| 1. |
- Keller, Annika, et al.
(författare)
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Mutations in the gene encoding PDGF-B cause brain calcifications in humans and mice
- 2013
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Ingår i: Nature Genetics. - : Springer Science and Business Media LLC. - 1061-4036 .- 1546-1718. ; 45:9, s. 1077-
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Tidskriftsartikel (refereegranskat)abstract
- Calcifications in the basal ganglia are a common incidental finding and are sometimes inherited as an autosomal dominant trait ( idiopathic basal ganglia calcification (IBGC)). Recently, mutations in the PDGFRB gene coding for the platelet-derived growth factor receptor beta (PDGF-R beta) were linked to IBGC. Here we identify six families of different ancestry with nonsense and missense mutations in the gene encoding PDGF-B, the main ligand for PDGF-R beta. We also show that mice carrying hypomorphic Pdgfb alleles develop brain calcifications that show age-related expansion. The occurrence of these calcium depositions depends on the loss of endothelial PDGF-B and correlates with the degree of pericyte and blood-brain barrier deficiency. Thus, our data present a clear link between Pdgfb mutations and brain calcifications in mice, as well as between PDGFB mutations and IBGC in humans.
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| 2. |
- Bhuiyan, Iftekhar Uddin, et al.
(författare)
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Microstructure of Bentonite in Iron Ore Green Pellets
- 2014
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Ingår i: Microscopy and Microanalysis. - 1431-9276 .- 1435-8115. ; 20:1, s. 33-41
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Tidskriftsartikel (refereegranskat)abstract
- Sodium-activated calcium bentonite is used as a binder in iron ore pellets and is known to increase strength of both wet and dry iron ore green pellets. In this article, the microstructure of bentonite in magnetite pellets is revealed for the first time using scanning electron microscopy. The microstructure of bentonite in wet and dry iron ore pellets, as well as in distilled water, was imaged by various imaging techniques (e.g., imaging at low voltage with monochromatic and decelerated beam or low loss backscattered electrons) and cryogenic methods (i.e., high pressure freezing and plunge freezing in liquid ethane). In wet iron ore green pellets, clay tactoids (stacks of parallel primary clay platelets) were very well dispersed and formed a voluminous network occupying the space available between mineral particles. When the pellet was dried, bentonite was drawn to the contact points between the particles and formed solid bridges, which impart strength to the solid compact.
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| 3. |
- Striednig, Bianca, et al.
(författare)
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Quorum sensing governs a transmissive Legionella subpopulation at the pathogen vacuole periphery
- 2021
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Ingår i: EMBO Reports. - : Wiley-Blackwell. - 1469-221X .- 1469-3178. ; 22:9
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Tidskriftsartikel (refereegranskat)abstract
- The Gram-negative bacterium Legionella pneumophila is the causative agent of Legionnaires disease and replicates in amoebae and macrophages within a distinct compartment, the Legionella-containing vacuole (LCV). The facultative intracellular pathogen switches between a replicative, non-virulent and a non-replicating, virulent/transmissive phase. Here, we show on a single-cell level that at late stages of infection, individual motile (P-flaA-GFP-positive) and virulent (P-ralF- and P-sidC-GFP-positive) L. pneumophila emerge in the cluster of non-growing bacteria within an LCV. Comparative proteomics of P-flaA-GFP-positive and P-flaA-GFP-negative L. pneumophila subpopulations reveals distinct proteomes with flagellar proteins or cell division proteins being preferentially produced by the former or the latter, respectively. Toward the end of an infection cycle (similar to 48 h), the P-flaA-GFP-positive L. pneumophila subpopulation emerges at the cluster periphery, predominantly escapes the LCV, and spreads from the bursting host cell. These processes are mediated by the Legionella quorum sensing (Lqs) system. Thus, quorum sensing regulates the emergence of a subpopulation of transmissive L. pneumophila at the LCV periphery, and phenotypic heterogeneity underlies the intravacuolar bi-phasic life cycle of L. pneumophila.
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