Physiology Commons^™

Structural And Functional Mapping Of The Archaeal Multi-Aminoacyl-Trna Synthetase Complex, Corinne D. Hausmann, Michael Ibba

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Methanothermobacter thermautotrophicus contains a multi-aminoacyl-tRNA synthetase complex (MSC) of LysRS, LeuRS and ProRS. Elongation factor (EF) 1A also associates to the MSC, with LeuRS possibly acting as a core protein. Analysis of the MSC revealed that LysRS and ProRS specifically interact with the idiosyncratic N- and C- termini of LeuRS, respectively. EF-1A instead interacts with the inserted CP1 proofreading domain, consistent with models for post-transfer editing by class I synthetases such as LeuRS. Together with previous genetic data, these findings show that LeuRS plays a central role in mediating interactions within the archaeal MSC by acting as a core scaffolding …

Adaptation And Mal-Adaptation To Ambient Hypoxia; Andean, Ethiopian And Himalayan Patterns, Guoqiang Xing, Clifford Qualls, Luis Huicho, Maria Rivera-Ch, Tsering Stobdan, Marat Slessarev, Eitan Prisman, Shoji Ito, Hong Wu, Angchuk Norboo, Diskit Dolma, Moses Kunzang, Tsering Norboo, Jorge L Gamboa, Victoria E. Claydon, Joseph Fisher, Guta Zenebe, Amha Gebremedhin, Roger Hainsworth, Ajay Verma, Otto Appenzeller

Physiology Faculty Publications

The study of the biology of evolution has been confined to laboratories and model organisms. However, controlled laboratory conditions are unlikely to model variations in environments that influence selection in wild populations. Thus, the study of "fitness" for survival and the genetics that influence this are best carried out in the field and in matching environments.

Therefore, we studied highland populations in their native environments, to learn how they cope with ambient hypoxia. The Andeans, African highlanders and Himalayans have adapted differently to their hostile environment.

Chronic mountain sickness (CMS), a loss of adaptation to altitude, is common in the …

Effect Of Long-Term Hypoxia On Myometrial Contractility In The Pregnant Sheep, Timothy Kimo Arakawa

Loma Linda University Electronic Theses, Dissertations & Projects

Previous research from our laboratory has shown that myometrial contractility is reduced in pregnant sheep exposed to long-term hypoxia (LTH). The studies in this dissertation examined the effect of LTH on various aspects of Ca² regulation, large-conductance, Ca²⁺ activated (BK) channels activity and protein expression, and cGMP-depended protein kinase (PKG) activity. Myometrium was collected from near-term pregnant sheep exposed to high altitude-associated LTH and from normoxic pregnant controls. After pretreatment with 10^-8 M oxytocin (OT), circular and longitudinal myometrial strips were treated with nifedipine (L-type Ca²⁺ channel blocker), ruthenium red, ryanodine (blockers of IPssensitive stores), 2-Nitro-4-carboxyphenyI-N,N-diphenyIcarbamate …

Parental Readiness For Change And Involvement In Treating Children With Obesity, Aileen Arratoonian Vedda

Loma Linda University Electronic Theses, Dissertations & Projects

Several studies have demonstrated benefits of parental involvement in intervention programs for Childhood Obesity. However, limited research is available on Parent Readiness for Change. This study utilized archival data from the LLU Growing Fit Obesity Clinic to assess Parent Readiness for Change (PRC) and involvement in a 12- week multidisciplinary program for obese children, as a predictor of medical and psychological outcomes. Data from forty-nine children aged 6-16 (M= 10.47) were eligible and included. Their caregivers who participated in the program included; 86% mothers, 7 % fathers, and 7 % relatives. The caregiver mean age was M=39.6. PRC was assessed …

Neuronal Connections From The Cervix To The Spinal Cord Before Parturition, Mary Medina Groves

