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1.
Int Arch Allergy Immunol ; 181(1): 51-55, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-31752005

RESUMO

BACKGROUND: Allergic rhinitis is an allergic inflammation of the nasal airways, and chronic rhinosinusitis is an inflammation of the paranasal sinuses. It can be induced by infection, allergy, or autoimmune problems. Diagnosis of these two diseases is made primarily based on clinical symptoms, allergen test, and imaging. The allergen test is invasive and expensive. The imaging test is harmful to children. Measurement of nasal nitric oxide (NNO) was noninvasive, without radiation, and inexpensive. This study was to evaluate the clinical significance of NNO in preschool children with nasal inflammatory diseases. METHODS: A total of 55 cases of allergic rhinitis, including 35 mild cases and 20 moderate to severe cases, and 33 cases of chronic rhinosinusitis, including 18 mild cases and 15 moderate to severe cases were selected as the experimental group. Fifty healthy preschool children were chosen as the control group. The levels of NNO in all children were measured. The differences in the levels of NNO among allergic rhinitis, chronic rhinosinusitis, and the control group were compared. The levels of NNO in the control group were also analyzed. RESULTS: The levels of NNO were significantly higher in preschool children with allergic rhinitis than in the control group, and the differences were significant. However, the levels of NNO in preschool children with chronic rhinosinusitis were lower than in the control group. In the control group, the levels of NNO were not significantly different between genders, and no significant correlation between NNO levels and the children's height was found. CONCLUSION: As a noninvasive method for detecting nasal inflammatory diseases, measuring the levels of NNO had a high clinical significance in preschool children.


Assuntos
Testes Respiratórios/métodos , Óxido Nítrico/análise , Rinite Alérgica/diagnóstico , Rinite/diagnóstico , Sinusite/diagnóstico , Criança , Pré-Escolar , Doença Crônica , Expiração , Feminino , Humanos , Masculino
2.
J Chromatogr B Analyt Technol Biomed Life Sci ; 1134-1135: 121857, 2019 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-31790918

RESUMO

In this study, the ionic profile and pH of exhaled breath condensate (EBC) in a group of patients with acid and weakly acid reflux and no-reflux controls were compared. A portable sampler was used for non-invasive EBC collection from five exhalations. The ionic profile (anions, cations, organic acids) and pH of the collected EBC samples were measured by capillary electrophoresis with contactless conductivity detection and a pH microelectrode, respectively. Several ions were elevated in the patient groups. Sodium cation was elevated in weakly acid reflux (significance level p < 0.01) and acid reflux (p < 0.05) compared to no-reflux controls. Butyrate and propionate were elevated in both acid reflux and weakly acid reflux compared to no-reflux controls (butyrate: p < 0.01, propionate: p < 0.05). The median values of pH (after de-aeration with N2) were also significantly higher (p < 0.01) in groups with acid reflux and weakly acid reflux than in the control group with no reflux. The ionic analysis and simultaneous pH measurement offer a simple, cheap, fast, and non-invasive approach in gastroesophageal reflux disease diagnostics.


Assuntos
Testes Respiratórios/métodos , Eletroforese Capilar/métodos , Refluxo Gastroesofágico/diagnóstico , Refluxo Gastroesofágico/metabolismo , Íons/análise , Adulto , Idoso , Butiratos/análise , Feminino , Humanos , Concentração de Íons de Hidrogênio , Íons/metabolismo , Masculino , Pessoa de Meia-Idade , Propionatos/análise , Sódio/análise
3.
Zhonghua Nei Ke Za Zhi ; 58(10): 777-781, 2019 Oct 01.
Artigo em Chinês | MEDLINE | ID: mdl-31594177

RESUMO

Objective: To detect the red blood cell lifespan in patients with polycythemia vera (PV), and explore the influencing factors. Methods: From February 2017 to December 2018, 27 patients with PV at Blood Diseases Hospital, Chinese Academy of Medical Science and 18 normal controls were recruited. Red blood cell lifespan was detected by endogenous carbon monoxide (CO) breath test. The related factors were analyzed. Results: The average red blood cell lifespan of 27 PV patients was 80 (range, 35-120) days (d), which was significantly shorter than that of the normal controls [110.5(69-166) d, P<0.05], namely 35.3 d shorter. The red blood cell lifespan of ten newly diagnosed patients and 17 patients who were treated with hydroxyurea and/or interferon were 98 (35-117) d and 69 (45-120) d, respectively, which were both shorter than that of the normal control (P=0.010, 0.000). Correlation analysis showed that red blood cell lifespan of patients with newly diagnosed PV was associated with JAK2 mutation allele burden (r=0.900, P=0.037), peripheral blood lymphocyte count (r=-0.742, P=0.014) and the level of serum vitamin B(12) (r=-0.821, P=0.023). Conclusion: The lifespan of red blood cells in patients with PV is about one-third shorter than normal, and is related to JAK2 mutation allele burden, absolute lymphocyte count, and serum vitamin B(12) level.


