| 1. |
- Sundin, Olof, et al.
(författare)
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Förord
- 2012
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Ingår i: En vänbok till Birgitta Olander: tankar och erfarenheter från f d studenter. - 9789163716058 ; BIVILs skriftserie 2012:1, s. 5-9
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Bokkapitel (populärvet., debatt m.m.)
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| 2. |
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| 3. |
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| 4. |
- Alrutz, Marie, et al.
(författare)
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Projektledning
- 2013
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Bok (populärvet., debatt m.m.)abstract
- Projektledning är ett yrke med egen certifiering. Det pågår en spännande utveckling inom området och det blir allt viktigare att hålla sig ajour med utvecklingen.Det övergripande målet med den här handboken är att vara en ständigt aktuell heltäckande bok om projektarbete. Innehållsmässigt täcker den både frågor som har med struktur och styrning att göra och frågor om ledning av människor och mänskliga processer i grupp. Kompetens inom projekt byggs av både kunskap och erfarenhet. Vi följer kontinuerligt aktuell forskning inom dessa områden och bjuder in intressanta forskare att medverka som författare. Vi skildrar verkliga projekt och låter erfarenheterna få plats, både de bästa erfarenheterna och de utmaningar som man tagit sig igenom.Handboken är levande och det innebär att artiklar tas bort för att ge plats för nya, i takt med att den uppdateras fortlöpande.
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| 5. |
- Andersson, Cecilia, et al.
(författare)
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The elusive search engine : How search engine use is reflected in survey reports
- 2024
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Ingår i: Journal of the Association for Information Science and Technology. - 2330-1635. ; 75:5, s. 613-624
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Tidskriftsartikel (refereegranskat)abstract
- The overall aim of this article is to contribute to a research-based understanding of the increasing invisibility of web search engines in society and to discussions about the potential impact of this invisibility. It examines how search engine use and online search activities are represented in national and regional reports on internet habits and experience published by public foundations and policy institutes. The elusiveness of search engines is understood through a theoretical perspective from infrastructure theory. National survey reports on internet habits and experience from the United States, UK, and Sweden from 2015 to 2021 are analyzed. The article shows how difficult it is to gain insights into how people search online and the role search engines play in everyday life. The nature of the survey report, which is often used to inform national policy, risks exacerbating the invisibility of search engines: what cannot be measured cannot be discussed at the policy level. This invisibility can lead to insufficient attention being paid to search engines, including their uses and effects, in legislation, in school education, and in the general formation of public knowledge about search engines in society.
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| 6. |
- Budd, John, et al.
(författare)
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Theoretical Foundations for Information Literacy : a Plan for Action
- 2014
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Ingår i: Proceedings of the American Society for Information Science and Technology : 2014 - 2014. - 2373-9231. ; 51, s. 1-4
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Konferensbidrag (refereegranskat)abstract
- Information literacy is both a common and an important learning activity with higher education. That said, it is under-theorized as a process and as a path to a product. In order to meet the need for theory, the four panelists will offer four distinct possibilities for theoretical frameworks. While the four frameworks are able to stand alone, there is also the likelihood that they might be melded together in order to form an even richer and more robust underpinning for the work of information literacy and instruction. This panel fills a need that has heretofore been found wanting in the topic.
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| 7. |
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| 8. |
- Börjesson, Lisa, 1985-
(författare)
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Resources for scholarly documentation in professional service organizations : A study of Swedish development-led archaeology report writing
- 2017
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- This information studies dissertation deals with the problem that results from research outside academia risk to receive little or no attention if communicated through reports, instead of in mainstream academic genres like research journal articles. The case in focus is Swedish development-led (DL) archaeology, i.e. state regulated archaeology preceding land development. Swedish DL archaeology is organized as a semi-regulated market. The organizations competing on the market are professional service organizations selling research services to land developers. Regional government departments, county administrative boards, function as intermediaries setting up procurement-like processes.In previous research on archaeological documentation, the problem with non-use of reports has been described as depending on cultural issues of access, possible to solve if individuals make efforts to communicate and use extra-academic results. This dissertation offers an alternative definition of the problem, highlighting a different set of solutions. The aim is to further the understanding of how the distribution of research duties to professional service organizations affects the scholarly documentation in Swedish archaeology. The aim is met through identification, operationalization and analysis of resources available to report writing DL archaeology practitioners, and an analysis of how practitioners draw on these resources. The results further the understanding of how reports are shaped within the DL archaeology institution. In view of these results, efforts to solve issues of access should target the organization of research in the archaeology discipline, and specifically how scholarly documentation is governed on the archaeology market.The dissertation draws on science and technology studies, practice theory, and document theory for the design of the study of documentation resources and contexts in extra-academic research. A mixed methods approach is applied to capture regulative, institutional, and infrastructural resources, and practitioners’ use thereof. Dissertation papers I-III contain analyses of concrete instantiations of the resources: information policy, documentation ideals, and information source use. The fourth paper presents an analysis of how practitioners draw on these resources in their everyday report writing. The dissertation concerns archaeology specifically, but serves as grounds to inquire into the premises for scholarly documentation in other areas of extra-academic research and knowledge-making as well.