Loma Linda University Electronic Theses, Dissertations & Projects

By the day before birth, the density of nerve fibers in the cervix has increased compared to earlier in pregnancy or in nonpregnant mice. Similar findings are reported in parturient women. To test the hypothesis that connections between the cervix and spinal cord are enhanced by term, the cervix of nonpregnant and time-dated pregnant mice (day 15 or 18 post-breeding) was injected with pseudorabies virus (PRV), a trans-synaptic retrograde neural tract tracer. Mice were euthanized and perfused 5 days later. The spinal cord and cervix were removed and postfixed overnight, immersed in sucrose, and cryostat sections through the thoracic to …

Relationship Of Vo2 Peak, Body Fat Percentage, And Power Output Measured During Repeated Bouts Of A Wingate Protocol, John R. Mclester‡, J. Matthew Green‡, P. Jason Wickwire†, Thaddeus R. Crews‡

International Journal of Exercise Science

The principle of specificity would indicate that being aerobically trained would not necessarily enhance performance in events relying principally on oxygen-independent metabolic pathways (i.e. “anaerobic” exercise). Body fatness may be associated with aerobic and anaerobic performance. VO2 Peak was determined with a graded cycle ergometry and, in a separate session 4 consecutive Wingate power tests (3 min recovery) in 31 males. Pearson correlations were calculated for VO2 Peak and Body Fat Percentage with Peak Power, Mean Power, Minimum Power, Fatigue Index, Peak Heart Rate, and Recovery Heart Rate. No significant correlations were found for VO2 Peak or Body Fat Percentage …

Exercise Induced Alterations In Rat Monocyte Number, Morphology, And Function, Marcia Guereschi†, Jonato Prestes‡, Felipe Donatto‡, Rodrigo Dias‡, Anelena Frollini‡, Clílton Ferreira‡, Claudia Cavaglieri‡, Adrianne Palanch‡

International Journal of Exercise Science

The purpose of this study was to verify the histophysiological alterations in monocytes and macrophages induced by short periods of exercise. Male Wistar rats (age = 2 months, body weight = 200g) were divided into seven groups (N=6 each): sedentary control (C), groups exercised (swimming) at low intensity for 5 (5L), 10 (10L), and 15 minutes (15L), and groups exercised at moderate intensity for 5 (5M), 10 (10M) or 15 minutes (15M). At moderate intensity the animals carried a load of 5% of body weight on their backs. Blood monocytes were evaluated for quantity and morphology, and peritoneal macrophages were …

Effect Of Hemoglobin-Based Oxygen Carriers On Arterial Pressure And Vasoactivity In The Rat Mesentery, Michael Kim

Theses and Dissertations

Hemoglobin-based oxygen carriers provide a promising future as an alternative to human blood transfusions. Hemoglobin-based oxygen carriers, HBOCs, provide a lowcost, easy to maintain, and safe solution. They require no refrigeration and are universally compatible, and the required transfusion volume is less than that of a normal transfusion. HBOCs have been known to have adverse side effects such as renal toxicity, gastrointestinal dismotility, and hypertension. Many of these problems stem from the lack of a membrane, which protects the hemoglobin from dissociating and extravasating into the blood vessel wall. Extracellular hemoglobin, like that found in HBOCs, has a greater affinity …

Tendinopathy Discrimination By Use Of Spatial Frequency Parameters In Ultrasound B-Mode Images, Gregory R. Bashford, Nicholas Tomsen, Shruti Arya, Judith M. Burnfield, Kornelia Kulig

Biomedical Imaging and Biosignal Analysis Laboratory

The structural characteristics of a healthy tendon are related to the anisotropic speckle patterns observed in ultrasonic images. This speckle orientation is disrupted upon damage to the tendon structure as observed in patients with tendinopathy. Quantification of the structural appearance of tendon shows promise in creating a tool for diagnosing, prognosing, or measuring changes in tendon organization over time. The current work describes a first step taken towards this goal—classification of Achilles tendon images into tendinopathy and control categories. Eight spatial frequency parameters were extracted from regions of interest on tendon images, filtered and classified using linear discriminant analysis. Resulting …

Effects Of Exercise Induced Fatigue On Postural Balance: A Comparison Of Treadmill Versus Cycle Fatiguing Protocols, Katherine Wright

