Physiology Commons^™

A Study Of Biological Photonic Crystals In The Effects Of Beta Amyloid On Nicotinic Acetylcholine Receptors In Alzheimer’S: Internal Opal Scale Structures Of Iridescent Beetle Species In The Cerambycidae Family, Andrew Romney, Dr. Sterling Sudweeks

Journal of Undergraduate Research

For the past two years, I have worked in Dr. Sterling Sudweeks’ research lab experimenting with neurotransmitter receptors that are implicated in the development of Alzheimer’s Disease. When functioning normally, these receptors act as ion channels which open upon binding nicotine or acetylcholine and are thus appropriately named nicotinic acetylcholine receptors (nAcRs). nAcRs’s are found at the neuromuscular junction as well as in nervous tissue and are comprised of 5 subunits. Dr. Sudweeks’ previous research suggests that the alpha 3 and beta 2 subunits are the most common subunits in receptors in the hippocampus, which is the primary area of …

Inhibition Of Notch Signaling Increases Neurogenesis In The Ophthalmic Trigeminal Placode Without Expanding The Domain Of Neurogenin2 Expression., Brian Wright, Dr. Michael Stark

Journal of Undergraduate Research

The ever-increasing knowledge regarding cellular regulation and programming requires important insights into the biochemical pathways that determine a cell’s fate. For example, the ability to take a stem cell and grow it into a neuron will directly depend on our knowledge of the steps used in the embryo for normal neurogenesis, or the formation of neurons. The ophthalmic placode (a region of thickening cells) of the trigeminal nerve provides a valuable model for studying sensory neurogenesis, since it gives rise exclusively to sensory neurons. This nerve provides tactile sensation to the upper region of the face.

Establishing The Spondyloepiphyseal Congenita Heterozygous Mouse As An Animal Model For Human Osteoarthritis, Michael Henderson, Dr. Robert Seegmiller

Journal of Undergraduate Research

Osteoarthritis (OA) causes discomfort and immobility to millions of Americans every year. Due to the high demand for patient pain relief and improved mobility, scientists are seeking to understand the pathway of OA and develop drugs which would illuminate the onset of, and/or the progression of, OA.

The Cerebral Cortex As An Effect Site For Anesthetic Induced Unconsciousness, Ryan Martin, David Busath

Journal of Undergraduate Research

General anesthetics are widely used today in medicine. Their molecular mechanisms however, still remain a mystery. For centuries, general anesthetics were thought to be “drugs without receptors” because of the lack of knowledge about their mechanism of action (Hemmings, et al., 2005). While some advances have been made by Neuroscientists and Biologists there is still a lot that is not known about general anesthetics. The exact location of general anesthetic action is thought to be complex, but two particular locations have been suggested—the cerebral cortex and the midbrain. Detailed understanding of where general anesthetics act is important because it would …

The Role Of Htra1, Ddr2, And Mmp-13 Proteins In The Mechanistic Pathway Leading To Osteoarthritis In Sedc Mice, David Holt, Robert Seegmiller

Journal of Undergraduate Research

In the present study, we report OA in a mouse model that, like the human families presented by Kannu et al., bears a heterozygous mutation in the Col2a1 gene but has a phenotypically normal skeleton.1 The mouse mutation was named sedc by Donahue et al. because when homozygous, it produces feature that resemble the most common clinical phenotypes of SED congenita in humans, including abnormal epiphyses, flattened vertebral bodies, and problems with the eyes and ears.2 The mutation consists of a single base pair substitution in exon 48 of the Col2a1 gene, which changes an arginine to a cysteine in …

Lifetime Dietary Exposure To Soy Isoflavones Is Beneficial To Prostate And Testicular Health In 100-Day Old Male Long-Evans Rats, Benjamin Hogan, Dr. Edwin Lephart

Journal of Undergraduate Research

Phytoestrogens are plant-derived compounds that are structurally and functionally similar to estradiol. Isoflavones are a major type of phytoestrogen that can be found in foods such as soy beans, tofu, and soy milk. They have become popular due to the health benefits they effect by binding to estrogen receptors throughout the body. However, while their action is similar to that of estradiol, they are non-steroidal and therefore less potent.

