Respiratory State Research Articles

Wearable Fiber SPR Respiration Sensor Based on a LiBr-Doped Silk Fibroin Film.

Respiration is essential for supporting human body functions. However, a biocompatible fiber respiration sensor has rarely been discussed. In this study, we propose a wearable fiber surface plasmon resonance (SPR) respiration sensor using a LiBr-doped silk fibroin (SF) film. The SPR sensor monitors respiration by responding to airway humidity variation during inhalation and exhalation. We fabricated the SPR respiration sensor by depositing the core of a plastic-clad optical fiber with a gold film and an SF-LiBr composite film. The SF-LiBr composite film can absorb water through the interaction between water molecules and hydrogen bonds linking fibroin chains. Thus, humidity variation can change the SF-LiBr composite film's refractive index (RI), altering the phase-matching condition of the surface plasmon polaritons and shifting the SPR spectral dip. In experiments, we test the effect of the LiBr doping ratio on humidity response and confirm that the SF-22.1 wt % LiBr sensor has balanced performances. The SF-22.1 wt % LiBr sensor has a broad sensing range of 35-99% relative humidity (RH), a reasonable overall sensitivity of -6.5 nm/% RH, a fast response time of 135 ms, a quick recovery time of 150 ms, good reversibility, and good repeatability, which is capable of tracking different respiration states and patterns. Finally, we encapsulate this sensor in a conventional nasal oxygen cannula for wearable respiration monitoring, proving that the sensor is suitable for high-sensitivity, real-time, and accurate respiration monitoring.

Sex differences and estrogen effects in cardiac mitochondria in human aortic stenosis and in the mouse heart.

Sex differences in the adaptation to pressure overload have been described in humans, as well as animal models, and have been related to sex-specific expression of mitochondrial genes. We therefore tested whether sex differences in cardiac mitochondrial respiration exist in humans with aortic stenosis (AS). We also examined whether these potential differences may be at least partially due to sex hormones by testing if mitochondrial respiration is affected by estrogen (17ß-estradiol (E2)). Consecutive patients undergoing transapical aortic valve implantation (TAVI) (women, n = 7; men, n = 10) were included. Cardiac biopsies were obtained during TAVI and used directly for mitochondrial function measurements. Male and female C57BL/6J mice (n = 8/group) underwent sham surgery or gonadectomy (GDX) at the age of 2 months. After 14 days, mice were treated once with intraperitoneally injected vehicle (placebo), 17ß-estradiol (E2), estrogen receptor alpha (ERα) agonist [propyl pyrazole triol (PPT)], or ER beta (ERβ) agonist (BAY-1214257). Thereafter, mitochondrial measurements were performed directly in cardiac skinned fibers from isolated left ventricles and musculus solei. Mitochondrial State-3 respiration was higher in female than that in male human heart biopsies (15.0 ± 2.30 vs. 10.3 ± 2.05 nmol/mL/min/mg, p< 0.05). In the mouse model, mitochondrial State-3 respiration decreased significantly after GDX in female (27.6 ± 1.55 vs. 21.4 ± 1.71 nmol/mL/min/mg; p< 0.05) and male hearts (30.7 ± 1,48 vs. 23.7 ± 2,23 nmol/mL/min/mg; p< 0.05). In ovariectomized female mice, E2 and ERβ-agonist treatment restored the State-3 respiration to intact placebo level, whereas ERα-agonist treatment did not modulate State-3 respiration. The treatment with E2, ERα-, or ERβ-agonist did not modulate the State-3 respiration in GDX male mice. We identified sex differences in mitochondrial respiration in the diseased human heart. This is in alignment with known sex differences in the gene expression and proteome level at the functional level. E2 and ERβ affect cardiac mitochondrial function in the mouse model, suggesting that they may also contribute to the sex differences in the human heart. Their roles should be further investigated.

