Brain Acetaldehyde Exposure Impacts upon Neonatal Respiratory Plasticity and Ethanol-Related Learning in Rodents.

PubMed

Acevedo, María B; D'Aloisio, Génesis; Haymal, Olga B; Molina, Juan C

2017-01-01

Prior studies indicate that neonates are very sensitive to ethanol's positive reinforcing effects and to its depressant effects upon breathing. Acetaldehyde (ACD) appears to play a major role in terms of modulating early reinforcing effects of the drug. Yet, there is no pre-existing literature relative to the incidence of this metabolite upon respiratory plasticity. The present study analyzed physiological and behavioral effects of early central administrations of ethanol, acetaldehyde or vehicle. Respiration rates (breaths/min) were registered at post-natal days (PDs) 2 and 4 (post-administration time: 5, 60, or 120 min). At PD5, all pups were placed in a context (plethysmograph) where they had previously experienced the effects of central administrations and breathing patterns were recorded. Following this test, pups were evaluated using and operant conditioning procedure where ethanol or saccharin served as positive reinforcers. Body temperatures were also registered prior to drug administrations as well as at the beginning and the end of each specific evaluation. Across days, breathing responses were high at the beginning of the evaluation session and progressively declined as a function of the passage of time. At PDs 2 and 4, shortly after central administration (5 min), ACD exerted a significant depression upon respiration frequencies. At PD5, non-intoxicated pups with a prior history of ACD central administrations, exhibited a marked increase in respiratory frequencies; a result that probably indicates a conditioned compensatory response. When operant testing procedures were conducted, prior ethanol or ACD central administrations were found to reduce the reinforcing effects of ethanol. This was not the case when saccharin was employed as a reinforcer. As a whole, the results indicate a significant role of central ACD upon respiratory plasticity of the neonate and upon ethanol's reinforcing effects; phenomena that affect the physiological integrity of the immature organism and its subsequent affinity for ethanol operationalized through self-administration procedures.

Early postnatal changes in respiratory activity in rat in vitro and modulatory effects of substance P.

PubMed

Shvarev, Y N; Lagercrantz, H

2006-10-01

Developmental changes in the respiratory activity and its modulation by substance P (SP) were studied in the neonatal rat brainstem-spinal cord preparation from the day of birth to day 3 (P0-P3). The respiratory network activity in the ventrolateral medulla was represented by two types of bursts: basic regular bursts with typical decrementing shape and biphasic bursts appearing after augmented biphasic discharges in inspiratory neurons. With advancing postnatal age the respiratory output was considerably modified; the basic rhythm became faster by 20%, whereas the biphasic burst rate, which was originally 15 times slower, declined further by 180% and the C4 burst duration significantly decreased by 20% due to reduced decay time without preceding changes in the central inspiratory drive. SP had an age-dependent excitatory effect on respiratory activity. In the basic rhythm, SP could induce transient rhythm cessations on P0-P2 but not on P3. For the biphasic burst frequency, the sensitivity to SP significantly decreased from P0 to P3, whereas the range of SP-induced changes increased. In both types of bursts, SP prolonged C4 burst duration due to increasing decay time. This effect was three times greater on P3 and did not depend on the central inspiratory drive. Our results suggest that the potency of SP to regulate the respiratory activity elevates during the early postnatal period. The developmental changes in the respiratory activity appear to represent the transient stage in the maturation of rhythm and pattern generation mechanisms facilitating adaptive behavior of a quickly growing organism.

Erythropoietin-Mediated Regulation of Central Respiratory Command.

PubMed

Seaborn, Tommy; Caravagna, Céline

2017-01-01

Erythropoietin (Epo) is a cytokine expressed throughout the body, including in the central nervous system where it can act as a breathing modulator in the central respiratory network. In vitro, Epo allows maintaining the activity of respiratory neurons during acute hypoxia, resulting in inhibition of the hypoxia-induced rhythm depression. In vivo, Epo action on the central respiratory command results in enhancement of the acute hypoxic ventilatory response, allowing a better oxygenation of the body by improvement of gases exchanges in the lungs. Importantly, this effect of Epo is age-dependent, being observed at adulthood and at both early and late postnatal ages, but not at middle postnatal ages, when an important setup of the central respiratory command occurs. Epo regulation of the central respiratory command involves at least two intracellular signaling pathways, PI3K-Akt and MEK-ERK pathways. However, the exact mechanism underlying the action of Epo on the central respiratory control remains to be deciphered, as well as the exact cell types and nuclei involved in this control. Epo-mediated effect on the central respiratory command is regulated by several factors, including hypoxia, sex hormones, and an endogen antagonist. Although more knowledge is needed before reaching the clinical trial step, Epo seems to be a promising therapeutic treatment, notably against newborn breathing disorders. © 2017 Elsevier Inc. All rights reserved.

A one-year community study of under-fives in rural Ethiopia: patterns of morbidity and public health risk factors.

PubMed

Muhe, L; Byass, P; Freij, L; Sandström, A; Wall, S

1995-03-01

A prospective weekly home surveillance study was undertaken to determine morbidity patterns within the Butajira Rural Health project in central Ethiopia. Overall prevalence of illness was 5.8% in 1216 person-years observed among rural Ethiopian children aged under 5 years. Acute respiratory infections (ARI) (prevalence 2.8%) and acute diarrhoea (2.4%) were the commonest conditions. Episodes of illness were distributed unequally among children, with a mean of 2.34 episodes per child. These included an average of 1.13 episodes of ARI (of which 0.16 had lower respiratory symptoms [ALRI]) and 1.17 episodes of acute diarrhoea. Sanitation factors were the principal risks for gastroenteritis, while living in rural areas predisposed children to ARI. Parental factors such as illiteracy were also linked to morbidity.

Optical recording from respiratory pattern generator of fetal mouse brainstem reveals a distributed network.

PubMed

Eugenin, J; Nicholls, J G; Cohen, L B; Muller, K J

2006-01-01

Unfailing respiration depends on neural mechanisms already present in mammals before birth. Experiments were made to determine how inspiratory and expiratory neurons are grouped in the brainstem of fetal mice. A further aim was to assess whether rhythmicity arises from a single pacemaker or is generated by multiple sites in the brainstem. To measure neuronal firing, a fluorescent calcium indicator dye was applied to embryonic central nervous systems isolated from mice. While respiratory commands were monitored electrically from third to fifth cervical ventral roots, activity was measured optically over areas containing groups of respiratory neurones, or single neurones, along the medulla from the facial nucleus to the pre-Bötzinger complex. Large optical signals allowed recordings to be made during individual respiratory cycles. Inspiratory and expiratory neurones were intermingled. A novel finding was that bursts of activity arose in a discrete area intermittently, occurring during some breaths, but failing in others. Raised CO2 partial pressure or lowered pH increased the frequency of respiration; neurons then fired reliably with every cycle. Movies of activity revealed patterns of activation of inspiratory and expiratory neurones during successive respiratory cycles; there was no evidence for waves spreading systematically from region to region. Our results suggest that firing of neurons in immature respiratory circuits is a stochastic process, and that the rhythm does not depend on a single pacemaker. Respiratory circuits in fetal mouse brainstem appear to possess a high safety factor for generating rhythmicity, which may or may not persist as development proceeds.

Epidemiology of central sleep apnoea in heart failure.

PubMed

Naughton, Matthew T

2016-03-01

Central sleep apnoea occurs in about a third of patients with reduced systolic heart failure and is a marker of increased mortality. Such patients usually are older males with advanced heart failure (i.e., high pulmonary wedge pressure), often in atrial fibrillation, with evidence of hyperventilation (i.e., low PaCO2) in the absence of hypoxemia. Characteristically, ventilation waxes and wanes in a sinusoidal pattern, with mild hypoxemia, occurring in the lighter levels of sleep usually when supine. Snoring may also occur in central sleep apnoea, often at the peak of hyperventilation, sometimes contributing to the confusion or overlap with obstructive sleep apnoea. Central sleep apnoea is associated with orthopnoea, paroxysmal nocturnal dyspnoea and an oscillatory respiratory pattern with an incremental cardiopulmonary exercise study. Importantly, heart failure therapies (e.g., afterload reduction, diuresis, pacemakers, transplantation) attenuate central sleep apnoea. Night to night variability in severity of central sleep apnoea may occur with changes in patients' posture during sleep (less severe when sleeping on-side or upright). Crown Copyright © 2016. Published by Elsevier Ireland Ltd. All rights reserved.

Acute lower respiratory tract infections in infants: the influence of central heating systems

PubMed Central

Stott, N. C. H.; West, R. R.

1981-01-01

A cohort of 342 infants in a group practice population were studied during the first year of life to assess whether hot-air central heating was associated with more severe respiratory infections than radiator central heating. Infants born into council house families with ducted hot-air central heating were at no greater risk of contracting severe respiratory infections than those with radiator central heating. The risk of a respiratory infection was positively correlated with size of sibship and maternal smoking habits. PMID:7277291

Bidirectional plasticity of pontine pneumotaxic postinspiratory drive: implication for a pontomedullary respiratory central pattern generator.

PubMed

Poon, Chi-Sang; Song, Gang

2014-01-01

The "pneumotaxic center" in the rostral dorsolateral pons as delineated by Lumsden nine decades ago is known to play an important role in promoting the inspiratory off-switch (IOS) for inspiratory-expiratory phase transition as a fail-safe mechanism for preventing apneusis in the absence of vagal input. Traditionally, the pontine pneumotaxic mechanism has been thought to contribute a tonic descending input that lowers the IOS threshold in medullary respiratory central pattern generator (rCPG) circuits, but otherwise does not constitute part of the rCPG. Recent evidence indicates that descending input from the Kölliker-Fuse nucleus (KFN) within the pneumotaxic center is essential for gating the postinspiratory phase of the three-phase respiratory rhythm to control the IOS in vagotomized animals. A critical question arising is whether such a descending pneumotaxic input from KFN that drives postinspiratory activity is tonic (null hypothesis) or rhythmic with postinspiratory phase modulation (alternative hypothesis). Here, we show that multifarious evidence reported in the literature collectively indicates that the descending pneumotaxic input may exhibit NMDA receptor-dependent short-term plasticity in the form of a biphasic neural differentiator that bidirectionally and phase-selectively modulates postinspiratory phase duration in response to vagal and peripheral chemoreceptor inputs independent of the responses in inspiratory and late-expiratory activities. The phase-selectivity property of the descending pneumotaxic input implicates a population of pontine early-expiratory (postinspiratory/expiratory-decrementing) neurons as the most likely neural correlate of the pneumotaxic mechanism that drives post-I activity, suggesting that the pontine pneumotaxic mechanism may be an integral part of a pontomedullary rCPG that underlies the three-phase respiratory rhythm. © 2014 Elsevier B.V. All rights reserved.

40 CFR 721.72 - Hazard communication program.

Code of Federal Regulations, 2011 CFR

2011-07-01

... irritation. (ii) Respiratory complications. (iii) Central nervous system effects. (iv) Internal organ effects... irritation (B) Respiratory complications (C) Central nervous system effects (D) Internal organ effects (E... irritation (B) Respiratory complications (C) Central nervous system effects (D) Internal organ effects (E...

40 CFR 721.72 - Hazard communication program.

Code of Federal Regulations, 2010 CFR

2010-07-01

... irritation. (ii) Respiratory complications. (iii) Central nervous system effects. (iv) Internal organ effects... irritation (B) Respiratory complications (C) Central nervous system effects (D) Internal organ effects (E... irritation (B) Respiratory complications (C) Central nervous system effects (D) Internal organ effects (E...

40 CFR 721.72 - Hazard communication program.

Code of Federal Regulations, 2012 CFR

2012-07-01

... irritation. (ii) Respiratory complications. (iii) Central nervous system effects. (iv) Internal organ effects... irritation (B) Respiratory complications (C) Central nervous system effects (D) Internal organ effects (E... irritation (B) Respiratory complications (C) Central nervous system effects (D) Internal organ effects (E...

40 CFR 721.72 - Hazard communication program.

Code of Federal Regulations, 2014 CFR

2014-07-01

... irritation. (ii) Respiratory complications. (iii) Central nervous system effects. (iv) Internal organ effects... irritation (B) Respiratory complications (C) Central nervous system effects (D) Internal organ effects (E... irritation (B) Respiratory complications (C) Central nervous system effects (D) Internal organ effects (E...

40 CFR 721.72 - Hazard communication program.

Code of Federal Regulations, 2013 CFR

2013-07-01

... irritation. (ii) Respiratory complications. (iii) Central nervous system effects. (iv) Internal organ effects... irritation (B) Respiratory complications (C) Central nervous system effects (D) Internal organ effects (E... irritation (B) Respiratory complications (C) Central nervous system effects (D) Internal organ effects (E...

Regulation of Breathing and Autonomic Outflows by Chemoreceptors

PubMed Central

Guyenet, Patrice G.

2016-01-01

Lung ventilation fluctuates widely with behavior but arterial PCO2 remains stable. Under normal conditions, the chemoreflexes contribute to PaCO2 stability by producing small corrective cardiorespiratory adjustments mediated by lower brainstem circuits. Carotid body (CB) information reaches the respiratory pattern generator (RPG) via nucleus solitarius (NTS) glutamatergic neurons which also target rostral ventrolateral medulla (RVLM) presympathetic neurons thereby raising sympathetic nerve activity (SNA). Chemoreceptors also regulate presympathetic neurons and cardiovagal preganglionic neurons indirectly via inputs from the RPG. Secondary effects of chemoreceptors on the autonomic outflows result from changes in lung stretch afferent and baroreceptor activity. Central respiratory chemosensitivity is caused by direct effects of acid on neurons and indirect effects of CO2 via astrocytes. Central respiratory chemoreceptors are not definitively identified but the retrotrapezoid nucleus (RTN) is a particularly strong candidate. The absence of RTN likely causes severe central apneas in congenital central hypoventilation syndrome. Like other stressors, intense chemosensory stimuli produce arousal and activate circuits that are wake- or attention-promoting. Such pathways (e.g., locus coeruleus, raphe, and orexin system) modulate the chemoreflexes in a state-dependent manner and their activation by strong chemosensory stimuli intensifies these reflexes. In essential hypertension, obstructive sleep apnea and congestive heart failure, chronically elevated CB afferent activity contributes to raising SNA but breathing is unchanged or becomes periodic (severe CHF). Extreme CNS hypoxia produces a stereotyped cardiorespiratory response (gasping, increased SNA). The effects of these various pathologies on brainstem cardiorespiratory networks are discussed, special consideration being given to the interactions between central and peripheral chemoreflexes. PMID:25428853

Brainstem mechanisms underlying the cough reflex and its regulation.

PubMed

Mutolo, Donatella

2017-09-01

Cough is a very important airway protective reflex. Cough-related inputs are conveyed to the caudal nucleus tractus solitarii (cNTS) that projects to the brainstem respiratory network. The latter is reconfigured to generate the cough motor pattern. A high degree of modulation is exerted on second-order neurons and the brainstem respiratory network by sensory inputs and higher brain areas. Two medullary structures proved to have key functions in cough production and to be strategic sites of action for centrally active drugs: the cNTS and the caudal ventral respiratory group (cVRG). Drugs microinjected into these medullary structures caused downregulation or upregulation of the cough reflex. The results suggest that inhibition and disinhibition are prominent regulatory mechanisms of this reflex and that both the cNTS and the cVRG are essential in the generation of the entire cough motor pattern. Studies on the basic neural mechanisms subserving the cough reflex may provide hints for novel therapeutic approaches. Different proposals for further investigations are advanced. Copyright © 2017 Elsevier B.V. All rights reserved.

Vagal tone as an index of mental state

NASA Technical Reports Server (NTRS)

Porges, Stephen W.

1988-01-01

The utility of monitoring oscillations in the heart rate pattern as a window to the brain is discussed as an index of general central nervous system status. Quantification of the amplitude of respiratory sinus arrhythmia provides an accurate index of cardiac vagal tone. A number of studies have demonstrated the validity of this measure; the relationship between flight performance and vagal tone has also been studied. In general, the vagal tone index appears to monitor global states of the central nervous system and may be useful in screening the general state of pilots.

Dysrhythmias of the respiratory oscillator

NASA Astrophysics Data System (ADS)

Paydarfar, David; Buerkel, Daniel M.

1995-03-01

Breathing is regulated by a central neural oscillator that produces rhythmic output to the respiratory muscles. Pathological disturbances in rhythm (dysrhythmias) are observed in the breathing pattern of children and adults with neurological and cardiopulmonary diseases. The mechanisms responsible for genesis of respiratory dysrhythmias are poorly understood. The present studies take a novel approach to this problem. The basic postulate is that the rhythm of the respiratory oscillator can be altered by a variety of stimuli. When the oscillator recovers its rhythm after such perturbations, its phase may be reset relative to the original rhythm. The amount of phase resetting is dependent upon stimulus parameters and the level of respiratory drive. The long-range hypothesis is that respiratory dysrhythmias can be induced by stimuli that impinge upon or arise within the respiratory oscillator with certain combinations of strength and timing relative to the respiratory cycle. Animal studies were performed in anesthetized or decerebrate preparations. Neural respiratory rhythmicity is represented by phrenic nerve activity, allowing use of open-loop experimental conditions which avoid negative chemical feedback associated with changes in ventilation. In animal experiments, respiratory dysrhythmias can be induced by stimuli having specific combinations of strength and timing. Newborn animals readily exhibit spontaneous dysrhythmias which become more prominent at lower respiratory drives. In human subjects, swallowing was studied as a physiological perturbation of respiratory rhythm, causing a pattern of phase resetting that is characterized topologically as type 0. Computational studies of the Bonhoeffer-van der Pol (BvP) equations, whose qualitative behavior is representative of many excitable systems, supports a unified interpretation of these experimental findings. Rhythmicity is observed when the BvP model exhibits recurrent periods of excitation alternating with refractory periods. The same system can be perturbed to a state in which amplitude of oscillation is attenuated or abolished. We have characterized critical perturbations which induce transitions between these two states, giving rise to patterns of dysrhythmic activity that are similar to those seen in the experiments. We illustrate the importance of noise in initiation and termination of rhythm, comparable to normal respiratory rhythm intermixed with spontaneous dysrhythmias. In the BvP system the incidence and duration of dysrhythmia is shown to be strongly influenced by the level of noise. These studies should lead to greater understanding of rhythmicity and integrative responses of the respiratory control system, and provide insight into disturbances in control mechanisms that cause apnea and aspiration in clinical disease states.

Assessing Airflow Sensitivity to Healthy and Diseased Lung Conditions in a Computational Fluid Dynamics Model Validated In Vitro.

PubMed

Sul, Bora; Oppito, Zachary; Jayasekera, Shehan; Vanger, Brian; Zeller, Amy; Morris, Michael; Ruppert, Kai; Altes, Talissa; Rakesh, Vineet; Day, Steven; Robinson, Risa; Reifman, Jaques; Wallqvist, Anders

2018-05-01

Computational models are useful for understanding respiratory physiology. Crucial to such models are the boundary conditions specifying the flow conditions at truncated airway branches (terminal flow rates). However, most studies make assumptions about these values, which are difficult to obtain in vivo. We developed a computational fluid dynamics (CFD) model of airflows for steady expiration to investigate how terminal flows affect airflow patterns in respiratory airways. First, we measured in vitro airflow patterns in a physical airway model, using particle image velocimetry (PIV). The measured and computed airflow patterns agreed well, validating our CFD model. Next, we used the lobar flow fractions from a healthy or chronic obstructive pulmonary disease (COPD) subject as constraints to derive different terminal flow rates (i.e., three healthy and one COPD) and computed the corresponding airflow patterns in the same geometry. To assess airflow sensitivity to the boundary conditions, we used the correlation coefficient of the shape similarity (R) and the root-mean-square of the velocity magnitude difference (Drms) between two velocity contours. Airflow patterns in the central airways were similar across healthy conditions (minimum R, 0.80) despite variations in terminal flow rates but markedly different for COPD (minimum R, 0.26; maximum Drms, ten times that of healthy cases). In contrast, those in the upper airway were similar for all cases. Our findings quantify how variability in terminal and lobar flows contributes to airflow patterns in respiratory airways. They highlight the importance of using lobar flow fractions to examine physiologically relevant airflow characteristics.

Influence of drive and timing mechanisms on breathing pattern and ventilation during mental task performance.

PubMed

Wientjes, C J; Grossman, P; Gaillard, A W

1998-09-01

Assessment of multiple respiratory measures may provide insight into how behavioral demands affect the breathing pattern. This is illustrated by data from a study among 44 subjects, in which tidal volume, respiration rate, minute ventilation and indices of central drive and timing mechanisms were assessed via inductive plethysmography, in addition to end-tidal PCO2. After a baseline, three conditions of a memory comparison task were presented. The first two conditions differed only with regard to the presence or absence of feedback of performance (NFB and FB). In the third 'all-or-nothing' (AON) condition, subjects only received a monetary bonus, if their performance exceeded that of the previous two conditions. Minute ventilation increased from baseline to all task conditions, and from NFB and FB to AON. Respiration rate increased in all task conditions, but there were no differences between task conditions. Tidal volume decreased during NFB, but was equal to baseline during FB and AON. Of the respiratory control indices, inspiratory flow rate covaried much more closely with minute ventilation than duty cycle. The task performance induced a minor degree of hyperventilation. The discussion focusses on how behavioral demands affect respiratory control processes to produce alterations in breathing pattern and ventilation.

Pacifier Stiffness Alters the Dynamics of the Suck Central Pattern Generator.

PubMed

Zimmerman, Emily; Barlow, Steven M

2008-06-01

Variation in pacifier stiffness on non-nutritive suck (NNS) dynamics was examined among infants born prematurely with a history of respiratory distress syndrome. Three types of silicone pacifiers used in the NICU were tested for stiffness, revealing the Super Soothie™ nipple is 7 times stiffer than the Wee™ or Soothie™ pacifiers even though shape and displaced volume are identical. Suck dynamics among 20 preterm infants were subsequently sampled using the Soothie™ and Super Soothie™ pacifiers during follow-up at approximately 3 months of age. ANOVA revealed significant differences in NNS cycles/min, NNS amplitude, NNS cycles/burst, and NNS cycle periods as a function of pacifier stiffness. Infants modify the spatiotemporal output of their suck central pattern generator when presented with pacifiers with significantly different mechanical properties. Infants show a non-preference to suck due to high stiffness in the selected pacifier. Therefore, excessive pacifier stiffness may decrease ororhythmic patterning and impact feeding outcomes.

Pacifier Stiffness Alters the Dynamics of the Suck Central Pattern Generator

PubMed Central

Zimmerman, Emily; Barlow, Steven M.

2008-01-01

Variation in pacifier stiffness on non-nutritive suck (NNS) dynamics was examined among infants born prematurely with a history of respiratory distress syndrome. Three types of silicone pacifiers used in the NICU were tested for stiffness, revealing the Super Soothie™ nipple is 7 times stiffer than the Wee™ or Soothie™ pacifiers even though shape and displaced volume are identical. Suck dynamics among 20 preterm infants were subsequently sampled using the Soothie™ and Super Soothie™ pacifiers during follow-up at approximately 3 months of age. ANOVA revealed significant differences in NNS cycles/min, NNS amplitude, NNS cycles/burst, and NNS cycle periods as a function of pacifier stiffness. Infants modify the spatiotemporal output of their suck central pattern generator when presented with pacifiers with significantly different mechanical properties. Infants show a non-preference to suck due to high stiffness in the selected pacifier. Therefore, excessive pacifier stiffness may decrease ororhythmic patterning and impact feeding outcomes. PMID:19492006

Dorsal and ventral aspects of the most caudal medullary reticular formation have differential roles in modulation and formation of the respiratory motor pattern in rat.

PubMed

Jones, Sarah E; Stanić, Davor; Dutschmann, Mathias

2016-12-01

The respiratory pattern generator of mammals is anatomically organized in lateral respiratory columns (LRCs) within the brainstem. LRC compartments serve specific functions in respiratory pattern and rhythm generation. While the caudal medullary reticular formation (cMRF) has respiratory functions reportedly related to the mediation of expulsive respiratory reflexes, it remains unclear whether neurons of the cMRF functionally belong to the LRC. In the present study we specifically investigated the respiratory functions of the cMRF. Tract tracing shows that the cMRF has substantial connectivity with key compartments of the LRC, particularly the parafacial respiratory group and the Kölliker-Fuse nuclei. These neurons have a loose topography and are located in the ventral and dorsal cMRF. Systematic mapping of the cMRF with glutamate stimulation revealed potent respiratory modulation of the respiratory motor pattern from both dorsal and ventral injection sites. Pharmacological inhibition of the cMRF with the GABA-receptor agonist isoguvacine produced significant and robust changes to the baseline respiratory motor pattern (decreased laryngeal post-inspiratory and abdominal expiratory motor activity, delayed inspiratory off-switch and increased respiratory frequency) after dorsal cMRF injection, while ventral injections had no effect. The present data indicate that the ventral cMRF is not an integral part of the respiratory pattern generator and merely serves as a relay for sensory and/or higher command-related modulation of respiration. On the contrary, the dorsal aspect of the cMRF clearly has a functional role in respiratory pattern formation. These findings revive the largely abandoned concept of a dorsal respiratory group that contributes to the generation of the respiratory motor pattern.

Laser ablation of Dbx1 neurons in the pre-Bötzinger complex stops inspiratory rhythm and impairs output in neonatal mice

PubMed Central

Wang, Xueying; Hayes, John A; Revill, Ann L; Song, Hanbing; Kottick, Andrew; Vann, Nikolas C; LaMar, M Drew; Picardo, Maria Cristina D; Akins, Victoria T; Funk, Gregory D; Del Negro, Christopher A

2014-01-01

To understand the neural origins of rhythmic behavior one must characterize the central pattern generator circuit and quantify the population size needed to sustain functionality. Breathing-related interneurons of the brainstem pre-Bötzinger complex (preBötC) that putatively comprise the core respiratory rhythm generator in mammals are derived from Dbx1-expressing precursors. Here, we show that selective photonic destruction of Dbx1 preBötC neurons in neonatal mouse slices impairs respiratory rhythm but surprisingly also the magnitude of motor output; respiratory hypoglossal nerve discharge decreased and its frequency steadily diminished until rhythm stopped irreversibly after 85±20 (mean ± SEM) cellular ablations, which corresponds to ∼15% of the estimated population. These results demonstrate that a single canonical interneuron class generates respiratory rhythm and contributes in a premotor capacity, whereas these functions are normally attributed to discrete populations. We also establish quantitative cellular parameters that govern network viability, which may have ramifications for respiratory pathology in disease states. DOI: http://dx.doi.org/10.7554/eLife.03427.001 PMID:25027440

A Sodium Leak Current Regulates Pacemaker Activity of Adult Central Pattern Generator Neurons in Lymnaea Stagnalis

PubMed Central

Lu, Tom Z.; Feng, Zhong-Ping

2011-01-01

The resting membrane potential of the pacemaker neurons is one of the essential mechanisms underlying rhythm generation. In this study, we described the biophysical properties of an uncharacterized channel (U-type channel) and investigated the role of the channel in the rhythmic activity of a respiratory pacemaker neuron and the respiratory behaviour in adult freshwater snail Lymnaea stagnalis. Our results show that the channel conducts an inward leak current carried by Na+ (ILeak-Na). The ILeak-Na contributed to the resting membrane potential and was required for maintaining rhythmic action potential bursting activity of the identified pacemaker RPeD1 neurons. Partial knockdown of the U-type channel suppressed the aerial respiratory behaviour of the adult snail in vivo. These findings identified the Na+ leak conductance via the U-type channel, likely a NALCN-like channel, as one of the fundamental mechanisms regulating rhythm activity of pacemaker neurons and respiratory behaviour in adult animals. PMID:21526173

Substance P modulation of TRPC3/7 channels improves respiratory rhythm regularity and ICAN-dependent pacemaker activity

PubMed Central

Ben-Mabrouk, Faiza; Tryba, Andrew Kieran

2011-01-01

Neuromodulators, such as Substance P (SubP) play an important role in modulating many rhythmic activities driven by central pattern generators (e.g., locomotion, respiration). However, the mechanism by which SubP enhances breathing regularity has not been determined. Here, we used mouse brainstem slices containing the pre-Bötzinger Complex (Pre-BötC) to demonstrate, for the first time, that SubP activates transient receptor protein canonical (TRPC) channels to enhance respiratory rhythm regularity. Moreover, SubP enhancement of network regularity is accomplished via selective enhancement of ICAN-dependent intrinsic bursting properties. In contrast to INaP-dependant pacemakers, ICAN-dependant pacemaker bursting activity is TRPC dependent. Western Blots reveal TRPC3 and TRPC7 channels are expressed in rhythmically active ventral respiratory group (VRG) island preparations. Taken together, these data suggest that SubP-mediated activation of TRPC3/7 channels underlies rhythmic ICAN-dependent pacemaker activity and enhances the regularity of respiratory rhythm activity. PMID:20345918

Substance P modulation of TRPC3/7 channels improves respiratory rhythm regularity and ICAN-dependent pacemaker activity.

PubMed

Ben-Mabrouk, Faiza; Tryba, Andrew K

2010-04-01

Neuromodulators, such as substance P (SubP), play an important role in modulating many rhythmic activities driven by central pattern generators (e.g. locomotion, respiration). However, the mechanism by which SubP enhances breathing regularity has not been determined. Here, we used mouse brainstem slices containing the pre-Bötzinger complex to demonstrate, for the first time, that SubP activates transient receptor protein canonical (TRPC) channels to enhance respiratory rhythm regularity. Moreover, SubP enhancement of network regularity is accomplished via selective enhancement of ICAN (inward non-specific cation current)-dependent intrinsic bursting properties. In contrast to INaP (persistent sodium current)-dependent pacemakers, ICAN-dependent pacemaker bursting activity is TRPC-dependent. Western Blots reveal TRPC3 and TRPC7 channels are expressed in rhythmically active ventral respiratory group island preparations. Taken together, these data suggest that SubP-mediated activation of TRPC3/7 channels underlies rhythmic ICAN-dependent pacemaker activity and enhances the regularity of respiratory rhythm activity.

Temporal and spatial patterns of ambient endotoxin concentrations in Fresno, California.

PubMed

Tager, Ira B; Lurmann, Frederick W; Haight, Thaddeus; Alcorn, Siana; Penfold, Bryan; Hammond, S Katharine

2010-10-01

Endotoxins are found in indoor dust generated by human activity and pets, in soil, and adsorbed onto the surfaces of ambient combustion particles. Endotoxin concentrations have been associated with respiratory symptoms and the risk of atopy and asthma in children. We characterized the temporal and spatial variability of ambient endotoxin in Fresno/Clovis, California, located in California's Central Valley, to identify correlates and potential predictors of ambient endotoxin concentrations in a cohort of children with asthma [Fresno Asthmatic Children's Environment Study (FACES)]. Between May 2001 and October 2004, daily ambient endotoxin and air pollutants were collected at the central ambient monitoring site of the California Air Resources Board in Fresno and, for shorter time periods, at 10 schools and indoors and outdoors at 84 residences in the community. Analyses were restricted to May-October, the dry months during which endotoxin concentrations are highest. Daily endotoxin concentration patterns were determined mainly by meteorologic factors, particularly the degree of air stagnation. Overall concentrations were lowest in areas distant from agricultural activities. Highest concentrations were found in areas immediately downwind from agricultural/pasture land. Among three other measured air pollutants [fine particulate matter, elemental carbon (a marker of traffic in Fresno), and coarse particulate matter (PMc)], PMc was the only pollutant correlated with endotoxin. Endotoxin, however, was the most spatially variable. Our data support the need to evaluate the spatial/temporal variability of endotoxin concentrations, rather than relying on a few measurements made at one location, in studies of exposure and and respiratory health effects, particularly in children with asthma and other chronic respiratory diseases.

The effect of centrally injected CDP-choline on respiratory system; involvement of phospholipase to thromboxane signaling pathway.

PubMed

Topuz, Bora B; Altinbas, Burcin; Yilmaz, Mustafa S; Saha, Sikha; Batten, Trevor F; Savci, Vahide; Yalcin, Murat

2014-05-01

CDP-choline is an endogenous metabolite in phosphatidylcholine biosynthesis. Exogenous administration of CDP-choline has been shown to affect brain metabolism and to exhibit cardiovascular, neuroendocrine neuroprotective actions. On the other hand, little is known regarding its respiratory actions and/or central mechanism of its respiratory effect. Therefore the current study was designed to investigate the possible effects of centrally injected CDP-choline on respiratory system and the mediation of the central cholinergic receptors and phospholipase to thromboxane signaling pathway on CDP-choline-induced respiratory effects in anaesthetized rats. Intracerebroventricularly (i.c.v.) administration of CDP-choline induced dose- and time-dependent increased respiratory rates, tidal volume and minute ventilation of male anaesthetized Spraque Dawley rats. İ.c.v. pretreatment with atropine failed to alter the hyperventilation responses to CDP-choline whereas mecamylamine, cholinergic nicotinic receptor antagonist, mepacrine, phospholipase A2 inhibitor, and neomycin phospholipase C inhibitor, blocked completely the hyperventilation induced by CDP-choline. In addition, central pretreatment with furegrelate, thromboxane A2 synthesis inhibitor, also partially blocked CDP-choline-evoked hyperventilation effects. These data show that centrally administered CDP-choline induces hyperventilation which is mediated by activation of central nicotinic receptors and phospholipase to thromboxane signaling pathway. Copyright © 2014 Elsevier B.V. All rights reserved.

PI3K and MEK1/2 molecular pathways are involved in the erythropoietin-mediated regulation of the central respiratory command.

PubMed

Caravagna, Céline; Soliz, Jorge

2015-01-15

Erythropoietin stimulation modulates the central respiratory command in newborn mice. Specifically, the central respiratory depression induced by hypoxia is attenuated by acute (1h) or abolished by chronic erythropoietin stimulation. However, the underlying mechanisms remain unknown. As MEK and PI3K pathways are commonly involved in Epo-mediated effects of neuroprotection and erythropoiesis, we investigated here the implication of PI3K and MEK1/2 in the Epo-mediated regulation of the central respiratory command. To this end, in vitro brainstem-spinal cord preparations from 3 days old transgenic (Tg21; constitutively overexpressing erythropoietin in the brain specifically) and control mice were used. Our results show that blockade of PI3K or MEK1/2 stimulates normoxic bursts frequency in Tg21 preparations and abolish hypoxia-induced frequency depression in control preparations. These results show that MEK1/2 and PI3K pathways are involved in the Epo-mediated regulation of the central respiratory command. Moreover, this is the first demonstration that MEK1/2 and PI3K are involved in the brainstem central respiratory command. Copyright © 2014 Elsevier B.V. All rights reserved.

Changes of neurotransmitters in the brainstem of patients with respiratory-pattern disorders during childhood.

PubMed

Saito, Y; Ito, M; Ozawa, Y; Obonai, T; Kobayashi, Y; Washizawa, K; Ohsone, Y; Takami, T; Oku, K; Takashima, S

1999-06-01

We examined neuropathologically and immunohistochemically the respiratory centers in the brainstem of two patients with Joubert syndrome (JS), three patients with congenital central hypoventilation syndrome (CCHS) and a patient with apneustic breathing (prolonged inspiratory pause) due to unknown etiology. Immunoreactivity (IR) of tryptophan hydroxylase (TPH) was decreased in the dorsal raphe nuclei of two patients with JS compared with age-matched controls, as well as in two patients with Dandy-Walker malformation. The two JS patients showed vermian defect and elongated cerebellar peduncles, and peculiar vascularities in the midline of the whole brainstem were also noted in one of these patients. These findings, as a whole, confirm that the midline structures of brainstem are disordered both structurally and functionally in JS, conceivably resulting in respiratory patterns and psychomotor deficits. IR of serotonin 1A receptor showed no significant changes in the medulla oblongata of these patients, however. In the parabrachial complex, IR of substance P was increased in two patients with CCHS, and one with apneustic breathing. IR of tyrosine hydroxylase was also increased in the latter. The brainstem of these patients showed reactive astrogliosis. These findings suggest preceding hypoxic episodes as well as an increased activity in the parabrachial complex which plays an important role in conducting the driving force to the medullary respiratory neurons from ascending sensory pathways.

The effects of centrally injected arachidonic acid on respiratory system: Involvement of cyclooxygenase to thromboxane signaling pathway.

PubMed

Erkan, Leman Gizem; Guvenc, Gokcen; Altinbas, Burcin; Niaz, Nasir; Yalcin, Murat

2016-05-01

Arachidonic acid (AA) is a polyunsaturated fatty acid that is present in the phospholipids of the cell membranes of the body and is abundant in the brain. Exogenously administered AA has been shown to affect brain metabolism and to exhibit cardiovascular and neuroendocrine actions. However, little is known regarding its respiratory actions and/or central mechanism of its respiratory effects. Therefore, the present study was designed to investigate the possible effects of centrally injected AA on respiratory system and the mediation of the central cyclooxygenase (COX) to thromboxane A2 (TXA2) signaling pathway on AA-induced respiratory effects in anaesthetized rats. Intracerebroventricular (i.c.v.) administration of AA induced dose- and time-dependent increase in tidal volume, respiratory rates and respiratory minute ventilation and also caused an increase in partial oxygen pressure (pO2) and decrease in partial carbon dioxide pressure (pCO2) in male anaesthetized Spraque Dawley rats. I.c.v. pretreatment with ibuprofen, a non-selective COX inhibitor, completely blocked the hyperventilation and blood gases changes induced by AA. In addition, central pretreatment with different doses of furegrelate, a TXA2 synthesis inhibitor, also partially prevented AA-evoked hyperventilation and blood gases effects. These data explicitly show that centrally administered AA induces hyperventilation with increasing pO2 and decreasing pCO2 levels which are mediated by the activation of central COX to TXA2 signaling pathway. Copyright © 2016 Elsevier B.V. All rights reserved.

Post-natal hypoxic activity of the central respiratory command is improved in transgenic mice overexpressing Epo in the brain.

PubMed

Caravagna, Céline; Kinkead, Richard; Soliz, Jorge

2014-08-15

Previous studies indicated that erythropoietin modulates central respiratory command in mice. Specifically, a one-hour incubation of the brainstems with erythropoietin attenuates hypoxia-induced central respiratory depression. Here, using transgenic mice constitutively overexpressing erythropoietin specifically in the brain (Tg21), we investigated the effect of chronic erythropoietin stimulation on central respiratory command activity during post-natal development. In vitro brainstem-spinal cord preparations from mice at 0 (P0) or 3 days of age (P3) were used to record the fictive inspiratory activity from the C4 ventral root. Our results show that erythropoietin already stimulates the hypoxic burst frequency at P0, and at P3, erythropoietin effectively stimulates the hypoxic burst frequency and amplitude. Because the maturation of the central respiratory command in mice is characterized by a decrease in the burst frequency with age, our results also suggest that erythropoietin accelerates the maturation of the newborn respiratory network and its response to hypoxia. Copyright © 2014 Elsevier B.V. All rights reserved.

Molecular evolution of respiratory syncytial virus subgroup A genotype NA1 and ON1 attachment glycoprotein (G) gene in central Vietnam.

PubMed

Yoshihara, Keisuke; Le, Minh Nhat; Nagasawa, Koo; Tsukagoshi, Hiroyuki; Nguyen, Hien Anh; Toizumi, Michiko; Moriuchi, Hiroyuki; Hashizume, Masahiro; Ariyoshi, Koya; Dang, Duc Anh; Kimura, Hirokazu; Yoshida, Lay-Myint

2016-11-01

We performed molecular evolutionary analyses of the G gene C-terminal 3rd hypervariable region of RSV-A genotypes NA1 and ON1 strains from the paediatric acute respiratory infection patients in central Vietnam during the 2010-2012 study period. Time-scaled phylogenetic analyses were performed using Bayesian Markov Chain Monte Carlo (MCMC) method, and pairwise distances (p-distances) were calculated. Bayesian Skyline Plot (BSP) was constructed to analyze the time-trend relative genetic diversity of central Vietnam RSV-A strains. We also estimated the N-glycosylation sites within G gene hypervariable region. Amino acid substitutions under positive and negative selection pressure were examined using Conservative Single Likelihood Ancestor Counting (SLAC), Fixed Effects Likelihood (FEL), Internal Fixed Effects Likelihood (IFEL) and Mixed Effects Model for Episodic Diversifying Selection (MEME) models. The majority of central Vietnam ON1 strains detected in 2012 were classified into lineage 1 with few positively selected substitutions. As for the Vietnamese NA1 strains, four lineages were circulating during the study period with a few positive selection sites. Shifting patterns of the predominantly circulating NA1 lineage were observed in each year during the investigation period. Median p-distance of central Vietnam NA1 strains was wider (p-distance=0.028) than that of ON1 (p-distance=0.012). The molecular evolutionary rate of central Vietnam ON1 strains was estimated to be 2.55×10 -2 (substitutions/site/year) and was faster than NA1 (7.12×10 -3 (substitutions/site/year)). Interestingly, the evolutionary rates of both genotypes ON1 and NA1 strains from central Vietnam were faster than the global strains respectively. Furthermore, the shifts of N-glycosylation pattern within the G gene 3rd hypervariable region of Vietnamese NA1 strains were observed in each year. BSP analysis indicated the rapid growth of RSV-A effective population size in early 2012. These results suggested that the molecular evolution of RSV-A G gene detected in central Vietnam was fast with unique evolutionary dynamics. Copyright © 2016 Elsevier B.V. All rights reserved.

Ventilatory Cycle Measurements and Loop Gain in Central Apnea in Mining Drivers Exposed to Intermittent Altitude.

PubMed

Rey de Castro, Jorge; Liendo, Alicia; Ortiz, Oswaldo; Rosales-Mayor, Edmundo; Liendo, César

2017-01-15

By measuring the apnea length, ventilatory phase, respiratory cycle length, and loop gain, we can further characterize the central apneas of high altitude (CAHA). Sixty-three drivers of all-terrain vehicles, working in a Peruvian mine located at 2,020 meters above sea level (MASL), were evaluated. A respiratory polygraph was performed in the first night they slept at high altitude. None of the subjects were exposed to oxygen during the test or acetazolamide in the preceding days of the test. Sixty-three respiratory polygraphs were performed, and 59 were considered for analysis. Forty-six (78%) were normal, 6 (10%) had OSA, and 7 (12%) had CAHA. Key data from subjects include: residing altitude: 341 ± 828 MASL, Lake Louise scoring: 0.4 ± 0.8, Epworth score: 3.4 ± 2.7, apneahypopnea index: 35.7 ± 19.3, CA index: 13.4 ± 14.2, CA length: 14.4 ± 3.6 sec, ventilatory length: 13.5 ± 2.9 sec, cycle length: 26.5 ± 4.0 sec, ventilatory length/CA length ratio 0.9 ± 0.3 and circulatory delay 13.3 ± 2.9 sec. Duty ratio media [ventilatory duration/cycle duration] was 0.522 ± 0 0.128 [0.308-0.700] and loop gain was calculated from the duty ratio utilizing this formula: LG = 2π / [(2πDR-sin(2πDR)]. All subjects have a high loop gain media 2.415 ± 1.761 [1.175-6.260]. Multiple correlations were established with loop gain values, but the only significant correlation detected was between central apnea index and loop gain. Twelve percent of the studied population had CAHA. Measurements of respiratory cycle in workers with CAHA are more similar to idiopathic central apneas rather than Hunter-Cheyne-Stokes respiration. Also, there was a high degree of correlation between severity of central apnea and the degree of loop gain. The abnormal breathing patterns in those subjects could affect the sleep quality and potentially increase the risk for work accidents. © 2017 American Academy of Sleep Medicine

Analysis of the respiratory component of heart rate variability in the Cururu toad Rhinella schneideri.

PubMed

Zena, Lucas A; Leite, Cléo A C; Longhini, Leonardo S; Dias, Daniel P M; da Silva, Glauber S F; Hartzler, Lynn K; Gargaglioni, Luciane H; Bícego, Kênia C

2017-11-23

Beat-to-beat variation in heart rate (f H ) has been used as a tool for elucidating the balance between sympathetic and parasympathetic modulation of the heart. A portion of the temporal changes in f H is evidenced by a respiratory influence (cardiorespiratory interaction) on heart rate variability (HRV) with heartbeats increasing and decreasing within a respiratory cycle. Nevertheless, little is known about respiratory effects on HRV in lower vertebrates. By using frequency domain analysis, we provide the first evidence of a ventilatory component in HRV similar to mammalian respiratory sinus arrhythmia in an amphibian, the toad Rhinella schneideri. Increases in the heartbeats arose synchronously with each lung inflation cycle, an intermittent breathing pattern comprised of a series of successive lung inflations. A well-marked peak in the HRV signal matching lung inflation cycle was verified in toads whenever lung inflation cycles exhibit a regular rhythm. The cardiac beat-to-beat variation evoked at the moment of lung inflation accounts for both vagal and sympathetic influences. This cardiorespiratory interaction may arise from interactions between central and peripheral feedback mechanisms governing cardiorespiratory control and may underlie important cardiorespiratory adjustments for gas exchange improvement especially under extreme conditions like low oxygen availability.

Daily isoflurane exposure increases barbiturate insensitivity in medullary respiratory and cortical neurons via expression of ε-subunit containing GABA ARs.

PubMed

Hengen, Keith B; Nelson, Nathan R; Stang, Kyle M; Johnson, Stephen M; Smith, Stephanie M; Watters, Jyoti J; Mitchell, Gordon S; Behan, Mary

2015-01-01

The parameters governing GABAA receptor subtype expression patterns are not well understood, although significant shifts in subunit expression may support key physiological events. For example, the respiratory control network in pregnant rats becomes relatively insensitive to barbiturates due to increased expression of ε-subunit-containing GABAARs in the ventral respiratory column. We hypothesized that this plasticity may be a compensatory response to a chronic increase in inhibitory tone caused by increased central neurosteroid levels. Thus, we tested whether increased inhibitory tone was sufficient to induce ε-subunit upregulation on respiratory and cortical neurons in adult rats. Chronic intermittent increases in inhibitory tone in male and female rats was induced via daily 5-min exposures to 3% isoflurane. After 7d of treatment, phrenic burst frequency was less sensitive to barbiturate in isoflurane-treated male and female rats in vivo. Neurons in the ventral respiratory group and cortex were less sensitive to pentobarbital in vitro following 7d and 30d of intermittent isoflurane-exposure in both male and female rats. The pentobarbital insensitivity in 7d isoflurane-treated rats was reversible after another 7d. We hypothesize that increased inhibitory tone in the respiratory control network and cortex causes a compensatory increase in ε-subunit-containing GABAARs.

Neural breathing patterns in preterm newborns supported with non-invasive neurally adjusted ventilatory assist.

PubMed

García-Muñoz Rodrigo, Fermín; Urquía Martí, Lourdes; Galán Henríquez, Gloria; Rivero Rodríguez, Sonia; Hernández Gómez, Alberto

2018-06-18

To characterize the neural breathing pattern in preterm infants supported with non-invasive neurally adjusted ventilatory assist (NIV-NAVA). Single-center prospective observational study. The electrical activity of the diaphragm (EAdi) was periodically recorded in 30-second series with the Edi catheter and the Servo-n software (Maquet, Solna, Sweden) in preterm infants supported with NIV-NAVA. The EAdi Peak , EAdi Min , EAdi Tonic , EAdi Phasic , neural inspiratory, and expiratory times (nTi and nTe) and the neural respiratory rate (nRR) were calculated. EAdi curves were generated by Excel for visual examination and classified according to the predominant pattern. 291 observations were analyzed in 19 patients with a mean GA of 27.3 weeks (range 24-36 weeks), birth weight 1028 g (510-2945 g), and a median (IQR) postnatal age of 18 days (4-27 days). The distribution of respiratory patterns was phasic without tonic activity 61.9%, phasic with basal tonic activity 18.6, tonic burst 3.8%, central apnea 7.9%, and mixed pattern 7.9%. In addition, 12% of the records showed apneas of >10 seconds, and 50.2% one or more "sighs", defined as breaths with an EAdi Peak and/or nTi greater than twice the average EAdi Peak and/or nTi of the recording. Neural times were measurable in 252 observations. The nTi was, median (IQR): 279 ms (253-285 ms), the nTe 764 ms (642-925 ms), and the nRR 63 bpm (51-70), with a great intra and inter-subjects variability. The neural breathing patterns in preterm infants supported with NIV-NAVA are quite variable and are characterized by the presence of significant tonic activity. Central apneas and sighs are common in this group of patients. The nTi seems to be shorter than the mechanical Ti commonly used in assisted ventilation.

Theoretical analysis of the influence of aerosol size distribution and physical activity on particle deposition pattern in human lungs.

PubMed

Voutilainen, Arto; Kaipio, Jari P; Pekkanen, Juha; Timonen, Kirsi L; Ruuskanen, Juhani

2004-01-01

A theoretical comparison of modeled particle depositions in the human respiratory tract was performed by taking into account different particle number and mass size distributions and physical activity in an urban environment. Urban-air data on particulate concentrations in the size range 10 nm-10 microm were used to estimate the hourly average particle number and mass size distribution functions. The functions were then combined with the deposition probability functions obtained from a computerized ICRP 66 deposition model of the International Commission on Radiological Protection to calculate the numbers and masses of particles deposited in five regions of the respiratory tract of a male adult. The man's physical activity and minute ventilation during the day were taken into account in the calculations. Two different mass and number size distributions of aerosol particles with equal (computed) <10 microm particle mass concentrations gave clearly different deposition patterns in the central and peripheral regions of the human respiratory tract. The deposited particle numbers and masses were much higher during the day (0700-1900) than during the night (1900-0700) because an increase in physical activity and ventilation were temporally associated with highly increased traffic-derived particles in urban outdoor air. In future analyses of the short-term associations between particulate air pollution and health, it would not only be important to take into account the outdoor-to-indoor penetration of different particle sizes and human time-activity patterns, but also actual lung deposition patterns and physical activity in significant microenvironments.

Short-term sustained hypoxia induces changes in the coupling of sympathetic and respiratory activities in rats

PubMed Central

Moraes, Davi J A; Bonagamba, Leni G H; Costa, Kauê M; Costa-Silva, João H; Zoccal, Daniel B; Machado, Benedito H

2014-01-01

Individuals experiencing sustained hypoxia (SH) exhibit adjustments in the respiratory and autonomic functions by neural mechanisms not yet elucidated. In the present study we evaluated the central mechanisms underpinning the SH-induced changes in the respiratory pattern and their impact on the sympathetic outflow. Using a decerebrated arterially perfused in situ preparation, we verified that juvenile rats exposed to SH (10% O2) for 24 h presented an active expiratory pattern, with increased abdominal, hypoglossal and vagal activities during late-expiration (late-E). SH also enhanced the activity of augmenting-expiratory neurones and depressed the activity of post-inspiratory neurones of the Bötzinger complex (BötC) by mechanisms not related to changes in their intrinsic electrophysiological properties. SH rats exhibited high thoracic sympathetic activity and arterial pressure levels associated with an augmented firing frequency of pre-sympathetic neurones of the rostral ventrolateral medulla (RVLM) during the late-E phase. The antagonism of ionotropic glutamatergic receptors in the BötC/RVLM abolished the late-E bursts in expiratory and sympathetic outputs of SH rats, indicating that glutamatergic inputs to the BötC/RVLM are essential for the changes in the expiratory and sympathetic coupling observed in SH rats. We also observed that the usually silent late-E neurones of the retrotrapezoid nucleus/parafacial respiratory group became active in SH rats, suggesting that this neuronal population may provide the excitatory drive essential to the emergence of active expiration and sympathetic overactivity. We conclude that short-term SH induces the activation of medullary expiratory neurones, which affects the pattern of expiratory motor activity and its coupling with sympathetic activity. PMID:24614747

Temporal and Spatial Patterns of Ambient Endotoxin Concentrations in Fresno, California

PubMed Central

Tager, Ira B.; Lurmann, Frederick W.; Haight, Thaddeus; Alcorn, Siana; Penfold, Bryan; Hammond, S. Katharine

2010-01-01

Background Endotoxins are found in indoor dust generated by human activity and pets, in soil, and adsorbed onto the surfaces of ambient combustion particles. Endotoxin concentrations have been associated with respiratory symptoms and the risk of atopy and asthma in children. Objective We characterized the temporal and spatial variability of ambient endotoxin in Fresno/Clovis, California, located in California’s Central Valley, to identify correlates and potential predictors of ambient endotoxin concentrations in a cohort of children with asthma [Fresno Asthmatic Children’s Environment Study (FACES)]. Methods Between May 2001 and October 2004, daily ambient endotoxin and air pollutants were collected at the central ambient monitoring site of the California Air Resources Board in Fresno and, for shorter time periods, at 10 schools and indoors and outdoors at 84 residences in the community. Analyses were restricted to May–October, the dry months during which endotoxin concentrations are highest. Results Daily endotoxin concentration patterns were determined mainly by meteorologic factors, particularly the degree of air stagnation. Overall concentrations were lowest in areas distant from agricultural activities. Highest concentrations were found in areas immediately downwind from agricultural/pasture land. Among three other measured air pollutants [fine particulate matter, elemental carbon (a marker of traffic in Fresno), and coarse particulate matter (PMc)], PMc was the only pollutant correlated with endotoxin. Endotoxin, however, was the most spatially variable. Conclusions Our data support the need to evaluate the spatial/temporal variability of endotoxin concentrations, rather than relying on a few measurements made at one location, in studies of exposure and and respiratory health effects, particularly in children with asthma and other chronic respiratory diseases. PMID:20494854

Ventilatory Cycle Measurements and Loop Gain in Central Apnea in Mining Drivers Exposed to Intermittent Altitude

PubMed Central

Rey de Castro, Jorge; Liendo, Alicia; Ortiz, Oswaldo; Rosales-Mayor, Edmundo; Liendo, César

2017-01-01

Study Objectives: By measuring the apnea length, ventilatory phase, respiratory cycle length, and loop gain, we can further characterize the central apneas of high altitude (CAHA). Methods: Sixty-three drivers of all-terrain vehicles, working in a Peruvian mine located at 2,020 meters above sea level (MASL), were evaluated. A respiratory polygraph was performed in the first night they slept at high altitude. None of the subjects were exposed to oxygen during the test or acetazolamide in the preceding days of the test. Results: Sixty-three respiratory polygraphs were performed, and 59 were considered for analysis. Forty-six (78%) were normal, 6 (10%) had OSA, and 7 (12%) had CAHA. Key data from subjects include: residing altitude: 341 ± 828 MASL, Lake Louise scoring: 0.4 ± 0.8, Epworth score: 3.4 ± 2.7, apneahypopnea index: 35.7 ± 19.3, CA index: 13.4 ± 14.2, CA length: 14.4 ± 3.6 sec, ventilatory length: 13.5 ± 2.9 sec, cycle length: 26.5 ± 4.0 sec, ventilatory length/CA length ratio 0.9 ± 0.3 and circulatory delay 13.3 ± 2.9 sec. Duty ratio media [ventilatory duration/cycle duration] was 0.522 ± 0 0.128 [0.308–0.700] and loop gain was calculated from the duty ratio utilizing this formula: LG = 2π / [(2πDR-sin(2πDR)]. All subjects have a high loop gain media 2.415 ± 1.761 [1.175–6.260]. Multiple correlations were established with loop gain values, but the only significant correlation detected was between central apnea index and loop gain. Conclusions: Twelve percent of the studied population had CAHA. Measurements of respiratory cycle in workers with CAHA are more similar to idiopathic central apneas rather than Hunter-Cheyne-Stokes respiration. Also, there was a high degree of correlation between severity of central apnea and the degree of loop gain. The abnormal breathing patterns in those subjects could affect the sleep quality and potentially increase the risk for work accidents. Citation: Rey de Castro J, Liendo A, Ortiz O, Rosales-Mayor E, Liendo C. Ventilatory cycle measurements and loop gain in central apnea in mining drivers exposed to intermittent altitude. J Clin Sleep Med. 2017;13(1):27–32. PMID:27707449

Modification of medullary respiratory-related discharge patterns by behaviors and states of arousal.

PubMed

Chang, F C

1992-02-07

The modulatory influences of behaviors and states of arousal on bulbar respiratory-related unit (RRU) discharge patterns were studied in an unanesthetized, freely behaving guinea pig respiratory model system. When fully instrumented, this model system permits concurrent monitoring and recording of (i) single units from either Bötzinger complex or nucleus para-ambiguus; (ii) electrocorticogram; and, (iii) diaphragmatic EMG. In addition to being used in surveys of RRU discharge patterns in freely behaving states, the model system also offered a unique opportunity in investigating the effects of pentobarbital on RRU discharge patterns before, throughout the course of, and during recovery from anesthesia. In anesthetized preparations, a particular RRU discharge pattern (such as tonic, incrementing or decrementing) typically displayed little, if any notable variation. The most striking development following pentobarbital was a state of progressive bradypnea attributable to a significantly augmented RRU cycle duration, burst duration and an increase in the RRU spike frequencies during anesthesia. In freely behaving states, medullary RRU activities rarely adhered to a fixed, immutable discharge pattern. More specifically, the temporal organization (such as burst duration, cycle duration, and the extent of modulation of within-burst spike frequencies) of RRU discharge patterns regularly showed complex and striking variations, not only with states of arousal (sleep/wakefulness, anesthesia) but also with discrete alterations in electrocorticogram (ECoG) activities and a multitude of on-going behavioral repertoires such as volitional movement, postural modification, phonation, mastication, deglutition, sniffing/exploratory behavior, alerting/startle reflexes. Only during sleep, and on occasions when the animal assumed a motionless, resting posture, could burst patterns of relatively invariable periodicity and uniform temporal attributes be observed. RRU activities during sniffing reflex is worthy of further note in that, based on power spectrum analyses of concurrently recorded ECoG activities, this particular discharge pattern was clearly associated with the activation of a 6-10 Hz theta rhythm. These findings indicated that bulbar RRU activity patterns are subject to change by not only behaviors and sleep/wakefulness cycles, but also a variety of modulatory influences and feedback/feedforward biases from other central and peripheral physiological control mechanisms.

Oscillatory patterns in sympathetic neural discharge and cardiovascular variables during orthostatic stimulus

NASA Technical Reports Server (NTRS)

Furlan, R.; Porta, A.; Costa, F.; Tank, J.; Baker, L.; Schiavi, R.; Robertson, D.; Malliani, A.; Mosqueda-Garcia, R.

2000-01-01

BACKGROUND: We tested the hypothesis that a common oscillatory pattern might characterize the rhythmic discharge of muscle sympathetic nerve activity (MSNA) and the spontaneous variability of heart rate and systolic arterial pressure (SAP) during a physiological increase of sympathetic activity induced by the head-up tilt maneuver. METHODS AND RESULTS: Ten healthy subjects underwent continuous recordings of ECG, intra-arterial pressure, respiratory activity, central venous pressure, and MSNA, both in the recumbent position and during 75 degrees head-up tilt. Venous samplings for catecholamine assessment were obtained at rest and during the fifth minute of tilt. Spectrum and cross-spectrum analyses of R-R interval, SAP, and MSNA variabilities and of respiratory activity provided the low (LF, 0.1 Hz) and high frequency (HF, 0.27 Hz) rhythmic components of each signal and assessed their linear relationships. Compared with the recumbent position, tilt reduced central venous pressure, but blood pressure was unchanged. Heart rate, MSNA, and plasma epinephrine and norepinephrine levels increased, suggesting a marked enhancement of overall sympathetic activity. During tilt, LF(MSNA) increased compared with the level in the supine position; this mirrored similar changes observed in the LF components of R-R interval and SAP variabilities. The increase of LF(MSNA) was proportional to the amount of the sympathetic discharge. The coupling between LF components of MSNA and R-R interval and SAP variabilities was enhanced during tilt compared with rest. CONCLUSIONS: During the sympathetic activation induced by tilt, a similar oscillatory pattern based on an increased LF rhythmicity characterized the spontaneous variability of neural sympathetic discharge, R-R interval, and arterial pressure.

Central Hypoventilation: A Case Study of Issues Associated with Travel Medicine and Respiratory Infection.

PubMed

Hon, Kam Lun; Leung, Alexander K C; Li, Albert M C; Ng, Daniel K K

2015-01-01

Aim. We presented the case of a child with central hypoventilation syndrome (CHS) to highlight issues that need to be considered in planning long-haul flight and problems that may arise during the flight. Case. The pediatric intensive care unit (PICU) received a child with central hypoventilation syndrome (Ondine's curse) on nocturnal ventilatory support who travelled to Hong Kong on a make-a-wish journey. He was diagnosed with central hypoventilation and had been well managed in Canada. During a long-haul aviation travel, he developed respiratory symptoms and desaturations. The child arrived in Hong Kong and his respiratory symptoms persisted. He was taken to a PICU for management. The child remained well and investigations revealed no pathogen to account for his respiratory infection. He went on with his make-a-wish journey. Conclusions. Various issues of travel medicine such as equipment, airline arrangement, in-flight ventilatory support, travel insurance, and respiratory infection are explored and discussed. This case illustrates that long-haul air travel is possible for children with respiratory compromise if anticipatory preparation is timely arranged.

The respiratory system.

PubMed

Zifko, U; Chen, R

1996-10-01

Neurological disorders frequently contribute to respiratory failure in critically ill patients. They may be the primary reason for the initiation of mechanical ventilation, or may develop later as a secondary complication. Disorders of the central nervous system leading to respiratory failure include metabolic encephalopathies, acute stroke, lesions of the motor cortex and brain-stem respiratory centres, and their descending pathways. Guillan-Barré syndrome, critical illness polyneuropathy and acute quadriplegic myopathy are the more common neuromuscular causes of respiratory failure. Clinical observations and pulmonary function tests are important in monitoring respiratory function. Respiratory electrophysiological studies are useful in the investigation and monitoring of respiratory failure. Transcortical and cervical magnetic stimulation can assess the central respiratory drive, and may be useful in determining the prognosis in ventilated patients, with cervical cord dysfunction. It is also helpful in the assessment of failure to wean, which is often caused by a combination of central and peripheral nervous system disorders. Phrenic nerve conduction studies and needle electromyography of the diaphragm and chest wall muscles are useful to characterize neuropathies and myopathies affecting the diaphragm. Repetitive phrenic nerve stimulation can assess neuromuscular transmission defects. It is important to identify patients at risk of respiratory failure. They should be carefully monitored and mechanical ventilation should be initiated before the development of severe hypoxaemia.

Advanced positive airway pressure modes: adaptive servo ventilation and volume assured pressure support.

PubMed

Selim, Bernardo; Ramar, Kannan

2016-09-01

Volume assured pressure support (VAPS) and adaptive servo ventilation (ASV) are non-invasive positive airway pressure (PAP) modes with sophisticated negative feedback control systems (servomechanism), having the capability to self-adjust in real time its respiratory controlled variables to patient's respiratory fluctuations. However, the widespread use of VAPS and ASV is limited by scant clinical experience, high costs, and the incomplete understanding of propriety algorithmic differences in devices' response to patient's respiratory changes. Hence, we will review and highlight similarities and differences in technical aspects, control algorithms, and settings of each mode, focusing on the literature search published in this area. One hundred twenty relevant articles were identified by Scopus, PubMed, and Embase databases from January 2010 to 2016, using a combination of MeSH terms and keywords. Articles were further supplemented by pearling. Recommendations were based on the literature review and the authors' expertise in this area. Expert commentary: ASV and VAPS differ in their respiratory targets and response to a respiratory fluctuation. The VAPS mode targets a more consistent minute ventilation, being recommended in the treatment of sleep related hypoventilation disorders, while ASV mode attempts to provide a more steady breathing airflow pattern, treating successfully most central sleep apnea syndromes.

Upper thoracic respiratory interneurons integrate noxious somatic and visceral information in rats.

PubMed

Qin, Chao; Chandler, Margaret J; Foreman, Robert D; Farber, Jay P

2002-11-01

The aim of this study was to determine if thoracic respiratory interneurons (TRINs) might receive peripheral noxious somatic and visceral inputs. Extracellular potentials of 78 respiration-related T(3) neurons, whose activity was driven by central respiratory output, were recorded from the intermediate zone in pentobarbital anesthetized, paralyzed, and ventilated male rats. These neurons were identified as interneurons by their locations and by the absence of antidromic activation from the cervical sympathetic trunk and cerebellum. Thoracic esophageal distension (ED) was produced by water inflation of a latex balloon (0.1-0.5 ml, 20 s). A catheter was placed in the pericardial sac to administer 0.2 ml bradykinin (10(-5) M) for noxious cardiac stimulation. Of 78 TRINs examined for ED, activity of 24 TRINs increased and activity of 8 TRINs decreased. Intrapericardial bradykinin increased activity in 26/65 TRINs tested and decreased activity in 5 TRINs. Seventy-four TRINs were tested for effects of brush, pressure, and pinch of the chest and upper back areas. No TRINs responded to brushing hair. Low-threshold responses to pressure were observed in 27 TRINs. Fourteen TRINs were wide dynamic range and 4 TRINs had high-threshold responses. Peripheral stimuli affected all types of TRINs, including inspiratory, expiratory, and biphasic neurons. Simultaneous phrenic recordings showed that effects of various somatic and visceral stimuli on TRINs were independent of central respiratory drive. Various somatovisceral and viscerovisceral patterns of input were observed in TRINs. The results suggested that TRINs participate in intraspinal processing and integration of nociceptive information from somatic fields and visceral organs.

Noncontact respiration-monitoring system using fiber grating sensor

NASA Astrophysics Data System (ADS)

Sato, Isao; Nakajima, Masato

2004-10-01

In this research, the new non-contact breathing motion monitoring system using Fiber Grating 3-dimension Sensor is used to measure the respiratory movement of the chest and the abdomen and the shape of the human body simultaneously. Respiratory trouble during sleep brings about various kinds of diseases. Particularly, Sleep Apnea Syndrome (SAS), which restricts respiration during sleep, has been in the spotlight in recent years. However, present equipment for analyzing the blessing motion requires attaching various sensors on the patient's body. This system adopted two CCD cameras to measure the movements of projected infrared bright spots on the patient's body which measure the body form, breathing motion of the chest and breathing motion of the abdomen in detail. Since the equipment does not contact the patient's body, the patient feels incompatibility, and there is no necessity to worry about the equipment coming off. Sleep Apnea Syndrome is classified into three types by their respiratory pattern-Obstructive, Central and Mixed SAS based on the characteristic. This paper reports the method of diagnosing SAS automatically. It is thought that this method will be helpful not only for the diagnosis of SAS but also for the diagnosis of other kinds of complicated respiratory disease.

Prognosis in Acute Cerebrovascular Accidents in Relation to Respiratory Pattern and Blood—gas Tensions

PubMed Central

Rout, M. W.; Lane, D. J.; Wollner, L.

1971-01-01

Respiratory pattern and arterial blood gas tensions were assessed in patients with acute cerebrovascular accidents. Hyperventilation, low Pco2, and high arterial pH were associated with a poor prognosis, whereas patients with normal respiratory pattern and blood gas tensions survived. Periodic and Cheyne-Stokes breathing carried an intermediate prognosis. PMID:5091916

Respiratory trace feature analysis for the prediction of respiratory-gated PET quantification.

PubMed

Wang, Shouyi; Bowen, Stephen R; Chaovalitwongse, W Art; Sandison, George A; Grabowski, Thomas J; Kinahan, Paul E

2014-02-21

The benefits of respiratory gating in quantitative PET/CT vary tremendously between individual patients. Respiratory pattern is among many patient-specific characteristics that are thought to play an important role in gating-induced imaging improvements. However, the quantitative relationship between patient-specific characteristics of respiratory pattern and improvements in quantitative accuracy from respiratory-gated PET/CT has not been well established. If such a relationship could be estimated, then patient-specific respiratory patterns could be used to prospectively select appropriate motion compensation during image acquisition on a per-patient basis. This study was undertaken to develop a novel statistical model that predicts quantitative changes in PET/CT imaging due to respiratory gating. Free-breathing static FDG-PET images without gating and respiratory-gated FDG-PET images were collected from 22 lung and liver cancer patients on a PET/CT scanner. PET imaging quality was quantified with peak standardized uptake value (SUV(peak)) over lesions of interest. Relative differences in SUV(peak) between static and gated PET images were calculated to indicate quantitative imaging changes due to gating. A comprehensive multidimensional extraction of the morphological and statistical characteristics of respiratory patterns was conducted, resulting in 16 features that characterize representative patterns of a single respiratory trace. The six most informative features were subsequently extracted using a stepwise feature selection approach. The multiple-regression model was trained and tested based on a leave-one-subject-out cross-validation. The predicted quantitative improvements in PET imaging achieved an accuracy higher than 90% using a criterion with a dynamic error-tolerance range for SUV(peak) values. The results of this study suggest that our prediction framework could be applied to determine which patients would likely benefit from respiratory motion compensation when clinicians quantitatively assess PET/CT for therapy target definition and response assessment.

Respiratory trace feature analysis for the prediction of respiratory-gated PET quantification

NASA Astrophysics Data System (ADS)

Wang, Shouyi; Bowen, Stephen R.; Chaovalitwongse, W. Art; Sandison, George A.; Grabowski, Thomas J.; Kinahan, Paul E.

2014-02-01

The benefits of respiratory gating in quantitative PET/CT vary tremendously between individual patients. Respiratory pattern is among many patient-specific characteristics that are thought to play an important role in gating-induced imaging improvements. However, the quantitative relationship between patient-specific characteristics of respiratory pattern and improvements in quantitative accuracy from respiratory-gated PET/CT has not been well established. If such a relationship could be estimated, then patient-specific respiratory patterns could be used to prospectively select appropriate motion compensation during image acquisition on a per-patient basis. This study was undertaken to develop a novel statistical model that predicts quantitative changes in PET/CT imaging due to respiratory gating. Free-breathing static FDG-PET images without gating and respiratory-gated FDG-PET images were collected from 22 lung and liver cancer patients on a PET/CT scanner. PET imaging quality was quantified with peak standardized uptake value (SUVpeak) over lesions of interest. Relative differences in SUVpeak between static and gated PET images were calculated to indicate quantitative imaging changes due to gating. A comprehensive multidimensional extraction of the morphological and statistical characteristics of respiratory patterns was conducted, resulting in 16 features that characterize representative patterns of a single respiratory trace. The six most informative features were subsequently extracted using a stepwise feature selection approach. The multiple-regression model was trained and tested based on a leave-one-subject-out cross-validation. The predicted quantitative improvements in PET imaging achieved an accuracy higher than 90% using a criterion with a dynamic error-tolerance range for SUVpeak values. The results of this study suggest that our prediction framework could be applied to determine which patients would likely benefit from respiratory motion compensation when clinicians quantitatively assess PET/CT for therapy target definition and response assessment.

Brainstem Involvement as a Cause of Central Sleep Apnea: Pattern of Microstructural Cerebral Damage in Patients with Cerebral Microangiopathy

PubMed Central

Duning, Thomas; Deppe, Michael; Brand, Eva; Stypmann, Jörg; Becht, Charlotte; Heidbreder, Anna; Young, Peter

2013-01-01

Background The exact underlying pathomechanism of central sleep apnea with Cheyne-Stokes respiration (CSA-CSR) is still unclear. Recent studies have demonstrated an association between cerebral white matter changes and CSA. A dysfunction of central respiratory control centers in the brainstem was suggested by some authors. Novel MR-imaging analysis tools now allow far more subtle assessment of microstructural cerebral changes. The aim of this study was to investigate whether and what severity of subtle structural cerebral changes could lead to CSA-CSR, and whether there is a specific pattern of neurodegenerative changes that cause CSR. Therefore, we examined patients with Fabry disease (FD), an inherited, lysosomal storage disease. White matter lesions are early and frequent findings in FD. Thus, FD can serve as a "model disease" of cerebral microangiopathy to study in more detail the impact of cerebral lesions on central sleep apnea. Patients and Methods Genetically proven FD patients (n = 23) and age-matched healthy controls (n = 44) underwent a cardio-respiratory polysomnography and brain MRI at 3.0 Tesla. We applied different MR-imaging techniques, ranging from semiquantitative measurement of white matter lesion (WML) volumes and automated calculation of brain tissue volumes to VBM of gray matter and voxel-based diffusion tensor imaging (DTI) analysis. Results In 5 of 23 Fabry patients (22%) CSA-CSR was detected. Voxel-based DTI analysis revealed widespread structural changes in FD patients when compared to the healthy controls. When calculated as a separate group, DTI changes of CSA-CSR patients were most prominent in the brainstem. Voxel-based regression analysis revealed a significant association between CSR severity and microstructural DTI changes within the brainstem. Conclusion Subtle microstructural changes in the brainstem might be a neuroanatomical correlate of CSA-CSR in patients at risk of WML. DTI is more sensitive and specific than conventional structural MRI and other advanced MR analyses tools in demonstrating these abnormalities. PMID:23637744

Reciprocal functional interactions between the brainstem and the lower spinal cord

PubMed Central

Yazawa, Itaru

2014-01-01

The interplay of the neuronal discharge patterns regarding respiration and locomotion was investigated using electrophysiological techniques in a decerebrate and arterially perfused in situ mouse preparation. The phrenic, tibial, and/or peroneal nerve discharge became clearly organized into discharge episodes of increasing frequency and duration, punctuated by periods of quiescence as the perfusion flow rate increased at room temperature. The modulated sympathetic tone induced by the hyperoxic/normocapnic state was found to activate the locomotor pattern generator (LPG) via descending pathways and generate a left and right alternating discharge during discharge episodes in the motor nerves. The rhythm coupling of respiration and locomotion occurred at a 1:1 frequency ratio. Although the phrenic discharge synchronized with the tibial discharge at all flow rates tested, the time lag between peaks of the two discharges during locomotion was ≈400 ms rather than ≈200 ms, suggesting spinal feedback via ascending pathways. The incidence of the phrenic and tibial discharge episodes decreased by ≈50% after spinalization at the twelfth thoracic cord and the respiratory rhythm was more regular. These results indicate that: (i) locomotion can be generated in a hyperoxic/normocapnic state induced by specific respiratory conditions, (ii) the central mechanism regarding entrainment of respiratory and locomotor rhythms relies on spinal feedback via ascending pathways, initiated by the activated LPG generating locomotion, and (iii) the increase in respiratory rate seen during locomotion is caused not only by afferent mechanical and nociceptive inputs but also by impulses from the activated spinal cord producing a locomotor-like discharge via ascending pathways. PMID:24910591

Contraindications to Athletic Participation. Cardiac, Respiratory, and Central Nervous System Conditions.

ERIC Educational Resources Information Center

Moeller, James L.

1996-01-01

Discusses contraindications to athletic participation, examining the cardiac, respiratory, and central nervous system conditions that warrant activity disqualification. Provides guidelines about when it is safe for individuals to participate, and discusses the physician's responsibility. (SM)

Central and peripheral effects of the non-neural substances on respiration before and after vagotomy.

PubMed

Sahin, G; Oruç, T; Simşek, G; Güner, I

1997-08-01

The central effects of capsaicin, veratrine, histamine and bradykinin were studied by injecting them directly into the oerebrospinal fluid and their peripheral effects were examined by injecting into femoral vein. Our experiments were performed in Na-pentobarbital-anaesthetized dogs. Tidal volume (VT), respiratory frequency (f/min), systemic arterial pressure (BP) were recorded. A significant increase in f, and an initial apnea or hypoventilation followed by a significant increase in VT were observed with central and peripheral capsaicin. Vagotomy removed the peripheral VT response, but not the central one. While central capsaicin administration increased BP, peripheral administration decreased. After vagotomy, a significant increase was observed in BP for both administrations. Respiratory responses to central and peripheral administrations of veratrine were similar to those of capsaicin. Significant increases were observed in f and VT of the intact group in response to central and peripheral administration of histamine. Response to peripheral administration disappeared after vagotomy. While central and peripheral bradykinin increased VT significantly, there was no significant change in f. Vagotomy only removed the increase in VT in response to peripheral administration. In conclusion, respiratory responses to central administration of capsaicin and veratrine are due to direct effects of these substances on respiratory neurons. In peripheral administration, disappearance of the responses after vagotomy indicate that the responses are brought about by stimulation of the lung receptors.

Effects of pacifier and taste on swallowing, esophageal motility, transit, and respiratory rhythm in human neonates.

PubMed

Shubert, T R; Sitaram, S; Jadcherla, S R

2016-04-01

Pacifier use is widely prevalent globally despite hygienic concerns and uncertain mechanistic effects on swallowing or airway safety. The effects of pacifier and taste interventions on pharyngo-esophageal motility, bolus transit, and respiratory rhythms were investigated by determining the upper esophageal sphincter (UES), esophageal body, esophagogastric junction (EGJ) motor patterns and deglutition apnea, respiratory rhythm disturbances, and esophageal bolus clearance. Fifteen infants (six males; median gestation 31 weeks and birth weight 1.4 kg) underwent high-resolution impedance manometry at 43 (41-44) weeks postmenstrual age. Manometric, respiratory, and impedance characteristics of spontaneous swallows, pacifier-associated dry swallowing and taste (pacifier dipped in 3% sucrose)-associated swallowing were analyzed. Linear mixed and generalized estimating equation models were used. Data are presented as mean ± SEM, %, or median (IQR). Pharyngo-esophageal motility, respiratory, and impedance characteristics of 209 swallows were analyzed (85 spontaneous swallows, 63 pacifier- swallows, 61 taste- swallows). Basal UES and EGJ pressures decreased upon pacifier (p < 0.05) and taste interventions (p < 0.05); however, esophageal motility, respiratory rhythm, and impedance transit characteristics were similar with both interventions. Oral stimulus with pacifier or taste interventions decreases UES and EGJ basal pressure, but has no effects on pharyngo-esophageal motility, airway interactions, or esophageal bolus transit. A decrease in central parasympathetic-cholinergic excitatory drive is likely responsible for the basal effects. © 2016 John Wiley & Sons Ltd.

Task2 potassium channels set central respiratory CO2 and O2 sensitivity

PubMed Central

Gestreau, Christian; Heitzmann, Dirk; Thomas, Joerg; Dubreuil, Véronique; Bandulik, Sascha; Reichold, Markus; Bendahhou, Saïd; Pierson, Patricia; Sterner, Christina; Peyronnet-Roux, Julie; Benfriha, Chérif; Tegtmeier, Ines; Ehnes, Hannah; Georgieff, Michael; Lesage, Florian; Brunet, Jean-Francois; Goridis, Christo; Warth, Richard; Barhanin, Jacques

2010-01-01

Task2 K+ channel expression in the central nervous system is surprisingly restricted to a few brainstem nuclei, including the retrotrapezoid (RTN) region. All Task2-positive RTN neurons were lost in mice bearing a Phox2b mutation that causes the human congenital central hypoventilation syndrome. In plethysmography, Task2−/− mice showed disturbed chemosensory function with hypersensitivity to low CO2 concentrations, leading to hyperventilation. Task2 probably is needed to stabilize the membrane potential of chemoreceptive cells. In addition, Task2−/− mice lost the long-term hypoxia-induced respiratory decrease whereas the acute carotid-body-mediated increase was maintained. The lack of anoxia-induced respiratory depression in the isolated brainstem–spinal cord preparation suggested a central origin of the phenotype. Task2 activation by reactive oxygen species generated during hypoxia could silence RTN neurons, thus contributing to respiratory depression. These data identify Task2 as a determinant of central O2 chemoreception and demonstrate that this phenomenon is due to the activity of a small number of neurons located at the ventral medullary surface. PMID:20133877

Breathing and Vocal Control: The Respiratory System as both a Driver and Target of Telencephalic Vocal Motor Circuits in Songbirds

PubMed Central

Schmidt, Marc F.; McLean, Judith; Goller, Franz

2011-01-01

The production of vocalizations is intimately linked to the respiratory system. Despite our understanding of neural circuits that generate normal respiratory patterns, very little is understood regarding how these ponto-medullary circuits become engaged during vocal production. Songbirds offer a potentially powerful model system for addressing this relationship. Songs dramatically alter the respiratory pattern in ways that are often highly predictable and songbirds have a specialized telencephalic vocal motor circuit that provides massive innervation to a brainstem respiratory network that shares many similarities with its mammalian counterpart. In this review, we highlight interactions between the song motor circuit and the respiratory system, describing how both systems likely interact to produce the complex respiratory patterns that are observed during vocalization. We also discuss how the respiratory system, through its bilateral bottom-up projections to thalamus, might play a key role in sending precisely timed signals that synchronize premotor activity in both hemispheres. PMID:21984733

Role of neurotensin and opioid receptors in the cardiorespiratory effects of [Ile⁹]PK20, a novel antinociceptive chimeric peptide.

PubMed

Kaczyńska, Katarzyna; Szereda-Przestaszewska, Małgorzata; Kleczkowska, Patrycja; Lipkowski, Andrzej W

2014-10-15

Ile(9)PK20 is a novel hybrid of opioid-neurotensin peptides synthesized from the C-terminal hexapeptide of neurotensin and endomorphin-2 pharmacophore. This chimeric compound shows potent central and peripheral antinociceptive activity in experimental animals, however nothing is known about its influence on the respiratory and cardiovascular parameters. The present study was designed to determine the cardiorespiratory effects exerted by an intravenous injection (i.v.) of [Ile(9)]PK20. Share of the vagal afferentation and the contribution of NTS1 neurotensin and opioid receptors were tested. Intravenous injection of the hybrid at a dose of 100 μg/kg in the intact, anaesthetized rats provoked an increase in tidal volume preceded by a prompt short-lived decrease. Immediately after the end of injection brief acceleration of the respiratory rhythm appeared, and was ensued by the slowing down of breathing. Changes in respiration were concomitant with a bi-phasic response of the blood pressure: an immediate increase was followed by a sustained hypotension. Midcervical vagotomy eliminated the increase in tidal volume and respiratory rate responses. Antagonist of opioid receptors - naloxone hydrochloride eliminated only [Ile(9)]PK20-evoked decline in tidal volume response. Blockade of NTS1 receptors with an intravenous dose of SR 142,948, lessened the remaining cardiorespiratory effects. This study depicts that [Ile(9)]PK20 acting through neurotensin NTS1 receptors augments the tidal component of the breathing pattern and activates respiratory timing response through the vagal pathway. Blood pressure effects occur outside vagal afferentation and might result from activation of the central and peripheral vascular NTS1 receptors. In summary the respiratory effects of the hybrid appeared not to be profound, but they were accompanied with unfavourable prolonged hypotension. Copyright © 2014 Elsevier B.V. All rights reserved.

Assessment of human respiration patterns via noncontact sensing using Doppler multi-radar system.

PubMed

Gu, Changzhan; Li, Changzhi

2015-03-16

Human respiratory patterns at chest and abdomen are associated with both physical and emotional states. Accurate measurement of the respiratory patterns provides an approach to assess and analyze the physical and emotional states of the subject persons. Not many research efforts have been made to wirelessly assess different respiration patterns, largely due to the inaccuracy of the conventional continuous-wave radar sensor to track the original signal pattern of slow respiratory movements. This paper presents the accurate assessment of different respiratory patterns based on noncontact Doppler radar sensing. This paper evaluates the feasibility of accurately monitoring different human respiration patterns via noncontact radar sensing. A 2.4 GHz DC coupled multi-radar system was used for accurate measurement of the complete respiration patterns without any signal distortion. Experiments were carried out in the lab environment to measure the different respiration patterns when the subject person performed natural breathing, chest breathing and diaphragmatic breathing. The experimental results showed that accurate assessment of different respiration patterns is feasible using the proposed noncontact radar sensing technique.

Assessment of Human Respiration Patterns via Noncontact Sensing Using Doppler Multi-Radar System

PubMed Central

Gu, Changzhan; Li, Changzhi

2015-01-01

Human respiratory patterns at chest and abdomen are associated with both physical and emotional states. Accurate measurement of the respiratory patterns provides an approach to assess and analyze the physical and emotional states of the subject persons. Not many research efforts have been made to wirelessly assess different respiration patterns, largely due to the inaccuracy of the conventional continuous-wave radar sensor to track the original signal pattern of slow respiratory movements. This paper presents the accurate assessment of different respiratory patterns based on noncontact Doppler radar sensing. This paper evaluates the feasibility of accurately monitoring different human respiration patterns via noncontact radar sensing. A 2.4 GHz DC coupled multi-radar system was used for accurate measurement of the complete respiration patterns without any signal distortion. Experiments were carried out in the lab environment to measure the different respiration patterns when the subject person performed natural breathing, chest breathing and diaphragmatic breathing. The experimental results showed that accurate assessment of different respiration patterns is feasible using the proposed noncontact radar sensing technique. PMID:25785310

Naloxone Antagonizes Soman-induced Central Respiratory Depression in Rats.

PubMed

Škrbić, Ranko; Stojiljković, Miloš P; Ćetković, Slavko S; Dobrić, Silva; Jeremić, Dejan; Vulović, Maja

2017-06-01

The influence of naloxone on respiration impaired by the highly toxic organophosphate nerve agent soman in anaesthetized rats was investigated. Soman, administered in a dose that was ineffective in blocking the electrically induced contractions of the phrenic nerve-diaphragm preparation in situ, induced a complete block of the spontaneous respiratory movements of the diaphragm, indicating the domination of central over the peripheral effects. Naloxone dose-dependently antagonized the soman-induced respiratory blockade. Atropine, at a dose that was per se ineffective in counteracting soman-induced respiratory depression, potentiated the protective effects of naloxone and completely restored respiration. Naloxone remained completely ineffective in antagonizing respiratory depression induced by the muscarinic receptor agonist the oxotremorine. It is assumed that naloxone antagonizes soman-induced respiratory inhibition by blocking endogenous opioidergic respiratory control pathways that are independent of the stimulation of muscarinic receptors. © 2016 Nordic Association for the Publication of BCPT (former Nordic Pharmacological Society).

A review of concepts regarding the origin of respiratory muscle fatigue

NASA Astrophysics Data System (ADS)

Kuraszkiewicz, Bożena; Piotrkiewicz, Maria

2011-01-01

In this review, the classification of respiratory muscle fatigue from the perspective of its origin is presented. The fatigue is classified as central or peripheral, and the latter further subdivided into high- and low-frequency fatigue. However, muscle fatigue is a complex process and all three types of fatigue probably occur simultaneously in the overloaded respiratory muscles. The relative importance of each type depends on the duration of respiratory loading and other physiological variables. However, central and high-frequency fatigue resolve rapidly once muscle overload is removed, whereas low-frequency fatigue persists over long time.

Histological and ultrastructural analysis of the respiratory tracheae of Galeodes granti (Chelicerata: Solifugae).

PubMed

Franz-Guess, Sandra; Starck, J Matthias

2016-09-01

Solifuges lack oxygen-carrying proteins like hemocyanins found in other chelicerates. For conduction of gases, therefore, we hypothesize that the tracheal system is divided into convective and respiratory parts, the latter having intimate association with respiring cells, tissues and organs. This hypothesis is supported by studies of tracheae in other arthropods. We used light, scanning, and transmission electron microscopy to examine the tracheae of Galeodes granti (Chelicerata, Solifugae). We studied tracheae in cheliceral and leg muscles, midgut and midgut diverticula, the heart and the supra- and subesophageal ganglia of the central nervous system. In all tissues examined, the tracheae penetrate into tissues and can be found between cells. Terminal branches with diameter less than one micron were found embedded into cell bodies of respiring tissue, thus reducing the diffusion distance. We suggest that the terminal branches are specialized for respiratory function due to their thin intima, with reduced endocuticle and exocuticle. Comparison with other tracheate chelicerates suggests parallel evolution of a common tracheal pattern based on homologous cellular building materials within the chelicerates and arthropods. Copyright © 2016 Elsevier Ltd. All rights reserved.

MafB deficiency causes defective respiratory rhythmogenesis and fatal central apnea at birth.

