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Flow volume loop

Yosuke Nakazawa, Mikako Oka, Megumi Funakoshi-Tago, Hiroomi Tamura, Makoto Takehana
PURPOSE: Although aquaporin 0 (AQP0) is a member of the AQP family, it has limited water permeability compared with other members. AQP0 may also have cell adhesion-related functions, but the evidence is still limited. Here, we studied the relationship of AQP0 to cell adhesion and determined the region required for cell adhesion. METHODS: L-cell fibroblasts stably expressing AQP0 or AQP1 (L-AQP0 or L-AQP1) were established. One group of cells was stained with CellTracker Red and cultured into a confluent monolayer, whereas the other group was loaded with CellTracker Blue and seeded over the monolayer...
October 18, 2016: Current Eye Research
Federica Trucco, Marina Pedemonte, Chiara Fiorillo, Paola Tacchetti, Giacomo Brisca, Claudio Bruno, Carlo Minetti
Facioscapulohumeral muscular dystrophy (FSHD) is an autosomal dominant inherited disorder characterized by selective weakness of face and upper arms and girdle. Respiratory involvement in FSHD has been described mainly in the most severely affected patients. In this work we tested the respiratory function by spirometry in 12 patients affected by FSHD with onset before 18 years. Spirometry results were correlated with motor involvement and compared to aged matched group of Becker patients. Of note FSHD patients present a peculiar pattern characterized by a flat shape in flow-volume loop...
October 2016: Respiratory Medicine
L Gattinoni, T Tonetti, M Cressoni, P Cadringher, P Herrmann, O Moerer, A Protti, M Gotti, C Chiurazzi, E Carlesso, D Chiumello, M Quintel
PURPOSE: We hypothesized that the ventilator-related causes of lung injury may be unified in a single variable: the mechanical power. We assessed whether the mechanical power measured by the pressure-volume loops can be computed from its components: tidal volume (TV)/driving pressure (∆P aw), flow, positive end-expiratory pressure (PEEP), and respiratory rate (RR). If so, the relative contributions of each variable to the mechanical power can be estimated. METHODS: We computed the mechanical power by multiplying each component of the equation of motion by the variation of volume and RR: [Formula: see text]where ∆V is the tidal volume, ELrs is the elastance of the respiratory system, I:E is the inspiratory-to-expiratory time ratio, and R aw is the airway resistance...
October 2016: Intensive Care Medicine
Leopoldo C Cancio, Jose Salinas, George C Kramer
Fluid resuscitation of burn patients is commonly initiated using modified Brooke or Parkland formula. The fluid infusion rate is titrated up or down hourly to maintain adequate urine output and other endpoints. Over-resuscitation leads to morbid complications. Adherence to paper-based protocols, flow sheets, and clinical practice guidelines is associated with decreased fluid resuscitation volumes and complications. Computerized tools assist providers. Although completely autonomous closed-loop control of resuscitation has been demonstrated in animal models of burn shock, the major advantages of open-loop and decision-support systems are identifying trends, enhancing situational awareness, and encouraging burn team communication...
October 2016: Critical Care Clinics
Stephanie Schmitz, Kristin Unthan, Marc Sedlaczek, Felix Wald, Thomas Finocchiaro, Sotirios Spiliopoulos, Reiner Koerfer, Ulrich Steinseifer
At our institute a total artificial heart is being developed. It is directly actuated by a linear drive in between two ventricles, which comprise membranes to separate the drive and blood flow. A compliance chamber (CC) is needed to reduce pressure peaks in the ventricles and to increase the pump capacity. Therefore, the movement of the membrane is supported by applying a negative pressure to the air volume inside the drive unit. This study presents the development of the implantable CC which is connected to the drive unit of the total artificial hearts (TAH)...
September 1, 2016: Artificial Organs
Janos Varga, Richard Casaburi, Shuyi Ma, Ariel Hecht, David Hsia, Attila Somfay, Janos Porszasz
Active expiration during exercise can increase intrathoracic pressure yielding concavity in the expiratory flow-volume loop in COPD. We investigated the relationship between this concavity and dynamic hyperinflation (DH). 17 COPD patients (FEV1: 38±10%pred, GOLD stage 3-4) and 12 healthy subjects performed cycle ergometer incremental exercise. Expiratory limb of the spontaneous flow-volume loop was analyzed breath-by-breath using a geometric approach (rectangular area ratio (RAR), Respir. Med., 104(3):389-96, 2010)...
August 26, 2016: Respiratory Physiology & Neurobiology
Leander A H Petersen, John Villadsen, Sten B Jørgensen, Krist V Gernaey
A system capable of handling a large volumetric gas fraction while providing a high gas to liquid mass transfer is a necessity if the metanotrophic bacterium Methylococcus capsulatus is to be used in single cell protein (SCP) production. In this study mixing time and mass transfer coefficients were determined in a 0.15 m(3) forced flow U-loop fermenter of a novel construction. The effect on the impeller drawn power when a gas was introduced into the system was also studied. Mixing time decreased and mass transfer increased with increasing volumetric liquid flow rate and specific power input...
