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Possnert, Göran
Alternative names
Publications (10 of 247) Show all publications
Huttner, H. B., Bergmann, O., Salehpour, M., El Cheikh, R., Nakamura, M., Tortora, A., . . . Frisen, J. (2018). Meningioma growth dynamics assessed by radiocarbon retrospective birth dating. EBioMedicine, 27, 176-181
Open this publication in new window or tab >>Meningioma growth dynamics assessed by radiocarbon retrospective birth dating
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2018 (English)In: EBioMedicine, ISSN 0360-0637, E-ISSN 2352-3964, Vol. 27, p. 176-181Article in journal (Refereed) Published
Abstract [en]

It is not known how long it takes from the initial neoplastic transformation of a cell to the detection of a tumor, which would be valuable for understanding tumor growth dynamics. Meningiomas show a broad histological, genetic and clinical spectrum, are usually benign and considered slowly growing. There is an intense debate regarding their age and growth pattern and when meningiomas should be resected. We have assessed the age and growth dynamics of 14 patients with meningiomas (WHO grade I: n = 6 with meningothelial and n = 6 with fibrous subtype, as well as n = 2 atypical WHO grade II meningiomas) by combining retrospective birth-dating of cells by analyzing incorporation of nuclear-bomb-test-derived 14C, analysis of cell proliferation, cell density, MRI imaging and mathematical modeling. We provide an integrated model of the growth dynamics of benign meningiomas. The mean age of WHO grade I meningiomas was 22.1 ± 6.5 years, whereas atypical WHO grade II meningiomas originated 1.5 ± 0.1 years prior to surgery (p < 0.01). We conclude that WHO grade I meningiomas are very slowly growing brain tumors, which are resected in average two decades after time of origination.

Keyword
Radiocarbon, C14, Meningioma, Tumor growth
National Category
Cancer and Oncology Biomedical Laboratory Science/Technology
Identifiers
urn:nbn:se:uu:diva-348780 (URN)10.1016/j.ebiom.2017.12.020 (DOI)000425875400023 ()29277322 (PubMedID)
Funder
Swedish Research CouncilSwedish Cancer SocietySwedish Foundation for Strategic Research Knut and Alice Wallenberg FoundationEU, European Research CouncilRagnar Söderbergs stiftelseÅke Wiberg FoundationGerman Research Foundation (DFG), HU1961/1-1; HU1961/2-1
Available from: 2018-04-17 Created: 2018-04-17 Last updated: 2018-04-17Bibliographically approved
Landsverk, O. J. B., Snir, O., Casado, R. B., Richter, L., Mold, J. E., Reu, P., . . . Jahnsen, F. L. (2017). Antibody-secreting plasma cells persist for decades in human intestine. Journal of Experimental Medicine, 214(2), 309-317
Open this publication in new window or tab >>Antibody-secreting plasma cells persist for decades in human intestine
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2017 (English)In: Journal of Experimental Medicine, ISSN 0022-1007, E-ISSN 1540-9538, Vol. 214, no 2, p. 309-317Article in journal (Refereed) Published
Abstract [en]

Plasma cells (PCs) produce antibodies that mediate immunity after infection or vaccination. In contrast to PCs in the bone marrow, PCs in the gut have been considered short lived. In this study, we studied PC dynamics in the human small intestine by cell-turnover analysis in organ transplants and by retrospective cell birth dating measuring carbon-14 in genomic DNA. We identified three distinct PC subsets: a CD19(+) PC subset was dynamically exchanged, whereas of two CD19(-) PC subsets, CD45(+) PCs exhibited little and CD45(-) PCs no replacement and had a median age of 11 and 22 yr, respectively. Accumulation of CD45(-) PCs during ageing and the presence of rotavirus-specific clones entirely within the CD19(-) PC subsets support selection and maintenance of protective PCs for life in human intestine.

