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- Plymoth, Amelie, et al.
(författare)
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Rapid proteome analysis of bronchoalveolar lavage samples of lifelong smokers and never-smokers by micro-scale liquid chromatography and mass spectrometry
- 2006
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Ingår i: Clin Chem.. - : Oxford University Press (OUP). ; 52:4, s. 671-679
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: The aim of this study was to determine whether relative qualitative and quantitative differences in protein expression could be related to smoke exposure or smoke-induced airway inflammation. We therefore explored and characterized the protein components found in bronchoalveolar lavage (BAL) fluid sampled from either lifelong smokers or never-smokers. METHODS: BAL fluid samples obtained by bronchoscopy from 60-year-old healthy never-smokers (n = 18) and asymptomatic smokers (n = 30) were analyzed in either pooled or individual form. Initial global proteomic analysis used shotgun digestion approaches on unfractionated BAL fluid samples (after minimal sample preparation) and separation of peptides by gradient (90-min) liquid chromatography (LC) coupled with on-line linear ion trap quadropole mass spectrometry (LTQ MS) for identification and analysis. RESULTS: LTQ MS identified 481 high- to low-abundance proteins. Relative differences in patterns of BAL fluid proteins in smokers compared with never-smokers were observed in pooled and individual samples as well as by 2-dimensional gel analysis. Gene ontology categorization of all annotated proteins showed a wide spectrum of molecular functions and biological processes. CONCLUSIONS: The described method provides comprehensive qualitative proteomic analysis of BAL fluid protein expression from never-smokers and from smokers at risk of developing chronic obstructive pulmonary disease. Many of the proteins identified had not been detected in previous studies of BAL fluid; thus, the use of LC-tandem MS with LTQ may provide new information regarding potentially important patterns of protein expression associated with lifelong smoking.
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- Varga, Z., et al.
(författare)
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Modelling the cloud condensation nucleus activity of organic acids on the basis of surface tension and osmolality measurements
- 2007
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Ingår i: Atmospheric Chemistry And Physics. - : Copernicus GmbH. - 1680-7316 .- 1680-7324. ; 7:17, s. 4601-4611
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Tidskriftsartikel (refereegranskat)abstract
- In this study vapour pressure osmometry was used to determine water activity in the solutions of organic acids. The surface tension of the solutions was also monitored in parallel and then Kohler curves were calculated for nine organic acids (oxalic, malonic, succinic, glutaric, adipic, maleic, malic, citric and cis-pinonic). Surface tension depression is negligible for most of the organic acids in dilute (<= 1 w/w%) solutions. Therefore, these compounds affect equilibrium vapour pressure only in the beginning phase of droplet formation when the droplet solution is more concentrated but not necessarily at the critical size. An exception is cis-pinonic acid which remarkably depress surface tension also in dilute (0.1 w/w%) solution and hence at the critical point. The surface tension of organic acid solutions is influenced by the solubility of the compound, the length of the carbon chain and also by the polar functional groups present in the molecule. Similarly to surface tension solubility plays an important role also in water activity: compounds with higher solubility (e.g. malonic, maleic and glutaric acid) reduce water activity significantly in the early phase of droplet formation while less soluble acids (e.g. succinic and adipic acid) are saturated in small droplets and the solution starts diluting only in bigger droplets. As a consequence, compounds with lower solubility have a minor effect on water activity in the early phase of droplet formation. To deduce the total effect Kohler curves were calculated and critical supersaturations (S-c) were determined for the organic acids using measured surface tension and water activity. It was found that critical supersaturation grew with growing carbon number. Oxalic acid had the lowest critical supersaturation in the size range studied and it was comparable to the activation of ammonium sulphate. The S-c values obtained in this study were compared to data from CCNC experiments. In most cases good agreement was found. For modelling purposes S-c vs. d(dry) plots are given and the dependence of water activity and surface tension on concentration are also formulated.
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