Breath Research Articles

Метаболомические исследования при хроническом риносинусите: обзор клинических перспектив

Chronic rhinosinusitis (CRS) is one of the most common otorhinolaryngological diseases, which significantly reduces the quality of life of patients. The etiopathogenesis of CRS has not been fully studied to date, it is problematic to predict the effectiveness of the therapy and the possible period of remission. To solve such issues in modern medicine, metabolomic studies are carried out that study various low-molecular metabolites, cell components in biological material taken from a person: in a cell, tissue, fluid, exhaled air, saliva, bronchial lavage, etc. Metabolomic studies allow identifying possible disease markers and also quantifying them. As a result, a set of individual molecular parameters is compiled that form the patient’s metabolic profile. Metabolomic studies define a new level of clinical prediction in a wide range of complex human diseases, including cardiovascular, oncological diseases, asthma, diabetes, etc. Today, it is typical to use a multiomics approach that combines various molecular omics technologies (genomics, proteomics, transcriptomics, lipidomics, etc.). Based on the identified quantitatively measured biomolecules, it becomes possible to compare genetic variability with complex phenotypic features. Publications on metabolomic studies in CRS are not extensive; however, they report the identified differences in various forms of rhinosinusitis. Metabolomic studies in CRS allow determining the diagnostically significant molecular markers of various forms of chronic sinusitis as well as creating a personal omics profile of the patient and providing an opportunity to control the effectiveness of the therapy. Together with complete data on the patient’s lifestyle and health status, the patient’s personal ohmic profile may be the basis of personalized medicine.

Safety and pulmonary function impact of surgical mask usage in stable COPD patients during the COVID-19 pandemic

There are hesitations about the use of surgical face masks, which are the main tools in protection from the COVID-19 pandemic, one of the biggest disasters of our age, in chronic airway diseases. The purpose of the study was to examine how stable patients with chronic obstructive pulmonary disease (COPD) responded to short-term surgical mask use in terms of in-mask air quality, oxygen saturation, and pulmonary function. Forty-one patients with stable COPD, by clinical presentation and pulmonary function tests (PFTs), were included in a quasi-experimental study. Stable COPD patients' PFTs, in-mask air quality, and pollution measures were collected before and after wearing surgical masks for two hours at rest. The findings of simultaneous tests of peripheral-blood-oxygen saturation were also recorded. The mean age of participants was 67.1 years and 87.8% were male. The pre- and post-mask PFTs parameters for GOLD (A+B) group were FEV1 (ml), FEV1 (%), FVC (ml), FVC (%), FEV1/FVC (%) and DLCO (%) (p=0.067, p=0. 065, p=0.062, p=0.083, p=0.083, p=0.269, p=0.956, respectively), whereas in GOLD (C+D) group (p=0.340, p=0.538, p=0.728, p=0.044, p=0.105, p=0.054, respectively). In post-mask measurements, the respiratory function was not impaired in GOLD-2022 (A-B-C-D) COPD subgroups. Oxygen and carbon-monoxide concentrations in exhaled air and oxygen saturation decreased after surgical mask use. The difference was statistically significant, but the difference was unimportant in terms of clinical implications. Surgical masks don’t appear to have a negative effect on pulmonary function and clinical parameters in stable COPD. This study may help provide evidence-based data to overcome hesitations in use of surgical masks in chronic airway diseases.

Применение метода абсорбционной диодной лазерной спектроскопии для измерения содержания -=SUP=-13-=/SUP=-С и -=SUP=-12-=/SUP=-С в выдыхаемом воздухе

The paper reports on experimental studies of the absorption of 13C16O2 in a mixture with 12C16O2 in exhaled air by laser absorption spectroscopy using a diode laser tunable in the frequency range 4860-4880 cm-1. The results of the studies showed that the minimum detectable concentration of 13C16O2 is at a level of less than 20 ppm, and this approach is promising for measuring the content of 13C16O2 in exhaled air for non-invasive online diagnosis of oncological diseases of the gastrointestinal tract at early stages

