Physiology Commons^™

Thermodynamic Evidence That Ganglioside-Mediated Insertion Of Botulinum A Into The Cholinergic Nerve Ending May Precede Endocytosis And Acidification: A Langmuir Film Study, Bradley Adam Strongin

Theses and Dissertations

Botulinum Neurotoxin (BoNT) is one of the most potent toxins known to human kind. The Atomic Force Microscope (AFM) was employed to investigate the conditions under which BoNT type A heavy chain would bind and/or insert into mica supported dipalmitoylphosphatidylcholine (DPPC) lipid bilayers. As an alternate technique, DPPC/GT1b or total ganglioside extract (80:20) monolayers of a Langmuir Blodgett (LB) Trough were adapted to be artificial membrane models for toxin insertion studies. We conclude that LB monolayer studies are a promising candidate for BoNT/A membrane insertion investigation. Botulinum neurotoxin serotype A insertions into the LB monolayers in the presence of BoNT/A …

Effects Of Endurance Training On The Ampk Response To Exercise., David Gerald Chesser

Theses and Dissertations

Activation of AMP-activated protein kinase (AMPK) results in the upregulation of several intracellular systems which help to prepare a cell for a high energy challenge. The magnitude of the AMPK response to a 10 min bout of exercise has been found to decrease in red quadriceps (RQ) following training, while putative AMPK roles seem to be maintained; specifically, the biogenesis of mitochondria and higher levels of hexokinase II and glucose transporter 4 (GLUT4). If the AMPK response to exercise is responsible in part for these adaptations, how can they be maintained if the AMPK response is attenuated? The purpose of …

Mapk Survival Signaling In Melanoma, Matthew W. Vanbrocklin

Dissertations

Extracellular signals activate mitogen-activated protein kinase (MAPK) cascades potentiating biological activities such as cell proliferation, differentiation, and survival. Constitutive activation of MAPK signaling pathways is implicated in the development and progression of many human cancers, including melanoma. Mutually exclusive activating mutations in NRAS or BRAF are found in ∼85% of all melanomas resulting in constitutive activation of the MAPK pathway (RAS-BRAF-MEK-ERK-RSK). We have previously demonstrated that inhibition of this pathway with small molecule MEK inhibitors selectively induces apoptosis in human melanoma cells both in vitro and in vivo, but not in normal melanocytes. These results support the notion that the …

Lack Of Depolarization-Induced Suppression Of Inhibition (Dsi) In Layer 2/3 Interneurons That Receive Cannabinoid-Sensitive Inhibitory Inputs, Fouad Lemtiri-Chlieh, Eric S. Levine

fouad Lemtiri-Chlieh

In layer 2/3 of neocortex, brief trains of action potentials in pyramidal neurons (PNs) induce the mobilization of endogenous cannabinoids (eCBs), resulting in a depression of GABA release from the terminals of inhibitory interneurons (INs). This depolarization-induced suppression of inhibition (DSI) is mediated by activation of the type 1 cannabinoid receptor (CB1) on presynaptic terminals of a subset of INs. However, it is not clear whether CB1 receptors are also expressed at synapses between INs, and whether INs can release eCBs in response to depolarization. In the present studies, brain slices containing somatosensory cortex were prepared from 14- to 21-day-old …

A Role For The Forebrain In Mediating Time-Of-Day Differences In Glucocorticoid Counterregulatory Responses To Hypoglycemia In Rats, Lori M. Gorton, Arshad M. Khan, Maryann Bohland, Graciela Sanchez-Watts, Casey M. Donovan, Alan G. Watts

Arshad M. Khan, Ph.D.

No abstract provided.

Phenylalanyl-Trna Synthetase Editing Defects Result In Efficient Mistranslation Of Phenylalanine Codons As Tyrosine, Jiqiang Ling, Srujana S. Yadavalli, Michael Ibba

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Translational quality control is monitored at several steps, including substrate selection by aminoacyl-tRNA synthetases (aaRSs), and discrimination of aminoacyl-tRNAs by elongation factor Tu (EF-Tu) and the ribosome. Phenylalanyl-tRNA synthetase (PheRS) misactivates Tyr but is able to correct the mistake using a proofreading activity named editing. Previously we found that overproduction of editing-defective PheRS resulted in Tyr incorporation at Phe-encoded positions in vivo , although the misreading efficiency could not be estimated. This raised the question as to whether or not EF-Tu and the ribosome provide further proofreading mechanisms to prevent mistranslation of Phe codons by Tyr. Here we show that, …

