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- Halim, Md. Abdul, 1983-, et al.
(författare)
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GLP-1 Inhibits Prandial Antro-Duodeno-Jejunal Motility in Humans: Native GLP-1 Compared With Analogue ROSE-010 In Vitro
- 2016
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Ingår i: Gastroenterology. - 0016-5085 .- 1528-0012. ; 150:4, suppl. 1, s. S97-S98
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Tidskriftsartikel (refereegranskat)abstract
- Background: Glucagon-like peptide-1 (GLP-1) is secreted from L-cells after nutrient ingestion, inhibiting motility. Aims: To clarify whether infused GLP-1 inhibits in vivo prandial motility response and determine the likeliest target cell type and mechanism of action of GLP-1 and its analogue ROSE-010 using in vitro human gut muscle strips. Methods: Sixteen healthy volunteers underwent antroduodenojejunal manometry. Recordings of 1 hour infusion of saline or GLP-1 (0.7 or 1.2 pmol/kg/min) were compared. Plasma GLP-1 and GLP-2 were measured by RIA. Gastrointestinal muscle strips from surgical re-sections, pre-contracted with bethanechol or electric field stimulation (EFS), were investigated for GLP-1 or ROSE-010 induced relaxation. GLP-1, GLP-2 and receptors for GLP-1 and GLP-2 (GLP-1R, GLP-2R) were visualized by immunohistochemistry. Mechanisms were studied employing exendin(9-39) amide, Lw-nitro-monomethyl arginine (L-NMMA), 2´5´-dideoxyadenosine (DDA) and tetrodotoxin (TTX). Results: Food-intake increased motility index from 4.0±0.5 to 6.4±0.3 (antrum), 4.2±0.4 to 5.7±0.4 (duodenum) and 4.6±0.3 to 5.9±0.2 (jejunum) ln(Σ(mmHg·s·min-1)). GLP-1 at 0.7 pmol/kg/minwas sufficient to suppress these indexes from 6.2±0.4 to 3.8±0.7, 5.6±0.6 to 3.9±0.6 and 5.8±0.1 to 4.6±0.4 ln(Σ(mmHg·s·min-1)). Both GLP-1 doses raised plasma GLP-1, but not GLP-2. GLP-1 (EC50 40 nM) and ROSE-010 (EC50 50 nM) relaxed bethanechol-induced contractions in muscle strips. Inhibitory responses were blocked by exendin(9-39) amide, L-NMMA, DDA or TTX pre-treatment. GLP-1R and GLP-2R were expressed in myenteric neurons, but not muscle. Conclusions: GLP-1 and ROSE-010 inhibit motility through GLP-1R at myenteric neurons, which also possess GLP-2 receptors. GLP-1 increases more than GLP-2 with meals and does not increase plasma GLP-2. GLP-1 and ROSE-010 relaxations are cAMP and NO dependent.
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- Hellström, Per M., 1954-, et al.
(författare)
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Luminal Nitric Oxide and Plasma Nitrite/Nitrate As Predictors of Colectomy in Corticosteroid-Treated Acute Colitis
- 2015
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Ingår i: Gastroenterology. - Uppsala. - 0016-5085 .- 1528-0012. ; 148:4, suppl. 1
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Tidskriftsartikel (refereegranskat)abstract
- Background: Nitric oxide (NO) is known to be up-regulated by the induction of induciblenitric oxide synthase (iNOS) in inflammatory conditions. NO gas can be used as a markerof inflammatory activity in hollow organs. In parallel, plasma nitrite + nitrate (NOx) canreflect the ongoing inflammatory activity. We analyzed rectal NO before and after threedays, as well as plasma NOx in patients on glucocorticosteroid (GC) therapy in hospitalizedpatients. The aim of the study was to evaluate the relationship of rectal luminal NO andcirculating plasma NOx in acute fulminant colitis to the outcome as therapeutic responseor colectomy.Methods: 50 patients with median age 41 (range 20-78) years were hospitalizeddue to acute fulminant colitis and received treatment with high-dose GCs. Luminal nitricoxide was analyzed with chemiluminescence before therapy onset of therapy with GC andon day 3 of treatment. NOx was measured by nitrite/nitrate colorimetric assay. NO levelsand plasma NOx were compared to clinical disease activity index and C-reactive protein(CRP).Results: 32 responded to GC treatment and 18 did not, resulting in colectomy.The responders had higher luminal NO than non-responders (day 1: 12525±2600, day 3:15590±4157 ppb) vs non-responders (day 1: 2874±1283, day 3: 1137±297 ppb) (p<0.0114).Using an optimal cut-off NO level of 2250 ppb, sensitivity and specificity was 86% and81% for colectomy (p<0.0001). The area under the curve was 0.88 and likelihood ratio4.8. Similarly, plasma NOx was higher in responders vs non-responders (day 1: 6.2±0.3 vs3.9±0.4 umol/L) (p<0.0001). Using plasma NOx, we found a corresponding cut-off at 5umol/L with sensitivity 87% and specificity 87%. The area under the curve was 0.88 andlikelihood ratio 6.7. Luminal NO was also correlated to plasma NOx (r=0.33, p=0.0205).In the responder group, CRP levels decreased (day 1: 22.31±2.95, day 3: 15.69±3.57mg/L), whereas among non-responders CRP levels increased (day 1: 45.83±11.10, day 3:76.35±16.96 mg/L) (p<0.0167). Kaplan-Meier analysis showed that patients with baselineNO levels lower than 2250 ppb were at a significantly higher risk of colectomy within onemonth from onset of GCS treatment (p<0.0001). Twelve out of 18 (67%) in patients withday 1 NO <2250 ppb were colectomized, the corresponding number of patients with NO>2250 ppb was 3 out of 32 (9%). In a similar manner, using plasma NOx <5 uml/L foranalysis, we found 13 (72%) to be colectomized, and with >5 umol/L only two (6%).Conclusion: NO and its oxidation product NOx are markers of inflammatory activity in thegut. However, with more intense inflammation and mucosal damage, the less NO is produced.Luminal NO as well as plasma NOx can be used as a sensitive biomarker to predict colectomyin the outcome of acute fulminant colitis
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- Rodrigues, JP, et al.
