Physiology Commons^™

Y27632, A Rho-Activated Kinase Inhibitor, Normalizes Dysregulation In Alpha1-Adrenergic Receptor-Induced Contraction Of Lyon Hypertensive Rat Artery Smooth Muscle., Maria Regina Freitas, Masumi Eto, Jason A Kirkbride, Christa Schott, Jean Sassard, Jean-Claude Stoclet

Department of Molecular Physiology and Biophysics Faculty Papers

RhoA-activated kinase (ROK) is involved in the disorders of smooth muscle contraction found in hypertension model animals and patients. We examined whether the alpha1-adrenergic receptor agonist-induced ROK signal is perturbed in resistance small mesentery artery (SMA) of Lyon genetically hypertensive (LH) rats, using a ROK antagonist, Y27632. Smooth muscle strips of SMA and aorta were isolated from LH and Lyon normotensive (LN) rats. After Ca(2+)-depletion and pre-treatment with phenylephrine (PE), smooth muscle contraction was induced by serial additions of CaCl(2). In LH SMA Ca(2+) permeated cells to a lesser extent as compared with LN SMA, while CaCl(2)-induced contraction of LH …

Adaptation Of The Bacterial Membrane To Changing Environments Using Aminoacylated Phospholipids, Hervé Roy, Kiley Dare, Michael Ibba

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Fine‐tuning of the biophysical properties of biological membranes is essential for adaptation of cells to changing environments. For instance, to lower the negative charge of the lipid bilayer, certain bacteria add lysine to phosphatidylglycerol (PG) converting the net negative charge of PG (−1) to a net positive charge in Lys‐PG (+1). Reducing the net negative charge of the bacterial cell wall is a common strategy used by bacteria to resist cationic antimicrobial peptides (CAMPs) secreted by other microbes or produced by the innate immune system of a host organism. The article by Klein et al. in the current issue of …

Resolving The Lateral Component Of Blood Flow Velocity Based On Ultrasound Speckle Size Change With Scan Direction And Speed, Tiantian Xu, Greg R. Bashford

Biomedical Imaging and Biosignal Analysis Laboratory

Conventional blood flow velocity measurement using ultrasound is capable of resolving the axial component (i.e., that aligned with the ultrasound propagation direction) of the blood flow velocity vector. However, these Doppler-based methods are incapable of detecting blood flow in the direction normal to the ultrasound beam. In addition, these methods require repeated pulse-echo interrogation at the same spatial location. In this paper, we introduce a method which estimates the lateral component of blood flow within a single image frame using the observation that the speckle pattern corresponding to the blood reflectors (typically red blood cells) stretches (i.e., is “smeared”) if …

Further Progress On Lateral Flow Estimation Using Speckle Size Variation With Scan Direction, Tiantian Xu, Gregory R. Bashford

Biomedical Imaging and Biosignal Analysis Laboratory

Conventional blood flow velocity measurement using ultrasound is capable of resolving the axial component (i.e., that aligned with the ultrasound propagation direction) of the blood flow velocity vector. However, these Doppler-based methods are incapable of detecting blood flow in the direction normal to the ultrasound beam. In addition, these methods require repeated pulse-echo interrogation at the same spatial location. In this paper, we report additional data on a new method recently introduced. This method estimates the lateral component of blood flow within a single image frame using the observation that the speckle pattern corresponding to the blood reflectors (typically red …

Single Molecule Diffusion Coefficient Estimation By Image Analysis Of Simulated Ccd Images To Aid High-Throughput Screening, Pengfei Song, Lloyd M. Davis, Greg Bashford

Biomedical Imaging and Biosignal Analysis Laboratory

Extension of one-dimensional signal analysis to two-dimensional image analysis could accelerate conventional methods of high-throughput screening in the discovery of new pharmaceutical agents. This work describes a first step taken towards this goal – the evaluation of image-analysis based estimation strategies of the diffusion coefficient of a single molecule transported within a microfabricated flowcell. A computer simulation of single-molecule imaging by a charge-coupled device (CCD) camera is used to determine if it is possible to distinguish three different types of molecules with different diffusion coefficients. The Gaussian fitting algorithm finds the variance of the transverse trajectory, which increases linearly with …

