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The quantitative and qualitative composition of volatile organic compounds (VOCs) of human exhaled air, the air environment of various types of entomopathogenic fungi (EPF) of the genus Lecanicillium, used as an alternative to chemical pesticides to protect plants from pests, cabbage moth caterpillars, as well as spined soldier bug from the shield family, was studied using a quadrupole mass spectrometer. The main components found were acetone, acetic acid, and isoprene. These components in human exhalation are significant indicators for non-invasive disease diagnosis. For the first time, sulfur dioxide was found in the composition of VOC EPF, as one of the possible repellents. The caterpillars of cabbage moth secrete exclusively acetic acid. [ABSTRACT FROM AUTHOR]

The review is aimed on the analysis the abilities of noninvasive diagnostics and monitoring of diabetes mellitus (DM) and DM‐associated complications through volatile molecular biomarkers detection in the exhaled breath. The specific biochemical reactions in the body of DM patients and their associations with volatile molecular biomarkers in the breath are considered. The applications of optical spectroscopy methods, including UV, IR, and terahertz spectroscopy for DM‐associated volatile molecular biomarkers measurements, are described. The applications of similar technique combined with machine learning methods in DM diagnostics using the profile of DM‐associated volatile molecular biomarkers in exhaled air or "pattern‐recognition" approach are discussed. [ABSTRACT FROM AUTHOR]

The field of organic-borne biomarkers has been gaining relevance due to its suitability for diagnosing pathologies and health conditions in a rapid, accurate, non-invasive, painless and low-cost way. Due to the lack of analytical techniques with features capable of analysing such a complex matrix as the human breath, the academic community has focused on developing electronic noses based on arrays of gas sensors. These sensors are assembled considering the excitability, sensitivity and sensing capacities of a specific nanocomposite, graphene. In this way, graphene-based sensors can be employed for a vast range of applications that vary from environmental to medical applications. This review work aims to gather the most relevant published papers under the scope of "Graphene sensors" and "Biomarkers" in order to assess the state of the art in the field of graphene sensors for the purposes of biomarker identification. During the bibliographic search, a total of six pathologies were identified as the focus of the work. They were lung cancer, gastric cancer, chronic kidney diseases, respiratory diseases that involve inflammatory processes of the airways, like asthma and chronic obstructive pulmonary disease, sleep apnoea and diabetes. The achieved results, current development of the sensing sensors, and main limitations or challenges of the field of graphene sensors are discussed throughout the paper, as well as the features of the experiments addressed. [ABSTRACT FROM AUTHOR]

The assessment of volatile breath biomarkers has been targeted with a lot of interest by the scientific and medical communities during the past decades due to their suitability for an accurate, painless, non-invasive, and rapid diagnosis of health states and pathological conditions. This paper reviews the most relevant bibliographic sources aiming to gather the most pertinent volatile organic compounds (VOCs) already identified as putative cancer biomarkers. Here, a total of 265 VOCs and the respective bibliographic sources are addressed regarding their scientifically proven suitability to diagnose a total of six carcinogenic diseases, namely lung, breast, gastric, colorectal, prostate, and squamous cell (oesophageal and laryngeal) cancers. In addition, future trends in the identification of five other forms of cancer, such as bladder, liver, ovarian, pancreatic, and thyroid cancer, through perspective volatile breath biomarkers are equally presented and discussed. All the results already achieved in the detection, identification, and quantification of endogenous metabolites produced by all kinds of normal and abnormal processes in the human body denote a promising and auspicious future for this alternative diagnostic tool, whose future passes by the development and employment of newer and more accurate collection and analysis techniques, and the certification for utilisation in real clinical scenarios. [ABSTRACT FROM AUTHOR]

The role of hydrogen peroxide molecule (Н2О2) in the vital functions of biological objects has been considered. The mechanisms of Н2О2 formation and its relationship with redox reactions, as well as some possible methods of analyzing the Н2О2 content in liquid and gaseous media, are discussed. In particular, the possibility of using highly sensitive methods of laser spectral analysis for detecting Н2О2 traces in exhaled air, which are promising for diagnostics of various pathologies, is considered. The absorption spectra of exhaled air are analyzed, and the strongest H2O2 spectral lines (isolated from the influence of other gaseous metabolites), applicable for detecting Н2О2 by diode laser spectroscopy, are chosen. [ABSTRACT FROM AUTHOR]

Additive manufacturing (AM), or 3D printing, is a growing industry involving a wide range of different techniques and materials. The potential toxicological effects of emissions produced in the process, involving both ultrafine particles and volatile organic compounds (VOCs), are unclear, and there are concerns regarding possible health implications among AM operators.The objective of this study was to screen the presence of respiratory health effects among people working with liquid, powdered, or filament plastic materials in AM.MethodsIn total, 18 subjects working with different additive manufacturing techniques and production of filament with polymer feedstock and 20 controls participated in the study. Study subjects filled out a questionnaire and underwent blood and urine sampling, spirometry, impulse oscillometry (IOS), exhaled NO test (FeNO), and collection of particles in exhaled air (PEx), and the exposure was assessed. Analysis of exhaled particles included lung surfactant components such as surfactant protein A (SP-A) and phosphatidylcholines. SP-A and albumin were determined using ELISA. Using reversed-phase liquid chromatography and targeted mass spectrometry, the relative abundance of 15 species of phosphatidylcholine (PC) was determined in exhaled particles. The results were evaluated by univariate and multivariate statistical analyses (principal component analysis).ResultsExposure and emission measurements in AM settings revealed a large variation in particle and VOC concentrations as well as the composition of VOCs, depending on the AM technique and feedstock. Levels of FeNO, IOS, and spirometry parameters were within clinical reference values for all AM operators. There was a difference in the relative abundance of saturated, notably dipalmitoylphosphatidylcholine (PC16:0_16:0), and unsaturated lung surfactant lipids in exhaled particles between controls and AM operators.ConclusionThere were no statistically significant differences between AM operators and controls for the different health examinations, which may be due to the low number of participants. However, the observed difference in the PC lipid profile in exhaled particles indicates a possible impact of the exposure and could be used as possible early biomarkers of adverse effects in the airways.