PubMed

Blanchi, Bruno; Kelly, Louise M; Viemari, Jean-Charles; Lafon, Isabelle; Burnet, Henri; Bévengut, Michelle; Tillmanns, Silke; Daniel, Laurent; Graf, Thomas; Hilaire, Gerard; Sieweke, Michael H

2003-10-01

The genetic basis for the development of brainstem neurons that generate respiratory rhythm is unknown. Here we show that mice deficient for the transcription factor MafB die from central apnea at birth and are defective for respiratory rhythmogenesis in vitro. MafB is expressed in a subpopulation of neurons in the preBötzinger complex (preBötC), a putative principal site of rhythmogenesis. Brainstems from Mafb(-/-) mice are insensitive to preBötC electrolytic lesion or stimulation and modulation of rhythmogenesis by hypoxia or peptidergic input. Furthermore, in Mafb(-/-) mice the preBötC, but not major neuromodulatory groups, presents severe anatomical defects with loss of cellularity. Our results show an essential role of MafB in central respiratory control, possibly involving the specification of rhythmogenic preBötC neurons.

Plasticity and Activation of Spared Intraspinal Respiratory Circuits Following Spinal Cord Injury

DTIC Science & Technology

2016-10-01

fluorescent immunohistochemistry (IHC) procedures. Accordingly, we performed IHC with two markers commonly used in the central nervous system (GFAP and...immunohistochemistry (IHC) procedures. Accordingly, we performed IHC with two 365 markers commonly used in the central nervous system (GFAP and NeuN) either...905 mammalian central nervous system . J Neurosci Methods 1: 107-132, 1979. 906 Kirkwood PA, Munson JB, Sears TA, and Westgaard RH. Respiratory

Respiratory and metabolic acidosis differentially affect the respiratory neuronal network in the ventral medulla of neonatal rats.

PubMed

Okada, Yasumasa; Masumiya, Haruko; Tamura, Yoshiyasu; Oku, Yoshitaka

2007-11-01

Two respiratory-related areas, the para-facial respiratory group/retrotrapezoid nucleus (pFRG/RTN) and the pre-Bötzinger complex/ventral respiratory group (preBötC/VRG), are thought to play key roles in respiratory rhythm. Because respiratory output patterns in response to respiratory and metabolic acidosis differ, we hypothesized that the responses of the medullary respiratory neuronal network to respiratory and metabolic acidosis are different. To test these hypotheses, we analysed respiratory-related activity in the pFRG/RTN and preBötC/VRG of the neonatal rat brainstem-spinal cord in vitro by optical imaging using a voltage-sensitive dye, and compared the effects of respiratory and metabolic acidosis on these two populations. We found that the spatiotemporal responses of respiratory-related regional activities to respiratory and metabolic acidosis are fundamentally different, although both acidosis similarly augmented respiratory output by increasing respiratory frequency. PreBötC/VRG activity, which is mainly inspiratory, was augmented by respiratory acidosis. Respiratory-modulated pixels increased in the preBötC/VRG area in response to respiratory acidosis. Metabolic acidosis shifted the respiratory phase in the pFRG/RTN; the pre-inspiratory dominant pattern shifted to inspiratory dominant. The responses of the pFRG/RTN activity to respiratory and metabolic acidosis are complex, and involve either augmentation or reduction in the size of respiratory-related areas. Furthermore, the activation pattern in the pFRG/RTN switched bi-directionally between pre-inspiratory/inspiratory and post-inspiratory. Electrophysiological study supported the results of our optical imaging study. We conclude that respiratory and metabolic acidosis differentially affect activities of the pFRG/RTN and preBötC/VRG, inducing switching and shifts of the respiratory phase. We suggest that they differently influence the coupling states between the pFRG/RTN and preBötC/VRG.

Noninvasive ventilation in a child affected by achondroplasia respiratory difficulty syndrome.

PubMed

Ottonello, Giancarlo; Villa, Giovanna; Moscatelli, Andrea; Diana, Maria Cristina; Pavanello, Marco

2007-01-01

Achondroplasia can result in respiratory difficulty in early infancy, from anatomical abnormalities such as mid-facial hypoplasia and/or adenotonsillar hypertrophy, leading to obstructive apnea, or to pathophysiological changes occurring in nasopharyngeal or glossal muscle tone, related to neurological abnormalities (foramen magnum and/or hypoglossal canal problems, hydrocephalus), leading to central apnea. More often, the two respiratory components (central and obstructive) are both evident in mixed apnea. Polysomnographic recording should be used during preoperative and postoperative assessment of achondroplastic children and in the subsequent follow-up to assess the adequacy of continuing home respiratory support, including supplemental oxygen, bilevel positive airway pressure, or assisted ventilation.

Sodium cyanide induced alteration in the whole animal oxygen consumption and behavioural pattern of freshwater fish Labeo rohita.

PubMed

David, Muniswamy; Sangeetha, Jeyabalan; Harish, Etigemane R

2015-03-01

Sodium cyanide is a common environmental pollutant which is mainly used in many industries such as mining, electroplating, steel manufacturing, pharmaceutical production and other specialized applications including dyes and agricultural products. It enters aquatic environment through effluents from these industries. Static renewal bioassay test has been conducted to determine LC, of sodium cyanide on indigenous freshwater carp, Labeo rohita. The behavioural pattern and oxygen consumption were observed in fish at both lethal and sub lethal concentrations. Labeo rohita in toxic media exhibited irregular and erratic swimming movements, hyper excitability, loss of equilibrium and shrinking to the bottom, which may be due to inhibition of cytochrome C oxidase activity and decreased blood pH. The combination of cytotoxic hypoxia with lactate acidosis depresses the central nervous system resulting in respiratory arrest and death. Decrease in oxygen consumption was observed at both lethal and sub lethal concentrations of sodium cyanide. Mortality was insignificant at sub lethal concentration test when fishes were found under stress. Consequence of impaired oxidative metabolism and elevated physiological response by fish against sodium cyanide stress showed alteration in respiratory rate.

Respiration-related discharge of hyoglossus muscle motor units in the rat.

PubMed

Powell, Gregory L; Rice, Amber; Bennett-Cross, Seres J; Fregosi, Ralph F

2014-01-01

Although respiratory muscle motor units have been studied during natural breathing, simultaneous measures of muscle force have never been obtained. Tongue retractor muscles, such as the hyoglossus (HG), play an important role in swallowing, licking, chewing, breathing, and, in humans, speech. The HG is phasically recruited during the inspiratory phase of the respiratory cycle. Moreover, in urethane anesthetized rats the drive to the HG waxes and wanes spontaneously, providing a unique opportunity to study motor unit firing patterns as the muscle is driven naturally by the central pattern generator for breathing. We recorded tongue retraction force, the whole HG muscle EMG and the activity of 38 HG motor units in spontaneously breathing anesthetized rats under low-force and high-force conditions. Activity in all cases was confined to the inspiratory phase of the respiratory cycle. Changes in the EMG were correlated significantly with corresponding changes in force, with the change in EMG able to predict 53-68% of the force variation. Mean and peak motor unit firing rates were greater under high-force conditions, although the magnitude of discharge rate modulation varied widely across the population. Changes in mean and peak firing rates were significantly correlated with the corresponding changes in force, but the correlations were weak (r(2) = 0.27 and 0.25, respectively). These data indicate that, during spontaneous breathing, recruitment of HG motor units plays a critical role in the control of muscle force, with firing rate modulation playing an important but lesser role.

The progestin etonogestrel enhances the respiratory response to metabolic acidosis in newborn rats. Evidence for a mechanism involving supramedullary structures.

PubMed

Loiseau, Camille; Osinski, Diane; Joubert, Fanny; Straus, Christian; Similowski, Thomas; Bodineau, Laurence

2014-05-01

Central congenital hypoventilation syndrome is a neuro-respiratory disease characterized by the dysfunction of the CO2/H(+) chemosensitive neurons of the retrotrapezoid nucleus/parafacial respiratory group. A recovery of CO2/H(+) chemosensitivity has been observed in some central congenital hypoventilation syndrome patients coincidental with contraceptive treatment by a potent progestin, desogestrel (Straus et al., 2010). The mechanisms of this progestin effect remain unknown, although structures of medulla oblongata, midbrain or diencephalon are known to be targets for progesterone. In the present study, on ex vivo preparations of central nervous system of newborn rats, we show that acute exposure to etonogestrel (active metabolite of desogestrel) enhanced the increased respiratory frequency induced by metabolic acidosis via a mechanism involving supramedullary structures located in pontine, mesencephalic or diencephalic regions. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

Pathogens, patterns of pneumonia, and epidemiologic risk factors associated with respiratory disease in recently weaned cattle in Ireland.

PubMed

Murray, Gerard M; More, Simon J; Sammin, Dónal; Casey, Mìcheàl J; McElroy, Máire C; O'Neill, Rónan G; Byrne, William J; Earley, Bernadette; Clegg, Tracy A; Ball, Hywel; Bell, Colin J; Cassidy, Joseph P

2017-01-01

We examined the pathogens, morphologic patterns, and risk factors associated with bovine respiratory disease (BRD) in 136 recently weaned cattle ("weanlings"), 6-12 mo of age, that were submitted for postmortem examination to regional veterinary laboratories in Ireland. A standardized sampling protocol included routine microbiologic investigations as well as polymerase chain reaction and immunohistochemistry. Lungs with histologic lesions were categorized into 1 of 5 morphologic patterns of pneumonia. Fibrinosuppurative bronchopneumonia (49%) and interstitial pneumonia (48%) were the morphologic patterns recorded most frequently. The various morphologic patterns of pulmonary lesions suggest the involvement of variable combinations of initiating and compounding infectious agents that hindered any simple classification of the etiopathogenesis of the pneumonias. Dual infections were detected in 58% of lungs, with Mannheimia haemolytica and Histophilus somni most frequently recorded in concert. M. haemolytica (43%) was the most frequently detected respiratory pathogen; H. somni was also shown to be frequently implicated in pneumonia in this age group of cattle. Bovine parainfluenza virus 3 (BPIV-3) and Bovine respiratory syncytial virus (16% each) were the viral agents detected most frequently. Potential respiratory pathogens (particularly Pasteurella multocida, BPIV-3, and H. somni) were frequently detected (64%) in lungs that had neither gross nor histologic pulmonary lesions, raising questions regarding their role in the pathogenesis of BRD. The breadth of respiratory pathogens detected in bovine lungs by various detection methods highlights the diagnostic value of parallel analyses in respiratory disease postmortem investigation.

Carbon dioxide induces erratic respiratory responses in bipolar disorder.

PubMed

Mackinnon, Dean F; Craighead, Brandie; Lorenz, Laura

2009-01-01

CO(2) respiration stimulates both anxiety and dyspnea ("air hunger") and has long been used to study panic vulnerability and respiratory control. High comorbidity with panic attacks suggests individuals with bipolar disorder may also mount a heightened anxiety response to CO(2). Moreover, problems in the arousal and modulation of appetites are central to the clinical syndromes of mania and depression; hence CO(2) may arouse an abnormal respiratory response to "air hunger". 72 individuals (34 bipolar I, 25 depressive and bipolar spectrum, 13 with no major affective diagnosis) breathed air and air with 5% CO(2) via facemask for up to 15 min each; subjective and respiratory responses were recorded. Nearly half the subjects diverged from the typical response to a fixed, mildly hypercapneic environment, which is to increase breathing acutely, and then maintain a hyperpneic plateau. The best predictors of an abnormal pattern were bipolar diagnosis and anxiety from air alone. 25 individuals had a panic response; panic responses from CO(2) were more likely in subjects with bipolar I compared to other subjects, however the best predictors of a panic response overall were anxiety from air alone and prior history of panic attacks. Heterogeneous sample, liberal definition of panic attack. Carbon dioxide produces abnormal respiratory and heightened anxiety responses among individuals with bipolar and depressive disorders. These may be due to deficits in emotional conditioning related to fear and appetite. Although preliminary, this work suggests a potentially useful test of a specific functional deficit in bipolar disorder.

[Disturbed respiratory cycle accompanying hypoxic-ischemic encephalopathy].

PubMed

Saito, Yoshiaki; Masuko, Kaori; Kaneko, Kaori; Saito, Kazuyo; Chikumaru, Yuri; Iwamoto, Hiroko; Matsui, Akira; Kimura, Seiji

2005-09-01

We report the case of a 2-year-old boy who experienced total asphyxia at 4 months of age, and suffered abnormalities at specific phases of the respiratory cycle. The patient was bedridden due to severe tetraplegia and showed little response to external stimuli. He has been tube-fed since the initial asphyxia and a tracheotomy was performed after recurrent hypoxic episodes as a result of the respiratory dysfunction. Upon examination, his respiratory pattern was characterized by arrest during the inspiratory phase with a possible over-riding secondary inspiration. The respiratory pause at the inspiratory phase was markedly prolonged during an episode of pulmonary infection, resulting in recurrent cyanosis that necessitated artificial ventilation. The "second" inspiration typically occurred during the mid- or late-inspiratory phases, with this pattern often shown to be variable after epileptic seizures. The characteristic breathing of this patient suggested that difficulty in forming a normal respiratory cycle, other than during periods of hypoventilation or apnoea, could be a significant respiratory dysfunction following asphyxiation. Strategies for the management of such patients should be carefully designed after close observation of breathing patterns within the respiratory cycle, and with consideration for the influence of epileptic seizures and other inputs from somatic afferents.

Respiratory Patterns in Students Enrolled in Schools for Disruptive Behaviour before, during, and after "Yoga Nidra" Relaxation

ERIC Educational Resources Information Center

Jensen, P. S.; Stevens, P. J.; Kenny, D. T.

2012-01-01

This study investigated the effects of one session of "Yoga Nidra" (relaxation technique) on the breathing patterns/respiratory effort in the thoracic and abdominal chest regions of boys with disruptive behaviour using a Respiratory Inductive Plethysmography (RIP). The participants (n = 7) were aged 10-15 years and attending NSW, Department of…

SU-F-T-479: Estimation of the Accuracy in Respiratory-Gated Radiotherapy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kurosawa, T; Miyakawa, S; Sato, M

Purpose: Irregular respiratory patterns affects dose outputs in respiratorygated radiotherapy and there is no commercially available quality assurance (QA) system for it. We designed and developed a patient specific QA system for respiratory-gated radiotherapy to estimate irradiated output. Methods: Our in-house QA system for gating was composed of a personal computer with the USB-FSIO electronic circuit connecting to the linear accelerator (ONCOR-K, Toshiba Medical Systems). The linac implements a respiratory gating system (AZ-733V, Anzai Medical). During the beam was on, 4.2 V square-wave pulses were continually sent to the system. Our system can receive and count the pulses. At first,more » our system and an oscilloscope were compared to check the performance of our system. Next, basic estimation models were generated when ionization-chamber measurements were performed in gating using regular sinusoidal wave patterns (2.0, 2.5, 4.0, 8.0, 15 sec/cycle). During gated irradiation with the regular patterns, the number of the pulses per one gating window was measured using our system. Correlation between the number of the pulses per one gating and dose per the gating window were assessed to generate the estimation model. Finally, two irregular respiratory patterns were created and the accuracy of the estimation was evaluated. Results: Compared to the oscilloscope, our system worked similarly. The basic models were generated with the accuracy within 0.1%. The results of the gated irradiations with two irregular respiratory patterns show good agreement within 0.4% estimation accuracy. Conclusion: Our developed system shows good estimation for even irregular respiration patterns. The system would be a useful tool to verify the output for respiratory-gated radiotherapy.« less

The effect of ambient humidity and metabolic rate on the gas-exchange pattern of the semi-aquatic insect Aquarius remigis.

PubMed

Contreras, Heidy L; Bradley, Timothy J

2011-04-01

We have examined the effects of temperature on metabolic rate and respiratory pattern in the water strider Aquarius remigis. As temperature was increased from 10 to 30°C, the metabolic rate of the insects increased and the respiratory pattern transitioned from discontinuous, to cyclic, to continuous. The discontinuous gas-exchange cycle (DGC) was observed even in insects standing on water when the respirometry chamber was being perfused with humid (>95% relative humidity) air. Comparisons of insects at 20°C in humid and dry air showed no statistically significant differences in metabolic rate or respiratory pattern (P>0.05). The proportion of time that the spiracles were closed was greater at 10°C than at 20°C (P<0.01), and greater at 20°C than at 30°C (P<0.05). These results are compatible with the hypothesis that the respiratory patterns of insects are determined by the relationship between oxygen supply and oxygen demand. There was no evidence in this insect that humidity had any effect on the respiratory pattern. The results are discussed in the context of the ongoing discussion in the literature of the origin, maintenance and adaptive significance of the DGC in insects.

Respiratory comfort and breathing pattern during volume proportional assist ventilation and pressure support ventilation: a study on volunteers with artificially reduced compliance.

PubMed

Mols, G; von Ungern-Sternberg, B; Rohr, E; Haberthür, C; Geiger, K; Guttmann, J

2000-06-01

To assess respiratory comfort and associated breathing pattern during volume assist (VA) as a component of proportional assist ventilation and during pressure support ventilation (PSV). Prospective, double-blind, interventional study. Laboratory. A total of 15 healthy volunteers (11 females, 4 males) aged 21-31 yrs. Decreased respiratory system compliance was simulated by banding of the thorax and abdomen. Volunteers breathed via a mouthpiece with VA and PSV each applied at two levels (VA, 8 cm H2O/L and 12 cm H2O/L; PSV, 10 cm H2O and 15 cm H2O) using a positive end-expiratory pressure of 5 cm H2O throughout. The study was subdivided into two parts. In Part 1, volunteers breathed three times with each of the four settings for 2 mins in random order. In Part 2, the first breath effects of multiple, randomly applied mode, and level shifts were studied. In Part 1, the volunteers were asked to estimate respiratory comfort in comparison with normal breathing using a visual analog scale. In Part 2, they were asked to estimate the change of respiratory comfort as increased, decreased, or unchanged immediately after a mode shift. Concomitantly, the respiratory pattern (change) was characterized with continuously measured tidal volume, respiratory rate, pressure, and gas flow. Respiratory comfort during VA was higher than during PSV. The higher support level was less important during VA but had a major negative influence on comfort during PSV. Both modes differed with respect to the associated breathing pattern. Variability of breathing was higher during VA than during PSV (Part 1). Changes in respiratory variables were associated with changes in respiratory comfort (Part 2). For volunteers breathing with artificially reduced respiratory system compliance, respiratory comfort is higher with VA than with PSV. This is probably caused by a better adaptation of the ventilatory support to the volunteer's need with VA.

Pathogenic Influenza Viruses and Coronaviruses Utilize Similar and Contrasting Approaches To Control Interferon-Stimulated Gene Responses

PubMed Central

Menachery, Vineet D.; Eisfeld, Amie J.; Schäfer, Alexandra; Josset, Laurence; Sims, Amy C.; Proll, Sean; Fan, Shufang; Li, Chengjun; Neumann, Gabriele; Tilton, Susan C.; Chang, Jean; Gralinski, Lisa E.; Long, Casey; Green, Richard; Williams, Christopher M.; Weiss, Jeffrey; Matzke, Melissa M.; Webb-Robertson, Bobbie-Jo; Schepmoes, Athena A.; Shukla, Anil K.; Metz, Thomas O.; Smith, Richard D.; Waters, Katrina M.; Katze, Michael G.; Kawaoka, Yoshihiro

2014-01-01

ABSTRACT The broad range and diversity of interferon-stimulated genes (ISGs) function to induce an antiviral state within the host, impeding viral pathogenesis. While successful respiratory viruses overcome individual ISG effectors, analysis of the global ISG response and subsequent viral antagonism has yet to be examined. Employing models of the human airway, transcriptomics and proteomics datasets were used to compare ISG response patterns following highly pathogenic H5N1 avian influenza (HPAI) A virus, 2009 pandemic H1N1, severe acute respiratory syndrome coronavirus (SARS-CoV), and Middle East respiratory syndrome CoV (MERS-CoV) infection. The results illustrated distinct approaches utilized by each virus to antagonize the global ISG response. In addition, the data revealed that highly virulent HPAI virus and MERS-CoV induce repressive histone modifications, which downregulate expression of ISG subsets. Notably, influenza A virus NS1 appears to play a central role in this histone-mediated downregulation in highly pathogenic influenza strains. Together, the work demonstrates the existence of unique and common viral strategies for controlling the global ISG response and provides a novel avenue for viral antagonism via altered histone modifications. PMID:24846384

Reconfiguration of the pontomedullary respiratory network: a computational modeling study with coordinated in vivo experiments.

PubMed

Rybak, I A; O'Connor, R; Ross, A; Shevtsova, N A; Nuding, S C; Segers, L S; Shannon, R; Dick, T E; Dunin-Barkowski, W L; Orem, J M; Solomon, I C; Morris, K F; Lindsey, B G

2008-10-01

A large body of data suggests that the pontine respiratory group (PRG) is involved in respiratory phase-switching and the reconfiguration of the brain stem respiratory network. However, connectivity between the PRG and ventral respiratory column (VRC) in computational models has been largely ad hoc. We developed a network model with PRG-VRC connectivity inferred from coordinated in vivo experiments. Neurons were modeled in the "integrate-and-fire" style; some neurons had pacemaker properties derived from the model of Breen et al. We recapitulated earlier modeling results, including reproduction of activity profiles of different respiratory neurons and motor outputs, and their changes under different conditions (vagotomy, pontine lesions, etc.). The model also reproduced characteristic changes in neuronal and motor patterns observed in vivo during fictive cough and during hypoxia in non-rapid eye movement sleep. Our simulations suggested possible mechanisms for respiratory pattern reorganization during these behaviors. The model predicted that network- and pacemaker-generated rhythms could be co-expressed during the transition from gasping to eupnea, producing a combined "burst-ramp" pattern of phrenic discharges. To test this prediction, phrenic activity and multiple single neuron spike trains were monitored in vagotomized, decerebrate, immobilized, thoracotomized, and artificially ventilated cats during hypoxia and recovery. In most experiments, phrenic discharge patterns during recovery from hypoxia were similar to those predicted by the model. We conclude that under certain conditions, e.g., during recovery from severe brain hypoxia, components of a distributed network activity present during eupnea can be co-expressed with gasp patterns generated by a distinct, functionally "simplified" mechanism.

Gamma glutamyl transferase and oxidative stress in obstructive sleep apnea: a study in 1744 patients.

PubMed

Sánchez-Armengol, A; Villalobos-López, P; Caballero-Eraso, C; Carmona-Bernal, C; Asensio-Cruz, M; Barbé, F; Capote, F

2015-09-01

We analyze a large population of patients to determine whether gamma glutamyl transferase (GGT) levels are increased in sleep apnea-hypopnea syndrome (OSA) and whether these levels are related to clinical characteristics or polygraphic indexes. A cross-sectional study in a population of 1744 patients referred for OSA suspicion was conducted. The following variables were determined: glucose, cholesterol, triglycerides, aspartate aminotransferase (GOT), alanine aminotransferase (GPT), GGT, body mass index, waist-hip ratio (WHR), and overnight sleep study. The 483 patients with GGT ≥40 IU/l were younger and more obese, and had a pattern of more centrally distributed fat than the 1261 with GGT <40 IU/l. Patients with high levels of GGT also consumed more alcohol, had a poorer biochemical profile, and had more respiratory and oximetric alterations during sleep. GGT levels were significantly correlated with AHI, DI, and CT90. In the binary regression test, WHR, glucose, cholesterol, triglycerides, and grams of alcohol consumed per day predicted GGT levels ≥40 IU/l, while none of the polygraphic variables had predictive value. High GGT levels were associated with the severity of OSA. However, this relationship seems to be due to the coexistence of other associated factors, mainly central obesity, rather than to the respiratory disorders found in this disease.

Multivariate assessment of the central-cardiorespiratory network structure in neuropathological disease.

PubMed

Schulz, Steffen; Haueisen, Jens; Bär, Karl-Juergen; Voss, Andreas

2018-06-22

The new interdisciplinary field of network physiology is getting more and more into the focus of interest in medicine. The autonomic nervous system (ANS) dysfunction is well described in schizophrenia (SZO). However, the linear and nonlinear coupling between the ANS and central nervous system (CNS) is only partly addressed until now. This coupling can be assumed as a feedback-feedforward network, reacting with flexible and adaptive responses to internal and external factors. Approach: For the first time, in this study, we investigated linear and nonlinear short-term central-cardiorespiratory couplings of 17 patients suffering from paranoid schizophrenia (SZO) in comparison to 17 age-gender matched healthy subjects (CON) analyzing heart rate (HR), respiration (RESP) and the power of frontal EEG activity (PEEG). The objective is to determine how the different regulatory aspects of the CNS-ANS compose the central-cardiorespiratory network (CCRN). To quantify these couplings within the CCRN the normalized short time partial directed coherence (NSTPDC) and the new multivariate high-resolution joint symbolic dynamics (mHRJSD) were applied. Main results: We found that the CCRN in SZO is characterized as a bidirectional one, with stronger central driving mechanisms (PEEG→HR) towards HR regulation than vice versa, and with stronger respiratory influence (RESP→PEEG) on central activity than vice versa. This suggests that the central-cardiorespiratory process (closed-loop) is mainly focusing on adapting the HR via the sinoatrial node than focusing on respiratory regulation. On the other side, the feedback-loop from ANS to CNS is strongly dominated via respiratory activity. Significance: We could demonstrate a considerably significantly different central-cardiorespiratory network structure in schizophrenia with strong central influence on the cardiac system and a strong respiratory influence on the central nervous system. Moreover, this study provides a more in-depth understanding of the interplay of the central and autonomic regulatory network in healthy subjects and schizophrenic patients. . © 2018 Institute of Physics and Engineering in Medicine.

A neuronal mechanism of propofol-induced central respiratory depression in newborn rats.

PubMed

Kashiwagi, Masanori; Okada, Yasumasa; Kuwana, Shun-Ichi; Sakuraba, Shigeki; Ochiai, Ryoichi; Takeda, Junzo

2004-07-01

The neural mechanisms of propofol-induced central respiratory depression remain poorly understood. In the present study, we studied these mechanisms and the involvement of gamma-aminobutyric acid (GABA)A receptors in propofol-induced central respiratory depression. The brainstem and the cervical spinal cord of 1- to 4-day-old rats were isolated, and preparations were maintained in vitro with oxygenated artificial cerebrospinal fluid. Rhythmic inspiratory burst activity was recorded from the C4 spinal ventral root. The activity of respiratory neurons in the ventrolateral medulla was recorded using a perforated patch-clamp technique. We found that bath-applied propofol decreased C4 inspiratory burst rate, which could be reversed by the administration of a GABAA antagonist, bicuculline. Propofol caused resting membrane potentials to hyperpolarize and suppressed the firing of action potentials in preinspiratory and expiratory neurons. In contrast, propofol had little effect on resting membrane potentials and action potential firing in inspiratory neurons. Our findings suggest that the depressive effects of propofol are, at least in part, mediated by the agonistic action of propofol on GABAA receptors. It is likely that the GABAA receptor-mediated hyperpolarization of preinspiratory neurons serves as the neuronal basis of propofol-induced respiratory depression in the newborn rat.

Graded hypoxia acts through a network of distributed peripheral oxygen chemoreceptors to produce changes in respiratory behaviour and plasticity.

PubMed

Janes, Tara A; Xu, Fenglian; Syed, Naweed I

2015-07-01

Respiratory behaviour relies critically upon sensory feedback from peripheral oxygen chemoreceptors. During environmental or systemic hypoxia, chemoreceptor input modulates respiratory central pattern generator activity to produce reflex-based increases in respiration and also shapes respiratory plasticity over longer timescales. The best-studied oxygen chemoreceptors are undoubtedly the mammalian carotid bodies; however, questions remain regarding this complex organ's role in shaping respiration in response to varying oxygen levels. Furthermore, many taxa possess distinct oxygen chemoreceptors located within the lungs, airways and cardiovasculature, but the functional advantage of multiple chemoreceptor sites is unclear. In this study, it is demonstrated that a distributed network of peripheral oxygen chemoreceptors exists in Lymnaea stagnalis and significantly modulates aerial respiration. Specifically, Lymnaea breath frequency and duration represent parameters that are shaped by interactions between hypoxic severity and its time-course. Using a combination of behaviour and electrophysiology approaches, the chemosensory pathways underlying hypoxia-induced changes in breath frequency/duration were explored. The current findings demonstrate that breath frequency is uniquely modulated by the known osphradial ganglion oxygen chemoreceptors during moderate hypoxia, while a newly discovered area of pneumostome oxygen chemoreception serves a similar function specifically during more severe hypoxia. Together, these findings suggest that multiple oxygen chemosensory sites, each with their own sensory and modulatory properties, act synergistically to form a functionally distributed network that dynamically shapes respiration in response to changing systemic or environmental oxygen levels. These distributed networks may represent an evolutionarily conserved strategy vis-à-vis respiratory adaptability and have significant implications for the understanding of fundamental respiratory control systems. © 2015 Federation of European Neuroscience Societies and John Wiley & Sons Ltd.

Identifying Early Target Cells of Nipah Virus Infection in Syrian Hamsters.

PubMed

Baseler, Laura; Scott, Dana P; Saturday, Greg; Horne, Eva; Rosenke, Rebecca; Thomas, Tina; Meade-White, Kimberly; Haddock, Elaine; Feldmann, Heinz; de Wit, Emmie

2016-11-01

Nipah virus causes respiratory and neurologic disease with case fatality rates up to 100% in individual outbreaks. End stage lesions have been described in the respiratory and nervous systems, vasculature and often lymphoid organs in fatal human cases; however, the initial target organs of Nipah virus infection have not been identified. Here, we detected the initial target tissues and cells of Nipah virus and tracked virus dissemination during the early phase of infection in Syrian hamsters inoculated with a Nipah virus isolate from Malaysia (NiV-M) or Bangladesh (NiV-B). Syrian hamsters were euthanized between 4 and 48 hours post intranasal inoculation and tissues were collected and analyzed for the presence of viral RNA, viral antigen and infectious virus. Virus replication was first detected at 8 hours post inoculation (hpi). Nipah virus initially targeted type I pneumocytes, bronchiolar respiratory epithelium and alveolar macrophages in the lung and respiratory and olfactory epithelium lining the nasal turbinates. By 16 hpi, virus disseminated to epithelial cells lining the larynx and trachea. Although the pattern of viral dissemination was similar for both virus isolates, the rate of spread was slower for NiV-B. Infectious virus was not detected in the nervous system or blood and widespread vascular infection and lesions within lymphoid organs were not observed, even at 48 hpi. Nipah virus initially targets the respiratory system. Virus replication in the brain and infection of blood vessels in non-respiratory tissues does not occur during the early phase of infection. However, virus replicates early in olfactory epithelium and may serve as the first step towards nervous system dissemination, suggesting that development of vaccines that block virus dissemination or treatments that can access the brain and spinal cord and directly inhibit virus replication may be necessary for preventing central nervous system pathology.

Role of the vagal afferents in substance P-induced respiratory responses in anaesthetized rabbits.

PubMed

Prabhakar, N R; Runold, M; Yamamoto, Y; Lagercrantz, H; Cherniack, N S; von Euler, C

1987-09-01

Since substance P (SP)-like immunoreactivity has been demonstrated in vagal sensory fibres of bronchopulmonary origin, it was considered of interest to (1) characterize the pattern of responses to SP injected into the pulmonary as well as the systemic arterial system, and (2) assess the types of vagal afferents that are affected by SP. Experiments were performed on 15 pentobarbital-anaesthetized, spontaneously breathing rabbits. Efferent phrenic nerve activity was monitored as an index of central respiratory neural output. Intra-atrial injections of SP into the pulmonary circulation (100 ng kg-1) increased the respiratory rate, and peak integrated phrenic amplitude by 47 +/- 8 and 40 +/- 4%, respectively, above the controls. In addition, SP elicited augmented breaths (ABs) within 2-3 s in 67% of the trials. In contrast to right atrial injections, no ABs and no significant changes in respiratory rate were observed in response to intra-aortic injections of SP (100 ng kg-1). Tidal phrenic activity rise after aortic injections of SP was significantly less as compared with right atrial administrations of SP. Since both routes of administration decreased the arterial blood pressure to the same extent, these respiratory responses were not likely secondary to cardiovascular changes. After administration of an SP antagonist (D-Arg-D-Trp7,9, Leu11, SP), respiratory responses to SP were significantly attenuated. Also, the rate of occurrence of ABs elicited by releasing the tracheal occlusions was reduced (control 95 vs. 14% SP antagonist). Bilateral vagotomy abolished the tachypnoeic response and reduced the magnitude of the phrenic nerve increments caused by right atrial injection of SP.(ABSTRACT TRUNCATED AT 250 WORDS)

Deposition and clearance of inhaled particles.

PubMed Central

Stuart, B O

1984-01-01

Theoretical models of respiratory tract deposition of inhaled particles are compared to experimental studies of deposition patterns in humans and animals, as governed principally by particle size, density, respiratory rate and flow parameters. Various models of inhaled particle deposition make use of approximations of the respiratory tract to predict fractional deposition caused by fundamental physical processes of particle impaction, sedimentation, and diffusion. These models for both total deposition and regional (nasopharyngeal, tracheobronchial, and pulmonary) deposition are compared with early and recent experimental studies. Reasonable correlation has been obtained between theoretical and experimental studies, but the behavior in the respiratory tract of very fine (less than 0.1 micron) particles requires further investigation. Properties of particle shape, charge and hygroscopicity as well as the degree of respiratory tract pathology also influence deposition patterns; definitive experimental work is needed in these areas. The influence upon deposition patterns of dynamic alterations in inspiratory flow profiles caused by a variety of breathing patterns also requires further study, and the use of differing ventilation techniques with selected inhaled particle sizes holds promise in diagnosis of respiratory tract diseases. Mechanisms of conducting airway and alveolar clearance processes involving the pulmonary macrophage, mucociliary clearance, dissolution, transport to systemic circulation, and translocation via regional lymphatic vessels are discussed. PMID:6376108

Trends and Patterns of Differences in Chronic Respiratory Disease Mortality Among US Counties, 1980-2014.

PubMed

Dwyer-Lindgren, Laura; Bertozzi-Villa, Amelia; Stubbs, Rebecca W; Morozoff, Chloe; Shirude, Shreya; Naghavi, Mohsen; Mokdad, Ali H; Murray, Christopher J L

2017-09-26

Chronic respiratory diseases are an important cause of death and disability in the United States. To estimate age-standardized mortality rates by county from chronic respiratory diseases. Validated small area estimation models were applied to deidentified death records from the National Center for Health Statistics and population counts from the US Census Bureau, National Center for Health Statistics, and Human Mortality Database to estimate county-level mortality rates from 1980 to 2014 for chronic respiratory diseases. County of residence. Age-standardized mortality rates by county, year, sex, and cause. A total of 4 616 711 deaths due to chronic respiratory diseases were recorded in the United States from January 1, 1980, through December 31, 2014. Nationally, the mortality rate from chronic respiratory diseases increased from 40.8 (95% uncertainty interval [UI], 39.8-41.8) deaths per 100 000 population in 1980 to a peak of 55.4 (95% UI, 54.1-56.5) deaths per 100 000 population in 2002 and then declined to 52.9 (95% UI, 51.6-54.4) deaths per 100 000 population in 2014. This overall 29.7% (95% UI, 25.5%-33.8%) increase in chronic respiratory disease mortality from 1980 to 2014 reflected increases in the mortality rate from chronic obstructive pulmonary disease (by 30.8% [95% UI, 25.2%-39.0%], from 34.5 [95% UI, 33.0-35.5] to 45.1 [95% UI, 43.7-46.9] deaths per 100 000 population), interstitial lung disease and pulmonary sarcoidosis (by 100.5% [95% UI, 5.8%-155.2%], from 2.7 [95% UI, 2.3-4.2] to 5.5 [95% UI, 3.5-6.1] deaths per 100 000 population), and all other chronic respiratory diseases (by 42.3% [95% UI, 32.4%-63.8%], from 0.51 [95% UI, 0.48-0.54] to 0.73 [95% UI, 0.69-0.78] deaths per 100 000 population). There were substantial differences in mortality rates and changes in mortality rates over time among counties, and geographic patterns differed by cause. Counties with the highest mortality rates were found primarily in central Appalachia for chronic obstructive pulmonary disease and pneumoconiosis; widely dispersed throughout the Southwest, northern Great Plains, New England, and South Atlantic for interstitial lung disease; along the southern half of the Mississippi River and in Georgia and South Carolina for asthma; and in southern states from Mississippi to South Carolina for other chronic respiratory diseases. Despite recent declines in mortality from chronic respiratory diseases, mortality rates in 2014 remained significantly higher than in 1980. Between 1980 and 2014, there were important differences in mortality rates and changes in mortality by county, sex, and particular chronic respiratory disease type. These estimates may be helpful for informing efforts to improve prevention, diagnosis, and treatment.

CHILDHOOD RESPIRATORY SYMPTOMS, HOSPITAL ADMISSIONS, AND LONG-TERM EXPOSURE TO AIRBORNE PARTICULATE MATTER

EPA Science Inventory

The effects of long-term exposure to air pollution on respiratory symptoms and respiratory hospitalization (for asthma, bronchitis or pneumonia) were assessed in a cross-sectional study of children (ages 7--11 years, N=667) living in a moderately industrialized city in Central Sl...

77 FR 4047 - Disease, Disability, and Injury Prevention and Control Special Emphasis Panel (SEP): Initial Review

Federal Register 2010, 2011, 2012, 2013, 2014

2012-01-26

... announced below concerns Epidemiology, Prevention and Treatment of Influenza and Other Respiratory... Diseases in Vietnam, IP12-002, The Incidence of Community Associated Influenza and Other Respiratory... Respiratory Infections in Panama and Central America Region, IP12-006, initial review. In accordance with...

Human respiration at rest in rapid compression and at high pressures and gas densities

NASA Technical Reports Server (NTRS)

Gelfand, R.; Lambertsen, C. J.; Strauss, R.; Clark, J. M.; Puglia, C. D.

1983-01-01

The ventilation (V), end-tidal PCO2 (PACO2), and CO2 elimination rate were determined in men at rest breathing CO2-free gas over the pressure range 1-50 ATA and the gas density range 0.4-25 g/l, during slow and rapid compressions, at stable elevated ambient pressures and during slow decompressions. Progressive increase in pulmonary gas flow resistance due to elevation of ambient pressure and inspired gas density to the He-O2 equivalent of 5000 feet of seawater was found to produce a complex pattern of change in PACO2. It was found that as both ambient pressure and pulmonary gas flow resistance were progressively raised, PACO2 at first increased, went through a maximum, and then declined towards values near the 1 ATA level. It is concluded that this pattern of PACO2 change results from the interaction on ventilation of the increase in pulmonary resistance due to the elevation of gas density with the increase in respiratory drive postulated as due to generalized central nervous system excitation associated with exposure to high hydrostatic pressure. It is suggested that a similar interaction exists between increased gas flow resistance and the increase in respiratory drive related to nitrogen partial pressure and the resulting narcosis.

Evidence of high rates of undiagnosed asthma in central Ohio elementary schoolchildren.

PubMed

Clark, Brenda R; Burkett, S Amanda; Andridge, Rebecca R; Buckley, Timothy J

2013-12-01

In Ohio, 14.5% of 5- to 9-year-olds and 17.3% of 10- to 17-year-olds have asthma. Moreover, there is concern that these numbers may underestimate the true disease burden. We sought to evaluate variability in asthma rates and respiratory symptoms among central Ohio fourth graders as a means to assess potential undiagnosed and undertreated asthma and its determinants. We recruited 13 central Ohio elementary schools representing a broad range of nonurban settings and surveyed fourth graders to estimate school-level physician-diagnosed asthma (PDA), respiratory morbidity, and home exposures to smoking and pets. We used generalized linear mixed models with random intercept for school to examine relationships among exposures, respiratory symptoms, and PDA. Across the 13 schools, 94% of students participated in the survey, and the estimated asthma prevalence rate was 10.2% (N = 101 of 987). An additional 41% reported not having PDA but then went on to report symptoms consistent with asthma potentially suggestive of undiagnosed asthma. Of students with PDA, 21% reported symptoms suggestive of poorly controlled asthma. High levels of secondhand smoke (SHS) exposure were associated both with PDA (p = .05) and with respiratory symptoms (p < .0001). Students who owned a cat or a bird were more likely to report respiratory symptoms (p = .02 and p = .04, respectively). We provide evidence that the already high childhood asthma public health burden in central Ohio may be underreported. Schools may be an ideal location to conduct screenings and implement environmental interventions oriented toward SHS and household pets that will yield respiratory morbidity benefits. © 2013, American School Health Association.

Perinatal Fluoxetine Exposure Impairs the CO2 Chemoreflex. Implications for Sudden Infant Death Syndrome.

PubMed

Bravo, Karina; Eugenín, Jaime L; Llona, Isabel

2016-09-01

High serotonin levels during pregnancy affect central nervous system development. Whether a commonly used antidepressant such as fluoxetine (a selective serotonin reuptake inhibitor) taken during pregnancy may adversely affect respiratory control in offspring has not been determined. The objective was to determine the effect of prenatal-perinatal fluoxetine exposure on the respiratory neural network in offspring, particularly on central chemoreception. Osmotic minipumps implanted into CF-1 mice on Days 5-7 of pregnancy delivered 7 milligrams per kilogram per day of fluoxetine, achieving plasma levels within the range found in patients. Ventilation was assessed in offspring at postnatal Days 0-40 using head-out body plethysmography. Neuronal activation was evaluated in the raphe nuclei and in the nucleus tractus solitarius by c-Fos immunohistochemistry during normoxic eucapnia and hypercapnia (10% CO2). Respiratory responses to acidosis were evaluated in brainstem slices. Prenatal-perinatal fluoxetine did not affect litter size, birth weight, or the postnatal growth curve. Ventilation under eucapnic normoxic conditions was similar to that of control offspring. Fluoxetine exposure reduced ventilatory responses to hypercapnia at P8-P40 (P < 0.001) but not at P0-P5. At P8, it reduced hypercapnia-induced neuronal activation in raphe nuclei (P < 0.05) and nucleus tractus solitarius (P < 0.01) and the acidosis-induced increase in the respiratory frequency in brainstem slices (P < 0.05). Fluoxetine applied acutely on control slices did not modify their respiratory response to acidosis. We concluded that prenatal-perinatal fluoxetine treatment impairs central respiratory chemoreception during postnatal life. These results are relevant in understanding the pathogenesis of respiratory failures, such as sudden infant death syndrome, associated with brainstem serotonin abnormalities and the failure of respiratory chemoreflexes.

First results from experiments performed with the ESA Anthrorack during the D-2 Spacelab mission.

PubMed

Kuipers, A

1996-06-01

In 1993 four astronauts performed physiological experiments on the payload "Anthrorack" during the second German Spacelab mission D-2. The Anthrorack set-up is a Spacelab double rack developed under the management of the European Space Agency. It consists of an ECHO machine, a respiratory monitoring system (gas analyzer with flow meter), a blood centrifuge, an ergometer, a finger blood pressure device, ECG, body impedance measurement device and a respiratory inductance plethysmograph. Experiment-specific equipment was used as well. Nineteen investigators performed experiments in the cardiovascular, pulmonary, fluid-renal and nutritional physiology area. Results on central venous pressure, ocular pressure, vascular resistance, cardiac output, tissue thickness and orthostatic intolerance are presented in the cardiovascular area. In the pulmonary area first results are mentioned on O2 transport perfusion and ventilation distribution and breathing pattern. From the fluid-renal experiments, data from diuresis, sodium excretion and hormonal determinations are given. Finally results from glucose metabolism and nitrogen turnover experiments are presented.

First results from experiments performed with the ESA Anthrorack during the D-2 spacelab mission

NASA Astrophysics Data System (ADS)

Kuipers, A.

1996-06-01

In 1993 four astronauts performed physiological experiments on the payload "Anthrorack" during the second German Spacelab mission D-2. The Anthrorack set-up is a Spacelab double rack developed under the management of the European Space Agency. It consists of an ECHO machine, a respiratory monitoring system (gas analyzer with flow meter), a blood centrifuge, an ergometer, a finger blood pressure device, ECG, body impedance measurement device and a respiratory inductance plethysmograph. Experiment-specific equipment was used as well. Nineteen investigators performed experiments in the cardiovascular, pulmonary, fluid-renal and nutritional physiology area. Results on central venous pressure, ocular pressure, vascular resistance, cardiac output, tissue thickness and orthostatic intolerance are presented in the cardiovascular area. In the pulmonary area first results are mentioned on O 2 transport perfusion and ventilation distribution and breathing pattern. From the fluid-renal experiments, data from diuresis, sodium excretion and hormonal determinations are given. Finally results from glucose metabolism and nitrogen turnover experiments are presented.

Neural control of breathing and CO2 homeostasis

PubMed Central

Guyenet, P.G.; Bayliss, D.A

2015-01-01

Summary Recent advances have clarified how the brain detects CO2 to regulate breathing (central respiratory chemoreception). These mechanisms are reviewed and their significance is presented in the general context of CO2/pH homeostasis through breathing. At rest, respiratory chemoreflexes initiated at peripheral and central sites mediate rapid stabilization of arterial PCO2 and pH. Specific brainstem neurons (e.g., retrotrapezoid nucleus, RTN; serotonergic) are activated by PCO2 and stimulate breathing. RTN neurons detect CO2 via intrinsic proton receptors (TASK-2, GPR4), synaptic input from peripheral chemoreceptors and signals from astrocytes. Respiratory chemoreflexes are arousal state-dependent whereas chemoreceptor stimulation produces arousal. When abnormal, these interactions lead to sleep-disordered breathing. During exercise, “central command” and reflexes from exercising muscles produce the breathing stimulation required to maintain arterial PCO2 and pH despite elevated metabolic activity. The neural circuits underlying central command and muscle afferent control of breathing remain elusive and represent a fertile area for future investigation. PMID:26335642

Cardiac and respiratory patterns synchronize between persons during choir singing.

PubMed

Müller, Viktor; Lindenberger, Ulman

2011-01-01

Dyadic and collective activities requiring temporally coordinated action are likely to be associated with cardiac and respiratory patterns that synchronize within and between people. However, the extent and functional significance of cardiac and respiratory between-person couplings have not been investigated thus far. Here, we report interpersonal oscillatory couplings among eleven singers and one conductor engaged in choir singing. We find that: (a) phase synchronization both in respiration and heart rate variability increase significantly during singing relative to a rest condition; (b) phase synchronization is higher when singing in unison than when singing pieces with multiple voice parts; (c) directed coupling measures are consistent with the presence of causal effects of the conductor on the singers at high modulation frequencies; (d) the different voices of the choir are reflected in network analyses of cardiac and respiratory activity based on graph theory. Our results suggest that oscillatory coupling of cardiac and respiratory patterns provide a physiological basis for interpersonal action coordination.

Cardiac and Respiratory Patterns Synchronize between Persons during Choir Singing

PubMed Central

Müller, Viktor; Lindenberger, Ulman

2011-01-01

Dyadic and collective activities requiring temporally coordinated action are likely to be associated with cardiac and respiratory patterns that synchronize within and between people. However, the extent and functional significance of cardiac and respiratory between-person couplings have not been investigated thus far. Here, we report interpersonal oscillatory couplings among eleven singers and one conductor engaged in choir singing. We find that: (a) phase synchronization both in respiration and heart rate variability increase significantly during singing relative to a rest condition; (b) phase synchronization is higher when singing in unison than when singing pieces with multiple voice parts; (c) directed coupling measures are consistent with the presence of causal effects of the conductor on the singers at high modulation frequencies; (d) the different voices of the choir are reflected in network analyses of cardiac and respiratory activity based on graph theory. Our results suggest that oscillatory coupling of cardiac and respiratory patterns provide a physiological basis for interpersonal action coordination. PMID:21957466

Respiratory pattern changes during costovertebral joint movement.

PubMed

Shannon, R

1980-05-01

Experiments were conducted to determine if costovertebral joint manipulation (CVJM) could influence the respiratory pattern. Phrenic efferent activity (PA) was monitored in dogs that were anesthetized with Dial-urethane, vagotomized, paralyzed, and artificially ventilated. Ribs 6-10 (bilaterally) were cut and separated from ribs 5-11. Branches of thoracic nerves 5-11 were cut, leaving only the joint nerve supply intact. Manual joint movement in an inspiratory or expiratory direction had an inhibitory effect on PA. Sustained displacement of the ribs could inhibit PA for a duration equal to numerous respiratory cycles. CVJM in synchrony with PA resulted in an increased respiratory rate. The inspiratory inhibitory effect of joint receptor stimulation was elicited with manual chest compression in vagotomized spontaneously breathing dogs, but not with artificial lung inflation or deflation. It is concluded that the effect of CVJM on the respiratory pattern is due to stimulation of joint mechanoreceptors, and that they exert their influence in part via the medullary-pontine rhythm generator.

Override of spontaneous respiratory pattern generator reduces cardiovascular parasympathetic influence

NASA Technical Reports Server (NTRS)

Patwardhan, A. R.; Vallurupalli, S.; Evans, J. M.; Bruce, E. N.; Knapp, C. F.

1995-01-01

We investigated the effects of voluntary control of breathing on autonomic function in cardiovascular regulation. Variability in heart rate was compared between 5 min of spontaneous and controlled breathing. During controlled breathing, for 5 min, subjects voluntarily reproduced their own spontaneous breathing pattern (both rate and volume on a breath-by-breath basis). With the use of this experimental design, we could unmask the effects of voluntary override of the spontaneous respiratory pattern generator on autonomic function in cardiovascular regulation without the confounding effects of altered respiratory pattern. Results from 10 subjects showed that during voluntary control of breathing, mean values of heart rate and blood pressure increased, whereas fractal and spectral powers in heart rate in the respiratory frequency region decreased. End-tidal PCO2 was similar during spontaneous and controlled breathing. These results indicate that the act of voluntary control of breathing decreases the influence of the vagal component, which is the principal parasympathetic influence in cardiovascular regulation.

Use of Chest Wall Electromyography to Detect Respiratory Effort during Polysomnography

PubMed Central

Berry, Richard B.; Ryals, Scott; Girdhar, Ankur; Wagner, Mary H.

2016-01-01

Study Objectives: To evaluate the ability of chest wall EMG (CW-EMG) using surface electrodes to classify apneas as obstructive, mixed, or central compared to classification using dual channel uncalibrated respiratory inductance plethysmography (RIP). Methods: CW-EMG was recorded from electrodes in the eighth intercostal space at the right mid-axillary line. Consecutive adult clinical sleep studies were retrospectively reviewed, and the first 60 studies with at least 10 obstructive and 10 mixed or central apneas and technically adequate tracings were selected. Four obstructive and six central or mixed apneas (as classified by previous clinical scoring) were randomly selected. A blinded experienced scorer classified the apneas on the basis of tracings showing either RIP channels or the CW-EMG channel. The agreement using the two classification methods was determined by kappa analysis and intraclass correlation. Results: The percentage agreement was 89.5%, the kappa statistic was 0.83 (95% confidence interval 0.79 to 0.87), and the intraclass correlation was 0.83, showing good agreement. Of the 249 apneas classified as central by RIP, 26 were classified as obstructive (10.4%) and 7 as mixed (2.8%) by CW-EMG. Of the 229 events classified as central by CW-EMG, 7 (3.1%) were classified as obstructive and 6 (2.6%) as mixed by RIP. Conclusions: Monitoring CW-EMG may provide a clinically useful method of detection of respiratory effort when used with RIP and can prevent false classification of apneas as central. RIP can rarely detect respiratory effort not easily discernible by CW-EMG and the combination of the two methods is more likely to avoid apnea misclassification. Citation: Berry RB, Ryals S, Girdhar A, Wagner MH. Use of chest wall electromyography to detect respiratory effort during polysomnography. J Clin Sleep Med 2016;12(9):1239–1244. PMID:27306391

SU-G-JeP3-09: Tumor Location Prediction Using Natural Respiratory Volume for Respiratory Gated Radiation Therapy (RGRT): System Verification Study

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kim, M; Jung, J; Yoon, D

Purpose: Respiratory gated radiation therapy (RGRT) gives accurate results when a patient’s breathing is stable and regular. Thus, the patient should be fully aware during respiratory pattern training before undergoing the RGRT treatment. In order to bypass the process of respiratory pattern training, we propose a target location prediction system for RGRT that uses only natural respiratory volume, and confirm its application. Methods: In order to verify the proposed target location prediction system, an in-house phantom set was used. This set involves a chest phantom including target, external markers, and motion generator. Natural respiratory volume signals were generated using themore » random function in MATLAB code. In the chest phantom, the target takes a linear motion based on the respiratory signal. After a four-dimensional computed tomography (4DCT) scan of the in-house phantom, the motion trajectory was derived as a linear equation. The accuracy of the linear equation was compared with that of the motion algorithm used by the operating motion generator. In addition, we attempted target location prediction using random respiratory volume values. Results: The correspondence rate of the linear equation derived from the 4DCT images with the motion algorithm of the motion generator was 99.41%. In addition, the average error rate of target location prediction was 1.23% for 26 cases. Conclusion: We confirmed the applicability of our proposed target location prediction system for RGRT using natural respiratory volume. If additional clinical studies can be conducted, a more accurate prediction system can be realized without requiring respiratory pattern training.« less

Patterns of illness in travelers visiting Mexico and Central America: the GeoSentinel experience.

PubMed

Flores-Figueroa, Jose; Okhuysen, Pablo C; von Sonnenburg, Frank; DuPont, Herbert L; Libman, Michael D; Keystone, Jay S; Hale, Devon C; Burchard, Gerd; Han, Pauline V; Wilder-Smith, Annelies; Freedman, David O

2011-09-01

Mexico and Central America are important travel destinations for North American and European travelers. There is limited information on regional differences in travel related morbidity. We describe the morbidity among 4779 ill travelers returned from Mexico and Central America who were evaluated at GeoSentinel network clinics during December 1996 to February 2010. The most frequent presenting syndromes included acute and chronic diarrhea, dermatologic diseases, febrile systemic illness, and respiratory disease. A higher proportion of ill travelers from the United States had acute diarrhea, compared with their Canadian and European counterparts (odds ratio, 1.9; P < .0001). During the 2009 H1N1 influenza outbreak from March 2009 through February 2010, the proportionate morbidity (PM) associated with respiratory illnesses in ill travelers increased among those returned from Mexico, compared with prior years (196.0 cases per 1000 ill returned travelers vs 53.7 cases per 1000 ill returned travelers; P < .0001); the PM remained constant in the rest of Central America (57.3 cases per 1000 ill returned travelers). We identified 50 travelers returned from Mexico and Central America who developed influenza, including infection due to 2009 H1N1 strains and influenza-like illness. The overall risk of malaria was low; only 4 cases of malaria were acquired in Mexico (PM, 2.2 cases per 1000 ill returned travelers) in 13 years, compared with 18 from Honduras (PM, 79.6 cases per 1000 ill returned travelers) and 14 from Guatemala (PM, 34.4 cases per 1000 ill returned travelers) during the same period. Plasmodium vivax malaria was the most frequent malaria diagnosis. Travel medicine practitioners advising and treating travelers visiting these regions should dedicate special attention to vaccine-preventable illnesses and should consider the uncommon occurrence of acute hepatitis A, leptospirosis, neurocysticercosis, acute Chagas disease, onchocerciasis, mucocutaneous leishmaniasis, neurocysticercosis, HIV, malaria, and brucellosis.

Respiratory muscles stretching acutely increases expansion in hemiparetic chest wall.

PubMed

Rattes, Catarina; Campos, Shirley Lima; Morais, Caio; Gonçalves, Thiago; Sayão, Larissa Bouwman; Galindo-Filho, Valdecir Castor; Parreira, Verônica; Aliverti, Andrea; Dornelas de Andrade, Armèle

2018-08-01

Individuals post-stroke may present restrictive ventilatory pattern generated from changes in the functionality of respiratory system due to muscle spasticity and contractures. Objective was to assess the acute effects after respiratory muscle stretching on the ventilatory pattern and volume distribution of the chest wall in stroke subjects. Ten volunteers with right hemiparesis after stroke and a mean age of 60 ± 5.7 years were randomised into the following interventions: respiratory muscle stretching and at rest (control). The ventilatory pattern and chest wall volume distribution were evaluated through optoelectronic plethysmography before and immediately after each intervention. Respiratory muscle stretching promoted a significant acute increase of 120 mL in tidal volume, with an increase in minute ventilation, mean inspiratory flow and mean expiratory flow compared with the control group. Pulmonary ribcage increased 50 mL after stretching, with 30 mL of contribution to the right pulmonary rib cage (hemiparetic side) in comparison to the control group. Respiratory muscle stretching in patients with right hemiparesis post-stroke demonstrated that acute effects improve the expansion of the respiratory system during tidal breathing. NCT02416349 (URL: https://clinicaltrials.gov/ct2/show/ NCT02416349). Copyright © 2018 Elsevier B.V. All rights reserved.

[Specific features of the functional state of the cardiorespiratory system in athletes differing in the types of muscular activity during the preparatory period of the training cycle].

PubMed

Ivanova, N B

2011-01-01

The present study of the functional state of the cadiorespiratory system included athletes engaged in cyclic team sports. The state of the cardiorespiratory system was estimated from the measurement of central hemodynamics and cardiac rhythm variability, results of electrocardiography, spirography, and pneumotachography performed during the preparatory period for the training cycle. It was shown that the cardiovascular and respiratory systems as well as vegetative regulation of the cardiac rhythm of the athletes under examination underwent differently directed structural modification depending on the specific patterns of muscular activity.

Effects of ion channel noise on neural circuits: an application to the respiratory pattern generator to investigate breathing variability.

PubMed

Yu, Haitao; Dhingra, Rishi R; Dick, Thomas E; Galán, Roberto F

2017-01-01

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. We illustrate this procedure with a well-established conductance-based model of the respiratory pattern generator, which allows us to investigate how channel noise affects neural dynamics at the circuit level and, in particular, to understand the relationship between the respiratory pattern and its breath-to-breath variability. We show that as the channel number increases, the duration of inspiration and expiration varies, and so does the coefficient of variation of the breath-to-breath interval, which attains a minimum when the mean duration of expiration slightly exceeds that of inspiration. For small channel numbers, the variability of the expiratory phase dominates over that of the inspiratory phase, and vice versa for large channel numbers. Among the four different cell types in the respiratory pattern generator, pacemaker cells exhibit the highest sensitivity to channel noise. The model shows that suppressing input from the pons leads to longer inspiratory phases, a reduction in breathing frequency, and larger breath-to-breath variability, whereas enhanced input from the raphe nucleus increases breathing frequency without changing its pattern. A major source of noise in neuronal circuits is the "flickering" of ion currents passing through the neurons' membranes (channel noise), which cannot be suppressed experimentally. Computational simulations are therefore the best way to investigate the effects of this physiological noise by manipulating its level at will. We investigate the role of noise in the respiratory pattern generator and show that endogenous, breath-to-breath variability is tightly linked to the respiratory pattern. Copyright © 2017 the American Physiological Society.

Correlation of respiratory symptoms and spirometric lung patterns in a rural community setting, Sindh, Pakistan: a cross sectional survey

PubMed Central

2012-01-01

Background Symptom-based questionnaires can be a cost effective tool enabling identification and diagnosis of patients with respiratory illnesses in resource limited setting. This study aimed to determine the correlation of respiratory symptoms and spirometric lung patterns and validity of ATS respiratory questionnaire in a rural community setting. Methods This cross sectional survey was conducted between January – March 2009 on a sample of 200 adults selected from two villages of district Khairpur, Sindh, Pakistan. A modified version of the American thoracic society division of lung disease questionnaire was used to record the presence of respiratory symptoms. Predicted lung volumes i.e. forced vital capacity (FVC), forced expiratory volume in one second (FEV1) and their ratio (FEV1/FVC) were recorded using portable spirometer. Results In the study sample there were 91 (45.5%) males and 109 (54.5%) females with overall mean age of 34 years (±11.69). Predominant respiratory symptom was phlegm (19%) followed by cough (17.5%), wheeze (14%) and dyspnea (10.5%). Prevalence of physician diagnosed and self-reported asthma was 5.5% and 9.5% respectively. Frequency of obstructive pattern on spirometry was 28.72% and that of restrictive pattern was 19.68%. After adjustment for age, gender, socioeconomic status, spoken dialect, education, smoking status, height, weight and arsenic in drinking water, FVC was significantly reduced for phlegm (OR 3.01; 95% CI: 1.14 – 7.94), wheeze (OR 7.22; 95% CI: 2.52 – 20.67) and shortness of breath (OR 4.91; 95% CI: 1.57 – 15.36); and FEV1 was significantly reduced for cough (OR 2.69; 95% CI: 1.12 – 6.43), phlegm (OR 3.01; 95% CI: 1.26 – 7.16) and wheeze (OR 10.77; 95% CI: 3.45 – 33.6). Presence of respiratory symptoms was significantly associated with restrictive and/or obstructive patterns after controlling for confounders. Similar findings were observed through linear regression where respiratory symptoms were found to be significantly associated with decrements in lung volumes. Specificity and positive predictive values were found to be higher for all the symptoms compared to sensitivity and negative predictive values. Conclusion Symptoms based respiratory questionnaires are a valuable tool for screening of respiratory symptoms in resource poor, rural community setting. PMID:23249311

Changes in the activity of a CpG neuron after the reinforcement of an operantly conditioned behavior in Lymnaea.

PubMed

Spencer, Gaynor E; Kazmi, Mustapha H; Syed, Naweed I; Lukowiak, Ken

2002-10-01

We have previously shown that the aerial respiratory behavior of the mollusk Lymnaea stagnalis can be operantly conditioned, and the central pattern generating (CPG) neurons underlying this behavior have been identified. As neural correlates of operant conditioning remain poorly defined in both vertebrates and invertebrates, we have used the Lymnaea respiratory CPG to investigate neuronal changes associated with the change in behavior after conditioning. After operant conditioning of the intact animals, semi-intact preparations were dissected, so that changes in the respiratory behavior (pneumostome openings) and underlying activity of the identified CPG neuron, right pedal dorsal 1 (RPeD1), could be monitored simultaneously. RPeD1 was studied because it initiates the rhythmic activity of the CPG and receives chemo-sensory input from the pneumostome area. Pneumostome openings and RPeD1 activity were monitored both before and after a reinforcing training stimulus applied to the open pneumostome of operantly conditioned and yoked control preparations. After presentation of the reinforcing stimulus, there was a significant reduction in both breathing behavior and RPeD1 activity in operant preparations but not in yoked and naïve controls. Furthermore these changes were only significant in the subgroup of operantly conditioned animals described as good learners and not in poor learners. These data strongly suggest that changes in RPeD1 activity may underlie the behavioral changes associated with the reinforcement of operant conditioning of the respiratory behavior.

Respiratory motor training and neuromuscular plasticity in patients with chronic obstructive pulmonary disease: A pilot study.

PubMed

Ovechkin, Alexander V; Sayenko, Dimitry G; Ovechkina, Elena N; Aslan, Sevda C; Pitts, Teresa; Folz, Rodney J

2016-07-15

The objective of this study was to examine the feasibility of a full-scale investigation of the neurophysiological mechanisms of COPD-induced respiratory neuromuscular control deficits. Characterization of respiratory single- and multi-muscle activation patterns using surface electromyography (sEMG) were assessed along with functional measures at baseline and following 21±2 (mean±SD) sessions of respiratory motor training (RMT) performed during a one-month period in four patients with GOLD stage II or III COPD. Pre-training, the individuals with COPD showed significantly increased (p<0.05) overall respiratory muscle activity and disorganized multi-muscle activation patterns in association with lowered spirometrical measures and decreased fast- and slow-twitch fiber activity as compared to healthy controls (N=4). Following RMT, functional and respiratory sEMG activation outcomes during quite breathing and forced expiratory efforts were improved suggesting that functional improvements, induced by task-specific RMT, are evidence respiratory neuromuscular networks re-organization. Published by Elsevier B.V.

Patterns of antimicrobial use for respiratory tract infections in older residents of long-term care facilities

USDA-ARS?s Scientific Manuscript database

OBJECTIVE: To describe patterns of antimicrobial use for respiratory tract infections (RTIs) among elderly residents of long-term care facilities (LTCFs). DESIGN: Data from a prospective, randomized, controlled study conducted from April 1998 through August 2001 to investigate the effect of vitamin ...

MODULAR APPLICATION OF COMPUTATIONAL MODELS OF INHALED REACTIVE GAS DOSIMETRY FOR RISK ASSESSMENT OF RESPIRATORY TRACT TOXICITY: CHLORINE

EPA Science Inventory

Inhaled reactive gases typically cause respiratory tract toxicity with a prominent proximal to distal lesion pattern. This pattern is largely driven by airflow and interspecies differences between rodents and humans result from factors such as airway architecture, ventilation ra...

Housing conditions, respiratory illness, and lung function in children in South Wales.

PubMed Central

Yarnell, J W; St Leger, A S

1977-01-01

The hypothesis was tested that respiratory illness in children occurs more commonly in old housing than in housing built to modern standards. Three areas of housing were chosen in a South Wales valley: a recently constructed council estate with district central heating; a modern council estate heated with open coal fires; and an area of much older, traditional valley housing. Mothers reported the greatest proportion of children free of colds and sore throats during the previous 12 months in the area of traditional valley housing; mothers of children in the centrally heated estate reported the least proportion of children free of colds. Children's lung function was best in the area of traditional valley housing and worst in the centrally heated council estate. Data on demographic indices and respiratory morbidity suggest that the inhabitants of the two council estates have comparable characteristics. Another hypothesis which may explain the findings is proposed. PMID:588858

Effect of Facemask Use on Respiratory Patterns of Women in Speech and Singing

ERIC Educational Resources Information Center

Collyer, Sally; Davis, Pamela J.

2006-01-01

Purpose: Research into respiratory behavior during singing and speech makes extensive use of standard respiratory and vented pneumotachograph facemasks. This study investigated whether the use of such facemasks would affect respiratory behavior in terms of lung volume (excursion, at initiation and at termination) or duration (of inspiration and of…

Respiratory mechanics and breathing pattern in the neonatal foal.

PubMed

Koterba, A M; Kosch, P C

1987-01-01

Breathing pattern, respiratory muscle activation pattern, lung volumes and volume-pressure characteristics of the respiratory system of normal, term, neonatal foals on Days 2 and 7 of age were determined to test the hypothesis that the foal actively maintains end-expiratory lung volume (EEV) greater than the relaxation volume of the respiratory system (Vrx) because of a highly compliant chest wall. Breathing pattern was measured in the awake, unsedated foal during quiet breathing in lateral and standing positions. The typical neonatal foal breathing pattern was characterized by a monophasic inspiratory and expiratory flow pattern. Both inspiration and expiration were active, with onset of Edi activity preceding onset of inspiratory flow, and phasic abdominal muscle activity detectable throughout most of expiration. No evidence was found to support the hypothesis that the normal, term neonatal foal actively maintains EEV greater than Vrx. In the neonatal foal, normalized lung volume and lung compliance values were similar to those reported for neonates of other species, while normalized chest wall compliance was considerably lower. We conclude that the chest wall of the term neonatal foal is sufficiently rigid to prevent a low Vrx. This characteristic probably prevents the foal from having to use a breathing strategy which maintains an EEV greater than Vrx.

Population calcium imaging of spontaneous respiratory and novel motor activity in the facial nucleus and ventral brainstem in newborn mice

PubMed Central

Persson, Karin; Rekling, Jens C

2011-01-01

Abstract The brainstem contains rhythm and pattern forming circuits, which drive cranial and spinal motor pools to produce respiratory and other motor patterns. Here we used calcium imaging combined with nerve recordings in newborn mice to reveal spontaneous population activity in the ventral brainstem and in the facial nucleus. In Fluo-8 AM loaded brainstem–spinal cord preparations, respiratory activity on cervical nerves was synchronized with calcium signals at the ventrolateral brainstem surface. Individual ventrolateral neurons at the level of the parafacial respiratory group showed perfect or partial synchrony with respiratory nerve bursts. In brainstem–spinal cord preparations, cut at the level of the mid-facial nucleus, calcium signals were recorded in the dorsal, lateral and medial facial subnuclei during respiratory activity. Strong activity initiated in the dorsal subnucleus, followed by activity in lateral and medial subnuclei. Whole-cell recordings from facial motoneurons showed weak respiratory drives, and electrical field potential recordings confirmed respiratory drive to particularly the dorsal and lateral subnuclei. Putative facial premotoneurons showed respiratory-related calcium signals, and were predominantly located dorsomedial to the facial nucleus. A novel motor activity on facial, cervical and thoracic nerves was synchronized with calcium signals at the ventromedial brainstem extending from the level of the facial nucleus to the medulla–spinal cord border. Cervical dorsal root stimulation induced similar ventromedial activity. The medial facial subnucleus showed calcium signals synchronized with this novel motor activity on cervical nerves, and cervical dorsal root stimulation induced similar medial facial subnucleus activity. In conclusion, the dorsal and lateral facial subnuclei are strongly respiratory-modulated, and the brainstem contains a novel pattern forming circuit that drives the medial facial subnucleus and cervical motor pools. PMID:21486812

Respiration in neonate sea turtles.

PubMed

Price, Edwin R; Paladino, Frank V; Strohl, Kingman P; Santidrián T, Pilar; Klann, Kenneth; Spotila, James R

2007-03-01

The pattern and control of respiration is virtually unknown in hatchling sea turtles. Using incubator-raised turtles, we measured oxygen consumption, frequency, tidal volume, and minute volume for leatherback (Dermochelys coriacea) and olive ridley (Lepidochelys olivacea) turtle hatchlings for the first six days after pipping. In addition, we tested the hatchlings' response to hypercapnic, hyperoxic, and hypoxic challenges over this time period. Hatchling sea turtles generally showed resting ventilation characteristics that are similar to those of adults: a single breath followed by a long respiratory pause, slow frequency, and high metabolic rate. With hypercapnic challenge, both species responded primarily by elevating respiratory frequency via a decrease in the non-ventilatory period. Leatherback resting tidal volume increased with age but otherwise, neither species' resting respiratory pattern nor response to gas challenge changed significantly over the first few days after hatching. At the time of nest emergence, sea turtles have achieved a respiratory pattern that is similar to that of actively diving adults.

Stress-induced thermotolerance of ventilatory motor pattern generation in the locust, Locusta migratoria.

PubMed

Newman, Amy E M; Foerster, Melody; Shoemaker, Kelly L; Robertson, R Meldrum

2003-11-01

Ventilation is a crucial motor activity that provides organisms with an adequate circulation of respiratory gases. For animals that exist in harsh environments, an important goal is to protect ventilation under extreme conditions. Heat shock, anoxia, and cold shock are environmental stresses that have previously been shown to trigger protective responses. We used the locust to examine stress-induced thermotolerance by monitoring the ability of the central nervous system to generate ventilatory motor patterns during a subsequent heat exposure. Preparations from pre-stressed animals had an increased incidence of motor pattern recovery following heat-induced failure, however, prior stress did not alter the characteristics of the ventilatory motor pattern. During constant heat exposure at sub-lethal temperatures, we observed a protective effect of heat shock pre-treatment. Serotonin application had similar effects on motor patterns when compared to prior heat shock. These studies are consistent with previous studies that indicate prior exposure to extreme temperatures and hypoxia can protect neural operation against high temperature stress. They further suggest that the protective mechanism is a time-dependent process best revealed during prolonged exposure to extreme temperatures and is mediated by a neuromodulator such as serotonin.

Optimized respiratory-resolved motion-compensated 3D Cartesian coronary MR angiography.

PubMed

Correia, Teresa; Ginami, Giulia; Cruz, Gastão; Neji, Radhouene; Rashid, Imran; Botnar, René M; Prieto, Claudia

2018-04-22

To develop a robust and efficient reconstruction framework that provides high-quality motion-compensated respiratory-resolved images from free-breathing 3D whole-heart Cartesian coronary magnetic resonance angiography (CMRA) acquisitions. Recently, XD-GRASP (eXtra-Dimensional Golden-angle RAdial Sparse Parallel MRI) was proposed to achieve 100% scan efficiency and provide respiratory-resolved 3D radial CMRA images by exploiting sparsity in the respiratory dimension. Here, a reconstruction framework for Cartesian CMRA imaging is proposed, which provides respiratory-resolved motion-compensated images by incorporating 2D beat-to-beat translational motion information to increase sparsity in the respiratory dimension. The motion information is extracted from interleaved image navigators and is also used to compensate for 2D translational motion within each respiratory phase. The proposed Optimized Respiratory-resolved Cartesian Coronary MR Angiography (XD-ORCCA) method was tested on 10 healthy subjects and 2 patients with cardiovascular disease, and compared against XD-GRASP. The proposed XD-ORCCA provides high-quality respiratory-resolved images, allowing clear visualization of the right and left coronary arteries, even for irregular breathing patterns. Compared with XD-GRASP, the proposed method improves the visibility and sharpness of both coronaries. Significant differences (p < .05) in visible vessel length and proximal vessel sharpness were found between the 2 methods. The XD-GRASP method provides good-quality images in the absence of intraphase motion. However, motion blurring is observed in XD-GRASP images for respiratory phases with larger motion amplitudes and subjects with irregular breathing patterns. A robust respiratory-resolved motion-compensated framework for Cartesian CMRA has been proposed and tested in healthy subjects and patients. The proposed XD-ORCCA provides high-quality images for all respiratory phases, independently of the regularity of the breathing pattern. © 2018 The Authors Magnetic Resonance in Medicine published by Wiley Periodicals, Inc. on behalf of International Society for Magnetic Resonance in Medicine.

Social contact patterns relevant to the spread of respiratory infectious diseases in Hong Kong.

PubMed

Leung, Kathy; Jit, Mark; Lau, Eric H Y; Wu, Joseph T

2017-08-11

The spread of many respiratory infections is determined by contact patterns between infectious and susceptible individuals in the population. There are no published data for quantifying social contact patterns relevant to the spread of respiratory infectious diseases in Hong Kong which is a hotspot for emerging infectious diseases due to its high population density and connectivity in the air transportation network. We adopted a commonly used diary-based design to conduct a social contact survey in Hong Kong in 2015/16 using both paper and online questionnaires. Participants using paper questionnaires reported more contacts and longer contact duration than those using online questionnaires. Participants reported 13 person-hours of contact and 8 contacts per day on average, which decreased over age but increased with household size, years of education and income level. Prolonged and frequent contacts, and contacts at home, school and work were more likely to involve physical contacts. Strong age-assortativity was observed in all age groups. We evaluated the characteristics of social contact patterns relevant to the spread of respiratory infectious diseases in Hong Kong. Our findings could help to improve the design of future social contact surveys, parameterize transmission models of respiratory infectious diseases, and inform intervention strategies based on model outputs.

Spatiotemporal patterns of infant bronchiolitis in a Tennessee Medicaid population.

PubMed

Sloan, Chantel D; Gebretsadik, Tebeb; Wu, Pingsheng; Carroll, Kecia N; Mitchel, Edward F; Hartert, Tina V

2013-09-01

Respiratory syncytial virus (RSV) is a major cause of worldwide morbidity and mortality in infants, primarily through the induction of bronchiolitis. RSV epidemics are highly seasonal, occurring in the winter months in the northern hemisphere. Within the United States, RSV epidemic dynamics vary both spatially and temporally. This analysis employs a retrospective space–time scan statistic to locate spatiotemporal clustering of infant bronchiolitis in a very large Tennessee (TN) Medicaid cohort. We studied infants less than 6 months of age (N = 52,468 infants) who had an outpatient visit, emergency department visit, or hospitalization for bronchiolitis between 1995 and 2008. The scan statistic revealed distinctive and consistent patterns of deviation in epidemic timing. Eastern TN (Knoxville area) showed clustering in January and February, and Central TN (Nashville area) in November and December. This is likely due to local variation in geography-associated factors which should be taken into consideration in future modeling of RSV epidemics.

Trends and Patterns of Differences in Chronic Respiratory Disease Mortality Among US Counties, 1980-2014

PubMed Central

Dwyer-Lindgren, Laura; Bertozzi-Villa, Amelia; Stubbs, Rebecca W.; Morozoff, Chloe; Shirude, Shreya; Naghavi, Mohsen; Mokdad, Ali H.

2017-01-01

Importance Chronic respiratory diseases are an important cause of death and disability in the United States. Objective To estimate age-standardized mortality rates by county from chronic respiratory diseases. Design, Setting, and Participants Validated small area estimation models were applied to deidentified death records from the National Center for Health Statistics and population counts from the US Census Bureau, National Center for Health Statistics, and Human Mortality Database to estimate county-level mortality rates from 1980 to 2014 for chronic respiratory diseases. Exposure County of residence. Main Outcomes and Measures Age-standardized mortality rates by county, year, sex, and cause. Results A total of 4 616 711 deaths due to chronic respiratory diseases were recorded in the United States from January 1, 1980, through December 31, 2014. Nationally, the mortality rate from chronic respiratory diseases increased from 40.8 (95% uncertainty interval [UI], 39.8-41.8) deaths per 100 000 population in 1980 to a peak of 55.4 (95% UI, 54.1-56.5) deaths per 100 000 population in 2002 and then declined to 52.9 (95% UI, 51.6-54.4) deaths per 100 000 population in 2014. This overall 29.7% (95% UI, 25.5%-33.8%) increase in chronic respiratory disease mortality from 1980 to 2014 reflected increases in the mortality rate from chronic obstructive pulmonary disease (by 30.8% [95% UI, 25.2%-39.0%], from 34.5 [95% UI, 33.0-35.5] to 45.1 [95% UI, 43.7-46.9] deaths per 100 000 population), interstitial lung disease and pulmonary sarcoidosis (by 100.5% [95% UI, 5.8%-155.2%], from 2.7 [95% UI, 2.3-4.2] to 5.5 [95% UI, 3.5-6.1] deaths per 100 000 population), and all other chronic respiratory diseases (by 42.3% [95% UI, 32.4%-63.8%], from 0.51 [95% UI, 0.48-0.54] to 0.73 [95% UI, 0.69-0.78] deaths per 100 000 population). There were substantial differences in mortality rates and changes in mortality rates over time among counties, and geographic patterns differed by cause. Counties with the highest mortality rates were found primarily in central Appalachia for chronic obstructive pulmonary disease and pneumoconiosis; widely dispersed throughout the Southwest, northern Great Plains, New England, and South Atlantic for interstitial lung disease; along the southern half of the Mississippi River and in Georgia and South Carolina for asthma; and in southern states from Mississippi to South Carolina for other chronic respiratory diseases. Conclusions and Relevance Despite recent declines in mortality from chronic respiratory diseases, mortality rates in 2014 remained significantly higher than in 1980. Between 1980 and 2014, there were important differences in mortality rates and changes in mortality by county, sex, and particular chronic respiratory disease type. These estimates may be helpful for informing efforts to improve prevention, diagnosis, and treatment. PMID:28973621

Synchronization of presynaptic input to motor units of tongue, inspiratory intercostal, and diaphragm muscles.

PubMed

Rice, Amber; Fuglevand, Andrew J; Laine, Christopher M; Fregosi, Ralph F

2011-05-01

The respiratory central pattern generator distributes rhythmic excitatory input to phrenic, intercostal, and hypoglossal premotor neurons. The degree to which this input shapes motor neuron activity can vary across respiratory muscles and motor neuron pools. We evaluated the extent to which respiratory drive synchronizes the activation of motor unit pairs in tongue (genioglossus, hyoglossus) and chest-wall (diaphragm, external intercostals) muscles using coherence analysis. This is a frequency domain technique, which characterizes the frequency and relative strength of neural inputs that are common to each of the recorded motor units. We also examined coherence across the two tongue muscles, as our previous work shows that, despite being antagonists, they are strongly coactivated during the inspiratory phase, suggesting that excitatory input from the premotor neurons is distributed broadly throughout the hypoglossal motoneuron pool. All motor unit pairs showed highly correlated activity in the low-frequency range (1-8 Hz), reflecting the fundamental respiratory frequency and its harmonics. Coherence of motor unit pairs recorded either within or across the tongue muscles was similar, consistent with broadly distributed premotor input to the hypoglossal motoneuron pool. Interestingly, motor units from diaphragm and external intercostal muscles showed significantly higher coherence across the 10-20-Hz bandwidth than tongue-muscle units. We propose that the lower coherence in tongue-muscle motor units over this range reflects a larger constellation of presynaptic inputs, which collectively lead to a reduction in the coherence between hypoglossal motoneurons in this frequency band. This, in turn, may reflect the relative simplicity of the respiratory drive to the diaphragm and intercostal muscles, compared with the greater diversity of functions fulfilled by muscles of the tongue.

Respiratory Patterns and Strategies during Feeding in Preterm Infants

ERIC Educational Resources Information Center

Vice, Frank L.; Gewolb, Ira H.

2008-01-01

Because patterns of integration of respiration into rhythmic suck-swallow efforts are highly variable, we examined the vagaries of respiratory efforts as they evolve from the first tentative attempts at integration through more complex rhythmic interactions, with a focus on several strategies in which breathing and suck-swallow are coordinated.…

Pontine Mechanisms of Respiratory Control

PubMed Central

Dutschmann, Mathias; Dick, Thomas E.

2015-01-01

Pontine respiratory nuclei provide synaptic input to medullary rhythmogenic circuits to shape and adapt the breathing pattern. An understanding of this statement depends on appreciating breathing as a behavior, rather than a stereotypic rhythm. In this review, we focus on the pontine-mediated inspiratory off-switch (IOS) associated with postinspiratory glottal constriction. Further, IOS is examined in the context of pontine regulation of glottal resistance in response to multimodal sensory inputs and higher commands, which in turn rules timing, duration, and patterning of respiratory airflow. In addition, network plasticity in respiratory control emerges during the development of the pons. Synaptic plasticity is required for dynamic and efficient modulation of the expiratory breathing pattern to cope with rapid changes from eupneic to adaptive breathing linked to exploratory (foraging and sniffing) and expulsive (vocalizing, coughing, sneezing, and retching) behaviors, as well as conveyance of basic emotions. The speed and complexity of changes in the breathing pattern of behaving animals implies that “learning to breathe” is necessary to adjust to changing internal and external states to maintain homeostasis and survival. PMID:23720253

Automatic classification of canine PRG neuronal discharge patterns using K-means clustering.

PubMed

Zuperku, Edward J; Prkic, Ivana; Stucke, Astrid G; Miller, Justin R; Hopp, Francis A; Stuth, Eckehard A

2015-02-01

Respiratory-related neurons in the parabrachial-Kölliker-Fuse (PB-KF) region of the pons play a key role in the control of breathing. The neuronal activities of these pontine respiratory group (PRG) neurons exhibit a variety of inspiratory (I), expiratory (E), phase spanning and non-respiratory related (NRM) discharge patterns. Due to the variety of patterns, it can be difficult to classify them into distinct subgroups according to their discharge contours. This report presents a method that automatically classifies neurons according to their discharge patterns and derives an average subgroup contour of each class. It is based on the K-means clustering technique and it is implemented via SigmaPlot User-Defined transform scripts. The discharge patterns of 135 canine PRG neurons were classified into seven distinct subgroups. Additional methods for choosing the optimal number of clusters are described. Analysis of the results suggests that the K-means clustering method offers a robust objective means of both automatically categorizing neuron patterns and establishing the underlying archetypical contours of subtypes based on the discharge patterns of group of neurons. Published by Elsevier B.V.

Respiratory pathophysiology: sleep-related breathing disorders

PubMed Central

Schäfer, Thorsten

2006-01-01

A widespread network of respiratory-related neurons within the brainstem controls the regular respiratory cycle, which is dependent upon unspecific and specific drives like hypoxia or hypercapnia. This respiratory network and its respiratory drives are subjects to typical changes during the transition from wakefulness to sleep and within the various sleep states, which favor a destabilization of breathing during sleep. There is also a respiratory-related innervation of the dilating and stiffening pharyngeal muscles as well as a local reflex control of the basic tone of upper airway muscles, both of which are influenced by the different states of wakefulness and sleep. These sleep-related changes cause an increase in upper airway resistance during sleep. In healthy subjects, however, these features during sleep are almost completely compensated and the gas exchange is hardly hindered. However, in the case of illness, severe disordered breathing, disturbed gas exchange and interrupted sleep may occur. The central hypoventilation syndrome, central apnea-hypopnea syndromes, as well as the obstructive sleep apnea syndrome belong to these diseases. Because of the intense research, we have a detailed picture of the pathophysiological mechanisms of the origin and the maintenance of sleep-related breathing disorders. PMID:22073070

A Nano-Thin Film-Based Prototype QCM Sensor Array for Monitoring Human Breath and Respiratory Patterns.

PubMed

Selyanchyn, Roman; Wakamatsu, Shunichi; Hayashi, Kenshi; Lee, Seung-Woo

2015-07-31

Quartz crystal microbalance (QCM) sensor array was developed for multi-purpose human respiration assessment. The sensor system was designed to provide feedback for human respiration. Thorough optimization of measurement conditions: air flow, temperature in the QCM chamber, frequency measurement rate, and electrode position regarding to the gas flow-was performed. As shown, acquisition of respiratory parameters (rate and respiratory pattern) could be achieved even with a single electrode used in the system. The prototype system contains eight available QCM channels that can be potentially used for selective responses to certain breath chemicals. At present, the prototype machine is ready for the assessment of respiratory functions in larger populations in order to gain statistical validation. To the best of our knowledge, the developed prototype is the only respiratory assessment system based on surface modified QCM sensors.

Central control of cardiorespiratory interactions in fish.

PubMed

Taylor, Edwin W; Leite, Cleo A C; Levings, Jennifer J

2009-01-01

Fish control the relative flow rates of water and blood over the gills in order to optimise respiratory gas exchange. As both flows are markedly pulsatile, close beat-to-beat relationships can be predicted. Cardiorespiratory interactions in fish are controlled primarily by activity in the parasympathetic nervous system that has its origin in cardiac vagal preganglionic neurons. Recordings of efferent activity in the cardiac vagus include units firing in respiration-related bursts. Bursts of electrical stimuli delivered peripherally to the cardiac vagus or centrally to respiratory branches of cranial nerves can recruit the heart over a range of frequencies. So, phasic, efferent activity in cardiac vagi, that in the intact fish are respiration-related, can cause heart rate to be modulated by the respiratory rhythm. In elasmobranch fishes this phasic activity seems to arise primarily from central feed-forward interactions with respiratory motor neurones that have overlapping distributions with cardiac neurons in the brainstem. In teleost fish, they arise from increased levels of efferent vagal activity arising from reflex stimulation of chemoreceptors and mechanoreceptors in the orobranchial cavity. However, these differences are largely a matter of emphasis as both groups show elements of feed-forward and feed-back control of cardiorespiratory interactions.

Effects of acute and chronic systemic methamphetamine on respiratory, cardiovascular and metabolic function, and cardiorespiratory reflexes

PubMed Central

Hassan, Sarah F.; Wearne, Travis A.; Cornish, Jennifer L.

2016-01-01

Key points Methamphetamine (METH) abuse is escalating worldwide, with the most common cause of death resulting from cardiovascular failure and hyperthermia; however, the underlying physiological mechanisms are poorly understood.Systemic administration of METH in anaesthetised rats reduced the effectiveness of some protective cardiorespiratory reflexes, increased central respiratory activity independently of metabolic function, and increased heart rate, metabolism and respiration in a pattern indicating that non‐shivering thermogenesis contributes to the well‐described hyperthermia.In animals that showed METH‐induced behavioural sensitisation following chronic METH treatment, no changes were evident in baseline cardiovascular, respiratory and metabolic measures and the METH‐evoked effects in these parameters were similar to those seen in saline‐treated or drug naïve animals.Physiological effects evoked by METH were retained but were neither facilitated nor depressed following chronic treatment with METH.These data highlight and identify potential mechanisms for targeted intervention in patients vulnerable to METH overdose. Abstract Methamphetamine (METH) is known to promote cardiovascular failure or life‐threatening hyperthermia; however, there is still limited understanding of the mechanisms responsible for evoking the physiological changes. In this study, we systematically determined the effects on both autonomic and respiratory outflows, as well as reflex function, following acute and repeated administration of METH, which enhances behavioural responses. Arterial pressure, heart rate, phrenic nerve discharge amplitude and frequency, lumbar and splanchnic sympathetic nerve discharge, interscapular brown adipose tissue and core temperatures, and expired CO2 were measured in urethane‐anaesthetised male Sprague‐Dawley rats. Novel findings include potent increases in central inspiratory drive and frequency that are not dependent on METH‐evoked increases in expired CO2 levels. Increases in non‐shivering thermogenesis correlate with well‐described increases in body temperature and heart rate. Unexpectedly, METH evoked minor effects on both sympathetic outflows and mean arterial pressure. METH modified cardiorespiratory reflex function in response to hypoxia, hypercapnia and baroreceptor unloading. Chronically METH‐treated rats failed to exhibit changes in baseline sympathetic, cardiovascular, respiratory and metabolic parameters. The tonic and reflex cardiovascular, respiratory and metabolic responses to METH challenge were similar to those seen in saline‐treated and drug naive animals. Overall, these findings describe independent and compound associations between physiological systems evoked by METH and serve to highlight that a single dose of METH can significantly impact basic homeostatic systems and protective functions. These effects of METH persist even following chronic METH treatment. PMID:26584821

Diarrhea and respiratory symptoms among travelers to Asia, Africa, and South and Central America from Scotland.

