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| 2. |
- Adlerberth, Ingegerd, 1959, et al.
(författare)
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P fimbriae and other adhesins enhance intestinal persistence of Escherichia coli in early infancy.
- 1998
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Ingår i: Epidemiology and infection. - 0950-2688. ; 121:3, s. 599-608
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Tidskriftsartikel (refereegranskat)abstract
- Resident and transient Escherichia coli strains were identified in the rectal flora of 22 Pakistani infants followed from birth to 6 months of age. All strains were tested for O-antigen expression, adhesin specificity (P fimbriae, other mannose-resistant adhesins or type 1 fimbriae) and adherence to the colonic cell line HT-29. Resident strains displayed higher mannose-resistant adherence to HT-29 cells, and expressed P fimbriae (P = 0.0036) as well as other mannose-resistant adhesins (P = 0.012) more often than transient strains. In strains acquired during the first month of life, P fimbriae were 12 times more frequent in resident than in transient strains (P = 0.0006). The O-antigen distribution did not differ between resident and transient strains, and none of the resident P-fimbriated strains belonged to previously recognized uropathogenic clones. The results suggest that adhesins mediating adherence to intestinal epithelial cells, especially P fimbriae, enhance the persistence of E. coli in the large intestine of infants.
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| 3. |
- Agace, W. W., et al.
(författare)
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Escherichia coli induces transuroepithelial neutrophil migration by an intercellular adhesion molecule-1-dependent mechanism
- 1995
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Ingår i: Infection and Immunity. - 0019-9567. ; 63:10, s. 4054-4062
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Tidskriftsartikel (refereegranskat)abstract
- During bacterial infections at mucosal sites, neutrophils migrate to the mucosa and cross the epithelial barrier. We have examined neutrophil migration across Escherichia coli-stimulated uroepithelial cell layers in an attempt to more fully understand this process. Stimulation of uroepithelial cells with E. coli or interleukin-1α (IL-1α) induced transepithelial neutrophil migration in a time- and stimulant dose-dependent manner. Uroepithelial cell lines and nontransformed uroepithelial cells expressed intercellular adhesion molecule-1 (ICAM-1) but not ICAM-2, E-selectin, or P- selectin. Epithelial ICAM-1 expression was enhanced after stimulation with E. coli or IL-1α. Anti-ICAM-1 antibody reduced transepithelial neutrophil migration by 61 to 85%, indicating that neutrophils bound ICAM-1 on the epithelial surface. Antibodies to CD18 and CD11b reduced migration by 70 to 79%, suggesting that CD11b/CD18 (Mac-1) was acting as the neutrophil receptor for ICAM-1 in this process. Anti-CD11a antibodies had no effect on neutrophil migration. In conclusion, E. coli induced ICAM-1- and Mac-1-dependent transepithelial neutrophil migration. Previous studies have shown that urinary tract epithelial cells secrete IL-8 when exposed to E. coli or IL- 1α. These observations suggest that epithelial cells play an active role in neutrophil migration during urinary tract infections.
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| 4. |
- Bodlund, Owe, et al.
(författare)
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Validation of the self-report questionnaire DIP-Q in diagnosing DSM-IV personality disorders : a comparison of three psychiatric samples.
- 1998
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Ingår i: Acta Psychiatrica Scandinavica. - : Wiley. - 0001-690X .- 1600-0447. ; 97:6, s. 433-9
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Tidskriftsartikel (refereegranskat)abstract
- The DSM-IV section of the DSM-IV and ICD-10 Personality Questionnaire (DIP-Q) was used to screen for personality disorders in 448 subjects from three clinical samples (general and forensic psychiatric patients and candidates for psychotherapy) and a sample of 139 healthy volunteers. Differences between the samples with regard to patterns of personality pathology in relation to concurrent Axis I disorders and sociodemographic variables were analysed. The prevalence of personality disorders according to DIP-Q was 14% among the healthy volunteers, compared to 59% in the general psychiatric sample, 68% in the forensic psychiatric sample and up to 90% among psychotherapy candidates. Moreover, from a dimensional perspective (i.e. the number of fulfilled Axis II criteria), all clinical groups differed significantly from the control group in all specified personality dimensions and clusters. Dimensional DIP-Q cluster scores also discriminated significantly between the three clinical samples. Unexpectedly, the odds ratio for an Axis II disorder was nearly five times higher among psychotherapy applicants than among general psychiatric patients, independent of concomitant Axis I disorders, gender or age. The strongest association between DIP-Q score and Axis I disorders was found for depressive disorders, which more than doubled the odds ratio for a personality disorder diagnosis. This association could result from high true comorbidity, but could also be due to the fact that a concomitant depressive state can increase self-reported personality difficulties. The high prevalence among psychotherapy candidates may to some extent reflect help-seeking exaggeration of problems. These are aspects to consider when using the DIP-Q, which overall appears to discriminate well between different samples.
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| 5. |
- Connell, H., et al.
(författare)
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Bacterial attachment to uro-epithelial cells : mechanisms and consequences.
- 1997
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Ingår i: Advances in dental research. - : SAGE Publications. - 0895-9374 .- 1544-0737. ; 11:1, s. 50-58
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Forskningsöversikt (refereegranskat)abstract
- Microbial attachment to mucosal surfaces is a first step in mucosal infection. Specific interactions between microbial surface ligands and host receptors influence the distribution of microbes in their sites of infection. Adhesion has often been regarded as a sufficient end point, explaining tissue tropism and bacterial persistence at mucosal sites. Adherence, however, is also a virulence factor through which microbes gain access to host tissues, upset the integrity of the mucosal barrier, and cause disease. The induction of mucosal inflammation is one aspect of this process. Bacterial attachment to mucosal surfaces activates the production of pro-inflammatory cytokines that cause both local and systemic inflammation. Epithelial cells are one source of these cytokines. The binding of fimbrial lectins to epithelial cell receptors triggers transmembrane signaling events that upregulate cytokine-specific mRNA and increase cytokine secretion. P fimbriae that bind the globoseries of glycolipids cause the release of ceramides and activation of the ceramide signaling pathway which contributes to the IL-6 response. Spread of cytokines and other pro-inflammatory mediators from the local site contributes to the symptoms and signs of infection.