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| 9. |
- Carlsson, Hanna, 1980-, et al.
(författare)
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À la recherche de la délégation de connaissances à l’école'
- 2018
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Ingår i: Education comparée. - 0339-5456. ; 19, s. 235-259
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Tidskriftsartikel (refereegranskat)abstract
- Dans la société contemporaine, l’accès et la dépendance accrus aux technologies numériques ont permis l'externalisation de la mémoire, ce qui représente un problème particulièrement important dans le contexte éducatif. Cet article cherche à rendre visible la façon dont les relations changent entre la recherche et la mémorisation de l'information à l’école, à partir d’une enquête menée auprès d’enseignants sur la base de la théorie de l’acteur-réseau. Le développement d’une culture de l'information est également essentiel pour comprendre l'évolution de l'acquisition des connaissances dans le contexte éducatif.
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| 10. |
- Carlsson, Hanna
(författare)
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Den nya stadens bibliotek : Om teknik, förnuft och känsla i gestaltningen av kunskaps- och upplevelsestadens folkbibliotek
- 2013
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- This dissertation explores how perceived challenges and changing conditions for public libraries are translated and enacted in a local library setting. In 2008, Malmoe City Library, a public library situated in the third largest city of Sweden, initiated an ambitious strategy for renewal and change of their services. The strategy was given the name The Darling Library and expressed a vision to enforce a “paradigm shift”. In recent years, public library sector debates have been coloured by calls for change. By conceptualising Malmoe City Library’s efforts to realize The darling library as an attempt to handle a perceived crisis and demands for change, this study investigates how current challenges are met by local public library services and handled in everyday library work practises. The aim of the study is thus to explore how conceptions of crisis and change are expressed and translated in the transformation process of Malmoe City Library, 2009-2011, and how the changes made to face the perceived challenges are enacted. Thereby it seeks to contribute to a research-based understanding of how the changed conditions for public libraries are handled in a local service an in the everyday work of library employees. The data collection was guided by an ethnographic approach. Drawing on practice theory and ANT, different articulations of the conceptions of crisis and change was followed through a chain of translations, from research about public libraries, through policy and strategy documents, to moments of doing in everyday work practices. The findings show how the enactment of the “paradigm shift” implied that services and everyday work in many respects took on a different shape. Still, several established elements remained significant, for instance the printed book, but were ascribed new roles and meanings. The study shreds light on how enacting change also implies enacting stability.
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| 11. |
- Carlsson, Hanna, et al.
(författare)
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Educating for democracy? : The role of media and information literacy education for pupils in Swedish compulsory school
- 2020
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Ingår i: Sustainable Digital Communities : 15th International Conference, iConference 2020, Boras, Sweden, March 23–26, 2020, Proceedings - 15th International Conference, iConference 2020, Boras, Sweden, March 23–26, 2020, Proceedings. - Cham : Springer International Publishing. - 1611-3349 .- 0302-9743. - 9783030436865 - 9783030436872 ; 12051, s. 307-326
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Konferensbidrag (refereegranskat)abstract
- This paper reports a study of pupils’ experiences of media and information literacy education in five Swedish schools by answering the following overarching question, what roles do the teaching of information seeking and critical assessment of information play for pupils in their school-work as well as in their everyday life? Pupils in ninth grade were asked to fill in a questionnaire regarding their use of digital technology as well as their thoughts on media and information literacy education. The study shows that many pupils are knowledgeable about the terms of production pertaining to content in most online sources they mention. Still, infrastructural meaning-making that take into consideration issues of personalization, data integrity and surveillance, are largely lacking. The study also shows that the school’s teaching is central to the pupils’ development of a critical stance towards the information that they encounter online. These findings underline the importance of how schools choose to treat media and information literacy education. It is concerning then that infrastructural meaning-making is quite absent in the pupils’ responses.
