Repozitorij Univerze v Novi Gorici

Iskanje po repozitoriju
A+ | A- | Pomoč | SLO | ENG

Iskalni niz: išči po
išči po
išči po
išči po
* po starem in bolonjskem študiju

Opcije:
  Ponastavi


11 - 16 / 16
Na začetekNa prejšnjo stran12Na naslednjo stranNa konec
11.
Circadian rhythm of exhaled biomarkers in health and asthma
Max Wilkinson, Robert Maidstone, Andrew Loudon, John Blaikley, Iain R. White, Dave Singh, David Ray, Royston Goodacre, Stephen Fowler, Hannah Durrington, 2019, izvirni znanstveni članek

Opis: Circadian rhythms control many biological processes in the body in both health and disease. Greater understanding of diurnal variability in disease related biomarkers is crucial for their application in clinical practice and biomarkers of circadian rhythm are required to facilitate further research into disturbed chronicity. To determine if fractional exhaled nitric oxide and breath volatile biomarkers vary rhythmically during the day in healthy and asthmatic individuals. Ten individuals with moderate, atopic asthma (on regular inhaled corticosteroids) and 10 healthy volunteers (all non-smokers) completed an overnight visit where their exhaled breath volatiles and forced exhaled nitric oxide levels were collected every 6 h. Breath volatiles were analysed using gas chromatography mass spectrometry, after trapping these volatiles on sorbent materials for thermal desorption. Nine breath volatiles (including acetone and isoprene) exhibit diurnal variation across all individuals. Furthermore the circadian pattern of several VOCs is altered in individuals with asthma and fractional exhaled nitric oxide is rhythmic in asthma but not in healthy controls. Markers of circadian rhythm can be identified in breath and may offer insight into circadian profiling to help treat disease. Additionally this work suggests that time of day must be controlled when designing future biomarker discovery studies. Further work is required with larger cohorts to validate and extend these findings.
Ključne besede: VOCs, breath, asthma, circadian
Objavljeno v RUNG: 21.10.2019; Ogledov: 3182; Prenosov: 0
Gradivo ima več datotek! Več...

12.
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, samostojni znanstveni sestavek ali poglavje v monografski publikaciji

Opis: 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.
Ključne besede: Metabolomics, breath research, VOCs, breathomics
Objavljeno v RUNG: 22.07.2019; Ogledov: 3063; Prenosov: 0
Gradivo ima več datotek! Več...

13.
Capturing and Storing Exhaled Breath for Offline Analysis
Iain R. White, Stephen J Fowler, 2019, samostojni znanstveni sestavek ali poglavje v monografski publikaciji

Opis: In this chapter we will summarize and discuss methods for the capture and storage of exhaled breath, prior to offline (and indirect online) analysis. We will detail and compare methods currently in use, including their applications, key strengths, and limitations. In synthesizing the best features of each technique, we will propose an ideal standardized breath sampling solution, and give a personal vision on the next steps to be taken in this exciting area of breath research.
Ključne besede: Breath analysis, Breath sampling, Offline analysis, Thermal desorption, Gas chromatography-mass spectrometry
Objavljeno v RUNG: 22.07.2019; Ogledov: 3291; Prenosov: 0
Gradivo ima več datotek! Več...

14.
Exhaled breath metabolomics reveals a pathogen-specific response in a rat pneumonia model for two human pathogenic bacteria: a proof-of-concept study
Pouline M van Oort, Iain R. White, 2019, izvirni znanstveni članek

Opis: Volatile organic compounds in breath can reflect host and pathogen metabolism and might be used to diagnose pneumonia. We hypothesized that rats with Streptococcus pneumoniae (SP) or Pseudomonas aeruginosa (PA) pneumonia can be discriminated from uninfected controls by thermal desorption-gas chromatography-mass-spectrometry (TD-GC-MS) and selected ion flow tube-mass spectrometry (SIFT-MS) of exhaled breath. Male adult rats (n = 50) received an intratracheal inoculation of 1) 200 µl saline, or 2) 1 × 107 colony-forming units of SP or 3) 1 × 107 CFU of PA. Twenty-four hours later the rats were anaesthetized, tracheotomized, and mechanically ventilated. Exhaled breath was analyzed via TD-GC-MS and SIFT-MS. Area under the receiver operating characteristic curves (AUROCCs) and correct classification rate (CCRs) were calculated after leave-one-out cross-validation of sparse partial least squares-discriminant analysis. Analysis of GC-MS data showed an AUROCC (95% confidence interval) of 0.85 (0.73-0.96) and CCR of 94.6% for infected versus noninfected animals, AUROCC of 0.98 (0.94-1) and CCR of 99.9% for SP versus PA, 0.92 (0.83-1.00), CCR of 98.1% for SP versus controls and 0.97 (0.92-1.00), and CCR of 99.9% for PA versus controls. For these comparisons the SIFT-MS data showed AUROCCs of 0.54, 0.89, 0.63, and 0.79, respectively. Exhaled breath analysis discriminated between respiratory infection and no infection but with even better accuracy between specific pathogens. Future clinical studies should not only focus on the presence of respiratory infection but also on the discrimination between specific pathogens.
Ključne besede: biomarkers, exhaled breath analysis, infection, pneumonia
Objavljeno v RUNG: 22.07.2019; Ogledov: 3014; Prenosov: 0
Gradivo ima več datotek! Več...

