Open Access. Powered by Scholars. Published by Universities.®

Physiology Commons

Open Access. Powered by Scholars. Published by Universities.®

Series

2013

Discipline
Institution
Keyword
Publication

Articles 1 - 30 of 68

Full-Text Articles in Physiology

Contrast Negation Differentiates Visual Pathways Underlying Dynamic And Invariant Facial Processing, Pamela M. Pallett, Ming Meng Dec 2013

Contrast Negation Differentiates Visual Pathways Underlying Dynamic And Invariant Facial Processing, Pamela M. Pallett, Ming Meng

Dartmouth Scholarship

Abstract Bruce and Young (1986) proposed a model for face processing that begins with structural encoding, followed by a split into two processing streams: one for the dynamic aspects of the face (e.g., facial expressions of emotion) and the other for the invariant aspects of the face (e.g., gender, identity). Yet how this is accomplished remains unclear. Here, we took a psychophysical approach using contrast negation to test the Bruce and Young model. Previous research suggests that contrast negation impairs processing of invariant features (e.g., gender) but not dynamic features (e.g., expression). In our first experiment, participants discriminated differences in …


Molecular Evolution Of Protein-Rna Mimicry As A Mechanism For Translational Control, Assaf Katz, Lindsey Solden, S. Betty Zou, William Wiley Navarre, Michael Ibba Dec 2013

Molecular Evolution Of Protein-Rna Mimicry As A Mechanism For Translational Control, Assaf Katz, Lindsey Solden, S. Betty Zou, William Wiley Navarre, Michael Ibba

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Elongation factor P (EF-P) is a conserved ribosome-binding protein that structurally mimics tRNA to enable the synthesis of peptides containing motifs that otherwise would induce translational stalling, including polyproline. In many bacteria, EF-P function requires post-translational modification with (R)-β-lysine by the lysyl-tRNA synthetase paralog PoxA. To investigate how recognition of EF-P by PoxA evolved from tRNA recognition by aminoacyl-tRNA synthetases, we compared the roles of EF-P/PoxA polar contacts with analogous interactions in a closely related tRNA/synthetase complex. PoxA was found to recognize EF-P solely via identity elements in the acceptor loop, the domain of the protein that interacts with the …


Differential Actions Of Orexin Receptors In Brainstem Cholinergic And Monoaminergic Neurons Revealed By Receptor Knockouts: Implications For Orexinergic Signaling In Arousal And Narcolepsy, Kristi Kohlmeier, Christopher Tyler, Mike Kalogiannis, Masaru Ishibashi, Iryna Gumenchuk, Masashi Yanagisawa, Christopher S. Leonard Dec 2013

Differential Actions Of Orexin Receptors In Brainstem Cholinergic And Monoaminergic Neurons Revealed By Receptor Knockouts: Implications For Orexinergic Signaling In Arousal And Narcolepsy, Kristi Kohlmeier, Christopher Tyler, Mike Kalogiannis, Masaru Ishibashi, Iryna Gumenchuk, Masashi Yanagisawa, Christopher S. Leonard

NYMC Faculty Publications

Orexin neuropeptides influence multiple homeostatic functions and play an essential role in the expression of normal sleep-wake behavior. While their two known receptors (OX1 and OX2) are targets for novel pharmacotherapeutics, the actions mediated by each receptor remain largely unexplored. Using brain slices from mice constitutively lacking either receptor, we used whole-cell and Ca(2+) imaging methods to delineate the cellular actions of each receptor within cholinergic [laterodorsal tegmental nucleus (LDT)] and monoaminergic [dorsal raphe (DR) and locus coeruleus (LC)] brainstem nuclei-where orexins promote arousal and suppress REM sleep. In slices from OX(-/-) 2 mice, orexin-A (300 nM) elicited wild-type responses …


Analgesic Tolerance Of Opioid Agonists In Mutant Mu-Opioid Receptors Expressed In Sensory Neurons Following Intrathecal Plasmid Gene Delivery, Guangwen Li, Fei Ma, Yanping Gu, Li-Yen Mae Huang Dec 2013

