Physiology Commons^™

Lateral Blood Flow Velocity Estimation Based On Ultrasound Speckle Size Change With Scan Velocity, Tiantian Xu, Gregory R. Bashford

Biomedical Imaging and Biosignal Analysis Laboratory

Conventional (Doppler-based) blood flow velocity measurement methods using ultrasound are capable of resolving the axial component (i.e., that aligned with the ultrasound propagation direction) of the blood flow velocity vector. However, these 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. A new method has been introduced which estimates the lateral component of blood flow within a single image frame using the observation that the speckle pattern corresponding to blood reflectors (typically red blood cells) stretches (i.e., is smeared) if the …

An Archaeal Trna-Synthetase Complex That Enhances Aminoacylation Under Extreme Conditions, Vlatka Godinic-Mikulcic, Jelena Jaric, Corinne D. Hausmann, Michael Ibba, Ivana Weygand-Durasevic

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Aminoacyl-tRNA synthetases (aaRSs) play an integral role in protein synthesis, functioning to attach the correct amino acid with its cognate tRNA molecule. AaRSs are known to associate into higher-order multi-aminoacyl-tRNA synthetase complexes (MSC) involved in archaeal and eukaryotic translation, although the precise biological role remains largely unknown. To gain further insights into archaeal MSCs, possible protein-protein interactions with the atypical Methanothermobacter thermautotrophicus seryl-tRNA synthetase (MtSerRS) were investigated. Yeast two-hybrid analysis revealed arginyl-tRNA synthetase (MtArgRS) as an interacting partner of MtSerRS. Surface plasmon resonance confirmed stable complex formation, with a dissociation constant (KD) of 250 nm. Formation of the MtSerRS·MtArgRS complex …

Selected Hormonal And Neurotransmitter Mechanisms Regulating, James L. Sartin, Joseph A. Daniel, Brian K. Whitlock, Robyn R. Wilborn

Brian K Whitlock, PhD, DVM, DACT

Appetite control is a major issue in normal growth and in suboptimal growth performance settings. A number of hormones, in particular leptin, activate or inhibit orexigenic or anorexigenic neurotransmitters within the arcuate nucleus of the hypothalamus, where feed intake regulation is integrated. Examples of appetite regulatory neurotransmitters are the stimulatory neurotransmitters neuropeptide Y (NPY), agouti-related protein (AgRP), orexin and melanin-concentrating hormone and the inhibitory neurotransmitter, melanocyte-stimulating hormone (MSH). Examination of messenger RNA (using in situ hybridization and realtime PCR) and proteins (using immunohistochemistry) for these neurotransmitters in ruminants has indicated that physiological regulation occurs in response to fasting for several …

Selected Hormonal And Neurotransmitter Mechanisms Regulating, James L. Sartin, Joseph A. Daniel, Brian K. Whitlock, Robyn R. Wilborn

Faculty Publications and Other Works -- Large Animal Clinical Sciences

Appetite control is a major issue in normal growth and in suboptimal growth performance settings. A number of hormones, in particular leptin, activate or inhibit orexigenic or anorexigenic neurotransmitters within the arcuate nucleus of the hypothalamus, where feed intake regulation is integrated. Examples of appetite regulatory neurotransmitters are the stimulatory neurotransmitters neuropeptide Y (NPY), agouti-related protein (AgRP), orexin and melanin-concentrating hormone and the inhibitory neurotransmitter, melanocyte-stimulating hormone (MSH). Examination of messenger RNA (using in situ hybridization and realtime PCR) and proteins (using immunohistochemistry) for these neurotransmitters in ruminants has indicated that physiological regulation occurs in response to fasting for several …

What Is The Number Needed To Treat When Exercise Training Heart Failure Patients?, Neil Smart

Neil Smart

Debate exists on the number needed to treat (NNT) to prevent one mortality with exercise training in heart failure patients. The primary aim of this work was to conduct a sensitivity analysis, removing outlying mortality data from a published meta-analysis of exercise training in heart failure patients. A sensitivity analysis was conducted by removing data from one randomized controlled trial that reported particularly high mortality rates and may be considered a data outlier. Annualized NNTs were subsequently calculated for mortality data from a meta-analysis of exercise training in heart failure patients. Sensitivity analysis showed that the mortality benefit reported by …

