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- Olofsson, Annelie, et al.
(författare)
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Biochemical and functional characterization of Helicobacter pylori vesicles
- 2010
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Ingår i: Molecular Microbiology. - : Wiley. - 0950-382X .- 1365-2958. ; 77:6, s. 1539-1555
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Tidskriftsartikel (refereegranskat)abstract
- Helicobacter pylori can cause peptic ulcer disease and/or gastric cancer. Adhesion of bacteria to the stomach mucosa is an important contributor to the vigor of infection and resulting virulence. H. pylori adheres primarily via binding of BabA adhesins to ABO/Lewis b (Leb) blood group antigens and the binding of SabA adhesins to sialyl-Lewis x/a (sLex/a) antigens. Similar to most Gram-negative bacteria, H. pylori continuously buds off vesicles and vesicles derived from pathogenic bacteria often include virulence-associated factors. Here we biochemically characterized highly purified H. pylori vesicles. Major protein and phospholipid components associated with the vesicles were identified with mass spectroscopy and NMR. A subset of virulence factors present was confirmed by immunoblots. Additional functional and biochemical analysis focused on the vesicle BabA and SabA adhesins and their respective interactions to human gastric epithelium. Vesicles exhibit heterogeneity in their protein composition, which were specifically studied in respect to the BabA adhesin. We also demonstrate that the oncoprotein, CagA, is associated with the surface of H. pylori vesicles. Thus, we have explored mechanisms for intimate H. pylori vesicle-host interactions and found that the vesicles carry effector-promoting properties that are important to disease development.
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| 2. |
- Schwarz, Johanna F. A., et al.
(författare)
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Shortened night sleep impairs facial responsiveness to emotional stimuli
- 2013
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Ingår i: Biological Psychology. - : Elsevier BV. - 0301-0511 .- 1873-6246. ; 93:1, s. 41-44
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Tidskriftsartikel (refereegranskat)abstract
- Sleep deprivation deteriorates mood, impairs the recognition of facial expressions, and affects the ability to regulate emotions. The present study investigated the effect of partial sleep deprivation on facial responses to emotional stimuli. Thirty-three healthy undergraduates were tested twice: after a night with (i) 8h and (ii) 4h sleep. Self-reported sleepiness and sustained attention (Psychomotor Vigilance Task) were assessed. Emotional reactivity was measured with facial Electromyogram (EMG) while participants were asked to respond with either compatible or incompatible facial muscles to emotional stimuli in order to study whether partial sleep deprivation caused slower reactions mainly in response to incompatible stimuli (due to an additional effort to suppress the compatible reaction caused by decreased inhibitory control) or in response to both compatible and incompatible stimuli. Self-reported sleepiness and reaction times in a sustained attention task significantly increased after one night of partial sleep deprivation. Facial reactions to emotional stimuli were decelerated. No significant interaction between sleep restriction and compatibility of the muscle to the picture valence could be observed. Hence, volitional facial reactions in response to emotional stimuli were slower after one night of reduced sleep, but affective inhibitory control was not significantly impaired. However, slowed facial responding to emotional stimuli may affect social interaction after sleep restriction.
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