Assuntos
Testes Respiratórios/métodos , Monóxido de Carbono/análise , Monóxido de Carbono/metabolismo , Eritrócitos/patologia , Policitemia Vera/patologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Estudos de Casos e Controles , Contagem de Eritrócitos , Feminino , Humanos , Janus Quinase 2 , Longevidade , Masculino , Pessoa de Meia-Idade
4.
Cardiovasc Intervent Radiol ; 42(12): 1702-1708, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31535181

RESUMO

PURPOSE: Transarterial chemoembolization (TACE) is associated with the risk of deteriorating liver function, especially in patients with preexisting liver damage. Current liver function tests may fail to accurately predict the functional liver reserve. Aim of this study was to investigate whether changes of liver function caused by TACE are associated with detectable changes of LiMAx values. METHODS AND MATERIALS: Forty patients with primary or secondary liver cancer underwent TACE and LiMAx test on the day before, the day after, and 4 weeks after TACE. LiMAx results were evaluated, referenced to liver volume (CT/MR volumetry), correlated with the respective TACE volume (subsegmental vs. segmental vs. lobar), established liver function tests, and Child-Pugh and ALBI scores. RESULTS: The individual LiMAx values were significantly reduced by 10% (p = 0.01) on the day after TACE and fully recovered to baseline 1 month after treatment. Similar changes were observed regarding levels of bilirubin, transaminases, albumin, INR, and creatinine. LiMAx did not correlate significantly with the treated liver volume, but did correlate with the baseline liver volume (< 1200 ml vs. > 1200 ml; p < 0.01). No significant changes were observed in the Child-Pugh score or ALBI score. CONCLUSION: LiMAx is capable of detecting changes in liver function, even modulations caused by superselective TACE procedures. Accordingly, it could be used as a tool for patient selection and monitoring of transarterial therapy. In comparison, Child-Pugh and ALBI scores did not reflect any of these changes. Some biochemical parameters also changed significantly after TACE, but they tend to be less specific in providing sufficient information on actual cellular dysfunction.


Assuntos
Testes Respiratórios/métodos , Isótopos de Carbono , Quimioembolização Terapêutica/métodos , Neoplasias Hepáticas/terapia , Fígado/fisiopatologia , Idoso , Feminino , Humanos , Testes de Função Hepática/métodos , Masculino , Estudos Retrospectivos , Resultado do Tratamento
5.
Nat Rev Gastroenterol Hepatol ; 16(12): 733-747, 2019 12.
Artigo em Inglês | MEDLINE | ID: mdl-31520080

RESUMO

The inner workings of the intestines, in which the body and microbiome intersect to influence gut function and systemic health, remain elusive. Carbon dioxide, hydrogen, methane and hydrogen sulfide, as well as a variety of trace gases, are generated by the chemical interactions and microbiota within the gut. Profiling of these intestinal gases and their responses to dietary changes can reveal the products and functions of the gut microbiota and their influence on human health. Indeed, different tools for measuring these intestinal gases have been developed, including newly developed gas-sensing capsule technology. Gases can, according to their type, concentration and volume, induce or relieve abdominal symptoms, and might also have physiological, pathogenic and therapeutic effects. Thus, profiling and modulating intestinal gases could be powerful tools for disease prevention and/or therapy. As the interactions between the microbiota, chemical constituents and fermentative substrates of the gut are principally influenced by dietary intake, altering the diet, which, in turn, changes gas profiles, is the main therapeutic approach for gastrointestinal disorders. An improved understanding of the complex interactions within the intestines that generate gases will enhance our ability to prevent, diagnose, treat and monitor many gastrointestinal disorders.


Assuntos
Dieta , Gases/metabolismo , Gastroenteropatias/fisiopatologia , Testes Respiratórios/métodos , Técnicas de Diagnóstico do Sistema Digestório , Fermentação/fisiologia , Gases/análise , Gastroenteropatias/microbiologia , Microbioma Gastrointestinal/fisiologia , Trato Gastrointestinal/metabolismo , Trato Gastrointestinal/microbiologia , Homeostase/fisiologia , Humanos
6.
Int J Mol Sci ; 20(18)2019 Sep 12.
Artigo em Inglês | MEDLINE | ID: mdl-31547269