Ror2/Wnt5a Mediated Directional Limb Outgrowth, Aaron Smith, Dr. Jeff Barrow

Journal of Undergraduate Research

The apical ectodermal ridge (AER) is a small strip of epithelial tissue that is found at the distal tip of the embryonic vertebrate limb and runs from anterior to posterior. It is known that the AER is necessary to maintain the life of mesenchymal cells (interior non-surface cells) of the limb and is also necessary to maintain other important signaling centers in the limb (citations). The AER is also believed to be responsible for patterning the limb along the proximal to distal axis. However, it is unknown what precise role the AER plays in this and researchers have been attempting …

Amantadine Blockage Of The Influenza A M2 Proton Transporter, Jared Kelson, David Busath

Journal of Undergraduate Research

The reproduction of influenza A is very closely regulated by the pH levels maintained both in the cytoplasm and in various organelles of a host cell. To accommodate this, the virus provides genetic coding to assemble an M2 transporter which regulates the flow of protons across the different membranes. Until recently, influenza A was treated with a drug known commonly as amantadine (1-aminoadamantane), which blocked M2 proton transport. Unfortunately, by the year 2005, 91% of known influenza A strains had mutated to the extent that amantadine was no longer an effective reagent (High, 2006 p. 44). The 2009 epidemic of …

Effect Of Muscle Stimulation On Gene Expression For Mitochondrial Proteins, Darren Goring, Dr. David Thomson

Journal of Undergraduate Research

The original purpose of this study was to elucidate the effects of muscle stimulation on gene expression for mitochondrial proteins in mLKB1-KO mice (mice in which the LKB1 gene has been knocked out of the muscles and heart). LKB1 is an important protein involved in the signaling of mitochondrial protein production. The original protocol was to run the mice on a treadmill fast enough and long enough to cause transcription of mitochondrial proteins. I hypothesized that the mLKB1-KO mice would still have some mitochondrial gene expression but to a lesser degree than the conditional mice.

Trash Brings A New Diet Water Conservation In Cape Verde, Africa, Tanner Goff, Dr. Bruce Woolley

Journal of Undergraduate Research

In Sub-Saharan African countries the resource of most significance, we Americans take for granted: water. The African people know this and strive to minimize wasting such a precious resource. However, with little education on how to conserve water, waste is inevitable. The country of Cape Verde is no stranger to a huge water deficit and this water deficit has a direct effect on the diet of the people. Most of the country relies on beans and rice with no variety of vegetables in their diet. The typical Cape Verdeans diet is characterized by “repeated rice meals” and “as the water …

The Role Of Nectin In Zyxin Localization, Jace Bullard, Dr. Marc Hansen

Journal of Undergraduate Research

A major difficulty of treating cancer rises from its ability to metastasize. During metastasis, strong adhesions between cells break, allowing individual cells to separate and migrate to different locations in the body. Strong cell-cell junctions are formed by protein interactions between actin cables and cell junction proteins. Zyxin is an actin regulator that localizes at cadherin-based cell-cell adhesions. Our lab has shown that cells expressing constitutively active forms of zyxin lose the ability to completely detach from each other, a result of maintained actin-membrane associations. How zyxin is localized to the cell membrane is unknown. Given zyxin’s role in maintaining …

Biophysical Cell Membrane Changes During Chemotherapeutic Drug-Induced Apoptosis, Amanda Berbert, Dr. John Bell

Journal of Undergraduate Research

Our project provided us the opportunity to gain insight into how chemotherapy drugs affect the cell membrane and how secretory phospholipase A₂ (sPLA₂) can work in tandem with these drugs to accelerate the cell death process. The enzyme sPLA2 produces a pro-inflammatory response that plays an important role in wound protection and healing and is also associated with diseases including septic shock, atherosclerosis, and cancer. This enzyme preferentially hydrolyzes cells that exhibit specific physical membrane properties in response to cellular trauma or apoptosis (programmed cell death). We hypothesized that although chemotherapeutic agents work through different mechanisms, the …

Exploring Folate Uptake In Chicken Understanding Prevention Of Neural Tube Defects, Bret Gardner, Dr. Michael Stark

Journal of Undergraduate Research

Neural tube defects (NTDs) are among the most common congenital malformations, afflicting .5- 8/1000 live births (Saitsu, 2003). Examples of such defects include spina bifida and anencephaly, resulting from failed closure of the posterior and anterior neural tube, respectively. The neural tube is the fetal precursor to the central nervous system. Currently the most common and effective method for preventing such defects consists of periconceptional folate intake. In developed countries, sufficient folate (folic acid or vitamin B12) is readily obtained from multivitamins, enriched cereals, or other items in a balanced diet. This preventative treatment, however, remains ineffective in 30-50% of …

Mouse Strain Determines Cardiac Growth Potential, Carmen Kiper, Barry Grimes, Gary Van Zant, Jonathan Satin

Physiology Faculty Publications

RATIONALE: The extent of heart disease varies from person to person, suggesting that genetic background is important in pathology. Genetic background is also important when selecting appropriate mouse models to study heart disease. This study examines heart growth as a function of strain, specifically C57BL/6 and DBA/2 mouse strains.

