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https://www.readbyqxmd.com/read/28533073/the-impact-of-sevoflurane-on-coupling-of-the-left-ventricular-to-systemic-vasculature-in-rats-with-chronic-pulmonary-hypertension
#1
Lu Wang, Hui Luo, Gang Qin, Yanan Cao, Xiaowei Gao, Zhong Zhang, Zhi Ye, Junjie Zhang, Qulian Guo, E Wang
OBJECTIVES: The relationship between left ventricular function and afterload has not been investigated as much as the right ventricular function under chronic pulmonary hypertension (PH) during anesthesia. This study was designed to investigate effects of sevoflurane on the intrinsic coupling relationship between the left ventricle and systemic vasculature in the presence of PH. DESIGN: A randomized, controlled study. SETTING: University hospital...
February 13, 2017: Journal of Cardiothoracic and Vascular Anesthesia
https://www.readbyqxmd.com/read/28476921/non-invasive-evaluation-of-left-ventricular-elastance-according-to-pressure-volume-curves-modeling-in-arterial-hypertension
#2
Benjamin Bonnet, Franck Jourdan, Guilhem du Cailar, Pierre Fesler
Background- End systolic left ventricular (LV) elastance (Ees) has been previously calculated and validated invasively using LV pressure-volume (PV) loops. Non invasive methods have been proposed, but clinical application remains complex. The aim of the present study was to 1) estimate Ees according to modeling of LV PV curve during ejection ("Ejection PV Curve" method) and validate our method with existing published LV PV loops data. 2) test clinical applicability to detect non invasively a difference in Ees between normotensive and hypertensive subjects...
May 5, 2017: American Journal of Physiology. Heart and Circulatory Physiology
https://www.readbyqxmd.com/read/28475560/hydrodynamic-and-geometric-behavior-of-two-pericardial-prostheses-implanted-in-small-aortic-roots
#3
Giordano Tasca, Gianfranco Beniamino Fiore, Paola Redaelli, Claudia Romagnoni, Alberto Redaelli, Amando Gamba, Carlo Antona, Riccardo Vismara
Hydrodynamic performance of stented bioprostheses is far below that of the native valve. One of the reasons is that the internal diameter of the prosthesis is usually smaller than that of the native valve. However, other valve characteristics are also important in generating the pressure drop. We aimed to assess, in an ex vivo pulsatile mock loop, the hydrodynamic behavior of two bioprostheses, Trifecta and Mitroflow, to ascertain which geometric terms are limiting factors in hydrodynamic performance. At stroke volumes between 30 and 60 ml, Trifecta showed lower pressure drop, energy dissipation and valve resistance, and greater effective orifice area...
May 4, 2017: ASAIO Journal: a Peer-reviewed Journal of the American Society for Artificial Internal Organs
https://www.readbyqxmd.com/read/28465251/danshen-injection-prevents-heart-failure-by-attenuating-post-infarct-remodeling
#4
Lingyan Wang, Jiahui Yu, Patrick Asare Fordjour, Xiaoxue Xing, Hui Gao, Yanyan Li, Lingyan Li, Yan Zhu, Xiumei Gao, Guanwei Fan
ETHNOPHARMACOLOGICAL RELEVANCE: Danshen Injection (DSI) is a traditional Chinese medicine extracted from Danshen, prepared from the dried root and rhizome of Salvia miltiorrhiza Bunge. Danshen is an ancient antipyretic traditional Chinese medicine which is mostly used to improve blood circulation and dispel blood stasis. Danshen decoction or liquor-fried Danshen (with grain-based liquor) which is cool in nature is traditionally used to 'cool the blood' and reduce the swelling of sores and abscesses...
April 29, 2017: Journal of Ethnopharmacology
https://www.readbyqxmd.com/read/28410262/life-saving-esophageal-intubation-in-neonate-with-undiagnosed-tracheal-agenesis-a-case-report
#5
Christopher Sattler, Franklin Chiao, David Stein, Denise Murphy
A 3-day-old, 2.2-kg former 34-week premature infant with imperforate anus required loop ileostomy surgery. At delivery, the child had respiratory distress. Endotracheal intubation was "confirmed" by detection of exhaled carbon dioxide with a Pedi-Cap (Covidien, Dublin, Ireland) and subsequent chest x-ray. On arrival to the operating room, the pulse oximeter reading was 100% despite a large leak around the endotracheal tube and high-airway pressures. Packing the throat reduced the leak and increased the tidal volume...