Analgesic Tolerance Of Opioid Agonists In Mutant Mu-Opioid Receptors Expressed In Sensory Neurons Following Intrathecal Plasmid Gene Delivery, Guangwen Li, Fei Ma, Yanping Gu, Li-Yen Mae Huang

Physiology Faculty Publications

Background: Phosphorylation sites in the C-terminus of mu-opioid receptors (MORs) are known to play critical roles in the receptor functions. Our understanding of their participation in opioid analgesia is mostly based on studies of opioid effects on mutant receptors expressed in in vitro preparations, including cell lines, isolated neurons and brain slices. The behavioral consequences of the mutation have not been fully explored due to the complexity in studies of mutant receptors in vivo. To facilitate the determination of the contribution of phosphorylation sites in MOR to opioid-induced analgesic behaviors, we expressed mutant and wild-type human MORs (hMORs) in sensory …


The Efficacy Of Partial Squats On Measures Of Strength And Explosiveness: An Exploratory Study, Caleb D. Bazyler, Kimitake Sato, Craig A. Wassinger, Hugh S. Lamont, Michael H. Stone Dec 2013

The Efficacy Of Partial Squats On Measures Of Strength And Explosiveness: An Exploratory Study, Caleb D. Bazyler, Kimitake Sato, Craig A. Wassinger, Hugh S. Lamont, Michael H. Stone

ETSU Faculty Works

Abstract available in the 8th Annual Coaches and Sport Science College.


Comparison Of Theophylline And 8-Cyclopentyltheophylline On The Heart Rates Of Neonatal Rats, Stephanie Arnold Dec 2013

Comparison Of Theophylline And 8-Cyclopentyltheophylline On The Heart Rates Of Neonatal Rats, Stephanie Arnold

Undergraduate Honors Theses

Neonatal apnea is a serious condition that affects the health of infants, especially those born prematurely. To stimulate breathing, methylxanthine drugs, such as theophylline and caffeine, are administered to reverse this condition in humans and avoid the use of breathing-assistance equipment. These drugs cause stimulation of the central nervous system and the heart, however, both detrimental side effects in preterm infants. Antagonism of adenosine receptors is the proposed mechanism of methylxanthine action. Synthetic chemists have produced xanthine analogs with increased affinity for adenosine receptors that could lead to respiratory stimulation while reducing cardiostimulant effects. For this study, theophylline and 8-cyclopentyltheophylline …


Single Nucleotide Polymorphisms Linked To Essential Hypertension In Kasigau, Kenya, Julia Carol Freeman Dec 2013

Single Nucleotide Polymorphisms Linked To Essential Hypertension In Kasigau, Kenya, Julia Carol Freeman

Masters Theses & Specialist Projects

Hypertension, or high blood pressure (BP), is an ever-growing epidemic in the developing world. Understanding the genetics behind essential hypertension (EH), or hypertension with no known cause, is especially important. In this study, three single nucleotide polymorphisms (SNPs) known to be linked to an increase in susceptibility to EH were quantified from a cohort of Kenyans living in the Kasigau region. The SNPs are located in three genes that are part of the renin angiotensin system, the primary regulatory pathway in humans controlling BP. They include: AGT (rs699), AGTR1 (rs5186), and HSD11β2 (rs5479). Overall, by using a fluorescent-based RT-PCR technique, …


Molecular Events In The Cell Types Of The Olfactory Epithelium During Adult Neurogenesis, Paula M. Heron, Arnold J. Stromberg, Patrick Breheny, Timothy S. Mcclintock Nov 2013

Molecular Events In The Cell Types Of The Olfactory Epithelium During Adult Neurogenesis, Paula M. Heron, Arnold J. Stromberg, Patrick Breheny, Timothy S. Mcclintock

Physiology Faculty Publications

BACKGROUND: Adult neurogenesis, fundamental for cellular homeostasis in the mammalian olfactory epithelium, requires major shifts in gene expression to produce mature olfactory sensory neurons (OSNs) from multipotent progenitor cells. To understand these dynamic events requires identifying not only the genes involved but also the cell types that express each gene. Only then can the interrelationships of the encoded proteins reveal the sequences of molecular events that control the plasticity of the adult olfactory epithelium.

