Gas Inhalation Research Articles

Decarbonisation of Fishing Vessels: Policy Challenges and Areas of Concern in View of Accident Investigation and Inspections

ABSTRACT Objective The fisheries sector is essential to the economies of developing countries, but it is a contributor to greenhouse gas emissions. Although emissions can be substantially reduced through energy efficiency measures, compliance with the Paris Agreement of 2015 requires further action through national frameworks for the decarbonization of fishing vessels. The objective of this paper is to explain the impact in greenhouse gas emissions from fishing vessels, discuss the possible regulatory indexes that could be made applicable to fishing vessels and how these ships can transition to alternative and low carbon fuels, identifying the main challenges in view of accident analysis and inspections. Methods It is recognized that mandatory indexes developed at the International Maritime Organisation are not feasible to apply, so new indexes are needed and possibly connected to fish captures. Most of these zero or near zero greenhouse gas emission fuels require technical and operational measures for accident prevention but, due to high rates of accidents related to fire, explosion and inhalation of gases, their use can lead to increase the rates of fatalities in an already dangerous profession. The main problem for their use is ventilation, enclosure of machinery spaces leading to preventive and design measures for the use of batteries and electricity and suitable training. Conclusion To avoid accidents, additional extra measures would be needed for fishing vessels. Therefore, to ease the transition towards new fuels those which are more similar to fossil marine diesels should be used; notwithstanding the use of other sources of energy such as solar and wind power.

Hydrogen gas inhalation ameliorates glomerular enlargement after hypoxic-ischemic insult in asphyxiated piglet model

Acute kidney injury (AKI) has been reported to occur in 30–70% of asphyxiated neonates. Hydrogen (H2) gas became a major research focus in neonatal medicine after the identification of its robust antioxidative properties. However, the ability of H2 gas to ameliorate AKI is unknown. We examined histopathological injuries in the piglet renal cortex on day 5 after a hypoxic-ischemic (HI) insult and if H2 gas can alleviate kidney injuries. Twenty piglets were divided into three groups: no insult (Control, n = 6), HI insult alone (HI, n = 8), and HI insult with H2 gas ventilation (HI-H2, 2.1–2.7% for 24 h, n = 6). The total glomerular cell count was significantly higher in the HI group than in the other groups, with no difference between the HI-H2 and control groups. Proximal tubular lumen narrowing was significantly increased in the HI group versus control, but not in the HI-H2 group. In this piglet model, glomerular enlargement with an increase in glomerular cell number due to tubular lumen narrowing was observed on day 5 after HI insult. H2 gas effectively suppressed this glomerular cell increase and tubular lumen narrowing.

Simultaneous assessment of cerebral glucose and oxygen metabolism and perfusion in rats using interleaved deuterium (2H) and oxygen-17 (17O) MRS.

Cerebral glucose and oxygen metabolism and blood perfusion play key roles in neuroenergetics and oxidative phosphorylation to produce adenosine triphosphate (ATP) energy molecules in supporting cellular activity and brain function. Their impairments have been linked to numerous brain disorders. This study aimed to develop an in vivo magnetic resonance spectroscopy (MRS) method capable of simultaneously assessing and quantifying the major cerebral metabolic rates of glucose (CMRGlc) and oxygen (CMRO2) consumption, lactate formation (CMRLac), and tricarboxylic acid (TCA) cycle (VTCA); cerebral blood flow (CBF); and oxygen extraction fraction (OEF) via a single dynamic MRS measurement using an interleaved deuterium (2H) and oxygen-17 (17O) MRS approach. We introduced a single-loop multifrequency radio-frequency (RF) surface coil that can be used to acquire proton (1H) magnetic resonance imaging (MRI) or interleaved low-γ X-nuclei 2H and 17O MRS. By combining this RF coil with a modified MRS pulse sequence, 17O-isotope-labeled oxygen gas inhalation, and intravenous 2H-isotope-labeled glucose administration, we demonstrate for the first time the feasibility of simultaneously and quantitatively measuring six important physiological parameters, CMRGlc, CMRO2, CMRLac, VTCA, CBF, and OEF, in rat brains at 16.4T. The interleaved 2H-17O MRS technique should be readily adapted to image and study cerebral energy metabolism and perfusion in healthy and diseased brains.