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| 12. |
- Carlsson, Hanna, et al.
(författare)
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Searching for delegated knowledge in elementary schools
- 2017
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Ingår i: Information Research. - : Högskolan i Borås. - 1368-1613. ; 22:1
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Tidskriftsartikel (refereegranskat)abstract
- Introduction. In contemporary society increased access to and dependence on digital technology has produced richer possibilities for outsourcing memory to external systems, an issue that becomes especially tangible in educational settings. The aim of this paper is to make visible how the changing relations between searching for and memorizing information is formed in the context of elementary schools, from the perspective of teachers.Method. Six focus groups were conducted with Swedish elementary school teachers during the fall of 2014. In total 39 teachers from four different compulsory schools participated in the study.Analysis. The empirical material was analysed from a sociomaterial perspective, particularly informed by Actor-Network-Theory. Technology is here not perceived as a tool to be mastered for different purposes but as an actor actively taking part in the co-construction of educational practices.Results. The study points to three important consequences of the changing relations between searching for and memorizing information in elementary schools: memorizing is to an increasing degree replaced by different activities related to “facts”; although more sophisticated cognitive labour is being outsourced to digital technology, analytical capability is still perceived as something particular to the human mind. As a consequence, analytical capability stood out as the most important criterion considered by the teachers when assessing their pupils’ performances.Conclusion. The analysis shows how external memory systems are not merely tools for pupils and teachers to make use of. These systems are also actors that co-shape requirements on pupils’ capacities and performances in contemporary schooling.
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| 13. |
- Carlsson, Hanna, 1980-, et al.
(författare)
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Sök- och källkritik i grundskolan : En forskningsrapport
- 2018
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- I den här rapporten presenteras resultaten från ett forskningsprojekt där undervisning om och lärande av informationssökning och källkritik i skolan studerats. Undersökningen har haft ungdomar i årskurs 9, samt deras lärare i samhällskunskap och svenska i fokus. Projektets övergripande forskningsfråga lyder: vilka olika roller spelar undervisning i informationssökning och källkritik i svenska och samhällskunskap för elever i årskurs 9 för a) skolundervisningen och för b) vardagen utanför skolan? Projektet, som finansierats av Internetstiftelsen, har som syfte skapa en fördjupad förståelse för olika sätt att undervisa i informationssökning och källkritik som idag praktiseras i grundskolan, samt för hur dessa olika undervisningssätt kan bidra till att förbereda elever för informationssamhällets utmaningar.Ungdomar lever numera stora delar av sina liv på internet, inte sällan med några få sociala medier i form av applikationer på mobiltelefonen som ingångar till omvärlden. I läroplanen Lgr 11 ges mycket utrymme åt informationssökning och källkritik och i den uppdaterade läroplanen för grundskolan respektive gymnasieskolan förtydligas digitala aspekter i kursplanerna. Ansvaret för hur undervisning om medie- och informationskunnighet (MIK) ska genomföras och vad den ska innehålla hamnar hos den enskilda läraren, ibland i samarbete med skolbibliotekarien. Inom ramen för projektet har under 2017 kvalitativa fallstudier av fem skolor genomförts. Sammantaget har 16 intervjuer gjorts med 8 lärare i svenska och/eller samhällskunskap, samt till detta 3 intervjuer med skolbibliotekarier. Därutöver har 239 elever i årskurs 9 besvarat en enkät.Resultaten synliggör tre olika typer av undervisning om informationssökning och källkritik i skolan: 1) informationssökning och källkritik som isolerat kunskapsinnehåll, 2) informationssökning och källkritik som integrerat kunskapsinnehåll, samt 3) informationssökning och källkritik som aspekt på kunskapsinnehåll. Vidare visar rapporten på att källkritikens traditionella kriterier – äkthet, tid, beroende, tendens – dominerar undervisningen i källkritik. Informationssökning är som undervisningsinnehåll ganska osynlig, särskilt när den diskuteras i samband med bedömning. Både när det gäller informationssökning och källkritik saknas till stor del en infrastrukturell förståelse. De viktigaste slutsatserna från studien kan sammanfattas med fem punkter:Undervisning i källkritik har betydelse för elevernas skolgång och för hur de interagerar med information på fritiden. Med källkritik avses i skolan främst de fyra kriterierna äkthet, tid, beroende och tendens.En kontextualiserad källkritik – där även förståelse för nätets infrastruktur, användargenererad data och algoritmers betydelse och funktion ingår – är sällsynt.Informationssökning som undervisningsinnehåll får stå tillbaka för källkritiken och som bedömningsunderlag är förmågan att söka information i det närmaste frånvarande.Det behövs en diskussion om vad som avses med informationssökning och källkritik, inklusive en diskussion kring källkritikens gränser.Den roll som skolbibliotekarier har i relation till undervisning om och bedömning av informationssökning och källkritik behöver förtydligas.