RESULTS: Of 4,057 differentially abundant mRNAs at 5 days after lesion-induced OSN replacement in adult mice, 2,334 were decreased mRNAs expressed by mature OSNs. Of the …


The Composite Effect For Inverted Faces Is Reliable At Large Sample Sizes And Requires The Basic Face Configuration, Tirta Susilo, Constantin Rezlescu, Bradley Duchaine Nov 2013

The Composite Effect For Inverted Faces Is Reliable At Large Sample Sizes And Requires The Basic Face Configuration, Tirta Susilo, Constantin Rezlescu, Bradley Duchaine

Dartmouth Scholarship

Abstract The absence of the face composite effect (FCE) for inverted faces is often considered evidence that holistic processing operates only on upright faces. However, such absence might be explained by power issues: Most studies that have failed to find the inverted FCE tested 24 participants or less. Here we find that the inverted FCE exists reliably when we tested at least 60 participants. The inverted FCE was ∼ 18% the size of the upright FCE, and it was unaffected by testing order: It did not matter whether participants did the upright condition first (Experiment 1, n = 64) or …


Insulin Responsiveness In Metabolic Syndrome After Eight Weeks Of Cycle Training, Charles A. Stuart, Mark A. South, Michelle L. Lee, Melanie P. Mccurry, Mary E. A. Howell, Michael W. Ramsey, Michael H. Stone Nov 2013

Insulin Responsiveness In Metabolic Syndrome After Eight Weeks Of Cycle Training, Charles A. Stuart, Mark A. South, Michelle L. Lee, Melanie P. Mccurry, Mary E. A. Howell, Michael W. Ramsey, Michael H. Stone

ETSU Faculty Works

Introduction Insulin resistance in obesity is decreased after successful diet and exercise. Aerobic exercise training alone was evaluated as an intervention in subjects with the metabolic syndrome.

Methods Eighteen nondiabetic, sedentary subjects, 11 with the metabolic syndrome, participated in 8 wk of increasing intensity stationary cycle training.

Results Cycle training without weight loss did not change insulin resistance in metabolic syndrome subjects or sedentary control subjects. Maximal oxygen consumption (V˙O2max), activated muscle AMP-dependent kinase, and muscle mitochondrial marker ATP synthase all increased. Strength, lean body mass, and fat mass did not change. The activated mammalian target of rapamycin was not …


Validity Of Boston Marathon Qualifying Times, Paul M. Vanderburgh Nov 2013

Validity Of Boston Marathon Qualifying Times, Paul M. Vanderburgh

Health and Sport Science Faculty Publications

Purpose: To assess the validity of Boston Marathon qualifying (BMQ) standards for men and women. Methods: Percent differences between BMQ and current world records (WR) by sex and age group were computed. WR was chosen as the criterion comparison because it is not confounded by intensity, body composition, lifestyle, or environmental factors. A consistent difference across age groups would indicate an appropriate slope of the age-vs-BMQ curve. Inconsistent differences were corrected by adjusting BMQ standards to achieve a uniform percentage difference from WR. Results: BMQ standards for men were consistently ~50% slower than WR (mean 51.5% ± …


Computational Optogenetics: Empirically-Derived Voltage- And Light-Sensitive Channelrhodopsin-2 Model, John C. Williams, Jianjin Xu, Zhongju Lu, Aleksandra Klimas, Xuxin Chen, Christina M. Ambrosi, Ira S. Cohen, Emilia Entcheva Sep 2013

Computational Optogenetics: Empirically-Derived Voltage- And Light-Sensitive Channelrhodopsin-2 Model, John C. Williams, Jianjin Xu, Zhongju Lu, Aleksandra Klimas, Xuxin Chen, Christina M. Ambrosi, Ira S. Cohen, Emilia Entcheva

Department of Biomedical Engineering Faculty Publications

Channelrhodospin-2 (ChR2), a light-sensitive ion channel, and its variants have emerged as new excitatory optogenetic tools not only in neuroscience, but also in other areas, including cardiac electrophysiology. An accurate quantitative model of ChR2 is necessary for in silicoprediction of the response to optical stimulation in realistic tissue/organ settings. Such a model can guide the rational design of new ion channel functionality tailored to different cell types/tissues. Focusing on one of the most widely used ChR2 mutants (H134R) with enhanced current, we collected a comprehensive experimental data set of the response of this ion channel to different irradiances and voltages, …