Enhanced cardiac vagal activity and mood after low-dose hypoxic gas inhalation in healthy young adults.

Developing strategies to enhance cardiac vagal activity (CVA) is essential for improving mood and managing stress. Although hypoxia inhalation may boost CVA, the optimal acute hypoxic conditions remain unclear. Therefore, we aimed to achieve a comprehensive understanding of the hypoxic conditions required to improve CVA and mood following hypoxia. Twenty-one healthy adults participated in both normobaric hypoxic (NH; FIO2: 13.5%) and normoxic (NN; FIO2: 20.9%) conditions. We monitored heart rate variability (HRV), percutaneous oxygen saturation (SpO2), and mood across pre-, hypoxia, and post-sessions and assessed psychophysiological stress using the Baevsky Stress Index (SI). Under hypoxia, SpO2 decreased to 88.1%, accompanied by reductions in vagally-mediated HRV, followed by supercompensation post-hypoxia. Additionally, mood declined during hypoxia but rapidly rebounded, correlating with CVA and SI fluctuations. These results indicate that acute low-dose hypoxic gas inhalation at FIO2: 13.5% enhances CVA and mood post-hypoxia, offering a practical method for building resilience.

Hydrogen gas inhalation prior to high-intensity training reduces attenuation of nitric oxide bioavailability in male rugby players.

Inhalation of hydrogen gas (H2) as an antioxidant supplement may alleviate exercise-induced oxidative damage and protect post-exercise hydrogen peroxide signaling, which may help mediate beneficial exercise adaptation. The aims of this study were to determine the effects of H2 inhalation on plasma nitric oxide (NO) level and its synthesis precursor in professional athletes. A randomized, placebo-controlled, double-blind, crossover trial was conducted with professional male rugby players for 3 weeks. Participants underwent 1 week of H2 supplementation and 1 week of placebo treatment prior to daily sessions of high-intensity exercise training, separated by 1 week of low-intensity training as a washout. Two-way (supplementation and time) repeated-measures analyses of variance showed that NO, L-arginine, and tetrahydrobiopterin levels in the H2 inhalation group were significantly higher than those in the placebo group after exercise (D6) and remained higher after 24 h of rest (D7). Levels of hydroxydeoxyguanosine and interleukin 6 were lower in the H2 inhalation week than in the placebo week on D6 and D7. In addition, total antioxidant levels were significantly higher with H2 inhalation than with placebo. These results suggest that H2 inhalation helps to maintain NO signaling after exercise and to alleviate inflammation and oxidative stress induced by high-intensity exercise training in professional athletes.

Characterising the anxiogenic network from functional connectivity analysis of the CO2 challenge model

The CO2 challenge model (CCM) is a gas inhalation paradigm that provides precisely controlled anxiety induction in experimental settings. Despite its potential as an experimental model of anxiety, our understanding of the neural effects of the CCM is incomplete. This study employs resting-state functional magnetic resonance imaging (rs-fMRI) to explore functional connectivity (FC) changes underlying the CCM. Following a preliminary CO2 tolerance assessment, participants completed an MRI session that included three rs-fMRI scans: during inhalation of control air (pre and post), and during a 6% CCM exposure. Here, we confirm that 6% CCM is a tolerable anxiogenic model in the MRI setting. We demonstrate that a transient CCM-induced increase in subjective anxiety is associated with an increase in FC within limbic and anxiety-related regions, with the insula emerging as a central node in this altered connectivity pattern. Further analysis revealed a significant correlation between the levels of subjective anxiety and enhanced FC between the brainstem and medial frontal cortex, highlighting the dynamic role of the brainstem in response to CO2-induced anxiety. These findings underscore the value of combining CCM and rs-fMRI to characterise the neural mechanisms of anxiety, with important implications for evaluating potential therapeutic interventions.

