Life Sciences Commons^™

The Relationship Between Frq-Protein Stability And Temperature Compensation In The Neurospora Circadian Clock, Peter Ruoff, Jennifer J. Loros, Jay C. Dunlap

Dartmouth Scholarship

Temperature compensation is an important property of all biological clocks. In Neurospora crassa, negative-feedback regulation on the frequency (frq) gene's transcription by the FRQ protein plays a central role in the organism's circadian pacemaker. Earlier model calculations predicted that the stability of FRQ should determine the period length of Neurospora's circadian rhythm as well as the rhythm's temperature compensation. Here, we report experimental FRQ protein stabilities in frq mutants at 20 degrees C and 25 degrees C, and estimates of overall activation energies for mutant FRQ protein degradation. The results are consistent with earlier model predictions, i.e., temperature compensation of …

Mechanisms Of Hbo-Induced Neuroprotection In A Neonatal Hypoxia-Ischemia Model, John Winter Calvert

Loma Linda University Electronic Theses, Dissertations & Projects

With an incidence approaching 1/4000 live births and as high as 60% in low birth weight infants, cerebral hypoxia-ischemia during the perinatal period is the single most important cause of acute mortality and chronic disability in newborns. Herein, we tested the hypothesis that following a hypoxic-ischemic insult hyperbaric oxygen (HBO) treatment can restore high energy metabolite levels in the affected regions of the brain and through this increase in energy levels ameliorate the spread of cell death following the insult. We also investigated if an additional mechanism by which HBO affords its neuroprotection is by altering the expression of the …

Loss Of Editing Activity During The Evolution Of Mitochondrial Phenylalanyl-Trna Synthetase, Hervé Roy, Jiqiang Ling, Juan D. Alfonzo, Michael Ibba

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Accurate selection of amino acids is essential for faithful translation of the genetic code. Errors during amino acid selection are usually corrected by the editing activity of aminoacyl-tRNA synthetases such as phenylalanyl-tRNA synthetases (PheRS), which edit misactivated tyrosine. Comparison of cytosolic and mitochondrial PheRS from the yeast Saccharomyces cerevisiae suggested that the organellar protein might lack the editing activity. Yeast cytosolic PheRS was found to contain an editing site, which upon disruption abolished both cis and trans editing of Tyr-tRNA^Phe. Wild-type mitochondrial PheRS lacked cis and trans editing and could synthesize Tyr-tRNA^Phe, an activity enhanced in …

Influences Of Dietary Soy Isoflavones On Metabolism But Not Nociception And Stress Hormone Responses In Ovariectomized Female Rats, Edwin D. Lephart, Lihong H. Bu, Kenneth Setchell

Faculty Publications

Isoflavones, the most abundant phytoestrogens in soy foods, are structurally similar to 17beta-estradiol. Few studies have examined the nociception and stress hormone responses after consumption of soy isoflavones. Methods: In this study, ovariectomized (OVX) female Long-Evans rats were fed either an isoflavone-rich diet (Phyto-600) or an isoflavone-free diet (Phyto-free). We examined the effects of soy isoflavones on metabolism by measuring body weights, food/water intake, adipose tissue weights as well as serum leptin levels. Also, circulating isoflavone levels were quantified. During chemically induced estrous, nociceptive thresholds were recorded. Then, the animals were subjected to a stressor and stress hormone levels were …

Effect Of Almond-Raisin Versus Commercial Sports Beverage On Antioxidant Status Of Runners, Anh Thu V. Tran

Loma Linda University Electronic Theses, Dissertations & Projects

Background: Whole foods are readily available antioxidant source and provide beneficial macromolecules and phytochemicals, which may contribute to optimal health. However, the approach to examining whole foods rich in antioxidants to play either an equivalent or better role in defending exercise-induced oxidant stress have not yet been taken. Objective: The objective of this study was to compare the effects of 2 isocaloric preexercise beverages: an almond-raisin beverage and a commercial sports beverage in male endurance runners on selected antioxidant status markers.