The -9/+9 Polymorphism Of The Bradykinin Receptor Beta 2 Gene And Athlete Status: A Study Involving Two European Cohorts., Marek Sawczuk, Yevgeniya I. Timshina, Irina V. Astratenkova, Agnieszka Maciejewska-Karłowska, Agata Leońska-Duniec, Krzysztof Ficek, Leysan J. Mustafina, Paweł Cięszczyk, Tomasz Klocek, Ildus I. Ahmetov Sep 2013

The -9/+9 Polymorphism Of The Bradykinin Receptor Beta 2 Gene And Athlete Status: A Study Involving Two European Cohorts., Marek Sawczuk, Yevgeniya I. Timshina, Irina V. Astratenkova, Agnieszka Maciejewska-Karłowska, Agata Leońska-Duniec, Krzysztof Ficek, Leysan J. Mustafina, Paweł Cięszczyk, Tomasz Klocek, Ildus I. Ahmetov

Human Biology Open Access Pre-Prints

Background: Previous studies concerning the relevance of the BDKRB2 gene polymorphisms revealed that the absence (–9 allele) of a 9 base pair sequence in exon 1 of the BDKRB2 gene is correlated with higher skeletal muscle metabolic efficiency, glucose uptake during exercise, as well as endurance athletic performance. Aim: The aim of the study was to investigate the association between the BDKRB2 -9/+9 polymorphism and elite athletic status in two cohorts of east-European athletes. Therefore, we examined the genotype distribution of the BDKRB2 9/+9 polymorphic site in a group of Polish athletes and confirmed the results obtained in a replication …


Acclimatization Of The Tropical Reef Coral Acropora Millepora To Hyperthermal Stress, Anthony John Bellantuono Sep 2013

Acclimatization Of The Tropical Reef Coral Acropora Millepora To Hyperthermal Stress, Anthony John Bellantuono

FIU Electronic Theses and Dissertations

The demise of reef-building corals potentially lies on the horizon, given ongoing climate change amid other anthropogenic environmental stressors. If corals cannot acclimatize or adapt to changing conditions, dramatic declines in the extent and health of the living reefs are expected within the next half century. The primary and proximal global threat to corals is climate change. Reef-building corals are dependent upon a nutritional symbiosis with photosynthetic dinoflagellates belonging to the group Symbiodinium. The symbiosis between the cnidarian host and algal partner is a stress-sensitive relationship; temperatures just 1°C above normal thermal maxima can result in the breakdown of …


Aspirin And Low-Molecular Weight Heparin Combination Therapy Effectively Prevents Recurrent Miscarriage In Hyperhomocysteinemic Women., Pratip Chakraborty, Sayani Banerjee, Piyali Saha, Shyam Sundar Nandi, Sunita Sharma, Sourendra K. Goswami, Baidyanath Chakravarty, Syed N. Kabir Sep 2013

Aspirin And Low-Molecular Weight Heparin Combination Therapy Effectively Prevents Recurrent Miscarriage In Hyperhomocysteinemic Women., Pratip Chakraborty, Sayani Banerjee, Piyali Saha, Shyam Sundar Nandi, Sunita Sharma, Sourendra K. Goswami, Baidyanath Chakravarty, Syed N. Kabir

Journal Articles: Cellular & Integrative Physiology

The management of recurrent pregnancy loss (RPL) still remains a great challenge, and women with polycystic ovarian syndrome (PCOS) are at a greater risk for spontaneous abortion. Treatment with low-molecular-weight heparin (LMWH) has become an accepted treatment option for women with RPL; however, the subgroup of women, who are likely to respond to LMWH, has not been precisely identified. The present study evaluated the efficacy of LMWH with reference to PCOS and associated metabolic phenotypes including hyperhomocysteinemia (HHcy), insulin resistance (IR) and obesity. This prospective observational study was conducted at Institute of Reproductive Medicine, Kolkata, India. A total of 967 …


