1. |
- Hansson, Malin, 1967, et al.
(author)
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CCL28 is increased in human Helicobacter pylori induced gastritis and mediates recruitment of gastric IgA-secreting cells.
- 2008
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In: Infection and Immunity. - 0019-9567. ; 76:7, s. 3304-11
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Journal article (peer-reviewed)abstract
- Human Helicobacter pylori infection gives rise to an active chronic gastritis and is a major risk factor for the development of duodenal ulcer disease and gastric adenocarcinoma. The infection is accompanied by a large accumulation of immunoglobulin A (IgA)-secreting cells in the gastric mucosa, and following mucosal immunization only H. pylori-infected volunteers mounted a B-cell response in the gastric mucosa. To identify the signals for recruitment of gastric IgA-secreting cells, we investigated the gastric production of CCL28 (mucosa-associated epithelial chemokine) and CCL25 (thymus-expressed chemokine) in H. pylori-infected and uninfected individuals and the potential of gastric B-cell populations to migrate toward these chemokines. Gastric tissue from H. pylori-infected individuals contained significantly more CCL28 protein and mRNA than that from uninfected individuals, while CCL25 levels remained unchanged. Chemokine-induced migration of gastric lamina propria lymphocytes isolated from patients undergoing gastric resection was then assessed using the Transwell system. IgA-secreting cells and IgA+ memory B cells from H. pylori-infected tissues migrated toward CCL28 but not CCL25, while the corresponding cells from uninfected patients did not. Furthermore, IgG-secreting cells from H. pylori-infected patients did not migrate to CCL28 but instead to CXCL12 (SDF-1). However, chemokine receptor expression did not correlate to the migratory pattern of the different B-cell populations. These studies are the first to show increased CCL28 production during gastrointestinal infection in humans and provide an explanation for the large influx of IgA-secreting cells to the gastric mucosa in H. pylori-infected individuals.
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2. |
- Gough, Simon, et al.
(author)
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A new method for isolating physiologically active Mg-protoporphyrin
- 2007
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In: Plant Physiology and Biochemistry. - : Elsevier BV. - 1873-2690 .- 0981-9428. ; 45:12, s. 932-936
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Journal article (peer-reviewed)abstract
- Mg-protoporphyrin monomethyl ester (MPE) is a biosynthetic intermediate of chlorophyll and converted by MPE cyclase to protochlorophyllide. Limited availability of MPE has so far hampered cyclase research. In a new, simplified, method MPE was prepared from freeze dried bchE mutant Rhodobacter capsulatus DB575 cells by extraction with acetone/H2O/25% NH3. Isolated MPE was identified by absorption and fluorescence spectroscopy, and its purity was analyzed by HPLC. The extracted MPE was dried and redissolved in buffered DMSO and its substrate activity is shown by enzymatic cyclase assays. A linear time course was observed for MPE conversion to protochlorophyllide by enzymes from barley etioplasts. Our innovation of freeze drying the R. capsulatus cells before extraction provides a high yield method for MPE, which is significantly faster and more reproducible than previous extraction methods.
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3. |
- Gough, Simon P, et al.
(author)
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A new method for isolating physiologically active Mg-protoporphyrin monomethyl ester, the substrate of the cyclase enzyme of the chlorophyll biosynthetic pathway.
- 2007
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In: Plant Physiology and Biochemistry. - : Elsevier BV. - 0981-9428. ; 45:12, s. 932-6
-
Journal article (peer-reviewed)abstract
- Mg-protoporphyrin monomethyl ester (MPE) is a biosynthetic intermediate of chlorophyll and converted by MPE cyclase to protochlorophyllide. Limited availability of MPE has so far hampered cyclase research. In a new, simplified, method MPE was prepared from freeze dried bchE mutant Rhodobacter capsulatus DB575 cells by extraction with acetone/H2O/25% NH3. Isolated MPE was identified by absorption and fluorescence spectroscopy, and its purity was analyzed by HPLC. The extracted MPE was dried and redissolved in buffered DMSO and its substrate activity is shown by enzymatic cyclase assays. A linear time course was observed for MPE conversion to protochlorophyllide by enzymes from barley etioplasts. Our innovation of freeze drying the R. capsulatus cells before extraction provides a high yield method for MPE, which is significantly faster and more reproducible than previous extraction methods.
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4. |
- Kindlund, Bert, 1969, et al.
(author)
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FOXP3-expressing CD4(+) T-cell numbers increase in areas of duodenal gastric metaplasia and are associated to CD4(+) T-cell aggregates in the duodenum of Helicobacter pylori-infected duodenal ulcer patients.
