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Changes in exhaled volatile organic compounds following indirect bronchial challenge in suspected asthma
Adam Peel, Ran Wang, Waqar Ahmed, Iain R. White, Maxim Wilkinson, Yoon K. Loke, Andrew M. Wilson, Stephen J. Fowler, 2023, original scientific article

Abstract: Background Inhaled mannitol provokes bronchoconstriction via mediators released during osmotic degranulation of inflammatory cells, and, hence represents a useful diagnostic test for asthma and model for acute attacks. We hypothesised that the mannitol challenge would trigger changes in exhaled volatile organic compounds (VOCs), generating both candidate biomarkers and novel insights into their origin. Methods Participants with a clinical diagnosis of asthma, or undergoing investigation for suspected asthma, were recruited. Inhaled mannitol challenges were performed, followed by a sham challenge after 2 weeks in participants with bronchial hyper-responsiveness (BHR). VOCs were collected before and after challenges and analysed using gas chromatography–mass spectrometry. Results Forty-six patients (mean (SD) age 52 (16) years) completed a mannitol challenge, of which 16 (35%) were positive, and 15 of these completed a sham challenge. Quantities of 16 of 51 identified VOCs changed following mannitol challenge (p<0.05), of which 11 contributed to a multivariate sparse partial least square discriminative analysis model, with a classification error rate of 13.8%. Five of these 16 VOCs also changed (p<0.05) in quantity following the sham challenge, along with four further VOCs. In patients with BHR to mannitol distinct postchallenge VOC signatures were observed compared with post-sham challenge. Conclusion Inhalation of mannitol was associated with changes in breath VOCs, and in people with BHR resulted in a distinct exhaled breath profile when compared with a sham challenge. These differentially expressed VOCs are likely associated with acute airway inflammation and/or bronchoconstriction and merit further investigation as potential biomarkers in asthma.
Keywords: asthma, exhaled volatile organic compounds, pulmonology, breath metabolomics
Published in RUNG: 31.07.2023; Views: 707; Downloads: 2
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Breath and plasma metabolomics to assess inflammation in acute stroke
Waqar Ahmed, Iain R. White, Maxim Wilkinson, Craig Johnson, Nicholas J. W. Rattray, Amit K. Kishore, Royston Goodacre, Craig J. Smith, Stephen J. Fowler, 2021, original scientific article

Abstract: Inflammation is strongly implicated in both injury and repair processes occurring after stroke. In this exploratory study we assessed the feasibility of repeated sampling of exhaled volatile organic compounds and performed an untargeted metabolomic analysis of plasma collected at multiple time periods after stroke. Metabolic profiles were compared with the time course of the inflammatory markers C-reactive protein (CRP) and interleukin-6 (IL-6). Serial breath sampling was well-tolerated by all patients and the measurement appears feasible in this group. We found that exhaled decanal tracks CRP and IL-6 levels post-stroke and correlates with several metabolic pathways associated with a post-stroke inflammatory response. This suggests that measurement of breath and blood metabolites could facilitate development of novel therapeutic and diagnostic strategies. Results are discussed in relation to the utility of breath analysis in stroke care, such as in monitoring recovery and complications including stroke associated infection.
Keywords: stroke, metabolomics, breath, VOCs, inflammation
Published in RUNG: 18.11.2021; Views: 1567; Downloads: 62
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Untargeted molecular analysis of exhaled breath as a diagnostic test for ventilator-associated lower respiratory tract infections (BreathDx)
Pouline M. van Oort, Tamara M. E. Nijsen, Iain R. White, Hugo Knobel, Timothy Felton, Nicholas J. W. Rattray, Oluwasola Lawal, Murtaza Bulut, Waqar Ahmed, Antonio Artigas, 2021, short scientific article

Abstract: Patients suspected of ventilator-associated lower respiratory tract infections (VA-LRTIs) commonly receive broad-spectrum antimicrobial therapy unnecessarily. We tested whether exhaled breath analysis can discriminate between patients suspected of VA-LRTI with confirmed infection, from patients with negative cultures. Breath from 108 patients suspected of VA-LRTI was analysed by gas chromatography-mass spectrometry. The breath test had a sensitivity of 98% at a specificity of 49%, confirmed with a second analytical method. The breath test had a negative predictive value of 96% and excluded pneumonia in half of the patients with negative cultures. Trial registration number: UKCRN ID number 19086, registered May 2015.
Keywords: ventilator-associated pneumonia, breath analysis, volatile organic compounds, metabolomics, intensive care, hospital acquired infections
Published in RUNG: 07.09.2021; Views: 3968; Downloads: 0
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A microbiome and metabolomic signature of phases of cutaneous healing identified by profiling sequential acute wounds of human skin: An exploratory study
Mohammed Ashrafi, Yun Xu, Howbeer Muhamadali, Iain R. White, Maxim Wilkinson, Mohamed Baguneid, Roy Goodacre, Ardeshir Bayat, 2020, original scientific article

