| 1. |
- Ling, Charlotte, et al.
(författare)
-
Genetic and epigenetic factors are associated with expression of respiratory chain component NDUFB6 in human skeletal muscle.
- 2007
-
Ingår i: The Journal of clinical investigation. - 0021-9738. ; 117:11, s. 3427-35
-
Tidskriftsartikel (refereegranskat)abstract
- Insulin resistance and type 2 diabetes are associated with decreased expression of genes that regulate oxidative phosphorylation in skeletal muscle. To determine whether this defect might be inherited or acquired, we investigated the association of genetic, epigenetic, and nongenetic factors with expression of NDUFB6, a component of the respiratory chain that is decreased in muscle from diabetic patients. Expression of NDUFB6 was influenced by age, with lower gene expression in muscle of elderly subjects. Heritability of NDUFB6 expression in muscle was estimated to be approximately 60% in twins. A polymorphism in the NDUFB6 promoter region that creates a possible DNA methylation site (rs629566, A/G) was associated with a decline in muscle NDUFB6 expression with age. Although young subjects with the rs629566 G/G genotype exhibited higher muscle NDUFB6 expression, this genotype was associated with reduced expression in elderly subjects. This was subsequently explained by the finding of increased DNA methylation in the promoter of elderly, but not young, subjects carrying the rs629566 G/G genotype. Furthermore, the degree of DNA methylation correlated negatively with muscle NDUFB6 expression, which in turn was associated with insulin sensitivity. Our results demonstrate that genetic, epigenetic, and nongenetic factors associate with NDUFB6 expression in human muscle and suggest that genetic and epigenetic factors may interact to increase age-dependent susceptibility to insulin resistance.
|
|
| 2. |
- Nilsson, K. Peter R., et al.
(författare)
-
Imaging distinct conformational states of amyloid-beta fibrils in Alzheimer's disease using novel luminescent probes
- 2007
-
Ingår i: ACS Chemical Biology. - : American Chemical Society (ACS). - 1554-8929 .- 1554-8937. ; 2:8, s. 553-560
-
Tidskriftsartikel (refereegranskat)abstract
- Using luminescent conjugated polyelectrolyte probes (LCPs), we demonstrate the possibility to distinguish amyloid-β 1–42 peptide (Aβ1–42) fibril conformations, by analyzing in vitro generated amyloid fibrils of Aβ1–42 formed under quiescent and agitated conditions. LCPs were then shown to resolve such conformational heterogeneity of amyloid deposits in vivo. A diversity of amyloid deposits depending upon morphology and anatomic location was illustrated with LCPs in frozen ex vivo brain sections from a transgenic mouse model (tg-APP swe) of Alzheimer’s disease. Comparative LCP fluorescence showed that compact-core plaques of amyloid β precursor protein transgenic mice were composed of rigid dense amyloid. A more abundant form of amyloid plaque displayed morphology of a compact center with a protruding diffuse exterior. Surprisingly, the compact center of these plaques showed disordered conformations of the fibrils, and the exterior was composed of rigid amyloid protruding from the disordered center. This type of plaque appears to grow from more loosely assembled regions toward solidified amyloid tentacles. This work demonstrates how application of LCPs can prove helpful to monitor aggregate structure of in vivo formed amyloid deposits such as architecture, maturity, and origin.
|
|
| 3. |
- Nilsson, Peter, et al.
(författare)
-
Imaging distinct conformational states of amyloid-β fibrils in Alzheimer's disease using novel luminescent probes
- 2007
-
Ingår i: ACS Chemical Biology. - : American Chemical Society (ACS). - 1554-8929 .- 1554-8937. ; 2:8, s. 553-560
-
Tidskriftsartikel (refereegranskat)abstract
- Using luminescent conjugated polyelectrolyte probes (LCPs), we demonstrate the possibility to distinguish amyloid-β 1-42 peptide (Aβ1-42) fibril conformations, by analyzing in vitro generated amyloid fibrils of Aβ1-42 formed under quiescent and agitated conditions. LCPs were then shown to resolve such conformational heterogeneity of amyloid deposits in vivo. A diversity of amyloid deposits depending upon morphology and anatomic location was illustrated with LCPs in frozen ex vivo brain sections from a transgenic mouse model (tg-APPswe) of Alzheimer's disease. Comparative LCP fluorescence showed that compact-core plaques of amyloid β precursor protein transgenic mice were composed of rigid dense amyloid. A more abundant form of amyloid plaque displayed morphology of a compact center with a protruding diffuse exterior. Surprisingly, the compact center of these plaques showed disordered conformations of the fibrils, and the exterior was composed of rigid amyloid protruding from the disordered center. This type of plaque appears to grow from more loosely assembled regions toward solidified amyloid tentacles. This work demonstrates how application of LCPs can prove helpful to monitor aggregate structure of in vivo formed amyloid deposits such as architecture, maturity, and origin.
|
|
| 4. |
- Viberg, Peter, et al.