PubMed

Redman, Christopher Allan; Maclennan, Alice; Wilson, Eleanor; Walker, Eric

2006-01-01

Surveillance using admissions to hospital, while being useful, is a poor indicator of the real incidence of disease encountered by travelers. An alternative is self-reported illness among those who attended at a pretravel clinic prior to their travels. Estimates of incidence and risk factors were determined for attendees at a travel clinic in Scotland using a questionnaire. Analysis for risk factors was carried out for those travelers visiting countries in Africa, Asia, or South and Central America, who had traveled for 1 week or more and had returned between 1997 and 2001 (N= 4,856). Multivariate logistic regression was used to test the hypotheses that time abroad and age-group would be significant for both respiratory and diarrheal symptoms regardless of which of the three geographical areas are visited. From 2006 returned questionnaires (response rate = 41.3%), diarrhea and respiratory symptoms were reported by 44.2 and 16.8% of respondents, respectively; the incidence was significantly greater among travelers to Asia for both diarrheal (55.5%) and respiratory (23.7%) symptoms than among travelers to Africa (36.6 and 12.2%, respectively) or South and Central America (39.5 and 16.2%, respectively). For diarrhea, age was a highly significant risk factor for travelers to Asia, South and Central America, and Africa. Being a self-organized tourist/backpacker, traveling to Asia was associated with increased risk, while for Africa and South and Central America visiting family or friends was associated with a lower risk. For travelers to Asia, traveling to the Indian subcontinent was significantly associated with increased risk. The majority of travelers had an adverse event while traveling abroad, with diarrhea and respiratory conditions being especially common despite attending a travel clinic for advice prior to departure. However, the limitations of this surveillance-based strategy have highlighted the requirement for more research to understand more fully the issues of risk and incidence among travelers to high-risk destinations from Scotland.

Testing the hypothesis of neurodegeneracy in respiratory network function with a priori transected arterially perfused brain stem preparation of rat

PubMed Central

Jones, Sarah E.

2016-01-01

Degeneracy of respiratory network function would imply that anatomically discrete aspects of the brain stem are capable of producing respiratory rhythm. To test this theory we a priori transected brain stem preparations before reperfusion and reoxygenation at 4 rostrocaudal levels: 1.5 mm caudal to obex (n = 5), at obex (n = 5), and 1.5 (n = 7) and 3 mm (n = 6) rostral to obex. The respiratory activity of these preparations was assessed via recordings of phrenic and vagal nerves and lumbar spinal expiratory motor output. Preparations with a priori transection at level of the caudal brain stem did not produce stable rhythmic respiratory bursting, even when the arterial chemoreceptors were stimulated with sodium cyanide (NaCN). Reperfusion of brain stems that preserved the pre-Bötzinger complex (pre-BötC) showed spontaneous and sustained rhythmic respiratory bursting at low phrenic nerve activity (PNA) amplitude that occurred simultaneously in all respiratory motor outputs. We refer to this rhythm as the pre-BötC burstlet-type rhythm. Conserving circuitry up to the pontomedullary junction consistently produced robust high-amplitude PNA at lower burst rates, whereas sequential motor patterning across the respiratory motor outputs remained absent. Some of the rostrally transected preparations expressed both burstlet-type and regular PNA amplitude rhythms. Further analysis showed that the burstlet-type rhythm and high-amplitude PNA had 1:2 quantal relation, with burstlets appearing to trigger high-amplitude bursts. We conclude that no degenerate rhythmogenic circuits are located in the caudal medulla oblongata and confirm the pre-BötC as the primary rhythmogenic kernel. The absence of sequential motor patterning in a priori transected preparations suggests that pontine circuits govern respiratory pattern formation. PMID:26888109

Testing the hypothesis of neurodegeneracy in respiratory network function with a priori transected arterially perfused brain stem preparation of rat.

PubMed

Jones, Sarah E; Dutschmann, Mathias

2016-05-01

Degeneracy of respiratory network function would imply that anatomically discrete aspects of the brain stem are capable of producing respiratory rhythm. To test this theory we a priori transected brain stem preparations before reperfusion and reoxygenation at 4 rostrocaudal levels: 1.5 mm caudal to obex (n = 5), at obex (n = 5), and 1.5 (n = 7) and 3 mm (n = 6) rostral to obex. The respiratory activity of these preparations was assessed via recordings of phrenic and vagal nerves and lumbar spinal expiratory motor output. Preparations with a priori transection at level of the caudal brain stem did not produce stable rhythmic respiratory bursting, even when the arterial chemoreceptors were stimulated with sodium cyanide (NaCN). Reperfusion of brain stems that preserved the pre-Bötzinger complex (pre-BötC) showed spontaneous and sustained rhythmic respiratory bursting at low phrenic nerve activity (PNA) amplitude that occurred simultaneously in all respiratory motor outputs. We refer to this rhythm as the pre-BötC burstlet-type rhythm. Conserving circuitry up to the pontomedullary junction consistently produced robust high-amplitude PNA at lower burst rates, whereas sequential motor patterning across the respiratory motor outputs remained absent. Some of the rostrally transected preparations expressed both burstlet-type and regular PNA amplitude rhythms. Further analysis showed that the burstlet-type rhythm and high-amplitude PNA had 1:2 quantal relation, with burstlets appearing to trigger high-amplitude bursts. We conclude that no degenerate rhythmogenic circuits are located in the caudal medulla oblongata and confirm the pre-BötC as the primary rhythmogenic kernel. The absence of sequential motor patterning in a priori transected preparations suggests that pontine circuits govern respiratory pattern formation. Copyright © 2016 the American Physiological Society.

Interaction between telencephalic signals and respiratory dynamics in songbirds

PubMed Central

Méndez, Jorge M.; Mindlin, Gabriel B.

2012-01-01

The mechanisms by which telencephalic areas affect motor activities are largely unknown. They could either take over motor control from downstream motor circuits or interact with the intrinsic dynamics of these circuits. Both models have been proposed for telencephalic control of respiration during learned vocal behavior in birds. The interactive model postulates that simple signals from the telencephalic song control areas are sufficient to drive the nonlinear respiratory network into producing complex temporal sequences. We tested this basic assumption by electrically stimulating telencephalic song control areas and analyzing the resulting respiratory patterns in zebra finches and in canaries. We found strong evidence for interaction between the rhythm of stimulation and the intrinsic respiratory rhythm, including naturally emerging subharmonic behavior and integration of lateralized telencephalic input. The evidence for clear interaction in our experimental paradigm suggests that telencephalic vocal control also uses a similar mechanism. Furthermore, species differences in the response of the respiratory system to stimulation show parallels to differences in the respiratory patterns of song, suggesting that the interactive production of respiratory rhythms is manifested in species-specific specialization of the involved circuitry. PMID:22402649

Identifying Early Target Cells of Nipah Virus Infection in Syrian Hamsters

PubMed Central

Baseler, Laura; Scott, Dana P.; Saturday, Greg; Horne, Eva; Rosenke, Rebecca; Thomas, Tina; Meade-White, Kimberly; Haddock, Elaine; Feldmann, Heinz

2016-01-01

Background Nipah virus causes respiratory and neurologic disease with case fatality rates up to 100% in individual outbreaks. End stage lesions have been described in the respiratory and nervous systems, vasculature and often lymphoid organs in fatal human cases; however, the initial target organs of Nipah virus infection have not been identified. Here, we detected the initial target tissues and cells of Nipah virus and tracked virus dissemination during the early phase of infection in Syrian hamsters inoculated with a Nipah virus isolate from Malaysia (NiV-M) or Bangladesh (NiV-B). Methodology/Principal Findings Syrian hamsters were euthanized between 4 and 48 hours post intranasal inoculation and tissues were collected and analyzed for the presence of viral RNA, viral antigen and infectious virus. Virus replication was first detected at 8 hours post inoculation (hpi). Nipah virus initially targeted type I pneumocytes, bronchiolar respiratory epithelium and alveolar macrophages in the lung and respiratory and olfactory epithelium lining the nasal turbinates. By 16 hpi, virus disseminated to epithelial cells lining the larynx and trachea. Although the pattern of viral dissemination was similar for both virus isolates, the rate of spread was slower for NiV-B. Infectious virus was not detected in the nervous system or blood and widespread vascular infection and lesions within lymphoid organs were not observed, even at 48 hpi. Conclusions/Significance Nipah virus initially targets the respiratory system. Virus replication in the brain and infection of blood vessels in non-respiratory tissues does not occur during the early phase of infection. However, virus replicates early in olfactory epithelium and may serve as the first step towards nervous system dissemination, suggesting that development of vaccines that block virus dissemination or treatments that can access the brain and spinal cord and directly inhibit virus replication may be necessary for preventing central nervous system pathology. PMID:27812087

Respiration of Chemodenervated Goats in Acute Metabolic Acidosis,

DTIC Science & Technology

1983-08-02

higher after CBx. We conclude that a respiratory adaptation to AMA does occur in goats deprived of peripheral chemoreceptors, and is probably mediated... respiratory adaptation to AMA does occur in goats deprived of peripheral chemoreceptors, and is probably mediated by the central chemo- receptors. Key...words: carotid bodies, CO2 rebreathing, CSF r’ INTRODUCTION Acid-base disturbances of primarily "metabolic" origin elicit respiratory compensation

Unilateral ablation of pre-Botzinger complex disrupts breathing during sleep but not wakefulness.

PubMed

McKay, Leanne C; Feldman, Jack L

2008-07-01

In adult rats, bilateral ablation of pre-Bötzinger complex (preBötC) neurokinin 1-expressing (NK1R) neurons leads to a progressive and irreversible disruption in breathing pattern, initially during sleep, eventually resulting in an ataxic breathing pattern during wakefulness. Here we determine whether ablation of fewer preBötC NK1R neurons leads to a persistent pattern of disordered breathing during sleep but not during wakefulness. Adult male Sprague-Dawley rats (n = 12) were instrumented to record diaphragmatic, abdominal, and neck EMG, and EEG. Fourteen days later, a second surgery was performed to stereotaxically microinject into the preBötC on one side the toxin saporin conjugated to substance P (SP-SAP), which selectively ablates NK1R neurons. Postinjection, rats were monitored within a plethysmograph until they were killed (Days 21-51). At Days 6-9 post-unilateral SP-SAP injection, respiratory pattern during sleep, particularly REM sleep, became increasingly disordered, characterized by an increase in frequency of central sleep apnea and hypopneas (36.8 +/- 7.4 episodes/h of REM vs. 6 +/- 2.0 episodes/h in preinjection controls; P < 0.05), whereas breathing during resting wakefulness remained stable. Unlike bilateral SP-SAP-injected rats, an ataxic breathing pattern did not develop during wakefulness. Rats that were monitored up to 51 days post-SP-SAP injection continued to have sleep-disordered breathing; breathing during wakefulness remained relatively stable. Histologic analysis of the ventrolateral medulla confirmed that NK1R neurons within the preBötC on the injected but not on the contralateral side of the medulla were ablated. Gradual loss of preBötC NK1R neurons may be an underlying factor of sleep-disordered breathing, in particular of central sleep apnea.

Ventilatory mechanics and the effects of water depth on breathing pattern in the aquatic caecilian Typhlonectes natans.

PubMed

Prabha, K C; Bernard, D G; Gardner, M; Smatresk, N J

2000-01-01

The breathing pattern in the aquatic caecilian Typhlonectes natans was investigated by recording airflow via a pneumotachograph under unrestrained normal physiological conditions. Ventilatory mechanics were assessed using airflow and pressure measurements from the buccal cavity and trachea. The breathing pattern consisted of an expiratory phase followed by a series of 10-15 small buccal pumps to inflate the lung, succeeded by a long non-ventilatory period. T. natans separate the expiratory and inspiratory gases in the buccal cavity and take several inspiratory pumps, distinguishing their breathing pattern from that of sarcopterygians. Hydrostatic pressure assisted exhalation. The tracheal pressure was greater than the water pressure at that depth, suggesting that pleuroperitoneal pressure as well as axial or pulmonary smooth muscles may have contributed to the process of exhalation. The frequency of lung ventilation was 6.33+/-0.84 breaths h(-)(1), and ventilation occurred via the nares. Compared with other amphibians, this low ventilatory frequency suggests that T. natans may have acquired very efficient pulmonary respiration as an adaptation for survival in their seasonally fluctuating natural habitat. Their respiratory pathway is quite unique, with the trachea separated into anterior, central and posterior regions. The anterior region serves as an air channel, the central region is attached to the tracheal lung, and the posterior region consists of a bifurcated air channel leading to the left and right posterior lungs. The lungs are narrow, elongated, profusely vascularized and compartmentalized. The posterior lungs extend to approximately two-thirds of the body length. On the basis of their breathing pattern, it appears that caecilians are phylogenetically derived from two-stroke breathers.

A Nano-Thin Film-Based Prototype QCM Sensor Array for Monitoring Human Breath and Respiratory Patterns

PubMed Central

Selyanchyn, Roman; Wakamatsu, Shunichi; Hayashi, Kenshi; Lee, Seung-Woo

2015-01-01

Quartz crystal microbalance (QCM) sensor array was developed for multi-purpose human respiration assessment. The sensor system was designed to provide feedback for human respiration. Thorough optimization of measurement conditions: air flow, temperature in the QCM chamber, frequency measurement rate, and electrode position regarding to the gas flow—was performed. As shown, acquisition of respiratory parameters (rate and respiratory pattern) could be achieved even with a single electrode used in the system. The prototype system contains eight available QCM channels that can be potentially used for selective responses to certain breath chemicals. At present, the prototype machine is ready for the assessment of respiratory functions in larger populations in order to gain statistical validation. To the best of our knowledge, the developed prototype is the only respiratory assessment system based on surface modified QCM sensors. PMID:26263994

Central pattern generation involved in oral and respiratory control for feeding in the term infant

PubMed Central

Barlow, Steven M.

2009-01-01

Purpose of review Drinking and eating are essential skills for survival and benefit from the coordination of several pattern generating networks and their musculoskeletal effectors to achieve safe swallows. Oral-pharyngo-esophageal motility develops during infancy and early childhood, and is influenced by various factors, including neuromuscular maturation, dietary and postural habits, arousal state, ongoing illnesses, congenital anomalies, and the effects of medical or surgical interventions. Gastroesophageal reflux is frequent in neonates and infants, and its role in neonatal morbidity including dysphagia, chronic lung disease, or apparent life-threatening events is not well understood. This review highlights recent studies aimed at understanding the development of oral feeding skills, and cross-system interactions among the brainstem, spinal, and cerebral networks involved in feeding. Recent Findings Functional linkages between suck-swallow and swallow-respiration manifest transitional forms during late gestation through the first year of life which can be delayed or modified by sensory experience and/or disease processes. Relevant central pattern generator (CPG) networks and their neuromuscular targets attain functional status at different rates, which ultimately influences cross-system CPG interactions. Entrainment of trigeminal primary afferents accelerates pattern genesis for the suck CPG and transition-to-oral feed in the RDS preterm infant. Summary The genesis of within-system CPG control for rate and amplitude scaling matures differentially for suck, mastication, swallow, and respiration. Cross-system interactions among these CPGs represent targets of opportunity for new interventions which optimize experience-dependent mechanisms to promote safe swallows among newborn and pediatric patients. PMID:19417662

The effects of breathing exercise types on respiratory muscle activity and body function in patients with mild chronic obstructive pulmonary disease.

PubMed

Kang, Jeong-Il; Jeong, Dae-Keun; Choi, Hyun

2016-01-01

[Purpose] Fragmentary studies on characteristics of respiratory muscles are being done to increase respiratory capacity by classifying exercises into voluntary respiratory exercise which relieves symptoms and prevents COPD and exercise using breathing exercise equipment. But this study found changes on respiratory pattern through changes on the activity pattern of agonist and synergist respiratory muscles and studied what effect they can have on body function improvement. [Subjects and Methods] Fifteen subjects in experimental group I that respiratory exercise of diaphragm and 15 subjects in experimental group II that feedback respiratory exercise were randomly selected among COPD patients to find the effective intervention method for COPD patients. And intervention program was conducted for 5 weeks, three times a week, once a day and 30 minutes a session. They were measured with BODE index using respiratory muscle activity, pulmonary function, the six-minute walking test, dyspnea criteria and BMI Then the results obtained were compared and analyzed. [Results] There was a significant difference in sternocleidomastoid muscle and scalene muscle and in 6-minute walk and BODE index for body function. Thus the group performing feedback respiratory had more effective results for mild COPD patients. [Conclusion] Therefore, the improvement was significant regarding the activity of respiratory muscles synergists when breathing before doing breathing exercise. Although, it is valuable to reduce too much mobilization of respiratory muscles synergists through the proper intervention it is necessary to study body function regarding improvement of respiratory function for patients with COPD.

A Respiratory Movement Monitoring System Using Fiber-Grating Vision Sensor for Diagnosing Sleep Apnea Syndrome

NASA Astrophysics Data System (ADS)

Takemura, Yasuhiro; Sato, Jun-Ya; Nakajima, Masato

2005-01-01

A non-restrictive and non-contact respiratory movement monitoring system that finds the boundary between chest and abdomen automatically and detects the vertical movement of each part of the body separately is proposed. The system uses a fiber-grating vision sensor technique and the boundary position detection is carried out by calculating the centers of gravity of upward moving and downward moving sampling points, respectively. In the experiment to evaluate the ability to detect the respiratory movement signals of each part and to discriminate between obstructive and central apneas, detected signals of the two parts and their total clearly showed the peculiarities of obstructive and central apnea. The cross talk between the two categories classified automatically according to several rules that reflect the peculiarities was ≤ 15%. This result is sufficient for discriminating central sleep apnea syndrome from obstructive sleep apnea syndrome and indicates that the system is promising as screening equipment. Society of Japan

Extraction of the respiratory signal from small-animal CT projections for a retrospective gating method

NASA Astrophysics Data System (ADS)

Chavarrías, C.; Vaquero, J. J.; Sisniega, A.; Rodríguez-Ruano, A.; Soto-Montenegro, M. L.; García-Barreno, P.; Desco, M.

2008-09-01

We propose a retrospective respiratory gating algorithm to generate dynamic CT studies. To this end, we compared three different methods of extracting the respiratory signal from the projections of small-animal cone-beam computed tomography (CBCT) scanners. Given a set of frames acquired from a certain axial angle, subtraction of their average image from each individual frame produces a set of difference images. Pixels in these images have positive or negative values (according to the respiratory phase) in those areas where there is lung movement. The respiratory signals were extracted by analysing the shape of the histogram of these difference images: we calculated the first four central and non-central moments. However, only odd-order moments produced the desired breathing signal, as the even-order moments lacked information about the phase. Each of these curves was compared to a reference signal recorded by means of a pneumatic pillow. Given the similar correlation coefficients yielded by all of them, we selected the mean to implement our retrospective protocol. Respiratory phase bins were separated, reconstructed independently and included in a dynamic sequence, suitable for cine playback. We validated our method in five adult rat studies by comparing profiles drawn across the diaphragm dome, with and without retrospective respiratory gating. Results showed a sharper transition in the gated reconstruction, with an average slope improvement of 60.7%.

Noncontact Monitoring of Respiration by Dynamic Air-Pressure Sensor.

PubMed

Takarada, Tohru; Asada, Tetsunosuke; Sumi, Yoshihisa; Higuchi, Yoshinori

2015-01-01

We have previously reported that a dynamic air-pressure sensor system allows respiratory status to be visually monitored for patients in minimally clothed condition. The dynamic air-pressure sensor measures vital information using changes in air pressure. To utilize this device in the field, we must clarify the influence of clothing conditions on measurement. The present study evaluated use of the dynamic air-pressure sensor system as a respiratory monitor that can reliably detect change in breathing patterns irrespective of clothing. Twelve healthy volunteers reclined on a dental chair positioned horizontally with the sensor pad for measuring air-pressure signals corresponding to respiration placed on the seat back of the dental chair in the central lumbar region. Respiratory measurements were taken under 2 conditions: (a) thinly clothed (subject lying directly on the sensor pad); and (b) thickly clothed (subject lying on the sensor pad covered with a pressure-reducing sheet). Air-pressure signals were recorded and time integration values for air pressure during each expiration were calculated. This information was compared with expiratory tidal volume measured simultaneously by a respirometer connected to the subject via face mask. The dynamic air-pressure sensor was able to receive the signal corresponding to respiration regardless of clothing conditions. A strong correlation was identified between expiratory tidal volume and time integration values for air pressure during each expiration for all subjects under both clothing conditions (0.840-0.988 for the thinly clothed condition and 0.867-0.992 for the thickly clothed condition). These results show that the dynamic air-pressure sensor is useful for monitoring respiratory physiology irrespective of clothing.

Polyvinylidene fluoride film based nasal sensor to monitor human respiration pattern: an initial clinical study.

PubMed

Roopa Manjunatha, G; Rajanna, K; Mahapatra, D Roy; Nayak, M M; Krishnaswamy, Uma Maheswari; Srinivasa, R

2013-12-01

Design and development of a piezoelectric polyvinylidene fluoride (PVDF) thin film based nasal sensor to monitor human respiration pattern (RP) from each nostril simultaneously is presented in this paper. Thin film based PVDF nasal sensor is designed in a cantilever beam configuration. Two cantilevers are mounted on a spectacle frame in such a way that the air flow from each nostril impinges on this sensor causing bending of the cantilever beams. Voltage signal produced due to air flow induced dynamic piezoelectric effect produce a respective RP. A group of 23 healthy awake human subjects are studied. The RP in terms of respiratory rate (RR) and Respiratory air-flow changes/alterations obtained from the developed PVDF nasal sensor are compared with RP obtained from respiratory inductance plethysmograph (RIP) device. The mean RR of the developed nasal sensor (19.65 ± 4.1) and the RIP (19.57 ± 4.1) are found to be almost same (difference not significant, p > 0.05) with the correlation coefficient 0.96, p < 0.0001. It was observed that any change/alterations in the pattern of RIP is followed by same amount of change/alterations in the pattern of PVDF nasal sensor with k = 0.815 indicating strong agreement between the PVDF nasal sensor and RIP respiratory air-flow pattern. The developed sensor is simple in design, non-invasive, patient friendly and hence shows promising routine clinical usage. The preliminary result shows that this new method can have various applications in respiratory monitoring and diagnosis.

Learning to breathe and sing: development of respiratory-vocal coordination in young songbirds

PubMed Central

Veit, Lena; Aronov, Dmitriy

2011-01-01

How do animals with learned vocalizations coordinate vocal production with respiration? Songbirds such as the zebra finch learn their songs, beginning with highly variable babbling vocalizations known as subsong. After several weeks of practice, zebra finches are able to produce a precisely timed pattern of syllables and silences, precisely coordinated with expiratory and inspiratory pulses (Franz M, Goller F. J Neurobiol 51: 129–141, 2002). While respiration in adult song is well described, relatively little is known about respiratory patterns in subsong or about the processes by which respiratory and vocal patterns become coordinated. To address these questions, we recorded thoracic air sac pressure in juvenile zebra finches prior to the appearance of any consistent temporal or acoustic structure in their songs. We found that subsong contains brief inspiratory pulses (50 ms) alternating with longer pulses of sustained expiratory pressure (50–500 ms). In striking contrast to adult song, expiratory pulses often contained multiple (0–8) variably timed syllables separated by expiratory gaps and were only partially vocalized. During development, expiratory pulses became shorter and more stereotyped in duration with shorter and fewer nonvocalized parts. These developmental changes eventually resulted in the production of a single syllable per expiratory pulse and a single inspiratory pulse filling each gap, forming a coordinated sequence similar to that of adult song. To examine the role of forebrain song-control nuclei in the development of respiratory patterns, we performed pressure recordings before and after lesions of nucleus HVC (proper name) and found that this manipulation reverses the developmental trends in measures of the respiratory pattern. PMID:21697438

Learning to breathe and sing: development of respiratory-vocal coordination in young songbirds.

PubMed

Veit, Lena; Aronov, Dmitriy; Fee, Michale S

2011-10-01

How do animals with learned vocalizations coordinate vocal production with respiration? Songbirds such as the zebra finch learn their songs, beginning with highly variable babbling vocalizations known as subsong. After several weeks of practice, zebra finches are able to produce a precisely timed pattern of syllables and silences, precisely coordinated with expiratory and inspiratory pulses (Franz M, Goller F. J Neurobiol 51: 129-141, 2002). While respiration in adult song is well described, relatively little is known about respiratory patterns in subsong or about the processes by which respiratory and vocal patterns become coordinated. To address these questions, we recorded thoracic air sac pressure in juvenile zebra finches prior to the appearance of any consistent temporal or acoustic structure in their songs. We found that subsong contains brief inspiratory pulses (50 ms) alternating with longer pulses of sustained expiratory pressure (50-500 ms). In striking contrast to adult song, expiratory pulses often contained multiple (0-8) variably timed syllables separated by expiratory gaps and were only partially vocalized. During development, expiratory pulses became shorter and more stereotyped in duration with shorter and fewer nonvocalized parts. These developmental changes eventually resulted in the production of a single syllable per expiratory pulse and a single inspiratory pulse filling each gap, forming a coordinated sequence similar to that of adult song. To examine the role of forebrain song-control nuclei in the development of respiratory patterns, we performed pressure recordings before and after lesions of nucleus HVC (proper name) and found that this manipulation reverses the developmental trends in measures of the respiratory pattern.

75 FR 24509 - Notice of Availability of the Regulatory Flexibility Act Review of the Methylene Chloride Standard

Federal Register 2010, 2011, 2012, 2013, 2014

2010-05-05

... respiratory protection, short-term exposure to large amounts of MC can cause respiratory or central nervous system failure. In 1985, the U.S. Environmental Protection Agency (EPA) determined that MC was a probable...

Dynamic changes in phrenic motor output following high cervical hemisection in the decerebrate rat.

PubMed

Ghali, Michael George Zaki; Marchenko, Vitaliy

2015-09-01

Hemisection of the spinal cord at C2 eliminates ipsilateral descending drive to the phrenic nucleus and causes hemidiaphragmatic paralysis in rats. Phrenic nerve (PhN) or diaphragmatic activity ipsilateral to hemisection can occasionally be induced acutely following hemisection by respiratory stressors (i.e., hypercapnia, asphyxia, contralateral phrenicotomy) and becomes spontaneously active days-to-weeks later. These investigations, however, are potentially confounded by the use of anesthesia, which may suppress spontaneously-active crossed phrenic pathways. Experiments were performed on vecuronium-paralyzed, unanesthetized, decerebrate adult male rats and whole PhN activity recorded continuously before, during, and after high cervical hemisection at the C1 spinal level. Crossed phrenic activity recovered spontaneously over minutes-to-hours with maximal recovery of 11.8 ± 3.1% (m ± SE) in the PhN ipsilateral to hemisection. Additionally, there was a significant increase in PhN activity contralateral to hemisection of 221.0 ± 4 0.4% (m ± SE); since animals were artificially-ventilated, these changes likely represent an increase in central respiratory drive. These results underscore the state-dependence of crossed bulbophrenic projections and suggest that unanesthetized models may be more sensitive in detecting acute recovery of respiratory output following spinal cord injury (SCI). Additionally, our results may suggest an important role for a group of C1-C2 neurons exhibiting respiratory-related activity, spared by the higher level of hemisection. These units may function as relays of polysynaptic bulbophrenic pathways and/or provide excitatory drive to phrenic motoneurons. Our findings provide a new model for investigating acute respiratory recovery following cervical SCI, the high C1-hemisected unanesthetized decerebrate rat and suggest a centrally-mediated increase in central respiratory drive in response to high cervical SCI. Copyright © 2015. Published by Elsevier Inc.

Scheffersomyces stipitis: a comparative systems biology study with the Crabtree positive yeast Saccharomyces cerevisiae

PubMed Central

2012-01-01

Background Scheffersomyces stipitis is a Crabtree negative yeast, commonly known for its capacity to ferment pentose sugars. Differently from Crabtree positive yeasts such as Saccharomyces cerevisiae, the onset of fermentation in S. stipitis is not dependent on the sugar concentration, but is regulated by a decrease in oxygen levels. Even though S. stipitis has been extensively studied due to its potential application in pentoses fermentation, a limited amount of information is available about its metabolism during aerobic growth on glucose. Here, we provide a systems biology based comparison between the two yeasts, uncovering the metabolism of S. stipitis during aerobic growth on glucose under batch and chemostat cultivations. Results Starting from the analysis of physiological data, we confirmed through 13C-based flux analysis the fully respiratory metabolism of S. stipitis when growing both under glucose limited or glucose excess conditions. The patterns observed showed similarity to the fully respiratory metabolism observed for S. cerevisiae under chemostat cultivations however, intracellular metabolome analysis uncovered the presence of several differences in metabolite patterns. To describe gene expression levels under the two conditions, we performed RNA sequencing and the results were used to quantify transcript abundances of genes from the central carbon metabolism and compared with those obtained with S. cerevisiae. Interestingly, genes involved in central pathways showed different patterns of expression, suggesting different regulatory networks between the two yeasts. Efforts were focused on identifying shared and unique families of transcription factors between the two yeasts through in silico transcription factors analysis, suggesting a different regulation of glycolytic and glucoenogenic pathways. Conclusions The work presented addresses the impact of high-throughput methods in describing and comparing the physiology of Crabtree positive and Crabtree negative yeasts. Based on physiological data and flux analysis we identified the presence of one metabolic condition for S. stipitis under aerobic batch and chemostat cultivations, which shows similarities to the oxidative metabolism observed for S. cerevisiae under chemostat cultivations. Through metabolome analysis and genome-wide transcriptomic analysis several differences were identified. Interestingly, in silico analysis of transciption factors was useful to address a different regulation of mRNAs of genes involved in the central carbon metabolism. To our knowledge, this is the first time that the metabolism of S. stiptis is investigated in details and is compared to S. cerevisiae. Our study provides useful results and allows for the possibility to incorporate these data into recently developed genome-scaled metabolic, thus contributing to improve future industrial applications of S. stipitis as cell factory. PMID:23043429

Common drive to the upper airway muscle genioglossus during inspiratory loading

PubMed Central

Woods, Michael J.; Nicholas, Christian L.; Semmler, John G.; Chan, Julia K. M.; Jordan, Amy S.

2015-01-01

Common drive is thought to constitute a central mechanism by which the efficiency of a motor neuron pool is increased. This study tested the hypothesis that common drive to the upper airway muscle genioglossus (GG) would increase with increased respiratory drive in response to an inspiratory load. Respiration, GG electromyographic (EMG) activity, single-motor unit activity, and coherence in the 0–5 Hz range between pairs of GG motor units were assessed for the 30 s before an inspiratory load, the first and second 30 s of the load, and the 30 s after the load. Twelve of twenty young, healthy male subjects provided usable data, yielding 77 pairs of motor units: 2 Inspiratory Phasic, 39 Inspiratory Tonic, 15 Expiratory Tonic, and 21 Tonic. Respiratory and GG inspiratory activity significantly increased during the loads and returned to preload levels during the postload periods (all showed significant quadratic functions over load trials, P < 0.05). As hypothesized, common drive increased during the load in inspiratory modulated motor units to a greater extent than in expiratory/tonic motor units (significant load × discharge pattern interaction, P < 0.05). Furthermore, this effect persisted during the postload period. In conclusion, common drive to inspiratory modulated motor units was elevated in response to increased respiratory drive. The postload elevation in common drive was suggestive of a poststimulus activation effect. PMID:26378207

Mesencephalic stimulation elicits inhibition of phrenic nerve activity in cat.

PubMed Central

Gallman, E A; Lawing, W L; Millhorn, D E

1991-01-01

1. Previous work from this laboratory has indicated that the mesencephalon is the anatomical substrate for a mechanism capable of inhibiting central respiratory drive in glomectomized cats for periods of up to 1 h or more following brief exposure to systemic hypoxia; phrenic nerve activity was used as an index of central respiratory drive. 2. The present study was undertaken to further localize the region responsible for the observed post-hypoxic inhibition of respiratory drive. We studied the phrenic nerve response to stimulations of the mesencephalon in anaesthetized, paralysed peripherally chemo-denervated cats with end-expired PCO2 and body temperature servo-controlled. 3. Stimulations of two types were employed. Electrical stimulation allowed rapid determination of sites from which phrenic inhibition could be elicited. Microinjections of excitatory amino acids were used subsequently in order to confine excitation to neuronal cell bodies and not axons of passage. 4. Stimulation of discrete regions of the ventromedial aspect of the mesencephalon in the vicinity of the red nucleus produced substantial inhibition of phrenic activity which lasted up to 45 min. Stimulation of other areas of the mesencephalon either produced no phrenic inhibition or resulted in a slight stimulation of phrenic activity. 5. The results are discussed in the context of the central respiratory response to hypoxia. PMID:1676420

Control of respiration in fish, amphibians and reptiles.

PubMed

Taylor, E W; Leite, C A C; McKenzie, D J; Wang, T

2010-05-01

Fish and amphibians utilise a suction/force pump to ventilate gills or lungs, with the respiratory muscles innervated by cranial nerves, while reptiles have a thoracic, aspiratory pump innervated by spinal nerves. However, fish can recruit a hypobranchial pump for active jaw occlusion during hypoxia, using feeding muscles innervated by anterior spinal nerves. This same pump is used to ventilate the air-breathing organ in air-breathing fishes. Some reptiles retain a buccal force pump for use during hypoxia or exercise. All vertebrates have respiratory rhythm generators (RRG) located in the brainstem. In cyclostomes and possibly jawed fishes, this may comprise elements of the trigeminal nucleus, though in the latter group RRG neurons have been located in the reticular formation. In air-breathing fishes and amphibians, there may be separate RRG for gill and lung ventilation. There is some evidence for multiple RRG in reptiles. Both amphibians and reptiles show episodic breathing patterns that may be centrally generated, though they do respond to changes in oxygen supply. Fish and larval amphibians have chemoreceptors sensitive to oxygen partial pressure located on the gills. Hypoxia induces increased ventilation and a reflex bradycardia and may trigger aquatic surface respiration or air-breathing, though these latter activities also respond to behavioural cues. Adult amphibians and reptiles have peripheral chemoreceptors located on the carotid arteries and central chemoreceptors sensitive to blood carbon dioxide levels. Lung perfusion may be regulated by cardiac shunting and lung ventilation stimulates lung stretch receptors.

Physiology of respiratory disturbances in muscular dystrophies

PubMed Central

Lo Mauro, Antonella

2016-01-01

Muscular dystrophy is a group of inherited myopathies characterised by progressive skeletal muscle wasting, including of the respiratory muscles. Respiratory failure, i.e. when the respiratory system fails in its gas exchange functions, is a common feature in muscular dystrophy, being the main cause of death, and it is a consequence of lung failure, pump failure or a combination of the two. The former is due to recurrent aspiration, the latter to progressive weakness of respiratory muscles and an increase in the load against which they must contract. In fact, both the resistive and elastic components of the work of breathing increase due to airway obstruction and chest wall and lung stiffening, respectively. The respiratory disturbances in muscular dystrophy are restrictive pulmonary function, hypoventilation, altered thoracoabdominal pattern, hypercapnia, dyspnoea, impaired regulation of breathing, inefficient cough and sleep disordered breathing. They can be present at different rates according to the type of muscular dystrophy and its progression, leading to different onset of each symptom, prognosis and degree of respiratory involvement. Key points A common feature of muscular dystrophy is respiratory failure, i.e. the inability of the respiratory system to provide proper oxygenation and carbon dioxide elimination. In the lung, respiratory failure is caused by recurrent aspiration, and leads to hypoxaemia and hypercarbia. Ventilatory failure in muscular dystrophy is caused by increased respiratory load and respiratory muscles weakness. Respiratory load increases in muscular dystrophy because scoliosis makes chest wall compliance decrease, atelectasis and fibrosis make lung compliance decrease, and airway obstruction makes airway resistance increase. The consequences of respiratory pump failure are restrictive pulmonary function, hypoventilation, altered thoracoabdominal pattern, hypercapnia, dyspnoea, impaired regulation of breathing, inefficient cough and sleep disordered breathing. Educational aims To understand the mechanisms leading to respiratory disturbances in patients with muscular dystrophy. To understand the impact of respiratory disturbances in patients with muscular dystrophy. To provide a brief description of the main forms of muscular dystrophy with their respiratory implications. PMID:28210319

Physiology of respiratory disturbances in muscular dystrophies.

PubMed

Lo Mauro, Antonella; Aliverti, Andrea

2016-12-01

Muscular dystrophy is a group of inherited myopathies characterised by progressive skeletal muscle wasting, including of the respiratory muscles. Respiratory failure, i.e . when the respiratory system fails in its gas exchange functions, is a common feature in muscular dystrophy, being the main cause of death, and it is a consequence of lung failure, pump failure or a combination of the two. The former is due to recurrent aspiration, the latter to progressive weakness of respiratory muscles and an increase in the load against which they must contract. In fact, both the resistive and elastic components of the work of breathing increase due to airway obstruction and chest wall and lung stiffening, respectively. The respiratory disturbances in muscular dystrophy are restrictive pulmonary function, hypoventilation, altered thoracoabdominal pattern, hypercapnia, dyspnoea, impaired regulation of breathing, inefficient cough and sleep disordered breathing. They can be present at different rates according to the type of muscular dystrophy and its progression, leading to different onset of each symptom, prognosis and degree of respiratory involvement. A common feature of muscular dystrophy is respiratory failure, i.e. the inability of the respiratory system to provide proper oxygenation and carbon dioxide elimination.In the lung, respiratory failure is caused by recurrent aspiration, and leads to hypoxaemia and hypercarbia.Ventilatory failure in muscular dystrophy is caused by increased respiratory load and respiratory muscles weakness.Respiratory load increases in muscular dystrophy because scoliosis makes chest wall compliance decrease, atelectasis and fibrosis make lung compliance decrease, and airway obstruction makes airway resistance increase.The consequences of respiratory pump failure are restrictive pulmonary function, hypoventilation, altered thoracoabdominal pattern, hypercapnia, dyspnoea, impaired regulation of breathing, inefficient cough and sleep disordered breathing. To understand the mechanisms leading to respiratory disturbances in patients with muscular dystrophy.To understand the impact of respiratory disturbances in patients with muscular dystrophy.To provide a brief description of the main forms of muscular dystrophy with their respiratory implications.

Respiratory Nursing Diagnoses: Presenting Evidence for Identification of the Defining Characteristics in Neonatal and Pediatric Populations.

PubMed

Avena, Marta J; da Luz Gonçalves Pedreira, Mavilde; Herdman, T Heather; Gutiérrez, Maria G R

2016-10-01

To identify and summarize clinical data supporting selection of nursing diagnoses related to the respiratory system for pediatric and neonatal populations. A literature review conducted in indexed publications was used. The final sample consisted of 13 studies conducted in children with cardiac disease, respiratory infection, and asthma with nursing diagnoses such as ineffective breathing pattern, impaired gas exchange, and ineffective airway clearance. The higher frequency defining characteristics were dyspnea, abnormal breathing pattern, use of accessory muscle to breathe, change in frequency and respiratory rate, decreased SaO 2 , and agitation. This literature review may provide a basis for consideration of important diagnostic criteria in the pediatric population; however, clinical validation in different stages of development is critical for ensuring diagnostic accuracy. © 2015 NANDA International, Inc.

Lung Ultrasound Pattern Is Normal during the Last Gestational Weeks: An Observational Pilot Study.

PubMed

Arbeid, Erik; Demi, Alessio; Brogi, Etrusca; Gori, Elisa; Giusto, Teresa; Soldati, Gino; Vetrugno, Luigi; Giunta, Francesco; Forfori, Francesco

2017-01-01

The normal lung ultrasound (US) pattern during a regular pregnancy has not been evaluated extensively in the current literature. Pregnancy-related changes in the respiratory tract affect maternal predisposition to several respiratory complications; consequently, it is important to differentiate between a physiologic pattern during pregnancy and a pathologic lung pattern, due to respiratory failure. The goal of our study was to assess the normal US lung pattern in women without known comorbidities in the last weeks of pregnancy. We conducted a prospective cross-sectional observational pilot study. Chest wall was examined in 8 areas, 1 scan for each area with women in supine position. One hundred fifty parturients were enrolled during the 36th-38th gestational weeks. None of the participants showed pleural effusion, pneumothorax or lung consolidation. None presented an interstitial syndrome US pattern. One hundred thirteen participants out of 150 (75%) showed A-lines in all the regions. The remaining 25% showed 1 or 2 B-lines in at least 3 regions. Only 2 participants showed 2 positive regions also. We found that, in the majority of the women examined, the lung US pattern matches the physiological pattern in non-pregnant patients. Lung US assessment is a feasible and a helpful diagnostic tool during pregnancy. © 2016 S. Karger AG, Basel.

Study of the distribution patterns of the constituent herbs in classical Chinese medicine prescriptions treating respiratory disease by data mining methods.

PubMed

Fu, Xian-Jun; Song, Xu-Xia; Wei, Lin-Bo; Wang, Zhen-Guo

2013-08-01

To provide the distribution pattern and compatibility laws of the constituent herbs in prescriptions, for doctor's convenience to make decision in choosing correct herbs and prescriptions for treating respiratory disease. Classical prescriptions treating respiratory disease were selected from authoritative prescription books. Data mining methods (frequent itemsets and association rules) were used to analyze the regular patterns and compatibility laws of the constituent herbs in the selected prescriptions. A total of 562 prescriptions were selected to be studied. The result exhibited that, Radix glycyrrhizae was the most frequently used in 47.2% prescriptions, other frequently used were Semen armeniacae amarum, Fructus schisandrae Chinese, Herba ephedrae, and Radix ginseng. Herbal ephedrae was always coupled with Semen armeniacae amarum with the confidence of 73.3%, and many herbs were always accompanied by Radix glycyrrhizae with high confidence. More over, Fructus schisandrae Chinese, Herba ephedrae and Rhizoma pinelliae was most commonly used to treat cough, dyspnoea and associated sputum respectively besides Radix glycyrrhizae and Semen armeniacae amarum. The prescriptions treating dyspnoea often used double herb group of Herba ephedrae & Radix glycyrrhizae, while prescriptions treating sputum often used double herb group of Rhizoma pinelliae & Radix glycyrrhizae and Rhizoma pinelliae & Semen armeniacae amarum, triple herb groups of Rhizoma pinelliae & Semen armeniacae amarum & Radix glycyrrhizae and Pericarpium citri reticulatae & Rhizoma pinelliae & Radix glycyrrhizae. The prescriptions treating respiratory disease showed common compatibility laws in using herbs and special compatibility laws for treating different respiratory symptoms. These principle patterns and special compatibility laws reported here could be useful for doctors to choose correct herbs and prescriptions in treating respiratory disease.

Breathing and Singing: Objective Characterization of Breathing Patterns in Classical Singers

PubMed Central

Salomoni, Sauro; van den Hoorn, Wolbert; Hodges, Paul

2016-01-01

Singing involves distinct respiratory kinematics (i.e. movements of rib cage and abdomen) to quiet breathing because of different demands on the respiratory system. Professional classical singers often advocate for the advantages of an active control of the abdomen on singing performance. This is presumed to prevent shortening of the diaphragm, elevate the rib cage, and thus promote efficient generation of subglottal pressure during phonation. However, few studies have investigated these patterns quantitatively and inter-subject variability has hindered the identification of stereotypical patterns of respiratory kinematics. Here, seven professional classical singers and four untrained individuals were assessed during quiet breathing, and when singing both a standard song and a piece of choice. Several parameters were extracted from respiratory kinematics and airflow, and principal component analysis was used to identify typical patterns of respiratory kinematics. No group differences were observed during quiet breathing. During singing, both groups adapted to rhythmical constraints with decreased time of inspiration and increased peak airflow. In contrast to untrained individuals, classical singers used greater percentage of abdominal contribution to lung volume during singing and greater asynchrony between movements of rib cage and abdomen. Classical singers substantially altered the coordination of rib cage and abdomen during singing from that used for quiet breathing. Despite variations between participants, principal component analysis revealed consistent pre-phonatory inward movements of the abdominal wall during singing. This contrasted with untrained individuals, who demonstrated synchronous respiratory movements during all tasks. The inward abdominal movements observed in classical singers elevates intra-abdominal pressure and may increase the length and the pressure-generating capacity of rib cage expiratory muscles for potential improvements in voice quality. PMID:27159498

Breathing and Singing: Objective Characterization of Breathing Patterns in Classical Singers.

PubMed

Salomoni, Sauro; van den Hoorn, Wolbert; Hodges, Paul

2016-01-01

Singing involves distinct respiratory kinematics (i.e. movements of rib cage and abdomen) to quiet breathing because of different demands on the respiratory system. Professional classical singers often advocate for the advantages of an active control of the abdomen on singing performance. This is presumed to prevent shortening of the diaphragm, elevate the rib cage, and thus promote efficient generation of subglottal pressure during phonation. However, few studies have investigated these patterns quantitatively and inter-subject variability has hindered the identification of stereotypical patterns of respiratory kinematics. Here, seven professional classical singers and four untrained individuals were assessed during quiet breathing, and when singing both a standard song and a piece of choice. Several parameters were extracted from respiratory kinematics and airflow, and principal component analysis was used to identify typical patterns of respiratory kinematics. No group differences were observed during quiet breathing. During singing, both groups adapted to rhythmical constraints with decreased time of inspiration and increased peak airflow. In contrast to untrained individuals, classical singers used greater percentage of abdominal contribution to lung volume during singing and greater asynchrony between movements of rib cage and abdomen. Classical singers substantially altered the coordination of rib cage and abdomen during singing from that used for quiet breathing. Despite variations between participants, principal component analysis revealed consistent pre-phonatory inward movements of the abdominal wall during singing. This contrasted with untrained individuals, who demonstrated synchronous respiratory movements during all tasks. The inward abdominal movements observed in classical singers elevates intra-abdominal pressure and may increase the length and the pressure-generating capacity of rib cage expiratory muscles for potential improvements in voice quality.

Continuous on-line measurements of respiratory system, lung and chest wall mechanics during mechanic ventilation.

PubMed

Kárason, S; Søndergaard, S; Lundin, S; Stenqvist, O

2001-08-01

We present a concept of on-line, manoeuvre-free monitoring of respiratory mechanics during dynamic conditions, displaying calculated alveolar pressure/volume curves continuously and separating lung and chest wall mechanics. Prospective observational study. Intensive care unit of a university hospital. Ten ventilator-treated patients with acute lung injury. Different positive end-expiratory pressure (PEEP) and tidal volumes, low flow inflation. Previously validated methods were used to present a single-value dynostatic compliance for the whole breath and a dynostatic volume-dependent initial, middle and final compliance within the breath. A high individual variation of respiratory mechanics was observed. Reproducibility of repeated measurements was satisfactory (coefficients of variations for dynostatic volume-dependent compliance: < or =9.2% for total respiratory system, < or =18% for lung). Volume-dependent compliance showed a statistically significant pattern of successively decreasing compliance from the initial segment through the middle and final parts within each breath at all respiratory settings. This pattern became more prominent with increasing PEEP and tidal volume, indicating a greater distension of alveoli. No lower inflection point (LIP) was seen in patients with respiratory rate 20/min and PEEP at 4 cmH2O. A trial with low flow inflation in four of the patients showed formation of a LIP in three of them and an upper inflection in one. The monitoring concept revealed a constant pattern of successively decreasing compliance within each breath, which became more prominent with increasing PEEP and tidal volume. The monitoring concept offers a simple and reliable method of monitoring respiratory mechanics during ongoing ventilator treatment.

Effect of exposure to fentanyl aerosol in mice on breathing pattern and respiratory variables.

PubMed

Manral, Laxmi; Muniappan, Natrajan; Gupta, Pradeep K; Ganesan, Kumaran; Malhotra, Ramesh Chandra; Vijayaraghavan, Rajagopalan

2009-01-01

The breathing pattern of mice that were exposed to fentanyl aerosol was studied (2.7, 5.7, 6.0, 10.0, and 23.6 microg/m(3); for 1 hour), using dimethyl sulfoxide as a vehicle. This study was conducted in a head-only exposure assembly. Body plethysmographs connected to a volumetric pressure transducer were used to capture the respiratory signals, and an on-line computer program capable of recognizing the changes in the breathing pattern was used for monitoring the respiratory pattern. The response of mice to fentanyl exposure was found to be concentration dependent. A lower concentration (2.7 microg/m(3)) showed fast recovery and no mortality, while 100% mortality was observed at a higher concentration (23.6 microg/m(3)). No sensory, pulmonary irritation, and airway limitation in mice was observed, and death occurred probably due to respiratory depression. The concentration that decreased 50% of the respiratory frequency (RD(50)) was estimated to be 6.4 microg/m(3). The extrapolated human threshold limit value, calculated from the RD(50) value, was found to be 0.192 microg/m(3). The concentration that caused 50% mortality in exposed mice (LC(50)) was estimated to be 8.8 microg/m(3). This study shows that aerosolized fentanyl does not cause sensory and pulmonary irritation, and since the RD(50) and LC(50) are very close with a low safety margin, this type of sedative should not be used as an incapacitating agent.

Impaired central respiratory chemoreflex in an experimental genetic model of epilepsy

PubMed Central

Totola, Leonardo T.; Takakura, Ana C.; Oliveira, José Antonio C.

2016-01-01

Key points It is recognized that seizures commonly cause apnoea and oxygen desaturation, but there is still a lack in the literature about the respiratory impairments observed ictally and in the post‐ictal period.Respiratory disorders may involve changes in serotonergic transmission at the level of the retrotrapezoid nucleus (RTN).In this study, we evaluated breathing activity and the role of serotonergic transmission in the RTN with a rat model of tonic–clonic seizures, the Wistar audiogenic rat (WAR).We conclude that the respiratory impairment in the WAR could be correlated to an overall decrease in the number of neurons located in the respiratory column. Abstract Respiratory disorders may involve changes in serotonergic neurotransmission at the level of the chemosensitive neurons located in the retrotrapezoid nucleus (RTN). Here, we investigated the central respiratory chemoreflex and the role of serotonergic neurotransmission in the RTN with a rat model of tonic–clonic seizures, the Wistar audiogenic rat (WAR). We found that naive or kindled WARs have reduced resting ventilation and ventilatory response to hypercapnia (7% CO2). The number of chemically coded (Phox2b+/TH−) RTN neurons, as well as the serotonergic innervation to the RTN, was reduced in WARs. We detected that the ventilatory response to serotonin (1 mm, 50 nl) within the RTN region was significantly reduced in WARs. Our results uniquely demonstrated a respiratory impairment in a genetic model of tonic–clonic seizures, the WAR strain. More importantly, we demonstrated an overall decrease in the number of neurons located in the ventral respiratory column (VRC), as well as a reduction in serotonergic neurons in the midline medulla. This is an important step forward to demonstrate marked changes in neuronal activity and breathing impairment in the WAR strain, a genetic model of epilepsy. PMID:27633663

Vagal-dependent nonlinear variability in the respiratory pattern of anesthetized, spontaneously breathing rats

PubMed Central

Dhingra, R. R.; Jacono, F. J.; Fishman, M.; Loparo, K. A.; Rybak, I. A.

2011-01-01

Physiological rhythms, including respiration, exhibit endogenous variability associated with health, and deviations from this are associated with disease. Specific changes in the linear and nonlinear sources of breathing variability have not been investigated. In this study, we used information theory-based techniques, combined with surrogate data testing, to quantify and characterize the vagal-dependent nonlinear pattern variability in urethane-anesthetized, spontaneously breathing adult rats. Surrogate data sets preserved the amplitude distribution and linear correlations of the original data set, but nonlinear correlation structure in the data was removed. Differences in mutual information and sample entropy between original and surrogate data sets indicated the presence of deterministic nonlinear or stochastic non-Gaussian variability. With vagi intact (n = 11), the respiratory cycle exhibited significant nonlinear behavior in templates of points separated by time delays ranging from one sample to one cycle length. After vagotomy (n = 6), even though nonlinear variability was reduced significantly, nonlinear properties were still evident at various time delays. Nonlinear deterministic variability did not change further after subsequent bilateral microinjection of MK-801, an N-methyl-d-aspartate receptor antagonist, in the Kölliker-Fuse nuclei. Reversing the sequence (n = 5), blocking N-methyl-d-aspartate receptors bilaterally in the dorsolateral pons significantly decreased nonlinear variability in the respiratory pattern, even with the vagi intact, and subsequent vagotomy did not change nonlinear variability. Thus both vagal and dorsolateral pontine influences contribute to nonlinear respiratory pattern variability. Furthermore, breathing dynamics of the intact system are mutually dependent on vagal and pontine sources of nonlinear complexity. Understanding the structure and modulation of variability provides insight into disease effects on respiratory patterning. PMID:21527661

Coronavirus Infections in the Central Nervous System and Respiratory Tract Show Distinct Features in Hospitalized Children.

PubMed

Li, Yuanyuan; Li, Haipeng; Fan, Ruyan; Wen, Bo; Zhang, Jian; Cao, Xiaoying; Wang, Chengwu; Song, Zhanyi; Li, Shuochi; Li, Xiaojie; Lv, Xinjun; Qu, Xiaowang; Huang, Renbin; Liu, Wenpei

2016-01-01

Coronavirus (CoV) infections induce respiratory tract illnesses and central nervous system (CNS) diseases. We aimed to explore the cytokine expression profiles in hospitalized children with CoV-CNS and CoV-respiratory tract infections. A total of 183 and 236 hospitalized children with acute encephalitis-like syndrome and respiratory tract infection, respectively, were screened for anti-CoV IgM antibodies. The expression profiles of multiple cytokines were determined in CoV-positive patients. Anti-CoV IgM antibodies were detected in 22/183 (12.02%) and 26/236 (11.02%) patients with acute encephalitis-like syndrome and respiratory tract infection, respectively. Cytokine analysis revealed that the level of serum granulocyte colony-stimulating factor (G-CSF) was significantly higher in both CoV-CNS and CoV-respiratory tract infection compared with healthy controls. Additionally, the serum level of granulocyte macrophage colony-stimulating factor (GM-CSF) was significantly higher in CoV-CNS infection than in CoV-respiratory tract infection. In patients with CoV-CNS infection, the levels of IL-6, IL-8, MCP-1, and GM-CSF were significantly higher in their cerebrospinal fluid samples than in matched serum samples. To the best of our knowledge, this is the first report showing a high incidence of CoV infection in hospitalized children, especially with CNS illness. The characteristic cytokine expression profiles in CoV infection indicate the importance of host immune response in disease progression. © 2017 S. Karger AG, Basel.

Attend or defend? Sex differences in behavioral, autonomic, and respiratory response patterns to emotion-eliciting films.

PubMed

Wilhelm, Frank H; Rattel, Julina A; Wegerer, Melanie; Liedlgruber, Michael; Schweighofer, Simon; Kreibig, Sylvia D; Kolodyazhniy, Vitaliy; Blechert, Jens

2017-12-01

Sex differences in emotional reactivity have been studied primarily for negative but less so for positive stimuli; likewise, sex differences in the psychophysiological response-patterning during such stimuli are poorly understood. Thus, the present study examined sex differences in response to negative/positive and high/low arousing films (classified as threat-, loss-, achievement-, and recreation-related, vs. neutral films), while measuring 18 muscular, autonomic, and respiratory parameters. Sex differences emerged for all films, but were most prominent for threat-related films: Despite equivalent valence and arousal ratings, women displayed more facial-muscular and respiratory responding than men and pronounced sympathetic activation (preejection period, other cardiovascular and electrodermal measures), while men showed coactivated sympathetic/parasympathetic responding (including increased respiratory sinus arrhythmia). This indicates a prototypical threat-related defense response in women, while men showed a pattern of sustained orienting, which can be understood as a shift toward less threat proximity in the defense cascade model. Clinical implications are discussed within a socio-evolutionary framework. Copyright © 2017 Elsevier B.V. All rights reserved.

Smart textile for respiratory monitoring and thoraco-abdominal motion pattern evaluation.

PubMed

Massaroni, Carlo; Venanzi, Cecilia; Silvatti, Amanda P; Lo Presti, Daniela; Saccomandi, Paola; Formica, Domenico; Giurazza, Francesco; Caponero, Michele A; Schena, Emiliano

2018-05-01

The use of wearable systems for monitoring vital parameters has gained wide popularity in several medical fields. The focus of the present study is the experimental assessment of a smart textile based on 12 fiber Bragg grating sensors for breathing monitoring and thoraco-abdominal motion pattern analysis. The feasibility of the smart textile for monitoring several temporal respiratory parameters (ie, breath-by-breath respiratory period, breathing frequency, duration of inspiratory and expiratory phases), volume variations of the whole chest wall and of its compartments is performed on 8 healthy male volunteers. Values gathered by the textile are compared to the data obtained by a motion analysis system, used as the reference instrument. Good agreement between the 2 systems on both respiratory period (bias of 0.01 seconds), breathing frequency (bias of -0.02 breaths/min) and tidal volume (bias of 0.09 L) values is demonstrated. Smart textile shows good performance in the monitoring of thoraco-abdominal pattern and its variation, as well. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Health Instruction Packages: Respiratory Therapy.

ERIC Educational Resources Information Center

Lavich, Margot; And Others

Text, illustrations, and exercises are utilized in these four learning modules to teach respiratory therapy students a variety of job-related skills. The first module, "Anatomy and Physiology of the Central Controls of Respiration" by Margot Lavich, describes the functions of the five centers of the brain that control respiration and…

Potential Changes in Disease Patterns and Pharmaceutical Use in Response to Climate Change

PubMed Central

Redshaw, Clare H.; Stahl-Timmins, Will M.; Fleming, Lora E.; Davidson, Iain; Depledge, Michael H.

2013-01-01

As climate change alters environmental conditions, the incidence and global patterns of human diseases are changing. These modifications to disease profiles and the effects upon human pharmaceutical usage are discussed. Climate-related environmental changes are associated with a rise in the incidence of chronic diseases already prevalent in the Northern Hemisphere, for example, cardiovascular disease and mental illness, leading to greater use of associated heavily used Western medications. Sufferers of respiratory diseases may exhibit exacerbated symptoms due to altered environmental conditions (e.g., pollen). Respiratory, water-borne, and food-borne toxicants and infections, including those that are vector borne, may become more common in Western countries, central and eastern Asia, and across North America. As new disease threats emerge, substantially higher pharmaceutical use appears inevitable, especially of pharmaceuticals not commonly employed at present (e.g., antiprotozoals). The use of medications for the treatment of general symptoms (e.g., analgesics) will also rise. These developments need to be viewed in the context of other major environmental changes (e.g., industrial chemical pollution, biodiversity loss, reduced water and food security) as well as marked shifts in human demographics, including aging of the population. To identify, prevent, mitigate, and adapt to potential threats, one needs to be aware of the major factors underlying changes in the use of pharmaceuticals and their subsequent release, deliberately or unintentionally, into the environment. This review explores the likely consequences of climate change upon the use of medical pharmaceuticals in the Northern Hemisphere. PMID:23909463

Patterns of C-reactive protein ratio response to antibiotics in pediatric sepsis: A prospective cohort study.

PubMed

Lanziotti, Vanessa Soares; Póvoa, Pedro; Prata-Barbosa, Arnaldo; Pulcheri, Lucas Berbet; Rabello, Ligia S C F; Lapa E Silva, José Roberto; Soares, Marcio; Salluh, Jorge I F

2018-04-01

Evaluate sequential C-reactive protein (CRP) measurements and patterns of CRP-ratio response to antibiotic therapy during first 7days in Pediatric Intensive Care Unit (PICU) of septic children. Prospective, cohort study of children (1month-12years) admitted at 3 PICUs, with diagnosis of sepsis with <72h course. CRP-ratio was calculated in relation to D0_CRP value. Children were classified according to an individual pattern of CRP-ratio response: fast - CRP_D4 of therapy was <0.4 of D0_CRP; slow - continuous but slow decrease of CRP; non - CRP remained ≥0.8 of D0_CRP; biphasic - initial CRP decrease to levels <0.8 of D0_CRP followed by secondary rise ≥0.8. 103 septic children (age-median: 2yrs; 54% male) were prospectively included (infection focus: 65% respiratory, 12.5% central nervous system). Overall PICU mortality was 11.7%. 102 children could be classified according to a predefined CRP-ratio response pattern. Time-dependent analysis of CRP-ratio and CRP course of the different patterns were significantly different. Besides, PICU mortality rate was significantly different according CRP-ratio response patterns: fast response 4.5%; slow response 5.8%; non-response 29.4%; biphasic response 42.8%. In pediatric sepsis, CRP-ratio serial evaluation was useful in early identification of patients with poor outcome. Copyright © 2017 Elsevier Inc. All rights reserved.

Structure of a human pulmonary acinus.

PubMed

Berend, N; Rynell, A C; Ward, H E

1991-02-01

The structure of the human pulmonary acinus has been described infrequently. The aim of the study was to determine the branching pattern of respiratory bronchioles and alveolar ducts in a human acinus from the peripheral part of the lung, where space constraints may have affected airway branching patterns. The lungs were obtained from an 18 year old victim of a motor vehicle accident and fixed in inflation under a pressure of 25 cm H2O. A block was cut from the lower edge of the right lower lobe and embedded in plastic. Serial sections were cut and the branching pattern of airways subtended by a terminal bronchiole were followed. The acinus was bounded on two sides by pleura and on the remaining sides by connective tissue septa. The terminal bronchiole divided into two respiratory bronchioles, each of which gave rise to four systems of alveolar ducts. Between successive systems of alveolar ducts the respiratory bronchioles continued as single airways, becoming progressively more alveolated towards the periphery but not subtending further branches of respiratory bronchioles. The duct systems became less complex towards the periphery, near to the edge of the lung. The total volume of the acinus was similar to that found in previous studies. This branching pattern has not been described previously in a human acinus.

Scoring Tools for the Analysis of Infant Respiratory Inductive Plethysmography Signals.

PubMed

Robles-Rubio, Carlos Alejandro; Bertolizio, Gianluca; Brown, Karen A; Kearney, Robert E

2015-01-01

Infants recovering from anesthesia are at risk of life threatening Postoperative Apnea (POA). POA events are rare, and so the study of POA requires the analysis of long cardiorespiratory records. Manual scoring is the preferred method of analysis for these data, but it is limited by low intra- and inter-scorer repeatability. Furthermore, recommended scoring rules do not provide a comprehensive description of the respiratory patterns. This work describes a set of manual scoring tools that address these limitations. These tools include: (i) a set of definitions and scoring rules for 6 mutually exclusive, unique patterns that fully characterize infant respiratory inductive plethysmography (RIP) signals; (ii) RIPScore, a graphical, manual scoring software to apply these rules to infant data; (iii) a library of data segments representing each of the 6 patterns; (iv) a fully automated, interactive formal training protocol to standardize the analysis and establish intra- and inter-scorer repeatability; and (v) a quality control method to monitor scorer ongoing performance over time. To evaluate these tools, three scorers from varied backgrounds were recruited and trained to reach a performance level similar to that of an expert. These scorers used RIPScore to analyze data from infants at risk of POA in two separate, independent instances. Scorers performed with high accuracy and consistency, analyzed data efficiently, had very good intra- and inter-scorer repeatability, and exhibited only minor confusion between patterns. These results indicate that our tools represent an excellent method for the analysis of respiratory patterns in long data records. Although the tools were developed for the study of POA, their use extends to any study of respiratory patterns using RIP (e.g., sleep apnea, extubation readiness). Moreover, by establishing and monitoring scorer repeatability, our tools enable the analysis of large data sets by multiple scorers, which is essential for longitudinal and multicenter studies.

Pattern of respiratory diseases in children presenting to the paediatric emergency unit of the University of Nigeria Teaching Hospital, Enugu: a case series report.

PubMed

Oguonu, Tagbo; Adaeze Ayuk, Chikaodinaka; Edelu, Benedict Onyeka; Ndu, Ikenna Kingsley

2014-06-10

Respiratory diseases are one of the causes of childhood morbidity and mortality as well as hospitalization globally. The patterns of different respiratory illnesses in several parts of the world have been reported but there are few on the combined burden of the diseases. Determination of the burden of respiratory diseases as a group will help ascertain their collective impact on the health systems in order to develop intervention measures. Data from case notes of children with respiratory diseases admitted to the University of Nigeria Teaching Hospital Enugu, Nigeria over a six year period were extracted. Age, gender, admission rates, types of respiratory illness, duration of admission, season of presentation and outcome were analysed. Descriptive and inferential (Chi square) statistics were used to describe the various disease types and ascertain association of the disease outcome, seasonal pattern with the types of diseases. Of the total of 8974 children admissions, 2214 (24.7%) were due to respiratory diseases. The mean age of all the children with respiratory diseases was 3.3 years (SD 3.9). Communicable diseases were the common cause of admission cases throughout the seasons, p < 0.001. The highest admission rates were for pneumonia, (34.0%), acute bronchial asthma, (27.7%) and rhinosinusitis (14.6%) p < 0.001. The frequency of respiratory disease decreases with age and children less than five years of age and of low socio-economic status were commonly affected, p=0.01. The median duration of hospital stay was two days [range 1 to 8 days], children less than five years old and those of low socio-economic status, spent more than four days (p=0.01 and p < 0.001 respectively). The all-cause mortality was 0.5% (11/2214) of which 81.8% (9/11) was due to pneumonia. Respiratory diseases constitute a significant burden of childhood illnesses in our centre. Efforts are required to reduce the impact as part of the steps towards the achievement of the Millennium Development Goals.

[Antibiotic prescribing in acute respiratory tract infections in general practice].

PubMed

Malo, S; Bjerrum, L; Feja, C; Lallana, M J; Poncel, A; Rabanaque, M J

2015-06-01

Antimicrobial resistance is a worldwide threat to public health. Acute respiratory tract infections are the main reason for antibiotic prescribing in the Spanish paediatric population. The aim of the study was to describe the frequency of antibiotic prescription and their pattern of use in acute respiratory tract infections diagnosed in children in Primary Care in Aragón (Spain). A study was conducted over a 1-year period on children between 0 and 14 years-old, recording all episodes of acute otitis, acute pharyngotonsillitis, non-specific upper respiratory infection, and acute bronchitis. The proportion of episodes within each diagnosis receiving an antibiotic prescription was calculated, and the prescribing pattern was determined. Half (50%) of the children in Aragón were diagnosed with a respiratory tract infection during the study period. Non-specific upper respiratory infection was the most frequent diagnosis. An antibiotic was prescribed in 75% of pharyngotonsillitis episodes, 72% of otitis, 27% of bronchitis, and 16% of non-specific upper respiratory infections. Broad spectrum antibiotics, mainly amoxicillin and amoxicillin-clavulanic, were predominantly prescribed. Antibiotic prescribing in respiratory tract infections in children was generally high, and the choice of antibiotics was probably inappropriate in a high percentage of cases. Therefore an improvement in antibiotic prescribing in children appears to be needed. Copyright © 2014 Asociación Española de Pediatría. Published by Elsevier España, S.L.U. All rights reserved.

Prevalence and seasonality of six respiratory viruses during five consecutive epidemic seasons in Belgium.

PubMed

Ramaekers, Kaat; Keyaerts, Els; Rector, Annabel; Borremans, Annie; Beuselinck, Kurt; Lagrou, Katrien; Van Ranst, Marc

2017-09-01

Acute Respiratory Infections (ARIs) are a major health problem, especially in young children and the elderly. Insights into the seasonality of respiratory viruses can help us understand when the burden on society is highest and which age groups are most vulnerable. We monitored six respiratory viruses during five consecutive seasons (2011-2016) in Belgium. Patient specimens (n=22876), tested for one or more of the following respiratory viruses, were included in this analysis: Influenza viruses (IAV & IBV), Human respiratory syncytial virus (hRSV), Human metapneumovirus (hMPV), Adenovirus (ADV) and Human parainfluenza virus (hPIV). Data were analysed for four age categories: <6y, 6-17y, 18-64y and ≥65y. Children <6y had the highest infection rates (39% positive vs. 20% positive adults) and the highest frequency of co-infections. hRSV (28%) and IAV (32%) caused the most common respiratory viral infections and followed, like hMPV, a seasonal pattern with winter peaks. hRSV followed an annual pattern with two peaks: first in young children and ±7 weeks later in elderly. This phenomenon has not been described in literature so far. hPIV and ADV occurred throughout the year with higher rates in winter. Children <6y are most vulnerable for respiratory viral infections and have a higher risk for co-infections. hRSV and IAV are the most common respiratory infections with peaks during the winter season in Belgium. Copyright © 2017 Elsevier B.V. All rights reserved.

Mandible behaviour interpretation during wakefulness, sleep and sleep-disordered breathing.

PubMed

Maury, Gisèle; Senny, Frédéric; Cambron, Laurent; Albert, Adelin; Seidel, Laurence; Poirrier, Robert

2014-12-01

The mandible movement (MM) signal provides information on mandible activity. It can be read visually to assess sleep-wake state and respiratory events. This study aimed to assess (1) the training of independent scorers to recognize the signal specificities; (2) intrascorer reproducibility and (3) interscorer variability. MM was collected in the mid-sagittal plane of the face of 40 patients. The typical MM was extracted and classified into seven distinct pattern classes: active wakefulness (AW), quiet wakefulness or quiet sleep (QW/S), sleep snoring (SS), sleep obstructive events (OAH), sleep mixed apnea (MA), respiratory related arousal (RERA) and sleep central events (CAH). Four scorers were trained; their diagnostic capacities were assessed on two reading sessions. The intra- and interscorer agreements were assessed using Cohen's κ. Intrascorer reproducibility for the two sessions ranged from 0.68 [95% confidence interval (CI): 0.59-0.77] to 0.88 (95% CI: 0.82-0.94), while the between-scorer agreement amounted to 0.68 (95% CI: 0.65-0.71) and 0.74 (95% CI: 0.72-0.77), respectively. The overall accuracy of the scorers was 75.2% (range: 72.4-80.7%). CAH MMs were the most difficult to discern (overall accuracy 65.6%). For the two sessions, the recognition rate of abnormal respiratory events (OAH, CAH, MA and RERA) was excellent: the interscorer mean agreement was 90.7% (Cohen's κ: 0.83; 95% CI: 0.79-0.88). The discrimination of OAH, CAH, MA characteristics was good, with an interscorer agreement of 80.8% (Cohen's κ: 0.65; 95% CI: 0.62-0.68). Visual analysis of isolated MMs can successfully diagnose sleep-wake state, normal and abnormal respiration and recognize the presence of respiratory effort. © 2014 European Sleep Research Society.

Respiration in vitro: I. Spontaneous activity.

PubMed

Hamada, O; Garcia-Rill, E; Skinner, R D

1992-01-01

The present report describes respiratory-like activity recorded from intercostal muscles in the neonatal rat in vitro brain stem-spinal cord, rib-attached preparation. In this preparation from 1- to 4-day-old rats, spontaneous rhythmic and synchronized upward movements of the rib cage coincided with the recorded muscle activity. Spontaneous respiratory-like activity showed a frequency in the range of 0.05-0.2 Hz, with single-, double-, and mixed-burst patterns. Spontaneous activity declined over time, but increased in frequency as temperature increased. Multilevel recordings showed a cephalocaudal order of bursting of intercostal muscles. Brain stem transections at the prepontine level did not affect spontaneous frequency, whereas premedullary transections resulted in an increase in spontaneous respiratory frequency. High spinal transections eliminated spontaneous respiratory-like activity. These results suggest that there is a well-organized pontomedullary pattern generator for respiratory-like activity in this preparation, which can be modulated by temperature. The characteristics of these electromyographic (EMG) recordings allow comparison with previous in vitro studies of respiratory-like activity using nerve activity and in vivo studies using EMG activity. These results provide basic information on the spontaneous activity of this preparation as a prelude to the study of the effects of electrical stimulation of the spinal cord to induce respiratory-like activity, as described in the companion article.

[Sleep and respiratory disorders in myotonic dystrophy of Steinert].

PubMed

López-Esteban, P; Peraita-Adrados, R

2000-03-01

It has been hypothesized that hypersomnia and sleep related respiratory impairment are both central in origin in myotonic dystrophy. To describe by means of video-polysomnographic recordings the central origin of the sleep respiratory disorders. We studied 11 patients, 6 men and 5 women (mean age 42.7 years) with myotonic dystrophy. A moderate to severe ventilatory impairment of a primarily restrictive type was seen in all patients, three of them after the first episode of respiratory insufficiency. The patients were evaluated in order to determine their body mass index and presence of sleep-related complaints. Video-polysomnographic recordings (EEG, EOG, EKG, submental and tibialis anterior EMGs, respiration and Sa02) and pulmonary function tests were performed in each patient. Identical recordings were repeated in six cases, which were to undergo non-invasive bi-level ventilation (BiPAP) in order to adjust the inspiratory and expiratory pressures and the machine mode. We found slight hypopnea and apnea, predominantly of a central type, in stage 1 and REM sleep and alveolar hypoventilation in all patients. Sleep was disrupted and the efficiency index was very low. In three patients HLA typing showed a positive DQ6 haplotype. Six patients were treated with n-BiPAP. Nasal-BIPAP should be considered as an alternative in ventilatory support during sleep in these patients and video-polysomnography as a valid method of evaluating the ideal time to start treatment.

Role of dorsolateral periaqueductal grey in the coordinated regulation of cardiovascular and respiratory function.

PubMed

Dampney, Roger A L; Furlong, Teri M; Horiuchi, Jouji; Iigaya, Kamon

2013-04-01

The midbrain periaqueductal grey (PAG) contains four longitudinal columns, referred to as the dorsomedial (dmPAG), dorsolateral (dlPAG), lateral (lPAG) and ventrolateral (vlPAG) subdivisions, which collectively have a pivotal role in integrating behavioural and physiological responses to external stressors as well as other functions. This review is focussed on the dlPAG, which is believed to be an important component of the central mechanisms that generate the defensive response to acute psychological stressors, such as the presence of a predator or other immediate threat. The anatomical connections of the dlPAG are highly specific and distinctly different from those of the other PAG subregions. The chemical properties of the dlPAG are also distinctly different from the other PAG subregions (e.g. there is a very high density of neurons that synthesize nitric oxide in the dlPAG but very few such neurons in the other PAG subregions). Recent functional studies have demonstrated that neurons in the dlPAG exert a powerful control over both sympathetic and respiratory activity, and that the pattern of the evoked respiratory changes is also distinctly different from those evoked from other PAG subregions. These studies also showed that the sympathetic and respiratory changes evoked from the dlPAG are highly correlated, suggesting the possibility that a common population of "command neurons" within this region may generate the sympathetic and respiratory changes that accompany defensive behavioural responses to acute psychological stressors. Finally, although the anatomical connections and functional properties of the dlPAG are distinctly different from the other PAG subregions, they have many similarities with adjacent parts of the superior colliculus, suggesting that the dlPAG and deep layers of the superior colliculus may be part of a common defence system in the midbrain. Copyright © 2013 Elsevier B.V. All rights reserved.

Antibiotic Prescription, Organisms and its Resistance Pattern in Patients Admitted to Respiratory ICU with Respiratory Infection in Mysuru.

PubMed

Mahendra, M; Jayaraj, B S; Lokesh, K S; Chaya, S K; Veerapaneni, Vivek Vardhan; Limaye, Sneha; Dhar, Raja; Swarnakar, Rajesh; Ambalkar, Shrikant; Mahesh, P A

2018-04-01

Respiratory infections account for significant morbidity, mortality and expenses to patients getting admitted to ICU. Antibiotic resistance is a major worldwide concern in ICU, including India. It is important to know the antibiotic prescribing pattern in ICU, organisms and its resistance pattern as there is sparse data on Indian ICUs. We conducted a prospective study from August 2015 to February 2016. All patients getting admitted to RICU with respiratory infection who were treated with antibiotics were included into study. Demographic details, comorbidities, Clinco-pathological score (CPI) on day1 and 2 of admission, duration of ICU admission, number of antibiotics used, antibiotic prescription, antimicrobial resistance pattern of patients were collected using APRISE questionnaire. During study period 352 patients were screened and 303 patients were included into study. Mean age was 56.05±16.37 and 190 (62.70%) were men. Most common diagnosis was Pneumonia (66%). Piperacillin-tazobactam was most common empirical antibiotic used. We found 60% resistance to piperacillin-tazobactam. Acinetobacter baumanii was the most common organism isolated (29.2%) and was highly resistant to Carbapenem (60%). Klebsiella pneumoniae was resistant to Amikacin (45%), piperacillin (55%) and Ceftazidime (50%). Piperacillin-tazobactam was the most common antibiotic prescribed to patients with respiratory infection admitted to ICU. More than half of patients (60%) had resistance to the empirical antibiotic used in our ICU, highlighting the need for antibiogram for each ICU. Thirty six percent of patient had prior antibiotic use and had mainly gram negative organisms with high resistance to commonly used antibiotics.

Enterovirus serotypes in patients with central nervous system and respiratory infections in Viet Nam 1997-2010.

PubMed

B'Krong, Nguyen Thi Thuy Chinh; Minh, Ngo Ngoc Quang; Qui, Phan Tu; Chau, Tran Thi Hong; Nghia, Ho Dang Trung; Do, Lien Anh Ha; Nhung, Nguyen Ngoc; Van Vinh Chau, Nguyen; Thwaites, Guy; Van Tan, Le; van Doorn, H Rogier; Thanh, Tran Tan

2018-04-12

Enteroviruses are the most common causative agents of human illness. Enteroviruses have been associated with regional and global epidemics, recently, including with severe disease (Enterovirus A71 and D68), and are of interest as emerging viruses. Here, we typed Enterovirus A-D (EV) from central nervous system (CNS) and respiratory infections in Viet Nam. Data and specimens from prospective observational clinical studies conducted between 1997 and 2010 were used. Species and serotypes were determined using type-specific RT-PCR and viral protein 1 or 4 (VP1, VP4) sequencing. Samples from patients with CNS infection (51 children - 10 CSF and 41 respiratory/rectal swabs) and 28 adults (28 CSF) and respiratory infection (124 children - 124 respiratory swabs) were analysed. Twenty-six different serotypes of the four Enterovirus species (A-D) were identified, including EV-A71 and EV-D68. Enterovirus B was associated with viral meningitis in children and adults. Hand, foot and mouth disease associated Enteroviruses A (EV-A71 and Coxsackievirus [CV] A10) were detected in children with encephalitis. Diverse serotypes of all four Enterovirus species were found in respiratory samples, including 2 polio-vaccine viruses, but also 8 CV-A24 and 8 EV-D68. With the exception of EV-D68, the relevance of these viruses in respiratory infection remains unknown. We describe the diverse spectrum of enteroviruses from patients with CNS and respiratory infections in Viet Nam between 1997 and 2010. These data confirm the global circulation of Enterovirus genera and their associations and are important for clinical diagnostics, patient management, and outbreak response.

The nucleus reticularis gigantocellularis modulates the cardiopulmonary responses to central and peripheral drives related to exercise.

PubMed

Richard, C A; Waldrop, T G; Bauer, R M; Mitchell, J H; Stremel, R W

1989-03-13

It is known that muscle afferents and the hypothalamic locomotor region (HLR) both project to the nucleus reticularis gigantocellularis (NGC) and that the NGC is capable of influencing cardiovascular and respiratory variables. Therefore, the role of NGC in the cardiovascular and respiratory response to exercise-related signals was investigated in anesthetized cats. These signals were generated by stimulation of: (1) spinal ventral roots to induce hindlimb muscle contraction (MC) and (2) the HLR. Bilateral electrolytic lesion of the NGC at the pontomedullary border caused tidal volume, respiratory frequency and heart rate responses to HLR stimulation to be greater than the responses recorded prior to lesioning. Lesioning had no effect on the ventilatory or cardiovascular responses to MC but did decrease phrenic responsiveness; lesion had no effect on any resting values. In this preparation, the pontomedullary NGC acts as an inhibitory influence on tidal volume, breathing frequency and heart rate responses to the central command for exercise. In addition, NGC modulation of ventilation would appear to be selective for certain respiratory muscle groups.

Electrophysiological diagnosis and patterns of response to treatment of botulism with neuromuscular respiratory failure.

PubMed

Kongsaengdao, Subsai; Samintarapanya, Kanoksri; Rusmeechan, Siwarit; Sithinamsuwan, Pasiri; Tanprawate, Surat

2009-08-01

In this study we describe the electrophysiological findings in botulism patients with neuromuscular respiratory failure from major botulism outbreaks in Thailand. High-rate repetitive nerve stimulation testing (RNST) of the abductor digiti minimi (ADM) muscle of 17 botulism patients with neuromuscular respiratory failure showed mostly incremental responses, especially in response to >20-HZ stimulation. In the most severe stage of neuromuscular respiratory failure, RNST failed to elicit a compound muscle action potential (CMAP) of the ADM muscle. In the moderately severe stage, the initial CMAPs were of very low amplitude, and a 3-HZ RNST elicited incremental or decremental responses. A 10-HZ RNST elicited mainly decremental responses. In the early recovery stage, the initial CMAP amplitudes of the ADM muscle improved, with initially low amplitudes and an incremental response to 3- and 10-HZ RNSTs. Improved electrophysiological patterns of the ADM muscle correlated with improved respiratory muscle function. Incremental responses to 20-HZ RNST were most useful for diagnosis. The initial electrodiagnostic sign of recovery following treatment of neuromuscular respiratory failure was an increased CMAP amplitude and an incremental response to 10-20-HZ RNST. Muscle Nerve 40: 271-278, 2009.

Respiratory modulation of human autonomic function on Earth.

PubMed

Eckberg, Dwain L; Cooke, William H; Diedrich, André; Biaggioni, Italo; Buckey, Jay C; Pawelczyk, James A; Ertl, Andrew C; Cox, James F; Kuusela, Tom A; Tahvanainen, Kari U O; Mano, Tadaaki; Iwase, Satoshi; Baisch, Friedhelm J; Levine, Benjamin D; Adams-Huet, Beverley; Robertson, David; Blomqvist, C Gunnar

2016-10-01

We studied healthy supine astronauts on Earth with electrocardiogram, non-invasive arterial pressure, respiratory carbon dioxide concentrations, breathing depth and sympathetic nerve recordings. The null hypotheses were that heart beat interval fluctuations at usual breathing frequencies are baroreflex mediated, that they persist during apnoea, and that autonomic responses to apnoea result from changes of chemoreceptor, baroreceptor or lung stretch receptor inputs. R-R interval fluctuations at usual breathing frequencies are unlikely to be baroreflex mediated, and disappear during apnoea. The subjects' responses to apnoea could not be attributed to changes of central chemoreceptor activity (hypocapnia prevailed); altered arterial baroreceptor input (vagal baroreflex gain declined and muscle sympathetic nerve burst areas, frequencies and probabilities increased, even as arterial pressure climbed to new levels); or altered pulmonary stretch receptor activity (major breathing frequency and tidal volume changes did not alter vagal tone or sympathetic activity). Apnoea responses of healthy subjects may result from changes of central respiratory motoneurone activity. We studied eight healthy, supine astronauts on Earth, who followed a simple protocol: they breathed at fixed or random frequencies, hyperventilated and then stopped breathing, as a means to modulate and expose to view important, but obscure central neurophysiological mechanisms. Our recordings included the electrocardiogram, finger photoplethysmographic arterial pressure, tidal volume, respiratory carbon dioxide concentrations and peroneal nerve muscle sympathetic activity. Arterial pressure, vagal tone and muscle sympathetic outflow were comparable during spontaneous and controlled-frequency breathing. Compared with spontaneous, 0.1 and 0.05 Hz breathing, however, breathing at usual frequencies (∼0.25 Hz) lowered arterial baroreflex gain, and provoked smaller arterial pressure and R-R interval fluctuations, which were separated by intervals that were likely to be too short and variable to be attributed to baroreflex physiology. R-R interval fluctuations at usual breathing frequencies disappear during apnoea, and thus cannot provide evidence for the existence of a central respiratory oscillation. Apnoea sets in motion a continuous and ever changing reorganization of the relations among stimulatory and inhibitory inputs and autonomic outputs, which, in our study, could not be attributed to altered chemoreceptor, baroreceptor, or pulmonary stretch receptor activity. We suggest that responses of healthy subjects to apnoea are driven importantly, and possibly prepotently, by changes of central respiratory motoneurone activity. The companion article extends these observations and asks the question, Might terrestrial responses to our 20 min breathing protocol find expression as long-term neuroplasticity in serial measurements made over 20 days during and following space travel? Published 2016. This article is a U.S. Government work and is in the public domain in the USA.

Respiratory modulation of human autonomic function on Earth

PubMed Central

Cooke, William H.; Diedrich, André; Biaggioni, Italo; Buckey, Jay C.; Pawelczyk, James A.; Ertl, Andrew C.; Cox, James F.; Kuusela, Tom A.; Tahvanainen, Kari U. O.; Mano, Tadaaki; Iwase, Satoshi; Baisch, Friedhelm J.; Levine, Benjamin D.; Adams‐Huet, Beverley; Robertson, David; Blomqvist, C. Gunnar

2016-01-01

Key points We studied healthy supine astronauts on Earth with electrocardiogram, non‐invasive arterial pressure, respiratory carbon dioxide concentrations, breathing depth and sympathetic nerve recordings.The null hypotheses were that heart beat interval fluctuations at usual breathing frequencies are baroreflex mediated, that they persist during apnoea, and that autonomic responses to apnoea result from changes of chemoreceptor, baroreceptor or lung stretch receptor inputs.R‐R interval fluctuations at usual breathing frequencies are unlikely to be baroreflex mediated, and disappear during apnoea.The subjects’ responses to apnoea could not be attributed to changes of central chemoreceptor activity (hypocapnia prevailed); altered arterial baroreceptor input (vagal baroreflex gain declined and muscle sympathetic nerve burst areas, frequencies and probabilities increased, even as arterial pressure climbed to new levels); or altered pulmonary stretch receptor activity (major breathing frequency and tidal volume changes did not alter vagal tone or sympathetic activity). Apnoea responses of healthy subjects may result from changes of central respiratory motoneurone activity. Abstract We studied eight healthy, supine astronauts on Earth, who followed a simple protocol: they breathed at fixed or random frequencies, hyperventilated and then stopped breathing, as a means to modulate and expose to view important, but obscure central neurophysiological mechanisms. Our recordings included the electrocardiogram, finger photoplethysmographic arterial pressure, tidal volume, respiratory carbon dioxide concentrations and peroneal nerve muscle sympathetic activity. Arterial pressure, vagal tone and muscle sympathetic outflow were comparable during spontaneous and controlled‐frequency breathing. Compared with spontaneous, 0.1 and 0.05 Hz breathing, however, breathing at usual frequencies (∼0.25 Hz) lowered arterial baroreflex gain, and provoked smaller arterial pressure and R‐R interval fluctuations, which were separated by intervals that were likely to be too short and variable to be attributed to baroreflex physiology. R‐R interval fluctuations at usual breathing frequencies disappear during apnoea, and thus cannot provide evidence for the existence of a central respiratory oscillation. Apnoea sets in motion a continuous and ever changing reorganization of the relations among stimulatory and inhibitory inputs and autonomic outputs, which, in our study, could not be attributed to altered chemoreceptor, baroreceptor, or pulmonary stretch receptor activity. We suggest that responses of healthy subjects to apnoea are driven importantly, and possibly prepotently, by changes of central respiratory motoneurone activity. The companion article extends these observations and asks the question, Might terrestrial responses to our 20 min breathing protocol find expression as long‐term neuroplasticity in serial measurements made over 20 days during and following space travel? PMID:27028958

SU-F-T-255: Accuracy and Precision of Dynamic Tracking Irradiation with VERO-4DRT System

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hayashi, N; Takada, Y; Mizuno, T

2016-06-15

Purpose: The VERO-4DRT system is able to provide dynamic tracking irradiation (DTI) for the target with respiratory motion. This technique requires enough commissioning for clinical implementation. The purpose of this study is to make sure the accuracy and precision of DTI using VERO- 4DRT through commissioning from fundamental evaluation to end-to-end test. Method: We evaluated several contents for DTI commissioning: the accuracy of absorption dose at isocenter in DTI, the field size and penumbra of DTI, the accuracy of 4D modeling in DTI. All evaluations were performed by respiratory motion phantom (Quasar phantom). These contents were compared the results betweenmore » static irradiation and DTI. The shape of radiation field was set to square from 3 cm × 3 cm to 10 cm × 10 cm. The micro 3D chamber and Gafchromic EBT3 film were used for absorbed dose and relative dose distribution measurement, respectively. The sine and irregular shaped waves were used for demonstrative respiratory motion. The visicoil was implanted into the phantom for guidance of respiratory motion. The respiration patterns of frequency and motion amount were set to 10–15 BPM and 1–2 cm, respectively. Results: As the result of absorbed dose of DTI in comparison with static irradiation, the average dose error at isocenter was 0.5% even though various respiratory patterns were set on. As the result of relative dose distribution, the field size (set it on 50% dose line) was not significantly changed in all respiratory patterns. However, the penumbra was larger in greater respiratory motion (up to 4.1 mm). The 4D modeling coincidence between actual and created waves was within 1%. Conclusion: The DTI using VERO-4DRT can provide sufficient accuracy and precision in absorbed dose and distribution. However, the patientspecific quantitative internal margin corresponding respiratory motion should be taken into consideration with image guidance.« less

Central lactic acidosis, hyperventilation, and respiratory alkalosis: leading clinical features in a 3-year-old boy with malignant meningeal melanoma.

