Medical Physiology Commons^™

Gene Delivery Of Adenoviral-Tmbim6 Vector Protects The Neonatal Brain After Hypoxic-Ischemic Injury, Desislava Doycheva

Loma Linda University Electronic Theses, Dissertations & Projects

Neonatal hypoxia ischemia (HI) is an injury caused to the immature brain due to reduced cerebral blood flow which is associated with life-long neurological impairments. HI causes oxidative protein folding in the endoplasmic reticulum (ER), which results in ER stress. Generation of reactive oxygen species (ROS), from cytochrome P450 members (CYP) and NADPH-P450 reductases (NPR), in combination with activation of the unfolded protein response (UPR) are two major consequences of ER stress that cause oxidative damage and cell death. Herein we identified the role of Bax Inhibitor-1 (BI-1), an evolutionary conserved protein encoded by the Transmembrane Bax inhibitor Motif Containing …

Changes In The Morphology Of Hypoglossal Motor Neurons In The Brainstem Of Developing Rats, Paul Allen Williams

Loma Linda University Electronic Theses, Dissertations & Projects

The autonomic brainstem generates and modifies breathing rhythm by integrating inputs from chemo- and mechanosensors in the viscera while coordinating descending outputs from higher CNS structures. Hypoglossal motoneurons (XII MNs) receive inputs from respiratory premotor neurons in the medulla. Previous studies in rodents have demonstrated significant changes in breathing control during the first three weeks of life, with a sensitive period at 10 to 13 days post-birth (P10–P13) characterized by pronounced changes in neurotransmitters, receptors, excitation-inhibition balance, and breathing. However, age-dependent morphological changes of XII MNs during the first three weeks post-birth and especially during this sensitive period, have not …

The Role Of Glucocorticoid Signaling In Prostate Cancer Health Disparities, Leanne W. Burnham

Loma Linda University Electronic Theses, Dissertations & Projects

African-American men are more likely to develop aggressive prostate cancer (PCa) and die from the disease than other ethnic groups. Glucocorticoid signaling is a contributing biological factor to worse PCa prognosis, and is emerging as a key driver of PCa progression in the absence of androgens. The mechanism involves glucocorticoids binding to glucocorticoid receptor (GR) and bypassing the androgen receptor (AR) signaling pathway to activate AR-target genes that promote tumor aggressiveness and therapy-resistance. This is problematic as African-American men have hypersensitive GR signaling and chronically-elevated levels of glucocorticoids linked to cumulative stressful life events. To explore the role of glucocorticoid …

Endothelin-1 And Hypoxic Vascular Remodeling In Ovine Fetal Cerebral Arteries, Jinjutha Silpanisong

Loma Linda University Electronic Theses, Dissertations & Projects

Intrauterine hypoxia resulting from decreased maternal oxygen uptake, insufficient oxygen carrying capacity, or compromised oxygen delivery to the fetus jeopardizes fetal oxygen delivery, detrimentally affecting growth and development of the immature vasculature. Hypoxia transiently increases Hypoxia Inducible Factor-1α (HIF- 1α), which complexes with HIF-1β to form the active HIF-1 dimer that can affect transcription. This temporary rise in HIF-1 can promote gene transcription of ligands such as Vascular Endothelial Growth Factor (VEGF) and Endothelin-1 (ET-1), which rises and falls with HIF levels. The absence of chronic elevation of these ligands prompted the question of how long-term effects of hypoxia is …

Neuroprotective Molecules And Strategies In A Rat Model Of Neonatal Hypoxic Ischemic Encephalopathy, Brandon Joseph Dixon

Loma Linda University Electronic Theses, Dissertations & Projects

Neonatal hypoxic ischemic encephalopathy (HIE) is a devastating disease that primarily causes neuronal and white matter injury and is among the leading cause of death among infants. Currently there are no well-established treatments; thus, it is important to understand the pathophysiology of the disease and elucidate complications that are creating a gap between basic science and clinical translation. In the development of neuroprotective strategies and translation of experimental results in HIE, there are many limitations and challenges to master based on an appropriate study design, drug delivery properties, dosage, and use in neonates. Since there are no established therapies for …

Mechanisms Of Post-Hemorrhagic Hydrocephalus After Germinal Matrix Hemorrhage, Damon William Klebe

