| 1. |
- Aabenhus, Rune, et al.
(författare)
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Lectin Typing of Campylobacter concisus
- 2002
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Ingår i: Journal of Clinical Microbiology. - 1098-660X. ; 40:2, s. 715-717
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Tidskriftsartikel (refereegranskat)abstract
- A total of 44 clinical isolates and the type strain of the putative pathogen Campylobacter concisus were grouped based on their reactions with plant lectins. The optimized lectin typing system used C. concisus strains proteolytically pretreated and subsequently typed by using a panel of four lectins. The system grouped all 45 strains into 13 lectin reaction patterns, leaving no strain untypeable due to autoagglutination. Lectin types were both stable and reproducible.
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| 2. |
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| 3. |
- Annuk, Heidi, et al.
(författare)
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Characterisation and differentiation of lactobacilli by lectin typing
- 2001
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Ingår i: Journal of Medical Microbiology. - 0022-2615. ; 50:12, s. 1069-1074
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Tidskriftsartikel (refereegranskat)abstract
- Lactobacillus isolates from healthy Estonian and Swedish children were characterised by a lectin typing technique; 56 isolates from six species (L. acidophilus, L. paracasei, L. plantarum, L. fermentum, L. brevis and L. buchneri) were tested. The typing system was based on an agglutination assay with a panel of six commercially available lectins, which,were chosen on the basis of their carbohydrate specificities. The isolates were also subjected to proteolytic degradation before lectin typing to decrease auto-agglutination of whole cells in the assay. The 56 isolates were divided into 15 different lectin types by their lectin agglutination patterns. Proteolytic treatment reduced auto-agglutination for the majority of species, apart from L. acidophilus, which remained predominantly auto-agglutinating (eight of nine strains). The system produced stable and reproducible results under standardised culture conditions. Lactobacilli are important bacteria for use as probiotics and this system may supplement current molecular typing techniques and may help in identification of strains that could be useful in this role.
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| 4. |
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| 5. |
- Bombarda, F., et al.
(författare)
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Runaway electron beam control
- 2019
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Ingår i: Plasma Physics and Controlled Fusion. - : IOP Publishing. - 1361-6587 .- 0741-3335. ; 61:1
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Tidskriftsartikel (refereegranskat)
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| 6. |
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| 7. |
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| 8. |
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| 9. |
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| 10. |
- Forde, Sean, et al.
(författare)
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Dissolution of glass compositions containing no added lead in simulated lung fluid
- 2008
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Ingår i: International journal of hygiene and environmental health. - : Elsevier BV. - 1438-4639 .- 1618-131X. ; 211:3-4, s. 357-366
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Tidskriftsartikel (refereegranskat)abstract
- Six crystal glass compositions containing no added lead were studied with respect to the potential exposure of workers during the cold end working of crystal type glasses. During cutting and grinding of crystal glass, fine dusts are produced. These may be inhaled by the workers with subsequent partial dissolution of the dusts in the lung fluid. In order to provide a measure of the degree of dissolution in the case of the six crystal glass compositions produced in this work the release of antimony, barium, silicon, and bismuth was investigated by passing simulated lung fluid over powdered samples of the crystal compositions having a diameter of ca. 0.5 micron for a period of 21 days. The results show that it is possible to produce durable glass containing no added lead. While the leaching and weathering of the glass compositions studied here could be correlated with the mole ratio of alkali/silica and the degree of depolymerisation of the silica network, the dissolution of silica in simulated lung fluid seems to be independent of this property.
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| 11. |
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| 12. |
- Hynes, Sean, et al.