Masters Theses & Specialist Projects

The purpose of this study was to examine the effects of muscle fatigue after a treadmill versus cycle ergometer incremental test on postural balance indices and recovery time recreationally trained individuals. The Bruce Treadmill Test and the Incremental Cycle Ergometer test were used to induce fatigue. Each subject (N=16) performed both exercises, but the order of the exercises was randomized. The subjects performed balance measures on a Biodex Balance System via the Dynamic Balance Test at level 5 and indices were recorded as given. Balance was measured a total of nine times (pre-exercise, immediately post, and at 3, 6, 9, …

Hypochlorous Acid Mediated Damage Of Chromatin, Joseph Insugn Kang

Loma Linda University Electronic Theses, Dissertations & Projects

Hypochlorous acid (HOCl), the primary product of activated neutrophils at sites of inflammation, can damage both DNA and associated histone proteins. HOCl damage to cytosine bases in DNA generates the chlorination damage products 5-chlorocytosine (ClC) and 5-chlorouracil (ClU) as well as the oxidation damage products 5- hydroxycytosine (HOC) and 5-hydroxyuracil (HOU). Histone damage by HOCl can be measured by quantitation of 3-chlorotyrosine and 3,5-dichlorotyrosine, stable and unique markers of protein damage caused by HOCl. The studies presented here investigate how and where these damage products occur and what implications they might have in the correlation between chronic inflammation and carcinogenesis. …

Colocalization And Distribution Of Hcn4 Channels And A Maguk Protein In Mammalian Sinoatrial Myocytes, Padmastuti Akella

Honors Scholar Theses

The sinoatrial node is known as the pacemaker of the heart. It controls the rate at which action potentials are generated and propagate through the sinoatrial myocytes. This thesis is an attempt to identify the colocalization of a specific ion channel (HCN4 channel) with a class of scaffolding protein (MAGUK proteins) within the sinoatrial myocyte. The colocalization of these two variables was performed using immunocytochemistry on murine sinoatrial myocytes and experimental results revealed the existence of a strong colocalization between the two variables. Images collected from the confocal microscope and analyzed using ImageJ software revealed a strong dependent correlation between …

Effects Of Hemoglobin-Based Oxygen Carriers On The Vasoactivity Of The Spinotrapezius Muscle Of The Rat, Pete Meliagros

Theses and Dissertations

Hemoglobin-based oxygen carriers (HBOCs) offer a safe, more plentiful and long term alternate to blood banks. However, they have been found to increase blood pressure which can be attributed to an increase in total peripheral resistance (TPR). Lumenal nitric oxide (NO) scavenging by these HBOCs seems to be responsible for this hypertensive effect. In addition, it is believed that hemoglobin (Hb) tetramers and dimers may extravasate and consume additional nitric oxide in the perivascular and interstitial space. The purpose of the present study was to elucidate the role of NO scavenging and to confirm extravasation as a contributor to HBOC …

Changes In Emg And Finger Force With Repeated Hangs From The Hands In Rock Climbers, Phillip B. Watts‡, Randall L. Jensen‡, Sara M. Agena†, John A. Majchrzak†, Rebecca A. Schellinger†, Cory S. Wubbels†

International Journal of Exercise Science

The nature and degree of fatigue in muscles that control finger position during repeated sustained efforts in rock climbing have not been described. The purpose of this study was to identify changes in maximum hang time and forearm electromyogram (EMG) during repeated maximum duration hangs from a simulated rock feature. A second objective was to determine the effect of different recovery times between hangs upon changes in finger force. Five experienced rock climbers performed 2 test sessions on different days in a randomized order. Each session involved 8 repetitions of a maximum duration hang with either 1 min (R1) or …

Do The Principles Of Motor Program Editing Apply To Longer Sequences Of Rapid Aiming Movements? Part Ii, Eric J. Wilson*, David E. Sherwood‡