Loma Linda University Electronic Theses, Dissertations & Projects

The inherently fragile vasculature of the germinal matrix is susceptible to rupture, possibly as a result of hemodynamic and cardiorespiratory instability associated with prematurity. Germinal matrix hemorrhage is a leading cause of morbidity and mortality in preterm and/or very low birthweight infants, and post-hemorrhagic hydrocephalus is major consequence of severe grade hemorrhages. Chronic post-hemorrhagic hydrocephalus treatment involves surgical insertion of shunts, which are costly and prone to complications. Thus, a safe non-invasive therapeutic approach towards post-hemorrhagic hydrocephalus clinical management would significantly improve the quality of life for this patient population. Thrombin, cerebroventricular blood clots, and iron have been identified as …

Mechanism Of Chimeric Vaccine Mediated Immune Suppression Of Human Dendritic Cells, Jacques Christian Mbongue

Loma Linda University Electronic Theses, Dissertations & Projects

Type 1 diabetes mellitus is a chronic inflammatory disease in which insulin producing β-cells of the pancreatic islets are killed by autoreactive cells of the immune system in response to a loss of tolerance. Dendritic cells (DC) interact predominantly with naïve T cells to regulate the delicate balance between immunity and tolerance required to maintain immunological homeostasis. In this dissertation, immature human dendritic cells (iDC) were inoculated with a chimeric fusion protein vaccine containing the pancreatic β-cell auto-antigen proinsulin linked to a mucosal adjuvant the cholera toxin B subunit (CTB-INS). Proteomic analysis of vaccine inoculated DCs revealed strong up-regulation of …

Role Of Slit2 In Reducing Complications After Surgical Brain Injury, Prativa Sherchan

Loma Linda University Electronic Theses, Dissertations & Projects

Surgical brain injury (SBI) is the inadvertent injury to brain tissue at the perisurgical site which occurs due to neurosurgical maneuvers such as incision, retraction, and electrocoagulation that can result in post-operative complications. Blood brain barrier (BBB) disruption and neuroinflammation are major pathophysiological consequences after neurosurgical injury. Blood brain barrier dysfunction leads to increased influx of water and plasma proteins as well as peripheral immune cell infiltration into the brain parenchyma that further potentiates brain edema and worsens post-operative neurological function. Activated resident immune cells and infiltrated peripheral immune cells release inflammatory mediators and promote oxidative stress and cell death …

Lipid Regulation As A Critical Factor In The Development Of Alzheimer's Disease, Michael A. Castello

Loma Linda University Electronic Theses, Dissertations & Projects

Alzheimer’s disease (AD) is the most common form of dementia in the United States, representing around eighty percent of all cases. For more than two decades, researchers have been led by the amyloid cascade hypothesis, which assumes that accumulation of the amyloid peptide Aβ, derived by proteolytic processing from the amyloid precursor protein (APP), is the key pathogenic trigger in AD. To date, therapies have largely focused on removing Aβ from the brain, an approach that has produced disappointing clinical outcomes. I present an alternative hypothesis in which Aβ production and aggregation is a symptom of a larger, systemic disease …

Long-Term Hypoxia Alters Ovine Fetal Adrenal Enos And Cortisol Biosynthesis, Elizabeth Anne Newby

Loma Linda University Electronic Theses, Dissertations & Projects

Maintaining normal levels of cortisol in response to chronic stress, while retaining the ability to respond to acute stress, is important for ensuring normal fetal growth and development. Long-term hypoxia (LTH) causes adaptations in the fetal hypothalamopituitary- adrenal (HPA) axis that maintain basal cortisol levels but enhance production in response to a secondary stress. Nitric oxide (NO), produced by endothelial nitric oxide synthase (eNOS) in the adrenal cortex, plays a significant role in regulating cortisol production in the LTH fetus. The production of NO is regulated by eNOS activity which can be altered via phosphorylation through key signaling pathways. In …

Role Of Astrocyte Network In Edema After Juvenile Traumatic Brain Injury, Andrew Minoru Fukuda