Association Between Chronic Liver And Colon Inflammation During The Development Of Murine Syngeneic Graft-Versus-Host Disease, Jason Anthony Brandon, Jacqueline Perez-Rodriguez, C. Darrell Jennings, Donald A. Cohen, Vishal J. Sindhava, Subbarao Bondada, Alan M. Kaplan, J. Scott Bryson

Microbiology, Immunology, and Molecular Genetics Faculty Publications

The murine model of cyclosporine A (CsA)-induced syngeneic graft-versus-host disease (SGVHD) is a bone marrow (BM) transplantation model that develops chronic colon inflammation identical to other murine models of CD4⁺ T cell-mediated colitis. Interestingly, SGVHD animals develop chronic liver lesions that are similar to the early peribiliary inflammatory stages of clinical chronic liver disease, which is frequently associated with inflammatory bowel disease (IBD). Therefore, studies were initiated to investigate the chronic liver inflammation that develops in the SGVHD model. To induce SGVHD, mice were lethally irradiated, reconstituted with syngeneic BM, and treated with CsA. All of the SGVHD animals …

Poxa, Yjek And Elongation Factor P Coordinately Modulate Virulence And Drug Resistance In Salmonella Enterica, William Wiley Navarre, Shicong Zou, Hervé Roy, Jinglin Lucy Xie, Alexei Savchenko, Alexander Singer, Elena Edvokimova, Lynne R. Prost, Runjun Kumar, Michael Ibba, Ferric C. Fang

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

We report an interaction between poxA, encoding a paralog of lysyl tRNA-synthetase, and the closely linked yjeK gene, encoding a putative 2,3-β-lysine aminomutase, that is critical for virulence and stress resistance in Salmonella enterica. Salmonella poxA and yjeK mutants share extensive phenotypic pleiotropy, including attenuated virulence in mice, an increased ability to respire under nutrient-limiting conditions, hypersusceptibility to a variety of diverse growth inhibitors, and altered expression of multiple proteins, including several encoded on the SPI-1 pathogenicity island. PoxA mediates posttranslational modification of bacterial elongation factor P (EF-P), analogous to the modification of the eukaryotic EF-P homolog, eIF5A, with …

Changes In Plasma Concentrations Of Leptin In Ewes During Pregnancy, Joseph A. Daniel, A B. Milam, M E. Gafnea, Brian K. Whitlock, D H. Keisler

Animal Science Publications and Other Works

Previous research has demonstrated circulating concentrations of leptin increase in ewes during mid pregnancy then decline in late pregnancy and early lactation. The objective of this study was to more narrowly define the timing of changes in circulating concentrations of leptin with pregnancy in ewes. Katahdin ewes (n= 19) located at latitude 34.275 and longitude -85.183 (Mount Berry, GA) were utilized. Blood samples were collected weekly via jugular veinpuncture beginning immediately before ram exposure on September 23 and continuing until 4 weeks post-lambing. Ewes were exposed to a ram fitted with a marking harness for a 63 day breeding season. …

Effect Of Leukemia Inhibitory Factor On Feed Intake And Body Temperature In Sheep, James L. Sartin, D L. Marks, Brian K. Whitlock, Joseph A. Daniel, Barbara P. Steele

Animal Science Publications and Other Works

Leukemia inhibitory factor (LIF) has been suggested to function as a potent inhibitor of feed intake in rodents. These studies were designed to determine whether LIF was found in the ovine hypothalamus and whether LIF inhibited feed intake in sheep. Sheep hypothalami were used to clone LIF to indicate presence of the gene in the hypothalamus. The sequence was similar to published data. Another group of sheep were provided intraventricular (ICV) cannulas and injected with doses of LIF at 250, 500, 1000 and 2500 ng per sheep, ICV. Feed intake was inhibited by the 1000 and 2500 ng dose (trt, …

Changes In Plasma Concentrations Of Growth Hormone And Luteinizing Hormone In Ewes Following Central And Peripheral Treatment With Kisspeptin, Brian K. Whitlock, Joseph A. Daniel, Barbara P. Steele, James L. Sartin