International Journal of Exercise Science

In Part I of this study, it was shown that performing a shorter distance aiming movement prior to a longer distance aiming movement resulted in overshooting of the short movement and undershooting of the longer movement compared to control conditions. However, the finding was limited, unexpectedly, to the nondominant hand. To replicate the prior result and to determine the effect of practice organization on movement accuracy, right-handed (n =24) participants (aged 18-22) produced a sequence of three rapid lever reversals combining short (20°) and long (60°) movements with an intermovement interval of 2.5 s with the dominant hand. Greater overshooting …

Reviewing An Original Research Manuscript For The International Journal Of Exercise Science: A Guide For Students And Professionals, Kathy J. Simpson

International Journal of Exercise Science

Considerations for the review process of manuscripts submitted to the International Journal of Exercise Science are presented. Initial steps to evaluation include reading the abstract to determine your ability as a reviewer, becoming familiar with the journal requirements, and formulating an initial impression of the manuscript. At this point an assessment is made to determine how the reviewer should treat the manuscript. If it is determined that the manuscript is acceptable with minor revisions, or may be acceptable with major changes, a full review should be performed. A full review of the manuscript requires a thorough examination of the major …

Maternal Cocaine Administration In Mice Alters Dna Methylation And Gene Expression In Hippocampal Neurons Of Neonatal And Prepubertal Offspring, Svetlana I. Novikova, Fang He, Jie Bai, Nicholas J. Cutrufello, Michael S. Lidow, Ashiwel S. Undieh

Publications and Research

Previous studies documented significant behavioral changes in the offspring of cocaine-exposed mothers. We now explore the hypothesis that maternal cocaine exposure could alter the fetal epigenetic machinery sufficiently to cause lasting neurochemical and functional changes in the offspring. Pregnant CD1 mice were administered either saline or 20 mg/kg cocaine twice daily on gestational days 8–19. Male pups from each of ten litters of the cocaine and control groups were analyzed at 3 (P3) or 30 (P30) days postnatum. Global DNA methylation, methylated DNA immunoprecipitation followed by CGI2 microarray profiling and bisulfite sequencing, as well as quantitative real-time RT-PCR gene expression …

A Carboxyl-Terminal Sequence In The Lutropin Β Subunit Contributes To The Sorting Of Lutropin To The Regulated Pathway, Albina Jablonka-Shariff, Christopher A. Pearl, Anna Comstock, Irving Boime

Peer Reviewed Articles

Although synthesized in the same pituitary gonadotropes, the secretion profiles of lutropin (LH) and follitropin (FSH) differ. LH is secreted through a regulated pathway and associated with a bolus release at mid-estrous cycle. In contrast, the majority of FSH is secreted constitutively with an incremental increase until ovulation. Both share an identicalα subunit, and thus theβ subunit contains determinants for sorting into the regulated pathway. Previously, we demonstrated that a hydrophobic carboxyl-terminal heptapeptide of the LHβ subunit (Leu-Ser-Gly-Leu-Leu-Phe-Leu), not found in the FSHβ subunit, influences the intracellular behavior of the LH dimer. To test the hypothesis that the peptide contributes …

Validation Of A New Method Of Estimating Vo2max Based On Vo2Reserve With Treadmill Exercise, Julie Lynn Ward

Human Movement Studies & Special Education Theses & Dissertations

The purpose of the current study was to establish and then validate a treadmill protocol to predict VO_2max based on VO₂Reserve.

Methods

A treadmill protocol was developed to elicit approximately 60-70% of heart rate reserve (HRR) in the fifth and sixth minutes of the final stage. The protocol involved walking on a treadmill at 3.0 mph, with grade increasing by 1 % each minute until 50% HRR was reached. Then, an additional 5 minutes of walking at the final grade was performed. A study population of 60 volunteers (30 male; 30 female), considered low risk by ACSM …

Systems Approach Identifies An Organic Nitrogen-Responsive Gene Network That Is Regulated By The Master Clock Control Gene Cca1, Rodrigo A. Gutierrez, Trevor L. Stokes, Karen Thum, Xiaodong Xu, Mariana Obertello, Manpreet S. Katari, Milos Tanurdzic, Alexis Dean, Damion C. Nero, C Robertson Mcclung, Gloria M. Coruzzi

