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- 2018
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Ingår i: Nuclear Fusion. - : IOP Publishing. - 1741-4326 .- 0029-5515. ; 58:1
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Forskningsöversikt (refereegranskat)
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| 2. |
- Joffrin, E., et al.
(författare)
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Overview of the JET preparation for deuterium-tritium operation with the ITER like-wall
- 2019
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Ingår i: Nuclear Fusion. - : IOP Publishing. - 1741-4326 .- 0029-5515. ; 59:11
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Forskningsöversikt (refereegranskat)abstract
- For the past several years, the JET scientific programme (Pamela et al 2007 Fusion Eng. Des. 82 590) has been engaged in a multi-campaign effort, including experiments in D, H and T, leading up to 2020 and the first experiments with 50%/50% D-T mixtures since 1997 and the first ever D-T plasmas with the ITER mix of plasma-facing component materials. For this purpose, a concerted physics and technology programme was launched with a view to prepare the D-T campaign (DTE2). This paper addresses the key elements developed by the JET programme directly contributing to the D-T preparation. This intense preparation includes the review of the physics basis for the D-T operational scenarios, including the fusion power predictions through first principle and integrated modelling, and the impact of isotopes in the operation and physics of D-T plasmas (thermal and particle transport, high confinement mode (H-mode) access, Be and W erosion, fuel recovery, etc). This effort also requires improving several aspects of plasma operation for DTE2, such as real time control schemes, heat load control, disruption avoidance and a mitigation system (including the installation of a new shattered pellet injector), novel ion cyclotron resonance heating schemes (such as the three-ions scheme), new diagnostics (neutron camera and spectrometer, active Alfven eigenmode antennas, neutral gauges, radiation hard imaging systems...) and the calibration of the JET neutron diagnostics at 14 MeV for accurate fusion power measurement. The active preparation of JET for the 2020 D-T campaign provides an incomparable source of information and a basis for the future D-T operation of ITER, and it is also foreseen that a large number of key physics issues will be addressed in support of burning plasmas.
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| 3. |
- Krasilnikov, A., et al.
(författare)
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Evidence of 9 Be + p nuclear reactions during 2ω CH and hydrogen minority ICRH in JET-ILW hydrogen and deuterium plasmas
- 2018
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Ingår i: Nuclear Fusion. - : IOP Publishing. - 1741-4326 .- 0029-5515. ; 58:2
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Tidskriftsartikel (refereegranskat)abstract
- The intensity of 9Be + p nuclear fusion reactions was experimentally studied during second harmonic (2ω CH) ion-cyclotron resonance heating (ICRH) and further analyzed during fundamental hydrogen minority ICRH of JET-ILW hydrogen and deuterium plasmas. In relatively low-density plasmas with a high ICRH power, a population of fast H+ ions was created and measured by neutral particle analyzers. Primary and secondary nuclear reaction products, due to 9Be + p interaction, were observed with fast ion loss detectors, γ-ray spectrometers and neutron flux monitors and spectrometers. The possibility of using 9Be(p, d)2α and 9Be(p, α)6Li nuclear reactions to create a population of fast alpha particles and study their behaviour in non-active stage of ITER operation is discussed in the paper.
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| 24. |
- Abel, I, et al.
(författare)
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Overview of the JET results with the ITER-like wall
- 2013
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Ingår i: Nuclear Fusion. - : IOP Publishing. - 1741-4326 .- 0029-5515. ; 53:10, s. 104002-
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Tidskriftsartikel (refereegranskat)abstract
- Following the completion in May 2011 of the shutdown for the installation of the beryllium wall and the tungsten divertor, the first set of JET campaigns have addressed the investigation of the retention properties and the development of operational scenarios with the new plasma-facing materials. The large reduction in the carbon content (more than a factor ten) led to a much lower Z(eff) (1.2-1.4) during L- and H-mode plasmas, and radiation during the burn-through phase of the plasma initiation with the consequence that breakdown failures are almost absent. Gas balance experiments have shown that the fuel retention rate with the new wall is substantially reduced with respect to the C wall. The re-establishment of the baseline H-mode and hybrid scenarios compatible with the new wall has required an optimization of the control of metallic impurity sources and heat loads. Stable type-I ELMy H-mode regimes with H-98,H-y2 close to 1 and beta(N) similar to 1.6 have been achieved using gas injection. ELM frequency is a key factor for the control of the metallic impurity accumulation. Pedestal temperatures tend to be lower with the new wall, leading to reduced confinement, but nitrogen seeding restores high pedestal temperatures and confinement. Compared with the carbon wall, major disruptions with the new wall show a lower radiated power and a slower current quench. The higher heat loads on Be wall plasma-facing components due to lower radiation made the routine use of massive gas injection for disruption mitigation essential.
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| 25. |
- Romanelli, F, et al.