An Aminoacyl-Trna Synthetase: Elongation Factor Complex For Substrate Channeling In Archaeal Translation, Corinne D. Hausmann, Mette Praetorius-Ibba, Michael Ibba

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Translation requires the specific attachment of amino acids to tRNAs by aminoacyl-tRNA synthetases (aaRSs) and the subsequent delivery of aminoacyl-tRNAs to the ribosome by elongation factor 1 alpha (EF-1α). Interactions between EF-1α and various aaRSs have been described in eukaryotes, but the role of these complexes remains unclear. To investigate possible interactions between EF-1α and other cellular components, a yeast two-hybrid screen was performed for the archaeon Methanothermobacter thermautotrophicus. EF-1α was found to form a stable complex with leucyl-tRNA synthetase (LeuRS; KD = 0.7 μ M). Complex formation had little effect on EF-1α activity, but increased the k_{cat …}

Fully Codon-Optimized Luciferase Uncovers Novel Temperature Characteristics Of The Neurospora Clock, Van D. Gooch, Arun Mehra, Luis F. Larrondo, Julie Fox, Melissa Touroutoutoudis, Jennifer J. Loros, Jay C. Dunlap

Dartmouth Scholarship

We report the complete reconstruction of the firefly luciferase gene, fully codon optimized for expression in Neurospora crassa. This reporter enhances light output by approximately 4 log orders over that with previously available versions, now producing light that is visible to the naked eye and sufficient for monitoring the activities of many poorly expressed genes. Time lapse photography of strains growing in race tubes, in which the frq or eas/ccg-2 promoter is used to drive luciferase, shows the highest levels of luciferase activity near the growth front and newly formed conidial bands. Further, we have established a sorbose medium colony …

Maternal High-Salt Diet During Pregnancy In Sprague Dawley Rats Programs Exaggerated Stress-Induced Blood Pressure And Heart Rate Responses In Adult Female Offspring, Summer Hayes King

Theses and Dissertations

The prenatal environment has been shown to have lasting effects on cardiovascular health. In the present study, pregnant rats were fed a 0.7% NaCl normal salt (NS) diet or an 8% NaCl high salt (HS) diet throughout pregnancy. Adult offspring were fitted with radiotelemetry probes to continuously measure blood pressure and heart rate. Rats were placed in restraining cages to test for a programmed acute stress hyperresponsiveness. Offspring were challenged with HS diet for one week to determine if blood pressure salt sensitivity had been programmed by the prenatal HS diet. Animals were killed following resting and acute stress conditions, …

Changes In Body Composition And Physical Activity Behavior In A Group Of College Freshmen, Tracy A. Swibas

Masters Theses

PURPOSE: To compare: 1-the physiological profile of former athletes (Ath) and non-athletes (Non-Ath) upon college entrance, 2-PA levels in these groups, and 3-changes in physiological profile and PA level of former Ath and Non-Ath and females and males over the course of freshman year. Sixty-two college freshmen were tested during the initial weeks of the school year and again during the final weeks of the school year; the sample consisted of 32 former Ath (18 females and 14 males) and 30 Non-Ath (19 females and 11 males). METHODS: Body composition (BC) was assessed using the Bod Pod with a conversion …

Amp-Activated Protein Kinase Kinase Activity And Phosphorylation Of Amp-Activated Protein Kinase In Contracting Muscle Of Sedentary And Endurance Trained Rats, Denise Hurst

Theses and Dissertations

This study was designed to examine activity of AMP-activated protein kinase kinase (AMPKK) and AMP-activated protein kinase (AMPK) in muscles from control (C) and endurance trained (T) rats. Rats were trained 5 days/wk, 2 hr/d for 8 wks at a final intensity of 32 m/min up a 15% grade with 30 second sprints at 52 m/min every 10 min. Gastrocnemius muscles were stimulated in situ in T and C rats for 5 min at frequencies of 0.4/sec and 1/sec. Gastrocnemius LKB1 protein, a putative component of the AMPKK complex (LKB1, STRAD, and MO25), increased approximately 2-fold in response to training. …