- 2009
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In: Helicobacter. - : Wiley. - 1523-5378 .- 1083-4389. ; 14:3, s. 192-201
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Journal article (peer-reviewed)abstract
- BACKGROUND: We have previously demonstrated that Helicobacter pylori infection is associated with an increased number of CD4(+)CD25(high) regulatory T cells in the gastric and duodenal mucosa. In this study, we determined the number and localization of CD4(+) cells expressing the regulatory T-cell-specific transcription factor FOXP3 in the antrum and duodenum of duodenal ulcer patients, asymptomatic carriers, and uninfected individuals. We also determined gene expression levels of FOXP3 as well as anti- and proinflammatory cytokines before and after H. pylori eradication. METHODS: Cellular FOXP3 expression was studied by immunofluorescence and flow cytometry, and transcription levels of FOXP3, interleukin (IL)-10, transforming growth factor-beta, CD4, and interferon-gamma were analyzed by real-time reverse transcription-polymerase chain reaction. RESULTS: We found an increased (6-fold) frequency of CD4(+)FOXP3(+) T cells in H. pylori-infected gastric mucosa; interestingly 26% of these cells did not co-express CD25. The increase of FOXP3-expressing T cells in the antrum of infected individuals was dependent on the presence of H. pylori, since eradication therapy resulted in 4-fold lower levels of FOXP3 and IL-10 mRNA in the antrum. Furthermore, higher numbers of CD4(+)FOXP3(+) T cells were found in areas of duodenal gastric metaplasia in the duodenum of duodenal ulcer patients compared to duodenal gastric metaplasia of asymptomatic individuals and healthy mucosa in both patient groups. In duodenal ulcer patients, the CD4(+)FOXP3(+) T cells were more highly associated to aggregates in the duodenal mucosa. CONCLUSION: The numbers of CD4(+)FOXP3(+) T cells are increased and localized in CD4(+) T-cell aggregates in areas of duodenal gastric metaplasia in duodenal ulcer patients.
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6. |
- Stenbaek, Anne, et al.
(author)
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NADPH-dependent thioredoxin reductase and 2-Cys peroxiredoxins are needed for the protection of Mg–protoporphyrin monomethyl ester cyclase
- 2008
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In: FEBS Letters. - : Wiley. - 1873-3468 .- 0014-5793. ; 582:18, s. 2773-2778
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Journal article (peer-reviewed)abstract
- Abstract The chloroplast-localized NADPH-dependent thioredoxin reductase (NTRC) has been found to be able to reduce hydrogen peroxide scavenging 2-Cys peroxiredoxins. We show that the Arabidopsis ntrc mutant is perturbed in chlorophyll biosynthesis and accumulate intermediates preceding protochlorophyllide formation. A specific involvement of NTRC during biosynthesis of protochlorophyllide is indicated from in vitro aerobic cyclase assays in which the conversion of Mg–protoporhyrin monomethyl ester into protochlorophyllide is stimulated by addition of the NTRC/2-Cys peroxiredoxin system. These findings support the hypothesis that this NADPH-dependent hydrogen peroxide scavenging system is particularly important during periods with limited reducing power from photosynthesis, e.g. under chloroplast biogenesis.
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7. |
- Uhlén, Mathias, et al.
(author)
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A human protein atlas for normal and cancer tissues based on antibody proteomics
- 2005
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In: Molecular & Cellular Proteomics. - 1535-9476 .- 1535-9484. ; 4:12, s. 1920-1932
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Journal article (peer-reviewed)abstract
- Antibody-based proteomics provides a powerful approach for the functional study of the human proteome involving the systematic generation of protein-specific affinity reagents. We used this strategy to construct a comprehensive, antibody-based protein atlas for expression and localization profiles in 48 normal human tissues and 20 different cancers. Here we report a new publicly available database containing, in the first version, similar to 400,000 high resolution images corresponding to more than 700 antibodies toward human proteins. Each image has been annotated by a certified pathologist to provide a knowledge base for functional studies and to allow queries about protein profiles in normal and disease tissues. Our results suggest it should be possible to extend this analysis to the majority of all human proteins thus providing a valuable tool for medical and biological research.
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8. |
- Andrae, Johanna, et al.
(author)
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A 1.8kb GFAP-promoter fragment is active in specific regions of theembryonic CNS
- 2001
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In: Mechanisms of Development. - 0925-4773 .- 1872-6356. ; 107:1-2, s. 181-5
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Journal article (peer-reviewed)abstract
- The intermediate filament glial fibrillary acidic protein (GFAP) constitutes the major cytoskeletal protein in astrocytes (J. Neuroimmunol. 8 (1985) 203) and is traditionally referred to as a specific marker for astrocytes. To identify early glial precursors, we created GFAPpromoter-lacZ transgenic mice, using a 1.8kb 5' fragment of human GFAP. The expression of the transgene was first detected in the neuroepithelium at embryonic day 9.5. It was further found in the ventricular zone of the developing telencephalon, in the cerebellar primordium, trigeminal ganglia, and radial glia. Later, scattered beta-gal+ cells were seen in pons, brain stem and glia limitans. The results indicate that GFAP activity is regulated in a region-specific manner during central nervous system (CNS) development and that the gene is turned on in different cell types independently.
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10. |
- Arvidsson, Inger, et al.
(author)
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Are neck-shoulder disorders associated with habitual neck extension in computer work?
- 2006
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In: Meeting diversity in ergonomics.
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Conference paper (other academic/artistic)abstract
- A common clinical conception is that prolonged neck extension during computer work is associated with an increased risk of neck-shoulder disorders. The aim of this study was to find out whether neck postures in computer work differed between females cases with neck-shoulderdisorders, compared to healthy referents. Based on physical examinations, 13 cases and 11 referents were selected among 70 female air traffic controllers with the same computer work and identical work stations. Neck angles were measured by inclinometry, during an ordinary work period of about 1 h. Results: Average neck angles (50thpercentile) in cases and referents was -10° (SP 8) and -9 (SD 10) respectively; p=0.9. Hence, we did not find any association between neck-shoulder disorders and neck extension during computer work.
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