ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

X
feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 1
    Electronic Resource
    Electronic Resource
    Role of Helicobacter pylori rfaJ genes (HP0159 and HP1416) in lipopolysaccharide synthesis (2004)
    Oxford, UK : Blackwell Publishing Ltd
    FEMS microbiology letters 241 (2004), S. 0 
    Details
    ISSN: 1574-6968
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Biology
    Notes: The genome of Helicobacter pylori 26695 has been sequenced and the lipopolysaccharide (LPS) O sidechain of this strain has been shown to express both Lewis x and Lewis y units. To determine the role of HP0159 and HP1416, genes recognized as rfaJ homologs and implicated in LPS synthesis, isogenic mutants of H. pylori 26695 were generated. The LPS of mutant 26695::HP0159Kan did not express either Lewis epitope as detected by immunoblotting, whereas the control strain and 26695::HP1416Kan produced both epitopes. Structural analysis of the LPS of the mutants showed that HP0159 encodes an α(1,2/3)-glucosyltransferase whereas HP1416 encodes an α(1,2/4)-glucosyltransferase.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1016/j.femsle.2004.10.004
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    Comparison of three serological methods for detection of Lewis antigens on the surface of Helicobacter pylori (2000)
    Oxford, UK : Blackwell Publishing Ltd
    FEMS microbiology letters 190 (2000), S. 0 
    Details
    ISSN: 1574-6968
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Biology
    Notes: Chemical studies have shown that lipopolysaccharide (LPS) from certain strains of Helicobacter pylori expresses the Lewis (Le) blood group antigens, predominantly Lex and/or Ley. Serological methods have been used in a number of studies to assess the level of Le expression by H. pylori. However, serological and chemical analyses of a strain's LPS do not always agree. The purpose of this study was to evaluate and compare serological methods used to detect the expression of these antigens by H. pylori. A set of 34 Irish clinical isolates and three culture collection strains had their Le antigen expression assessed using three serological methods, serodot, Western blotting and enzyme-linked immunosorbent assay. A combination of all three methods was used to estimate Lex (59%) and Ley (94%) expression and this may allow a more accurate assessment of Le expression by isolates for pathogenesis studies.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1574-6968.2000.tb09264.x
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    In vivo expression of the 25-kDa laminin-binding protein of Helicobacter pylori (2005)
    Oxford, UK : Blackwell Publishing Ltd
    FEMS immunology and medical microbiology 43 (2005), S. 0 
    Details
    ISSN: 1574-695X
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Biology , Medicine
    Notes: The gastroduodenal pathogen Helicobacter pylori has been shown to inhibit the interaction between the extracellular matrix protein laminin and its receptor on gastric epithelial cells, potentially contributing to a loss of mucosal integrity. As a 25-kDa outer membrane protein of H. pylori in association with the bacterial lipopolysaccharides (LPS) mediates attachment to laminin, the aim of this study was to determine whether the 25-kDa protein is produced by H. pylori in infected hosts. We examined the immune response to the 25-kDa laminin binding protein in 12 paediatric patients; samples from a H. pylori-negative healthy adult were used as controls. In immunoblotting, antibodies to a 25-kDa protein were found in the serum and saliva of H. pylori-positive individuals only, and using the positive sera and saliva, laminin binding to the 25-kDa protein was inhibited. Thus, the 25-kDa laminin-binding protein is produced by H. pylori in infected hosts.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1016/j.femsim.2004.09.006
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    Effect of host Lewis and ABO blood group antigen expression on Helicobacter pylori colonisation density and the consequent inflammatory response (1998)
    Oxford, UK : Blackwell Publishing Ltd
    FEMS immunology and medical microbiology 20 (1998), S. 0 
    Details
    ISSN: 1574-695X
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Biology , Medicine
    Notes: The Lewisb blood group antigen has been implicated as a putative receptor for Helicobacter pylori in the gastric mucosa. Furthermore, an increased prevalence of duodenal ulcer was found in non-secretors and it has been suggested that secretor status may influence bacterial colonisation density. Other investigators have hypothesised that severity of antral gastritis may be related to colonisation density of the bacterium alone, and that a critical bacterial load is necessary for the development of duodenal ulcer. Our objectives were to investigate whether a relationship existed between host Lewis and ABO blood group phenotype and prevalence of H. pylori infection. In addition we investigated whether bacterial colonisation density and the ensuing inflammatory response was influenced by secretor status and ABO blood group phenotype. The Lewis and ABO blood group phenotype of 207 patients undergoing upper endoscopy was determined. Of these, 136 were secretors and 62 were non-secretors. Forty-five percent of patients were infected with H. pylori. No significant association was found between H. pylori infection and expression of Lewisa or Lewisb blood group antigen. The mean histological density of H. pylori was 1.8±0.2 among non-secretors and 1.51±0.13 among secretors (P=0.209), with a mean grade of lymphocytic infiltration significantly greater in H. pylori-infected non-secretors (2.23±0.123 vs 1.8±0.074; P=0.003). In addition, blood group O non-secretors had a significantly higher grade of lymphocyte infiltration of their gastric mucosa compared to non-O non-secretors (2.53±0.133 vs 1.93±0.181, P=0.027). These results suggest that although no in vivo relationship exists between H. pylori and preferential adhesion to the putative Lewisb receptor, bacterial colonisation and the ensuing inflammatory response may be influenced at least in part by host expression of ABO and Lewisa blood group antigens.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1574-695X.1998.tb01135.x
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 5
    Electronic Resource
    Electronic Resource
    Genotyping of cagA and vacA, Lewis antigen status, and analysis of the poly-(C) tract in the α(1,3)-fucosyltransferase gene of Irish Helicobacter pylori isolates (2000)
    Oxford, UK : Blackwell Publishing Ltd
    FEMS immunology and medical microbiology 28 (2000), S. 0 
    Details
    ISSN: 1574-695X
