous carcinoma whether ovarian, tubal or primary peritoneal, continues to be the most lethal gynecologic malignancy in the USA. Although combination chemotherapy and aggressive surgical resection has improved survival in the past decade the majority of patients still succumb to chemo-resistant disease recurrence. It has recently been reported that amplification of 5q31-5q35.3 is associated with poor prognosis in patients with high grade serous ovarian carcinoma. Although the amplicon contains over 50 genes, it is notable for the presence of several members of the fibroblast growth factor signaling axis. In particular acidic fibroblast growth factor (FGF1) …

In-Vivo Ct Dosimetry During Virtual Colonoscopy, Jonathon W. Mueller

Dissertations & Theses (Open Access)

Virtual colonoscopy (VC) is a minimally invasive means for identifying colorectal polyps and colorectal lesions by insufflating a patient’s bowel, applying contrast agent via rectal catheter, and performing multi-detector computed tomography (MDCT) scans. The technique is recommended for colonic health screening by the American Cancer Society but not funded by the Centers for Medicare and Medicaid Services (CMS) partially because of potential risks from radiation exposure. To date, no in‐vivo organ dose measurements have been performed for MDCT scans; thus, the accuracy of any current dose estimates is currently unknown.

In this study, two TLDs were affixed to the inner …

Tp53 As A Biomarker In Head And Neck Squamous Cell Carcinoma, Thomas J. Ow Md

Dissertations & Theses (Open Access)

Currently, there are no molecular biomarkers that guide treatment decisions for patients with head and neck squamous cell carcinoma (HNSCC). Several retrospective studies have evaluated TP53 in HNSCC, and results have suggested that specific mutations are associated with poor outcome. However, there exists heterogeneity among these studies in the site and stage of disease of the patients reviewed, the treatments rendered, and methods of evaluating TP53 mutation. Thus, it remains unclear as to which patients and in which clinical settings TP53 mutation is most useful in predicting treatment failure.

In the current study, we reviewed the records of a cohort …

Role Of Prostaglandin E2 In The Regulation Of Pancreatic Stellate Cells Hyper Activity Associated With Pancreatic Cancer, Chantale Charo

Dissertations & Theses (Open Access)

Pancreatic cancer is one of the most lethal type of cancer due to its high metastasis rate and resistance to chemotherapy. Pancreatic fibrosis is a constant pathological feature of chronic pancreatitis and the hyperactive stroma associated with pancreatic cancer. Strong evidence supports an important role of cyclooxygenase-2 (COX-2) and COX-2 generated prostaglandin E2 (PGE2) during pancreatic fibrosis. Pancreatic stellate cells (PSC) are the predominant source of extracellular matrix production (ECM), thus being the key players in both diseases. Given this background, the primary objective is to delineate the role of PGE2 on human pancreatic stellate cells (PSC) hyper activation associated …

Impact Of An Online Support System On Health Related Quality Of Life Among Men Diagnosed With Prostate Cancer, Daniel K. Osei

Loma Linda University Electronic Theses, Dissertations & Projects

Prostate cancer is a major public health issue worldwide and a significant cause of male cancer death in the USA. Though early screening and treatment has greatly enhanced the outcome, men diagnosed with prostate cancer face problems that compromise quality of life after treatment. Online support for prostate cancer clients is a convenient way to help because it is anonymous, inexpensive, and can be used at clients’ convenience. Yet few studies have explored how these supports impact these clients. This study used a longitudinal randomized experimental design to examine the impact of online services on quality of life of prostate …

Clinical Impact Of Couch Top And Rails On Imrt And Arc Therapy, Kiley B. Pulliam

Dissertations & Theses (Open Access)

Purpose: To evaluate the clinical impact of the Varian Exact Couch on dose and volume coverage to targets and critical structures and tumor control probability (TCP) for 6-MV IMRT and Arc Therapy.

Methods: Five clinical prostate patients were planned with both, 6-MV 8-field IMRT and 6-MV 2-field RapidArc using the Eclipse treatment planning system (TPS). These plans neglected treatment couch attenuation, as is standard clinical practice. Dose distributions were then recalculated in Eclipse with the inclusion of the Varian Exact Couch (imaging couch top) and the rails in varying configurations. The changes in dose and coverage were evaluated using the …

A Comparison Of Spatio-Temporal Prediction Methods Of Cancer Incidence In The U.S, Michelle Hamlyn

UNLV Theses, Dissertations, Professional Papers, and Capstones

Cancer is the cause of one out of four deaths in the United States, and in 2009, researchers expected over 1.5 million new patients to be diagnosed with some form of cancer. People diagnosed with cancer, whether a common or rare type, need to undergo treatments, the amount and kind of which will depend on the severity of the cancer. So how do healthcare providers know how much funding is needed for treatment? What would better enable a pharmaceutical company to determine how much to allocate for research and development of drugs, the amount of each drug to manufacture, or …

Metastatic Disease: Interactions Between Tumor Cells And Host Environment During Cancer Cell Spread, Jennifer M. Maclean

