| 1. |
- Kvitne, K. E., et al.
(författare)
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Short- and long-term effects of body weight, calorie restriction and gastric bypass on CYP1A2, CYP2C19 and CYP2C9 activity
- 2022
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Ingår i: British Journal of Clinical Pharmacology. - : Wiley. - 0306-5251 .- 1365-2125. ; 88:9, s. 4121-4133
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Tidskriftsartikel (refereegranskat)abstract
- Aim Roux-en-Y gastric bypass (RYGB) may influence drug disposition due to surgery-induced gastrointestinal alterations and/or subsequent weight loss. The objective was to compare short- and long-term effects of RYGB and diet on the metabolic ratios of paraxanthine/caffeine (cytochrome P450 [CYP] 1A2 activity), 5-hydroxyomeprazole/omeprazole (CYP2C19 activity) and losartan/losartan carboxylic acid (CYP2C9 activity), and cross-sectionally compare these CYP-activities with normal-to-overweight controls. Methods This trial included patients with severe obesity preparing for RYGB (n = 40) or diet-induced (n = 41) weight loss, and controls (n = 18). Both weight loss groups underwent a 3-week low-energy diet (<1200 kcal/day, weeks 0-3) followed by a 6-week very-low-energy diet or RYGB (both <800 kcal/day, weeks 3-9). Follow-up time was 2 years, with four pharmacokinetic investigations. Results Mean +/- SD weight loss from baseline was similar in the RYGB-group (13 +/- 2.4%) and the diet group (10.5 +/- 3.9%) at week 9, but differed at year 2 (RYGB -30 +/- 6.9%, diet -3.1 +/- 6.3%). From weeks 0 to 3, mean (95% confidence interval [CI]) CYP2C19 activity similarly increased in both groups (RYGB 43% [16, 55], diet 48% [22, 60]). Mean CYP2C19 activity increased by 30% (2.6, 43) after RYGB (weeks 3-9), but not in the diet-group (between-group difference -0.30 [-0.63, 0.03]). CYP2C19 activity remained elevated in the RYGB group at year 2. Baseline CYP2C19 activity was 2.7-fold higher in controls compared with patients with obesity, whereas no difference was observed in CYP1A2 and CYP2C9 activities. Conclusion Our findings suggest that CYP2C19 activity is lower in patients with obesity and increases following weight loss. This may be clinically relevant for drug dosing. No clinically significant effect on CYP1A2 and CYP2C9 activities was observed.
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| 2. |
- Eide, P. K., et al.
(författare)
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Plasma neurodegeneration biomarker concentrations associate with glymphatic and meningeal lymphatic measures in neurological disorders
- 2023
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Ingår i: Nature Communications. - 2041-1723. ; 14:1
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Tidskriftsartikel (refereegranskat)abstract
- Clearance of neurotoxic brain proteins via cerebrospinal fluid (CSF) to blood has recently emerged to be crucial, and plasma biomarkers of neurodegeneration were newly introduced to predict neurological disease. This study examines in 106 individuals with neurological disorders associations between plasma biomarkers [40 and 42 amino acid-long amyloid-beta (A beta 40 and A beta 42), total-tau, glial fibrillary acidic protein (GFAP), and neurofilament light (NfL)] and magnetic resonance imaging measures of CSF-mediated clearance from brain via extra-vascular pathways (proxy of glymphatic function) and CSF-to-blood clearance variables from pharmacokinetic modeling (proxy of meningeal lymphatic egress). We also examine how biomarkers vary during daytime and associate with subjective sleep quality. Plasma concentrations of neurodegeneration markers associate with indices of glymphatic and meningeal lymphatic functions in individual- and disease-specific manners, vary during daytime, but are unaffected by sleep quality. The results suggest that plasma concentrations of neurodegeneration biomarkers associate with measures of glymphatic and meningeal lymphatic function. Plasma neurodegeneration biomarkers are increasingly utilized to predict neurological disease. Here, authors show in different neurological disorders associations between plasma neurodegeneration biomarker concentrations and various measures of glymphatic and meningeal lymphatic functions.
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| 3. |
- Hovd, M., et al.
(författare)
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Neither Gastric Bypass Surgery Nor Diet-Induced Weight-Loss Affect OATP1B1 Activity as Measured by Rosuvastatin Oral Clearance
- 2023
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Ingår i: Clinical Pharmacokinetics. - : Springer Science and Business Media LLC. - 0312-5963 .- 1179-1926. ; 62:5, s. 725-735
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Tidskriftsartikel (refereegranskat)abstract
- IntroductionRosuvastatin pharmacokinetics is mainly dependent on the activity of hepatic uptake transporter OATP1B1. In this study, we aimed to investigate and disentangle the effect of Roux-en-Y gastric bypass (RYGB) and weight loss on oral clearance (CL/F) of rosuvastatin as a measure of OATP1B1-activity.MethodsPatients with severe obesity preparing for RYGB (n = 40) or diet-induced weight loss (n = 40) were included and followed for 2 years, with four 24-hour pharmacokinetic investigations. Both groups underwent a 3-week low-energy diet (LED; < 1200 kcal/day), followed by RYGB or a 6-week very-low-energy diet (VLED; < 800 kcal/day).ResultsA total of 80 patients were included in the RYGB group (40 patients) and diet-group (40 patients). The weight loss was similar between the groups following LED and RYGB. The LED induced a similar (mean [95% CI]) decrease in CL/F in both intervention groups (RYGB: 16% [0, 31], diet: 23% [8, 38]), but neither induced VLED resulted in any further changes in CL/F. At Year 2, CL/F had increased by 21% from baseline in the RYGB group, while it was unaltered in the diet group. Patients expressing the reduced function SLCO1B1 variants (c.521TC/CC) showed similar changes in CL/F over time compared with patients expressing the wild-type variant.ConclusionsNeither body weight, weight loss nor RYGB per se seem to affect OATP1B1 activity to a clinically relevant degree. Overall, the observed changes in rosuvastatin pharmacokinetics were minor, and unlikely to be of clinical relevance.