Tricellulin Deficiency Affects Tight Junction Architecture And Cochlear Hair Cells, Gowri Nayak, Sue I. Lee, Rizwan Yousaf, Stephanie E. Edelmann, Claire Trincot, Christina M. Van Itallie, Ghanshyam P. Sinha, Maria Rafeeq, Sherri M. Jones, Inna A. Belyantseva, James M. Anderson, Andrew Forge, Gregory I. Frolenkov, Saima Riazuddin Aug 2013

Tricellulin Deficiency Affects Tight Junction Architecture And Cochlear Hair Cells, Gowri Nayak, Sue I. Lee, Rizwan Yousaf, Stephanie E. Edelmann, Claire Trincot, Christina M. Van Itallie, Ghanshyam P. Sinha, Maria Rafeeq, Sherri M. Jones, Inna A. Belyantseva, James M. Anderson, Andrew Forge, Gregory I. Frolenkov, Saima Riazuddin

Physiology Faculty Publications

The two compositionally distinct extracellular cochlear fluids, endolymph and perilymph, are separated by tight junctions that outline the scala media and reticular lamina. Mutations in TRIC (also known as MARVELD2), which encodes a tricellular tight junction protein known as tricellulin, lead to nonsyndromic hearing loss (DFNB49). We generated a knockin mouse that carries a mutation orthologous to the TRIC coding mutation linked to DFNB49 hearing loss in humans. Tricellulin was absent from the tricellular junctions in the inner ear epithelia of the mutant animals, which developed rapidly progressing hearing loss accompanied by loss of mechanosensory cochlear hair cells, while …


Dirigent Domain-Containing Protein Is Part Of The Machinery Required For Formation Of The Lignin-Based Casparian Strip In The Root, Prashant S. Hosmani, Takehiro Kamiya, John Danku, Sadaf Naseer, Niko Geldner, Mary Lou Guerinot, David Salt Aug 2013

Dirigent Domain-Containing Protein Is Part Of The Machinery Required For Formation Of The Lignin-Based Casparian Strip In The Root, Prashant S. Hosmani, Takehiro Kamiya, John Danku, Sadaf Naseer, Niko Geldner, Mary Lou Guerinot, David Salt

Dartmouth Scholarship

The endodermis acts as a "second skin" in plant roots by providing the cellular control necessary for the selective entry of water and solutes into the vascular system. To enable such control, Casparian strips span the cell wall of adjacent endodermal cells to form a tight junction that blocks extracellular diffusion across the endodermis. This junction is composed of lignin that is polymerized by oxidative coupling of monolignols through the action of a NADPH oxidase and peroxidases. Casparian strip domain proteins (CASPs) correctly position this biosynthetic machinery by forming a protein scaffold in the plasma membrane at the site where …


Colour And Odour Drive Fruit Selection And Seed Dispersal By Mouse Lemurs, Kim Valenta, Ryan J. Burke, Sarah A. Styler, Derek A. Jackson, Amanda D. Melin, Shawn M. Lehman Aug 2013

Colour And Odour Drive Fruit Selection And Seed Dispersal By Mouse Lemurs, Kim Valenta, Ryan J. Burke, Sarah A. Styler, Derek A. Jackson, Amanda D. Melin, Shawn M. Lehman

Dartmouth Scholarship

Animals and fruiting plants are involved in a complex set of interactions, with animals relying on fruiting trees as food resources, and fruiting trees relying on animals for seed dispersal. This interdependence shapes fruit signals such as colour and odour, to increase fruit detectability, and animal sensory systems, such as colour vision and olfaction to facilitate food identification and selection. Despite the ecological and evolutionary importance of plant-animal interactions for shaping animal sensory adaptations and plant characteristics, the details of the relationship are poorly understood. Here we examine the role of fruit chromaticity, luminance and odour on seed dispersal by …


Mouse Strain Determines Cardiac Growth Potential, Carmen Kiper, Barry Grimes, Gary Van Zant, Jonathan Satin Aug 2013

Mouse Strain Determines Cardiac Growth Potential, Carmen Kiper, Barry Grimes, Gary Van Zant, Jonathan Satin

Physiology Faculty Publications

RATIONALE: The extent of heart disease varies from person to person, suggesting that genetic background is important in pathology. Genetic background is also important when selecting appropriate mouse models to study heart disease. This study examines heart growth as a function of strain, specifically C57BL/6 and DBA/2 mouse strains.