Dartmouth Scholarship

Understanding how nutrients affect gene expression will help us to understand the mechanisms controlling plant growth and development as a function of nutrient availability. Nitrate has been shown to serve as a signal for the control of gene expression in Arabidopsis. There is also evidence, on a gene-by-gene basis, that downstream products of nitrogen (N) assimilation such as glutamate (Glu) or glutamine (Gln) might serve as signals of organic N status that in turn regulate gene expression. To identify genome-wide responses to such organic N signals, Arabidopsis seedlings were transiently treated with ammonium nitrate in the presence or absence of …

The Effects Of A Resveratrol Derivative On Regulatory Behaviors And Reproductive Health In Male And Female Long-Evans Rats, Kimberly Michelle Fabick

Theses and Dissertations

Phytoestrogens are chemicals produced by plants that act like estrogens and have the ability to bind to the mammalian estrogen receptor system. The purpose of this study is to evaluate a new phytoestrogen analog called 4-acetoxy Resveratrol. Resveratrol is a phytoestrogen that has been found in the skin of grapes. Resveratrol has been shown to be able to bind to the estrogen receptors and has a similar molecular structure as estradiol. Resveratrol has been shown to have many positive health benefits such as improving cardiovascular health, serving as a neuroprotective agent, acting as an anti-inflammatory agent, working as an anti-cancer …

Mechanisms By Which Apoptotic Membranes Become Susceptible To Secretory Phospholipase A2, Rachel Williams Bailey

Theses and Dissertations

During apoptosis, changes occur in T-lymphocyte membranes that render them susceptible to hydrolysis by secretory phospholipase A2 (sPLA2). To study the relevant mechanisms, a simplified model of apoptosis using a calcium ionophore was first applied. Kinetic and flow cytometry experiments provided key observations regarding ionophore treatment: initial hydrolysis rate was elevated, total reaction product was increased four-fold, and adsorption of the enzyme to the membrane surface was unaltered. Analysis of these results suggested that susceptibility during calcium-induced apoptosis is limited by substrate availability rather than enzyme adsorption. Fluorescence experiments identified three membrane alterations that might affect substrate access to the …

The Effects Of Prenatally Administered Phytoestrogens On The Reproductive And Behavioral Development Of Long-Evans Rats, Crystal Blake

Theses and Dissertations

Equol is known to be a selective androgen modulator and has the ability to bind and inhibit 5-alpha dihydrotestosterone (5α-DHT). Equol is also a selective estrogen receptor modulator and is able to bind beta estrogen receptors with high affinity. As estrogen receptors are found in the hypothalamus, pituitary, and gonads, prenatally administered equol could affect the morphological and reproductive development of offspring. To test this hypothesis, during gestational days 14 to 20, forty-two pregnant Long-Evans rats were given one of six treatments: 1) no treatment, 2) injection with dimethyl sulfoxide (DMSO), 3) injection with 10 mg/kg equol, 4) injection with …

Body Mass Bias In A Competition Of Muscle Strength And Aerobic Power, Paul M. Vanderburgh, Lloyd L. Laubach

Health and Sport Science Faculty Publications

Recently, a fitness competition called the Pump and Run (PR) has been popularized. Composed of 2 events, a 5-km road race time (RT) in seconds and a maximal-repetition bench press (BPR) with resistance based on a percentage of body mass (M), the final score (RTadj) equals RT - 30(BPR). From published findings, the authors hypothesized that the PR would impose a bias against heavier competitors. Furthermore, the potential for age bias in this event has not been evaluated. Therefore, the purpose of this study was to investigate M and age bias in the PR for men and women. For 74 …

Radiation-Induced Glutamate Transport Alterations In Neuron-Astrocyte Coupling, Martha Celia Sanchez

Loma Linda University Electronic Theses, Dissertations & Projects

Exposure of the central nervous system (CNS) to ionizing radiation is known to result in behavioral, cognitive, and motor deficits - effects similar to those seen in many neurodegenerative disorders. Neurons and astrocytes, two principal cell types in the brain, coexist as an interdependent metabolic unit via the neurotransmitter glutamate. Disruption of this metabolic coupling would have widespread effects within the CNS, therefore it is hypothesized that ionizing radiation impairs glutamate transport and metabolism, and increases oxidative stress, ultimately impairing neuron-astrocyte coupling. We propose to investigate the mechanism and determine the impetus for radiation-induced neurotoxicity by measuring the temporal sequence …