PubMed

Blüher, Susann; Schulz, Manuela; Bierbach, Uta; Meixensberger, Jürgen; Tröbs, Ralf-Bodo; Hirsch, Wolfgang; Schober, Ralf; Kiess, Wieland; Siekmeyer, Werner

2008-04-01

Meningeal tumors are extremely rare in children and are diagnostically as well as therapeutically challenging. Among the least common types of malignancies in childhood is malignant melanoma, counting for less than 1% of pediatric tumors. Due to the rarity and the wide spectrum of appearance, initial clinical features may be misleading. A 3-year-old boy was referred to our hospital with symptoms of hyperventilation, dyspnoea, tachycardia, respiratory alkalosis, inarticulate speech, and fatigue. Measurement of pH in cerebrospinal fluid (CSF) yielded central lactic acidosis despite alkalosis in peripheral blood. Diagnostic imaging procedures as well as histology and immunohistochemistry revealed the diagnosis of a malignant meningeal melanoma. We hypothesize that central lactate production of the tumor nests might have induced central acidification, thus inducing hyperventilation by stimulation of central chemoreceptors. This case is a model example of the key role of central pH as an inducer/suppressor of ventilation in humans and illustrates the critical importance of central pH for regulating both ventilation and acid-base homeostasis. Thus, pH of CSF should be measured whenever a malignant brain tumor is suspected.

Central Sleep Apnea - a Rare Cause for Acute Respiratory Insufficiency in Children. Case Report.

PubMed

Popescu, Nicoleta Aurelia; Ionescu, Marcela Daniela; Balan, Georgiana; Visan, Simina; Cinteza, Eliza; Stanescu, Diana; Gobej, Ionut; Balgradean, Mihaela

2018-03-01

Central sleep apnea is characterized by frequent cessation of breathing during sleep, resulting in repetitive episodes of insufficient ventilation and abnormalities of acid-base balance. It may be primary or secondary, and it is uncommon in children, with limited data for this population. We present here the case of a five-year-old girl, known to have thoracolumbar myelomeningocele (for which she underwent a surgical procedure in infancy), secondary hydrocephalus (with a ventriculoperitoneal shunt) and flaccid paralysis, who was admitted in our hospital with prolonged fever syndrome, productive cough, severe dyspnea and perioral cyanosis. Following physical examination, laboratory investigations and thoracic radiography, we established the diagnosis of aspiration pneumonia with acute respiratory failure. Medical treatment with multiple systemic antibiotics, antifungal agents, systemic and inhaled bronchodilator, oxygen therapy and respiratory nursing were initiated, with favorable evolution. During the entire hospitalization, the patient showed nocturnal respiratory rhythm disorders, with sleep apnea crisis of approximately 20 seconds and desaturation, followed by severe hypercapnic respiratory acidosis, manifestations that persisted even after the remission of pulmonary infection, raising the suspicion of an apnea syndrome. After excluding the causes of obstructive apnea, a cerebral CT scan was performed, revealing isolated fourth ventricle compressing the brainstem. The patient underwent neurosurgical intervention and postoperatively, the evolution was favorable, with remission of apnea crisis.

Inactivity-induced respiratory plasticity: Protecting the drive to breathe in disorders that reduce respiratory neural activity☆

PubMed Central

Strey, K.A.; Baertsch, N.A.; Baker-Herman, T.L.

2013-01-01

Multiple forms of plasticity are activated following reduced respiratory neural activity. For example, in ventilated rats, a central neural apnea elicits a rebound increase in phrenic and hypoglossal burst amplitude upon resumption of respiratory neural activity, forms of plasticity called inactivity-induced phrenic and hypoglossal motor facilitation (iPMF and iHMF), respectively. Here, we provide a conceptual framework for plasticity following reduced respiratory neural activity to guide future investigations. We review mechanisms giving rise to iPMF and iHMF, present new data suggesting that inactivity-induced plasticity is observed in inspiratory intercostals (iIMF) and point out gaps in our knowledge. We then survey conditions relevant to human health characterized by reduced respiratory neural activity and discuss evidence that inactivity-induced plasticity is elicited during these conditions. Understanding the physiological impact and circumstances in which inactivity-induced respiratory plasticity is elicited may yield novel insights into the treatment of disorders characterized by reductions in respiratory neural activity. PMID:23816599

Relationship between dysfunctional breathing patterns and ability to achieve target heart rate variability with features of "coherence" during biofeedback.

PubMed

Courtney, Rosalba; Cohen, Marc; van Dixhoorn, Jan

2011-01-01

Heart rate variability (HRV) biofeedback is a self-regulation strategy used to improve conditions including asthma, stress, hypertension, and chronic obstructive pulmonary disease. Respiratory muscle function affects hemodynamic influences on respiratory sinus arrhythmia (RSA), and HRV and HRV-biofeedback protocols often include slow abdominal breathing to achieve physiologically optimal patterns of HRV with power spectral distribution concentrated around the 0.1-Hz frequency and large amplitude. It is likely that optimal balanced breathing patterns and ability to entrain heart rhythms to breathing reflect physiological efficiency and resilience and that individuals with dysfunctional breathing patterns may have difficulty voluntarily modulating HRV and RSA. The relationship between breathing movement patterns and HRV, however, has not been investigated. This study examines how individuals' habitual breathing patterns correspond with their ability to optimize HRV and RSA. Breathing pattern was assessed using the Manual Assessment of Respiratory Motion (MARM) and the Hi Lo manual palpation techniques in 83 people with possible dysfunctional breathing before they attempted HRV biofeedback. Mean respiratory rate was also assessed. Subsequently, participants applied a brief 5-minute biofeedback protocol, involving breathing and positive emotional focus, to achieve HRV patterns proposed to reflect physiological "coherence" and entrainment of heart rhythm oscillations to other oscillating body systems. Thoracic-dominant breathing was associated with decreased coherence of HRV (r = -.463, P = .0001). Individuals with paradoxical breathing had the lowest HRV coherence (t(8) = 10.7, P = .001), and the negative relationship between coherence of HRV and extent of thoracic breathing was strongest in this group (r = -.768, P = .03). Dysfunctional breathing patterns are associated with decreased ability to achieve HRV patterns that reflect cardiorespiratory efficiency and autonomic nervous system balance. This suggests that dysfunctional breathing patterns are not only biomechanically inefficient but also reflect decreased physiological resilience. Breathing assessment using simple manual techniques such as the MARM and Hi Lo may be useful in HRV biofeedback to identify if poor responders require more emphasis on correction of dysfunctional breathing.

Enterovirus D68 in Viet Nam (2009-2015).

PubMed

Ny, Nguyen Thi Han; Anh, Nguyen To; Hang, Vu Thi Ty; Nguyet, Lam Anh; Thanh, Tran Tan; Ha, Do Quang; Minh, Ngo Ngoc Quang; Ha, Do Lien Anh; McBride, Angela; Tuan, Ha Manh; Baker, Stephen; Tam, Pham Thi Thanh; Phuc, Tran My; Huong, Dang Thao; Loi, Tran Quoc; Vu, Nguyen Tran Anh; Hung, Nguyen Van; Minh, Tran Thi Thuy; Xang, Nguyen Van; Dong, Nguyen; Nghia, Ho Dang Trung; Chau, Nguyen Van Vinh; Thwaites, Guy; van Doorn, H Rogier; Anscombe, Catherine; Le Van, Tan

2017-01-01

Since 1962, enterovirus D68 (EV-D68) has been implicated in multiple outbreaks and sporadic cases of respiratory infection worldwide, but especially in the USA and Europe with an increasing frequency between 2010 and 2014. We describe the detection, associated clinical features and molecular characterization of EV-D68 in central and southern Viet Nam between 2009 and 2015. Enterovirus/rhinovirus PCR positive respiratory or CSF samples taken from children and adults with respiratory/central nervous system infections in Viet Nam were tested by an EV-D68 specific PCR. The included samples were derived from 3 different observational studies conducted at referral hospitals across central and southern Viet Nam between 2009 and 2015. Whole-genome sequencing was carried out using a MiSeq based approach. Phylogenetic reconstruction and estimation of evolutionary rate and recombination were carried out in BEAST and Recombination Detection Program, respectively. EV-D68 was detected in 21/625 (3.4%) enterovirus/rhinovirus PCR positive respiratory samples but in none of the 15 CSF. All the EV-D68 patients were young children (age range: 11.8 - 24.5 months) and had moderate respiratory infections. Phylogenetic analysis suggested that the Vietnamese sequences clustered with those from Asian countries, of which 9 fell in the B1 clade, and the remaining sequence was identified within the A2 clade. One intra sub-clade recombination event was detected, representing the second reported recombination within EV-D68. The evolutionary rate of EV-D68 was estimated to be 5.12E -3 substitutions/site/year. Phylogenetic analysis indicated that the virus was imported into Viet Nam in 2008. We have demonstrated for the first time EV-D68 has been circulating at low levels in Viet Nam since 2008, associated with moderate acute respiratory infection in children. EV-D68 in Viet Nam is most closely related to Asian viruses, and clusters separately from recent US and European viruses that were suggested to be associated with acute flaccid paralysis.

Multivariate pattern classification reveals autonomic and experiential representations of discrete emotions.

PubMed

Kragel, Philip A; Labar, Kevin S

2013-08-01

Defining the structural organization of emotions is a central unresolved question in affective science. In particular, the extent to which autonomic nervous system activity signifies distinct affective states remains controversial. Most prior research on this topic has used univariate statistical approaches in attempts to classify emotions from psychophysiological data. In the present study, electrodermal, cardiac, respiratory, and gastric activity, as well as self-report measures were taken from healthy subjects during the experience of fear, anger, sadness, surprise, contentment, and amusement in response to film and music clips. Information pertaining to affective states present in these response patterns was analyzed using multivariate pattern classification techniques. Overall accuracy for classifying distinct affective states was 58.0% for autonomic measures and 88.2% for self-report measures, both of which were significantly above chance. Further, examining the error distribution of classifiers revealed that the dimensions of valence and arousal selectively contributed to decoding emotional states from self-report, whereas a categorical configuration of affective space was evident in both self-report and autonomic measures. Taken together, these findings extend recent multivariate approaches to study emotion and indicate that pattern classification tools may improve upon univariate approaches to reveal the underlying structure of emotional experience and physiological expression. PsycINFO Database Record (c) 2013 APA, all rights reserved.

Multivariate Pattern Classification Reveals Autonomic and Experiential Representations of Discrete Emotions

PubMed Central

Kragel, Philip A.; LaBar, Kevin S.

2013-01-01

Defining the structural organization of emotions is a central unresolved question in affective science. In particular, the extent to which autonomic nervous system activity signifies distinct affective states remains controversial. Most prior research on this topic has used univariate statistical approaches in attempts to classify emotions from psychophysiological data. In the present study, electrodermal, cardiac, respiratory, and gastric activity, as well as self-report measures were taken from healthy subjects during the experience of fear, anger, sadness, surprise, contentment, and amusement in response to film and music clips. Information pertaining to affective states present in these response patterns was analyzed using multivariate pattern classification techniques. Overall accuracy for classifying distinct affective states was 58.0% for autonomic measures and 88.2% for self-report measures, both of which were significantly above chance. Further, examining the error distribution of classifiers revealed that the dimensions of valence and arousal selectively contributed to decoding emotional states from self-report, whereas a categorical configuration of affective space was evident in both self-report and autonomic measures. Taken together, these findings extend recent multivariate approaches to study emotion and indicate that pattern classification tools may improve upon univariate approaches to reveal the underlying structure of emotional experience and physiological expression. PMID:23527508

Intermittent hypoxia promotes recovery of respiratory motor function in spinal cord-injured mice depleted of serotonin in the central nervous system.

PubMed

Komnenov, Dragana; Solarewicz, Julia Z; Afzal, Fareeza; Nantwi, Kwaku D; Kuhn, Donald M; Mateika, Jason H

2016-08-01

We examined the effect of repeated daily exposure to intermittent hypoxia (IH) on the recovery of respiratory and limb motor function in mice genetically depleted of central nervous system serotonin. Electroencephalography, diaphragm activity, ventilation, core body temperature, and limb mobility were measured in spontaneously breathing wild-type (Tph2(+/+)) and tryptophan hydroxylase 2 knockout (Tph2(-/-)) mice. Following a C2 hemisection, the mice were exposed daily to IH (i.e., twelve 4-min episodes of 10% oxygen interspersed with 4-min normoxic periods followed by a 90-min end-recovery period) or normoxia (i.e., sham protocol, 21% oxygen) for 10 consecutive days. Diaphragm activity recovered to prehemisection levels in the Tph2(+/+) and Tph2(-/-) mice following exposure to IH but not normoxia [Tph2(+/+) 1.3 ± 0.2 (SE) vs. 0.3 ± 0.2; Tph2(-/-) 1.06 ± 0.1 vs. 0.3 ± 0.1, standardized to prehemisection values, P < 0.01]. Likewise, recovery of tidal volume and breathing frequency was evident, although breathing frequency values did not return to prehemisection levels within the time frame of the protocol. Partial recovery of limb motor function was also evident 2 wk after spinal cord hemisection. However, recovery was not dependent on IH or the presence of serotonin in the central nervous system. We conclude that IH promotes recovery of respiratory function but not basic motor tasks. Moreover, we conclude that spontaneous or treatment-induced recovery of respiratory and motor limb function is not dependent on serotonin in the central nervous system in a mouse model of spinal cord injury.

Effects of rocuronium bromide on globe position and respiratory function in isoflurane-anesthetized dogs: a comparison between three different dosages.

PubMed

Briganti, Angela; Barsotti, Giovanni; Portela, Diego A; Di Nieri, Camilla; Breghi, Gloria

2015-03-01

To evaluate the effect on globe position and respiration of three dosages of intravenous rocuronium in isoflurane-anesthetized dogs. Thirty-two dogs anesthetized for ophthalmic procedures. The dogs were divided into four groups, each of eight animals (G1-G4). G1, G2, G3 received 0.075, 0.05, 0.03 mg/kg of IV rocuronium, respectively; G4 received 0.9% NaCl IV; all the treatments were administered when an end-tidal isoflurane of 1.1-1.2% was reached. Anesthesia was obtained with dexmedetomidine (2.5 mcg/kg IV), methadone (0.1 mg/kg IV), propofol (2 mg/kg IV), and isoflurane in oxygen. Neuromuscular function was assessed with acceleromyography by stimulation of the peroneal nerve using the train-of-four (ToF) and the ToF ratio (ToFR). Monitoring of cardiovascular and respiratory functions was performed. Changes in globe position were recorded. All three dosages of rocuronium produced centralization of the globe. Duration was 24.3 ± 4.2, 23.4 ± 3.6, and 8.7 ± 2.8 min, for G1, G2, and G3, respectively. The control group did not show globe centralization. No significant differences were found among the four groups in cardiovascular and respiratory parameters. Minute volume and ToFR were significantly lower in G1 compared with baseline values. All doses of rocuronium resulted in globe centralization. The higher dose provoked a transient respiratory depression and some degree of skeletal muscular blockade detectable with ToFR. No alterations in respiratory activity were present when 0.05 mg/kg was used. The 0.03 mg/kg dosage could be useful for very short ophthalmic procedures. © 2013 American College of Veterinary Ophthalmologists.

Respiratory morbidity of pattern and model makers exposed to wood, plastic, and metal products

DOE Office of Scientific and Technical Information (OSTI.GOV)

Robins, T.G.; Haboubi, G.; Demers, R.Y.

Pattern and model makers are skilled tradespersons who may be exposed to hardwoods, softwoods, phenol-formaldehyde resin-impregnated woods, epoxy and polyester/styrene resin systems, and welding and metal-casting fumes. The relationship of respiratory symptoms (wheezing, chronic bronchitis, dyspnea) and pulmonary function (FVC% predicted, FEV1% predicted, FEV1/FVC% predicted) with interview-derived cumulative exposure estimates to specific workplace agents and to all work with wood, plastic, or metal products was investigated in 751 pattern and model makers in southeast Michigan. In stratified analyses and age- and smoking-adjusted linear and logistic regression models, measures of cumulative wood exposures were associated with decrements in pulmonary function andmore » dyspnea, but not with other symptoms. In similar analyses, measures of cumulative plastic exposures were associated with wheezing, chronic bronchitis, and dyspnea, but not with decrements in pulmonary function. Prior studies of exposure levels among pattern and model makers and of respiratory health effects of specific agents among other occupational groups support the plausibility of wood-related effects more strongly than that of plastic-related effects.« less

The etiologic and epidemiologic spectrum of bronchiolitis in pediatric practice.

PubMed

Henderson, F W; Clyde, W A; Collier, A M; Denny, F W; Senior, R J; Sheaffer, C I; Conley, W G; Christian, R M

1979-08-01

To develop a broad understanding of the causes and patterns of occurrence of wheezing associated respiratory infections, we analyzed data from an 11-year study of acute lower respiratory illness in a pediatric practice. Although half of the WARI occurred in children less than 2 years of age, wheezing continued to be observed in 19% of children greater than 9 years of age who had lower respiratory illness. Males experienced LRI 1.25 times more often than did females; the relative risk of males for WARI was 1.35. A nonbacterial pathogen was recovered from 21% of patients with WARI; respiratory syncytial virus, parainfluenza virus types 1 and 3, adenoviruses, and Mycoplasma pneumoniae accounted for 81% of the isolates. Patient age influenced the pattern of recovery of these agents. The most common cause of WARI in children under 5 years of age was RSV whereas Mycoplasma pneumoniae was the most frequent isolate from school age children with wheezing illness. The data expand our understanding of the causes of WARI and are useful to diagnosticians and to researchers interested in the control of lower respiratory disease.

Respiratory muscle function in infants with spinal muscular atrophy type I.

PubMed

Finkel, Richard S; Weiner, Daniel J; Mayer, Oscar H; McDonough, Joseph M; Panitch, Howard B

2014-12-01

To determine the feasibility and safety of respiratory muscle function testing in weak infants with a progressive neuromuscular disorder. Respiratory insufficiency is the major cause of morbidity and mortality in infants with spinal muscular atrophy type I (SMA-I). Tests of respiratory muscle strength, endurance, and breathing patterns can be performed safely in SMA-I infants. Useful data can be collected which parallels the clinical course of pulmonary function in SMA-I. An exploratory study of respiratory muscle function testing and breathing patterns in seven infants with SMA-I seen in our neuromuscular clinic. Measurements were made at initial study visit and, where possible, longitudinally over time. We measured maximal inspiratory (MIP) and transdiaphragmatic pressures, mean transdiaphragmatic pressure, airway occlusion pressure at 100 msec of inspiration, inspiratory and total respiratory cycle time, and aspects of relative thoracoabdominal motion using respiratory inductive plethysmography (RIP). The tension time index of the diaphragm and of the respiratory muscles, phase angle (Φ), phase relation during the total breath, and labored breathing index were calculated. Age at baseline study was 54-237 (median 131) days. Reliable data were obtained safely for MIP, phase angle, labored breathing index, and the invasive and non-invasive tension time indices, even in very weak infants. Data obtained corresponded to the clinical estimate of severity and predicted the need for respiratory support. The testing employed was both safe and feasible. Measurements of MIP and RIP are easily performed tests that are well tolerated and provide clinically useful information for infants with SMA-I. © 2014 Wiley Periodicals, Inc.

Anatomical architecture and responses to acidosis of a novel respiratory neuron group in the high cervical spinal cord (HCRG) of the neonatal rat.

PubMed

Okada, Y; Yokota, S; Shinozaki, Y; Aoyama, R; Yasui, Y; Ishiguro, M; Oku, Y

2009-01-01

It has been postulated that there exists a neuronal mechanism that generates respiratory rhythm and modulates respiratory output pattern in the high cervical spinal cord. Recently, we have found a novel respiratory neuron group in the ventral portion of the high cervical spinal cord, and named it the high cervical spinal cord respiratory group (HCRG). In the present study, we analyzed the detailed anatomical architecture of the HCRG region by double immunostaining of the region using a neuron-specific marker (NeuN) and a marker for motoneurons (ChAT) in the neonatal rat. We found a large number of small NeuN-positive cells without ChAT-immunoreactivity, which were considered interneurons. We also found two and three clusters of motoneurons in the ventral portion of the ventral horn at C1 and C2 levels, respectively. Next, we examined responses of HCRG neurons to respiratory and metabolic acidosis in vitro by voltage-imaging together with cross correlation techniques, i.e., by correlation coefficient imaging, in order to understand the functional role of HCRG neurons. Both respiratory and metabolic acidosis caused the same pattern of changes in their spatiotemporal activation profiles, and the respiratory-related area was enlarged in the HCRG region. After acidosis was introduced, preinspiratory phase-dominant activity was recruited in a number of pixels, and more remarkably inspiratory phase-dominant activity was recruited in a large number of pixels. We suggest that the HCRG composes a local respiratory neuronal network consisting of interneurons and motoneurons and plays an important role in respiratory augmentation in response to acidosis.

Lung function, respiratory symptoms and venous thromboembolism risk: the Atherosclerosis Risk in Communities Study.

PubMed

Kubota, Y; London, S J; Cushman, M; Chamberlain, A M; Rosamond, W D; Heckbert, S R; Zakai, N; Folsom, A R

2016-12-01

Essentials The association of lung function with venous thromboembolism (VTE) is unclear. Chronic obstructive pulmonary disease (COPD) patterns were associated with a higher risk of VTE. Symptoms were also associated with a higher risk of VTE, but a restrictive pattern was not. COPD may increase the risk of VTE and respiratory symptoms may be a novel risk marker for VTE. Background The evidence for the association between chronic obstructive pulmonary disease (COPD) and venous thromboembolism (VTE) is limited. There is no study investigating the association between restrictive lung disease (RLD) and respiratory symptoms with VTE. Objectives To investigate prospectively the association of lung function and respiratory symptoms with VTE. Patients/Methods In 1987-1989, we assessed lung function by using spirometry, and obtained information on respiratory symptoms (cough, phlegm, and dyspnea) in 14 654 participants aged 45-64 years, without a history of VTE or anticoagulant use, and followed them through 2011. Participants were classified into four mutually exclusive groups: 'COPD' (forced expiratory volume in 1 s [FEV 1 ]/forced vital capacity [FVC] below the lower limit of normal [LLN]), 'RLD' (FEV 1 /FVC ≥ LLN and FVC < LLN), 'respiratory symptoms with normal spirometic results' (without RLD or COPD), and 'normal' (without respiratory symptoms, RLD, or COPD). Results We documented 639 VTEs (238 unprovoked and 401 provoked VTEs). After adjustment for VTE risk factors, VTE risk was increased for individuals with either respiratory symptoms with normal spirometric results (hazard ratio [HR] 1.40, 95% confidence interval [CI] 1.12-1.73) or COPD (HR 1.33, 95% CI 1.07-1.67) but not for those with RLD (HR 1.15, 95% CI 0.82-1.60). These elevated risks of VTE were derived from both unprovoked and provoked VTE. Moreover, FEV 1 and FEV 1 /FVC showed dose-response relationships with VTE. COPD was more strongly associated with pulmonary embolism than with deep vein thrombosis. Conclusions Obstructive spirometric patterns were associated with an increased risk of VTE, suggesting that COPD may increase the risk of VTE. Respiratory symptoms may represent a novel risk marker for VTE. © 2016 International Society on Thrombosis and Haemostasis.

Spatial Correlation Analysis between Particulate Matter 10 (PM10) Hazard and Respiratory Diseases in Chiang Mai Province, Thailand

NASA Astrophysics Data System (ADS)

Trang, N. Ha; Tripathi, N. K.

2014-11-01

Every year, during dry season, Chiang Mai and other northern provinces of Thailand face the problem of haze which is mainly generated by the burning of agricultural waste and forest fire, contained high percentage of particulate matter. Particulate matter 10 (PM10), being very small in size, can be inhaled easily to the deepest parts of the human lung and throat respiratory functions. Due to this, it increases the risk of respiratory diseases mainly in the case of continuous exposure to this seasonal smog. MODIS aerosol images (MOD04) have been used for four weeks in March 2007 for generating the hazard map by linking to in-situ values of PM10. Simple linear regression model between PM10 and AOD got fair correlation with R2 = 0.7 and was applied to transform PM10 pattern. The hazard maps showed the dominance of PM10 in northern part of Chiang Mai, especially in second week of March when PM10 level was three to four times higher than standard. The respiratory disease records and public health station of each village were collected from Provincial Public Health Department in Chiang Mai province. There are about 300 public health stations out of 2070 villages; hence thiessen polygon was created to determine the representative area of each public health station. Within each thiessen polygon, respiratory disease incident rate (RDIR) was calculated based on the number of patients and population. Global Moran's I was computed for RDIR to explore spatial pattern of diseases through four weeks of March. Moran's I index depicted a cluster pattern of respiratory diseases in 2nd week than other weeks. That made sense for a relationship between PM10 and respiratory diseases infections. In order to examine how PM10 affect the human respiratory system, geographically weighted regression model was used to observe local correlation coefficient between RDIR and PM10 across study area. The result captured a high correlation between respiratory diseases and high level of PM10 in northeast districts of Chiang Mai in second week of March.

Motion robust high resolution 3D free-breathing pulmonary MRI using dynamic 3D image self-navigator.

PubMed

Jiang, Wenwen; Ong, Frank; Johnson, Kevin M; Nagle, Scott K; Hope, Thomas A; Lustig, Michael; Larson, Peder E Z

2018-06-01

To achieve motion robust high resolution 3D free-breathing pulmonary MRI utilizing a novel dynamic 3D image navigator derived directly from imaging data. Five-minute free-breathing scans were acquired with a 3D ultrashort echo time (UTE) sequence with 1.25 mm isotropic resolution. From this data, dynamic 3D self-navigating images were reconstructed under locally low rank (LLR) constraints and used for motion compensation with one of two methods: a soft-gating technique to penalize the respiratory motion induced data inconsistency, and a respiratory motion-resolved technique to provide images of all respiratory motion states. Respiratory motion estimation derived from the proposed dynamic 3D self-navigator of 7.5 mm isotropic reconstruction resolution and a temporal resolution of 300 ms was successful for estimating complex respiratory motion patterns. This estimation improved image quality compared to respiratory belt and DC-based navigators. Respiratory motion compensation with soft-gating and respiratory motion-resolved techniques provided good image quality from highly undersampled data in volunteers and clinical patients. An optimized 3D UTE sequence combined with the proposed reconstruction methods can provide high-resolution motion robust pulmonary MRI. Feasibility was shown in patients who had irregular breathing patterns in which our approach could depict clinically relevant pulmonary pathologies. Magn Reson Med 79:2954-2967, 2018. © 2017 International Society for Magnetic Resonance in Medicine. © 2017 International Society for Magnetic Resonance in Medicine.

Ventilatory accommodation of oxygen demand and respiratory water loss in kangaroos from mesic and arid environments, the eastern grey kangaroo (Macropus giganteus) and the red kangaroo (Macropus rufus).

PubMed

Dawson, T J; Munn, A J; Blaney, C E; Krockenberger, A; Maloney, S K

2000-01-01

We studied ventilation in kangaroos from mesic and arid environments, the eastern grey kangaroo (Macropus giganteus) and the red kangaroo (Macropus rufus), respectively, within the range of ambient temperatures (T(a)) from -5 degrees to 45 degrees C. At thermoneutral temperatures (Ta=25 degrees C), there were no differences between the species in respiratory frequency, tidal volume, total ventilation, or oxygen extraction. The ventilatory patterns of the kangaroos were markedly different from those predicted from the allometric equation derived for placentals. The kangaroos had low respiratory frequencies and higher tidal volumes, even when adjustment was made for their lower basal metabolism. At Ta>25 degrees C, ventilation was increased in the kangaroos to facilitate respiratory water loss, with percent oxygen extraction being markedly lowered. Ventilation was via the nares; the mouth was closed. Differences in ventilation between the two species occurred at higher temperatures, and at 45 degrees C were associated with differences in respiratory evaporative heat loss, with that of M. giganteus being higher. Panting in kangaroos occurred as a graded increase in respiratory frequency, during which tidal volume was lowered. When panting, the desert red kangaroo had larger tidal volumes and lower respiratory frequencies at equivalent T(a) than the eastern grey kangaroo, which generally inhabits mesic forests. The inference made from this pattern is that the red kangaroo has the potential to increase respiratory evaporative heat loss to a greater level.

Features of mtDNA mutation patterns in European pedigrees and sporadic cases with leber hereditary optic neuropathy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Obermaier-Kusser, B.; Schubring, S.; Paprotta, A.

1994-11-01

Leber hereditary optic neuropathy (LHON) is maternally transmitted and is characterized by bilateral loss of central vision in young adults as a result of optic nerve degeneration. Fifteen transition mutations located in different genes for the mitochondrially encoded subunits of respiratory chain complexes have been associated thus far with the disease. Genetic studies have led to the classification of the pathogenic significance of these different mutations. However, more research is required to determine the causality of the mutations and the penetrance of the disease. The present study compares studies of populations of different ethnic origins, namely European LHON pedigrees andmore » sporadic cases, in order to elucidate the pathogenic mechanisms involved. 21 refs., 2 figs., 1 tab.« less

Developmental nicotine exposure adversely effects respiratory patterning in the barbiturate anesthetized neonatal rat.

PubMed

Barreda, Santiago; Kidder, Ian J; Mudery, Jordan A; Bailey, E Fiona

2015-03-01

Neonates at risk for sudden infant death syndrome (SIDS) are hospitalized for cardiorespiratory monitoring however, monitoring is costly and generates large quantities of averaged data that serve as poor predictors of infant risk. In this study we used a traditional autocorrelation function (ACF) testing its suitability as a tool to detect subtle alterations in respiratory patterning in vivo. We applied the ACF to chest wall motion tracings obtained from rat pups in the period corresponding to the mid-to-end of the third trimester of human pregnancy. Pups were drawn from two groups: nicotine-exposed and saline-exposed at each age (i.e., P7, P8, P9, and P10). Respiratory-related motions of the chest wall were recorded in room air and in response to an arousal stimulus (FIO2 14%). The autocorrelation function was used to determine measures of breathing rate and respiratory patterning. Unlike alternative tools such as Poincare plots that depict an averaged difference in a measure breath to breath, the ACF when applied to a digitized chest wall trace yields an instantaneous sample of data points that can be used to compare (data) points at the same time in the next breath or in any subsequent number of breaths. The moment-to-moment evaluation of chest wall motion detected subtle differences in respiratory pattern in rat pups exposed to nicotine in utero and aged matched saline-exposed peers. The ACF can be applied online as well as to existing data sets and requires comparatively short sampling windows (∼2 min). As shown here, the ACF could be used to identify factors that precipitate or minimize instability and thus, offers a quantitative measure of risk in vulnerable populations. Copyright © 2015 Elsevier B.V. All rights reserved.

Antibiotic Prescription, Organisms and its Resistance Pattern in Patients Admitted to Respiratory ICU with Respiratory Infection in Mysuru

PubMed Central

Mahendra, M; Jayaraj, BS; Lokesh, KS; Chaya, SK; Veerapaneni, Vivek Vardhan; Limaye, Sneha; Dhar, Raja; Swarnakar, Rajesh; Ambalkar, Shrikant; Mahesh, PA

2018-01-01

Aim of Study: Respiratory infections account for significant morbidity, mortality and expenses to patients getting admitted to ICU. Antibiotic resistance is a major worldwide concern in ICU, including India. It is important to know the antibiotic prescribing pattern in ICU, organisms and its resistance pattern as there is sparse data on Indian ICUs. Materials and Methods: We conducted a prospective study from August 2015 to February 2016. All patients getting admitted to RICU with respiratory infection who were treated with antibiotics were included into study. Demographic details, comorbidities, Clinco-pathological score (CPI) on day1 and 2 of admission, duration of ICU admission, number of antibiotics used, antibiotic prescription, antimicrobial resistance pattern of patients were collected using APRISE questionnaire. Results: During study period 352 patients were screened and 303 patients were included into study. Mean age was 56.05±16.37 and 190 (62.70%) were men. Most common diagnosis was Pneumonia (66%). Piperacillin-tazobactam was most common empirical antibiotic used. We found 60% resistance to piperacillin-tazobactam. Acinetobacter baumanii was the most common organism isolated (29.2%) and was highly resistant to Carbapenem (60%). Klebsiella pneumoniae was resistant to Amikacin (45%), piperacillin (55%) and Ceftazidime (50%). Conclusion: Piperacillin-tazobactam was the most common antibiotic prescribed to patients with respiratory infection admitted to ICU. More than half of patients (60%) had resistance to the empirical antibiotic used in our ICU, highlighting the need for antibiogram for each ICU. Thirty six percent of patient had prior antibiotic use and had mainly gram negative organisms with high resistance to commonly used antibiotics. PMID:29743760

Discharge properties of upper airway motor units during wakefulness and sleep.

PubMed

Trinder, John; Jordan, Amy S; Nicholas, Christian L

2014-01-01

Upper airway muscle motoneurons, as assessed at the level of the motor unit, have a range of different discharge patterns, varying as to whether their activity is modulated in phase with the respiratory cycle, are predominantly inspiratory or expiratory, or are phasic as opposed to tonic. Two fundamental questions raised by this observation are: how are synaptic inputs from premotor neurons distributed over motoneurons to achieve these different discharge patterns; and how do different discharge patterns contribute to muscle function? We and others have studied the behavior of genioglossus (GG) and tensor palatini (TP) single motor units at transitions from wakefulness to sleep (sleep onset), from sleep to wakefulness (arousal from sleep), and during hypercapnia. Results indicate that decreases or increases in GG and TP muscle activity occur as a consequence of derecruitment or recruitment, respectively, of phasic and tonic inspiratory-modulated motoneurons, with only minor changes in rate coding. Further, sleep-wake state and chemical inputs to this "inspiratory system" appear to be mediated through the respiratory pattern generator. In contrast, phasic and tonic expiratory units and units with a purely tonic pattern, the "tonic system," are largely unaffected by sleep-wake state, and are only weakly influenced by chemical stimuli and the respiratory cycle. We speculate that the "inspiratory system" produces gross changes in upper airway muscle activity in response to changes in respiratory drive, while the "tonic system" fine tunes airway configuration with activity in this system being determined by local mechanical conditions. © 2014 Elsevier B.V. All rights reserved.

Unilateral Ablation of Pre-Bötzinger Complex Disrupts Breathing during Sleep but Not Wakefulness

PubMed Central

McKay, Leanne C.; Feldman, Jack L.

2008-01-01

Rationale: In adult rats, bilateral ablation of pre-Bötzinger complex (preBötC) neurokinin 1–expressing (NK1R) neurons leads to a progressive and irreversible disruption in breathing pattern, initially during sleep, eventually resulting in an ataxic breathing pattern during wakefulness. Objectives: Here we determine whether ablation of fewer preBötC NK1R neurons leads to a persistent pattern of disordered breathing during sleep but not during wakefulness. Methods: Adult male Sprague-Dawley rats (n = 12) were instrumented to record diaphragmatic, abdominal, and neck EMG, and EEG. Fourteen days later, a second surgery was performed to stereotaxically microinject into the preBötC on one side the toxin saporin conjugated to substance P (SP-SAP), which selectively ablates NK1R neurons. Measurements and Main Results: Postinjection, rats were monitored within a plethysmograph until they were killed (Days 21–51). At Days 6–9 post–unilateral SP-SAP injection, respiratory pattern during sleep, particularly REM sleep, became increasingly disordered, characterized by an increase in frequency of central sleep apnea and hypopneas (36.8 ± 7.4 episodes/h of REM vs. 6 ± 2.0 episodes/h in preinjection controls; P < 0.05), whereas breathing during resting wakefulness remained stable. Unlike bilateral SP-SAP–injected rats, an ataxic breathing pattern did not develop during wakefulness. Rats that were monitored up to 51 days post–SP-SAP injection continued to have sleep-disordered breathing; breathing during wakefulness remained relatively stable. Histologic analysis of the ventrolateral medulla confirmed that NK1R neurons within the preBötC on the injected but not on the contralateral side of the medulla were ablated. Conclusions: Gradual loss of preBötC NK1R neurons may be an underlying factor of sleep-disordered breathing, in particular of central sleep apnea. PMID:18420958

[Hospital management of acute respiratory failure: the role of the pulmonologist and of the respiratory intensive care unit].

PubMed

Scala, Raffaele

2009-04-01

Acute respiratory failure (ARF) is one of the most common and severe urgencies of the modern medicine which may require the application of mechanical ventilation and a careful monitoring of the patient's conditions. With the popularity of non-invasive ventilation and the interest of the pulmonologist for the care of the respiratory critical patient, in Italy there has been the spreading of Respiratory Intensive Care Units (RICU), which are as intermediate specialist structures in terms of intensity of care between the General Intensive Care Unit and the ordinary ward. In this article, the author analysed the cultural, scientific and organizational aspects of the central role played by the pulmonologist who's working in the RICU in the complex intra-hospital multi-disciplinary management of ARF.

Rules for scoring respiratory events in sleep: update of the 2007 AASM Manual for the Scoring of Sleep and Associated Events. Deliberations of the Sleep Apnea Definitions Task Force of the American Academy of Sleep Medicine.

PubMed

Berry, Richard B; Budhiraja, Rohit; Gottlieb, Daniel J; Gozal, David; Iber, Conrad; Kapur, Vishesh K; Marcus, Carole L; Mehra, Reena; Parthasarathy, Sairam; Quan, Stuart F; Redline, Susan; Strohl, Kingman P; Davidson Ward, Sally L; Tangredi, Michelle M

2012-10-15

The American Academy of Sleep Medicine (AASM) Sleep Apnea Definitions Task Force reviewed the current rules for scoring respiratory events in the 2007 AASM Manual for the Scoring and Sleep and Associated Events to determine if revision was indicated. The goals of the task force were (1) to clarify and simplify the current scoring rules, (2) to review evidence for new monitoring technologies relevant to the scoring rules, and (3) to strive for greater concordance between adult and pediatric rules. The task force reviewed the evidence cited by the AASM systematic review of the reliability and validity of scoring respiratory events published in 2007 and relevant studies that have appeared in the literature since that publication. Given the limitations of the published evidence, a consensus process was used to formulate the majority of the task force recommendations concerning revisions.The task force made recommendations concerning recommended and alternative sensors for the detection of apnea and hypopnea to be used during diagnostic and positive airway pressure (PAP) titration polysomnography. An alternative sensor is used if the recommended sensor fails or the signal is inaccurate. The PAP device flow signal is the recommended sensor for the detection of apnea, hypopnea, and respiratory effort related arousals (RERAs) during PAP titration studies. Appropriate filter settings for recording (display) of the nasal pressure signal to facilitate visualization of inspiratory flattening are also specified. The respiratory inductance plethysmography (RIP) signals to be used as alternative sensors for apnea and hypopnea detection are specified. The task force reached consensus on use of the same sensors for adult and pediatric patients except for the following: (1) the end-tidal PCO(2) signal can be used as an alternative sensor for apnea detection in children only, and (2) polyvinylidene fluoride (PVDF) belts can be used to monitor respiratory effort (thoracoabdominal belts) and as an alternative sensor for detection of apnea and hypopnea (PVDFsum) only in adults.The task force recommends the following changes to the 2007 respiratory scoring rules. Apnea in adults is scored when there is a drop in the peak signal excursion by ≥ 90% of pre-event baseline using an oronasal thermal sensor (diagnostic study), PAP device flow (titration study), or an alternative apnea sensor, for ≥ 10 seconds. Hypopnea in adults is scored when the peak signal excursions drop by ≥ 30% of pre-event baseline using nasal pressure (diagnostic study), PAP device flow (titration study), or an alternative sensor, for ≥ 10 seconds in association with either ≥ 3% arterial oxygen desaturation or an arousal. Scoring a hypopnea as either obstructive or central is now listed as optional, and the recommended scoring rules are presented. In children an apnea is scored when peak signal excursions drop by ≥ 90% of pre-event baseline using an oronasal thermal sensor (diagnostic study), PAP device flow (titration study), or an alternative sensor; and the event meets duration and respiratory effort criteria for an obstructive, mixed, or central apnea. A central apnea is scored in children when the event meets criteria for an apnea, there is an absence of inspiratory effort throughout the event, and at least one of the following is met: (1) the event is ≥ 20 seconds in duration, (2) the event is associated with an arousal or ≥ 3% oxygen desaturation, (3) (infants under 1 year of age only) the event is associated with a decrease in heart rate to less than 50 beats per minute for at least 5 seconds or less than 60 beats per minute for 15 seconds. A hypopnea is scored in children when the peak signal excursions drop is ≥ 30% of pre-event baseline using nasal pressure (diagnostic study), PAP device flow (titration study), or an alternative sensor, for ≥ the duration of 2 breaths in association with either ≥ 3% oxygen desaturation or an arousal. In children and adults, surrogates of the arterial PCO(2) are the end-tidal PCO(2) or transcutaneous PCO(2) (diagnostic study) or transcutaneous PCO(2) (titration study). For adults, sleep hypoventilation is scored when the arterial PCO(2) (or surrogate) is > 55 mm Hg for ≥ 10 minutes or there is an increase in the arterial PCO(2) (or surrogate) ≥ 10 mm Hg (in comparison to an awake supine value) to a value exceeding 50 mm Hg for ≥ 10 minutes. For pediatric patients hypoventilation is scored when the arterial PCO(2) (or surrogate) is > 50 mm Hg for > 25% of total sleep time. In adults Cheyne-Stokes breathing is scored when both of the following are met: (1) there are episodes of ≥ 3 consecutive central apneas and/or central hypopneas separated by a crescendo and decrescendo change in breathing amplitude with a cycle length of at least 40 seconds (typically 45 to 90 seconds), and (2) there are five or more central apneas and/or central hypopneas per hour associated with the crescendo/decrescendo breathing pattern recorded over a minimum of 2 hours of monitoring.

Using Mathematical Transmission Modelling to Investigate Drivers of Respiratory Syncytial Virus Seasonality in Children in the Philippines

PubMed Central

Paynter, Stuart; Yakob, Laith; Simões, Eric A. F.; Lucero, Marilla G.; Tallo, Veronica; Nohynek, Hanna; Ware, Robert S.; Weinstein, Philip; Williams, Gail; Sly, Peter D.

2014-01-01

We used a mathematical transmission model to estimate when ecological drivers of respiratory syncytial virus (RSV) transmissibility would need to act in order to produce the observed seasonality of RSV in the Philippines. We estimated that a seasonal peak in transmissibility would need to occur approximately 51 days prior to the observed peak in RSV cases (range 49 to 67 days). We then compared this estimated seasonal pattern of transmissibility to the seasonal patterns of possible ecological drivers of transmissibility: rainfall, humidity and temperature patterns, nutritional status, and school holidays. The timing of the seasonal patterns of nutritional status and rainfall were both consistent with the estimated seasonal pattern of transmissibility and these are both plausible drivers of the seasonality of RSV in this setting. PMID:24587222

Seasonal and pandemic human influenza viruses attach better to human upper respiratory tract epithelium than avian influenza viruses.

PubMed

van Riel, Debby; den Bakker, Michael A; Leijten, Lonneke M E; Chutinimitkul, Salin; Munster, Vincent J; de Wit, Emmie; Rimmelzwaan, Guus F; Fouchier, Ron A M; Osterhaus, Albert D M E; Kuiken, Thijs

2010-04-01

Influenza viruses vary markedly in their efficiency of human-to-human transmission. This variation has been speculated to be determined in part by the tropism of influenza virus for the human upper respiratory tract. To study this tropism, we determined the pattern of virus attachment by virus histochemistry of three human and three avian influenza viruses in human nasal septum, conchae, nasopharynx, paranasal sinuses, and larynx. We found that the human influenza viruses-two seasonal influenza viruses and pandemic H1N1 virus-attached abundantly to ciliated epithelial cells and goblet cells throughout the upper respiratory tract. In contrast, the avian influenza viruses, including the highly pathogenic H5N1 virus, attached only rarely to epithelial cells or goblet cells. Both human and avian viruses attached occasionally to cells of the submucosal glands. The pattern of virus attachment was similar among the different sites of the human upper respiratory tract for each virus tested. We conclude that influenza viruses that are transmitted efficiently among humans attach abundantly to human upper respiratory tract, whereas inefficiently transmitted influenza viruses attach rarely. These results suggest that the ability of an influenza virus to attach to human upper respiratory tract is a critical factor for efficient transmission in the human population.

78 FR 9311 - Hazard Communication; Corrections and Technical Amendment

Federal Register 2010, 2011, 2012, 2013, 2014

2013-02-08

... Column for Standard No. 1910.1051. ``Cancer; eye and respiratory tract irritation; center nervous system... irritation; central nervous system effects; and flammability.'' The following table contains a summary of the... (l)(1)(ii) ``center nervous system effects'' is paragraph. corrected to ``central nervous system...

Caffeine in the milk prevents respiratory disorders caused by in utero caffeine exposure in rats.

PubMed

Bodineau, Laurence; Saadani-Makki, Fadoua; Jullien, Hugues; Frugière, Alain

2006-01-25

Consequences of postnatal caffeine exposure by the milk on ponto-medullary respiratory disturbances observed following an in utero caffeine exposure were analysed. Ponto-medullary-spinal cord preparations from newborn rats exposed to caffeine during gestation but not after the birth display an increase in respiratory frequency and an exaggeration of the hypoxic respiratory depression compared to not treated preparations. These data suggest that tachypneic and apneic episodes encountered in human newborns whose mother consumed caffeine during pregnancy are due in large part to central effect of caffeine at the ponto-medullary level. Both baseline respiratory frequency increase and emphasis of hypoxic respiratory depression are not encountered if rat dams consumed caffeine during nursing. Our hypothesis is that newborn rats exposed to caffeine during gestation but not after the birth would be in withdrawal situation whereas, when caffeine is present in drinking fluid of lactating dams, it goes down the milk and is able to prevent ponto-medullary respiratory disturbances.

Cheyne-Stokes respiration in patients with congestive heart failure: causes and consequences.

PubMed

Lorenzi-Filho, Geraldo; Genta, Pedro R; Figueiredo, Adelaide C; Inoue, Daniel

2005-08-01

Cheyne-Stokes respiration is a form of periodic breathing in which central apneas and hypopneas alternate with periods of hyperventilation, producing a waxing and waning pattern of tidal volume. This review focuses on the causes and consequences of Cheyne-Stokes respiration in patients with congestive heart failure, in whom the prevalence is strikingly high and ranges from 30% to 50%. Several factors have been implicated in the genesis of Cheyne-Stokes respiration, including low cardiac output and recurrent hypoxia. The key pathophysiological mechanism triggering Cheyne-Stokes respiration is hyperventilation and low arterial CO2 (PaCO2) that when below the apneic threshold triggers a central apnea. Hyperventilation is associated with pulmonary congestion, and Cheyne-Stokes respiration is more prone to occur during sleep, when the respiratory system is mainly dependent on chemical control. It is associated with recurrent dips in oxygen saturation and arousals from sleep, with oscillations in blood pressure and heart rate, sympathetic activation and increased risk of ventricular tachycardia. Cheyne-Stokes respiration is an independent marker of poor prognosis and may participate in a vicious cycle, further stressing the failing heart.

Report of Two Fatal Cases of Mycobacterium mucogenicum Central Nervous System Infection in Immunocompetent Patients

PubMed Central

Adékambi, Toïdi; Foucault, Cedric; La Scola, Bernard; Drancourt, Michel

2006-01-01

Neurological infections due to rapidly growing mycobacteria (RGM) have rarely been reported. We recently investigated two unrelated immunocompetent patients, one with community-acquired lymphocytic meningitis and the other with cerebral thrombophlebitis. Mycobacterium mucogenicum was isolated in pure culture and detected by PCR sequencing of cerebrospinal fluid samples. Both patients eventually died. The two isolates exhibited an overlapping antimicrobial susceptibility pattern. They were susceptible in vitro to tetracyclines, macrolides, quinolones, amikacin, imipenem, cefoxitin, and trimethoprim-sulfamethoxazole and resistant to ceftriaxone. They shared 100% 16S rRNA gene sequence similarity with M. mucogenicum ATCC 49650T over 1,482 bp. Their partial rpoB sequences shared 97.8% and 98.1% similarity with M. mucogenicum ATCC 49650T, suggesting that the two isolates were representative of two sequevars of M. mucogenicum species. This case report should make clinicians aware that M. mucogenicum, an RGM frequently isolated from tap water or from respiratory specimens and mostly without clinical significance, can even be encountered in the central nervous system of immunocompetent patients. PMID:16517863

Early pathology in sleep studies of patients with familial Creutzfeldt-Jakob disease.

PubMed

Givaty, Gili; Maggio, Nicola; Cohen, Oren S; Blatt, Ilan; Chapman, Joab

2016-10-01

In this study, we aimed to assess sleep function in patients with recent-onset familial Creutzfeldt-Jakob disease (fCJD). The largest cluster of fCJD patients is found in Jews of Libyan origin, linked to the prion protein gene (PRNP) E200K mutation. The high index of suspicion in these patients often leads to early diagnosis, with complaints of insomnia being a very common presenting symptom of the disease. The study included 10 fCJD patients diagnosed by clinical manifestations, magnetic resonance imaging (MRI) scan of the brain, elevated tau protein in the cerebrospinal fluid (CSF) and positive PRNP E200K mutation. Standard polysomnography was performed after a brief interview confirming the presence of sleep disturbances. All patients showed a pathological sleep pattern according to all scoring evaluation settings. The sleep stages were characterized by (i) disappearance of sleep spindles; (ii) outbursts of periodic sharp waves and shallowing of sleep consisting in increased Stage 2 and wake periods during the night, as well as decrease of slow-wave sleep and rapid eye movement (REM) sleep. Recordings of respiratory functions reported irregular breathing with central and obstructive apnea and hypopnea. The typical hypotonia occurring during the night and atonia during REM sleep were replaced by hyperactive sleep consisting of multiple jerks, movements and parasomnia (mainly talking) throughout the night. In conclusion, we report unique pathological sleep patterns in early fCJD associated with the E200K mutation. Specific respiratory disturbances and lack of atonia could possibly serve as new, early diagnostic tools in the disease. © 2016 European Sleep Research Society.

Cough aerosol in healthy participants: fundamental knowledge to optimize droplet-spread infectious respiratory disease management.

PubMed

Zayas, Gustavo; Chiang, Ming C; Wong, Eric; MacDonald, Fred; Lange, Carlos F; Senthilselvan, Ambikaipakan; King, Malcolm

2012-03-21

The Influenza A H1N1 virus can be transmitted via direct, indirect, and airborne route to non-infected subjects when an infected patient coughs, which expels a number of different sized droplets to the surrounding environment as an aerosol. The objective of the current study was to characterize the human cough aerosol pattern with the aim of developing a standard human cough bioaerosol model for Influenza Pandemic control. 45 healthy non-smokers participated in the open bench study by giving their best effort cough. A laser diffraction system was used to obtain accurate, time-dependent, quantitative measurements of the size and number of droplets expelled by the cough aerosol. Voluntary coughs generated droplets ranging from 0.1 - 900 microns in size. Droplets of less than one-micron size represent 97% of the total number of measured droplets contained in the cough aerosol. Age, sex, weight, height and corporal mass have no statistically significant effect on the aerosol composition in terms of size and number of droplets. We have developed a standard human cough aerosol model. We have quantitatively characterized the pattern, size, and number of droplets present in the most important mode of person-to-person transmission of IRD: the cough bioaerosol. Small size droplets (< 1 μm) predominated the total number of droplets expelled when coughing. The cough aerosol is the single source of direct, indirect and/or airborne transmission of respiratory infections like the Influenza A H1N1 virus. Open bench, Observational, Cough, Aerosol study. © 2012 Zayas et al; licensee BioMed Central Ltd.

The 1918–1920 influenza pandemic in Peru

PubMed Central

Chowell, G.; Viboud, C.; Simonsen, L.; Miller, M.A.; Hurtado, J.; Soto, G.; Vargas, R.; Guzman, M.A.; Ulloa, M.; Munayco, C.V.

2011-01-01

Background Increasing our knowledge of past influenza pandemic patterns in different regions of the world is crucial to guide preparedness plans against future influenza pandemics. Here, we undertook extensive archival collection efforts from 3 representative cities of Peru (Lima in the central coast, Iquitos in the northeastern Amazon region, Ica in the southern coast) to characterize the age and geographic patterns of the 1918–1920 influenza pandemic in this country. Materials and Methods We analyzed historical documents describing the 1918–1920 influenza pandemic in Peru and retrieved individual mortality records from local provincial archives for quantitative analysis. We applied seasonal excess mortality models to daily and monthly respiratory mortality rates for 1917–1920 and quantified transmissibility estimates based on the daily growth rate in respiratory deaths. Results A total of 52,739 individual mortality records were inspected from local provincial archives. We found evidence for an initial mild pandemic wave during July-September 1918 in Lima, identified a synchronized severe pandemic wave of respiratory mortality in all three locations in Peru during November 1918-February 1919, and a severe pandemic wave during January 1920- March 1920 in Lima and July-October 1920 in Ica. There was no recrudescent pandemic wave in 1920 in Iquitos. Remarkably, Lima experienced the brunt of the 1918–20 excess mortality impact during the 1920 recrudescent wave, with all age groups experiencing an increase in all cause excess mortality from 1918–19 to 1920. Middle age groups experienced the highest excess mortality impact, relative to baseline levels, in the 1918–19 and 1920 pandemic waves. Cumulative excess mortality rates for the 1918–20 pandemic period were higher in Iquitos (2.9%) than Lima (1.6%). The mean reproduction number for Lima was estimated in the range 1.3–1.5. Conclusions We identified synchronized pandemic waves of intense excess respiratory mortality during November 1918-February 1919 in Lima, Iquitos, Ica, followed by asynchronous recrudescent waves in 1920. Cumulative data from quantitative studies of the 1918 influenza pandemic in Latin American settings have confirmed the high mortality impact associated with this pandemic. Further historical studies in lesser-studied regions of Latin America, Africa, and Asia are warranted for a full understanding of the global impact of the 1918 pandemic virus. PMID:21757099

Perturbations of Respiratory Rhythm and Pattern by Disrupting Synaptic Inhibition within Pre-Bötzinger and Bötzinger Complexes123

PubMed Central

Koizumi, Hidehiko; Mosher, Bryan; Tariq, Mohammad F.; Zhang, Ruli; Molkov, Yaroslav I.

2016-01-01

The pre-Bötzinger (pre-BötC) and Bötzinger (BötC) complexes are the brainstem compartments containing interneurons considered to be critically involved in generating respiratory rhythm and motor pattern in mammals. Current models postulate that both generation of the rhythm and coordination of the inspiratory-expiratory pattern involve inhibitory synaptic interactions within and between these regions. Both regions contain glycinergic and GABAergic neurons, and rhythmically active neurons in these regions receive appropriately coordinated phasic inhibition necessary for generation of the normal three-phase respiratory pattern. However, recent experiments attempting to disrupt glycinergic and GABAergic postsynaptic inhibition in the pre-BötC and BötC in adult rats in vivo have questioned the critical role of synaptic inhibition in these regions, as well as the importance of the BötC, which contradicts previous physiological and pharmacological studies. To further evaluate the roles of synaptic inhibition and the BötC, we bilaterally microinjected the GABAA receptor antagonist gabazine and glycinergic receptor antagonist strychnine into the pre-BötC or BötC in anesthetized adult rats in vivo and in perfused in situ brainstem–spinal cord preparations from juvenile rats. Muscimol was microinjected to suppress neuronal activity in the pre-BötC or BötC. In both preparations, disrupting inhibition within pre-BötC or BötC caused major site-specific perturbations of the rhythm and disrupted the three-phase motor pattern, in some experiments terminating rhythmic motor output. Suppressing BötC activity also potently disturbed the rhythm and motor pattern. We conclude that inhibitory circuit interactions within and between the pre-BötC and BötC critically regulate rhythmogenesis and are required for normal respiratory motor pattern generation. PMID:27200412

Respiratory and sleep disorders in female children with atypical Rett syndrome caused by mutations in the CDKL5 gene.

PubMed

Hagebeuk, Eveline E O; van den Bossche, Renilde A S; de Weerd, Al W

2013-05-01

In female children with drug-resistant seizures and developmental delay from birth, atypical Rett syndrome caused by mutations in the CDKL5 gene should be considered. Several clinical features resemble classic Rett syndrome. Respiratory and sleep abnormalities are frequently present in Rett syndrome, whereas little is known in patients with CDKL5 mutations. In four genetically confirmed female patients with CDKL5 mutations (age range 2-15 y), the presence of breathing and sleep abnormalities was evaluated using the validated Sleep Disturbance Scale for Children and polysomnography (PSG). The Sleep Disturbance Scale for Children indicated disorders of initiating and maintaining sleep, daytime somnolence, and sleep breathing disorders. In one patient, PSG showed central apnoeas during sleep: her total apnoea-hypopnoea index (AHI) was 4.9, of which the central AHI was 3.4/h. When awake, central apnoeas were present in two of the four female children (central AHI 28/h and 41/h respectively), all preceded by hyperventilation. PSG showed low rapid eye movement (REM) sleep (9.7-18.3%), frequent awakenings, and low sleep efficiency (range 59-78%). Episodic hyperventilation followed by central apnoeas was present while awake in two of four patients. This may indicate failure of brainstem respiratory centres. In addition, low REM sleep, frequent arousals (not caused by apnoeas/seizures), and low sleep efficiency were present. Similar to Rett syndrome, in patients with CDKL5 mutations PSG seems warranted to evaluate breathing and sleep disturbances. © The Authors. Developmental Medicine & Child Neurology © 2012 Mac Keith Press.

Patient training in respiratory-gated radiotherapy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kini, Vijay R.; Vedam, Subrahmanya S.; Keall, Paul J.

2003-03-31

Respiratory gating is used to counter the effects of organ motion during radiotherapy for chest tumors. The effects of variations in patient breathing patterns during a single treatment and from day to day are unknown. We evaluated the feasibility of using patient training tools and their effect on the breathing cycle regularity and reproducibility during respiratory-gated radiotherapy. To monitor respiratory patterns, we used a component of a commercially available respiratory-gated radiotherapy system (Real Time Position Management (RPM) System, Varian Oncology Systems, Palo Alto, CA 94304). This passive marker video tracking system consists of reflective markers placed on the patient's chestmore » or abdomen, which are detected by a wall-mounted video camera. Software installed on a PC interfaced to this camera detects the marker motion digitally and records it. The marker position as a function of time serves as the motion signal that may be used to trigger imaging or treatment. The training tools used were audio prompting and visual feedback, with free breathing as a control. The audio prompting method used instructions to 'breathe in' or 'breathe out' at periodic intervals deduced from patients' own breathing patterns. In the visual feedback method, patients were shown a real-time trace of their abdominal wall motion due to breathing. Using this, they were asked to maintain a constant amplitude of motion. Motion traces of the abdominal wall were recorded for each patient for various maneuvers. Free breathing showed a variable amplitude and frequency. Audio prompting resulted in a reproducible frequency; however, the variability and the magnitude of amplitude increased. Visual feedback gave a better control over the amplitude but showed minor variations in frequency. We concluded that training improves the reproducibility of amplitude and frequency of patient breathing cycles. This may increase the accuracy of respiratory-gated radiation therapy.« less

Deposition efficiency of inhaled particles (15-5000 nm) related to breathing pattern and lung function: an experimental study in healthy children and adults.

PubMed

Rissler, Jenny; Gudmundsson, Anders; Nicklasson, Hanna; Swietlicki, Erik; Wollmer, Per; Löndahl, Jakob

2017-04-08

Exposure to airborne particles has a major impact on global health. The probability of these particles to deposit in the respiratory tract during breathing is essential for their toxic effects. Observations have shown that there is a substantial variability in deposition between subjects, not only due to respiratory diseases, but also among individuals with healthy lungs. The factors determining this variability are, however, not fully understood. In this study we experimentally investigate factors that determine individual differences in the respiratory tract depositions of inhaled particles for healthy subjects at relaxed breathing. The study covers particles of diameters 15-5000 nm and includes 67 subjects aged 7-70 years. A comprehensive examination of lung function was performed for all subjects. Principal component analyses and multiple regression analyses were used to explore the relationships between subject characteristics and particle deposition. A large individual variability in respiratory tract deposition efficiency was found. Individuals with high deposition of a certain particle size generally had high deposition for all particles <3500 nm. The individual variability was explained by two factors: breathing pattern, and lung structural and functional properties. The most important predictors were found to be breathing frequency and anatomical airway dead space. We also present a linear regression model describing the deposition based on four variables: tidal volume, breathing frequency, anatomical dead space and resistance of the respiratory system (the latter measured with impulse oscillometry). To understand why some individuals are more susceptible to airborne particles we must understand, and take into account, the individual variability in the probability of particles to deposit in the respiratory tract by considering not only breathing patterns but also adequate measures of relevant structural and functional properties.

Evaluation of interventions to reduce air pollution from biomass smoke on mortality in Launceston, Australia: retrospective analysis of daily mortality, 1994-2007.

PubMed

Johnston, Fay H; Hanigan, Ivan C; Henderson, Sarah B; Morgan, Geoffrey G

2013-01-08

To assess the effect of reductions in air pollution from biomass smoke on daily mortality. Age stratified time series analysis of daily mortality with Poisson regression models adjusted for the effects of temperature, humidity, day of week, respiratory epidemics, and secular mortality trends, applied to an intervention and control community. Central Launceston, Australia, a town in which coordinated strategies were implemented to reduce pollution from wood smoke and central Hobart, a comparable city in which there were no specific air quality interventions. 67,000 residents of central Launceston and 148,000 residents of central Hobart (at 2001 census). Community education campaigns, enforcement of environmental regulations, and a wood heater replacement programme to reduce ambient pollution from residential wood stoves started in the winter of 2001. Changes in daily all cause, cardiovascular, and respiratory mortality during the 6.5 year periods before and after June 2001 in Launceston and Hobart. Mean daily wintertime concentration of PM(10) (particulate matter with particle size <10 µm diameter) fell from 44 µg/m(3) during 1994-2000 to 27 µg/m(3) during 2001-07 in Launceston. The period of improved air quality was associated with small non-significant reductions in annual mortality. In males the observed reductions in annual mortality were larger and significant for all cause (-11.4%, 95% confidence interval -19.2% to -2.9%; P=0.01), cardiovascular (-17.9%, -30.6% to -2.8%; P=0.02), and respiratory (-22.8%, -40.6% to 0.3%; P=0.05) mortality. In wintertime reductions in cardiovascular (-19.6%, -36.3% to 1.5%; P=0.06) and respiratory (-27.9%, -49.5% to 3.1%; P=0.07) mortality were of borderline significance (males and females combined). There were no significant changes in mortality in the control city of Hobart. Decreased air pollution from ambient biomass smoke was associated with reduced annual mortality in males and with reduced cardiovascular and respiratory mortality during winter months.

Generation of fluoroscopic 3D images with a respiratory motion model based on an external surrogate signal

NASA Astrophysics Data System (ADS)

Hurwitz, Martina; Williams, Christopher L.; Mishra, Pankaj; Rottmann, Joerg; Dhou, Salam; Wagar, Matthew; Mannarino, Edward G.; Mak, Raymond H.; Lewis, John H.

2015-01-01

Respiratory motion during radiotherapy can cause uncertainties in definition of the target volume and in estimation of the dose delivered to the target and healthy tissue. In this paper, we generate volumetric images of the internal patient anatomy during treatment using only the motion of a surrogate signal. Pre-treatment four-dimensional CT imaging is used to create a patient-specific model correlating internal respiratory motion with the trajectory of an external surrogate placed on the chest. The performance of this model is assessed with digital and physical phantoms reproducing measured irregular patient breathing patterns. Ten patient breathing patterns are incorporated in a digital phantom. For each patient breathing pattern, the model is used to generate images over the course of thirty seconds. The tumor position predicted by the model is compared to ground truth information from the digital phantom. Over the ten patient breathing patterns, the average absolute error in the tumor centroid position predicted by the motion model is 1.4 mm. The corresponding error for one patient breathing pattern implemented in an anthropomorphic physical phantom was 0.6 mm. The global voxel intensity error was used to compare the full image to the ground truth and demonstrates good agreement between predicted and true images. The model also generates accurate predictions for breathing patterns with irregular phases or amplitudes.

Rules for Scoring Respiratory Events in Sleep: Update of the 2007 AASM Manual for the Scoring of Sleep and Associated Events

PubMed Central

Berry, Richard B.; Budhiraja, Rohit; Gottlieb, Daniel J.; Gozal, David; Iber, Conrad; Kapur, Vishesh K.; Marcus, Carole L.; Mehra, Reena; Parthasarathy, Sairam; Quan, Stuart F.; Redline, Susan; Strohl, Kingman P.; Ward, Sally L. Davidson; Tangredi, Michelle M.

2012-01-01

The American Academy of Sleep Medicine (AASM) Sleep Apnea Definitions Task Force reviewed the current rules for scoring respiratory events in the 2007 AASM Manual for the Scoring and Sleep and Associated Events to determine if revision was indicated. The goals of the task force were (1) to clarify and simplify the current scoring rules, (2) to review evidence for new monitoring technologies relevant to the scoring rules, and (3) to strive for greater concordance between adult and pediatric rules. The task force reviewed the evidence cited by the AASM systematic review of the reliability and validity of scoring respiratory events published in 2007 and relevant studies that have appeared in the literature since that publication. Given the limitations of the published evidence, a consensus process was used to formulate the majority of the task force recommendations concerning revisions. The task force made recommendations concerning recommended and alternative sensors for the detection of apnea and hypopnea to be used during diagnostic and positive airway pressure (PAP) titration polysomnography. An alternative sensor is used if the recommended sensor fails or the signal is inaccurate. The PAP device flow signal is the recommended sensor for the detection of apnea, hypopnea, and respiratory effort related arousals (RERAs) during PAP titration studies. Appropriate filter settings for recording (display) of the nasal pressure signal to facilitate visualization of inspiratory flattening are also specified. The respiratory inductance plethysmography (RIP) signals to be used as alternative sensors for apnea and hypopnea detection are specified. The task force reached consensus on use of the same sensors for adult and pediatric patients except for the following: (1) the end-tidal PCO2 signal can be used as an alternative sensor for apnea detection in children only, and (2) polyvinylidene fluoride (PVDF) belts can be used to monitor respiratory effort (thoracoabdominal belts) and as an alternative sensor for detection of apnea and hypopnea (PVDFsum) only in adults. The task force recommends the following changes to the 2007 respiratory scoring rules. Apnea in adults is scored when there is a drop in the peak signal excursion by ≥ 90% of pre-event baseline using an oronasal thermal sensor (diagnostic study), PAP device flow (titration study), or an alternative apnea sensor, for ≥ 10 seconds. Hypopnea in adults is scored when the peak signal excursions drop by ≥ 30% of pre-event baseline using nasal pressure (diagnostic study), PAP device flow (titration study), or an alternative sensor, for ≥ 10 seconds in association with either ≥ 3% arterial oxygen desaturation or an arousal. Scoring a hypopnea as either obstructive or central is now listed as optional, and the recommended scoring rules are presented. In children an apnea is scored when peak signal excursions drop by ≥ 90% of pre-event baseline using an oronasal thermal sensor (diagnostic study), PAP device flow (titration study), or an alternative sensor; and the event meets duration and respiratory effort criteria for an obstructive, mixed, or central apnea. A central apnea is scored in children when the event meets criteria for an apnea, there is an absence of inspiratory effort throughout the event, and at least one of the following is met: (1) the event is ≥ 20 seconds in duration, (2) the event is associated with an arousal or ≥ 3% oxygen desaturation, (3) (infants under 1 year of age only) the event is associated with a decrease in heart rate to less than 50 beats per minute for at least 5 seconds or less than 60 beats per minute for 15 seconds. A hypopnea is scored in children when the peak signal excursions drop is ≥ 30% of pre-event baseline using nasal pressure (diagnostic study), PAP device flow (titration study), or an alternative sensor, for ≥ the duration of 2 breaths in association with either ≥ 3% oxygen desaturation or an arousal. In children and adults, surrogates of the arterial PCO2 are the end-tidal PCO2 or transcutaneous PCO2 (diagnostic study) or transcutaneous PCO2 (titration study). For adults, sleep hypoventilation is scored when the arterial PCO2 (or surrogate) is > 55 mm Hg for ≥ 10 minutes or there is an increase in the arterial PCO2 (or surrogate) ≥ 10 mm Hg (in comparison to an awake supine value) to a value exceeding 50 mm Hg for ≥ 10 minutes. For pediatric patients hypoventilation is scored when the arterial PCO2 (or surrogate) is > 50 mm Hg for > 25% of total sleep time. In adults Cheyne-Stokes breathing is scored when both of the following are met: (1) there are episodes of ≥ 3 consecutive central apneas and/or central hypopneas separated by a crescendo and decrescendo change in breathing amplitude with a cycle length of at least 40 seconds (typically 45 to 90 seconds), and (2) there are five or more central apneas and/or central hypopneas per hour associated with the crescendo/decrescendo breathing pattern recorded over a minimum of 2 hours of monitoring. Commentary: A commentary on this article appears in this issue on page 621. Citation: Berry RB; Budhiraja R; Gottlieb DJ; Gozal D; Iber C; Kapur VK; Marcus CL; Mehra R; Parthasarathy S; Quan SF; Redline S; Strohl KP; Ward SLD; Tangredi MM. Rules for scoring respiratory events in sleep: update of the 2007 AASM Manual for the Scoring of Sleep and Associated Events. J Clin Sleep Med 2012;8(5):597-619. PMID:23066376

Substance P and central respiratory activity: a comparative in vitro study in NK1 receptor knockout and wild-type mice.

PubMed

Ptak, K; Hunt, S P; Monteau, R

2000-07-01

Neurokinin-1 receptors (NK1) are present within the respiratory medullary network and in the phrenic nucleus, which controls the diaphragm. We compared the efficacy of substance P (SP) at inducing changes in respiratory frequency or the amplitude of the respiratory motor output between NK1 knockout (NK1-/-) and wild-type mice, using the in vitro brainstem-spinal cord preparation. The in vitro respiratory frequency, as well as the variability of the rhythm and the amplitude of the motor output were similar in both lines. In wild-type mice, application of exogenous SP induced either an increase in respiratory frequency (superfusion of the medulla) or an increase of the inspiratory motor output, as defined by the integral of C4 cervical ventral root activity (superfusion of the spinal cord). These two effects were not apparent in NK1-/- mice. In conclusion, NK1 receptors mediate the respiratory responses to SP but the lack of NK1 receptors in newborn NK1-/- mice does not change the respiratory activity.

Comparison of Contact Patterns Relevant for Transmission of Respiratory Pathogens in Thailand and the Netherlands Using Respondent-Driven Sampling

PubMed Central

Stein, Mart L.; van Steenbergen, Jim E.; Buskens, Vincent; van der Heijden, Peter G. M.; Chanyasanha, Charnchudhi; Tipayamongkholgul, Mathuros; Thorson, Anna E.; Bengtsson, Linus; Lu, Xin; Kretzschmar, Mirjam E. E.

2014-01-01

Understanding infection dynamics of respiratory diseases requires the identification and quantification of behavioural, social and environmental factors that permit the transmission of these infections between humans. Little empirical information is available about contact patterns within real-world social networks, let alone on differences in these contact networks between populations that differ considerably on a socio-cultural level. Here we compared contact network data that were collected in the Netherlands and Thailand using a similar online respondent-driven method. By asking participants to recruit contact persons we studied network links relevant for the transmission of respiratory infections. We studied correlations between recruiter and recruited contacts to investigate mixing patterns in the observed social network components. In both countries, mixing patterns were assortative by demographic variables and random by total numbers of contacts. However, in Thailand participants reported overall more contacts which resulted in higher effective contact rates. Our findings provide new insights on numbers of contacts and mixing patterns in two different populations. These data could be used to improve parameterisation of mathematical models used to design control strategies. Although the spread of infections through populations depends on more factors, found similarities suggest that spread may be similar in the Netherlands and Thailand. PMID:25423343

Quantitative Evaluation of PET Respiratory Motion Correction Using MR Derived Simulated Data

NASA Astrophysics Data System (ADS)

Polycarpou, Irene; Tsoumpas, Charalampos; King, Andrew P.; Marsden, Paul K.

2015-12-01

The impact of respiratory motion correction on quantitative accuracy in PET imaging is evaluated using simulations for variable patient specific characteristics such as tumor uptake and respiratory pattern. Respiratory patterns from real patients were acquired, with long quiescent motion periods (type-1) as commonly observed in most patients and with long-term amplitude variability as is expected under conditions of difficult breathing (type-2). The respiratory patterns were combined with an MR-derived motion model to simulate real-time 4-D PET-MR datasets. Lung and liver tumors were simulated with diameters of 10 and 12 mm and tumor-to-background ratio ranging from 3:1 to 6:1. Projection data for 6- and 3-mm PET resolution were generated for the Philips Gemini scanner and reconstructed without and with motion correction using OSEM (2 iterations, 23 subsets). Motion correction was incorporated into the reconstruction process based on MR-derived motion fields. Tumor peak standardized uptake values (SUVpeak) were calculated from 30 noise realizations. Respiratory motion correction improves the quantitative performance with the greatest benefit observed for patients of breathing type-2. For breathing type-1 after applying motion correction, SUVpeak of 12-mm liver tumor with 6:1 contrast was increased by 46% for a current PET resolution (i.e., 6 mm) and by 47% for a higher PET resolution (i.e., 3 mm). Furthermore, the results of this study indicate that the benefit of higher scanner resolution is small unless motion correction is applied. In particular, for large liver tumor (12 mm) with low contrast (3:1) after motion correction, the SUVpeak was increased by 34% for 6-mm resolution and by 50% for a higher PET resolution (i.e., 3-mm resolution. This investigation indicates that there is a high impact of respiratory motion correction on tumor quantitative accuracy and that motion correction is important in order to benefit from the increased resolution of future PET scanners.

FLOW SIMULATION IN THE HUMAN UPPER RESPIRATORY TRACT

EPA Science Inventory

ABSTRACT

Computer simulations of airflow patterns within the human upper respiratory tract (URT) are presented. The URT model includes airways of the head (nasal and oral), throat (pharyngeal and laryngeal), and lungs (trachea and main bronchi). The head and throat mor...

Changes in breathing pattern in the normal horse at rest up to age one year.

PubMed

Koterba, A M; Wozniak, J A; Kosch, P C

1995-07-01

Changes in pattern of airflow, sequence of respiratory muscle activation and generated pressures were measured serially in a group of foals during the first year post partum, in order to describe the maturation of the equine breathing pattern. In neonatal foals, inspiration and expiration were both primarily active and airflow pattern was essentially monophasic. By age 1 year, foals displayed essentially the same breathing pattern previously described in adult horses, utilising a combination of active and passive inspiration and expiration to breathe around, rather than from, the relaxation volume of the respiratory system (Vrx). A strong temporal relationship during growth was found between the timing of changes observed in airflow pattern and in the neuromuscular strategy of breathing. The transition to the adult breathing pattern appeared to involve a time delay in activation of both inspiratory and expiratory muscle groups, establishing a passive and active component to both inspiration and expiration. Throughout the study period, concurrent with the increase in delay of abdominal muscle activation, the expiratory flow pattern became progressively more biphasic in appearance. The time of appearance of a consistent biphasic inspiratory flow pattern was considerably later, at approximately age 1 year and coincided with the appearance of a delay in inspiratory muscle activation. From our results, we conclude that the transition from the neonatal to the adult breathing strategy in the horse appears not to be induced by the time course of chest wall stiffening during maturation. While changes in relative body proportions and size of abdominal contents during growth may influence the transition in breathing, our results also indicate that respiratory control mechanisms play an essential role in the expression of the polyphasic breathing pattern.

Oscillation patterns are enhanced and firing threshold is lowered in medullary respiratory neuron discharges by threshold doses of a μ-opioid receptor agonist

PubMed Central

Mifflin, Steve W.

2017-01-01

μ-Opioid receptors are distributed widely in the brain stem respiratory network, and opioids with selectivity for μ-type receptors slow in vivo respiratory rhythm in lowest effective doses. Several studies have reported μ-opioid receptor effects on the three-phase rhythm of respiratory neurons, but there are until now no reports of opioid effects on oscillatory activity within respiratory discharges. In this study, effects of the μ-opioid receptor agonist fentanyl on spike train discharge properties of several different types of rhythm-modulating medullary respiratory neuron discharges were analyzed. Doses of fentanyl that were just sufficient for prolongation of discharges and slowing of the three-phase respiratory rhythm also produced pronounced enhancement of spike train properties. Oscillation and burst patterns detected by autocorrelation measurements were greatly enhanced, and interspike intervals were prolonged. Spike train properties under control conditions and after fentanyl were uniform within each experiment, but varied considerably between experiments, which might be related to variability in acid-base balance in the brain stem extracellular fluid. Discharge threshold was shifted to more negative levels of membrane potential. The effects on threshold are postulated to result from opioid-mediated disinhibition and postsynaptic enhancement of N-methyl-d- aspartate receptor current. Lowering of firing threshold, enhancement of spike train oscillations and bursts and prolongation of discharges by lowest effective doses of fentanyl could represent compensatory adjustments in the brain stem respiratory network to override opioid blunting of CO2/pH chemosensitivity. PMID:28202437

Sleep-Disordered Breathing in Children with Rare Skeletal Disorders: A Survey of Clinical Records.

PubMed

Zaffanello, Marco; Piacentini, Giorgio; Sacchetto, Luca; Pietrobelli, Angelo; Gasperi, Emma; Barillari, Marco; Cardobi, Nicolò; Nosetti, Luana; Ramaroli, Diego; Antoniazzi, Franco

2018-06-21

Craniofacial disharmony in skeletal diseases is strongly associated with sleep-disordered breathing. Our aim was to study sleep respiratory patterns in young children with rare skeletal disorders. This retrospective study included children with achondroplasia, osteogenesis imperfecta and Ellis van Creveld Syndrome. Our subjects underwent an in-laboratory overnight respiratory polygraph between January 2012 and April 2016. All medical records were reviewed and brain Magnetic Resonance Imaging was conducted on patients with achondroplasia, nasopharynx, oropharynx and laryngopharynx spaces. 24 children were enrolled, 13 with Achondroplasia, 2 with spondyloepiphyseal dysplasia, 1 with odontochondrodysplasia, 6 with osteogenesis imperfecta and 2 with Ellis van Creveld Syndrome. Children with achondroplasia, who had adenotonsillectomy, showed fewer sleep respiratory involvement than untreated children. Among 13 patients with Achondroplasia, brain magnetic resonance imaging was available in 10 subjects and significant negative correlation was found between sleep respiratory patterns, nasopharynx and oropharynx space (p < 0.05). In 2 patients with spondyloepiphyseal dysplasia, mild to moderate sleep respiratory involvement was found. Both subjects had history of adenotonsillectomy. Mild sleep respiratory involvement was also shown in 4 out of 6 patients with osteogenesis imperfecta. One patient with Ellis van Creveld syndrome had mild sleep respiratory disturbance. Sleep respiratory disturbances were detected in children with achondroplasia, and with less severity also in osteogenesis imperfecta and Ellis van Creveld syndrome. Adenotonsillectomy was successful in achondroplasia in reducing symptoms. In light of our findings, multicenter studies are needed to obtain further information on these rare skeletal diseases. ©2018The Author(s). Published by S. Karger AG, Basel.

Oscillation patterns are enhanced and firing threshold is lowered in medullary respiratory neuron discharges by threshold doses of a μ-opioid receptor agonist.

PubMed

Lalley, Peter M; Mifflin, Steve W

2017-05-01

μ-Opioid receptors are distributed widely in the brain stem respiratory network, and opioids with selectivity for μ-type receptors slow in vivo respiratory rhythm in lowest effective doses. Several studies have reported μ-opioid receptor effects on the three-phase rhythm of respiratory neurons, but there are until now no reports of opioid effects on oscillatory activity within respiratory discharges. In this study, effects of the μ-opioid receptor agonist fentanyl on spike train discharge properties of several different types of rhythm-modulating medullary respiratory neuron discharges were analyzed. Doses of fentanyl that were just sufficient for prolongation of discharges and slowing of the three-phase respiratory rhythm also produced pronounced enhancement of spike train properties. Oscillation and burst patterns detected by autocorrelation measurements were greatly enhanced, and interspike intervals were prolonged. Spike train properties under control conditions and after fentanyl were uniform within each experiment, but varied considerably between experiments, which might be related to variability in acid-base balance in the brain stem extracellular fluid. Discharge threshold was shifted to more negative levels of membrane potential. The effects on threshold are postulated to result from opioid-mediated disinhibition and postsynaptic enhancement of N -methyl-d- aspartate receptor current. Lowering of firing threshold, enhancement of spike train oscillations and bursts and prolongation of discharges by lowest effective doses of fentanyl could represent compensatory adjustments in the brain stem respiratory network to override opioid blunting of CO 2 /pH chemosensitivity. Copyright © 2017 the American Physiological Society.

Optimal ventilatory patterns in periodic breathing.

PubMed

Ghazanshahi, S D; Khoo, M C

1993-01-01

The goal of this study was to determine whether periodic breathing (PB), which is highly prevalent during sleep at high altitudes, imposes physiological penalties on the respiratory system in the absence of any accompanying disease. Using a computer model of respiratory gas exchange, we compared the effects of a variety of PB patterns on the chemical and mechanical costs of breathing to those resulting from regular tidal breathing. Although PB produced considerable fluctuation in arterial blood gas tensions, for the same cycle-averaged ventilation, higher arterial oxygen saturation and lower arterial carbon dioxide levels were achieved. This result can be explained by the fact that the combination of large breaths and apnea in PB leads to a substantial reduction in dead space ventilation. At the same time, the savings in mechanical cost achieved by the respiratory muscles during apnea partially offset the increase during the breathing phase. Consequently, the "pressure cost," a criterion based on mean inspiratory pressure, was elevated only slightly, although the average work rate of breathing increased significantly. We found that, at extreme altitudes, PB patterns with clusters of 2 to 4 large breaths that alternate with apnea produce the highest arterial oxygenation levels and lowest pressure costs. The common occurrence of PB patterns with closely similar features has been reported in sleeping healthy sojourners at extreme altitudes. Taken together, these findings suggest that PB favors a reduction in the oxygen demands of the respiratory muscles and therefore may not be as detrimental as it is generally believed to be.

Respiratory Constraints in Verbal and Non-verbal Communication.

PubMed

Włodarczak, Marcin; Heldner, Mattias

2017-01-01

In the present paper we address the old question of respiratory planning in speech production. We recast the problem in terms of speakers' communicative goals and propose that speakers try to minimize respiratory effort in line with the H&H theory. We analyze respiratory cycles coinciding with no speech (i.e., silence), short verbal feedback expressions (SFE's) as well as longer vocalizations in terms of parameters of the respiratory cycle and find little evidence for respiratory planning in feedback production. We also investigate timing of speech and SFEs in the exhalation and contrast it with nods. We find that while speech is strongly tied to the exhalation onset, SFEs are distributed much more uniformly throughout the exhalation and are often produced on residual air. Given that nods, which do not have any respiratory constraints, tend to be more frequent toward the end of an exhalation, we propose a mechanism whereby respiratory patterns are determined by the trade-off between speakers' communicative goals and respiratory constraints.

Central respiratory chemosensitivity and cerebrovascular CO2 reactivity: a rebreathing demonstration illustrating integrative human physiology.

PubMed

MacKay, Christina M; Skow, Rachel J; Tymko, Michael M; Boulet, Lindsey M; Davenport, Margie H; Steinback, Craig D; Ainslie, Philip N; Lemieux, Chantelle C M; Day, Trevor A

2016-03-01

One of the most effective ways of engaging students of physiology and medicine is through laboratory demonstrations and case studies that combine 1) the use of equipment, 2) problem solving, 3) visual representations, and 4) manipulation and interpretation of data. Depending on the measurements made and the type of test, laboratory demonstrations have the added benefit of being able to show multiple organ system integration. Many research techniques can also serve as effective demonstrations of integrative human physiology. The "Duffin" hyperoxic rebreathing test is often used in research settings as a test of central respiratory chemosensitivity and cerebrovascular reactivity to CO2. We aimed to demonstrate the utility of the hyperoxic rebreathing test for both respiratory and cerebrovascular responses to increases in CO2 and illustrate the integration of the respiratory and cerebrovascular systems. In the present article, methods such as spirometry, respiratory gas analysis, and transcranial Doppler ultrasound are described, and raw data traces can be adopted for discussion in a tutorial setting. If educators have these instruments available, instructions on how to carry out the test are provided so students can collect their own data. In either case, data analysis and quantification are discussed, including principles of linear regression, calculation of slope, the coefficient of determination (R(2)), and differences between plotting absolute versus normalized data. Using the hyperoxic rebreathing test as a demonstration of the complex interaction and integration between the respiratory and cerebrovascular systems provides senior undergraduate, graduate, and medical students with an advanced understanding of the integrative nature of human physiology. Copyright © 2016 The American Physiological Society.

Biomimetics of fetal alveolar flow phenomena using microfluidics.

PubMed

Tenenbaum-Katan, Janna; Fishler, Rami; Rothen-Rutishauser, Barbara; Sznitman, Josué

2015-01-01

At the onset of life in utero, the respiratory system begins as a liquid-filled tubular organ and undergoes significant morphological changes during fetal development towards establishing a respiratory organ optimized for gas exchange. As airspace morphology evolves, respiratory alveolar flows have been hypothesized to exhibit evolving flow patterns. In the present study, we have investigated flow topologies during increasing phases of embryonic life within an anatomically inspired microfluidic device, reproducing real-scale features of fetal airways representative of three distinct phases of in utero gestation. Micro-particle image velocimetry measurements, supported by computational fluid dynamics simulations, reveal distinct respiratory alveolar flow patterns throughout different stages of fetal life. While attached, streamlined flows characterize the shallow structures of premature alveoli indicative of the onset of saccular stage, separated recirculating vortex flows become the signature of developed and extruded alveoli characteristic of the advanced stages of fetal development. To further mimic physiological aspects of the cellular environment of developing airways, our biomimetic devices integrate an alveolar epithelium using the A549 cell line, recreating a confluent monolayer that produces pulmonary surfactant. Overall, our in vitro biomimetic fetal airways model delivers a robust and reliable platform combining key features of alveolar morphology, flow patterns, and physiological aspects of fetal lungs developing in utero.