RESUMO

Comprehensive studies of the effects of prolonged exposure to space conditions and the overload experienced during landing on physiological and biochemical changes in the human body are extremely important in the context of planning long-distance space flights, which can be associated with constant overloads and various risk factors for significant physiological changes. Exhaled breath condensate (EBC) can be considered as a valuable subject for monitoring physiological changes and is more suitable for long-term storage than traditional monitoring subjects such as blood and urine. Herein, the EBC proteome changes due to the effects of spaceflight factors are analyzed. Thirteen EBC samples were collected from five Russian cosmonauts (i) one month before flight (background), (ii) immediately upon landing modules in the field (R0) after 169-199 days spaceflights, and (iii) on the seventh day after landing (R+7). Semi-quantitative label-free EBC proteomic analysis resulted in 164 proteins, the highest number of which was detected in EBC after landing (R0). Pathways enrichment analysis using the GO database reveals a large group of proteins which take part in keratinization processes (CASP14, DSG1, DSP, JUP, and so on). Nine proteins (including KRT2, KRT9, KRT1, KRT10, KRT14, DCD, KRT6C, KRT6A, and KRT5) were detected in all three groups. A two-sample Welch's t-test identified a significant change in KRT2 and KRT9 levels after landing. Enrichment analysis using the KEGG database revealed the significant participation of detected proteins in pathogenic E. coli infection (ACTG1, TUBA1C, TUBA4A, TUBB, TUBB8, and YWHAZ), which may indicate microbiota changes associated with being in space. This assumption is confirmed by microbial composition analysis. In general, the results suggest that EBC can be used for noninvasive monitoring of health status and respiratory tract pathologies during spaceflights, and that the obtained data are important for the development of medicine for use in extreme situations. Data are available from ProteomeXchange using the identifier PXD014191.


Assuntos
Testes Respiratórios/métodos , Proteoma/análise , Voo Espacial , Escherichia coli/isolamento & purificação , Infecções por Escherichia coli/microbiologia , Humanos , Mapas de Interação de Proteínas , Proteoma/metabolismo , Proteômica/métodos , Espectrometria de Massas em Tandem/métodos , Fatores de Tempo
7.
Technol Cancer Res Treat ; 18: 1533033819872271, 2019 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-31495334

RESUMO

OBJECTIVE: Lung cancer is one of the most common malignant tumors in humans. Finding a highly sensitive and specific marker is very important. This study investigated the clinical significance of epidermal growth factor in exhaled breath condensate and serum of patients with non-small cell lung cancer. METHODS: From October 17, 2013, to June 5, 2017, exhaled breath condensate and blood samples from 155 patients with non-small cell lung cancer, 63 patients with benign pulmonary nodules, and 115 healthy controls were collected using a breath condenser. Each sample was analyzed by enzyme-linked immunosorbent assay. RESULTS: Epidermal growth factor level in the exhaled breath condensate from the non-small cell lung cancer group (197.86 ± 60.67 pg/mL) was higher than that in the healthy group (124.75 ± 36.09 pg/mL), P < .05. Epidermal growth factor level in the exhaled breath condensate of the smoking group (208.85 ± 40.94 pg/mL) was higher than that of the nonsmoking group (185.52 ± 36.88 pg/mL), P < .05. Epidermal growth factor level in the exhaled breath condensate in phases III and IV of non-small cell lung cancer group (212.17 ± 35.41 pg/mL) was higher than that in phases I and II (173.91 ± 38.08 pg/mL), P < .05. Epidermal growth factor level in the exhaled breath condensate of the death group (241.05 ± 27.19 pg/mL) was higher than that of the survival group (188.75 ± 37.07 pg/mL), P < .05. The epidermal growth factor exhaled breath condensate levels were positively correlated with the serum epidermal growth factor levels with a correlation coefficient of 0.495 (P < .05). The sensitivity and specificity of epidermal growth factor exhaled breath condensate test were 80.0% and 89.6%, respectively. CONCLUSION: The detection of epidermal growth factor level in exhaled breath condensate exhibits is important in the diagnosis, disease monitoring, and prognosis of non-small cell lung cancer.


Assuntos
Testes Respiratórios , Carcinoma Pulmonar de Células não Pequenas/diagnóstico , Carcinoma Pulmonar de Células não Pequenas/metabolismo , Fator de Crescimento Epidérmico/metabolismo , Neoplasias Pulmonares/diagnóstico , Neoplasias Pulmonares/metabolismo , Adulto , Idoso , Biomarcadores , Testes Respiratórios/métodos , Carcinoma Pulmonar de Células não Pequenas/sangue , Estudos de Casos e Controles , Fator de Crescimento Epidérmico/sangue , Expiração , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Prognóstico , Curva ROC , Fatores de Risco
8.
Helicobacter ; 24 Suppl 1: e12641, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31486244