Place, publisher, year, edition, pages
NewYork, USA: , 2017
National Category
Biophysics Immunology in the medical area
Research subject
Physics with specialization in Ion Physics
Identifiers
urn:nbn:se:uu:diva-317759 (URN)10.1084/jem.20161590 (DOI)000394251400004 ()28104812 (PubMedID)
Projects
The Human Regenerative Map
Funder
Swedish Research CouncilSwedish Cancer SocietyThe Karolinska Institutet's Research FoundationKnut and Alice Wallenberg FoundationTorsten Söderbergs stiftelse
Available from: 2017-03-17 Created: 2017-03-17 Last updated: 2018-01-13Bibliographically approved
Chen, P., Yu, Z. B., Aldahan, A., Yi, P., Possnert, G. & Mugwaneza, V. d. (2017). Comparison of measurement and modeling results of the global Be-10 flux in topsoil. Journal of Radioanalytical and Nuclear Chemistry, 311(3), 2039-2045
Open this publication in new window or tab >>Comparison of measurement and modeling results of the global Be-10 flux in topsoil
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2017 (English)In: Journal of Radioanalytical and Nuclear Chemistry, ISSN 0236-5731, E-ISSN 1588-2780, Vol. 311, no 3, p. 2039-2045Article in journal (Refereed) Published
Abstract [en]

Soils are among the major terrestrial reservoirs of atmospheric Be-10 isotope and provide information of landscape evolution history. Despite this importance, there is no overview of the global soil Be-10 fluxes in topsoil that is linked with atmospheric flux models. A comparison between measured (in topsoil) and atmospherically modeled Be-10 fluxes is presented here. The data show relatively good agreement in the latitudinal trends. This feature demonstrates the potential to use the modeling data in estimating soil development/erosion rates in large scale basins where extensive Be-10 measurements can be limited.

Place, publisher, year, edition, pages
Springer, 2017
Keyword
Be-10 flux, Atmosphere, Global, Landscape, Topsoil
National Category
Physical Geography
Identifiers
urn:nbn:se:uu:diva-320282 (URN)10.1007/s10967-017-5171-8 (DOI)000398027800055 ()
Available from: 2017-04-25 Created: 2017-04-25 Last updated: 2018-01-13Bibliographically approved
Suteerasak, T., Elming, S.-Å., Possnert, G., Ingri, J. & Widerlund, A. (2017). Deposition rates and C-14 apparent ages of Holocene sediments in the Bothnian Bay of the Gulf of Bothnia using paleomagnetic dating as a reference. Marine Geology, 383, 1-13
Open this publication in new window or tab >>Deposition rates and C-14 apparent ages of Holocene sediments in the Bothnian Bay of the Gulf of Bothnia using paleomagnetic dating as a reference
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2017 (English)In: Marine Geology, ISSN 0025-3227, E-ISSN 1872-6151, Vol. 383, p. 1-13Article in journal (Refereed) Published
Abstract [en]

Three 6-m-long cores of sediments were collected in the northern, middle and southern part of the Bothnian Bay. The sediments were dated by paleomagnetic dating techniques, constrained by magnetic properties and geochemical data. The results indicate the ages of the sediments in the bottom part of the cores in the northern, middle and southern parts of the Bothnian Bay to be approximately 5300 years BP, 5350 years BP and 3500 years BP, respectively. The deposition rate calculated from the estimated ages at various depths show that the deposition rate was generally in the range 0.5-1.5 mm/year but it was higher in the southern part than in the middle and northern parts of the bay. There was a significant increase in the deposition rate at ca 2200 years BP, recorded in all three cores, a rate varying between 2.47 and 3.07 mm/year and lasting until ca 1840 years BP. A proposed constant uplift rate of the crust during the period ca 5500 years BP to present is thus not reflected by a constant deposition rate. The peaks in deposition rates at ca 2200-1840 years BP were followed by a decrease in salinity. This phenomenon is suggested to be caused by crustal uplift, with a threshold being formed in the southern part of the bay, thereby increasing the reactivation of bottom sediments and reducing the inflow of brackish water from the Bothnian Sea. The C-14 ages of the sediments reveal differences in age compared with the paleomagnetic ages. In the southern core, the C-14 ages are ca 1350 years older, and in the north, the age offset is mixed. The reactivation and re-deposition of sediments is argued to be the reason for the apparent C-14 age differences. This finding demonstrates that C-14 cannot be used for the dating of Bothnian Bay sediments unless the radiocarbon age offset has been determined.