ВЕРОЯТНОСТЬ ИЗМЕНЕНИЯ ПОКАЗАТЕЛЕЙ ФУНКЦИИ ВНЕШНЕГО ДЫХАНИЯ ПРИ РАЗВИТИИ ХОБЛ В ЗАВИСИМОСТИ ОТ КОЛИЧЕСТВА ВЫКУРИВАЕМЫХ СИГАРЕТ НА ФОНЕ ГОРМОНАЛЬНЫХ ИЗМЕНЕНИЙ ПРИ БЕРЕМЕННОСТИ

Introduction. This is a study of possible changes in the respiration function indicators in the development of chronic obstructive pulmonary disease (COPD), depending on the number of cigarettes smoked and associated with pregnancy-related hormone fluctuations. Aim. Our study aimed to determine the dependence of changes in first- second forced expiratory volume upon the level of anti-inflammatory hormones cortisol and progesterone in female smokers with different number of cigarettes smoked. Materials and Methods. The study is based on the findings of the analysis of changes in the level of hormones cortisol and progesterone in 243 pregnant women in antenatal care and on how such changes affect the first-second forced exhalation volume. The control group consisted of healthy non-smoking female patients. 4 groups were formed. For each group, the expected values of the first-second forced exhalation volume were calculated, in parallel with changes in the cortisol and progesterone profile and with forming the relevant statistical data matrices. Results and Discussion. With an increase in cortisol and progesterone levels, there is an increase in the first-second of forced exhalation volume, which indicates an increase in the lung tissue elasticity and in the air flow rate in the first second under the influence of hormones that have a pronounced anti-inflammatory effect. Conclusion. Pregnancy progress in smokers consuming different amounts of cigarettes is accompanied by an increase in the cortisol and progesterone levels. Hormone fluctuations improve the functional state of external respiration in pregnant smokers with COPD, creating the illusion of preserving the physiological capabilities of lungs regardless of the number of cigarettes smoked. With this variant of the COPD developing during pregnancy, a temporary physiological increase in the anti-inflammatory hormonal profile masks the extent, to which the number of cigarettes smoked affects the COPD severity.

Towards intelligent workstations: Investigating the feasibility of Doppler radar sensors for personal respiratory quantification in thermal comfort

Along the line of research efforts utilizing occupant thermophysiological responses in operation of Heating, Ventilation, and Air-Conditioning (HVAC), this study assessed feasibility of Doppler Radar Sensors (DRSs) in quantifying respiration. Respiration has been known as one of the physiological processes which gets adjusted based on metabolic rate and DRSs are capable of capturing characteristics of periodic movements of chest/abdomen area induced by respiration. Accordingly, we have devised two approaches of quantifying respiration in context of thermoregulation states – by checking (1) frequency and intensity of the signal representing respiration (i.e., respiration state) and (2) ratio between exhale and inhale (i.e., respiratory ratio). With these, two experimental studies have been conducted with human subjects to evaluate reliability, applicability/sensitivity. Results showed that 60 s of a measurement time could provide reliability, which opens a chance to eliminate a validation process and respiration might not be a physiological response that rapidly gets activated for heat adjustment. Also, it has been shown that, with sufficient acclimation time (20 min), five out of eight participants increased respiration states in a high temperature setup and seven out of eight participants raised their respiratory ratios. In other words, individuals have different ways of utilizing respiration to deal with heat adjustment and acclimation time plays a key role in the use of respiration. Given DRSs' conventional application is occupancy detection, the versatility of DRSs has been shown and it contributes to realizing an intelligent workstation that is capable of contextualizing user's behaviors and perceptions.

Registration between 2D and 3D Ultrasound Images to Track Liver Blood Vessel Movement.

For the accurate positioning of surgical tools, conventional intraoperative navigation systems have been developed to recognize the relationship between target positions and the tools. However, since an internal organ is deformed during the operation, registration between realtime two-dimensional (2D) ultrasound images and three-dimensional (3D) CT or MRI images is not always effective. Therefore, this study developed image registration between 2D and 3D ultrasound images considering deformation for tracking target vessel movement in the liver. 3D ultrasound image was obtained in advance with 3D coordinates, including the target vessel. Then real-time 2D images and ultrasound probe position were simultaneously acquired using a 3D position sensor. We applied multiple image resolution registration, where rapid and fine optimizations can be expected at higher and lower levels, respectively. Meanwhile, the gradient descent method was adopted for the optimization, which determines the relative arrangements to obtain maximum similarity between 2D and 3D images. We experimentally established resolution level parameters using a phantom before applying it to track liver blood vessel movements in a normal healthy subject. Comparing the 2D images and the registered images, although the approach has some limitations in tracking large displacement, we confirmed that the cross-section of the target blood vessel was clearly visualized. This method has the potential for an ultrasound therapy targeting blood vessels under natural respiration conditions.