(författare)
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Comparative chemical and biological characterization of the lipopolysaccharides of gastric and enterohepatic helicobacters
- 2004
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Ingår i: Helicobacter. - : Wiley. - 1083-4389 .- 1523-5378. ; 9:4, s. 313-323
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Tidskriftsartikel (refereegranskat)abstract
- Background. The lipopolysaccharide of Helicobacter pylori plays an important role in colonization and pathogenicity. The present study sought to compare structural and biological features of lipopolysaccharides from gastric and enterohepatic Helicobacter spp. not previously characterized.Materials and methods. Purified lipopolysaccharides from four gastric Helicobacter spp. (H. pylori, Helicobacter felis, Helicobacter bizzozeronii and Helicobacter mustelae) and four enterohepatic Helicobacter spp. (Helicobacter hepaticus, Helicobacter bilis, Helicobacter sp. flexispira and Helicobacter pullorum) were structurally characterized using electrophoretic, serological and chemical methods.Results. Structural insights into all three moieties of the lipopolysaccharides, i.e. lipid A, core and O-polysaccharide chains, were gained. All species expressed lipopolysaccharides bearing an O-polysaccharide chain, but H. mustelae and H. hepaticus produced truncated semirough lipopolysaccharides. However, in contrast to lipopolysaccharides of H. pylori and H. mustelae, no blood group mimicry was detected in the other Helicobacter spp. examined. Intra-species, but not interspecies, fatty acid profiles of lipopolysaccharides were identical within the genus. Although shared lipopolysaccharide-core epitopes with H. pylori occurred, differing structural characteristics were noted in this lipopolysaccharide region of some Helicobacter spp. The lipopolysaccharides of the gastric helicobacters, H. bizzozeronii and H. mustelae, had relative Limulus amoebocyte lysate activities which clustered around that of H. pylori lipopolysaccharide, whereas H. bilis, Helicobacter sp. flexispira and H. hepaticus formed a cluster with approximately 100010,000-fold lower activities. H. pullorum lipopolysaccharide had the highest relative Limulus amoebocyte lysate activity of all the helicobacter lipopolysaccharides (10-fold higher than that of H. pylori lipopolysaccharide), and all the lipopolysaccharides of enterohepatic Helicobacter spp. were capable of inducing nuclear factor-Kappa B(NF-B) activation.Conclusions. The collective results demonstrate the structural heterogeneity and pathogenic potential of lipopolysaccharides of the Helicobacter genus as a group and these differences in lipopolysaccharides may be indicative of adaptation of the bacteria to different ecological niches.
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| 13. |
- Hynes, Sean, et al.
(författare)
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Differentiation of Helicobacter pylori isolates based on lectin binding of cell extracts in an agglutination assay
- 1999
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Ingår i: Journal of Clinical Microbiology. - 1098-660X. ; 37:6, s. 1994-1998
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Tidskriftsartikel (refereegranskat)abstract
- Plant and animal lectins with various carbohydrate specificities were used to type 35 Irish clinical isolates of Helicobacter pylori and the type strain NCTC 11637 in a microtiter plate assay. Initially, a panel of eight lectins with the indicated primary specificities were used: Anguilla anguilla (AAA), Lotus tetragonolobus (Lotus A), and Ulex europaeus I (UEA I), specific for -L-fucose; Solanum tuberosum (STA) and Triticum vulgaris (WGA), specific for -N-acetylglucosamine; Glycine max (SBA), specific for -N-acetylgalactosamine; Erythrina cristagali (ECA), specific for -galactose and -N-acetylgalactosamine; and Lens culinaris (LCA), specific for -mannose and -glucose. Three of the lectins (SBA, STA, and LCA) were not useful in aiding in strain discrimination. An optimized panel of five lectins (AAA, ECA, Lotus A, UEA I, and WGA) grouped all 36 strains tested into eight lectin reaction patterns. For optimal typing, pretreatment by washing bacteria with a low-pH buffer to allow protein release, followed by proteolytic degradation to eliminate autoagglutination, was used. Lectin types of treated samples were stable and reproducible. No strain proved to be untypeable by this system. Electrophoretic and immunoblotting analyses of lipopolysaccharides (LPSs) indicated that the lectins interact primarily, but not solely, with the O side chain of H. pylori LPS.
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| 14. |
- Hynes, Sean, et al.
(författare)
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Glycoconjugate Binding of Gastric and Enterohepatic Helicobacter spp.