Electronic Thesis and Dissertation Repository

Tumor and metastasis formation are not cell autonomous phenomena, but rather an evolution of disease within and responding to the host environment. Metastatic spread from a primary tumor occurs as a result of a complex interplay between tumor cells and the host, wherein tumor cells must escape the primary tumor, enter the host vasculature, travel to and arrest in a distant tissue and survive and grow in that new organ. It is known that cells that progress through these stages must both escape and exploit host systems, yet the mechanisms used are not fully understood. Therefore, the goal of this …

The Role Of Protein Kinase C Epsilon In Hydrogen Peroxide And Nitric Oxide Release During Oxidative Stress Caused By Extracorporeal Shockwave Lithotripsy, Edward S. Iames

PCOM Biomedical Studies Student Scholarship

Clinical extracorporeal shock wave lithotripsy (ESWL) treatment to ablate kidney stones can cause acute damage to the renal microvasculature. Accumulation of continued treatment with shockwave therapy can lead to chronic damage to the kidney, and lead to clinical hypertension. Shockwaves have been shown to stimulate endothelial cells to release superoxide (SO), which is converted to hydrogen peroxide (H₂O₂), and reacts with nitric oxide (NO) to produce peroxynitrite anion (OONO^-), creating a powerful oxidant that increases oxidative stress while simultaneously reducing NO bioavailability. Increased oxidative stress during events such as ESWL, also uncouples NO production …

The Association Of Religious Coping On Reports Of Low Back Pain And Inflammatory Markers, Jacqueline D. Bougie

Loma Linda University Electronic Theses, Dissertations & Projects

Chronic pain is the most common cause of disability in the United States with depression, anxiety, and stress often occurring co-morbidly. The purpose of the study was to explore how religion may modulate the frequency of back pain, influence inflammatory markers, influence the use of medications, and impact functional ability.

Participants were from the Biological Manifestations of Religion Study (BioMRS; N= 508) and the Psychological Manifestations of Religion Study (PsyMRS; N = 10,988). All participants completed a 20-page questionnaire and BioMRS participants provided blood, salivary, and urine samples, performance tests, and learning tests all collected within 1 week of …

A High Fiber Diet Versus A Low-Carbohydrate Diet For Weight Loss In Obese Individuals With Or Without Type 2 Diabetes, Neal G. Malik

Loma Linda University Electronic Theses, Dissertations & Projects

In the United States, obesity rates have climbed steadily over the years. Many different diets for weight loss have been proposed and studied, yet no one diet seems to clearly be more beneficial. Among diets that have been promoted are those high in fiber and low in carbohydrates, yet thus far, results of these studies have been mixed.

Using a 2x2 complete factorial design, 173 obese men and women with or without type 2 diabetes were randomized to one of two conditions: (a) a high fiber diet (> 40 grams of fiber per day for women, >50 grams of fiber …

Neuropsychological And Neurophysiological Effects Of Low-Intensity Strengthening Exercise On Cognition, Vadim V. Yerokhin

Honors Theses

With the growing aging population, it’s becoming increasingly important to find ways to either deter or prevent dementia. To date, most research has concentrated on the effects of aerobic exercise on cognition. Unfortunately, a large portion of older adults are often contraindicated to perform aerobic exercise due to different risk factors, which increase with age. Alas, alternate ways of exercise are necessary. Low-intensity strengthening exercise is a type of exercise aimed at improving balance and strengthening muscles without requiring one to overstrain. The current 11-week long exercise study test neuropsychological effects of exercise with a neuropsychological battery and neurophysiological effects …

Child And Family Responses To Weight Management Programs : A Qualitative Investigation, Andra Lynn Fjone

Loma Linda University Electronic Theses, Dissertations & Projects

Introduction: The purpose of this study is to explore what happens within families in which a child participates in a pediatric weight management program for the treatment of overweight or obesity and identify strategies and processes for successful weight management.

Method: A qualitative approach was used to collect data from seven families. Individual interviews were conducted with parents, target children, and siblings. Data was analyzed within families and compared between families.

Results: Grounded theory analysis revealed three major essential themes: Shared Burden, Family Congruence, and Collaboration. Descriptive analysis was used to identify recommendations for improving family based weight management programs. …

Relationship Of Vitamin D Levels To Blood Pressure In A Biethnic Cohort, Rosario O. Sakamoto

Loma Linda University Electronic Theses, Dissertations & Projects

Background: Serum hydroxyvitamin D [25(OH)D] has been well-accepted as not an ordinary vitamin but a pro-hormone that has many benefits beyond its well-known effects on bone. Cardiovascular risk factors such as hypertension remain a huge health burden and Blacks have been recognized to have higher prevalence of hypertension compared to non-Hispanic Whites. Despite increasing evidence of the benefits of vitamin D on blood pressure control, there is much more to be learned about the relationship of serum 25(OH)D to blood pressure among different ethnicities.

Purpose: The goal of this study was to determine whether vitamin D serum 25(OH)D levels were …