Laser‐Induced Hierarchical Microcone Arrays for Flexible Tactile Sensors with High Sensitivity and Ultrabroad Detection Range

Flexible tactile sensors have received widespread attention in many potential applications such as intelligence robots, the Internet of Things, and various wearable devices. However, most structure‐enhanced devices are in single‐patterns with limited improvement of sensitivity and working range. Herein, a double‐layered capacitive tactile sensor (DLCTS) with hierarchical microcone arrays, which consists of carbon nanotubes (CNTs) and polydimethylsiloxane (PDMS) is reported. Relying on its intrinsic hierarchical framework and optimized CNTs/PDMS ratios, the DLCTS exhibits an ultrabroad working range of 0–1400 kPa and a high sensitivity of 0.082 kPa−1. Moreover, this sensor shows favorable sensing performance with excellent durability (over 5500 cycles) and a fast response time (≈40 ms). Diverse powerful applications are demonstrated, including active monitoring of human elbow/knee flexion, respiratory state, walking mode, and convenient Morse code communication. It is envisioned that this sensor should be widely used in potential scenarios such as intelligent wearable devices and medical monitoring.

Al2(SO4)3 alters the antioxidant mitochondrial metabolism of Botritys cinerea and optimizes the production of cellulose and oxidative degrading enzymes

The enzymes produced by pathogenic fungi, especially Botritys cinerea, deserve specific attention due to the diversity of their applications, mainly in biofuel production, food processing, and the pharmaceutical industry. Thus, this work used Al2(SO4)3 as a stressor in order to evaluate if the stress levels caused by the concentrations of 100, 250, 500, and 1000 ppm were sufficient to increase the production of hydrolytic cellulolytic enzymes (FPase, CMCase, Avicelase, β-glucosidase, xylanase) and oxidative (laccase and manganese peroxidase). The study also evaluated the stress levels in previously treated mycelia of B. cinerea and whether they corresponded to the different states of mitochondrial respiration. Our study indicates that Al2(SO4)3 increased the production of cellulolytic and oxidative enzymes in all concentrations in a dose-dependent manner and that Al2(SO4)3 alters the mitochondrial respiratory rate, with lower ATP productions, indicating that less-coupled mitochondria were obtained and that this may be due to the increase of oxidative stress. Thus, it is plausible to suggest the use of Al2(SO4)3 in the production of cellulolytic enzymes, which could be used in the hydrolysis stage of second-generation ethanol production processes, as it reduces the time required for enzymatic expression applications in industrial processes.

Physiological changes of mitochondria under the diabetes condition and pharmacological approaches to eliminate them

The state of lipid peroxidation (LPO), respiration and oxidative phosphorylation, mitochondrial permeability transition pore (mPTP), and the antiradical activity of rat liver mitochondria in the streptozotocin (STZ)-induced diabetes condition were studied with the consideration of the ways of correcting detected membrane damages using gossitan isolated from the cotton plant Gossypium hirsutum L. It was shown that the rate of respiration of liver mitochondria in states V3 and V4 increases during STZ-induced diabetes, which significantly reduces the respiratory control (RC) and ADP/O coefficients in comparison with the control. The findings suggest that the uncoupling of respiration and oxidative phosphorylation takes place during STZ-induced diabetes. It was shown that in the STZ-induced diabetes condition, the rate of swelling of rat liver mitochondria is higher than that of the healthy ones; this means that mPTP of rat liver mitochondria is in the open state. Gossitan recovers mPTP to the normal condition, thereby removing the STZ effect on mitochondria. Gossitan (a personal dose is 10 mg/kg of body weight, during 8 days) eliminates the detected functional disorders of rat liver mitochondria, probably due to its antioxidant properties.

