Influence of circadian rhythm on exhaled breath profiling by electronic nose.

Electronic noses (e-noses) are a cheap and easy method for exhaled Volatile Organic Compound (VOC)-analysis which has shown its potential in several diseases. Before obtaining a full validation of these instruments in clinical settings, a number of methodological issues still have to be established. We aimed to investigate a potential influence of circadian variation on VOC-profile analyzed by an e-nose in healthy subjects. We enrolled 22 adults free of any known diseases. A sequence of exhaled breath samplings were performed on all participants at predetermined hours (7am, 12pm, 17pm, 23pm) and analyzed by an e-nose (Cyranose 320). According to Principal Component Analysis, significant circadian variations of the exhaled VOC-profile were shown for Principal Component (PC) 1 and 3. In detail, PC1 and PC3 values were significantly higher in the morning compared to the afternoon and evening (for all parameters p less than 0.05). Successive Linear Discriminant analysis confirmed the findings above. The daily variations in VOCs-profile, with the peak in the morning, could be relevant for future clinical applications, especially in the choice of optimal time for sampling patients.

Analysis of Aortic Remodeling and Stiffness in Patients with Obstructive Sleep Apnea Syndrome: Preliminary Results.

Obstructive sleep apnea (OSA) is a well-known risk factor for cardiovascular diseases. Several studies have shown that OSA is associated with vessel remodeling, but few studies have examined aorta. AIM: to analyse aortic remodelling in OSA. METHODS: Thirty consecutive OSA patients (22 males and 8 females, aged 58.5 ± 13.2 years) were studied. All patients underwent a morning blood gas analysis, a full cardiorespiratory evaluation, including nocturnal polygraphy and echocardiography, that assessed aortic root diameter (ARD) and aortic stiffness index (ASI). Patients were grouped as follows: Group 1, non-severe OSA (Apnea-Hypopnea Index; AHI <30, 14 patients); Group 2, severe OSA (AHI ≥30, 16 patients). RESULTS: No difference was found between the groups in ARD as absolute value (Group 1, 33.64 ± 0.91 mm; Group 2, 33.64 ± 1.02, p = ns) and as normalized value for the body surface area - ARDi (Group 1, 16.72 ± 0.63 mm/m2; Group 2, 16.09 ± 0.44, p = ns). Moreover, no difference was found in the ASI (Group 1, 14.04 ± 2.26; Group 2, 13.41 ± 2.22, p = ns). Considering all OSA patients, AHI showed an inverse correlation with ARDi (p = 0.018) and ASI (p = 0.0449). Moreover, the ASI showed a direct correlation with ARDi (p = 0.01) and morning PaO2 (p = 0.0349) as well as an inverse correlation with the oxygen desaturation index (ODI, p = 0.031) and total time with apnea and hypopnea (p = 0.039). CONCLUSION: No difference was found between severe and non-severe OSA in ARD. Surprisingly, the data show that the severity of OSA correlates inversely with the ASI and ARDi. The relation between PaO2 and stiffness might be explained by a feedback mechanism that tries to overcome the reduction of aortic elasticity due to night desaturation. These findings need to be investigated in further studies with a larger study population.

Exhaled volatile organic compounds identify patients with colorectal cancer.

