15 results on '"Pawel Mochalski"'
Search Results
2. In vitro profiling of volatile organic compounds released by Simpson-Golabi-Behmel syndrome adipocytes
- Author
-
Pawel Mochalski, Karl Unterkofler, Andreas Leiherer, Axel Mündlein, Chris A. Mayhew, Eva Diem, and Heinz Drexel
- Subjects
Heart Defects, Congenital ,Pentanal ,Clinical Biochemistry ,Ethyl acetate ,Adipose tissue ,610 Medicine & health ,030226 pharmacology & pharmacy ,01 natural sciences ,Biochemistry ,Hexanal ,Gas Chromatography-Mass Spectrometry ,Gigantism ,Analytical Chemistry ,03 medical and health sciences ,chemistry.chemical_compound ,0302 clinical medicine ,Intellectual Disability ,Adipocytes ,Humans ,Cells, Cultured ,Isoprene ,Volatile Organic Compounds ,Chromatography ,Chemistry ,010401 analytical chemistry ,Arrhythmias, Cardiac ,Genetic Diseases, X-Linked ,Cell Biology ,General Medicine ,Metabolism ,3. Good health ,0104 chemical sciences ,Breath gas analysis ,Gas chromatography ,Biomarkers - Abstract
Breath analysis offers a non-invasive and rapid diagnostic method for detecting various volatile organic compounds that could be indicators for different diseases, particularly metabolic disorders including type 2 diabetes mellitus. The development of type 2 diabetes mellitus is closely linked to metabolic dysfunction of adipose tissue and adipocytes. However, the VOC profile of human adipocytes has not yet been investigated. Gas chromatography with mass spectrometric detection and head-space needle trap extraction (two-bed Carbopack X/Carboxen 1000 needle traps) were applied to profile VOCs produced and metabolised by human Simpson Golabi Behmel Syndrome adipocytes. In total, sixteen compounds were identified to be related to the metabolism of the cells. Four sulphur compounds (carbon disulphide, dimethyl sulphide, ethyl methyl sulphide and dimethyl disulphide), three heterocyclic compounds (2-ethylfuran, 2-methyl-5-(methyl-thio)-furan, and 2-pentylfuran), two ketones (acetone and 2-pentanone), two hydrocarbons (isoprene and n-heptane) and one ester (ethyl acetate) were produced, and four aldehydes (2-methyl-propanal, butanal, pentanal and hexanal) were found to be consumed by the cells of interest. This study presents the first profile of VOCs formed by human adipocytes, which may reflect the activity of the adipose tissue enzymes and provide evidence of their active role in metabolic regulation. Our data also suggest that a previously reported increase of isoprene and sulphur compounds in diabetic patients may be explained by their production by adipocytes. Moreover, the unique features of this profile, including a high emission of dimethyl sulphide and the production of furan-containing VOCs, increase our knowledge about metabolism in adipose tissue and provide diagnostic potential for future applications.
- Published
- 2019
3. Effect of inhaled acetone concentrations on exhaled breath acetone concentrations at rest and during exercise
- Author
-
Chris A. Mayhew, Clemens Ager, Karl Unterkofler, Pawel Mochalski, and Julian King
- Subjects
Pulmonary and Respiratory Medicine ,Inhalation Exposure ,Volatile Organic Compounds ,Chromatography ,Time Factors ,Rest ,010401 analytical chemistry ,Exhalation ,Deuterated acetone ,01 natural sciences ,0104 chemical sciences ,Partition coefficient ,Acetone ,03 medical and health sciences ,chemistry.chemical_compound ,0302 clinical medicine ,Water soluble ,030228 respiratory system ,chemistry ,Breath Tests ,Humans ,Exercise ,Proton-transfer-reaction mass spectrometry - Abstract
Real-time measurements of the differences in inhaled and exhaled, unlabeled and fully deuterated acetone concentration levels, at rest and during exercise, have been conducted using proton transfer reaction mass spectrometry. A novel approach to continuously differentiate between the inhaled and exhaled breath acetone concentration signals is used. This leads to unprecedented fine grained data of inhaled and exhaled concentrations. The experimental results obtained are compared with those predicted using a simple three compartment model that theoretically describes the influence of inhaled concentrations on exhaled breath concentrations for volatile organic compounds with high blood:air partition coefficients, and hence is appropriate for acetone. An agreement between the predicted and observed concentrations is obtained. Our results highlight that the influence of the upper airways cannot be neglected for volatiles with high blood:air partition coefficients, i.e. highly water soluble volatiles.
