Closed circuit rebreathing to achieve inert gas wash-in for multiple breath wash-out

Multiple breath wash-out (MBW) testing requires prior wash-in of inert tracer gas. Wash-in efficiency can be enhanced by a rebreathing tracer in a closed circuit. Previous attempts to deploy this did not account for the impact of CO2 accumulation on patients and were unsuccessful. We hypothesised that an effective rebreathe wash-in could be delivered and it would not alter wash-out parameters. Computer modelling was used to assess the impact of the rebreathe method on wash-in efficiency. Clinical testing of open and closed circuit wash-in–wash-out was performed in healthy controls and adult patients with cystic fibrosis (CF) using a circuit with an effective CO2 scrubber and a refined wash-in protocol. Wash-in efficiency was enhanced by rebreathing. There was no difference in mean lung clearance index between the two wash-in methods for controls (6.5 versus 6.4; p=0.2, n=12) or patients with CF (10.9 versus 10.8; p=0.2, n=19). Test time was reduced by rebreathe wash-in (156 versus 230 s for CF patients, p<0.001) and both methods were well tolerated. End wash-in CO2 was maintained below 2% in most cases. Rebreathe–wash-in is a promising development that, when correctly deployed, reduces wash-in time and facilitates portable MBW testing. For mild CF, wash-out outcomes are equivalent to an open circuit.

The Body and the Parent-Daughter Bond : Negotiating Haitian Filial Relationships in Edwidge Danticat’s Breath, Eyes, Memory and The Dew Breaker

The Body and the Parent-Daughter Bond: Negotiating Filial Relationships in Edwidge Danticat’s Breath, Eyes, Memory and The Dew Breaker est une étude sur les différentes façons dont le corps déséquilibré, torturé et traumatisé influence la relation parent-fille. Cette thèse examine l’impact du pouvoir et de la violence sur le corps aussi bien des parents que celui des filles et les différentes manières dont ces corps deviennent déséquilibrés. Cette thèse porte sur la construction et la négociation de chacune des conditions de parents et de filles sous l’angle du corps sexué traumatisé. Le premier chapitre traite la littérature précédemment écrite sur le corps en premier lieu, et sur les liens de filiation dans les deux œuvres en second lieu. J'ai introduit ma contribution au domaine et les différents aspects de la relation parent-fille qui ne sont pas pris en considération et que ma thèse essaye de démontrer. Ce chapitre contextualise ces deux œuvres pendant l’ère de la dictature des deux Duvaliers, père et fils, en exposant et discutant l’impacte néfaste de cette dictature sur les familles. Ce chapitre conceptualise et définit le corps, qui est une construction culturelle et un site d'interaction entre le pouvoir et la violence, par rapport aux relations filiales. Dans le deuxième chapitre, l'accent est mis sur la relation de Martine et Sophie par rapport à la pratique rituelle du test de la virginité. Dans ce chapitre, j’ai soulevé des questions sur le pouvoir de Martine de discipliner et contrôler l’attitude et le corps de Sophie et la manière avec laquelle la fille peut réagir au contrôle et à la subjugation de sa mère. J’ai examiné le conflit intergénérationnel qui est intensifié par le désordre corporel. J’ai essayé de démontrer comment Sophie souhaite rejeter et se séparer du corps de sa mère et son incapacité à le faire. Dans le troisième chapitre, j’ai étudié la relation de M. Bienaimé avec sa fille Ka qui est perturbée à la fois par le corps de son père et l’identité antérieure de ce dernier en tant qu’ancien Tonton Macoute. La question soulevée dans ce chapitre concerne le corps du père comme un agent de violence politique et comme une source d’inspiration artistique pour sa fille. L'identification de Ka avec et plus tard sa séparation du corps de son père est au cœur de mon étude, car c’est ce corps là qui modifie cette relation filiale particulière, qui résulte en un traumatisme transgénérationnel. Mots-clés: corps, relation parent-fille, pouvoir, violence, Edwidge Danticat

Non-invasive strategy in assessing asthma through biofluids metabolomics exploration: exhaled breath and urine potentialities