Optimal Thresholds Of Feature Tracking For Blood Velocity And Tissue Motion Estimation, Tiantian Xu, Gregory R. Bashford

Biomedical Imaging and Biosignal Analysis Laboratory

Feature tracking is an algorithm for estimating blood flow velocity and tissue motion using pulse-echo ultrasound. In contrast to cross-correlation speckle-tracking techniques, feature tracking identifies features at discrete locations and corresponds them from frame to frame. Prior studies have demonstrated that feature-tracking estimates exhibit lower variance than those obtained by the conventional autocorrelation method and require less computational complexity than either speckle tracking or autocorrelation. To date, not much attention has been paid to the process by which trackable features (normally local maxima) are selected from the set of all available features. In the selection process, it is desired to …

The Effect Of A Commercially Available Caffeine Based Dietary Supplement On 40-Kilometer Time Trial Performance, Lee A. Weidauer

Electronic Theses and Dissertations

Purpose: To determine wheather ot not the nutritional supplement PreRace containing L-Taurine, Citrulline Malate, Quercetin, DiMethyl Amino Ethanol, Caffeine, Metabromine, Catechin, and Malic acid will improve performance in an indoor 40 Kilometer cycling time trial.
Methods: Seven male cyclists ages 21-58 participated in a placebo-controlled investigation which consisted of two trials in which they consumed either the supplement PreRace or aloe vera juice. In each of the trials the placebo or supplement was mixed with a sports beverage. Subjects performed a 40 kilometer time trial and measurements of oxygen consumption and lactate were taken every 15 minutes as well as …

Numerical Modeling Of Hemodynamics In The Thoracic Aorta And Alterations By Dacron Patch Treatment Of Aortic Coarctation, Ronak Jashwant Dholakia

Master's Theses (2009 -)

Coarctation of the aorta (CoA) is a major congenital heart disease, characterized by a severe stenosis of the proximal descending thoracic aorta. Traditionally, surgery has been the treatment of choice for CoA. Dacron patch aortoplasty gained increased popularity after its introduction in the mid-twentieth century due to its advantages over other surgical treatment methods available at the time. A major complication with Dacron patch aortoplasty has been the formation of late aneurysm with as much as 51% incidence reported in follow up studies. The change in aortic morphology and formation of aneurysms after Dacron patch surgery could lead to local …

Acute Effects Of Whole-Body Vibration On Lower Extremity Muscle Performance In Persons With Multiple Sclerosis, Kurt Jackson, Harold L. Merriman, Paul M. Vanderburgh, C. Jayne Brahler

Health and Sport Science Faculty Publications

Background and Purpose: Whole-body vibration (WBV) is a relatively new form of exercise training that may influence muscle performance. This study investigated the acute effects of high (26 Hz) and low (2 Hz) frequency WBV on isometric muscle torque of the quadriceps and hamstrings in persons with multiple sclerosis (MS).

Participants and Method: Fifteen individuals (mean age = 54.6 years, SD = 9.6) with MS and Expanded Disability Status Scale (EDSS) scores ranging from 0-6.5 (mean = 4.2, SD = 2.3) participated in this randomized cross-over study. Following baseline measures of isometric quadricep and hamstring torque, subjects were exposed to …

The Effects Of A 40mg Lasik Treatment On The Threshold Frequency Of Electrically Induced Muscle Cramps, Sara F. Bergeron

All-Inclusive List of Electronic Theses and Dissertations

Context: Muscle cramps that are caused by exercise can be painful and debilitating to an active individual. One theory to explain the cause of exerciseassociated muscle cramps is dehydration. While dehydration is a popular theory it has 111 yet to be studied as a sole factor to the incidence of muscle cramps. Objective: To examine the effect of mild dehydration on the threshold frequency (TF) of electrically induced muscle cramps (EIMC) in the flexor hallucis brevis.