April 13, 2017: A & A Case Reports
https://www.readbyqxmd.com/read/28402411/impact-of-acute-hypertension-transients-on-diastolic-function-in-patients-with-heart-failure-with-preserved-ejection-fraction
#6
Candelas Pérez Del Villar, Konstantinos Savvatis, Begoña López, Mario Kasner, Pablo Martinez-Legazpi, Raquel Yotti, Arantxa González, Javier Díez, Francisco Fernández-Avilés, Carsten Tschöpe, Javier Bermejo
Aim: To address the mechanisms responsible for the increase in LV filling pressures induced by acute hypertension transients in patients with heart failure with preserved ejection fraction (HFpEF). Methods and results: Multiple-beat pressure-volume loops were recorded during inferior vena cava occlusion in 39 HFpEF patients and 20 controls during handgrip and atrial pacing. We measured the contribution of relaxation, elastic recoil, and stiffness to instantaneous diastolic pressure using a novel processing method...
April 11, 2017: Cardiovascular Research
https://www.readbyqxmd.com/read/28400369/in-utero-particulate-matter-exposure-produces-heart-failure-electrical-remodeling-and-epigenetic-changes-at-adulthood
#7
Vineeta Tanwar, Matthew W Gorr, Markus Velten, Clayton M Eichenseer, Victor P Long, Ingrid M Bonilla, Vikram Shettigar, Mark T Ziolo, Jonathan P Davis, Stephen H Baine, Cynthia A Carnes, Loren E Wold
BACKGROUND: Particulate matter (PM; PM2.5 [PM with diameters of <2.5 μm]) exposure during development is strongly associated with adverse cardiovascular outcomes at adulthood. In the present study, we tested the hypothesis that in utero PM2.5 exposure alone could alter cardiac structure and function at adulthood. METHODS AND RESULTS: Female FVB mice were exposed either to filtered air or PM2.5 at an average concentration of 73.61 μg/m(3) for 6 h/day, 7 days/week throughout pregnancy...
April 11, 2017: Journal of the American Heart Association
https://www.readbyqxmd.com/read/28375841/a-mock-heart-engineered-with-helical-aramid-fibers-for-in-vitro-cardiovascular-device-testing
#8
So-Hyun Jansen-Park, Po-Lin Hsu, Indra Müller, Ulrich Steinseifer, Dirk Abel, Rüdiger Autschbach, Rolf Rossaint, Thomas Schmitz-Rode
Mock heart circulation loops (MHCLs) serve as in-vitro platforms to investigate the physiological interaction between circulatory systems and cardiovascular devices. A mock heart (MH) engineered with silicone walls and helical aramid fibers, to mimic the complex contraction of a natural heart, has been developed to advance the MHCL previously developed in our group. A mock aorta with an anatomical shape enables the evaluation of a cannulation method for ventricular assist devices (VADs) and investigation of the usage of clinical measurement systems like pressure-volume catheters...
April 1, 2017: Biomedizinische Technik. Biomedical Engineering
https://www.readbyqxmd.com/read/28375709/a-novel-hands-free-abdominal-compression-device-for-colonoscopy-significantly-decreases-cecal-intubation-time-a-prospective-single-blinded-pilot-study
#9
Allison R Schulman, Marvin Ryou, Walter W Chan
BACKGROUND: Colonoscopy outcome is limited by endoscope looping, which leads to patient discomfort, prolonged procedure, and increased sedation requirement. Traditional manual abdominal pressure is imprecise and manually intensive. A hands-free abdominal compression device (ACD) may improve colonoscopy outcome. We aimed to assess the effect of a novel ACD on colonoscopy outcomes compared to manual pressure. MATERIALS AND METHODS: This was a prospective single-blinded study of patients undergoing outpatient colonoscopy...
April 4, 2017: Journal of Laparoendoscopic & Advanced Surgical Techniques. Part A
https://www.readbyqxmd.com/read/28373412/ventriculo-arterial-coupling-detects-occult-rv-dysfunction-in-chronic-thromboembolic-pulmonary-vascular-disease
#10
Richard G Axell, Simon J Messer, Paul A White, Colm McCabe, Andrew Priest, Thaleia Statopoulou, Maja Drozdzynska, Jamie Viscasillas, Elizabeth C Hinchy, James Hampton-Till, Hatim I Alibhai, Nicholas Morrell, Joanna Pepke-Zaba, Stephen R Large, Stephen P Hoole
Chronic thromboembolic disease (CTED) is suboptimally defined by a mean pulmonary artery pressure (mPAP) <25 mmHg at rest in patients that remain symptomatic from chronic pulmonary artery thrombi. To improve identification of right ventricular (RV) pathology in patients with thromboembolic obstruction, we hypothesized that the RV ventriculo-arterial (Ees/Ea) coupling ratio at maximal stroke work (Ees/Eamax sw) derived from an animal model of pulmonary obstruction may be used to identify occult RV dysfunction (low Ees/Ea) or residual RV energetic reserve (high Ees/Ea)...