- Published
- 2020
- Full Text
- View/download PDF
4. Studies pertaining to the monitoring of volatile halogenated anaesthetics in breath by proton transfer reaction mass spectrometry
- Author
-
Tilmann D. Märk, David Olivenza-León, Prema D Chellayah, Wolfgang Lederer, P. Watts, Pawel Mochalski, Judith Martini, Chris A. Mayhew, Veronika Ruzsanyi, Karl Unterkofler, and Michaela Malásková
- Subjects
Pulmonary and Respiratory Medicine ,Male ,Drift tube ,Mass spectrometry ,01 natural sciences ,Sevoflurane ,Mass Spectrometry ,03 medical and health sciences ,Desflurane ,0302 clinical medicine ,Electricity ,medicine ,Humans ,Proton-transfer-reaction mass spectrometry ,Density Functional Theory ,Ions ,Volatile Organic Compounds ,Inhalation ,Isoflurane ,Chemistry ,Hydrocarbons, Halogenated ,010401 analytical chemistry ,Radiochemistry ,Enflurane ,Signal Processing, Computer-Assisted ,0104 chemical sciences ,030228 respiratory system ,Breath Tests ,Anesthetics, Inhalation ,Female ,Protons ,medicine.drug - Abstract
Post-operative isoflurane has been observed to be present in the end-tidal breath of patients who have undergone major surgery, for several weeks after the surgical procedures. A major new non-controlled, non-randomized, and open-label approved study will recruit patients undergoing various surgeries under different inhalation anaesthetics, with two key objectives, namely (1) to record the washout characteristics following surgery, and (2) to investigate the influence of a patient’s health and the duration and type of surgery on elimination. In preparation for this breath study using proton transfer reaction time-of-flight mass spectrometry (PTR-TOF-MS), it is important to identify first the analytical product ions that need to be monitored and under what operating conditions. In this first paper of this new research programme, we present extensive PTR-TOF-MS studies of three major anaesthetics used worldwide, desflurane (CF3CHFOCHF2), sevoflurane ((CF3)2CHOCH2F), and isoflurane (CF3CHClOCHF2) and a fourth one, which is used less extensively, enflurane (CHF2OCF2CHFCl), but is of interest because it is an isomer of isoflurane. Product ions are identified as a function of reduced electric field (E/N) over the range of approximately 80 Td to 210 Td, and the effects of operating the drift tube under ‘normal’ or ‘humid’ conditions on the intensities of the product ions are presented. To aid in the analyses, density functional theory (DFT) calculations of the proton affinities and the gas-phase basicities of the anaesthetics have been determined. Calculated energies for the ion-molecule reaction pathways leading to key product ions, identified as ideal for monitoring the inhalation anaesthetics in breath with a high sensitivity and selectivity, are also presented.