Design: In a randomized crossover study, 10 male runners (ages 28+1.2 years) ran to exhaustion on a treadmill at …

Isokinetic Knee Strength In Females With Fibromyalgia, Flora F. Shafiee

Loma Linda University Electronic Theses, Dissertations & Projects

Objectives: To compare knee flexors and extensors muscle strength, total work, and power between females with fibromyalgia (FM) and matched healthy controls.

Methods: This is the first study to measure knee muscle power and total work in females with FM. Thirty-one females with FM and thirty-one healthy females completed isokinetic testing of knee flexors and extensors of their dominant leg using a Cybex Norm Isokinetic Dynamometer. Two knee muscle groups (flexors and extensors) at two angular velocities (607sec and 1807sec) were tested for both groups. Both muscle groups were assessed continuously using five reciprocal concentric-concentric cycles, followed by five eccentric-eccentric …

Functional Electric Stimulation Cycle Ergometry Training Effect On Lower Limb Muscles In Acute Sci Individuals, Timothy J. Demchak, Jon K. Linderman, W. Jerry Mysiw, Rebecca Jackson, Jihong Sunn, Steven T. Devor

Health and Sport Science Faculty Publications

The purpose of this study was to compare three different intervals for a between sets rest period during a common isokinetic knee extension strength-testing protocol of twenty older Brazilian men (66.30 ± 3.92 yrs). The volunteers underwent unilateral knee extension (Biodex System 3) testing to determine their individual isokinetic peak torque at 60, 90, and 120° ·s-1. The contraction speeds and the rest periods between sets (30, 60 and 90 s) were randomly performed in three different days with a minimum rest period of 48 hours. Significant differences between and within sets were analyzed using a One Way Analysis of …

Charge-Switch Nucleotides, John G. K. Williams, Gregory R. Bashford, Jiyan Chen, Dan Draney, Nara Narayanan, Bambi L. Reynolds, Pamela Sheaff

Biomedical Imaging and Biosignal Analysis Laboratory

The present invention provides compounds, methods and systems for sequencing nucleic acid using single molecule detection. Using labeled NPs that exhibit charge-switching behavior, single-molecule DNA sequencing in a microchannel sorting system is realized. In operation, sequencing products are detected enabling real-time sequencing as successive detectable moieties flow through a detection channel. By electrically sorting charged molecules, the cleaved product molecules are detected in isolation Without interference from unincorporated NPs and Without illuminating the polymerase-DNA complex.

Effects Of Dietary Curcumin Or N-Acetylcysteine On Nf-Kappab Activity And Contractile Performance In Ambulatory And Unloaded Murine Soleus, Mehran Farid, Michael B. Reid, Yi-Ping Li, Eric Gerken, William J. Durham

Physiology Faculty Publications

BACKGROUND: Unloading of skeletal muscle causes atrophy and loss of contractile function. In part, this response is believed to be mediated by the transcription factor nuclear factor-kappa B (NF-kappaB). Both curcumin, a component of the spice turmeric, and N-acetylcysteine (NAC), an antioxidant, inhibit activation of NF-kappaB by inflammatory stimuli, albeit by different mechanisms. In the present study, we tested the hypothesis that dietary curcumin or NAC supplementation would inhibit unloading-induced NF-kappaB activity in skeletal muscle and thereby protect muscles against loss of mass and function caused by prolonged unloading.

METHODS: We used hindlimb suspension to unload the hindlimb muscles of …

Fatigue Resistance Of Rat Extraocular Muscles Does Not Depend On Creatine Kinase Activity, Colleen A. Mcmullen, Katrin Hayeß, Francisco H. Andrade

Physiology Faculty Publications

BACKGROUND: Creatine kinase (CK) links phosphocreatine, an energy storage system, to cellular ATPases. CK activity serves as a temporal and spatial buffer for ATP content, particularly in fast-twitch skeletal muscles. The extraocular muscles are notoriously fast and active, suggesting the need for efficient ATP buffering. This study tested the hypotheses that (1) CK isoform expression and activity in rat extraocular muscles would be higher, and (2) the resistance of these muscles to fatigue would depend on CK activity.

