Journal of breath research最新文献

The measurement of trace breath gases is of growing interest for its potential to provide non-invasive physiological information in health and disease. While instrumental techniques such as selected-ion flow-tube mass spectrometry (SIFT-MS) can achieve this, these are less suitable for clinical application. Sensitive sensor-based systems for breath ammonia could be more widely deployed, but have proven challenging to develop. This work demonstrates the sequential analytical validation of an electrochemical impedance-based sensor system for the measurement of ammonia in breath using SIFT-MS. Qualitative and relative responses between the two methods were comparable, although there were consistent differences in absolute concentration. When tested in artificial breath ammonia, sensors had a relative impedance sensitivity of 3.43 × 10^-5ppbv^-1for each breath in the range of 249-1653 ppbv (r²= 0.87,p< 0.05). When correlated with SIFT-MS using human breath (n= 14), ammonia was detected in the range of 100-700 ppbv (r= 0.78,p< 0.001), demonstrating acceptable sensitivity, reproducibility and dynamic range for clinical application.

Idiopathic halitosis is an unusual condition of unclear causes, which has never been thoroughly investigated. We aimed to explore the role of small intestinal bacterial overgrowth (SIBO) in the pathogenesis of idiopathic halitosis, and to evaluate the therapeutic efficacy of a probiotic preparation on this condition. This retrospective observational study included 162 idiopathic halitosis patients and 198 healthy controls (HCs). Halitosis was diagnosed using the organoleptic test, and idiopathic halitosis was diagnosed by excluding known causes. SIBO was identified through the hydrogen/methane lactulose breath test, and accordingly, patients were identified as SIBO-positive or SIBO-negative. Idiopathic halitosis patients were treated with the probiotic preparationBifidobacteriumtriple viable capsule for two months, followed by re-evaluation of halitosis and SIBO. This study found that all cases of idiopathic halitosis were extra-oral. The SIBO positivity rate in idiopathic halitosis patients was significantly higher than that in HCs (74.69% [121/162] vs 3.03% [6/198],P< 0.001), with an odds ratio of 94.44% (95% CI: 39.99%-211.35%). After treatment, 80.17% (97/121) of the SIBO-positive patients became SIBO-negative. Moreover, 87.60% (106/121) of the SIBO-positive patients experienced improved halitosis, a rate significantly higher than that observed in SIBO-negative patients (2.75%, 3/41) (P< 0.001). In addition, 98.97% (96/97) of the post-treatment SIBO-negative patients experienced improved halitosis, a rate significantly higher than that of post-treatment sustained SIBO-positive patients (41.67%, 10/24) (P< 0.001). Our findings suggest that idiopathic halitosis is an extra-oral condition which mostly originates from the small intestine. SIBO is one of its underlying causes. The probiotic preparation can effectively improve idiopathic halitosis, probably through its impact on SIBO.

Volatile organic compounds (VOCs) produced by human respiratory cells reflect metabolic and pathophysiological processes which can be detected with the use of modern technology. Analysis of exhaled breath or indoor air may potentially play an important role in screening of upper respiratory tract infections such as COVID-19 or influenza in the future. In this experimental study, air samples were collected and analyzed from the headspace of anin vitrocell culture infected by selected pathogens (influenza A H1N1 and seasonal coronaviruses OC43 and NL63). VOCs were measured with a real-time proton-transfer-reaction time-of-flight mass spectrometer and a differential mobility spectrometer. Measurements were performed every 12 h for 7 d. Non-infected cells and cell culture media served as references. In H1N1 and OC43 we observed four different VOCs which peaked during the infection. Different, individual VOCs were also observed in both infections. Activity began to clearly increase after 2 d in all analyses. We did not see increased VOC production in cells infected with NL63. VOC analysis seems to be suitable to differentiate the infected cells from those which are not infected as well as different viruses, from another. In the future, this could have practical value in both individual diagnostics and indoor environment screening.