The assessment of volatile breath biomarkers has been targeted with a lot of interest by the scientific and medical communities during the past decades due to their suitability for an accurate, painless, non-invasive, and rapid diagnosis of health states and pathological conditions. This paper reviews the most relevant bibliographic sources aiming to gather the most pertinent volatile organic compounds (VOCs) already identified as putative cancer biomarkers. Here, a total of 265 VOCs and the respective bibliographic sources are addressed regarding their scientifically proven suitability to diagnose a total of six carcinogenic diseases, namely lung, breast, gastric, colorectal, prostate, and squamous cell (oesophageal and laryngeal) cancers. In addition, future trends in the identification of five other forms of cancer, such as bladder, liver, ovarian, pancreatic, and thyroid cancer, through perspective volatile breath biomarkers are equally presented and discussed. All the results already achieved in the detection, identification, and quantification of endogenous metabolites produced by all kinds of normal and abnormal processes in the human body denote a promising and auspicious future for this alternative diagnostic tool, whose future passes by the development and employment of newer and more accurate collection and analysis techniques, and the certification for utilisation in real clinical scenarios.

The field of organic-borne biomarkers has been gaining relevance due to its suitability for diagnosing pathologies and health conditions in a rapid, accurate, non-invasive, painless and low-cost way. Due to the lack of analytical techniques with features capable of analysing such a complex matrix as the human breath, the academic community has focused on developing electronic noses based on arrays of gas sensors. These sensors are assembled considering the excitability, sensitivity and sensing capacities of a specific nanocomposite, graphene. In this way, graphene-based sensors can be employed for a vast range of applications that vary from environmental to medical applications. This review work aims to gather the most relevant published papers under the scope of “Graphene sensors” and “Biomarkers” in order to assess the state of the art in the field of graphene sensors for the purposes of biomarker identification. During the bibliographic search, a total of six pathologies were identified as the focus of the work. They were lung cancer, gastric cancer, chronic kidney diseases, respiratory diseases that involve inflammatory processes of the airways, like asthma and chronic obstructive pulmonary disease, sleep apnoea and diabetes. The achieved results, current development of the sensing sensors, and main limitations or challenges of the field of graphene sensors are discussed throughout the paper, as well as the features of the experiments addressed.

Background: There is a lack of early and precise biomarkers for personalized respiratory medicine. Breath contains an aerosol of droplet particles, which are formed from the epithelial lining fluid when the small airways close and re-open during inhalation succeeding a full expiration. These particles can be collected by impaction using the PExA® method (Particles in Exhaled Air), and are derived from an area of high clinical interest previously difficult to access, making them a potential source of biomarkers reflecting pathological processes in the small airways. Research question: Our aim was to investigate if PExA method is useful for discovery of biomarkers that reflect pathology of small airways. Methods and analysis: Ten healthy controls and 20 subjects with asthma, of whom 10 with small airway involvement as indicated by a high lung clearance index (LCI ≥ 2.9 z-score), were examined in a cross-sectional design, using the PExA instrument. The samples were analysed with the SOMAscan proteomics platform (SomaLogic Inc.). Results: Two hundred-seven proteins were detected in up to 80% of the samples. Nine proteins showed differential abundance in subjects with asthma and high LCI as compared to healthy controls. Two of these were less abundant (ALDOA4, C4), and seven more abundant (FIGF, SERPINA1, CD93, CCL18, F10, IgM, IL1RAP). sRAGE levels were lower in ex-smokers (n = 14) than in never smokers (n = 16). Gene Ontology (GO) annotation database analyses revealed that the PEx proteome is enriched in extracellular proteins associated with extracellular exosome-vesicles and innate immunity. Conclusion: The applied analytical method was reproducible and allowed identification of pathologically interesting proteins in PEx samples from asthmatic subjects with high LCI. The results suggest that PEx based proteomics is a novel and promising approach to study respiratory diseases with small airway involvement. Key messages: Key question: Can the PExA method identify individual protein profiles that reflect pathology of small airways, using the SOMAscan platform? What is the bottom line?: Two hundred-seven proteins were detected in up to 80% of the PEx samples, with a strong overrepresentation of proteins related to innate immune responses, including nine proteins that that discriminated subjects with asthma and high LCI as compared to healthy controls. Why read on: The results support that PEx based proteomics is a novel and promising approach to study respiratory diseases with small airway involvement. [ABSTRACT FROM AUTHOR]

Fine and nanosize particles of both natural and anthropogenic origin can be present in the atmospheric air and affect the environment and human health. The effect of cobalt ferrite (CoFe2O4), magnetite (Fe3O4), and tin dioxide (SnO2) nanopowder inhalation of laboratory animals on the carbon dioxide content in air samples taken from the noses of these animals is studied. The CO2 concentration is determined from the absorption spectra of air samples recorded with a laser photoacoustic (PA) gas analyzer. It is ascertained that inhalation of magnetite nanoparticles leads to a decrease in the concentration of carbon dioxide in the samples of exhaled air of laboratory animals, which can indicate a negative effect of this exposure. [ABSTRACT FROM AUTHOR]