- Published
- 2019
5. Ex vivo emission of volatile organic compounds from gastric cancer and non-cancerous tissue
- Author
-
Chris A. Mayhew, Carsten Jaeschke, Pawel Mochalski, Armands Sivins, Evita Gasenko, Gidi Shani, Hossam Haick, Roberts Skapars, Marcis Leja, Jan Mitrovics, Daiga Santare, Dan Erik Aronsson, and Clemens Ager
- Subjects
Pulmonary and Respiratory Medicine ,Adult ,Male ,Urine ,01 natural sciences ,Gas Chromatography-Mass Spectrometry ,03 medical and health sciences ,chemistry.chemical_compound ,0302 clinical medicine ,Limit of Detection ,Stomach Neoplasms ,medicine ,Humans ,Aged ,Detection limit ,Carbon disulfide ,Volatile Organic Compounds ,Chromatography ,010401 analytical chemistry ,Cancer ,Reproducibility of Results ,Middle Aged ,medicine.disease ,Toluene ,0104 chemical sciences ,3. Good health ,chemistry ,Breath Tests ,030220 oncology & carcinogenesis ,Female ,Gas chromatography ,Gas chromatography–mass spectrometry ,Ex vivo ,Biomarkers - Abstract
The presence of certain volatile organic compounds (VOCs) in the breath of patients with gastric cancer has been reported by a number of research groups; however, the source of these compounds remains controversial. Comparison of VOCs emitted from gastric cancer tissue to those emitted from non-cancerous tissue would help in understanding which of the VOCs are associated with gastric cancer and provide a deeper knowledge on their generation. Gas chromatography with mass spectrometric detection (GC-MS) coupled with head-space needle trap extraction (HS-NTE) as the pre-concentration technique, was used to identify and quantify VOCs released by gastric cancer and non-cancerous tissue samples collected from 41 patients during surgery. Excluding contaminants, a total of 32 VOCs were liberated by the tissue samples. The emission of four of them (carbon disulfide, pyridine, 3-methyl-2-butanone and 2-pentanone) was significantly higher from cancer tissue, whereas three compounds (isoprene, γ-butyrolactone and dimethyl sulfide) were in greater concentration from the non-cancerous tissues (Wilcoxon signed-rank test, p < 0.05). Furthermore, the levels of three VOCs (2-methyl-1-propene, 2-propenenitrile and pyrrole) were correlated with the occurrence of H. pylori; and four compounds (acetonitrile, pyridine, toluene and 3-methylpyridine) were associated with tobacco smoking. Ex vivo analysis of VOCs emitted by human tissue samples provides a unique opportunity to identify chemical patterns associated with a cancerous state and can be considered as a complementary source of information on volatile biomarkers found in breath, blood or urine.
- Published
- 2018
- Full Text
- View/download PDF
6. Assessment, origin, and implementation of breath volatile cancer markers
- Author
-
Yoav Y. Broza, Anton Amann, Pawel Mochalski, Hossam Haick, and Vera Ruzsanyi
- Subjects
Volatile Organic Compounds ,Lung Neoplasms ,Future perspective ,Computer science ,010401 analytical chemistry ,Nanotechnology ,Biosensing Techniques ,02 engineering and technology ,General Chemistry ,021001 nanoscience & nanotechnology ,01 natural sciences ,Data science ,Article ,Nanostructures ,3. Good health ,0104 chemical sciences ,Breath Tests ,Breath gas analysis ,Biomarkers, Tumor ,Humans ,0210 nano-technology - Abstract
A new non-invasive and potentially inexpensive frontier in the diagnosis of cancer relies on the detection of volatile organic compounds (VOCs) in exhaled breath samples. Breath can be sampled and analyzed in real-time, leading to fascinating and cost-effective clinical diagnostic procedures. Nevertheless, breath analysis is a very young field of research and faces challenges, mainly because the biochemical mechanisms behind the cancer-related VOCs are largely unknown. In this review, we present a list of 115 validated cancer-related VOCs published in the literature during the past decade, and classify them with respect to their “fat-to-blood” and “blood-to-air” partition coefficients. These partition coefficients provide an estimation of the relative concentrations of VOCs in alveolar breath, in blood and in the fat compartments of the human body. Additionally, we try to clarify controversial issues concerning possible experimental malpractice in the field, and propose ways to translate the basic science results as well as the mechanistic understanding to tools (sensors) that could serve as point-of-care diagnostics of cancer. We end this review with a conclusion and a future perspective.