(författare)
-
Reversed phase continuous full filling CEC-ESI-MS
- 2007
-
Ingår i: Chromatographia. - : Springer Science and Business Media LLC. - 0009-5893 .- 1612-1112. ; 65:5-6, s. 291-297
-
Tidskriftsartikel (refereegranskat)abstract
- Nanoparticles were used as a pseudostationary phase in capillary electrochromatography (CEC) electrospray ionisation-mass spectrometry (ESI-MS) for separation of both neutral analytes by a reversed phase mechanism, as well as for cationic analytes by a cation exchange mechanism. Nanoparticles suspended in electrolyte, were injected as a plug prior to the sample using a partial filling technique (PF), or used as electrolyte in a continuous full filling (CFF) technique. An orthogonal ESI probe was used to hinder the nanoparticles from entering the mass spectrometer and to allow detection of analytes co-eluting with concentrated nanoparticle slurries. Two types of nanoparticles were synthesised and used, both of them having a hydrophobic core and a hydrophilic surface. The hydrophobic core gave the nanoparticles reversed phase properties and the hydrophilic surface promoted the formation of stable slurries of nanoparticles in electrolytes with a low concentration of organic modifier. The surface of one of the nanoparticle types was covered with sulphate groups that, besides from enhancing slurry stability and thus enabling reversed phase CEC, also enabled ion exchange CEC. Both nanoparticle types showed reproducible and interpretable retention properties.
|
|
| 5. |
|
|
| 6. |
- Ebenhag, Sven-Christian, 1976, et al.
(författare)
-
Time transfer using an asynchronous computer network: Results from three weeks of measurements
- 2007
-
Ingår i: European Frequency and Time Forum, 29/5 - 1/6, Geneva, CH.
-
Konferensbidrag (refereegranskat)abstract
- We have performed a time transfer experimentbetween two atomic clocks, over a distance of approximately 75km using an 10 Gbit/s asynchronous fiber-optic computernetwork. The time transfer was accomplished through passivelistening on existing data traffic and a pilot sequence in the SDHbit stream. In order to assess the fiber-link clock comparison, wesimultaneously compared the clocks using a GPS carrier phaselink. The standard deviation of the difference between the twotime transfer links over the three-week time period was 243 ps.
|
|
| 7. |
- Kozakova, Michaela, et al.
(författare)
-
Habitual Physical Activity and Vascular Aging in a Young to Middle-Age Population at Low Cardiovascular Risk.
- 2007
-
Ingår i: Stroke: a journal of cerebral circulation. - 1524-4628. ; 38:9, s. 2549-2555
-
Tidskriftsartikel (refereegranskat)abstract
- Background and Purpose - Regular endurance exercise has been shown to reduce the age-related increase in arterial stiffness that is thought to contribute to cardiovascular risk. The aim of this study was to evaluate the influence of age and habitual physical activity on carotid artery wall thickness and stiffness in a population of young to middle-age subjects at low cardiovascular risk. Methods - The study population consisted of 432 healthy subjects (166 men; mean +/- SD age, 43 +/- 8 years; range, 30 to 60 years) free of carotid atherosclerosis and with low coronary heart disease risk, as determined by the Framingham prediction score sheet. All subjects underwent B-mode ultrasonography of the extracranial carotid arteries and physical activity assessment by actigraph, an accelerometer capable of monitoring the intensity and duration of body movements. The intima-media thickness of the common carotid artery was measured on ultrasound images, along with systodiastolic changes in luminal diameter, and indices of carotid stiffness were calculated. Results - Intima-media thickness and carotid stiffness increased with age in both men and women (r = 0.24 to 0.52, P<0.001). The magnitude of objectively assessed daily physical activity was negatively related to indices of carotid stiffness (r from -0.20 to -0.25, P<0.001) but not to intima-media thickness. In multivariate regression analyses that included several cardiovascular risk factors such as obesity, blood pressure, plasma lipids, and smoking habits, age and physical activity were independently related to carotid stiffness. Conclusions - This study provides cross-sectional evidence that habitual physical activity is inversely related to the age-dependent increase in carotid wall stiffness in a young to middle-age population at low risk.
|
|
| 8. |
- Leosdottir, Margrét, et al.