RESULTS: We found that mRNA and protein levels for cytosolic and mitochondrial CK isoforms were lower in the extraocular muscles than in …

Runx-Dependent Expression Of Pkc Is Critical For Cell Survival In The Sea Urchin Embryo, Carrie Dickey-Sims, Anthony J. Robertson, Dawn E. Rupp, John J. Mccarthy, James A. Coffman

Physiology Faculty Publications

BACKGROUND: Runx transcription factors play critical roles in the developmental control of cell fate and contribute variously as oncoproteins and tumor suppressors to leukemia and other cancers. To discover fundamental Runx functions in the cell biology of animal development, we have employed morpholino antisense-mediated knockdown of the sea urchin Runx protein SpRunt-1. Previously we showed that embryos depleted of SpRunt-1 arrest development at early gastrula stage and underexpress the conventional protein kinase C SpPKC1.

RESULTS: We report here that SpRunt-1 deficiency leads to ectopic cell proliferation and extensive apoptosis. Suppression of the apoptosis by pharmacological inhibition of caspase-3 prevents the …

The Influence Of Landing Technique Versus Technique And Strength Training On Valgus Knee Deformity In Females, Kirsten R. Holmes

Masters Theses

The purpose of this study was to evaluate the effectiveness of landing technique training versus landing technique and plyometric/strength training program on knee valgus during landing in females. Subjects participated in a 6-week training program. A 2 X 3 repeated measures ANOVA with two within subjects’ factors Test and Group was used to test for differences in the knee valgus angle in the landing condition and the five jump condition. A 2 x 2 repeated measures ANOVA with two within subjects’ factors, was used to test for difference in knee extension strength and knee flexion strength. Pre-test knee-valgus 4.76 ± …

Specific Functions Of Synaptically Localized Potassium Channels In Synaptic Transmission At The Neocortical Gabaergic Fast-Spiking Cell Synapse, Ethan Goldberg, Shigeo Watanabe, Su Ying Chang, Rolf Joho, Z Josh Huang, Christopher S. Leonard, Bernardo Rudy

NYMC Faculty Publications

Potassium (K+) channel subunits of the Kv3 subfamily (Kv3.1-Kv3.4) display a positively shifted voltage dependence of activation and fast activation/deactivation kinetics when compared with other voltage-gated K+ channels, features that confer on Kv3 channels the ability to accelerate the repolarization of the action potential (AP) efficiently and specifically. In the cortex, the Kv3.1 and Kv3.2 proteins are expressed prominently in a subset of GABAergic interneurons known as fast-spiking (FS) cells and in fact are a significant determinant of the fast-spiking discharge pattern. However, in addition to expression at FS cell somata, Kv3.1 and Kv3.2 proteins also are expressed prominently at …

Association Between Archaeal Prolyl- And Leucyl-Trna Synthetases Enhances TrnaPro Aminoacylation, Mette Praetorius-Ibba, Theresa E. Rogers, Rachel Samson, Zvi Kelman, Michael Ibba

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Aminoacyl-tRNA synthetase-containing complexes have been identified in different eukaryotes, and their existence has also been suggested in some Archaea. To investigate interactions involving aminoacyl-tRNA synthetases in Archaea, we undertook a yeast two-hybrid screen for interactions between Methanothermobacter thermautotrophicus proteins using prolyl-tRNA synthetase (ProRS) as the bait. Interacting proteins identified included components of methanogenesis, protein-modifying factors, and leucyl-tRNA synthetase (LeuRS). The association of ProRS with LeuRS was confirmed in vitro by native gel electrophoresis and size exclusion chromatography. Determination of the steady-state kinetics of tRNA^Pro charging showed that the catalytic efficiency (k_cat/K_m) of ProRS increased 5-fold …

The Science Of Addiction, Karl Bailey

Lake Union Herald

No abstract provided.