(författare)
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Overview of the JET results
- 2011
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Ingår i: Nuclear Fusion. - : IOP Publishing. - 1741-4326 .- 0029-5515. ; 51:9
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Tidskriftsartikel (refereegranskat)abstract
- Since the last IAEA Conference JET has been in operation for one year with a programmatic focus on the qualification of ITER operating scenarios, the consolidation of ITER design choices and preparation for plasma operation with the ITER-like wall presently being installed in JET. Good progress has been achieved, including stationary ELMy H-mode operation at 4.5 MA. The high confinement hybrid scenario has been extended to high triangularity, lower ρ*and to pulse lengths comparable to the resistive time. The steady-state scenario has also been extended to lower ρ*and ν*and optimized to simultaneously achieve, under stationary conditions, ITER-like values of all other relevant normalized parameters. A dedicated helium campaign has allowed key aspects of plasma control and H-mode operation for the ITER non-activated phase to be evaluated. Effective sawtooth control by fast ions has been demonstrated with3He minority ICRH, a scenario with negligible minority current drive. Edge localized mode (ELM) control studies using external n = 1 and n = 2 perturbation fields have found a resonance effect in ELM frequency for specific q95values. Complete ELM suppression has, however, not been observed, even with an edge Chirikov parameter larger than 1. Pellet ELM pacing has been demonstrated and the minimum pellet size needed to trigger an ELM has been estimated. For both natural and mitigated ELMs a broadening of the divertor ELM-wetted area with increasing ELM size has been found. In disruption studies with massive gas injection up to 50% of the thermal energy could be radiated before, and 20% during, the thermal quench. Halo currents could be reduced by 60% and, using argon/deuterium and neon/deuterium gas mixtures, runaway electron generation could be avoided. Most objectives of the ITER-like ICRH antenna have been demonstrated; matching with closely packed straps, ELM resilience, scattering matrix arc detection and operation at high power density (6.2 MW m-2) and antenna strap voltages (42 kV). Coupling measurements are in very good agreement with TOPICA modelling. © 2011 IAEA, Vienna.
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| 26. |
- Eriksson, Jan W, 1959, et al.
(författare)
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Successful treatment with plasmapheresis, cyclophosphamide, and cyclosporin A in type B syndrome of insulin resistance. Case report.
- 1998
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Ingår i: Diabetes care. - 0149-5992 .- 1935-5548. ; 21:8, s. 1217-20
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Tidskriftsartikel (refereegranskat)abstract
- CASE HISTORY: A woman born in 1949 was diagnosed in 1990 with systemic lupus erythematosus. She was treated with prednisolone, and < 1 year later she presented with marked hyperglycemia. Large doses of insulin were given four times per day. Even though the patient was thin (BMI 17.4 kg/m2), very little improvement was seen. INVESTIGATIONS AND TREATMENT: Serum insulin levels were high, and a euglycemic clamp investigation confirmed severe insulin resistance. The patient's serum contained insulin receptor antibodies inhibiting insulin binding, and thus the patient had a type B syndrome of insulin resistance. After diet and exercise, glycemic control stabilized and insulin treatment was withdrawn. However, in late 1993 she was in a catabolic and hyperglycemic state even though prednisolone doses were increased and azathioprin was added. In early 1994 she was treated with plasmapheresis and cyclophosphamide i.v. Subsequently, cyclosporin A was started as a maintenance therapy in addition to azathioprin. There was a rapid and sustained clinical improvement. Since late 1994 and onward, there is no sign of diabetes or glucose intolerance and there are no demonstrable insulin receptor antibodies in the patient's serum. DISCUSSION: Severe type B insulin resistance may respond favorably to treatment with plasmapheresis and cyclophosphamide followed by cyclosporin A in combination with azathioprin.
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| 27. |
- Folkersen, Lasse, et al.
(författare)
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Genomic and drug target evaluation of 90 cardiovascular proteins in 30,931 individuals.
- 2020
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Ingår i: Nature metabolism. - : Springer Science and Business Media LLC. - 2522-5812. ; 2:10, s. 1135-1148
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Tidskriftsartikel (refereegranskat)abstract
- Circulating proteins are vital in human health and disease and are frequently used as biomarkers for clinical decision-making or as targets for pharmacological intervention. Here, we map and replicate protein quantitative trait loci (pQTL) for 90 cardiovascular proteins in over 30,000 individuals, resulting in 451 pQTLs for 85 proteins. For each protein, we further perform pathway mapping to obtain trans-pQTL gene and regulatory designations. We substantiate these regulatory findings with orthogonal evidence for trans-pQTLs using mouse knockdown experiments (ABCA1 and TRIB1) and clinical trial results (chemokine receptors CCR2 and CCR5), with consistent regulation. Finally, we evaluate known drug targets, and suggest new target candidates or repositioning opportunities using Mendelian randomization. This identifies 11 proteins with causal evidence of involvement in human disease that have not previously been targeted, including EGF, IL-16, PAPPA, SPON1, F3, ADM, CASP-8, CHI3L1, CXCL16, GDF15 and MMP-12. Taken together, these findings demonstrate the utility of large-scale mapping of the genetics of the proteome and provide a resource for future precision studies of circulating proteins in human health.
