| 1. |
- Acciari, V. A., et al.
(författare)
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Radio Imaging of the Very-High-Energy gamma-Ray Emission Region in the Central Engine of a Radio Galaxy
- 2009
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Ingår i: Science. - : American Association for the Advancement of Science (AAAS). - 0036-8075 .- 1095-9203. ; 325:5939, s. 444-448
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Tidskriftsartikel (refereegranskat)abstract
- The accretion of matter onto a massive black hole is believed to feed the relativistic plasma jets found in many active galactic nuclei (AGN). Although some AGN accelerate particles to energies exceeding 10(12) electron volts and are bright sources of very-high-energy (VHE) gamma-ray emission, it is not yet known where the VHE emission originates. Here we report on radio and VHE observations of the radio galaxy Messier 87, revealing a period of extremely strong VHE gamma-ray flares accompanied by a strong increase of the radio flux from its nucleus. These results imply that charged particles are accelerated to very high energies in the immediate vicinity of the black hole.
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| 2. |
- Persson, B David, et al.
(författare)
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An arginine switch in the species B adenovirus knob determines high-affinity engagement of cellular receptor CD46.
- 2009
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Ingår i: Journal of Virology. - 0022-538X .- 1098-5514. ; 83:2, s. 673-686
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Tidskriftsartikel (refereegranskat)abstract
- Adenoviruses (Ads) are icosahedral, nonenveloped viruses with a double-stranded DNA genome. The 51 known Ad serotypes exhibit profound variations in cell tropism and disease types. The number of observed Ad infections is steadily increasing, sometimes leading to fatal outcomes even in healthy individuals. Species B Ads can cause kidney infections, hemorrhagic cystitis, and severe respiratory infections, and most of them use the membrane cofactor protein CD46 as a cellular receptor. The crystal structure of the human Ad type 11 (Ad11) knob complexed with CD46 is known; however, the determinants of CD46 binding in related species B Ads remain unclear. We report here a structural and functional analysis of the Ad11 knob, as well as the Ad7 and Ad14 knobs, which are closely related in sequence to the Ad11 knob but have altered CD46-binding properties. The comparison of the structures of the three knobs, which we determined at very high resolution, provides a platform for understanding these differences and allows us to propose a mechanism for productive high-affinity engagement of CD46. At the center of this mechanism is an Ad knob arginine that needs to switch its orientation in order to engage CD46 with high affinity. Quantum chemical calculations showed that the CD46-binding affinity of Ad11 is significantly higher than that of Ad7. Thus, while Ad7 and Ad14 also bind CD46, the affinity and kinetics of these interactions suggest that these Ads are unlikely to use CD46 productively. The proposed mechanism is likely to determine the receptor usage of all CD46-binding Ads.
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| 3. |
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| 4. |
- Scherbaum, W. A., et al.
(författare)
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Evidence that vildagliptin attenuates deterioration of glycaemic control during 2-year treatment of patients with type 2 diabetes and mild hyperglycaemia
- 2008
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Ingår i: Diabetes, Obesity and Metabolism. - : Wiley. - 1462-8902 .- 1463-1326. ; 10:11, s. 1114-1124
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Tidskriftsartikel (refereegranskat)abstract
- Aim: To assess the 2-year efficacy and tolerability of vildagliptin (50 mg once daily) in patients with type 2 diabetes (T2DM) and mild hyperglycaemia. Methods: This was a multicentre, randomized, double-blind, placebo-controlled trial comprising a 52-week core study with a 4-week, active treatment-free washout followed by a 52-week extension study with another washout period conducted in 131 drug-naive patients with T2DM and mild hyperglycaemia [glycosylated haemoglobin ( HbA(1c)) 6.2-7.2%]. All patients received lifestyle counselling at each study visit. Efficacy and tolerability were assessed during visits at weeks 0 (core study baseline), 4, 8, 12, 16, 24, 32, 40 and 52 of active treatment; at week 56 (i.e. after the first washout period); at weeks 68, 80, 96 and 108 and at week 112 (i.e. after the second washout period). Standard meal tests were also performed at weeks 0, 24, 52, 56, 80, 108 and 112 to assess postprandial glycaemia and beta-cell function, which was quantified by glucose area under the curve (AUC(0-2) (h))/insulin secretory rate (ISR) AUC(0-2) (h) (ISR/G). Changes from baseline and between-treatment differences (placebo-adjusted changes from baseline during vildagliptin treatment) were analysed by ANCOVA. Results: The placebo-adjusted change from week 0 in HbA(1c) was -0.3 +/- 0.1% after 1 year of vildagliptin treatment (p < 0.001) and -0.5 +/- 0.2% after 2 years (p = 0.008). The placebo-adjusted change from core study baseline in fasting plasma glucose, in glucose AUC(0-2) (h) and in the beta-cell function parameter, ISR/G, tended to be greater after 2 years than after 1 year of treatment with vildagliptin. Even after a 4-week washout, the placebo-adjusted change from week 0 to week 112 in ISR/G was 3.2 +/- 1.6 pmol/min/m(2)/mM (p = 0.058) and the placebo-adjusted difference in the change from week 0 to week 112 in HbA(1c) was -0.3 +/- 0.1% (p = 0.051). The incidences of adverse events (AEs), serious AEs and discontinuations because of AEs were similar in the two treatment groups, and hypoglycaemic episodes were reported by no patient receiving vildagliptin and by two patients receiving placebo. Conclusions: In drug-naive patients with mild hyperglycaemia, 2-year treatment with vildagliptin 50 mg once daily attenuated the progressive loss of glycaemic control seen in patients receiving only lifestyle counselling ( and placebo). This appears to be because of a corresponding attenuation of the deterioration of beta-cell function as assessed by ISR/G.
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