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Mengye Li, Karan R Chadda, Gareth D K Matthews, Celia M Marr, Christopher L-H Huang, Kamalan Jeevaratnam
Exercising horses uniquely accommodate 7-8-fold increases in heart rate (HR). The present experiments for the first time analysed the related adaptations in action potential (AP) restitution properties recorded by in vivo telemetric electrocardiography from Thoroughbred horses. The horses were subjected to a period of acceleration from walk to canter. The QRS durations, and QT and TQ intervals yielded AP conduction velocities, AP durations (APDs) and diastolic intervals respectively. From these, indices of active, λ = QT/(QRS duration), and resting, λ0 = TQ/(QRS duration), AP wavelengths were calculated...
2018: PloS One
Zhenghang Zhao, Raymond K Kudej, Hairuo Wen, Nadezhda Fefelova, Lin Yan, Dorothy E Vatner, Stephen F Vatner, Lai-Hua Xie
Hibernating animals show resistance to hypothermia-induced cardiac arrhythmias. However, it is not clear whether and how mammalian hibernators are resistant to ischemia-induced arrhythmias. The goal of this investigation was to determine the susceptibility of woodchucks ( Marmota monax) to arrhythmias and their mechanisms after coronary artery occlusion at the same room temperature in both winter, the time for hibernation, and summer, when they do not hibernate. By monitoring telemetric electrocardiograms, we found significantly higher arrhythmia scores, calculated as the severity of arrhythmias, with incidence of ventricular tachycardia, ventricular fibrillation, and thus sudden cardiac death (SCD) in woodchucks in summer than they had in winter...
February 28, 2018: FASEB Journal: Official Publication of the Federation of American Societies for Experimental Biology
Julie Royo, Nicolas Villain, Delphine Champeval, Federico Del Gallo, Giuseppe Bertini, Fabienne Aujard, Fabien Pifferi
Among environmental factors that may affect on brain function, some nutrients and particularly n-3 polyunsaturated fatty acids (n-3 PUFA) are required for optimal brain development. Their effects on cognitive functions, however, are still unclear, and studies in humans and rodents have yielded contradictory results. We used a non-human primate model, the grey mouse lemur, phylogenetically close to human. The aim of this study was to demonstrate the impact of n-3 PUFA supplementation on cognitive functions, neuronal activity and neurogenesis...
February 24, 2018: Behavioural Brain Research
Qi Huang, Dwayne Cohen, Sandra Komarzynski, Xiao-Mei Li, Pasquale Innominato, Francis Lévi, Bärbel Finkenstädt
Wearable computing devices allow collection of densely sampled real-time information on movement enabling researchers and medical experts to obtain objective and non-obtrusive records of actual activity of a subject in the real world over many days. Our interest here is motivated by the use of activity data for evaluating and monitoring the circadian rhythmicity of subjects for research in chronobiology and chronotherapeutic healthcare. In order to translate the information from such high-volume data arising we propose the use of a Markov modelling approach which (i) naturally captures the notable square wave form observed in activity data along with heterogeneous ultradian variances over the circadian cycle of human activity, (ii) thresholds activity into different states in a probabilistic way while respecting time dependence and (iii) gives rise to circadian rhythm parameter estimates, based on probabilities of transitions between rest and activity, that are interpretable and of interest to circadian research...
February 2018: Journal of the Royal Society, Interface
Cornelis Peter Bogerd, Kimberley B Velt, Simon Annaheim, Coen C W G Bongers, Thijs M H Eijsvogels, Hein A M Daanen
The experienced discomfort of rectal probes and esophageal probes for the estimation of body core temperatures has triggered the development of GI-capsules that are easy acceptable for athletes and workers due to their non-invasive characteristics. We compare two new GI-capsule devices with rectal temperature during cycle ergometer exercise and rest. Eight participants followed a protocol of (i) 30 min exercise with a power output of 130 W, (ii) 5 min rest, (iii) 10 min self-paced maximum exercise, and (iv) 15 min rest...
February 6, 2018: Physiological Measurement
Marisa Jelinek, Charlotte Wallach, Heimo Ehmke, Alexander Peter Schwoerer
In cardiovascular research, several mouse strains with differing genetic backgrounds are used to investigate mechanisms leading to and sustaining ventricular arrhythmias. The genetic background has been shown to affect the studied phenotype in other research fields. Surprisingly little is known about potential strain-specific susceptibilities towards ventricular arrhythmias in vivo. Here, we hypothesized that inter-strain differences reported in the responsiveness of the β-adrenergic pathway, which is relevant for the development of arrhythmias, translate into a strain-specific vulnerability...