(författare)
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Once Upon a Time in the Esophagus
- 2019
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Ingår i: Gastroenterology. - : Elsevier BV. - 1528-0012 .- 0016-5085. ; 156:4, s. 874-875
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Tidskriftsartikel (refereegranskat)
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| 6. |
- Bonfiglio, F., et al.
(författare)
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Female-Specific Association Between Variants on Chromosome 9 and Self-Reported Diagnosis of Irritable Bowel Syndrome
- 2018
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Ingår i: Gastroenterology. - : Elsevier BV. - 0016-5085 .- 1528-0012. ; 155:1, s. 168-179
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND & AIMS: Genetic factors are believed to affect risk for irritable bowel syndrome (IBS), but there have been no sufficiently powered and adequately sized studies. To identify DNA variants associated with IBS risk, we performed a genome-wide association study (GWAS) of the large UK Biobank population-based cohort, which includes genotype and health data from 500,000 participants. METHODS: We studied 7,287,191 high-quality single nucleotide polymorphisms in individuals who self-reported a doctor's diagnosis of IBS (cases; n = 9576) compared to the remainder of the cohort (controls; n = 336,499) (mean age of study subjects, 40-69 years). Genome-wide significant findings were further investigated in 2045 patients with IBS from tertiary centers and 7955 population controls from Europe and the United States, and a small general population sample from Sweden (n = 249). Functional annotation of GWAS results was carried out by integrating data from multiple biorepositories to obtain biological insights from the observed associations. RESULTS: We identified a genome-wide significant association on chromosome 9q31.2 (single nucleotide polymorphism rs10512344; P = 3.57 x 10(-8)) in a region previously linked to age at menarche, and 13 additional loci of suggestive significance (P < 5.0 x 10(-6)). Sex-stratified analyses revealed that the variants at 9q31.2 affect risk of IBS in women only (P = 4.29 x 10(-10) in UK Biobank) and also associate with constipation-predominant IBS in women (P = .015 in the tertiary cohort) and harder stools in women (P = .0012 in the population-based sample). Functional annotation of the 9q31.2 locus identified 8 candidate genes, including the elongator complex protein 1 gene (ELP1 or IKB-KAP), which is mutated in patients with familial dysautonomia. CONCLUSIONS: In a sufficiently powered GWAS of IBS, we associated variants at the locus 9q31.2 with risk of IBS in women. This observation may provide additional rationale for investigating the role of sex hormones and autonomic dysfunction in IBS.
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- Bednarska, Olga, et al.
(författare)
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Vasoactive Intestinal Polypeptide and Mast Cells Regulate Increased Passage of Colonic Bacteria in Patients With Irritable Bowel Syndrome
- 2017
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Ingår i: Gastroenterology. - : W B SAUNDERS CO-ELSEVIER INC. - 0016-5085 .- 1528-0012. ; 153:4, s. 948-
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND amp; AIMS: Irritable bowel syndrome (IBS) is associated with intestinal dysbiosis and symptoms of IBS develop following gastroenteritis. We aimed to study the passage of live bacteria through the colonic epithelium, and determine the role of mast cells (MCs) and vasoactive intestinal polypeptide (VIP) in barrier regulation in IBS and healthy individuals. METHODS: Colon biopsies from 32 women with IBS and 15 age-matched healthy women (controls) were mounted in Ussing chambers; we measured numbers of fluorescently labeled Escherichia coli HS and Salmonella typhimurium that passed through from the mucosal side to the serosal side of the tissue. Some biopsies were exposed to agents that block the VIP receptors (VPAC1 and VPAC2) or MCs. Levels of VIP and tryptase were measured in plasma and biopsy lysates. Number of MCs and MCs that express VIP or VIP receptors were quantified by immunofluorescence. Biopsies from an additional 5 patients with IBS and 4 controls were mounted in chambers and Salmonella were added; we studied passage routes through the epithelium by transmission electron microscopy and expression of tight junctions by confocal microscopy. RESULTS: In colon biopsies from patients with IBS, larger numbers of E coli HS and S typhimurium passed through the epithelium than in biopsies from controls (P amp;lt;.0005). In transmission electron microscopy analyses, bacteria were found to cross the epithelium via only the transcellular route. Bacterial passage was reduced in biopsies from patients with IBS and controls after addition of antibodies against VPACs or ketotifen, which inhibits MCs. Plasma samples from patients with IBS had higher levels of VIP than plasma samples from controls. Biopsies from patients with IBS had higher levels of tryptase, larger numbers of MCs, and a higher percentage of MCs that express VPAC1 than biopsies from controls. In biopsies from patients with IBS, addition of Salmonella significantly reduced levels of occludin; subsequent addition of ketotifen significantly reversed this effect. CONCLUSIONS: We found that colonic epithelium tissues from patients with IBS have increased translocation of commensal and pathogenic live bacteria compared with controls. The mechanisms of increased translocation include MCs and VIP.
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