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| 28. |
- Kalani, Majid, et al.
(författare)
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Beneficial effects of dalteparin on haemostatic function and local tissue oxygenation in patients with diabetes, severe vascular disease and foot ulcers.
- 2007
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Ingår i: Thrombosis research. - : Elsevier BV. - 0049-3848 .- 1879-2472. ; 120:5, s. 653-61
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Tidskriftsartikel (refereegranskat)abstract
- INTRODUCTION: A state of hypercoagulation and fibrinolytic dysfunction is present in individuals with diabetes, which may contribute to disturbed skin microcirculation and impaired ulcer healing. We have previously reported an improved outcome of chronic diabetic foot ulcers during treatment with dalteparin. In the present study we investigated the effects of dalteparin on skin microcirculation and haemostatic function. MATERIALS AND METHODS: 87 patients with diabetes, peripheral arterial obliterative disease and chronic foot ulcers were investigated in a prospective, randomised, double-blind and placebo-controlled study. They were randomised to treatment with subcutaneous injections of 5000 U dalteparin (n=44) or placebo (n=43), once daily until ulcer healing or for a maximum of six months. Plasma fibrinogen, fibrin gel structure [permeability coefficient (Ks) and fiber mass/length ratio (mu)], prothrombin fragment 1+2 (F1+2) antigen, plasminogen activator inhibitor-1 (PAI-1) activity and tissue plasminogen activator (tPA) antigen were analysed before randomization (baseline value), and at the end of the treatment period. The skin microcirculation of the foot was investigated by transcutaneous oxygen tension (TcPO(2)) and laser Doppler fluxmetry (LDF). RESULTS: The changes (Delta-values) of Ks, mu, tPA and TcPO(2) were higher (p<0.05) during treatment with dalteparin, as compared to the changes during treatment with placebo. At baseline, plasma fibrinogen and Ks were significantly correlated to TcPO(2). CONCLUSIONS: Local skin oxygenation improved and a less thrombogenic fibrin gel structure was formed in patients treated with dalteparin. Beneficial effects on haemostatic function are likely to contribute to the improved skin oxygenation observed during treatment with dalteparin.
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| 29. |
- Kalani, Majid, et al.
(författare)
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Effect of dalteparin on healing of chronic foot ulcers in diabetic patients with peripheral arterial occlusive disease: a prospective, randomized, double-blind, placebo-controlled study.
- 2003
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Ingår i: Diabetes care. - : American Diabetes Association. - 0149-5992 .- 1935-5548. ; 26:9, s. 2575-80
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVE: Chronic foot ulcers are a common, severe, and expensive complication threatening life and limb in patients with diabetes. The aim of the present study was to investigate the effect of dalteparin on ulcer outcome in patients with diabetes, peripheral arterial occlusive disease, and chronic foot ulcers. RESEARCH DESIGN AND METHODS: A total of 87 patients were investigated in a prospective, randomized, double-blind, placebo-controlled trial. Participants were randomized to treatment with subcutaneous injection of 5000 units dalteparin (Fragmin, Pharmacia Corporation; n = 44) or an equivalent volume of physiological saline (n = 43) once daily until ulcer healing or for a maximum of 6 months. Ulcer outcome was investigated by evaluating the number of patients 1). who healed with intact skin; 2). in whom the study ulcer was improved, unchanged, or impaired; or 3). who were amputated above or below the ankle level, as compared with control subjects. RESULTS: Two patients, one on dalteparin and one on placebo, dropped out of the study. Ulcer outcome was significantly better (P = 0.042, two-sided chi(2) test for trend) in the dalteparin group (n = 43) compared with the placebo group (n = 42). A total of 29 patients healed with intact skin (n = 14) or decreased the ulcer area >or=50% (n = 15) in the dalteparin group compared with 20 (n = 9 and 11, respectively) in the placebo group. Five patients in each group showed impaired ulcer healing, i.e., the ulcer area increased >or=50%. Two patients in the dalteparin group were amputated compared with eight in the placebo group. Time to healing with intact skin was 17 +/- 8 weeks in the dalteparin group compared with 16 +/- 7 weeks in placebo group (NS). CONCLUSIONS: The results of the present study indicate that dalteparin improves the outcome of chronic foot ulcers in diabetic patients with peripheral arterial occlusive disease.
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| 30. |
- Newcomer, J. W., et al.