Keyword
Bothnian Bay, Holocene sediments, Paleomagnetism, C-14 dating, Deposition rate, Radiocarbon age offset
National Category
Geosciences, Multidisciplinary
Identifiers
urn:nbn:se:uu:diva-316961 (URN)10.1016/j.margeo.2016.10.009 (DOI)000392786800001 ()
Funder
Swedish Research CouncilThe Geological Survey of Sweden (SGU)
Available from: 2017-03-08 Created: 2017-03-08 Last updated: 2017-11-29Bibliographically approved
Spalding, K. L., Bernard, S., Näslund, E., Salehpour, M., Possnert, G., Appelsved, L., . . . Arner, P. (2017). Impact of fat mass and distribution on lipid turnover in human adipose tissue. Nature Communications, 8, Article ID 15253.
Open this publication in new window or tab >>Impact of fat mass and distribution on lipid turnover in human adipose tissue
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2017 (English)In: Nature Communications, ISSN 2041-1723, E-ISSN 2041-1723, Vol. 8, article id 15253Article in journal (Refereed) Published
Abstract [en]

Differences in white adipose tissue (WAT) lipid turnover between the visceral (vWAT) and subcutaneous (sWAT) depots may cause metabolic complications in obesity. Here we compare triglyceride age and, thereby, triglyceride turnover in vWAT and sWAT biopsies from 346 individuals and find that subcutaneous triglyceride age and storage capacity are increased in overweight or obese individuals. Visceral triglyceride age is only increased in excessively obese individuals and associated with a lower lipid removal capacity. Thus, although triglyceride storage capacity in sWAT is higher than in vWAT, the former plateaus at substantially lower levels of excess WAT mass than vWAT. In individuals with central or visceral obesity, lipid turnover is selectively increased in vWAT. Obese individuals classified as 'metabolically unhealthy' (according to ATPIII criteria) who have small subcutaneous adipocytes exhibit reduced triglyceride turnover. We conclude that excess WAT results in depot-specific differences in lipid turnover and increased turnover in vWAT and/or decreased turnover in sWAT may result in metabolic complications of overweight or obesity.

National Category
Medical Biotechnology (with a focus on Cell Biology (including Stem Cell Biology), Molecular Biology, Microbiology, Biochemistry or Biopharmacy)
Identifiers
urn:nbn:se:uu:diva-325697 (URN)10.1038/ncomms15253 (DOI)000401831600001 ()28534500 (PubMedID)
Funder
EU, European Research CouncilSwedish Research CouncilNovo Nordisk, NNF15CC0018486
Available from: 2017-06-27 Created: 2017-06-27 Last updated: 2017-11-29Bibliographically approved
Zhou, Y., Bergsaker, H., Bykov, I., Petersson, P., Possnert, G., Likonen, J., . . . Widdowson, A. M. (2017). Microanalysis of deposited layers in the inner divertor of JET with ITER-like wall. NUCLEAR MATERIALS AND ENERGY, 12(SI), 412-417
Open this publication in new window or tab >>Microanalysis of deposited layers in the inner divertor of JET with ITER-like wall
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2017 (English)In: NUCLEAR MATERIALS AND ENERGY, ISSN 2352-1791, Vol. 12, no SI, p. 412-417Article in journal (Refereed) Published
Abstract [en]

In JET with ITER-like wall, beryllium eroded in the main chamber is transported to the divertor and deposited mainly at the horizontal surfaces of tiles 1 and 0 (high field gap closure, HFGC). These surfaces are tungsten coated carbon fibre composite (CFC). Surface sampleswere collected following the plasma operations in 2011-2012 and 2013-2014 respectively. The surfaces, as well as polished cross sections of the deposited layers at the surfaces have been studied with micro ion beam analysis methods (mu-IBA). Deposition of Beand other impurities, and retention of D is microscopically inhomogeneous. Impurities and trapped deuterium accumulate preferentially in cracks, pits and depressed regions, and at the sides of large pits in the substrate (e.g. arc tracks where the W coating has been removed). With careful overlaying of mu-NRA elemental maps with optical microscopy images, it is possible to separate surface roughness effects from depth profiles at microscopically flat surface regions.