- Published
- 2014
7. Proton transfer reaction time-of-flight mass spectrometric measurements of volatile compounds contained in peppermint oil capsules of relevance to real-time pharmacokinetic breath studies
- Author
-
Simona M. Cristescu, Veronika Ruzsanyi, Chris A. Mayhew, Pawel Mochalski, Ben Henderson, Michaela Malásková, and Prema D Chellayah
- Subjects
Pulmonary and Respiratory Medicine ,Menthofuran ,Time Factors ,Capsules ,Protonation ,Mass spectrometry ,01 natural sciences ,Gas Chromatography-Mass Spectrometry ,Matrix (chemical analysis) ,03 medical and health sciences ,chemistry.chemical_compound ,0302 clinical medicine ,Electricity ,Humans ,Plant Oils ,Density Functional Theory ,Ions ,Volatile Organic Compounds ,Limonene ,Chromatography ,010401 analytical chemistry ,Reproducibility of Results ,Mentha piperita ,Reference Standards ,Menthone ,0104 chemical sciences ,Time of flight ,Breath Tests ,030228 respiratory system ,chemistry ,Exhalation ,Molecular and Laser Physics ,Protons ,Menthol - Abstract
With the growing interest in the use of breath volatiles in the health sciences, the lack of standardization for the sampling and analysis of exhaled breath is becoming a major issue leading to an absence of conformity, reproducibility and reliability in spectrometric measurements. Through the creation of a worldwide ‘peppermint consortium’, the International Association of Breath Research has set up a task force to deal with this problem. Pharmacokinetic studies are proposed, and a real-time analytical technique that is being used is proton transfer reaction-time-of-flight-mass spectrometry (PTR-ToF-MS). This paper presents details on how the volatile compounds contained in a peppermint oil capsule, and hence on breath, appear in a PTR-ToF-MS. To aid that study, the key volatiles in the headspace of peppermint oil were first identified using gas chromatography-mass spectrometry, notably: menthol, menthone, 1,8-cineole, menthofuran, limonene, α-pinene and β-pinene. A PTR-ToF-MS analysis of these compounds has been undertaken, divorced from the complexity of the peppermint oil matrix using ‘normal’ and ‘saturated’ humidity drift-tube conditions, with the latter used to mimic breath samples, and over a range of reduced electric fields. There are no characteristic product ions that can distinguish monoterpenes and 1,8-cineole, and hence, without pre-separation, a combined washout for these volatiles can only be provided. By operating the drift tube above about 130 Td, there are characteristic product ions for menthone, menthofuran and menthol, namely m/z 155.14 (protonated menthone), m/z 151.11 (protonated menthofuran), m/z 139.15 (loss of H2O from protonated menthol) and m/z 83.09 (a fragment ion, C6H11 +, from menthol). These have been used to monitor, with a high specificity, the temporal profile of these three compounds in breath following the ingestion of a peppermint oil capsule. To aid in the analyses, the proton affinities and gas-phase basicities for the key volatiles investigated have been determined using density functional theory.
- Published
- 2019
8. Non-contact breath sampling for sensor-based breath analysis
- Author
-
Gidi Shani, Carsten Jaeschke, Evita Gasenko, Karl Unterkofler, Marcis Leja, Jan Mitrovics, Inese Polaka, Gregory Shuster, Pawel Mochalski, Hossam Haick, Edgars Vasiljevs, Chris A. Mayhew, and Roberts Skapars
- Subjects
Adult ,Male ,Pulmonary and Respiratory Medicine ,Spectrum analyzer ,MEDICINE [Research Subject Categories] ,breath sampling ,Diaphragmatic breathing ,Context (language use) ,01 natural sciences ,Young Adult ,03 medical and health sciences ,0302 clinical medicine ,volatile organic compounds ,Humans ,breath analysis ,Volatile Organic Compounds ,Respiration ,010401 analytical chemistry ,Breath sampling ,Exhalation ,Sampling (statistics) ,Middle Aged ,PTR-MS ,0104 chemical sciences ,Breath Tests ,030228 respiratory system ,Breath gas analysis ,Breathing ,Environmental science ,Female ,Biomedical engineering - Abstract
Breath analysis holds great promise for real-time and non-invasive medical diagnosis. Thus, there is a considerable need for simple-in-use and portable analyzers for rapid detection of breath indicators for different diseases in their early stages. Sensor technology meets all of these demands. However, miniaturized breath analyzers require adequate breath sampling methods. In this context, we propose non-contact sampling; namely the collection of breath samples by exhalation from a distance into a miniaturized collector without bringing the mouth into direct contact with the analyzing device. To evaluate this approach different breathing maneuvers have been tested in a real-time regime on a cohort of 23 volunteers using proton transfer reaction mass spectrometry. The breathing maneuvers embraced distinct depths of respiration, exhalation manners, size of the mouth opening and different sampling distances. Two inhalation modes(normal, relaxed breathing and deep breathing) and two exhalation manners(via smaller and wider lips opening)forming four sampling scenarios were selected. A sampling distance of approximately 2 cm was found to be a reasonable trade-off between sample dilution and requirement of no physical contact of the subject with the analyzer. All four scenarios exhibited comparable measurement reproducibility spread of around 10%. For normal, relaxed inspiration both dead-space and end-tidal phases of exhalation lasted approximately 1.5 s for both expiration protocols. Deep inhalation prolongs the end-tidal phase to about 3 s in the case of blowing via a small lips opening, and by 50% when the air is exhaled via a wide one. In conclusion, non-contact breath sampling can be considered as a promising alternative to the existing breath sampling methods, being relatively close to natural spontaneous breathing. --///-- This work is licensed under a CC BY 4.0 license., This work has received funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement no. 644031, Smart Phone for Disease Detection from Exhaled Breath. PM and KU gratefully acknowledge financial support from the Austrian Science Fund (FWF) under Grant No. P24736-B23.