Quantifying the Pulmonary Risks of Volcanic Gas Inhalation: A Meta-Analysis

Background: Volcanic eruptions release a complex mixture of gases and particulate matter, posing significant respiratory health risks. This meta-analysis aims to quantify the association between volcanic gas inhalation and adverse pulmonary effects. Methods: A systematic search of PubMed, Scopus, and Web of Science was conducted for studies published between 2013 and 2024 investigating the respiratory effects of volcanic gas exposure. Studies reporting quantitative data on lung function, respiratory symptoms, or disease prevalence were included. Random-effect models were used to pool effect estimates, and heterogeneity was assessed using the I² statistic. Results: Six studies (n = 2,215 participants) met the inclusion criteria. Volcanic gas exposure was associated with a significant decrease in FEV1 (forced expiratory volume in 1 second) (standardized mean difference [SMD] = -0.55, 95% CI: -0.67 to -0.42, I² = 51%), increased prevalence of asthma (odds ratio [OR] = 3.31, 95% CI: 1.84 to 5.96, I² = 76%), and chronic bronchitis (OR = 2.86, 95% CI: 1.97 to 4.15, I² =0%). Subgroup analysis revealed a stronger association between gas exposure and respiratory effects in children and individuals with pre-existing lung conditions. Conclusion: This meta-analysis provides compelling evidence that volcanic gas inhalation is detrimental to respiratory health. Public health interventions should prioritize vulnerable populations during and after volcanic eruptions.

Hypoxic irreversible brain cells damage, associated risk factors and antihypoxants

It is reported that in the final stage of many diseases the immediate cause of biological death in humans and warm-blooded animals is hypoxic irreversible damage to brain cells. This explains the fact that to prevent biological death in all critical conditions without exception, inhalation with breathing gases containing oxygen has long been successfully used. This is also why oxygenation of the blood is considered one of the main conditions for preserving human life in all critical situations and forms the basis of emergency medical care in the intensive care unit. However, inhalation of oxygen gas and increasing blood oxygen saturation should be carried out as early as possible, and more precisely — before the onset of the stage of hypoxic irreversible damage in brain cells. The fact is that after the onset of irreversible da­mage brain cells die even in the presence of oxygen. In this connection, the mechanisms of adaptation of the organism to oxygen deficiency play a great role for longer preservation of brain cells viability and human life in conditions of hypoxemia. In order to increase resistance to hypoxemia, antihypoxants are traditionally used. But they can preserve the viability of brain cells not always, but only if they are introduced into the body before the onset of hypoxic irreversible damage to brain cells and in the case of unused reserves of adaptation to hypoxemia in the body. Risk factors of hypoxic irreversible damage of brain cells are indicated, among which excessively long duration of hypoxemia and hyperthermia are emphasized. It is shown that the most important circumstance for the development of hypoxic irreversible damage of brain cells is not so much the degree of hypoxemia as the degree of hypoxia of brain tissue and its duration, which exceeds the period of human resistance to hypoxia. It has been shown that human resistance to hypoxia can be assessed using the Stange test. It has been reported that fever and local cerebral hyperthermia decrease, and hibernation and local cerebral hypothermia increase, the resistance of brain cells to hypoxia. In this regard, recommendations not only to eliminate fever and local inflammatory processes in the head, but also recommendations to reduce brain temperature are highly appropriate to improve resistance to hypoxia. It is pointed out that among the methods of local therapeutic hypothermia, targeted temperature management is the most advanced. In addition, it is reported that in recent years a new group of promising antihypoxants — alkaline solutions of hydrogen peroxide — has been created. It is shown that hydrogen peroxide is able to decompose very quickly into water and oxygen gas under the action of catalase, which is found in all tissues. The peculiarities of using alkaline solutions of hydrogen peroxide as antihypoxants we all have to study in the future.

The strategy of using heme proteins and synthetic porphyrins as injectable antidotes for fire gas poisoning

Abstract During fire accidents, 2 highly toxic components of fire smoke, carbon monoxide (CO) and hydrogen cyanide (HCN), are produced simultaneously, and more than 50% of fire-related deaths can be attributed to the inhalation of these toxic gases. Despite the different CO and HCN detoxification mechanisms, oxygen (O2) ventilation is currently the primary clinical treatment, and no alternative methods are available at present. In this review, the toxicological mechanisms of CO and HCN are investigated with an emphasis on the toxic effects of their combination. On the basis of these toxic mechanisms, the advantages and disadvantages of the current clinical detoxification methods are analyzed and discussed. We also summarize the latest advancements in the development of CO- and HCN-scavenging antidotes, highlighting the strategy of using synthetic iron porphyrins that have been synthesized mainly in our laboratory as water-soluble synthetic hemoglobin biomimetics.