OBJECTIVE: In this study, we test the hypothesis that two strains of mice, C57BL/6 and DBA/2, will produce varying degrees of heart growth in both physiological and pathological settings.

METHODS AND RESULTS: Differences in heart dimensions are detectable by echocardiography at 8 weeks of age. Percentages of cardiac progenitor cells (c-kit+ …


Neurotensin And Cholecystokinin Contract Gallbladder Circular Muscle In Chickens, Teresa F. Degolier, D. R. Brown, Gary E. Duke, M. M. Palmer, J. R. Swenson, Robert E. Carraway Aug 2013

Neurotensin And Cholecystokinin Contract Gallbladder Circular Muscle In Chickens, Teresa F. Degolier, D. R. Brown, Gary E. Duke, M. M. Palmer, J. R. Swenson, Robert E. Carraway

Biological Sciences Faculty Publications

The contractile effects of neurotensin (NT) and cholecystokinin octapeptide (CCK-8) on isolated circular smooth muscle strips of chicken gallbladder were investigated. The NT (0.25-300 nM) produced concentration-dependent contractions on smooth muscle with an EC50 of 8.5 nM (95% confidence limits = 5.3-13.6 nM). In comparison, CCK-8 produced concentration-dependent contractions with an EC50 of 13 nM (95% confidence limits of 9-20 nM). There were no statistical differences in contractile responses when comparing NT and CCK-8 at equimolar concentrations. The NT appears to act directly on smooth muscle tissue in the chicken; the contractile responses were not blocked by 10 μM atropine …


Physiologically-Based Pharmacokinetic Modeling For Predicting Caffeine/Theophylline-Ciprofloxacin Interactions, David M. Ng, Ali Navid Aug 2013

Physiologically-Based Pharmacokinetic Modeling For Predicting Caffeine/Theophylline-Ciprofloxacin Interactions, David M. Ng, Ali Navid

STAR Program Research Presentations

Dynamics of interactions between the drugs caffeine, theophylline, and ciprofloxacin are predicted using physiologically-based pharmacokinetic (PBPK) modeling. Pharmacokinetic means the model determines where the drugs are distributed in the body over time. Physiologically-based means the anatomy and physiology of the human body are reflected in the structure and functioning of the model. Multiple drugs can interact to increase or decrease their beneficial and/or undesired effects. This is important because some common substances, such as caffeine in coffee, soft drinks, and energy drinks, are actually drugs that affect the body. Ciprofloxacin is an inhibitor of caffeine and theophylline metabolism; such inhibition …


Dexamethasone Rapidly Increases Gaba Release In The Dorsal Motor Nucleus Of The Vagus Via Retrograde Messenger-Mediated Enhancement Of Trpv1 Activity, Andrei V. Derbenev, Bret N. Smith Jul 2013

Dexamethasone Rapidly Increases Gaba Release In The Dorsal Motor Nucleus Of The Vagus Via Retrograde Messenger-Mediated Enhancement Of Trpv1 Activity, Andrei V. Derbenev, Bret N. Smith

Physiology Faculty Publications

Glucocorticoids influence vagal parasympathetic output to the viscera via mechanisms that include modulation of neural circuitry in the dorsal vagal complex, a principal autonomic regulatory center. Glucocorticoids can modulate synaptic neurotransmitter release elsewhere in the brain by inducing release of retrograde signalling molecules. We tested the hypothesis that the glucocorticoid agonist dexamethasone (DEX) modulates GABA release in the rat dorsal motor nucleus of the vagus (DMV). Whole-cell patch-clamp recordings revealed that DEX (1-10 µM) rapidly (i.e. within three minutes) increased the frequency of tetrodotoxin-resistant, miniature IPSCs (mIPSCs) in 67% of DMV neurons recorded in acutely prepared slices. Glutamate-mediated mEPSCs were …


Direction Of Aminoacylated Transfer Rnas Into Antibiotic Synthesis And Peptidoglycan-Mediated Antibiotic Resistance, Jennifer Shepherd, Michael Ibba Jul 2013