Regulation Of Adrenal Steroidogenesis By Interleukin-6, Stephen A. Mcilmoil

Theses and Dissertations

Cortisol and dehydroepiandrosterone (DHEA) are steroids produced by the zona fasciculata (ZF) and reticularis (ZR), respectively, of the adrenal cortex. Both steroids are upregulated in response to adrenocorticotropic hormone (ACTH). Cortisol is a glucorticoid that is important in the regulation of inflammation and metabolism. DHEA is an adrenal androgen important in fetal growth and puberty but tends to decrease gradually after puberty in both men and women. DHEA has various effects on metabolism and immune function including inhibiting the effects of cortisol on some tissues. During the acute phase of stress, cortisol and DHEA rise due to an increase in …

Regulation Of Lkb1-Strad-Mo25 Complex Expression And Activation Of Ampk In Skeletal Muscle By Thyroid Hormone, Devon Jack Branvold

Theses and Dissertations

AMP-activated protein kinase (AMPK), a heterotrimeric protein which serves as a metabolic master switch in skeletal muscle, is a research target for the pharmaceutical treatment and prevention of type 2 diabetes. The expression of all of the isoforms of the subunits of AMPK and AMPK activity are increased in skeletal muscle tissue of hyperthyroid rats. Activity of AMPK is regulated by an upstream kinase (AMPKK). The LKB1-STRAD-MO25 complex is a major AMPKK in skeletal muscle. This experiment was designed to determine whether the increase in AMPK activity is accompanied by a thyroid hormone-induced increase in the expression of the LKB1-STRAD-MO25 …

Catecholaminergic Control Of Mitogen-Activated Protein Kinase Signaling In Paraventricular Neuroendocrine Neurons In Vivo And In Vitro: A Proposed Role During Glycemic Challenges, Arshad M. Khan, Todd A. Ponzio, Graciela Sanchez-Watts, B. Glenn Stanley, Glenn I. Hatton, Alan G. Watts

Arshad M. Khan, Ph.D.

No abstract provided.

The Effect Of Intensity Of Aerobic Vo2max Resting Heart Rate And Blood Pressure, Shannan Elizabeth Gormley

Human Movement Sciences Theses & Dissertations

The AGSM recommends 20 to 60 minutes of continuous or intermittent activity 3 to 5 times per week to maintain cardio respiratory fitness (Pollock et al., 1998). The 1996 Surgeon General's Report on Physical Activity and Health indicates that Americans are not meeting these physical activity recommendations (DHHS). Several clear consequences of physical inactivity are the appearance of cardiovascular disease risk factors, such as hypertension, hyperlipidemia and obesity. Two recent review articles suggested that higher intensity exercise will elicit a greater reduction in cardiovascular disease risk factors (Swain and Franklin, 2002; Swain and Franklin, 2006). In order to determine whether …

Inhibition Of Nitric Oxide And Soluble Guanylyl Cyclase Signaling Affects Olfactory Neuron Activity In The Moth, Manduca Sexta, Caroline H. Wilson, Thomas A. Christensen, Alan J. Nighorn

Health Sciences and Kinesiology Faculty Articles

Nitric oxide is emerging as an important modulator of many physiological processes including olfaction, yet the function of this gas in the processing of olfactory information remains poorly understood. In the antennal lobe of the moth, Manduca sexta, nitric oxide is produced in response to odor stimulation, and many interneurons express soluble guanylyl cyclase, a well-characterized nitric oxide target. We used intracellular recording and staining coupled with pharmacological manipulation of nitric oxide and soluble guanylyl cyclase to test the hypothesis that nitric oxide modulates odor responsiveness in olfactory interneurons through soluble guanylyl cyclase-dependent pathways. Nitric oxide synthase inhibition resulted …

A Theoretical Model For Blood Flow In Small Vessels, V. P. Srivastava

Applications and Applied Mathematics: An International Journal (AAM)

A two-fluid model consisting of a core region of suspension of all the erythrocytes (particles) in plasma (fluid) assumed to be a particle-fluid mixture and a peripheral layer of cell-free plasma (Newtonian fluid), has been proposed to represent blood flow in small diameter tubes. The analytical results obtained in the proposed model for effective viscosity, velocity profiles and flow rate have been evaluated numerically for various values of the parameters available from published works. Quantitative comparison has shown that present model suitability represents blood flow at hematocrit (less than or equal to 40%) and in vessels up to 70 micrometers …

Electromagnetic Differences In The Brain During Memory Retrieval, Warren Scott Merrifield