Numerical investigations of translocation characteristics of non-spherical silica nanoparticles across pulmonary surfactant monolayer under different respiratory states using coarse-grained molecular dynamics method

Understanding translocation characteristics of non-spherical silica nanoparticles (SiNPs) across pulmonary surfactant (PS) monolayer is of great significance for their applications in inhaled nanoparticles (NPs) drugs, as their shapes may impact drug delivery efficiency. Therefore, this study has performed coarse-grained molecular dynamics (CGMD) simulation to study the characteristics of SiNPs across the PS monolayer and adsorption of dipalmitoylphosphatidylcholine (DPPC) molecules. It is found that SiNPs smaller than 8 nm are more likely to cross the PS monolayer in expansion state than other states and crossing times required for ellipsoidal SiNPs are the shortest, and when SiNPs are in penetrating and embedding states, the number of DPPC molecules adsorbed by bulged-spherical SiNPs is the highest. In conclusion, ellipsoidal SiNPs have the strongest crossing ability and bulged-spherical SiNPs cause the greatest damage. Therefore, it is suggested to adopt ellipsoidal SiNPs and avoid bulged-spherical SiNPs when improving transportation efficiencies of spherical SiNP drug carriers.

Effects of Shenling Baizhu powder on intestinal microflora metabolites and liver mitochondrial energy metabolism in nonalcoholic fatty liver mice.

Non-alcoholic fatty liver disease (NAFLD) is characterised by the excessive accumulation of triglycerides in the liver. Shenling Baizhu powder (SLBZP) is formulated from various natural medicinal plants that protect the liver and are used to treat intestinal diseases. SLBZP improves the symptoms of NAFLD. However, its mechanism of action remains unclear. Herein, we investigated the ameliorative effect of SLBZP on model mice with high-fat-diet (HFD)-induced NAFLD. Additionally, we evaluated the impact of SLBZP on the intestinal flora and its metabolites and mitochondrial energy metabolism in NAFLD. We used HFD to establish a mouse model of NAFLD. Different drug interventions were administered. We measured serum biochemical indices. Liver sections were visualised with hematoxylin-eosin and oil red O staining. 16S rDNA amplicon sequencing technology was used to analyse the diversity and abundance of the intestinal flora. Short-chain fatty acids (SCFAs) in the intestinal contents were detected using GC-MS. Liver tissue was sampled to detect mitochondrial membrane functional indices. Western blotting was used to determine the levels of mitochondrial pathway-related proteins, namely, uncoupling protein 2 (UCP2), adenosine monophosphate-activated protein kinase (AMPK) and inhibitory factor 1 (IF1) of F1Fo ATP synthesis/hydrolase, in the liver. The spleen-invigorating classic recipe of SLBZP reduced liver lipid deposition in mice with HFD-induced NAFLD. Additionally, SCFAs produced by intestinal flora metabolism regulated the UCP2/AMPK/IF1 signalling pathway involved in liver mitochondrial energy metabolism to improve the liver mitochondrial membrane permeability, respiratory state and oxidative phosphorylation efficiency of mice with NAFLD. Finally, SLBZP increased the liver ATP level. Our results suggest that the therapeutic effect of SLBZP on NAFLD is related to the regulation of hepatic mitochondrial energy metabolism by intestinal flora and its metabolites and is possibly associated with the UCP2/AMPK/IF1 signalling pathway.

Transcutaneous Spinal Cord Stimulation Facilitates Respiratory Functional Performance in Patients with Post-Acute COVID-19.

A growing number of studies have reported Coronavirus disease (COVID-19) related to both respiratory and central nervous system dysfunctions. This study evaluates the neuromodulatory effects of spinal cord transcutaneous stimulation (scTS) on the respiratory functional state in healthy controls and patients with post-COVID-19 respiratory deficits as a step toward the development of a rehabilitation strategy for these patients. In this before-after, interventional, case-controlled clinical study, ten individuals with post-acute COVID-19 respiratory deficits and eight healthy controls received a single twenty-minute-long session of modulated monophasic scTS delivered over the T5 and T10 spinal cord segments. Forced vital capacity (FVC), peak forced inspiratory flow (PIF), peak expiratory flow (PEF), time-to-peak of inspiratory flow (tPIF), and time-to-peak of expiratory flow (tPEF), as indirect measures of spinal motor network activity, were assessed before and after the intervention. In the COVID-19 group, the scTS intervention led to significantly increased PIF (p = 0.040) and PEF (p = 0.049) in association with significantly decreased tPIF (p = 0.035) and tPEF (p = 0.013). In the control group, the exposure to scTS also resulted in significantly increased PIF (p = 0.010) and significantly decreased tPIF (p = 0.031). Unlike the results in the COVID-19 group, the control group had significantly decreased PEF (p = 0.028) associated with significantly increased tPEF (p = 0.036). There were no changes for FVC after scTS in both groups (p = 0.67 and p = 0.503). In post-COVID-19 patients, scTS facilitates excitation of both inspiratory and expiratory spinal neural networks leading to an immediate improvement of respiratory functional performance. This neuromodulation approach could be utilized in rehabilitation programs for patients with COVID-19 respiratory deficits.