Loma Linda University Electronic Theses, Dissertations & Projects

Juvenile traumatic brain injury (jTBI) is the leading cause of death and disability in young children and adolescents. Despite its lasting detrimental effects on the developing brain, no pharmacological treatment exists. One of the pathological hallmarks of jTBI is edema. Astrocytes play a key role in the edema process, and have been hypothesized that numerous astrocyte networks allow communication and propagation of edema and secondary injury spread. Two key astrocyte proteins are hypothesized to have a central role in the edema process: Aquaporin 4 (AQP4) and Connexin 43 (Cx43). AQP4 is expressed extensively in astrocyte endfeet, which surrounds the blood …

Caveolins And Njks Influence Brain Endothelial Permeability After Juvenile Tbi, David Olufemi Ajao

Loma Linda University Electronic Theses, Dissertations & Projects

Disruption of blood-brain barrier (BBB) is a key secondary event that exacerbates brain damage following traumatic brain injury (TBI). BBB disruption is particularly damaging to the developing brain – which is highly vulnerable to various stress stimuli, resulting in increased brain swelling, disrupted cerebral blood flow (CBF) autoregulation, long-term disabilities and death following TBI in young demographic. Unsurprisingly, BBB disruption and the resultant cerebral edema have emerged as therapeutic targets in juvenile TBI. It is therefore important to understand the molecular players and mechanisms involved in TBI-induced BBB disruption in the juvenile brain. To this end, the endothelial caveolins and …

Vegf And Sympathetic Perivascular Nerves Contribute To Hypoxic Remodeling Of Ovine Cranial Arteries, Olayemi Olufikayo Adeoye

Loma Linda University Electronic Theses, Dissertations & Projects

Chronic hypoxia complicates many pregnancies and can result in postnatal pathologies that include compromised fetal cardiovascular structure and function. Mechanisms involved remain unclear. Because hypoxia increases production of VEGF, known to modulate smooth muscle (SM) phenotype, this thesis explored the hypothesis that VEGF contributes to hypoxic fetal vascular remodeling through direct effects on SM cells and indirectly through perivascular nerves. Using a chronic hypoxia sheep model, this work demonstrated that: 1) hypoxia potently upregulates VEGF receptor expression but not endogenous VEGF level in fetal ovine carotid arteries; 2) both chronic hypoxia and VEGF exert similar effects on smooth muscle contractile …

Chronic Hypoxia Induces Epigenetic Modifications In The Fetal Rat Heart, Andrew James Grant Patterson

Loma Linda University Electronic Theses, Dissertations & Projects

Heart disease remains the leading cause of death worldwide. As a result of studies done by Barker and associates, our awareness of the significance of stress during gestation as a risk factor for heart diseases has expanded. We now know that events in utero can significantly alter gene expression patterns in heart tissue leading to increase susceptibility to ischemia reperfusion injury in adulthood. The focus of this project was to elucidate the role of chronic hypoxia in the programming of the cardio-protective gene, Protein Kinase C epsilon (PKCε) in fetal rat heart. We used an animal, organ base, and cell …

Mechanisms Of Brain Edema Formation In Mouse Models Of Intracerebral Hemorrhage, Qingyi Ma

Loma Linda University Electronic Theses, Dissertations & Projects

Perihematomal edema causes major neurologic deterioration following intracerebral hemorrhage (ICH), mainly resulting from the disruption of the blood-brain barrier (BBB) by multiple mediators, including inflammatory mediators and thrombin. The objective of our study was to investigate the mechanisms by which inflammation and thrombin respectively lead to the formation of brain edema following ICH. Our long-term goal is to develop new therapeutic strategies against ICH-induced brain edema by targeting: (1) VAP-1 mediated inflammatory response and (2) PDGFR-α orchestrated BBB impairment. Vascular adhesion protein-1 (VAP-1) was previously shown to promote leukocyte adhesion and transmigration. Additionally, PDGFR-α was also found to play a …

Aging And Sympathetic Neurotransmission In Two Strains Of Rats That Differ In Longevity And Immune Profiles, Sam David Perez

