Physiology Commons^™

Functional Association Between Three Archaeal Aminoacyl-Trna Synthetases, Mette Praetorius-Ibba, Corinne D. Hausmann, Molly Paras, Theresa E. Rogers, Michael Ibba

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Aminoacyl-tRNA synthetases (aaRSs) are responsible for attaching amino acids to their cognate tRNAs during protein synthesis. In eukaryotes aaRSs are commonly found in multi-enzyme complexes, although the role of these complexes is still not completely clear. Associations between aaRSs have also been reported in archaea, including a complex between prolyl-(ProRS) and leucyl-tRNA synthetases (LeuRS) in Methanothermobacter thermautotrophicus that enhances tRNA^Pro aminoacylation. Yeast two-hybrid screens suggested that lysyl-tRNA synthetase (LysRS) also associates with LeuRS in M. thermautotrophicus. Co-purification experiments confirmed that LeuRS, LysRS, and ProRS associate in cell-free extracts. LeuRS bound LysRS and ProRS with a comparable K_{D …}

Wavelet-Based Functional Mixed Models To Characterize Population Heterogeneity In Accelerometer Profiles: A Case Study. , Jeffrey S. Morris, Cassandra Arroyo, Brent A. Coull, Louise M. Ryan, Steven L. Gortmaker

Jeffrey S. Morris

We present a case study illustrating the challenges of analyzing accelerometer data taken from a sample of children participating in an intervention study designed to increase physical activity. An accelerometer is a small device worn on the hip that records the minute-by-minute activity levels of the child throughout the day for each day it is worn. The resulting data are irregular functions characterized by many peaks representing short bursts of intense activity. We model these data using the wavelet-based functional mixed model. This approach incorporates multiple fixed effects and random effect functions of arbitrary form, the estimates of which are …

Validation Of A 5k Age And Weight Run Handicap Model, Paul M. Vanderburgh, Lloyd L. Laubach

Health and Sport Science Faculty Publications

Though increasing age and body weight (BW) have been widely known to be associated with slower distance run times, the common convention in 5K road races is to categorize competitors by age and, sometimes, BW. This has the disadvantage of assigning only small numbers of competitors to age categories and giving advantage to runners close to the minimum age or BW values allowable. Using recent advances in the modeling of distance run performance by BW combined with empirical evidence quantifying the independent effect of age on cardiovascular endurance, we previously published the derivation of the 5K Handicap (5KH), an age …

Age-Related Dystrophin–Glycoprotein Complex Structure And Function In The Rat Extensor Digitorum Longus And Soleus Muscle, Kevin M. Rice, Deborah L. Preston, David Neff, Michael L. Norton, Eric R. Blough

Eric Blough

Age-Related Dystrophin–Glycoprotein Complex Structure And Function In The Rat Extensor Digitorum Longus And Soleus Muscle, Kevin M. Rice, Deborah L. Preston, David Neff, Michael L. Norton, Eric R. Blough

Kevin M Rice

Age-Related Dystrophin–Glycoprotein Complex Structure And Function In The Rat Extensor Digitorum Longus And Soleus Muscle, Kevin M. Rice, Deborah L. Preston, David Neff, Michael L. Norton, Eric R. Blough

Deborah L Preston

Single Molecule Detection Systems And Methods, John G. K. Williams, Gregory R. Bashford

Biomedical Imaging and Biosignal Analysis Laboratory

A micofluidic system is provided that includes a substrate, a first microchannel disposed in the substrate for providing a reactant to a reaction zone, a second microchannel disposed in the substrate, the third microchannel providing fluid communication between the first and second microchannels. The system also typically includes first and second electrodes, positioned at opposite ends of the second microchannel, for providing an electric field within the second microchannel. In operation, when the reactant is in the reaction zone, a reaction product is produced having a net electric charge different from the electric of the reactant.

Gene Expression In The Mouse Placenta: Developmental And Stress Responses, Ciprian P. Gheorghe

Loma Linda University Electronic Theses, Dissertations & Projects

Successful placental development is crucial for optimal growth, maturation, and survival of the embryo/fetus. Placental failure and placental pathology contributes to both morbidity and mortality of the fetus. We sought to understand normal placental development and also placental responses to stress using oligonucleotide microarray technology. To examine genetic aspects of normal placental development, we investigated gene expression patterns in the murine placenta at embryonic day 10.5 (E10.5), E12.5, E15.5, and E17.5. Hypoxia has been identified as a major stressor in placental and fetal development. In order to comprehend more completely hypoxic stress responses we sought to measure gene expression changes …

The Effect Of Varying Cadence In Cycle Ergometry On Submaximal Predictions Of Peak Oxygen Uptake, Zachary Callahan