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| 14. |
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| 15. |
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| 16. |
- Dirndorfer Anderson, Theresa, et al.
(författare)
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In form & informing: Materiality and Information Seeking
- 2008
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Ingår i: Proceedings of the American Society for Information Science and Technology. - : Wiley. - 1550-8390 .- 0044-7870. ; 45:1, s. 1-6
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Konferensbidrag (refereegranskat)
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| 17. |
- Eich, Torsten, et al.
(författare)
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Positron emission tomography : A real-time tool to quantify early islet engraftment in a preclinical large animal model
- 2007
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Ingår i: Transplantation. - : Ovid Technologies (Wolters Kluwer Health). - 0041-1337 .- 1534-6080. ; 84:7, s. 893-898
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Tidskriftsartikel (refereegranskat)abstract
- Background. Clinical islet transplantation is currently being explored as a therapeutic option for persons with type I diabetes and hypoglycemic unawareness. Techniques to monitor graft survival are urgently needed to optimize the procedure. Therefore, the objective of the present study was to develop a technique for imaging survival of transplanted islets in the peritransplant and early posttransplant phase.Methods. Isolated porcine islets were labeled in vitro with 2-deoxy-2[18F]fluoro-D-glucose ([18F]FDG) and infused intraportally into anesthetized pigs (n=10). Dynamic examination was performed on a positron emission tomography/computed tomography hybrid system.Results. More than 95% of the radioactivity was confined to the islets at the time of transplantation. The peak percentage of infused radioactivity within the liver, quantified at the end of the islet infusion, was only 54±5.1%. The distribution of the radioactivity in the liver was found to be heterogeneous. A whole-body examination showed no accumulation in the lungs or brain; extrahepatic radioactivity was, except urinary excretion, evenly distributed in the pig body.Conclusions. Our results imply that almost 50% of the islets were damaged to the extent that the FDG contained was release within minutes after intraportal transplantation. The distribution of radioactivity without accumulation in the brain indicates that the activity is released from lysed islet cells in the form of [18F]FDG-6P rather than native [18F]FDG. The presented technique shows promise to become a powerful and quantitative tool, readily available in the clinic, to evaluate initial islet engraftment and survival.
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| 18. |
- Ekström, Olof, et al.
(författare)
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Förutsättningar för prövningar och tillsyn i Natura 2000-områden : Handbok 2017:1
- 2017
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Natura 2000 heter det nätverk av områden som alla EU: s medlemsstater skabidra till att skapa enligt två EU-direktiv, art- och habitatdirektivet1respektivefågeldirektivet.2Direktiven är bindande för medlemsstaterna. Syftet meddirektiven är att bidra till bevarandet av den biologiska mångfalden inom gemenskapen genom att alla länderna behöver ta ett ansvar för att säkra sin del av det gemensamma arv som naturen är. Precis som när det gäller luftföroreningar känner fåglar, skogar och annan biologisk mångfald inga gränser mellan länder. För att säkra detta måste därför alla bidra.I bilagor till ovanstående direktiv listas de arter och naturtyper för vilka områden ska pekas ut. Delar av urvalet kan anses ha lägre relevans för svenska förhållanden, men då ska man betänka att detta är till stor del ett mellaneuropeiskt perspektiv på vad som är skyddsvärt. Det beror på att båda direktiven beslutades före det svenska medlemskapet i EU. En del för Sverige vanliga naturtyper och arter är nästan helt borta i Centraleuropa. Här har Sverige ett ansvar. Detta kan ses som ett steg mot ett globalt perspektiv på vad som är skyddsvärt.Urvalet av områden