Microbial volatile organic compounds (mVOCs) are metabolites developed by indoor molds responsible for several health effects. Their detection may be an alternative approach for fungal exposure assessment, given that the classical methods have limitations. The goal of this study was to develop and validate an analytical method to quantify 21 mVOCs in ambient and exhaled air using active sampling on sorbent tubes followed by thermal desorption and gas chromatography–mass spectrometry analysis. Tenax/Carbograph sorbent was selected for its extraction/desorption efficiency. Reliable linearity was obtained over the concentration range of mVOCs with low limits of detection (≥1.76 ng/m3) and quantification (≥5.32 ng/m3). Furthermore, accuracy and precision in the percentage recoveries ranged between 80–118% with coefficients of variations lower than 4.35% for all mVOCs. Feasibility tests with ambient air of different places (toxicology laboratory, office, and mold contaminated bedroom) showed that variations between settings were observable and that the highest mVOCs concentrations in the bedroom. Consequently, concentrations of 17 mVOCs were higher in the volunteer's exhalate after exposure in the bedroom than in the laboratory. In conclusion, this method allows the detection of mVOCs in a new matrix, i.e., exhaled air and targeting the contaminated environment and, therefore, intervening for the protection of human health. [ABSTRACT FROM AUTHOR]

The airborne transmission of COVID-19 has drawn immense attention to bioaerosols. The topic is highly relevant in the indoor hospital environment where vulnerable patients are treated and healthcare workers are exposed to various pathogenic and non-pathogenic microbes. Knowledge of the microbial communities in such settings will enable precautionary measures to prevent any hospital-mediated outbreak and better assess occupational exposure of the healthcare workers. This study presents a baseline of the bacterial and fungal population of two major hospitals in Kuwait dealing with COVID patients, and in a non-hospital setting through targeted amplicon sequencing. The predominant bacteria of bioaerosols were Variovorax (9.44%), Parvibaculum (8.27%), Pseudonocardia (8.04%), Taonella (5.74%), Arthrospira (4.58%), Comamonas (3.84%), Methylibium (3.13%), Sphingobium (4.46%), Zoogloea (2.20%), and Sphingopyxis (2.56%). ESKAPEE pathogens, such as Pseudomonas, Acinetobacter, Staphylococcus, Enterococcus, and Escherichia, were also found in lower abundances. The fungi were represented by Wilcoxinia rehmii (64.38%), Aspergillus ruber (9.11%), Penicillium desertorum (3.89%), Leptobacillium leptobactrum (3.20%), Humicola grisea (2.99%), Ganoderma sichuanense (1.42%), Malassezia restricta (0.74%), Heterophoma sylvatica (0.49%), Fusarium proliferatum (0.46%), and Saccharomyces cerevisiae (0.23%). Some common and unique operational taxonomic units (OTUs) of bacteria and fungi were also recorded at each site; this inter-site variability shows that exhaled air can be a source of this variation. The alpha-diversity indices suggested variance in species richness and abundance in hospitals than in non-hospital sites. The community structure of bacteria varied spatially (ANOSIM r2 = 0.181–0.243; p < 0.05) between the hospital and non-hospital sites, whereas fungi were more or less homogenous. Key taxa specific to the hospitals were Defluvicoccales, fungi, Ganodermataceae, Heterophoma, and H. sylvatica compared to Actinobacteria, Leptobacillium, L. leptobacillium, and Cordycipitaceae at the non-hospital site (LefSe, FDR q ≤ 0.05). The hospital/non-hospital MD index > 1 indicated shifts in the microbial communities of indoor air in hospitals. These findings highlight the need for regular surveillance of indoor hospital environments to prevent future outbreaks. [ABSTRACT FROM AUTHOR]

The measurement of nitric oxide (NO) in exhaled air is used in diagnostics and monitoring the pathologies not only in the respiratory system but also in the oral cavity. It has shown a huge increase in its level in asthma and diseases of the oral cavity. It seems reasonable to undertake research on the impact of inflammation on the level of NO in exhaled air. The aim of the study is to make an evidence-based review of the application of NO levels in exhaled air in the diagnosis of inflammation and treatment monitoring on the basis of selected measuring devices. Methods and Results: This paper presents an example of the application of NO measurement in exhaled air in individual human systems. Selected measuring devices, their non-invasiveness, and their advantages are described. Discussion: The usefulness of this diagnostic method in pathologies of the oral cavity was noted. Conclusions: Measuring the level of NO in exhaled air seems to be a useful diagnostic method. [ABSTRACT FROM AUTHOR]