RESUMO

Endoscopic imaging of the stomach is improving. In addition to narrow band imaging, other methods, for example, blue light imaging and linked color imaging, are now available and can be combined with artificial intelligence systems to obtain information on the gastric mucosa and detect early gastric cancer. Immunohistochemistry is only recommended as an ancillary stain in case of chronic active gastritis without Helicobacter pylori detection by standard staining, and recommendations to exclude false negative H. pylori results have been made. Molecular methods using real-time PCR, droplet digital PCR, or amplification refractory mutation system PCR have shown a high accuracy, both for detecting H. pylori and for clarithromycin susceptibility testing, and can now be used in clinical practice for targeted therapy. The most reliable non-invasive test remains the 13 C-urea breath test. Large data sets show that DOB values are higher in women and that the cut-off for positivity could be decreased to 2.74 DOB. Stool antigen tests using monoclonal antibodies are widely used and may be a good alternative to UBT, particularly in countries with a high prevalence of H. pylori infection. Attempts to improve serology by looking at specific immunodominant antigens to distinguish current and past infection have been made. The interest of Gastropanel® which also tests pepsinogen levels was confirmed.


Assuntos
Testes Respiratórios/métodos , Testes Diagnósticos de Rotina/métodos , Endoscopia Gastrointestinal/métodos , Infecções por Helicobacter/diagnóstico , Imunoensaio/métodos , Técnicas de Diagnóstico Molecular/métodos , Testes Diagnósticos de Rotina/tendências , Endoscopia Gastrointestinal/tendências , Humanos , Imunoensaio/tendências , Técnicas de Diagnóstico Molecular/tendências
9.
Phys Chem Chem Phys ; 21(35): 19083-19091, 2019 Sep 21.
Artigo em Inglês | MEDLINE | ID: mdl-31432839

RESUMO

The development of new techniques or instruments for detecting and accurately measuring biomarker concentrations in living organisms is essential for early diagnosis of diseases, and for tracking the effectiveness of treatments. In chronic diseases, such as asthma, precise phenotyping can help predict the response of patients to treatments and reduce the risk of complications. Fractional exhaled nitric oxide (FeNO) is a positive biomarker for eosinophilic asthma in humans, and it can be directly detected in the respiratory tract, at very low and volatile concentrations, which makes real-time measurement a challenge. This work describes the first-principles design and characterization of a molecular- and back-gated electronic field-effect transistor device for the detection and measurement of ultra-low FeNO concentrations (pM-nM) from a person' s exhaled breath, as a cost-efficient alternative to the slower and more expensive techniques based on off-line sputum characterization via mass spectrometry. The proposed device uses a partially oxidized phosphorene semiconducting channel material for FeNO detection, allowing nM L-1 concentration measurements of this analyte in an array configuration with an effective sensing surface area of 8.775 µm2, which results in a predicted limit of detection (LOD) of 19 nM L-1. In spite of the limited stability of phosphorene in oxygen-rich and humid environments, the proposed device would be practical for mobile applications with disposable sensors.


Assuntos
Biomarcadores/análise , Testes Respiratórios/instrumentação , Testes Respiratórios/métodos , Óxido Nítrico/análise , Asma/diagnóstico , Expiração , Humanos , Limite de Detecção
10.
World J Gastroenterol ; 25(30): 4043-4050, 2019 Aug 14.
Artigo em Inglês | MEDLINE | ID: mdl-31435162

RESUMO

Liver disease is characterized by breath exhalation of peculiar volatile organic compounds (VOCs). Thanks to the availability of sensitive technologies for breath analysis, this empiric approach has recently gained increasing attention in the context of hepatology, following the good results obtained in other fields of medicine. After the first studies that led to the identification of selected VOCs for pathophysiological purposes, subsequent research has progressively turned towards the comprehensive assessment of exhaled breath for potential clinical application. Specific VOC patterns were found to discriminate subjects with liver cirrhosis, to rate disease severity, and, eventually, to forecast adverse clinical outcomes even beyond existing scores. Preliminary results suggest that breath analysis could be useful also for detecting and staging hepatic encephalopathy and for predicting steatohepatitis in patients with nonalcoholic fatty liver disease. However, clinical translation is still hampered by a number of methodological limitations, including the lack of standardization and the consequent poor comparability between studies and the absence of external validation of obtained results. Given the low-cost and easy execution at bedside of the new technologies (e-nose), larger and well-structured studies are expected in order to provide the adequate level of evidence to support VOC analysis in clinical practice.