THE IMPACT OF PHOSPHORUS WEAPONS DURING A FULL-SCALE WAR

Due to military actions, there is destruction of Ukraine's ecosystems, deterioration of sanitary and hygienic indicators of drinking water, air, and soil. With the onset of full-scale war, the negative impact of harmful and dangerous substances (the use of chemical, phosphorus bombs, and other weapons) prohibited by the Geneva Convention leads to unforeseen consequences for the environment of Ukraine. The purpose of the study is to analyze injuries resulting from the action of white phosphorus of various types of phosphorus weapons, namely explosive weapons with a wide area of effect, mines, ammunition, long-range missiles; artillery, mortar shells, various types of grenades in the conditions of russian aggression against Ukraine. The following methods were used in the work: content analysis, comparative analysis, and systematization of the researched material. Research of scientific publications by domestic and foreign scientists using the PubMed and Google Scholar databases for the period 2001-2023 was conducted. Phosphorus munitions such as WP are known for their high effectiveness in combat operations, but also lead to serious injuries, both traumatic and post-traumatic psychological changes. White phosphorus (explosive bombs) causes burns of human body tissues upon contact with burning material, as well as burns of the upper respiratory tract due to inhalation of smoke or gases emitted during combustion. The article analyzes the regulatory framework prohibiting the use of phosphorus munitions in armed conflicts. Clinical cases of gunshot combined injuries of limbs with massive soft tissue defects, gunshot fractures, and the presence of multiple foreign bodies of metal density due to the use of phosphorus munitions are considered. An analysis of scientific research by foreign scientists on this issue was conducted. The article provides algorithms for providing first aid due to the action of phosphorus munitions, as well as methodological recommendations of the Ministry of Health of Ukraine (Order of the Ministry of Health of Ukraine No. 506 of March 20, 2022) for providing medical assistance at the prehospital stage in case of phosphorus munition injuries, burns, enteral poisoning, exposure to white phosphorus in the eyes.

Mild hypercapnia before reperfusion reduces ischemia-reperfusion injury in hyperacute ischemic stroke rat model.

Endovascular thrombectomy has a recanalization rate over 80%; however, approximately 50% of ischemic stroke patients still experience dependency or mortality. Recently, clinical trials demonstrated the benefits of administering neuroprotective agents prior to endovascular thrombectomy. Additionally, recent studies showed neuroprotective effects of mild hypercapnia in patients resuscitated after cardiac arrest. However, its efficacy in ischemic stroke remains unclear. We aimed to investigate whether carbon dioxide (CO2) per-conditioning has neuroprotective effects in rat models with middle cerebral artery occlusion (MCAO). Rat models received intermittent inhalation of mixed gas during the MCAO period. After surgery, behavioral assessments, infarct size measurement, immunohistochemistry, and western blot analysis were performed. We found CO2 per-conditioning reduced infarct size and neurological deficit. The number of 8-hydroxy-2-deoxyguanosine (8-OHdG) positive cells and matrix metalloproteinase 9 (MMP-9)/platelet derived growth factor receptor beta (PDGFRβ) double positive cells were significantly decreased after CO2 per-conditioning. The expressions of tight junction protein and pericytes survival were preserved. This study underscores mild hypercapnia before reperfusion not only reduces neurologic deficit and infarct size, but also maintains the integrity of the blood-brain barrier and neurovascular unit, alongside mitigating oxidative stress in hyperacute stroke rat models. Therapeutic mild hypercapnia before reperfusion is promising and requires further clinical application.

A Review on Nanotechnological Approaches for the Management of Stored Insect-Pests: Present Scenario and Future Prospects