OBJECTIVE: In this study, we test the hypothesis that two strains of mice, C57BL/6 and DBA/2, will produce varying degrees of heart growth in both physiological and pathological settings.

METHODS AND RESULTS: Differences in heart dimensions are detectable by echocardiography at 8 weeks of age. Percentages of cardiac progenitor cells (c-kit+ …

Neurotensin And Cholecystokinin Contract Gallbladder Circular Muscle In Chickens, Teresa F. Degolier, D. R. Brown, Gary E. Duke, M. M. Palmer, J. R. Swenson, Robert E. Carraway

Biological Sciences Faculty Publications

The contractile effects of neurotensin (NT) and cholecystokinin octapeptide (CCK-8) on isolated circular smooth muscle strips of chicken gallbladder were investigated. The NT (0.25-300 nM) produced concentration-dependent contractions on smooth muscle with an EC50 of 8.5 nM (95% confidence limits = 5.3-13.6 nM). In comparison, CCK-8 produced concentration-dependent contractions with an EC50 of 13 nM (95% confidence limits of 9-20 nM). There were no statistical differences in contractile responses when comparing NT and CCK-8 at equimolar concentrations. The NT appears to act directly on smooth muscle tissue in the chicken; the contractile responses were not blocked by 10 μM atropine …

Med13p Prevents Stress-Independent Mitochondrial Hyperfragmentation And Aberrant Apoptosis Activation In Saccharomyces Cerevisiae By Controlling Cyclin C Nuclear Localization, Svetlana Khakhina

Graduate School of Biomedical Sciences Theses and Dissertations

During aging, and as a result of environmental changes, cells are exposed to elevated levels of reactive oxygen species (ROS). High ROS levels induce lipid oxidation, protein aggregation, mitochondrial hyperfragmentation, DNA damage and programmed cell death (PCD), also called apoptosis. PCD is a highly regulated process and its misregulation has been linked to neurodegenerative diseases and cancer development.

Our hypothesis is that cyclin C plays a role in the initiation of apoptosis. During normal conditions, cyclin C represses the transcription of stress response genes (SRG). In response to stress, cyclin C translocates to the cytoplasm where it facilitates mitochondrial hyperfragmentation …

Exercise Participation During Weight Loss On A High Protein – Low Carbohydrate Diet Plan In Females Aged 15-25 Years, Margaret Mobley-Meulman

Electronic Theses and Dissertations

Weight gain due to poor diet and lack of exercise is responsible for over 300,000 deaths each year (U.S. Department of Health and Human Services, 2010). Obese adults have an increased risk for serious health conditions including high blood pressure and cholesterol, type 2 diabetes, coronary heart disease, stroke, gallbladder disease, osteoarthritis, sleep apnea, respiratory problems, and certain cancers (National Cancer Institute, 2012). Participation in exercise can help control weight, strengthen muscles and bones, and reduce the incidence of cardiac events, stroke, hypertension, type 2 diabetes, colon and breast cancers, osteoporotic fractures, gallbladder disease, obesity, depression, anxiety, and delay mortality …

Surfing Injuries Requiring First Aid In New Zealand, 2007-2012, Kevin Moran, Jonathon Webber

International Journal of Aquatic Research and Education

In an island nation such as New Zealand with easy access to surf beaches, surfing activities are very popular and, while generally perceived as a healthy form of outdoor recreation, they do have attendant risks. This study reports on nondrowning, surfing-related incidents that required medical first aid on beaches during five summer seasons from 2007-2012. Retrospective descriptive analysis of data from lifeguard first aid reports found that 16% (n = 1,327) of injuries were the consequence of surfing activity. More males than females were treated for surfing injuries (68% male, 31% female). Lacerations (59%) and bruising (15%) accounted for most …

Fetal Programming And Later Obesity In A Predominantly Latino Wic Population, Eric George Walsh

Loma Linda University Electronic Theses, Dissertations & Projects

Background: In utero stressors may work to program the metabolism of the developing fetus in such a way that predisposes him/her to obesity later on. Studies have shown that breastfeeding is protective against childhood obesity and suggest that after six months the weight gain in breastfed babies slows opposed to formula fed babies who continue with rapid weight gain. This slowing of weight gain has been shown to be protective against adiposity and later life weight gain.