Masters Theses & Specialist Projects

The purpose of this study was to investigate the effect that varying cadence had on the ability of a submaximal cycle ergometry test to accurately predict peak oxygen uptake (VO2) using the standard YMCA protocol workloads. There has been limited scholarship investigating the effect that varying cadence has on trained cyclists and almost none on untrained participants. For this study twelve moderately healthy participants (age: 20.75 ± 1.87, body fat: 15.8 ± 4.91 %) who did not use cycling as part of their workout regime performed a peak VO2 cycle test and three randomized submaximal tests. The three submaximal tests …

The Relationship Between High Sensitivity C-Reactive Protein, Metabolic Syndrome And Exercise, Micheline A. Vargas

Loma Linda University Electronic Theses, Dissertations & Projects

Background: It is well known that regular physical activity is associated with lower risk of chronic diseases such as diabetes and cardiovascular disease. Physical activity is also considered an important determinant of metabolic syndrome. All levels of metabolic syndrome, diabetes, and cardiovascular disease are thought to involve inflammation. Physical activity may reduce risk, at least in part, by modifying the inflammatory process. Recent studies have demonstrated an inverse relationship between inflammatory markers, such as high sensitivity C-reactive protein (hs-CRP), and physical activity. Elevated hs-CRP appears to be an independent predictor of both CVD and diabetes. Recent evidence also suggests that …

Factors That Influence The Blood Flow Response Of Skin To Electrical Stimulation, Abdul-Majeed Raja Al-Malty

Loma Linda University Electronic Theses, Dissertations & Projects

Female reproductive hormones, aging, global heating and local heating are factors affecting skin blood flow (SBF), but their effect on electrical stimulation (ES) has never been examined until the present investigation. To investigate female reproductive hormones, nine women (age= 25.6±3.5 years) with a normal menstrual cycle (MC) underwent ES in thermoneutral (25°±0.5°C) and warm environments (35°±0.5°C). To investigate aging, ES was applied on active young (n=15, age=32.1±8.3 years) and old (n=8, 64.5±6.2 years) groups in thermoneutral and warm environments. To investigate the effect of global and local heating, groups of 15 and 18 subjects (age= 18-40 years) experienced ES under …

Effects Of Advancing Age On Er Calcium Regulation In Rat Superior Cervical Ganglia, Conwin Kodel Vanterpool

Loma Linda University Electronic Theses, Dissertations & Projects

Intracellular calcium ([Ca²⁺]i) release from endoplasmic reticulum (ER) stores plays an important role in cell signaling. These stores are rapidly refilled via voltage-gated calcium channels or spontaneously via store-operated calcium channels and subsequent pumping by ER Ca²⁺-ATPases. Calcium release is triggered by the activation of the ryanodine receptor (RyR) channels and their function is in part dependent on their expression. We analyzed the [Ca²⁺]i transients in fura 2-loaded superior cervical ganglion (SCG) cells from 6, 12, 20, and 24-month-old Fischer 344 rats for their ability to rapidly and spontaneously refill. For rapid refilling, the …

Activation In Neural Networks Controlling Ingestive Behaviors: What Does It Mean, And How Do We Map And Measure It?, Alan G. Watts, Arshad M. Khan, Graciela Sanchez-Watts, Dawna Salter, Christina M. Neuner

Arshad M. Khan, Ph.D.

No abstract provided.

Biochemical Characterization Of The Major Sorghum Grain Peroxidase, Mamoudou H. Dicko, Harry Gruppen, Riet Hilhorst, Alphons G. J. Voragen, Willen W. H. Van Berkel

Pr. Mamoudou H. DICKO, PhD

The Study Of Nitric Oxide Synthase Expression, Function, And Regulation In The Renal Vasculature During Postnatal Renal Development, Brian Blake Ratliff

Theses and Dissertations in Biomedical Sciences

The newborn kidney is vulnerable to vasomotor acute renal failure (ARF) from adverse perinatal events or complications of prematurity. Nitric oxide (NO) vasodilation is vitally protective in this type of ARF, but its relationship with other vasoactive factors, such as angiotensin II (AII) has not been examined. In the immature kidney, nitric oxide synthase (NOS) isoforms, specifically eNOS and nNOS, are developmentally regulated, but their specific role and regulation are unknown.