The airborne transmission of COVID-19 has drawn immense attention to bioaerosols. The topic is highly relevant in the indoor hospital environment where vulnerable patients are treated and healthcare workers are exposed to various pathogenic and non-pathogenic microbes. Knowledge of the microbial communities in such settings will enable precautionary measures to prevent any hospital-mediated outbreak and better assess occupational exposure of the healthcare workers. This study presents a baseline of the bacterial and fungal population of two major hospitals in Kuwait dealing with COVID patients, and in a non-hospital setting through targeted amplicon sequencing. The predominant bacteria of bioaerosols were Variovorax (9.44%), Parvibaculum (8.27%), Pseudonocardia (8.04%), Taonella (5.74%), Arthrospira (4.58%), Comamonas (3.84%), Methylibium (3.13%), Sphingobium (4.46%), Zoogloea (2.20%), and Sphingopyxis (2.56%). ESKAPEE pathogens, such as Pseudomonas, Acinetobacter, Staphylococcus, Enterococcus, and Escherichia, were also found in lower abundances. The fungi were represented by Wilcoxinia rehmii (64.38%), Aspergillus ruber (9.11%), Penicillium desertorum (3.89%), Leptobacillium leptobactrum (3.20%), Humicola grisea (2.99%), Ganoderma sichuanense (1.42%), Malassezia restricta (0.74%), Heterophoma sylvatica (0.49%), Fusarium proliferatum (0.46%), and Saccharomyces cerevisiae (0.23%). Some common and unique operational taxonomic units (OTUs) of bacteria and fungi were also recorded at each site; this inter-site variability shows that exhaled air can be a source of this variation. The alpha-diversity indices suggested variance in species richness and abundance in hospitals than in non-hospital sites. The community structure of bacteria varied spatially (ANOSIM r2 = 0.181–0.243; p < 0.05) between the hospital and non-hospital sites, whereas fungi were more or less homogenous. Key taxa specific to the hospitals were Defluvicoccales, fungi, Ganodermataceae, Heterophoma, and H. sylvatica compared to Actinobacteria, Leptobacillium, L. leptobacillium, and Cordycipitaceae at the non-hospital site (LefSe, FDR q ≤ 0.05). The hospital/non-hospital MD index > 1 indicated shifts in the microbial communities of indoor air in hospitals. These findings highlight the need for regular surveillance of indoor hospital environments to prevent future outbreaks.

Direct determination of the oxidative potential in exhaled air (OPEA) as a biological indicator of the redox balance status in airways requires an extremely sensitive sensing approach to counterbalance the high dilution of the exhaled air matrix. In opposite to standard colorimetric assays based on Beer-Lambert Law, the use of simple multiscattering-enhanced absorbance (MEA) strategy results in an improved photonic sensing system. Based on this strategy and using the ferrous-xylenol orange assay, analytical performances allowing the detection of 3 ​pmol of H2O2 could be obtained. The comparative analysis of photometric configurations – standard vs MEA – highlights the large absorbance gain obtained for tiny H2O2 amounts – from 0 to 30 ​pmol – whereas similar sensing trends are observed at higher concentration range. The automated introduction of exhaled air sample into the reaction compartment via needle-impinger coupled with the MEA-based photonic cell enables ultrasensitive determination of OPEA in short time (

Background: Infection with SARS-CoV-2 causes corona virus disease (COVID-19). The most standard diagnostic method is reverse transcription-polymerase chain reaction (RT-PCR) on a nasopharyngeal and/or an oropharyngeal swab. The high occurrence of false-negative results due to the non-presence of SARS-CoV-2 in the oropharyngeal environment renders this sampling method not ideal. Therefore, a new sampling device is desirable. This proof-of-principle study investigated the possibility to train machine-learning classifiers with an electronic nose (Aeonose) to differentiate between COVID-19-positive and negative persons based on volatile organic compounds (VOCs) analysis. Methods: Between April and June 2020, participants were invited for breath analysis when a swab for RT-PCR was collected. If the RT-PCR resulted negative, the presence of SARS-CoV-2-specific antibodies was checked to confirm the negative result. All participants breathed through the Aeonose for five minutes. This device contains metal-oxide sensors that change in conductivity upon reaction with VOCs in exhaled breath. These conductivity changes are input data for machine learning and used for pattern recognition. The result is a value between − 1 and + 1, indicating the infection probability. Results: 219 participants were included, 57 of which COVID-19 positive. A sensitivity of 0.86 and a negative predictive value (NPV) of 0.92 were found. Adding clinical variables to machine-learning classifier via multivariate logistic regression analysis, the NPV improved to 0.96. Conclusions: The Aeonose can distinguish COVID-19 positive from negative participants based on VOC patterns in exhaled breath with a high NPV. The Aeonose might be a promising, non-invasive, and low-cost triage tool for excluding SARS-CoV-2 infection in patients elected for surgery. [ABSTRACT FROM AUTHOR]