ska ske på vetenskapliga grunder. Alla områden som innehåller arterna eller naturtyperna i direktiven behöver inte finnas med i nätverket, men tillräckligt mycket för att säkra deras långsiktiga existens. Detta har avgjorts vid speciella utvärderingsmöten.Det räcker dock inte med att peka ut områden. Medlemsländerna måste också arbeta för att naturtyperna och arterna har gynnsam bevarandestatus, dvs. att de finns kvar i en långsiktigt hållbar omfattning genom att vidta bevarandeåtgärder. Hur medlemsstaterna gör detta avgör de själva. Allt från nationalparker till olika slags avtal utgör möjliga bevarandeåtgärder. Viktigt är också att områdena sköts för att nå bevarandemålen. Alla bevarandeåtgärder samt statusen för arterna och naturtyperna ska sedan följas upp. Medlemsländerna ska rapportera resultatet av denna uppföljning till Kommissionen vart sjätte år.Alla av regeringen beslutade Natura 2000 områden har status av riksintresse enligt 4 kap. miljöbalken vilket får betydelse för beslut om användning av mark- och vatten som påverkar Natura 2000-områden på ett betydande sätt.Alla åtgärder som på ett betydande sätt kan påverka miljön i ett Natura 2000-område kräver ett särskilt Natura 2000-tillstånd. Till en sådan ansökan ska det finnas en miljökonsekvensbeskrivning. Tillstånd får endast lämnas om skada eller betydande störning inte uppkommer i en bedömning av åtgärdentillsammans med andra pågående eller planerade åtgärder. Under särskilda förutsättningar kan regeringen lämna sin tillåtelse till att tillstånd lämnas trots en bedömning om att åtgärden medför skada/betydande störning.Även redan pågående verksamheter kan behöva åtgärdas om de kan innebära försämring eller betydande störning i ett Natura 2000-område.Natura 2000 har hittills bidragit till att lyfta upp naturvårdsfrågorna på den politiska agendan och säkert också bidragit till ökade anslag för skydd och skötsel av natur. Det är viktigt att använda det redskap Natura 2000 innebär till att säkra en viktig del av vår biologiska mångfald vilket bidrar till att nå både de svenska och internationella miljömålen.
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| 19. |
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| 20. |
- Eriksson, Olof, et al.
(författare)
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Distribution of adoptively transferred porcine T-lymphoblasts tracked by (18)F-2-fluoro-2-deoxy-D-glucose and position emission tomography
- 2011
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Ingår i: Nuclear Medicine and Biology. - : Elsevier BV. - 0969-8051 .- 1872-9614. ; 38:6, s. 827-833
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Tidskriftsartikel (refereegranskat)abstract
- Introduction: Autologous or allogeneic transfer of tumor-infiltrating T-Iymphocytes is a promising treatment for metastatic cancers, but a major concern is the difficulty in evaluating cell trafficking and distribution in adoptive cell therapy. This study presents a method of tracking transfusion of T-Iymphoblasts in a porcine model by (18)F-2-fluoro-2-deoxy-D-glucose ([(18)F]FDG) and positron emission tomography. Methods: T-Iymphoblasts were labeled with the positron-emitting tracer [(18)F]FDG through incubation. The T-Iymphoblasts were administered into the bloodstream, and the distribution was followed by positron emission tomography for 120 min. The cells were administered either intravenously into the internal jugular vein (n=5) or intraarterially into the ascending aorta (n=1). Two of the pigs given intravenous administration were pretreated with low-molecular-weight dextran sulphate. Results: The cellular kinetics and distribution were readily quantifiable for up to 120 min. High (78.6% of the administered cells) heterogeneous pulmonary uptake was found after completed intravenous transfusion. The pulmonary uptake was decreased either by preineubating and coadministrating the T-Iymphoblasts with low-molecular-weight dextran sulphate or by administrating them intraarterially. Conclusions: The present work shows the feasibility of quantitatively monitoring and evaluating cell trafficking and distribution following administration of [(18)F]FDG-labeled T-Iymphoblasts. The protocol can potentially be transferred to the clinical setting with few modifications.