Approximately 10% to 30% of the stored agricultural produce is damaged out of which 26% is due to insect-pest infestation thus seriously impacting the food security. The infestation also leads to loss of quality and thereby affecting the overall profitability. In absence of enough storage space, usually farmers dispose-off their produce immediately after harvest and thus do not get remunerative prices. For those opting for storage, physical and chemical methods are in vogue to manage the storage insect-pests. Fumigation with chemical pesticides such as methyl bromide and aluminium phosphide is a common method, though it has its own health and environmental risks. Inhalation of phosphine gas released when aluminium phosphide is used could seriously affect human animal health, sometimes leading to deaths. Thus for using these fumigants, strict supervision of government recognized experts is required. Due to their wide usage, some insect-pests have developed resistance against these molecules. Nanotechnology has created numerous new opportunities in agriculture and allied sectors. Insecticide formulations based on nanotechnology could be a viable alternative to toxic chemicals like aluminium phosphide to manage storage insect-pests. In recent years, a variety of formulations including solid nanopesticides, controlled-release formulations, nano-emulsions, and nano-suspensions have been developed possessing different modes of actions and applications. Their small size is a significant advantage because it provides higher insect-body surface area coverage and thus enhanced efficacy as compared to traditional pesticides. Aside from their small size, they are reported to be safe for non-target beneficial organisms. Nano-pesticides can thus prove as effective and eco-friendly alternatives for insect pest control in storage. However, there is a need to establish their safety on the human and animal ecosystems to rule out their ecological hazards over time. In absence of such information, nanopesticides will not be widely accepted despite their other beneficial effects. In this article, an effort is made to review the current status of nano-formulations for the management of storage-insect-pests, the research and extension gaps and ways to bridge the gaps to ensure safe use of the technology for efficient management of postharvest storage losses.

Effect of Pilates exercises on pulmonary function, respiratory muscle strength, and functional capacity in patients with inhalation injury after flame thermal burn: A prospective randomized controlled trial

BackgroundInhalation injury is an acute respiratory tract injury that occurrs by inhalation of smoke, toxic gases, or steam. Early management is needed to reduce its mortality and morbidity. The purpose of this study was to ascertain whether Pilates training could help burn patients with inhalation injury after flame thermal burn in increasing pulmonary function, respiratory muscle strength, and functional ability. MethodsIn this prospective, randomized, controlled trial, sixty participants (26 males and 34 females) with inhalation injury and deep partial-thickness flame burns of 30–40 % total body surface area (TBSA) were randomized in blocks of four, with a 1:1 allocation ratio into two groups: Group A (Pilates Group); received Pilates training plus conventional physical therapy program, and Group B (Control Group); received conventional physical therapy program only. This study was conducted at the Faculty of Physical Therapy's outpatient clinic, Cairo University, 3 sessions/week for 12 weeks. The primary outcome measure was the forced vital capacity (FVC) measured by a spirometer, while the secondary outcome measures were peak expiratory flow rate (PEFR), forced expiratory volume in 1 s (FEV1), FEV1/FVC% assessed by a spirometer, strength of respiratory muscles (maximum inspiratory pressure (MIP) and maximum expiratory pressure (MEP) assessed by the digital manovacuometer, and the functional capacity evaluated by 6-Minute Walk Test (6-MWT). ResultsA two-way mixed-design MANOVA was used to analyze the results within and between groups. There were no significant differences in demographic data between groups (P > 0.05). There were significant differences in all variables after treatment in group A compared with group B; FVC (95 % CI: 0.38, 1.13) (P = 0.001), FEV1 (95 % CI: 0.39, 0.97) (P = 0.001), FEV1/FVC % (95 % CI: 1.90, 17.19) (P = 0.02), PEFR (95 % CI: 0.47, 0.99) (P = 0.001), MIP (95 % CI: 5.12, 11.44) (P = 0.001), MEP (95 % CI: 2.57, 8.24) (P = 0.001), 6-MWT (95 % CI: 27.22, 54.96) (P = 0.001), FVC (% predicted) (95 % CI: 3.58, 12.58) (P = 0.001), FEV1 (% predicted) (95 % CI: 1.21, 11.11) (P = 0.02), PEFR (% predicted) (95 % CI: 1.33, 10.83) (P = 0.01), MIP (% predicted) (95 % CI: 2.26, 11.72) (P = 0.001) and MEP (% predicted) (95 % CI: 1.33, 10.37) (P = 0.01). ConclusionThe current study demonstrated that a Pilates exercise program in addition to a traditional physical therapy program for 12 weeks significantly improved the pulmonary function (FVC, FEV1, PEFR and FEV1/FEV), strength of respiratory muscles (MIP and MEP), and functional capacity (6-MWT) in patients with inhalation injury after flame burns. These results underscore the importance of including Pilates exercises in the rehabilitation plan for burn patients with inhalation injury. Future studies are needed to evaluate the effect of Pilates exercises on other degrees and TBSA of burn, long-term follow up, and to measure cardiopulmonary parameters.