For decades, intake monitoring of drugs using urine as the matrix of choice is the gold standard in drug treatment centers. A properly conducted urine drug test can identify recent use of prescribed, non-prescribed and illicit drugs. However, issues like adulteration, substitution and privacy issues have driven the search for alternative matrices. This prospective pilot study evaluates the use of an impaction-based breath sampling device, Breath Explor^®, as an alternative to traditional urine-based drug monitoring. Breath samples were analyzed using a validated 32-component liquid chromatography-tandem mass spectrometry method. Recovery data represent the efficiency of extracting the analytes from the breath devices. Both automated and manual processing of the Breath Explor® devices showed mean recovery rates ranging from 39.5% to 55.4% for the 32 analytes. Despite the small number of subjects, breath analysis proved to be a convenient and easy-to-use methodology. An overall kappa-values of 0.5 indicated a moderate level of agreement with urine analysis, underscoring its potential as a complementary diagnostic tool. All participants tested positive in their breath sample for methadone (70% methadone and 100% EDDP), while a significant portion (90%) tested positive for 6-monoacetylmorphine. This innovative approach offers several advantages, including non-invasiveness, reduced risk of adulteration, and the ability to perfom repeated automated sampling and confirmation testing. These findings suggest that breath-based substance monitoring could complement or even replace traditional urine-based methods in clinical practice.

Depression is a pervasive and often undetected mental health condition, which poses significant challenges for early diagnosis due to its silent and subtle nature. To evaluate exhaled volatile organic compounds (VOCs) as non-invasive biomarkers for the detection of depression using a virtual surface acoustic wave sensors array (VSAW-SA). A total of 245 participants were recruited from the Hangzhou Community Health Service Center, including 38 individuals diagnosed with depression and 207 control subjects. Breath samples were collected from all participants and subjected to analysis using VSAW-SA. Univariate and multivariate analyses were employed to assess the relationship between VOCs and depression. The findings revealed that the responses of virtual sensor ID 14, 44, 59, and 176, which corresponded respectively to ethanol, trichloroethylene or isoleucine, octanoic acid or lysine, and an unidentified compound, were sensitive to depression. Taking into account potential confounders, these sensor responses were utilized to calculate a depression detection indicator. It has a sensitivity of 81.6% and a specificity of 81.6%, with an area under the curve of 0.870 (95% CI = 0.816-0.923). Conclusions: exhaled VOCs as non-invasive biomarkers of depression could be detected by a VSAW-SA. Large-scale cohort studies should be conducted to confirm the potential ability of the VSAW-SA to diagnose depression.

Patients with respiratory infections (e.g., COVID-19, antimicrobial resistant bacteria) discharge pathogens to the environment, exposing healthcare workers and inpatients to deleterious complications. This study tested the performance of SPEAR-P1 (synchronized personal exhaled air removal system - prototype 1), which actively detects expiration and removes exhaled air using an open, non-sealing lightweight facemask connected to a deep vacuum generating unit (DVGU). Fourteen healthy examinees practiced breathing through facemasks at 30, 25 and 20 breaths per minute; oxygen and nebulized saline were added at later steps. To test the efficacy of removing exhaled air, CO2 was used as a proxy and its level was measured from the outer surface of the open facemask. Compared to the baseline recording, SPEAR-P1 reduced CO2 escaping from the facemask by 66% on average for all study steps and respiratory rates (p<0.001), reaching 85.55% on average at 20 breaths per minute (p<0.001). This study shows that removing exhaled air from examinees using an open, non-sealing lightweight facemask is feasible. Future development of this system will enhance its efficacy and provide a method to remove a patient's contaminating aerosol without the need to "seal" the patient, especially in settings where isolation rooms are not readily available.

Malignant pleural mesothelioma (MPM) is an aggressive cancer associated with asbestos exposure. MPM is often diagnosed late, at a point where limited treatment options are available, but early intervention could improve the chances of successful treatment for MPM patients. Biomarkers to detect MPM in at-risk individuals are needed to implement early diagnosis technologies. Volatile organic compounds (VOCs) have previously shown diagnostic potential as biomarkers when analysed in MPM patient breath. In this study, chorioallantoic membrane (CAM) xenografts of MPM cell lines were used as models of MPM tumour development for VOC biomarker discovery with the aim of generating targets for investigation in breath, biopsies or other complex matrices. VOC headspace analysis of biphasic or epithelioid MPM CAM xenografts was performed using solid-phase microextraction and gas chromatography-mass spectrometry. We successfully demonstrated the capture, analysis and separation of VOC signatures from CAM xenografts and controls. A panel of VOCs was identified that showed discrimination between MPM xenografts generated from biphasic and epithelioid cells and CAM controls. This is the first application of the CAM xenograft model for the discovery of VOC biomarkers associated with MPM histological subtypes. These findings support the potential utility of non-invasive VOC profiling from breath or headspace analysis of tissues for detection and monitoring of MPM.