Assuntos
Nariz Eletrônico , Gastroenterologia/métodos , Hepatopatias/diagnóstico , Compostos Orgânicos Voláteis/análise , Testes Respiratórios/instrumentação , Testes Respiratórios/métodos , Expiração , Gastroenterologia/instrumentação , Gastroenterologia/tendências , Humanos
11.
EBioMedicine ; 46: 202-214, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31401197

RESUMO

BACKGROUND: Breath tests may diagnose tuberculosis (TB) through detecting specific volatile organic compounds produced by Mycobacterium tuberculosis or the infected host. METHODS: To estimate the diagnostic accuracy of breath test with electronic-nose and other devices against culture or other tests for TB, we screened multiple databases until January 6, 2019. FINDINGS: We included fourteen studies, with 1715 subjects in the analysis. The pooled sensitivity and specificity of electronic-nose were 0.93 (95% CI 0.82-0.97) and 0.93 (95% CI 0.82-0.97), respectively, and no heterogeneity was found. The sensitivity and specificity of other breath test devices ranged from 0.62 to 1.00, and 0.11 to 0.84, respectively. INTERPRETATION: The low to moderate evidence of these studies shows that breath tests can diagnose TB accurately, however, to give a real-time test result, additional development is needed. Research should also focus on sputum smear negative TB, children, and the positioning of breath testing in the diagnostic work flow. FUNDING: The authors received no specific funding for this work.


Assuntos
Testes Respiratórios/métodos , Tuberculose/diagnóstico , Técnicas Biossensoriais/instrumentação , Técnicas Biossensoriais/métodos , Testes Respiratórios/instrumentação , Nariz Eletrônico , Feminino , Humanos , Masculino , Mycobacterium tuberculosis/metabolismo , Curva ROC , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Tuberculose/metabolismo , Tuberculose/microbiologia , Tuberculose Pulmonar/diagnóstico , Tuberculose Pulmonar/microbiologia , Compostos Orgânicos Voláteis/análise , Compostos Orgânicos Voláteis/metabolismo
12.
Biomed Chromatogr ; 33(12): e4684, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31423612

RESUMO

An analytical method to identify volatile organic compounds (VOCs) in the exhaled breath from patients with a diagnosis of chronic obstructive pulmonary disease (COPD) using a ultrafast gas chromatography system equipped with an electronic nose detector (FGC eNose) has been developed. A prospective study was performed in 23 COPD patients and 33 healthy volunteers; exhalation breathing tests were performed with Tedlar bags. Each sample was analyzed by FCG eNose and the identification of VOCs was based on the Kovats index. Raw data were reduced by principal component analysis (PCA) and canonical discriminant analysis [canonical analysis of principal coordinates (CAP)]. The FCG eNose technology was able to identify 17 VOCs that distinguish COPD patients from healthy volunteers. At all stages of PCA and CAP the discrimination between groups was obvious. Chemical prints were correctly classified up to 82.2%, and were matched with 78.9% of the VOCs detected in the exhaled breath samples. Receiver operating characteristic curve analysis indicated the sensitivity and specificity to be 96% and 91%, respectively. This pilot study demonstrates that FGC eNose is a useful tool to identify VOCs as biomarkers in exhaled breath from COPD patients. Further studies should be performed to enhance the clinical relevance of this quick and ease methodology for COPD diagnosis.


Assuntos
Testes Respiratórios/métodos , Cromatografia Gasosa/métodos , Nariz Eletrônico , Doença Pulmonar Obstrutiva Crônica , Compostos Orgânicos Voláteis/análise , Idoso , Biomarcadores/análise , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Projetos Piloto , Doença Pulmonar Obstrutiva Crônica/diagnóstico , Doença Pulmonar Obstrutiva Crônica/metabolismo , Curva ROC , Reprodutibilidade dos Testes
13.
Arq Gastroenterol ; 56(2): 197-201, 2019 Aug 13.
Artigo em Inglês | MEDLINE | ID: mdl-31460586

RESUMO

BACKGROUND: 13C-urea breath test (UBT) is the gold-standard, noninvasive method for H. pylori diagnosis. However, there is no uniform standardization of the test. This situation can be unpractical for laboratories running with two or more devices. OBJECTIVE: To perform a prospective comparison validation study of UBT employing one validated protocol for two different devices: BreathID Hp Lab System® (Exalenz Bioscience Ltd, Israel), here called device A and IRIS-Doc2® (Wagner Analysen-Technik, Germany, now Mayoly Spindler Group, France), here called device B, in the diagnosis of H. pylori infection. METHODS: A total of 518 consecutive patients (365 females, 153 males, mean age 53 years) referred for UBT were included. All patients received device A protocol as follow: after at least one hour fasting, patients filled two bags prior to the test, then ingested an aqueous solution containing 75 mg of 13C-urea with a 4.0 g citric acid powder and filled another two bags 15 min after ingesting the test solution. One pair of breath sample bags (before and after ingestion) was analyzed by the two different devices. A delta over baseline (DOB) ≥5‰ indicated H. pylori infection. Statistics: Wilcoxon test, kappa coefficient with 95% CI, Wilson's method. RESULTS: Considering the device A protocol as the gold standard, its comparison with device B showed a sensitivity of 99.3% (95% CI: 96.3-99.9) and a specificity of 98.9% (95% CI: 97.3-99.6). Kappa coefficient was 0.976 (95% IC: 0.956-0.997). CONCLUSION: Correlation between the two devices was excellent and supports a uniform standardization of UBT.