Buccal Bone Changes Following Rapid Maxillary Expansion (Rmf), Long-Term Results, Elena S. Iacob

Loma Linda University Electronic Theses, Dissertations & Projects

The purpose of this study was to use Cone Beam Computed Tomography (CBCT) images to quantitatively evaluate buccal bone changes of maxillary first premolar (P1), second premolar (P2) and first molar (M1) shortly after Rapid Maxillary Expansion (RME) and at the end of orthodontic treatment, as well as to evaluate the variables that may be associated with the short-term and long-term changes. Forty-seven consecutive patients (25 males and 22 females) with a mean age of 14.5years and who required RME as part of their orthodontic treatment and had pre-RME (T1) and post-RME (T2) CBCT images available were used for the …

Female Collegiate Gymnasts And Experiences In Sport Retirement Due To Injury, Coleen Harrington Barry

Dissertations

There has been very limited research on sport retirement concerning the experiences that female collegiate athletes face when retiring from a sport due to injury. The purpose of this qualitative study was to explore, understand, and describe experiences that former NCAA Division I female gymnasts had when they retired from gymnastics, part-way through college, due to injury. The main objective of the study was to attempt to understand female collegiate gymnasts' sport retirement experiences and the impact these experiences may have had on their identity development and college experience. The study also considered female collegiate gymnasts' perceived needs and coping …

Contributions Of Body Fat And Effort In The 5k Run: Age And Body Weight Handicap, Anne R. Crecelius, Paul M. Vanderburgh, Lloyd L. Laubach

Health and Sport Science Faculty Publications

The 5K handicap (5KH), designed to eliminate the body weight (BW) and age biases inherent in the 5K run time (RT), yields an adjusted RT (RTadj) that can be compared between runners of different BW and age. As hypothesized in a validation study, however, not all BW bias may be removed, because of the influences of body fatness (BF) and effort (run speed; essentially the inverse as measured by rating of perceived exertion (RPE)). This study's purpose was to determine the effects of BF and RPE on BW bias in the 5KH. For 99 male runners in a regional 5K …

Anti-Inflammatory Effects Of Ppar-Gamma In Surgical Brain Injury (Sbi), Amy Hyong

Loma Linda University Electronic Theses, Dissertations & Projects

Introduction: Brain injury can be caused by neurosurgical procedures themselves, due to direct trauma, retractor stretch, intraoperative hemorrhage and electrocautery damage. As a result of this surgical brain injury (SBI) postoperative complications such as inflammation, brain edema, and cell death can occur in the susceptible brain areas. Cerebral inflammation is a known contributor to the pathophysiology of brain injury. Following brain injury, the release of inflammatory mediators facilitates the development of BBB breakdown, cerebral edema, oxidative stress and neuronal death, resulting in further tissue damage in the brain and poor neurological outcomes. This study evaluates whether the use of a …

Occupational Relevance And Body Mass Bias In Military Physical Fitness Tests, Paul M. Vanderburgh

Health and Sport Science Faculty Publications

Recent evidence makes a compelling case that U.S. Army, Navy, and Air Force health-related physical fitness tests penalize larger, not just fatter, service members. As a result, they tend to receive lower scores than their lighter counterparts, the magnitude of which can be explained by biological scaling laws. Larger personnel, on the other hand, tend to be better performers of work-related fitness tasks such as load carriage, heavy lifting and materiel handling. This has been explained by empirical evidence that lean body mass and lean body mass to dead mass ratio (dead mass = fat mass and external load to …

Bilateral Claudication Results In Alterations In The Gait Biomechanics At The Hip And Ankle Joints, Shing-Jye Chen, Iraklis Pipinos, Jason Johanning, Matija Radovic, Jessie M. Huisinga, Sara A. Myers, Nikolaos Stergiou

Health and Kinesiology Faculty Publications

Claudication is the most common symptomatic manifestation of peripheral arterial disease (PAD), producing significant ambulatory compromise. The purpose of this study was to use advanced biomechanical gait analysis to determine the gait alterations occurring in claudicating patients both before and after onset of claudication pain in their legs. Hip, knee, and ankle joint moments were measured in claudicating patients (age: 64.46±8.47 years; body mass: 80.70±12.64 kg; body height: 1.72±0.08 m) and were compared to gender–age–body mass–height-matched healthy controls (age 66.27±9.22 years; body mass: 77.89±10.65 kg; body height: 1.74±0.08 m). The claudicating patients were evaluated both before (pain-free (PF) condition) and …