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Biology , Medicine
    Notes: Much work has focused on trying to identify markers in Helicobacter pylori that might allow the eventual disease outcome of an infection to be predicted. In this study we examined the cagA and vacA genotype, and Lewis status in a panel of 43 Irish H. pylori clinical isolates, and investigated a possible correlation with disease pathology. In addition, differences in the poly-(C) tract of the α(1,3)-fucosyltransferase gene were examined to identify a possible correlation with gene expression. Only three of 43 isolates were cagA-negative, whereas the remaining 40 isolates, independent of pathology, were cagA-positive. In all the strains we examined, the vacA signal-sequence was type s1a. For the vacA mid-region 12/43 isolates were type m1 and 31/43 isolates were type m2. These data, and examination of isolates from different pathology groups, suggests that there is no correlation between virulence and vacA genotype in the Irish population of H. pylori isolates. Western blotting of whole cell lysates from 32 H. pylori isolates showed 3/32 displayed only the Lex epitope, 12/32 only the Ley, 13/32 both epitopes and 4/32 neither epitope. No apparent association between Lewis phenotype and disease pathology was evident. A range of lengths of poly-(C) tract were observed in the α(1,3)-fucosyltransferase gene, however the length of the tract in an isolate did not correlate with the Lewis structures present. We conclude that future studies on H. pylori pathogenesis should not alone focus on the importance of molecular markers, but also on the host response, including genetic background and immune responsiveness.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1574-695X.2000.tb01464.x
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 6
    Electronic Resource
    Electronic Resource
    Lack of a relationship between Lewis antigen expression and cagA, CagA, vacA and VacA status of Irish Helicobacter pylori isolates (1999)
    Oxford, UK : Blackwell Publishing Ltd
    FEMS immunology and medical microbiology 24 (1999), S. 0 
    Details
    ISSN: 1574-695X
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Biology , Medicine
    Notes: The cagA gene, vacA gene, CagA (cytotoxin-associated gene A product) and VacA (vacuolating cytotoxin) status of a collection of Helicobacter pylori isolates from the geographically distinct Irish population was determined, the potential association of these traits with Lewis (Le) antigen expression was assessed, and the relationship between these bacterial properties and the pathology associated with H. pylori infection was evaluated. Of the 57 isolates, a higher proportion from ulcer than from non-ulcer patients expressed VacA (71% vs. 53%). H. pylori isolates which were cagA-positive were no more significantly associated with peptic ulcers than non-ulcer disease (71% vs. 67%, P=0.775), nor were CagA-positive isolates (57% vs. 50%, P=0.783), but 80% of the isolates from duodenal ulcer patients were cagA-positive. Thirty-seven of the 57 isolates were tested for Le antigen expression. No statistically significant relationship (P〉0.05) was found between the occurrence and level of expression of Lex or Ley and cagA, vacA, or VacA status. This lack of an association in the Irish H. pylori isolates contrasts with that previously reported for predominantly North American isolates, and may be attributable to the adaptation of H. pylori strains with differing attributes to different human populations.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1574-695X.1999.tb01268.x
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 7
    Electronic Resource
    Electronic Resource
    The relationship between O-chain expression and colonisation ability of Helicobacter pylori in a mouse model (2000)
    Oxford, UK : Blackwell Publishing Ltd
    FEMS immunology and medical microbiology 29 (2000), S. 0 
    Details
    ISSN: 1574-695X
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Biology , Medicine
    Notes: 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, Lex and/or Ley. Except for low expression of Ley 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.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1574-695X.2000.tb01532.x
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 8
    Electronic Resource
    Electronic Resource
    Bacterial surface structures — An update (1996)
    Oxford, UK : Blackwell Publishing Ltd
    FEMS immunology and medical microbiology 16 (1996), S. 0 
    Details
    ISSN: 1574-695X
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Biology , Medicine
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1574-695X.1996.tb00123.x
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 9
    Electronic Resource
    Electronic Resource
    Interactions of bacterial adhesins with extracellular matrix and plasma proteins: pathogenic implications and therapeutic possibilities (1996)
    Oxford, UK : Blackwell Publishing Ltd
    FEMS immunology and medical microbiology 16 (1996), S. 0 
    Details
    ISSN: 1574-695X
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Biology , Medicine
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1574-695X.1996.tb00128.x
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 10
    Electronic Resource
    Electronic Resource
    Biological characterization of Campylobacter fetus lipopolysaccharides (1996)
    Oxford, UK : Blackwell Publishing Ltd
    FEMS immunology and medical microbiology 15 (1996), S. 0 
    Details
    ISSN: 1574-695X
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Biology , Medicine
    Notes: Abstract Lipopolysaccharides (LPS) of three strains of Campylobacter fetus (subspp. fetus and venerealis, and serotypes A and B), a bacterium of veterinary importance but also a cause of various infections in humans, were assessed for their ability to induce mitogenicity, gelation of Limulus amebocyte lysate, lethal toxicity in mice, and pyrogenicity in rabbits. All C. fetus LPS exhibited activities lower than those of Salmonella typhimurium LPS. LPS of C. fetus subsp. fetus serotype A had the lowest activity in all assays. Since the majority of C. fetus subsp. fetus isolates from humans are serotype A, the lower biological activities of this LPS may aid the pathogenesis of such strains. The lower activities of C. fetus LPS compared with those of S. typhimurium LPS may reflect the presence of longer fatty acid chains in the lipid A of C. fetus LPS, whereas interstrain differences in C. fetus LPS bioactivities may be related to some property influenced by composition of the saccharide moiety.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1574-695X.1996.tb00357.x
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...