- Published
- 2019
9. Breath isoprene: Muscle dystrophy patients support the concept of a pool of isoprene in the periphery of the human body
- Author
-
Julian King, Anton Amann, M. Stein, Martin Klieber, Matthias Baumann, Pawel Mochalski, Gerald Teschl, and Karl Unterkofler
- Subjects
Male ,Muscle tissue ,Adolescent ,Duchenne muscular dystrophy ,Biophysics ,Physiology ,01 natural sciences ,Biochemistry ,Article ,Body Temperature ,Cohort Studies ,Young Adult ,03 medical and health sciences ,chemistry.chemical_compound ,Hemiterpenes ,0302 clinical medicine ,Pentanes ,Respiration ,Butadienes ,medicine ,Humans ,Muscular dystrophy ,Molecular Biology ,Isoprene ,Chemistry ,010401 analytical chemistry ,Exhalation ,Cell Biology ,Muscle dystrophy ,Venous blood ,medicine.disease ,0104 chemical sciences ,Muscular Dystrophy, Duchenne ,Oxidative Stress ,medicine.anatomical_structure ,030228 respiratory system ,Female - Abstract
Breath isoprene accounts for most of the hydrocarbon removal via exhalation and is thought to serve as a non-invasive indicator for assaying several metabolic effects in the human body. The primary objective of this paper is to introduce a novel working hypothesis with respect to the endogenous source of this compound in humans: the idea that muscle tissue acts as an extrahepatic production site of substantial amounts of isoprene. This new perspective has its roots in quantitative modeling studies of breath isoprene dynamics under exercise conditions and is further investigated here by presenting pilot data from a small cohort of late stage Duchenne muscle dystrophy patients (median age 21, 4 male, 1 female). For these prototypic test subjects isoprene concentrations in end-tidal breath and peripheral venous blood range between 0.09-0.47 and 0.11-0.72 nmol/l, respectively, amounting to a reduction by a factor of 8 and more as compared to established nominal levels in normal healthy adults. While it remains unclear whether isoprene can be ascribed a direct physiological mechanism of action, some indications are given as to why isoprene production might have evolved in muscle.