Animal Science Publications and Other Works

Kisspeptin (KP), a neuroendocrine regulator of gonadotropin releasing hormone, has been hypothesized as an integrator of nutrition and hormones critical to metabolism and regulation of reproduction. Recent evidence suggests growth hormone (GH) secretion may be influenced by KP. The objective of this study was to determine if the GH stimulatory effect of KP is due to actions on the hypothalamus or anterior pituitary gland in ewes. Adult ovariectomized ewes (n=8) were fitted with intracerebroventricular (ICV) cannula to facilitate central administration of experimental treatments. Ewes received one of eight treatments [four intravenously (IV) and four ICV]. Peripheral treatments [0 (Veh), 100, …

Effect Of Leukemia Inhibitory Factor On Feed Intake And Body Temperature In Sheep, James L. Sartin, D L. Marks, Brian K. Whitlock, Joseph A. Daniel, Barbara P. Steele

Brian K Whitlock, PhD, DVM, DACT

Leukemia inhibitory factor (LIF) has been suggested to function as a potent inhibitor of feed intake in rodents. These studies were designed to determine whether LIF was found in the ovine hypothalamus and whether LIF inhibited feed intake in sheep. Sheep hypothalami were used to clone LIF to indicate presence of the gene in the hypothalamus. The sequence was similar to published data. Another group of sheep were provided intraventricular (ICV) cannulas and injected with doses of LIF at 250, 500, 1000 and 2500 ng per sheep, ICV. Feed intake was inhibited by the 1000 and 2500 ng dose (trt, …

Changes In Plasma Concentrations Of Growth Hormone And Luteinizing Hormone In Ewes Following Central And Peripheral Treatment With Kisspeptin, Brian K. Whitlock, Joseph A. Daniel, Barbara P. Steele, James L. Sartin

Brian K Whitlock, PhD, DVM, DACT

Kisspeptin (KP), a neuroendocrine regulator of gonadotropin releasing hormone, has been hypothesized as an integrator of nutrition and hormones critical to metabolism and regulation of reproduction. Recent evidence suggests growth hormone (GH) secretion may be influenced by KP. The objective of this study was to determine if the GH stimulatory effect of KP is due to actions on the hypothalamus or anterior pituitary gland in ewes. Adult ovariectomized ewes (n=8) were fitted with intracerebroventricular (ICV) cannula to facilitate central administration of experimental treatments. Ewes received one of eight treatments [four intravenously (IV) and four ICV]. Peripheral treatments [0 (Veh), 100, …

Changes In Plasma Concentrations Of Leptin In Ewes During Pregnancy, Joseph A. Daniel, A B. Milam, M E. Gafnea, Brian K. Whitlock, D H. Keisler

Brian K Whitlock, PhD, DVM, DACT

Previous research has demonstrated circulating concentrations of leptin increase in ewes during mid pregnancy then decline in late pregnancy and early lactation. The objective of this study was to more narrowly define the timing of changes in circulating concentrations of leptin with pregnancy in ewes. Katahdin ewes (n= 19) located at latitude 34.275 and longitude -85.183 (Mount Berry, GA) were utilized. Blood samples were collected weekly via jugular veinpuncture beginning immediately before ram exposure on September 23 and continuing until 4 weeks post-lambing. Ewes were exposed to a ram fitted with a marking harness for a 63 day breeding season. …

Redox Status Affects The Catalytic Activity Of Glutamyl-Trna Synthetase, Assaf Katz, Ranat Banerjee, Merly De Armas, Michael Ibba, Omar Orellana

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Glutamyl-tRNA synthetases (GluRS) provide Glu-tRNA for different processes including protein synthesis, glutamine transamidation and tetrapyrrole biosynthesis. Many organisms contain multiple GluRSs, but whether these duplications solely broaden tRNA specificity or also play additional roles in tetrapyrrole biosynthesis is not known. Previous studies have shown that GluRS1, one of two GluRSs from the extremophile Acidithiobacillus ferrooxidans, is inactivated when intracellular heme is elevated suggesting a specific role for GluRS1 in the regulation of tetrapyrrole biosynthesis. We now show that, in vitro, GluRS1 activity is reversibly inactivated upon oxidation by hemin and hydrogen peroxide. The targets for oxidation-based inhibition were …

Protein Evolution Via Amino Acid And Codon Elimination, Lise Goltermann, Marie Sofie Yoo Larsen, Ranat Banerjee, Andreas C. Joerger, Michael Ibba, Thomas Bentin

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Background
Global residue-specific amino acid mutagenesis can provide important biological insight and generate proteins with altered properties, but at the risk of protein misfolding. Further, targeted libraries are usually restricted to a handful of amino acids because there is an exponential correlation between the number of residues randomized and the size of the resulting ensemble. Using GFP as the model protein, we present a strategy, termed protein evolution via amino acid and codon elimination, through which simplified, native-like polypeptides encoded by a reduced genetic code were obtained via screening of reduced-size ensembles.