BACKGROUND: An effective screening tool for colorectal cancer is still lacking. Analysis of the volatile organic compounds (VOCs) linked to cancer is a new frontier in cancer screening, as tumour growth involves several metabolic changes leading to the production of specific compounds that can be detected in exhaled breath. This study investigated whether patients with colorectal cancer have a specific VOC pattern compared with the healthy population. METHODS: Exhaled breath was collected in an inert bag (Tedlar(®) ) from patients with colorectal cancer and healthy controls (negative at colonoscopy), and processed offline by thermal-desorber gas chromatography-mass spectrometry to evaluate the VOC profile. During the trial phase VOCs of interest were identified and selected, and VOC patterns able to discriminate patients from controls were set up; in the validation phase their discriminant performance was tested on blinded samples. A probabilistic neural network (PNN) validated by the leave-one-out method was used to identify the pattern of VOCs that better discriminated between the two groups. RESULTS: Some 37 patients and 41 controls were included in the trial phase. Application of a PNN to a pattern of 15 compounds showed a discriminant performance with a sensitivity of 86 per cent, a specificity of 83 per cent and an accuracy of 85 per cent (area under the receiver operating characteristic (ROC) curve 0·852). The accuracy of PNN analysis was confirmed in the validation phase on a further 25 subjects; the model correctly assigned 19 patients, giving an overall accuracy of 76 per cent. CONCLUSION: The pattern of VOCs in patients with colorectal cancer was different from that in healthy controls. The PNN in this study was able to discriminate patients with colorectal cancer with an accuracy of over 75 per cent. Breath VOC analysis appears to have potential clinical application in colorectal cancer screening, although further studies are required to confirm its reliability in heterogeneous clinical settings.

Bilateral diaphragmatic paralysis after kidney surgery.

A 57-year-old woman underwent an enucleoresection of her right kidney angiomyolipoma. Two weeks later she was admitted to our hospital because of dyspnea at rest with orthopnea. The chest x-ray showed the elevation of both hemidiaphragms and the measurement of the sniff transdiaphragmatic pressure confirmed the diagnosis of bilateral diaphragmatic paralysis. A diaphragm paralysis can be ascribed to several causes, i.e. trauma, compressive events, inflammations, neuropathies, or it can be idiopathic. In this case, it was very likely that the patient suffered from post-surgery neuralgic amyotrophy. To our knowledge, there are only a few reported cases of neuralgic amyotrophy, also known as Parsonage-Turner Syndrome, which affects only the phrenic nerve as a consequence of a surgery in an anatomically distant site.

[A case report: an university professor suffering from malignant mesothelioma]. / Un caso clinico: un professore universitario affetto da mesotelioma maligno.

During the activities of the Apulia Regional Operative Center (COR Puglia), pertaining to the National Registry of Mesothelioma (ReNaM), there was reported a case of malignant mesothelioma occurred in a male of 66 years old. The case we bring to the attention is about an university professor of chemistry who, since the early '70s, has conducted several studies on the physico-chemical properties of some metals, particulary in the field of thermochemical treatments of superficial hardening of steel for greater wear resistance, using a laboratory with ovens and asbestos-containing materials and consumables. In 2011, after almost 40 years, the subject comes to the attention of the Apulia Regional Operative Center, with histologic and immunohistochemical diagnosis of epithelioid mesothelioma, after completing the diagnostic procedure in a thoracic surgery ward, for the assessment and treatment of a right pleural effusion revealed during health checks.

[Asbestos and agriculture: new perspectives of risk]. / Amianto e agricoltura: nuove prospettive di rischio.

The presence of ophiolites in areas of Basilicata, where there have been reports of mesothelioma in farmers, is known. This study evaluates the increased risk of exposure to tremolite in carrying out agricultural activities. Cases of mesothelioma occurred in farmers with unknown exposure to asbestos have been selected and assessed the employment in areas contaminated by tremolite. Personal samplings were conducted in a group of farmers employed in these areas and a group of subjects used in activities that do not involve contact with the ground. For the 5% of cases of mesothelioma in the lucan register emerged exposure to asbestos exclusively in farming activities in areas at tremolite risk. The analysis of the samples showed the presence of personal fibers of tremolite in 2/3 of the cases. In 60% there was an overcoming of the natural limit of 2 ff/l, with a peak up to 23.6 ff/l. The study shows that the risk of exposure to tremolite in agriculture is significantly higher than natural exposure.

Chemical characterization of exhaled breath to differentiate between patients with malignant plueral mesothelioma from subjects with similar professional asbestos exposure.