Background and aim: In the hot workplaces, the increase of body core temperature is induced in result of exposure to high air temperature and metabolism heating due to worker activity. Heat exposure can affect how well chemicals are absorbed into the body. Core temperature change can alter absorption, distribution, metabolism and excretion of the toxicants. Increases in respiration can cause further toxicant exposure through inhalation, while increases in sweat and skin blood and pulmonary ventilation flow can make more efficient transcutaneous absorption of toxicants. Therefore, the amounts of xenobiotic absorbed through the lungs and the skin during heat exposure can be raised significantly in result of higher pulmonary ventilation and cutaneous blood flow. Animal studies which are investigated the effects of thermal stress on chemical toxicity showed that heat exposure plays a role on toxins absorption. However, it is difficult to interpret these findings when trying to compare differences between humans and the animal models. It is observed that workers exposure in some work environment suggests that concomitant exposure to heat stress and chemicals is likely to increase the absorption and effects of certain xenobiotics. Tetrachlorethylene is a particular chemical compound is often used for laundry. The main route for human exposure to tetrachlorethylene is via inhalation, but the compound is also adsorbed by mouth contact. As mentioned, most of what is known on the effect of heat exposure on absorption of chemicals comes from animal studies. With regard to the importance of analyzing how thermal stresses can effect on toxicity response of chemical agents and moreover, need to better understanding of its related mechanisms in humans, the present study aimed to investigate the relation of body heat strain level with Tetrachlorethylene concentration in exhaled air among laundry workers in Hamadan city. Method: This descriptive analytical study was conducted in two steps of winter and summer in 2017. Twenty-four healthy workers employed in laundry workrooms located in the city of Hamadan, Iran, were enrolled in the study. Their age, height and weight were respectively 32.1 ± 5.16 year, 173.7±11.5 cm, 70.3±16.5 kg. The participants were screened using a self-reported questionnaire in terms of their state of mental and physical health. Before initiation of the tests, a written informed consent form was signed by the subjects participating in this research. Based on ISO 9920 (2007), clothing insulations (Clo unit) of the participants were 1 Clo and 0.75 in winter and summer, respectively. Ambient air samples of laundry workroom were obtained using 150 mg coconut shell charcoal tubes (20/40 mesh) SKC and using SKC personal sampling pumps model 222 calibrated to a flow rate of 100 cc/min. The air samples were analyzed by the NIOSH method no 1003 recommended for Tetrachlorethylene. Desorption of Tetrachlorethylene from activated charcoals was done with 1ml of carbon disulfide. After 30 minutes an aliquot of the resultant solution (1 µl) was injected into Shimadzu 2010 gas chromatograph equipped with a flame ionization detector (F.I.D) and Rtx-1 column. One ml volume of the sample was injected into the gas chromatograph with a Hamilton gas—tight syringe. The instrumental temperatures were as follows: injector temperature, 250C; initial oven temperature, 70C (held for 5 min), increased to 120C at a rate of 10C min-1, held for 5 min. For exhaled air samples of the same participants, individuals were asked to exhale normally into a 3 liter Tedlar air bags (SKC) until it was filled. Measuring Tetrachlorethylene in exhaled air was conducted through integrating NIOSH 1003 and NIOSH 3704 methods through optimizing analysis parameters using analytical device GC-FID. Thermal strain of exposed workers was measured based on oral temperature, heart rate and respiratory rate in accordance standard method ISO 9886:2004. The heart rate was measured using a heart rate device (Beurer PM100). Statistical analysis of the data was performed using the SPSS software version 20. The significance level of the tests was considered 0.05. Results: The mean of dry temperature, natural wet bulb temperature and globe bulb temperature were 29.42°C, 23.96°C and 30.77°C, respectively. The mean of Tetrachlorethylene concentrations in ambient air of laundry workplace in summer and winter were 45.91 ppm, 50.64 ppm, respectively. The mean values of the thermal strain indexes included oral temperature, heart rate, and pulmonary ventilation in summer and winter were 37.3°C and 37.1°C, 99.95 and 90.95 beats per minute, 26 and 20.5 breath rate per minute, respectively. The mean values work metabolism in summer and winter were 110.86 and 108.73 kcal/h, respectively. The mean of Tetrachlorethylene concentration in exhaled air in summer and winter is 3.18 and 2.23 ppm, respectively, which were higher and lower than national occupational exposure limit (3 ppm). The significant difference was observed between the mean Tetrachlorethylene concentrations in exhaled air in summer and winter (p0.05). According to the results of paired sample t-test, core temperature, heart beat rate and pulmonary ventilation of workers were significantly increased in summer compared to winter (p

The aim of our study was to determine the power of exhaled air CO (E-CO) levels to predict the severity of nicotine dependency and its effect on predicting the one-year smoking cessation success. It also aimed to detect other factors related to smoking cessation success. The smokers who applied to the ADU hospital family medicine and smoking cessation clinic between October 2018 and March 2019 participated in this prospective cohort study, conducted with an analytical design. A significant correlation was found between the E-CO levels and the Fagerstrom Test for Nicotine Dependence (FTND) score, Heaviness of Smoking index (HSI) score, and the amount of smoking per day. The sensitivity of predicting high nicotine dependency based on the FTND score (=6) at the 8.5 ppm cut-off point for E-CO level was 70.6%, and the specificity was 67.7%. The sensitivity of predicting high nicotine dependency based on the HSI score (=4) at the 9.5 ppm cut-off point for E-CO level was 68.0%, and specificity was 71.9%. E-CO measurements can be used to determine the level of dependency. Low initial E-CO levels increase smoking cessation success. [ABSTRACT FROM AUTHOR]

In clinical practice, exhaled air analysis is a promising approach for diagnosing lung cancer due to a possibility of rapid and noninvasive sampling. We analyzed the exhaled air of 80 patients with lung cancer to identify differences in the profiles of volatile organic compounds in patients with different histological types and localization of cancer using gas chromatography–mass spectrometry. Some volatile organic compounds and their ratios have been identified, statistically signficant differences in concentrations of which have been found in samples with different localization and histological type. [ABSTRACT FROM AUTHOR]

An experimental setup and a method for analyzing multicomponent gas mixtures, including human-exhaled air, have been presented. The installation consists of a quantum cascade laser that is tunable in the wavelength range of 5.3–12.8 µm and has a peak power of 150 mW and a multi-pass Herriot gas cell that allows obtaining an optical path of up to 76 m. The registration time of a single spectrum is about 50 ms. For acetone and ethanol which are potential biomarkers of some human diseases the sensitivity threshold at the sub-ppm level has been experimentally determined. A system of sample preparation and pre-drying that allows analyzing both multicomponent gas mixtures and the air exhaled by a person has been proposed. The variants of application of the described installation in biomedical applications has been proposed. [ABSTRACT FROM AUTHOR]

Microbial volatile organic compounds (mVOCs) are metabolites developed by indoor molds responsible for several health effects. Their detection may be an alternative approach for fungal exposure assessment, given that the classical methods have limitations. The goal of this study was to develop and validate an analytical method to quantify 21 mVOCs in ambient and exhaled air using active sampling on sorbent tubes followed by thermal desorption and gas chromatography–mass spectrometry analysis. Tenax/Carbograph sorbent was selected for its extraction/desorption efficiency. Reliable linearity was obtained over the concentration range of mVOCs with low limits of detection (≥1.76 ng/m3) and quantification (≥5.32 ng/m3). Furthermore, accuracy and precision in the percentage recoveries ranged between 80–118% with coefficients of variations lower than 4.35% for all mVOCs. Feasibility tests with ambient air of different places (toxicology laboratory, office, and mold contaminated bedroom) showed that variations between settings were observable and that the highest mVOCs concentrations in the bedroom. Consequently, concentrations of 17 mVOCs were higher in the volunteer’s exhalate after exposure in the bedroom than in the laboratory. In conclusion, this method allows the detection of mVOCs in a new matrix, i.e., exhaled air and targeting the contaminated environment and, therefore, intervening for the protection of human health.

