| 1. |
- Astrup, Arne, et al.
(författare)
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The role of reducing intakes of saturated fat in the prevention of cardiovascular disease : where does the evidence stand in 2010?
- 2011
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Ingår i: American Journal of Clinical Nutrition. - : Elsevier BV. - 0002-9165 .- 1938-3207. ; 93:4, s. 684-688
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Tidskriftsartikel (refereegranskat)abstract
- Current dietary recommendations advise reducing the intake of saturated fatty acids (SFAs) to reduce coronary heart disease (CHD) risk, but recent findings question the role of SFAs. This expert panel reviewed the evidence and reached the following conclusions: the evidence from epidemiologic, clinical, and mechanistic studies is consistent in finding that the risk of CHD is reduced when SFAs are replaced with polyunsaturated fatty acids (PUFAs). In populations who consume a Western diet, the replacement of 1% of energy from SFAs with PUFAs lowers LDL cholesterol and is likely to produce a reduction in CHD incidence of >= 2-3%. No clear benefit of substituting carbohydrates for SFAs has been shown, although there might be a benefit if the carbohydrate is unrefined and has a low glycemic index. Insufficient evidence exists to judge the effect on CHD risk of replacing SFAs with MUFAs. No clear association between SFA intake relative to refined carbohydrates and the risk of insulin resistance and diabetes has been shown. The effect of diet on a single biomarker is insufficient evidence to assess CHD risk. The combination of multiple biomarkers and the use of clinical end-points could help substantiate the effects on CHD. Furthermore, the effect of particular foods on CHD cannot be predicted solely by their content of total SFAs because individual SFAs may have different cardiovascular effects and major SFA food sources contain other constituents that could influence CHD risk. Research is needed to clarify the role of SFAs compared with specific forms of carbohydrates in CHD risk and to compare specific foods with appropriate alternatives.
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| 2. |
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| 3. |
- Elberling, Bo, et al.
(författare)
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Soil and Plant Community Characteristics and Dynamics at Zackenberg
- 2008
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Ingår i: High-arctic ecosystem dynamics in a changing climate - Ten years of monitoring and research at Zackenberg Research Station, Northeast Greenland (Advances in Ecological Research). - 0065-2504. - 9780123736659 ; 40, s. 223-248
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Bokkapitel (övrigt vetenskapligt/konstnärligt)abstract
- Arctic soils hold large amounts of nutrients in the weatherable minerals and the soil organic matter, which slowly decompose. The decomposition processes release nutrients to the plant-available nutrient pool as well as greenhouse gases to the atmosphere. Changes in climatic conditions, for example, changes in the distribution of snow, water balance and the length of the growing season, are likely to affect the complex interactions between plants, abiotic and biotic soil processes as well as the composition of soil micro- and macro-fauna and thereby the overall decomposition rates. These interactions, in turn, will influence soil-plant functioning and vegetation composition in the short as well as in the long term. In this chapter, we report on soils and. plant communities and their distribution patterns in the valley Zackenbergdalen and focus on the detailed investigations within five dominating plant communities. These five communities are located along an ecological gradient in the landscape and are closely related to differences in water availability. They are therefore indirectly formed as a result of the distribution of landforms, redistribution of snow and drainage conditions. Each of the plant communities is closely related to specific nutrient levels and degree of soil development including soil element accumulation and translocation, for example, organic carbon. Results presented here show that different parts of the landscape have responded quite differently to the same overall climate changes the last 10 years and thus, most likely in the future too. Fens represent the wettest sites holding large reactive buried carbon stocks. A warmer climate will cause a permafrost degradation, which most likely will result in anoxic decomposition and increasing methane emissions. However, the net gas emissions at fen sites are sensitive to long-term changes in the water table level. Indeed, increasing maximum active layer depth at fen sites has been recorded together with a decreasing water level at Zackenberg. This is in line with the first signs of increasing extension of grasslands at the expense of fens. In contrast, the most exposed and dry areas have less soil carbon, and decomposition processes are periodically water limited. Here, an increase in air temperatures may increase active layer depth more than at fen sites, but water availability will be critical in determining nutrient cycling and plant production. Field manipulation experiments of increasing temperature, water supply and nutrient addition show that soil-plant interactions are sensitive to these variables. However, additional plant-specific investigations are needed before net effects of climate changes on different landscape and plant communities can be integrated in a landscape context and used to assess the net ecosystem effect of future climate scenarios.
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| 4. |
- Hansson, Nils Henrik, et al.