(författare)
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A 24-week, multicenter, open-label, randomized study to compare changes in glucose metabolism in patients with schizophrenia receiving treatment with olanzapine, quetiapine, or risperidone
- 2009
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Ingår i: J Clin Psychiatry. - 1555-2101 .- 1555-2101 .- 0160-6689. ; 70:4, s. 487-99
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVE: This randomized, 24-week, flexible-dose study compared changes in glucose metabolism in patients with DSM-IV schizophrenia receiving initial exposure to olanzapine, quetiapine, or risperidone. METHOD: The hypothesized primary endpoint was change (baseline to week 24) in area under the curve (AUC) 0- to 2-hour plasma glucose values during an oral glucose tolerance test (OGTT); primary analysis: olanzapine versus quetiapine. Secondary endpoints included mean change in AUC 0- to 2-hour plasma insulin values, insulin sensitivity index, and fasting lipids. The first patient enrolled on April 29, 2004, and the last patient completed the study on October 24, 2005. RESULTS: Mean weight change (kg) over 24 weeks was +3.7 (quetiapine), +4.6 (olanzapine), and +3.6 (risperidone). Based on data from 395 patients (quetiapine, N = 115 [mean dose = 607.0 mg/day], olanzapine, N = 146 [mean dose = 15.2 mg/day], and risperidone, N = 134 [mean dose = 5.2 mg/day]), mean change in AUC 0- to 2-hour glucose value (mg/dL x h) at week 24 was significantly lower for quetiapine versus olanzapine (t = 1.98, df = 377, p = .048). Increases in AUC 0- to 2-hour glucose values were statistically significant with olanzapine (+21.9 mg/dL x h, 95% CI = 11.5 to 32.4 mg/dL x h) and risperidone (+18.8 mg/dL x h, 95% CI = 8.1 to 29.4 mg/dL x h), but not quetiapine (+9.1 mg/dL x h, 95% CI = -2.3 to 20.5 mg/dL x h). AUC 0- to 2-hour insulin values increased statistically significantly with olanzapine (+24.5%, 95% CI = 11.5% to 39.0%), but not with quetiapine or risperidone. Reductions in insulin sensitivity index were statistically significant with olanzapine (-19.1%, 95% CI = -27.9% to -9.3%) and risperidone (-15.8%, 95% CI = -25.1% to -5.4%), but not quetiapine. Total cholesterol and low-density lipoprotein levels increased statistically significantly with olanzapine (+21.1 mg/dL, 95% CI = 13.0 to 29.2 mg/dL, and +20.5 mg/dL, 95% CI = 13.8 to 27.1 mg/dL, respectively) and quetiapine (+13.1 mg/dL, 95% CI = 4.3 to 21.9 mg/dL, and +13.3 mg/dL, 95% CI = 6.1 to 20.5 mg/dL, respectively), but not risperidone. Statistically significant increases in triglycerides (+30.9 mg/dL, 95% CI = 10.9 to 51.0 mg/dL), total cholesterol/high-density lipoprotein (HDL) ratio (0.5, 95% CI = 0.2 to 0.8), and triglyceride/HDL ratio (0.3, 95% CI = 0.0 to 0.6) were observed with olanzapine only. CONCLUSION: The results indicate a significant difference in the change in glucose tolerance during 6 months' treatment with olanzapine versus quetiapine, with significant reductions on olanzapine and risperidone, but not quetiapine; these differential changes were largely explained by changes in insulin sensitivity. TRIAL REGISTRATION: clinicaltrials.gov Identifier: NCT00214578.
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| 32. |
- Eriksson, Jan W, 1959, et al.
(författare)
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Diabetisk kärlsjukdom och diabetesfoten
- 2009
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Ingår i: Kärlsjukdom - Vaskulär medicin, Lindgärde F, Thulin T, Östergren J (eds). - Lund : Studentlitteratur. ; , s. 191-211
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Bokkapitel (övrigt vetenskapligt/konstnärligt)
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| 33. |
- Fryk, Emanuel, et al.