The measurement of nitric oxide (NO) in exhaled air is used in diagnostics and monitoring the pathologies not only in the respiratory system but also in the oral cavity. It has shown a huge increase in its level in asthma and diseases of the oral cavity. It seems reasonable to undertake research on the impact of inflammation on the level of NO in exhaled air. The aim of the study is to make an evidence-based review of the application of NO levels in exhaled air in the diagnosis of inflammation and treatment monitoring on the basis of selected measuring devices. Methods and Results: This paper presents an example of the application of NO measurement in exhaled air in individual human systems. Selected measuring devices, their non-invasiveness, and their advantages are described. Discussion: The usefulness of this diagnostic method in pathologies of the oral cavity was noted. Conclusions: Measuring the level of NO in exhaled air seems to be a useful diagnostic method.

Improvement of gas chromatography methods for analyzing the exhaled air of patients when diagnosing the presence and development of pathologies of their respiratory organs is an urgent task. The aim of this work is to analyze proven and promising methods for monitoring the content of vaporous and (or) gaseous biological markers in the exhaled air of patients with respiratory pathologies, as well as the choice of optimal measurement techniques using gas chromatography methods. The analysis of scientific researches and publications in the field of modern methods of control of the content of vapor and (or) gaseous biological markers in the exhaled air of patients is made. The technical requirements are determined and the structural scheme of the multichannel gas chromatograph for measuring the content of vapor and (or) gaseous biological markers in the air exhaled by patients is improved. The main metrological characteristics of the results of measurements of concentrations of vapor and / or gaseous biological markers in air using gas chromatography methods are determined. The main technical requirements for a multichannel gas chromatograph for determining the content of vaporous and (or) gaseous biological markers in exhaled air have been determined. It has been determined that the boundaries of the total relative error of the measurement results at a confidence level of P = 0.95 depend on the ranges of the concentrations of biological markers in the exhaled air of patients. The obtained results make it possible to simplify the procedures for determining the content of biological markers by gas chromatography in the exhaled air, as well as non-invasively to diagnose the presence and development of pathologies of the patients' respiratory organs. [ABSTRACT FROM AUTHOR]

Patients with asthma exhale high concentrations of nitric oxide (NO), making the measurement of NO clinically important. Although we previously developed a 2-phenyl-4,4,5,5-tetramethylimidazoline-3-oxide-1-oxyl (PTIO) chip that relied on the reaction between NO gas and PTIO in the chip, the sensitivity and accuracy were insufficient for measuring NO in air exhaled by asthma patients. In this study, we focus on the conversion of NO to NO2 in the reaction with PTIO, and devise a new method to measure the converted NO2 using our previously developed NO2 analytical chip. NO is converted to NO2 in the PTIO chip and immediately released upon exposure to the atmosphere. This released NO2 is trapped on the adjacent NO2 analytical chip and reacts with diazo-coupling reagents to form an azo dye; a linear relationship was identified between the NO concentration and the change in absorbance at 525 nm due to production of the azo dye. The NO concentration could be measured in the 0−142 ppb range with a maximum error of ± 10 ppb at 142 ppb using the devised method, demonstrating sufficient sensitivity and accuracy for measuring NO in exhaled air. Furthermore, we successfully measured NO in the exhaled air of seven healthy adults, and detected ~19 ppb of NO, thus illustrating its feasibility for clinical use.

Methods of diode laser spectroscopy were applied for monitoring of fast physiological variations in the content of endogenous carbon monoxide (CO) in exhaled air. To this end, a CO analyzer based on a tunable diode laser emitting radiation around 2.35 μm at room temperature was constructed. CO concentration in exhaled air was determined by measuring resonance absorption of CO molecule at the R(6) line of the 0–2 band in the vicinity of 4285 cm–1. Using this line that is well separated from the nearby absorption lines of Н2О enables high selectivity of CO analysis under the conditions of high humidity of analyzed air. The possibility of monitoring fast physiological variations of CO content in exhaled air of humans and animals by means of the developed system was demonstrated in studies involving a number of physiological load tests, such as breathing pure oxygen (both humans and rats), physical load, and hyperventilation. The dynamics of CO release caused by certain pharmaceutical drugs was also studied. It is demonstrated that laser diagnostics of CO in the spectral region near 2.35 μm allows detecting fast dynamic processes of release of this gas molecule that represents one of the signaling and metabolite molecules in exhaled air when conducting various physiological and medical studies, investigating trends and interrelation of processes responsible for production, transport, buffering, and release of CO in an organism. [ABSTRACT FROM AUTHOR]

Currently, patients with stomach and duodenum diseases should be examined using diagnostic tests for Helicobacter pylori infection. Diagnostic methods available in the arsenal of clinicians make it possible to identify Helicobacter pylori in almost 100% of cases. A competent approach to the selection of a diagnostic test provides high-quality, timely, and economical verification of the pathogen. The paper provides information on the currently available diagnostic procedures for the detection of Helicobacter pylori infection and the results of the diagnosis of helicobacteriosis based on the activity of urease in saliva. The main area of research is the development of an analytical method based on the quantitative determination of ammonia and the detection of amines and aliphatic acids in exhaled air using signals from an array of diverse piezoelectric chemical sensors. Simple data processing algorithms were applied, and qualitative and quantitative decision-making criteria were substantiated. The method of analysis using chemical sensors is characterized by high specificity (96% for ammonia) and sensitivity (90%); it does not require special sample preparation and is indispensable in large-scale studies and personal monitoring and for choosing treatment tactics. [ABSTRACT FROM AUTHOR]