Enkephalin-Encoding Herpes Simplex Virus-1 Decreases Inflammation And Hotplate Sensitivity In A Chronic Pancreatitis Model, Hong Yang, Terry A. Mcnearney, Rong Chu, Ying Lu, Yong Ren, David C. Yeomans, Steven P. Wilson, Karin N. Westlund

Physiology Faculty Publications

Background: A chronic pancreatitis model was developed in young male Lewis rats fed a high-fat and alcohol liquid diet beginning at three weeks. The model was used to assess time course and efficacy of a replication defective herpes simplex virus type 1 vector construct delivering human cDNA encoding preproenkephalin (HSV-ENK).

Results: Most surprising was the relative lack of inflammation and tissue disruption after HSV-ENK treatment compared to the histopathology consistent with pancreatitis (inflammatory cell infiltration, edema, acinar cell hypertrophy, fibrosis) present as a result of the high-fat and alcohol diet in controls. The HSV-ENK vector delivered to the pancreatic surface …

A Scale Invariant Measure Of Clutter, Mary J. Bravo, Hany Farid

Dartmouth Scholarship

We propose a measure of clutter for real images that can be used to predict search times. This measure uses an efficient segmentation algorithm (P. Felzenszwalb & D. Huttenlocher, 2004) to count the number of regions in an image. This number is not uniquely defined, however, because it varies with the scale of segmentation. The relationship between the number of regions and the scale of segmentation follows a power law, and the exponent of the power law is similar across images. We fit power law functions to the multiple scale segmentations of 160 images. The power law exponent was set …

Monitoring Lys-TrnaLys Phosphatidylglycerol Transferase Activity, Michael Ibba

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

In some bacteria Lys-tRNA^Lys is used both in translation and for the specific addition of Lys to phosphatidylglycerol in the cytoplasmic membrane. This reaction is catalyzed by the membrane protein MprF, and the lysyl-phosphatidylglycerol formed contributes to the resistance of these bacteria to various cationic antibacterial molecules. Obtaining proteins and reconstituting an in vitro system mimicking membrane conditions is a major challenge to studying the function of membrane proteins, especially when labile substrates such as Lys-tRNA^Lys are required. Here we report methods to obtain a stable enriched membrane fraction containing MprF, and the techniques necessary to quantitatively monitor …

Do The Principles Of Motor Program Editing Apply To Longer Sequences Of Rapid Aiming Movements? Part I, Eric J. Wilson, David E. Sherwood

International Journal of Exercise Science

Prior work had shown that performing a shorter distance aiming movement prior to a longer distance aiming movement resulted in overshooting of the short movement and undershooting of the longer movement compared to repetition of the same movement. The main question was whether the same interference effects would be found in a three-movement sequence. Right-handed (N = 24) participants (aged 18-22) produced a sequence of two or three bimanual rapid lever reversals combining short (20°) and long (60°) movements with an intermovement interval of 2.5 s beginning with either the dominant or nondominant hand. Participants overshot the short target and …

The Relationship Between Upper Arm Anthropometrical Measures And Vertical Jump Displacement, Richard A. Reeves, Ocie D. Hicks, James W. Navalta

International Journal of Exercise Science

The purpose of this study was to determine if upper body segment length or mass contributes to vertical jump (VJ) displacement. Seventeen men (n=9) and women (n=8) who were active recreationally participated in this investigation. Subjects performed VJ for maximal displacement, and skeletal length measurements of the humerus (acromion following the lateral lip to the greater tuberosity), ulna (olecranon to the ulnar styloid process), and hand (lunate to distal end of third phalanx) were obtained by palpation of boney landmarks and a standard tape measure. Pearson Product Moment Correlation Coefficients were used to compare the data with statistical significance accepted …