February 2, 2018: Scientific Reports
Y Sun, L H Qin, X Chen, X Yan, L Mao, W Bai, J Kang
OBJECTIVES: To investigate the effects of black cohosh and estrogen on the temperature in ovariectomized rats, the core body temperature (CBT) and tail-skin temperature (TST) were simultaneously monitored and the relationship between these two temperatures was explored. METHODS: Twenty-four female Sprague-Dawley rats aged 8 weeks were randomly divided into four groups: sham-operated (SHAM), ovariectomized (OVX), OVX treated with estradiol valerate (OVX + E), and OVX treated with isopropanolic black cohosh extract (OVX + ICR)...
January 11, 2018: Climacteric: the Journal of the International Menopause Society
Yuko Kozasa, Noriyuki Nakashima, Masayuki Ito, Taisuke Ishikawa, Hiroki Kimoto, Kazuo Ushijima, Naomasa Makita, Makoto Takano
The heart rate is dynamically controlled by the sympathetic and parasympathetic nervous systems that regulate the sinoatrial node (SAN). HCN4 pacemaker channels are well-known causative molecule of congenital sick sinus syndrome. Although HCN4 channels are activated by cAMP, the sympathetic response of SAN was preserved in the patients carrying loss-of-function mutations of HCN4 gene. In order to clarify the contribution of HCN4 channels in the autonomic regulation of SAN, we developed novel gain-of-function mutant mice in which expression level of HCN4 channels could be reversibly changed from zero to ∼3 times of that in wild type mice, using tetracycline trans-activator and tetracycline responsive element...
January 9, 2018: Journal of Physiology
Akhil Deepika, Bhagavatula Indira Devi, Dhaval P Shukla, Talakad N Sathyaprabla, Rita Christopher, Shruthi S Ramesh
The purpose of the present study is to evaluate the inter-dependency between the electrophysiological (Heart rate variability) and inflammatory markers in traumatic brain injury (TBI) patients and the outcome in patients with severe TBI. A prospective exploratory study was done with a sample size of 89 severe traumatic brain injury patients. The Heart rate variability of these patients was recorded using a telemetric device BioHarness® (Zephyr technologies). The recordings were made on day 1 of the patients' admission into the ICU followed by serial recordings on Day 3 and day 10...
January 5, 2018: Journal of Neurotrauma
Motahareh Moghtadaei, Ellen Langille, Sara A Rafferty, Oleg Bogachev, Robert A Rose
Natriuretic peptides (NPs) play essential roles in the regulation of cardiovascular function. NP effects are mediated by receptors known as NPR-A, NPR-B or NPR-C. NPs have potent effects on regulation of heart rate (HR) by the autonomic nervous system (ANS), but the role of NPR-C in these effects has not been investigated. Accordingly, we have used telemetric ECG recordings in awake, freely moving wildtype and NPR-C knockout (NPR-C-/-) mice and performed heart rate variability (HRV) analysis to assess alterations in sympatho-vagal balance on the heart following loss of NPR-C...
December 14, 2017: Scientific Reports
Will Vickery, Alice Harkness
The purpose of this study was to provide a position specific (middle, link [male], link [female], wing) analysis of mixed gender touch on the physical physiological and perceptual demands of amateur players during match-play across a season. Distance and speed measures were obtained through the use of 10-Hz global positioning system devices, whilst telemetric heart rate devices were used determine a range of physiological measures. Players also provided a rating of perceived exertion following each match. The greatest physical demand was associated with the middle playing position by comparison to all others (Distance travelled ≥5...
December 2017: Journal of Sports Science & Medicine
Catherine O'Brien, Anthony J Karis, William J Tharion, Heather M Sullivan, Reed W Hoyt
Heat strain is common in military working dogs (MWDs), but can be mitigated by limiting duration of activity to avoid overheating and allowing sufficient time for recovery. To determine work/rest times for MWDs, temperature responses during training must be characterized. This study measured body core temperature of 48 MWDs at Lackland Air Force Base, San Antonio, TX. Twenty-four MWDs in training for patrol and detection activities participated under a range of ambient temperatures in August (27°C-32°C), October (22°C-26°C) and March (approximately 13°C)...
October 2017: U.S. Army Medical Department Journal
A C Matin, J-H Wang, Mimi Keyhan, Rachna Singh, Michael Benoit, Macarena P Parra, Michael R Padgen, Antonio J Ricco, Matthew Chin, Charlie R Friedericks, Tori N Chinn, Aaron Cohen, Michael B Henschke, Timothy V Snyder, Matthew P Lera, Shannon S Ross, Christina M Mayberry, Sungshin Choi, Diana T Wu, Ming X Tan, Travis D Boone, Christopher C Beasley, Matthew E Piccini, Stevan M Spremo
Human immune response is compromised and bacteria can become more antibiotic resistant in space microgravity (MG). We report that under low-shear modeled microgravity (LSMMG), stationary-phase uropathogenic Escherichia coli (UPEC) become more resistant to gentamicin (Gm), and that this increase is dependent on the presence of σs (a transcription regulator encoded by the rpoS gene). UPEC causes urinary tract infections (UTIs), reported to afflict astronauts; Gm is a standard treatment, so these findings could impact astronaut health...