Loma Linda University Electronic Theses, Dissertations & Projects

Age-related changes in sympathetic neurotransmission in immune organs may be associated with immunosenescence; however no causal relationship has been established. From previous studies in Fischer rats (F344), we have found that during middle age, sympathetic nerve activity (SNA) rises in the spleen followed by a decline in noradrenergic (NA) innervation. Also, increased sympathetic signaling via betaadrenergic receptor (β-AR) and reduced proliferation of lymphocytes are evident with increasing age. Although SNA progressively rises with age, effects of age on sympathetic factors may be different across rat strains. If causal relationships exist between sympathetic activity and immune function, they may be related …

Novel Molecules That Regulate Bone Formation And Bone Resorption, Gabriel Robert Linares

Loma Linda University Electronic Theses, Dissertations & Projects

Osteoporosis is a disease characterized by decreased bone mass and microarchitectural deterioration of bone. Bone loss occurs when the increased bone resorption that occurs with age is not compensated by a corresponding increase in bone formation. Therefore, understanding the mechanisms which regulate bone formation and bone resorption is important for developing diagnostic and treatment strategies for osteoporosis. In my dissertation, we investigated the role of Glutaredoxin 5 (Grx5), Diabetes and Obesity Related protein (DOR), and Claudin 18 (Cldn-18), novel molecules involved in regulating bone formation and bone resorption. We demonstrated that Grx5 protects osteoblasts from oxidative stress induced apoptosis via …

Long-Term Hypoxia Regulates Cortisol Biosynthesis In The Ovine Fetal Adrenal Cortex, Vladimir Enrique Vargas

Loma Linda University Electronic Theses, Dissertations & Projects

Previous studies demonstrated enhanced fetal adrenal cortisol biosynthesis following exposure to long-term hypoxia (LTH). The studies presented here were designed to determine the mechanism(s) regulating this important adaptive endocrine response. Ewes were maintained at high altitude (3,820 m) from approximately day 40 to 138-141 of gestation. Fetal adrenal glands were then collected from LTH and age matched normoxic controls. Dispersed fetal adrenal cortical cells (FACs) were untreated, treated with ACTH, treated in combination with ACTH precursors (POMC and 22-kDa pro-ACTH), or pre-treated with H-89 and or UO126 followed by ACTH treatment. Following ACTH treatment, cortisol biosynthesis increased in both groups …

Quantification Of Localized Brain Iron Sources Using Magnetic Resonance Phase, Grant Alexander Mcauley

Loma Linda University Electronic Theses, Dissertations & Projects

Brain microbleeds (BMB), often present in cerebrovascular and neurodegenerative diseases and neurotrauma, are associated with both chronic and acute illness of significant social and economic impact. Because BMB present a source of potentially cyctotoxic iron to the brain proportional to the amount of extravasated blood, non-invasive quantification of this iron pool is potentially valuable both to assess tissue risk and as a biomarker to monitor disease progression, treatment efficacy, and inform treatment. Past efforts to quantify brain iron have focused on distributed (e.g., anatomical) brain regions. However, BMB represent localized sources of iron deposition. In addition, conventional "magnitude" MR images …

Predictive Measures Of Cognitive Outcome In Adults Sustaining Brain Injury, Herminia De La Rosa-Trujillo

Loma Linda University Electronic Theses, Dissertations & Projects

To date, there is no consistent and accurate outcome prediction method for patients with traumatic brain injury (TBI). Commonly used clinical measures such as the Glasgow Coma Scale (GCS) and traditional radiological methods of x-rays and computed tomography (CT) scans do not always accurately predict patient functional outcome. These radiological methods are adequate in determining gross structural anatomical disturbances, however, they are unable to detect more diffuse cellular damage believed to be responsible for the functional impairments evidenced in patients sustaining TBI. Magnetic resonance imaging allows for various non-invasive sequencing techniques that have demonstrated to be a potentially valuable method …

Effect Of 3-Electrode Electrical Stimulation On Current Delivery And Healing In Chronic Wounds, Hyejin Suh

Loma Linda University Electronic Theses, Dissertations & Projects

Chronic wounds have been an enormous burden on the healthcare system due to their prevalence and the lack of efficacy of current treatment modalities. Over the years, electrical stimulation (ES) has been widely used in the treatment of wounds. Unfortunately, the effectiveness of this treatment is under scrutiny, since many studies have failed to report successive and/or consistent effects of ES on wound healing. This inconsistency may be due to the uneven current produced by the conventional 2-electrode delivery system (2-channel ES) and the reduced resting blood flow resulting from thermally cool treatment rooms. In this study, a new approach …