April 2017: Physiological Reports
https://www.readbyqxmd.com/read/28372840/restriction-capillaries-as-an-innovative-mixing-unit-for-intermediate-mobile-phase-exchange-in-multidimensional-analysis
#11
Glenn Loos, Konstantin Shoykhet, Monika Dittmann, Deirdre Cabooter
A novel mixing unit is proposed for the serial coupling of orthogonal columns to analyze polar and non-polar compounds in a single run. The principle relies on the isolation of unretained peaks eluting from a first dimension column in a sample loop, before directing them to a second column for separation. Since the mobile phases employed in highly orthogonal separations are not directly compatible, a mixing unit is required to alter the mobile phase composition before executing the second dimension separation...
May 12, 2017: Journal of Chromatography. A
https://www.readbyqxmd.com/read/28368344/the-combination-of-micro-diaphragm-pumps-and-flow-sensors-for-single-stroke-based-liquid-flow-control
#12
Christoph Jenke, Jaume Pallejà Rubio, Sebastian Kibler, Johannes Häfner, Martin Richter, Christoph Kutter
With the combination of micropumps and flow sensors, highly accurate and secure closed-loop controlled micro dosing systems for liquids are possible. Implementing a single stroke based control mode with piezoelectrically driven micro diaphragm pumps can provide a solution for dosing of volumes down to nanoliters or variable average flow rates in the range of nL/min to μL/min. However, sensor technologies feature a yet undetermined accuracy for measuring highly pulsatile micropump flow. Two miniaturizable in-line sensor types providing electrical readout-differential pressure based flow sensors and thermal calorimetric flow sensors-are evaluated for their suitability of combining them with mircopumps...
April 3, 2017: Sensors
https://www.readbyqxmd.com/read/28360259/influence-of-left-atrial-function-on-exercise-capacity-and-left-ventricular-function-in-patients-with-heart-failure-and-preserved-ejection-fraction
#13
Maximilian von Roeder, Karl-Philipp Rommel, Johannes Tammo Kowallick, Stephan Blazek, Christian Besler, Karl Fengler, Joachim Lotz, Gerd Hasenfuß, Christian Lücke, Matthias Gutberlet, Gerhard Schuler, Andreas Schuster, Philipp Lurz
BACKGROUND: Although left atrial (LA) dysfunction is common in heart failure with preserved ejection fraction (HFpEF), its functional implications beyond the reflection of left ventricular (LV) pathology are not well understood. The aim of this study was to further characterize LA function in HFpEF patients. METHODS AND RESULTS: We performed cardiac magnetic resonance myocardial feature tracking in 22 patients with HFpEF and 12 patients without HFpEF. LA reservoir strain, LA conduit strain, and LA booster pump strain were quantified...
April 2017: Circulation. Cardiovascular Imaging
https://www.readbyqxmd.com/read/28351966/the-quest-for-load-independent-left-ventricular-chamber-properties-exploring-the-normalized-pressure-volume-loop
#14
Keshav Kohli, Sándor J Kovács
Left ventricular (LV) pressure-volume (P-V) loop analysis is the gold standard for chamber function assessment. To advance beyond traditional P-V and pressure phase plane (dP/dt-P) analysis in the quest for novel load-independent chamber properties, we introduce the normalized P-V loop. High-fidelity LV pressure and volume data (161 P-V loops) from 13 normal control subjects were analyzed. Normalized LV pressure (PN) was defined by 0 ≤ P(t) ≤ 1. Normalized LV volume (VN) was defined as VN=V(t)/Vdiastasis, since the LV volume at diastasis (Vdiastasis) is the in-vivo equilibrium volume relative to which the LV volume oscillates...
March 2017: Physiological Reports
https://www.readbyqxmd.com/read/28259865/parametrization-of-an-in-silico-circulatory-simulation-by-clinical-datasets-towards-prediction-of-ventricular-function-following-assist-device-implantation
#15
Ajay Moza, Jonas Gesenhues, Rüdiger Autschbach, Dirk Abel, Rolf Rossaint, Thomas Schmitz-Rode, Andreas Goetzenich
BACKGROUND: Left ventricular assist device (LVAD) therapy has revolutionized the way end stage heart failure is treated today. Analysis of LVAD interaction with the whole cardiovascular system and its biological feedback loops is often conducted by means of computer models. Generating real time pressure volume loops (PV-loops) in patients, not using conductance catheters but routine diagnostics to feed an in-silico model could help to predict postoperative complications. METHODS: Routinely obtained hemodynamic measurements to evaluate myocardial function prior to LVAD implantation like pressure readings in the aorta, the left atrium and the left ventricle and simultaneous three-dimensional (3D) echocardiography recordings were assessed to parametrize a reduced computational model of the cardiovascular system...