(författare)
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Evaluation of ECG-gated [(11)C]acetate PET for measuring left ventricular volumes, mass, and myocardial external efficiency
- 2016
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Ingår i: Journal of Nuclear Cardiology. - : Springer Science and Business Media LLC. - 1071-3581 .- 1532-6551. ; 23:4, s. 670-9
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Noninvasive estimation of myocardial external efficiency (MEE) requires measurements of left ventricular (LV) oxygen consumption with [(11)C]acetate PET in addition to LV stroke volume and mass with cardiovascular magnetic resonance (CMR). Measuring LV geometry directly from ECG-gated [(11)C]acetate PET might enable MEE evaluation from a single PET scan. Therefore, we sought to establish the accuracy of measuring LV volumes, mass, and MEE directly from ECG-gated [(11)C]acetate PET.METHODS: Thirty-five subjects with aortic valve stenosis underwent ECG-gated [(11)C]acetate PET and CMR. List mode PET data were rebinned into 16-bin ECG-gated uptake images before measuring LV volumes and mass using commercial software and compared to CMR. Dynamic datasets were used for calculation of mean LV oxygen consumption and MEE.RESULTS: LV mass, volumes, and ejection fraction measured by CMR and PET correlated strongly (r = 0.86-0.92, P < .001 for all), but were underestimated by PET (P < .001 for all except ESV P = .79). PET-based MEE, corrected for bias, correlated fairly with PET/CMR-based MEE (r = 0.60, P < .001, bias -3 ± 21%, P = .56). PET-based MEE bias was strongly associated with LV wall thickness.CONCLUSIONS: Although analysis-related improvements in accuracy are recommended, LV geometry estimated from ECG-gated [(11)C]acetate PET correlate excellently with CMR and can indeed be used to evaluate MEE.
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| 5. |
- Harms, Hendrik Johannes, et al.
(författare)
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Automatic Extraction of Myocardial Mass and Volume Using Parametric Images from Dynamic Nongated PET
- 2016
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Ingår i: Journal of Nuclear Medicine. - : Society of Nuclear Medicine. - 0161-5505 .- 1535-5667 .- 2159-662X. ; 57:9, s. 1382-1387
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Tidskriftsartikel (refereegranskat)abstract
- Dynamic cardiac PET is used to quantify molecular processes in vivo. However, measurements of left ventricular (LV) mass and volume require electrocardiogram-gated PET data. The aim of this study was to explore the feasibility of measuring LV geometry using nongated dynamic cardiac PET. Methods: Thirty-five patients with aortic-valve stenosis and 10 healthy controls underwent a 27-min C-11-acetate PET/CT scan and cardiac MRI (CMR). The controls were scanned twice to assess repeatability. Parametric images of uptake rate K-1 and the blood pool were generated from nongated dynamic data. Using software-based structure recognition, the LV wall was automatically segmented from K-1 images to derive functional assessments of LV mass (m(LV)) and wall thickness. End systolic and end-diastolic volumes were calculated using blood pool images and applied to obtain stroke volume and LV ejection fraction (LVEF). PET measurements were compared with CMR. Results: High, linear correlations were found for LV mass (r = 0.95), end-systolic volume (r = 0.93), and end-diastolic volume (r = 0.90), and slightly lower correlations were found for stroke volume (r = 0.74), LVEF (r = 0.81), and thickness (r = 0.78). Bland Altman analyses showed significant differences for m(LV) and thickness only and an overestimation for LVEF at lower values. Intra- and interobserver correlations were greater than 0.95 for all PET measurements. PET repeatability accuracy in the controls was comparable to CMR. Conclusion: LV mass and volume are accurately and automatically generated from dynamic C-11-acetate PET without electrocardiogram gating. This method can be incorporated in a standard routine without any additional workload and can, in theory, be extended to other PET tracers.
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| 8. |
- Kemp, Adam F., et al.
(författare)
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EEG Frequency Correlates with α2-Receptor Density in Parkinson’s Disease
- 2024
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Ingår i: Biomolecules. - 2218-273X. ; 14:2
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Tidskriftsartikel (refereegranskat)abstract
- Introduction: Increased theta and delta power and decreased alpha and beta power, measured with quantitative electroencephalography (EEG), have been demonstrated to have utility for predicting the development of dementia in patients with Parkinson’s disease (PD). Noradrenaline modulates cortical activity and optimizes cognitive processes. We claim that the loss of noradrenaline may explain cognitive impairment and the pathological slowing of EEG waves. Here, we test the relationship between the number of noradrenergic α2 adrenoceptors and changes in the spectral EEG ratio in patients with PD. Methods: We included nineteen patients with PD and thirteen healthy control (HC) subjects in the study. We used positron emission tomography (PET) with [11C]yohimbine to quantify α2 adrenoceptor density. We used EEG power in the delta (δ, 1.5–3.9 Hz), theta (θ, 4–7.9 Hz), alpha (α, 8–12.9 Hz) and beta (β, 13–30 Hz) bands in regression analyses to test the relationships between α2 adrenoceptor density and EEG band power. Results: PD patients had higher power in the theta and delta bands compared to the HC volunteers. Patients’ theta band power was inversely correlated with α2 adrenoceptor density in the frontal cortex. In the HC subjects, age was correlated with, and occipital background rhythm frequency (BRF) was inversely correlated with, α2 adrenoceptor density in the frontal cortex, while occipital BRF was inversely correlated with α2 adrenoceptor density in the thalamus. Conclusions: The findings support the claim that the loss or dysfunction of noradrenergic neurotransmission may relate to the parallel processes of cognitive decline and EEG slowing.