Abstract: Profiling skin microbiome and metabolome has been utilised to gain further insight into wound healing processes. The aims of this multi-part temporal study in 11 volunteers were to analytically profile the dynamic wound tissue and headspace metabolome and sequence microbial communities in acute wound healing at days 0, 7, 14, 21 and 28, and to investigate their relationship to wound healing, using non-invasive quantitative devices. Metabolites were obtained using tissue extraction, sorbent and polydimethylsiloxane patches and analysed using GCMS. PCA of wound tissue metabolome clearly separated time points with 10 metabolites of 346 being involved in separation. Analysis of variance-simultaneous component analysis identified a statistical difference between the wound headspace metabolome, sites (P = 0.0024) and time points (P<0.0001), with 10 out of the 129 metabolites measured involved with this separation between sites and time points. A reciprocal relationship between Staphylococcus spp. and Propionibacterium spp. was observed at day 21 (P<0.05) with a statistical correlation between collagen and Propionibacterium (r = 0.417; P = 0.038) and Staphylococcus (r = -0.434; P = 0.03). Procrustes analysis showed a statistically significant similarity between wound headspace and tissue metabolome with non-invasive wound devices. This exploratory study demonstrates the temporal and dynamic nature of acute wound metabolome and microbiome presenting a novel class of biomarkers that correspond to wound healing, with further confirmatory studies now necessary.
Keywords: metabolomics, skin, volatile organic compounds, VOCs, wound healing
Published in RUNG: 03.03.2020; Views: 2893; Downloads: 0
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Facilitating green care improvements in viticulture
Melita Sternad Lemut, Lorena Butinar, Adesida Rowland, Urban Česnik, Tjaša Jug, Paolo Sivilotti, Urška Vrhovšek, 2019, published scientific conference contribution

Abstract: The growing demand of consumers for environment-friendly and safe food products already forced many winemakers to restrict the application of synthetic fungicides to earlier season, trying to reduce the risk of residues being detected in wines. Main risk for infection by B. cinerea, however, occurs later in the season. To support an improvement in whole-season B. cinerea green care, the potential of yeasts as biocontrol agent (PBA) was studied. Selected yeasts were tested for their antifungal activities. Furthermore, a field experiment in Pinot noir and Pinot gris vineyards was designed to study different combinations of optimized canopy microclimate manipulation (CMM) techniques and PBA application. In experimental conditions, PBA's ability to maintain appropriate population density for disease prevention was observed. Grape and wine quality parameters were evaluated. Analytical approach of metabolomics was applied to upgrade the understanding of potentially induced changes in plant metabolism. Based on yeasts testing results, biocontrol yeast P. guilliermondii ZIM 624 was selected and after its field application, we were able to detect its suitable density on grapes until harvest. In case of early defoliation for both varieties smaller grape compactness was confirmed together with lower yield. Among grape basic quality parameters, optimized techniques showed positive effect on sugar content, but unexpectedly, in the treatments with biocontrol yeasts the trends toward higher acidity were noticed in Pinot gris. CMM and PBA introduction indicated some effects on grapevine biosynthetic behaviour but the differences in content of these metabolites compared to control were poorly detected in final wines with exception of mainly some flavonols, stilbenes and flavan-3-ols (and consequently total phenolic content).
Keywords: sustainable viticulture, Botrytis cinerea, yeasts, biocontrol, canopy microclimate manipulation, metabolomics, grapevine metabolites
Published in RUNG: 28.02.2020; Views: 3600; Downloads: 0
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Metabolic dysregulation in vitamin E and carnitine shuttle energy mechanisms associate with human frailty
Nicholas Rattray, Drupad Trivedi, Yun Xu, Tarani Chandola, Caroline Johnson, Alan Marshall, Krisztina Mekli, Zahra Rattray, Gindo Tampubolon, Bram Vanhoutte, Iain R. White, Frederick Wu, Neil Pendleton, James Nazroo, Royston Goodacre, 2019, original scientific article