Correction of respiratory motion for IMRT using aperture adaptive technique and visual guidance: A feasibility study

NASA Astrophysics Data System (ADS)

Chen, Ho-Hsing; Wu, Jay; Chuang, Keh-Shih; Kuo, Hsiang-Chi

2007-07-01

Intensity-modulated radiation therapy (IMRT) utilizes nonuniform beam profile to deliver precise radiation doses to a tumor while minimizing radiation exposure to surrounding normal tissues. However, the problem of intrafraction organ motion distorts the dose distribution and leads to significant dosimetric errors. In this research, we applied an aperture adaptive technique with a visual guiding system to toggle the problem of respiratory motion. A homemade computer program showing a cyclic moving pattern was projected onto the ceiling to visually help patients adjust their respiratory patterns. Once the respiratory motion becomes regular, the leaf sequence can be synchronized with the target motion. An oscillator was employed to simulate the patient's breathing pattern. Two simple fields and one IMRT field were measured to verify the accuracy. Preliminary results showed that after appropriate training, the amplitude and duration of volunteer's breathing can be well controlled by the visual guiding system. The sharp dose gradient at the edge of the radiation fields was successfully restored. The maximum dosimetric error in the IMRT field was significantly decreased from 63% to 3%. We conclude that the aperture adaptive technique with the visual guiding system can be an inexpensive and feasible alternative without compromising delivery efficiency in clinical practice.

A closed-loop model of the respiratory system: focus on hypercapnia and active expiration.

PubMed

Molkov, Yaroslav I; Shevtsova, Natalia A; Park, Choongseok; Ben-Tal, Alona; Smith, Jeffrey C; Rubin, Jonathan E; Rybak, Ilya A

2014-01-01

Breathing is a vital process providing the exchange of gases between the lungs and atmosphere. During quiet breathing, pumping air from the lungs is mostly performed by contraction of the diaphragm during inspiration, and muscle contraction during expiration does not play a significant role in ventilation. In contrast, during intense exercise or severe hypercapnia forced or active expiration occurs in which the abdominal "expiratory" muscles become actively involved in breathing. The mechanisms of this transition remain unknown. To study these mechanisms, we developed a computational model of the closed-loop respiratory system that describes the brainstem respiratory network controlling the pulmonary subsystem representing lung biomechanics and gas (O2 and CO2) exchange and transport. The lung subsystem provides two types of feedback to the neural subsystem: a mechanical one from pulmonary stretch receptors and a chemical one from central chemoreceptors. The neural component of the model simulates the respiratory network that includes several interacting respiratory neuron types within the Bötzinger and pre-Bötzinger complexes, as well as the retrotrapezoid nucleus/parafacial respiratory group (RTN/pFRG) representing the central chemoreception module targeted by chemical feedback. The RTN/pFRG compartment contains an independent neural generator that is activated at an increased CO2 level and controls the abdominal motor output. The lung volume is controlled by two pumps, a major one driven by the diaphragm and an additional one activated by abdominal muscles and involved in active expiration. The model represents the first attempt to model the transition from quiet breathing to breathing with active expiration. The model suggests that the closed-loop respiratory control system switches to active expiration via a quantal acceleration of expiratory activity, when increases in breathing rate and phrenic amplitude no longer provide sufficient ventilation. The model can be used for simulation of closed-loop control of breathing under different conditions including respiratory disorders.

Apoptosis, Toll-like, RIG-I-like and NOD-like Receptors Are Pathways Jointly Induced by Diverse Respiratory Bacterial and Viral Pathogens

PubMed Central

Martínez, Isidoro; Oliveros, Juan C.; Cuesta, Isabel; de la Barrera, Jorge; Ausina, Vicente; Casals, Cristina; de Lorenzo, Alba; García, Ernesto; García-Fojeda, Belén; Garmendia, Junkal; González-Nicolau, Mar; Lacoma, Alicia; Menéndez, Margarita; Moranta, David; Nieto, Amelia; Ortín, Juan; Pérez-González, Alicia; Prat, Cristina; Ramos-Sevillano, Elisa; Regueiro, Verónica; Rodriguez-Frandsen, Ariel; Solís, Dolores; Yuste, José; Bengoechea, José A.; Melero, José A.

2017-01-01

Lower respiratory tract infections are among the top five leading causes of human death. Fighting these infections is therefore a world health priority. Searching for induced alterations in host gene expression shared by several relevant respiratory pathogens represents an alternative to identify new targets for wide-range host-oriented therapeutics. With this aim, alveolar macrophages were independently infected with three unrelated bacterial (Streptococcus pneumoniae, Klebsiella pneumoniae, and Staphylococcus aureus) and two dissimilar viral (respiratory syncytial virus and influenza A virus) respiratory pathogens, all of them highly relevant for human health. Cells were also activated with bacterial lipopolysaccharide (LPS) as a prototypical pathogen-associated molecular pattern. Patterns of differentially expressed cellular genes shared by the indicated pathogens were searched by microarray analysis. Most of the commonly up-regulated host genes were related to the innate immune response and/or apoptosis, with Toll-like, RIG-I-like and NOD-like receptors among the top 10 signaling pathways with over-expressed genes. These results identify new potential broad-spectrum targets to fight the important human infections caused by the bacteria and viruses studied here. PMID:28298903

Effect of Rho-kinase inhibition on complexity of breathing pattern in a guinea pig model of asthma

PubMed Central

Pazhoohan, Saeed; Javan, Mohammad; Hajizadeh, Sohrab

2017-01-01

Asthma represents an episodic and fluctuating behavior characterized with decreased complexity of respiratory dynamics. Several evidence indicate that asthma severity or control is associated with alteration in variability of lung function. The pathophysiological basis of alteration in complexity of breathing pattern in asthma has remained poorly understood. Regarding the point that Rho-kinase is involved in pathophysiology of asthma, in present study we investigated the effect of Rho-kinase inhibition on complexity of respiratory dynamics in a guinea pig model of asthma. Male Dunkin Hartley guinea pigs were exposed to 12 series of inhalations with ovalbumin or saline. Animals were treated by the Rho-kinase inhibitor Y-27632 (1mM aerosols) prior to each allergen challenge. We recorded respiration of conscious animals using whole-body plethysmography. Exposure to ovalbumin induced lung inflammation, airway hyperresponsiveness and remodeling including goblet cell hyperplasia, increase in the thickness of airways smooth muscles and subepithelial collagen deposition. Complexity analysis of respiratory dynamics revealed a dramatic decrease in irregularity of respiratory rhythm representing less complexity in asthmatic guinea pigs. Inhibition of Rho-kinase reduced the airway remodeling and hyperreponsiveness, but had no significant effect on lung inflammation and complexity of respiratory dynamics in asthmatic animals. It seems that airway hyperresponsiveness and remodeling do not significantly affect the complexity of respiratory dynamics. Our results suggest that inflammation might be the probable cause of shift in the respiratory dynamics away from the normal fluctuation in asthma. PMID:29088265

US Army Institute of Surgical Research Annual Research Progress Report for Fiscal Year 1987.

DTIC Science & Technology

1987-10-01

oases, respiratory rate, chest roentgenograms), cardiovascular (blood pressure, central venous pressure, cardiac output), and renal (urine output, urine...Monitoring includes the precordial and/or esophageal stethoscope, peripheral pulse, blood pressure, central venous pressure, Swan-Ganz catheter... central venous , peripheral venous , and Swan-Ganz (7F, American Edward Laboratories, Irvine CA) catheters and an esophageal balloon were inserted. After a 2

Frequency of Respiratory Nursing Diagnoses and Accuracy of Clinical Indicators in Preterm Infants.

PubMed

Avena, Marta José; Pedreira, Mavilde da Luz Gonçalves; Bassolli de Oliveira Alves, Lucas; Herdman, T Heather; de Gutiérrez, Maria Gaby Rivero

2018-03-05

To identify the frequency of the nursing diagnoses, ineffective breathing pattern, impaired gas exchange and impaired spontaneous ventilation in newborns; and, to analyze the accuracy of diagnostic indicators identified for each of these diagnoses. This was a cross-sectional study conducted with a nonprobability sample of 92 infants. Data collected were represented by demographic and clinical variables, clinical indicators of the three respiratory nursing diagnoses from NANDA International, and were analyzed according to frequency and agreement between pairs of expert nurses (Kappa). Ineffective breathing pattern was identified in 74.5% of infants; impaired gas exchange was noted in 31.5%; impaired spontaneous ventilation was found in 16.8% of subjects. Use of accessory muscles to breathe showed the highest sensitivity for ineffective breathing pattern; abnormal blood gases had the best predictive value for impaired gas exchange. Use of accessory muscles to breathe had the highest sensitivity for impaired spontaneous ventilation. Ineffective breathing pattern was the most frequently identified; use of accessory muscles, alteration in depth of breathing, abnormal breathing, and dyspnea were the most representative signs/symptoms. Early recognition of respiratory conditions can support safe interventions to ensure appropriate outcomes. © 2018 NANDA International, Inc.

Early childhood growth patterns and school-age respiratory resistance, fractional exhaled nitric oxide and asthma.

PubMed

Casas, Maribel; den Dekker, Herman T; Kruithof, Claudia J; Reiss, Irwin K; Vrijheid, Martine; de Jongste, Johan C; Jaddoe, Vincent W V; Duijts, Liesbeth

2016-12-01

Greater infant weight gain is associated with lower lung function and increased risk of childhood asthma. The role of early childhood peak growth patterns is unclear. We assessed the associations of individually derived early childhood peak growth patterns with respiratory resistance, fractional exhaled nitric oxide, wheezing patterns, and asthma until school-age. We performed a population-based prospective cohort study among 5364 children. Repeated growth measurements between 0 and 3 years of age were used to derive standard deviation scores (s.d.s) of peak height and weight velocities (PHV and PWV, respectively), and body mass index (BMI) and age at adiposity peak. Respiratory resistance and fractional exhaled nitric oxide were measured at 6 years of age. Wheezing patterns and asthma were prospectively assessed by annual questionnaires. We also assessed whether any association was explained by childhood weight status. Greater PHV was associated with lower respiratory resistance [Z-score (95% CI): -0.03 (-0.04, -0.01) per s.d.s increase] (n = 3382). Greater PWV and BMI at adiposity peak were associated with increased risks of early wheezing [relative risk ratio (95% CI): 1.11 (1.06, 1.16), 1.26 (1.11, 1.43), respectively] and persistent wheezing [relative risk ratio (95% CI): 1.09 (1.03, 1.16), 1.37 (1.17, 1.60), respectively] (n = 3189 and n = 3005, respectively). Childhood weight status partly explained these associations. No other associations were observed. PWV and BMI at adiposity peak are critical for lung developmental and risk of school-age wheezing. Follow-up studies at older ages are needed to elucidate whether these effects persist at later ages. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

THREE-DIMENSIONAL COMPUTATIONAL FLUID DYNAMICS SIMULATIONS OF LOCAL PARTICLE DEPOSITION PATTERNS IN LUNG AIRWAYS

EPA Science Inventory

EPA has identified respirable particulate matter (PM) as a significant threat to human health, particularly in the elderly, in children, and in persons with respiratory disease. However, deposition of PM in the respiratory system is highly variable, depending upon particle chara...

LOWER RESPIRATORY TRACT STRUCTURE OF LABORATORY ANIMALS AND HUMANS: DOSIMETRY IMPLICATIONS

EPA Science Inventory

Significant differences in lower respiratory tract structure exist both within an animal and between species at each level of anatomy. rregular bipodial and tripodial branching patterns of airways are present in human an nonhuman primate lungs. n contrast, the dog and common labo...

Sleep apnoea during upper respiratory infection and metabolic alkalosis in infancy.

PubMed Central

Abreu e Silva, F A; MacFadyen, U M; Williams, A; Simpson, H

1986-01-01

Three to four hour polygraphic sleep studies were carried out in 10 infants, five with upper respiratory infection and five with metabolic alkalosis secondary to vomiting during and after recovery from illness. During upper respiratory infection, the main abnormality detected was brief (greater than 3 less than 6 seconds) or prolonged (greater than 6 seconds) attacks of obstructive apnoea. Other indices of apnoea were similar to recovery data. Gross body movements were also increased. In infants with metabolic alkalosis indices of central apnoea were significantly increased when compared with recovery or case control data. Prolonged (greater than 15 seconds) attacks of central apnoea and obstructive apnoea (greater than 6 seconds) were only observed during illness. Gross body movements and periodic breathing were also increased. These findings suggest that the functional consequences of apparently 'mild' illnesses in young infants may be greater than is generally suspected and perhaps relevant to mechanism(s) of death in sudden infant death syndrome. PMID:3789786

Molecular epidemiology of porcine reproductive and respiratory syndrome virus in Central China since 2014: The prevalence of NADC30-like PRRSVs.

PubMed

Wang, Lin-Jian; Xie, Weitao; Chen, Xin-Xin; Qiao, Songlin; Zhao, Mengmeng; Gu, Yu; Zhao, Bao-Lei; Zhang, Gaiping

2017-08-01

Porcine reproductive and respiratory syndrome (PRRS), characterized by respiratory disorders in piglets and reproductive failure in sows, is still the great threat of swine industry. Recently, Emergence of the novel NADC30-like PRRS viruses (PRRSVs) has caused widespread outbreaks of PRRS. To investigate the epidemic characteristics of PRRSVs in Central China since 2014, 6372 clinical serum samples were tested by ELISA, 250 tissue samples were tested by RT-PCR, and among these, 30 ORF5 and 17 Nsp2 genes sequences were analyzed. Phylogenetic tree based on ORF5 revealed that, 17 isolates were clustered into subgroup 1, represented by the NADC30. And for the Nsp2, The strains which had a discontinuous 131-amino-acid deletion in Nsp2, called NADC30-like strains, were clustered into subgroup 2. Our data suggested that the NADC30-like PRRSV strains spread quickly and are now circulating and prevalent in Central China as well as the classical HP-PRRSV strains. In addition, amino acid variation analysis of GP5 revealed that the amino acid sequences of NADC30-like PRRSV strains underwent rapid evolution and contained extensive amino acid substitutions in important motifs, such as potential neutralization epitope and the N-glycosylation sites. In summary, our data would provide a large amount of detailed information on molecular variation and genetic diversity of PRRSV in central China. Copyright © 2017. Published by Elsevier Ltd.

The Effects of Lidocaine on Central Respiratory Neuron Activity and Nociceptive-Related Responses in the Brainstem-Spinal Cord Preparation of the Newborn Rat.

PubMed

Shakuo, Tomoharu; Lin, Shih-Tien; Onimaru, Hiroshi

2016-05-01

Lidocaine is widely used in the clinical setting as a local anesthetic and antiarrhythmic drug. Although it has been suggested that lidocaine exerts inhibitory effects on the central and peripheral neurons, there are no reports on its effects on central respiratory activity in vertebrates. In this study, we examined the effects of lidocaine on respiratory rhythm generation and nociceptive response in brainstem-spinal cord preparations from the newborn rats. Preparations were isolated from Wistar rats (postnatal day 0-3) and superfused with artificial cerebrospinal fluid equilibrated with 95% O2 and 5% CO2, pH 7.4, at 25°C to 26°C. We examined the effects of lidocaine on the fourth cervical ventral root (C4)-inspiratory activity and on the preinspiratory and inspiratory neurons in the rostral medulla. We also examined the effects on the C4/C5 reflex responses induced by ipsilateral C7/C8 dorsal root stimulation, which are thought to be related to the nociceptive response. The application of low doses of lidocaine (10-20 μM) resulted in a slight increase of the C4 burst rate, whereas high doses of lidocaine (100-400 μM) decreased the burst rate in a dose-dependent manner, eventually resulting in the complete cessation of respiratory rhythm. High doses of lidocaine decreased the burst duration and negative slope conductance of preinspiratory neurons, suggesting that lidocaine blocked persistent Na+ current. After the burst generation of the respiratory neurons ceased, depolarizing current stimulation continued to induce action potentials; however, the induction of the spike train was depressed because of strong adaptation. A low dose of lidocaine (20 μM) depressed C4/C5 spinal reflex responses. Our findings indicate that lidocaine depressed nociception-related responses at lower concentrations than those that induced respiratory depression. Our report provides the basic neuronal mechanisms to support the clinical use of lidocaine, which shows antinociceptive effects with minimal side effects on breathing.

A review of the effects of some endocrinological factors on respiratory mechanics.

PubMed

Rubini, Alessandro; Frigo, Alessandro; Carniel, Emanuele Luigi

2016-12-01

Endocrinological factors have been recently described to affect respiratory mechanics. To review recent literature data, most of all obtained by the end-inflation occlusion method, describing the effects of molecules of endocrinological interest such as endothelin, erythropoietin and renin-angiotensin, on respiratory mechanics parameters. The papers considered in this review were found by inserting in Pubmed/Medline the following indexing terms: hormones, endothelin, erythropoietin, angiotensin and respiratory mechanics. It was found that the above cited molecules, beside their well known physiological main effects, exhibit influences on respiratory mechanics, most of all on the airflow resistance, which was described to be increased by endothelin and angiotensin, and decreased by erythropoietin. A number of molecules of biological interest exhibit unexpected influences on respiratory mechanics. The clinical effects depend on the consequences of modified inspiratory pressure values the respiratory muscles have to perform for a given breathing pattern.

The respiratory-vocal system of songbirds: anatomy, physiology, and neural control.

PubMed

Schmidt, Marc F; Martin Wild, J

2014-01-01

This wide-ranging review presents an overview of the respiratory-vocal system in songbirds, which are the only other vertebrate group known to display a degree of respiratory control during song rivalling that of humans during speech; this despite the fact that the peripheral components of both the respiratory and vocal systems differ substantially in the two groups. We first provide a brief description of these peripheral components in songbirds (lungs, air sacs and respiratory muscles, vocal organ (syrinx), upper vocal tract) and then proceed to a review of the organization of central respiratory-related neurons in the spinal cord and brainstem, the latter having an organization fundamentally similar to that of the ventral respiratory group of mammals. The second half of the review describes the nature of the motor commands generated in a specialized "cortical" song control circuit and how these might engage brainstem respiratory networks to shape the temporal structure of song. We also discuss a bilaterally projecting "respiratory-thalamic" pathway that links the respiratory system to "cortical" song control nuclei. This necessary pathway for song originates in the brainstem's primary inspiratory center and is hypothesized to play a vital role in synchronizing song motor commands both within and across hemispheres. © 2014 Elsevier B.V. All rights reserved.

The respiratory-vocal system of songbirds: Anatomy, physiology, and neural control

PubMed Central

Schmidt, Marc F.; Wild, J. Martin

2015-01-01

This wide-ranging review presents an overview of the respiratory-vocal system in songbirds, which are the only other vertebrate group known to display a degree of respiratory control during song rivalling that of humans during speech; this despite the fact that the peripheral components of both the respiratory and vocal systems differ substantially in the two groups. We first provide a brief description of these peripheral components in songbirds (lungs, air sacs and respiratory muscles, vocal organ (syrinx), upper vocal tract) and then proceed to a review of the organization of central respiratory-related neurons in the spinal cord and brainstem, the latter having an organization fundamentally similar to that of the ventral respiratory group of mammals. The second half of the review describes the nature of the motor commands generated in a specialized “cortical” song control circuit and how these might engage brainstem respiratory networks to shape the temporal structure of song. We also discuss a bilaterally projecting “respiratory-thalamic” pathway that links the respiratory system to “cortical” song control nuclei. This necessary pathway for song originates in the brainstem’s primary inspiratory center and is hypothesized to play a vital role in synchronizing song motor commands both within and across hemispheres. PMID:25194204

Comparison of pulmonary artery and central venous pressure waveform measurements via digital and graphic measurement methods.

PubMed

Ahrens, T S; Schallom, L

2001-01-01

Techniques to measure pulmonary artery (PA) pressure waveforms include digital measurement, graphic measurement, and freeze-cursor measurement. Previous studies reported the inaccuracy of digital and freeze-cursor measurements. However, many of the previous studies were small and did not thoroughly examine the circumstances of when digital measurements might be inaccurate. To compare digital measurements and graphic measurements of PA and central venous pressure (CVP) waveforms in patients with a variety of respiratory patterns, and to compare digital measurements and graphic measurements of CVPs in patients with abnormal or right ventricular waveforms. A total of 928 patients were enrolled in this study. Waveforms from the PA and CVP were collected from each patient. The monitor pressure value (digital measurement) printed on the recorded waveform was compared with the pressure value obtained by a graphic strip recording and measured by one of the primary investigators (graphic measurement). Digital measurements were found to be inaccurate in measuring waveforms in all respiratory categories and in measuring right ventricular waveforms. PA diastolic values and CVP values were the most inaccurately measured waveforms. Digital errors of more than 4 mm Hg were common. There were instances in which the monitor's digital measurement was substantially different from the graphically measured value. This difference has the potential to mislead interpretation of clinical situations. The monitor's ability to occasionally give digital measurement values similar to the graphic measurements may lead to a false sense of security in clinicians. Because the accuracy of the monitor is inconsistent, the bedside clinician should interpret waveforms through use of a graphic recording rather than rely on the digital measurement on the monitor.

Land Use and Land Cover Change, Urban Heat Island Phenomenon, and Health Implications: A Remote Sensing Approach

NASA Technical Reports Server (NTRS)

Lo, C. P.; Quattrochi, Dale A.

2003-01-01

Land use and land cover maps of Atlanta Metropolitan Area in Georgia were produced from Landsat MSS and TM images for 1973,1979,1983,1987,1992, and 1997, spanning a period of 25 years. Dramatic changes in land use and land cover have occurred with loss of forest and cropland to urban use. In particular, low-density urban use, which includes largely residential use, has increased by over 119% between 1973 and 1997. These land use and land cover changes have drastically altered the land surface characteristics. An analysis of Landsat images revealed an increase in surface temperature and a decline in NDVI from 1973 to 1997. These changes have forced the development of a significant urban heat island effect and an increase in ground level ozone production to such an extent, that Atlanta has violated EPA's ozone level standard in recent years. The urban heat island initiated precipitation events that were identified between 1996 and 2000 tended to occur near high-density urban areas but outside the I-285 loop that traverses around the Central Business District, i.e. not in the inner city area, but some in close proximity to the highways. The health implications were investigated by comparing the spatial patterns of volatile organic compounds (VOC) and nitrogen oxides (NOx) emissions, the two ingredients that form ozone by reacting with sunlight, with those of rates of cardiovascular and chronic lower respiratory diseases. A clear core-periphery pattern was revealed for both VOC and NOx emissions, but the spatial pattern was more random in the cases of rates of cardiovascular and chronic lower respiratory diseases. Clearly, factors other than ozone pollution were involved in explaining the rates of these diseases. Further research is therefore needed to understand the health geography and its relationship to land use and land cover change as well as urban heat island effect. This paper illustrates the usefulness of a remote sensing approach for this purpose.

Amyloidosis involving the respiratory system: 5-year's experience of a multi-disciplinary group's activity.

PubMed

Scala, Raffaele; Maccari, Uberto; Madioni, Chiara; Venezia, Duccio; La Magra, Lidia Calogera

2015-01-01

Amyloidosis may involve the respiratory system with different clinical-radiological-functional patterns which are not always easy to be recognized. A good level of knowledge of the disease, an active integration of the pulmonologist within a multidisciplinary setting and a high level of clinical suspicion are necessary for an early diagnosis of respiratory amyloidosis. The aim of this retrospective study was to evaluate the number and the patterns of amyloidosis involving the respiratory system. We searched the cases of amyloidosis among patients attending the multidisciplinary rare and diffuse lung disease outpatients' clinic of Pulmonology Unit of the Hospital of Arezzo from 2007 to 2012. Among the 298 patients evaluated during the study period, we identified three cases of amyloidosis with involvement of the respiratory system, associated or not with other extra-thoracic localizations, whose diagnosis was histo-pathologically confirmed after the pulmonologist, the radiologist, and the pathologist evaluation. Our experience of a multidisciplinary team confirms that intra-thoracic amyloidosis is an uncommon disorder, representing 1.0% of the cases of rare and diffuse lung diseases referred to our center. The diagnosis of the disease is not always easy and quick as the amyloidosis may involve different parts of the respiratory system (airways, pleura, parenchyma). It is therefore recommended to remind this orphan disease in the differential diagnosis of the wide clinical scenarios the pulmonologist may intercept in clinical practice.

Cardiorespiratory interactions during resistive load breathing.

PubMed

Calabrese, P; Perrault, H; Dinh, T P; Eberhard, A; Benchetrit, G

2000-12-01

The addition to the respiratory system of a resistive load results in breathing pattern changes and in negative intrathoracic pressure increases. The aim of this study was to use resistive load breathing as a stimulus to the cardiorespiratory interaction and to examine the extent of the changes in heart rate variability (HRV) and respiratory sinus arrhythmia (RSA) in relation to the breathing pattern changes. HRV and RSA were studied in seven healthy subjects where four resistive loads were applied in a random order during the breath and 8-min recording made in each condition. The HRV spectral power components were computed from the R-R interval sequences, and the RSA amplitude and phase were computed from the sinusoid fitting the instantaneous heart rate within each breath. Adding resistive loads resulted in 1) increasing respiratory period, 2) unchanging heart rate, and 3) increasing HRV and changing RSA characteristics. HRV and RSA characteristics are linearly correlated to the respiratory period. These modifications appear to be linked to load-induced changes in the respiratory period in each individual, because HRV and RSA characteristics are similar at a respiratory period obtained either by loading or by imposed frequency breathing. The present results are discussed with regard to the importance of the breathing cycle duration in these cardiorespiratory interactions, suggesting that these interactions may depend on the time necessary for activation and dissipation of neurotransmitters involved in RSA.

Amyloidosis involving the respiratory system: 5-year's experience of a multi-disciplinary group's activity

PubMed Central

Scala, Raffaele; Maccari, Uberto; Madioni, Chiara; Venezia, Duccio; La Magra, Lidia Calogera

2015-01-01

Amyloidosis may involve the respiratory system with different clinical-radiological-functional patterns which are not always easy to be recognized. A good level of knowledge of the disease, an active integration of the pulmonologist within a multidisciplinary setting and a high level of clinical suspicion are necessary for an early diagnosis of respiratory amyloidosis. The aim of this retrospective study was to evaluate the number and the patterns of amyloidosis involving the respiratory system. We searched the cases of amyloidosis among patients attending the multidisciplinary rare and diffuse lung disease outpatients' clinic of Pulmonology Unit of the Hospital of Arezzo from 2007 to 2012. Among the 298 patients evaluated during the study period, we identified three cases of amyloidosis with involvement of the respiratory system, associated or not with other extra-thoracic localizations, whose diagnosis was histo-pathologically confirmed after the pulmonologist, the radiologist, and the pathologist evaluation. Our experience of a multidisciplinary team confirms that intra-thoracic amyloidosis is an uncommon disorder, representing 1.0% of the cases of rare and diffuse lung diseases referred to our center. The diagnosis of the disease is not always easy and quick as the amyloidosis may involve different parts of the respiratory system (airways, pleura, parenchyma). It is therefore recommended to remind this orphan disease in the differential diagnosis of the wide clinical scenarios the pulmonologist may intercept in clinical practice. PMID:26229565

Expression profiles of genes for mitochondrial respiratory energy-dissipating systems and antioxidant enzymes in wheat leaves during de-etiolation.

PubMed

Garmash, Elena V; Velegzhaninov, Ilya O; Grabelnych, Olga I; Borovik, Olga A; Silina, Ekaterina V; Voinikov, Victor K; Golovko, Tamara K

2017-08-01

Mitochondrial respiratory components participate in the maintenance of chloroplast functional activity. This study investigates the effects 48h de-etiolation of spring wheat seedlings (Triticum aestivum L., var. Irgina) on the expression of genes that encode energy-dissipating respiratory components and antioxidant enzymes under continuous light conditions. The expression of AOX1a following the prolonged darkness exhibited a pattern indicating a prominent dependence on light. The expression of other respiratory genes, including NDA2, NDB2, and UCP1b, increased during de-etiolation and dark-to-light transition; however, changes in the expression of these genes occurred later than those in AOX1a expression. A high expression of NDA1 was detected after 12h of de-etiolation. The suppression of AOX1a, NDA2, NDB2, and UCP1b was observed 24h after de-etiolation when the photosynthetic apparatus and its defence systems against excess light were completely developed. The expression patterns of the respiratory genes and several genes encoding antioxidant enzymes (MnSOD, Cu-ZnSOD, t-APX, GR, and GRX) were quite similar. Our data indicate that the induction of nuclear genes encoding respiratory and antioxidant enzymes allow the plants to control reactive oxygen species (ROS) production and avoid oxidative stress during de-etiolation. Copyright © 2017 Elsevier GmbH. All rights reserved.

Cardiorespiratory Coupling: Common Rhythms in Cardiac, Sympathetic, and Respiratory Activities

PubMed Central

Dick, Thomas E.; Hsieh, Yee-Hsee; Dhingra, Rishi R.; Baekey, David M.; Galán, Roberto F.; Wehrwein, Erica; Morris, Kendall F.

2014-01-01

Cardiorespiratory coupling is an encompassing term describing more than the well-recognized influences of respiration on heart rate and blood pressure. Our data indicate that cardiorespiratory coupling reflects a reciprocal interaction between autonomic and respiratory control systems, and the cardiovascular system modulates the ventilatory pattern as well. For example, cardioventilatory coupling refers to the influence of heart beats and arterial pulse pressure on respiration and is the tendency for the next inspiration to start at a preferred latency after the last heart beat in expiration. Multiple complementary, well-described mechanisms mediate respiration’s influence on cardiovascular function, whereas mechanisms mediating the cardiovascular system’s influence on respiration may only be through the baroreceptors but are just being identified. Our review will describe a differential effect of conditioning rats with either chronic intermittent or sustained hypoxia on sympathetic nerve activity but also on ventilatory pattern variability. Both intermittent and sustained hypoxia increase sympathetic nerve activity after 2 weeks but affect sympatho-respiratory coupling differentially. Intermittent hypoxia enhances sympatho-respiratory coupling, which is associated with low variability in the ventilatory pattern. In contrast, after constant hypobaric hypoxia, 1-to-1 coupling between bursts of sympathetic and phrenic nerve activity is replaced by 2-to-3 coupling. This change in coupling pattern is associated with increased variability of the ventilatory pattern. After baro-denervating hypobaric hypoxic-conditioned rats, splanchnic sympathetic nerve activity becomes tonic (distinct bursts are absent) with decreases during phrenic nerve bursts and ventilatory pattern becomes regular. Thus, conditioning rats to either intermittent or sustained hypoxia accentuates the reciprocal nature of cardiorespiratory coupling. Finally, identifying a compelling physiologic purpose for cardiorespiratory coupling is the biggest barrier for recognizing its significance. Cardiorespiratory coupling has only a small effect on the efficiency of gas exchange; rather, we propose that cardiorespiratory control system may act as weakly coupled oscillator to maintain rhythms within a bounded variability. PMID:24746049

CAP, epilepsy and motor events during sleep: the unifying role of arousal.

PubMed

Parrino, Liborio; Halasz, Peter; Tassinari, Carlo Alberto; Terzano, Mario Giovanni

2006-08-01

Arousal systems play a topical neurophysiologic role in protecting and tailoring sleep duration and depth. When they appear in NREM sleep, arousal responses are not limited to a single EEG pattern but are part of a continuous spectrum of EEG modifications ranging from high-voltage slow rhythms to low amplitude fast activities. The hierarchic features of arousal responses are reflected in the phase A subtypes of CAP (cyclic alternating pattern) including both slow arousals (dominated by the <1Hz oscillation) and fast arousals (ASDA arousals). CAP is an infraslow oscillation with a periodicity of 20-40s that participates in the dynamic organization of sleep and in the activation of motor events. Physiologic, paraphysiologic and pathologic motor activities during NREM sleep are always associated with a stereotyped arousal pattern characterized by an initial increase in EEG delta power and heart rate, followed by a progressive activation of faster EEG frequencies. These findings suggest that motor patterns are already written in the brain codes (central pattern generators) embraced with an automatic sequence of EEG-vegetative events, but require a certain degree of activation (arousal) to become visibly apparent. Arousal can appear either spontaneously or be elicited by internal (epileptic burst) or external (noise, respiratory disturbance) stimuli. Whether the outcome is a physiologic movement, a muscle jerk or a major epileptic attack will depend on a number of ongoing factors (sleep stage, delta power, neuro-motor network) but all events share the common trait of arousal-activated phenomena.

Activation of respiratory muscles does not occur during cold-submergence in bullfrogs, Lithobates catesbeianus.

PubMed

Santin, Joseph M; Hartzler, Lynn K

2017-04-01

Semiaquatic frogs may not breathe air for several months because they overwinter in ice-covered ponds. In contrast to many vertebrates that experience decreased motor performance after inactivity, bullfrogs, Lithobates catesbeianus , retain functional respiratory motor processes following cold-submergence. Unlike mammalian hibernators with unloaded limb muscles and inactive locomotor systems, respiratory mechanics of frogs counterintuitively allow for ventilatory maneuvers when submerged. Thus, we hypothesized that bullfrogs generate respiratory motor patterns during cold-submergence to avoid disuse and preserve motor performance. Accordingly, we measured activity of respiratory muscles (buccal floor compressor and glottal dilator) via electromyography in freely behaving bullfrogs at 20 and 2°C. Although we confirm that ventilation cycles occur underwater at 20°C, bullfrogs did not activate either respiratory muscle when submerged acutely or chronically at 2°C. We conclude that cold-submerged bullfrogs endure respiratory motor inactivity, implying that other mechanisms, excluding underwater muscle activation, maintain a functional respiratory motor system throughout overwintering. © 2017. Published by The Company of Biologists Ltd.

Memory, reconsolidation and extinction in Lymnaea require the soma of RPeD1.

PubMed

Sangha, Susan; Varshney, Nishi; Fras, Mary; Smyth, Kim; Rosenegger, David; Parvez, Kashif; Sadamoto, Hisayo; Lukowiak, Ken

2004-01-01

The central pattern generator (CPG) that drives aerial respiratory behaviour in Lymnaea consists of 3 neurons. One of these, RPeD1--the cell that initiates activity in the circuit, plays an absolutely necessary role as a site for memory formation, memory reconsolidation, and extinction. Using an operant conditioning training procedure that results in a long-term non-declarative memory (LTM), we decrease the occurrence of aerial respiratory behaviour. Since snails can still breathe cutaneously learning this procedure is not harmful. Concomitant with behavioural memory are changes in the spiking activity of RPeD1. Going beyond neural correlates of memory we directly show that RPeD1 is a necessary site for LTM formation. Expanding on this finding we show that this neuron is also a necessary site for memory reconsolidation and 'Pavlovian' extinction. As far as we can determine, this is the first time a single neuron has been shown to be a necessary site for these different aspects memory. RPeD1 is thus a key neuron mediating different hierarchical aspects of memory. We are now in a position to determine the necessary neuronal, molecular and proteomic events in this neuron that are causal to memory formation, reconsolidation and extinction.

A molluscan model system in the search for the engram.

PubMed

Lukowiak, Ken; Sangha, Susan; Scheibenstock, Andi; Parvez, Kashif; McComb, Chloe; Rosenegger, David; Varshney, Nishi; Sadamoto, Hisayo

2003-01-01

A 3-neuron central pattern generator, whose sufficiency and necessity has been directly demonstrated, mediates aerial respiratory behaviour in the pond snail, Lymnaea stagnalis. This behaviour can be operantly conditioned, and this associative learning is consolidated into long-lasting memory. Depending on the operant conditioning training procedure used the learning can be consolidated into intermediate term (ITM) or long-term memory (LTM). ITM persists for only 2-3 h, whilst LTM persists for days to weeks. LTM is dependent on both altered gene activity and new protein synthesis while ITM is only dependent on new protein synthesis. We have now directly established that one of the 3-CPG neurons, RPeD1, is a site of LTM formation and storage. We did this by ablating the soma of RPeD1 and leaving behind a functional primary neurite capable of mediating the necessary synaptic interactions to drive aerial respiratory behaviour by the 3-neuron CPG. However, following soma ablation the neuronal circuit is only capable of mediating learning and ITM. LTM can no longer be demonstrated. However, if RPeD1's soma is ablated after LTM consolidation memory is still present. Thus the soma is not needed for the retention of LTM. Using a similar strategy it may be possible to block forgetting.

Respiratory Complications of Organophosphorus Nerve Agent and Insecticide Poisoning. Implications for Respiratory and Critical Care

PubMed Central

Hulse, Elspeth J.; Davies, James O. J.; Simpson, A. John; Sciuto, Alfred M.

2014-01-01

Organophosphorus (OP) compound poisoning is a major global public health problem. Acute OP insecticide self-poisoning kills over 200,000 people every year, the majority from self-harm in rural Asia. Highly toxic OP nerve agents (e.g., sarin) are a significant current terrorist threat, as shown by attacks in Damascus during 2013. These anticholinesterase compounds are classically considered to cause an acute cholinergic syndrome with decreased consciousness, respiratory failure, and, in the case of insecticides, a delayed intermediate syndrome that requires prolonged ventilation. Acute respiratory failure, by central and peripheral mechanisms, is the primary cause of death in most cases. However, preclinical and clinical research over the last two decades has indicated a more complex picture of respiratory complications after OP insecticide poisoning, including onset of delayed neuromuscular junction dysfunction during the cholinergic syndrome, aspiration causing pneumonia and acute respiratory distress syndrome, and the involvement of solvents in OP toxicity. The treatment of OP poisoning has not changed over the last 50 years. However, a better understanding of the multiple respiratory complications of OP poisoning offers additional therapeutic opportunities. PMID:25419614

Joint symbolic dynamics as a model-free approach to study interdependence in cardio-respiratory time series.

PubMed

Baumert, Mathias; Brown, Rachael; Duma, Stephen; Broe, G Anthony; Kabir, Muammar M; Macefield, Vaughan G

2012-01-01

Heart rate and respiration display fluctuations that are interlinked by central regulatory mechanisms of the autonomic nervous system (ANS). Joint assessment of respiratory time series along with heart rate variability (HRV) may therefore provide information on ANS dysfunction. The aim of this study was to investigate cardio-respiratory interaction in patients with Parkinson's disease (PD), a neurodegenerative disorder that is associated with progressive ANS dysfunction. Short-term ECG and respiration were recorded in 25 PD patients and 28 healthy controls during rest. To assess ANS dysfunction we analyzed joint symbolic dynamics of heart rate and respiration, cardio-respiratory synchrograms along with heart rate variability. Neither HRV nor cardio-respiratory synchrograms were significantly altered in PD patients. Symbolic analysis, however, identified a significant reduction in cardio-respiratory interactions in PD patients compared to healthy controls (16 ± 3.6 % vs. 20 ± 6.1 %; p= 0.02). In conclusion, joint symbolic analysis of cardio-respiratory dynamics provides a powerful tool to detect early signs of autonomic nervous system dysfunction in Parkinson's disease patients at an early stage of the disease.

The mechanisms underlying the production of discontinuous gas exchange cycles in insects.

PubMed

Matthews, Philip G D

2018-03-01

This review examines the control of gas exchange in insects, specifically examining what mechanisms could explain the emergence of discontinuous gas exchange cycles (DGCs). DGCs are gas exchange patterns consisting of alternating breath-hold periods and bouts of gas exchange. While all insects are capable of displaying a continuous pattern of gas exchange, this episodic pattern is known to occur within only some groups of insects and then only sporadically or during certain phases of their life cycle. Investigations into DGCs have tended to emphasise the role of chemosensory thresholds in triggering spiracle opening as critical for producing these gas exchange patterns. However, a chemosensory basis for episodic breathing also requires an as-of-yet unidentified hysteresis between internal respiratory stimuli, chemoreceptors, and the spiracles. What has been less appreciated is the role that the insect's central nervous system (CNS) might play in generating episodic patterns of ventilation. The active ventilation displayed by many insects during DGCs suggests that this pattern could be the product of directed control by the CNS rather than arising passively as a result of self-sustaining oscillations in internal oxygen and carbon dioxide levels. This paper attempts to summarise what is currently known about insect gas exchange regulation, examining the location and control of ventilatory pattern generators in the CNS, the influence of chemoreceptor feedback in the form of O 2 and CO 2 /pH fluctuations in the haemolymph, and the role of state-dependent changes in CNS activity on ventilatory control. This information is placed in the context of what is currently known regarding the production of discontinuous gas exchange patterns.

Estimating respiratory rate from FBG optical sensors by using signal quality measurement.

PubMed

Yongwei Zhu; Maniyeri, Jayachandran; Fook, Victor Foo Siang; Haihong Zhang

2015-08-01

Non-intrusiveness is one of the advantages of in-bed optical sensor device for monitoring vital signs, including heart rate and respiratory rate. Estimating respiratory rate reliably using such sensors, however, is challenging, due to body movement, signal variation according to different subjects or body positions, etc. This paper presents a method for reliable respiratory rate estimation for FBG optical sensors by introducing signal quality estimation. The method estimates the quality of the signal waveform by detecting regularly repetitive patterns using proposed spectrum and cepstrum analysis. Multiple window sizes are used to cater for a wide range of target respiratory rates. Furthermore, the readings of multiple sensors are fused to derive a final respiratory rate. Experiments with 12 subjects and 2 body positions were conducted using polysomnography belt signal as groundtruth. The results demonstrated the effectiveness of the method.

Effect of thoracic mobilization on respiratory parameters in chronic non-specific low back pain: A randomized controlled trial.

PubMed

Babina, R; Mohanty, P P; Pattnaik, M

2016-02-19

Altered respiratory function has been found to be associated with back pain. Limited chest excursion in subjects with chronic low back pain (CLBP) may be due to co-contraction or bracing of erector spinae and abdominal muscles; their flexed spinal posture; and/or their compromised spinal stability resulting from dysfunctional transversus abdominis. To check for the effects of thoracic mobilization on respiratory parameters in subjects with chronic non-specific low back pain. Sixty-two subjects (excluding 11 dropouts) with CLBP of age group 30-60 were randomly allocated to two groups. Both groups received individualized treatment for low back pain (LBP) and HEP (home exercise program) regime of breathing exercises. In addition, group 1 received Maitland's Central postero-anterior vertebral pressure for thoracic spine (T1-T8). Total treatment duration was 10 sessions in 2 weeks (5 sessions/week). Results showed significant improvement in respiratory parameters viz. Forced Vital Capacity (FVC), Sustained Maximal Inspiratory Pressure (SMIP) and Chest Wall Expansion (CWE) and Oswestry Disability Index (ODI) in both groups (p< 0.05) at end of 2 weeks of intervention. However, improvement was significantly more in group 1 (p < 0.05) receiving additional thoracic mobilization. Subjects with non-specific chronic low back pain with or without radiation to lower limbs when treated with thoracic central PA mobilization, in addition to LBP specific treatment and breathing exercises, show an improvement in respiratory parameters and reduction in disability.

The phylogeny and ontogeny of autonomic control of the heart and cardiorespiratory interactions in vertebrates.

PubMed

Taylor, Edwin W; Leite, Cleo A C; Sartori, Marina R; Wang, Tobias; Abe, Augusto S; Crossley, Dane A

2014-03-01

Heart rate in vertebrates is controlled by activity in the autonomic nervous system. In spontaneously active or experimentally prepared animals, inhibitory parasympathetic control is predominant and is responsible for instantaneous changes in heart rate, such as occur at the first air breath following a period of apnoea in discontinuous breathers like inactive reptiles or species that surface to air breathe after a period of submersion. Parasympathetic control, exerted via fast-conducting, myelinated efferent fibres in the vagus nerve, is also responsible for beat-to-beat changes in heart rate such as the high frequency components observed in spectral analysis of heart rate variability. These include respiratory modulation of the heartbeat that can generate cardiorespiratory synchrony in fish and respiratory sinus arrhythmia in mammals. Both may increase the effectiveness of respiratory gas exchange. Although the central interactions generating respiratory modulation of the heartbeat seem to be highly conserved through vertebrate phylogeny, they are different in kind and location, and in most species are as yet little understood. The heart in vertebrate embryos possesses both muscarinic cholinergic and β-adrenergic receptors very early in development. Adrenergic control by circulating catecholamines seems important throughout development. However, innervation of the cardiac receptors is delayed and first evidence of a functional cholinergic tonus on the heart, exerted via the vagus nerve, is often seen shortly before or immediately after hatching or birth, suggesting that it may be coordinated with the onset of central respiratory rhythmicity and subsequent breathing.

Programming of respiratory health in childhood: influence of outdoor air pollution.

PubMed

Wright, Rosalind J; Brunst, Kelly J

2013-04-01

This overview highlights recent experimental and epidemiological evidence for the programming effects of outdoor air pollution exposures during early development on lung function and chronic respiratory disorders, such as asthma and related allergic disorders. Air pollutants may impact anatomy and/or physiological functioning of the lung and interrelated systems. Programming effects may result from pollutant-induced shifts in a number of molecular, cellular, and physiological states and their interacting systems. Specific key regulatory systems susceptible to programming may influence lung development and vulnerability to respiratory diseases, including both central and peripheral components of neuroendocrine pathways and autonomic nervous system (ANS) functioning which, in turn, influence the immune system. Starting in utero, environmental factors, including air pollutants, may permanently organize these systems toward trajectories of enhanced pediatric (e.g., asthma, allergy) as well as adult disease risk (e.g., chronic obstructive pulmonary disease). Evidence supports a central role of oxidative stress in the toxic effects of air pollution. Additional research suggests xenobiotic metabolism and subcellular components, such as mitochondria are targets of ambient air pollution and play a role in asthma and allergy programming. Mechanisms operating at the level of the placenta are being elucidated. Epigenetic mechanisms may be at the roots of adaptive developmental programming. Optimal coordinated functioning of many complex processes and their networks of interaction are necessary for normal lung development and the maintenance of respiratory health. Outdoor air pollution may play an important role in early programming of respiratory health and is potentially amenable to intervention.

Sleep/wake firing patterns of human genioglossus motor units.

PubMed

Bailey, E Fiona; Fridel, Keith W; Rice, Amber D

2007-12-01

Although studies of the principal tongue protrudor muscle genioglossus (GG) suggest that whole muscle GG electromyographic (EMG) activities are preserved in nonrapid eye movement (NREM) sleep, it is unclear what influence sleep exerts on individual GG motor unit (MU) activities. We characterized the firing patterns of human GG MUs in wakefulness and NREM sleep with the aim of determining 1) whether the range of MU discharge patterns evident in wakefulness is preserved in sleep and 2) what effect the removal of the "wakefulness" input has on the magnitude of the respiratory modulation of MU activities. Microelectrodes inserted into the extrinsic tongue protrudor muscle, the genioglossus, were used to follow the discharge of single MUs. We categorized MU activities on the basis of the temporal relationship between the spike train and the respiration cycle and quantified the magnitude of the respiratory modulation of each MU using the eta (eta(2)) index, in wakefulness and sleep. The majority of MUs exhibited subtle increases or decreases in respiratory modulation but were otherwise unaffected by NREM sleep. In contrast, 30% of MUs exhibited marked sleep-associated changes in discharge frequency and respiratory modulation. We suggest that GG MUs should not be considered exclusively tonic or phasic; rather, the discharge pattern appears to be a flexible feature of GG activities in healthy young adults. Whether such flexibility is important in the response to changes in the chemical and/or mechanical environment and whether it is preserved as a function of aging or in individuals with obstructive sleep apnea are critical questions for future research.

Possible prevalence and transmission of acute respiratory tract infections caused by Streptococcus pneumoniae and Haemophilus influenzae among the internally displaced persons in tsunami disaster evacuation camps of Sri Lanka.

PubMed

Watanabe, Hiroshi; Batuwanthudawe, Ranjith; Thevanesam, Vasanthi; Kaji, Chiharu; Qin, Liang; Nishikiori, Nobuyuki; Saito, Wakana; Saito, Mariko; Watanabe, Kiwao; Oishi, Kazunori; Abeysinghe, Nihal; Kunii, Osamu

2007-01-01

The objective of this prospective study was to investigate the status of acute respiratory tract infections caused by Haemophilus influenzae and Streptococcus pneumoniae in tsunami disaster evacuation camps. Nasopharyngeal swabs (NP) of 324 internally displaced persons (IDP) in 3 different tsunami disaster evacuation camps of Sri Lanka were collected between March 18th and 20th, 2005, and analyzed for MIC, beta-lactamase production, serotypes, PCR and pulsed-field gel electrophoresis (PFGE). Many IDP had respiratory symptoms and the prevalence of cough and/or sputum was 84%, 70.5% and 64.7% in the three camps. Twenty-one H. influenzae from 20 IDP and 25 S. pneumoniae from 22 IDP were isolated from the NP. All H. influenzae isolates were nontypeable, and 5 were beta-lactamase producing. Seventeen pneumococci were susceptible, 5 showed intermediate resistance and 3 were fully resistant to penicillin G. Molecular analysis showed the 21 H. influenzae strains had 13 PFGE patterns and 25 pneumococci had 16 PFGE patterns. All 4 different PFGE patterns of H. influenzae strains were detected in a few IDP in camps 1 and 3, and 5 different PFGE patterns of serotype 3, 22A, 9A, 10A and 11A pneumococci were detected in a few IDP in camps 1 and 3. Our data indicate acute respiratory tract infections caused by various types of H. influenzae and S. pneumoniae appear to have been prevalent, some of which were potentially transmitted from person to person in tsunami disaster evacuation camps.

Development of Non-contact Respiratory Monitoring System for Newborn Using a FG Vision Sensor

NASA Astrophysics Data System (ADS)

Kurami, Yoshiyuki; Itoh, Yushi; Natori, Michiya; Ohzeki, Kazuo; Aoki, Yoshimitsu

In recent years, development of neonatal care is strongly hoped, with increase of the low-birth-weight baby birth rate. Especially respiration of low-birth-weight baby is incertitude because central nerve and respiratory function is immature. Therefore, a low-birth-weight baby often causes a disease of respiration. In a NICU (Neonatal Intensive Care Unit), neonatal respiration is monitored using cardio-respiratory monitor and pulse oximeter at all times. These contact-type sensors can measure respiratory rate and SpO2 (Saturation of Peripheral Oxygen). However, because a contact-type sensor might damage the newborn's skin, it is a real burden to monitor neonatal respiration. Therefore, we developed the respiratory monitoring system for newborn using a FG (Fiber Grating) vision sensor. FG vision sensor is an active stereo vision sensor, it is possible for non-contact 3D measurement. A respiratory waveform is calculated by detecting the vertical motion of the thoracic and abdominal region with respiration. We attempted clinical experiment in the NICU, and confirmed the accuracy of the obtained respiratory waveform was high. Non-contact respiratory monitoring of newborn using a FG vision sensor enabled the minimally invasive procedure.

Cardiorespiratory interactions in patients with atrial flutter.

PubMed

Masè, Michela; Disertori, Marcello; Ravelli, Flavia

2009-01-01

Respiratory sinus arrhythmia (RSA) is generally known as the autonomically mediated modulation of the sinus node pacemaker frequency in synchrony with respiration. Cardiorespiratory interactions have been largely investigated during sinus rhythm, whereas little is known about interactions during reentrant arrhythmias. In this study, cardiorespiratory interactions at the atrial and ventricular level were investigated during atrial flutter (AFL), a supraventricular arrhythmia based on a reentry, by using cross-spectral analysis and computer modeling. The coherence and phase between respiration and atrial (gamma(AA)(2), phi(AA)) and ventricular (gamma(RR)(2), phi(RR)) interval series were estimated in 20 patients with typical AFL (68.0 +/- 8.8 yr) and some degree of atrioventricular (AV) conduction block. In all patients, atrial intervals displayed oscillations strongly coupled and in phase with respiration (gamma(AA)(2)= 0.97 +/- 0.05, phi(AA) = 0.71 +/- 0.31 rad), corresponding to a paradoxical lengthening of intervals during inspiration. The modulation pattern was frequency independent, with in-phase oscillations and short time delays (0.40 +/- 0.15 s) for respiratory frequencies in the range 0.1-0.4 Hz. Ventricular patterns were affected by AV conduction type. In patients with fixed AV conduction, ventricular intervals displayed oscillations strongly coupled (gamma(RR)(2)= 0.97 +/- 0.03) and in phase with respiration (phi(RR) = 1.08 +/- 0.80 rad). Differently, in patients with variable AV conduction, respiratory oscillations were secondary to Wencheback rhythmicity, resulting in a decreased level of coupling (gamma(RR)(2)= 0.50 +/- 0.21). Simulations with a simplified model of AV conduction showed ventricular patterns to originate from the combination of a respiratory modulated atrial input with the functional properties of the AV node. The paradoxical frequency-independent modulation pattern of atrial interval, the short time delays, and the complexity of ventricular rhythm characterize respiratory arrhythmia during AFL and distinguish it from normal RSA. These peculiar features can be explained by assuming a direct mechanical action of respiration on AFL reentrant circuit.

Autonomic nervous system response patterns specificity to basic emotions.

PubMed

Collet, C; Vernet-Maury, E; Delhomme, G; Dittmar, A

1997-01-12

The aim of this study was to test the assumption that the autonomic nervous system responses to emotional stimuli are specific. A series of six slides was randomly presented to the subjects while six autonomic nervous system (ANS) parameters were recorded: skin conductance, skin potential, skin resistance, skin blood flow, skin temperature and instantaneous respiratory frequency. Each slide induced a basic emotion: happiness, surprise, anger, fear, sadness and disgust. Results have been first considered with reference to electrodermal responses (EDR) and secondly through thermo-vascular and respiratory variations. Classical as well as original indices were used to quantify autonomic responses. The six basic emotions were distinguished by Friedman variance analysis. Thus, ANS values corresponding to each emotion were compared two-by-two. EDR distinguished 13 emotion-pairs out of 15. 10 emotion-pairs were separated by skin resistance as well as skin conductance ohmic perturbation duration indices whereas conductance amplitude was only capable of distinguishing 7 emotion-pairs. Skin potential responses distinguished surprise and fear from sadness, and fear from disgust, according to their elementary pattern analysis in form and sign. Two-by-two comparisons of skin temperature, skin blood flow (estimated by the new non-oscillary duration index) and instantaneous respiratory frequency, enabled the distinction of 14 emotion-pairs out of 15. 9 emotion-pairs were distinguished by the non-oscillatory duration index values. Skin temperature was demonstrated to be different i.e. positive versus negative in response to anger and fear. The instantaneous respiratory frequency perturbation duration index was the only one capable of separating sadness from disgust. From the six ANS parameters study, different autonomic patterns were identified, each characterizing one of the six basic emotion used as inducing signals. No index alone, nor group of parameters (EDR and thermovascular for instance) were capable of distinguishing each emotion from another. However, electrodermal, thermo-vascular and respiratory responses taken as a whole, redundantly separated each emotion thus demonstrating the specificity of autonomic patterns.

Strength and Cycle Time of Ventilatory Oscillations in Unacclimatized Humans at High Altitude,

DTIC Science & Technology

1983-03-04

that our respiratory monitor- ing techniques were identical. We assume this difference is due to lack of acclimatization in our current subjects. In the...instability in the blood gas feedback con- trol system. Respiratory control system modeling by Khoo et al (8) has shown that such instability is...In a respiratory control sys- tem model a stronger pattern corresponds to increased loop gain at a phase angle of 180 degrees. As shown by Khoo, et

Respiratory virus laboratory pandemic planning and surveillance in central Viet Nam, 2008–2010

PubMed Central

Chien, Bui Trong; Papadakis, Georgina; Druce, Julian; Birch, Chris; Chibo, Doris; An, Truong Phuoc; Trang, Le Thi Kim; Trieu, Nguyen Bao; Thuy, Doan Thi Thanh; Catton, Mike; Mai, Trinh Xuan

2012-01-01

Introduction Laboratory capacity is needed in central Viet Nam to provide early warning to public health authorities of respiratory outbreaks of importance to human health, for example the outbreak of influenza A(H1N1) pandemic in 2009. Polymerase chain reaction (PCR) procedures established as part of a capacity-building process were used to conduct prospective respiratory surveillance in a region where few previous studies have been undertaken. Methods Between October 2008 and September 2010, nose and throat swabs from adults and children (approximately 20 per week) presenting with an acute respiratory illness to the Ninh Hoa General Hospital were collected. Same-day PCR testing and result reporting for 13 respiratory viruses were carried out by locally trained scientists. Results Of 2144 surveillance samples tested, 1235 (57.6%) were positive for at least one virus. The most common were influenza A strains (17.9%), with pandemic influenza A(H1N1) 2009 and seasonal H3N2 strain accounting for 52% and 43% of these, respectively. Other virus detections included: rhinovirus (12.4%), enterovirus (8.9%), influenza B (8.3%), adenovirus (5.3%), parainfluenza (4.7%), respiratory syncytial virus (RSV) (3.9%), human coronavirus (3.0%) and human metapneumovirus (0.3%). The detection rate was greatest in the 0–5 year age group. Viral co-infections were identified in 148 (6.9%) cases. Discussion The outbreak in 2009 of the influenza A(H1N1) pandemic strain provided a practical test of the laboratory’s pandemic plan. This study shows that the availability of appropriate equipment and molecular-based testing can contribute to important individual and public health outcomes in geographical locations susceptible to emerging infections. PMID:23908924

Assessment of breathing patterns and respiratory muscle recruitment during singing and speech in quadriplegia.

PubMed

Tamplin, Jeanette; Brazzale, Danny J; Pretto, Jeffrey J; Ruehland, Warren R; Buttifant, Mary; Brown, Douglas J; Berlowitz, David J

2011-02-01

To explore how respiratory impairment after cervical spinal cord injury affects vocal function, and to explore muscle recruitment strategies used during vocal tasks after quadriplegia. It was hypothesized that to achieve the increased respiratory support required for singing and loud speech, people with quadriplegia use different patterns of muscle recruitment and control strategies compared with control subjects without spinal cord injury. Matched, parallel-group design. Large university-affiliated public hospital. Consenting participants with motor-complete C5-7 quadriplegia (n=6) and able-bodied age-matched controls (n=6) were assessed on physiologic and voice measures during vocal tasks. Not applicable. Standard respiratory function testing, surface electromyographic activity from accessory respiratory muscles, sound pressure levels during vocal tasks, the Voice Handicap Index, and the Perceptual Voice Profile. The group with quadriplegia had a reduced lung capacity (vital capacity, 71% vs 102% of predicted; P=.028), more perceived voice problems (Voice Handicap Index score, 22.5 vs 6.5; P=.046), and greater recruitment of accessory respiratory muscles during both loud and soft volumes (P=.028) than the able-bodied controls. The group with quadriplegia also demonstrated higher accessory muscle activation in changing from soft to loud speech (P=.028). People with quadriplegia have impaired vocal ability and use different muscle recruitment strategies during speech than the able-bodied. These findings will enable us to target specific measurements of respiratory physiology for assessing functional improvements in response to formal therapeutic singing training. Copyright © 2011 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.

Afferent Neural Feedback Overrides the Modulating Effects of Arousal, Hypercapnia and Hypoxemia on Neonatal Cardio-respiratory Control.

PubMed

Lumb, Kathleen J; Schneider, Jennifer M; Ibrahim, Thowfique; Rigaux, Anita; Hasan, Shabih U

2018-04-20

Evidence at whole animal, organ-system, and cellular and molecular levels suggests that afferent volume feedback is critical for establishment of adequate ventilation at birth. Due to the irreversible nature of vagal ablation studies to date, it was difficult to quantify the roles of afferent volume input, arousal and changes in blood gas tensions on neonatal respiratory control. During reversible perineural vagal block, profound apneas, and hypoxemia and hypercarbia were observed necessitating termination of perineural blockade. Respiratory depression and apneas were independent of the sleep states. We demonstrate that profound apneas and life-threatening respiratory failure in vagally denervated animals do not result from lack of arousal or hypoxemia. Change in sleep state and concomitant respiratory depression result from lack of afferent volume feedback, which appears to be critical for the maintenance of normal breathing patterns and adequate gas exchange during the early postnatal period. Afferent volume feedback plays a vital role in neonatal respiratory control. Mechanisms for the profound respiratory depression and life-threatening apneas observed in vagally denervated neonatal animals remain unclear. We investigated the roles of sleep states, hypoxic-hypercapnia and afferent volume feedback on respiratory depression using reversible perineural vagal block during early postnatal period. Seven lambs were instrumented during the first 48h of life to record/analyze sleep states, diaphragmatic electromyograph, arterial blood gas tensions, systemic arterial blood pressure and rectal temperature. Perineural cuffs were placed around the vagi to attain reversible blockade. Post-operatively, during the awake state, both vagi were blocked using 2% xylocaine for up to 30 minutes. Compared with baseline values, pHa, PaO 2 and SaO 2 decreased and PaCO 2 increased during perineural blockade (P < 0.05). Four of seven animals exhibited apneas of ≥20 sec requiring immediate termination of perineural blockade. Breathing rates decreased from the baseline value of 53 ± 12 to 24 ± 20 breaths/min during blockade despite an increased PaCO 2 (P < 0.001). Following blockade, breathing patterns returned to baseline values despite marked hypocapnia (PaCO 2 33 ± 3 torr; P = 0.03). Respiratory depression and apneas were independent of sleep states. This study provides the much needed physiologic evidence that profound apneas and life-threatening respiratory failure in vagally denervated animals do not result from lack of arousal or hypoxemia. Rather, change in sleep state and concomitant respiratory depression result from lack of afferent volume feedback, which appears to be critical for the maintenance of normal breathing patterns and adequate gas exchange during the early postnatal period. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

Multiplexed Molecular Diagnostics for Respiratory, Gastrointestinal, and Central Nervous System Infections.

PubMed

Hanson, Kimberly E; Couturier, Marc Roger

2016-11-15

The development and implementation of highly multiplexed molecular diagnostic tests have allowed clinical microbiology laboratories to more rapidly and sensitively detect a variety of pathogens directly in clinical specimens. Current US Food and Drug Administration-approved multiplex panels target multiple different organisms simultaneously and can identify the most common pathogens implicated in respiratory viral, gastrointestinal, or central nervous system infections. This review summarizes the test characteristics of available assays, highlights the advantages and limitations of multiplex technology for infectious diseases, and discusses potential utilization of these new tests in clinical practice. © The Author 2016. Published by Oxford University Press for the Infectious Diseases Society of America. All rights reserved. For permissions, e-mail journals.permissions@oup.com.

Sleep Related Breathing Disorders in Adults with Down Syndrome.

ERIC Educational Resources Information Center

Resta, Onofrio; Barbaro, Maria Pia Foschino; Giliberti, Tiziana; Caratozzolo, Gennaro; Cagnazzo, Maria Grazia; Scarpelli, Franco; Nocerino, Maria Cristina

2003-01-01

This study evaluated sleep-related breathing disorders in six adults with Down syndrome. Five were found to have respiratory events justifying the diagnosis of sleep apnea syndrome. Results suggest that the nocturnal respiratory pattern of adults with Down syndrome depends on several pathogenetic factors such as age, severity of upper airway…

Climate change, extreme weather events, air pollution and respiratory health in Europe.

PubMed

De Sario, M; Katsouyanni, K; Michelozzi, P

2013-09-01

Due to climate change and other factors, air pollution patterns are changing in several urbanised areas of the world, with a significant effect on respiratory health both independently and synergistically with weather conditions; climate scenarios show Europe as one of the most vulnerable regions. European studies on heatwave episodes have consistently shown a synergistic effect of air pollution and high temperatures, while the potential weather-air pollution interaction during wildfires and dust storms is unknown. Allergen patterns are also changing in response to climate change, and air pollution can modify the allergenic potential of pollens, especially in the presence of specific weather conditions. The underlying mechanisms of all these interactions are not well known; the health consequences vary from decreases in lung function to allergic diseases, new onset of diseases, exacerbation of chronic respiratory diseases, and premature death. These multidimensional climate-pollution-allergen effects need to be taken into account in estimating both climate and air pollution-related respiratory effects, in order to set up adequate policy and public health actions to face both the current and future climate and pollution challenges.

Running and Breathing in Mammals

NASA Astrophysics Data System (ADS)

Bramble, Dennis M.; Carrier, David R.

1983-01-01

Mechanical constraints appear to require that locomotion and breathing be synchronized in running mammals. Phase locking of limb and respiratory frequency has now been recorded during treadmill running in jackrabbits and during locomotion on solid ground in dogs, horses, and humans. Quadrupedal species normally synchronize the locomotor and respiratory cycles at a constant ratio of 1:1 (strides per breath) in both the trot and gallop. Human runners differ from quadrupeds in that while running they employ several phase-locked patterns (4:1, 3:1, 2:1, 1:1, 5:2, and 3:2), although a 2:1 coupling ratio appears to be favored. Even though the evolution of bipedal gait has reduced the mechanical constraints on respiration in man, thereby permitting greater flexibility in breathing pattern, it has seemingly not eliminated the need for the synchronization of respiration and body motion during sustained running. Flying birds have independently achieved phase-locked locomotor and respiratory cycles. This hints that strict locomotor-respiratory coupling may be a vital factor in the sustained aerobic exercise of endothermic vertebrates, especially those in which the stresses of locomotion tend to deform the thoracic complex.

Temporal patterns of radiographic infiltration in severely traumatized patients with and without adult respiratory distress syndrome.

PubMed

Johnson, K S; Bishop, M H; Stephen, C M; Jorgens, J; Shoemaker, W C; Shori, S K; Ordog, G; Thadepalli, H; Appel, P L; Kram, H B

1994-05-01

We prospectively evaluated the patterns of pulmonary structural and functional changes in 100 consecutive surgical intensive care unit trauma patients who had (1) emergent major surgery, (2) a pelvic fracture, or (3) two or more major long bone fractures. For each patient, arterial blood gas measurements (ABGs), central venous pressure (CVP), pulmonary capillary occlusion pressure (PAOP), thoracic compliance, arterial oxygen tension/fraction of inspired oxygen (PAO2/FIO2), pulmonary venous admixture (Qs/Qt), and portable chest roentgenograms were sequentially tracked. The senior staff radiologist interpreted all chest roentgenograms. Pulmonary infiltration was quantitated in each of six fields using a scale ranging from 0 to 4, with 0 being no infiltration and 4 being the maximum. Adult respiratory distress syndrome (ARDS) was defined as follows: Qs/Qt > or = 20%, PAO2/FIO2 < 250 or both; dependence on mechanical ventilation for life support for > or = 24 hours; PAOP or CVP or both < 20 mm Hg; and thoracic compliance < 50 mL/cm H2O. Time zero (T0) the time of onset of ARDS, was defined as the time these criteria were met. Eighty-three of 100 study group patients had penetrating injuries, and 17 were admitted with blunt trauma. Fifty-one of 100 patients developed ARDS: 36 of 51 died. Only 4 of 49 (8%) patients without ARDS died. The injured lungs of patients with and without ARDS had similar amounts of infiltration over most measured time intervals. The noninjured lungs of the ARDS patients, however, had significantly greater infiltration than those without ARDS at T0 and over subsequent time intervals.(ABSTRACT TRUNCATED AT 250 WORDS)

Improved attenuation correction for respiratory gated PET/CT with extended-duration cine CT: a simulation study

NASA Astrophysics Data System (ADS)

Zhang, Ruoqiao; Alessio, Adam M.; Pierce, Larry A.; Byrd, Darrin W.; Lee, Tzu-Cheng; De Man, Bruno; Kinahan, Paul E.

2017-03-01

Due to the wide variability of intra-patient respiratory motion patterns, traditional short-duration cine CT used in respiratory gated PET/CT may be insufficient to match the PET scan data, resulting in suboptimal attenuation correction that eventually compromises the PET quantitative accuracy. Thus, extending the duration of cine CT can be beneficial to address this data mismatch issue. In this work, we propose to use a long-duration cine CT for respiratory gated PET/CT, whose cine acquisition time is ten times longer than a traditional short-duration cine CT. We compare the proposed long-duration cine CT with the traditional short-duration cine CT through numerous phantom simulations with 11 respiratory traces measured during patient PET/CT scans. Experimental results show that, the long-duration cine CT reduces the motion mismatch between PET and CT by 41% and improves the overall reconstruction accuracy by 42% on average, as compared to the traditional short-duration cine CT. The long-duration cine CT also reduces artifacts in PET images caused by misalignment and mismatch between adjacent slices in phase-gated CT images. The improvement in motion matching between PET and CT by extending the cine duration depends on the patient, with potentially greater benefits for patients with irregular breathing patterns or larger diaphragm movements.

Central respiratory effects of substance P in neonatal mice: an in vitro study.

PubMed

Ptak, K; Hilaire, G

1999-05-14

Experiments were performed on neonatal mice to know whether substance P (SP) modified the rhythm and the amplitude of the phrenic bursts generated in vitro in brainstem-cervical cord preparations. In OF1 and C3H neonatal preparations, SP or the tachykinin NK1 receptor agonist [Sar9,Met(O2)11] substance P both increased significantly phrenic burst amplitude (10(-7) M) but had no significant effect on respiratory rhythm unless used at concentrations 10 times larger. In neonates from the monoamine oxidase-A deficient transgenic Tg8 line, SP increased phrenic burst amplitude but had no effect on the respiratory rhythm at the tested concentrations. The role of SP in regulating neonatal respiratory activity is discussed on the basis of rat and mouse results.

A circular model for song motor control in Serinus canaria

PubMed Central

Alonso, Rodrigo G.; Trevisan, Marcos A.; Amador, Ana; Goller, Franz; Mindlin, Gabriel B.

2015-01-01

Song production in songbirds is controlled by a network of nuclei distributed across several brain regions, which drives respiratory and vocal motor systems to generate sound. We built a model for birdsong production, whose variables are the average activities of different neural populations within these nuclei of the song system. We focus on the predictions of respiratory patterns of song, because these can be easily measured and therefore provide a validation for the model. We test the hypothesis that it is possible to construct a model in which (1) the activity of an expiratory related (ER) neural population fits the observed pressure patterns used by canaries during singing, and (2) a higher forebrain neural population, HVC, is sparsely active, simultaneously with significant motor instances of the pressure patterns. We show that in order to achieve these two requirements, the ER neural population needs to receive two inputs: a direct one, and its copy after being processed by other areas of the song system. The model is capable of reproducing the measured respiratory patterns and makes specific predictions on the timing of HVC activity during their production. These results suggest that vocal production is controlled by a circular network rather than by a simple top-down architecture. PMID:25904860

Hydrothorax after Central Venous Catheterization

PubMed Central

Rudge, C. J.; Bewick, M.; McColl, I.

1973-01-01

Three patients are described who developed hydrothorax as a complication of central venous catheterization. Respiratory distress associated with physical signs of fluid in the chest should arouse suspicion that the venous catheter has perforated the wall of the vein. The complications of central venous catheterization are reviewed and three cases of hydrothorax are presented. Comments on the prevention of these complications, their diagnosis and treatment if they occur, are made. ImagesFIG. 1FIG. 2 PMID:4717421

A new paradigm in respiratory hygiene: modulating respiratory secretions to contain cough bioaerosol without affecting mucus clearance.

PubMed

Zayas, Gustavo; Valle, Juan C; Alonso, Mauricio; Alfaro, Henry; Vega, Daniel; Bonilla, Gloria; Reyes, Miguel; King, Malcolm

2007-08-13

Several strategies and devices have been designed to protect health care providers from acquiring transmissible respiratory diseases while providing care. In modulating the physical characteristics of the respiratory secretions to minimize the aerosolization that facilitates transmission of airborne diseases, a fundamental premise is that the prototype drugs have no adverse effect on the first line of respiratory defense, clearance of mucus by ciliary action. To assess and demonstrate the primary mechanism of our mucomodulators (XLs), we have built our evidence moving from basic laboratory studies to an ex-vivo model and then to an in-vivo large animal model. We exposed anesthetized dogs without hypersecretion to different dose concentrations of aerosolized XL "B", XL "D" and XL "S". We assessed: cardio-respiratory pattern, tracheal mucus clearance, airway patency, and mucus viscoelastic changes. Exposure of frog palate mucus to XLs did not affect the clearance of mucus by ciliary action. Dogs maintained normal cardio-respiratory pattern with XL administration. Tracheal mucociliary clearance in anesthetized dogs indicated a sustained 40% mean increase. Tracheal mucus showed increased filance, and there was no mucus retention in the airways. The ex-vivo frog palate and the in-vivo mammalian models used in this study, appear to be appropriate and complement each other to better assess the effects that our mucomodulators exert on the mucociliary clearance defence mechanism. The physiological function of the mucociliary apparatus was not negatively affected in any of the two epithelial models. Airway mucus crosslinked by mucomodulators is better cleared from an intact airway and normally functioning respiratory system, either due to enhanced interaction with cilia or airflow-dependent mechanisms. Data obtained in this study allow us to assure that we have complied with the fundamental requirement criteria established in the initial phase of developing the concept of mucomodulation: Can we modulate the physical characteristics of the respiratory secretions to reduce aerosolization without affecting normal mucociliary clearance function, or even better improving it?

Superinfection between Influenza and RSV Alternating Patterns in San Luis Potosí State, México

PubMed Central

Velasco-Hernández, Jorge Xicoténcatl; Núñez-López, Mayra; Comas-García, Andreu; Cherpitel, Daniel Ernesto Noyola; Ocampo, Marcos Capistrán

2015-01-01

The objective of this paper is to explain through the ecological hypothesis superinfection and competitive interaction between two viral populations and niche (host) availability, the alternating patterns of Respiratory Syncytial Virus (RSV) and influenza observed in a regional hospital in San Luis Potosí State, México using a mathematical model as a methodological tool. The data analyzed consists of community-based and hospital-based Acute Respiratory Infections (ARI) consultations provided by health-care institutions reported to the State Health Service Epidemiology Department from 2003 through 2009. PMID:25803450

A Wearable Capacitive Sensor for Monitoring Human Respiratory Rate

NASA Astrophysics Data System (ADS)

Kundu, Subrata Kumar; Kumagai, Shinya; Sasaki, Minoru

2013-04-01

Realizing an untethered, low-cost, and comfortably wearable respiratory rate sensor for long-term breathing monitoring application still remains a challenge. In this paper, a conductive-textile-based wearable respiratory rate sensing technique based on the capacitive sensing approach is proposed. The sensing unit consists of two conductive textile electrodes that can be easily fabricated, laminated, and integrated in garments. Respiration cycle is detected by measuring the capacitance of two electrodes placed on the inner anterior and posterior sides of a T-shirt at either the abdomen or chest position. A convenient wearable respiratory sensor setup with a capacitance-to-voltage converter has been devised. Respiratory rate as well as breathing mode can be accurately identified using the designed sensor. The sensor output provides significant information on respiratory flow. The effectiveness of the proposed system for different breathing patterns has been evaluated by experiments.

Chronic respiratory effects of exposure to diesel emissions in coal mines.

PubMed

Ames, R G; Hall, D S; Reger, R B

1984-01-01

A 5-yr prospective design was employed to test the hypothesis that exposure to diesel emissions leads to chronic respiratory effects among underground coal miners. Changes in respiratory function and development of chronic respiratory symptoms were measured during a 5-yr study period (i.e., 1977 to 1982) in 280 diesel-exposed and 838 control miners from Eastern and Western United States underground coal mines. Spirometry measures of respiratory function included forced expiratory volume in 1 sec (FEV1.0), forced vital capacity (FVC), and forced expiratory flow rate at 50% of FVC (FEF50). Chronic respiratory symptom measures, which included chronic cough, chronic phlegm, and breathlessness, were obtained by questionnaires, as were smoking status and occupational history. Based upon these data, the pattern of evidence did not support the hypothesis either in an age-adjusted comparison of diesel vs. nondiesel miners or in an internal analysis by cumulative years of diesel exposure.

Viral Co-Infections in Pediatric Patients Hospitalized with Lower Tract Acute Respiratory Infections.

PubMed

Cebey-López, Miriam; Herberg, Jethro; Pardo-Seco, Jacobo; Gómez-Carballa, Alberto; Martinón-Torres, Nazareth; Salas, Antonio; Martinón-Sánchez, José María; Gormley, Stuart; Sumner, Edward; Fink, Colin; Martinón-Torres, Federico

2015-01-01

Molecular techniques can often reveal a broader range of pathogens in respiratory infections. We aim to investigate the prevalence and age pattern of viral co-infection in children hospitalized with lower tract acute respiratory infection (LT-ARI), using molecular techniques. A nested polymerase chain reaction approach was used to detect Influenza (A, B), metapneumovirus, respiratory syncytial virus (RSV), parainfluenza (1-4), rhinovirus, adenovirus (A-F), bocavirus and coronaviruses (NL63, 229E, OC43) in respiratory samples of children with acute respiratory infection prospectively admitted to any of the GENDRES network hospitals between 2011-2013. The results were corroborated in an independent cohort collected in the UK. A total of 204 and 97 nasopharyngeal samples were collected in the GENDRES and UK cohorts, respectively. In both cohorts, RSV was the most frequent pathogen (52.9% and 36.1% of the cohorts, respectively). Co-infection with multiple viruses was found in 92 samples (45.1%) and 29 samples (29.9%), respectively; this was most frequent in the 12-24 months age group. The most frequently observed co-infection patterns were RSV-Rhinovirus (23 patients, 11.3%, GENDRES cohort) and RSV-bocavirus / bocavirus-influenza (5 patients, 5.2%, UK cohort). The presence of more than one virus in pediatric patients admitted to hospital with LT-ARI is very frequent and seems to peak at 12-24 months of age. The clinical significance of these findings is unclear but should warrant further analysis.

Nutrition in the first 1000 days and respiratory health: A descriptive review of the last five years' literature.

PubMed

Verduci, E; Martelli, A; Miniello, V L; Landi, M; Mariani, B; Brambilla, M; Diaferio, L; Peroni, D G

The aim of this paper is to discuss the current evidence regarding short and long-term health respiratory effects of nutrients and dietary patterns during the first 1000 days from conception. Population of interest included children from birth to two years and their mothers (during pregnancy and lactation). Studies were searched on MEDLINE® and Cochrane database, inserting individually and using the Boolean ANDs and ORs, 'nutrients', 'micronutrients', 'LC-PUFA', 'Mediterranean Diet', 'human milk', 'complementary food', 'pregnancy', 'respiratory disease', 'pulmonary disease', 'asthma', 'epigenetics', 'first 1000 days', 'maternal diet' and 'respiratory health'. All sources were retrieved between 01-09-2015 and 07-12-2016. While unhealthy maternal dietary patterns (high fat intake) during pregnancy can result in alteration of foetal lung development, with increased risk of respiratory disorders, Mediterranean diet has been associated with a lower risk of allergic sensitisation and allergic rhinitis. Breastfeeding has beneficial effects on respiratory infections while evidences about its protective effect on allergic disorders are unclear. During complementary feeding there is no evidence to avoid or encourage exposition to 'highly allergenic' foods to have modification of tolerance development. In children from birth to two years of age, Mediterranean diet has been associated with a lower risk of atopy, wheezing and asthma. Micronutrients, antioxidant and LCPUFA supplementation is not recommended and a whole food approach should be preferred, except for Vitamin D. Copyright © 2017 SEICAP. Published by Elsevier España, S.L.U. All rights reserved.

Viral Co-Infections in Pediatric Patients Hospitalized with Lower Tract Acute Respiratory Infections

PubMed Central

Cebey-López, Miriam; Herberg, Jethro; Pardo-Seco, Jacobo; Gómez-Carballa, Alberto; Martinón-Torres, Nazareth; Salas, Antonio; Martinón-Sánchez, José María; Gormley, Stuart; Sumner, Edward; Fink, Colin; Martinón-Torres, Federico

2015-01-01

Background Molecular techniques can often reveal a broader range of pathogens in respiratory infections. We aim to investigate the prevalence and age pattern of viral co-infection in children hospitalized with lower tract acute respiratory infection (LT-ARI), using molecular techniques. Methods A nested polymerase chain reaction approach was used to detect Influenza (A, B), metapneumovirus, respiratory syncytial virus (RSV), parainfluenza (1–4), rhinovirus, adenovirus (A—F), bocavirus and coronaviruses (NL63, 229E, OC43) in respiratory samples of children with acute respiratory infection prospectively admitted to any of the GENDRES network hospitals between 2011–2013. The results were corroborated in an independent cohort collected in the UK. Results A total of 204 and 97 nasopharyngeal samples were collected in the GENDRES and UK cohorts, respectively. In both cohorts, RSV was the most frequent pathogen (52.9% and 36.1% of the cohorts, respectively). Co-infection with multiple viruses was found in 92 samples (45.1%) and 29 samples (29.9%), respectively; this was most frequent in the 12–24 months age group. The most frequently observed co-infection patterns were RSV—Rhinovirus (23 patients, 11.3%, GENDRES cohort) and RSV—bocavirus / bocavirus—influenza (5 patients, 5.2%, UK cohort). Conclusion The presence of more than one virus in pediatric patients admitted to hospital with LT-ARI is very frequent and seems to peak at 12–24 months of age. The clinical significance of these findings is unclear but should warrant further analysis. PMID:26332375

Human respiratory syncytial virus genomic and antigenic variants isolated in two hospitals during one epidemic, in Santiago, Chile.

PubMed

Luchsinger, Vivian; Noy, Andrea Elgueta; Avendaño, Luis F

2008-07-01

Human respiratory syncytial virus (HRSV) is a major cause of severe lower respiratory tract infection (LRI) in children. Distinct variants of the viruses have been described. The objective was to compare the antigenic and genetic variability of HRSV strains recovered from infants admitted to two hospitals during one epidemic in a big city. We analyzed nasopharyngeal aspirates from 201 infants admitted for LRI to two hospitals during 2002 in Santiago, Chile. The analyses were carried out using a panel of monoclonal antibodies against G glycoprotein epitopes (EIA) and RFLP for N and G genes. No differences in HRSV groups A/B and in N patterns distribution were observed among both hospitals. On the contrary, antigenic and genetic G patterns displayed a wide diversity of strains circulating during one epidemic, in one big city. RSV variability assessment depended rather on the tool used for analysis than on the geographical location.

Acute respiratory disease in University of the Philippines and University of Wisconsin students. A comparative study.

PubMed

Evans, A S; D'Allessio, D A; Espiritu-Campos, L; Dick, E C

1967-01-01

In a comparison of acute respiratory disease patterns and incidence in students in a semi-tropical climate at the University of the Philippines with those in students in a temperate climate at the University of Wisconsin, USA, it was found that, while respiratory infections were the commonest cause of infirmary admissions in both institutions, yet, contrary to expectations, their incidence and relative importance were actually greater in the Philippine students than in the Wisconsin students. Peak rates occurred during the rainy season in the Philippines and during the coldest months in Wisconsin. Acute infectious mononucleosis was absent in the Philippines and streptococcal sore throat and primary atypical pneumonia were rare, but the three conditions were common in Wisconsin. The authors suggest that this difference in clinical pattern may be due to immunity in the Philippines students as a result of prior childhood infection.

Usefulness of a new online patient-specific quality assurance system for respiratory-gated radiotherapy.

PubMed

Kurosawa, Tomoyuki; Tachibana, Hidenobu; Moriya, Shunsuke; Miyakawa, Shin; Nishio, Teiji; Sato, Masanori

2017-11-01

The accuracy of gated irradiation may decrease when treatment is performed with short "beam-on" times. Also, the dose is subject to variation between treatment sessions if the respiratory rate is irregular. We therefore evaluated the impact of the differences between gated and non-gated treatment on doses using a new online quality assurance (QA) system for respiratory-gated radiotherapy. We generated dose estimation models to associate dose and pulse information using a 0.6 cc Farmer chamber and our QA system. During gated irradiation with each of seven regular and irregular respiratory patterns, with the Farmer chamber readings as references, we evaluated our QA system's accuracy. We then used the QA system to assess the impact of respiratory patterns on dose distribution for three lung and three liver radiotherapy plans. Gated and non-gated plans were generated and compared. There was agreement within 1.7% between the ionization chamber and our system for several regular and irregular motion patterns. For dose distributions with measured errors, there were larger differences between gated and non-gated treatment for high-dose regions within the planned treatment volume (PTV). Compared with a non-gated plan, PTV D 95% for a gated plan decreased by -1.5% to -2.6%. Doses to organs at risk were similar with both plans. Our simple system estimated the radiation dose to the patient using only pulse information from the linac, even during irregular respiration. The quality of gated irradiation for each patient can be verified fraction by fraction. Copyright © 2017 Associazione Italiana di Fisica Medica. Published by Elsevier Ltd. All rights reserved.

Radiation necrosis causing failure of automatic ventilation during sleep with central sleep apnea

DOE Office of Scientific and Technical Information (OSTI.GOV)

Udwadia, Z.F.; Athale, S.; Misra, V.P.

A patient operated upon for a midline cerebellar hemangioblastoma developed failure of automatic respiration during sleep, together with central sleep apnea syndrome, approximately two years after receiving radiation therapy to the brain. Clinical and CT scan findings were compatible with a diagnosis of radiation necrosis as the cause of his abnormal respiratory control.

Current and future developments in the field of central sleep apnoea.

PubMed

Bekfani, Tarek; Abraham, William T

2016-08-01

Central sleep apnoea (CSA) occurs in ∼30-50% of patients with heart failure (HF) with reduced left ventricular ejection fraction (LVEF) and in as much as in 18-30% of patients with preserved LVEF. In HF patients, it is characterized by periodic breathing also known as the Cheyne-Stokes respiration followed by pauses of breathing. Central sleep apnoea remains often unrecognized due to its chronic and insidious incidences. Patients may report excessive daytime somnolence, poor sleep quality, nocturnal angina, recurrent arrhythmias, refractory HF symptoms, or demonstrate abnormal respiratory pattern or apnoeas. The pathogenesis of CSA remains incompletely understood, but changes in CO2 above and below the apnoea threshold play a major role in its pathogenesis. The presence of CSA in patients with HF is associated with some neurohumoral and haemodynamic responses that are detrimental to the failing heart including increased morbidity and mortality. The development of successful therapies targeting CSA and its harmful downstream effects is therefore important. Several different therapies from medications to implantable devices have been tested with varying effects and primarily in small non-randomized and/or single-centre studies. Large studies to date have been disappointing, but therapeutic options targeting the physiology of the disease may herald a new era in understanding and treating CSA. Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2016. For permissions please email: journals.permissions@oup.com.

Imaging and dosimetric errors in 4D PET/CT-guided radiotherapy from patient-specific respiratory patterns: a dynamic motion phantom end-to-end study

NASA Astrophysics Data System (ADS)

Bowen, S. R.; Nyflot, M. J.; Herrmann, C.; Groh, C. M.; Meyer, J.; Wollenweber, S. D.; Stearns, C. W.; Kinahan, P. E.; Sandison, G. A.