Assuntos
Testes Respiratórios/instrumentação , Infecções por Helicobacter/diagnóstico , Ureia/análise , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Testes Respiratórios/métodos , Criança , Protocolos Clínicos , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Sensibilidade e Especificidade , Adulto Jovem
14.
Sensors (Basel) ; 19(17)2019 Aug 25.
Artigo em Inglês | MEDLINE | ID: mdl-31450646

RESUMO

The qualitative and quantitative analysis to trace gas in exhaled human breath has become a promising technique in biomedical applications such as disease diagnosis and health status monitoring. This paper describes an application of a high spectral resolution optical feedback cavity enhanced absorption spectroscopy (OF-CEAS) for ammonia detection in exhaled human breath, and the main interference of gases such as CO2 and H2O are approximately eliminated at the same time. With appropriate optical feedback, a fibered distributed feedback (DFB) diode laser emitting at 1531.6 nm is locked to the resonance of a V-shaped cavity with a free spectral range (FSR) of 300 MHz and a finesse of 14,610. A minimum detectable absorption coefficient of αmin = 2.3 × 10-9 cm-1 is achieved in a single scan within 5 s, yielding a detection limit of 17 ppb for NH3 in breath gas at low pressure, and this stable system allows the detection limit down to 4.5 ppb when the spectra to be averaged over 16 laser scans. Different from typical CEAS with a static cavity, which is limited by the FSR in frequency space, the attainable spectral resolution of our experimental setup can be up to 0.002 cm-1 owing to the simultaneous laser frequency tuning and cavity dither. Hence, the absorption line profile is more accurate, which is most suitable for low-pressure trace gas detection. This work has great potential for accurate selectivity and high sensitivity applications in human breath analysis and atmosphere sciences.


Assuntos
Amônia/isolamento & purificação , Técnicas Biossensoriais , Gases/isolamento & purificação , Amônia/química , Testes Respiratórios/métodos , Expiração , Gases/química , Humanos , Limite de Detecção , Espectroscopia de Luz Próxima ao Infravermelho
15.
Nutrients ; 11(7)2019 Jul 17.
Artigo em Inglês | MEDLINE | ID: mdl-31319625

RESUMO

Hydrogen (H2) measurement in exhaled breath is a reliable and non-invasive method to diagnose carbohydrate malabsorption. Currently, breath H2 measurement is typically limited to clinic-based equipment. A portable breath analyser (AIRE, FoodMarble Digestive Health Limited, Dublin, Ireland) is a personalised device marketed for the detection and self-management of food intolerances, including lactose malabsorption (LM). Currently, the validity of this device for breath H2 analysis is unknown. Individuals self-reporting dairy intolerance (six males and six females) undertook a lactose challenge and a further seven individuals (all females) underwent a milk challenge. Breath samples were collected prior to and at frequent intervals post-challenge for up to 5 h with analysis using both the AIRE and a calibrated breath hydrogen analyser (BreathTracker, QuinTron Instrument Company Inc., Milwaukee, WI, USA). A significant positive correlation (p < 0.001, r > 0.8) was demonstrated between AIRE and BreathTracker H2 values, after both lactose and milk challenges, although 26% of the AIRE readings demonstrated the maximum score of 10.0 AU. Based on our data, the cut-off value for LM diagnosis (25 ppm H2) using AIRE is 3.0 AU and it is effective for the identification of a response to lactose-containing foods in individuals experiencing LM, although its upper limit is only 81 ppm.


Assuntos
Testes Respiratórios/instrumentação , Intolerância à Lactose/diagnóstico , Lactose/metabolismo , Adulto , Testes Respiratórios/métodos , Feminino , Humanos , Masculino , Adulto Jovem
16.
Alcohol Alcohol ; 54(5): 487-496, 2019 Jan 09.
Artigo em Inglês | MEDLINE | ID: mdl-31322647

RESUMO

AIMS: Chronic alcohol use is associated with cerebral metabolite abnormalities, yet alcohol's acute effects on neurometabolism are not well understood. This preliminary study investigated cerebral metabolite changes in vivo on the descending limb of blood alcohol in healthy moderate drinkers. METHODS: In a pre/post design, participants (N = 13) completed magnetic resonance imaging (MRI) scans prior to and approximately 5 hours after consuming a moderate dose of alcohol (0.60 grams alcohol per kilogram of body weight). Magnetic resonance spectroscopy (1H MRS) was used to quantify cerebral metabolites related to glutamatergic transmission (Glx) and neuroimmune activity (Cho, GSH, myo-inositol) in the thalamus and frontal white matter. RESULTS: Breath alcohol concentration (BrAC) peaked at 0.070±0.008% (mean ± standard deviation) and averaged 0.025±0.011% directly prior to the descending limb scan. In the thalamus, Glx/Cr and Cho/Cr were significantly elevated on the descending limb scan relative to baseline. BrAC area under the curve, an index of alcohol exposure during the session, was significantly, positively associated with levels of Glx/Cr, Cho/Cr and GSH/Cr in the thalamus. GSH/Cr on the descending limb was inversely correlated with subjective alcohol sedation. CONCLUSIONS: This study offers preliminary evidence of alcohol-related increases in Glx/Cr, Cho/Cr and GSH/Cr on the descending limb of blood alcohol concentration. Findings add novel information to previous research on neurometabolic changes at peak blood alcohol in healthy individuals and during withdrawal in individuals with alcohol use disorder.