The enhanced vasodilatory role of NO in the immature kidney was hypothesized to be attributed to regulatory, expressional, and functional differences in eNOS and nNOS isoforms from the adult. …

Aspartyl-Trna Synthetase Is The Target Of Peptidenucleotide Antibiotic Microcin C, Anastasia Metlitskaya, Teymur Kazakov, Aigar Kommer, Olga Pavlova, Mette Praetorius-Ibba, Michael Ibba, Igor Krasheninnkov, Vyacheslav Kolb, Inessa Khmel, Konstantin Severinov

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Microcin C is a ribosome-synthesized heptapeptide that contains a modified adenosine monophosphate covalently attached to the C-terminal aspartate. Microcin C is a potent inhibitor of bacterial cell growth. Based on the in vivo kinetics of inhibition of macromolecular synthesis, Microcin C targets translation, through a mechanism that remained undefined. Here, we show that Microcin C is a subject of specific degradation inside the sensitive cell. The product of degradation, a modified aspartyl-adenylate containing an N-acylphosphoramidate linkage, strongly inhibits translation by blocking the function of aspartyl-tRNA synthetase.

Mineralized Bone Allograft In Maxillary Sinuses Histology And Histomorphometry, Sammy Stefan Noumbissi

Loma Linda University Electronic Theses, Dissertations & Projects

Background: Demineralized freeze-dried bone allografts (DFDBA) and deproteinized bovine bone xenografts (DMBBX) have been used for sinus augmentation for many years with varying results, but very little has been reported on the clinical efficacy or the histological analysis of mineralized solvent dehydrated bone allografts (MSDBA) as sinus graft materials. This study histologically and histomorphometrically evaluated an MSDBA material called PUROS to augment atrophic human maxillary sinuses.

Materials & Methods: Seven partially and completely edentulous patients requiring unilateral (n=4) or bilateral (n=3) sinus grafts prior to implant placement were selected for this study. Test grafts consisted of MSDBA, and control …

Disaggregating The Relative Influence Of Genetic, Environmental And Individual Factors On Ldl And Hdl Cholesterols And Bmi For A Sample Of African American (Aa) Mothers And Daughters, C. Jayne Brahler, Jewel Harden, Michelle Mchone, Matthew Soules, Eric Evans, Ann Alyanak, Fred Diakpieng, Paul M. Vanderburgh

Health and Sport Science Faculty Publications

There are many reports about the associations between blood lipids, body mass index (BMI) and dietary cholesterol intakes both within the individual and between related individuals. The purpose of this descriptive research project was to investigate the relationships between LDL and HDL cholesterols, body mass index and dietary cholesterol intakes for a sample of African American (AA) mothers and their daughters and to attempt to separate the contribution of genetic versus environmental factors. Mother and daughter participants (n =42 and 66, respectively) were 12-14-hours fasted when blood samples were drawn, heights and weights measured, and 24 hour food recalls completed.

C To U Editing Stimulates A To I Editing In The Anticodon Loop Of A Cytoplasmic Threonyl Trna In Trypanosoma Brucei, Mary Anne T. Rubio, Frank L. Ragone, Kirk W. Gaston, Michael Ibba, Juan D. Alfonzo

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Editing of tRNAs is widespread in nature and either changes the decoding properties or restores the folding of a tRNA. Unlike the phylogenetically disperse adenosine (A) to inosine (I) editing, cytosine (C) to uridine (U) editing has only been previously described in organellar tRNAs. We have shown that cytoplasmic tRNA^Thr(AGU) undergoes two distinct editing events in the anticodon loop: C to U and A to I. In vivo, every inosine-containing tRNA^Thr is also C to U edited at position 32. In vitro, C to U editing stimulates conversion of A to I at the wobble base. Although …

Physiological Effects On Demography: A Long‐Term Experimental Study Of Testosterone’S Effects On Fitness, W. Reed, M. Clark, P. Parker, S. Raouf, N. Arguedas, D. Monk, E. Snajdr, V. Nolan, E. Ketterson

Biology Department Faculty Works

Understanding physiological and behavioral mechanisms underlying the diversity of observed life‐history strategies is challenging because of difficulties in obtaining long‐term measures of fitness and in relating fitness to these mechanisms. We evaluated effects of experimentally elevated testosterone on male fitness in a population of dark‐eyed juncos studied over nine breeding seasons using a demographic modeling approach. Elevated levels of testosterone decreased survival rates but increased success of producing extra‐pair offspring. Higher overall fitness for testosterone‐treated males was unexpected and led us to consider indirect effects of testosterone on offspring and females. Nest success was similar for testosterone‐treated and control males, …

Body Weight Penalties In The Physical Fitness Tests Of The Army, Air Force, And Navy, Paul M. Vanderburgh, Todd A. Crowder

Health and Sport Science Faculty Publications

Recent research has empirically documented a consistent penalty against heavier service members for events identical or similar to those in the physical fitness tests of the Army, Air Force, and Navy. These penalties, not related to body fatness, are based on biological scaling models and have a physiologic basis. Using hypothetical cases, we quantified the penalties for males, 60 vs. 90 kg body weight, and females, 45 vs. 75 kg, to be 15-20% for the fitness tests of these three services. Such penalties alone can adversely impact awards and promotions for heavier service members. To deal equitably with these penalties …