2015-05-01

Effective positron emission tomography / computed tomography (PET/CT) guidance in radiotherapy of lung cancer requires estimation and mitigation of errors due to respiratory motion. An end-to-end workflow was developed to measure patient-specific motion-induced uncertainties in imaging, treatment planning, and radiation delivery with respiratory motion phantoms and dosimeters. A custom torso phantom with inserts mimicking normal lung tissue and lung lesion was filled with [18F]FDG. The lung lesion insert was driven by six different patient-specific respiratory patterns or kept stationary. PET/CT images were acquired under motionless ground truth, tidal breathing motion-averaged (3D), and respiratory phase-correlated (4D) conditions. Target volumes were estimated by standardized uptake value (SUV) thresholds that accurately defined the ground-truth lesion volume. Non-uniform dose-painting plans using volumetrically modulated arc therapy were optimized for fixed normal lung and spinal cord objectives and variable PET-based target objectives. Resulting plans were delivered to a cylindrical diode array at rest, in motion on a platform driven by the same respiratory patterns (3D), or motion-compensated by a robotic couch with an infrared camera tracking system (4D). Errors were estimated relative to the static ground truth condition for mean target-to-background (T/Bmean) ratios, target volumes, planned equivalent uniform target doses, and 2%-2 mm gamma delivery passing rates. Relative to motionless ground truth conditions, PET/CT imaging errors were on the order of 10-20%, treatment planning errors were 5-10%, and treatment delivery errors were 5-30% without motion compensation. Errors from residual motion following compensation methods were reduced to 5-10% in PET/CT imaging, <5% in treatment planning, and <2% in treatment delivery. We have demonstrated that estimation of respiratory motion uncertainty and its propagation from PET/CT imaging to RT planning, and RT delivery under a dose painting paradigm is feasible within an integrated respiratory motion phantom workflow. For a limited set of cases, the magnitude of errors was comparable during PET/CT imaging and treatment delivery without motion compensation. Errors were moderately mitigated during PET/CT imaging and significantly mitigated during RT delivery with motion compensation. This dynamic motion phantom end-to-end workflow provides a method for quality assurance of 4D PET/CT-guided radiotherapy, including evaluation of respiratory motion compensation methods during imaging and treatment delivery.

Imaging and dosimetric errors in 4D PET/CT-guided radiotherapy from patient-specific respiratory patterns: a dynamic motion phantom end-to-end study.

PubMed

Bowen, S R; Nyflot, M J; Herrmann, C; Groh, C M; Meyer, J; Wollenweber, S D; Stearns, C W; Kinahan, P E; Sandison, G A

2015-05-07

Effective positron emission tomography / computed tomography (PET/CT) guidance in radiotherapy of lung cancer requires estimation and mitigation of errors due to respiratory motion. An end-to-end workflow was developed to measure patient-specific motion-induced uncertainties in imaging, treatment planning, and radiation delivery with respiratory motion phantoms and dosimeters. A custom torso phantom with inserts mimicking normal lung tissue and lung lesion was filled with [(18)F]FDG. The lung lesion insert was driven by six different patient-specific respiratory patterns or kept stationary. PET/CT images were acquired under motionless ground truth, tidal breathing motion-averaged (3D), and respiratory phase-correlated (4D) conditions. Target volumes were estimated by standardized uptake value (SUV) thresholds that accurately defined the ground-truth lesion volume. Non-uniform dose-painting plans using volumetrically modulated arc therapy were optimized for fixed normal lung and spinal cord objectives and variable PET-based target objectives. Resulting plans were delivered to a cylindrical diode array at rest, in motion on a platform driven by the same respiratory patterns (3D), or motion-compensated by a robotic couch with an infrared camera tracking system (4D). Errors were estimated relative to the static ground truth condition for mean target-to-background (T/Bmean) ratios, target volumes, planned equivalent uniform target doses, and 2%-2 mm gamma delivery passing rates. Relative to motionless ground truth conditions, PET/CT imaging errors were on the order of 10-20%, treatment planning errors were 5-10%, and treatment delivery errors were 5-30% without motion compensation. Errors from residual motion following compensation methods were reduced to 5-10% in PET/CT imaging, <5% in treatment planning, and <2% in treatment delivery. We have demonstrated that estimation of respiratory motion uncertainty and its propagation from PET/CT imaging to RT planning, and RT delivery under a dose painting paradigm is feasible within an integrated respiratory motion phantom workflow. For a limited set of cases, the magnitude of errors was comparable during PET/CT imaging and treatment delivery without motion compensation. Errors were moderately mitigated during PET/CT imaging and significantly mitigated during RT delivery with motion compensation. This dynamic motion phantom end-to-end workflow provides a method for quality assurance of 4D PET/CT-guided radiotherapy, including evaluation of respiratory motion compensation methods during imaging and treatment delivery.

Imaging and dosimetric errors in 4D PET/CT-guided radiotherapy from patient-specific respiratory patterns: a dynamic motion phantom end-to-end study

PubMed Central

Bowen, S R; Nyflot, M J; Hermann, C; Groh, C; Meyer, J; Wollenweber, S D; Stearns, C W; Kinahan, P E; Sandison, G A

2015-01-01

Effective positron emission tomography/computed tomography (PET/CT) guidance in radiotherapy of lung cancer requires estimation and mitigation of errors due to respiratory motion. An end-to-end workflow was developed to measure patient-specific motion-induced uncertainties in imaging, treatment planning, and radiation delivery with respiratory motion phantoms and dosimeters. A custom torso phantom with inserts mimicking normal lung tissue and lung lesion was filled with [18F]FDG. The lung lesion insert was driven by 6 different patient-specific respiratory patterns or kept stationary. PET/CT images were acquired under motionless ground truth, tidal breathing motion-averaged (3D), and respiratory phase-correlated (4D) conditions. Target volumes were estimated by standardized uptake value (SUV) thresholds that accurately defined the ground-truth lesion volume. Non-uniform dose-painting plans using volumetrically modulated arc therapy (VMAT) were optimized for fixed normal lung and spinal cord objectives and variable PET-based target objectives. Resulting plans were delivered to a cylindrical diode array at rest, in motion on a platform driven by the same respiratory patterns (3D), or motion-compensated by a robotic couch with an infrared camera tracking system (4D). Errors were estimated relative to the static ground truth condition for mean target-to-background (T/Bmean) ratios, target volumes, planned equivalent uniform target doses (EUD), and 2%-2mm gamma delivery passing rates. Relative to motionless ground truth conditions, PET/CT imaging errors were on the order of 10–20%, treatment planning errors were 5–10%, and treatment delivery errors were 5–30% without motion compensation. Errors from residual motion following compensation methods were reduced to 5–10% in PET/CT imaging, < 5% in treatment planning, and < 2% in treatment delivery. We have demonstrated that estimation of respiratory motion uncertainty and its propagation from PET/CT imaging to RT planning, and RT delivery under a dose painting paradigm is feasible within an integrated respiratory motion phantom workflow. For a limited set of cases, the magnitude of errors was comparable during PET/CT imaging and treatment delivery without motion compensation. Errors were moderately mitigated during PET/CT imaging and significantly mitigated during RT delivery with motion compensation. This dynamic motion phantom end-to-end workflow provides a method for quality assurance of 4D PET/CT-guided radiotherapy, including evaluation of respiratory motion compensation methods during imaging and treatment delivery. PMID:25884892

[Hemodynamic changes in hypoglycemic shock].

PubMed

Gutiérrez, C; Piza, R; Chousleb, A; Hidalgo, M A; Ortigosa, J L

1977-01-01

Severe hypoglycemia may be present in seriously ill patients; if it is not corrected opportunely a series of neuroendocrinal mechanisms take place aimed at correcting metabolic alterations. These mechanisms can produce hemodynamic alterations as well. Nine mongrel dogs were studied with continuous registration of: blood pressure, central venous pressure, cardiac frequency, respiratory frequency, electrocardiogram and first derivative (Dp/Dt). Six dogs received crystalline (fast acting) insuline intravenously (group 1). After hemodynamic changes were registered hypoglycemia was corrected with 50 per cent glucose solution. Complementary insuline doses were administered to three dogs (group 2); in this group hypoglycemia was not corrected. In group 1 during hypoglycemia there was an increase in blood pressure, central venous pressure, cardiac frequency, respiratory frequency and Dp/Dt, and changes in QT and T wave on the EKG; these changes were partially reversible after hypoglycemia was corrected. The above mentioned alterations persisted in group 2, breathing became irregular irregular and respiratory arrest supervened. It can be inferred that the hemodynamic response to hypoglycemia is predominantly adrenergic. The role of catecolamines, glucocorticoides, glucagon, insuline, cyclic AMP in metabolic and hemodynamic alterations consecutive to hypoglycemia are discussed.

Central sleep apnea detection from ECG-derived respiratory signals. Application of multivariate recurrence plot analysis.

PubMed

Maier, C; Dickhaus, H

2010-01-01

This study examines the suitability of recurrence plot analysis for the problem of central sleep apnea (CSA) detection and delineation from ECG-derived respiratory (EDR) signals. A parameter describing the average length of vertical line structures in recurrence plots is calculated at a time resolution of 1 s as 'instantaneous trapping time'. Threshold comparison of this parameter is used to detect ongoing CSA. In data from 26 patients (duration 208 h) we assessed sensitivity for detection of CSA and mixed apnea (MSA) events by comparing the results obtained from 8-channel Holter ECGs to the annotations (860 CSA, 480 MSA) of simultaneously registered polysomnograms. Multivariate combination of the EDR from different ECG leads improved the detection accuracy significantly. When all eight leads were considered, an average instantaneous vertical line length above 5 correctly identified 1126 of the 1340 events (sensitivity 84%) with a total number of 1881 positive detections. We conclude that recurrence plot analysis is a promising tool for detection and delineation of CSA epochs from EDR signals with high time resolution. Moreover, the approach is likewise applicable to directly measured respiratory signals.

[Sleep apnea and heart failure: pathophysiology, diagnosis and therapy].

PubMed

Monda, Cinzia; Scala, Oriana; Paolillo, Stefania; Savarese, Gianluigi; Cecere, Milena; D'Amore, Carmen; Parente, Antonio; Musella, Francesca; Mosca, Susanna; Filardi, Pasquale Perrone

2010-11-01

Sleep apnea, defined as a pathologic pause in breathing during sleep >10 s, promotes the progression of chronic heart failure and may be a predictor of poor prognosis. It causes, in fact, several mechanical, hemodynamic, chemical and inflammatory changes that negatively compromise cardiovascular homeostasis of heart failure patients. Sleep apnea is recognized as sleep apnea syndrome when specific symptoms, such as sleepiness and headache during the daytime and snoring, are present and is diagnosed with an overnight test called polysomnography. There are two different forms of sleep apnea, central and obstructive. Breathing is interrupted by the loss of respiratory drive and the lack of respiratory effort in the central form, which affects about 40-60% of heart failure patients. In obstructive sleep apnea, breathing stops when throat muscles relax, despite respiratory effort. This form affects about 3% of the general population, while it is present in at least 30% of heart failure patients. The diagnosis of sleep disorders in heart failure becomes very important to help patients adopting lifestyle changes and starting specific therapies to improve quality of life and retard the progression of chronic heart failure.

Simulation of range imaging-based estimation of respiratory lung motion. Influence of noise, signal dimensionality and sampling patterns.

PubMed

Wilms, M; Werner, R; Blendowski, M; Ortmüller, J; Handels, H

2014-01-01

A major problem associated with the irradiation of thoracic and abdominal tumors is respiratory motion. In clinical practice, motion compensation approaches are frequently steered by low-dimensional breathing signals (e.g., spirometry) and patient-specific correspondence models, which are used to estimate the sought internal motion given a signal measurement. Recently, the use of multidimensional signals derived from range images of the moving skin surface has been proposed to better account for complex motion patterns. In this work, a simulation study is carried out to investigate the motion estimation accuracy of such multidimensional signals and the influence of noise, the signal dimensionality, and different sampling patterns (points, lines, regions). A diffeomorphic correspondence modeling framework is employed to relate multidimensional breathing signals derived from simulated range images to internal motion patterns represented by diffeomorphic non-linear transformations. Furthermore, an automatic approach for the selection of optimal signal combinations/patterns within this framework is presented. This simulation study focuses on lung motion estimation and is based on 28 4D CT data sets. The results show that the use of multidimensional signals instead of one-dimensional signals significantly improves the motion estimation accuracy, which is, however, highly affected by noise. Only small differences exist between different multidimensional sampling patterns (lines and regions). Automatically determined optimal combinations of points and lines do not lead to accuracy improvements compared to results obtained by using all points or lines. Our results show the potential of multidimensional breathing signals derived from range images for the model-based estimation of respiratory motion in radiation therapy.

Evaluation of bovine coronavirus antibody levels, virus shedding, and respiratory disease incidence throughout the beef cattle production cycle

USDA-ARS?s Scientific Manuscript database

Objective- Determine how levels of serum antibody to bovine coronavirus (BCV) are related to virus shedding patterns and respiratory disease incidence in beef calves at various production stages. Animals- 890 crossbred beef calves from four separately managed herds at the U.S. Meat Animal Research C...

Unraveling the contact patterns and network structure of pig shipments in the United States and its association with porcine reproductive and respiratory syndrome virus (PRRSV) outbreaks.

PubMed

Lee, Kyuyoung; Polson, Dale; Lowe, Erin; Main, Rodger; Holtkamp, Derald; Martínez-López, Beatriz

2017-03-01

The analysis of the pork value chain is becoming key to understanding the risk of infectious disease dissemination in the swine industry. In this study, we used social network analysis to characterize the swine shipment network structure and properties in a typical multisite swine production system in the US. We also aimed to evaluate the association between network properties and porcine respiratory and reproductive syndrome virus (PRRSV) transmission between production sites. We analyzed the 109,868 swine shipments transporting over 93 million swine between more than 500 production sites from 2012 to 2014. A total of 248 PRRSV positive occurrences were reported from 79 production sites during those 3 years. The temporal dynamics of swine shipments was evaluated by computing network properties in one-month and three-month networks. The association of PRRS occurrence in sow farms with centrality properties from one-month and three-month networks was assessed by using the multilevel logistic regression. All monthly networks showed a scale-free network topology with positive degree assortativity. The regression model revealed that out-degree centrality had a negative association with PRRS occurrence in sow farms in both one-month and three-month networks [OR=0.79 (95% CI, 0.63-0.99) in one-month network and 0.56 (95% CI, 0.36, 0.88) in three-month network] and in-closeness centrality model was positively associated with PRRS occurrence in sow farms in the three-month network [OR=2.45 (95% CI, 1.14-5.26)]. We also describe how the occurrence of porcine epidemic diarrheac (PED) outbreaks severely affected the network structure as well as the PRRS occurrence reports and its association with centrality measures in sow farms. The structure of the swine shipment network and the connectivity between production sites influenced on the PRRSV transmission. The use of network topology and characteristics combining with spatial analysis based on fine scale geographical location of production sites will be useful to inform the design of more cost-efficient, risk-based surveillance and control measures for PRRSV as well as other diseases in the US swine industry. Copyright © 2017 Elsevier B.V. All rights reserved.

Deposition of Aerosols in the Lung: Physiological Factors

EPA Science Inventory

Ventilation and mechanics of breathing are an integral part of respiratory physiology that directly affect aerosol transport and deposition in the lung. Although natural breathing pattern varies widely among individuals, breathing pattern is controllable, and by using an appropri...

[Respiratory diseases in black African carceral area].

PubMed

Toloba, Y; Soumaré, D; Ouattara, K; Kanouté, T; Boré, O; Dolo, O; Baya, B; Berthé, G; Diallo, S

2017-09-01

The measures for people in specific situations such as prisoners are part of the Millennium Development Goals (MDGs). The objective of this study was to assess respiratory pathologies in a black African carceral center. Retrospective study about the prevalence of respiratory pathologies in the arrest central house for men in Bamako (Mali), from May 2012 to April 2013. The admission records have served as data checking support on detainee's records. Statistical significance was investigated by the SAS 9.3 software with a threshold of 5%. Of 2740 admissions, 207 concerned respiratory pathologies (7.5%). All men, were of mean age 30±13 years (range 19-71). The respiratory diseases found were: pneumonia (33.8%), chronic bronchitis (26.6%), acute respiratory infection (14%), asthma (13.5%) and tuberculosis (5.3%). A definite diagnosis was made in 42% of cases. A tobacco intoxication was found in all age groups (CI 95%, R-square=0.01), without significant difference between the occurrence of cough in smoking and non-smoking men. According to their relative frequencies, the management of respiratory diseases requires collaboration between carceral health facilities and pneumological specialized services. Copyright © 2017 SPLF. Published by Elsevier Masson SAS. All rights reserved.

The Association of Geographic Coordinates with Mortality in People with Lower and Higher Education and with Mortality Inequalities in Spain.

PubMed

Regidor, Enrique; Reques, Laura; Giráldez-García, Carolina; Miqueleiz, Estrella; Santos, Juana M; Martínez, David; de la Fuente, Luis

2015-01-01

Geographic patterns in total mortality and in mortality by cause of death are widely known to exist in many countries. However, the geographic pattern of inequalities in mortality within these countries is unknown. This study shows mathematically and graphically the geographic pattern of mortality inequalities by education in Spain. Data are from a nation-wide prospective study covering all persons living in Spain's 50 provinces in 2001. Individuals were classified in a cohort of subjects with low education and in another cohort of subjects with high education. Age- and sex-adjusted mortality rate from all causes and from leading causes of death in each cohort and mortality rate ratios in the low versus high education cohort were estimated by geographic coordinates and province. Latitude but not longitude was related to mortality. In subjects with low education, latitude had a U-shaped relation to mortality. In those with high education, mortality from all causes, and from cardiovascular, respiratory and digestive diseases decreased with increasing latitude, whereas cancer mortality increased. The mortality-rate ratio for all-cause death was 1.27 in the southern latitudes, 1.14 in the intermediate latitudes, and 1.20 in the northern latitudes. The mortality rate ratios for the leading causes of death were also higher in the lower and upper latitudes than in the intermediate latitudes. The geographic pattern of the mortality rate ratios is similar to that of the mortality rate in the low-education cohort: the highest magnitude is observed in the southern provinces, intermediate magnitudes in the provinces of the north and those of the Mediterranean east coast, and the lowest magnitude in the central provinces and those in the south of the Western Pyrenees. Mortality inequalities by education in Spain are higher in the south and north of the country and lower in the large region making up the central plateau. This geographic pattern is similar to that observed in mortality in the low-education cohort.

The Toxicity of Inhaled Sulphur Mustard

DTIC Science & Technology

2012-10-01

Index − CO – Cardiac Output − CvO2 – Mixed Venous Oxygenation − CVP – Central Venous Pressure − DO2 – Oxygen Delivery − dpMax – Maximum...in central venous pressure following exposure to HD: HD controls () and HD + NAC (). Data are expressed as mean ± SEM. UK UNCLASSIFIED Page 64 of...Respiratory rate (RR) Heart rate (HR) Expired CO2 Pulse oximetry Mean arterial pressure Central venous pressure Blood Chemistry (arterial and

Effectiveness of respiratory-gated radiotherapy with audio-visual biofeedback for synchrotron-based scanned heavy-ion beam delivery

NASA Astrophysics Data System (ADS)

He, Pengbo; Li, Qiang; Zhao, Ting; Liu, Xinguo; Dai, Zhongying; Ma, Yuanyuan

2016-12-01

A synchrotron-based heavy-ion accelerator operates in pulse mode at a low repetition rate that is comparable to a patient’s breathing rate. To overcome inefficiencies and interplay effects between the residual motion of the target and the scanned heavy-ion beam delivery process for conventional free breathing (FB)-based gating therapy, a novel respiratory guidance method was developed to help patients synchronize their breathing patterns with the synchrotron excitation patterns by performing short breath holds with the aid of personalized audio-visual biofeedback (BFB) system. The purpose of this study was to evaluate the treatment precision, efficiency and reproducibility of the respiratory guidance method in scanned heavy-ion beam delivery mode. Using 96 breathing traces from eight healthy volunteers who were asked to breathe freely and guided to perform short breath holds with the aid of BFB, a series of dedicated four-dimensional dose calculations (4DDC) were performed on a geometric model which was developed assuming a linear relationship between external surrogate and internal tumor motions. The outcome of the 4DDCs was quantified in terms of the treatment time, dose-volume histograms (DVH) and dose homogeneity index. Our results show that with the respiratory guidance method the treatment efficiency increased by a factor of 2.23-3.94 compared with FB gating, depending on the duty cycle settings. The magnitude of dose inhomogeneity for the respiratory guidance methods was 7.5 times less than that of the non-gated irradiation, and good reproducibility of breathing guidance among different fractions was achieved. Thus, our study indicates that the respiratory guidance method not only improved the overall treatment efficiency of respiratory-gated scanned heavy-ion beam delivery, but also had the advantages of lower dose uncertainty and better reproducibility among fractions.

Evolution of viviparous reproduction in Paleozoic and Mesozoic reptiles.

PubMed

Blackburn, Daniel G; Sidor, Christian A

2014-01-01

Although viviparity (live-bearing reproduction) is widely distributed among lizards and snakes, it is entirely absent from other extant Reptilia and many extinct forms. However, paleontological evidence reveals that viviparity was present in at least nine nominal groups of pre-Cenozoic reptiles, representing a minimum of six separate evolutionary origins of this reproductive mode. Two viviparous clades (sauropterygians and ichthyopterygians) lasted more than 155 million years, a figure that rivals the duration of mammalian viviparity. Circumstantial evidence indicates that extinct viviparous reptiles had internal fertilization, amniotic fetal membranes, and placentas that sustained developing embryos via provision of respiratory gases, water, calcium, and possibly organic nutrients. Production of offspring via viviparity facilitated the invasion of marine habitats in at least five reptilian lineages. Thus, this pattern of embryonic development and reproduction was central to the ecology and evolution of these ancient animals, much as it is to numerous extant species of vertebrates.

The vesicular glutamate transporter VGLUT3 contributes to protection against neonatal hypoxic stress

PubMed Central

Miot, Stéphanie; Voituron, Nicolas; Sterlin, Adélaïde; Vigneault, Erika; Morel, Lydie; Matrot, Boris; Ramanantsoa, Nelina; Amilhon, Bénédicte; Poirel, Odile; Lepicard, Ève; El Mestikawy, Salah; Hilaire, Gérard; Gallego, Jorge

2012-01-01

Neonates respond to hypoxia initially by increasing ventilation, and then by markedly decreasing both ventilation (hypoxic ventilatory decline) and oxygen consumption (hypoxic hypometabolism). This latter process, which vanishes with age, reflects a tight coupling between ventilatory and thermogenic responses to hypoxia. The neurological substrate of hypoxic hypometabolism is unclear, but it is known to be centrally mediated, with a strong involvement of the 5-hydroxytryptamine (5-HT, serotonin) system. To clarify this issue, we investigated the possible role of VGLUT3, the third subtype of vesicular glutamate transporter. VGLUT3 contributes to glutamate signalling by 5-HT neurons, facilitates 5-HT transmission and is expressed in strategic regions for respiratory and thermogenic control. We therefore assumed that VGLUT3 might significantly contribute to the response to hypoxia. To test this possibility, we analysed this response in newborn mice lacking VGLUT3 using anatomical, biochemical, electrophysiological and integrative physiology approaches. We found that the lack of VGLUT3 did not affect the histological organization of brainstem respiratory networks or respiratory activity under basal conditions. However, it impaired respiratory responses to 5-HT and anoxia, showing a marked alteration of central respiratory control. These impairments were associated with altered 5-HT turnover at the brainstem level. Furthermore, under cold conditions, the lack of VGLUT3 disrupted the metabolic rate, body temperature, baseline breathing and the ventilatory response to hypoxia. We conclude that VGLUT3 expression is dispensable under basal conditions but is required for optimal response to hypoxic stress in neonates. PMID:22890712

A multivariate time-frequency method to characterize the influence of respiration over heart period and arterial pressure

NASA Astrophysics Data System (ADS)

Orini, Michele; Bailón, Raquel; Laguna, Pablo; Mainardi, Luca T.; Barbieri, Riccardo

2012-12-01

Respiratory activity introduces oscillations both in arterial pressure and heart period, through mechanical and autonomic mechanisms. Respiration, arterial pressure, and heart period are, generally, non-stationary processes and the interactions between them are dynamic. In this study we present a methodology to robustly estimate the time course of cross spectral indices to characterize dynamic interactions between respiratory oscillations of heart period and blood pressure, as well as their interactions with respiratory activity. Time-frequency distributions belonging to Cohen's class are used to estimate time-frequency (TF) representations of coherence, partial coherence and phase difference. The characterization is based on the estimation of the time course of cross spectral indices estimated in specific TF regions around the respiratory frequency. We used this methodology to describe the interactions between respiration, heart period variability (HPV) and systolic arterial pressure variability (SAPV) during tilt table test with both spontaneous and controlled respiratory patterns. The effect of selective autonomic blockade was also studied. Results suggest the presence of common underling mechanisms of regulation between cardiovascular signals, whose interactions are time-varying. SAPV changes followed respiratory flow both in supine and standing positions and even after selective autonomic blockade. During head-up tilt, phase differences between respiration and SAPV increased. Phase differences between respiration and HPV were comparable to those between respiration and SAPV during supine position, and significantly increased during standing. As a result, respiratory oscillations in SAPV preceded respiratory oscillations in HPV during standing. Partial coherence was the most sensitive index to orthostatic stress. Phase difference estimates were consistent among spontaneous and controlled breathing patterns, whereas coherence was higher in spontaneous breathing. Parasympathetic blockade did not affect interactions between respiration and SAPV, reduced the coherence between SAPV and HPV and between respiration and HPV. Our results support the hypothesis that non-autonomic, possibly mechanically mediated, mechanisms also contributes to the respiratory oscillations in HPV. A small contribution of sympathetic activity on HPV-SAPV interactions around the respiratory frequency was also observed.

Influenza and other respiratory viruses in three Central American countries

PubMed Central

Laguna‐Torres, Victor A.; Sánchez‐Largaespada, José F.; Lorenzana, Ivette; Forshey, Brett; Aguilar, Patricia; Jimenez, Mirna; Parrales, Eduardo; Rodriguez, Francisco; García, Josefina; Jimenez, Ileana; Rivera, Maribel; Perez, Juan; Sovero, Merly; Rios, Jane; Gamero, María E.; Halsey, Eric S.; Kochel, Tadeusz J.

2010-01-01

Please cite this paper as: Laguna‐Torres et al. (2011) Influenza and other respiratory viruses in three Central American countries. Influenza and Other Respiratory Viruses 5(2), 123–134. Background  Despite the disease burden imposed by respiratory diseases on children in Central America, there is a paucity of data describing the etiologic agents of the disease. Aims  To analyze viral etiologic agents associated with influenza‐like illness (ILI) in participants reporting to one outpatient health center, one pediatric hospital, and three general hospitals in El Salvador, Honduras, and Nicaragua Material & Methods  Between August 2006 and April 2009, pharyngeal swabs were collected from outpatients and inpatients. Patient specimens were inoculated onto cultured cell monolayers, and viral antigens were detected by indirect and direct immunofluorescence staining. Results  A total of 1,756 patients were enrolled, of whom 1,195 (68.3%) were under the age of 5; and 183 (10.4%) required hospitalization. One or more viral agents were identified in 434 (24.7%) cases, of which 17 (3.9%) were dual infections. The most common viruses isolated were influenza A virus (130; 7.4% of cases), respiratory syncytial virus (122; 6.9%), adenoviruses (63; 3.6%), parainfluenza viruses (57; 3.2%), influenza B virus (47; 2.7% of cases), and herpes simplex virus 1 (22; 1.3%). In addition, human metapneumovirus and enteroviruses (coxsackie and echovirus) were isolated from patient specimens. Discussion  When compared to the rest of the population, viruses were isolated from a significantly higher percentage of patients age 5 or younger. The prevalence of influenza A virus or influenza B virus infections was similar between the younger and older age groups. RSV was the most commonly detected pathogen in infants age 5 and younger and was significantly associated with pneumonia (p < 0.0001) and hospitalization (p < 0.0001). Conclusion  Genetic analysis of influenza isolates identified A (H3N2), A (H1N1), and B viruses. It also showed that the mutation H274Y conferring resistance to oseltamivir was first detected in Honduran influenza A/H1N1 strains at the beginning of 2008. These data demonstrate that a diverse range of respiratory pathogens are associated with ILI in Honduras, El Salvador, and Nicaragua. RSV infection in particular appears to be associated with severe disease in infants in the region. PMID:21306576

Physical interventions to interrupt or reduce the spread of respiratory viruses.

PubMed

Jefferson, Tom; Del Mar, Chris; Dooley, Liz; Ferroni, Eliana; Al-Ansary, Lubna A; Bawazeer, Ghada A; van Driel, Mieke L; Nair, Sreekumaran; Foxlee, Ruth; Rivetti, Alessandro

2010-01-20

Viral epidemics or pandemics of acute respiratory infections like influenza or severe acute respiratory syndrome pose a world-wide threat. Antiviral drugs and vaccinations may be insufficient to prevent catastrophe. To systematically review the effectiveness of physical interventions to interrupt or reduce the spread of respiratory viruses. We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2009, issue 2); MEDLINE (1966 to May 2009); OLDMEDLINE (1950 to 1965); EMBASE (1990 to May 2009); and CINAHL (1982 to May 2009). We scanned 2958 titles, excluded 2790 and retrieved the full papers of 168 trials, to include 59 papers of 60 studies. We included any physical interventions (isolation, quarantine, social distancing, barriers, personal protection and hygiene) to prevent transmission of respiratory viruses. We included the following study designs: randomised controlled trials (RCTs), cohorts, case controls, cross-over, before-after, and time series studies. We used a standardised form to assess trial eligibility. RCTs were assessed by: randomisation method; allocation generation; concealment; blinding; and follow up. Non-RCTs were assessed for the presence of potential confounders, and classified into low, medium, and high risks of bias. The risk of bias for the four RCTs, and most cluster RCTs, was high. The observational studies were of mixed quality. Only case-control data were sufficiently homogeneous to allow meta-analysis.The highest quality cluster RCTs suggest respiratory virus spread can be prevented by hygienic measures, such as handwashing, especially around younger children. Additional benefit from reduced transmission from children to other household members is broadly supported in results of other study designs, where the potential for confounding is greater. Six case-control studies suggested that implementing barriers to transmission, isolation, and hygienic measures are effective at containing respiratory virus epidemics. We found limited evidence that N95 respirators were superior to simple surgical masks, but were more expensive, uncomfortable, and caused skin irritation. The incremental effect of adding virucidals or antiseptics to normal handwashing to decrease respiratory disease remains uncertain. Global measures, such as screening at entry ports, were not properly evaluated. There was limited evidence that social distancing was effective especially if related to the risk of exposure. Many simple and probably low-cost interventions would be useful for reducing the transmission of epidemic respiratory viruses. Routine long-term implementation of some of the measures assessed might be difficult without the threat of a looming epidemic.

DEPOSITION PATTERNS OF RAGWEED POLLEN IN THE HUMAN RESPIRATORY TRACT

EPA Science Inventory

Inhaled particle deposition sites must be identified to effectively treat human airway diseases. e have determined distribution patterns of a selected aeroallergen, ragweed pollen, among human extrathoracic (ET: .e., oro-nasopharyngeal) regions and the lung. A predictive model va...

Interaction between AIF and CHCHD4 Regulates Respiratory Chain Biogenesis.

PubMed

Hangen, Emilie; Féraud, Olivier; Lachkar, Sylvie; Mou, Haiwei; Doti, Nunzianna; Fimia, Gian Maria; Lam, Ngoc-Vy; Zhu, Changlian; Godin, Isabelle; Muller, Kevin; Chatzi, Afroditi; Nuebel, Esther; Ciccosanti, Fabiola; Flamant, Stéphane; Bénit, Paule; Perfettini, Jean-Luc; Sauvat, Allan; Bennaceur-Griscelli, Annelise; Ser-Le Roux, Karine; Gonin, Patrick; Tokatlidis, Kostas; Rustin, Pierre; Piacentini, Mauro; Ruvo, Menotti; Blomgren, Klas; Kroemer, Guido; Modjtahedi, Nazanine

2015-06-18

Apoptosis-inducing factor (AIF) is a mitochondrial flavoprotein that, beyond its apoptotic function, is required for the normal expression of major respiratory chain complexes. Here we identified an AIF-interacting protein, CHCHD4, which is the central component of a redox-sensitive mitochondrial intermembrane space import machinery. Depletion or hypomorphic mutation of AIF caused a downregulation of CHCHD4 protein by diminishing its mitochondrial import. CHCHD4 depletion sufficed to induce a respiratory defect that mimicked that observed in AIF-deficient cells. CHCHD4 levels could be restored in AIF-deficient cells by enforcing its AIF-independent mitochondrial localization. This modified CHCHD4 protein reestablished respiratory function in AIF-deficient cells and enabled AIF-deficient embryoid bodies to undergo cavitation, a process of programmed cell death required for embryonic morphogenesis. These findings explain how AIF contributes to the biogenesis of respiratory chain complexes, and they establish an unexpected link between the vital function of AIF and the propensity of cells to undergo apoptosis. Copyright © 2015 Elsevier Inc. All rights reserved.

Visual and Quantitative Analysis Methods of Respiratory Patterns for Respiratory Gated PET/CT.

PubMed

Son, Hye Joo; Jeong, Young Jin; Yoon, Hyun Jin; Park, Jong-Hwan; Kang, Do-Young

2016-01-01

We integrated visual and quantitative methods for analyzing the stability of respiration using four methods: phase space diagrams, Fourier spectra, Poincaré maps, and Lyapunov exponents. Respiratory patterns of 139 patients were grouped based on the combination of the regularity of amplitude, period, and baseline positions. Visual grading was done by inspecting the shape of diagram and classified into two states: regular and irregular. Quantitation was done by measuring standard deviation of x and v coordinates of Poincaré map (SD x , SD v ) or the height of the fundamental peak ( A 1 ) in Fourier spectrum or calculating the difference between maximal upward and downward drift. Each group showed characteristic pattern on visual analysis. There was difference of quantitative parameters (SD x , SD v , A 1 , and MUD-MDD) among four groups (one way ANOVA, p = 0.0001 for MUD-MDD, SD x , and SD v , p = 0.0002 for A 1 ). In ROC analysis, the cutoff values were 0.11 for SD x (AUC: 0.982, p < 0.0001), 0.062 for SD v (AUC: 0.847, p < 0.0001), 0.117 for A 1 (AUC: 0.876, p < 0.0001), and 0.349 for MUD-MDD (AUC: 0.948, p < 0.0001). This is the first study to analyze multiple aspects of respiration using various mathematical constructs and provides quantitative indices of respiratory stability and determining quantitative cutoff value for differentiating regular and irregular respiration.

Effect of environmental exposure to hydrogen sulfide on central nervous system and respiratory function: a systematic review of human studies

PubMed Central

Lim, Eunjung; Mbowe, Omar; Lee, Angela S. W.; Davis, James

2016-01-01

Background Assessment of the health effects of low-level exposure to hydrogen sulfide (H2S) on humans through experiments, industrial, and community studies has shown inconsistent results. Objective To critically appraise available studies investigating the effect of H2S on the central nervous system (CNS) and on respiratory function. Methods A search was conducted in 16 databases for articles published between January 1980 and July 2014. Two researchers independently evaluated potentially relevant papers based on a set of inclusion/exclusion criteria. Results Twenty-seven articles met the inclusion criteria: 6 experimental, 12 industry-based studies, and 10 community-based studies (one article included both experimental and industry-based studies). The results of the systematic review varied by study setting and quality. Several community-based studies reported associations between day-to-day variations in H2S levels and health outcomes among patients with chronic respiratory conditions. However, evidence from the largest and better-designed community-based studies did not support that chronic, ambient H2S exposure has health effects on the CNS or respiratory function. Results from industry-based studies varied, reflecting the diversity of settings and the broad range of H2S exposures. Most studies did not have individual measurements of H2S exposure. Discussion The results across studies were inconsistent, justifying the need for further research. PMID:27128692

Effect of environmental exposure to hydrogen sulfide on central nervous system and respiratory function: a systematic review of human studies.

PubMed

Lim, Eunjung; Mbowe, Omar; Lee, Angela S W; Davis, James

2016-01-01

Assessment of the health effects of low-level exposure to hydrogen sulfide (H2S) on humans through experiments, industrial, and community studies has shown inconsistent results. To critically appraise available studies investigating the effect of H2S on the central nervous system (CNS) and on respiratory function. A search was conducted in 16 databases for articles published between January 1980 and July 2014. Two researchers independently evaluated potentially relevant papers based on a set of inclusion/exclusion criteria. Twenty-seven articles met the inclusion criteria: 6 experimental, 12 industry-based studies, and 10 community-based studies (one article included both experimental and industry-based studies). The results of the systematic review varied by study setting and quality. Several community-based studies reported associations between day-to-day variations in H2S levels and health outcomes among patients with chronic respiratory conditions. However, evidence from the largest and better-designed community-based studies did not support that chronic, ambient H2S exposure has health effects on the CNS or respiratory function. Results from industry-based studies varied, reflecting the diversity of settings and the broad range of H2S exposures. Most studies did not have individual measurements of H2S exposure. The results across studies were inconsistent, justifying the need for further research.

The Central Conserved Region (CCR) of Respiratory Syncytial Virus (RSV) G Protein Modulates Host miRNA Expression and Alters the Cellular Response to Infection

PubMed Central

Haynes, Lia M.; Anderson, Larry J.

2017-01-01

Respiratory Syncytial Virus (RSV) infects respiratory epithelial cells and deregulates host gene expression by many mechanisms including expression of RSV G protein (RSV G). RSV G protein encodes a central conserved region (CCR) containing a CX3C motif that functions as a fractalkine mimic. Disruption of the CX3C motif (a.a. 182–186) located in the CCR of the G protein has been shown to affect G protein function in vitro and the severity of RSV disease pathogenesis in vivo. We show that infection of polarized Calu3 respiratory cells with recombinant RSV having point mutations in Cys173 and 176 (C173/176S) (rA2-GC12), or Cys186 (C186S) (rA2-GC4) is associated with a decline in the integrity of polarized Calu-3 cultures and decreased virus production. This is accompanied with downregulation of miRNAs let-7f and miR-24 and upregulation of interferon lambda (IFNλ), a primary antiviral cytokine for RSV in rA2-GC12/rA2-GC4 infected cells. These results suggest that residues in the cysteine noose region of RSV G protein can modulate IFN λ expression accompanied by downregulation of miRNAs, and are important for RSV G protein function and targeting. PMID:28671606

The Central Conserved Region (CCR) of Respiratory Syncytial Virus (RSV) G Protein Modulates Host miRNA Expression and Alters the Cellular Response to Infection.

PubMed

Bakre, Abhijeet A; Harcourt, Jennifer L; Haynes, Lia M; Anderson, Larry J; Tripp, Ralph A

2017-07-03

Respiratory Syncytial Virus (RSV) infects respiratory epithelial cells and deregulates host gene expression by many mechanisms including expression of RSV G protein (RSV G). RSV G protein encodes a central conserved region (CCR) containing a CX3C motif that functions as a fractalkine mimic. Disruption of the CX3C motif (a.a. 182-186) located in the CCR of the G protein has been shown to affect G protein function in vitro and the severity of RSV disease pathogenesis in vivo. We show that infection of polarized Calu3 respiratory cells with recombinant RSV having point mutations in Cys173 and 176 (C173/176S) (rA2-GC12), or Cys186 (C186S) (rA2-GC4) is associated with a decline in the integrity of polarized Calu-3 cultures and decreased virus production. This is accompanied with downregulation of miRNAs let-7f and miR-24 and upregulation of interferon lambda (IFNλ), a primary antiviral cytokine for RSV in rA2-GC12/rA2-GC4 infected cells. These results suggest that residues in the cysteine noose region of RSV G protein can modulate IFN λ expression accompanied by downregulation of miRNAs, and are important for RSV G protein function and targeting.

Bactericidal peptidoglycan recognition protein induces oxidative stress in Escherichia coli through a block in respiratory chain and increase in central carbon catabolism.

PubMed

Kashyap, Des R; Kuzma, Marcin; Kowalczyk, Dominik A; Gupta, Dipika; Dziarski, Roman

2017-09-01

Mammalian Peptidoglycan Recognition Proteins (PGRPs) kill both Gram-positive and Gram-negative bacteria through simultaneous induction of oxidative, thiol and metal stress responses in bacteria. However, metabolic pathways through which PGRPs induce these bactericidal stress responses are unknown. We screened Keio collection of Escherichia coli deletion mutants and revealed that deleting genes for respiratory chain flavoproteins or for tricarboxylic acid (TCA) cycle resulted in increased resistance of E. coli to PGRP killing. PGRP-induced killing depended on the production of hydrogen peroxide, which required increased supply of NADH for respiratory chain oxidoreductases from central carbon catabolism (glycolysis and TCA cycle), and was controlled by cAMP-Crp. Bactericidal PGRP induced a rapid decrease in respiration, which suggested that the main source of increased production of hydrogen peroxide was a block in respiratory chain and diversion of electrons from NADH oxidoreductases to oxygen. CpxRA two-component system was a negative regulator of PGRP-induced oxidative stress. By contrast, PGRP-induced thiol stress (depletion of thiols) and metal stress (increase in intracellular free Zn 2+ through influx of extracellular Zn 2+ ) were mostly independent of oxidative stress. Thus, manipulating pathways that induce oxidative, thiol and metal stress in bacteria could be a useful strategy to design new approaches to antibacterial therapy. © 2017 John Wiley & Sons Ltd.

Analysis of respiratory and muscle activity by means of cross information function between ventilatory and myographic signals.

PubMed

Alonso, J F; Mañanas, M A; Hoyer, D; Topor, Z L; Bruce, E N

2004-01-01

Analysis of respiratory muscle activity is a promising technique for the study of pulmonary diseases such as obstructive sleep apnea syndrome (OSAS). Evaluation of interactions between muscles is very useful in order to determine the muscular pattern during an exercise. These interactions have already been assessed by means of different linear techniques like cross-spectrum, magnitude squared coherence or cross-correlation. The aim of this work is to evaluate interactions between respiratory and myographic signals through nonlinear analysis by means of cross mutual information function (CMIF), and finding out what information can be extracted from it. Some parameters are defined and calculated from CMIF between ventilatory and myographic signals of three respiratory muscles. Finally, differences in certain parameters were obtained between OSAS patients and healthy subjects indicating different respiratory muscle couplings.

Acute respiraotry diseases in students at the University of the Philippines, 1964-69.

PubMed

Evans, A S; Espiritu-Campos, L

1971-01-01

Acute respiratory infections have been found to be a common cause of morbidity in young adults in the tropical setting of the Philippines, with incidence rates equalling those of colder northern countries. Influenza outbreaks have occurred as part of a worldwide pattern and parainfluenza infections are common, as revealed by serological tests on such students. About half of the respiratory infections could be identified etiologically. In contrast, clinical infections from group A haemolytic streptococci, Mycoplasma pneumoniae, adenoviruses, and infections due to Epstein-Barr virus (infectious mononucleosis) were rare in this population. The role of prior immunity is discussed in relation to these patterns.

Cell-specific Expression of CYP2A5 in the Mouse Respiratory Tract: Effects of Olfactory Toxicants

PubMed Central

Piras, Elena; Franzén, Anna; Fernández, Estíbaliz L.; Bergström, Ulrika; Raffalli-Mathieu, Françoise; Lang, Matti; Brittebo, Eva B.

2003-01-01

We performed a detailed analysis of mouse cytochrome P450 2A5 (CYP2A5) expression by in situ hybridization (ISH) and immunohistochemistry (IHC) in the respiratory tissues of mice. The CYP2A5 mRNA and the corresponding protein co-localized at most sites and were predominantly detected in the olfactory region, with an expression in sustentacular cells, Bowman's gland, and duct cells. In the respiratory and transitional epithelium there was no or only weak expression. The nasolacrimal duct and the excretory ducts of nasal and salivary glands displayed expression, whereas no expression occurred in the acini. There was decreasing expression along the epithelial linings of the trachea and lower respiratory tract, whereas no expression occurred in the alveoli. The hepatic CYP2A5 inducers pyrazole and phenobarbital neither changed the CYP2A5 expression pattern nor damaged the olfactory mucosa. In contrast, the olfactory toxicants dichlobenil and methimazole induced characteristic changes. The damaged Bowman's glands displayed no expression, whereas the damaged epithelium expressed the enzyme. The CYP2A5 expression pattern is in accordance with previously reported localization of protein and DNA adducts and the toxicity of some CYP2A5 substrates. This suggests that CYP2A5 is an important determinant for the susceptibility of the nasal and respiratory epithelia to protoxicants and procarcinogens. PMID:14566026

Development of respiratory rhythms in perinatal chick embryos.

PubMed

Chiba, Y; Khandoker, A H; Nobuta, M; Moriya, K; Akiyama, R; Tazawa, H

2002-04-01

In chick embryos, gas exchange takes place via the chorioallantoic membrane (CAM) and the lungs at approximately 1 day prior to hatching. The present study was designed to elucidate the development of respiratory rhythms in the chick embryo during the whole pipping (perinatal) period with a condenser-microphone measuring system. The microphone was hermetically attached on the eggshell over the air cell on day 18 of incubation. It first detected a cardiogenic signal (i.e. acoustocardiogram), and then beak clapping and breathing signals (acoustorespirogram, ARG). The first signals of lung ventilation appeared intermittently and irregularly approximately once per 5 s among the clapping signals after the embryo penetrated its beak into the air cell (internal pipping, IP). The respiratory rhythm then developed irregularly, with a subsequent more regular rate. The envelope pattern of breathing from the onset of IP through external pipping (EP) to hatching was constructed by a specially devised procedure, which eliminated external and internal noises. The envelope patterns indicated that the IP, EP and whole perinatal periods of 10 embryos were 14.1+/-6.4 (S.D.), 13.6+/-4.0 and 27.6+/-5.4 h, respectively. In addition, they also indicated the period of embryonic hatching activity (i.e. climax) which was 48+/-19 min. The development of respiratory rhythm was also shown by the instantaneous respiratory rate (IRR) which was designated as an inverse value of two adjacent ARG waves.

Definition, discrimination, diagnosis and treatment of central breathing disturbances during sleep.

PubMed

Randerath, Winfried; Verbraecken, Johan; Andreas, Stefan; Arzt, Michael; Bloch, Konrad E; Brack, Thomas; Buyse, Bertien; De Backer, Wilfried; Eckert, Danny Joel; Grote, Ludger; Hagmeyer, Lars; Hedner, Jan; Jennum, Poul; La Rovere, Maria Teresa; Miltz, Carla; McNicholas, Walter T; Montserrat, Josep; Naughton, Matthew; Pepin, Jean-Louis; Pevernagie, Dirk; Sanner, Bernd; Testelmans, Dries; Tonia, Thomy; Vrijsen, Bart; Wijkstra, Peter; Levy, Patrick

2017-01-01

The complexity of central breathing disturbances during sleep has become increasingly obvious. They present as central sleep apnoeas (CSAs) and hypopnoeas, periodic breathing with apnoeas, or irregular breathing in patients with cardiovascular, other internal or neurological disorders, and can emerge under positive airway pressure treatment or opioid use, or at high altitude. As yet, there is insufficient knowledge on the clinical features, pathophysiological background and consecutive algorithms for stepped-care treatment. Most recently, it has been discussed intensively if CSA in heart failure is a "marker" of disease severity or a "mediator" of disease progression, and if and which type of positive airway pressure therapy is indicated. In addition, disturbances of respiratory drive or the translation of central impulses may result in hypoventilation, associated with cerebral or neuromuscular diseases, or severe diseases of lung or thorax. These statements report the results of an European Respiratory Society Task Force addressing actual diagnostic and therapeutic standards. The statements are based on a systematic review of the literature and a systematic two-step decision process. Although the Task Force does not make recommendations, it describes its current practice of treatment of CSA in heart failure and hypoventilation. Copyright ©ERS 2017.

Image acquisition optimization of a limited-angle intrafraction verification (LIVE) system for lung radiotherapy.

PubMed

Zhang, Yawei; Deng, Xinchen; Yin, Fang-Fang; Ren, Lei

2018-01-01

Limited-angle intrafraction verification (LIVE) has been previously developed for four-dimensional (4D) intrafraction target verification either during arc delivery or between three-dimensional (3D)/IMRT beams. Preliminary studies showed that LIVE can accurately estimate the target volume using kV/MV projections acquired over orthogonal view 30° scan angles. Currently, the LIVE imaging acquisition requires slow gantry rotation and is not clinically optimized. The goal of this study is to optimize the image acquisition parameters of LIVE for different patient respiratory periods and gantry rotation speeds for the effective clinical implementation of the system. Limited-angle intrafraction verification imaging acquisition was optimized using a digital anthropomorphic phantom (XCAT) with simulated respiratory periods varying from 3 s to 6 s and gantry rotation speeds varying from 1°/s to 6°/s. LIVE scanning time was optimized by minimizing the number of respiratory cycles needed for the four-dimensional scan, and imaging dose was optimized by minimizing the number of kV and MV projections needed for four-dimensional estimation. The estimation accuracy was evaluated by calculating both the center-of-mass-shift (COMS) and three-dimensional volume-percentage-difference (VPD) between the tumor in estimated images and the ground truth images. The robustness of LIVE was evaluated with varied respiratory patterns, tumor sizes, and tumor locations in XCAT simulation. A dynamic thoracic phantom (CIRS) was used to further validate the optimized imaging schemes from XCAT study with changes of respiratory patterns, tumor sizes, and imaging scanning directions. Respiratory periods, gantry rotation speeds, number of respiratory cycles scanned and number of kV/MV projections acquired were all positively correlated with the estimation accuracy of LIVE. Faster gantry rotation speed or longer respiratory period allowed less respiratory cycles to be scanned and less kV/MV projections to be acquired to estimate the target volume accurately. Regarding the scanning time minimization, for patient respiratory periods of 3-4 s, gantry rotation speeds of 1°/s, 2°/s, 3-6°/s required scanning of five, four, and three respiratory cycles, respectively. For patient respiratory periods of 5-6 s, the corresponding respiratory cycles required in the scan changed to four, three, and two cycles, respectively. Regarding the imaging dose minimization, for patient respiratory periods of 3-4 s, gantry rotation speeds of 1°/s, 2-4°/s, 5-6°/s required acquiring of 7, 5, 4 kV and MV projections, respectively. For patient respiratory periods of 5-6 s, 5 kV and 5 MV projections are sufficient for all gantry rotation speeds. The optimized LIVE system was robust against breathing pattern, tumor size and tumor location changes. In the CIRS study, the optimized LIVE system achieved the average center-of-mass-shift (COMS)/volume-percentage-difference (VPD) of 0.3 ± 0.1 mm/7.7 ± 2.0% for the scanning time priority case, 0.2 ± 0.1 mm/6.1 ± 1.2% for the imaging dose priority case, respectively, among all gantry rotation speeds tested. LIVE was robust against different scanning directions investigated. The LIVE system has been preliminarily optimized for different patient respiratory periods and treatment gantry rotation speeds using digital and physical phantoms. The optimized imaging parameters, including number of respiratory cycles scanned and kV/MV projection numbers acquired, provide guidelines for optimizing the scanning time and imaging dose of the LIVE system for its future evaluations and clinical implementations through patient studies. © 2017 American Association of Physicists in Medicine.

Impact of nasopharyngeal microbiota on the development of respiratory tract diseases.

PubMed

Esposito, S; Principi, N

2018-01-01

Knowledge of whether and how respiratory microbiota composition can prime the immune system and provide colonisation resistance, limiting consecutive pathobiont overgrowth and infections, is essential to improving the prevention and therapy of respiratory disorders. Modulation of dysbiotic ecosystems or reconstitution of missing microbes might be a possible measure to reduce respiratory diseases. The aim of this review is to analyse the role of nasopharyngeal microbiota in the development of respiratory tract disease in paediatric-age subjects. PubMed was used to search for all studies published over the last 15 years using the following key words: "microbiota" or "microbioma" and "nasopharyngeal" or "respiratory" or "nasal" and "children" or "paediatric" or "infant". Analysis of the literature showed that respiratory microbiota can regulate health and disease development in the respiratory tract. Like the gut microbiota, the respiratory microbiota is established at birth, and early respiratory microbiota composition determines bacterial succession patterns and respiratory health in children. Protective and dangerous bacteria have been identified, and this can be considered the base for developing new approaches to diseases that respond poorly to traditional interventions. Reconstitution of missing microbes can be achieved by the administration of pre- and probiotics. Modulation of respiratory microbiota by favouring colonisation of the upper respiratory tract by beneficial commensals can interfere with the proliferation and activity of resident pathobionts and is a possible new measure to reduce the risk of disease. However, further studies are needed because a deeper understanding of these and related issues can be transferred to clinical practice.

Effect of Cues to Increase Sound Pressure Level on Respiratory Kinematic Patterns during Connected Speech

ERIC Educational Resources Information Center

Huber, Jessica E.

2007-01-01

Purpose: This study examined the response of the respiratory system to 3 cues used to elicit increased vocal loudness to determine whether the effects of cueing, shown previously in sentence tasks, were present in connected speech tasks and to describe differences among tasks. Method: Fifteen young men and 15 young women produced a 2-paragraph…

EFFECT OF RAPID SHALLOW BREATHING ON THE DISTRIBUTION OF 18-O-LABELED OZONE REACTION PRODUCT IN THE RESPIRATORY TRACT OF THE RAT

EPA Science Inventory

We examined the effect of breathing pattern on ozone reaction product content within the respiratory tract. Thirty-four anesthetized, maleWistar rats were exposed to oxygen-18 (18O)-labeled ozone at 1.0 ppm for 2 h using a dual-chamber, negative-pressure ventilation system. Fre...

Respiratory Sinus Arrhythmia as an Index of Vagal Activity during Stress in Infants: Respiratory Influences and Their Control

PubMed Central

Ritz, Thomas; Bosquet Enlow, Michelle; Schulz, Stefan M.; Kitts, Robert; Staudenmayer, John; Wright, Rosalind J.

2012-01-01

Respiratory sinus arrhythmia (RSA) is related to cardiac vagal outflow and the respiratory pattern. Prior infant studies have not systematically examined respiration rate and tidal volume influences on infant RSA or the extent to which infants' breathing is too fast to extract a valid RSA. We therefore monitored cardiac activity, respiration, and physical activity in 23 six-month old infants during a standardized laboratory stressor protocol. On average, 12.6% (range 0–58.2%) of analyzed breaths were too short for RSA extraction. Higher respiration rate was associated with lower RSA amplitude in most infants, and lower tidal volume was associated with lower RSA amplitude in some infants. RSA amplitude corrected for respiration rate and tidal volume influences showed theoretically expected strong reductions during stress, whereas performance of uncorrected RSA was less consistent. We conclude that stress-induced changes of peak-valley RSA and effects of variations in breathing patterns on RSA can be determined for a representative percentage of infant breaths. As expected, breathing substantially affects infant RSA and needs to be considered in studies of infant psychophysiology. PMID:23300753

Shared developmental and evolutionary origins for neural basis of vocal–acoustic and pectoral–gestural signaling

PubMed Central

Bass, Andrew H.; Chagnaud, Boris P.

2012-01-01

Acoustic signaling behaviors are widespread among bony vertebrates, which include the majority of living fishes and tetrapods. Developmental studies in sound-producing fishes and tetrapods indicate that central pattern generating networks dedicated to vocalization originate from the same caudal hindbrain rhombomere (rh) 8-spinal compartment. Together, the evidence suggests that vocalization and its morphophysiological basis, including mechanisms of vocal–respiratory coupling that are widespread among tetrapods, are ancestral characters for bony vertebrates. Premotor-motor circuitry for pectoral appendages that function in locomotion and acoustic signaling develops in the same rh8-spinal compartment. Hence, vocal and pectoral phenotypes in fishes share both developmental origins and roles in acoustic communication. These findings lead to the proposal that the coupling of more highly derived vocal and pectoral mechanisms among tetrapods, including those adapted for nonvocal acoustic and gestural signaling, originated in fishes. Comparative studies further show that rh8 premotor populations have distinct neurophysiological properties coding for equally distinct behavioral attributes such as call duration. We conclude that neural network innovations in the spatiotemporal patterning of vocal and pectoral mechanisms of social communication, including forelimb gestural signaling, have their evolutionary origins in the caudal hindbrain of fishes. PMID:22723366

US Army Institute of Surgical Research Annual Research Progress Report FY 1982.

DTIC Science & Technology

1982-10-01

arterial blood gases, respiratory rate, daily chest roentgenograms), cardiovascular (blood pressure, central venous pressure, cardiac output measured...confirmed by the finding that central venous plasma histamine rose from 3.79 + 0.86 to 77.58 + 27.28 and 74.22 + 32.79 ng/ml at one and two minutes postburn...wounds at 2 - 4 weeks after injury. Central venous indwelling catheters were placed via the right jugular vein on the day prior to use as previously

The pattern of pediatric respiratory illnesses admitted in ebonyi state university teaching hospital South-East Nigeria.

PubMed

Ezeonu, Ct; Uneke, Cj; Ojukwu, Jo; Anyanwu, Ou; Okike, Co; Ezeanosike, Ob; Agumadu, Hu

2015-01-01

Reports from the developed nations reveal respiratory tract infections as the leading cause of childhood hospital admissions. Children may be admitted for a variety of respiratory illnesses. Data on the spectrum of pediatric respiratory illnesses admitted in the hospital is scarce. To determine the pattern of pediatrics respiratory illness admissions, seasonal frequency, underlying risk factors and outcome. A retrospective assessment of respiratory cases admitted in the pediatric ward from 2005 to 2010 was conducted using case notes. Parameters considered included month of presentation, age, sex, immunization and nutritional status, tools of diagnosis and patient outcome. Results were analyzed using the Statistical Package for the Social Sciences with the level of significance P ≤ 0.05. Of the 239 cases admitted, there were more males than females (1.4:1). The commonest case was Bronchopneumonia, 71.6% (171/239 out of which 161 were uncomplicated, 5 had effusions and 6 were associated with measles). Other cases were Pulmonary Tuberculosis, 10.9% (26/239), Lobar pneumonia 8.8% (21/239), Bronchiolitis, 5% (12/239), Aspiration pneumonitis 2.1% (5/239) and Bronchial asthma, 0.8% (2/239). Mortality was 7.5% (18/239) mostly from Bronchopneumonia amongst the 1-5 years old. Mortality was significantly associated with malnutrition (P < 0.001) and poor immunization status (P < 0.01). Bronchopneumonia was found to be the commonest illness with significant mortality and peak occurrence in the rainy season. More emphasis must be laid on anticipatory guidance and prevention by encouraging the immunization, good nutrition and increased attention on children even after 1 year of age.

Peripheral chemoreceptors tune inspiratory drive via tonic expiratory neuron hubs in the medullary ventral respiratory column network.

PubMed

Segers, L S; Nuding, S C; Ott, M M; Dean, J B; Bolser, D C; O'Connor, R; Morris, K F; Lindsey, B G

2015-01-01

Models of brain stem ventral respiratory column (VRC) circuits typically emphasize populations of neurons, each active during a particular phase of the respiratory cycle. We have proposed that "tonic" pericolumnar expiratory (t-E) neurons tune breathing during baroreceptor-evoked reductions and central chemoreceptor-evoked enhancements of inspiratory (I) drive. The aims of this study were to further characterize the coordinated activity of t-E neurons and test the hypothesis that peripheral chemoreceptors also modulate drive via inhibition of t-E neurons and disinhibition of their inspiratory neuron targets. Spike trains of 828 VRC neurons were acquired by multielectrode arrays along with phrenic nerve signals from 22 decerebrate, vagotomized, neuromuscularly blocked, artificially ventilated adult cats. Forty-eight of 191 t-E neurons fired synchronously with another t-E neuron as indicated by cross-correlogram central peaks; 32 of the 39 synchronous pairs were elements of groups with mutual pairwise correlations. Gravitational clustering identified fluctuations in t-E neuron synchrony. A network model supported the prediction that inhibitory populations with spike synchrony reduce target neuron firing probabilities, resulting in offset or central correlogram troughs. In five animals, stimulation of carotid chemoreceptors evoked changes in the firing rates of 179 of 240 neurons. Thirty-two neuron pairs had correlogram troughs consistent with convergent and divergent t-E inhibition of I cells and disinhibitory enhancement of drive. Four of 10 t-E neurons that responded to sequential stimulation of peripheral and central chemoreceptors triggered 25 cross-correlograms with offset features. The results support the hypothesis that multiple afferent systems dynamically tune inspiratory drive in part via coordinated t-E neurons. Copyright © 2015 the American Physiological Society.

Portable Sleep Monitoring for Diagnosing Sleep Apnea in Hospitalized Patients With Heart Failure.

PubMed

Aurora, R Nisha; Patil, Susheel P; Punjabi, Naresh M

2018-04-21

Sleep apnea is an underdiagnosed condition in patients with heart failure. Efficient identification of sleep apnea is needed, as treatment may improve heart failure-related outcomes. Currently, use of portable sleep monitoring in hospitalized patients and those at risk for central sleep apnea is discouraged. This study examined whether portable sleep monitoring with respiratory polygraphy can accurately diagnose sleep apnea in patients hospitalized with decompensated heart failure. Hospitalized patients with decompensated heart failure underwent concurrent respiratory polygraphy and polysomnography. Both recordings were scored for obstructive and central disordered breathing events in a blinded fashion, using standard criteria, and the apnea-hypopnea index (AHI) was determined. Pearson's correlation coefficients and Bland-Altman plots were used to examine the concordance among the overall, obstructive, and central AHI values derived by respiratory polygraphy and polysomnography. The sample consisted of 53 patients (47% women) with a mean age of 59.0 years. The correlation coefficient for the overall AHI from the two diagnostic methods was 0.94 (95% CI, 0.89-0.96). The average difference in AHI between the two methods was 3.6 events/h. Analyses of the central and obstructive AHI values showed strong concordance between the two methods, with correlation coefficients of 0.98 (95% CI, 0.96-0.99) and 0.91 (95% CI, 0.84-0.95), respectively. Complete agreement in the classification of sleep apnea severity between the two methods was seen in 89% of the sample. Portable sleep monitoring can accurately diagnose sleep apnea in hospitalized patients with heart failure and may promote early initiation of treatment. Copyright © 2018 American College of Chest Physicians. Published by Elsevier Inc. All rights reserved.

Peripheral chemoreceptors tune inspiratory drive via tonic expiratory neuron hubs in the medullary ventral respiratory column network

PubMed Central

Segers, L. S.; Nuding, S. C.; Ott, M. M.; Dean, J. B.; Bolser, D. C.; O'Connor, R.; Morris, K. F.

2014-01-01

Models of brain stem ventral respiratory column (VRC) circuits typically emphasize populations of neurons, each active during a particular phase of the respiratory cycle. We have proposed that “tonic” pericolumnar expiratory (t-E) neurons tune breathing during baroreceptor-evoked reductions and central chemoreceptor-evoked enhancements of inspiratory (I) drive. The aims of this study were to further characterize the coordinated activity of t-E neurons and test the hypothesis that peripheral chemoreceptors also modulate drive via inhibition of t-E neurons and disinhibition of their inspiratory neuron targets. Spike trains of 828 VRC neurons were acquired by multielectrode arrays along with phrenic nerve signals from 22 decerebrate, vagotomized, neuromuscularly blocked, artificially ventilated adult cats. Forty-eight of 191 t-E neurons fired synchronously with another t-E neuron as indicated by cross-correlogram central peaks; 32 of the 39 synchronous pairs were elements of groups with mutual pairwise correlations. Gravitational clustering identified fluctuations in t-E neuron synchrony. A network model supported the prediction that inhibitory populations with spike synchrony reduce target neuron firing probabilities, resulting in offset or central correlogram troughs. In five animals, stimulation of carotid chemoreceptors evoked changes in the firing rates of 179 of 240 neurons. Thirty-two neuron pairs had correlogram troughs consistent with convergent and divergent t-E inhibition of I cells and disinhibitory enhancement of drive. Four of 10 t-E neurons that responded to sequential stimulation of peripheral and central chemoreceptors triggered 25 cross-correlograms with offset features. The results support the hypothesis that multiple afferent systems dynamically tune inspiratory drive in part via coordinated t-E neurons. PMID:25343784

The effects of locomotor-respiratory coupling on the pattern of breathing in horses.

PubMed Central

Lafortuna, C L; Reinach, E; Saibene, F

1996-01-01

1. To investigate the effect of locomotor activity on the pattern of breathing in quadrupeds, ventilatory response was studied in four healthy horses during horizontal and inclined (7%) treadmill exercise at different velocities (1.4-6.9 m s(-1)) and during chemical stimulation with a rebreathing method. Stride frequency (f(s)) and locomotor-respiratory coupling (LRC) were also simultaneously determined by means of video recordings synchronized with respiratory events. 2. Tidal volume (V(T)) was positively correlated with pulmonary ventilation (V(E)) but significantly different linear regression equations were found between the experimental conditions (P < 0.0001), since the chemical hyperventilation was mainly due to increases in V(T), whereas the major contribution to exercise hyperpnoea came from changes in respiratory frequency (f(R)). 3. The average f(R) at each exercise level was not significantly different from f(S), although there was not always a tight 1:1 LRC. At constant speeds, f(S) was independent of the treadmill slope and hence the greater V(E) during inclined exercise was due to increased V(T). 4. At any ventilatory level, the differences in breathing patterns between locomotion and rebreathing or locomotion at different slopes derived from different set points of the inspiratory off-switch mechanism. 5. The percentage of single breaths entrained with locomotor rhythm rose progressively and significantly with treadmill speed (P < 0.0001) up to a 1:1 LRC and was significantly affected by treadmill slope (P < 0.001). 6. A LRC of 1:1 was systematically observed at canter (10 out of 10 trials) and sometimes at trot (5 out of 14) and it entailed (i) a 4- to 5-fold reduction in both V(T) and f(R) variability, and (ii) a gait-specific phase locking of inspiratory onset during the locomotor cycle. 7. It is concluded that different patterns of breathing are employed during locomotion and rebreathing due to the interference between locomotor and respiratory functions, which may play a role in the optimization and control of exercise ventilation in horses. PMID:9019552

Cough: are children really different to adults?

PubMed Central

Chang, Anne B

2005-01-01

Worldwide paediatricians advocate that children should be managed differently from adults. In this article, similarities and differences between children and adults related to cough are presented. Physiologically, the cough pathway is closely linked to the control of breathing (the central respiratory pattern generator). As respiratory control and associated reflexes undergo a maturation process, it is expected that the cough would likewise undergo developmental stages as well. Clinically, the 'big three' causes of chronic cough in adults (asthma, post-nasal drip and gastroesophageal reflux) are far less common causes of chronic cough in children. This has been repeatedly shown by different groups in both clinical and epidemiological studies. Therapeutically, some medications used empirically for cough in adults have little role in paediatrics. For example, anti-histamines (in particular H1 antagonists) recommended as a front-line empirical treatment of chronic cough in adults have no effect in paediatric cough. Instead it is associated with adverse reactions and toxicity. Similarly, codeine and its derivatives used widely for cough in adults are not efficacious in children and are contraindicated in young children. Corticosteroids, the other front-line empirical therapy recommended for adults, are also minimally (if at all) efficacious for treating non-specific cough in children. In summary, current data support that management guidelines for paediatric cough should be different to those in adults as the aetiological factors and treatment in children significantly differ to those in adults. PMID:16270937

Changing patterns of inpatient respiratory care services over a decade at the Cleveland Clinic: challenges posed and proposed responses.

PubMed

Orens, Douglas K; Kester, Lucy; Konrad, Dale J; Stoller, James K

2005-08-01

Changing characteristics of hospitalized patients over the last decade have created challenges for all health-care providers in delivering optimal care. In the specific case of respiratory care, trends that hospitalized patients have generally become sicker over time and that average lengths of stay have generally become shorter have posed the challenge of meeting demands for more services delivered with greater immediacy. We undertook the current analysis to assess how the delivery of respiratory care services at a tertiary-care academic medical center, the Cleveland Clinic Foundation Hospital, has evolved over the decade 1991 to 2001. In this observational study, we examined concurrent departmental trends and speculated that the capability to increase clinical activity with maintained or improved clinical outcomes, preserved costs, and a lower turnover rate among respiratory therapists reflects features of the professional environment within our Section of Respiratory Therapy. This analysis compares patterns of respiratory care service delivery in two 5-year intervals: from 1991 to 1996 and from 1996 to 2001. Data were collected using a respiratory care information-management system and an inpatient hospital information system, which track the volume and actual cost of services provided. These analyses accounted for the actual time-based cost of the services, including labor (with benefits), necessary equipment and supplies, medications, and equipment maintenance and depreciation. Hospital case-mix index values were determined according to guidelines from the Centers for Medicare and Medicaid Services, as the weighted average of resource allocation scores assigned to diagnosis-related-group categories of hospitalized patients. From 1991 to 2001, there were important expansions in the scope of respiratory care practice by our Section of Respiratory Care, while the volume of respiratory care services delivered per year increased 1.96-fold (from 339,600 to 665,921 services/y). The number of respiratory therapy consults performed yearly, beginning in 1992 when the service was first implemented, rose to over 10,000/y by 2001. At the same time, the cost of respiratory therapy services delivered per patient decreased by 4.2%. Regarding staffing trends, the number of full-time-equivalent employees increased by 50% (from 65 to 97.5). However, the percent turnover rate among respiratory therapists decreased by 2.3-fold (from 11.5% to 5%). In the face of these trends, the hospital mortality rate for patients with diagnosis-related group 088 (high users of respiratory care services) decreased by 53%, and the length of hospital stay for all patients receiving respiratory treatments decreased by 30%. This analysis shows that trends of growing demands for respiratory care services have been accompanied by generally improving clinical outcomes and favorable retention of respiratory therapists in our section. We believe that a focus on the process of care, including enhanced professionalism, communication, and participation, has permitted a favorable response to these rising demands.

Bi-level CPAP does not change central blood flow in preterm infants with respiratory distress syndrome.

PubMed

Aquilano, Giulia; Galletti, Silvia; Aceti, Arianna; Vitali, Francesca; Faldella, Giacomo

2014-06-21

Current literature provides limited data on the hemodynamic changes that may occur during bi-level continuous positive airway pressure (CPAP) support in preterm infants. However, the application of a positive end-expiratory pressure may be transmitted to the heart and the great vessels resulting in changes of central blood flow. To assess changes in central blood flow in infants with respiratory distress syndrome (RDS) during bi-level CPAP support. A prospective study was performed in a cohort of 18 Very-Low-Birth-Weight Infants who were put on nasal CPAP support (4-5 cmH2O) because they developed RDS within the first 24-72 hours of life. Each subject was switched to bi-level CPAP support (Phigh 8 cmH2O, Plow 4-5 cmH2O, Thigh 0.5-0.6 seconds, 20 breaths/min) for an hour. An echocardiographic study and a capillary gas analysis were performed before and after the change of respiratory support. No differences between n-CPAP and bi-level CPAP in left ventricular output (LVO, 222.17 ± 81.4 vs 211.4 ± 75.3 ml/kg/min), right ventricular output (RVO, 287.8 ± 96 vs 283.4 ± 87.4 ml/kg/min) and superior vena cava flow (SVC, 135.38 ± 47.8 vs 137.48 ± 46.6 ml/kg/min) were observed. The hemodynamic characteristics of the ductus arteriosus were similar. A significant decrease in pCO2 levels after bi-level CPAP ventilation was observed; pCO2 variations did not correlate with modifications of central blood flow (LVO: ρ=0.11, p=0,657; RVO: ρ=-0.307, p=0.216; SVC: ρ=-0.13, p=0.197). Central blood flow doesn't change during bi-level CPAP support, which could become a hemodinamically safe tool for the treatment of RDS in preterm infants.

Effect of Influenza Vaccination on Acute Respiratory Symptoms in Malaysian Hajj Pilgrims.

PubMed

Hasan, Habsah; Deris, Zakuan Zainy; Sulaiman, Siti Amrah; Abdul Wahab, Mohd Suhaimi; Naing, Nyi Nyi; Ab Rahman, Zulkefle; Othman, Nor Hayati

2015-08-01

Respiratory illness were a major problem and caused high hospital admission during hajj seasons. One of the contributing cause to this illness is infection. Various measures had been implemented to reduce respiratory infections. The aim on the study is to determine the effect of influenza vaccination against acute respiratory illness among Malaysian Hajj pilgrims. This is an observational cohort study. Influenza vaccination was given to pilgrims at least 2 weeks prior to departure. The occurrence of symptoms for respiratory illness such as cough, fever, sore throat and runny nose was monitored daily for 6 weeks during pilgrimage using a health diary. A total of 65 vaccinated hajj pilgrims and 41 controls were analyzed. There was no significant difference in pattern of occurrence of symptoms of respiratory illness by duration of pilgrimage as well as the number of symptoms between both groups. Hajj pilgrims have frequent respiratory symptoms. We were unable to document benefit from influenza vaccination, but our study was limited by a small sample size and lack of laboratory testing for influenza.

Replication and Shedding of MERS-CoV in Upper Respiratory Tract of Inoculated Dromedary Camels

PubMed Central

Adney, Danielle R.; van Doremalen, Neeltje; Brown, Vienna R.; Bushmaker, Trenton; Scott, Dana; de Wit, Emmie; Munster, Vincent J.

2014-01-01

In 2012, a novel coronavirus associated with severe respiratory disease in humans emerged in the Middle East. Epidemiologic investigations identified dromedary camels as the likely source of zoonotic transmission of Middle East respiratory syndrome coronavirus (MERS-CoV). Here we provide experimental support for camels as a reservoir for MERS-CoV. We inoculated 3 adult camels with a human isolate of MERS-CoV and a transient, primarily upper respiratory tract infection developed in each of the 3 animals. Clinical signs of the MERS-CoV infection were benign, but each of the camels shed large quantities of virus from the upper respiratory tract. We detected infectious virus in nasal secretions through 7 days postinoculation, and viral RNA up to 35 days postinoculation. The pattern of shedding and propensity for the upper respiratory tract infection in dromedary camels may help explain the lack of systemic illness among naturally infected camels and the means of efficient camel-to-camel and camel-to-human transmission. PMID:25418529

Correction of respiratory disorders in a mouse model of Rett syndrome

PubMed Central

Abdala, Ana P. L.; Dutschmann, Mathias; Bissonnette, John M.; Paton, Julian F. R.

2010-01-01

Rett syndrome (RTT) is an autism spectrum disorder caused by mutations in the X-linked gene that encodes the transcription factor methyl-CpG-binding protein 2 (MeCP2). A major debilitating phenotype in affected females is frequent apneas, and heterozygous Mecp2-deficient female mice mimic the human respiratory disorder. GABA defects have been demonstrated in the brainstem of Mecp2-deficient mice. Here, using an intact respiratory network, we show that apnea in RTT mice is characterized by excessive excitatory activity in expiratory cranial and spinal nerves. Augmenting GABA markedly improves the respiratory phenotype. In addition, a serotonin 1a receptor agonist that depresses expiratory neuron activity also reduces apnea, corrects the irregular breathing pattern, and prolongs survival in MeCP2 null males. Combining a GABA reuptake blocker with a serotonin 1a agonist in heterozygous females completely corrects their respiratory defects. The results indicate that GABA and serotonin 1a receptor activity are candidates for treatment of the respiratory disorders in Rett syndrome. PMID:20921395

[Development of expert diagnostic system for common respiratory diseases].

PubMed

Xu, Wei-hua; Chen, You-ling; Yan, Zheng

2014-03-01

To develop an internet-based expert diagnostic system for common respiratory diseases. SaaS system was used to build architecture; pattern of forward reasoning was applied for inference engine design; ASP.NET with C# from the tool pack of Microsoft Visual Studio 2005 was used for website-interview medical expert system.The database of the system was constructed with Microsoft SQL Server 2005. The developed expert system contained large data memory and high efficient function of data interview and data analysis for diagnosis of various diseases.The users were able to perform this system to obtain diagnosis for common respiratory diseases via internet. The developed expert system may be used for internet-based diagnosis of various respiratory diseases,particularly in telemedicine setting.

A new paradigm in respiratory hygiene: modulating respiratory secretions to contain cough bioaerosol without affecting mucus clearance

PubMed Central

Zayas, Gustavo; Valle, Juan C; Alonso, Mauricio; Alfaro, Henry; Vega, Daniel; Bonilla, Gloria; Reyes, Miguel; King, Malcolm

2007-01-01

Background Several strategies and devices have been designed to protect health care providers from acquiring transmissible respiratory diseases while providing care. In modulating the physical characteristics of the respiratory secretions to minimize the aerosolization that facilitates transmission of airborne diseases, a fundamental premise is that the prototype drugs have no adverse effect on the first line of respiratory defense, clearance of mucus by ciliary action. Methods To assess and demonstrate the primary mechanism of our mucomodulators (XLs), we have built our evidence moving from basic laboratory studies to an ex-vivo model and then to an in-vivo large animal model. We exposed anesthetized dogs without hypersecretion to different dose concentrations of aerosolized XL "B", XL "D" and XL "S". We assessed: cardio-respiratory pattern, tracheal mucus clearance, airway patency, and mucus viscoelastic changes. Results Exposure of frog palate mucus to XLs did not affect the clearance of mucus by ciliary action. Dogs maintained normal cardio-respiratory pattern with XL administration. Tracheal mucociliary clearance in anesthetized dogs indicated a sustained 40% mean increase. Tracheal mucus showed increased filance, and there was no mucus retention in the airways. Conclusion The ex-vivo frog palate and the in-vivo mammalian models used in this study, appear to be appropriate and complement each other to better assess the effects that our mucomodulators exert on the mucociliary clearance defence mechanism. The physiological function of the mucociliary apparatus was not negatively affected in any of the two epithelial models. Airway mucus crosslinked by mucomodulators is better cleared from an intact airway and normally functioning respiratory system, either due to enhanced interaction with cilia or airflow-dependent mechanisms. Data obtained in this study allow us to assure that we have complied with the fundamental requirement criteria established in the initial phase of developing the concept of mucomodulation: Can we modulate the physical characteristics of the respiratory secretions to reduce aerosolization without affecting normal mucociliary clearance function, or even better improving it? PMID:17697323

Sudden death in Lesch-Nyhan disease.

PubMed

Neychev, Vladimir Kostadinov; Jinnah, H A

2006-11-01

To increase awareness of sudden and unexpected death in Lesch-Nyhan disease (LND) and to explore its potential causes, we report the anteceding clinical features and laboratory evaluations of five males with LND who ultimately experienced sudden and unexpected death, along with three additional males who suffered serious respiratory events during life. The ages of patients ranged from 2 to 45 years. The cause of sudden death in LND appears to have a respiratory rather than a cardiogenic basis. All cases cannot be linked readily with a single respiratory process. Instead, different respiratory processes appear to operate in different cases. These may include aspiration, laryngospasm, central apnea, cyanotic breath-holding spells, and high cervical spine damage. Better recognition of these processes will help to guide appropriate workup and management that could include chest imaging, endoscopy of the airways, polysomnography, electroencephalogram, and brain and/or spine imaging.

The patient with a complex chronic respiratory disease: a specialist of his own life?

PubMed

Houben-Wilke, Sarah; Augustin, Ingrid Ml; Wouters, Birgit Bref; Stevens, Rosita Ah; Janssen, Daisy Ja; Spruit, Martijn A; Vanfleteren, Lowie Egw; Franssen, Frits Me; Wouters, Emiel Fm

2017-12-01

The independent and central role of the patient with a complex chronic respiratory disease in targeted, personalized disease management strategies is becoming increasingly important. Patients are the ones living with the disease and are finally responsible for their lives underlining their role as essential members of the interdisciplinary treatment team. Areas covered: The present paper narratively reviews existing research and discusses the special, as well as specialized, role of the patient with a complex chronic respiratory disease in the healthcare system and highlights fundamental elements of the (future) relationship between patient and healthcare professionals. Expert commentary: Since the chronic respiratory disease at hand is part of the patient's entire life, we need holistic, personalized approaches optimizing patients' quality of life by not only treating the disease but considering the patients' whole environment and where healthcare professionals and patients are co-creating value care.

Pulmonary complications of endocrine and metabolic disorders.

PubMed

Milla, Carlos E; Zirbes, Jacquelyn

2012-03-01

There are many important respiratory manifestations of endocrine and metabolic diseases in children. Acute and chronic pulmonary infections are the most common respiratory abnormalities in patients with diabetes mellitus, although cardiogenic and non-cardiogenic pulmonary oedema are also possible. Pseudohypoaldosteronism type 1 may be indistinguishable from cystic fibrosis (CF) unless serum aldosterone, plasma renin activity, and urinary electrolytes are measured and mutation analysis rules out CF. Hypo- and hyperthyroidism may alter lung function and affect the central respiratory drive. The thyroid hormone plays an essential role in lung development, surfactant synthesis, and lung defence. Complications of hypoparathyroidism are largely due to hypocalcaemia. Laryngospasm can lead to stridor and airway obstruction. Ovarian tumours, benign or malignant, may present with unilateral or bilateral pleural effusions. Metabolic storage disorders, primarily as a consequence of lysosomal dysfunction from enzymatic deficiencies, constitute a diverse group of rare conditions that can have profound effects on the respiratory system. Copyright © 2011 Elsevier Ltd. All rights reserved.

Plasticity in Glutamatergic NTS Neurotransmission

PubMed Central

Kline, David D.

2008-01-01

Changes in the physiological state of an animal or human can result in alterations in the cardiovascular and respiratory system in order to maintain homeostasis. Accordingly, the cardiovascular and respiratory systems are not static but readily adapt under a variety of circumstances. The same can be said for the brainstem circuits that control these systems. The nucleus tractus solitarius (NTS) is the central integration site of baroreceptor and chemoreceptor sensory afferent fibers. This central nucleus, and in particular the synapse between the sensory afferent and second-order NTS cell, possesses a remarkable degree of plasticity in response to a variety of stimuli, both acute and chronic. This brief review is intended to describe the plasticity observed in the NTS as well as the locus and mechanisms as they are currently understood. The functional consequence of NTS plasticity is also discussed. PMID:18524694

[Regional cerebral oxygen saturation as a marker of hemodynamic state following cardiac surgery].

PubMed

García-Hernández, J A; Aldemira-Liz, A; Martínez-López, A I; Cayuela, A; Charlo-Molina, M T; Cano-Franco, J; Loscertales-Abril, M

2013-10-01

Regional cerebral oxygen saturation (rSO₂) is a measure of the general state of perfusion and oxygenation. We aim to analyze the relationship between this and various hemodynamic and respiratory parameters. Forty-three patients, operated on between October 2011 and July 2012, were included in this prospective observational descriptive study. The following parameters were measured: mean arterial pressure, both arterial and central venous oxygen saturation and partial pressures of oxygen and carbon dioxide, and lactate levels. From these parameters, the oxygenation index and the oxygen extraction ratio were calculated. These measurements were studied to evaluate whether rSO₂ correlated significantly with the other parameters. The average age and weight of the patients were 27.3 months and 9.2 kg, respectively. The rSO₂ correlated positively with both central venous oxygen saturation (r=0.73, P<.01) and mean arterial pressure (r=0.59, P<.01), and negatively with the oxygen extraction ratio (r=-0.7, P<.01). No correlation was found with the respiratory parameters. Concordance analysis established an acceptable Kappa index (> 0.4) between the rSO₂ and central venous oxygen saturation, and between the rSO₂ and oxygen extraction ratio. Regional cerebral oxygen saturation correlates well with hemodynamic parameters - mean arterial pressure, venous saturation, and the tissue oxygen extraction. However, it does not correlate with respiratory parameters. Copyright © 2012 Asociación Española de Pediatría. Published by Elsevier Espana. All rights reserved.

A Molecular atlas of Xenopus respiratory system development.

PubMed

Rankin, Scott A; Thi Tran, Hong; Wlizla, Marcin; Mancini, Pamela; Shifley, Emily T; Bloor, Sean D; Han, Lu; Vleminckx, Kris; Wert, Susan E; Zorn, Aaron M

2015-01-01

Respiratory system development is regulated by a complex series of endoderm-mesoderm interactions that are not fully understood. Recently Xenopus has emerged as an alternative model to investigate early respiratory system development, but the extent to which the morphogenesis and molecular pathways involved are conserved between Xenopus and mammals has not been systematically documented. In this study, we provide a histological and molecular atlas of Xenopus respiratory system development, focusing on Nkx2.1+ respiratory cell fate specification in the developing foregut. We document the expression patterns of Wnt/β-catenin, fibroblast growth factor (FGF), and bone morphogenetic protein (BMP) signaling components in the foregut and show that the molecular mechanisms of respiratory lineage induction are remarkably conserved between Xenopus and mice. Finally, using several functional experiments we refine the epistatic relationships among FGF, Wnt, and BMP signaling in early Xenopus respiratory system development. We demonstrate that Xenopus trachea and lung development, before metamorphosis, is comparable at the cellular and molecular levels to embryonic stages of mouse respiratory system development between embryonic days 8.5 and 10.5. This molecular atlas provides a fundamental starting point for further studies using Xenopus as a model to define the conserved genetic programs controlling early respiratory system development. © 2014 Wiley Periodicals, Inc.

Variation in respiratory substrates of co-occurring tree species with different geographical range limits

NASA Astrophysics Data System (ADS)

Angelica, P. E.; Griffin, K. L.

2016-12-01

The Hudson Valley Region of New York State, USA is known for a convergence of tree species within the eastern deciduous forest that are near the margin of their geographical range limits. This convergence of primarily southern ranged species with primarily northern ranged species provides the back drop to our study of respiratory activity of 16 forest tree species - 10 broadleaf and 6 coniferous. We found that broadleaved species at the southern edge of their range have significantly higher rates of respiration than trees that are in the center or northern edge of their range, which is contrasting to the lower respiration rates found in northern ranged conifers when compared to their central ranged counterparts . Using a simple closed system to estimate the Respiratory Quotient (RQ - CO2 uptake vs. O2 released) for 10 broadleaved species, we found that northern broadleaved species were more likely to be incorporating some proteins and/or fats as respiratory substrates (RQ<1), compared to central or southern species (RQ 1). All 16 species had similar temperature response of respiration, regardless of the species range or growth type (broadleaved vs. coniferous). In addition, broadleaved species showed an increasing RQ with increasing leaf temperature (from <1 at 15 °C to >1 at 35 °C) indicating the temperature dependence of respiratory substrates that transitions from proteins and fats to carbohydrates and eventually some organic acids as temperatures increase. Overall, this work suggests the fate of fixed carbon in an eastern deciduous forest is controlled by a variety of factors including genetic and environmental variables. As a result, the impact of climate change is likely to change the composition and biogeochemistry of this widespread forest biome.

Effects of maturation and acidosis on the chaos-like complexity of the neural respiratory output in the isolated brainstem of the tadpole, Rana esculenta

PubMed Central

Samara, Ziyad; Fiamma, Marie-Noëlle; Bautin, Nathalie; Ranohavimparany, Anja; Le Coz, Patrick; Golmard, Jean-Louis; Darré, Pierre; Zelter, Marc; Poon, Chi-Sang; Similowski, Thomas

2011-01-01

Human ventilation at rest exhibits mathematical chaos-like complexity that can be described as long-term unpredictability mediated (in whole or in part) by some low-dimensional nonlinear deterministic process. Although various physiological and pathological situations can affect respiratory complexity, the underlying mechanisms remain incompletely elucidated. If such chaos-like complexity is an intrinsic property of central respiratory generators, it should appear or increase when these structures mature or are stimulated. To test this hypothesis, we employed the isolated tadpole brainstem model [Rana (Pelophylax) esculenta] and recorded the neural respiratory output (buccal and lung rhythms) of pre- (n = 8) and postmetamorphic tadpoles (n = 8), at physiologic (7.8) and acidic pH (7.4). We analyzed the root mean square of the cranial nerve V or VII neurograms. Development and acidosis had no effect on buccal period. Lung frequency increased with development (P < 0.0001). It also increased with acidosis, but in postmetamorphic tadpoles only (P < 0.05). The noise-titration technique evidenced low-dimensional nonlinearities in all the postmetamorphic brainstems, at both pH. Chaos-like complexity, assessed through the noise limit, increased from pH 7.8 to pH 7.4 (P < 0.01). In contrast, linear models best fitted the ventilatory rhythm in all but one of the premetamorphic preparations at pH 7.8 (P < 0.005 vs. postmetamorphic) and in four at pH 7.4 (not significant vs. postmetamorphic). Therefore, in a lower vertebrate model, the brainstem respiratory central rhythm generator accounts for ventilatory chaos-like complexity, especially in the postmetamorphic stage and at low pH. According to the ventilatory generators homology theory, this may also be the case in mammals. PMID:21325645

Effects of maturation and acidosis on the chaos-like complexity of the neural respiratory output in the isolated brainstem of the tadpole, Rana esculenta.