Assuntos
Encéfalo/efeitos dos fármacos , Encéfalo/metabolismo , Etanol/administração & dosagem , Espectroscopia de Prótons por Ressonância Magnética/métodos , Adulto , Encéfalo/diagnóstico por imagem , Testes Respiratórios/métodos , Feminino , Ácido Glutâmico/metabolismo , Glutamina/metabolismo , Humanos , Imagem por Ressonância Magnética/métodos , Masculino , Pessoa de Meia-Idade , Adulto Jovem
17.
BMC Gastroenterol ; 19(1): 132, 2019 Jul 25.
Artigo em Inglês | MEDLINE | ID: mdl-31345165

RESUMO

BACKGROUND: Eradicating Helicobacter pylori infection is clinically challenging, notably in cases with penicillin allergy. Cephalosporin could be used in lieu of amoxicillin to eradicate Helicobacter pylori. The current work aimed to assess therapeutic efficacy and safety of a cefuroxime-based quadruple regimen in treatment-naïve individuals with penicillin allergy, as well as patient compliance. METHODS: In the present prospective single-center cohort study, 152 Helicobacter pylori infected individuals with penicillin allergy received eradication therapy with cefuroxime (500 mg twice/day), levofloxacin (500 mg once/day), esomeprazole (20 mg twice/day) and bismuth potassium citrate (220 mg twice/day; 14 days). Safety and compliance were evaluated 1 to 3 days upon eradication. The urea breath test was carried out 8 to 12 weeks upon eradication for efficacy assessment. RESULTS: This quadruple antimicrobial regimen eradicated the pathogen at 85.5% (95% confidence interval (CI) 79.6-90.8%), 88.4% (95% CI 83.0-93.2%) and 90.1% (95% CI 85.2-94.4%) in intention-to-treat, modified intention-to-treat and per-protocol analyses, respectively, with resistance rates of 4.6 and 40.0% in the background of cefuroxime and levofloxacin, respectively. Meanwhile, 21.3% of patients had adverse reactions, but none was serious. A total of 95.3% of patients showed good compliance. Poor compliance and cefuroxime resistance were detected by uni- or multivariate analyses as independent factors predicting therapeutic failure. Eradication rates in patients with dual levofloxacin and cefuroxime susceptibility, isolated levofloxacin resistance, isolated cefuroxime resistance and dual resistance were 97.2, 84.0, 50.0, and 0%, respectively (P = 0.002). CONCLUSIONS: Cefuroxime, levofloxacin, esomeprazole, and bismuth achieved decent efficacy, safety and compliance as first-line antimicrobial regimen in patients with Helicobacter pylori and penicillin allergy.


Assuntos
Cefuroxima/administração & dosagem , Esomeprazol/administração & dosagem , Infecções por Helicobacter , Helicobacter pylori , Levofloxacino/administração & dosagem , Antiácidos/administração & dosagem , Antibacterianos/administração & dosagem , Bismuto/administração & dosagem , Testes Respiratórios/métodos , China , Hipersensibilidade a Drogas/diagnóstico , Quimioterapia Combinada/métodos , Feminino , Infecções por Helicobacter/diagnóstico , Infecções por Helicobacter/tratamento farmacológico , Helicobacter pylori/efeitos dos fármacos , Helicobacter pylori/isolamento & purificação , Humanos , Masculino , Adesão à Medicação/estatística & dados numéricos , Pessoa de Meia-Idade , Penicilinas/efeitos adversos , Estudos Prospectivos , Resultado do Tratamento
18.
Br J Surg ; 106(9): 1122-1125, 2019 08.
Artigo em Inglês | MEDLINE | ID: mdl-31259390

RESUMO

BACKGROUND: The aim was to derive a breath-based classifier for gastric cancer using a nanomaterial-based sensor array, and to validate it in a large screening population. METHODS: A new training algorithm for the diagnosis of gastric cancer was derived from previous breath samples from patients with gastric cancer and healthy controls in a clinical setting, and validated in a blinded manner in a screening population. RESULTS: The training algorithm was derived using breath samples from 99 patients with gastric cancer and 342 healthy controls, and validated in a population of 726 people. The calculated training set algorithm had 82 per cent sensitivity, 78 per cent specificity and 79 per cent accuracy. The algorithm correctly classified all three patients with gastric cancer and 570 of the 723 cancer-free controls in the screening population, yielding 100 per cent sensitivity, 79 per cent specificity and 79 per cent accuracy. Further analyses of lifestyle and confounding factors were not associated with the classifier. CONCLUSION: This first validation of a nanomaterial sensor array-based algorithm for gastric cancer detection from breath samples in a large screening population supports the potential of this technology for the early detection of gastric cancer.