Peripheral blood mononuclear cells exhibit increased mitochondrial respiration after adjuvant chemo- and radiotherapy for early breast cancer.

Adjuvant chemo- and radiotherapy cause cellular damage to tumorous and healthy dividing cells. Chemotherapy has been shown to cause mitochondrial respiratory dysfunction in non-tumorous tissues, but the effects on human peripheral blood mononuclear cells (PBMCs) remain unknown. We aimed to investigate mitochondrial respiration of PBMCs before and after adjuvant chemo- and radiotherapy in postmenopausal patients with early breast cancer (EBC) and relate these to metabolic parameters of the patients. Twenty-three postmenopausal women diagnosed with EBC were examined before and shortly after chemotherapy with (n = 18) or without (n = 5) radiotherapy. Respiration (O2 flux per million PBMCs) was assessed by high-resolution respirometry of intact and permeabilized PBMCs. Clinical metabolic characteristics and mitochondrial DNA (mtDNA) content of PBMCs (mtDN relative to nuclear DNA) were furthermore assessed. Respiration of intact and permeabilized PBMCs from EBC patients significantly increased with adjuvant chemo- and radiotherapy (p = 6 × 10-5 and p = 1 × 10-7 , respectively). The oxygen flux attributed to specific mitochondrial complexes and respiratory states increased by 17-43% compared to before therapy initiation. Similarly, PBMC mtDNA content increased by 40% (p = 0.002). Leukocytes (p = 0.0001), hemoglobin (p = 0.0003), and HDL cholesterol (p = 0.003) concentrations decreased whereas triglyceride (p = 0.01) and LDL (p = 0.02) concentrations increased after treatment suggesting a worsened metabolic state. None of the metabolic parameters or the mtDNA content of PBMCs correlated significantly with PBMC respiration. This study shows that mitochondrial respiration and mtDNA content in circulating PBMCs increase after adjuvant chemo- and radiotherapy in postmenopausal patients with EBC. Besides the increased mtDNA content, a shift in PBMC subpopulation proportions towards cells relying on oxidative phosphorylation, who may be less sensitive to chemotherapy, might influence the increased mitochondrial respiration observed iafter chemotherapy.

Investigating the interactions between multiple memory stores in the pond snail Lymnaea stagnalis.

The pond snail Lymnaea stagnalis exhibits various forms of associative learning including (1) operant conditioning of aerial respiration where snails are trained not to open their pneumostome in a hypoxic pond water environment using a weak tactile stimulus to their pneumostome as they attempt to open it; and (2) a 24 h-lasting taste-specific learned avoidance known as the Garcia effect utilizing a lipopolysaccharide (LPS) injection just after snails eat a novel food substance (carrot). Typically, lab-inbred snails require two 0.5 h training sessions to form long-term memory (LTM) for operant conditioning of aerial respiration. However, some stressors (e.g., heat shock or predator scent) act as memory enhancers and thus a single 0.5 h training session is sufficient to enhance LTM formation lasting at least 24 h. Here, we found that snails forming a food-aversion LTM following Garcia-effect training exhibited enhanced LTM following operant condition of aerial respiration if trained in the presence of the food substance (carrot) they became averse to. Control experiments led us to conclude that carrot becomes a 'sickness' risk signal and acts as a stressor, sufficient to enhance LTM formation for another conditioning procedure.

Non-contact cardiopulmonary signal monitoring based on magnetic eddy current induction.