PubMed

Straus, Christian; Samara, Ziyad; Fiamma, Marie-Noëlle; Bautin, Nathalie; Ranohavimparany, Anja; Le Coz, Patrick; Golmard, Jean-Louis; Darré, Pierre; Zelter, Marc; Poon, Chi-Sang; Similowski, Thomas

2011-05-01

Human ventilation at rest exhibits mathematical chaos-like complexity that can be described as long-term unpredictability mediated (in whole or in part) by some low-dimensional nonlinear deterministic process. Although various physiological and pathological situations can affect respiratory complexity, the underlying mechanisms remain incompletely elucidated. If such chaos-like complexity is an intrinsic property of central respiratory generators, it should appear or increase when these structures mature or are stimulated. To test this hypothesis, we employed the isolated tadpole brainstem model [Rana (Pelophylax) esculenta] and recorded the neural respiratory output (buccal and lung rhythms) of pre- (n = 8) and postmetamorphic tadpoles (n = 8), at physiologic (7.8) and acidic pH (7.4). We analyzed the root mean square of the cranial nerve V or VII neurograms. Development and acidosis had no effect on buccal period. Lung frequency increased with development (P < 0.0001). It also increased with acidosis, but in postmetamorphic tadpoles only (P < 0.05). The noise-titration technique evidenced low-dimensional nonlinearities in all the postmetamorphic brainstems, at both pH. Chaos-like complexity, assessed through the noise limit, increased from pH 7.8 to pH 7.4 (P < 0.01). In contrast, linear models best fitted the ventilatory rhythm in all but one of the premetamorphic preparations at pH 7.8 (P < 0.005 vs. postmetamorphic) and in four at pH 7.4 (not significant vs. postmetamorphic). Therefore, in a lower vertebrate model, the brainstem respiratory central rhythm generator accounts for ventilatory chaos-like complexity, especially in the postmetamorphic stage and at low pH. According to the ventilatory generators homology theory, this may also be the case in mammals.

Pacific Pediatric Advanced Care Initiative

DTIC Science & Technology

2010-10-01

cracked stopcock on the venous side c. Air introduced from medications infusing into the patient via a central venous line 6. After you have made sure...stopcock or pigtail. Withdraw volume to make venous pressures more negative History : Day 3 for a newborn infant with Group B sepsis. Eveything has...clinical laboratories, operating room, central supply, pharmacy, respiratory care, Neonatal Intensive Care Unit (NICU) nursing, Pediatric Intensive

Evidence of High Rates of Undiagnosed Asthma in Central Ohio Elementary School children

ERIC Educational Resources Information Center

Clark, Brenda R.; Burkett, S. Amanda; Andridge, Rebecca R.; Buckley, Timothy J.

2013-01-01

Background: In Ohio, 14.5% of 5- to 9-year-olds and 17.3% of 10- to 17-year-olds have asthma. Moreover, there is concern that these numbers may underestimate the true disease burden. We sought to evaluate variability in asthma rates and respiratory symptoms among central Ohio fourth graders as a means to assess potential undiagnosed and…

The movement and deposition of PM2.5 in the upper respiratory tract for the patients with heart failure: an elementary CFD study.

PubMed

Zhang, Tiantian; Gao, Bin; Zhou, Zhixiang; Chang, Yu

2016-12-28

PM2.5 is an important factor to affect the patients with respiratory and cardiovascular diseases. Clinical studies have found that the morbidity and mortality of patients with heart failure (HF) have a close relationship with the movement and deposition state of PM2.5. One reason is that the breathing pattern of patients with HF has obvious difference with healthy people, however the effect caused by these differences on the distribution regularity of PM2.5 in the respiratory tract is still unclear. Hence, a computational fluid dynamics simulation was conducted to clarify the aerodynamic effect of breathing pattern of patients with HF on respiratory system. Ideal upper respiratory tract geometric model was established based on standardized aerosol research laboratory of Alberta and Weibel A dimension. The discrete phase method is used to calculate the movement of the airflow and particles. The flow rate were chosen as the inlet boundary conditions, and the outlets are set at a constant pressure. The rate of particle deposition, distribution location, wall pressure, flow velocity and wall shear stress are obtained, and compared to the normal control. The results demonstrated that the rate of escaped particles in every bronchial outlet of the patients with HF was more than the normal controls, meanwhile the trapped was less (1024 < 1160). There was higher by 12.9% possibility that the PM2.5 entered the lungs than the normal control. The aerodynamic performances of HF patients are different from normal control. Compared to the normal control, under similar environment, there is higher possibility of PM2.5 moving into lungs, and these particles could affect the function of the respiratory system, resulting in the deterioration of the state of cardiovascular system. In short, it's necessary to pay more attention to the living environment of HF patients, to reduce the content of PM2.5 particles in the air, and reduce the damage of PM2.5 particles caused by breathing patterns.

Altered surfactant homeostasis and recurrent respiratory failure secondary to TTF-1 nuclear targeting defect.

PubMed

Peca, Donatella; Petrini, Stefania; Tzialla, Chryssoula; Boldrini, Renata; Morini, Francesco; Stronati, Mauro; Carnielli, Virgilio P; Cogo, Paola E; Danhaive, Olivier

2011-08-25

Mutations of genes affecting surfactant homeostasis, such as SFTPB, SFTPC and ABCA3, lead to diffuse lung disease in neonates and children. Haploinsufficiency of NKX2.1, the gene encoding the thyroid transcription factor-1 (TTF-1)--critical for lung, thyroid and central nervous system morphogenesis and function--causes a rare form of progressive respiratory failure designated brain-lung-thyroid syndrome. Molecular mechanisms involved in this syndrome are heterogeneous and poorly explored. We report a novel TTF-1 molecular defect causing recurrent respiratory failure episodes in an infant. The subject was an infant with severe neonatal respiratory distress syndrome followed by recurrent respiratory failure episodes, hypopituitarism and neurological abnormalities. Lung histology and ultrastructure were assessed by surgical biopsy. Surfactant-related genes were studied by direct genomic DNA sequencing and array chromatine genomic hybridization (aCGH). Surfactant protein expression in lung tissue was analyzed by confocal immunofluorescence microscopy. For kinetics studies, surfactant protein B and disaturated phosphatidylcholine (DSPC) were isolated from serial tracheal aspirates after intravenous administration of stable isotope-labeled (2)H(2)O and (13)C-leucine; fractional synthetic rate was derived from gas chromatography/mass spectrometry (2)H and (13)C enrichment curves. Six intubated infants with no primary lung disease were used as controls. Lung biopsy showed desquamative interstitial pneumonitis and lamellar body abnormalities suggestive of genetic surfactant deficiency. Genetic studies identified a heterozygous ABCA3 mutation, L941P, previously unreported. No SFTPB, SFTPC or NKX2.1 mutations or deletions were found. However, immunofluorescence studies showed TTF-1 prevalently expressed in type II cell cytoplasm instead of nucleus, indicating defective nuclear targeting. This pattern has not been reported in human and was not found in two healthy controls and in five ABCA3 mutation carriers. Kinetic studies demonstrated a marked reduction of SP-B synthesis (43.2 vs. 76.5 ± 24.8%/day); conversely, DSPC synthesis was higher (12.4 vs. 6.3 ± 0.5%/day) compared to controls, although there was a marked reduction of DSPC content in tracheal aspirates (29.8 vs. 56.1 ± 12.4% of total phospholipid content). Defective TTF-1 signaling may result in profound surfactant homeostasis disruption and neonatal/pediatric diffuse lung disease. Heterozygous ABCA3 missense mutations may act as disease modifiers in other genetic surfactant defects.

Altered surfactant homeostasis and recurrent respiratory failure secondary to TTF-1 nuclear targeting defect

PubMed Central

2011-01-01

Background Mutations of genes affecting surfactant homeostasis, such as SFTPB, SFTPC and ABCA3, lead to diffuse lung disease in neonates and children. Haploinsufficiency of NKX2.1, the gene encoding the thyroid transcription factor-1 (TTF-1) - critical for lung, thyroid and central nervous system morphogenesis and function - causes a rare form of progressive respiratory failure designated brain-lung-thyroid syndrome. Molecular mechanisms involved in this syndrome are heterogeneous and poorly explored. We report a novel TTF-1 molecular defect causing recurrent respiratory failure episodes in an infant. Methods The subject was an infant with severe neonatal respiratory distress syndrome followed by recurrent respiratory failure episodes, hypopituitarism and neurological abnormalities. Lung histology and ultrastructure were assessed by surgical biopsy. Surfactant-related genes were studied by direct genomic DNA sequencing and array chromatine genomic hybridization (aCGH). Surfactant protein expression in lung tissue was analyzed by confocal immunofluorescence microscopy. For kinetics studies, surfactant protein B and disaturated phosphatidylcholine (DSPC) were isolated from serial tracheal aspirates after intravenous administration of stable isotope-labeled 2H2O and 13C-leucine; fractional synthetic rate was derived from gas chromatography/mass spectrometry 2H and 13C enrichment curves. Six intubated infants with no primary lung disease were used as controls. Results Lung biopsy showed desquamative interstitial pneumonitis and lamellar body abnormalities suggestive of genetic surfactant deficiency. Genetic studies identified a heterozygous ABCA3 mutation, L941P, previously unreported. No SFTPB, SFTPC or NKX2.1 mutations or deletions were found. However, immunofluorescence studies showed TTF-1 prevalently expressed in type II cell cytoplasm instead of nucleus, indicating defective nuclear targeting. This pattern has not been reported in human and was not found in two healthy controls and in five ABCA3 mutation carriers. Kinetic studies demonstrated a marked reduction of SP-B synthesis (43.2 vs. 76.5 ± 24.8%/day); conversely, DSPC synthesis was higher (12.4 vs. 6.3 ± 0.5%/day) compared to controls, although there was a marked reduction of DSPC content in tracheal aspirates (29.8 vs. 56.1 ± 12.4% of total phospholipid content). Conclusion Defective TTF-1 signaling may result in profound surfactant homeostasis disruption and neonatal/pediatric diffuse lung disease. Heterozygous ABCA3 missense mutations may act as disease modifiers in other genetic surfactant defects. PMID:21867529

Efficiency index: a new parameter to define breathing patterns during dynamic Xe-127 ventilation studies

DOE Office of Scientific and Technical Information (OSTI.GOV)

Slosman, D.; Susskind, H.; Bossuyt, A.

1986-03-01

Ventilation imaging can be improved by gating scintigraphic data with the respiratory cycle using temporal Fourier analysis (TFA) to quantify the temporal behavior of the ventilation. Sixteen consecutive images, representing equal-time increments of an average respiratory cycle, were produced by TFA in the posterior view on a pixel-by-pixel basis. An Efficiency Index (EFF), defined as the ratio of the summation of all the differences between maximum and minimum counts for each pixel to that for the entire lung during the respiratory cycle, was derived to describe the pattern of ventilation. The gated ventilation studies were carried out with Xe-127 inmore » 12 subjects: normal lung function (4), small airway disease (2), COPD (5), and restrictive disease (1). EFF for the first three harmonics correlated linearly with FEV1 (r = 0.701, p< 0.01). This approach is suggested as a very sensitive method to quantify the extent and regional distribution of airway obstruction.« less

Neurotoxicity in Snakebite—The Limits of Our Knowledge

PubMed Central

Ranawaka, Udaya K.; Lalloo, David G.; de Silva, H. Janaka

2013-01-01

Snakebite is classified by the WHO as a neglected tropical disease. Envenoming is a significant public health problem in tropical and subtropical regions. Neurotoxicity is a key feature of some envenomings, and there are many unanswered questions regarding this manifestation. Acute neuromuscular weakness with respiratory involvement is the most clinically important neurotoxic effect. Data is limited on the many other acute neurotoxic manifestations, and especially delayed neurotoxicity. Symptom evolution and recovery, patterns of weakness, respiratory involvement, and response to antivenom and acetyl cholinesterase inhibitors are variable, and seem to depend on the snake species, type of neurotoxicity, and geographical variations. Recent data have challenged the traditional concepts of neurotoxicity in snake envenoming, and highlight the rich diversity of snake neurotoxins. A uniform system of classification of the pattern of neuromuscular weakness and models for predicting type of toxicity and development of respiratory weakness are still lacking, and would greatly aid clinical decision making and future research. This review attempts to update the reader on the current state of knowledge regarding this important issue. PMID:24130909

The influence of respiratory motion on CT image volume definition.

PubMed

Rodríguez-Romero, Ruth; Castro-Tejero, Pablo

2014-04-01

Radiotherapy treatments are based on geometric and density information acquired from patient CT scans. It is well established that breathing motion during scan acquisition induces motion artifacts in CT images, which can alter the size, shape, and density of a patient's anatomy. The aim of this work is to examine and evaluate the impact of breathing motion on multislice CT imaging with respiratory synchronization (4DCT) and without it (3DCT). A specific phantom with a movable insert was used. Static and dynamic phantom acquisitions were obtained with a multislice CT. Four sinusoidal breath patterns were simulated to move known geometric structures longitudinally. Respiratory synchronized acquisitions (4DCT) were performed to generate images during inhale, intermediate, and exhale phases using prospective and retrospective techniques. Static phantom data were acquired in helical and sequential mode to define a baseline for each type of respiratory 4DCT technique. Taking into account the fact that respiratory 4DCT is not always available, 3DCT helical image studies were also acquired for several CT rotation periods. To study breath and acquisition coupling when respiratory 4DCT was not performed, the beginning of the CT image acquisition was matched with inhale, intermediate, or exhale respiratory phases, for each breath pattern. Other coupling scenarios were evaluated by simulating different phantom and CT acquisition parameters. Motion induced variations in shape and density were quantified by automatic threshold volume generation and Dice similarity coefficient calculation. The structure mass center positions were also determined to make a comparison with their theoretical expected position. 4DCT acquisitions provided volume and position accuracies within ± 3% and ± 2 mm for structure dimensions >2 cm, breath amplitude ≤ 15 mm, and breath period ≥ 3 s. The smallest object (1 cm diameter) exceeded 5% volume variation for the breath patterns of higher frequency and amplitude motion. Larger volume differences (>10%) and inconsistencies between the relative positions of objects were detected in image studies acquired without respiratory control. Increasing the 3DCT rotation period caused a higher distortion in structures without obtaining their envelope. Simulated data showed that the slice acquisition time should be at least twice the breath period to average object movement. Respiratory 4DCT images provide accurate volume and position of organs affected by breath motion detecting higher volume discrepancies as amplitude length or breath frequency are increased. For 3DCT acquisitions, a CT should be considered slow enough to include lesion envelope as long as the slice acquisition time exceeds twice the breathing period. If this requirement cannot be satisfied, a fast CT (along with breath-hold inhale and exhale CTs to estimate roughly the ITV) is recommended in order to minimize structure distortion. Even with an awareness of a patient's respiratory cycle, its coupling with 3DCT acquisition cannot be predicted since patient anatomy is not accurately known. © 2014 American Association of Physicists in Medicine.

The influence of respiratory motion on CT image volume definition

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rodríguez-Romero, Ruth, E-mail: rrromero@salud.madrid.org; Castro-Tejero, Pablo, E-mail: pablo.castro@salud.madrid.org

Purpose: Radiotherapy treatments are based on geometric and density information acquired from patient CT scans. It is well established that breathing motion during scan acquisition induces motion artifacts in CT images, which can alter the size, shape, and density of a patient's anatomy. The aim of this work is to examine and evaluate the impact of breathing motion on multislice CT imaging with respiratory synchronization (4DCT) and without it (3DCT). Methods: A specific phantom with a movable insert was used. Static and dynamic phantom acquisitions were obtained with a multislice CT. Four sinusoidal breath patterns were simulated to move knownmore » geometric structures longitudinally. Respiratory synchronized acquisitions (4DCT) were performed to generate images during inhale, intermediate, and exhale phases using prospective and retrospective techniques. Static phantom data were acquired in helical and sequential mode to define a baseline for each type of respiratory 4DCT technique. Taking into account the fact that respiratory 4DCT is not always available, 3DCT helical image studies were also acquired for several CT rotation periods. To study breath and acquisition coupling when respiratory 4DCT was not performed, the beginning of the CT image acquisition was matched with inhale, intermediate, or exhale respiratory phases, for each breath pattern. Other coupling scenarios were evaluated by simulating different phantom and CT acquisition parameters. Motion induced variations in shape and density were quantified by automatic threshold volume generation and Dice similarity coefficient calculation. The structure mass center positions were also determined to make a comparison with their theoretical expected position. Results: 4DCT acquisitions provided volume and position accuracies within ±3% and ±2 mm for structure dimensions >2 cm, breath amplitude ≤15 mm, and breath period ≥3 s. The smallest object (1 cm diameter) exceeded 5% volume variation for the breath patterns of higher frequency and amplitude motion. Larger volume differences (>10%) and inconsistencies between the relative positions of objects were detected in image studies acquired without respiratory control. Increasing the 3DCT rotation period caused a higher distortion in structures without obtaining their envelope. Simulated data showed that the slice acquisition time should be at least twice the breath period to average object movement. Conclusions: Respiratory 4DCT images provide accurate volume and position of organs affected by breath motion detecting higher volume discrepancies as amplitude length or breath frequency are increased. For 3DCT acquisitions, a CT should be considered slow enough to include lesion envelope as long as the slice acquisition time exceeds twice the breathing period. If this requirement cannot be satisfied, a fast CT (along with breath-hold inhale and exhale CTs to estimate roughly the ITV) is recommended in order to minimize structure distortion. Even with an awareness of a patient's respiratory cycle, its coupling with 3DCT acquisition cannot be predicted since patient anatomy is not accurately known.« less

A model study of periodic breathing, stability of the neonatal respiratory system, and causes of sudden infant death syndrome.

PubMed

Tehrani, F T

1997-09-01

A mathematical model of the neonatal respiratory system has been modified and used to examine the system under various physiological conditions at different stages of maturity. The respiratory responses in hypoxia, periodic breathing and following a sign have been analyzed. The effects of different respiratory parameters on the stability of the system for normal and premature infants have been investigated. The causes of periodic breathing, apnea spells and sudden infant death syndrome for full-term and premature infants have been studied, and the results compared with the available experimental findings. The response of the infant respiratory system has been found to be highly sensitive to several parameters of the system, as indicated by the results of this study. These significant parameters are sensitivity factor of central receptors to carbon dioxide, sensitivity factor of arterial receptors to carbon dioxide, sensitivity factor of arterial receptors to oxygen, functional residual capacity of the lungs, the alveolar-arterial oxygen difference and the lungs shunt ratio. It has been shown that different parts of the respiratory controller have antagonistic effects on hypoxic periodic breathing and apnea of infancy.

An In Silico Subject-Variability Study of Upper Airway Morphological Influence on the Airflow Regime in a Tracheobronchial Tree

PubMed Central

Chen, Xiaole; Lin, Jiang

2017-01-01

Determining the impact of inter-subject variability on airflow pattern and nanoparticle deposition in the human respiratory system is necessary to generate population-representative models, useful for several biomedical engineering applications. Thus, the overall research objective is to quantitatively correlate geometric parameters and coupled transport characteristics of air, vapor, and nanoparticles. Focusing on identifying morphological parameters that significantly influence airflow field and nanoparticle transport, an experimentally validated computational fluid-particle dynamics (CFPD) model was employed to simulate airflow pattern in three human lung-airway configurations. The numerical results will be used to generate guidelines to construct a representative geometry of the human respiratory system. PMID:29144436

The occurrence of respiratory events in young subjects with a frequent rhythmic masticatory muscle activity: a pilot study.

PubMed

Tsujisaka, Akiko; Haraki, Shingo; Nonoue, Shigeru; Mikami, Akira; Adachi, Hiroyoshi; Mizumori, Takahiro; Yatani, Hirofumi; Yoshida, Atsushi; Kato, Takafumi

2018-02-21

Concomitant occurrence of respiratory events can be often overlooked in the clinical practice of SB. This study assessed physiological characteristics of rhythmic masticatory muscle activity (RMMA) and concomitant respiratory events in young SB subjects asymptomatic to obstructive sleep apnea (OSA). Twenty-two subjects (age: 24.1±1.9years; F 8: M 14; BMI: 20.2±1.9kg/m 2 ) were polysomnographically diagnosed as moderate-severe SB. Sleep architecture, oromotor (RMMA and non-specific masseter activity [NSMA]) and apnea/hypopnea events were scored. All subjects showed normal sleep architecture whereas 6 exhibited respiratory events at a mild level of OSA. In all subjects, RMMA predominantly occurred in Stage N1+N2 while NSMA occurred in Stage N1+N2 (approximately 60 %) and in Stage R (up to 30 %). Up to 50% of respiratory events were scored in Stage R. RMMA occurred more frequently in close association (e.g., within 10s) with respiratory events in 6 subjects with OSA than those without. The percentage of RMMA occurring closely to respiratory events was positively correlated with apnea-hypopnea index (AHI) in Stage N1+N2 only while that of NSMA was positively correlated with AHI in Stage N1+N2 and Stage R. A sub-analysis in 6 subjects with OSA, RMMA after respiratory events was followed to arousals while those before respiratory events were mostly associated with central apnea. A subpopulation of young SB subjects can show concomitant respiratory events. Further large sample studies are needed to demonstrate that the occurrence of subclinical respiratory events represents a clinical subtype of SB. Copyright © 2017 Japan Prosthodontic Society. Published by Elsevier Ltd. All rights reserved.

Tissue-specific programming of memory CD8 T cell subsets impacts protection against lethal respiratory virus infection

PubMed Central

Tahiliani, Vikas

2016-01-01

How tissue-specific anatomical distribution and phenotypic specialization are linked to protective efficacy of memory T cells against reinfection is unclear. Here, we show that lung environmental cues program recently recruited central-like memory cells with migratory potentials for their tissue-specific functions during lethal respiratory virus infection. After entering the lung, some central-like cells retain their original CD27hiCXCR3hi phenotype, enabling them to localize near the infected bronchiolar epithelium and airway lumen to function as the first line of defense against pathogen encounter. Others, in response to local cytokine triggers, undergo a secondary program of differentiation that leads to the loss of CXCR3, migration arrest, and clustering within peribronchoarterial areas and in interalveolar septa. Here, the immune system adapts its response to prevent systemic viral dissemination and mortality. These results reveal the striking and unexpected spatial organization of central- versus effector-like memory cells within the lung and how cooperation between these two subsets contributes to host defense. PMID:27879287

Smoking-related interstitial lung diseases.

PubMed

Caminati, A; Graziano, P; Sverzellati, N; Harari, S

2010-12-01

In pulmonary pathology, a wide spectrum of morphological changes is related to the consequences of smoking, and recognizing them on surgical specimens and on small transbronchial biopsies represents a challenge for the pathologist. Respiratory bronchiolitis, also referred to as smoker's bronchiolitis, is a common histologic feature found in the lung tissue of cigarette smokers. When identified as the sole histopathologic finding in the clinical setting of symptomatic interstitial lung disease, a diagnosis of respiratory bronchiolitis-interstitial lung disease is made. Since smoking is recognized to cause a variety of histologic patterns encompassing respiratory bronchiolitis, respiratory bronchiolitis-interstitial lung disease, desquamative interstitial pneumonia and pulmonary Langerhans cell hystiocytosis, smoking-related interstitial lung disease may be a useful concept to keep in mind for the pathologists. The relationship of smoking with each of these entities has been largely established on the basis of epidemiologic evidence. Although they have been retained as distinct and separate conditions in various classifications of interstitial lung diseases, these entities share a number of clinical, radiologic, and pathologic features suggesting that they represent a spectrum of patterns of interstitial lung disease occurring in predisposed individuals who smoke. Evaluation of histologic features, particularly in surgical lung biopsy samples, is important in making the distinction between these disorders. However, even after tissue biopsy, it may sometimes be difficult to clearly separate these entities. Recently, respiratory bronchiolitis-interstitial lung disease with fibrosis has been described and postulated that this is a smoking-related condition distinct from fibrotic non-specific interstitial pneumonia.

American Academy of Allergy, Asthma, and Immunology

MedlinePlus

... Life Spectrum of Asthma Meeting School-based Asthma Management Program – (SAMPRO TM ) This central resource focuses on ... endorse HR 2285, the School-Based Respiratory Health Management Act Read Practice Matters! Allergy, Asthma & Immunology Quality ...

A prospective controlled study of sleep respiratory events in patients with craniovertebral junction malformation.

PubMed

Botelho, Ricardo Vieira; Bittencourt, Lia Rita Azeredo; Rotta, José Marcos; Tufik, Sergio

2003-12-01

Craniovertebral junction malformation (CVJM) or Chiari malformation in adults, with or without syringomyelia and basilar invagination, produces neuronal dysfunction of the brainstem, cerebellum, cranial nerves, and upper spinal cord. The respiratory center and some of its afferent and efferent components can be altered in these diseases. The authors studied patients with and without CVJM to determine whether this physical feature contributed to sleep disturbances. Respiratory manifestations during sleep were studied prospectively, by using whole-night polysomnography, in 32 symptomatic patients (CVJM group) and 16 healthy volunteers (control group). Patients with CVJM presented with more sleep disturbances (reports of snoring and apnea) than those in the control group. The apnea/hypopnea index values were higher in patients with CVJMs than in the control group (13 +/- 15 compared with 3 +/- 6; p = 0.007) and the rate of central sleep apneas was higher in the CVJM than in the control group (22 +/- 30 compared with 4 +/- 8%; p = 0.009). The apnea/hypopnea index was highest in the subgroup with basilar invagination than in the other subgroups. The central apneic episodes were more frequent in the patients with basilar invagination (35 +/- 40%; p = 0.001) and in those with syringomyelia (17.6 +/- 24.6%; p = 0.003) than in the control group (4 +/- 8%). Patients with symptomatic CVJM, especially those with basilar invagination, presented with more sleep respiratory compromise than did those in the control group. The incidence of sleep apnea/hypopnea syndrome is significantly higher in patients with CVJM.

Genetic variability of respiratory syncytial virus A in hospitalized children in the last five consecutive winter seasons in Central Spain.

PubMed

Calderón, Ana; Pozo, Francisco; Calvo, Cristina; García-García, Mluz; González-Esguevillas, Mónica; Molinero, Mar; Casas, Inmaculada

2017-05-01

Human respiratory syncytial virus group A (RSV-A) was detected in symptomatic hospital attended children in Central Spain for a continuous time period, September 2010 to April 2015. In order to accurately describe the epidemiology of this virus, the genetic diversity of the complete G gene and the clinical manifestations observed were jointly analyzed. Out of 3,011 respiratory specimens taken from 2,308 children, 640 were positive to RSV (21.3%) and 405 were RSV-A (63.2%). Complete G gene sequences of 166 randomly selected RSV-A virus identified NA1 and ON1 genotypes. In 2011-2012, ON1 emerged sporadically and become dominant in 2012-2013 with 38 cases (70%). In 2014-2015, all the 44 sequences contained the 72-nt duplication (100%). Clinical diagnosis of children with ON1 genotype were bronchiolitis in 55 (62.5%), recurrent wheezing or asthma exacerbations in 22 (25%), laryngotracheobronchitis in 3 (3.4%), and upper respiratory tract infections in eight. Results showed replacement and substitution of circulating NA1 genotype with the new ON1 genotype. Nevertheless, at this stage, none of the RSV-A genotypes identified have resulted in significant clinical differences. The amino acid composition of the complete G gene ON1 sequences demonstrated an accumulation of single changes not related with different clinical presentation. J. Med. Virol. 89:767-774, 2017. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

Human respiratory syncytial virus in children with lower respiratory tract infections or influenza-like illness and its co-infection characteristics with viruses and atypical bacteria in Hangzhou, China.

PubMed

Yu, Xinfen; Kou, Yu; Xia, Daozong; Li, Jun; Yang, Xuhui; Zhou, Yinyan; He, Xiaoyan

2015-08-01

Human respiratory syncytial virus (RSV) is the most important viral pathogen in children. However, its epidemic patterns and co-infection characteristics are not fully understood. We attempted to determine the level of genetic variation of RSV, and describe the prevalence and co-infection characteristics of RSV in Hangzhou during two epidemic seasons. Single respiratory samples from 1820 pediatric patients were screened for RSV and genotyped by RT-PCR and sequencing. In all RSV positive specimens, we screened for viruses and atypical bacteria. Demographic and clinical information was recorded and analyzed. A total of 34.5% and 3.8% of samples from acute lower respiratory tract infections (ALRI) and influenza-like illness (ILI) were positive for RSV, respectively. Phylogenetic analysis revealed that 61.1% of the selected 167 RSV strains were NA1, 31.1% were BA, 3.6% were ON1, 2.4% were CB1, and 1.8% were NA3. A new genotype, BA11 was identified, which comprised 98.1% of BA strains in this study, while the rest were BA10. A total of 36.4% and 9.1% of RSV-positive children with ALRI and ILI respectively were found to be co-infected. Rhinovirus was the most common additional respiratory virus, followed by human metapneumovirus. Except for fever, no significant differences in other clinical presentation between the RSV mono-infection and co-infection groups were observed. The circulating RSV strains had high genetic variability with RSV-B showing a more local pattern. In ALRI cases, co-infection of RSV with other viruses or atypical bacteria has no significant effect on the clinical presentation except fever. Copyright © 2015 Elsevier B.V. All rights reserved.

Numerical simulation of two consecutive nasal respiratory cycles: toward a better understanding of nasal physiology.

PubMed

de Gabory, Ludovic; Reville, Nicolas; Baux, Yannick; Boisson, Nicolas; Bordenave, Laurence

2018-01-16

Computational fluid dynamic (CFD) simulations have greatly improved the understanding of nasal physiology. We postulate that simulating the entire and repeated respiratory nasal cycles, within the whole sinonasal cavities, is mandatory to gather more accurate observations and better understand airflow patterns. A 3-dimensional (3D) sinonasal model was constructed from a healthy adult computed tomography (CT) scan which discretized in 6.6 million cells (mean volume, 0.008 mm 3 ). CFD simulations were performed with ANSYS©FluentTMv16.0.0 software with transient and turbulent airflow (k-ω model). Two respiratory cycles (8 seconds) were simulated to assess pressure, velocity, wall shear stress, and particle residence time. The pressure gradients within the sinus cavities varied according to their place of connection to the main passage. Alternations in pressure gradients induced a slight pumping phenomenon close to the ostia but no movement of air was observed within the sinus cavities. Strong movements were observed within the inferior meatus during expiration contrary to the inspiration, as in the olfactory cleft at the same time. Particle residence time was longer during expiration than inspiration due to nasal valve resistance, as if the expiratory phase was preparing the next inspiratory phase. Throughout expiration, some particles remained in contact with the lower turbinates. The posterior part of the olfactory cleft was gradually filled with particles that did not leave the nose at the next respiratory cycle. This pattern increased as the respiratory cycle was repeated. CFD is more efficient and reliable when the entire respiratory cycle is simulated and repeated to avoid losing information. © 2018 ARS-AAOA, LLC.

Characterization of Cardiopulmonary Exercise Testing Variables in Patients with Endomyocardial Fibrosis after Endocardial Resection

PubMed Central

Sayegh, Ana Luiza C.; dos Santos, Marcelo R.; de Oliveira, Patricia; Fernandes, Fábio; Rondon, Eduardo; de Souza, Francis R.; Salemi, Vera M. C.; Alves, Maria Janieire de N. N.; Mady, Charles

2017-01-01

Background Endomyocardial fibrosis (EMF) is a rare disease, characterized by diastolic dysfunction which leads to reduced peak oxygen consumption (VO2). Cardiopulmonary exercise testing (CPET) has been proved to be a fundamental tool to identify central and peripheral alterations. However, most studies prioritize peak VO2 as the main variable, leaving aside other important CPET variables that can specify the severity of the disease and guide the clinical treatment. Objective The aim of this study was to evaluate central and peripheral limitations in symptomatic patients with EMF by different CPET variables. Methods Twenty-six EMF patients (functional class III, NYHA) were compared with 15 healthy subjects (HS). Functional capacity was evaluated using CPET and diastolic and systolic functions were evaluated by echocardiography. Results Age and gender were similar between EMF patients and HS. Left ventricular ejection fraction was normal in EMF patients, but decreased compared to HS. Peak heart rate, peak workload, peak VO2, peak oxygen (O2) pulse and peak pulmonary ventilation (VE) were decreased in EMF compared to HS. Also, EMF patients showed increased Δ heart rate /Δ oxygen uptake and Δ oxygen uptake /Δ work rate compared to HS. Conclusion Determination of the aerobic capacity by noninvasive respiratory gas exchange during incremental exercise provides additional information about the exercise tolerance in patients with EMF. The analysis of different CPET variables is necessary to help us understand more about the central and peripheral alterations cause by both diastolic dysfunction and restrictive pattern. PMID:29364349

Occurrence of respiratory symptoms in persons with restrictive ventilatory impairment compared with persons with chronic obstructive pulmonary disease: The PLATINO study.

PubMed

Nonato, Nívia L; Nascimento, Oliver A; Padilla, Rogelio P; de Oca, Maria M; Tálamo, Carlos; Valdivia, Gonzalo; Lisboa, Carmen; López, Maria V; Celli, Bartolomé; Menezes, Ana Maria B; Jardim, José R

2015-08-01

Patients with chronic obstructive pulmonary disease (COPD) usually complain of symptoms such as cough, sputum, wheezing, and dyspnea. Little is known about clinical symptoms in individuals with restrictive ventilatory impairment. The aim of this study was to compare the prevalence and type of respiratory symptoms in patients with COPD to those reported by individuals with restrictive ventilatory impairment in the Proyecto Latinoamericano de Investigacion en Obstruccion Pulmonar study. Between 2002 and 2004, individuals ≥40 years of age from five cities in Latin America performed pre and post-bronchodilator spirometry and had their respiratory symptoms recorded in a standardized questionnaire. Among the 5315 individuals evaluated, 260 (5.1%) had a restrictive spirometric diagnosis (forced vital capacity (FVC) < lower limit of normal (LLN) with forced expiratory volume in the first second to forced vital capacity ratio (FEV1/FVC) ≥ LLN; American Thoracic Society (ATS)/European Respiratory Society (ERS) 2005) and 610 (11.9%) were diagnosed with an obstructive pattern (FEV1/FVC < LLN; ATS/ERS 2005). Patients with mild restriction wheezed more ((30.8%) vs. (17.8%); p < 0.028). No difference was seen in dyspnea, cough, and sputum between the two groups after adjusting for severity stage. The health status scores for the short form 12 questionnaire were similar in restricted and obstructed patients for both physical (48.4 ± 9.4 vs. 48.3 ± 9.8) and mental (50.8 ± 10.6 vs. 50.0 ± 11.5) domains. Overall, respiratory symptoms are not frequently reported by patients with restricted and obstructed patterns as defined by spirometry. Wheezing was more frequent in patients with restricted pattern compared with those with obstructive ventilatory defect. However, the prevalence of cough, sputum production, and dyspnea are not different between the two groups when adjusted by the same severity stage. © The Author(s) 2015.

Low breast milk levels of long-chain n-3 fatty acids in allergic women, despite frequent fish intake.

PubMed

Johansson, S; Wold, A E; Sandberg, A-S

2011-04-01

Long-chain n-3 polyunsaturated fatty acids (PUFAs) have immune regulating and anti-inflammatory effects. However, their role in allergic disease is unclear. Allergic diseases are immunologically heterogeneous, and we hypothesized that n-3 fatty acid composition in serum and breast milk may vary according to clinical manifestations. Further, animal studies have shown reduction of serum-PUFA levels during allergic inflammation. To investigate fatty acid composition in breast milk and serum from women with different atopic disease manifestations. Secondly, to determine whether low PUFA levels reflected insufficient intakes. Fatty acids were analysed in breast milk and serum of women with atopic eczema and respiratory allergy (n=16), only respiratory allergy (n=7), as well as healthy women (n=22). Dietary intake of foods expected to affect long-chain n-3 PUFA levels were estimated by food-frequency questionnaire. The fatty acid pattern was related to diagnostic group and intake of relevant food items using a multivariate pattern recognition method (partial least squares projections to latent structures and discriminant analysis). Results Women with a combination of eczema and respiratory allergy had lower breast milk levels of several PUFAs (arachidonic acid, eicosapentaenoic acid, EPA, docosahexaenoic acid, DHA, and docosapentaenoic acid, DPA), and a lower ratio of long-chain n-3 PUFAs/n-6 PUFAs. Their PUFA levels differed not only from that of healthy women, but also from that of women with only respiratory allergy. The latter had a fatty acid pattern similar to that of healthy women. Despite low EPA, DHA and DPA levels women with eczema and respiratory allergy consumed no less fish than did healthy women. Our data suggest that reduced levels of long-chain n-3 fatty acids in serum and breast milk characterize women with extensive allergic disease including eczema, and are not related to low fish intake. Consumption of PUFAs during the allergic process may explain these findings. © 2011 Blackwell Publishing Ltd.

Morbidity Forecast in Cities: A Study of Urban Air Pollution and Respiratory Diseases in the Metropolitan Region of Curitiba, Brazil.

PubMed

de Souza, Fabio Teodoro

2018-05-29

In the last two decades, urbanization has intensified, and in Brazil, about 90% of the population now lives in urban centers. Atmospheric patterns have changed owing to the high growth rate of cities, with negative consequences for public health. This research aims to elucidate the spatial patterns of air pollution and respiratory diseases. A data-based model to aid local urban management to improve public health policies concerning air pollution is described. An example of data preparation and multivariate analysis with inventories from different cities in the Metropolitan Region of Curitiba was studied. A predictive model with outstanding accuracy in prediction of outbreaks was developed. Preliminary results describe relevant relations among morbidity scales, air pollution levels, and atmospheric seasonal patterns. The knowledge gathered here contributes to the debate on social issues and public policies. Moreover, the results of this smaller scale study can be extended to megacities.

APEX_SCOPE: A graphical user interface for visualization of multi-modal data in inter-disciplinary studies.

PubMed

Kanbar, Lara J; Shalish, Wissam; Precup, Doina; Brown, Karen; Sant'Anna, Guilherme M; Kearney, Robert E

2017-07-01

In multi-disciplinary studies, different forms of data are often collected for analysis. For example, APEX, a study on the automated prediction of extubation readiness in extremely preterm infants, collects clinical parameters and cardiorespiratory signals. A variety of cardiorespiratory metrics are computed from these signals and used to assign a cardiorespiratory pattern at each time. In such a situation, exploratory analysis requires a visualization tool capable of displaying these different types of acquired and computed signals in an integrated environment. Thus, we developed APEX_SCOPE, a graphical tool for the visualization of multi-modal data comprising cardiorespiratory signals, automated cardiorespiratory metrics, automated respiratory patterns, manually classified respiratory patterns, and manual annotations by clinicians during data acquisition. This MATLAB-based application provides a means for collaborators to view combinations of signals to promote discussion, generate hypotheses and develop features.

Hypoxemia, hypercapnia, and breathing pattern in patients with chronic obstructive pulmonary disease.

PubMed

Parot, S; Miara, B; Milic-Emili, J; Gautier, H

1982-11-01

The results of lung function tests (total and functional residual capacities, residual volume/total lung capacity ratio, forced expiratory volume in one second) breathing patterns and arterial PO2 and PCO2 were studied in 651 ambulatory male patients with chronic obstructive pulmonary disease, functionally and clinically stable. Function tests were only loosely correlated with gas tensions: abnormalities in mechanics and in gas exchange are not necessarily related. In patients matched for the degree of obstruction, the breathing pattern depended upon both PaO2 and PaCO2. Isolated hypoxemia was accompanied by increased respiratory frequency without any variation in tidal volume: this suggests that the chemoreceptive systems still responded to changes in PaO2. Isolated hypercapnia was accompanied by a decrease in tidal volume and an increase in respiratory frequency. Consequently, the dead space/tidal volume ratio increased, leading to a drop in alveolar ventilation and to CO2 retention.

α1- and α2-adrenergic receptors in the retrotrapezoid nucleus differentially regulate breathing in anesthetized adult rats.

PubMed

Oliveira, Luiz M; Moreira, Thiago S; Kuo, Fu-Shan; Mulkey, Daniel K; Takakura, Ana C

2016-09-01

Norepinephrine (NE) is a potent modulator of breathing that can increase/decrease respiratory activity by α1-/α2-adrenergic receptor (AR) activation, respectively. The retrotrapezoid nucleus (RTN) is known to contribute to central chemoreception, inspiration, and active expiration. Here we investigate the sources of catecholaminergic inputs to the RTN and identify respiratory effects produced by activation of ARs in this region. By injecting the retrograde tracer Fluoro-Gold into the RTN, we identified back-labeled catecholaminergic neurons in the A7 region. In urethane-anesthetized, vagotomized, and artificially ventilated male Wistar rats unilateral injection of NE or moxonidine (α2-AR agonist) blunted diaphragm muscle activity (DiaEMG) frequency and amplitude, without changing abdominal muscle activity. Those inhibitory effects were reduced by preapplication of yohimbine (α2-AR antagonist) into the RTN. Conversely, unilateral RTN injection of phenylephrine (α1-AR agonist) increased DiaEMG amplitude and frequency and facilitated active expiration. This response was blocked by prior RTN injection of prazosin (α1-AR antagonist). Interestingly, RTN injection of propranolol (β-AR antagonist) had no effect on respiratory inhibition elicited by applications of NE into the RTN; however, the combined blockade of α2- and β-ARs (coapplication of propranolol and yohimbine) revealed an α1-AR-dependent excitatory response to NE that resulted in increase in DiaEMG frequency and facilitation of active expiration. However, blockade of α1-, α2-, or β-ARs in the RTN had minimal effect on baseline respiratory activity, on central or peripheral chemoreflexes. These results suggest that NE signaling can modulate RTN chemoreceptor function; however, endogenous NE signaling does not contribute to baseline breathing or the ventilatory response to central or peripheral chemoreceptor activity in urethane-anesthetized rats. Copyright © 2016 the American Physiological Society.

Assessing Modeled CO2 Retention and Rebreathing of a Facemask Designed for Efficient Delivery of Aerosols to Infants

PubMed Central

Mundt, Christian; Sventitskiy, Alexander; Cehelsky, Jeffrey E.; Patters, Andrea B.; Tservistas, Markus; Hahn, Michael C.; Juhl, Gerd; DeVincenzo, John P.

2012-01-01

Background. New aerosol drugs for infants may require more efficient delivery systems, including face masks. Maximizing delivery efficiency requires tight-fitting masks with minimal internal mask volumes, which could cause carbon dioxide (CO2) retention. An RNA-interference-based antiviral for treatment of respiratory syncytial virus in populations that may include young children is designed for aerosol administration. CO2 accumulation within inhalation face masks has not been evaluated. Methods. We simulated airflow and CO2 concentrations accumulating over time within a new facemask designed for infants and young children (PARI SMARTMASK® Baby). A one-dimensional model was first examined, followed by 3-dimensional unsteady computational fluid dynamics analyses. Normal infant breathing patterns and respiratory distress were simulated. Results. The maximum average modeled CO2 concentration within the mask reached steady state (3.2% and 3% for normal and distressed breathing patterns resp.) after approximately the 5th respiratory cycle. After steady state, the mean CO2 concentration inspired into the nostril was 2.24% and 2.26% for normal and distressed breathing patterns, respectively. Conclusion. The mask is predicted to cause minimal CO2 retention and rebreathing. Infants with normal and distressed breathing should tolerate the mask intermittently delivering aerosols over brief time frames. PMID:22792479

Antimicrobial multidrug resistance and coresistance patterns of Mannheimia haemolytica isolated from bovine respiratory disease cases--a three-year (2009-2011) retrospective analysis.

PubMed

Lubbers, Brian V; Hanzlicek, Gregg A

2013-05-01

Bovine respiratory disease continues to be the most important ailment of feed yard cattle. While the disease is multifactorial in nature, therapy continues to target the primary bacterial pathogens, Mannheimia haemolytica, Pasteurella multocida, and Histophilus somni. A survey of records from a single diagnostic laboratory was conducted to evaluate the percentage of M. haemolytica isolates that were resistant to multiple antimicrobials and if coresistance patterns could be detected. All susceptibility test results for M. haemolytica recovered from lung tissues of cattle were eligible for inclusion in the survey. There were no isolates over the course of the analysis that were resistant to all 6 antimicrobials, primarily due to a lack of resistance to ceftiofur. In 2009, just over 5% of isolates were resistant to 5 or more antimicrobials (pan-resistant). In 2011, more than 35% of the M. haemolytica isolates were characterized as pan-resistant. Significant antimicrobial coresistance patterns were only seen with oxytetracycline and tilmicosin; bacterial isolates that were resistant to either oxytetracycline or tilmicosin were more likely to be resistant to at least one other antimicrobial. The mechanisms by which M. haemolytica is developing multidrug resistance warrant investigation if antimicrobial utility in the therapy of bovine respiratory disease is to be preserved.

Prescribing Patterns of Drugs in Acute Respiratory Distress Syndrome (ARDS): An Observational Study

PubMed Central

Rao, Shobitha; Chogtu, Bharti

2015-01-01

Introduction: Acute respiratory distress syndrome (ARDS) is characterized by acute respiratory failure and is associated with wide range of clinical disorders. Controversy prevails over the pharmacological intervention in this disease. The aim of the study was to observe the prescribing pattern of drugs in patients with ARDS managed at a tertiary care hospital. Materials and Methods: This observational study was conducted at tertiary care hospital in India. Data of patients admitted from January 2010 to December 2012 was collected. Patients aged more than 18 years admitted in ICU, who were diagnosed to have ARDS during the study period, were included. A total of 150 patients of ARDS were selected. Data was collected as per the pre designed proforma and it included patients’ age, gender, clinical disorders precipitating ARDS, prescribing pattern of drugs and outcome. The data of the subjects was collected till discharge from hospital or death. Results: Infection was the cause of ARDS in 81.3% (n=122) of subjects. Antibiotics were prescribed in all the subjects and beta-lactams were prescribed in 97.3% (n=146). 41.3% (n=62) were prescribed corticosteroids, 39.3% (n=59) diuretics and 89.3% (n=134) intravenous fluids. Conclusion: The outcome of patients on different pharmacological treatment did not show any statistically significant difference. PMID:25859465

Respiratory cooling and thermoregulatory coupling in reptiles.

PubMed

Tattersall, Glenn J; Cadena, Viviana; Skinner, Matthew C

2006-11-01

Comparative physiological research on reptiles has focused primarily on the understanding of mechanisms of the control of breathing as they relate to respiratory gases or temperature itself. Comparatively less research has been done on the possible link between breathing and thermoregulation. Reptiles possess remarkable thermoregulatory capabilities, making use of behavioural and physiological mechanisms to regulate body temperature. The presence of thermal panting and gaping in numerous reptiles, coupled with the existence of head-body temperature differences, suggests that head temperature may be the primary regulated variable rather than body temperature. This review examines the preponderance of head and body temperature differences in reptiles, the occurrence of breathing patterns that possess putative thermoregulatory roles, and the propensity for head and brain temperature to be controlled by reptiles, particularly at higher temperatures. The available evidence suggests that these thermoregulatory breathing patterns are indeed present, though primarily in arid-dwelling reptiles. More importantly, however, it appears that the respiratory mechanisms that have the capacity to cool evolved initially in reptiles, perhaps as regulatory mechanisms for preventing overheating of the brain. Examining the control of these breathing patterns and their efficacy at regulating head or brain temperature may shed light on the evolution of thermoregulatory mechanisms in other vertebrates, namely the endothermic mammals and birds.

HOXA5 plays tissue-specific roles in the developing respiratory system.

PubMed

Landry-Truchon, Kim; Houde, Nicolas; Boucherat, Olivier; Joncas, France-Hélène; Dasen, Jeremy S; Philippidou, Polyxeni; Mansfield, Jennifer H; Jeannotte, Lucie

2017-10-01

Hoxa5 is essential for development of several organs and tissues. In the respiratory system, loss of Hoxa5 function causes neonatal death due to respiratory distress. Expression of HOXA5 protein in mesenchyme of the respiratory tract and in phrenic motor neurons of the central nervous system led us to address the individual contribution of these Hoxa5 expression domains using a conditional gene targeting approach. Hoxa5 does not play a cell-autonomous role in lung epithelium, consistent with lack of HOXA5 expression in this cell layer. In contrast, ablation of Hoxa5 in mesenchyme perturbed trachea development, lung epithelial cell differentiation and lung growth. Further, deletion of Hoxa5 in motor neurons resulted in abnormal diaphragm innervation and musculature, and lung hypoplasia. It also reproduced the neonatal lethality observed in null mutants, indicating that the defective diaphragm is the main cause of impaired survival at birth. Thus, Hoxa5 possesses tissue-specific functions that differentially contribute to the morphogenesis of the respiratory tract. © 2017. Published by The Company of Biologists Ltd.

Fluoxetine treatment abolishes the in vitro respiratory response to acidosis in neonatal mice.

PubMed

Voituron, Nicolas; Shvarev, Yuri; Menuet, Clément; Bevengut, Michelle; Fasano, Caroline; Vigneault, Erika; El Mestikawy, Salah; Hilaire, Gérard

2010-10-26

To secure pH homeostasis, the central respiratory network must permanently adapt its rhythmic motor drive to environment and behaviour. In neonates, it is commonly admitted that the retrotrapezoid/parafacial respiratory group of neurons of the ventral medulla plays the primary role in the respiratory response to acidosis, although the serotonergic system may also contribute to this response. Using en bloc medullary preparations from neonatal mice, we have shown for the first time that the respiratory response to acidosis is abolished after pre-treatment with the serotonin-transporter blocker fluoxetine (25-50 µM, 20 min), a commonly used antidepressant. Using mRNA in situ hybridization and immunohistology, we have also shown the expression of the serotonin transporter mRNA and serotonin-containing neurons in the vicinity of the RTN/pFRG of neonatal mice. These results reveal that the serotonergic system plays a pivotal role in pH homeostasis. Although obtained in vitro in neonatal mice, they suggest that drugs targeting the serotonergic system should be used with caution in infants, pregnant women and breastfeeding mothers.

Fluoxetine Treatment Abolishes the In Vitro Respiratory Response to Acidosis in Neonatal Mice

PubMed Central

Voituron, Nicolas; Shvarev, Yuri; Menuet, Clément; Bevengut, Michelle; Fasano, Caroline; Vigneault, Erika; Mestikawy, Salah El; Hilaire, Gérard

2010-01-01

Background To secure pH homeostasis, the central respiratory network must permanently adapt its rhythmic motor drive to environment and behaviour. In neonates, it is commonly admitted that the retrotrapezoid/parafacial respiratory group of neurons of the ventral medulla plays the primary role in the respiratory response to acidosis, although the serotonergic system may also contribute to this response. Methodology/Principal Findings Using en bloc medullary preparations from neonatal mice, we have shown for the first time that the respiratory response to acidosis is abolished after pre-treatment with the serotonin-transporter blocker fluoxetine (25–50 µM, 20 min), a commonly used antidepressant. Using mRNA in situ hybridization and immunohistology, we have also shown the expression of the serotonin transporter mRNA and serotonin-containing neurons in the vicinity of the RTN/pFRG of neonatal mice. Conclusions These results reveal that the serotonergic system plays a pivotal role in pH homeostasis. Although obtained in vitro in neonatal mice, they suggest that drugs targeting the serotonergic system should be used with caution in infants, pregnant women and breastfeeding mothers. PMID:21048979

Curtailed respiration by repeated vs. isolated hypoxia in maturing piglets is unrelated to NTS ME or SP levels.

PubMed

Waters, K A; Laferrière, A; Paquette, J; Goodyer, C; Moss, I R

1997-08-01

In early development, respiratory disorders can produce recurring hypoxic episodes during sleep. To examine possible effects of daily repeated vs. isolated hypoxic hypoxia, cardiorespiratory functions and central, respiratory-related neuromodulator levels in 21- to 32-day-old, chronically instrumented, unsedated piglets were compared between a fifth sequential daily hypoxia and an isolated hypoxia (10% O2-90% N2 for 30 min). Diaphragmatic electromyographic activity, heart rate and arterial pressure, and pH and gas tensions were measured. In vivo microdialysis, via chronically implanted guides, served to sample interstitial substance P (SP) and methionine-enkephalin (ME) at the level of the respiratory-related nucleus tractus solitarii (NTS). Compared with an isolated hypoxia, repeated hypoxia resulted in 1) lower respiratory frequency (f), ventilation equivalent, and arterial pH, higher arterial PO2 during hypoxia, and lower f in recovery from hypoxia; and 2) increased SP concentrations but no change in ME concentrations. We conclude that, in these maturing swine, repeated vs. isolated hypoxic exposure curtails respiratory responses to hypoxia by a mechanism(s) unrelated to SP or ME levels at the NTS.

The American Academy of Sleep Medicine Inter-scorer Reliability Program: Respiratory Events

PubMed Central

Rosenberg, Richard S.; Van Hout, Steven

2014-01-01

Study Objectives: The American Academy of Sleep Medicine (AASM) Inter-scorer Reliability program provides a unique opportunity to compare a large number of scorers with varied levels of experience to determine agreement in the scoring of respiratory events. The objective of this paper is to examine areas of disagreement to inform future revisions of the AASM Manual for the Scoring of Sleep and Associated Events. Methods: The sample included 15 monthly records, 200 epochs each. The number of scorers increased steadily during the period of data collection, reaching more than 3,600 scorers by the final record. Scorers were asked to identify whether an obstructive, mixed, or central apnea; a hypopnea; or no event was seen in each of the 200 epochs. The “correct” respiratory event score was defined as the score endorsed by the most scorers. Percentage agreement with the majority score was determined for each epoch and the mean agreement determined. Results: The overall agreement for scoring of respiratory events was 93.9% (κ = 0.92). There was very high agreement on epochs without respiratory events (97.4%), and the majority score for most of the epochs (87.8%) was no event. For the 364 epochs scored as having a respiratory event, overall agreement that some type of respiratory event occurred was 88.4% (κ = 0.77). The agreement for epochs scored as obstructive apnea by the majority was 77.1% (κ = 0.71), and the most common disagreement was hypopnea rather than obstructive apnea (14.4%). The agreement for hypopnea was 65.4% (κ = 0.57), with 16.4% scoring no event and 14.8% scoring obstructive apnea. The agreement for central apnea was 52.4% (κ = 0.41). A single epoch was scored as a mixed apnea by a plurality of scorers. Conclusions: The study demonstrated excellent agreement among a large sample of scorers for epochs with no respiratory events. Agreement for some type of event was good, but disagreements in scoring of apnea vs. hypopnea and type of apnea were common. A limitation of the analysis is that most of the records had normal breathing. A review of controversial events yielded no consistent bias that might be resolved by a change of scoring rules. Citation: Rosenberg RS; Van Hout S. The American Academy of Sleep Medicine inter-scorer reliability program: respiratory events. J Clin Sleep Med 2014;10(4):447-454. PMID:24733993

TH-CD-207A-04: Optimized Respiratory Gating for Abnormal Breathers in Pancreatic SBRT

DOE Office of Scientific and Technical Information (OSTI.GOV)

Campbell, W; Miften, M; Schefter, T

Purpose: Pancreatic SBRT is uniquely challenging due to both the erratic/unstable motion of the pancreas and the close proximity of the radiosensitive small bowel. Respiratory gating can mitigate this effect, but the irregularity of motion severely affects traditional phase-based gating. The purpose of this study was to analyze real-time motion data of pancreatic tumors to optimize the efficacy and accuracy of respiratory gating, with the overall goal of enabling dose escalated pancreatic SBRT. Methods: Fifteen pancreatic SBRT patients received 30–33 Gy in 5 fractions on a Varian TrueBeam STx unit. Abdominal compression was used to reduce the amplitude of tumormore » motion, and daily cone-beam computed tomography (CBCT) scans were acquired prior to each treatment for target localization purposes. For this study, breathing data (phase and amplitude) were collected during each CBCT scan using Varian’s Real-Time Position Management system. An in-house template matching technique was used to track the superior-inferior motion of implanted fiducial markers in CBCT projection images. Using tumor motion and breathing data, phase-based or amplitude-based respiratory gating was simulated for all 75 fractions, targeting either end-exhalation or end-inhalation phases of breathing. Results: For the average patient, gating at end-exhalation offered the best reductions in effective motion for equal duty cycles. However, optimal central phase angle varied widely (range: 0–92%, mean±SD: 49±12%), and phase-based gating windows typically associated with end-exhalation (i.e., “30–70%”) were rarely ideal. Amplitude-based gating significantly outperformed phase-based gating, with average effective ranges for amplitude-based gating 25% lower than phase-based gating ranges (as much as 73% lower). Amplitude-based gating was consistently better suited to accommodate abnormal breathing patterns. For both phase-based and amplitude-based gating, end-exhalation provided significantly better results than end-inhalation. Conclusion: Amplitude-based gating reliably outperformed phase-based gating, and end-exhalation was more suitable than end-inhalation. These results will be used to guide future dose-escalation trials. Research funding provided by Varian Medical Systems to Miften and Jones.« less

Dietary Pattern Is Associated with Obesity in Older People in China: Data from China Health and Nutrition Survey (CHNS).

PubMed

Xu, Xiaoyue; Hall, John; Byles, Julie; Shi, Zumin

2015-09-23

No studies have been conducted to explore the associations between dietary patterns and obesity among older Chinese people, by considering gender and urbanization level differences. We analyzed data from the 2009 China Health and Nutrition Survey (2745 individuals, aged ≥ 60 years). Dietary data were obtained using 24 hour-recall over three consecutive days. Height, Body Weight, and Waist Circumference were measured. Exploratory factor analysis was used to identify dietary patterns. Multinomial and Poisson regression models were used to examine the association between dietary patterns and Body Mass Index (BMI) status/central obesity. The prevalence of general and central obesity was 9.5% and 53.4%. Traditional dietary pattern (high intake of rice, pork and vegetables) was inversely associated with general/central obesity; modern dietary pattern (high intake of fruit, fast food, and processed meat) was positively associated with general/central obesity. The highest quartile of traditional dietary pattern had a lower risk of general/central obesity compared with the lowest quartile, while an inverse picture was found for the modern dietary pattern. These associations were consistent by gender and urbanization levels. Dietary patterns are associated with general/central obesity in older Chinese. This study reinforces the importance of a healthy diet in promoting healthy ageing in China.

Management of the infant with respiratory syncytial virus.

PubMed

Corey, M A; Clore, E R

1991-04-01

This article examines updated clinical information concerning respiratory syncytial virus (RSV) infection including epidemiology, pathology, clinical manifestations, diagnosis, treatment, nosocomial infection, and prognosis. Also presented is current information on ribavirin therapy, its side effects, and precautions. Research related to the most effective isolation methodology is discussed, as well as nursing diagnoses based on Gordon's Functional Health Patterns and interventions for the infant hospitalized with RSV bronchiolitis and/or pneumonia.

On the respiratory flow in the cuttlefish sepia officinalis.

PubMed

Bone, Q; Brown, E; Travers, G

1994-09-01

The respiratory flow of water over the gills of the cuttlefish Sepia officinalis at rest is produced by the alternate activity of the radial muscles of the mantle and the musculature of the collar flaps; mantle circular muscle fibres are not involved. Inspiration takes place as the radial fibres contract, thinning the mantle and expanding the mantle cavity. The rise in mantle cavity pressure (up to 0.15 kPa), expelling water via the siphon during expiration, is brought about by inward movement of the collar flaps and (probably) mainly by elastic recoil of the mantle connective tissue network 'wound up' by radial fibre contraction during inspiration. Sepia also shows a second respiratory pattern, in which mantle cavity pressures during expiration are greater (up to 0.25 kPa). Here, the mantle circular fibres are involved, as they are during the large pressure transients (up to 10 kPa) seen during escape jetting. Active contraction of the muscles of the collar flaps is seen in all three patterns of expulsion of water from the mantle cavity, electrical activity increasing with increasing mantle cavity pressures. Respiratory expiration in the resting squid Loligo vulgaris is probably driven as in Sepia, whereas in the resting octopus Eledone cirrhosa, the mantle circular musculature is active during expiration. The significance of these observations is discussed.

Challenges of Developing Communicative Interaction in Individuals with Congenital Profound Intellectual and Multiple Disabilities

ERIC Educational Resources Information Center

Blain-Moraes, Stefanie; Chau, Tom

2012-01-01

Background: Physiological responses have been used in individuals with acquired disability to enable communicative interaction without motor movement. This study explored four autonomic nervous system (ANS) signals--electrodermal activity, skin temperature, cardiac patterns and respiratory patterns--to enable interaction with individuals born with…

Epidemiological Features and Antibiotic Resistance Patterns of Haemophilus influenzae Originating from Respiratory Tract and Vaginal Specimens in Pediatric Patients.

PubMed

Li, Jian-Ping; Hua, Chun-Zhen; Sun, Li-Ying; Wang, Hong-Jiao; Chen, Zhi-Min; Shang, Shi-Qiang

2017-12-01

Haemophilus influenzae (H. influenzae) is a common pathogen of respiratory tract infections in children, however, as a possible cause of vulvovaginitis in prepubertal girls, its epidemiological features, antibiotic-resistance patterns, and treatment are seldom noted. DESIGN, SETTING, PARTICIPANTS, INTERVENTIONS, AND MAIN OUTCOME MEASURES: Specimens obtained from patients were inoculated on Haemophilus selective medium; and drug-sensitivities tests were determined using the disk diffusion method. A cefinase disk was used to detect β-lactamase. A total of 610 H. influenzae strains, 81.6% (498/610) from the respiratory tract and 18.0% (110/610) from the vagina, were identified in the Children's Hospital in 2015. The age of the children with respiratory tract strains were significantly younger than those with vaginal strains (P < .001). The H. influenzae isolation rate in May was the highest. The β-lactamase positive rate was 51.5% (314/610), and 52.5% (320/610) were resistant to ampicillin. The susceptibilities rates to cefuroxime, ampicillin/sulbactam, cefotaxime, clarithromycin, and sulfamethoxazole-trimethoprim were 72.1% (440/610), 95.9%, 96.4% (588/610), 81.8% (499/610), and 36.4% (222/610), respectively. Higher resistance to ampicillin, cefuroxime, clarithromycin, and sulfamethoxazole-trimethoprim were found in respiratory tract strains, compared with vaginal strains (P < .05). All of the patients with H. influenzae in the respiratory tract were cured with oral or intravenous β-lactam antibiotics. Of all patients with vaginal strains, 50% (55/110) were cured with topical ofloxacin gel, and 44.5% (49/110) were cured with oral β-lactam antibiotics. The drug-resistance rates of H. influenzae isolated from vagina were lower than those from the respiratory tract. Topical ofloxacin gel or oral β-lactam antibiotics are effective treatments to eliminate the H. influenza causing infection in the vagina. Copyright © 2017 North American Society for Pediatric and Adolescent Gynecology. Published by Elsevier Inc. All rights reserved.

Novel insights in cough and breathing patterns of patients with idiopathic pulmonary fibrosis performing repeated 24-hour-respiratory polygraphies.

PubMed

Schertel, Anke; Funke-Chambour, Manuela; Geiser, Thomas; Brill, Anne-Kathrin

2017-11-13

The main symptoms of patients with idiopathic pulmonary fibrosis (IPF) are cough and dyspnea. IPF leads to a restrictive lung disorder impacting daytime and nocturnal breathing patterns. In this pilot study we assessed the course of day- and nighttime respiration, oxygenation, and cough over a period of 8 months as well as differences between wakefulness and sleep in IPF patients. Repetitive 24-h respiratory polygraphies (RP) and pulmonary function tests were performed at baseline and after 3, 4, 7 and 8 months. Cough-index, oxygenation parameters (SpO2, time with SpO2 < 90%, desaturation index), respiratory rate and heart rate were assessed for differences between wakefulness and sleep. The first and the last RP were compared to identify changes of these parameters over time. Statistical analyses were performed with Wilcoxon signed rank tests. Nine IPF patients (8 male, median age 67 years (IQR 60, 77) with 37 valid 24-h RPs were included. Eight patients (88.9%) received antifibrotic treatment. Cough was more prevalent during wakefulness with a median cough-index of 14.8/h (IQR 10.9, 16.8) and 1.6/h (IQR 1.3-2.8) during sleep, p = 0.0039. Oxygenation parameters showed no difference, while respiratory- and heart rate were significantly higher during wakefulness. Despite stable pulmonary function tests over 8 months, the initially elevated respiratory rate increased further during wakefulness (baseline RR median 25.7/min (IQR 19.8, 26.6) vs. RR median 32.2/min (IQR 26.5, 40.9) at follow-up, p = 0.0273). The other respiratory parameters remained stable over time. Cough in IPF patients is more prevalent during wakefulness than during sleep. Further studies with a larger sample size and longer a follow-up period are needed to evaluate the role of the respiratory rate during wakefulness as a potential clinical follow up parameter in IPF.

Pacific Pediatric Advanced Care Initiative

DTIC Science & Technology

2011-01-01

infusing into the patient via a central venous line 6. After you have made sure the patient is safe, remove air from system. 7. Identify and fix...site. Push blood. Take fluid out of bladder to create a more negative venous pressure History : Day 1 for a 2 month old who had a witnessed...operating room, central supply, pharmacy, respiratory care, Neonatal Intensive Care Unit (NICU) nursing, Pediatric Intensive Care Unit (PICU) nursing, Risk

Pbx3 Deficiency Results in Central Hypoventilation

PubMed Central

Rhee, Joon Whan; Arata, Akiko; Selleri, Licia; Jacobs, Yakop; Arata, Satoru; Onimaru, Hiroshi; Cleary, Michael L.

2004-01-01

Pbx proteins comprise a family of TALE (three amino acid loop extension) class homeodomain transcription factors that are implicated in developmental gene expression through their abilities to form hetero-oligomeric DNA-binding complexes and function as transcriptional regulators in numerous cell types. We demonstrate here that one member of this family, Pbx3, is expressed at high levels predominantly in the developing central nervous system, including a region of the medulla oblongata that is implicated in the control of respiration. Pbx3-deficient mice develop to term but die within a few hours of birth from central respiratory failure due to abnormal activity of inspiratory neurons in the medulla. This partially phenocopies the defect in mice deficient for Rnx, a metaHox homeodomain transcription factor, that we demonstrate here is capable of forming a DNA-binding complex with Pbx3. Rnx expression is unperturbed in Pbx3-deficient mice, but its ability to enhance transcription in vitro as a complex with TALE proteins is compromised in the absence of Pbx3. Thus, Pbx3 is essential for respiration and, like its DNA-binding partner Rnx, is critical for proper development of medullary respiratory control mechanisms. Pbx3-deficient mice provide a model for congenital central hypoventilation syndrome and suggest that Pbx3 mutations may promote the pathogenesis of this disorder. PMID:15466398

Rib Cage Deformities Alter Respiratory Muscle Action and Chest Wall Function in Patients with Severe Osteogenesis Imperfecta

PubMed Central

LoMauro, Antonella; Pochintesta, Simona; Romei, Marianna; D'Angelo, Maria Grazia; Pedotti, Antonio; Turconi, Anna Carla; Aliverti, Andrea

2012-01-01

Background Osteogenesis imperfecta (OI) is an inherited connective tissue disorder characterized by bone fragility, multiple fractures and significant chest wall deformities. Cardiopulmonary insufficiency is the leading cause of death in these patients. Methods Seven patients with severe OI type III, 15 with moderate OI type IV and 26 healthy subjects were studied. In addition to standard spirometry, rib cage geometry, breathing pattern and regional chest wall volume changes at rest in seated and supine position were assessed by opto-electronic plethysmography to investigate if structural modifications of the rib cage in OI have consequences on ventilatory pattern. One-way or two-way analysis of variance was performed to compare the results between the three groups and the two postures. Results Both OI type III and IV patients showed reduced FVC and FEV1 compared to predicted values, on condition that updated reference equations are considered. In both positions, ventilation was lower in OI patients than control because of lower tidal volume (p<0.01). In contrast to OI type IV patients, whose chest wall geometry and function was normal, OI type III patients were characterized by reduced (p<0.01) angle at the sternum (pectus carinatum), paradoxical inspiratory inward motion of the pulmonary rib cage, significant thoraco-abdominal asynchronies and rib cage distortions in supine position (p<0.001). Conclusions In conclusion, the restrictive respiratory pattern of Osteogenesis Imperfecta is closely related to the severity of the disease and to the sternal deformities. Pectus carinatum characterizes OI type III patients and alters respiratory muscles coordination, leading to chest wall and rib cage distortions and an inefficient ventilator pattern. OI type IV is characterized by lower alterations in the respiratory function. These findings suggest that functional assessment and treatment of OI should be differentiated in these two forms of the disease. PMID:22558284

Healthcare-seeking behaviors for acute respiratory illness in two communities of Java, Indonesia: a cross-sectional survey

PubMed Central

Praptiningsih, Catharina Y.; Lafond, Kathryn E.; Wahyuningrum, Yunita; Storms, Aaron D.; Mangiri, Amalya; Iuliano, Angela D.; Samaan, Gina; Titaley, Christiana R.; Yelda, Fitra; Kreslake, Jennifer; Storey, Douglas; Uyeki, Timothy M.

2017-01-01

Understanding healthcare-seeking patterns for respiratory illness can help improve estimations of disease burden and inform public health interventions to control acute respiratory disease in Indonesia. The objectives of this study were to describe healthcare-seeking behaviors for respiratory illnesses in one rural and one urban community in Western Java, and to explore the factors that affect care seeking. From February 8, 2012 to March 1, 2012, a survey was conducted in 2520 households in the East Jakarta and Bogor districts to identify reported recent respiratory illnesses, as well as all hospitalizations from the previous 12-month period. We found that 4% (10% of those less than 5 years) of people had respiratory disease resulting in a visit to a healthcare provider in the past 2 weeks; these episodes were most commonly treated at government (33%) or private (44%) clinics. Forty-five people (0.4% of those surveyed) had respiratory hospitalizations in the past year, and just over half of these (24/45, 53%) occurred at a public hospital. Public health programs targeting respiratory disease in this region should account for care at private hospitals and clinics, as well as illnesses that are treated at home, in order to capture the true burden of illness in these communities. PMID:26930154

Healthcare-seeking behaviors for acute respiratory illness in two communities of Java, Indonesia: a cross-sectional survey.

PubMed

Praptiningsih, Catharina Y; Lafond, Kathryn E; Wahyuningrum, Yunita; Storms, Aaron D; Mangiri, Amalya; Iuliano, Angela D; Samaan, Gina; Titaley, Christiana R; Yelda, Fitra; Kreslake, Jennifer; Storey, Douglas; Uyeki, Timothy M

2016-06-01

Understanding healthcare-seeking patterns for respiratory illness can help improve estimations of disease burden and inform public health interventions to control acute respiratory disease in Indonesia. The objectives of this study were to describe healthcare-seeking behaviors for respiratory illnesses in one rural and one urban community in Western Java, and to explore the factors that affect care seeking. From February 8, 2012 to March 1, 2012, a survey was conducted in 2520 households in the East Jakarta and Bogor districts to identify reported recent respiratory illnesses, as well as all hospitalizations from the previous 12-month period. We found that 4% (10% of those less than 5years) of people had respiratory disease resulting in a visit to a healthcare provider in the past 2weeks; these episodes were most commonly treated at government (33%) or private (44%) clinics. Forty-five people (0.4% of those surveyed) had respiratory hospitalizations in the past year, and just over half of these (24/45, 53%) occurred at a public hospital. Public health programs targeting respiratory disease in this region should account for care at private hospitals and clinics, as well as illnesses that are treated at home, in order to capture the true burden of illness in these communities. Published by Elsevier Ltd.

Fosfomycin i.v. for Treatment of Severely Infected Patients

ClinicalTrials.gov

2018-05-08

Bacterial Infections; Bone Diseases, Infectious; Osteomyelitis; Central Nervous System Bacterial Infections; Meningitis, Bacterial; Encephalitis; Brain Abscess; Urinary Tract Infections; Respiratory Tract Infections; Pneumonia, Bacterial; Skin Diseases, Bacterial; Soft Tissue Infections; Intraabdominal Infections; Sepsis; Bacteremia; Endocarditis, Bacterial

Current research and prospects for health effects of nanoparticles on offspring

NASA Astrophysics Data System (ADS)

Umezawa, Masakazu; Takeda, Ken

2011-10-01

Caution in handling ceramic nanoparticles is required by workers and consumers if they are to be used safely and profitably. The small size of nanoparticles can bestow high reactivity and unique translocational properties. Studies have shown that exposure to some types of nanoparticles affects the respiratory, cardiovascular and central nervous systems and various organs. When pregnant mice were exposed to nanoparticles, various organs of offspring are also affected. Our recent studies showed that prenatal exposure to nanoparticles (carbon black and titanium dioxide) causes long-term adverse effects on the reproductive, respiratory and central nervous systems of offspring. The effects of nanoparticles on fetuses and children and the possibility of them leading to the onset of diseases in adulthood are of concern. Thus, it is important to research the risk of unintentional exposure to nanoparticles, including ceramic nanoparticles, from the environment and to attempt to identify methods to protect against their toxicity.

New clinical and histological patterns of acute disseminated histoplasmosis in human immunodeficiency virus-positive patients with acquired immunodeficiency syndrome.

PubMed

Ollague Sierra, Jose E; Ollague Torres, Jose M

2013-04-01

Histoplasmosis has attained increasing relevance in the past 3 decades because of the appearance of the human immunodeficiency virus (HIV). In most immunocompetent persons, the infection is asymptomatic or can produce a respiratory condition with symptoms and radiological images similar to those observed in pulmonary tuberculosis; in non-HIV+ immunocompromised patients, it can cause respiratory symptoms or evolve into a disseminated infection. The same can occur in acquired immunodeficiency syndrome (AIDS) patients. We have observed a series of HIV+ patients with AIDS who presented with cutaneous histoplasmosis and in whom the clinical and histopathological features were highly unusual, including variable mucocutaneous lesions that were difficult to diagnose clinically. These patients displayed unusual, previously undescribed, histological patterns, including lichenoid pattern, nodular pseudomyxoid pattern, pyogenic granuloma-like pattern, perifollicular pattern, and superficial (S), mid (M), and deep perivascular dermatitis; and more commonly encountered patterns, such as histiocytic lobular panniculitis and focal nodular dermatitis. The novel histopathological patterns of cutaneous involvement by histoplasmosis seen in these patients resembled other common inflammatory and infectious conditions and required a high level of suspicion and the application of special stains for organisms for confirmation. These new, clinical, and histological findings do not seem to be commonly encountered in HIV- patients infected with the fungus but seem to be displayed most prominently in HIV+ patients with AIDS.

Behavior change, environmental hazards and respiratory protection among a southern farm community.

PubMed

Carruth, Ann K; Duthu, Stacie G; Levin, Jeffrey; Lavigne, Thadd

2008-01-01

The agricultural industry ranks as one of the most dangerous in terms of occupational deaths and injuries. A wide variety of respiratory illnesses can result from the exposure to grain and organic dusts and working in animal confinement facilities and barns. This article analyzes the Transtheoretical Model of Change for implications relevant to health promotion and education. This study explored differences of perception of occupational health, environmental exposures, and stages of change consistent with the readiness to take action and the confidence to act toward respiratory health among farmers who report respiratory symptoms with physical activity and those who do not. A convenience sample of 123 farm owners and agricultural employees recruited from community-based agricultural events in southeast and central Louisiana completed three surveys: (a) Health Risk and Environmental Assessment; (b) Identification of Respiratory Mask Use; (c) Stage of Awareness and Preventive Respiratory Health; and demographic information. Subjects performed pulmonary function tests including three Forced Vital Capacity (FVC) maneuvers while connected to a Renaissance spirometer. Even though the majority of subjects rated themselves in action stage of change, subjects reported using respiratory protective devices less than 10% of the time. No significant differences were found in environmental exposures. Using chi-square analysis, those farmers who reported breathlessness were significantly more likely to report fatigue, chest pain, and dizziness. Those farmers who report breathlessness are significantly less likely to perceive respiratory health as important compared to other occupational illnesses/conditions. There is a need for additional studies to further examine the relationship between respiratory symptoms, exposure risks, and behavior change theory.

Characterization of dermatoglyphics in PHOX2B-confirmed congenital central hypoventilation syndrome.

PubMed

Todd, Emily S; Scott, Nicole M; Weese-Mayer, Debra E; Weinberg, Seth M; Berry-Kravis, Elizabeth M; Silvestri, Jean M; Kenny, Anna S; Hauptman, Susan A; Zhou, Lili; Marazita, Mary L

2006-08-01

Individuals with congenital central hypoventilation syndrome have characteristic variants in the PHOX2B gene (primarily polyalanine expansion mutations). The PHOX2B gene acts as a transcriptional activator in the promotion of pan-neuronal differentiation in the autonomic nervous system during early embryologic development, with a primary role in the sympathetic noradrenergic phenotype in vertebrates. Because sympathetic innervation has been hypothesized to affect the development of dermatoglyphic pattern types, we hypothesized that individuals with PHOX2B-confirmed congenital central hypoventilation syndrome would have characteristic dermatoglyphic patterning and that the dermatoglyphic phenotype would be related to the disease-defining PHOX2B genotype. Dermatoglyphic pattern type frequency, left/right symmetry, and genotype/phenotype correlation were assessed for 33 individuals with PHOX2B-confirmed congenital central hypoventilation syndrome and compared with published control data. Dermatoglyphic pattern type frequencies were altered in congenital central hypoventilation syndrome cases versus controls. In particular, there was an increase of arches in females and ulnar loops in males, with the largest differences for the left hand and for individuals with both congenital central hypoventilation syndrome and Hirschsprung disease. Dissimilarity scores between the congenital central hypoventilation syndrome and congenital central hypoventilation syndrome + Hirschsprung disease cases were not significantly different, nor were dissimilarity scores between all of the female and all of the male cases. No significant association was found between the number of polyalanine repeats in the PHOX2B genotypic category and dermatoglyphic pattern frequencies in the congenital central hypoventilation syndrome study groups. These results represent the first report describing specific dermatoglyphic patterning in congenital central hypoventilation syndrome and suggest a relationship between PHOX2B and the expression of dermatoglyphic pattern types. An expanded congenital central hypoventilation syndrome data set to include the full spectrum of PHOX2B mutations is necessary to further delineate the role of PHOX2B in dermatoglyphic patterning.

Respiratory care management information systems.

PubMed

Ford, Richard M

2004-04-01

Hospital-wide computerized information systems evolved from the need to capture patient information and perform billing and other financial functions. These systems, however, have fallen short of meeting the needs of respiratory care departments regarding work load assessment, productivity management, and the level of outcome reporting required to support programs such as patient-driven protocols. The respiratory care management information systems (RCMIS) of today offer many advantages over paper-based systems and hospital-wide computer systems. RCMIS are designed to facilitate functions specific to respiratory care, including assessing work demand, assigning and tracking resources, charting, billing, and reporting results. RCMIS incorporate mobile, point-of-care charting and are highly configurable to meet the specific needs of individual respiratory care departments. Important and substantial benefits can be realized with an RCMIS and mobile, wireless charting devices. The initial and ongoing costs of an RCMIS are justified by increased charge capture and reduced costs, by way of improved productivity and efficiency. It is not unusual to recover the total cost of an RCMIS within the first year of its operation. In addition, such systems can facilitate and monitor patient-care protocols and help to efficiently manage the vast amounts of information encountered during the practitioner's workday. Respiratory care departments that invest in RCMIS have an advantage in the provision of quality care and in reducing expenses. A centralized respiratory therapy department with an RCMIS is the most efficient and cost-effective way to monitor work demand and manage the hospital-wide allocation of respiratory care services.

Morphology of the Oligoryzomys nigripes respiratory system.

PubMed

Mario, Lara Carolina; Borghesi, Jéssica; G Hayashi, Rafael; O Favaron, Phelipe; N Rodrigues, Marcio; C Carvalho, Rafael; Miglino, Maria A

2018-06-04

Rodents are important in the transmission of infectious diseases that affect the respiratory tract, including simple infections and those caused by specific pathogens. These animals are natural reservoirs of zoonoses that cause many public health diseases. Basic knowledge on the morphology of these animals is important as basic research is useful for applied studies, such as the development of clinical, therapeutic, surgical and clinical models. Morphological data of respiratory tract in Oligoryzomys nigripes are absent in the literature. Therefore, the aim of this study was to perform a morphological analysis of the respiratory tract of O. nigripes. Five adult females from the environmental reserve in São Joaquim da Barra, São Paulo were used, donated to the Museum of Veterinary Anatomy (FMVZ/USP). Several morphological features follow the same pattern seen in rodents; however, this species showed some differences such as the presence of three lobar bronchi, nonlobed left lung and the right lung constituted by two lobes. Respiratory epithelium lined the whole respiratory tract and was seen using scanning electron microscopy the oval shape of the parenchyma and alveoli. © 2018 Blackwell Verlag GmbH.

Ensemble framework based real-time respiratory motion prediction for adaptive radiotherapy applications.

PubMed

Tatinati, Sivanagaraja; Nazarpour, Kianoush; Tech Ang, Wei; Veluvolu, Kalyana C

2016-08-01

Successful treatment of tumors with motion-adaptive radiotherapy requires accurate prediction of respiratory motion, ideally with a prediction horizon larger than the latency in radiotherapy system. Accurate prediction of respiratory motion is however a non-trivial task due to the presence of irregularities and intra-trace variabilities, such as baseline drift and temporal changes in fundamental frequency pattern. In this paper, to enhance the accuracy of the respiratory motion prediction, we propose a stacked regression ensemble framework that integrates heterogeneous respiratory motion prediction algorithms. We further address two crucial issues for developing a successful ensemble framework: (1) selection of appropriate prediction methods to ensemble (level-0 methods) among the best existing prediction methods; and (2) finding a suitable generalization approach that can successfully exploit the relative advantages of the chosen level-0 methods. The efficacy of the developed ensemble framework is assessed with real respiratory motion traces acquired from 31 patients undergoing treatment. Results show that the developed ensemble framework improves the prediction performance significantly compared to the best existing methods. Copyright © 2016 IPEM. Published by Elsevier Ltd. All rights reserved.

Neural network for photoplethysmographic respiratory rate monitoring

NASA Astrophysics Data System (ADS)

Johansson, Anders

2001-10-01

The photoplethysmographic signal (PPG) includes respiratory components seen as frequency modulation of the heart rate (respiratory sinus arrhythmia, RSA), amplitude modulation of the cardiac pulse, and respiratory induced intensity variations (RIIV) in the PPG baseline. The aim of this study was to evaluate the accuracy of these components in determining respiratory rate, and to combine the components in a neural network for improved accuracy. The primary goal is to design a PPG ventilation monitoring system. PPG signals were recorded from 15 healthy subjects. From these signals, the systolic waveform, diastolic waveform, respiratory sinus arrhythmia, pulse amplitude and RIIV were extracted. By using simple algorithms, the rates of false positive and false negative detection of breaths were calculated for each of the five components in a separate analysis. Furthermore, a simple neural network (NN) was tried out in a combined pattern recognition approach. In the separate analysis, the error rates (sum of false positives and false negatives) ranged from 9.7% (pulse amplitude) to 14.5% (systolic waveform). The corresponding value of the NN analysis was 9.5-9.6%.

Exhaled Aerosol Pattern Discloses Lung Structural Abnormality: A Sensitivity Study Using Computational Modeling and Fractal Analysis

PubMed Central

Xi, Jinxiang; Si, Xiuhua A.; Kim, JongWon; Mckee, Edward; Lin, En-Bing

2014-01-01

Background Exhaled aerosol patterns, also called aerosol fingerprints, provide clues to the health of the lung and can be used to detect disease-modified airway structures. The key is how to decode the exhaled aerosol fingerprints and retrieve the lung structural information for a non-invasive identification of respiratory diseases. Objective and Methods In this study, a CFD-fractal analysis method was developed to quantify exhaled aerosol fingerprints and applied it to one benign and three malign conditions: a tracheal carina tumor, a bronchial tumor, and asthma. Respirations of tracer aerosols of 1 µm at a flow rate of 30 L/min were simulated, with exhaled distributions recorded at the mouth. Large eddy simulations and a Lagrangian tracking approach were used to simulate respiratory airflows and aerosol dynamics. Aerosol morphometric measures such as concentration disparity, spatial distributions, and fractal analysis were applied to distinguish various exhaled aerosol patterns. Findings Utilizing physiology-based modeling, we demonstrated substantial differences in exhaled aerosol distributions among normal and pathological airways, which were suggestive of the disease location and extent. With fractal analysis, we also demonstrated that exhaled aerosol patterns exhibited fractal behavior in both the entire image and selected regions of interest. Each exhaled aerosol fingerprint exhibited distinct pattern parameters such as spatial probability, fractal dimension, lacunarity, and multifractal spectrum. Furthermore, a correlation of the diseased location and exhaled aerosol spatial distribution was established for asthma. Conclusion Aerosol-fingerprint-based breath tests disclose clues about the site and severity of lung diseases and appear to be sensitive enough to be a practical tool for diagnosis and prognosis of respiratory diseases with structural abnormalities. PMID:25105680

Complexity measures of the central respiratory networks during wakefulness and sleep

NASA Astrophysics Data System (ADS)

Dragomir, Andrei; Akay, Yasemin; Curran, Aidan K.; Akay, Metin

2008-06-01

Since sleep is known to influence respiratory activity we studied whether the sleep state would affect the complexity value of the respiratory network output. Specifically, we tested the hypothesis that the complexity values of the diaphragm EMG (EMGdia) activity would be lower during REM compared to NREM. Furthermore, since REM is primarily generated by a homogeneous population of neurons in the medulla, the possibility that REM-related respiratory output would be less complex than that of the awake state was also considered. Additionally, in order to examine the influence of neuron vulnerabilities within the rostral ventral medulla (RVM) on the complexity of the respiratory network output, we inhibited respiratory neurons in the RVM by microdialysis of GABAA receptor agonist muscimol. Diaphragm EMG, nuchal EMG, EEG, EOG as well as other physiological signals (tracheal pressure, blood pressure and respiratory volume) were recorded from five unanesthetized chronically instrumented intact piglets (3-10 days old). Complexity of the diaphragm EMG (EMGdia) signal during wakefulness, NREM and REM was evaluated using the approximate entropy method (ApEn). ApEn values of the EMGdia during NREM and REM sleep were found significantly (p < 0.05 and p < 0.001, respectively) lower than those of awake EMGdia after muscimol inhibition. In the absence of muscimol, only the differences between REM and wakefulness ApEn values were found to be significantly different.

Rényi entropy and Lempel-Ziv complexity of mechanomyographic recordings of diaphragm muscle as indexes of respiratory effort.

PubMed

Torres, Abel; Fiz, Jose A; Jane, Raimon; Laciar, Eric; Galdiz, Juan B; Gea, Joaquim; Morera, Josep

2008-01-01

The study of the mechanomyographic (MMG) signals of respiratory muscles is a promising technique in order to evaluate the respiratory muscles effort. A new approach for quantifying the relationship between respiratory MMG signals and respiratory effort is presented by analyzing the spatio-temporal patterns in the MMG signal using two non-linear methods: Rényi entropy and Lempel-Ziv (LZ) complexity analysis. Both methods are well suited to the analysis of non-stationary biomedical signals of short length. In this study, MMG signals of the diaphragm muscle acquired by means of a capacitive accelerometer applied on the costal wall were analyzed. The method was tested on an animal model (dogs), and the diaphragmatic MMG signal was recorded continuously while two non anesthetized mongrel dogs performed a spontaneous ventilation protocol with an incremental inspiratory load. The performance in discriminating high and low respiratory effort levels with these two methods was analyzed with the evaluation of the Pearson correlation coefficient between the MMG parameters and respiratory effort parameters extracted from the inspiratory pressure signal. The results obtained show an increase of the MMG signal Rényi entropy and LZ complexity values with the increase of the respiratory effort. Compared with other parameters analyzed in previous works, both Rényi entropy and LZ complexity indexes demonstrates better performance in all the signals analyzed. Our results suggest that these non-linear techniques are useful to detect and quantify changes in the respiratory effort by analyzing MMG respiratory signals.

