| 61. |
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| 62. |
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| 63. |
- Sundbom, Marcus, et al.
(författare)
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Alteration in human defensin-5 expression following gastric bypass surgery
- 2007
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Ingår i: Journal of Clinical Pathology. - : BMJ. - 0021-9746 .- 1472-4146. ; 60:9, s. 1029-1034
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Tidskriftsartikel (refereegranskat)abstract
- Background: Roux-en-Y gastric bypass surgery provides a novel human model to investigate small bowel mucosal innate immunity, in which there is loss of gastric acid-mediated protection against orally-acquired microorganisms. Aim: To study changes in jejunal mucosal immunoreactivity of human defensin (HD)-5,an antimicrobial peptide normally produced by Paneth cells. Methods: Mucosal samples were obtained from 18 female patients ( 24 - 54 years), from the same segment of jejunum during and after gastric bypass surgery. Samples were used for bacterial culture and immunohistochemistry using anti-HD-5 antibody. The number of immunoreactive cells per crypt and villus were determined and expressed as mean (SD). Results: No bacteria were cultured from any of the perioperative jejunal samples but colonies of bacteria normally present in the pharynx were identified during culture of all postoperative jejunal biopsy specimens (1-> 100 colonies). Paneth cell numbers per crypt were unchanged after gastric bypass ( 4.16 (0.71) vs 4.24 (0.78)). However, following surgery, there was an increase in HD-5-positive intermediate cells per crypt (0.25 (0.41) vs 1.12 (0.66), p < 0.01), HD-5 staining enterocytes per crypt ( 0.03 ( 0.09) vs 1.38 ( 1.10), p < 0.01), HD-5 staining material in the crypt lumen (crypt lumens: 5.0% ( 10.9%) vs 68.1% ( 27.9%), p < 0.01) and HD-5 immunoreactivity coating the luminal surface of villus enterocytes ( villi sampled: 15.0% ( 31.0%) vs 67.5% ( 42.0%), p < 0.01). Conclusions: Bacteria normally resident in the pharynx were present in the proximal jejunal mucosa following Roux-en-Y gastric bypass surgery. After gastric bypass, there was increased secretion of HD-5 and an increase in HD-5 expressing intermediate cells and enterocytes in the crypt. The increase in HD-5 expression in the jejunal mucosa following gastric bypass surgery is likely to be secondary to exposure to orally-acquired microorganisms.
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| 64. |
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| 65. |
- Thorpe, H. A., et al.
(författare)
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Repeated out-of-Africa expansions of Helicobacter pylori driven by replacement of deleterious mutations
- 2022
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Ingår i: Nature Communications. - : Springer Science and Business Media LLC. - 2041-1723. ; 13:1
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Tidskriftsartikel (refereegranskat)abstract
- Helicobacter pylori lives in the human stomach and has a population structure resembling that of its host. However, H. pylori from Europe and the Middle East trace substantially more ancestry from modern African populations than the humans that carry them. Here, we use a collection of Afro-Eurasian H. pylori genomes to show that this African ancestry is due to at least three distinct admixture events. H. pylori from East Asia, which have undergone little admixture, have accumulated many more non-synonymous mutations than African strains. European and Middle Eastern bacteria have elevated African ancestry at the sites of these mutations, implying selection to remove them during admixture. Simulations show that population fitness can be restored after bottlenecks by migration and subsequent admixture of small numbers of bacteria from non-bottlenecked populations. We conclude that recent spread of African DNA has been driven by deleterious mutations accumulated during the original out-of-Africa bottleneck.
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| 66. |
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| 67. |
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| 68. |
- Vaga, S., et al.
(författare)
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Compositional and functional differences of the mucosal microbiota along the intestine of healthy individuals
- 2020
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Ingår i: Scientific Reports. - : Springer Science and Business Media LLC. - 2045-2322. ; 10:1
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Tidskriftsartikel (refereegranskat)abstract
- Gut mucosal microbes evolved closest to the host, developing specialized local communities. There is, however, insufficient knowledge of these communities as most studies have employed sequencing technologies to investigate faecal microbiota only. This work used shotgun metagenomics of mucosal biopsies to explore the microbial communities' compositions of terminal ileum and large intestine in 5 healthy individuals. Functional annotations and genome-scale metabolic modelling of selected species were then employed to identify local functional enrichments. While faecal metagenomics provided a good approximation of the average gut mucosal microbiome composition, mucosal biopsies allowed detecting the subtle variations of local microbial communities. Given their significant enrichment in the mucosal microbiota, we highlight the roles of Bacteroides species and describe the antimicrobial resistance biogeography along the intestine. We also detail which species, at which locations, are involved with the tryptophan/indole pathway, whose malfunctioning has been linked to pathologies including inflammatory bowel disease. Our study thus provides invaluable resources for investigating mechanisms connecting gut microbiota and host pathophysiology.
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| 69. |
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| 70. |
- Abrahamsson, TR, et al.
(författare)
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Reply: To PMID 22153774
- 2013
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Ingår i: The Journal of allergy and clinical immunology. - : Elsevier BV. - 1097-6825 .- 0091-6749. ; 131:1, s. 248-249
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)
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