Physiological Processes Commons^™

Signaling Components Involved In The Hormone Induced Translocation Of Enac In Cultured Adult Human Fungiform (Hbo) Taste Cells, Deanna Hojati

Theses and Dissertations

The amiloride-sensitive epithelial Na⁺ channel, ENaC, is the Na⁺-specific salt taste receptor in rodents. Compared to rodents, human salt taste perception is amiloride-insensitive. In rodents the ENaC is composed of aβg-subunits. Whereas humans express an additional subunit, the d-ENaC subunit. ENaC in human taste cells is composed of aβg-subunits or dβg-subunits, with the latter being amiloride-insensitive. Currently, it is not known if dβg-ENaC expression and trafficking is regulated by hormones and their downstream intracellular signaling effectors. The aim of this study is to investigate if arginine vasopressin (AVP), aldosterone, and cAMP regulate d-ENaC expression and trafficking in …

An Analysis Of The Physiological And Psychological Wellbeing Of Irish Naval Service Personnel, Cliodhna Sargent

Theses

Whilst all military cohorts have been seen to experience both physiological and psychological stressors during occupational duties, the naval service experience different stressors due the prolonged periods of time spent at sea. Research has analysed some of these stressors however many them have focused on how individuals are affected because of time spent in combat zones. The Irish Naval Service (INS) is an organisation under the Irish Defence Forces organisation and as such many of its physiological and psychological assessment procedures have come from the Defenee Forces. Very limited researeh has been carried out in relation to the INS as …

The Effects Of Exercise Preconditioning On Focal Ischemic Stroke, Gillian Grohs

Theses and Dissertations--Medical Sciences

Cleaved fragments of the extracellular matrix protein perlecan have been shown to promote neuroprotection and repair after ischemic stroke. The cysteine proteases cathepsin B and L as well as the metalloprotease bone morphogenic protein 1 (BMP-1) are capable of releasing the biologically active C-terminal laminin-like globular domain (LG3) of perlecan. Exercise, a known method of reducing stroke risk and severity, has been shown to increase the expression of some proteases associated with perlecan processing. Using a transient distal middle cerebral artery occlusion (MCAo) model for focal ischemic stroke we show that while 7 days of running only slightly decreased infarct …

Neuroinflammation In Alzheimer's Disease And Vascular Cognitive Impairment, Erica M. Weekman

Theses and Dissertations--Physiology

It was once believed that the brain was immunologically privileged with no resident or infiltrating immune cells; however, now it is understood that the cells of the brain are capable of a wide range of inflammatory processes and phenotypes. Inflammation in the brain has been implicated in several disease processes such as Alzheimer’s disease (AD) and vascular cognitive impairment and dementia (VCID); however, the role of inflammation in these two dementias is poorly understood.

When we stimulated a pro-inflammatory phenotype with an adeno-associated viral vector in a transgenic mouse model of AD that develops Aβ plaques, we saw a pro-inflammatory …

Biomarkers Of Sepsis: A Retrospective Approach, Jose M. Roberts

Williams Honors College, Honors Research Projects

Background: Biomarkers are taking the spotlight in becoming the norm for early diagnoses. Sepsis is an inflammatory disease that increases metabolic rate in children. The first biomarker is hyponatremia. Hyponatremia is a frequent electrolyte imbalance in clinical practice, often observed in children with inflammatory disease and infection. Presence of hyponatremia is associated with electrical signaling imbalances, inflammation and renal dysfunction. The clinical value of hyponatremia in pediatric patients is unknown. The C-reactive protein is a second biomarker. Its presence signifies that necrotic cells and inflammation are present.