Malignant pleural mesothelioma (MPM) is an aggressive tumour whose main aetiology is the long-term exposure to asbestos fibres. The diagnostic procedure of MPM is difficult and often requires invasive approaches; therefore, it is clinically important to find accurate markers for MPM by new noninvasive methods that may facilitate the diagnostic process and identify patients at an earlier stage. In the present study, the exhaled breath of 13 patients with histology-established diagnosis of MPM, 13 subjects with long-term certified professional exposure to asbestos (EXP) and 13 healthy subjects without exposure to asbestos (healthy controls, HC) were analysed. An analytical procedure to determine volatile organic compounds by sampling of air on a bed of solid sorbent and thermal desorption GC-MS analysis was developed in order to identify the compounds capable of discriminating among the three groups. The application of univariate (ANOVA) and multivariate statistical treatments (PCA, DFA and CP-ANN) showed that cyclopentane and cyclohexane were the dominant variables able to discriminate among the three groups. In particular, it was found that cyclohexane is the only compound able to differentiate the MPM group from the other two; therefore, it can be a possible marker of MPM. Cyclopentane is the dominant compound in the discrimination between EXP and the other groups (MPM and HC); then, it can be considered a good indicator for long-term asbestos exposure. This result suggests the need to perform frequent and thorough investigations on people exposed to asbestos in order to constantly monitor their state of health or possibly to study the evolution of disease over time.

Markers of airway inflammation in pulmonary diseases assessed by induced sputum.

During recent years there has been a growing interest in using non-invasive biomarkers to understand and monitor the airway inflammation in subjects with respiratory tract disorders. To date, the best validated and performing non-invasive biomarkers are measures of inflammation in induced sputum in both cellular and fluid phase, which can provide biological insights into the pathogenesis of respiratory diseases such as asthma and chronic obstructive pulmonary disease. The purpose of this review is to examine the principal literature on the different markers of inflammation in pulmonary diseases assessed by induced sputum analysis in either cellular or fluid phase.

Early and late failure of noninvasive ventilation in chronic obstructive pulmonary disease with acute exacerbation.

BACKGROUND: Despite recent encouraging results, the use of noninvasive ventilation (NIV) in the management of acute exacerbations in chronic obstructive pulmonary disease (COPD), complicated by acute respiratory failure (ARF), is not always successful. Failure of NIV may require an immediate intubation after a few hours (usually 1-3) of ventilation ('early failure') or may result in clinical deterioration (one or more days later) after an initial improvement of blood gas tension and general conditions ('late failure'). MATERIALS AND METHODS: We enrolled 122 patients affected by COPD complicated by ARF, and treated with NIV. The schedule of NIV provided sessions of 2-6 h twice daily. RESULTS: Ninety-nine (81%) patients showed a progressive improvement of the clinical parameters and were discharged. Among the remaining 23 patients, 13 had an early failure and 10 had a late failure. In the 'success' group and 'late failure' groups we found after an increase of pH 2 h of NIV (from 7.31 +/- 0.05 to 7.38 +/- 0.04 P < 0.001 and from 7.29 +/- 0.03 to 7.36 +/- 0.02 P < 0.001, respectively) and a decrease of PaCO2 (from 80.93 +/- 9.79 to 66.48 +/- 5.95 P < 0.001 and from 85.96 +/- 10.77 to 76.41 +/- 11.02 P < 0.001, respectively). After 2 h of NIV in the 'late failure' group there were no significant changes in terms of pH (from 7.20 +/- 0.10 to 7.28 +/- 0.06) nor PaCO2 (from 92.86 +/- 35.49 to 93.68 +/- 23.68). The 'early failure' group had different characteristics and, owing to more severe conditions, the value of pH, of Glasgow Coma Score, and Apache II Score were the best predictors of the failure; while, among the complications on admission, metabolic alterations were the only independently significant predictor. CONCLUSIONS: Our study confirms that NIV may be useful to avoid intubation in approximately 80% of patients with COPD complicated by moderate-severe hypercapnic respiratory failure.