Methodology/Principal Findings
The strategy involves combining a sequential …

How The Sequence Of A Gene Can Tune Its Translation, Kurt Fredrick, Michael Ibba

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Sixty-one codons specify 20 amino acids, offering cells many options for encoding a polypeptide sequence. Two new studies (Cannarrozzi et al., 2010, Tuller et al., 2010) now foster the idea that patterns of codon usage can control ribosome speed, fine-tuning translation to increase the efficiency of protein synthesis.

Farm Focus - Spring 2010, Brian K. Whitlock, Matt Welborn, Maria Prado, Amy Plummer

Faculty Publications and Other Works -- Large Animal Clinical Sciences

No abstract provided.

The Effects Of Cocaine And Ecstasy On Cardiac Myocytes And The Intact Myocardium, David A. Tiangco

Theses and Dissertations in Biomedical Sciences

Cocaine and ecstasy are widely used illicit drugs. Both drugs have undergone intense scrutiny as information regarding their side-effects has become available. One important yet incomplete area of investigation pertains to their effects on the heart. The purpose of the current studies was to test the hypothesis that exposure to cocaine or ecstasy will adversely affect cellular homeostasis and normal heart function. Cultured cardiac myocytes (H9c2) and New Zealand White rabbits (Oryctolagus cuniculus) were used to measure the responses to various concentrations of cocaine or ecstasy at both the cellular and intact organ system levels. We observed that cocaine and …

The Correlation Between Visual Observations And Inclinometric Measurements For Special Tests Related To Patellofemoral Pain Syndrome, Erin Quada

Human Movement Sciences & Special Education Theses & Dissertations

Patellofemoral pain syndrome (PFPS) is generally described as an insidious onset with pain increasing during running, jumping, ascending and descending stairs as well as sitting with the knees flexed for an extended period of time. Clinicians often use special tests in injury evaluations and range of motion assessments, usually making a visual observation of that status of the patient. The purpose of this study was to examine how interval measurements utilized in flexibility and range of motion assessments correlate with visual observations of special tests (active knee extension test, Thomas test, Ober's test, rectus femoris flexibility, and Craig's test). The …

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.

Breast Disorders In Children And Adolescents, Donald E. Greydanus, Hatim A. Omar, Lyubov A. Matytsina, Artemis Tsitsika

Pediatrics Faculty Publications

Concerns about problems of the breast are often noted in adolescents and their parents. This review discusses issues and disorders of the breast in children and adolescents, starting with basic principles of embryology and adolescent breast development. Concepts that are covered include congenital breast disorders, abnormal timing of breast development, breast asymmetry, underdeveloped breasts, breast atrophy, tuberous breasts, mammary hyperplasia, fibroadenoma, giant fibroadenoma, cystosarcoma phyllodes, intraductal breast papilloma, adenocarcinoma, mastitis, traumatic breast disorders, benign breast disease, fibrocystic change, mastalgia, gynocomastia, and galactorrhea. A number of figures are provided illustrating breast pathology. Clinicians caring for children and adolescents are encouraged to …

The Female Athlete, Dilip R. Patel, Donald E. Greydanus, Hatim A. Omar

Pediatrics Faculty Publications

The female athlete has today became an accepted part of sports in elementary school, junior high, senior high, and college. This chapter covers various aspects of the prepubertal and pubertal female athlete. An historical perspective will be presented and selected comments provided on psychological and physiologic aspects of the female athlete. Concepts of adolescent gynecology are reviewed, including breast concerns and menstrual dilemmas in relation to sports activity. Exercise during pregnancy is also considered. Iron deficiency anemia and stress urinary incontinence

Menstrual Disorders In Adolescent Females, Donald E. Greydanus, Hatim A. Omar, Artemis Tsitsika, Dilip R. Patel

Pediatrics Faculty Publications

Onset of menstruation (i.e., menarche) is a determining event of the adolescent female signifying the progress of puberty, which in the majotity of cases is visibly initiated with thelarche (onset of breast development or breast buds). Menarche usually occurs during the earlier time of the second decade of life and ends with menopause, typically in the 5th decade of life. The adolescent can present with a wide variety of menstrual dilemmas and disorders which will be discussed in this chapter.