Nucleic Acid Sequencing Using Charge-Switch Nucleotides, John G. K. Williams, Gregory R. Bashford

Biomedical Imaging and Biosignal Analysis Laboratory

The present invention provides compounds, methods and systems for sequencing nucleic acid using single molecule detection. Using labeled NPs that exhibit charge-switching behavior, single-molecule DNA sequencing in a microchannel sorting system is realized. In operation, sequencing products are detected enabling real-time sequencing as successive detectable moieties flow through a detection channel. By electrically sorting charged molecules, the cleaved product molecules are detected in isolation without interference from unincorporated NPs and without illuminating the polymerase-DNA complex.

Using Media Messaging To Promote Healthful Eating And Physical Activity Among Urban Youth, B.J Carter, Amanda Birnbaum, Lisa Hark, Brian Vickery, Charles Potter, Michael P. Osborne

Department of Public Health Scholarship and Creative Works

National trends show consistent increases, as well as racial and ethnic dis- parities, in the prevalence of overweight children and adolescents. Such disparity is evident regarding behaviors such as a poor diet and a lack of physical activity and in the prevalence and outcomes of associated health problems. It has been suggested that grounding interventions in cultural traditions and norms are critical for preventing obesity among ethnic and racial minority youth; however, with some notable exceptions, few community interventions have used this approach. Moreover, urban minority youth may face additional barriers to healthful eating and physical activity behaviors, such as …

No Relationship Between Sequence Variation In Protein Coding Regions Of The Tas1r3 Gene And Saccharin Preference In Rats., Clinton Chapman, Ke Lu, Amanda Mcdaniel, Michael Tordoff, Li Xia, Gary Beauchamp, Nancy Dess, Dennis Vanderweele, Liquan Huang, Hong Wang, Danielle Reed

Clinton D Chapman

Nearly all mammalian species like sweet-tasting foods and drinks, but there are differences in the degree of 'sweet tooth' both between species and among individuals of the same species. Some individual differences can be explained by genetic variability. Polymorphisms in a sweet taste receptor (Tas1r3) account for a large fraction of the differences in consumption of sweet solutions among inbred mouse strains. We wondered whether mice and rats share the same Tas1r3 alleles, and whether this gene might explain the large difference in saccharin preference among rats. We conducted three experiments to test this. We examined DNA sequence differences in …

From The Cover: Assignment Of An Essential Role For The Neurospora Frequency Gene In Circadian Entrainment To Temperature Cycles, Antonio M. Pregueiro, Nathan Price-Lloyd, Deborah Bell-Pedersen, Christian Heintzen, Jennifer J. Loros, Jay C. Dunlap

Dartmouth Scholarship

Circadian systems include slave oscillators and central pacemakers, and the cores of eukaryotic circadian clocks described to date are composed of transcription and translation feedback loops (TTFLs). In the model system Neurospora, normal circadian rhythmicity requires a TTFL in which a White Collar complex (WCC) activates expression of the frequency (frq) gene, and the FRQ protein feeds back to attenuate that activation. To further test the centrality of this TTFL to the circadian mechanism in Neurospora, we used low-amplitude temperature cycles to compare WT and frq-null strains under conditions in which a banding rhythm was elicited. WT cultures were entrained …

Targeted Expression Of A Dominant-Negative Fibroblast Growth Factor (Fgf) Receptor In Gonadotropin-Releasing Hormone (Gnrh) Neurons Reduces Fgf Responsiveness And The Size Of Gnrh Neuronal Population, Pei-San Tsai, Suzanne M. Moenter, Hector R. Postigo, Mohammed El Majdoubi, Toni R. Pak, John C. Gill, Sreenivasan Paruthiyil, Sabine Werner, Richard I. Weiner