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| 4. |
- Kvitne, K. E., et al.
(författare)
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Digoxin Pharmacokinetics in Patients with Obesity Before and After a Gastric Bypass or a Strict Diet Compared with Normal Weight Individuals
- 2024
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Ingår i: Clinical Pharmacokinetics. - 0312-5963. ; 63:1, s. 109-120
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Tidskriftsartikel (refereegranskat)abstract
- Background and Objective Several drugs on the market are substrates for P-glycoprotein (P-gp), an efflux transporter highly expressed in barrier tissues such as the intestine. Body weight, weight loss, and a Roux-en-Y gastric bypass (RYGB) may influence P-gp expression and activity, leading to variability in the drug response. The objective of this study was therefore to investigate digoxin pharmacokinetics as a measure of the P-gp phenotype in patients with obesity before and after weight loss induced by an RYGB or a strict diet and in normal weight individuals. Methods This study included patients with severe obesity preparing for an RYGB (n = 40) or diet-induced weight loss (n = 40) and mainly normal weight individuals scheduled for a cholecystectomy (n = 18). Both weight loss groups underwent a 3-week low-energy diet (<1200 kcal/day) followed by an additional 6 weeks of <800 kcal/day induced by an RYGB (performed at week 3) or a very-low-energy diet. Follow-up time was 2 years, with four digoxin pharmacokinetic investigations at weeks 0, 3, and 9, and year 2. Hepatic and jejunal P-gp levels were determined in biopsies obtained from the patients undergoing surgery. Results The RYGB group and the diet group had a comparable weight loss in the first 9 weeks (13 +/- 2.3% and 11 +/- 3.6%, respectively). During this period, we observed a minor increase (16%) in the digoxin area under the concentration-time curve from zero to infinity in both groups: RYGB: 2.7 mu g h/L [95% confidence interval (CI) 0.67, 4.7], diet: 2.5 mu g h/L [95% CI 0.49, 4.4]. In the RYGB group, we also observed that the time to reach maximum concentration decreased after surgery: from 1.0 +/- 0.33 hours at week 3 to 0.77 +/- 0.08 hours at week 9 (-0.26 hours [95% CI -0.47, -0.05]), corresponding to a 25% reduction. Area under the concentration-time curve from zero to infinity did not change long term (week 0 to year 2) in either the RYGB (1.1 mu g h/L [-0.94, 3.2]) or the diet group (0.94 mu g h/L [-1.2, 3.0]), despite a considerable difference in weight loss from baseline (RYGB: 30 +/- 7%, diet: 3 +/- 6%). At baseline, the area under the concentration-time curve from zero to infinity was -5.5 mu g h/L [95% CI -8.5, -2.5] (-26%) lower in patients with obesity (RYGB plus diet) than in normal weight individuals scheduled for a cholecystectomy. Further, patients undergoing an RYGB had a 0.05 fmol/mu g [95% CI 0.00, 0.10] (29%) higher hepatic P-gp level than the normal weight individuals. Conclusions Changes in digoxin pharmacokinetics following weight loss induced by a pre-operative low-energy diet and an RYGB or a strict diet (a low-energy diet plus a very-low-energy diet) were minor and unlikely to be clinically relevant. The lower systemic exposure of digoxin in patients with obesity suggests that these patients may have increased biliary excretion of digoxin possibly owing to a higher expression of P-gp in the liver.
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| 5. |
- Villegas-Hernandez, LE, et al.
(författare)
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Chip-based multimodal super-resolution microscopy for histological investigations of cryopreserved tissue sections
- 2022
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Ingår i: Light, science & applications. - : Springer Science and Business Media LLC. - 2047-7538. ; 11:1, s. 43-
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Tidskriftsartikel (refereegranskat)abstract
- Histology involves the observation of structural features in tissues using a microscope. While diffraction-limited optical microscopes are commonly used in histological investigations, their resolving capabilities are insufficient to visualize details at subcellular level. Although a novel set of super-resolution optical microscopy techniques can fulfill the resolution demands in such cases, the system complexity, high operating cost, lack of multi-modality, and low-throughput imaging of these methods limit their wide adoption for histological analysis. In this study, we introduce the photonic chip as a feasible high-throughput microscopy platform for super-resolution imaging of histological samples. Using cryopreserved ultrathin tissue sections of human placenta, mouse kidney, pig heart, and zebrafish eye retina prepared by the Tokuyasu method, we demonstrate diverse imaging capabilities of the photonic chip including total internal reflection fluorescence microscopy, intensity fluctuation-based optical nanoscopy, single-molecule localization microscopy, and correlative light-electron microscopy. Our results validate the photonic chip as a feasible imaging platform for tissue sections and pave the way for the adoption of super-resolution high-throughput multimodal analysis of cryopreserved tissue samples both in research and clinical settings.
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