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Epilepsy remains a disease that affects many people around the world. With the development of new drugs to treat this condition, the importance of therapeutic drug monitoring continues to rise and remains a challenge for the medical community. This review article explores recent advances in the detection of antiepileptic drugs across various sample types commonly used for drug monitoring, with a focus on their applications and impact. Some of these new methods have proven to be simpler, greener, and faster, making them easier to apply in the context of therapeutic drug monitoring. Additionally, besides the classic use of blood and its derivatives, there has been significant research into the application of alternative matrices due to their ease of sample collection and capacity to reflect drug behavior in blood. These advances have contributed to increasing the efficacy of therapeutic drug monitoring while enhancing its accessibility to the population. [ABSTRACT FROM AUTHOR]

The purpose of the study was to evaluate diagnostic capabilities of the gas analysis sensor device used for the study of exhaled gas samples obtained from patients with oropharyngeal and laryngeal cancers.Material and Methods. Exhaled gas samples from 31 oropharyngeal and laryngeal cancer patients and 31 healthy volunteers were studied using a diagnostic device based on the detection of volatile compounds in inhaled air using semiconductor gas sensors with subsequent neural network analysis.Results. Based on the signals from gas sensors, the neural network classified and identified patients with malignant neoplasms. The sensitivity and specificity of the method were 67.74% and 87.1%, respectively.Conclusion. The gas analysis sensor device and the method for detecting oropharyngeal and laryngeal tumors using the exhaled gas analysis are an accessible and cheap diagnostic tools, and are promising for screening the population in order to select individuals for a comprehensive examination (endoscopic, radiological and morphological) in identifying suspicion of cancer.

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]

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.

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]

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.

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 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

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.

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]

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.

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]

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]

Aging is accompanied with increased frailty and comorbidities, which is potentially associated with microbiome perturbations. Dietary fibers could contribute to healthy aging by beneficially impacting gut microbiota and metabolite profiles. We aimed to compare young adults with elderly and investigate the effect of pectin supplementation on fecal microbiota composition, short chain fatty acids (SCFAs), and exhaled volatile organic compounds (VOCs) while using a randomized, double-blind, placebo-controlled parallel design. Fifty-two young adults and 48 elderly consumed 15 g/day sugar beet pectin or maltodextrin for four weeks. Fecal and exhaled breath samples were collected before and after the intervention period. Fecal samples were used for microbiota profiling by 16S rRNA gene amplicon sequencing, and for analysis of SCFAs by gas chromatography (GC). Breath was used for VOC analysis by GC-tof-MS. Young adults and elderly showed similar fecal SCFA and exhaled VOC profiles. Additionally, fecal microbiota profiles were similar, with five genera significantly different in relative abundance. Pectin supplementation did not significantly alter fecal microbiota, SCFA or exhaled VOC profiles in elderly or young adults. In conclusion, aside from some minor differences in microbial composition, healthy elderly and young adults showed comparable fecal microbiota composition and activity, which were not altered by pectin supplementation.

This paper shows the use of exhaled air as a biomonitoring method to assess perchloroethylene (PERC) environmental and occupational exposure. A sensitive, fast, and solvent free analytical method was developed to determine PERC in ambient and exhaled air of individuals occupationally exposed. The developed method used cold fiber solid phase microextraction (CF-SPME) as the sampling technique, and a standard permeation method to simulation of air matrix. The analysis were conducted by gas chromatography coupled to mass spectrometry (GC/MS). The methods were validated and were found to be precise, linear and sensitive for environmental and biological monitoring. The developed methods were applied to twenty-seven sampling points spread across Belo Horizonte city, Brazil, twenty four dry cleaners, an electroplating industry, a research laboratory, and an automotive paint preparation shop. The results of ambient air analyses ranging from 14.0 to 3205.0 µg m −3 with median concentration of 599.0 µg m −3 . Furthermore, sampling of exhaled air of individuals occupationally exposed presented results ranging from 6.0 to 2635.0 µg m −3 with median concentration of 325.0 µg m −3 . The strong correlation observed between ambient and exhaled air (r =0.930) demonstrates that exhaled air is a suitable biomarker for evaluating occupational exposure to PERC. [ABSTRACT FROM AUTHOR]