The magnetic eddy current induction method has become an excellent solution for building home cardiopulmonary monitoring systems because of its non-contact and unobtrusive characteristics, but it has problems such as low precision and complex extraction of cardiopulmonary signals. Therefore, this paper designs a magnetic eddy current sensing system based on a Field Programmable Gate Array that can realize simultaneous real-time monitoring of cardiopulmonary signals. This system adopts a magnetic eddy current sensor design scheme that can improve the amount of cardiopulmonary information in the sensing signal. In addition, it uses a signal acquisition scheme that combines an inductance-to-digital converter (LDC) and oversampling technology to improve the resolution and signal-to-noise ratio of the sensing signal. Moreover, an optimized adaptive discrete wavelet transform algorithm is proposed in this system, which can realize the effective separation and extraction of cardiopulmonary signals in different respiration states. Comparing this system with the medical monitor, the cardiopulmonary signals obtained by the two have good consistency in the time-frequency domain. Under low motion, respiration rate and heart rate detected by this system are within the confidence interval of the 95% limit of agreement; the relative errors are less than 2.63% and 1.37%, respectively; and the accuracy rates are greater than 99.30% and 99.60%, respectively. In addition, an experiment with an asthmatic patient showed that the system still has good detection performance under pathological conditions and can monitor abnormal conditions such as coughing.

Respiratory system functional state in patients after the left ventricle geometric reconstruction followed by conventional respiratory rehabilitation

Respiratory system functional state in patients after the left ventricle geometric reconstruction followed by conventional respiratory rehabilitation

HYPERTENSION AND ANTIHYPERTENSIVE THERAPY IMPAIR RESPIRATORY FUNCTION

Objective: Tight relationship between respiratory and vascular system appear obvious and several studies showed an association between lung function and hypertension. Furthermore, antihypertensive treatment itself might have an effect on lung function. Thus, the aim of this study was to determine association of hypertension and its treatment with respiratory function. Design and method: In order to evaluate the respiratory system functional state in hypertensive patients we studied 107 patients (mean 49,5±2,7 years old) with mild (1st group), moderate (2nd group) essential hypertension (EH) and neurocirculatory hypertensive asthenia (3d group), for control we observed 30 healthy subjects (4th group). Furthermore, stratification of treatment non-compliant and compliant patients was made to observe the possible impact of antihypertensive treatment. All patients had no chronic respiratory disease in anamnesis and were randomized dependently from the blood pressure levels. Parameters of the respiratory system function were examined by computer spirography. Results: Such predictive and active parameters of computer spirography as Maximum Voluntary Ventilation (MVV), Forced Vital Capacity (FVC), Forced Expiratory Volume after 1s (FEV1), FEV1 as % of Inspiratory Vital Capacity (FEV1%VCIN), FEV1 as % of FVC (FEV1E), and Peak Inspiratory Flow (PIF) did not significantly differ between 1st, 3d and 4th observed groups. But in the 1st and a little bit less in the 3d groups data of active parameters mentioned above were insignificantly lower (p&gt;0.05) compared to healthy individuals. In the 2nd group patients MVV, FEV1%VCIN, FEV1E were uncertainly lower (p&gt;0.05) than in the 1st and 3d groups, but were still border-normal with tendency to forming combined respiratory and heart failure. Antihypertensive treatment was associated with a deterioration in FEV1 by -150.3±12.78 ml (p = 0.01) and in FVC by -190.2±20.05 ml (p&lt;0.01). With both high blood pressure and antihypertensive medication as individual variables in one regression model, only medication decreased FEV1 and FVC statistically significantly (p&lt;0.01). Conclusions: Thus, a tendency for aggravation of the active parameters of respiratory function in patients with arterial hypertension is dependent on the blood pressure levels and use of antihypertensive medications.

Measuring Expiratory Diaphragm Activity: An Electrifying Tool to Guide Positive End-Expiratory Pressure Strategy in Critically Ill Children?

Measuring Expiratory Diaphragm Activity: An Electrifying Tool to Guide Positive End-Expiratory Pressure Strategy in Critically Ill Children?

Impact of maximal exercise on immune cell mobilization and bioenergetics.

