34 research outputs found
Chemical signature of colorectal cancer: case–control study for profiling the breath print
Background: Effective screening for colorectal cancer can reduce mortality by early detection of tumours
and colonic polyps. An altered pattern of volatile organic compounds (VOCs) in exhaled breath has been
proposed as a potential non-invasive diagnostic tool for detection of cancer. The aim of this study was
to evaluate the reliability of breath-testing for colorectal cancer screening and early diagnosis using an
advanced breath sampler.
Methods: The exhaled breath of patients with colorectal cancer and non-cancer controls with negative
findings on colonoscopy was collected using the ReCIVA® Breath Sampler. This portable device is
able to capture the alveolar breath fraction without environmental contamination. VOCs were desorbed
thermally and analysed by gas chromatography–mass spectrometry. The discriminatory ability of VOCs
in detecting colorectal cancer was evaluated by receiver operating characteristic (ROC) curve analysis for
each VOC, followed by cross-validation by the leave-one-out method, and by applying stepwise logistic
regression analysis.
Results: The study included 83 patients with colorectal cancer and 90 non-cancer controls. Fourteen
VOCs were found to have significant discriminatory ability in detecting patients with colorectal cancer.
The model with the diagnosis of cancer versus no cancer resulted in a statistically significant likelihood
of discrimination of 173â‹…45 (P <0â‹…001), with an area under the ROC curve of 0â‹…979. Cross-validation of
the model resulted in a true predictive value for colorectal cancer of 93 per cent overall. Reliability of the
breath analysis was maintained irrespective of cancer stage.
Conclusion: This study demonstrated that analysis of exhaled VOCs can discriminate patients with
colorectal cancer from those without. This finding may eventually lead to the creation of a smart online
sensory device, capable of providing a binary answer (cancer/no cancer) and directing to further screening
Determination of commercial animal and vegetable milks’ lipid profile and its correlation with cell viability and antioxidant activity on human intestinal caco-2 cells
Lipids from milk are important nutritional components, although their health effects, especially for animal milks, are still questioned. Four types of commercial milks, two semi-skimmed animal milks (bovine and goat) and two vegetable ones (soy and rice), along with their total and free lipid fractions recovered by sequential centrifugation or by ethyl acetate extraction, respectively, have been analyzed. A higher antioxidant ability, reported as Trolox equivalent antioxidant capacity, was found for all raw milks compared to that of rice. This trend was confirmed, except for soy milk, as ROS reduction in Caco-2 cells. The free lipid fraction was shown to have the highest antioxidant potential in both chemical and biological tests. Moreover, goat and soy raw milks positively regulated Caco-2 cell viability after an inflammatory stimulus. This effect was lost when their total lipid fraction was tested. Finally, only the free lipid fraction from rice milk preserved the Caco-2 viability after LPS stimulation. Our data demonstrated that the lipid profile of each milk, characterized by GC-MS analysis, could contribute to dictate its biological effects, and, although additional in vitro and in vivo studies are needed, they could support the literature re-evaluating the health effects of animal-based versus plant-based milks in the intestinal cellular model
Ageing exacerbates damage of systemic and salivary neutrophils from patients presenting Candida-related denture stomatitis
<p>Abstract</p> <p>Background</p> <p>Ageing leads to a decline in the function of the immune system, increasing the body's susceptibility to infections through the impairment of T-cells, macrophages, neutrophils and dendritic cells Denture stomatitis is a primary oral disease affecting elderly denture wearers. The major etiologic factor involved in this pathology is the infection by <it>Candida albicans</it>, an opportunistic pathogen that causes local and disseminated diseases in immunosuppressed humans. Neutrophils play a critical role in the immune response against <it>C. albicans </it>and are continually present in the salivary fluid and in the blood. The aim of this study was to determine ageing-related changes in salivary and blood neutrophils and their potential implications in <it>Candida</it>-related denture stomatitis.</p> <p>Results</p> <p>Our results showed a lower number of neutrophils in the saliva from patients presenting <it>Candida</it>-related denture stomatitis in comparison to their matched controls. Furthermore, fewer neutrophils were isolated from the saliva of aged control individuals in comparison to matched younger subjects. CXCR1, CD62L and CD11b expression were significantly greater on systemic neutrophils from younger control individuals. Elderly individuals showed more apoptotic salivary neutrophils and lower GM-CSF levels than younger ones, regardless of the occurrence of <it>Candida </it>infection. On the other hand, CXCL-8 concentrations were higher in the saliva from elderly individuals. Besides, TNF-α was detected at elevated levels in the saliva from infected elderly subjects. Salivary neutrophils from elderly and young patients presented impaired phagocytic activity against <it>C. albicans</it>. However, just systemic neutrophils from elderly showed decreased phagocytosis when compared to the younger ones, regardless of the occurrence of infection. In addition, neutrophils from aged individuals and young patients presented low fungicidal activity.</p> <p>Conclusion</p> <p>The data suggests that the <it>Candida </it>related-denture stomatitis is associated to neutrophils function deficiency, and ageing drastically appears to alter important characteristics of such cells, facilitating the establishment of this infection.</p