Performance of combination of local exhaust system and floor‐supply displacement ventilation system as prevention measure of infection in consulting room

AbstractDroplet nuclei and tiny enough droplets to move as an aerosol are regarded as one of the modes of infection transmission SARS‐CoV‐2. Various measures have been taken to prevent it worldwide. Nevertheless, many scenarios cannot be avoided close‐distance conversations, for example, in a consulting room, restaurant, or crowded train. A consulting room has significant potential for doctors to contact infected patients. Therefore, this study proposes a novel approach combining a local exhaust ventilation (LEV) and floor‐supply displacement ventilation system (FSDV) in a consulting room. This study assumes that two persons (doctor and patient) are sitting face to face and talking without a mask in a simple room regarded as a consulting room. The velocity and volume of exhaled air from talking were acquired through field measurements. Then, computational fluid dynamics (CFD) steady analysis was carried out, using the results of exhaled air measurement with various parameters (hood height, hood flow rate, horizontal hood position, and air flow rate). The capture efficiency for tracer gas and contribution distribution for the hood (SVE5: scale for ventilation efficiency 5) have been calculated to reveal the hood's capture performance. In addition, infection risk for the doctor was also calculated using the Wells–Riley model to estimate the infection performance of this ventilation system. By measuring exhaled air from talking, a speed of 0.30 m/s, a volume of 5.21 L/min, and a vertical angle of 11.9° were obtained, and these values were installed into CFD. The CFD results showed that hood flow rate significantly impacts capture efficiency at SA 120 m3/h (6 ACH), and horizontal hood position significantly impacts at SA 1000 m3/h (50 ACH). SVE5 also showed hood's effective area is greatly influenced by the flow rate balance between the hood and the other exhaust routes. Under high air supply conditions: SA 1000 m3/h (50 ACH), there was almost no airborne transmission risk for a doctor with or without a hood. However, under 120 m3/h (6 ACH) conditions, the combination of the hood and FSDV system could reduce an infection risk sufficiently. The hood should be located above the infected person's head to keep the counter person's infectious risk low, indicating that the introduction of the hood is reasonable in the consulting room, where it is easy to find where the infected person is.

Reduced personal exposure to airborne cross-infection using wearable exhaust ventilation

This study aimed to explore an alternative solution for protection against cross-infection. Exposure reduction to exhaled airborne contaminants by wearing an exhaust nozzle was studied. Experiments were performed in a full-scale test room (64.8 m3) equipped with a small section of a stadium tribune with six seats. Two breathing thermal manikins and four heated dummies were placed on the tribune. The manikins were equipped with artificial lungs simulating a realistic breathing cycle and respiratory flow. One of the breathing manikins was used to mimic a sick person having an infectious respiratory disease. The exhaled air of the “infecting person” was mixed with tracer gas to imitate pathogens. Four types of air exhaust nozzles were studied for their efficiency to reduce exposure to exhaled contaminants. The nozzle was positioned in front of the mouth of the infecting person. The test room was ventilated with mixing background ventilation. The use of the exhaust nozzle resulted in cleaner air in the room and at the breathing zone of the simulated occupants compared to only using dilution by the background ventilation. The novel device has the potential to capture exhaled air and reduce airborne cross-infection in densely occupied sitting areas.

Применение машинного обучения для диагностики некоторых социально значимых заболеваний по выдыхаемому человеком воздуху методом инфракрасной лазерной спектроскопии

The infrared spectra of the air exhaled by several groups of volunteers were studied: those suffering from type 1 diabetes, bronchial asthma, and pneumonia. To record infrared spectra, a tunable quantum-cascade laser (QCL) was used. QCL emits in the wavelength range from 5.3 to 12.8 μm in a pulsed mode with a pulse width of 50 ns, a power of up to 150 mW, and a tuning step of 1 cm-1. The laser is optically coupled to an astigmatic gas cell of the Herriot type with an optical path length of 76 m. A difference was found in the intensity of selective lines of biomarker molecules in the spectra of exhaled air of healthy volunteers compared to similar indicators of volunteers suffering from a certain disease. For an example of methods such as the support vector machine (SVM), the k-nearest neighbors (k-NN) and the random forest algorithm (RandomForest), the possibility of classifying volunteers by the infrared spectra of their exhaled air is shown. The use of dimensionality reduction methods (PCA and t-SNE) made it possible to increase the accuracy of disease classification up to 98% in terms of the accuracy metric.