Objectives: To evaluate the use of biomarkers in children seen in the Emergency …

Role Of Translation Initiation In Regulation Of Epithelial Junctions And Cell Motility, Fahda Fawaz Alsharief

Theses and Dissertations

The integrity and barrier properties of intestinal epithelium are determined by specialized adhesive structures known as intercellular junctions; composed of adherens junctions (AJs), tight junctions (TJs) and focal adhesions that mediate cell-cell and cell matrix interactions, respectively. These two types of epithelial cell adhesions regulate each other during disruption and restitution of the epithelial barrier. Inflammatory cytokines such as interferon gamma (IFNγ) and tumor necrosis factor alpha (TNFα) are elevated during intestinal inflammation. The most notable effects of IFNγ and TNFα on intestinal epithelial homeostasis involve disruption of apical junctions and attenuation of cell migration. Although molecular mechanisms underlying these …

Perceptual Variations In Thermoregulation During Exercise In A Hot Environment, William C. Alger

Electronic Theses and Dissertations

ABSTRACT

Professionals are seeking to find ways to prevent exertional heat illness (EHI) in populations working in hot environments as well as populations that are physically active. The purpose of the present study was to evaluate individuals’ ability to accurately perceive core temperature ranges associated with homeothermic and EHI temperatures during exercise. Ten physically active males exercised on a treadmill at a self-selected rate until core temperature reached 39°C. Participants rated perceived core and skin temperature on 100 mm scales each time core temperature increased 0.25˚ C (37.5-39.0˚ C), along with thermal comfort and sweating sensation. During exercise core temperature …

The Effects Of Direct Peritoneal Resuscitation On Leukocyte Infiltration After Acute Brain Death., Jessica Lee Weaver

Electronic Theses and Dissertations

Background: Brain death triggers an inflammatory response that is associated with worse outcomes for recipients of transplanted organs procured from brain dead donors. The intestine has been shown to release inflammatory mediators in other types of shock, but its role is brain death is not well described. Direct peritoneal resuscitation (DPR) improves visceral organ blood flow and has been shown to reduce inflammation after hemorrhagic shock. Better understanding of this inflammatory process within the peripheral organs, the effects of DPR, and the role of the intestine could aid in better resuscitation of potential organ donors. Methods: Male Sprague-Dawley rats were …

Seniors Welcome! Avoiding The Trap Of Age Limits In Health Research, Arshad Jahangir

Journal of Patient-Centered Research and Reviews

The guest editor introduces this specialty issue of the Journal of Patient-Centered Research and Reviews, which focuses on cardiovascular diseases in the elderly. The reality of an aging population has increased the need for better evidence-based medicine in older patients. However, randomized controlled trials frequently exclude such patients, especially those with comorbidities, from study. This practice ignores the fact that physiologic changes to the cardiovascular system caused by the aging process and aging-associated diseases create clinical dilemmas distinct from those in younger patients. Considering the rising costs of health care and growing incidence of cardiovascular disease, research efforts and …

Effects Of Auditory Vection Speed And Directional Congruence On Perceptions Of Visual Vection, Isabella Alexis Gagliano

Psychology Theses & Dissertations

Spatial disorientation is a major contributor to aircraft mishaps. One potential contributing factor is vection, an illusion of self-motion. Although vection is commonly thought of as a visual illusion, it can also be produced through audition. The purpose of the current experiment was to explore interactions between conflicting visual and auditory vection cues, specifically with regard to the speed and direction of rotation. The ultimate goal was to explore the extent to which aural vection could diminish or enhance the perception of visual vection. The study used a 3 × 2 within-groups factorial design. Participants were exposed to three levels …

The Substrate Of The Biopsychosocial Influences In The Carcinogenesis Of The Digestive Tract, Georgică C. Târtea, Cristina Florescu, Daniel Pirici, Daniel Caragea, Elena A. Târtea, Cristin C. Vere

Journal of Mind and Medical Sciences

Digestive cancer represents a severe public health problem, being one of the main causes of death. It is considered a multifactorial disease, with hereditary predisposition, environmental factors, and other factors involved in carcinogenesis. Both the evolution and the pathogenesis of digestive neoplasms remain incompletely elucidated. As a multifactorial disease, it can be approached by taking into account the biopsychosocial influences via enteric nervous system. Many peptides and non-peptides having a neurotransmitter role can be found in the enteric nervous system, which can influence the neoplastic process directly or indirectly by affecting some angiogenic, growth, and metastasis factors. However, neurotransmitters can …

A Note Regarding The Mathematical Treatment Of A Class Of Steady-State Compartmental Models Of The Circulation, Ronald White

Center for Advanced Mineral and Metallurgical Processing (CAMP)