15.
Real-time multi-marker measurement of organic compounds in human breath: Towards fingerprinting breath
Iain R. White, Kerry A Willis, Christopher Whyte, Rebecca Cordell, Robert S Blake, Andrew J Wardlaw, 2013, izvirni znanstveni članek

Opis: The prospects for exploiting proton transfer reaction-time of flight-mass spectrometry (PTR-ToF-MS) in medical diagnostics are illustrated through a series of case studies. Measurements of acetone levels in the breath of 68 healthy people are presented along with a longitudinal study of a single person over a period of 1 month. The median acetone concentration across the population was 484 ppbV with a geometric standard deviation (GSD) of 1.6, whilst the average GSD during the single subject longtitudinal study was 1.5. An additional case study is presented which highlights the potential of PTR-ToF-MS in pharmacokinetic studies, based upon the analysis of online breath samples of a person following the consumption of ethanol. PTR-ToF-MS comes into its own when information across a wide mass range is required, particularly when such information must be gathered in a short time during a breathing cycle. To illustrate this property, multicomponent breath analysis in a small study of cystic fibrosis patients is detailed, which provides tentative evidence that online PTR-ToF-MS analysis of tidal breath can distinguish between active infection and non-infected patients.
Ključne besede: Volatile Organic Compounds, breath, proton transfer reaction mass spectrometry, Cystic Fibrosis
Objavljeno v RUNG: 22.07.2019; Ogledov: 3228; Prenosov: 0
Gradivo ima več datotek! Več...

16.
Headspace volatile organic compounds from bacteria implicated in ventilator-associated pneumonia analysed by TD-GC/MS
Oluwasola Lawal, Howbeer Muhamadali, Waqar M Ahmed, Iain R. White, Tamara M E Nijsen, Roy Goodacre, Stephen J Fowler, 2018, izvirni znanstveni članek

Opis: Ventilator-associated pneumonia (VAP) is a healthcare-acquired infection arising from the invasion of the lower respiratory tract by opportunistic pathogens in ventilated patients. The current method of diagnosis requires the culture of an airway sample such as bronchoalveolar lavage, which is invasive to obtain and may take up to seven days to identify a causal pathogen, or indeed rule out infection. While awaiting results, patients are administered empirical antibiotics; risks of this approach include lack of effect on the causal pathogen, contribution to the development of antibiotic resistance and downstream effects such as increased length of intensive care stay, cost, morbidity and mortality. Specific biomarkers which could identify causal pathogens in a timely manner are needed as they would allow judicious use of the most appropriate antimicrobial therapy. Volatile organic compound (VOC) analysis in exhaled breath is proposed as an alternative due to its non-invasive nature and its potential to provide rapid diagnosis at the patient's bedside. VOCs in exhaled breath originate from exogenous, endogenous, as well as microbial sources. To identify potential markers, VAP-associated pathogens Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, and Staphylococcus aureus were cultured in both artificial sputum medium and nutrient broth, and their headspaces were sampled and analysed for VOCs. Previously reported volatile markers were identified in this study, including indole and 1-undecene, alongside compounds that are novel to this investigation, cyclopentanone and 1-hexanol. We further investigated media components (substrates) to identify those that are essential for indole and cyclopentanone production, with potential implications for understanding microbial metabolism in the lung.
Ključne besede: bacteria, exhaled breath, infection, ventilator-associated pneumonia, volatile organic compounds
Objavljeno v RUNG: 18.07.2019; Ogledov: 2776; Prenosov: 0

Iskanje izvedeno v 0.03 sek.
Na vrh