Collected Faculty and Staff Scholarship

Increasing evidence suggests that fibroblast growth factors (FGFs) are neurotrophic in GnRH neurons. However, the extent to which FGFs are involved in establishing a functional GnRH system in the whole organism has not been investigated. In this study, transgenic mice with the expression of a dominant-negative FGF receptor mutant (FGFRm) targeted to GnRH neurons were generated to examine the consequence of disrupted FGF signaling on the formation of the GnRH system. To first test the effectiveness of this strategy, GT1 cells, a GnRH neuronal cell line, were stably transfected with FGFRm. The transfected cells showed attenuated neurite outgrowth, diminished FGF-2 …

Imposed Constraints On The Smith-Waterman Alignment Algorithm For Enhanced Modeling Of A Single-Molecule Dna Sequencer, Patrick G. Humphrey, Gregory R. Bashford

Biomedical Imaging and Biosignal Analysis Laboratory

An effort has been underway to develop a system for de novo sequencing of single DNA molecules with very long reads. The system operates by optically detecting the passage of fluorescently tagged DNA bases through a detection zone. A successful system would be revolutionary with respect to speed, read length, cost and minimized laboratory infrastructure. An important part of system development is modeling of the detection process. In particular, predicting the expected error from a set of sequencing parameters is helpful in system design. This paper describes variations on the Smith-Waterman algorithm for subsequence alignment used in a single-molecule detection …

Aging Affects Stretch-Induced P70s6k And 4e-Bp1 Phosphorylation In Fast- And Slow-Twitch Muscle, Sreevani Uddemarri

Theses, Dissertations and Capstones

In the present investigation we compare the expression, basal activation and the ability of muscle stretch to activate the p70^S6k pathway in the fast-twitch extensor digitorum longus (EDL) and slow-twitch soleus of adult (6 mo. old), aged (30 mo. old) and very aged (36 mo. old) Fischer 344 x Brown Norway rats. Immunoblotting demonstrated that the tissue content of mTOR, p70^S6k, 4E-BP1 and GSK-3β decreased in the EDL and soleus in aged rats, while SHP-2 increased in the EDL and decreased in the soleus when compared to adult rats. Basal phosphorylation of 4E-BP1 increased in both the …

Medical Technology: Contexts And Content In Science And Technology, Michael A. De Miranda, Mark Doggett, Jane T. Evans

Architectural and Manufacturing Sciences Faculty Publications

No abstract provided.

Long-Term Cardioprotection With Phosphodiesterase-5 Inhibition Against Ischemia-Reperfusion Injury: Role Of Nitric Oxide., Vladimir Paul Daoud

Theses and Dissertations

Recent studies have shown that the potent phosphodiesterase-5 (PDE-5) inhibitor, sildenafil citrate, induces a powerful cardioprotective effect against ischemia-reperfusion (I/R) injury in rabbit and mouse hearts. However, the effect of this drug in inducing long-term protection against I/R injury remains unknown. The goal of this study was to identify the duration of the protective window of sildenafil citrate as well as vardenafil, a more potent PDE-5 inhibitor. Rabbits were treated with sildenafil (0.7 mg/kg, iv), vardenafil (0.143 mg/kg), or an equivalent volume of saline. After 24 hrs, 48 hrs, 96 hrs, or 7 days of sildenafil treatment, the hearts were …

The Effect Of Red Blood Cell Velocity On Oxygenation Measurements Using Resonance Raman Spectroscopy, Derrick Williams

Theses and Dissertations

Resonance Raman spectroscopy can be used to estimate the hemoglobin oxygen saturation. Previous studies have demonstrated that exposure of oxygenated red blood cells to laser illumination may result in photo-induced displacement of oxygen from hemoglobin. In this study, an in vitro model was used to evaluate the relationship between this photo-induced effect and the red blood cell velocity. A computer-controlled system was implemented to acquire variables such as red cell velocity, microvessel diameter and hemoglobin oxygen saturation at multiple sites in selected microvascular networks. Using this system, resonance Raman spectroscopy was employed to measure hemoglobin oxygen saturation gradients in arterioles …

Preservation Of Eumelanin Hair Pigmentation In Proopiomelanocortin-Deficient Mice On A Nonagouti (A/A) Genetic Background, Andrzej Slominski, Przemyslaw M. Plonka, Alexander Pisarchik, James L. Smart, Virgine Tolle, Jacobo Wortsman, Malcolm J. Low

Faculty Publications - Department of Biological & Molecular Science

No abstract provided.

