Search results for "Breath tests"

Towards the determination of isoprene in human breath using substrate-integrated hollow waveguide mid-infrared sensors

2014

Selected volatile organic compounds (VOCs) in breath may be considered biomarkers if they are indicative of distinct diseases or disease states. Given the inherent molecular selectivity of vibrational spectroscopy, infrared sensing technologies appear ideally suitable for the determination of endogenous VOCs in breath. The aim of this study was to determine that mid-infrared (MIR; 3-20 µm) gas phase sensing is capable of determining isoprene in exhaled breath as an exemplary medically relevant VOC by hyphenating novel substrate-integrated hollow waveguides (iHWG) with a likewise miniaturized preconcentration system. A compact preconcentrator column for sampling isoprene from exhaled breath …

Detection of lung cancer with electronic nose and logistic regression analysis.

2018

Lung cancer is a very common malignancy with a low five-year survival rate. Artificial olfactory sensor (electronic nose) is a tool that recently has been studied as a probable optimal screening tool for early detection of lung cancer, but still no statistical method has been put forward as the preferable one. The aim of the study was to explore the use of logistic regression analysis (LRA) to analyse patients' exhaled breath samples with electronic nose in order to differentiate lung cancer patients (regardless of the stage of the cancer) from patients with other lung diseases and healthy individuals. Patients with histologically or cytologically verified, untreated lung cancer, patients w…

Analysis of the effects of microbiome-related confounding factors on the reproducibility of the volatolomic test.

2016

Volatile organic compound (VOC) testing in breath has potential in gastric cancer (GC) detection. Our objective was to assess the reproducibility of VOCs in GC, and the effects of conditions modifying gut microbiome on the test results. Ten patients with GC were sampled for VOC over three consecutive days; 17 patients were sampled before and after H. pylori eradication therapy combined with a yeast probiotic; 61 patients were sampled before and after bowel cleansing (interventions affecting the microbiome). The samples were analyzed by: (1) gas chromatography linked to mass spectrometry (GC-MS), applying the non-parametric Wilcoxon test (level of significance p    0.05); (2) by cross-reacti…

Potential of non-invasive breath tests for preselecting individuals for invasive gastric cancer screening endoscopy.

2018

Background. Regular screening for gastric cancer (GC) is based on invasive upper gastrointestinal endoscopy and is limited to few high-incidence countries. As GC is a major cause of cancer death worldwide, a non-invasive, simple screening test is of value. We assessed the prevalence of preclinical GC and the corresponding numbers needed to screen (NNS) to detect GC cases both without and with preselection using breath tests from the literature in various populations. Methods. Using age- and sex-specific GC incidence data and rates of transition from preclinical to clinical GC, we estimated the prevalences of preclinical GC worldwide in populations aged 50–74 years, and we evaluated the accu…

Factors that influence exhaled nitric oxide in Italian schoolchildren

2008

Conflicting results exist about the meaning of exhaled nitric oxide (eNO) in epidemiologic studies, mainly because of the numerous factors that may affect the measurement.To evaluate the role of the factors that influence eNO levels in a sample of schoolchildren with or without respiratory diseases. We studied 335 schoolchildren, ages 10 to 16 years, from 8 schools in Palermo, Italy. After a respiratory questionnaire was completed, spirometry, skin tests, and eNO measurements were performed.Among 335 children, 13.7% reported symptoms of bronchial asthma, 46.9% reported symptoms of rhinitis, and 39.4% were asymptomatic. The ratio of forced expiratory volume in 1 second to forced vital capaci…

Assessment of lung microstructure with magnetic resonance imaging of hyperpolarized Helium-3

2005

Magnetic resonance imaging of the apparent diffusion coefficient (ADC) of hyperpolarized Helium-3 is a new technique for probing pulmonary microstructure in vivo. The aim of this study was the assessment of potential sources of systematic errors of the ADC measurement. The influence of macroscopic motion was determined by measurements at two different delays after initiating the breath-hold, and before and after cardiac arrest. An intercentre comparison was performed in two age- and lung function-matched groups of lung-healthy volunteers at two research sites. Moreover, measurements of diffusion anisotropy were performed. We found no dependency of the ADC as a function of the delay after st…

Pathologies currently identified by exhaled biomarkers.

2013

Ancient Greek physicians already knew that the smell of human breath could provide a clue to the pathology. Nowadays, volatile breath biomarkers are known to be released in a broad range of diseases. However, their identification, isolation, and quantification as indicative of relevant alterations in clinical status have required the development of new techniques and analytical methods. Breath sample analysis encounters several obstacles. Particularly, there is a need of a system that could work in a continuous manner, with the low concentration and small volume of a sample. Herein we review, in the light of literature and our experience, clinical applications of the metal oxide semiconduct…

Assessing and accessing the small airways; implications for asthma management

2013

Despite the wealth of experience in the management of asthma, the disease remains inadequately controlled in some patients, who face long-term respiratory impairment and disability. The disease has been characterised as an inflammatory condition affecting first the larger airways and eventually the smaller airways, but there is evidence that peripheral airway involvement defines a particular and more severe phenotype of asthma. For this reason, assessing functional and biological parameters reflective of small airways involvement is important prognostically. No assessment method is universally and directly representative of peripheral airway function, but the traditional spirometric tests, …

Reply to the Letter Entitled "FeNO Variability when Using Different Analyzers at the Joint ATS/ERS Guideline Cutoff".

2019

The potential role of SP-D as an early biomarker of severity of asthma

2021

Surfactant decreases the surface tension of peripheral airways and modulates the immunological responses of the lung. The alterations of surfactant due to the airway inflammation suggest a role in the pathogenesis of asthma. We aim to test the hypothesis that serum levels of SP-A (Surfactant Protein A) and SP-D (Surfactant Protein-D) are altered in patients with mild asthma compared to healthy controls and those alterations are related to functional abnormalities of peripheral airways, which are an early marker of progression of asthma. In this pilot study, we recruited 20 mild asthmatics and 10 healthy controls. We measured serum SP-A and SP-D and all subjects underwent clinical, lung func…