August 29, 2016: Biotechnology and Bioengineering
Liuba Soldatova, Candace Hrelec, Laura Matrka
OBJECTIVE: To determine if the results of routine spirometry and flow volume loops (Pulmonary Function Tests (PFTs)) can be used to distinguish Paradoxic Vocal Fold Movement Disorder (PVFMD) from Subglottic Stenosis (SGS). METHODS: PFT records and medical history of 49 patients with diagnosis of PVFMD and 39 patients with SGS were compared. Groups were then subdivided to compare PFTs in patients with and without smoking history or lung disease. RESULTS: Peak expiratory flow rate (PEFR) and Expiratory Disproportion Index (ratio of forced expiratory volume in 1 second (FEV1) over PEFR (FEV1/PEFR)) were both significantly different between patients with SGS and those with PVFMD (p<0...
August 23, 2016: Annals of Otology, Rhinology, and Laryngology
Giordano Tasca, Riccardo Vismara, Andrea Mangini, Claudia Romagnoni, Monica Contino, Alberto Redaelli, Gianfranco Beniamino Fiore, Carlo Antona
BACKGROUND: Aortic valve replacement has evolved recently with the development of the sutureless bioprosthesis. One such valve is the Perceval bioprosthesis, which is built by mounting leaflets of bovine pericardium to a thin stent; this approach has the potential to provide an excellent fluid dynamic performance. We undertook an in vitro study to compare the hydrodynamic performance of the sutureless bioprosthesis with two standard pericardial stented bioprostheses (Crown and Magna)...
August 17, 2016: Annals of Thoracic Surgery
Pei Ma, Shi Gu, Ganga H Karunamuni, Michael W Jenkins, Michiko Watanabe, Andrew M Rollins
Cardiac neural crest cell (CNCC) ablation creates congenital heart defects (CHDs) that resemble those observed in many syndromes with craniofacial and cardiac consequences. The loss of CNCCs causes a variety of great vessel defects, including persistent truncus arteriosus and double outlet right ventricle. However, due to the lack of quantitative volumetric measurements, less severe defects, such as great vessel size changes and valve defects have not been assessed. Also poorly understood is the role of abnormal cardiac function in the progression of CNCC-related CHDs...
August 19, 2016: American Journal of Physiology. Heart and Circulatory Physiology
Andrew Ladwiniec, Paul A White, Sukhjinder S Nijjer, Michael O'Sullivan, Nick E J West, Justin E Davies, Stephen P Hoole
BACKGROUND: Wave intensity analysis can distinguish proximal (propulsion) and distal (suction) influences on coronary blood flow and is purported to reflect myocardial performance and microvascular function. Quantifying the amplitude of the peak, backwards expansion wave (BEW) may have clinical utility. However, simultaneously acquired wave intensity analysis and left ventricular (LV) pressure-volume loop data, confirming the origin and effect of myocardial function on the BEW in humans, have not been previously reported...
September 2016: Circulation. Cardiovascular Interventions
Tanya Swaine, Yiqing Tang, Pedro Garcia, Jasmine John, Laura J Waters, Andrew L Lewis
An improved method for evaluating drug release behaviour of drug-eluting embolization beads (DEBs) was developed utilizing an open-loop flow-through system, in which the beads were packed into an occlusive mass within the system and extracted with a flowing elution medium over time. Glass beads were introduced into the beads mass in order to ensure laminar flow, reduce dead volume and improve reproducibility by compensating for swelling phenomena. The effects of glass bead ratio, elution medium flow rate and ion concentration, DEB size and drug concentration and drug type (doxorubicin and irinotecan) were evaluated using DEB composed of a sulfonate-modified polyvinyl alcohol hydrogel (DC Bead™) as the test article...
October 10, 2016: European Journal of Pharmaceutical Sciences
Ivana Calice, Yves Moens
Modern spirometry, like no other monitoring technique, allows insight into breath-to-breath respiratory mechanics. Spirometers continuously measure volume, airway pressure, and flow while calculating and continuously displaying respiratory system compliance and resistance in the form of loops. The aim of this case series is to show how observation of spirometric loops, similar to electrocardiogram or CO2 curve monitoring, can improve safety of anesthetic management in small animals. Spirometric monitoring cases described in this case series are based on use of the anaesthesia monitor Capnomac Ultima with a side stream spirometry sensor...
September 2016: Journal of the American Animal Hospital Association
Priya Prabhakaran, William C Sasser, Yuvrai Kalra, Chrystal Rutledge, Nancy M Tofil
Providing optimal mechanical ventilation to critically-ill children remains a challenge. Patient-ventilator dyssynchrony results frequently with numerous deleterious consequences on patient outcome including increased requirement for sedation, prolonged duration of ventilation, and greater imposed work of breathing. Most currently used ventilators have real-time, continuously-displayed graphics of pressure, volume, and flow versus time (scalars) as well as pressure, and flow versus volume (loops). A clear understanding of these graphics provides a lot of information about the mechanics of the respiratory system and the patient ventilator interaction in a dynamic fashion...
