Journal of breath research最新文献

Sarcoidosis is considered a T-helper (Th) 1 related disease, but a transition from Th1 to Th2 pathway activation has been postulated in sarcoidosis-associated pulmonary fibrosis (SAPF). Fraction of exhaled nitric oxide (F_ENO) is a marker of Th2 airway inflammation, but alveolar concentration of nitric oxide (C_ANO) can be measured to assess Th2 inflammation in the periphery of the lung. The aim of this study is to assess whether C_ANO can be considered a biomarker of SAPF or active pulmonary sarcoidosis. In this single-center retrospective study, we compared exhaled NO levels of patients with pulmonary sarcoidosis without fibrosis (N= 11) with those obtained from patients with SAPF (N= 15). Clinical data, as well as respiratory function tests, were also analyzed. F_ENO (28.5 ± 16 ppb vs 30.9 ± 17.2 ppb,p= 0.72) and C_ANO (4.4 ± 3.5 ppb vs 3.2 ± 1.7 ppb,p= 0.73) levels did not differ significantly between patients with or without SAPF, even when dividing them according to treatment or disease activity. C_ANO appeared reduced in patients with active sarcoidosis (2.1 ± 0.8 ppb vs 4.1 ± 3 ppb,p< 0.05). In conclusion, C_ANO cannot be considered a biomarker of SAPF. Its lower level in patients with active disease confirms the prevalence of Th1 inflammation in granuloma formation and suggests its potential role as a biomarker of active pulmonary sarcoidosis, but further studies with larger samples are needed to confirm this hypothesis.

The concentrations of nasal nitric oxide (nNO) vary in patients with chronic rhinosinusitis (CRS) supposedly depending upon whether the paranasal ostia are open or obstructed. Our aim was to assess whether nNO levels and their response to topical xylometazoline (a local vasoconstrictor used to alleviate nasal congestion) in patients with CRS differ between those with open or obstructed ostia and if the results were altered by the use of nasal corticosteroids. Sixty-six patients with CRS (43% with nasal polyps) or recurrent acute rhinosinusitis and 23 healthy controls were included. Nasal NO was measured (EcoMedics CLD 88p analyser) before and after two xylometazoline sprays during three consecutive visits: with the medication they were using when they were referred, after 4 weeks of medication pause, and after 4 weeks of using intranasal fluticasone propionate. The relative difference between the nNO before and after dosing of xylometazoline was calculated, and ostial obstruction was evaluated with cone-beam computed tomography at every visit. The nNO measurements were lowest in the patients with CRS and obstructed paranasal ostia. The presence or absence of nasal polyps did not affect the results. Xylometazoline did not significantly affect nNO in the subjects with obstructed ostia, but there was a significant reduction of nNO in those with open ostia. The Xylometazoline-induced change in nNO between the groups with open or obstructed ostia was significantly different at each visit: 'on previous medication' 10% (-5-25) versus -14% (-19 to -9),p= 0.004, 'after medication pause' 6% (-5-17) versus -16% (-23 to -9),p= 0.001 and 'after regular fluticasone spray' 6% (-3-15) versus -9% (-16 to -3),p= 0.04. The native nNO and xylometazoline-induced change in nNO can be used to detect the status of ostial obstruction in patients with CRS irrespective of their topical corticosteroid usage.

Halitosis specialists can be found all over the world, but very little is known about how they approach patients with halitosis complaints. Therefore, this web-based questionnaire study tried to reach as many of them to gain insight in their methods and tools used to diagnose the condition. Since this study was carried out in the aftermath of the COVID-19 pandemic, its impact was also examined. This survey encompassed 19 questions interrogating the responders' profile; their diagnostic process in general; the methods and tools used to examine the breath; and the impact of COVID-19 on them. It was accessible online from May till October 2022. Eighty halitosis professionals from 19 different countries replied. Their answers showed that the community behind the field of halitosis seems to be largely driven by oral health professionals. The respondents had been active in this niche for on average 12 years in consultations (41%), research (23%) or a combination (36%). To achieve a diagnosis 96% believed a thorough history is a must and 94% felt that a breath odor examination (instrumental and/or organoleptically) was necessary. The Halimeter® was the most common instrument used for breath odor analysis. There was a large variation in the organoleptic examination regarding the calibration and number of judges and the specific odors sources that were assessed (i.e. mouth odor versus nose odor). Less variation was noted on the rating scale used: 87% made use of the 6-point odor strength scale. For those that performed organoleptic examinations COVID-19 forced them to modify their examination (20%) or to stop performing it (67%). This international survey showed that there is not a consensus between specialists on how the diagnosis of halitosis should be carried out. However, a common thread can be noted: thoroughly interviewing the patients and examining the breath odor are of upmost importance.