Aminoacyl-Trna Synthetase Complexes: Molecular Multitasking Revealed, Corinne D. Hausmann, Michael Ibba

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

The accurate synthesis of proteins, dictated by the corresponding nucleotide sequence encoded in mRNA, is essential for cell growth and survival. Central to this process are the aminoacyl-tRNA synthetases (aaRSs), which provide amino acid substrates for the growing polypeptide chain in the form of aminoacyl-tRNAs. The aaRSs are essential for coupling the correct amino acid and tRNA molecules, but are also known to associate in higher order complexes with proteins involved in processes beyond translation. Multiprotein complexes containing aaRSs are found in all three domains of life playing roles in splicing, apoptosis, viral assembly, and regulation of transcription and translation. …

The Effect Of Intensity Of Aerobic Training On Insulin Sensitivity, Carmine Richard Grieco Iii

Human Movement Studies & Special Education Theses & Dissertations

Epidemiological studies have demonstrated that the prevalence of type 2 diabetes is increasing. It is estimated that I 0. 7% of adults over the age of 20 years and 23.1 % of adults over the age of 60 years have diabetes (NIH, 2007). Individuals with type 2 diabetes are 2-4 times more likely to die from heart disease than those without diabetes and twice as likely to die of all-cause mortality (CDC, 2005). Additionally Mokdad et al. (2000) report that the prevalence of diabetes increased 33% between 1990 and 1998. Furthermore it has been estimated that nearly 26% of the …

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 …

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 …

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, …

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 …

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 …

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 …

The Instructor’S Role In Aquatic Education: Some Personal Observations, Leland Yarger, Steven P. Dalcher

International Journal of Aquatic Research and Education

No abstract provided.

International Perspective Of Aquatic Instructors’ Attitudes Toward Teaching Swimming To Children With Disabilities, Phillip Conatser

International Journal of Aquatic Research and Education

The purpose of this study was to examine attitudes of aquatic instructors (N = 23) toward teaching swimming to children with mild and severe disabilities in an inclusive setting. Aquatic instructors from 23 cities in 7 countries participated in the study. Data were collected by mail survey using the Aquatic Instructors Attitudes Toward Teaching Swimming to Individuals With Disabilities questionnaire (Conatser, Block, & Lapore, 2000). A correlated t test showed that aquatic instructors were significantly more favorable toward teaching aquatics to children with mild disabilities than children with severe disabilities. Instructors agreed they should include children with mild disabilities and …

Motivations And Reasons For Exercising In Water: Gender And Age Differences In A Sample Of Spanish Exercisers, Juan Antonio Moreno Murcia, Celestina Martínez Galindo, Pablo Marcos Pardo

International Journal of Aquatic Research and Education

The purposes of this study were, on the one hand, to relate the reasons for exercising with self-determination and, on the other, to check gender and age differences with a sample of 311 exercisers in water. The data were collected using the Behavioral Regulation in Exercise Questionnaire–2 and Motives for Physical Activities Measure–Revised. A positive and significant correlation was seen between self-determination and the reasons for exercise, with self-determination predicting 22% by enjoyment and 8% by fitness/health reasons. Similarly, the multivariate analysis showed that the women had more self-determination than the men and that they also rated fitness/health, social, enjoyment, …

The Need For Advanced Cardiac Life Support Certification For Open-Water Lifeguards At Huntington Beach, Ca, Daniel Jerome, Peter R. Chambers, Steve Reuter, John Porcari

International Journal of Aquatic Research and Education

The number of people visiting U.S. beaches increased in 2007 to more than 240 million people. This increase in activities does not come without danger. Lifeguards maintain beach safety, but little research is available to assist us in determining appropriate certification levels for lifeguards. The authors analyzed various injuries that occurred in the open-water environment of Huntington Beach, CA. Based on the nature of the injuries, they attempted to determine the level of training lifeguards needed. The vast majority of injuries (99%) were soft-tissue injuries, musculoskeletal injuries, or environmental injuries. It was felt that lifeguards with first-aid and basic-life-support (BLS) …