Erythrocyte-Associated Transients In Capillary Po2 In The Rat Spinotrapezius Muscle During Hemodilution With Hespan And A Hemoglobin-Based Oxygen Carrier, Matthew Barker

Theses and Dissertations

Hemoglobin-based oxygen carriers for use as transfusion fluids have emerged as a leading technology directed at stemming shortages of a safe blood supply and providing a readily available resuscitation fluid in various trauma situations. The purpose of this investigation was to determine the effects of isovolemic hemodilution with Hespan and a hemoglobin-based oxygen carrier (HBOC) on erythrocyte-associated transients (EATs) in capillary PO2. The particulate nature of blood flow in capillaries, when observed from a stationary observation point, results in fluctuations of PO2 as alternating red blood cells and plasma gaps move through the detection region. Therefore, through experimental methods which …

In Vivo Role Of 20-Hydroxyecdysone In The Regulation Of The Vitellogenin Mrna And Egg Development In The American Dog Tick, Dermacentor Variabilis (Say), Deborah M. Thompson, Sayed M.S. Khalil, Laura A. Jeffers, Usha Ananthapadadmanaban, Daniel E. Sonenshine, Robert D. Mitchell, Christopher J. Osgood, Charles S. Apperson, R. Michael Roe

Biological Sciences Faculty Publications

Injection of the hormone 20-hydroxyecdysone (20-E) into partially fed (virgin) female adults of the American dog tick, Dermacentor variabilis, while they are attached and feeding on the rabbit host, initiated the expression of the vitellogenin (Vg) gene, and Vg protein secretion and uptake by the ovary. The induction of egg production by 20-E in this bioassay was dose dependent in the range of 1-50 times the concentration normally found in a replete, vitellogenic female. Ticks examined 4d after the 50x treatment were still attached to the host, had numerous enlarged vitellin-filled (brown) oocytes in their ovaries, but had not …

3,4-Methylenedioxymethamphetamine Activates Nuclear Factor- Κb, Increases Intracellular Calcium, And Modulates Gene Transcription In Rat Heart Cells, David A. Tiangco, Frank A. Lattanzio Jr., Christopher J. Osgood, Stephen J. Beebe, Julie A. Kerry, Barbara Y. Hargrave

Biological Sciences Faculty Publications

3,4-Methylenedioxymethamphetamine (MDMA) is an illicit psychoactive drug that has gained immense popularity among teenagers and young adults. The cardiovascular toxicological consequences of abusing this compound have not been fully characterized. The present study utilized a transient transfection/dual luciferase genetic reporter assay, fluorescence confocal microscopy, and gene expression macroarray technology to determine nuclear factor-κB (NF-κB) activity, intracellular calcium balance, mitochondrial depolarization, and gene transcription profiles, respectively, in cultured rat striated cardiac myocytes (H9c2) exposed to MDMA. At concentrations of 1×10⁻³ M and 1×10⁻² M, MDMA significantly enhanced NF-κB reporter activity compared with 0 M (medium only) control. This …

Novel Strategies In Cardioprotection Against Ischemia/Reperfusion Injury, Fadi N. Salloum

Theses and Dissertations

Cell damage represents a major pathomechanism in many diseases of high clinical interest, such as myocardial infarction (MI), where it plays an important role in ischemia-reperfusion (I/R) injury. Considerable progress has been made towards identifying physiological and pharmacological agents that play a key role in myocardial preconditioning against I/R injury and also elucidating the molecular changes leading to such protection.Second messengers in cellular signaling pathways, such as cGMP have been well implicated as key players in ischemic and pharmacological preconditioning (PC) of the heart. Phosphodiesterase type 5 (PDE-5) is an enzyme that specifically hydrolyzes cGMP thereby decreasing its tissue concentration. …