A class of steady-state compartmental models of the circulation is examined and it is shown that the mathematical problem for this model class involves a single nonlinear equation. In an important subclass and with certain assumptions regarding the form of the Starling-type cardiac function curves, the single equation is of the form Z = μ + λ log[(1 − Z)/Z] where μ and λ are mathematical parameters related to the physiological parameters of the system and Z is proportional to the cardiac output. This result holds regardless of the number and arrangement of compartments within the model …

Respiratory Rate Variability In Sleeping Adults Without Obstructive Sleep Apnea, Guillermo Gutierrez, Jeffrey Williams, Ghadah Alrehaili, Anna Mclean, Ramin Pirouz, Richard L. Amdur, Vivek Jain, Jalil Ahari, Amandeep Bawa, Shawn Kimbro

Surgery Faculty Publications

Characterizing respiratory rate variability (RRV) in humans during sleep is challenging, since it requires the analysis of respiratory signals over a period of several hours. These signals are easily distorted by movement and volitional inputs. We applied the method of spectral analysis to the nasal pressure transducer signal in 38 adults with no obstructive sleep apnea, defined by an apnea‐hypopnea index <5, who underwent all‐night polysomnography (PSG). Our aim was to detect and quantitate RRV during the various sleep stages, including wakefulness. The nasal pressure transducer signal was acquired at 100 Hz and consecutive frequency spectra were generated for the length of the PSG with the Fast Fourier Transform. For each spectrum, we computed the amplitude ratio of the first harmonic peak to the zero frequency peak (H1/DC), and defined as RRV as (100 − H1/DC) %. RRV was greater during wakefulness compared to any sleep stage, including rapid‐eye‐movement. Furthermore, RRV correlated with the depth of sleep, being lowest during N3. Patients spent most their sleep time supine, but we found no correlation between RRV and body position. There was a correlation between respiratory rate and sleep stage, being greater in wakefulness than in any sleep stage. We conclude that RRV varies according to sleep stage. Moreover, spectral analysis of nasal pressure signal appears to provide a valid measure of RRV during sleep. It remains to be seen if the method can differentiate normal from pathological sleep patterns.

Neuropsychological Effects Of Pomegranate Supplementation Following Ischemic Stroke, John A. Bellone

Loma Linda University Electronic Theses, Dissertations & Projects

Polyphenols are compounds found in fruits and vegetables that have antioxidant and anti-inflammatory properties. Mounting evidence suggests that dietary polyphenol intake can reduce the detrimental effects of various disease processes, and pomegranates have frequently been examined because of their particularly high polyphenol content. Since stroke induces both oxidative stress and inflammation and is currently the leading cause of long-term disability in the U.S., we sought to determine whether dietary supplementation with polyphenols could enhance cognitive recovery in individuals who had suffered an ischemic stroke. We administered polyphenols via 2 POMx pills containing polyphenols derived from pomegranates equivalent to the content …

Reduced Motor Neuron Excitability Is An Important Contributor To Weakness In A Rat Model Of Sepsis, Paul Nardelli, Jacob A. Vincent, Randall K. Powers, Timothy C. Cope, Mark M. Rich

Neuroscience, Cell Biology & Physiology Faculty Publications

The mechanisms by which sepsis triggers intensive care unit acquired weakness (ICUAW) remain unclear. We previously identified difficulty with motor unit recruitment in patients as a novel contributor to ICUAW. To study the mechanism underlying poor recruitment of motor units we used the rat cecal ligation and puncture model of sepsis. We identified striking dysfunction of alpha motor neurons during repetitive firing. Firing was more erratic, and often intermittent. Our data raised the possibility that reduced excitability of motor neurons was a significant contributor to weakness induced by sepsis. In this study we quantified the contribution of reduced motor neuron …

Toll-Like Receptor 4 Mutation Suppresses Hyperhomocysteinemia-Mediated Hypertension., Anastasia Familtseva