Purpose: This study looks to further explore these findings in a low income Latino population adding mother’s feelings about the pregnancy and the …

Physiologically-Based Pharmacokinetic Modeling For Predicting Caffeine/Theophylline-Ciprofloxacin Interactions, David M. Ng, Ali Navid

STAR Program Research Presentations

Dynamics of interactions between the drugs caffeine, theophylline, and ciprofloxacin are predicted using physiologically-based pharmacokinetic (PBPK) modeling. Pharmacokinetic means the model determines where the drugs are distributed in the body over time. Physiologically-based means the anatomy and physiology of the human body are reflected in the structure and functioning of the model. Multiple drugs can interact to increase or decrease their beneficial and/or undesired effects. This is important because some common substances, such as caffeine in coffee, soft drinks, and energy drinks, are actually drugs that affect the body. Ciprofloxacin is an inhibitor of caffeine and theophylline metabolism; such inhibition …

The Relationship Among Ankle Function, Functional Capacity, And Body Composition To Balance In Geriatric Populations, Joseph Robert Chaney

Graduate Theses and Dissertations

The primary purpose of this research study was to identify significant relationships among measures of ankle strength, ankle range of motion, body composition, and functional capacity to balance ability in geriatric populations which may potentially assist in identifying older individuals with increased risk of falling. A battery of five test (ankle strength assessments, ankle range of motion , DXA, functional fitness, and balance) were administered to 20 participants (6 males, 14 females, mean age 69.78 ± 3.98) that had indicated to be at least 65 years of age or older and no history of falls within the previous 12 months. …

The Effect Of Temperature Extremes On Cardiorespiratory Function In The Grass Shrimp Palaemonetes Pugio: Oxygen Limited Thermal Tolerance, Teresa Mika

UNLV Theses, Dissertations, Professional Papers, and Capstones

Aquatic poikilothermic animals must either cope with or compensate for the mismatch in oxygen supply and demand present at high temperatures. Oxygen limited thermal tolerance explains how aerobic scope is limited by insufficient oxygen supply and sets the performance window in animals. This work explores the effects of temperature on the different components of the oxygen delivery system, in both normoxic and hyperoxic conditions to determine if supplying more oxygen to the system mitigates the effects of temperature effects on the cardiorespiratory system and extends oxygen limited thermal tolerance to higher temperatures. The effect of temperature and oxygen condition was …

Dexamethasone Rapidly Increases Gaba Release In The Dorsal Motor Nucleus Of The Vagus Via Retrograde Messenger-Mediated Enhancement Of Trpv1 Activity, Andrei V. Derbenev, Bret N. Smith

Physiology Faculty Publications

Glucocorticoids influence vagal parasympathetic output to the viscera via mechanisms that include modulation of neural circuitry in the dorsal vagal complex, a principal autonomic regulatory center. Glucocorticoids can modulate synaptic neurotransmitter release elsewhere in the brain by inducing release of retrograde signalling molecules. We tested the hypothesis that the glucocorticoid agonist dexamethasone (DEX) modulates GABA release in the rat dorsal motor nucleus of the vagus (DMV). Whole-cell patch-clamp recordings revealed that DEX (1-10 µM) rapidly (i.e. within three minutes) increased the frequency of tetrodotoxin-resistant, miniature IPSCs (mIPSCs) in 67% of DMV neurons recorded in acutely prepared slices. Glutamate-mediated mEPSCs were …

Direction Of Aminoacylated Transfer Rnas Into Antibiotic Synthesis And Peptidoglycan-Mediated Antibiotic Resistance, Jennifer Shepherd, Michael Ibba

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Prokaryotic aminoacylated‐transfer RNAs often need to be efficiently segregated between translation and other cellular biosynthetic pathways. Many clinically relevant bacteria, including Streptococcus pneumoniae, Staphylococcus aureus, Enterococcus faecalis and Pseudomonas aeruginosa direct some aminoacylated‐tRNA species into peptidoglycan biosynthesis and/or membrane phospholipid modification. Subsequent indirect peptidoglycan cross‐linkage or change in membrane permeability is often a prerequisite for high‐level antibiotic resistance. In Streptomycetes, aminoacylated‐tRNA species are used for antibiotic synthesis as well as antibiotic resistance. The direction of coding aminoacylated‐tRNA molecules away from translation and into antibiotic resistance and synthesis pathways are discussed in this review.