(författare)
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Microdialysis and proteomics of subcutaneous interstitial fluid reveals increased galectin-1 in type 2 diabetes patients
- 2016
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Ingår i: Metabolism-Clinical and Experimental. - : Elsevier BV. - 0026-0495 .- 1532-8600. ; 65:7, s. 998-1006
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Tidskriftsartikel (refereegranskat)abstract
- Objective. To identify a potential therapeutic target for type 2 diabetes by comparing the subcutaneous interstitial fluid from type 2 diabetes patients and healthy men. Methods. Proteomics was performed on the interstitial fluid of subcutaneous adipose tissue obtained by microdialysis from 7 type 2 diabetes patients and 8 healthy participants. 851 proteins were detected, of which 36 (including galectin-1) showed significantly altered expression in type 2 diabetes. We also measured galectin-1 expression in: (1) adipocytes isolated from adipose tissue biopsies from these participants; (2) subcutaneous adipose tissue of 24 obese participants before, during and after 16 weeks on a very low calorie diet (VLCD); and (3) adipocytes isolated from 6 healthy young participants after 4 weeks on a diet and lifestyle intervention to promote weight gain. We also determined the effect of galectin-1 on glucose uptake in human adipose tissue. Results. Galectin-1 protein levels were elevated in subcutaneous dialysates from type 2 diabetes compared with healthy controls (p < 0.05). In agreement, galectin-1 mRNA expression was increased in adipocytes from the type 2 diabetes patients (p < 0.05). Furthermore, galectin-1 mRNA expression was decreased in adipose tissue after VLCD (p < 0.05) and increased by overfeeding (p < 0.05). Co-incubation of isolated human adipocytes with galectin-1 reduced glucose uptake (p < 0.05) but this was independent of the insulin signal. Conclusion. Proteomics of the interstitial fluid in subcutaneous adipose tissue in vivo identified a novel adipokine, galectin-1, with a potential role in the pathophysiology of type 2 diabetes. (C) 2016 Elsevier Inc. All rights reserved.
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| 34. |
- Jansson, Per-Anders, 1961, et al.
(författare)
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Endocrine abnormalities in healthy first-degree relatives of type 2 diabetes patients--potential role of steroid hormones and leptin in the development of insulin resistance.
- 2002
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Ingår i: European journal of clinical investigation. - : Wiley. - 0014-2972 .- 1365-2362. ; 32:3, s. 172-8
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: First-degree relatives of type 2 diabetes patients are at risk of developing diabetes and they display several metabolic and hormonal perturbations. The interplay between insulin resistance, steroid hormones and circulating leptin is, however, still not fully explored in this group. DESIGN: Thirty-three healthy first-degree relatives of type 2 diabetic patients (relatives; M/F 19/14) were compared to 33 healthy subjects without a family history of diabetes (controls) and the groups were matched for gender, age and body mass index (BMI). We performed euglycaemic hyperinsulinaemic clamps and blood was sampled for hormone analyses. RESULTS: Relatives exhibited decreased insulin sensitivity (index of metabolic clearance rate of glucose; MCRI) but when genders were analysed separately, this difference was significant only in males (11.3 +/- 1.3 vs. 15.0 +/- 1.5 units, means +/- SEM, P = 0.030). In male relatives morning cortisol and testosterone levels were lower, whereas leptin was higher than in male controls (P = 0.018, 0.008 and 0.063, respectively). In male relatives plasma testosterone levels were significantly associated with insulin sensitivity (r = 0.48, P = 0.040). Circulating leptin levels were inversely correlated with insulin sensitivity in all subject groups (r-values -0.49 to -0.66; P < 0.05, except in female control subjects P = 0.063). These associations were present also when age and BMI or waist:hip ratio were included in stepwise multiple regression analyses. CONCLUSION: Male subjects genetically predisposed for type 2 diabetes display several endocrine abnormalities including leptin, cortisol and testosterone levels. Dysregulation of these hormones may be important in the development of insulin resistance and type 2 diabetes.
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| 35. |
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| 36. |
- Sahli, David, et al.
(författare)
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Assessment of toe blood pressure is an effective screening method to identify diabetes patients with lower extremity arterial disease.
- 2004
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Ingår i: Angiology. - : SAGE Publications. - 0003-3197 .- 1940-1574. ; 55:6, s. 641-51
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Tidskriftsartikel (refereegranskat)abstract
- The authors evaluated a screening program for lower extremity arterial disease (LEAD) in diabetic patients and focused on the value of toe blood pressure assessment. They recruited 437 subjects, ages 30-70 years (134 healthy controls, 166 type 1 and 137 type 2 diabetic patients; control [Ctr], DM1, and DM2) with no previous history of LEAD. They were enrolled in a longitudinal study with a planned follow-up of 10 years. Patients were consecutively enrolled from outpatient diabetes units of 2 university hospitals. Subjects were screened with respect to peripheral circulation by use of established noninvasive techniques. These included arm, ankle (AP), and toe (TP) blood pressure measurements; evaluation of peripheral neuropathy; and a standardized physical examination. Results from the baseline examination are presented in this report. The number of patients who presented peripheral pressures or indices below normal (< mean -2 SD for controls) was higher among diabetic patients; 24% of DM1 and 31% of DM2, as compared to 6% of Ctr, had at least 1 lower limb with a low TP, AP, toe/arm index (TI), or ankle/arm index (AI), and these subjects were mainly identified by using the toe/arm index. TI was independently and negatively associated with fasting blood glucose in both patient groups, and with smoking, age, and diabetes duration in DM1. The mean AP was higher in the DM1 and DM2 groups compared to Ctr, whereas overall TP, TI, and AI were similar in the groups. It was also shown that abnormally low TI was significantly more common than low AI among diabetics (p<0.001), and this was true for TP vs AP as well (p<0.05). It is beneficial to include assessment of toe blood pressure and toe/arm blood pressure index to detect early LEAD in diabetic patients. Ankle blood pressure and indices alone are less efficient, owing probably to medial sclerosis in diabetic patients. Up to 30% of diabetic patients with no ischemic symptoms may have signs of impaired arterial circulation.