Clinical characteristics and toxicological spectrum analysis of 493 cases of acute poisoning in children

ObjectiveThis retrospective study aimed to analyze the clinical characteristics and toxicological spectrum of acute poisoning in children treated at our pediatric intensive care unit. The findings provide a basis for the treatment and prevention of acute poisoning in children.MethodsClinical data of hospitalized children aged 0 to14 years with acute poisoning, treated between January 2015 and December 2023, were collected and analyzed. The analysis included the types of poisoning, sex and age distribution of children, routes and causes of poisoning, time from poisoning to medical consultation, length of hospital stays, and treatment outcomes.ResultsAmong the 493 cases of acute poisoning in children, pesticide poisoning (n = 252, 51.1%) was the most common type, followed by medication poisoning (n = 182, 36.9%). Chemical poisoning accounted for 7.7% (n = 38), while food poisoning and inhalation of harmful gases accounted for 3.0% (n = 15) and 1.2% (n = 6), respectively. The main route of poisoning was oral ingestion (n = 477, 96.8%), while accidental ingestion accounted for a large proportion (n = 379, 79.4%), and adolescents aged 11 to 14 years accounted for 20.6% (n = 98).Apart from the predominance of girls attempting suicide by self-administering antipsychotic medications (n = 88, 75.9%) due to depression, there was no significant difference in sex distribution among other types of poisoning children. The highest incidence of poisoning except children who self-administer antipsychotic drugs occurred in children aged 1–3 years (n = 267, 54.2%) and 8–14 years (n = 135, 27.4%), with the highest proportion in the preschool age group. The average time from poisoning to medical consultation was 33.4 ± 54.9 h, and majority of children received treatment within 48 h after poisoning (n = 423, 85.8%). The overall effective treatment rate was 96.8%.ConclusionAcute poisoning in children has complex and diverse causes, with accidental ingestion being the main route. Prevention should be emphasized, including strengthening child safety education and improving parental supervision. Moreover, psychological health education is crucial for adolescents during their puberty. In the event of acute poisoning, prompt medical consultation and appropriate treatment are necessary to mitigate adverse outcomes.

Sulforaphane attenuates phosgene-induced acute lung injury via the Nrf2-HO-1/NQO1 pathway.

Sulforaphane (SFN) has been demonstrated to exert a protective role in various diseases. However, the role of SFN in phosgene-induced acute lung injury (P-ALI) remains unclear. This study aimed to explore the role and mechanism of SFN in P-ALI and provide a theoretical basis for the clinical prevention and treatment of P-ALI. A mouse model of P-ALI was established followed by phosgene gas inhalation at a dose of 4.17 g/m3 for 5 min. The survival rate, lung coefficient and hematoxylin and eosin (H&E) staining, lung pathology scoring, and bronchoalveolar lavage fluid (BALF) analysis were performed to evaluate lung tissue damage. The real-time quantitative polymerase chain reaction (RT-qPCR) and Western blotting analysis were utilized to evaluate the relative expression levels of inflammation factors and protein expression. Compared with the control group, destruction of alveolar structure, pulmonary edema, lung tissue inflammation and oxidative stress occurred after phosgene exposure. After the administration of SFN, the massive exudation of red blood cells and significant thickening of alveolar interstitium were ameliorated, the lung tissue inflammation was improved, and oxidative stress level was reduced. Mechanically, SFN could increase the expression of nuclear factor erythroid 2 (NFE2)-related factor 2 (Nrf2) protein and the downstream heme oxgenase-1 (HO-1) and NAD(P)H:quinone oxidoreductase 1 (NQO1), thereby improving P-ALI. And the Nrf2 inhibitor ML385 attenuated the lung protective effect of SFN. Phosgene inhalation led to edema, inflammation, and oxidative stress of lung tissue in mice. SFN might ameliorate phosgene-induced lung injury through Nrf2-HO-1/NQO1 signaling pathway.