- 2003
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Ingår i: Infection and Immunity. - 1098-5522. ; 71:5, s. 2976-2980
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Tidskriftsartikel (refereegranskat)abstract
- Helicobacter pylori is able to utilize several lectin-like, protein-carbohydrate interactions for binding to mucins, cell surfaces, and extracellular matrix proteins. As determined by hemagglutination assays and binding of radiolabeled bacteria to glycosphingolipids on thin-layer chromatograms, strains of gastric helicobacters and enterohepatic helicobacters, including Helicobacter canis, Helicobacter hepaticus, and Helicobacter bilis, also demonstrated evidence for the presence of lectin-hemagglutinin adhesins. In addition, in H. hepaticus and H. bilis, binding may be sialic acid dependent. The presence or absence and differences in the levels of activity of lectin adhesins may reflect the species' ecological niche.
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| 15. |
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| 16. |
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| 17. |
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| 18. |
- Hynes, Sean, et al.
(författare)
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Toxins of the helicobacter genus and their roles in pathogenesis
- 2004
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Ingår i: Toxin Reviews. - 1556-9543. ; 23:1, s. 1-35
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Forskningsöversikt (refereegranskat)abstract
- In the 20 years since the discovery of Helicobacter pylori the number of formally described Helicobacter spp. has increased dramatically. The majority of species in the genus have been associated with some form of pathology. Similar to other Gram-negative bacteria, all helicobacters have lipopolysaccharides or endotoxins in the outer leaflet of their outer membrane which is an important modulator of the immune system. H. pylori endotoxin has a number of roles in the pathogenesis of the bacterium. Its relatively low biological and immunological activity and molecular mimicry may contribute to the chronic nature of infection through avoidance of host defence mechanisms and adhesion. In addition to endotoxins, various helicobacters also secrete distinct exotoxins capable of host cell damage. H. pylori has been shown to possess a cytotoxin capable of inducing vacuoles in epithelial cells termed vacuolating cytotoxin or VacA. Although VacA has a number of roles in the pathogenesis of H. pylori its use as a predictor of clinical outcome has yet to be established. In addition, similar to the closely related Campylobacter jejuni, a number of enterohepatic helicobacters express a cytolethal distending toxin capable of inducing severe cell damage in vivo and in vitro. Both endotoxins and exotoxins may play a combined role in the pathogenesis of Helicobacter spp. Both toxin types have been identified as being present on outer membrane vesicles shed by H. pylori which may act as antigen delivery vehicles and contribute to pathogenesis.
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| 19. |
- Joffrin, E., et al.
(författare)
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Overview of the JET preparation for deuterium-tritium operation with the ITER like-wall
- 2019
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Ingår i: Nuclear Fusion. - : IOP Publishing. - 1741-4326 .- 0029-5515. ; 59:11
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Forskningsöversikt (refereegranskat)abstract
- For the past several years, the JET scientific programme (Pamela et al 2007 Fusion Eng. Des. 82 590) has been engaged in a multi-campaign effort, including experiments in D, H and T, leading up to 2020 and the first experiments with 50%/50% D-T mixtures since 1997 and the first ever D-T plasmas with the ITER mix of plasma-facing component materials. For this purpose, a concerted physics and technology programme was launched with a view to prepare the D-T campaign (DTE2). This paper addresses the key elements developed by the JET programme directly contributing to the D-T preparation. This intense preparation includes the review of the physics basis for the D-T operational scenarios, including the fusion power predictions through first principle and integrated modelling, and the impact of isotopes in the operation and physics of D-T plasmas (thermal and particle transport, high confinement mode (H-mode) access, Be and W erosion, fuel recovery, etc). This effort also requires improving several aspects of plasma operation for DTE2, such as real time control schemes, heat load control, disruption avoidance and a mitigation system (including the installation of a new shattered pellet injector), novel ion cyclotron resonance heating schemes (such as the three-ions scheme), new diagnostics (neutron camera and spectrometer, active Alfven eigenmode antennas, neutral gauges, radiation hard imaging systems...) and the calibration of the JET neutron diagnostics at 14 MeV for accurate fusion power measurement. The active preparation of JET for the 2020 D-T campaign provides an incomparable source of information and a basis for the future D-T operation of ITER, and it is also foreseen that a large number of key physics issues will be addressed in support of burning plasmas.