Direction Of Aminoacylated Transfer Rnas Into Antibiotic Synthesis And Peptidoglycan-Mediated Antibiotic Resistance, Jennifer Shepherd, Michael Ibba

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Prokaryotic aminoacylated‐transfer RNAs often need to be efficiently segregated between translation and other cellular biosynthetic pathways. Many clinically relevant bacteria, including Streptococcus pneumoniae, Staphylococcus aureus, Enterococcus faecalis and Pseudomonas aeruginosa direct some aminoacylated‐tRNA species into peptidoglycan biosynthesis and/or membrane phospholipid modification. Subsequent indirect peptidoglycan cross‐linkage or change in membrane permeability is often a prerequisite for high‐level antibiotic resistance. In Streptomycetes, aminoacylated‐tRNA species are used for antibiotic synthesis as well as antibiotic resistance. The direction of coding aminoacylated‐tRNA molecules away from translation and into antibiotic resistance and synthesis pathways are discussed in this review.


Lipid Ii-Independent Trans Editing Of Mischarged Trnas By The Penicillin Resistance Factor Murm, Jennifer Shepherd, Michael Ibba Jul 2013

Lipid Ii-Independent Trans Editing Of Mischarged Trnas By The Penicillin Resistance Factor Murm, Jennifer Shepherd, Michael Ibba

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Streptococcus pneumoniae is a causative agent of nosocomial infections such as pneumonia, meningitis, and septicemia. Penicillin resistance in S. pneumoniae depends in part upon MurM, an aminoacyl-tRNA ligase that attaches l-serine or l-alanine to the stem peptide lysine of Lipid II in cell wall peptidoglycan. To investigate the exact substrates the translation machinery provides MurM, quality control by alanyl-tRNA synthetase (AlaRS) was investigated. AlaRS mischarged serine and glycine to tRNAAla, as observed in other bacteria, and also transferred alanine, serine, and glycine to tRNAPhe. S. pneumoniae tRNAPhe has an unusual U4:C69 mismatch in its acceptor stem that …


Down's Syndrome, Neroinflammation, And Alzheimer Neuropathogenesis, Donna M. Wilcock, W. Sue T. Griffin Jul 2013

Down's Syndrome, Neroinflammation, And Alzheimer Neuropathogenesis, Donna M. Wilcock, W. Sue T. Griffin

Physiology Faculty Publications

Down syndrome (DS) is the result of triplication of chromosome 21 (trisomy 21) and is the prevailing cause of mental retardation. In addition to the mental deficiencies and physical anomalies noted at birth, triplication of chromosome 21 gene products results in the neuropathological and cognitive changes of Alzheimer's disease (AD). Mapping of the gene that encodes the precursor protein (APP) of the β-amyloid (Aβ) present in the Aβ plaques in both AD and DS to chromosome 21 was strong evidence that this chromosome 21 gene product was a principal neuropathogenic culprit in AD as well as DS. The discovery of …


Effect Of Shear Stress On Ecnos Expression And Dilation In Soleus Feed Arteries, Blanca Perez, Jay L. Brewster, Jeffrey Jasperse Jul 2013

Effect Of Shear Stress On Ecnos Expression And Dilation In Soleus Feed Arteries, Blanca Perez, Jay L. Brewster, Jeffrey Jasperse

Featured Research

Shear stress causes artery dilation and increased expression of endothelial cell nitric oxide synthase (ecNOS) in coronary and placental arteries. We sought to determine the importance of shear stress in maintaining normal dilation and normal levels of ecNOS in rat soleus feed arteries (SFA). SFA were isolated from male Sprague-Dawley rats and cannulated for in vitro microscopy (Fig. 6). SFA were exposed to no shear stress, low shear stress, or high shear stress conditions for 4 hours. After 4 hours, endothelium-dependent dilation (acetylcholine: ACh) and endothelium-independent dilation (sodium nitroprusside: SNP) were tested. Arteries were then uncannulated, mRNA was isolated, and …


Review Of Ourselves Unborn: A History Of The Fetus In Modern America, By Sara Dubow, Rose Holz Jul 2013

Review Of Ourselves Unborn: A History Of The Fetus In Modern America, By Sara Dubow, Rose Holz