National Category
Subatomic Physics
Identifiers
urn:nbn:se:uu:diva-344535 (URN)10.1016/j.nme.2017.02.015 (DOI)000417293300062 ()
Available from: 2018-03-07 Created: 2018-03-07 Last updated: 2018-03-07Bibliographically approved
Litaudon, X., Abduallev, S., Abhangi, M., Abreu, P., Afzal, M., Aggarwal, K. M., . . . Zychor, I. (2017). Overview of the JET results in support to ITER. Nuclear Fusion, 57(10), Article ID 102001.
Open this publication in new window or tab >>Overview of the JET results in support to ITER
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2017 (English)In: Nuclear Fusion, ISSN 0029-5515, E-ISSN 1741-4326, Vol. 57, no 10, article id 102001Article in journal (Refereed) Published
Abstract [en]

The 2014-2016 JET results are reviewed in the light of their significance for optimising the ITER research plan for the active and non-active operation. More than 60 h of plasma operation with ITER first wall materials successfully took place since its installation in 2011. New multi-machine scaling of the type I-ELM divertor energy flux density to ITER is supported by first principle modelling. ITER relevant disruption experiments and first principle modelling are reported with a set of three disruption mitigation valves mimicking the ITER setup. Insights of the L-H power threshold in Deuterium and Hydrogen are given, stressing the importance of the magnetic configurations and the recent measurements of fine-scale structures in the edge radial electric. Dimensionless scans of the core and pedestal confinement provide new information to elucidate the importance of the first wall material on the fusion performance. H-mode plasmas at ITER triangularity (H = 1 at beta(N) similar to 1.8 and n/n(GW) similar to 0.6) have been sustained at 2 MA during 5 s. The ITER neutronics codes have been validated on high performance experiments. Prospects for the coming D-T campaign and 14 MeV neutron calibration strategy are reviewed.

Place, publisher, year, edition, pages
IOP PUBLISHING LTD, 2017
Keyword
JET, plasma, fusion, ITER
National Category
Fusion, Plasma and Space Physics
Identifiers
urn:nbn:se:uu:diva-340063 (URN)10.1088/1741-4326/aa5e28 (DOI)000416419100001 ()
Available from: 2018-01-25 Created: 2018-01-25 Last updated: 2018-02-21Bibliographically approved
Xing, S., Hou, X., Aldahan, A. & Possnert, G. (2017). Speciation analysis of I-129 in seawater using coprecipitation and accelerator mass spectrometry and its applications. Journal of Radioanalytical and Nuclear Chemistry, 311(1), 833-841
Open this publication in new window or tab >>Speciation analysis of I-129 in seawater using coprecipitation and accelerator mass spectrometry and its applications
2017 (English)In: Journal of Radioanalytical and Nuclear Chemistry, ISSN 0236-5731, E-ISSN 1588-2780, Vol. 311, no 1, p. 833-841Article in journal (Refereed) Published
Abstract [en]

Speciation analysis of long-lived I-129 in seawater can provide useful information on the source of water masses. This paper presents an improved method for speciation analysis of I-129 based on coprecipitation of iodide as AgI with Ag2SO3 and AgCl. By adding a small amount of I-127 carrier, the separation efficiency of iodine species and the accuracy and precision of I-129 measurement are remarkably improved. I-129 species in depth profiles of seawater from the Antarctic were analyzed for investigation of water circulation in the Antarctic.