An Analysis of the Three Realms of Musical Performing Arts in Bel Canto

The three realms of music performance are intuition, interest, and style. Intuition is a feeling in music performance; interest is a choice that one persists in, and style is the result of effort and perception based on it. As the highest artistic achievement in the world of singing today, Bel canto (Italian: Bel canto) refers to the singing method in which the larynx blows the vocal cords with exhaled air while maintaining the inhalation position so that the open resonance cavity can resonate completely and evenly. This article, based on the research of the three realms of musical performing art, analyses the application of the three realms of musical performing art in Bel canto, aiming to let Bel canto performance better grasp the application of this art.

Science, Medicine, and the Anesthesiologist

Science, Medicine, and the Anesthesiologist

Time-of-flight mass spectrometry with pulsed glow discharge for direct determination of volatile organic compounds in air, nitrogen and argon. Volatile organic compounds ionization processes

Determination of volatile organic compounds (VOCs) in various gases, including atmospheric and exhaled human air, is required to solve a wide range of environmental problems, control the composition of various gases and is increasingly used for diagnosis of various diseases. Lately, methods of soft ionization with minimal fragmentation of the components have been rapidly developed. In particular, our research group is developing an approach to direct analysis of mixtures of VOCs using time-of-flight pulsed glow discharge mass spectrometry. Previously, the effects of different gases and gas mixtures on ionization processes were not compared. Therefore, the ionization mechanisms of VOCs in argon, nitrogen, and air were investigated in the present work. Toluene, p-xylene, chlorobenzene and 1,2,4-trimethylbenzene were chosen as the model VOCs. Optimization of microsecond pulsed glow discharge parameters (period and duration of the discharge pulse, repelling pulse delay time and pressure in the discharge cell) for each compound and a gas mixture of several VOCs was carried out. The predominant ionization mechanisms are the formation of a VOC molecular ion by Penning ionization and the proton transfer reaction; their influence being different for various gases. It is shown that the use of argon even with a small addition of water leads to the predominance of the proton transfer reaction, whereas in nitrogen and air the Penning ionization predominates. The maximum VOC intensities were achieved in air, and the developed approach

Measurement of Breath Velocity and Volume on Speaking, and Performance of Local Exhaust System as Prevention Measure of Infection

This study proposes a novel approach combining a local exhaust ventilation system (LEV) and a whole underfloor air distribution system (WUFAD) in the consulting room. This study assumes that two persons (doctor and patient) are sitting face to face and talking without a mask in a simple room regarded as a consulting room. To model people talking, exhaled air velocity and volume from talking were required, so we estimated velocity speed using an ultrasonic anemometer and volume using a PET bag and mask. Then CFD steady analyses were carried out, setting various parameters (hood height, hood flow rate, horizontal hood position, and ACH) using the breath experiment results. Capture efficiency and contribution distribution for the hood (SVE5: scale for ventilation efficiency 5) for tracer gas have been calculated. Infection risk for the doctor also has been calculated using the Wells-Riley model. The estimation’s results showed that exhaled air velocity was 0.30m/s and volume was 5.2L/min from talking. The CFD results showed that hood flow rate significantly affected capture efficiency. SVE5 showed that ACH greatly influenced the hood’s effective area. The infection risk for the doctor revealed that the combination of the LEV and WUFAD could protect doctors from infection risk under low supply conditions: 60 m3/h/person (6 ACH).