Improvement of the adsorption properties of carbon black granules by means of plasma enhanced-chemical vapour deposition with acrylic acid vapours
Ultra-Trace Determination of Sudan I, II, III, and IV in Wastewater by Solid-Phase Microextraction (SPME) and on-Line Solid-Phase Extraction (SPE) with High-Performance Liquid Chromatography (HPLC)
Two extraction/preconcentration methods are reported for the high-performance liquid chromatography (HPLC) determination of Sudan I, II, III, and IV in wastewater at trace (μg/L) and ultra-trace (ng/L) levels for the first time. The first approach, based on solid-phase microextraction (SPME), allows sub-μg/L determination of Sudan I and II, while Sudan III and IV are not detectable at these levels due to strong binding to dissolved organic matter. For Sudan I and II, the linearity was tested in the range from 0.5 to 50 μg/L and limits of detection (based on a signal-to-noise ratio of 3) and quantification (based on a signal-to-noise ratio of 10) of 0.2 and 0.5 μg/L, respectively, were estimated for both dyes. The on-line solid-phase extraction (SPE) using a C18 based enrichment precolumn was employed in the second approach. The only sample pretreatment employed was a required centrifugation step to remove suspended solids. In this case, the linearity was verified in the range from 50 to 500 ng/L for Sudan I, II, and III and from 100 to 500 ng/L for Sudan IV. The detection limits for a sample volume of 20 mL were on the order of 20 ng/L for Sudan I, 25 ng/L for Sudan II and III, and 30 ng/L for Sudan IV
Measurement of squalene in olive oil by fractional crystallization or headspace solid phase microextraction coupled with gas chromatography
Squalene is the most abundant component in the unsaponifiable fraction of olive oil with strong antioxidant properties. Its concentration in olive oils varies between 0.2 and 16.2 g/kg depending on the cultivar(s) used. The propose of this work was to determine the effectiveness of two different extraction methods for squalene determination by gas chromatography (GC) coupled to a flame ionization detector (FID) or to mass spectrometry (MS). In a first approach, oil samples were dissolved in methanol/acetone mixture 7:3 (v/v) and triglycerides separated by fractional crystallization at −20°C. The organic layer was removed, reduced to dryness and the residue reconstituted in n-heptane (containing squalane as external standard) and analyzed by GC-FID. A headspace (HS) solid phase microextraction (SPME) GC-MS method has been also developed in order to have an environmentally friendly (i.e. solventless) extraction procedure. The linear range investigated with both methods was 1.0-10 g/kg. Within-day and between days precision values, expressed as RSD%, were 4 and 7% (GC-FID), and 3 and 6% (GC-MS), respectively. The limit of detection (LOD) at a signal-to-noise (S/N) ratio of 3 were 0.019 (GC-FID) and 0.003 (GC-MS) g/kg; the limit of quantification (LOQ) calculated at S/N = 10 were 0.063 (GC-FID) and 0.008 (GC-MS) g/kg, well below the typical squalene concentration levels found in olive oils. The obtained percentage recoveries were 70 ± 2 (GC-FID) and 98 ± 3 (GC-MS), and were not concentration dependent. The potential of the method has been demonstrated by the analysis of several different olive oil samples produced from different cultivars and different locations
Acid/Base Gas/Liquid Adsorption Properties of Carbon Black Modified in NH3/O2 RF Glow Discharges
Solid phase microextraction-gas chromatography mass spectrometry: a fast and simple screening method for the assessment of organophosphorus pesticides residues in wine and fruit juices
A SPME-GCMS method for the determination of a mixture of organophosphorus pesticides (phorate, diazinon, methylparathion,
fenitrothion, malathion, fenthion, ethyl-parathion and methidathion) in wine and different fruit juices was developed.
The procedure is solvent-free, simple (direct SPME without further sample pre-treatment) and highly sensitive. Estimated LOD and
LOQ ranged from 2 to 33 ng/ml and from 7 to 109 ng/ml, respectively, in wine, and from 2 to 90 ng/ml and from 7 to 297 ng/ml,
respectively, in fruit juices. LOQ achieved by the present method are almost always below the maximum residue levels recommended
by the European legislation
Natural stones coated with a protective layer, process for their production and plasmochemical reactor
Plasma deposition processes from acrylic acid/methane on natural fibres to control the kinetic release of lysozyme from PVOH monolayer film
In this study, polyvinyl alcohol films incorporated with lysozyme, as active compound, and natural fibres were investigated. Various composite systems were developed to control the release of lysozyme from the matrix by using different surface treatments of the natural fibres. Specifically, the plasma enhanced-chemical vapour deposition of acrylic acid and diamond-like coating on spelt bran powders, in a particular home-made rotating plasma reactor, were studied. Moreover, a mathematical model able to describe the release kinetics of the active compound from the polyvinyl alcohol film into water was presented. To validate the model the release kinetic of lysozyme were determined. The model was successfully used to fit the above experimental data, corroborating the validity of the hypothesis made to derive it. Results showed that the incorporation of treated natural fibres to the polymeric matrix allows to obtaining a decrease of the lysozyme diffusion coefficient up to 73.5% compared to active film without fibre