(författare)
-
Cardiovascular event risk in relation to dietary fat intake in middle-aged individuals: data from The Malmo Diet and Cancer Study
- 2007
-
Ingår i: European Journal of Cardiovascular Prevention & Rehabilitation. - 1741-8275. ; 14:5, s. 701-706
-
Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND AND DESIGN: The hypothesis that diets rich in total and saturated fat and poor in unsaturated fats increase the risk for cardiovascular disease is still vividly debated. The aim of this study was to examine whether total fat, saturated fat, or unsaturated fat intakes are independent risk factors for cardiovascular events in a large population-based cohort. METHODS: 28 098 middle-aged individuals (61% women) participated in the Malmo Diet and Cancer Study between 1991 and 1996. In this analysis, individuals with an earlier history of cardiovascular disease were excluded. With adjustments made for confounding by age and various anthropometric, social, dietary, and life-style factors, hazard ratios (HR) were estimated for individuals categorized by quartiles of fat intake [HR (95% confidence interval, CI), Cox's regression model]. RESULTS: No trend towards higher cardiovascular event risk for women or men with higher total or saturated fat intakes, was observed. Total fat: HR (95% CI) for fourth quartile was 0.98 (0.77-1.25) for women, 1.02 (0.84-1.23) for men; saturated fat: 0.98 (0.71-1.33) for women and 1.05 (0.83-1.34) for men. Inverse associations between unsaturated fat intake and cardiovascular event risk were not observed. CONCLUSIONS: In relation to risks of cardiovascular events, our results do not suggest any benefit from a limited total or saturated fat intake, nor from relatively high intake of unsaturated fat.
|
|
| 9. |
- Lyssenko, Valeriya, et al.
(författare)
-
Mechanisms by which common variants in the TCF7L2 gene increase risk of type 2 diabetes.
- 2007
-
Ingår i: Journal of Clinical Investigation. - 0021-9738. ; 117:8, s. 2155-2163
-
Tidskriftsartikel (refereegranskat)abstract
- Genetic variants in the gene encoding for transcription factor-7-like 2 (TCF7L2) have been associated with type 2 diabetes (T2D) and impaired beta cell function, but the mechanisms have remained unknown. We therefore studied prospectively the ability of common variants in TCF7L2 to predict future T2D and explored the mechanisms by which they would do this. Scandinavian subjects followed for up to 22 years were genotyped for 3 SNPs (rs7903146, rs12255372, and rs10885406) in TCF7L2, and a subset of them underwent extensive metabolic studies. Expression of TCF7L2 was related to genotype and metabolic parameters in human islets. The CT/TT genotypes of SNP rs7903146 strongly predicted future T2D in 2 independent cohorts (Swedish and Finnish). The risk T allele was associated with impaired insulin secretion, incretin effects, and enhanced rate of hepatic glucose production. TCF7L2 expression in human islets was increased 5-fold in T2D, particularly in carriers of the TT genotype. Overexpression of TCF7L2 in human islets reduced glucose-stimulated insulin secretion. In conclusion, the increased risk of T2D conferred by variants in TCF7L2 involves the enteroinsular axis, enhanced expression of the gene in islets, and impaired insulin secretion.
|
|
| 10. |
- Saxena, Richa, et al.
(författare)
-
Genome-wide association analysis identifies loci for type 2 diabetes and triglyceride levels
- 2007
-
Ingår i: Science. - : American Association for the Advancement of Science (AAAS). - 1095-9203 .- 0036-8075. ; 316:5829, s. 1331-1336
-
Tidskriftsartikel (refereegranskat)abstract
- New strategies for prevention and treatment of type 2 diabetes (T2D) require improved insight into disease etiology. We analyzed 386,731 common single-nucleotide polymorphisms (SNPs) in 1464 patients with T2D and 1467 matched controls, each characterized for measures of glucose metabolism, lipids, obesity, and blood pressure. With collaborators (FUSION and WTCCC/UKT2D), we identified and confirmed three loci associated with T2D - in a noncoding region near CDKN2A and CDKN2B, in an intron of IGF2BP2, and an intron of CDKAL1 - and replicated associations near HHEX and in SLC30A8 found by a recent whole-genome association study. We identified and confirmed association of a SNP in an intron of glucokinase regulatory protein (GCKR) with serum triglycerides. The discovery of associated variants in unsuspected genes and outside coding regions illustrates the ability of genome-wide association studies to provide potentially important clues to the pathogenesis of common diseases.
|
|