Isoprene and its Overall Impacts: Review

A clean environment is a suitable medium for providing requirements that sustain the organisms living therein. Hence, it is a ‘natural-store house’ to receive and provide the metabolic needs of the biotic and abiotic systems. It also accomplishes the crucial geochemical cycles that maintain their appropriate balance. The metabolites may be quantitatively and qualitatively meagre but cause good and bad impacts. The organisms also contribute to these metabolites. The anthropogenic interference a prime causes of environmental disturbances and renders the environment unsuitable. Isoprene is one of the biogenic and abiogenic volatile organic compounds prominently present in the lower troposphere. Normally, this volatile compound interacts with ozone, hydroxyl and oxides of nitrogen and causes depletion of ozone. Trees that combat unfavorable fluctuations in environmental parameters like high winds, tornadoes, extreme temperature, drought (a complex impact), flood, wild fires, and deficiency of nutrition, experience the influence of isoprene. Mostly the developing countries encounter poor air quality that contains particulate matter, pollutants resulting in respiratory illness, cardiovascular and cancerous ailments. The presence of volatile organic components in human exhaled air indicates their metabolic or the ambient environmental origin. The endogenous organic volatile compounds present in human breath are the biomarkers for the pathophysiological conditions and are of clinical and biomedical significance, specifically during non-invasive estimations. Although, isoprene has attracted researchers but its pathophysiological impacts need more investigations, hence, this presentation to evaluate the effects of isoprene in biosphere.

Face mask use and effects on the ocular surface health: A comprehensive review.

In the COVID-19 period, face masks increased exponentially. Several studies suggest that the rise in ocular discomfort symptoms during the pandemic is mostly part of dry eye disease and that these are due to the effect of face masks, resulting in the newly described term MADE, for "mask-associated dry eye". The most commonly proposed mechanism states that wearing a face mask creates an unnatural upward airflow towards the ocular surface during expiration, although the increased temperature, humidity and levels of carbon dioxide of the exhaled air, stress, increased use of video display terminals, as well as changes in the ocular microbiota may contribute. Evidence supports that the use of face masks causes an increase in dry eye disease symptoms, a decreased tear break-up time, corneal epithelial trauma, periocular temperature changes and inflammatory markers secretion. Given that the use of masks may be frequent in some settings in the near future, it is important to establish its effects and consequences on the ocular surface.

FEV1 (FORCED EXPIRATORY VOLUME IN THE 1ST SECOND) REVERSIBILITY AFTER NEBULISATION WITH SABA (SHORT ACTING BETA AGONIST) AS A MARKER OF CONTROL OF ASTHMA

INTRODUCTION: Variable expiratory airow due to bronchoconstriction, airway wall thickening and increased mucus is an obvious feature in asthma. Variable airow obstruction is evidenced by reversibility of FEV1 following a bronchodilator inhalation. PFT (Pulmonary Function Testing) using spirometry is often used for the estimation of FEV1. Reversibility is not uniform in all cases and vary with respect to severity and control of asthma. AIMS & OBJECTIVES: 1) To determine the control of asthma in 5-15-year-old children using GINA checklist and estimate FEV1 before and after SABA nebulisation. 2) To nd out the association between FEV1 reversibility and control of asthma. MATERIALS & METHODS: This cross-sectional study included 90 consecutive 5-15-year-old-children with a clinical diagnosis of asthma attending the Paediatric OPD of a teaching hospital from October-May 2021. The symptoms, signs, comorbidities, treatment, compliance and assessment of control of asthma into 2 subgroups: Well-controlled and Partly-controlled/Uncontrolled asthma, as per GINA 2020 were recorded. All were subjected to spirometry for assessment of FEV1 before and 20 minutes after nebulisation with SABA. Depending upon FEV1, they were grouped as those with >12% reversibility and <12% reversibility. Data analysed using SPSS 20.0, Paired t test for comparison of means, Chi-square test for statistical difference in proportion, and post hoc tests. The RESULTS: M:F ratio was 1.2:1, 52.2% were 10-15 years and 47.8% 5-10 years. 68.9% had partly/uncontrolled, the rest well-controlled asthma (38.1%). The difference between mean FEV1 before (67.9±10.6) and after nebulisation (80.6±9.7) was statistically signicant (p<0.00*). Among those with >12 reversibility, 64.5% were in partly/uncontrolled and 35.5% in well-controlled asthma and the difference was statistically signicant (p -0.013*). The CONCLUSION: nding in the study that 68.9% had partly/uncontrolled asthma is an eye-opener to optimise protocol-based treatment among children. The statistically signicant difference of >12% before and after nebulisation a marker of poor control was observed in 64.5% of partly/uncontrolled asthma compared to 35.5% of well controlled asthma. Hence, the persistence of a signicant degree of bronchodilator response noted in those with partly/uncontrolled asthma is recommended as an objective surrogate of poor asthma control in children who can co-operate for a PFT in order to optimise protocol-based treatment.

