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Respiratory physiology

Leszek Kubin
Upper airway muscles subserve many essential for survival orofacial behaviors, including their important role as accessory respiratory muscles. In the face of certain predisposition of craniofacial anatomy, both tonic and phasic inspiratory activation of upper airway muscles is necessary to protect the upper airway against collapse. This protective action is adequate during wakefulness, but fails during sleep which results in recurrent episodes of hypopneas and apneas, a condition known as the obstructive sleep apnea syndrome (OSA)...
September 15, 2016: Comprehensive Physiology
Antonia Lanni, Maria Moreno, Fernando Goglia
The hypermetabolic effects of thyroid hormones (THs), the major endocrine regulators of metabolic rate, are widely recognized. Although, the cellular mechanisms underlying these effects have been extensively investigated, much has yet to be learned about how TH regulates diverse cellular functions. THs have a profound impact on mitochondria, the organelles responsible for the majority of cellular energy production, and several studies have been devoted to understand the respective importance of the nuclear and mitochondrial pathways for organelle activity...
September 15, 2016: Comprehensive Physiology
Marlon E F Wilsterman, Pauline de Jager, Robert Blokpoel, Inez Frerichs, Sandra K Dijkstra, Marcel J I J Albers, Johannes G M Burgerhof, Dick G Markhorst, Martin C J Kneyber
BACKGROUND: Neuromuscular blockade (NMB) has been shown to improve outcome in acute respiratory distress syndrome (ARDS) in adults, challenging maintaining spontaneous breathing when there is severe lung injury. We tested in a prospective physiological study the hypothesis that continuous administration of NMB agents in mechanically ventilated children with severe acute hypoxemic respiratory failure (AHRF) improves the oxygenation index without a redistribution of tidal volume V T toward non-dependent lung zones...
December 2016: Annals of Intensive Care
D Wang, A Fu
Mitochondria possess oxygen-consuming respiratory electron transfer chains (RETCs), and the oxygen-evolving photosynthetic electron transfer chain (PETC) resides in chloroplasts. Evolutionarily mitochondria and chloroplasts are derived from ancient α-proteobacteria and cyanobacteria, respectively. However, cyanobacteria harbor both RETC and PETC on their thylakoid membranes. It is proposed that chloroplasts could possess a RETC on the thylakoid membrane, in addition to PETC. Identification of a plastid terminal oxidase (PTOX) in the chloroplast from the Arabidopsis variegation mutant immutans (im) demonstrated the presence of a RETC in chloroplasts, and the PTOX is the committed oxidase...
2016: Enzymes
Oksana N Khokhlova, Elena A Tukhovskaya, Irina N Kravchenko, Elena S Sadovnikova, Irina A Pakhomova, Elena A Kalabina, Alexander V Lobanov, Elvira R Shaykhutdinova, Alina M Ismailova, Arkady N Murashev
INTRODUCTION: It is important that the method of anesthesia of mice does not considerably alter the animal's physiological and metabolic status before terminal blood sampling taken in order to analyze clinical pathology parameters. METHODS: Hematology, hemostasis, and clinical chemistry parameters were compared in male and female BALB/c mice exposed to either tiletamine-zolazepam-xylazine (TZX) anesthesia or euthanasia in carbon dioxide (CO2) chamber to reveal an alternative method of anesthesia vs...
October 20, 2016: Journal of Pharmacological and Toxicological Methods
Sterghios A Moschos, Louise Usher, Mark A Lindsay
The discovery of an ever-expanding plethora of coding and non-coding RNAs with nodal and causal roles in the regulation of lung physiology and disease is reinvigorating interest in the clinical utility of the oligonucleotide therapeutic class. This is strongly supported through recent advances in nucleic acids chemistry, synthetic oligonucleotide delivery and viral gene therapy that have succeeded in bringing to market at least three nucleic acid-based drugs. As a consequence, multiple new candidates such as RNA interference modulators, antisense, and splice switching compounds are now progressing through clinical evaluation...
October 19, 2016: Pharmacology & Therapeutics
Yi Li, Xueqian Lei, Yanting Xu, Hong Zhu, Meiying Xu, Lijun Fu, Wei Zheng, Jinli Zhang, Tianling Zheng
A Gram-stain-negative, aerobic bacterial strain, designated Y21(T), was isolated from surface lake water in Xiamen, Fujian Province of China. Growth was observed at temperatures from 4 to 37 °C, at salinities from 0 to 7.0 % and at pH from 6.0 to 10.0. Optimum growth was observed at 28 °C, at pH 7.0 and with 1.5-2.0 % (w/v) NaCl. The highest similarity of 16S rRNA gene sequence between strain Y21(T) and the other strains was 96.9 %. Phylogenetic analysis based on 16S rRNA gene sequencing revealed that the strain was a member of the genus Rhizobium, forming a distinct lineage with R...
