Extending PTR based breath analysis to real-time monitoring of reactive volatile organic compounds

Pugliese, Giovanni; Trefz, Phillip; Brock, Beate; Schubert, Jochen K.; Miekisch, Wolfram

doi:10.1039/c9an01478k

Cited by 18 publications

(15 citation statements)

References 36 publications

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“…When IL-1β was added to an exhaled breath sample obtained from a healthy volunteer, a 2 orders decrease in sensitivity was observed (Figure 3B). Probably some components of the sample (not only proteins, but also small molecules, such as ammonia, amines, and thiols, which are present in exhaled breath 28 ) may interfere with covalent immobilization of an analyte. To overcome this problem, an additional step of electrophoretic separation of the sample prior to photochemical immobilization was introduced into the assay procedure.…”

Section: ■ Results and Discussionmentioning

confidence: 99%

Rapid Ultrasensitive Gel-Free Immunoblotting with Magnetic Labels

2020

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Immunoblotting is widely used for the detection of proteins using specific antibodies. We present here a new immunoblotting method, which is characterized by exceptional sensitivity, rapidness, and low consumption of antibodies. A thin conductive layer between touching hydrophilic cellulose membranes instead of polyacrylamide gel is used for the electrophoretic separation of proteins. Contrary to common Western blotting, the separation occurs in nondenaturing conditions. The membrane surface is smoothed by deposition of the cellulose layer and modified with azidophenyl groups, allowing for the photochemical in situ immobilization of proteins, which are carried out after the electrophoresis. Thus, the additional step of transferring the protein from the gel onto the membrane is eliminated. Specific protein bands are then visualized by decoration with magnetic beads. The limit of detection of interleukin IL-1β reaches 0.3 fg or ∼104 molecules, whereas the total blotting time is about 5 min. The application of the technique is demonstrated by the detection of IL-1β, total IgA, and IgA specific to Mycobacterium tuberculosis antigen in the exhaled breath samples, obtained from healthy subjects and tuberculosis patients.

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Section: ■ Results and Discussionmentioning

confidence: 99%

Rapid Ultrasensitive Gel-Free Immunoblotting with Magnetic Labels

2020

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“…These aforementioned three masses were tentatively attributed to phenol (C 6 H 6 O), cresol (C 7 H 8 O) and indole (C 8 H 7 N) which are produced by the gut microbiota from tryptophan and tyrosine, respectively 39 , 40 . Increased breath concentrations of indole and phenol were observed after the ingestion of a protein oral challenge as result of gut bacterial degradation of tryptophan and tyrosine 41 . Tryptophan and tyrosine are the precursors of serotonin, dopamine, and noradrenalin, neurotransmitters which are rapidly generated upon sexual arousal and play a critical role in human sexual behavior 7 , 42 , 43 .…”

Section: Discussionmentioning

confidence: 99%

Breath chemical markers of sexual arousal in humans

Wang

Pugliese

Carrito

et al. 2022

Sci Rep

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The chemical composition of exhaled breath was examined for volatile organic compound (VOC) indicators of sexual arousal in human beings. Participants (12-male, 12-female) were shown a randomized series of three emotion-inducing 10-min film clips interspersed with 3-min neutral film clips. The films caused different arousals: sports film (positive-nonsexual); horror film (negative-nonsexual); and erotic (sexual) that were monitored with physiological measurements including genital response and temperature. Simultaneously the breath was monitored for VOC and CO2. While some breath compounds (methanol and acetone) changed uniformly irrespective of the film order, several compounds did show significant arousal associated changes. For both genders CO2 and isoprene decreased in the sex clip. Some male individuals showed particularly strong increases of indole, phenol and cresol coincident with sexual arousal that decreased rapidly afterwards. These VOCs are degradation products of tyrosine and tryptophan, precursors for dopamine, noradrenalin, and serotonin, and therefore represent potential breath markers of sexual arousal.

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“…Such compounds tend to react with the tubing materials of the analytical system and response time can be delayed. While our system is optimised for breath analysis [14], further optimizations of the measurement conditions and inlet system could reduce possible interactions of o-toluidine with the surfaces within the analytical system [15]. In the regional anaesthesia group B, prilocaine and o-toluidine blood concentrations as well as o-toluidine breath concentrations reached their peak median concentrations after 30 min and slowly decreased afterward.…”

Section: Discussionmentioning

confidence: 99%

Non-Invasive O-Toluidine Monitoring during Regional Anaesthesia with Prilocaine and Detection of Accidental Intravenous Injection in an Animal Model

et al. 2022

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Regional anaesthesia is well established as a standard method in clinical practice. Currently, the local anaesthetics of amino-amide types such as prilocaine are frequently used. Despite routine use, complications due to overdose or accidental intravenous injection can arise. A non-invasive method that can indicate such complications early would be desirable. Breath gas analysis offers great potential for the non-invasive monitoring of drugs and their volatile metabolites. The physicochemical properties of o-toluidine, the main metabolite of prilocaine, allow its detection in breath gas. Within this study, we investigated whether o-toluidine can be monitored in exhaled breath during regional anaesthesia in an animal model, if correlations between o-toluidine and prilocaine blood levels exist and if accidental intravenous injections are detectable by o-toluidine breath monitoring. Continuous o-toluidine monitoring was possible during regional anaesthesia of the cervical plexus and during simulated accidental intravenous injection of prilocaine. The time course of exhaled o-toluidine concentrations considerably differed depending on the injection site. Intravenous injection led to an immediate increase in exhaled o-toluidine concentrations within 2 min, earlier peak and higher maximum concentrations, followed by a faster decay compared to regional anaesthesia. The strength of correlation of blood and breath parameters depended on the injection site. In conclusion, real time monitoring of o-toluidine in breath gas is possible by means of PTR-ToF-MS. Since simulated accidental intravenous injection led to an immediate increase in exhaled o-toluidine concentrations within 2 min and higher maximum concentrations, monitoring exhaled o-toluidine may potentially be applied for the non-invasive real-time detection of accidental intravenous injection of prilocaine.

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Extending PTR based breath analysis to real-time monitoring of reactive volatile organic compounds

Abstract: Direct time resolved mass spectrometric monitoring of reactive exhaled nitrogen- and sulfur-containing volatile organic compounds (VOCs) related to metabolic processes, diseases and bacterial activity.

Cited by 18 publications

References 36 publications

Rapid Ultrasensitive Gel-Free Immunoblotting with Magnetic Labels

Rapid Ultrasensitive Gel-Free Immunoblotting with Magnetic Labels

Breath chemical markers of sexual arousal in humans

Non-Invasive O-Toluidine Monitoring during Regional Anaesthesia with Prilocaine and Detection of Accidental Intravenous Injection in an Animal Model

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