Women's and Gender Studies Program: Faculty Publications

With the publication of the Bancroft Prize-winning Ourselves Unborn, Sara Dubow offers a long overdue analysis and historicization of what has become a central feature in battles over reproductive rights: the fetus. Drawing upon legal and legislative records as well as educational tracts, museum exhibits, medical textbooks and journals, personal memoirs, and the popular press, Dubow traces what she calls “fetal stories” (4) in America from the late nineteenth century through the early twenty-first. In so doing, she persuasively reminds her readers the following: First, that our understanding of the fetus is not simply a product of biology or theology. …


Voluntary Exercise Protects Against Methamphetamine-Induced Oxidative Stress In Brain Microvasculature And Disruption Of The Blood--Brain Barrier, Michal Toborek, Melissa J. Seelbach, Cetewayo S. Rashid, Ibolya E. András, Lei Chen, Minseon Park, Karyn A. Esser Jun 2013

Voluntary Exercise Protects Against Methamphetamine-Induced Oxidative Stress In Brain Microvasculature And Disruption Of The Blood--Brain Barrier, Michal Toborek, Melissa J. Seelbach, Cetewayo S. Rashid, Ibolya E. András, Lei Chen, Minseon Park, Karyn A. Esser

Physiology Faculty Publications

BACKGROUND: There is no effective therapeutic intervention developed targeting cerebrovascular toxicity of drugs of abuse, including methamphetamine (METH). We hypothesize that exercise protects against METH-induced disruption of the blood--brain barrier (BBB) by enhancing the antioxidant capacity of cerebral microvessels and modulating caveolae-associated signaling. Mice were subjected to voluntary wheel running for 5 weeks resembling the voluntary pattern of human exercise, followed by injection with METH (10 mg/kg). The frequency, duration, and intensity of each running session were monitored for each mouse via a direct data link to a computer and the running data are analyzed by Clock labTM Analysis software. …


Neural Circuit Mechanisms Of Post-Traumatic Epilepsy, Robert F. Hunt, Jeffery A. Boychuk, Bret N. Smith Jun 2013

Neural Circuit Mechanisms Of Post-Traumatic Epilepsy, Robert F. Hunt, Jeffery A. Boychuk, Bret N. Smith

Physiology Faculty Publications

Traumatic brain injury (TBI) greatly increases the risk for a number of mental health problems and is one of the most common causes of medically intractable epilepsy in humans. Several models of TBI have been developed to investigate the relationship between trauma, seizures, and epilepsy-related changes in neural circuit function. These studies have shown that the brain initiates immediate neuronal and glial responses following an injury, usually leading to significant cell loss in areas of the injured brain. Over time, long-term changes in the organization of neural circuits, particularly in neocortex and hippocampus, lead to an imbalance between excitatory and …


Modeling The Influence Of Vitamin D Deficiency On Cigarette Smoke-Induced Emphysema, Mardi A. Crane-Godreau, Candice C. Black, Andrew J. Giustini, Tenzin Dechen, Jihan Ryu, James A. Jukosky, Hong-Kee Lee, Katherine Bessette, Nora R. Ratcliffe, P. Jack Hoopes, Steven Fiering, John A. Kelly, J. C. Leiter Jun 2013

Modeling The Influence Of Vitamin D Deficiency On Cigarette Smoke-Induced Emphysema, Mardi A. Crane-Godreau, Candice C. Black, Andrew J. Giustini, Tenzin Dechen, Jihan Ryu, James A. Jukosky, Hong-Kee Lee, Katherine Bessette, Nora R. Ratcliffe, P. Jack Hoopes, Steven Fiering, John A. Kelly, J. C. Leiter

Dartmouth Scholarship

Chronic obstructive pulmonary disease (COPD) is a major cause of morbidity and mortality worldwide. While the primary risk factor for COPD is cigarette smoke exposure, vitamin D deficiency has been epidemiologically implicated as a factor in the progressive development of COPD-associated emphysema. Because of difficulties inherent to studies involving multiple risk factors in the progression of COPD in humans, we developed a murine model in which to study the separate and combined effects of vitamin D deficiency and cigarette smoke exposure. During a 16-week period, mice were exposed to one of four conditions, control diet breathing room air (CD-NS), control …