Pulmonary changes among asymptomatic smokers using high-resolution computed tomography and pulmonary function tests

Objective To detect pulmonary changes among asymptomatic smokers using an inspiratory and expiratory high-resolution computed tomography (HRCT) and pulmonary function tests (PFT). Pulmonary changes associated with smoking are now an increasing public health concern. Computed tomography, especially HRCT, is the best choice for visualizing lung morphology. Patients and methods The study was a cohort study conducted at Shebeen Chest Hospital from January 2019 to January 2021. The study was carried out on 120 adult males; 80 of them were asymptomatic smokers and 40 matched healthy nonsmokers served as the control group. All underwent routine chest radiograph, PA view, HRCT (inspiratory, expiratory) film, and PFTs in the form of forced expiratory vital capacity (FVC), forced expiratory volume after 1 s (FEV1), FEV1/FVC, mean forced expiratory flow, and peak expiratory flow. Comparison between the two groups was done according to HRCT and PFT. Result There was significant difference between inspiratory and expiratory HRCT regarding air trapping between cases. Inspiratory air trapping was present in 4% while expiratory air trapping was present in 18%. There was highly significant difference between cases and controls regarding emphysema and bronchial thickening, subpleural line. There was no statistically significant difference between the two groups regarding FVC, forced expiratory flow 25–75, and FEV1/FVC, while there was a significant difference between them regarding PFT pattern results (P<0.05). Conclusion HRCT is the most sensitive imaging modality for diagnosing early emphysema in asymptomatic smokers. HRCT of the lung can detect lung abnormalities noninvasively.

An attempt to differentiate dysmetabolism variants based on biological age in combination with the induction of physiological ketosis: mini-review and own results

Background: Metabolic flexibility describes the body's adaptive ability to changing metabolic or energy requirements. Objective: To determine the possibility of detecting dysmetabolism based on bioimpedancometry (systemic dysmetabolism) and metabolic flexibility (local dysmetabolism) by the intensity of switching from the glucogenic to the ketogenic variant of energy supply. Biological (metabolic) clock was calculated by the difference between chronological age (CHR-age) minus biological (metabolic) age (MET-age), as more than 1year difference. Material and methods: The biological age was determined with tetrapolar bioimpedansometry. The amino acid L-lysine was taken orally to induce ketosis, the content of ketones in the exhaled air was dynamically recorded for 3 hours. Results: Group with younger MET-age FM(fate mass): r = -0,36; p = 0,04( y = 18,1 - 0,08*x) and intracellular fluid (ICF): r = -0,5 p = 0,002( y = 1796,2 - 8,9*x) and group with older MET-age - ICF: r = -0,32; p = 0,074 (y = 24,38 - 0,08*x) (not significant or loss of reliability), FM: r = -0,36; p = 0,04 (y = 18,1 - 0,08*x). At the same time, highly sensitive CRP (hsCRP) above 5 mg/l was found much more often in group (26% v.s.2%, Chi-square (df=1) - 6,50, p= 0,01), as well as cholesterol over 6.5 mmol/l. Moreover, hsCRP significant more higher in older MET-age group: mean - 3,5 (95%CI =2,3 - 4,7) v.s. 1,9 (95%CI=1,5 - 2,3). These data clearly indicate the presence metabolic dysfunction (systemic dysmetabolism) in the group with premature metabolic (biological) age. A significant relationship was found between the degree of hepatic ketosis and the difference between biological and chronological age, i.e. younger age was characterized by higher metabolic flexibility. The KETO-MET-younger group (group-2) has significantly more Body Cells Mass (BCM) proportion (50,5 (95%CI =50,0-51,1) v.s. 43,9(95%CI =42,8-45,0) ) and less content of Fat Mass (in kg) (14,7 (95%CI =13,7-15,6) v.s. 27,9(95%CI =25,3-30,5), according to the results of BIM-V. KETO-Lysine test revealed a significantly more frequent increase in blood ALT activity (more than 30 IU) in the older MET-age group (41% vs. 5%), Conclusions: The results deepen the scientific understanding of the metabolic flexibility assessment according to the original indicator - the induction of physiological ketosis by an amino acid metabolized in the liver, and make it possible to implement a personalized approach in the diagnosis and differentiation of metabolic disorders