- Published
- 2012
10. Dynamic profiles of volatile organic compounds in exhaled breath as determined by a coupled PTR-MS/GC-MS study
- Author
-
Susanne Teschl, Pawel Mochalski, Julian King, Anton Amann, Hartmann Hinterhuber, Karl Unterkofler, Alexander Kupferthaler, H. Koc, and Wojciech Filipiak
- Subjects
Adult ,Male ,Physiology ,Methyl acetate ,Biomedical Engineering ,Biophysics ,Mass spectrometry ,01 natural sciences ,Concentration ratio ,Noble Gases ,Gas Chromatography-Mass Spectrometry ,Acetone ,03 medical and health sciences ,chemistry.chemical_compound ,Young Adult ,0302 clinical medicine ,Hemiterpenes ,Physiology (medical) ,Pentanes ,Butadienes ,Ventilation-Perfusion Ratio ,Humans ,Organic Chemicals ,Isoprene ,Proton-transfer-reaction mass spectrometry ,Solid Phase Microextraction ,Chromatography ,010401 analytical chemistry ,Butane ,0104 chemical sciences ,Kinetics ,030228 respiratory system ,chemistry ,Breath Tests ,Exhalation ,Breathing ,Female ,Gas chromatography–mass spectrometry ,Protons ,Volatilization - Abstract
In this phenomenological study we focus on dynamic measurements of volatile organic compounds (VOCs) in exhaled breath under exercise conditions. An experimental setup efficiently combining breath-by-breath analyses using proton transfer reaction mass spectrometry (PTR-MS) with data reflecting the behaviour of major hemodynamic and respiratory parameters is presented. Furthermore, a methodology for complementing continuous VOC profiles obtained by PTR-MS with simultaneous SPME/GC-MS measurements is outlined. These investigations aim at evaluating the impact of breathing patterns, cardiac output or blood pressure on the observed breath concentration and allow for the detection and identification of several VOCs revealing characteristic rest-to-work transitions in response to variations in ventilation or perfusion. Examples of such compounds include isoprene, methyl acetate, butane, DMS and 2-pentanone. In particular, both isoprene and methyl acetate exhibit a drastic rise in concentration shortly after the onset of exercise, usually by a factor of about 3?5 within approximately 1 min of pedalling. These specific VOCs might also be interpreted as potentially sensitive indicators for fluctuations of blood or respiratory flow and can therefore be viewed as candidate compounds for future assessments of hemodynamics, pulmonary function and gas exchange patterns via observed VOC behaviour.
- Published
- 2010
- Full Text
- View/download PDF
11. Blood and breath levels of selected volatile organic compounds in healthy volunteers
- Author
-
Martin Klieber, Karl Unterkofler, Anton Amann, Hartmann Hinterhuber, Matthias Baumann, Pawel Mochalski, and Julian King
- Subjects
Adult ,Male ,Analyte ,Adolescent ,Solid-phase microextraction ,01 natural sciences ,Biochemistry ,Article ,Analytical Chemistry ,Terpene ,03 medical and health sciences ,0302 clinical medicine ,Healthy volunteers ,Electrochemistry ,Environmental Chemistry ,Humans ,Spectroscopy ,Solid Phase Microextraction ,Detection limit ,Volatile Organic Compounds ,Chromatography ,Chemistry ,Terpenes ,010401 analytical chemistry ,Smoking ,Ketones ,Middle Aged ,Mass spectrometric ,Hydrocarbons ,0104 chemical sciences ,030228 respiratory system ,Breath Tests ,Room air distribution ,Female ,Gas chromatography - Abstract
Gas chromatography with mass spectrometric detection (GC-MS) was used to identify and quantify volatile organic compounds in the blood and breath of healthy individuals. Blood and breath volatiles were pre-concentrated using headspace solid phase micro-extraction (HS-SPME) and needle trap devices (NTDs), respectively. The study involved a group of 28 healthy test subjects and resulted in the quantification of a total of 74 compounds in both types of samples. The concentrations of the species under study varied between 0.01 and 6700 nmol L(-1) in blood and between 0.02 and 2500 ppb in exhaled air. Limits of detection (LOD) ranged from 0.01 to 270 nmol L(-1) for blood compounds and from 0.01 to 0.7 ppb for breath species. Relative standard deviations for both measurement regimes varied from 1.5 to 14%. The predominant chemical classes among the compounds quantified were hydrocarbons (24), ketones (10), terpenes (8), heterocyclic compounds (7) and aromatic compounds (7). Twelve analytes were found to be highly present in both blood and exhaled air (with incidence rates higher than 80%) and for 32 species significant differences (Wilcoxon signed-rank test) between room air and exhaled breath were observed. By comparing blood, room air and breath levels in parallel, a tentative classification of volatiles into endogenous and exogenous compounds can be achieved.