Assuntos
Testes Respiratórios , Programas de Rastreamento/métodos , Neoplasias Gástricas/diagnóstico , Adulto , Algoritmos , Testes Respiratórios/métodos , Estudos de Casos e Controles , Humanos , Masculino , Pessoa de Meia-Idade , Reprodutibilidade dos Testes , Sensibilidade e Especificidade
19.
PLoS One ; 14(7): e0219309, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31269068

RESUMO

The lung clearance index (LCI), measured by multiple breath washout (MBW), reflects global ventilation inhomogeneity and is a sensitive marker of early obstructive airway disease. For the MBW test to accurately reflect a subject's gas mixing within the lungs, the breathing pattern should represent physiologically appropriate tidal volumes (VT) and respiratory rate (RR). We aimed to assess whether changes in VT impact MBW outcome measures with a series of prospective and retrospective studies. MBW testing was performed using the Exhalyzer ® D (EcoMedics AG, Switzerland). Healthy adult subjects performed MBW with uninstructed tidal breathing and a series of instructed tidal breathing tests, designed to isolate specific features of the breathing pattern. In addition, we retrospectively analyzed MBW data from two pediatric multi-centre interventional studies of cystic fibrosis (CF) subjects to determine the range of VT observed during uninstructed breathing, and whether breathing outside this range impacted results. The LCI was lower, but not significantly different between deep breathing at 20 ml/kg body weight and uninstructed tidal breathing; whereas LCI was significantly higher during shallow breathing compared with normal tidal breathing. For the majority of subjects with CF (80%), VT ranged from 9-15mL/kg. Within the observed VT range, LCI was similar in trials with mean VT /kg below this range compared to trials with VT /kg within the range. If subjects breathe naturally and are not instructed to use specific targets, the range of VT is within physiologically appropriate limits and normal variations observed do not impact MBW outcomes.


Assuntos
Testes Respiratórios/métodos , Adulto , Criança , Fibrose Cística/fisiopatologia , Humanos , Sobrepeso/fisiopatologia , Taxa Respiratória , Magreza/fisiopatologia , Volume de Ventilação Pulmonar
20.
Acta Oncol ; 58(9): 1216-1224, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31311375

RESUMO

Background: It has been reported that canine scent tests offer the possibility to screen for cancer. Assuming that breath samples can be collected with carrier materials, we tested the practicability of different carrier materials to be presented to dogs and validated and compared results with an electronic nose (eNose). Moreover, we hypothesized that cancer detection ability of dogs differs according to their working experience. Methods: In a methodological approach, two dog teams participated, one using experienced working dogs and the other ordinary household dogs to find the most qualified dogs and training method. To find best carrier material for breath sampling we compared charcoal containing glass tubes and fleece masks. In a second validating part, experienced working dogs were trained with improved training strategies. For breath sampling, two different, previously successfully tested fleece-based carrier materials were used: one was used with the dog team and both materials were compared with eNose. Results: In the methodological approach, it turned out that the charcoal-based sampling strategy qualified not sufficiently for VOC-detection. Moreover, we could determine that using experienced working dogs provided several advantages. Overall results of dogs in the validating part regarding specificity were 83%, regarding sensitivity 56%, but with great variability among dogs. Using eNose for breath analysis collected with both fleece carrier materials, specificity was 97% and sensitivity 89-100%. Conclusion: Our data confirmed that the diagnostic accuracy of dogs depended on the type of dog training and on the carrier materials. A comparison of breath samples analysis with an eNose achieved better results for both, sensitivity and specificity than for dogs. The use of fleece masks or fleeces in glass tubes as a sampling material can be recommended as successful VOC carriers, encouraging their use for clinical screenings.


Assuntos
Testes Respiratórios/métodos , Cães , Nariz Eletrônico , Neoplasias Pulmonares/diagnóstico , Olfato , Compostos Orgânicos Voláteis/análise , Adulto , Idoso , Idoso de 80 Anos ou mais , Animais , Testes Respiratórios/instrumentação , Expiração , Feminino , Vidro , Humanos , Masculino , Máscaras , Pessoa de Meia-Idade , Animais de Estimação , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Especificidade da Espécie , Ensino
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