Acute aerobic exercise increases the number and proportions of circulating peripheral blood mononuclear cells (PMBC) and can alter PBMC mitochondrial bioenergetics. In this study, we aimed to examine the impact of a maximal exercise bout on immune cell metabolism in collegiate swimmers. Eleven (7 M/4F) collegiate swimmers completed a maximal exercise test to measure anaerobic power and capacity. Pre- and postexercise PBMCs were isolated to measure the immune cell phenotypes and mitochondrial bioenergetics using flow cytometry and high-resolution respirometry. The maximal exercise bout increased circulating levels of PBMCs, particularly in central memory (KLRG1+/CD57-) and senescent (KLRG1+/CD57+) CD8+ T cells, whether measured as a % of PMBCs or as absolute concentrations (all p < 0.05). At the cellularlevel, the routine oxygen flow (IO2 [pmol·s-1 ·106 PBMCs-1 ]) increased following maximal exercise (p = 0.042); however, there were no effects of exercise on the IO2 measured under the LEAK, oxidative phosphorylation (OXPHOS), or electron transfer (ET) capacities. There were exercise-induced increases in the tissue-level oxygen flow (IO2-tissue [pmol·s-1 ·mL blood-1 ]) for all respiratory states (all p < 0.01), except for the LEAK state, after accounting for the mobilization of PBMCs. Future subtype-specific studies are needed to characterize further maximal exercise's true impact on immune cell bioenergetics.

Application of N,N,N',N'-Tetramethyl-p-Phenylenediamine and α,ω-Hexadecanedioic Acid for Determination of the H+/O Ratios of Complexes III and IV of the Liver Mitochondrial Respiratory Chain under Free Respiration Conditions

Application of N,N,N',N'-Tetramethyl-p-Phenylenediamine and α,ω-Hexadecanedioic Acid for Determination of the H+/O Ratios of Complexes III and IV of the Liver Mitochondrial Respiratory Chain under Free Respiration Conditions

Interoceptive Awareness of the Breath Preserves Attention and Language Networks amidst Widespread Cortical Deactivation: A Within-Participant Neuroimaging Study.

Interoception, the representation of the body's internal state, serves as a foundation for emotion, motivation, and wellbeing. Yet despite its centrality in human experience, the neural mechanisms of interoceptive attention are poorly understood. The Interoceptive/Exteroceptive Attention Task (IEAT) is a novel neuroimaging paradigm that compares behavioral tracking of the respiratory cycle (Active Interoception) to tracking of a visual stimulus (Active Exteroception). Twenty-two healthy participants completed the IEAT during two separate scanning sessions (N = 44) as part of a randomized control trial of Mindful Awareness in Body-oriented Therapy (MABT). Compared to Active Exteroception, Active Interoception deactivated somatomotor and prefrontal regions. Greater self-reported interoceptive sensibility (MAIA scale) predicted sparing from deactivation within the anterior cingulate cortex (ACC) and left-lateralized language regions. The right insula-typically described as a primary interoceptive cortex-was only specifically implicated by its deactivation during an exogenously paced respiration condition (Active Matching) relative to self-paced Active Interoception. Psychophysiological interaction (PPI) analysis characterized Active Interoception as promoting greater ACC connectivity with lateral prefrontal and parietal regions commonly referred to as the Dorsal Attention Network (DAN). In contrast to evidence relating accurate detection of liminal interoceptive signals such as the heartbeat to anterior insula activity, interoceptive attention towards salient signals such as the respiratory cycle may involve reduced cortical activity but greater ACC-DAN connectivity, with greater sensibility linked to reduced deactivation within the ACC and language-processing regions.Significance StatementInteroception, the representation of the body's internal state, is poorly understood compared to the external senses, with existing neuroimaging studies failing to match task difficulty between interoceptive and exteroceptive tasks. The present study used a novel fMRI task to compare interoceptive and exteroceptive attention and explore whether this distinction was moderated by self-reported interoceptive awareness. The results implicate three novel interoceptive mechanisms: interoceptive attention reduces widespread cortical activity while increasing prefrontal connectivity, wherein greater self-reported interoceptive awareness is linked to preserved activation of the anterior cingulate cortex and language regions. Rather than increasing activation of interoceptive cortex, interoceptive attention to the breath may involve attending to body representations typically ignored in favor of exteroceptive information and other forms of cognition.