Paired Interactions Between Kir Channels And Tertiapin-Q, Chul Ho Yang

Theses and Dissertations

Kir channels serve diverse and important roles throughout the human body and malfunctions of these channels are implicated in various channelopathies. Specific inhibitors for different subtypes of Kir channels are not available. However, Tertiapin-Q (TPNQ), a polypeptide isolated from honey bee venom, differentially inhibits certain subtypes of Kir channels with nanomolar affinity: ROMK1 (Kir1.1) and GIRK1/GIRK4 (Kir3.1/Kir3.4). Modification of TPNQ to increase selectivity for target channels bears great therapeutic potential. The in silico studies based on TPNQ-docked channel models, ROMK1_IRK2 (Kir1.1_Kir2.2) and GIRK2 (Kir3.2), predicted specific paired residue interactions and were experimentally validated here. In ROMK1 E123A mutant, the TPNQ …

Lipid Ii-Independent Trans Editing Of Mischarged Trnas By The Penicillin Resistance Factor Murm, Jennifer Shepherd, Michael Ibba

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Streptococcus pneumoniae is a causative agent of nosocomial infections such as pneumonia, meningitis, and septicemia. Penicillin resistance in S. pneumoniae depends in part upon MurM, an aminoacyl-tRNA ligase that attaches l-serine or l-alanine to the stem peptide lysine of Lipid II in cell wall peptidoglycan. To investigate the exact substrates the translation machinery provides MurM, quality control by alanyl-tRNA synthetase (AlaRS) was investigated. AlaRS mischarged serine and glycine to tRNAAla, as observed in other bacteria, and also transferred alanine, serine, and glycine to tRNA^Phe. S. pneumoniae tRNA^Phe has an unusual U4:C69 mismatch in its acceptor stem that …

Acquisition Delays Affect Lymphocyte Subset Counts But Not Markers Of Exercise-Induced Apoptosis, Holly B. Kell, Guilherme Borges Pereira, Ramires Alsamir Tibana, Michael Jarrett, Mark A. Schafer, Jonato Prestes, Antonio Santo, James W. Navalta

International Journal of Exercise Science

International Journal of Exercise Science 6(3) : 250-255, 2013. With the emergence of shared facilities, the possibility of a processing delay is increased as time on instrumentation becomes less available. The purpose of this investigation was the evaluate the effect of a 24h time delay on lymphocyte subset concentration, as well as for the apoptotic marker annexin V. Fourteen healthy individuals completed an incremental treadmill test to exhaustion, and blood samples were obtained before and after exercise. The samples were labeled in duplicate with mixtures consisting of flow cytometry staining buffer, the biomarker for early-phase cell death (annexin V), and …

Activity-Specific Effects Of Fatigue Protocols May Influence Landing Kinematics: A Pilot Study, Adrian Chavez, Duane Knudson, Rod Harter, Kevin Mccurdy

International Journal of Exercise Science

International Journal of Exercise Science 6(3) : 242-249, 2013. Fatigue is a common neuromuscular factor examined in relation to risk of ACL injury. Unfortunately, variations between the protocols used to induce fatigue in studies examining this phenomenon may have contributed to reported inconsistencies in the effects of fatigue on movements with high-risk of ACL injury. In addition, the ecological validity of fatigue experienced as a result of protocols commonly administered in the experimental setting is unclear. The purpose of this study was to examine the ecological validity, using basketball competition as the criterion measure, of two fatigue protocols commonly used …

Manuscript Has Been Retracted, Michael Smith, Nicholas Hanson, Alexander Lucas, Steven Devor

International Journal of Exercise Science

International Journal of Exercise Science 6(3) : 236-241, 2013. Manuscript has been retracted.

Children And Pedometers: A Study In Reactivity And Knowledge, Steven L. Prewitt, James C. Hannon, Timothy A. Brusseau

International Journal of Exercise Science

International Journal of Exercise Science 6(3) : 230-235, 2013. Pedometers are simple inexpensive tools that are widely used for the measurement of physical activity. Reactivity is always a concern when using pedometers. An issue not yet addressed is the role previous knowledge has on the impact of reactivity. The primary purpose of this study was to examine if reactivity exists in 4^th-6^th grade students and if prior knowledge about pedometers had an effect on reactivity. Participants included 109 (54 females) 4^th- 6^th grade students from a suburban charter school. Prior to data collection, students …