High-precision mapping reveals rare N6-deoxyadenosine methylation in the mammalian genome

N6-deoxyadenosine methylation (6mA) is the most widespread type of DNA modification in prokaryotes and is also abundantly distributed in some unicellular eukaryotes. However, 6mA levels are remarkably low in mammals. The lack of a precise and comprehensive mapping method has hindered more advanced investigations of 6mA. Here, we report a new method MM-seq (modification-induced mismatch sequencing) for genome-wide 6mA mapping based on a novel detection principle. We found that modified DNA bases are prone to form a local open region that allows capture by antibody, for example, via a DNA breathing or base-flipping mechanism. Specified endonuclease or exonuclease can recognize the antibody-stabilized mismatch-like structure and mark the exact modified sites for sequencing readout. Using this method, we examined the genomic positions of 6mA in bacteria (E. coli), green algae (C. reinhardtii), and mammalian cells (HEK239T, Huh7, and HeLa cells). In contrast to bacteria and green algae, human cells possess a very limited number of 6mA sites which are sporadically distributed across the genome of different cell types. After knocking out the RNA m6A methyltransferase METTL3 in mouse ES cells, 6mA becomes mostly diminished. Our results imply that rare 6mA in the mammalian genome is introduced by RNA m6A machinery via a non-targeted mechanism.

Clinical and Epidemiological Features of Allergies in Schoolchildren of the Chechen Republic: Results of an Epidemiological Study

Background. One of the topical issues of modern medicine is the widespread increase in the incidence of allergic pathology. Objective. The aim of the study is to investigate clinical and epidemiological features of allergies in schoolchildren of the Chechen Republic. Methods. We performed clinical and diagnostic verification of allergies according to clinical guidelines in patients who positively answered the ISAAC questionnaire (n = 80) — 46 first-grade and 34 eighth-grade pupils. The first diagnostic step on studying the clinical manifestations in observed children was the history taking, complaints, physical examination. Laboratory and instrumental diagnosis included: IgE total, detection of skin sensitivity to allergens via standard pollen, domestic, epidermal, and food allergens (produced by I.M. Mechnikov Research Institute of Vaccines and Sera, Stavropol Research Institute of Vaccines and Sera), revealing of allergen-specific antibodies, component-divided allergen diagnosis via indirect immunofluorescence with ImmunoCAP analyzer, respiratory function evaluation with CareFusion, nitric oxide level detection in exhaled air via portable NObreath analyzer. If needed, specialised medical consultation were performed. Results. Asthma was detected in 37 (46.3%) children, allergic rhinitis (AR) — in 37 (46.3%), atopic dermatitis (AD) — in 5 (6.3%) according to the results of our study. The most common combination of medical conditions in examined patients was combination of asthma and AR. There were no statistically significant differences in age groups. No gender differences were reported in the study. The highest incidence of asthma and AR was revealed in city residents (p < 0.05), while the AD incidence in the city and rural areas did not differ significantly. The sensibilization spectrum analysis in schoolchildren of the Chechen Republic revealed predominance of sensitivity to pollen (ragweed, herd grass) and domestic allergens (Dermatophagoides pteronyssinus, Dermatophagoides farinae). Sensitization to food allergens in children of the Chechen Republic did not have significant differences in the frequency of occurrence of individual allergens, that is, unlike pollen and household sensitization, a regional rating on the dominance of certain food allergens was not obtained. Sensibilization to epidermal allergens was also less common, the predominant one was the cat allergen. Conclusion. Thus, the first study on the territory of the Chechen Republic carried out according to the ISAAC program has revealed high prevalence of allergies in schoolchildren. Moreover, regional features of sensibilization structure have been identified. It will allow us to maintain economically optimal diagnosis of allergic diseases in children living in the Chechen Republic.