October 22, 2016: Current Microbiology
Michael C Sklar, Karen Burns, Nuttapol Rittayamai, Ashley Lanys, Michela Rauseo, Lu Chen, Martin Dres, Guang-Qiang Chen, Ewan C Goligher, Neill Kj Adhikari, Laurent Brochard, Jan O Friedrich
Introduction Spontaneous breathing trials (SBTs) are designed to simulate conditions following extubation and it is essential to understand the physiological impact of different methods. We conducted a systematic review and pooled measures reflecting patient respiratory effort among studies comparing SBT methods in a meta-analysis. Methods We searched Medline, EMBASE, and Web of Science from inception to January 2016 to identify randomized and non-randomized clinical trials reporting physiological measurements of respiratory effort (pressure-time product, PTP) or work of breathing during at least 2 SBT techniques...
October 21, 2016: American Journal of Respiratory and Critical Care Medicine
Carlota Saldanha
Nitric oxide (NO) produced by endothelial cells interacts with erythrocyte through band 3 protein, being scavenged by haemoglobin. A signal transduction mechanism involving protein Gi and protein band 3 stimulates erythrocyte NO efflux when acetylcholine (ACh) binds to erythrocyte membrane acetylcholinesterase. Binding of normal plasma fibrinogen (Fib) levels, to erythrocyte membrane CD47 decreases the NO efflux. When high Fib concentration and ACh were present the efflux of NO from erythrocytes was normalized...
October 20, 2016: Clinical Hemorheology and Microcirculation
Denis E O'Donnell, J Alberto Neder, Ingrid Harle, Onofre Moran-Mendoza
Idiopathic pulmonary fibrosis (IPF) is one of the most common forms of interstitial lung disease, with a median survival time of two to five years. Most patients with IPF experience chronic breathlessness, which is closely linked to poor perceived quality of life and significant restriction of daily activities; therefore, effective management of this distressing symptom is a major goal of patient care. Areas covered: This report summarizes the physiology of IPF during rest and exercise, outlines current concepts of the mechanisms of breathlessness, and provides a physiological rationale for optimal management of individual patient...
October 21, 2016: Expert Review of Respiratory Medicine
Joseph M Blankush, Robbie Freeman, Joy McIlvaine, Trung Tran, Stephen Nassani, I Michael Leitman
Modified Early Warning Scores (MEWS) provide real-time vital sign (VS) trending and reduce ICU admissions in post-operative patients. These early warning calculations classically incorporate oxygen saturation, heart rate, respiratory rate, systolic blood pressure, and temperature but have not previously included end-tidal CO2 (EtCO2), more recently identified as an independent predictor of critical illness. These systems may be subject to failure when physiologic data is incorrectly measured, leading to false alarms and increased workload...
October 20, 2016: Journal of Clinical Monitoring and Computing
Matthias Jacob, Daniel Chappell, Bernhard F Becker
Oxygen delivery to cells is the basic prerequisite of life. Within the human body, an ingenious oxygen delivery system, comprising steps of convection and diffusion from the upper airways via the lungs and the cardiovascular system to the microvascular area, bridges the gap between oxygen in the outside airspace and the interstitial space around the cells. However, the complexity of this evolutionary development makes us prone to pathophysiological problems. While those problems related to respiration and macrohemodynamics have already been successfully addressed by modern medicine, the pathophysiology of the microcirculation is still often a closed book in daily practice...
October 21, 2016: Critical Care: the Official Journal of the Critical Care Forum
Robert P Ellis, Mauricio A Urbina, Rod W Wilson
Exponentially rising CO2 (currently ~400 μatm) is driving climate change and causing acidification of both marine and freshwater environments. Physiologists have long known that CO2 directly affects acid-base and ion regulation, respiratory function and aerobic performance in aquatic animals. More recently, many studies have demonstrated that elevated CO2 projected for end of this century (e.g. 800-1000 μatm) can also impact physiology, and have substantial effects on behaviours linked to sensory stimuli (smell, hearing and vision) both having negative implications for fitness and survival...