Background: When workplace air monitoring is not sufficient to determine the exposure levels, the determination of compounds and some metabolites in exhaled air and personal exposure levels is considered a practical method for biological monitoring. The aim of this study was to determine the relationship between the concentration of tetrachlorethylene in exhaled air and personal exposure levels in the dry cleaning workers Methods: In this descriptive cross - sectional study was performed in 2017, in addition to the collecting samples of exhaled air and personal exposure of 12 workers, the ambient air samples of dry cleaning workplace were examined. Also the ambient air samples were studied simultaneously. Measurement of tetrachlorethylene in the exhaled air was performed using gas chromatograph equipped with flame ionization detector (FID) through an incorporation of 1003 and 3704 NIOSH methods and optimization of analysis parameters. Results: In this study, the personal exposure levels were above the recommended national occupational exposure limits (OEL-TWA), and tetrachlorethylene concentration in exhaled air of workers were above the biological exposure index (BEI) respectively. The results showed that there is a significant relationship between the concentration of tetrachlorethylene in exhaled air and personal exposure levels (r=0.66, P=0.046). Also, was obtained the significant relationship between the concentration of ambient air with exhaled air concentrations (r=0.59, P=0.003), and personal exposure levels (r=0.91, P

We optimized procedures for the collection, preparation, and storage of samples of exhaled air and the conditions for determining volatile organic compounds in exhaled air by gas chromatography–mass spectrometry (GC–MS), the presence or change in the concentration of which can be caused by lung cancer. The analysis circuit includes group adsorption preconcentration followed by the thermal desorption and determination of analytes by GC–MS. Polymer bags of a Tedlar® film were used for sample collection. The conditions and periods of the storage of samples in bags and adsorption tubes are determined. A method for cleaning and conditioning bags is proposed. For preconcentrating exhaled air components, we used hydrophobic adsorbents (Porapak™ P, Porapak™ Q, and Tenax® TA) and three-section tubes containing Tenax® GR, Carbopack™ B, and Carbosieve® S-III. Their relative efficiency was evaluated by assessing the residual background of gas emission from the adsorbent, the magnitude of the analytical signal, the efficiency of adsorption/desorption, and the efficiency of storage. The conditions for the preconcentration of volatile organic compounds (volume and rate of aspiration, time, and temperature of thermal desorption) are optimized. The main volatile organic compounds in the exhaled air of conditionally healthy volunteers were identified, and their concentrations are evaluated. [ABSTRACT FROM AUTHOR]

Exhaled air has been demonstrated as a reliable medium for monitoring propofol concentration. However, online monitoring of exhaled ciprofol have not been reported. Thirty-six beagles undergoing mechanical ventilation were divided into 6 groups, including bolus injection of low (Group BL, n = 6), medium (Group BM, n = 6), and high dose of ciprofol (Group BH, n = 6) groups; as well as 1 h continuous infusion of low (Group IL, n = 6), medium (Group IM, n = 6), and high dose of ciprofol (Group IH, n = 6) groups. The ciprofol concentration in exhaled air (C E) was determined by the ultraviolet time-of-flight mass spectrometer (UV-TOFMS). The correlations of C E and plasma concentration (C p), C E and the bispectral index (BIS) were explored. Additionally, the pharmacokinetics (PK) models of C E and C p , the pharmacodynamics (PD) models of C E and BIS were also established. Online monitoring of exhaled ciprofol can be achieved with the UV-TOFMS instrument. The C E of ciprofol in beagles was found at parts per billion by volume (ppbv) level. The linear correlation of C E and C p was weak in bolus injection groups (R 2 = 0.01) nonetheless moderate in continuous infusion groups (R 2 = 0.53). The i.v. bolus PK model of C E and C p can be fitted with the non-compartment models. Additionally, the the PD models of C E and BIS can be well fitted with the inhibitory sigmoid E max model with the estimate values of IC 50 = 0.05 ± 0.01 ppbv, γ = 4.74 ± 1.51, E 0 = 81.40 ± 3.75, I max = 16.35 ± 4.27 in bolus injection groups; and IC 50 = 0.05 ± 0.01 ppbv, γ = 6.92 ± 1.30, E 0 = 83.08 ± 1.62, I max = 12.58 ± 1.65 in continuous infusion groups. Online monitoring of exhaled ciprofol concentration in beagles can be achieved with the UV-TOFMS instrument. Good correlations can be observed between exhaled ciprofol concentration and its cerebral effects reflected by the BIS value, demonstrating the potential of exhaled ciprofol monitoring for titrating depth of anesthesia in future clinical setting. ● UV-TOFMS is a mass spectrometer suitable for the application in the operating rooms. ● Our study shows for the first time that ciprofol can be measured continuously from exhaled air. ● The concentration of ciprofol in exhaled air is at the pptv level. ● The depth of anesthesia can be well predicted by the concentration of ciprofol in exhaled air. [ABSTRACT FROM AUTHOR]