- Published
- 2013
12. Human blood and plasma partition coefficients for C4-C8 n-alkanes, isoalkanes, and 1-alkenes
- Author
-
Julian King, Karl Unterkofler, Alexander Kupferthaler, Pawel Mochalski, Anton Amann, and Hartmann Hinterhuber
- Subjects
Adult ,Male ,Analytical chemistry ,Alkenes ,Toxicology ,Solid-phase microextraction ,01 natural sciences ,Gas Chromatography-Mass Spectrometry ,03 medical and health sciences ,0302 clinical medicine ,Alkanes ,Humans ,Solubility ,Solid Phase Microextraction ,Whole blood ,Chromatography ,Chemistry ,Air ,010401 analytical chemistry ,Extraction (chemistry) ,Middle Aged ,0104 chemical sciences ,Partition coefficient ,Boiling point ,030220 oncology & carcinogenesis ,Female ,Gas chromatography ,Dimensionless quantity - Abstract
Human blood:air and plasma:air partition coefficients for C4-C8 n-alkanes, isoalkanes, and 1-alkenes were determined using multiple headspace extraction coupled with solid phase microextraction and gas chromatography. Mean blood:air partition coefficients expressed in the form of dimensionless blood-to-air concentration ratio (g/mLb/g/mLa) were 0.183, 0.416, 1.08, 2.71, and 5.77 for C4-C8 n-alkanes; 0.079, 0.184, 0.473, 1.3, and 3.18 for C4-C8 isoalkanes; and 0.304, 0.589, 1.32, 3.5, and 7.01 for C4-C8 1-alkenes, respectively (n = 8). The reported partition coefficient values increased exponentially with boiling points, molecular weights, and the carbon atoms in the particle. The solubility of 1-alkenes in blood was higher than in plasma, whereas the blood:air and plasma:air partition coefficients of n-alkanes and isoalkanes did not differ significantly. Consequently, additional interactions of 1-alkenes with whole blood seem to occur. The presented findings are expected to be particularly useful for assessing the uptake, distribution, and elimination of hydrocarbons in human organism.
- Published
- 2012
13. A modeling-based evaluation of isothermal rebreathing for breath gas analyses of highly soluble volatile organic compounds
- Author
-
Susanne Teschl, Anton Amann, Hartmann Hinterhuber, Julian King, Helin Koc, Gerald Teschl, Karl Unterkofler, and Pawel Mochalski
- Subjects
Pulmonary and Respiratory Medicine ,Adult ,Male ,FOS: Physical sciences ,01 natural sciences ,Quantitative Biology - Quantitative Methods ,Isothermal process ,Acetone ,03 medical and health sciences ,chemistry.chemical_compound ,0302 clinical medicine ,Tidal breathing ,Humans ,Inert gas ,Lung ,Quantitative Methods (q-bio.QM) ,Volatile Organic Compounds ,Chromatography ,Pulmonary Gas Exchange ,Methanol ,Respiration ,010401 analytical chemistry ,Exhalation ,Middle Aged ,Physics - Medical Physics ,3. Good health ,0104 chemical sciences ,030228 respiratory system ,chemistry ,Breath Tests ,Spirometry ,FOS: Biological sciences ,Medical Physics (physics.med-ph) - Abstract
Isothermal rebreathing has been proposed as an experimental technique for estimating the alveolar levels of hydrophilic volatile organic compounds (VOCs) in exhaled breath. Using the prototypic test compound acetone we demonstrate that the end-tidal breath profiles of such substances during isothermal rebreathing show characteristics that contradict the conventional pulmonary inert gas elimination theory due to Farhi. On the other hand, these profiles can reliably be captured by virtue of a previously developed mathematical model for the general exhalation kinetics of highly soluble, blood-borne VOCs, which explicitly takes into account airway gas exchange as major determinant of the observable breath output. This model allows for a mechanistic analysis of various rebreathing protocols suggested in the literature. In particular, it clarifies the discrepancies between in vitro and in vivo blood-breath ratios of hydrophilic VOCs and yields further quantitative insights into the physiological components of isothermal rebreathing., Comment: 21 pages
- Published
- 2012
14. The role of mathematical modeling in VOC analysis using isoprene as a prototypic example
- Author
-
Pawel Mochalski, Karl Unterkofler, Helin Koc, Anton Amann, Hartmann Hinterhuber, Gerald Teschl, Julian King, and Susanne Teschl
- Subjects