November 2017: Life Sciences in Space Research
Madalena D Costa, Roger B Davis, Ary L Goldberger
Background: We recently introduced the concept of heart rate fragmentation along with a set of metrics for its quantification. The term was coined to refer to an increase in the percentage of changes in heart rate acceleration sign, a dynamical marker of a type of anomalous variability. The effort was motivated by the observation that fragmentation, which is consistent with the breakdown of the neuroautonomic-electrophysiologic control system of the sino-atrial node, could confound traditional short-term analysis of heart rate variability...
2017: Frontiers in Physiology
Thomas Mondritzki, Philip Boehme, Lena Schramm, Julia Vogel, Ilka Mathar, Peter Ellinghaus, Peter Kolkhof, Erwin Bischoff, Jörg Hüser, Wilfried Dinh, Peter Sandner, Hubert Truebel
PURPOSE: Testing of investigational drugs in animal models is a critical step in drug development. Current models of pulmonary hypertension (PH) have limitations. The most relevant outcome parameters such as pulmonary artery pressure (PAP) are measured invasively which requires anesthesia of the animal. We developed a new canine PH model in which pulmonary vasodilators can be characterized in conscious dogs and lung selectivity can be assessed non-invasively. METHODS: Telemetry devices were implanted to measure relevant hemodynamic parameters in conscious dogs...
January 2018: European Journal of Applied Physiology
Casper Schwartz Riedel, Birgitte Georg, Henrik L Jørgensen, Jens Hannibal, Jan Fahrenkrug
Early growth response transcription factor 1 (EGR1) is expressed in the suprachiasmatic nucleus (SCN) after light stimulation. We used EGR1-deficient mice to address the role of EGR1 in the clock function and light-induced resetting of the clock. The diurnal rhythms of expression of the clock genes BMAL1 and PER1 in the SCN were evaluated by semi-quantitative in situ hybridization. We found no difference in the expression of PER1 mRNA between wildtype and EGR1-deficient mice; however, the daily rhythm of BMAL1 mRNA was completely abolished in the EGR1-deficient mice...
November 14, 2017: Journal of Molecular Neuroscience: MN
Antonis Koutsonas, Peter Walter, Gernot Roessler, Niklas Plange
IMPORTANCE: To investigate the long-term safety of a novel intraocular telemetric pressure sensor. BACKGROUND: Acquisition of accurate intraocular pressure (IOP) data is vital for sufficient medical care of glaucoma patients. Non-invasive self-tonometry with a telemetric IOP sensor can provide important information regarding the individual IOP profile. DESIGN: Retrospective analysis of long-term follow-up data assessed during outpatient visits in a university hospital...
November 14, 2017: Clinical & Experimental Ophthalmology
Philip H Siebler, Jared D Heinze, Drake M Kienzle, Matthew W Hale, Jodi L Lukkes, Nina C Donner, Jared M Kopelman, Orlando A Rodriguez, Christopher A Lowry
Peripheral immune activation can have profound physiologic and behavioral effects. One mechanism through which immune activation may affect physiology and behavior is through actions on brainstem neuromodulatory systems, such as serotonergic systems. To test this hypothesis, in Experiment 1, adult male BALB/c mice were implanted with telemetric recording devices and then immunized with Mycobacterium vaccae NCTC 11659 (0.1 mg, s.c.; Days - 28, - 14; N = 36). On Day 1, mice received an acute challenge with M...
November 13, 2017: Cellular and Molecular Neurobiology
M L Blagonravov, E V Medvedeva, A A Bryk, V A Goryachev, M M Azova, E V Velichko
Daytime and nighttime systolic and diastolic BP was recorded in 23-week-old SHR and Wistar rats by telemetric monitoring. Urine concentrations of sodium, potassium, and calcium were determined in SHR rats during of light (07.00-19.00 h) and dark hours (19.00-07.00 h) at the age of 18, 19, 20, 21, 22, and 23 week; 23-week-old Wistar rats were used as the control. At early stages of the experiment, urine sodium concentration was elevated in SHR rats both at daytime and at night. Thereafter, this value declined and by 22-23 week was significantly lower than in normotensive Wistar rats, but only during daytime...
November 9, 2017: Bulletin of Experimental Biology and Medicine
Ramakrishna Nirogi, Saivishal Daripelli, Vijay Benade, Chaitanya Tirumalasetty, Gopinadh Bhyrapuneni, Pradeep Jayarajan
Drug-induced changes in electroencephalographic (EEG) characteristics in animals may be used to predict central activity of drugs in humans. Previous studies have established that drugs affect EEG characteristics in humans and rodents in a similar manner. However, there has been little work to establish correlations between drug effects on behavioral and EEG characteristics in rats. In the current study, we have simultaneously monitored EEG characteristics during a novel object recognition task (NORT) or open field (OF) test in rats...
December 2017: Behavioural Pharmacology
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