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| 37. |
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| 38. |
- Axelsen, Mette, 1965, et al.
(författare)
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Postprandial hypertriglyceridemia and insulin resistance in normoglycemic first-degree relatives of patients with type 2 diabetes.
- 1999
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Ingår i: Annals of internal medicine. - 0003-4819 .- 1539-3704. ; 131:1, s. 27-31
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Impaired ability to eliminate lipids in the postprandial state is an atherogenic trait associated with insulin resistance. OBJECTIVE: To assess insulin sensitivity and postprandial triglyceride metabolism in prediabetic persons. DESIGN: Cross-sectional study. SETTING: Sahlgrenska University Hospital, Göteborg, Sweden. PARTICIPANTS: 13 healthy, normotriglyceridemic men with two first-degree relatives with type 2 diabetes and 13 carefully matched controls without known diabetes heredity. MEASUREMENTS: Oral glucose tolerance test, insulin sensitivity (euglycemic clamp technique), and fasting and postprandial triglyceride levels after a mixed meal. RESULTS: Relatives of persons with type 2 diabetes were insulin resistant but had normal glucose tolerance. They exhibited postprandial hypertriglyceridemia; the 6-hour triglyceride incremental area under the curve was 50% higher than that of the control group (P = 0.037). CONCLUSIONS: These healthy male first-degree relatives of patients with type 2 diabetes are insulin resistant and exhibit postprandial lipid intolerance despite having normal fasting triglyceride levels. These characteristics, which occur in the absence of glucose intolerance, are associated with an increased risk for macroangiopathy.
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| 41. |
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| 42. |
- Liu, L, et al.
(författare)
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DGAT1 deficiency decreases PPAR expression and does not lead to lipotoxicity in cardiac and skeletal muscle
- 2011
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Ingår i: JOURNAL OF LIPID RESEARCH. - 0022-2275 .- 1539-7262. ; 52:4, s. 732-744
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Tidskriftsartikel (refereegranskat)abstract
- Diacylglycerol (DAG) acyl transferase 1 (Dgat1) knockout (−/−) mice are resistant to high-fat-induced obesity and insulin resistance, but the reasons are unclear. Dgat1−/− mice had reduced mRNA levels of all three Ppar genes and genes involved in fatty acid oxidation in the myocardium of Dgat1−/− mice. Although DGAT1 converts DAG to triglyceride (TG), tissue levels of DAG were not increased in Dgat1−/− mice. Hearts of chow-diet Dgat1−/− mice were larger than those of wild-type (WT) mice, but cardiac function was normal. Skeletal muscles from Dgat1−/− mice were also larger. Muscle hypertrophy factors phospho-AKT and phospho-mTOR were increased in Dgat1−/− cardiac and skeletal muscle. In contrast to muscle, liver from Dgat1−/− mice had no reduction in mRNA levels of genes mediating fatty acid oxidation. Glucose uptake was increased in cardiac and skeletal muscle in Dgat1−/− mice. Treatment with an inhibitor specific for DGAT1 led to similarly striking reductions in mRNA levels of genes mediating fatty acid oxidation in cardiac and skeletal muscle. These changes were reproduced in cultured myocytes with the DGAT1 inhibitor, which also blocked the increase in mRNA levels of Ppar genes and their targets induced by palmitic acid. Thus, loss of DGAT1 activity in muscles decreases mRNA levels of genes involved in lipid uptake and oxidation.
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| 43. |
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| 44. |
- Pereira, Maria J, 1981, et al.
(författare)
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Effects of decavanadate and insulin enhancing vanadium compounds on glucose uptake in isolated rat adipocytes
- 2009
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Ingår i: J Inorg Biochem. - : Elsevier BV. - 1873-3344 .- 1873-3344 .- 0162-0134. ; 103:12, s. 1687-92
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Tidskriftsartikel (refereegranskat)abstract
- The effects of different vanadium compounds namely pyridine-2,6-dicarboxylatedioxovanadium(V) (V5-dipic), bis(maltolato) oxovanadium(IV) (BMOV) and amavadine, and oligovanadates namely metavanadate and decavanadate were analysed on basal and insulin stimulated glucose uptake in rat adipocytes. Decavanadate (50 microM), manifest a higher increases (6-fold) on glucose uptake compared with basal, followed by BMOV (1 mM) and metavanadate (1 mM) solutions (3-fold) whereas V5 dipic and amavadine had no effect. Decavanadate (100 microM) also shows the highest insulin like activity when compared with the others compounds studied. In the presence of insulin (10 nM), only decavanadate increases (50%) the glucose uptake when compared with insulin stimulated glucose uptake whereas BMOV and metavanadate, had no effect and V5 dipic and amavadine prevent the stimulation to about half of the basal value. Decavanadate is also able to reduce or eradicate the suppressor effect caused by dexamethasone on glucose uptake at the level of the adipocytes. Altogether, vanadium compounds and oligovanadates with several structures and coordination spheres reveal different effects on glucose uptake in rat primary adipocytes.