April 1, 2017: Biomedizinische Technik. Biomedical Engineering
https://www.readbyqxmd.com/read/28228405/inhibition-of-romk-blocks-macula-densa-tubuloglomerular-feedback-yet-causes-renal-vasoconstriction-in-anesthetized-rats
#16
Magali Araujo, William J Welch, Xiaoyan Zhou, Kathleen Sullivan, Shawn Walsh, Alexander Pasternak, Christopher S Wilcox
The Na+/K+/2Cl- cotransporter (NKCC2) on the loop of Henle is the site of action of furosemide. Since outer medullary potassium channel (ROMK) inhibitors prevent reabsorption by NKCC2, we tested the hypothesis that ROMK inhibition with a novel, selective ROMK inhibitor (Compound C) blocks tubuloglomerular feedback (TGF) and reduces vascular resistance. Loop perfusion of either ROMK inhibitor or furosemide caused dose-dependent blunting of TGF, but the response to furosemide was 10-fold more sensitive (IC50= 10-6M for furosemide and IC50=10-5M for Compound C)...
February 22, 2017: American Journal of Physiology. Renal Physiology
https://www.readbyqxmd.com/read/28202552/airway-dynamics-in-copd-patients-by-within-breath-impedance-tracking-effects-of-continuous-positive-airway-pressure
#17
András Lorx, Dorottya Czövek, Zoltán Gingl, Gergely Makan, Bence Radics, Dóra Bartusek, Szabolcs Szigeti, János Gál, György Losonczy, Peter D Sly, Zoltán Hantos
Tracking of the within-breath changes of respiratory mechanics using the forced oscillation technique may provide outcomes that characterise the dynamic behaviour of the airways during normal breathing.We measured respiratory resistance (Rrs) and reactance (Xrs) at 8 Hz in 55 chronic obstructive pulmonary disease (COPD) patients and 20 healthy controls, and evaluated Rrs and Xrs as functions of gas flow (V') and volume (V) during normal breathing cycles. In 12 COPD patients, additional measurements were made at continuous positive airway pressure (CPAP) levels of 4, 8, 14 and 20 hPa...
February 2017: European Respiratory Journal: Official Journal of the European Society for Clinical Respiratory Physiology
https://www.readbyqxmd.com/read/28188007/volumetric-contributions-of-loop-regions-of-g-quadruplex-dna-to-the-formation-of-the-tertiary-structure
#18
Shuntaro Takahashi, Naoki Sugimoto
DNA guanine-quadruplexes (G-quadruplexes) are unique DNA structures formed by guanine-rich sequences. The loop regions of G-quadruplexes play key roles in stability and topology of G-quadruplexes. Here, we investigated volumetric changes induced by pressure in the folding of the G-quadruplex formed by the thrombin binding aptamer (TBA) with mutations within the loop regions. The change of partial molar volume in the transition from coil to G-quadruplex, ∆Vtr, of TBA with a mutation from T to A in the 5' most loop (TBA T3A) was 75...
February 6, 2017: Biophysical Chemistry
https://www.readbyqxmd.com/read/28162829/the-role-of-loops-and-cation-on-the-volume-of-unfolding-of-g-quadruplexes-related-to-htel
#19
Yang Yun Li, David N Dubins, Dianna My Nhi Thi Le, Karen Leung, Robert B Macgregor
In aqueous solutions containing sodium or potassium cations, oligodeoxyribonucleotides (ODNs) rich in guanine form four-stranded DNA structures called G-quadruplexes (G4s). These structures are destabilized by elevated hydrostatic pressure. Here, we use pressure to investigate the volumetric changes arising from the formation of G4 structures. G4s display a great deal of structural heterogeneity that depends on the stabilizing cation as well as the oligonucleotide sequence. Using UV thermal unfolding at different pressures, we have investigated the volume change of the helix-coil equilibrium of a series of ODNs whose sequences are related to the G-rich ODN HTel (d[A(GGGTTA)3GGG]), which contains four repeats of the human telomeric sequence...
January 6, 2017: Biophysical Chemistry
https://www.readbyqxmd.com/read/28134561/long-term-low-dose-dietary-resveratrol-supplement-reduces-cardiovascular-structural-and-functional-deterioration-in-chronic-heart-failure-in-rats
#20
Ismayil Ahmet, Hyun-Jin Tae, Edward G Lakatta, Mark Talan
A short-term exposure to resveratrol at high dosages exerts a remarkable cardioprotective effect. Whether a long-term exposure to resveratrol at low dosages that can be obtained through consumption of a resveratrol-rich diet is beneficial to heart diseases is unknown. We tested the effects of a resveratrol-enriched diet on cardiovascular remodeling of chronic heart failure (CHF) in rats resulting from permanent ligation of left coronary artery. Two weeks after surgery, rats were started on either a resveratrol-enriched (R; 5 mg/kg per day; n = 23) or normal (Control; n = 23) diet for next 10 months...
March 2017: Canadian Journal of Physiology and Pharmacology
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