Mixed-integer quadratic programming approach for noninvasive estimation of respiratory effort profile during pressure support ventilation.

Information about respiratory mechanics such as resistance, elastance, and muscular pressure is important to mitigate ventilator-induced lung injury. Particularly during pressure support ventilation, the available options to quantify breathing effort and calculate respiratory system mechanics are often invasive or complex. We herein propose a robust and flexible estimation of respiratory effort better than current methods. We developed a method for non-invasively estimating breathing effort using only flow and pressure signals. Mixed-integer quadratic programming (MIQP) was employed, and the binary variables were the switching moments of the respiratory effort waveform. Mathematical constraints, based on ventilation physiology, were set for some variables to restrict feasible solutions. Simulated and patient data were used to verify our method, and the results were compared to an established estimation methodology. Our algorithm successfully estimated the respiratory effort, resistance, and elastance of the respiratory system, resulting in more robust performance and faster solver times than a previously proposed algorithm that used quadratic programming (QP) techniques. In a numerical simulation benchmark, the worst-case errors for resistance and elastance were 25% and 23% for QP versus <0.1% and <0.1% for MIQP, whose solver times were 4.7s and 0.5s, respectively. This approach can estimate several breathing effort profiles and identify the respiratory system's mechanical properties in invasively ventilated critically ill patients.

Exhaled phospholipid transfer protein and hepatocyte growth factor receptor in lung adenocarcinoma

BackgroundScreening decreases mortality among lung cancer patients but is not widely implemented, thus there is an unmet need for an easily accessible non-invasive method to enable early diagnosis. Particles in exhaled air offer a promising such diagnostic tool. We investigated the validity of a particles in exhaled air device (PExA) to measure the particle flow rate (PFR) and collect exhaled breath particles (EBP) to diagnose primary lung adenocarcinoma (LUAD).MethodsSeventeen patients listed for resection of LUAD stages IA–IIIA and 18 non-cancer surgical control patients were enrolled. EBP were collected before and after surgery for LUAD, and once for controls. Proteomic analysis was carried out using a proximity extension assay technology. Results were validated in both plasma from the same cohort and with microarray data from healthy lung tissue and LUAD tissue in the GSE10072 dataset.ResultsOf the 92 proteins analyzed, levels of five proteins in EBP were significantly higher in the LUAD patients compared to controls. Levels of phospholipid transfer protein (PLTP) and hepatocyte growth factor receptor (MET) decreased in LUAD patients after surgery compared to control patients. PFR was significantly higher in the LUAD cohort at all timepoints compared to the control group. MET in plasma correlated significantly with MET in EBP.ConclusionCollection of EBP and measuring of PFR has never been performed in patients with LUAD. In the present study PFR alone could distinguish between LUAD and patients without LUAD. PLTP and MET were identified as potential biomarkers to evaluate successful tumor excision.

Breath Tests Used in the Context of Bariatric Surgery.

This review article focuses on the use of breath tests in the field of bariatrics and obesitology. The first part of the review is an introduction to breath test problematics with a focus on their use in bariatrics. The second part provides a brief history of breath testing. Part three describes how breath tests are used for monitoring certain processes in various organs and various substances in exhaled air and how the results are analyzed and evaluated. The last part covers studies that described the use of breath tests for monitoring patients that underwent bariatric treatments. Although the number of relevant studies is small, this review could promote the future use of breath testing in the context of bariatric treatments.