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| 20. |
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| 21. |
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| 22. |
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| 23. |
- Kruszewska, Danuta, et al.
(författare)
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Effect of the antibacterial activity of pig pancreatic juice on human multiresistant bacteria.
- 2004
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Ingår i: Pancreas. - 0885-3177. ; 28:2, s. 191-199
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Tidskriftsartikel (refereegranskat)abstract
- Introduction: The role of the exocrine pancreas in regulating gut microflora colonization is unclear. The main objective in the current study was to assess the effect of pancreatic fluid on the growth of pathogenic bacteria and fungi. Methods: The antibacterial activity of pure pig pancreatic juice collected from catheterized, healthy, conscious, and anesthetized pigs was investigated with multiresistant microbial isolates and nonpathogenic strains. Studies were performed on pathogenic bacterial and fungi as well as lactic acid bacteria and reference strains. Results: Pancreatic juice was effective (P < 0.01) against multidrug resistant bacterial pathogens, whereas lactic acid bacteria were insensitive. The antibacterial action was independent of pancreatic juice proteolytic activity. The in vitro antibacterial properties of pancreatic juice last for several hours. Data suggest that broth composition may modulate the intensity of pancreatic juice antibacterial activity. Conclusions: Pancreatic juice antibacterial activity may be an important factor in limiting the colonization of pathogenic bacteria in the gastrointestinal tract. We postulate that observed antibacterial activity of the pancreatic juice could play an important role as one of the factors of innate immunity.
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| 24. |
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| 25. |
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| 26. |
- Moran, A P, et al.
(författare)
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The relationship between O-chain expression and colonisation ability of Helicobacter pylori in a mouse model
- 2000
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Ingår i: Pathogens and Disease. - 2049-632X. ; 29:4, s. 263-270
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Tidskriftsartikel (refereegranskat)abstract
- The influence of lipopolysaccharide (LPS) O-polysaccharide chain production on the colonisation ability of Helicobacter pylori in four mouse models (NMRI, C57BL/6, CBA/Ca, and BALB/cA mice) was studied. H. pylori strains that produced smooth-form LPS (S-LPS) detectable in silver-stained electrophoretic gels colonised mice. In contrast, a laboratory-passaged strain G50 and the culture collection strain CCUG 17874 did not colonise mice; the former strain produced low amounts of O-chains only detectable in immunoblotting but not in silver-stained gels, whereas the latter produced rough-form LPS (R-LPS) without O-chains. Furthermore, a galE isogenic mutant, which produced R-LPS, did not colonise mice. However, after repeated broth culture, strains G50 and CCUG 17874 produced S-LPS detectable in silver-stained gels and were capable of colonising mice. Consistent with the production of O-chains, all colonising strains produced Lewis (Le) antigens, Le(x) and/or Le(y). Except for low expression of Le(y) by non-colonising G50, reflecting low production of O-chains, all other non-colonising strains and the galE mutant lacked expression of Le antigens consistent with their production of R-LPS. Lectin typing of strains supported these findings, and also showed that lectin types did not differ before and after colonisation. The low level of O-chain production and Le antigen expression by the non-colonising G50 may not be sufficient to aid colonisation. Examination of protein profiles of H. pylori strains before inoculation showed that protein expression was not significantly different between colonising and non-colonising strains. These results show that S-LPS production with O-chain expression is required by H. pylori for colonisation in a number of mouse models and that care should be taken with inoculating H. pylori strains that loss of O-chains does not occur during subculturing.
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| 27. |
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| 28. |
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| 29. |
- On, SLW, et al.
(författare)
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Extragastric Helicobacter species
- 2002
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Ingår i: Helicobacter. - : Wiley. - 1083-4389 .- 1523-5378. ; 7:Suppl. 1, s. 63-67
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Tidskriftsartikel (refereegranskat)abstract
- The genus Helicobacter has expanded at a rapid pace and no fewer than 31 species have been named since the proposal of the genus in 1989. Of these 31 species, 22 are principally associated with extragastric niches and there is increasing interest in the role of these taxa in diseases of humans and animals. Substantial evidence attests to certain species playing a role in the pathogenesis of enteric, hepatic and biliary disorders and some taxa demonstrate zoonotic potential. The importance of extragastric Helicobacters is likely to be an important topic for research in the near future. Here, important papers published in the field this last year are reviewed.