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| 45. |
- Pereira, Maria J, 1981, et al.
(författare)
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The immunosuppressive agents rapamycin, cyclosporin A and tacrolimus increase lipolysis, inhibit lipid storage and alter expression of genes involved in lipid metabolism in human adipose tissue.
- 2013
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Ingår i: Molecular and cellular endocrinology. - : Elsevier BV. - 1872-8057 .- 0303-7207. ; 365:2, s. 260-9
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Tidskriftsartikel (refereegranskat)abstract
- Cyclosporin A (CsA), tacrolimus and rapamycin are immunosuppressive agents (IAs) associated with insulin resistance and dyslipidemia, although their molecular effects on lipid metabolism in adipose tissue are unknown. We explored IAs effects on lipolysis, lipid storage and expression of genes involved on lipid metabolism in isolated human adipocytes and/or adipose tissue obtained via subcutaneous and omental fat biopsies. CsA, tacrolimus and rapamycin increased isoproterenol-stimulated lipolysis and inhibited lipid storage by 20-35% and enhanced isoproterenol-stimulated hormone-sensitive lipase Ser552 phosphorylation. Rapamycin also increased basal lipolysis (∼20%) and impaired insulin's antilipolytic effect. Rapamycin, down-regulated the gene expression of perilipin, sterol regulatory element-binding protein 1 (SREBP1) and lipin 1, while tacrolimus down-regulated CD36 and aP2 gene expression. All three IAs increased IL-6 gene expression and secretion, but not expression and secretion of TNF-α or adiponectin. These findings suggest that CsA, tacrolimus and rapamycin enhance lipolysis, inhibit lipid storage and expression of lipogenic genes in adipose tissue, which may contribute to the development of dyslipidemia and insulin resistance associated with immunosuppressive therapy.
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| 46. |
- Renström, Frida, et al.
(författare)
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Factors in serum from type 2 diabetes patients can cause cellular insulin resistance
- 2009
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Ingår i: Horm Metab Res. - : Georg Thieme Verlag KG. - 1439-4286 .- 1439-4286 .- 0018-5043. ; 41:10, s. 767-72
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Tidskriftsartikel (refereegranskat)abstract
- This pilot study was aimed to investigate whether there are humoral factors in serum from type 2 diabetic subjects that, in addition to glucose, insulin and free fatty acids are able to induce or contribute to peripheral insulin resistance with respect to glucose transport. Isolated subcutaneous adipocytes from 11 type 2 diabetic subjects and 10 nondiabetic controls were incubated for 24-h in medium supplemented with 25 % serum from a control or a type 2 diabetic donor, in the presence of a low (5 mM) or a high (15 mM) glucose concentration, respectively. After the incubation period glucose uptake capacity was assessed. Serum from type 2 diabetic donors, compared to serum from controls, significantly reduced the maximal insulin eff ect to stimulate glucose uptake (approximately 40 %, p < 0.05) in adipocytes from control subjects, independent of surrounding glucose concentrations. Glucose uptake capacity in adipocytes isolated from type 2 diabetic subjects was similar regardless of culture condition. No significant alterations were found in cellular content of key proteins in the insulin signaling cascade (insulin receptor substrate-1 and -2, and glucose transporter 4) that could explain the impaired insulin-stimulated glucose transport in control adipocytes incubated with serum from type 2 diabetic donors. The present findings indicate the presence of biomolecules in the circulation of type 2 diabetic subjects, apart from glucose, insulin, and free fatty acids with the ability to induce peripheral insulin resistance. This further implies that even though normoglycemia is achieved other circulating factors can still negatively aff ect insulin sensitivity in type 2 diabetic patients.
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| 47. |
- Ruge, T., et al.