Pulmonary and Respiratory Medicine ,FOS: Physical sciences ,01 natural sciences ,Quantitative Biology - Quantitative Methods ,03 medical and health sciences ,chemistry.chemical_compound ,Hemiterpenes ,Pentanes ,Butadienes ,Humans ,Isoprene ,Quantitative Methods (q-bio.QM) ,030304 developmental biology ,0303 health sciences ,Pulmonary Gas Exchange ,010401 analytical chemistry ,Models, Theoretical ,Respiratory activity ,Clinical routine ,Physics - Medical Physics ,0104 chemical sciences ,3. Good health ,chemistry ,Breath Tests ,Exhalation ,FOS: Biological sciences ,Environmental science ,Biochemical engineering ,Medical Physics (physics.med-ph) - Abstract
Isoprene is one of the most abundant endogenous volatile organic compounds (VOCs) contained in human breath and is considered to be a potentially useful biomarker for diagnostic and monitoring purposes. However, neither the exact biochemical origin of isoprene nor its physiological role are understood in sufficient depth, thus hindering the validation of breath isoprene tests in clinical routine. Exhaled isoprene concentrations are reported to change under different clinical and physiological conditions, especially in response to enhanced cardiovascular and respiratory activity. Investigating isoprene exhalation kinetics under dynamical exercise helps to gather the relevant experimental information for understanding the gas exchange phenomena associated with this important VOC. A first model for isoprene in exhaled breath has been developed by our research group. In the present paper, we aim at giving a concise overview of this model and describe its role in providing supportive evidence for a peripheral (extrahepatic) source of isoprene. In this sense, the results presented here may enable a new perspective on the biochemical processes governing isoprene formation in the human body., Comment: 17 pages
- Published
- 2011
15. Instrumental sensing of trace volatiles—a new promising tool for detecting the presence of entrapped or hidden people
- Author
-
Helmut Wiesenhofer, Chris A. Mayhew, Veronika Ruzsanyi, and Pawel Mochalski
- Subjects
Pulmonary and Respiratory Medicine ,Chemical signature ,Volatile Organic Compounds ,Computer science ,010401 analytical chemistry ,Survivability ,Early detection ,Context (language use) ,02 engineering and technology ,021001 nanoscience & nanotechnology ,Computer security ,computer.software_genre ,01 natural sciences ,Urban search and rescue ,0104 chemical sciences ,Disasters ,ROC Curve ,Odorants ,Humans ,0210 nano-technology ,Electronic Nose ,computer ,Search and rescue ,Biomarkers ,TRACE (psycholinguistics) - Abstract
There is a growing demand for rapid analytical systems to detect the presence of humans who are either entrapped as a result of a disaster or, in particular, hidden, as in the case of smuggling or trafficking. The trafficking and smuggling of people to Europe have reached epidemic proportions in recent years. This does not only put a major strain on European resources, but puts at risk the health and lives of the people being trafficked or smuggled. In this context, the early detection and interception of smuggled/trafficked people is of particular importance in terms of saving migrants from life-threatening situations. Similarly, the early and rapid location of entrapped people is crucial for urban search and rescue (USaR) operations organized after natural or man-made disasters. Since the duration of entrapment determines the survivability of victims, each novel detecting tool could considerably improve the effectiveness of the rescue operations and hence potentially save lives. Chemical analysis aiming at using a volatile chemical fingerprint typical for the presence of hidden humans has a huge potential to become an extremely powerful technology in this context. Interestingly, until now this approach has received little attention, despite the fact that trained dogs have been used for decades to detect the presence of buried people through scent. In this article we review the current status of using analytical techniques for chemical analysis for search and rescue operations, and discuss the challenges and future directions. As a practical implementation of this idea, we describe a prototype portable device for use in the rapid location of hidden or entrapped people that employs ion mobility spectrometry and a sensor array for the recognition of the chemical signature of the presence of humans.
- Full Text
- View/download PDF
Catalog
Discovery Service for Jio Institute Digital Library
For full access to our library's resources, please sign in.