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| 6. |
- Connell, H., et al.
(författare)
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Type 1 fimbrial expression enhances Escherichia coli virulence for the urinary tract
- 1996
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Ingår i: Proceedings of the National Academy of Sciences of the United States of America. - : Proceedings of the National Academy of Sciences. - 0027-8424. ; 93:18, s. 9827-9832
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Tidskriftsartikel (refereegranskat)abstract
- Type 1 fimbriae are adhesion organelles expressed by many Gram-negative bacteria. They facilitate adherence to mucosal surfaces and inflammatory cells in vitro, but their contribution to virulence has not been defined. This study presents evidence that type 1 fimbriae increase the virulence of Escherichia coli for the urinary tract by promoting bacterial persistence and enhancing the inflammatory response to infection. In a clinical study, we observed that disease severity was greater in children infected with E. coli O1:K1:H7 isolates expressing type 1 fimbriae than in those infected with type 1 negative isolates of the same serotype. The E. coli O1:K1:H7 isolates had the same electrophoretic type, were hemolysin-negative, expressed P fimbriae, and carried the fim DNA sequences. When tested in a mouse urinary tract infection model, the type 1-positive E. coli O1:K1:H7 isolates survived in higher numbers, and induced a greater neutrophil influx into the urine, than O1:K1:H7 type 1-negative isolates. To confirm a role of type 1 fimbriae, a fimH null mutant (CNI016) was constructed from an O1:K1:H7 type 1-positive parent. E. coli CNI016 had reduced survival and inflammatogenicity in the mouse urinary tract infection model. E. coli CNI016 reconstituted with type 1 fimbriae (E. coli CN1018) had restored virulence similar to that of the wild- type parent strain. These results show that type 1 fimbriae in the genetic background of a uropathogenic strain contribute to the pathogenesis of E. coli in the urinary tract.
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| 7. |
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| 8. |
- HAKANSSON, A, et al.
(författare)
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Apoptosis induced by a human milk protein
- 1995
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Ingår i: Proceedings of the National Academy of Sciences of the United States of America. - : Proceedings of the National Academy of Sciences. - 0027-8424. ; 92:17, s. 8064-8068
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Tidskriftsartikel (refereegranskat)abstract
- To the breast-fed infant, human milk is more than a source of nutrients; it furnishes a wide array of molecules that restrict microbes, such as antibodies, bactericidins, and inhibitors of bacterial adherence. However, it has rarely been considered that human milk may also contain substances bioactive toward host cells. While investigating the effect of human milk on bacterial adherence to a human lung cancer cell line, we were surprised to discover that the milk killed the cells. Analysis of this effect revealed that a component of milk in a particular physical state--multimeric alpha-lact-albumin--is a potent Ca(2+)-elevating and apoptosis-inducing agent with broad, yet selective, cytotoxic activity. Multimeric alpha-lactalbumin killed all transformed, embryonic, and lymphoid cells tested but spared mature epithelial elements. These findings raise the possibility that milk contributes to mucosal immunity not only by furnishing antimicrobial molecules but also by policing the function of lymphocytes and epithelium. Finally, analysis of the mechanism by which multimeric alpha-lactalbumin induces apoptosis in transformed epithelial cells could lead to the design of antitumor agents.
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| 9. |
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| 10. |
- Hang, L, et al.
(författare)
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Cytokine repertoire of epithelial cells lining the human urinary tract
- 1998
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Ingår i: The Journal of urology. - 0022-5347. ; 159:6, s. 92-2185
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Tidskriftsartikel (refereegranskat)abstract
- PURPOSE: To examine the cytokine profile of epithelial cells lining the human urinary tract with the aim of differentiating between the constitutive and disease-related cytokine production in these tissues.MATERIALS AND METHODS: Sections from the renal pelvis, ureter, bladder or urethra were obtained from 22 patients undergoing urinary tract surgery and were stained with monoclonal antibodies to interleukin(IL)-1beta, IL-4, IL-6, IL-8, interferon gamma (IFNgamma) and transforming growth factor beta (TGFbeta). Sections were classified according to the presence or absence of disease in the tissue.RESULTS: Epithelial cells lining the renal pelvis, ureter, bladder or urethra all stained for IL-8 and TGFbeta (100%) in disease-free tissues and sections with cancer or interstitial cystitis (IC). In contrast, staining for IL-1beta, IL-4, IL-6 and IFNgamma varied with the disease state of the patient. Epithelial IL-1beta staining was absent (0%) in sections from healthy bladder, but positive in tissues with IC or cancer-associated pathology (50 to 100%). IL-6 staining was detected in the epithelial layer of several patients with IC or cancer related pathology, but only in cells with non-epithelial morphology and not in disease-free tissues. IFNgamma and IL-4 staining were only observed in patients with IC and only in cells with non-epithelial morphology.CONCLUSIONS: The results show that epithelial cells from all parts of the urinary tract constitutively produce IL-8 and TGFbeta and suggest that the production of other cytokines varies with the disease of the patient. Constitutive cytokine production provides the basis for a rapid host response, in the defense against mucosal attack by microbes or toxic agents.
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