Loma Linda University Electronic Theses, Dissertations & Projects

The primary objectives for this experiment were to analyze the neuroanatomical correlates of autobiographical, episodic and semantic memory, use a different paradigm to promote episodic memory retrieval, and employ a different analysis technique to understand retrieval processes. Autobiographical and episodic memories are personal memories from the past. Autobiographical is more general (e.g. a street name of a house growing up) and episodic is more specific to time (e.g. 13th birthday party that took place on a street). For autobiographical and episodic memory retrieval operations, there is no general consensus as to the localization of function, but bilateral activation of the …

Parasites Alter Community Structure, Chelsea L. Wood, James E. Byers, Kathryn L. Cottingham, Irit Altman

Dartmouth Scholarship

Parasites often play an important role in modifying the physiology and behavior of their hosts and may, consequently, mediate the influence hosts have on other components of an ecological community. Along the northern Atlantic coast of North America, the dominant herbivorous snail Littorina littorea structures rocky intertidal communities through strong grazing pressure and is frequently parasitized by the digenean trematode Cryptocotyle lingua. We hypothesized that the effects of parasitism on host physiology would induce behavioral changes in L. littorea, which in turn would modulate L. littorea's influence on intertidal community composition. Specifically, we hypothesized that C. lingua …

The Relationship Between Parental Literacy And Language Practices And Beliefs And Toddlers’ Emergent Literacy Skills, Claire Maples Edwards

Doctoral Dissertations

This study involved the examination of parental beliefs and practices about early literacy and language and how they influence observed literacy behaviors of their 18-36 month old toddlers. Observed literacy behaviors of the toddlers included phonological awareness (PA) and written language awareness (WLA). The objectives of this study were to (a) characterize the emergent literacy behaviors of toddlers, (b) characterize parental beliefs and practices regarding emergent literacy with respect to toddlers, and (c) determine the relationship between toddlers’ emergent literacy behaviors and their parents’ beliefs and behaviors. Participants included 15 mother-toddler dyads. Mean age of mothers was 35.2 years (SD …

Gender-Specific Effects Of Hiv Protease Inhibitors On Body Mass In Mice, Melinda E. Wilson, Kimberly F. Allred, Elizabeth M. Kordik, Deana K. Jasper, Amanda N. Rosewell, Anthony J. Bisotti

Physiology Faculty Publications

Protease inhibitors, as part of highly active anti-retroviral therapy (HAART), have significantly increased the lifespan of human immunodeficiency virus (HIV) infected patients. Several deleterious side effects including dyslipidemia and lipodystrophy, however, have been observed with HAART. Women are at a higher risk of developing adipose tissue alterations and these alterations have different characteristics as compared to men. We have previously demonstrated that in mice the HIV protease inhibitor, ritonavir, caused a reduction in weight gain in females, but had no effect on male mice. In the present study, we examined the potential causes of this difference in weight gain. Low-density …

Physical Activity Levels Of College Freshman: Comparison Of Surveys With Objective Measures Of Physical Activity, Lois Amber Mcmahan

Masters Theses

PURPOSE: This study compared measures of physical activity (PA) taken from the 7- day Physical Activity Recall (PAR) and the International Physical Activity Questionnaire (IPAQ) with those obtained from the NL 2000 (NL) and Lifecorder (LC) accelerometers in entering, college freshmen.

METHODS: 47 males and 64 females (overall age =18.5±.3 yrs, wt. = 68.7±14.4 kg, and BMI = 23.7 ±4.9) volunteered and signed an informed consent form. All subjects wore the NL for 7 days, and half wore the LC as well. After the 7 days the subjects completed the PAR and IPAQ.

RESULTS: There was a strong agreement between …

Video Game Addiction: Truth Or Fiction, Lyles Thibodeaux-Harmony

Honors Theses

No abstract provided.

Regulation Of Alpha-1-Adrenoceptor-Mediated Contractions Of The Uterine Artery By Pkc, Hongying Zhang

Loma Linda University Electronic Theses, Dissertations & Projects

Pregnancy is associated with a significant decrease in uterine vascular tone and a striking increase in uterine blood flow, which ensures normal fetal development. Multiple mechanisms are involved in the adaptation of uterine artery contractility during pregnancy. Both protein kinase C (PKC) and activation of ai-adrenoceptors play important roles in the regulation of uterine artery contractility. In addition, PKC mediates the pregnancyassociated decrease in myogenic tone of the uterine artery, and interacts with ajadrenoceptors leading to modulation of ai-adrenoceptor-mediated contractions of vascular smooth muscle. Yet, whether or to what extent PKC regulates ai-adrenoceptormediated contractions of the uterine artery and their …