Effect Of Exogenous Leptin On Thrombotic And Metabolic Profiles Of Fvb/B6 Lipodystrophic Mice, Hoda Chaouki Kadouh

Wayne State University Theses

Lipodystrophy caused by fat deficiency contributes to metabolic disease for which several treatment modalities have been implemented, with leptin therapy being the most effective to date. In addition to playing a role in energy homeostasis and metabolism, leptin was also shown to play a pro-thrombotic role in mice. This role was not examined in fatless mice, neither was thrombosis measured. The AZIP/F-1 (FVB) lipodystrophic mouse appeared to have a prolonged arterial occlusion time (p〈0.05) in a trial done in our lab, with clotting factors being normal. The present study was designed to observe the thrombotic and metabolic characteristics of fatless …

Mechanism Of Catch Force: Tethering Of Thick And Thin Filaments By Twitchin., Thomas M Butler, Marion J Siegman

Department of Molecular Physiology and Biophysics Faculty Papers

Catch is a mechanical state occurring in some invertebrate smooth muscles characterized by high force maintenance and resistance to stretch during extremely slow relaxation. During catch, intracellular calcium is near basal concentration and myosin crossbridge cyctng rate is extremely slow. Catch force is relaxed by a protein kinase A-mediated phosphorylation of sites near the N- and C- temini of the minititin twitchin (approximately 526 kDa). Some catch force maintenance car also occur together with cycling myosin crossbridges at submaximal calcium concentrations, but not when the muscle is maximally activated. Additionally, the link responsible for catch can adjust during shortening of …

Farm Focus - Spring 2010, Brian K. Whitlock, Matt Welborn, Maria Prado, Amy Plummer

Brian K Whitlock, PhD, DVM, DACT

No abstract provided.

Relationships Between Jump Characteristics Of Collegiate Female Athletes Competing In Different Disciplines, Christopher J. Macdonalds, Hugh S. Lamont, John C. Garner, Jeremy A. Gentles, Ashley A. Kavanaugh, Michael H. Stone

ETSU Faculty Works

No abstract provided.

A Specific Regulatory Role For Sgtα On The Maturation And Activation Of Steroid Hormone Receptors, Atanu Paul

Open Access Theses & Dissertations

Steroid hormone receptors (SHRs) are ligand-dependent transcription factors belonging to the nuclear receptor superfamily. These receptors regulate various physiological functions in higher ordered eukaryotes. In the absence of hormone these receptors form a complex with molecular chaperones such as Hsp90 and Hsp70 and other cochaperones in the cytoplasm. Association with the Hsp90-Hsp70 chaperone machinery leads to the maturation of the Ligand Binding Domain (LBD) of the receptors and enables the receptors to bind hormone with high affinity. Upon binding with a specific hormone the receptors are translocated into the nucleus where they initiate transcription of specific genes. Although the involvement …

Balance Training Reduces Falls Risk In Older Individuals With Type 2 Diabetes, Steven Morrison, Sheri R. Colberg, Mita Mariano, Henri K. Parson, Arthur I. Vinik

Rehabilitation Sciences Faculty Publications

OBJECTIVE - This study assessed the effects of balance/strength training on falls risk and posture in older individuals with type 2 diabetes.

RESEARCH DESIGN AND METHODS - Sixteen individuals with type 2 diabetes and 21 age-matched control subjects (aged 50-75 years) participated. Postural stability and falls risk was assessed before and after a 6-week exercise program.

RESULTS - Diabetic individuals had significantly higher falls risk score compared with control subjects. The diabetic group also exhibited evidence of mild-to-moderate neuropathy, slower reaction times, and increased postural sway. Following exercise, the diabetic group showed significant improvements in leg strength, faster reaction times, …

Pharmacology Supplement, Ahmed Mustafa, Ellioott Blumenthal

Ahmed Mustafa Dr.

No abstract provided.