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| 9. |
- Lars Louis, Andersen, et al.
(författare)
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Cardiovascular Health Effects of Internet-Based Encouragements to Do Daily Workplace Stair-Walks: Randomized Controlled Trial
- 2013
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Ingår i: Journal of Medical Internet Research. - : JMIR Publications Inc.. - 1438-8871. ; 15:6, s. 127-127
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Tidskriftsartikel (refereegranskat)abstract
- Background: Although the hazardous health effects of a sedentary lifestyle are well known, many adults struggle with regular physical activity. Simple and efficient encouragements for increased physical activity are needed. Objective: To determine the effect on cardiovascular health of email-based encouragements to do daily stair-walks at work together with colleagues among adults in sedentary occupations. Methods: A single-blind randomized controlled trial was performed at a large administrative company in Copenhagen, Denmark. Participants were 160 office workers (125 women, 35 men; mean age 42 years, SD 10; sitting 89.5% of work time). At baseline, aerobic fitness was 37 mL/min/kg (SD 9), mean blood pressure was 118/79 mmHg (SD 14/9), and mean body mass index (BMI) was 23 kg/m2 (SD 4). Participants were randomly assigned (2:1 ratio) to an email group receiving weekly email-based encouragements to walk the stairs for 10 minutes a day or to a control group receiving weekly reminders to continue their usual physical activities. The primary outcome was the change from baseline to 10-week follow-up in aerobic fitness determined from a maximal cycle test. The examiner was blinded to group allocation. Results: Adherence to the email encouragements was fairly high with 82.7% of the participants performing at least 3 sessions of 10-minute stair-walks per week (mean 3.3, SD 1.3). Mean heart rate reached 167 beats/min (SD 10) during stair-walks. In the intention-to-treat analysis, aerobic fitness increased 1.45 mL/min/kg (95% CI 0.64-2.27) at 10-week follow-up in the email group compared with the control group. In participants with low aerobic fitness at baseline (n=56), aerobic fitness increased 1.89 mL/min/kg (95% CI 0.53-3.24), and systolic and diastolic blood pressure decreased 4.81 mmHg (95% CI 0.47-9.16) and 2.67 mmHg (95% CI 0.01-5.32), respectively , in the email group compared with the control group. Body weight decreased in the email group of those with low aerobic fitness compared with the control group, but this was not statistically significant. Conclusions: Simple and inexpensive email-based encouragements to do daily stair-walks together with colleagues at work improves cardiovascular health among adults in sedentary occupations. There exists an enormous potential to prevent the hazardous health effects of a sedentary lifestyle through the use of email-based encouragements to do short bouts of physical activity at the workplace.
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| 10. |
- Lillethorup, Thea Pinholt, et al.
(författare)
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In vivo quantification of glial activation in minipigs overexpressing human α-synuclein
- 2018
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Ingår i: Synapse. - : Wiley. - 0887-4476. ; 72:12
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Tidskriftsartikel (refereegranskat)abstract
- Parkinson’s disease is characterized by a progressive loss of substantia nigra (SN) dopaminergic neurons and the formation of Lewy bodies containing accumulated alpha-synuclein (α-syn). The pathology of Parkinson’s disease is associated with neuroinflammatory microglial activation, which may contribute to the ongoing neurodegeneration. This study investigates the in vivo microglial and dopaminergic response to overexpression of α-syn. We used positron emission tomography (PET) and the 18 kDa translocator protein radioligand, [11C](R)PK11195, to image brain microglial activation and (+)-α-[11C]dihydrotetrabenazine ([11C]DTBZ), to measure vesicular monoamine transporter 2 (VMAT2) availability in Göttingen minipigs following injection with recombinant adeno-associated virus (rAAV) vectors expressing either mutant A53T α-syn or green fluorescent protein (GFP) into the SN (4 rAAV-α-syn, 4 rAAV-GFP, 5 non-injected control minipigs). We performed motor symptom assessment and immunohistochemical examination of tyrosine hydroxylase (TH) and transgene expression. Expression of GFP and α-syn was observed at the SN injection site and in the striatum. We observed no motor symptoms or changes in striatal [11C]DTBZ binding potential in vivo or striatal or SN TH staining in vitro between the groups. The mean [11C](R)PK11195 total volume of distribution was significantly higher in the basal ganglia and cortical areas of the α-syn group than the control animals. We conclude that mutant α-syn expression in the SN resulted in microglial activation in multiple sub- and cortical regions, while it did not affect TH stains or VMAT2 availability. Our data suggest that microglial activation constitutes an early response to accumulation of α-syn in the absence of dopamine neuron degeneration.
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