Keyword
I-129, Speciation analysis, Accelerator mass spectrometry, Seawater
National Category
Analytical Chemistry
Identifiers
urn:nbn:se:uu:diva-315844 (URN)10.1007/s10967-016-5060-6 (DOI)000392075200089 ()
Funder
Swedish Polar Research Secretariat
Available from: 2017-02-21 Created: 2017-02-21 Last updated: 2017-11-29Bibliographically approved
Reu, P., Khosravi, A., Bernard, S., Mold, J. E., Salehpour, M., Alkass, K., . . . Frisen, J. (2017). The Lifespan and Turnover of Microglia in the Human Brain. Cell reports, 20(4), 779-784
Open this publication in new window or tab >>The Lifespan and Turnover of Microglia in the Human Brain
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2017 (English)In: Cell reports, ISSN 2211-1247, E-ISSN 2211-1247, Vol. 20, no 4, p. 779-784Article in journal (Refereed) Published
Abstract [en]

The hematopoietic system seeds the CNS with microglial progenitor cells during the fetal period, but the subsequent cell generation dynamics and maintenance of this population have been poorly understood. We report that microglia, unlike most other hematopoietic lineages, renew slowly at a median rate of 28% per year, and some microglia last for more than two decades. Furthermore, we find no evidence for the existence of a substantial population of quiescent long-lived cells, meaning that the microglia population in the human brain is sustained by continuous slow turnover throughout adult life.

Place, publisher, year, edition, pages
Cambridge, MA 02139, USA: , 2017
Keyword
Cell turnover, regeneration, microglia, human brain
National Category
Biophysics Cell Biology
Research subject
Ion Physics; Biology with specialization in Molecular Cell Biology
Identifiers
urn:nbn:se:uu:diva-328314 (URN)10.1016/j.celrep.2017.07.004 (DOI)000406198900002 ()28746864 (PubMedID)
Projects
The Human Regeneration Map
Available from: 2017-08-21 Created: 2017-08-21 Last updated: 2017-11-29Bibliographically approved
Xing, S., Hou, X., Aldahan, A., Possnert, G., Shi, K., Yi, P. & Zhou, W. (2017). Water Circulation and Marine Environment in the Antarctic Traced by Speciation of I-129 and I-127. Scientific Reports, 7, Article ID 7726.
Open this publication in new window or tab >>Water Circulation and Marine Environment in the Antarctic Traced by Speciation of I-129 and I-127
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2017 (English)In: Scientific Reports, ISSN 2045-2322, E-ISSN 2045-2322, Vol. 7, article id 7726Article in journal (Refereed) Published
Abstract [en]

Emissions of anthropogenic I-129 from human nuclear activities are now detected in the surface water of the Antarctic seas. Surface seawater samples from the Drake Passage, Bellingshausen, Amundsen, and Ross Seas were analyzed for total I-129 and I-127, as well as for iodide and iodate of these two isotopes. The variability of I-127 and I-129 concentrations and their species (I-127(-)/(IO3-)-I-127, I-129(-)/(IO3-)-I-129) suggest limited environmental impact where ((1.15-3.15) x 10(6) atoms/L for I-129 concentration and (0.61-1.98) x 10(-11) for I-129/I-127 atomic ratios are the lowest ones compared to the other oceans. The iodine distribution patterns provide useful information on surface water transport and mixing that are vital for better understanding of the Southern Oceans effects on the global climate change. The results indicate multiple spatial interactions between the Antarctic Circumpolar Current (ACC) and Antarctic Peninsula Coastal Current (APCC). These interactions happen in restricted circulation pathways that may partly relate to glacial melting and icebergs transport. Biological activity during the warm season should be one of the key factors controlling the reduction of iodate in the coastal water in the Antarctic.

Place, publisher, year, edition, pages
Nature Publishing Group, 2017
National Category
Oceanography, Hydrology and Water Resources
Identifiers
urn:nbn:se:uu:diva-334040 (URN)10.1038/s41598-017-07765-w (DOI)000407400100013 ()28798296 (PubMedID)
Available from: 2017-11-22 Created: 2017-11-22 Last updated: 2018-01-13Bibliographically approved
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