Maturational Changes In Cerebrovascular Thick- And Thin-Filament Regulation, Renan Joel Sandoval

Loma Linda University Electronic Theses, Dissertations & Projects

The present study focused on the main hypothesis that age-related changes in myofilament Ca²⁺ sensitivity involve simultaneous changes in the relations between cytosolic Ca²⁺ transients, myosin phosphorylation, and force development. To define the effects of late fetal and early postnatal maturation, parallel experiments were carried out using cerebral arteries from both term lamb fetuses (140-141 days of gestation) and nonpregnant adult sheep. Fetal and adult cerebral arteries were stimulated by either mechanically, electromechanically, and/or pharmacomechanically-induced contractions, and the relations of cytosolic Ca²⁺, MLC phosphorylation, and contractile tensions were measured. These measurements allowed for stimulus and age-dependent …

Similarities Between Etiological Models Of Eating Disorder Symptomatology And Muscle Dysmorphia Symptomatology, Jennifer Jonda

Masters Theses & Specialist Projects

Muscle Dysmorphia (MD) has recently been conceptualized as the male form of Eating Disorders (ED), although it is not currently classified as an ED. The current study compares etiological models of MD symptomatology (based on Grieve's [2007] conceptual model of MD) and ED symptomatology (based on Stice's [1994] conceptual model of Bulimia Nervosa). In both models, it was hypothesized that sociocultural influences on appearance (SIA) would predict body dissatisfaction (BD), and that this relationship would be mediated by self-esteem (SE) and perfectionism (P); that BD would predict negative affect (NA); and that NA would predict MD and ED symptomatology. Two-hundred-forty-seven …

Direct Comparison Of Feature Tracking And Autocorrelation For Velocity Estimation, Gregory R. Bashford, Derek J. Robinson

Biomedical Imaging and Biosignal Analysis Laboratory

Feature tracking is an algorithm for estimating tissue motion and blood flow using pulse-echo ultrasound. It was proposed as a computationally simpler alternative to other techniques such as autocorrelation and time-domain cross correlation. The advantage of feature tracking is that it selectively extracts easily identifiable parts of the speckle signal (e.g., the local maxima), reducing the amount of information being processed. Studies on feature tracking to date have used stationary, specklegenerating targets to simulate blood flow. Also, feature tracking has not been compared with accepted commercial methods. This study directly compares feature tracking performance with the complex autocorrelation method, which …

The Role Of Stat And The Jak/Stat Pathway In Mediating The Effects Of Interleukin-6 On Star Expression, Janae Strickland

Theses and Dissertations

Cortisol, a hormone produced by a hormone produced by the adrenal gland, is responsible for many regulatory functions in the body. Cortisol release is mediated by adrenocorticotrophic hormone, or ACTH, through the hypothalamus-pituitary-adrenal or HPA axis. This HPA axis is the major release pathway used during acute stress, during which the levels of ACTH parallel those of cortisol. However, in states of chronic stress, the level of ACTH drops dramatically, while cortisol remains high. This study focuses on the pathway of cortisol release during these chronic stress states, specifically examining the role of IL-6 with respect to STATs and the …

Derivation Of An Age And Weight Handicap For The 5k Run, Paul M. Vanderburgh, Lloyd L. Laubach

Health and Sport Science Faculty Publications

The adverse effect of increasing age and/or body weight on distance run performance has been well documented. Accordingly, nearly all five kilometer (5K) road races employ age categories and, sometimes, a heavier body weight classification. Problems with such conventions include small numbers of runners within older age categories and the advantage given to the lightest runners within each weight category. We developed a 5K Handicap (5KH), a model that calculates an adjusted run time based on the inputs of actual 5K run time, age, and body weight for men and women. This adjusted time, then, can be compared between runners …

Handling Immediate Medical Care At Aquatic Facilities: Do We Need Different Levels Of Lifeguard Certification?, Leland Yarger

International Journal of Aquatic Research and Education

The first-responder and professional-rescuer training materials and training programs consider lifeguards to be first responders in emergencies (Aehlert, 2005; American Red Cross, 2001). This article asks readers to consider whether our agency lifeguard-training programs reflect a philosophy that truly view and prepare lifeguards as first responders. If not, I challenge readers to consider whether we should alter our hiring, staffing, and in-service training procedures at aquatic facilities based on the scope and need for providing adequate emergency care at those facilities.