Interaction Between Adrenergic And Nitric Oxide-Releasing Nerves In Cerebral Arteries, Emmanuel Ngu Mbaku

Loma Linda University Electronic Theses, Dissertations & Projects

Of all body tissues, the brain is the least tolerant of ischemia so much that interruption of cerebral blood flow by 5 sec can cause syncope, with irreversible tissue damage if the ischemia last a few minutes. In this respect, the body has an imperative duty of ensuring constant and adequate blood supply to the brain. It does so through a series of intrinsic and extrinsic control factors of which adrenergic and nitric oxide-releasing nerves are components. My research examined the interaction between these two nerve-types with emphasis on the mechanisms involved as well as on changes in their functions …

Chronic Hypoxia, Exercise Training, And Skeletal Muscle Capillarity: Angiogenic Regulation And Morphological Consequences, Ivan Mark Olfert

Loma Linda University Electronic Theses, Dissertations & Projects

Angiogenesis is important in health and disease. In particular, exercise training is known to increase skeletal muscle capillarity, providing there is sufficient training intensity. The stimulus for this may be intracellular hypoxia activating angiogenic growth factor gene expression. Acute hypoxia alone has been shown to increase the gene expression of several key angiogenic regulators, e.g. vascular endothelial growth factor (VEGF) and to a lesser degree transforming growth factor-β1 (TGF-β1), basic fibroblast growth factor (bFGF), and thrombospondin-1 (TSP-1), an endogenous negative angiogenic regulator. Paradoxically, however, chronic hypoxia is generally not found to increase mammalian skeletal muscle capillarity. Accordingly, we hypothesized that …

Effect Of Photoperiod On Developmental Morphology And Enolase Isoenzyme Immunohistochemistry In Rat And Djungarian Hamster Superficial Pineal Glands, Chalmer D. Mcclure

Loma Linda University Electronic Theses, Dissertations & Projects

The best understood functional activity of the pineal gland is its diurnal production of melatonin in response to environmental lighting cues. Several enzymes of the melatonin pathway respond to daily photoperiod changes, for example hydroxyindole-O-methyltransferase (HIOMT) and serotonin N-acetyltransferase (SNAT). Increased levels of the glycolytic enzyme neuron-specific enolase (NSE) are thought to reflect increased physiological demands placed on neurons and neuroendocrine tissues. Homodimer non-neuronal enolase isoenzyme (NNE) is immunolocalized to cells, and the hybrid enolase (consisting of subunits from NSE and NNE) has been seen in cerebellar stellate and basket cells. Although not rate limiting, concentrations of both NSE and …

Development Of A Mathematical Model Of Renal Function For Clinical Application, Barbara A. Holshouser

Loma Linda University Electronic Theses, Dissertations & Projects

This model describes the orthoiodohippurate (OIH) distribution and clearance in the renovascular system. The model is described by five compartments: the blood, left and right kidneys, bladder and the red blood cell compartment. Data for these compartments, except the RBC compartment, are collected with scintillation detectors monitoring OIH tagged with 1-131 as the radiopharmaceutical passes through each compartment. Time/ activity curves are plotted for the data and used as inputs to the model parameter estimation routine. The compartments are described by a set of first order ordinary differential equations solved using the Adam's methods. For parameter estimation, an iterative predictor-corrector …

Effects Of Music Therapy And Personal Interaction On The Preoperative Patient, Phyllis Jean Nix

Loma Linda University Electronic Theses, Dissertations & Projects

This study was conducted to discover the effects of (1) an interpersonal relationship and (2) an interpersonal relationship and music therapy on preoperative patients in a selected hospital.

The descriptive survey was chosen as the method of study. A checklist and a tape recording of selected music were used as a tool of research. Two groups of preoperative patients were given nursing care by the researcher. Patients in Group One received care with an aim toward developing an interpersonal relationship, while patients in Group Two received the same as Group One with the addition of music therapy.

Findings revealed a …

Pathological Physiology As A Basis For Medical Practice, Walter E. Macpherson

Medical Arts and Sciences: A Scientific Journal of the College of Medical Evangelists

No abstract provided.