October 20, 2016: Global Change Biology
Haitao Yu, Rishi R Dhingra, Thomas E Dick, Roberto Fernandez Galan
Neural activity generally displays irregular firing patterns even in circuits with apparently regular outputs, such as motor pattern generators, in which the output frequency fluctuates randomly around a mean value. This "circuit noise" is inherited from the random firing of single neurons, which emerges from stochastic ion-channel gating (channel noise), spontaneous neurotransmitter release, and its diffusion and binding to synaptic receptors. Here, we demonstrate how to expand conductance-based network models that are originally deterministic to include realistic, physiological noise, focusing on stochastic ion-channel gating...
October 19, 2016: Journal of Neurophysiology
P Sławuta, G Sapikowski, B Sobieraj
: Buffer systems of blood and tissues, which have the ability to bind with and give up hydrogen ions, participate in maintaining the acid-base balance (ABB) of the organism. According to the classic model, the system of carbonic acid and bicarbonates, where the first component serves the role of an acid and the second a base, determines plasma pH. The so-called Stewart model, which assumes that ions in blood serum can be separated into completely dissociated - nonbuffer and not dissociated - buffer ions which may give up or accept H+ions, also describes the ABB of the organism...
September 1, 2016: Polish Journal of Veterinary Sciences
Deng-Wei Chou, Shu-Ling Wu, Kuo-Mou Chung, Shu-Chen Han, Bruno Man-Hon Cheung
OBJECTIVES: Septic pulmonary embolism is an uncommon but life-threatening disorder. However, data on patients with septic pulmonary embolism who require critical care have not been well reported. This study elucidated the clinicoradiological spectrum, causative pathogens and outcomes of septic pulmonary embolism in patients requiring critical care. METHODS: The electronic medical records of 20 patients with septic pulmonary embolism who required intensive care unit admission between January 2005 and December 2013 were reviewed...
October 1, 2016: Clinics
Wei Lu, Zhenhong Wang
The present studies examined the influence of extraversion on physiological reactivity, recovery, and physiological habituation-sensitization to repeated social stressors. In Study 1, subjective and physiological data were collected from 97 college students who were categorized as high (n = 51) and low (n = 46) on extraversion (NEO-FFI) across five laboratory stages: baseline, stress 1, poststress 1, stress 2, and poststress 2. Results indicated high extraversion (HE) participants exhibited relative lesser heart rate (HR) reactivity and respiratory sinus arrhythmia (RSA) withdrawals to, and more complete HR and RSA recovery after the first social stress, and also exhibited relative lesser HR reactivity to the second social stress...
October 18, 2016: Psychophysiology
Jonathan D Power, Mark Plitt, Timothy O Laumann, Alex Martin
Whole-brain fMRI signals are a subject of intense interest: variance in the global fMRI signal (the spatial mean of all signals in the brain) indexes subject arousal, and psychiatric conditions such as schizophrenia and autism have been characterized by differences in the global fMRI signal. Further, vigorous debates exist on whether global signals ought to be removed from fMRI data. However, surprisingly little research has focused on the empirical properties of whole-brain fMRI signals. Here we map the spatial and temporal properties of the global signal, individually, in 1000+ fMRI scans...
October 14, 2016: NeuroImage
Sanjoy K Sureka, Nitesh Patidar, Varun Mittal, Rakesh Kapoor, Aneesh Srivastava, Kamal Kishore, Sanjay Dhiraj, M S Ansari
OBJECTIVE: A safe and optimal pneumoperitoneal pressure (PP) for laparoscopic renal surgery in infants is difficult to define. In a broad sense, a safe and optimal PP should cause least intraoperative and postoperative physiological stress for the infants and should be optimal for surgeon's technical feasibility. Unfortunately, the safe and optimal PP in infant for transperitoneal laparoscopic surgery has not been established by well validated study. To determine safe and optimal PP for laparoscopic renal surgery (LRS) in infants less than 10 kg...
March 4, 2016: Journal of Pediatric Urology
Magnus von Seth, Miklós Lipcsey, Peter Engström, Anders Larsson, Lars Hillered, Enn Maripuu, Charles Widström, Jan Sjölin
Some experimental data suggest that rapid bolus administration of albumin causes less plasma-expanding effects than slow, continuous infusion. To determine whether rapid bolus administration, in comparison with slow infusion, results in greater extravasation of albumin in experimental septic shock we performed a randomized controlled trial with 32 endotoxemic pigs. The animals were monitored and ventilated with standard intensive care equipment and given 10 mL x kg 5% albumin labeled with Technetium-99m, either as a rapid 15-minute bolus (Bolus group, n = 16) or as a 2-hour (h) infusion (Infusion group, n = 16)...
October 5, 2016: Shock
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