Asthma is a significant health issue in the pediatric population with a noteworthy growth over the years. The proposed challenge for this PhD thesis was the development of advanced methodologies to establish metabolomic patterns in urine and exhaled breath associated with asthma whose applicability was subsequently exploited to evaluate the disease state, the therapy adhesion and effect and for diagnostic purposes. The volatile composition of exhaled breath was studied combining headspace solid phase microextraction (HS-SPME) with gas chromatography coupled to mass spectrometry or with comprehensive two-dimensional gas chromatography coupled to mass spectrometry with a high resolution time of flight analyzer (GC×GC–ToFMS). These methodologies allowed the identification of several hundred compounds from different chemical families. Multivariate analysis (MVA) led to the conclusion that the metabolomic profile of asthma individuals is characterized by higher levels of compounds associated with lipid peroxidation, possibly linked to oxidative stress and inflammation (alkanes and aldehydes) known to play an important role in asthma. For future applications in clinical settings a set of nine compounds was defined and the clinical applicability was proven in monitoring the disease status and in the evaluation of the effect and / or adherence to therapy. The global volatile metabolome of urine was also explored using an HSSPME/GC×GC–ToFMS method and c.a. 200 compounds were identified. A targeted analysis was performed, with 78 compounds related with lipid peroxidation and consequently to oxidative stress levels and inflammation. The urinary non-volatile metabolomic pattern of asthma was established using proton nuclear magnetic resonance (1H NMR). This analysis allowed identifying central metabolic pathways such as oxidative stress, amino acid and lipid metabolism, gut microflora alterations, alterations in the tricarboxylic acid (TCA) cycle, histidine metabolism, lactic acidosis, and modification of free tyrosine residues after eosinophil stimulation. The obtained results allowed exploring and demonstrating the potential of analyzing the metabolomic profile of exhaled air and urine in asthma. Besides the successful development of analysis methodologies, it was possible to explore through exhaled air and urine biochemical pathways affected by asthma, observing complementarity between matrices, as well as, verify the clinical applicability.

Allergic asthma exhaled breath metabolome: a challenge for comprehensive two-dimensional gas chromatography

Allergic asthma represents an important public health issue, most common in the paediatric population, characterized by airway inflammation that may lead to changes in volatiles secreted via the lungs. Thus, exhaled breath has potential to be a matrix with relevant metabolomic information to characterize this disease. Progress in biochemistry, health sciences and related areas depends on instrumental advances, and a high throughput and sensitive equipment such as comprehensive two-dimensional gas chromatography–time of flight mass spectrometry (GC × GC–ToFMS) was considered. GC × GC–ToFMS application in the analysis of the exhaled breath of 32 children with allergic asthma, from which 10 had also allergic rhinitis, and 27 control children allowed the identification of several hundreds of compounds belonging to different chemical families. Multivariate analysis, using Partial Least Squares-Discriminant Analysis in tandem with Monte Carlo Cross Validation was performed to assess the predictive power and to help the interpretation of recovered compounds possibly linked to oxidative stress, inflammation processes or other cellular processes that may characterize asthma. The results suggest that the model is robust, considering the high classification rate, sensitivity, and specificity. A pattern of six compounds belonging to the alkanes characterized the asthmatic population: nonane, 2,2,4,6,6-pentamethylheptane, decane, 3,6-dimethyldecane, dodecane, and tetradecane. To explore future clinical applications, and considering the future role of molecular-based methodologies, a compound set was established to rapid access of information from exhaled breath, reducing the time of data processing, and thus, becoming more expedite method for the clinical purposes.

Efeitos das técnicas breath-stacking e espirometria de incentivo nos volumes da caixa torácica em pacientes com Doença de Parkinson

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior

Aerosols monitoring in Rio Claro, Brazil: Using lidar and air pollution analyzers

Brazil has an important role in the biomass burning aerosol activity. During the Dry Season (June-September) of 2009 an aerosol profiling campaign was carried out using a backscattering and Raman lidar system in Rio Claro-SP, Brazil (22°23'S and 47°32'W). The main goal of this campaign was to observe the biomass burning aerosol load due to sugarcane crops and also study the air dispersion conditions, planetary boundary and mixed layer daily evolution. In this paper we aim to present the preliminary results of the influence of this type of aerosol over the city of Rio Claro-SP, Brazil and one case study to evaluate the aerosol profile in a biomass burning episode that occurred in July, 2009. On July 15 an intense burning was observed about 300 m away from the lidar location. Throughout the measurements it was observed that the plumes reached up to 900 m, and that there was a time gap between the plumes. The gas analyzers showed a strong influence of this burning as it was noticed in the measurements of CO, NO x and nephelometer, whereas the PM10 did not have due to this burning, possibly because the particulate was deposited further from the emission source, not being detected by the equipment. © Sociedad Española de Óptica.