Abstract: Global ageing poses a substantial economic burden on health and social care costs. Enabling a greater proportion of older people to stay healthy for longer is key to the future sustainability of health, social and economic policy. Frailty and associated decrease in resilience plays a central role in poor health in later life. In this study, we present a population level assessment of the metabolic phenotype associated with frailty. Analysis of serum from 1191 older individuals (aged between 56 and 84 years old) and subsequent longitudinal validation (on 786 subjects) was carried out using liquid and gas chromatography-mass spectrometry metabolomics and stratified across a frailty index designed to quantitatively summarize vulnerability. Through multivariate regression and network modelling and mROC modeling we identified 12 significant metabolites (including three tocotrienols and six carnitines) that differentiate frail and non-frail phenotypes. Our study provides evidence that the dysregulation of carnitine shuttle and vitamin E pathways play a role in the risk of frailty.
Keywords: metabolomics, frailty, ageing, LC-MS, serum
Published in RUNG: 08.11.2019; Views: 3125; Downloads: 90
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Breathomics and its Application for Disease Diagnosis: A Review of Analytical Techniques and Approaches
David J Beale, Oliver A H Jones, Avinash V Karpe, Ding Y Oh, Iain R. White, Konstantinos A Kouremenos, Enzo A Palombo, 2018, independent scientific component part or a chapter in a monograph

Abstract: The application of metabolomics to an ever-greater variety of sample types is a key focus of systems biology research. Recently, there has been a strong focus on applying these approaches toward the rapid analysis of metabolites found in non-invasively acquired samples, such as exhaled breath (also known as ‘breathomics’). The sampling process involved in collecting exhaled breath is nonintrusive and comparatively low-cost. It uses a series of globally approved methods and provides researchers with easy access to the metabolites secreted by the human body. Owing to its accuracy and rapid nature, metabolomic analysis of breath is a rapidly growing field that has proven effective in detecting and diagnosing the early stages of numerous diseases and infections. This review discusses the various collection and analysis methods currently applied in breathomics research. Some of the salient research completed in this field to date is also assessed and discussed in order to provide a basis for possible future scientific directions.
Keywords: Metabolomics, breath research, VOCs, breathomics
Published in RUNG: 22.07.2019; Views: 3000; Downloads: 0
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Grapes to wine: the nexus between berry ripening, composition and wine style
Katja Šuklje, Guillaume Antalick, Campbell Meeks, John W. Blackman, Alain Deloire, Leigh Schmidtke, 2017, published scientific conference contribution

Keywords: ACOMDIM, metabolomics, terroir, maturation
Published in RUNG: 04.04.2018; Views: 3911; Downloads: 0
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Sree Gowrinadh Javvadi, 2017, doctoral dissertation

Abstract: In the past two decades emerging and re-emerging plant pathogens have caused new threats to the production of several economically important crops, one among them is P. syringae pv. actinidiae (PSA) which causes canker or leaf spot on kiwifruit plants. PSA enters plant through wounds and remains dormant in cortex tissue of the branches, and spreads in the tissue to cause severe symptoms from winter to early spring. The disease can be visualized by brown discoloration of buds, dark brown angular spots surrounded by yellow haloes on leaves, cankers with white to reddish (oxydation) exudate on twigs and trunks, fruit collapse, wilting and eventually plant mortality. Current control methods have their own significance in disease control, however there is considerable lack of clear understanding of PSA pathogenicity. Virulence of plant pathogens often relies on the synchronized/coordinated expression of pathogenicity factors via quorum sensing (QS). Therefore, investigations on QS in PSA may lead to develop novel disease control strategies and reliable methods to curb the disease. It is currently unknown whether PSA produces a QS signal molecule thus the aim of this thesis is to investigate whether PSA possesses a QS system. As genome mining did not reveal the presence of any currently known QS system, this study initially by metabolomics was aimed at identifying potentially low molecular weight secondary metabolite QS molecules produced by PSA. Azelaic acid was discovered to be produced by PSA, this is the first report of azelaic acid production by bacteria. The characterization and possible role of azelaic acid in QS is presented. Since azelaic acid is ubiquitous in nature, in addition to determining its biological role, the catabolism of azelaic acid in bacteria using the efficient degrader Pseudomonas nitroreducens DSM 9128 was also studied.
Keywords: Quorum sensing, Azelaic acid, Metabolomics, Catabolism
Published in RUNG: 19.12.2017; Views: 4556; Downloads: 212
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