Halitosis has a multifactorial etiology being of interest by different health areas. The aim of this study was to perform a bibliometric and altmetric analyzes of the top 100 most-cited papers on halitosis to provide a comprehensive view of their scientific and alternative metrics. This would give perspectives on citation dynamics and online attention of the research outputs. A search strategy was designed, tested and applied in the Web of Science database on August 1st, 2023. The 100 most-cited papers were selected by two reviewers. Data on title, year of publication, number of citations, authorship, journal title, study design, halitosis etiology and subject/field of the study or pathogenesis of halitosis were extracted from each paper. Altmetric attention score (AAS) for each paper was registered. Papers were published between 1972 and 2019. Most cited papers were non-systematic reviews (28%). USA was the country with the greatest number of publications (20%). Journals with the greater number of citations were related to dentistry. The altmetric analysis did not show correlation with the citation count but showed a few papers with elevated AAS and a good diffusion in social media. The level of evidence of the study design did not influence the citation number. This can indicate the need for citing studies with more robust designs in order to provide better scientific evidence of citations in epidemiology, etiology, diagnosis and treatment. Databases showed positive correlation among citation counts, but no correlation with the online attention.

Exhaled breath volatile organic compounds (VOCs) are often collected and stored in sorbent tubes before thermal desorption-gas chromatography-mass spectrometry (TD-GC-MS) analysis. Information about the stability of VOCs during storage is needed to account for potential artifacts and monitor for losses. Additionally, information about the stability of VOC standards in solution is required to assess their performance as quality control and internal standards. We evaluated the stability of a standard mixture of 42 VOCs in dual-sorbent tubes containing Tenax® TA and Carbotrap 1TD over 60 d at commonly used storage conditions: room temperature (∼21 °C), 4 °C, and -80 °C. The same 42 VOCs were also evaluated for their stability in methanol over 60 d while stored at -20 °C. All samples were analyzed using TD-GC-MS. During storage, most VOCs were stable on sorbent after 60 d: 36/42 (86%), 39/42 (93%), and 41/42 (98%) had not statistically changed for room temperature, 4 °C and -80 °C, respectively, based on Spearman rank correlation coefficients and linear regression analysis. The isotopically labeled VOCs tested here are well-suited to serve as internal standards for pre-analysis or storage. Degradation of VOCs in solution was apparent after 60 d: 27/42 (64%) of VOCs had statistically decreased. The total VOC mixture had dropped to 90% of its original intensity after ∼22 d and a subset of VOCs typically used as internal standards dropped to 90% in ∼16 d. Analysts using similar mixtures should make a fresh solution at least every two weeks to ensure analytical accuracy. This study provides important insights into storage practices for both sorbent tubes and standard solutions, guiding analysts toward improved reliability and accuracy in exhaled breath analysis.

The ocean is facing many anthropogenic stressors caused from both pollution and climate change. These stressors are significantly impacting and changing the ocean's ecosystem, and as such, methods must continually be developed that can improve our ability to monitor the health of marine life. For cetaceans, the current practice for health assessments of individuals requires live capture and release, which is expensive, usually stressful, and for larger species impractical. In this study, we investigated the potential of exhaled breath condensate (EBC) samples to provide unique metabolomic profiles from healthy killer whales (Orcinus orca) of varying known age and sex. EBC collection is a non-invasive procedure that has potential for remote collection using unmanned aerial vehicles, thus improving our ability to understand physiologic parameters within wild populations while minimizing stress from collection procedures. However, descriptions of the available metabolome within EBC and its clinical significance within animals of known health and age must be described before this technique can be considered diagnostically useful. We describe normal variations of the metabolome across age and sex and provide evidence for the potential of this breath analysis method to become a valuable adjunctive tool for assessing the health of managed-care and free-ranging killer whales.

Volatolomics (or volatilomics), the study of volatile organic compounds, has emerged as a significant branch of metabolomics due to its potential for non-invasive diagnostics and disease monitoring. However, the analysis of high-resolution data from mass spectrometry and gas sensor array-based instruments remains challenging. The careful consideration of experimental design, data collection, and processing strategies is essential to enhance the quality of results obtained from subsequent analyses. This comprehensive guide provides an in-depth exploration of volatolomics data analysis, highlighting the essential steps, such as data cleaning, pretreatment, and the application of statistical and machine learning techniques, including dimensionality reduction, clustering, classification, and variable selection. The choice of these methodologies, along with data handling practices, such as missing data imputation, outlier detection, model validation, and data integration, is crucial for identifying meaningful metabolites and drawing accurate diagnostic conclusions. By offering researchers the tools and knowledge to navigate the complexities of volatolomics data analysis, this guide emphasizes the importance of understanding the strengths and limitations of each method. Such informed decision-making enhances the reliability of findings, ultimately advancing the field and improving the understanding of metabolic processes in health and disease.