Biotechnology of polyketides: new breath of life for the novel antibiotic genetic pathways discovery through metagenomics

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Nitric Oxide in the Exhaled Breath Condensate of Healthy Volunteers Collected With a Reusable Device

Background: The analysis of exhaled breath condensate (EBC) is a non-invasive technique that enables the determination of several volatile and nonvolatile substances produced in the respiratory tract, whose measurement may be useful for the diagnosis and monitoring of several respiratory diseases. Objective: The aim of this study was to produce a low-cost reusable device in order to sample exhaled breath condensate in healthy adult volunteers, and to determine the concentration of nitric oxide in the sample collected. Material and methods: The apparatus was made with a U-shaped tube of borosilicate glass. The tube was placed in a container with ice, and unidirectional respiratory valves were fitted to the distal end. Afterwards, nitric oxide was measured in the exhaled breath condensate (EBC) by chemiluminescence. Results: The total cost of the device was $120.20. EBC samples were obtained from 116 volunteers of both sexes, aged between 20 and 70. The mean volume of exhaled breath condensate collected during 10 minutes was 1.0 +/- 0.6 mL, and the mean level of nitric oxide was 12.99 +/- 14.38 mu M (median 8.72 mu M). There was no correlation between the nitric oxide levels in the exhaled breath condensate and age or gender. Conclusion: We demonstrate that it is possible to fabricate a low-cost, efficient, reusable device in order to collect and determine nitric oxide levels in EBC. We have identified no correlation between the nitric oxide levels present in the EBC obtained with this method with either age or sex. (C) 2011 SEPAR. Published by Elsevier Espana, S.L. All rights reserved.

Excellent agreement between genetic and hydrogen breath tests for lactase deficiency and the role of extended symptom assessment

Clinical manifestations of lactase (LCT) deficiency include intestinal and extra-intestinal symptoms. Lactose hydrogen breath test (H2-BT) is considered the gold standard to evaluate LCT deficiency (LD). Recently, the single-nucleotide polymorphism C/T(-13910) has been associated with LD. The objectives of the present study were to evaluate the agreement between genetic testing of LCT C/T(-13910) and lactose H2-BT, and the diagnostic value of extended symptom assessment. Of the 201 patients included in the study, 194 (139 females; mean age 38, range 17-79 years, and 55 males, mean age 38, range 18-68 years) patients with clinical suspicion of LD underwent a 3-4 h H2-BT and genetic testing for LCT C/T(-13910). Patients rated five intestinal and four extra-intestinal symptoms during the H2-BT and then at home for the following 48 h. Declaring H2-BT as the gold standard, the CC(-13910) genotype had a sensitivity of 97% and a specificity of 95% with a of 0.9 in diagnosing LCT deficiency. Patients with LD had more intense intestinal symptoms 4 h following the lactose challenge included in the H2-BT. We found no difference in the intensity of extra-intestinal symptoms between patients with and without LD. Symptom assessment yielded differences for intestinal symptoms abdominal pain, bloating, borborygmi and diarrhoea between 120 min and 4 h after oral lactose challenge. Extra-intestinal symptoms (dizziness, headache and myalgia) and extension of symptom assessment up to 48 h did not consistently show different results. In conclusion, genetic testing has an excellent agreement with the standard lactose H2-BT, and it may replace breath testing for the diagnosis of LD. Extended symptom scores and assessment of extra-intestinal symptoms have limited diagnostic value in the evaluation of LD.

Tidal volume single breath washout of two tracer gases--a practical and promising lung function test

Background Small airway disease frequently occurs in chronic lung diseases and may cause ventilation inhomogeneity (VI), which can be assessed by washout tests of inert tracer gas. Using two tracer gases with unequal molar mass (MM) and diffusivity increases specificity for VI in different lung zones. Currently washout tests are underutilised due to the time and effort required for measurements. The aim of this study was to develop and validate a simple technique for a new tidal single breath washout test (SBW) of sulfur hexafluoride (SF6) and helium (He) using an ultrasonic flowmeter (USFM). Methods The tracer gas mixture contained 5% SF6 and 26.3% He, had similar total MM as air, and was applied for a single tidal breath in 13 healthy adults. The USFM measured MM, which was then plotted against expired volume. USFM and mass spectrometer signals were compared in six subjects performing three SBW. Repeatability and reproducibility of SBW, i.e., area under the MM curve (AUC), were determined in seven subjects performing three SBW 24 hours apart. Results USFM reliably measured MM during all SBW tests (n = 60). MM from USFM reflected SF6 and He washout patterns measured by mass spectrometer. USFM signals were highly associated with mass spectrometer signals, e.g., for MM, linear regression r-squared was 0.98. Intra-subject coefficient of variation of AUC was 6.8%, and coefficient of repeatability was 11.8%. Conclusion The USFM accurately measured relative changes in SF6 and He washout. SBW tests were repeatable and reproducible in healthy adults. We have developed a fast, reliable, and straightforward USFM based SBW method, which provides valid information on SF6 and He washout patterns during tidal breathing.

Rifaximin treatment for the irritable bowel syndrome with a positive lactulose hydrogen breath test improves symptoms for at least 3 months

While rifaximin was able to improve symptoms in patients with irritable bowel syndrome (IBS) in phase III trials, these results are yet to be repeated in phase IV studies.

Treatment response of airway clearance assessed by single-breath washout in children with cystic fibrosis

We studied the ability of 4 single-breath gas washout (SBW) tests to measure immediate effects of airway clearance in children with CF.