Measurement and modeling of xenon gas transfer in the human brain with 1H and hyperpolarized 129Xe MRI

BackgroundThe feasibility of imaging hyperpolarized 129Xe dissolved in brain tissue following inhalation of xenon gas in the lungs has recently been demonstrated in humans. The image contrast in 129Xe brain MRI represents a combination of factors, including regional perfusion, polarization decay and gas transfer rate across the blood-brain barrier. PurposeTo investigate the repeatability of hyperpolarized 129Xe brain MRI in healthy normal individuals and to identify the dominant mechanisms of image contrast by assessing voxel-wise correlation between HP 129Xe brain MRI and models of 129Xe brain uptake derived from 1H arterial spin labeling (ASL) perfusion mapping. Materials and MethodsTo assess repeatability, 3 sets of hyperpolarized 129Xe brain images were acquired from 5 healthy volunteers. Quantitative maps of the human brain, including cerebral blood flow, volume and predicted xenon uptake, were derived from 1H arterial spin labeling and T2-weighted MRI. These maps were then spatially cross-correlated with hyperpolarized 129Xe brain MRI. ResultsSignal to noise ratios of 8.7–17.7 were observed across volunteers for a voxel size of 8 × 8 × 50 mm3 with intra-subject repeatability of between 6 and 29 %. Hyperpolarized 129Xe brain images showed voxel-wise correlations with cerebral blood flow (R = 0.32 to 0.62), volume (R = 0.33 to 0.63) and predicted xenon uptake (R = 0.34 to 0.63), but did not correlate with arterial transit time (R = 0.05 to 0.26). ConclusionVoxel-wise cross correlation between 129Xe and 1H ASL suggests that the regional quantity of dissolved xenon delivered by cerebral blood flow is the dominant mechanism of image contrast in HP 129Xe brain MRI, assuming normal blood-brain barrier function. Combining 1H and 129Xe brain MRI provides new opportunities to quantitatively investigate brain pathophysiology and function.

Natural hydrogen gas and engineered microalgae prevent acute lung injury in sepsis

BackgroundHydrogen gas and microalgae both exist in the natural environment. We aimed to integrate hydrogen gas and biology nano microalgae together to expand the treatment options in sepsis. MethodsPhosphoproteomics, metabolomics and proteomics data were obtained from mice undergoing cecum ligation and puncture (CLP) and inhalation of hydrogen gas. All omics analysis procedure were accordance with standards. Multi R packages were used in single cell and spatial transcriptomics analysis to identify primary cells expressing targeted genes, and the genes’ co-expression relationships in sepsis related lung landscape. Then, network pharmacology method was used to identify candidate drugs. We used hydrophobic-force-driving self-assembly method to construct dihydroquercetin (DQ) nanoparticle. To cooperate with molecular hydrogen, ammonia borane (B) was added to DQ surface. Then, Chlorella vulgaris (C) was used as biological carrier to improve self-assembly nanoparticle. Vivo and vitro experiments were both conducted to evaluate anti-inflammation, anti-ferroptosis, anti-infection and organ protection capability. ResultsAs a result, we identified Esam and Zo-1 were target phosphorylation proteins for molecular hydrogen treatment in lung. Ferroptosis and glutathione metabolism were two target pathways. Chlorella vulgaris improved the dispersion of DQB and reconstructed morphological features of DQB, formed DQB@C nano-system (size = 307.3 nm, zeta potential = −22mv), with well infection-responsive hydrogen release capability and biosafety. In addition, DQB@C was able to decrease oxidative stress and inflammation factors accumulation in lung cells. Through increasing expression level of Slc7a11/xCT and decreasing Cox2 level to participate with the regulation of ferroptosis. Also, DQB@C played lung and multi organ protection and anti-inflammation roles on CLP mice. ConclusionOur research proposed DQB@C as a novel biology nano-system with enormous potential on treatment for sepsis related acute lung injury to solve the limitation of hydrogen gas utilization in clinics.

Inhalation of Hydrogen-rich Gas before Acute Exercise Alleviates Exercise Fatigue: A Randomized Crossover Study.