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| 30. |
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| 31. |
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| 32. |
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| 33. |
- Sjunnesson, Håkan, et al.
(författare)
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Five month persistence of Helicobacter pylori infection in guinea pigs
- 2003
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Ingår i: APMIS : acta pathologica, microbiologica, et immunologica Scandinavica. - : Wiley. - 1600-0463. ; 111:6, s. 634-642
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Tidskriftsartikel (refereegranskat)abstract
- Seven Dunkin-Hartley guinea pigs were infected with the Sydney strain of H. pylori (SS1). Gastric histopathology was evaluated and serum antibody response to H. pylori cell-surface proteins was analysed by enzyme immunoassay (EIA) and immunoblot. Tissue and faecal samples from five control animals were analysed for the presence of naturally occurring Helicobacter spp. infection by culture and Helicobacter genus-specific PCR. The H. pylori infection persisted for 5 months, in most animals accompanied by a histologically severe antral gastritis, exhibiting focal degeneration and necrosis of gastric crypt epithelium. Increased numbers of mitotic figures were observed in the gastric epithelium, indicating a regenerative process. Infected animals displayed specific antibodies towards H. pylori cell-surface proteins in immunoblot, whereas EIA was of dubious value creating false-positive results. Serum complement C3 and cholesterol levels appeared to be elevated in infected animals. Helicobacter spp. infection was not detected in the control animals. The persistent infection, accompanied by severe gastritis and a prominent serum antibody response, and the apparent absence of a natural Helicobacter spp. infection makes the guinea pig model useful in H. pylori research.
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| 34. |
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| 35. |
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| 36. |
- Taneera, Jalal, et al.
(författare)
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Influence of activated charcoal, porcine gastric mucin and beta-cyclodextrin on the morphology and growth of intestinal and gastric Helicobacter spp.
- 2002
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Ingår i: Microbiology. - 1465-2080. ; 148:3, s. 677-684
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Tidskriftsartikel (refereegranskat)abstract
- Bile-tolerant Helicobacter spp. are emerging human and animal pathogens. However, due to their fastidious nature, which requires nutrient-rich complex media to grow, infection with these bacteria may be underestimated. The accumulation of toxic metabolites in cultures may be one of the main obstacles for successful culture of these organisms. The present study examined various potential growth-enhancing substances for Helicobacter spp. and, furthermore, how they may affect spiral to coccoid conversion. Five Helicobacter spp. were cultured on agar and in broth media supplemented with activated charcoal, beta-cyclodextrin, or porcine gastric mucin. Growth was determined by estimating the numbers of colony-forming units and colony diameter, as well as bacterial cell mass. Coccoid transformation was estimated every 24 h by both Gram and acridine-orange staining. Activated charcoal was superior in supporting growth and increased cell mass on agar and in broth media. beta-Cyclodextrin delayed spiral to coccoid conversion by Helicobacter pylori and Helicobacter canis, whereas activated charcoal delayed the conversion to coccoid forms of Helicobacter hepaticus and Helicobacter bilis. The progression to coccoid forms by Helicobacter pullorum on agar media was not influenced by any growth supplement. The spiral to coccoid conversion was more rapid in broth media than on agar media. The growth enhancement observed is probably related to the capacity of activated charcoal to remove toxic compounds in culture media.
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| 37. |
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| 38. |
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- 2018
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Ingår i: Nuclear Fusion. - : IOP Publishing. - 1741-4326 .- 0029-5515. ; 58:9
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Tidskriftsartikel (refereegranskat)
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| 39. |
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- 2018
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Ingår i: Nuclear Fusion. - : IOP Publishing. - 1741-4326 .- 0029-5515. ; 58:1
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Forskningsöversikt (refereegranskat)
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