Novel Associations between FAAH Genetic Variants and Postoperative Central Opioid related Adverse Effects

PubMed Central

Sadhasivam, Senthilkumar; Zhang, Xue; Chidambaran, Vidya; Mavi, Jagroop; Pilipenko, Valentina; Mersha, Tesfaye B.; Meller, Jaroslaw; Kaufman, Kenneth M.; Martin, Lisa J.; McAuliffe, John

2014-01-01

Opioid effects are potentiated by cannabinoid agonists including anandamide, an endocannabinoid. Inter-individual variability in responses to opioids is a major clinical problem. Multiple deaths and anoxic brain injuries occur every year in due to opioid induced respiratory depression in surgical patients and drug abusers of opioids and cannabinoids. This study aimed to determine specific associations between genetic variants of fatty acid amide hydrolase (FAAH) and postoperative central opioid adverse effects in children undergoing tonsillectomy. This is a prospective genotype blinded observational study 259 healthy children between 6 and 15 years that received standard perioperative care with a standard anesthetic and an intraoperative dose of morphine were enrolled. Associations between frequent polymorphisms of FAAH and central postoperative opioid adverse effects including, respiratory depression (RD), postoperative nausea and vomiting (PONV) and prolonged stay in Post Anesthesia Recovery Room (PACU) due to RD and PONV were analyzed. Five specific FAAH SNPs had significant associations with more than 2 fold increased risk for refractory PONV (adjusted p<0.0018), and nominal associations (p<0.05) with RD and prolonged PACU stay in white children undergoing tonsillectomy. FAAH SNP, rs324420 is a missense mutation with altered FAAH function and it is linked with other FAAH SNPs associated with PONV and RD in our cohort; association between PONV and rs324420 was confirmed in our extended cohort with additional 66 white children. Specific FAAH polymorphisms are associated with refractory PONV, opioid-related respiratory depression, and prolonged PACU stay due to opioid adverse effects in white children undergoing tonsillectomy. PMID:25558980

Proton detection and breathing regulation by the retrotrapezoid nucleus

PubMed Central

Bayliss, Douglas A.; Stornetta, Ruth L.; Ludwig, Marie‐Gabrielle; Kumar, Natasha N.; Shi, Yingtang; Burke, Peter G. R.; Kanbar, Roy; Basting, Tyler M.; Holloway, Benjamin B.; Wenker, Ian C.

2016-01-01

Abstract We discuss recent evidence which suggests that the principal central respiratory chemoreceptors are located within the retrotrapezoid nucleus (RTN) and that RTN neurons are directly sensitive to [H+]. RTN neurons are glutamatergic. In vitro, their activation by [H+] requires expression of a proton‐activated G protein‐coupled receptor (GPR4) and a proton‐modulated potassium channel (TASK‐2) whose transcripts are undetectable in astrocytes and the rest of the lower brainstem respiratory network. The pH response of RTN neurons is modulated by surrounding astrocytes but genetic deletion of RTN neurons or deletion of both GPR4 and TASK‐2 virtually eliminates the central respiratory chemoreflex. Thus, although this reflex is regulated by innumerable brain pathways, it seems to operate predominantly by modulating the discharge rate of RTN neurons, and the activation of RTN neurons by hypercapnia may ultimately derive from their intrinsic pH sensitivity. RTN neurons increase lung ventilation by stimulating multiple aspects of breathing simultaneously. They stimulate breathing about equally during quiet wake and non‐rapid eye movement (REM) sleep, and to a lesser degree during REM sleep. The activity of RTN neurons is regulated by inhibitory feedback and by excitatory inputs, notably from the carotid bodies. The latter input operates during normo‐ or hypercapnia but fails to activate RTN neurons under hypocapnic conditions. RTN inhibition probably limits the degree of hyperventilation produced by hypocapnic hypoxia. RTN neurons are also activated by inputs from serotonergic neurons and hypothalamic neurons. The absence of RTN neurons probably underlies the sleep apnoea and lack of chemoreflex that characterize congenital central hypoventilation syndrome. PMID:26748771

Critically Ill Patients With the Middle East Respiratory Syndrome: A Multicenter Retrospective Cohort Study.

PubMed

Arabi, Yaseen M; Al-Omari, Awad; Mandourah, Yasser; Al-Hameed, Fahad; Sindi, Anees A; Alraddadi, Basem; Shalhoub, Sarah; Almotairi, Abdullah; Al Khatib, Kasim; Abdulmomen, Ahmed; Qushmaq, Ismael; Mady, Ahmed; Solaiman, Othman; Al-Aithan, Abdulsalam M; Al-Raddadi, Rajaa; Ragab, Ahmed; Al Mekhlafi, Ghaleb A; Al Harthy, Abdulrahman; Kharaba, Ayman; Ahmadi, Mashael Al; Sadat, Musharaf; Mutairi, Hanan Al; Qasim, Eman Al; Jose, Jesna; Nasim, Maliha; Al-Dawood, Abdulaziz; Merson, Laura; Fowler, Robert; Hayden, Frederick G; Balkhy, Hanan H

2017-10-01

To describe patient characteristics, clinical manifestations, disease course including viral replication patterns, and outcomes of critically ill patients with severe acute respiratory infection from the Middle East respiratory syndrome and to compare these features with patients with severe acute respiratory infection due to other etiologies. Retrospective cohort study. Patients admitted to ICUs in 14 Saudi Arabian hospitals. Critically ill patients with laboratory-confirmed Middle East respiratory syndrome severe acute respiratory infection (n = 330) admitted between September 2012 and October 2015 were compared to consecutive critically ill patients with community-acquired severe acute respiratory infection of non-Middle East respiratory syndrome etiology (non-Middle East respiratory syndrome severe acute respiratory infection) (n = 222). None. Although Middle East respiratory syndrome severe acute respiratory infection patients were younger than those with non-Middle East respiratory syndrome severe acute respiratory infection (median [quartile 1, quartile 3] 58 yr [44, 69] vs 70 [52, 78]; p < 0.001), clinical presentations and comorbidities overlapped substantially. Patients with Middle East respiratory syndrome severe acute respiratory infection had more severe hypoxemic respiratory failure (PaO2/FIO2: 106 [66, 160] vs 176 [104, 252]; p < 0.001) and more frequent nonrespiratory organ failure (nonrespiratory Sequential Organ Failure Assessment score: 6 [4, 9] vs 5 [3, 7]; p = 0.002), thus required more frequently invasive mechanical ventilation (85.2% vs 73.0%; p < 0.001), oxygen rescue therapies (extracorporeal membrane oxygenation 5.8% vs 0.9%; p = 0.003), vasopressor support (79.4% vs 55.0%; p < 0.001), and renal replacement therapy (48.8% vs 22.1%; p < 0.001). After adjustment for potential confounding factors, Middle East respiratory syndrome was independently associated with death compared to non-Middle East respiratory syndrome severe acute respiratory infection (adjusted odds ratio, 5.87; 95% CI, 4.02-8.56; p < 0.001). Substantial overlap exists in the clinical presentation and comorbidities among patients with Middle East respiratory syndrome severe acute respiratory infection from other etiologies; therefore, a high index of suspicion combined with diagnostic testing is essential component of severe acute respiratory infection investigation for at-risk patients. The lack of distinguishing clinical features, the need to rely on real-time reverse transcription polymerase chain reaction from respiratory samples, variability in viral shedding duration, lack of effective therapy, and high mortality represent substantial clinical challenges and help guide ongoing clinical research efforts.

Functional and histopathological identification of the respiratory failure in a DMSXL transgenic mouse model of myotonic dystrophy

PubMed Central

Panaite, Petrica-Adrian; Kuntzer, Thierry; Gourdon, Geneviève; Lobrinus, Johannes Alexander; Barakat-Walter, Ibtissam

2013-01-01

SUMMARY Acute and chronic respiratory failure is one of the major and potentially life-threatening features in individuals with myotonic dystrophy type 1 (DM1). Despite several clinical demonstrations showing respiratory problems in DM1 patients, the mechanisms are still not completely understood. This study was designed to investigate whether the DMSXL transgenic mouse model for DM1 exhibits respiratory disorders and, if so, to identify the pathological changes underlying these respiratory problems. Using pressure plethysmography, we assessed the breathing function in control mice and DMSXL mice generated after large expansions of the CTG repeat in successive generations of DM1 transgenic mice. Statistical analysis of breathing function measurements revealed a significant decrease in the most relevant respiratory parameters in DMSXL mice, indicating impaired respiratory function. Histological and morphometric analysis showed pathological changes in diaphragmatic muscle of DMSXL mice, characterized by an increase in the percentage of type I muscle fibers, the presence of central nuclei, partial denervation of end-plates (EPs) and a significant reduction in their size, shape complexity and density of acetylcholine receptors, all of which reflect a possible breakdown in communication between the diaphragmatic muscles fibers and the nerve terminals. Diaphragm muscle abnormalities were accompanied by an accumulation of mutant DMPK RNA foci in muscle fiber nuclei. Moreover, in DMSXL mice, the unmyelinated phrenic afferents are significantly lower. Also in these mice, significant neuronopathy was not detected in either cervical phrenic motor neurons or brainstem respiratory neurons. Because EPs are involved in the transmission of action potentials and the unmyelinated phrenic afferents exert a modulating influence on the respiratory drive, the pathological alterations affecting these structures might underlie the respiratory impairment detected in DMSXL mice. Understanding mechanisms of respiratory deficiency should guide pharmaceutical and clinical research towards better therapy for the respiratory deficits associated with DM1. PMID:23180777

The adenoid as a key factor in upper airway infections.

PubMed

van Cauwenberge, P B; Bellussi, L; Maw, A R; Paradise, J L; Solow, B

1995-06-01

The adenoids (and the nasopharynx) play a key role in the normal functioning and in various pathologies of the upper respiratory tract. In this paper the role of adenoidal pathology and the beneficial effect of adenoidectomy in some upper respiratory tract and facial anomalies and diseases are discussed; otitis media with effusion, recurrent acute otitis media, sinusitis, snoring and sleep apnea and abnormal patterns in the midface growth and development.

Dietary Pattern Is Associated with Obesity in Older People in China: Data from China Health and Nutrition Survey (CHNS)

PubMed Central

Xu, Xiaoyue; Hall, John; Byles, Julie; Shi, Zumin

2015-01-01

Background: No studies have been conducted to explore the associations between dietary patterns and obesity among older Chinese people, by considering gender and urbanization level differences. Methods: We analyzed data from the 2009 China Health and Nutrition Survey (2745 individuals, aged ≥ 60 years). Dietary data were obtained using 24 h-recall over three consecutive days. Height, Body Weight, and Waist Circumference were measured. Exploratory factor analysis was used to identify dietary patterns. Multinomial and Poisson regression models were used to examine the association between dietary patterns and Body Mass Index (BMI) status/central obesity. Results: The prevalence of general and central obesity was 9.5% and 53.4%. Traditional dietary pattern (high intake of rice, pork and vegetables) was inversely associated with general/central obesity; modern dietary pattern (high intake of fruit, fast food, and processed meat) was positively associated with general/central obesity. The highest quartile of traditional dietary pattern had a lower risk of general/central obesity compared with the lowest quartile, while an inverse picture was found for the modern dietary pattern. These associations were consistent by gender and urbanization levels. Conclusions: Dietary patterns are associated with general/central obesity in older Chinese. This study reinforces the importance of a healthy diet in promoting healthy ageing in China. PMID:26404368

Central Pattern Generation and the Motor Infrastructure for Suck, Respiration, and Speech

ERIC Educational Resources Information Center

Barlow, Steven M.; Estep, Meredith

2006-01-01

The objective of the current report is to review experimental findings on centrally patterned movements and sensory and descending modulation of central pattern generators (CPGs) in a variety of animal and human models. Special emphasis is directed toward speech production muscle systems, including the chest wall and orofacial complex during…

Non-REM sleep EEG power distribution in fatigue and sleepiness.

PubMed

Neu, Daniel; Mairesse, Olivier; Verbanck, Paul; Linkowski, Paul; Le Bon, Olivier

2014-04-01

The aim of this study is to contribute to the sleep-related differentiation between daytime fatigue and sleepiness. 135 subjects presenting with sleep apnea-hypopnea syndrome (SAHS, n=58) or chronic fatigue syndrome (CFS, n=52) with respective sleepiness or fatigue complaints and a control group (n=25) underwent polysomnography and psychometric assessments for fatigue, sleepiness, affective symptoms and perceived sleep quality. Sleep EEG spectral analysis for ultra slow, delta, theta, alpha, sigma and beta power bands was performed on frontal, central and occipital derivations. Patient groups presented with impaired subjective sleep quality and higher affective symptom intensity. CFS patients presented with highest fatigue and SAHS patients with highest sleepiness levels. All groups showed similar total sleep time. Subject groups mainly differed in sleep efficiency, wake after sleep onset, duration of light sleep (N1, N2) and slow wave sleep, as well as in sleep fragmentation and respiratory disturbance. Relative non-REM sleep power spectra distributions suggest a pattern of power exchange in higher frequency bands at the expense of central ultra slow power in CFS patients during all non-REM stages. In SAHS patients, however, we found an opposite pattern at occipital sites during N1 and N2. Slow wave activity presents as a crossroad of fatigue and sleepiness with, however, different spectral power band distributions during non-REM sleep. The homeostatic function of sleep might be compromised in CFS patients and could explain why, in contrast to sleepiness, fatigue does not resolve with sleep in these patients. The present findings thus contribute to the differentiation of both phenomena. Copyright © 2014 Elsevier Inc. All rights reserved.

Comparative analysis of viral shedding in pediatric and adult subjects with central nervous system-associated enterovirus infections from 2013 to 2015 in Switzerland.

PubMed

Cordey, S; Schibler, M; L'Huillier, A G; Wagner, N; Gonçalves, A R; Ambrosioni, J; Asner, S; Turin, L; Posfay-Barbe, K M; Kaiser, L

2017-04-01

Several enterovirus (EV) genotypes can result in aseptic meningitis, but their routes of access to the central nervous system remain to be elucidated and may differ between the pediatric and adult populations. To assess the pattern of viral shedding in pediatric and adult subjects with acute EV meningitis and to generate EV surveillance data for Switzerland. All pediatric and adult subjects admitted to the University Hospitals of Geneva with a diagnosis of EV meningitis between 2013 and 2015 were enrolled. A quantitative EV real-time reverse transcriptase (rRT)-PCR was performed on the cerebrospinal fluid (CSF), blood, stool, urine and respiratory specimens to assess viral shedding and provide a comparative analysis of pediatric and adult populations. EV genotyping was systematically performed. EV positivity rates differed significantly between pediatric and adult subjects; 62.5% of pediatric cases (no adult case) were EV-positive in stool and blood for subjects for whom these samples were all collected. Similarly, the EV viral load in blood was significantly higher in pediatric subjects. Blood C-reactive protein levels were lower and the number of leucocytes/mm 3 in the CSF were higher in non-viremic than in viremic pediatric subjects, respectively. A greater diversity of EV genotypes was observed in pediatric cases, with a predominance of echovirus 30 in children ≥3 years old and adults. In contrast to adults, EV-disseminated infections are predominant in pediatric subjects and show different patterns of EV viral shedding. This observation may be useful for clinicians and contribute to modify current practices of patient care. Copyright © 2017 The Author(s). Published by Elsevier B.V. All rights reserved.

Organization of the core respiratory network: Insights from optogenetic and modeling studies

PubMed Central

John, Tibin T.; Zhang, Ruli; Smith, Jeffrey C.

2018-01-01

The circuit organization within the mammalian brainstem respiratory network, specifically within and between the pre-Bötzinger (pre-BötC) and Bötzinger (BötC) complexes, and the roles of these circuits in respiratory pattern generation are continuously debated. We address these issues with a combination of optogenetic experiments and modeling studies. We used transgenic mice expressing channelrhodopsin-2 under the VGAT-promoter to investigate perturbations of respiratory circuit activity by site-specific photostimulation of inhibitory neurons within the pre-BötC or BötC. The stimulation effects were dependent on the intensity and phase of the photostimulation. Specifically: (1) Low intensity (≤ 1.0 mW) pulses delivered to the pre-BötC during inspiration did not terminate activity, whereas stronger stimulations (≥ 2.0 mW) terminated inspiration. (2) When the pre-BötC stimulation ended in or was applied during expiration, rebound activation of inspiration occurred after a fixed latency. (3) Relatively weak sustained stimulation (20 Hz, 0.5–2.0 mW) of pre-BötC inhibitory neurons increased respiratory frequency, while a further increase of stimulus intensity (> 3.0 mW) reduced frequency and finally (≥ 5.0 mW) terminated respiratory oscillations. (4) Single pulses (0.2–5.0 s) applied to the BötC inhibited rhythmic activity for the duration of the stimulation. (5) Sustained stimulation (20 Hz, 0.5–3.0 mW) of the BötC reduced respiratory frequency and finally led to apnea. We have revised our computational model of pre-BötC and BötC microcircuits by incorporating an additional population of post-inspiratory inhibitory neurons in the pre-BötC that interacts with other neurons in the network. This model was able to reproduce the above experimental findings as well as previously published results of optogenetic activation of pre-BötC or BötC neurons obtained by other laboratories. The proposed organization of pre-BötC and BötC circuits leads to testable predictions about their specific roles in respiratory pattern generation and provides important insights into key circuit interactions operating within brainstem respiratory networks. PMID:29698394

Air Pressure Responses to Sudden Vocal Tract Pressure Bleeds During Production of Stop Consonants: New Evidence of Aeromechanical Regulation

PubMed Central

Zajac, David J.; Weissler, Mark C.

2011-01-01

Two studies were conducted to evaluate short-latency vocal tract air pressure responses to sudden pressure bleeds during production of voiceless bilabial stop consonants. It was hypothesized that the occurrence of respiratory reflexes would be indicated by distinct patterns of responses as a function of bleed magnitude. In Study 1, 19 adults produced syllable trains of /pΛ/ using a mouthpiece coupled to a computer-controlled perturbator. The device randomly created bleed apertures that ranged from 0 to 40 mm2 during production of the 2nd or 4th syllable of an utterance. Although peak oral air pressure dropped in a linear manner across bleed apertures, it averaged 2 to 3 cm H2O at the largest bleed. While slope of oral pressure also decreased in a linear trend, duration of the oral pressure pulse remained relatively constant. The patterns suggest that respiratory reflexes, if present, have little effect on oral air pressure levels. In Study 2, both oral and subglottal air pressure responses were monitored in 2 adults while bleed apertures of 20 and 40 mm2 were randomly created. For 1 participant, peak oral air pressure dropped across bleed apertures, as in Study 1. Subglottal air pressure and slope, however, remained relatively stable. These patterns provide some support for the occurrence of respiratory reflexes to regulate subglottal air pressure. Overall, the studies indicate that the inherent physiologic processes of the respiratory system, which may involve reflexes, and passive aeromechanical resistance of the upper airway are capable of developing oral air pressure in the face of substantial pressure bleeds. Implications for understanding speech production and the characteristics of individuals with velopharyngeal dysfunction are discussed. PMID:15324286

CLINICAL APPLICATION OF THE RIGHT SIDELYING RESPIRATORY LEFT ADDUCTOR PULL BACK EXERCISE

PubMed Central

2013-01-01

Problem: Lumbopelvic‐femoral conditions are common and may be associated with asymmetrical musculoskeletal and respiratory impairments and postural mal‐alignment called a Left Anterior Interior Chain (AIC) pattern. An inherent pattern of asymmetry involves the trunk/ribs/spine/pelvis/hip joints and includes the tendency to stand on the right leg and shift the center of gravity to the right which may result for example, in a tight left posterior hip capsule, poorly approximated left hip, long/weak left adductors, internal obliques (IO) and transverse abdominus (TA), short/strong/over active paraspinals and muscles on the right anterior outlet (adductors, levator ani and obturator internus), a left rib flare and a decreased respiratory diaphragm zone of apposition (ZOA). The Solution: A therapeutic exercise technique that can address impairments associated with postural asymmetry may be beneficial in improving function, reducing and/or eliminating pain causation, and improving breathing. The Right Sidelying Left Respiratory Adductor Pull Back is an exercise designed to affect alignment of the lumbopelvic‐femoral region by influencing the left posterior ischiofemoral ligament, ZOA and right anterior outlet and left anterior inlet (rectus femoris, sartorius), activating/shortening the left adductors, left IO/TA's and inhibiting/lengthening the paraspinals, bilaterally. Discussion: The exercise technique is often used by Physical Therapists, Physical Therapist assistants and Athletic Trainers as an initial exercise to positively affect position/alignment of the lumbopelvic‐femoral region, referred to as “repositioning,” by clinicians who use it. Four published case studies have used similar exercises to address the above impairments associated with a Left AIC pattern and in each 100% improvement in function and pain intensity was described. This particular exercise technique is relatively new and warrants future research. PMID:23772350

Inspiratory muscular weakness is most evident in chronic stroke survivors with lower walking speeds.

PubMed

Pinheiro, M B; Polese, J C; Faria, C D; Machado, G C; Parreira, V F; Britto, R R; Teixeira-Salmela, L F

2014-06-01

Respiratory muscular weakness and associated changes in thoracoabdominal motion have been poorly studied in stroke subjects, since the individuals' functional levels were not previously considered in the investigations. To investigate the breathing patterns, thoracoabdominal motion, and respiratory muscular strength in chronic stroke subjects, who were stratified into two groups, according to their walking speeds. Cross-sectional, observational study. University laboratory. Eighty-nine community-dwelling chronic stroke subjects The subjects, according to their gait speeds, were stratified into community (gait speed ≥0.8 m/s) and non-community ambulators (gait speed <0.8 m/s). Variables related to pulmonary function, breathing patterns, and thoracoabdominal motions were assessed. Measures of maximal inspiratory pressure (MIP) and maximal expiratory pressure (MEP) were obtained and were compared with the reference values for the Brazilian population. The MIP and MEP values were expressed as percentages of the predicted values. Mann-Whitney-U or independent Student t-tests were employed to compare the differences between the two groups for the selected variables. No significant between-group differences were found for the variables related to the breathing patterns and thoracoabdominal motions (0.01 < z/t < 1.51; 0.14

Clinical application of the right sidelying respiratory left adductor pull back exercise.

PubMed

Boyle, Kyndall L

2013-06-01

Lumbopelvic-femoral conditions are common and may be associated with asymmetrical musculoskeletal and respiratory impairments and postural mal-alignment called a Left Anterior Interior Chain (AIC) pattern. An inherent pattern of asymmetry involves the trunk/ribs/spine/pelvis/hip joints and includes the tendency to stand on the right leg and shift the center of gravity to the right which may result for example, in a tight left posterior hip capsule, poorly approximated left hip, long/weak left adductors, internal obliques (IO) and transverse abdominus (TA), short/strong/over active paraspinals and muscles on the right anterior outlet (adductors, levator ani and obturator internus), a left rib flare and a decreased respiratory diaphragm zone of apposition (ZOA). A therapeutic exercise technique that can address impairments associated with postural asymmetry may be beneficial in improving function, reducing and/or eliminating pain causation, and improving breathing. The Right Sidelying Left Respiratory Adductor Pull Back is an exercise designed to affect alignment of the lumbopelvic-femoral region by influencing the left posterior ischiofemoral ligament, ZOA and right anterior outlet and left anterior inlet (rectus femoris, sartorius), activating/shortening the left adductors, left IO/TA's and inhibiting/lengthening the paraspinals, bilaterally. The exercise technique is often used by Physical Therapists, Physical Therapist assistants and Athletic Trainers as an initial exercise to positively affect position/alignment of the lumbopelvic-femoral region, referred to as "repositioning," by clinicians who use it. Four published case studies have used similar exercises to address the above impairments associated with a Left AIC pattern and in each 100% improvement in function and pain intensity was described. This particular exercise technique is relatively new and warrants future research.

Respiratory system dynamical mechanical properties: modeling in time and frequency domain.

PubMed

Carvalho, Alysson Roncally; Zin, Walter Araujo

2011-06-01

The mechanical properties of the respiratory system are important determinants of its function and can be severely compromised in disease. The assessment of respiratory system mechanical properties is thus essential in the management of some disorders as well as in the evaluation of respiratory system adaptations in response to an acute or chronic process. Most often, lungs and chest wall are treated as a linear dynamic system that can be expressed with differential equations, allowing determination of the system's parameters, which will reflect the mechanical properties. However, different models that encompass nonlinear characteristics and also multicompartments have been used in several approaches and most specifically in mechanically ventilated patients with acute lung injury. Additionally, the input impedance over a range of frequencies can be assessed with a convenient excitation method allowing the identification of the mechanical characteristics of the central and peripheral airways as well as lung periphery impedance. With the evolution of computational power, the airway pressure and flow can be recorded and stored for hours, and hence continuous monitoring of the respiratory system mechanical properties is already available in some mechanical ventilators. This review aims to describe some of the most frequently used models for the assessment of the respiratory system mechanical properties in both time and frequency domain.

Neurotransmitters and neuromodulators controlling the hypoxic respiratory response in anaesthetized cats.

PubMed

Richter, D W; Schmidt-Garcon, P; Pierrefiche, O; Bischoff, A M; Lalley, P M

1999-01-15

1. The contributions of neurotransmitters and neuromodulators to the responses of the respiratory network to acute hypoxia were analysed in anaesthetized cats. 2. Samples of extracellular fluid were collected at 1-1.5 min time intervals by microdialysis in the medullary region of ventral respiratory group neurones and analysed for their content of glutamate, gamma-aminobutyric acid (GABA), serotonin and adenosine by high performance liquid chromatography. Phrenic nerve activity was correlated with these measurements. 3. Levels of glutamate and GABA increased transiently during early periods of hypoxia, coinciding with augmented phrenic nerve activity and then fell below control during central apnoea. Serotonin and adenosine increased slowly and steadily with onset of hypoxic depression of phrenic nerve activity. 4. The possibility that serotonin contributes to hypoxic respiratory depression was tested by microinjecting the 5-HT-1A receptor agonist 8-OH-DPAT into the medullary region that is important for rhythmogenesis. Hypoxic activation of respiratory neurones and phrenic nerve activity were suppressed. Microinjections of NAN-190, a 5-HT-1A receptor blocker, enhanced hypoxic augmentation resulting in apneustic prolongation of inspiratory bursts. 5. The results reveal a temporal sequence in the release of neurotransmitters and neuromodulators and suggest a specific role for each of them in the sequential development of hypoxic respiratory disturbances.

Fragrance sensitisers: Is inhalation an allergy risk?

PubMed

Basketter, David; Kimber, Ian

2015-12-01

It is well established that some fragrance substances have the potential to cause skin sensitisation associated with the development of allergic contact dermatitis (ACD). Fragrances are invariably relatively volatile leading to the consideration that inhalation of fragrances might be a relevant route for either the induction of allergic sensitisation or the elicitation of allergic reactions. Moreover, there has been increasing recognition that allergic sensitisation of the respiratory tract can be induced by topical exposure to certain chemical allergens. Here the central question addressed is whether inhalation exposure to fragrance allergens has the potential to cause skin and/or respiratory sensitisation via the respiratory tract, or elicit allergic symptoms in those already sensitised. In addressing those questions, the underlying immunobiology of skin and respiratory sensitisation to chemicals has been reviewed briefly, and the relevant experimental and clinical evidence considered. The essential mechanistic differences between skin and respiratory allergy appear consistent with other sources of information, including the phenomenon of ACD that can arise from topical exposure to airborne allergens, but in the absence of accompanying respiratory effects. The conclusion is that, in contrast to topical exposure (including topical exposure to airborne material), inhalation of fragrance sensitisers does not represent a health risk with respect to allergy. Copyright © 2015 Elsevier Inc. All rights reserved.

Chiari malformation and central sleep apnea syndrome: efficacy of treatment with adaptive servo-ventilation*

PubMed Central

do Vale, Jorge Marques; Silva, Eloísa; Pereira, Isabel Gil; Marques, Catarina; Sanchez-Serrano, Amparo; Torres, António Simões

2014-01-01

The Chiari malformation type I (CM-I) has been associated with sleep-disordered breathing, especially central sleep apnea syndrome. We report the case of a 44-year-old female with CM-I who was referred to our sleep laboratory for suspected sleep apnea. The patient had undergone decompressive surgery 3 years prior. An arterial blood gas analysis showed hypercapnia. Polysomnography showed a respiratory disturbance index of 108 events/h, and all were central apnea events. Treatment with adaptive servo-ventilation was initiated, and central apnea was resolved. This report demonstrates the efficacy of servo-ventilation in the treatment of central sleep apnea syndrome associated with alveolar hypoventilation in a CM-I patient with a history of decompressive surgery. PMID:25410846

Respiratory research networks in Europe and beyond: aims, achievements and aspirations for the 21st century

PubMed Central

Zampieri, Fernando; Povoa, Pedro; Ranzani, Otavio; Bos, Lieuwe D.; Aliberti, Stefano; Torres, Antoni

2017-01-01

Healthcare-associated infection, such as intensive care unit (ICU)-related respiratory infections, remain the most frequently encountered morbidity of ICU admission, prolonging hospital stay and increasing mortality rates. The epidemiology of ICU-related respiratory infections, particularly nonventilated ICU-associated pneumonia and ventilator-associated tracheobronchitis, appears to be quite different among different countries. European countries have different prevalence, patterns and mechanism of resistance, as well as different treatments chosen by different attending physicians. The classical clinical research process in respiratory infections consists of the following loop: 1) identification of knowledge gaps; 2) systematic review and search for adequate answers; 3) generation of study hypotheses; 4) design of study protocols; 5) collection clinical data; 6) analysis and interpretation of the results; and 7) implementation of the results in clinical practice. PMID:28894481

Sigh rate and respiratory variability during mental load and sustained attention.

PubMed

Vlemincx, Elke; Taelman, Joachim; De Peuter, Steven; Van Diest, Ilse; Van den Bergh, Omer

2011-01-01

Spontaneous breathing consists of substantial correlated variability: Parameters characterizing a breath are correlated with parameters characterizing previous and future breaths. On the basis of dynamic system theory, negative emotion states are predicted to reduce correlated variability whereas sustained attention is expected to reduce total respiratory variability. Both are predicted to evoke sighing. To test this, respiratory variability and sighing were assessed during a baseline, stressful mental arithmetic task, nonstressful sustained attention task, and recovery in between tasks. For respiration rate (excluding sighs), reduced total variability was found during the attention task, whereas correlated variation was reduced during mental load. Sigh rate increased during mental load and during recovery from the attention task. It is concluded that mental load and task-related attention show specific patterns in respiratory variability and sigh rate. Copyright © 2010 Society for Psychophysiological Research.

Respiratory Sinus Arrhythmia and Heart Period in Infancy as Correlates of Later Oppositional Defiant and Callous-Unemotional Behaviors

ERIC Educational Resources Information Center

Wagner, Nicholas; Mills-Koonce, Roger; Willoughby, Michael; Propper, Cathi; Rehder, Peter; Gueron-Sela, Noa

2017-01-01

Extant literature suggests that oppositional defiant disorder (ODD) and callous-unemotional (CU) behaviors in childhood and adolescence are associated with distinct patterns of psychophysiological functioning, and that individual differences in these patterns have implications for developmental pathways to disorder. Very little is known about the…

REGIONAL DEPOSITION DOSE OF INHALED NANO-SIZE PARTICLES IN HUMAN LUNGS DURING CONTROLLED NORMAL BREATHING

EPA Science Inventory

INTRODUCTION

One of the key factors for affecting respiratory

deposition of particles is the breathing pattern of

individual subjects. Although idealized breathing

patterns (square or sine wave form) are frequently used

for studying lung deposit...

29 CFR 801.2 - Definitions.

Code of Federal Regulations, 2012 CFR

2012-07-01

... stress analyzers, or psychological stress evaluators, include any systems that utilize voice stress..., respiratory, and electrodermal patterns as minimum instrumentation standards; and (2) Is used, or the results...

29 CFR 801.2 - Definitions.

Code of Federal Regulations, 2014 CFR

2014-07-01

... stress analyzers, or psychological stress evaluators, include any systems that utilize voice stress..., respiratory, and electrodermal patterns as minimum instrumentation standards; and (2) Is used, or the results...

29 CFR 801.2 - Definitions.

Code of Federal Regulations, 2013 CFR

2013-07-01

... stress analyzers, or psychological stress evaluators, include any systems that utilize voice stress..., respiratory, and electrodermal patterns as minimum instrumentation standards; and (2) Is used, or the results...

New perspectives concerning feedback influences on cardiorespiratory control during rhythmic exercise and on exercise performance.

PubMed

Dempsey, Jerome A

2012-09-01

The cardioaccelerator and ventilatory responses to rhythmic exercise in the human are commonly viewed as being mediated predominantly via feedforward 'central command' mechanisms, with contributions from locomotor muscle afferents to the sympathetically mediated pressor response. We have assessed the relative contributions of three types of feedback afferents on the cardiorespiratory response to voluntary, rhythmic exercise by inhibiting their normal 'tonic' activity in healthy animals and humans and in chronic heart failure. Transient inhibition of the carotid chemoreceptors during moderate intensity exercise reduced muscle sympathetic nerve activity (MSNA) and increased limb vascular conductance and blood flow; and reducing the normal level of respiratory muscle work during heavier intensity exercise increased limb vascular conductance and blood flow. These cardiorespiratory effects were prevented via ganglionic blockade and were enhanced in chronic heart failure and in hypoxia. Blockade of μ opioid sensitive locomotor muscle afferents, with preservation of central motor output via intrathecal fentanyl: (a) reduced the mean arterial blood pressure (MAP), heart rate and ventilatory responses to all steady state exercise intensities; and (b) during sustained high intensity exercise, reduced O(2) transport, increased central motor output and end-exercise muscle fatigue and reduced endurance performance. We propose that these three afferent reflexes - probably acting in concert with feedforward central command - contribute significantly to preserving O(2) transport to locomotor and to respiratory muscles during exercise. Locomotor muscle afferents also appear to provide feedback concerning the metabolic state of the muscle to influence central motor output, thereby limiting peripheral fatigue development.

Expandable metallic stents for tracheobronchial stenoses in esophageal cancer.

PubMed

Takamori, S; Fujita, H; Hayashi, A; Tayama, K; Mitsuoka, M; Ohtsuka, S; Shirouzu, K

1996-09-01

Tracheobronchial stenosis in patients with esophageal cancer can be life threatening. Few reports have discussed use of expandable metallic stents for central airway stenoses in patients with esophageal cancer. Twelve patients with esophageal cancer underwent placement of expandable metallic stents for respiratory distress caused by tracheobronchial stricture. Single or double metallic stents were placed in the stenotic airways under fluoroscopic guidance. Improvement in respiratory symptoms and clinical outcome were assessed. Most stenoses were located in the trachea or the left main bronchus. From one to four expandable metallic stents were placed in each stricture site, with immediate relief of respiratory symptoms in 8 patients. One patient with tracheomalacia in alive 3 years after stent placement and another is alive 6 months after stent insertion. The other 10 patients lived from 10 to 70 days (mean; survival, 35 days) after stent placement. Death was due to progression of disease. Although metallic stents are useful for relieving respiratory distress in patients with advanced esophageal cancer, additional therapies should be considered.

Locomotor-respiratory coupling patterns and oxygen consumption during walking above and below preferred stride frequency.

PubMed

O'Halloran, Joseph; Hamill, Joseph; McDermott, William J; Remelius, Jebb G; Van Emmerik, Richard E A

2012-03-01

Locomotor respiratory coupling patterns in humans have been assessed on the basis of the interaction between different physiological and motor subsystems; these interactions have implications for movement economy. A complex and dynamical systems framework may provide more insight than entrainment into the variability and adaptability of these rhythms and their coupling. The purpose of this study was to investigate the relationship between steady state locomotor-respiratory coordination dynamics and oxygen consumption [Formula: see text] of the movement by varying walking stride frequency from preferred. Twelve male participants walked on a treadmill at a self-selected speed. Stride frequency was varied from -20 to +20% of preferred stride frequency (PSF) while respiratory airflow, gas exchange variables, and stride kinematics were recorded. Discrete relative phase and return map techniques were used to evaluate the strength, stability, and variability of both frequency and phase couplings. Analysis of [Formula: see text] during steady-state walking showed a U-shaped response (P = 0.002) with a minimum at PSF and PSF - 10%. Locomotor-respiratory frequency coupling strength was not greater (P = 0.375) at PSF than any other stride frequency condition. The dominant coupling across all conditions was 2:1 with greater occurrences at the lower stride frequencies. Variability in coupling was the greatest during PSF, indicating an exploration of coupling strategies to search for the coupling frequency strategy with the least oxygen consumption. Contrary to the belief that increased strength of frequency coupling would decrease oxygen consumption; these results conclude that it is the increased variability of frequency coupling that results in lower oxygen consumption.

CEREBROSPINAL FLUID STASIS AND ITS CLINICAL SIGNIFICANCE

PubMed Central

Whedon, James M.; Glassey, Donald

2010-01-01

We hypothesize that stasis of the cerebrospinal fluid (CSF) occurs commonly and is detrimental to health. Physiologic factors affecting the normal circulation of CSF include cardiovascular, respiratory, and vasomotor influences. The CSF maintains the electrolytic environment of the central nervous system (CNS), influences systemic acid-base balance, serves as a medium for the supply of nutrients to neuronal and glial cells, functions as a lymphatic system for the CNS by removing the waste products of cellular metabolism, and transports hormones, neurotransmitters, releasing factors, and other neuropeptides throughout the CNS. Physiologic impedance or cessation of CSF flow may occur commonly in the absence of degenerative changes or pathology and may compromise the normal physiologic functions of the CSF. CSF appears to be particularly prone to stasis within the spinal canal. CSF stasis may be associated with adverse mechanical cord tension, vertebral subluxation syndrome, reduced cranial rhythmic impulse, and restricted respiratory function. Increased sympathetic tone, facilitated spinal segments, dural tension, and decreased CSF flow have been described as closely related aspects of an overall pattern of structural and energetic dysfunction in the axial skeleton and CNS. Therapies directed at affecting CSF flow include osteopathic care (especially cranial manipulation), craniosacral therapy, chiropractic adjustment of the spine and cranium, Network Care (formerly Network Chiropractic), massage therapy (including lymphatic drainage techniques), yoga, therapeutic breathwork, and cerebrospinal fluid technique. Further investigation into the nature and causation of CSF stasis, its potential effects upon human health, and effective therapies for its correction is warranted. PMID:19472865

Breathing is affected by dopamine D2-like receptors in the basolateral amygdala.

PubMed

Sugita, Toshihisa; Kanamaru, Mitsuko; Iizuka, Makito; Sato, Kanako; Tsukada, Setsuro; Kawamura, Mitsuru; Homma, Ikuo; Izumizaki, Masahiko

2015-04-01

The precise mechanisms underlying how emotions change breathing patterns remain unclear, but dopamine is a candidate neurotransmitter in the process of emotion-associated breathing. We investigated whether basal dopamine release occurs in the basolateral amygdala (BLA), where sensory-related inputs are received and lead to fear or anxiety responses, and whether D1- and D2-like receptor antagonists affect breathing patterns and dopamine release in the BLA. Adult male mice (C57BL/6N) were perfused with artificial cerebrospinal fluid, a D1-like receptor antagonist (SCH 23390), or a D2-like receptor antagonist ((S)-(-)-sulpiride) through a microdialysis probe in the BLA. Respiratory variables were measured using a double-chamber plethysmograph. Dopamine release was measured by an HPLC. Perfusion of (S)-(-)-sulpiride in the BLA, not SCH 23390, specifically decreased respiratory rate without changes in local release of dopamine. These results suggest that basal dopamine release in the BLA, at least partially, increases respiratory rates only through post-synaptic D2-like receptors, not autoreceptors, which might be associated with emotional responses. Copyright © 2014 Elsevier B.V. All rights reserved.

Apnoea and bradycardia during epileptic seizures: relation to sudden death in epilepsy.

PubMed Central

Nashef, L; Walker, F; Allen, P; Sander, J W; Shorvon, S D; Fish, D R

1996-01-01

OBJECTIVE--To record non-invasively ictal cardiorespiratory variables. METHODS--Techniques employed in polysomnography were used in patients with epilepsy undergoing EEG-video recording at a telemetry unit. RESULTS--Apnoea (> 10, range > 10-63, mean 24 s) was seen in 20 of 47 clinical seizures (three secondary generalised, 16 complex partial, and one tonic) and 10 of 17 patients. Apnoea was central in 10 patients, but obstructive apnoea was also recorded in three of 10. Oxyhaemoglobin saturation (SpO2) dropped to less than 85% in 10 seizures (six patients). An increase in heart rate was common (91% of seizures). Bradycardia/sinus arrest was documented in four patients (mean maximum RR interval 5.36, range 2.8-8.6 s) but always in the context of a change in respiratory pattern. CONCLUSION--Ictal apnoea was often seen. The occurrence of bradycardia in association with apnoea suggests the involvement of cardiorespiratory reflexes. Similar mechanisms may operate in cases of sudden death in epilepsy. PMID:8609507

Bi-level CPAP does not change central blood flow in preterm infants with respiratory distress syndrome

PubMed Central

2014-01-01

Background Current literature provides limited data on the hemodynamic changes that may occur during bi-level continuous positive airway pressure (CPAP) support in preterm infants. However, the application of a positive end-expiratory pressure may be transmitted to the heart and the great vessels resulting in changes of central blood flow. Objective To assess changes in central blood flow in infants with respiratory distress syndrome (RDS) during bi-level CPAP support. Design A prospective study was performed in a cohort of 18 Very-Low-Birth-Weight Infants who were put on nasal CPAP support (4–5 cmH2O) because they developed RDS within the first 24–72 hours of life. Each subject was switched to bi-level CPAP support (Phigh 8 cmH2O, Plow 4–5 cmH2O, Thigh 0.5-0.6 seconds, 20 breaths/min) for an hour. An echocardiographic study and a capillary gas analysis were performed before and after the change of respiratory support. Results No differences between n-CPAP and bi-level CPAP in left ventricular output (LVO, 222.17 ± 81.4 vs 211.4 ± 75.3 ml/kg/min), right ventricular output (RVO, 287.8 ± 96 vs 283.4 ± 87.4 ml/kg/min) and superior vena cava flow (SVC, 135.38 ± 47.8 vs 137.48 ± 46.6 ml/kg/min) were observed. The hemodynamic characteristics of the ductus arteriosus were similar. A significant decrease in pCO2 levels after bi-level CPAP ventilation was observed; pCO2 variations did not correlate with modifications of central blood flow (LVO: ρ = 0.11, p = 0,657; RVO: ρ = −0.307, p = 0.216; SVC: ρ = −0.13, p = 0.197). Conclusions Central blood flow doesn’t change during bi-level CPAP support, which could become a hemodinamically safe tool for the treatment of RDS in preterm infants. PMID:24952579

Neural Control of the Upper Airway: Respiratory and State-Dependent Mechanisms

PubMed Central

Kubin, Leszek

2017-01-01

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). Although OSA is almost exclusively a human disorder, animal models help unveil the basic principles governing the impact of sleep on breathing and upper airway muscle activity. This article discusses the neuroanatomy, neurochemistry, and neurophysiology of the different neuronal systems whose activity changes with sleep-wake states, such as the noradrenergic, serotonergic, cholinergic, orexinergic, histaminergic, GABAergic and glycinergic, and their impact on central respiratory neurons and upper airway motoneurons. Observations of the interactions between sleep-wake states and upper airway muscles in healthy humans and OSA patients are related to findings from animal models with normal upper airway, and various animal models of OSA, including the chronic-intermittent hypoxia model. Using a framework of upper airway motoneurons being under concurrent influence of central respiratory, reflex and state-dependent inputs, different neurotransmitters, and neuropeptides are considered as either causing a sleep-dependent withdrawal of excitation from motoneurons or mediating an active, sleep-related inhibition of motoneurons. Information about the neurochemistry of state-dependent control of upper airway muscles accumulated to date reveals fundamental principles and may help understand and treat OSA. PMID:27783860

The respiratory drive to thoracic motoneurones in the cat and its relation to the connections from expiratory bulbospinal neurones

PubMed Central

Saywell, S A; Anissimova, N P; Ford, T W; Meehan, C F; Kirkwood, P A

2007-01-01

The descending control of respiratory-related motoneurones in the thoracic spinal cord remains the subject of some debate. In this study, direct connections from expiratory bulbospinal neurones to identified motoneurones were investigated using spike-triggered averaging and the strengths of connection revealed were related to the presence and size of central respiratory drive potentials in the same motoneurones. Intracellular recordings were made from motoneurones in segments T5–T9 of the spinal cord of anaesthetized cats. Spike-triggered averaging from expiratory bulbospinal neurones in the caudal medulla revealed monosynaptic EPSPs in all groups of motoneurones, with the strongest connections to expiratory motoneurones with axons in the internal intercostal nerve. In the latter, connection strength was similar irrespective of the target muscle (e.g. external abdominal oblique or internal intercostal) and the EPSP amplitude was positively correlated with the amplitude of the central respiratory drive potential of the motoneurone. For this group, EPSPs were found in 45/83 bulbospinal neurone/motoneurone pairs, with a mean amplitude of 40.5 μV. The overall strength of the connection supports previous measurements made by cross-correlation, but is about 10 times stronger than that reported in the only previous similar survey to use spike-triggered averaging. Calculations are presented to suggest that this input alone is sufficient to account for all the expiratory depolarization seen in the recorded motoneurones. However, extra sources of input, or amplification of this one, are likely to be necessary to produce a useful motoneurone output. PMID:17204500

Cardiovascular activity in blood-injection-injury phobia during exposure: evidence for diphasic response patterns?

PubMed

Ritz, Thomas; Meuret, Alicia E; Simon, Erica

2013-08-01

Exposure to feared stimuli in blood-injection-injury (BII)-phobia is thought to elicit a diphasic response pattern, with an initial fight-flight-like cardiovascular activation followed by a marked deactivation and possible fainting (vasovagal syncope). However, studies have remained equivocal on the importance of such patterns. We therefore sought to determine the prevalence and clinical relevance of diphasic responses using criteria that require a true diphasic response to exceed cardiovascular activation of an emotional episode of a negative valence and to exceed deactivation of an emotionally neutral episode. Sixty BII-phobia participants and 20 healthy controls were exposed to surgery, anger and neutral films while measuring heart rate, blood pressure, respiratory pattern, and end-tidal partial pressure of carbon dioxide (as indicator of hyperventilation). Diphasic response patterns were observed in up to 20% of BII-phobia participants and 26.6% of healthy controls for individual cardiovascular parameters. BII-phobia participants with diphasic patterns across multiple parameters showed more fear of injections and blood draws, reported the strongest physical symptoms during the surgery film, and showed the strongest tendency to hyperventilate. Thus, although only a minority of individuals with BII phobia shows diphasic responses, their occurrence indicates significant distress. Respiratory training may add to the treatment of BII phobia patients that show diphasic response patterns. Copyright © 2013 Elsevier Ltd. All rights reserved.

Sleep patterns and sleep-related complaints of Brazilian interstate bus drivers.

PubMed

Mello, M T; Santana, M G; Souza, L M; Oliveira, P C; Ventura, M L; Stampi, C; Tufik, S

2000-01-01

Sleep-related complaints have become a highlight for physicians as well as public health administrators. Studies of sleep patterns and sleep-related complaints of shift workers have been useful in minimizing reduction in the quality of life due to the warping of the sleep-wake cycle. The objective of the present study was to assess patterns of sleep, sleep-related complaints as well as physical activity and scoring rates for depression and anxiety in interstate bus drivers. Data were obtained with a sleep questionnaire, with the Beck inventory for depression, and the State-Trait Anxiety Inventory (STAI). A total of 400 interstate bus drivers from the northern, southern, central-western and south-eastern regions of Brazil were interviewed. Sixty percent of the subjects interviewed presented at least one sleep-related complaint, 16% admitted to have dozed at the wheel while on duty, and 41% stated that they exercised on a regular basis. Other sleep disturbance complaints reported were: sleep latency 29'17"; physical fatigue, 59.8%; mental fatigue, 45.4%; sleepiness, 25.8%; irritability, 20.6%; insomnia, 37.5%, respiratory disturbances, 19. 25% and snoring, 20.75%. Scores for anxiety and depression were not in the pathological range. The present data reinforce the view that bus drivers are generally discontent with shift work and its effects on sleep. Consequently, it is very important to establish an appropriate work schedule for drivers, besides implementing photo-therapy and physical activities in order to minimize sleepiness when driving.

From Central Pattern Generator to Sensory Template in the Evolution of Birdsong

ERIC Educational Resources Information Center

Konishi, Masakazu

2010-01-01

Central nervous networks, be they a part of the human brain or a group of neurons in a snail, may be designed to produce distinct patterns of movement. Central pattern generators can account for the development and production of normal vocal signals without auditory feedback in non-songbirds. Songbirds need auditory feedback to develop and…

SU-E-T-538: Does Abdominal Compression Through Prone Patient Position Reduce Respiratory Motion in Lung Cancer Radiotherapy?

DOE Office of Scientific and Technical Information (OSTI.GOV)

Catron, T; Rosu, M; Weiss, E

2014-06-01

Purpose: This study assesses the effect of physiological abdominal compression from prone positioning by comparing respiratory-induced tumor movements in supine and prone positions. Methods: 19 lung cancer patients underwent repeated supine and prone free-breathing 4DCT scans. The effect of patient position on motion magnitude was investigated for tumors, lymph nodes (9 cases), and subgroups of central (11 cases), peripheral (8 cases) and small peripheral tumors (5 cases), by evaluating the population average excursions, absolute and relative to a carina-point. Results: Absolute motion analysis: In prone, motion increased by ~20% for tumors and ~25% for lymph nodes. Central tumors moved moremore » compared to peripheral tumors in both supine and prone (~22%, and ~4% respectively). Central tumors movement increased by ~12% in prone. For peripheral tumors the increase in prone position was ~25% (~40% and 29% changes on along RL and AP directions). Motion relative to carina-point analysis: Overall, tumor excursions relative to carina-point increased by ~17% in prone. Lymph node relative magnitudes were lower by ~4%. Likewise, the central tumors moved ~7% less in prone. The subgroup of peripheral tumors exhibited increased amplitudes by ~44%; the small peripheral tumors had even larger relative displacements in prone (~46%). Conclusion: Tumor and lymph node movement in the patient population from this study averaged to be higher in prone than in supine position. Results from carina analysis also suggest that peripheral tissues have more physiologic freedom of motility when placed in the prone position, regardless of size. From these observations we should continue to avoid prone positioning for all types of primary lung tumor, suggesting that patients should receive radiotherapy for primary lung cancer in supine position to minimize target tissue mobility during normal respiratory effort. Further investigation will include more patients with peripheral tumors to validate our observations.« less

SU-G-JeP4-02: An Investigation of Respiratory Surrogate Motion Data Requirements for Multiple-Step Ahead Prediction

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zawisza, I; Ren, L; Yin, F

Purpose: Respiratory-gated radiotherapy and dynamic tracking employ real-time imaging and surrogate motion-monitoring methods with tumor motion prediction in advance of real-time. This study investigated respiratory motion data length on prediction accuracy of tumor motion. Methods: Predictions generated from the algorithm are validated against a one-dimensional surrogate signal of amplitude versus time. Prediction consists of three major components: extracting top-ranked subcomponents from training data matching the last respiratory cycle; calculating weighting factors from best-matched subcomponents; fusing data proceeding best-matched subcomponents with respective weighting factors to form predictions. Predictions for one respiratory cycle (∼3-6seconds) were assessed using 351 patient data from themore » respiratory management device. Performance was evaluated for correlation coefficient and root mean square error (RMSE) between prediction and final respiratory cycle. Results: Respiratory prediction results fell into two classes, where best predictions for 70 cycles or less performed using relative prediction and greater than 70 cycles are predicted similarly using relative and derivative relative. For 70 respiratory cycles or less, the average correlation between prediction and final respiratory cycle was 0.9999±0.0001, 0.9999±0.0001, 0.9988±0.0003, 0.9985±0.0023, and 0.9981±0.0023 with RMSE values of 0.0091±0.0030, 0.0091±0.0030, 0.0305±0.0051, 0.0299±0.0259, and 0.0299±0.0259 for equal, relative, pattern, derivative equal and derivative relative weighting methods, respectively. Respectively, the total best prediction for each method was 37, 65, 20, 22, and 22. For data with greater than 70 cycles average correlation was 0.9999±0.0001, 0.9999±0.0001, 0.9988±0.0004, 0.9988±0.0020, and 0.9988±0.0020 with RMSE values of 0.0081±0.0031, 0.0082±0.0033, 0.0306±0.0056, 0.0218±0.0222, and 0.0218±0.0222 for equal, relative, pattern, derivative equal and derivative relative weighting methods, respectively. Respectively, the total best prediction for each method was 24, 44, 42, 30, and 45. Conclusion: The prediction algorithms are effective in estimating surrogate motion in advance. These results indicate an advantage in using relative prediction for shorter data and either relative or derivative relative prediction for longer data.« less

Vestibular system and neural correlates of motion sickness

NASA Technical Reports Server (NTRS)

Miller, Alan D.

1986-01-01

Initial studies re-examine the role of certain central nervous system structures in the production of vestibular-induced vomiting and vomiting in general. All experiments were conducted using cats. Since these studies demonstrated that the essential role of various central structures in vestibular-induced vomiting is only poorly understood, efforts were re-directed to study the control of the effector muscles (diaphragm and abdominal muscles) that produce the pressure changes responsible for vomiting, with the goal of determining how this control mechanism is engaged during motion sickness. Experiments were conducted to localize the motoneurons that innervate the individual abdominal muscles and the portion of the diaphragm that surrounds the esophagus. A central question regarding respiratory muscle control during vomiting is whether these muscles are activated via the same brain stem pre-motor neurons that provide descending respiratory drive and/or by other descending input(s). In other experiments, the use of a combination of pitch and roll motions to produce motion sickness in unrestrained cats was evaluated. This stimulus combination can produce vomiting in only the most susceptible cats and is thus not as provacative a stimulus for cats as vertical linear acceleration.

Alternative approaches to treatment of Central Sleep Apnea.

PubMed

Thomas, Robert Joseph

2014-03-01

Divergent approaches to treatment of hypocapnic central sleep apnea syndromes reflect the difficulties in taming a hyperactive respiratory chemoreflex. As both sleep fragmentation and a narrow CO 2 reserve or increased loop gain drive the disease, sedatives (to induce longer periods of stable non-rapid eye movement (NREM) sleep and reduce the destabilizing effects of arousals in NREM sleep) and CO 2 -based stabilization approaches are logical. Adaptive ventilation reduces mean hyperventilation yet can induce ventilator-patient dyssynchrony, while enhanced expiratory rebreathing space (EERS, dead space during positive pressure therapy) and CO 2 manipulation directly stabilize respiratory control by moving CO 2 above the apnea threshold. Carbonic anhydrase inhibition can provide further adjunctive benefits. Provent and Winx may be less likely to trigger central apneas or periodic breathing in those with a narrow CO 2 reserve. An oral appliance can meaningfully reduce positive pressure requirements and thus enable treatment of complex apnea. Novel pharmacological approaches may target mediators of carotid body glomus cell excitation, such as the balance between gas neurotransmitters. In complex apnea patients, single mode therapy is not always successful, and multi-modality therapy might need to be considered. Phenotyping of sleep apnea beyond conventional scoring approaches is the key to optimal management.

Mechanisms of CO2/H+ chemoreception by respiratory rhythm generator neurons in the medulla from newborn rats in vitro.

PubMed

Kawai, Akira; Onimaru, Hiroshi; Homma, Ikuo

2006-04-15

We investigated mechanisms of CO(2)/H(+) chemoreception in the respiratory centre of the medulla by measuring membrane potentials of pre-inspiratory neurons, which are putative respiratory rhythm generators, in the brainstem-spinal cord preparation of the neonatal rat. Neuronal response was tested by changing superfusate CO(2) concentration from 2% to 8% at constant HCO(3)(-) concentration (26 mm) or by changing pH from 7.8 to 7.2 by reducing HCO(3)(-) concentration at constant CO(2) (5%). Both respiratory and metabolic acidosis lead to depolarization of neurons with increased excitatory synaptic input and increased burst rate. Respiratory acidosis potentiated the amplitude of the neuronal drive potential. In the presence of tetrodotoxin (TTX), membrane depolarization persisted during respiratory and metabolic acidosis. However, the depolarization was smaller than that before application of TTX, which suggests that some neurons are intrinsically, and others synaptically, chemosensitive to CO(2)/H(+). Application of Ba(2+) blocked membrane depolarization by respiratory acidosis, whereas significant depolarization in response to metabolic acidosis still remained after application of Cd(2+) and Ba(2+). We concluded that the intrinsic responses to CO(2)/H(+)changes were mediated by potassium channels during respiratory acidosis, and that some other mechanisms operate during metabolic acidosis. In low-Ca(2+), high-Mg(2+) solution, an increased CO(2) concentration induced a membrane depolarization with a simultaneous increase of the burst rate. Pre-inspiratory neurons could adapt their baseline membrane potential to external CO(2)/H(+) changes by integration of these mechanisms to modulate their burst rates. Thus, pre-inspiratory neurons might play an important role in modulation of respiratory rhythm by central chemoreception in the brainstem-spinal cord preparation.

Mechanisms of CO2/H+ chemoreception by respiratory rhythm generator neurons in the medulla from newborn rats in vitro

PubMed Central

Kawai, Akira; Onimaru, Hiroshi; Homma, Ikuo

2006-01-01

We investigated mechanisms of CO2/H+ chemoreception in the respiratory centre of the medulla by measuring membrane potentials of pre-inspiratory neurons, which are putative respiratory rhythm generators, in the brainstem–spinal cord preparation of the neonatal rat. Neuronal response was tested by changing superfusate CO2 concentration from 2% to 8% at constant HCO3− concentration (26 mm) or by changing pH from 7.8 to 7.2 by reducing HCO3− concentration at constant CO2 (5%). Both respiratory and metabolic acidosis lead to depolarization of neurons with increased excitatory synaptic input and increased burst rate. Respiratory acidosis potentiated the amplitude of the neuronal drive potential. In the presence of tetrodotoxin (TTX), membrane depolarization persisted during respiratory and metabolic acidosis. However, the depolarization was smaller than that before application of TTX, which suggests that some neurons are intrinsically, and others synaptically, chemosensitive to CO2/H+. Application of Ba2+ blocked membrane depolarization by respiratory acidosis, whereas significant depolarization in response to metabolic acidosis still remained after application of Cd2+ and Ba2+. We concluded that the intrinsic responses to CO2/H+changes were mediated by potassium channels during respiratory acidosis, and that some other mechanisms operate during metabolic acidosis. In low-Ca2+, high-Mg2+ solution, an increased CO2 concentration induced a membrane depolarization with a simultaneous increase of the burst rate. Pre-inspiratory neurons could adapt their baseline membrane potential to external CO2/H+ changes by integration of these mechanisms to modulate their burst rates. Thus, pre-inspiratory neurons might play an important role in modulation of respiratory rhythm by central chemoreception in the brainstem–spinal cord preparation. PMID:16469786

Realistic respiratory motion margins for external beam partial breast irradiation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Conroy, Leigh; Quirk, Sarah; Department of Physics and Astronomy, University of Calgary, Calgary, Alberta T2N 1N4

Purpose: Respiratory margins for partial breast irradiation (PBI) have been largely based on geometric observations, which may overestimate the margin required for dosimetric coverage. In this study, dosimetric population-based respiratory margins and margin formulas for external beam partial breast irradiation are determined. Methods: Volunteer respiratory data and anterior–posterior (AP) dose profiles from clinical treatment plans of 28 3D conformal radiotherapy (3DCRT) PBI patient plans were used to determine population-based respiratory margins. The peak-to-peak amplitudes (A) of realistic respiratory motion data from healthy volunteers were scaled from A = 1 to 10 mm to create respiratory motion probability density functions. Dosemore » profiles were convolved with the respiratory probability density functions to produce blurred dose profiles accounting for respiratory motion. The required margins were found by measuring the distance between the simulated treatment and original dose profiles at the 95% isodose level. Results: The symmetric dosimetric respiratory margins to cover 90%, 95%, and 100% of the simulated treatment population were 1.5, 2, and 4 mm, respectively. With patient set up at end exhale, the required margins were larger in the anterior direction than the posterior. For respiratory amplitudes less than 5 mm, the population-based margins can be expressed as a fraction of the extent of respiratory motion. The derived formulas in the anterior/posterior directions for 90%, 95%, and 100% simulated population coverage were 0.45A/0.25A, 0.50A/0.30A, and 0.70A/0.40A. The differences in formulas for different population coverage criteria demonstrate that respiratory trace shape and baseline drift characteristics affect individual respiratory margins even for the same average peak-to-peak amplitude. Conclusions: A methodology for determining population-based respiratory margins using real respiratory motion patterns and dose profiles in the AP direction was described. It was found that the currently used respiratory margin of 5 mm in partial breast irradiation may be overly conservative for many 3DCRT PBI patients. Amplitude alone was found to be insufficient to determine patient-specific margins: individual respiratory trace shape and baseline drift both contributed to the dosimetric target coverage. With respiratory coaching, individualized respiratory margins smaller than the full extent of motion could reduce planning target volumes while ensuring adequate coverage under respiratory motion.« less

[Computed tomographic semiotics of respiratory tuberculosis in HIV-infected patients].

PubMed

Gavrilov, P V; Lazareva, A S; Malashenkov, E A

2013-01-01

to study the computed tomographic (CT) semiotics of respiratory tuberculosis in HIV-infected patients in relation to the degree of immunosuppression. The study enrolled 74 patients with verified respiratory tuberculosis in the presence of HIV infection. According to the degree of immunosuppression and the Centers for Disease Control (CDC) and Prevention classification (Atlanta, USA, 1993), the patients were divided into 3 groups: (1) CD4 > or = 500 cells/microl (n = 10); 2) CD4 200-499 cells/microl (n = 28); (3) CD4 <200 cells/microl (n = 36). With spiral CT, focal changes with a predominance of clear-cut foci are visualized at a high frequency in the patients with pulmonary tuberculosis in the presence of HIV infection. In progressive immunosuppression, the CT pattern displays atypical syndromes (frosted glass-type foci, interstitial infiltration, and thin-walled cavities) with the lower rate of alveolar infiltration with confluent foci, as well as lung tissue decay. Enlarged intrathoracic lymph nodes are characteristic of 70.0% of the patients with HIV infection and tuberculosis regardless of the level of CD4 cells. As immunosuppression progresses, the CT pattern of respiratory tuberculosis in the presence of HIV infection shows as atypical syndromes (unclearly defined frosted glass-type focal changes, interstitial infiltrations, and thin-walled cavernous masses). A marked polymorphism in changes and a high rate of lymph node involvement are characteristic.

Asian Dust Storm Elevates Children’s Respiratory Health Risks: A Spatiotemporal Analysis of Children’s Clinic Visits across Taipei (Taiwan)

PubMed Central

Yu, Hwa-Lung; Chien, Lung-Chang; Yang, Chiang-Hsing

2012-01-01

Concerns have been raised about the adverse impact of Asian dust storms (ADS) on human health; however, few studies have examined the effect of these events on children’s health. Using databases from the Taiwan National Health Insurance and Taiwan Environmental Protection Agency, this study investigates the documented daily visits of children to respiratory clinics during and after ADS that occurred from 1997 to 2007 among 12 districts across Taipei City by applying a Bayesian structural additive regressive model controlled for spatial and temporal patterns. This study finds that the significantly impact of elevated children’s respiratory clinic visits happened after ADS. Five of the seven lagged days had increasing percentages of relative rate, which was consecutively elevated from a 2-day to a 5-day lag by 0.63%∼2.19% for preschool children (i.e., 0∼6 years of age) and 0.72%∼3.17% for school children (i.e., 7∼14 years of age). The spatial pattern of clinic visits indicated that geographical heterogeneity was possibly associated with the clinic’s location and accessibility. Moreover, day-of-week effects were elevated on Monday, Friday, and Saturday. We concluded that ADS may significantly increase the risks of respiratory diseases consecutively in the week after exposure, especially in school children. PMID:22848461

Social contact patterns of infants in deciding vaccination strategy: a prospective, cross-sectional, single-centre study.

PubMed

Oguz, M M; Camurdan, A D; Aksakal, F N; Akcaboy, M; Altinel Acoglu, E

2018-05-09

Social contact between individuals is believed to be a fundamental cause in the transmission of many respiratory tract infections. Because they have not yet been fully vaccinated, infants are at high risk for contracting whooping cough, influenza and their serious complications. Therefore, determining infant social contact patterns is an important step in protecting them from respiratory tract infection. This study included 1200 healthy infants (<12 months of age). Social contact diaries were used to estimate the frequency and nature of the infants' social contacts. This survey also gathered information regarding the infants' respiratory symptoms and their frequency of attendance at crowded places over a period of 1 week. The diary return rate was 83.8% (N = 1006), and there was a total of 4706 contacts reported for these infants. The median daily contact number per capita was 4 (range 1-18). The median number of contacts with adolescents was 0 (range 0-7). Of the infants, 50.3% had contact with non-household individuals. The mothers had the longest contacts with their babies. Contacts with school children, frequency of attendance at crowded places and age were determined to be significant effective factors for reporting respiratory symptoms. Results suggest that school-age siblings and the mothers should be primarily vaccinated, and parents should keep their babies away from crowded places for protecting their infants.

Influenza hospitalization epidemiology from a severe acute respiratory infection surveillance system in Jordan, January 2008-February 2014.

PubMed

Al-Abdallat, Mohammad; Dawson, Patrick; Haddadin, Aktham Jeries; El-Shoubary, Waleed; Dueger, Erica; Al-Sanouri, Tarek; Said, Mayar M; Talaat, Maha

2016-03-01

Acute respiratory infections (ARIs) are a major cause of morbidity and mortality worldwide. Influenza typically contributes substantially to the burden of ARI, but only limited data are available on influenza activity and seasonality in Jordan. Syndromic case definitions were used to identify individuals with severe acute respiratory infections (SARI) admitted to four sentinel hospitals in Jordan. Demographic and clinical data were collected. Nasopharyngeal and oropharyngeal swabs were tested for influenza using real-time reverse transcription polymerase chain reaction and typed as influenza A or B, with influenza A further subtyped. From January 2008-February 2014, 2891 SARI cases were tested for influenza, and 257 (9%) were positive. While 73% of all SARI cases were under 5 years of age, only 57% of influenza-positive cases were under 5 years of age. Eight (3%) influenza-positive cases died. An annual seasonal pattern of influenza activity was observed. The proportion of influenza-positive cases peaked during November-January (14-42%) in the non-pandemic years. Influenza is associated with substantial morbidity and mortality in Jordan. The seasonal pattern of influenza aligns with known Northern Hemisphere seasonality. Further characterization of the clinical and financial burden of influenza in Jordan will be critical in supporting decisions regarding disease control activities. © 2015 The Authors. Influenza and Other Respiratory Viruses Published by John Wiley & Sons Ltd.

Effects of breathing maneuver and sitting posture on muscle activity in inspiratory accessory muscles in patients with chronic obstructive pulmonary disease

PubMed Central

2012-01-01

Background To determine the influence of breathing maneuver and sitting posture on tidal volume (TV), respiratory rate (RR), and muscle activity of the inspiratory accessory muscles in patients with chronic obstructive pulmonary disease (COPD). Methods Twelve men with COPD participated in the study. Inductive respiratory plethysmography and surface electromyography were used to simultaneously measure TV, RR, and muscle activity of the inspiratory accessory muscles [the scalenus (SM), sternocleidomastoid (SCM), and pectoralis major (PM) muscles] during quiet natural breathing (QB) and pursed-lips breathing (PLB) in three sitting postures: neutral position (NP), with armm support (WAS), and with arm and head support (WAHS). Results Two-way repeated-measures analysis of variance was employed. In a comparison of breathing patterns, PLB significantly increased TV and decreased RR compared to QB. Muscle activity in the SM and SCM increased significantly in PLB compared to QB. In a comparison of sitting postures, the muscle activity of the SM, SCM, and PM increased in the forward-leaning position. Conclusions The results suggest that in COPD, PLB induced a favorable breathing pattern (increased TV and reduced RR) compared to QB. Additionally, WAS and WAHS positions increased muscle activity of the inspiratory accessory muscles during inspiration versus NP. Differential involvement of accessory respiratory muscles can be readily studied in COPD patients, allowing monitoring of respiratory load during pulmonary rehabilitation. PMID:22958459

The preBötzinger complex as a hub for network activity along the ventral respiratory column in the neonate rat.

PubMed

Gourévitch, Boris; Mellen, Nicholas

2014-09-01

In vertebrates, respiratory control is ascribed to heterogeneous respiration-modulated neurons along the Ventral Respiratory Column (VRC) in medulla, which includes the preBötzinger Complex (preBötC), the putative respiratory rhythm generator. Here, the functional anatomy of the VRC was characterized via optical recordings in the sagittaly sectioned neonate rat hindbrain, at sampling rates permitting coupling estimation between neuron pairs, so that each neuron was described using unitary, neuron-system, and coupling attributes. Structured coupling relations in local networks, significantly oriented coupling in the peri-inspiratory interval detected in pooled data, and significant correlations between firing rate and expiratory duration in subsets of neurons revealed network regulation at multiple timescales. Spatially averaged neuronal attributes, including coupling vectors, revealed a sharp boundary at the rostral margin of the preBötC, as well as other functional anatomical features congruent with identified structures, including the parafacial respiratory group and the nucleus ambiguus. Cluster analysis of attributes identified two spatially compact, homogenous groups: the first overlapped with the preBötC, and was characterized by strong respiratory modulation and dense bidirectional coupling with itself and other groups, consistent with a central role for the preBötC in respiratory control; the second lay between preBötC and the facial nucleus, and was characterized by weak respiratory modulation and weak coupling with other respiratory neurons, which is congruent with cardiovascular regulatory networks that are found in this region. Other groups identified using cluster analysis suggested that networks along VRC regulated expiratory duration, and the transition to and from inspiration, but these groups were heterogeneous and anatomically dispersed. Thus, by recording local networks in parallel, this study found evidence for respiratory regulation at multiple timescales along the VRC, as well as a role for the preBötC in the integration of functionally disparate respiratory neurons. Copyright © 2014 Elsevier Inc. All rights reserved.

Respiratory Problems Associated with Surfing in Coastal Waters.

PubMed

O'Halloran, Chris; Silver, Mary W; Lahiff, Maureen; Colford, John

2017-03-01

A pilot project was conducted to examine the health status and possible adverse health effects associated with seawater exposure (microbial water-quality indicators and phytoplankton abundance and their toxins) of surfers in Monterey Bay, Central California coastal waters. Forty-eight surfers enrolled in the study and completed an initial health background survey and weekly health surveys online using Survey Monkey. Descriptive statistics and generalized estimating equation, a regression technique, were used to identify longitudinal and correlated results. The surfers were predominately Caucasian, male, and physically active. They surfed approximately 4 h a week. Their average age was 34 years. The data indicated that the surfers were generally "healthy," with a low prevalence of diabetes, high cholesterol, and hypertension. Their most common health problems were allergies and asthma. During the study, 10% of the surfers reported gastrointestinal symptoms and 29% reported upper respiratory symptoms. This study suggests surfers were significantly more likely to report upper respiratory symptoms when they had a history of allergies, housemates with upper respiratory symptoms, and/or a history of previous adverse health symptoms while surfing during a "red tide" (an event often associated with the presence of phytoplankton toxins). Additionally, female surfers reported upper respiratory symptoms more than males.

Feedback of End-tidal pCO2 as a Therapeutic Approach for Panic Disorder

PubMed Central

Meuret, Alicia E.; Wilhelm, Frank H.; Ritz, Thomas; Roth, Walton T.

2009-01-01

Background Given growing evidence that respiratory dysregulation is a central feature of panic disorder (PD) interventions for panic that specifically target respiratory functions could prove clinically useful and scientifically informative. We tested the effectiveness of a new, brief, capnometry-assisted breathing therapy (BRT) on clinical and respiratory measures in PD. Methods Thirty-seven participants with PD with or without agoraphobia were randomly assigned to BRT or to a delayed-treatment control group. Clinical status, respiration rate, and end-tidal pCO2 were assessed at baseline, posttreatment, 2-month and 12-month follow-up. Respiratory measures were also assessed during homework exercises using a portable capnometer as a feedback device. Results Significant improvements (in PD severity, agoraphobic avoidance, anxiety sensitivity, disability, and respiratory measures) were seen in treated but not untreated patients, with moderate to large effect sizes. Improvements were maintained at follow-up. Treatment compliance was high for session attendance and homework exercises; dropouts were few. Conclusions The data provide preliminary evidence that raising end-tidal pCO2 by means of capnometry feedback is therapeutically beneficial for panic patients. Replication and extension will be needed to verify this new treatment’s efficacy and determine its mechanisms. PMID:17681544

Pediatric acute respiratory distress syndrome: definition, incidence, and epidemiology: proceedings from the Pediatric Acute Lung Injury Consensus Conference.

PubMed

Khemani, Robinder G; Smith, Lincoln S; Zimmerman, Jerry J; Erickson, Simon

2015-06-01

Although there are similarities in the pathophysiology of acute respiratory distress syndrome in adults and children, pediatric-specific practice patterns, comorbidities, and differences in outcome necessitate a pediatric-specific definition. We sought to create such a definition. A subgroup of pediatric acute respiratory distress syndrome investigators who drafted a pediatric-specific definition of acute respiratory distress syndrome based on consensus opinion and supported by detailed literature review tested elements of the definition with patient data from previously published investigations. International PICUs. Children enrolled in published investigations of pediatric acute respiratory distress syndrome. None. Several aspects of the proposed pediatric acute respiratory distress syndrome definition align with the Berlin Definition of acute respiratory distress syndrome in adults: timing of acute respiratory distress syndrome after a known risk factor, the potential for acute respiratory distress syndrome to coexist with left ventricular dysfunction, and the importance of identifying a group of patients at risk to develop acute respiratory distress syndrome. There are insufficient data to support any specific age for "adult" acute respiratory distress syndrome compared with "pediatric" acute respiratory distress syndrome. However, children with perinatal-related respiratory failure should be excluded from the definition of pediatric acute respiratory distress syndrome. Larger departures from the Berlin Definition surround 1) simplification of chest imaging criteria to eliminate bilateral infiltrates; 2) use of pulse oximetry-based criteria when PaO2 is unavailable; 3) inclusion of oxygenation index and oxygen saturation index instead of PaO2/FIO2 ratio with a minimum positive end-expiratory pressure level for invasively ventilated patients; 4) and specific inclusion of children with preexisting chronic lung disease or cyanotic congenital heart disease. This pediatric-specific definition for acute respiratory distress syndrome builds on the adult-based Berlin Definition, but has been modified to account for differences between adults and children with acute respiratory distress syndrome. We propose using this definition for future investigations and clinical care of children with pediatric acute respiratory distress syndrome and encourage external validation with the hope for continued iterative refinement of the definition.

Thermal noise variance of a receive radiofrequency coil as a respiratory motion sensor.

PubMed

Andreychenko, A; Raaijmakers, A J E; Sbrizzi, A; Crijns, S P M; Lagendijk, J J W; Luijten, P R; van den Berg, C A T

2017-01-01

Development of a passive respiratory motion sensor based on the noise variance of the receive coil array. Respiratory motion alters the body resistance. The noise variance of an RF coil depends on the body resistance and, thus, is also modulated by respiration. For the noise variance monitoring, the noise samples were acquired without and with MR signal excitation on clinical 1.5/3 T MR scanners. The performance of the noise sensor was compared with the respiratory bellow and with the diaphragm displacement visible on MR images. Several breathing patterns were tested. The noise variance demonstrated a periodic, temporal modulation that was synchronized with the respiratory bellow signal. The modulation depth of the noise variance resulting from the respiration varied between the channels of the array and depended on the channel's location with respect to the body. The noise sensor combined with MR acquisition was able to detect the respiratory motion for every k-space read-out line. Within clinical MR systems, the respiratory motion can be detected by the noise in receive array. The noise sensor does not require careful positioning unlike the bellow, any additional hardware, and/or MR acquisition. Magn Reson Med 77:221-228, 2017. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

Sex-dependent differences in the in vivo respiratory phenotype of the TASK-1 potassium channel knockout mouse.

PubMed

Jungbauer, Stefan; Buehler, Philipp Karl; Neubauer, Jacqueline; Haas, Cordula; Heitzmann, Dirk; Tegtmeier, Ines; Sterner, Christina; Barhanin, Jacques; Georgieff, Michael; Warth, Richard; Thomas, Jörg

2017-11-01

TASK-1 potassium channels have been implicated in central and peripheral chemoreception; however, the precise contribution of TASK-1 for the control of respiration is still under debate. Here, we investigated the respiration of unrestrained adult and neonatal TASK-1 knockout mice (TASK-1 -/- ) using a plethysmographic device. Respiration in adult female TASK-1 -/- mice under control (21% O 2 ), hypoxia and hypercapnia was unaffected. Under acute hypoxia male TASK-1 -/- mice exhibited a reduced increase of the respiratory frequency (f R ) compared to wildtypes. However, the tidal volume (V T ) of male TASK-1 -/- mice was strongly enhanced. The volatile anesthetic isoflurane induced in male TASK-1 -/- and male wild type mice (TASK-1 +/+ ) a similar respiratory depression. Neonatal TASK-1 -/- mice demonstrated a 30-40% decrease of the minute volume, caused by a reduction of the f R under control condition (21% O 2 ). Under hypoxia, neonatal TASK-1 -/- mice more frequently stopped breathing (apnea>3s) suggesting an increased hypoxia-sensitivity. As reported before, this increased hypoxia sensitivity had no influence on the survival rate of neonatal TASK-1 -/- mice. In adult and neonatal mice, TASK-1 gene deletion induced a significant prolongation of the relaxation time (R T ), which is a parameter for expiration kinetics. Additionally, screening for mutations in the human TASK-1 gene in 155 cases of sudden infant death syndrome (SIDS) was inconclusive. In conclusion, these data are suggestive for an increased hypoxia-sensitivity of neonatal TASK-1 -/- mice, however, without causing an increase in neonatal lethality. In adult female TASK-1 -/- mice respiration was unaffected, whereas adult male TASK-1 -/- mice showed a modified breathing pattern. These results are suggestive for sex-specific mechanisms for compensating the inactivation of TASK-1 in mice. Copyright © 2016 Elsevier B.V. All rights reserved.

Stability of the human respiratory control system. I. Analysis of a two-dimensional delay state-space model.

PubMed

Batzel, J J; Tran, H T

2000-07-01

A number of mathematical models of the human respiratory control system have been developed since 1940 to study a wide range of features of this complex system. Among them, periodic breathing (including Cheyne-Stokes respiration and apneustic breathing) is a collection of regular but involuntary breathing patterns that have important medical implications. The hypothesis that periodic breathing is the result of delay in the feedback signals to the respiratory control system has been studied since the work of Grodins et al. in the early 1950's [12]. The purpose of this paper is to study the stability characteristics of a feedback control system of five differential equations with delays in both the state and control variables presented by Khoo et al. [17] in 1991 for modeling human respiration. The paper is divided in two parts. Part I studies a simplified mathematical model of two nonlinear state equations modeling arterial partial pressures of O2 and CO2 and a peripheral controller. Analysis was done on this model to illuminate the effect of delay on the stability. It shows that delay dependent stability is affected by the controller gain, compartmental volumes and the manner in which changes in the ventilation rate is produced (i.e., by deeper breathing or faster breathing). In addition, numerical simulations were performed to validate analytical results. Part II extends the model in Part I to include both peripheral and central controllers. This, however, necessitates the introduction of a third state equation modeling CO2 levels in the brain. In addition to analytical studies on delay dependent stability, it shows that the decreased cardiac output (and hence increased delay) resulting from the congestive heart condition can induce instability at certain control gain levels. These analytical results were also confirmed by numerical simulations.

Stability of the human respiratory control system. II. Analysis of a three-dimensional delay state-space model.

PubMed

Batzel, J J; Tran, H T

2000-07-01

A number of mathematical models of the human respiratory control system have been developed since 1940 to study a wide range of features of this complex system. Among them, periodic breathing (including Cheyne-Stokes respiration and apneustic breathing) is a collection of regular but involuntary breathing patterns that have important medical implications. The hypothesis that periodic breathing is the result of delay in the feedback signals to the respiratory control system has been studied since the work of Grodins et al. in the early 1950's [1]. The purpose of this paper is to study the stability characteristics of a feedback control system of five differential equations with delays in both the state and control variables presented by Khoo et al. [4] in 1991 for modeling human respiration. The paper is divided in two parts. Part I studies a simplified mathematical model of two nonlinear state equations modeling arterial partial pressures of O2 and CO2 and a peripheral controller. Analysis was done on this model to illuminate the effect of delay on the stability. It shows that delay dependent stability is affected by the controller gain, compartmental volumes and the manner in which changes in the ventilation rate is produced (i.e., by deeper breathing or faster breathing). In addition, numerical simulations were performed to validate analytical results. Part II extends the model in Part I to include both peripheral and central controllers. This, however, necessitates the introduction of a third state equation modeling CO2 levels in the brain. In addition to analytical studies on delay dependent stability, it shows that the decreased cardiac output (and hence increased delay) resulting from the congestive heart condition can induce instability at certain control gain levels. These analytical results were also confirmed by numerical simulations.

Comparative epidemiology of human metapneumovirus- and respiratory syncytial virus-associated hospitalizations in Guatemala

PubMed Central

McCracken, John P; Arvelo, Wences; Ortíz, José; Reyes, Lissette; Gray, Jennifer; Estevez, Alejandra; Castañeda, Oscar; Langley, Gayle; Lindblade, Kim A

2014-01-01

Background Human metapneumovirus (HMPV) is an important cause of acute respiratory infections (ARI), but little is known about how it compares with respiratory syncytial virus (RSV) in Central America. Objectives In this study, we describe hospitalized cases of HMPV- and RSV-ARI in Guatemala. Methods We conducted surveillance at three hospitals (November 2007–December 2012) and tested nasopharyngeal and oropharyngeal swab specimens for HMPV and RSV using real-time reverse transcription-polymerase chain reaction. We calculated incidence rates, and compared the epidemiology and outcomes of HMPV-positive versus RSV-positive and RSV-HMPV-negative cases. Results We enrolled and tested specimens from 6288 ARI cases; 596 (9%) were HMPV-positive and 1485 (24%) were RSV-positive. We observed a seasonal pattern of RSV but not HMPV. The proportion HMPV-positive was low (3%) and RSV-positive high (41%) for age <1 month, whereas these proportions were similar (∼20%) by age 2 years. The annual incidence of hospitalized HMPV-ARI was 102/100 000 children aged <5 years [95% confidence interval (CI): 75–178], 2·6/100 000 persons aged 5–17 years (95%CI: 1·2–5·0), and 2·6/100 000 persons aged ≥18 years (95%CI: 1·5–4·9). Among children aged <5 years, HMPV-positive cases were less severe than HMPV-RSV-negative cases after adjustment for confounders [odds ratio (OR) for intensive care = 0·63, 95% CI 0·47–0·84]; OR for death = 0·46, 95% CI 0·23–0·92). Conclusions Human metapneumovirus is a substantial contributor to ARI hospitalization in Guatemala, but HMPV hospitalizations are less frequent than RSV and, in young children, less severe than other etiologies. Preventive interventions should take into account the wide variation in incidence by age and unpredictable timing of incidence peaks. PMID:24761765

Long-term Non-Invasive Ventilation in Infants: A Systematic Review and Meta-Analysis.

PubMed

Bedi, Prabhjot K; Castro-Codesal, Maria Luisa; Featherstone, Robin; AlBalawi, Mohammed M; Alkhaledi, Bashar; Kozyrskyj, Anita L; Flores-Mir, Carlos; MacLean, Joanna E

2018-01-01

The use of long-term non-invasive ventilation (NIV) to treat sleep and breathing disorders in children has increased substantially in the last decade; however, less data exist about its use in infants. Given that infants have distinct sleep and breathing patterns when compared to older children, the outcomes of infants on long-term NIV may differ as well. The aim of this study is to systematically review the use and outcomes of long-term NIV in infants. Ovid Medline, Ovid Embase, CINAHL (via EbscoHOST), PubMed, and Wiley Cochrane Library were systematically searched from January 1990 to July 2017. Studies on infants using long-term NIV outside of an acute care setting were included. Data were extracted on study design, population characteristics, and NIV outcomes. A total of 327 studies were full-text reviewed, with final inclusion of 60. Studies were distributed across airway (40%), neuromuscular (28%), central nervous system (10%), cardio-respiratory (2%), and multiple (20%) disease categories. Of the 18 airway studies reporting on NIV outcomes, 13 (72%) reported improvements in respiratory parameters. Of the 12 neuromuscular studies exclusively on spinal muscular atrophy type 1 (SMA1), six (50%) reported decreased hospitalizations and nine (75%) reported on mortality outcomes. Risk of bias was moderate to serious, and quality of the evidence was low to very low for all studies. Most studies had an observational design with no control group, limiting the potential for a meta-analysis. The outcomes reported in studies differed by the disease category being studied. Studies on airway conditions showed improvements in respiratory parameters for infants using NIV. Studies on neuromuscular disorder, which were almost exclusively on SMA1, reported decreased hospitalizations and prolonged survival. Overall, it appears that NIV is an effective long-term therapy for infants. However, the high risk of bias and low quality of the available evidence limited strong conclusions.

Primary Respiratory Chain Disease Causes Tissue-Specific Dysregulation of the Global Transcriptome and Nutrient-Sensing Signaling Network

PubMed Central

Zhang, Zhe; Tsukikawa, Mai; Peng, Min; Polyak, Erzsebet; Nakamaru-Ogiso, Eiko; Ostrovsky, Julian; McCormack, Shana; Place, Emily; Clarke, Colleen; Reiner, Gail; McCormick, Elizabeth; Rappaport, Eric; Haas, Richard; Baur, Joseph A.; Falk, Marni J.

2013-01-01

Primary mitochondrial respiratory chain (RC) diseases are heterogeneous in etiology and manifestations but collectively impair cellular energy metabolism. Mechanism(s) by which RC dysfunction causes global cellular sequelae are poorly understood. To identify a common cellular response to RC disease, integrated gene, pathway, and systems biology analyses were performed in human primary RC disease skeletal muscle and fibroblast transcriptomes. Significant changes were evident in muscle across diverse RC complex and genetic etiologies that were consistent with prior reports in other primary RC disease models and involved dysregulation of genes involved in RNA processing, protein translation, transport, and degradation, and muscle structure. Global transcriptional and post-transcriptional dysregulation was also found to occur in a highly tissue-specific fashion. In particular, RC disease muscle had decreased transcription of cytosolic ribosomal proteins suggestive of reduced anabolic processes, increased transcription of mitochondrial ribosomal proteins, shorter 5′-UTRs that likely improve translational efficiency, and stabilization of 3′-UTRs containing AU-rich elements. RC disease fibroblasts showed a strikingly similar pattern of global transcriptome dysregulation in a reverse direction. In parallel with these transcriptional effects, RC disease dysregulated the integrated nutrient-sensing signaling network involving FOXO, PPAR, sirtuins, AMPK, and mTORC1, which collectively sense nutrient availability and regulate cellular growth. Altered activities of central nodes in the nutrient-sensing signaling network were validated by phosphokinase immunoblot analysis in RC inhibited cells. Remarkably, treating RC mutant fibroblasts with nicotinic acid to enhance sirtuin and PPAR activity also normalized mTORC1 and AMPK signaling, restored NADH/NAD+ redox balance, and improved cellular respiratory capacity. These data specifically highlight a common pathogenesis extending across different molecular and biochemical etiologies of individual RC disorders that involves global transcriptome modifications. We further identify the integrated nutrient-sensing signaling network as a common cellular response that mediates, and may be amenable to targeted therapies for, tissue-specific sequelae of primary mitochondrial RC disease. PMID:23894440