(författare)
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Acute hyperinsulinemia raises plasma interleukin-6 in both nondiabetic and type 2 diabetes mellitus subjects, and this effect is inversely associated with body mass index
- 2009
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Ingår i: Metabolism. - 1532-8600 .- 1532-8600. ; 58:6, s. 860-6
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Tidskriftsartikel (refereegranskat)abstract
- Hyperinsulinemia is a characteristic of type 2 diabetes mellitus (T2DM) and is believed to play a role in the low-grade inflammation seen in T2DM. The main aim was to study the effect of hyperinsulinemia on adipokines in individuals with different levels of insulin resistance, glycemia, and obesity. Three groups of sex-matched subjects were studied: young healthy subjects (YS; n = 10; mean age, 26 years; body mass index [BMI], 22 kg/m(2)), patients with T2DM (DS; n = 10; 61 years; BMI, 27 kg/m(2)), and age- and BMI-matched controls to DS (CS; n = 10; 60 years; BMI, 27 kg/m(2)). Plasma concentrations of adipokines were measured during a hyperinsulinemic euglycemic clamp lasting 4 hours. Moreover, insulin-stimulated glucose uptake in isolated adipocytes was analyzed to address adipose tissue insulin sensitivity. Plasma interleukin (IL)-6 increased significantly (P < or = .01) in all 3 groups during hyperinsulinemia. However, the increase was smaller in both DS (P = .06) and CS (P < .05) compared with YS (approximately 2.5-fold vs approximately 4-fold). A significant increase of plasma tumor necrosis factor (TNF) alpha was observed only in YS. There were only minor or inconsistent effects on adiponectin, leptin, and high-sensitivity C-reactive protein levels during hyperinsulinemia. Insulin-induced rise in IL-6 correlated negatively to BMI (P = .001), waist to hip ratio (P = .05), and baseline (fasting) insulin (P = .03) and IL-6 (P = .02) levels and positively to insulin-stimulated glucose uptake in isolated adipocytes (P = .07). There was no association with age or insulin sensitivity. In a multivariate analysis, also including T2DM/no T2DM, an independent correlation (inverse) was found only between BMI and fold change of IL-6 (r(2) = 0.41 for model, P < .005). Hyperinsulinemia per se can produce an increase in plasma IL-6 and TNFalpha, and this can potentially contribute to the low-grade inflammation seen in obesity and T2DM. However, obesity seems to attenuate the ability of an acute increase in insulin to further raise circulating levels of IL-6 and possibly TNFalpha.
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| 48. |
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| 49. |
- Sjostrand, M., 1964, et al.
(författare)
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Neuroendocrine mechanisms in insulin resistance
- 2009
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Ingår i: Mol Cell Endocrinol. - : Elsevier BV. - 0303-7207 .- 0303-7207 .- 1872-8057. ; 297:1-2, s. 104-11
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Tidskriftsartikel (refereegranskat)abstract
- Dysregulated hormonal, metabolic and neural signalling within and between organs can contribute to development of metabolic diseases including type 2 diabetes. Insulin-antagonistic effects of hormones, cytokines and excess metabolic substrates such as glucose and fatty acids may be exerted via common mechanisms involving for example reactive oxygen species (ROS) accumulation and associated inflammatory responses. Visceral adiposity is a central component of the metabolic syndrome and it is also strongly associated with insulin resistance. Both visceral obesity and insulin resistance are important risk factors for the development of type 2 diabetes. In the development of insulin resistance, it is likely that intra-abdominal adipose tissue plays a critical role in a complex endocrine and neural network involving several tissues. This review paper focuses on neuroendocrine 'stress' factors that target insulin-responsive tissues, in particular adipose tissue. We propose that there are common pathways by which dysregulation in different endocrine systems may contribute to the development of type 2 diabetes.
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| 50. |
- Sjöholm, Kajsa, 1971, et al.
(författare)
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Association of serum amyloid A levels with adipocyte size and serum levels of adipokines: differences between men and women.
- 2009
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Ingår i: Cytokine. - : Elsevier BV. - 1096-0023 .- 1043-4666. ; 48:3, s. 260-6
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Tidskriftsartikel (refereegranskat)abstract
- The aim of this study was to characterize the association between adipocyte enlargement and circulating levels of serum amyloid A (SAA). Furthermore, we wanted to search for possible associations with measures of glycemic control and levels of circulating adipokines and/or inflammatory markers in men and women with a large range in body mass index. The study cohort consisted of 167 subjects, 114 non-diabetic and 53 with Type 2 diabetes. Adipocyte diameter as well as circulating levels of SAA, C-reactive protein (CRP), adiponectin, leptin, interleukin-6, tumor necrosis factor alpha, glucose and insulin were measured. Women had higher serum levels of SAA than men (p=0.044). SAA levels were weakly but positively correlated with BMI (p=0.043) and % body fat (p=0.027) in all subjects as well as subcutaneous adipocyte diameter (p=0.034) in women. Furthermore, in all subjects we found correlations between SAA levels and levels of CRP (p<0.001), interleukin-6 (p<0.001), leptin (p=0.003), insulin (p=0.006), HbA1c (p=0.02) and HOMA-IR (p=0.002). A majority of the correlations were strongest in women. In conclusion, serum levels of SAA are strongly correlated with serum levels of inflammatory markers as well as measures of glycemic control. There seems to be large sex differences in these associations suggesting that sex-specific factors need to be considered when analyzing SAA levels in relation to metabolic disease.
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