Acute exacerbations of chronic obstructive pulmonary disease (AECOPD) show high variability in individual susceptibility and promote disease progression; thus, accurate diagnosis and treatment is essential. Unravelling the molecular metabolic changes during AECOPD in breath could promote understanding of AECOPD and its treatment. Our objective was to investigate the metabolic breath profiles during AECOPD for biomarker detection. We conducted real-time breath analysis in patients with COPD during AECOPD and during subsequent stable phase. Molecular breath patterns were compared between AECOPD and stable phase by dimension reduction techniques and paired t-tests. Pathway enrichment analyses were performed to investigate underlying metabolic pathways. Partial least-squares discriminant analysis and XGboost were utilised to build a prediction model to differentiate AECOPD from stable state. 35 patients (60% male) with a mean age of 65 (10.2) yr with AECOPD were included. AECOPD could be predicted with a high sensitivity of 82.5% (95% confidence interval of 68.8%-93.8%) and an excellent discriminative power (AUC = 0.86). Metabolic changes in the linoleate, tyrosine, and tryptophan pathways during AECOPD were predominant. Significant metabolic changes occur during COPD exacerbations, predominantly in the linoleate, tyrosine, and tryptophan pathways, which are all linked to inflammation. Real-time exhaled breath analysis enables a good prediction of AECOPD compared to stable state and thus could enhance precision of AECOPD diagnosis and efficacy in clinical practice.

Several clinical studies have reported promising correlations between propofol concentration in exhaled breath (Ce-pro) and the bispectral index (BIS) in patients, suggesting the potential of exhaled propofol measurement as a non-invasive method for adjusting anesthesia depth. However, these studies are still in the validation phase of instrument effectiveness, often limited by small sample sizes or inappropriate instrument selection, and thus lack convincing results regarding these correlations. In this study, one hundred patients aged 18-65, undergoing elective thyroid surgery under general anesthesia were included. The vacuum ultraviolet photoionization and time-of-flight mass spectrometry was employed to monitor Ce-pro at 20 s intervals, alongside continuous BIS measurement. The association between Ce-pro and BIS was analyzed using linear mixed-effects models, with marginalR²used to assess the correlation. The threshold of Ce-pro at awakening was also explored. Additionally, the univariate and multifactorial diagnostic model, including end-of-surgery Ce-pro, were employed to assess the accuracy of predicting delayed recovery. A weak correlation was observed between intraoperative Ce-pro and BIS (marginalR²= 0.348). Predictive models utilizing end-of-surgery Ce-pro levels showed good accuracy (area under the curve (AUC) = 0.75, 95% CI: 0.62-0.89,P= 0.003) in predicting delayed recovery, while the model using end-of-surgery Ce-pro combined with gender, sufentanil dosage, the time from the last administration of sufentanil to the end of surgery, and anesthesia duration demonstrated stronger predicting accuracy (AUC = 0.91, 95% CI: 0.85-0.98,P< 0.001). This study suggests that Ce-pro alone may not reliably predict the depth of anesthesia in clinical practice, but shows promising accuracy in predicting delayed recovery from anesthesia.

The differentiation between malignant and benign thyroid nodules represents a significant challenge for clinicians globally. The identification of volatile organic compounds (VOCs) has emerged as a novel approach in the field of cancer diagnosis. This prospective pilot study aims to identify VOCs in exhaled breath, blood, and urine that can differentiate benign from malignant thyroid nodules using gas chromatography-ion mobility spectrometry (GC-IMS). Patients with thyroid nodules scheduled for surgery were enrolled at the Maastricht University Medical Center (MUMC+). Breath samples were analyzed using a BreathSpec GC-IMS machine (G.A.S. Dortmund, Germany), specifically designed for breath analysis. All blood and urine samples were analyzed using a separate GC-IMS device, the FlavourSpec® (G.A.S., Dortmund, Germany). In this proof-of-concept study, 70 consecutive patients undergoing thyroid surgery at MUMC+ were included. Of these patients, 29 were confirmed to have thyroid cancer after surgical resection. The overall analysis did not reveal statistically significant differences in VOCs in breath, urine and blood, between patients with benign and malignant thyroid cancer. This proof-of-concept study demonstrated that GC-IMS could not effectively differentiate between the VOC profiles of malignant and benign thyroid nodules. However, due to the small sample size of this study, larger prospective studies are needed to investigate the potential of using VOCs to distinguish between benign and malignant thyroid nodules. Additionally, future research should focus on identifying potential confounding factors that may influence patient VOC profiles. (NCT04883294).