Acrolein is a pollutant released daily to the indoor environment from different sources. The present study reports the development of a simple and sensitive cold fiber solid phase microextraction sampling method for the determination of acrolein in exhaled air and indoor air by gas chromatography mass spectrometry. O-(2,3,4,5,6-pentafluorobenzyl) hydroxylamine was used as derivatizing agent supported on a 65-μm polydimethylsiloxane-divinylbenzene SPME fiber. An acrolein permeation tube at 326.25 ng min rate was used to generate gaseous standards. The method shows good results for main validation parameters. The limits of detection and quantification were 2.88 and 5.08 μg m, respectively, for indoor analysis; and 2.40 and 3.79 μg m, respectively, for exhaled air analysis. The precision showed standard deviation ranges from 6.00 to 8.00% for intra-assay analyses and from 8.00 to 10.00% for inter-assay analyses. After optimizing the conditions, analyses of real samples were performed on indoor environments contaminated by cigarette smoke, or heated oil, including pastry shops, restaurants, churros stands, and closed parking cars located in the city of Belo Horizonte, Brazil. Acrolein breaths of exposed people were also determined. A good Pearson correlation coefficient ( r = 0.901) was observed between the concentration of acrolein in indoor air and exhaled air, allowing to propose acrolein breath as environmental exposure biomarker. [ABSTRACT FROM AUTHOR]

Monitoring exhaled breath is a very attractive, noninvasive screening technique for early diagnosis of diseases, especially lung cancer. However, the technique provides insufficient accuracy because the exhaled air has many crucial volatile organic compounds (VOCs) at very low concentrations (ppb level). We analyzed the breath exhaled by lung cancer patients and healthy subjects (controls) using gas chromatography/mass spectrometry (GC/MS), and performed a subsequent statistical analysis to diagnose lung cancer based on the combination of multiple lung cancer-related VOCs. We detected 68 VOCs as marker species using GC/MS analysis. We reduced the number of VOCs and used support vector machine (SVM) algorithm to classify the samples. We observed that a combination of five VOCs (CHN, methanol, CH3CN, isoprene, 1-propanol) is sufficient for 89.0% screening accuracy, and hence, it can be used for the design and development of a desktop GC-sensor analysis system for lung cancer. [ABSTRACT FROM AUTHOR]

The infrared laser photoacoustic spectroscopy (LPAS) and the pattern-recognition-based approach for noninvasive express diagnostics of pulmonary diseases on the basis of absorption spectra analysis of the patient's exhaled air are presented. The study involved lung cancer patients (N = 9), patients with chronic obstructive pulmonary disease (N = 12), and a control group of healthy, nonsmoking volunteers (N = 11). The analysis of the measured absorption spectra was based at first on reduction of the dimension of the feature space using principal component analysis; thereafter, the dichotomous classification was carried out using the support vector machine. The gas chromatography-mass spectrometry method (GC-MS) was used as the reference. The estimated mean value of the sensitivity of exhaled air sample analysis by the LPAS in dichotomous classification was not less than 90% and specificity was not less than 69%; the analogous results of analysis by GC-MS were 68% and 60%, respectively. Also, the approach to differential diagnostics based on the set of SVM classifiers usage is presented. [ABSTRACT FROM AUTHOR]

The gaseous signaling molecules, nitric oxide (NO), carbon monoxide (CO) and hydrogen sulfide (H2S) have been identified as being produced endogenously in a variety of cells, and are also found to be involved in diverse and pivotal pathophysiological roles including neurotransmission, cellular metabolism, immunological/inflammatory responses, and various aspects of cardiovascular regulation in the human body. These gases can diffuse freely through a membrane and exert their own roles when binding with a variety of molecular targets in a cell. These gaseous molecules can also be detected in the exhaled air, and can change their volume in the presence of diseases and/or exercise. However, the real origin and pathophysiological implications of these gases in the exhaled air are largely uncertain. This review attempts to summarize the generation and biological roles of NO, CO and H2S, and to advert the pathophysiological significance of measuring these gases in exhaled air with respect to exercise and exercise training.

Objectives: Benzene is commonly emitted in several industries, leading to widespread environmental and occupational exposure hazards. While less toxic solvents have been substituted for benzene, it is still a component of petroleum products and is a trace impurity in industrial products resulting in continued higher occupational exposures in industrial settings in developing countries. Materials and Methods: We investigated the potential use of an electronic nose (e-nose) to monitor the headspace volatiles in biological samples from benzene-exposed Egyptian workers and non-exposed controls. The study population comprised 150 non-smoking male workers exposed to benzene and an equal number of matching non-exposed controls. We determined biomarkers of benzene used to estimate exposure and risk including: benzene in exhaled air and blood; and its urinary metabolites such as phenol and muconic acid using gas chromatography technique and a portable e-nose. Results: The average benzene concentration measured in the ambient air of the workplace of all studied industrial settings in Alexandria, Egypt; was 97.56±88.12 μg/m3 (range: 4.69–260.86 μg/m3). Levels of phenol and muconic acid were signifi cantly (p < 0.001) higher in both blood and urine of benzene-exposed workers as compared to non-exposed controls. Conclusions: The e-nose technology has successfully classifi ed and distinguished benzene-exposed workers from non-exposed controls for all measured samples of blood, urine and the exhaled air with a very high degree of precision. Thus, it will be a very useful tool for the low-cost mass screening and early detection of health hazards associated with the exposure to benzene in the industry.