| 1. |
- Booksmythe, I., et al.
(författare)
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Sexual dimorphism in epicuticular compounds despite similar sexual selection in sex role-reversed seed beetles
- 2017
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Ingår i: Journal of Evolutionary Biology. - : Wiley. - 1010-061X .- 1420-9101. ; 30:11, s. 2005-2016
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Tidskriftsartikel (refereegranskat)abstract
- Sexual selection imposed by mating preferences is often implicated in the evolution of both sexual dimorphism and divergence between species in signalling traits. Epicuticular compounds (ECs) are important signalling traits in insects and show extensive variability among and within taxa. Here, we investigate whether variation in the multivariate EC profiles of two sex role-reversed beetle species, Megabruchidius dorsalis and Megabruchidius tonkineus, predicts mate attractiveness and mating success in males and females. The two species had highly distinct EC profiles and both showed significant sexual dimorphism in ECs. Age and mating status in both species were also distinguishable by EC profile. Males and females of both species showed significant association between their EC profile and attractiveness, measured both as latency to mating and as success in mate-choice trials. Remarkably, the major multivariate vector describing attractiveness was correlated in both species, both sexes, and in both choice and no-choice experiments such that increased attractiveness was in all cases associated with a similar multivariate modification of EC composition. Furthermore, in both sexes this vector of attractiveness was associated with more male-like EC profiles, as well as those characterizing younger and nonvirgin individuals, which might reflect a general preference for individuals of high condition in both sexes. Despite significant sexual selection on EC composition, however, we found no support for the proposition that sexual selection is responsible for divergence in ECs between these species.
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| 2. |
- Van dijk, Peter R, et al.
(författare)
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After 6years of intraperitoneal insulin administration IGF-I concentrations in T1DM patients are at low-normal level.
- 2015
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Ingår i: Growth Hormone & IGF Research. - : Elsevier BV. - 1096-6374 .- 1532-2238. ; 25:6, s. 316-319
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVE: Low concentrations of insulin-like growth factor-I (IGFI) have been reported in type 1 diabetes mellitus (T1DM), suggested to be due to low insulin concentrations in the portal vein. The aim was to describe the long-term course of IGFI concentrations among T1DM subjects treated with continuous intraperitoneal (IP) insulin infusion (CIPII).DESIGN: Nineteen patients that participated in a randomized cross-over trial comparing CIPII and subcutaneous (SC) insulin therapy in 2006 were followed until 2012. IGF-I measurements were performed at the start of the 2006 study, after the 6month SC- and CIPII treatment phase in 2006 and during CIPII therapy in 2012. Z-scores were calculated to compare the IGF-I concentrations with age-specific normative range values of a non-DM reference population.RESULTS: In 2012, IGF-I Z-scores (-0.7; 95% confidence interval -1.3, -0.2) were significantly higher than at the start of the 2006 study (-2.5; -3.3, -1.8), the end of the SC (-2.0; -2.6, -1.5) and CIPII (-1.6; -2.1, -1.0) treatment phase with a mean difference of: 1.8 (0.9, 2.7), 1.3 (0.5, 2.1) and 0.8 (0.1, 1.6), respectively.CONCLUSION: After 6years of treatment with CIPII, IGF-I concentrations among T1DM patients increased to a level that is higher than during prior SC insulin treatment and is in the lower normal range compared to a non-DM reference population. The results of this study suggest that long-term IP insulin administration influences the IGF system in T1DM.
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| 3. |
- van Dijk, Peter R., et al.
(författare)
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Different Effects of Intraperitoneal and Subcutaneous Insulin Administration on the GH-IGF-1 Axis in Type 1 Diabetes
- 2016
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Ingår i: Journal of Clinical Endocrinology and Metabolism. - : ENDOCRINE SOC. - 0021-972X .- 1945-7197. ; 101:6, s. 2493-2501
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Tidskriftsartikel (refereegranskat)abstract
- Context: In type 1 diabetes mellitus, low levels of insulin-like growth factor -1 (IGF-1) and IGF binding protein-3 (IGFBP-3) and high levels of GH and IGFBP-1 are present, probably due to portal vein insulinopenia. Objective: To test the hypothesis that continuous ip insulin infusion (CIPII) has a more pronounced effect than sc insulin therapy on regulation of the GH-IGF-1 axis. Design: This was a prospective, observational case-control study. Measurements were performed twice at a 26-week interval. Setting: Two secondary care hospitals in the Netherlands participated in the study. Patients: There were a total of 184 patients, age-and gender-matched, of which 39 used CIPII and 145 sc insulin therapy for the past 4 years. Outcomes: Primary endpoint included differences in IGF-1. Secondary outcomes were differences in GH, IGFBP-1, and IGFBP-3. Results: IGF-1 was higher with CIPII as compared to SC insulin therapy: 124 mu g/liter (95% confidence interval [CI], 111-138) vs 108 mu g/liter (95% CI 102-115) (P = .035). Additionally, IGFBP-3 concentrations were higher and IGFBP-1 and GH concentrations were lower with CIPII as compared to SC insulin therapy: 3.78 mg/liter (95% CI, 3.49 - 4.10) vs 3.31 mg/liter (95% CI, 3.173.47) for IGFBP-3, 50.9 mu g/liter (95% CI, 37.9 - 68.2) vs 102.6 mu g/liter (95% CI, 87.8 - 119.8) for IGFBP-1 and 0.68 mu g/liter (95% CI, 0.44 - 1.06) vs 1.21 mu g/liter (95% CI, 0.95-1.54) for GH, respectively. In multivariate analysis, IGF-1 had no significant association with HbA1c. Conclusions: The GH-IGF-1 axis may be affected by the route of insulin administration with CIPII counteracting dysregulation of the GH-IGF1 axis present during sc insulin therapy.
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| 4. |
- Åberg, Anna, et al.
(författare)
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Helicobacter pylori adapts to chronic infection and gastric disease via ph-responsive baba-mediated adherence
- 2017
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Ingår i: Cell Host and Microbe. - : Elsevier BV. - 1931-3128 .- 1934-6069. ; 21:3, s. 376-389
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Tidskriftsartikel (refereegranskat)abstract
- The BabA adhesin mediates high-affinity binding of Helicobacter pylori to the ABO blood group antigen-glycosylated gastric mucosa. Here we show that BabA is acid responsive-binding is reduced at low pH and restored by acid neutralization. Acid responsiveness differs among strains; often correlates with different intragastric regions and evolves during chronic infection and disease progression; and depends on pH sensor sequences in BabA and on pH reversible formation of high-affinity binding BabA multimers. We propose that BabA's extraordinary reversible acid responsiveness enables tight mucosal bacterial adherence while also allowing an effective escape from epithelial cells and mucus that are shed into the acidic bactericidal lumen and that bio-selection and changes in BabA binding properties through mutation and recombination with babA-related genes are selected by differences among individuals and by changes in gastric acidity over time. These processes generate diverse H. pylori subpopulations, in which BabA's adaptive evolution contributes to H. pylori persistence and overt gastric disease.
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