Exhaled breath contains numerous volatile organic compounds (VOCs) known to be related to lung disease like asthma. Its collection is non-invasive, simple to perform and therefore an attractive method for the use even in young children. We analysed breath in children of the multicenter All Age Asthma Cohort (ALLIANCE) to evaluate if 'breathomics' have the potential to phenotype patients with asthma and wheeze, and to identify extrinsic risk factors for underlying disease mechanisms. A breath sample was collected from 142 children (asthma: 51, pre-school wheezers: 55, healthy controls: 36) and analysed using gas chromatography-mass spectrometry (GC/MS). Children were diagnosed according to Global Initiative for Asthma guidelines and comprehensively examined each year over up to seven years. Forty children repeated the breath collection after 24 or 48 months. Most breath VOCs differing between groups reflect the exposome of the children. We observed lower levels of lifestyle-related VOCs and higher levels of the environmental pollutants, especially naphthalene, in children with asthma or wheeze. Naphthalene was also higher in symptomatic patients and in wheezers with recent inhaled corticosteroid use. No relationships with lung function or TH2 inflammation were detected. Increased levels of naphthalene in asthmatics and wheezers and the relationship to disease severity could indicate a role of environmental or indoor air pollution for the development or progress of asthma. Breath VOCs might help to elucidate the role of the exposome for the development of asthma. The study was registered at ClinicalTrials.gov (NCT02496468)., (Creative Commons Attribution license.)

First-generation Chinese and Korean male immigrants in the United States are at high risk for tobacco use. This study pilot-tested a graphic, native-language text-messaging intervention to promote smoking cessation among these groups. First-generation Chinese and Korean male immigrant smokers (N = 71) were recruited from the Washington DC area. Participants were randomly assigned to one of four conditions based on a between-subjects 2 (graphic plus text or text-only messages) × 2 (quitline information or quitting tips) design. The text-messaging intervention included 30 text messages in total and lasted one month. Participants completed an expired air carbon monoxide (CO) assessment and self-reported measures at both baseline and follow-up. Results show that, from baseline to follow-up, participants' expired air CO levels decreased significantly (P = 0.001). Attitude toward quitting also became more positive (P = 0.028). Compared with text-only messages, graphic text messages produced greater positive changes in quitting attitudes (P = 0.039) and elicited greater fear response (P = 0.005). Compared with quitting tip messages, quitline information resulted in greater regret (P = 0.016) and fear (P = 0.051). These findings suggest that graphic text-messaging can be an effective method to promote smoking cessation among first-generation Chinese and Korean male immigrants. [ABSTRACT FROM AUTHOR]

Novel non-invasive methods for the diagnosis of malignancies should be effective for early diagnosis, reproducible, inexpensive, and independent from the human factor. Our aim was to establish the applicability of the non-invasive method, based on the analysis of air exhaled by patients who are at different stages of oropharyngeal, larynx and lung cancer. The diagnostic device includes semiconductor sensors capable of measuring the concentrations of gas components in exhaled air, with the high sensitivity of 1 ppm. The neural network uses signals from these sensors to perform classification and identify cancer patients. Prior to the diagnostic procedure of the non-invasive method, we clarified the extent and stage of the tumor according to current international standards and recommendations for the diagnosis of malignancies. The statistical dataset for neural network training and method validation included samples from 121 patients with the most common tumor localizations (lungs, oropharyngeal region and larynx). The largest number of cases (21 patients) were lung cancer, while the number of patients with oropharyngeal or laryngeal cancer varied from 1 to 9, depending on tumor localization (oropharyngeal, tongue, oral cavity, larynx and mucosa of the lower jaw). In the case of lung cancer, the parameters of the diagnostic device are determined as follows: sensitivity—95.24%, specificity—76.19%. For oropharyngeal cancer and laryngeal cancer, these parameters were 67.74% and 87.1%, respectively. This non-invasive method could lead to relevant medicinal findings and provide an opportunity for clinical utility and patient benefit upon early diagnosis of malignancies.

Isoprostanes are physiopathologic mediators of oxidative stress, resulting in lipid peroxidation. 8-isoprostane seems particularly useful for measuring oxidative stress damage. However, no reference range values are available for 8-isoprosante in exhaled breath condensate (EBC) of healthy adults, enabling its meaningful interpretation as a biomarker. We conducted this systematic review and meta-analysis according to the protocol following PROSPERO (CRD42020146623). After searching and analyzing the literature, we included 86 studies. After their qualitative synthesis and risk of bias assessment, 52 studies were included in meta-analysis. The latter focused on studies using immunological analytical methods and investigated how the concentrations of 8-isoprostane differ based on gender. We found that gender had no significant effect in 8-isoprostane concentration. Among other studied factors, such as individual characteristics and factors related to EBC collection, only the device used for EBC collection significantly affected measured 8-isoprostane concentrations. However, adjustment for the factors related to EBC collection, yielded uncertainty whether this effect is due to the device itself or to the other factors. Given this uncertainty, we estimated the reference range values of 8-isoprostane stratified by gender and EBC collection device. A better standardization of EBC collection seems necessary; as well more studies using chemical analytical methods to extend this investigation.

Here we describe how individual sub-micron exhaled droplets and dry residue particles (DRPs) could be quickly collected on mica, glass, highly oriented pyrolytic graphite, and carboxymethyl cellulose film using a simple impactor. Most collected DRPs had size between 200 nm and 1000 nm and were readily seen under a low power optical microscope with dark-field illumination. The size and shape of the collected DRPs were analyzed with atomic force microscopy (AFM). It was found that the collection efficiency and the shape of the collected DRP depend on a number of factors, including (i) temperature and humidity of exhaled air, (ii) substrate temperature, and (iii) substrate hydrophobicity. Exposure of collected DRPs to humid air or to high temperature resulted in their spreading over the substrate surface, revealing the presence of lipid monolayers and solid nanoparticles inside the DRPs. [ABSTRACT FROM AUTHOR]