Electronic Theses and Dissertations

Background: Hyperhomocysteinemia (HHcy) has been observed to promote hypertension, but the mechanisms are unclear. Toll-like receptor 4 (TLR-4) is a cellular membrane protein that is ubiquitously expressed in all cell types of the vasculature. TLR-4 activation has been shown to promote inflammation that has been associated with pathogenesis of hypertension. In this study, we hypothesize that HHcy induces hypertension by TLR-4 activation that promotes inflammatory cytokine up-regulation (IL-1β, IL-6, TNF-α) and initiation of mitochondrial dysfunction leading to cell death and chronic vascular inflammation. Methods: To test this hypothesis, we used C57BL/6J mice (WT); Cystathionine-β-synthase deficient mice (CBS+/-) with genetic mild …

Incidence Of Hypomagnesemia On Proton Pump Inhibitors At The Huntington Veterans Affairs Medical Center – Ihop, Ebrahim Sabbagh, Do, Chelsey R. Houchins, James Allman, Ii, Pharmd, Samson Teka, Md

Marshall Journal of Medicine

Abstract

Title: Incidence of hypomagnesemia on proton pump inhibitors at the Huntington Veterans Affairs Medical Center – IHOP

Purpose:

Proton pump inhibitors (PPIs), both prescription and over-the-counter, are widely used for the treatment of acid-related disease states such as dyspepsia, gastroesophageal reflex disease, esophagitis, and peptic ulcers. These medications are generally considered safe in most patient populations; however, there are several adverse effects that may occur with long-term use. Hypomagnesemia is a newer complication arising in the literature following multiple case reports over the past several years, although the true incidence of hypomagnesemia associated with PPI use remains unclear at …

Combining Real-Time Fmri Neurofeedback Training Of The Dlpfc With N-Back Practice Results In Neuroplastic Effects Confined To The Neurofeedback Target Region, Matthew Sherwood, Michael P. Weisend, Jessica H. Kane, Jason G. Parker

Neuroscience, Cell Biology & Physiology Faculty Publications

In traditional fMRI, individuals respond to exogenous stimuli and are naïve to the effects of the stimuli on their neural activity patterns. Changes arising in the fMRI signal are analyzed post-hoc to elucidate the spatial and temporal activation of brain regions associated with the tasks performed. The advent of real-time fMRI has enabled a new method to systematically alter brain activity across space and time using neurofeedback training (NFT), providing a new tool to study internally-driven processes such as neuroplasticity. In this work, we combined n-back practice with fMRI-NFT of the left dorsolateral prefrontal cortex (DLPFC) to better understand the …

Synapse Formation In Monosynaptic Sensory–Motor Connections Is Regulated By Presynaptic Rho Gtpase Cdc42, Fumiyasu Imai, David R. Ladle, Jennifer R. Leslie, Xin Duan, Tilat A. Rizvi, Georgianne M. Ciraolo, Yi Zheng, Yutaka Yoshida

Neuroscience, Cell Biology & Physiology Faculty Publications

Spinal reflex circuit development requires the precise regulation of axon trajectories, synaptic specificity, and synapse formation. Of these three crucial steps, the molecular mechanisms underlying synapse formation between group Ia proprioceptive sensory neurons and motor neurons is the least understood. Here, we show that the Rho GTPase Cdc42 controls synapse formation in monosynaptic sensory–motor connections in presynaptic, but not postsynaptic, neurons. In mice lacking Cdc42 in presynaptic sensory neurons, proprioceptive sensory axons appropriately reach the ventral spinal cord, but significantly fewer synapses are formed with motor neurons compared with wild-type mice. Concordantly, electrophysiological analyses show diminished EPSP amplitudes in monosynaptic …

Mechanisms Of Lateral-Inhibitory Feedback From Horizontal Cells To Cone Photoreceptors At The First Synapse Of The Retina, Ted J. Warren

Theses & Dissertations

Polarization of the horizontal cell (HC) membrane potential causes changes in the synaptic cleft pH that result in inhibitory feedback from HCs to cone photoreceptors (PRs). HCs average signals from many PRs and so negative feedback onto PR terminals from HCs subtracts the average luminance of the visual scene from the light responses of an individual cone. This feedback operates by changing the voltage-dependence and amplitude of the L-type Ca²⁺ current (I_Ca) that regulates synaptic release. Feedback regulation of PR Ca²⁺ channels involves protons but the mechanism by which this pH change occurs is unclear. We …