December 2016: Minerva Pediatrica
Haifeng Shi, Ruokun Li, Jinwei Qiang, Ying Li, Li Wang, Rongxun Sun
OBJECTIVE: To evaluate multi-slice computed tomography (CT) perfusion imaging (CTPI) for identifying microcirculatory dysfunction in small intestinal ischemia-reperfusion (IR) injury in a porcine model. MATERIALS AND METHODS: Fifty-two pigs were randomly divided into 4 groups: (1) the IR group (n = 24), where intestinal ischemia was induced by separating and clamping the superior mesenteric artery (SMA) for 2 h, followed by reperfusion for 1, 2, 3, and 4 h (IR-1h, IR-2h, IR-3h, and IR-4h; n = 6, respectively); (2) the sham-operated (SO) group (n = 20), where the SMA was separated without clamping and controlled at postoperative 3, 4, 5, and 6 h (SO-3h, SO-4h, SO-5h, and SO-6h; n = 5, respectively); (3) the ischemia group (n = 4), where the SMA was separated and clamped for 2 h, without reperfusion, and (4) baseline group (n = 4), an additional group that was not manipulated...
2016: PloS One
Abhinav Agrawal, Sonu Sahni, Galina Marder, Rakesh Shah, Arunabh Talwar
Spirometry flow-volume measurement is used routinely in the outpatient setting to rule out obstructive lung diseases. Biphasic flow-volume loop is a classic presentation of unilateral bronchial stenosis due to multiple etiologies and it should raise clinical suspicion. Granulomatosis with polyangiitis (GPA) is a systemic inflammatory condition with pulmonary manifestations that may be infiltrative (e.g., pneumonia), hemorrhagic, and may rarely cause bronchial stenosis. Herein, we present a case of GPA-related, bronchial obstruction that caused biphasic flow-volume loop along with a literature review...
July 2016: Respiratory Investigation
Renuka Arumainathan, Stephen A C Morris, Marina George
Pulmonary function tests such as flow-volume loops and reconstructive radiological imaging may aid the detection of large airway obstruction prior to corrective surgery for severe scoliosis. Intraoperative use of halo-gravity traction may help to reduce the severity of the scoliosis, and thus the extrinsic compression or torsion of the airways.
July 2016: Clinical Case Reports
Yaxin Wang, P Alex Smith, Daniel L Timms, Po-Lin Hsu, Richard A McMahon
The intra-aortic ventricular assist device (IntraVAD) is a miniature intra-aortic axial-flow ventricular assist device (VAD) that works in series with the left ventricle (LV) to assist the compromised heart. Previous in vitro results have shown that the IntraVAD can successfully increase coronary perfusion and offload ventricular volume by operating in reverse-rotation control (RRc) mode. The RRc mode includes forward rotation in systole and reverse rotation (RR) in diastole. It is necessary to derive a new diffuser design that can be used for the bi-directional rotation of the IntraVAD...
September 2016: Artificial Organs
Christoph Kolb, Andreas Wetscherek, Maria Teodora Buzan, René Werner, Christopher M Rank, Marc Kachelrie, Michael Kreuter, Julien Dinkel, Claus Peter Heuel, Klaus Maier-Hein
OBJECTIVE: We propose a computer-aided method for regional ventilation analysis and observation of lung diseases in temporally resolved magnetic resonance imaging (4D MRI). METHODS: A shape model-based segmentation and registration workflow was used to create an atlas-derived reference system in which regional tissue motion can be quantified and multimodal image data can be compared regionally. Model-based temporal registration of the lung surfaces in 4D MRI data was compared with the registration of 4D computed tomography (CT) images...
June 22, 2016: Journal of Computer Assisted Tomography
Giuseppe Natalini, Daniele Tuzzo, Antonio Rosano, Marco Testa, Michele Grazioli, Vincenzo Pennestrì, Guido Amodeo, Francesco Berruto, Marialinda Fiorillo, Alberto Peratoner, Andrea Tinnirello, Matteo Filippini, Paolo F Marsilia, Cosetta Minelli, Achille Bernardini
BACKGROUND: In some patients with auto-positive end-expiratory pressure (auto-PEEP), application of PEEP lower than auto-PEEP maintains a constant total PEEP, therefore reducing the inspiratory threshold load without detrimental cardiovascular or respiratory effects. We refer to these patients as "complete PEEP-absorbers." Conversely, adverse effects of PEEP application could occur in patients with auto-PEEP when the total PEEP rises as a consequence. From a pathophysiological perspective, all subjects with flow limitation are expected to be "complete PEEP-absorbers," whereas PEEP should increase total PEEP in all other patients...
December 2016: Annals of Intensive Care
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