Hydrogen, as an antioxidant, may have the potential to mitigate fatigue and improve selected oxidative stress markers induced by strenuous exercise. This study focused on a previously unexplored approach involving pre-exercise inhalation of hydrogen-rich gas (HRG). Twenty-four healthy adult men first completed pre-laboratories to determine maximum cycling power (Wmax) and maximum cycling time (Tmax). Then they were subjected to ride Tmax at 80% Wmax and 60-70 rpm on cycle ergometers after inhaled HRG or placebo gas (air) for 60-minute in a double-blind, counterbalanced, randomized, and crossover design. The cycling frequency in the fatigue modeling process and the rating of perceived exertion (RPE) at the beginning and end of the ride were recorded. Before gas inhalation and after fatigue modeling, visual analog scale (VAS) for fatigue and counter-movement jump (CMJ) were tested, and blood samples were obtained. The results showed that compared to a placebo, HRG inhalation induced significant improvement in VAS, RPE, the cycling frequency during the last 30 seconds in the fatigue modeling process, the ability to inhibit hydroxyl radicals, and serum lactate after exercise (p<0.028), but not in CMJ height and glutathione peroxidase activity. The cycling frequency during the last 30 seconds of all other segments in the fatigue modeling process was within the range of 60-70 rpm. In conclusion, HRG inhalation prior to acute exercise can alleviate exercise-induced fatigue, maintain functional performance, and improve hydroxyl radical and lactate levels.

Release of ATP in the lung evoked by inhalation of irritant gases in rats.

Adenosine triphosphate (ATP) can be released into the extracellular milieu from various types of cells in response to a wide range of physical or chemical stresses. In the respiratory tract, extracellular ATP is recognized as an important signal molecule and trigger of airway inflammation. Chlorine (Cl2), sulfur dioxide (SO2), and ammonia (NH3) are potent irritant gases and common industrial air pollutants due to their widespread uses as chemical agents. This study was carried out to determine if acute inhalation challenges of these irritant gases, at the concentration and duration simulating the accidental exposures to these chemical gases in industrial operations, triggered the release of ATP in the rat respiratory tract; and if so, whether the level of ATP in bronchoalveolar lavage fluid (BALF) evoked by inhalation challenge of a given irritant gas was elevated by chronic allergic airway inflammation. Our results showed: 1) inhalation of these irritant gases caused significant increases in the ATP level in BALF, and the magnitude of evoked ATP release was in the order of Cl2 > SO2 > NH3. 2) Chronic airway inflammation induced by ovalbumin-sensitization markedly elevated the ATP level in BALF during baseline (breathing room air) but did not potentiate the release of ATP in the lung triggered by inhalation challenges of these irritant gases. These findings suggested a possible involvement of the ATP release in the lung in the regulation of overall airway responses to acute inhalation of irritant gases and the pathogenesis of chronic allergic airway inflammation.NEW & NOTEWORTHY Extracellular adenosine triphosphate (ATP) is a contributing factor and signaling molecule of airway inflammation. This study demonstrated for the first time that the ATP release in the lung was markedly elevated after acute inhalation challenges of three common industrial air pollutants; the order of the response magnitude was chlorine > sulfur dioxide > ammonia. These findings provided new information and improved our understanding of the adverse pulmonary effects caused by accidental inhalation exposures to these irritant gases.

Quantitative assessment of chlorine gas inhalation injury based on endoscopic OCT and spectral encoded interferometric microscope imaging with deep learning.

Chlorine exposure can cause severe airway injuries. While the acute effects of chlorine inhalation are well-documented, the structural changes resulting from the post-acute, high-level chlorine exposure remain less understood. Airway sloughing is one of the standards for doctors to evaluate the lung function. Here, we report the application of a high-resolution swept-source optical coherence tomography system to investigate the progression of injury based on airway sloughing evaluation in a chlorine inhalation rabbit model. This system employs a 1.2mm diameter flexible fiberoptic endoscopic probe via an endotracheal tube to capture in vivo large airway anatomical changes before and as early as 30minafter acute chlorine exposure. We conducted an animal study using New Zealand white rabbits exposed to acute chlorine gas (800 ppm, 6min) during ventilation and monitored them using optical coherence tomography (OCT) for 6h. To measure the volume of airway sloughing induced by chlorine gas, we utilized deep learning for the segmentation task on OCT images. The results showed that the volume of chlorine induced epithelial sloughing on rabbit tracheal walls initially increased, peaked around 30min, and then decreased. Furthermore, we utilized a spectral encoded interferometric microscopy system to study ex vivo airway cilia beating dynamics based on Doppler shift, aiding in elucidating how chlorine gas affects cilia beating function. Cilia movability and beating frequency were decreased because of the epithelium damage. This quantitative approach has the potential to enhance the diagnosis and monitoring of injuries from toxic gas inhalation and to evaluate the efficacy of antidote treatments for these injuries.