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| 21. |
- Eriksson, Olof, 1978-
(författare)
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Imaging Islets of Langerhans by Positron Emission Tomography : Quantification of Beta-Cell Mass in the Native Pancreas and the Islet Graft
- 2011
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Type 1 and 2 Diabetes Mellitus are a growing health problem throughout the world. There is an increasing need for methodologies, which are both reliable and non-invasive to measure the amount of insulin-producing tissue (Beta-cell mass, or BCM), as well as rapidly quantify changes in the BCM due to the onset of disease, beta-cell replacement therapy, or other treatments. Positron Emission Tomography (PET) is a non-invasive, quantitative functional imaging technique which can be used to study dynamical or static processes inside the body. In this thesis, we present a study protocol for in vivo imaging of the most common form of beta- cell replacement therapy; islet transplantation. Islets were labeled with the PET tracer, 2-deoxy-2[18F]fluoro-D-glucose ([18F]FDG), and administered intra-portally, while the recipient was monitored by PET/CT. The hepatic distribution of the islets was highly heterogeneous, and around 25% (human) or 50% (porcine) of the administered islets could not be found in the liver after completed transplantation, confirming previous reports of considerable cell injury during the procedure leading to low hepatic engraftment. Native BCM in the pancreas can potentially be quantified using a PET tracer with sufficiently high specificity, but the major obstacle is the relative low amounts of insulin producing tissue (only 1-2% of the pancreatic volume). Two tetrabenazine analogues, [18F]FE-(+)-DTBZ and [18F]FE-(+)-DTBZ-d4, are ligands to VMAT2, which is expressed in islet tissue. Both analogues were investigated and characterized as potential BCM imaging agents both in vitro and in vivo. Both tracers exhibited high preferential binding to islet tissue compared to exocrine pancreatic tissue. However, the specificity was not high enough to overcome the obscuring exocrine signal in vivo (7-10% of the signal originating from specific islet tracer uptake). This thesis demonstrates that it is possible to quantitatively assess islet transplantation by PET imaging. In vivo determination of native pancreatic BCM is, in theory, possible with both [18F]FE-(+)-DTBZ and [18F]FE-(+)-DTBZ-d4, but tracer analogues with higher islet specificity is needed for quantification of smaller BCM changes with physiological impact.
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| 22. |
- Eriksson, Olof, et al.
(författare)
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In vivo and in vitro characterization of [18F]-FE-(+)-DTBZ as a tracer for beta-cell mass
- 2010
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Ingår i: Nuclear Medicine and Biology. - : Elsevier BV. - 0969-8051 .- 1872-9614. ; 37:3, s. 357-363
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Tidskriftsartikel (refereegranskat)abstract
- INTRODUCTION: The positron emission tomography (PET) tracer 9-[(18)F]fluoroethyl-(+)-dihydrotetrabenazine ([(18)F]-FE-(+)-DTBZ) is a potential candidate for quantifying beta-cell mass in vivo. The purpose was to investigate in vitro and in vivo utility of this tracer for the assessment of beta-cell mass. METHODS: Three pigs were intravenously administered [(18)F]-FE-(+)-DTBZ and examined by PET/computed tomography. Binding parameters were estimated by kinetic modeling. In vitro k(D) and B(max) were determined by saturation binding studies of endocrine and exocrine human tissue homogenates. In vitro pancreatic uptake was determined by tissue autoradiography with pancreases from patients with types 1 (T1DM) and 2 diabetes mellitus (T2DM) and healthy controls. RESULTS: [(18)F]-FE-(+)-DTBZ had a k(D) of 3.5+/-1.0 nM, a B(max) of 382+/-108 fmol/mg protein and a specificity of 89+/-1.8% in islet homogenates. The total exocrine uptake was lower and 65% was nondisplaceable. No uptake difference was observed in pancreatic tissue slices from patients with T1DM, T2DM or healthy controls. The in vivo porcine pancreatic uptake reached a peak of standardized uptake value (SUV) of 2.8 with a low distribution volume ratio in all animals. Moderate to high tracer uptake was identified in the bile system and in bone. CONCLUSIONS: [(18)F]-FE-(+)-DTBZ binds to vesicular monoamine transporter 2 (VMAT2) with high specificity in pure islet tissue in vitro. However, there is high nondisplaceable binding to exocrine tissue. In addition, in vivo tracer metabolism and dehalogenation result in severe underestimation of porcine pancreatic VMAT2 expression and BCM. The results do not support [(18)F]-FE-(+)-DTBZ as a suitable tracer for in vivo beta-cell imaging.
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| 23. |
- Eriksson, Olof, et al.
(författare)
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Positron emission tomography in clinical islet transplantation
- 2009
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Ingår i: American Journal of Transplantation. - : Elsevier BV. - 1600-6135 .- 1600-6143. ; 9:12, s. 2816-2824
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Tidskriftsartikel (refereegranskat)abstract
- The fate of islets in clinical transplantation is unclear. To elude on this positron emission tomography combined with computed tomography (PET/CT) was performed for 60 min during islet transplantation in five patients receiving six transplants. A fraction of the islets (23%) were labeled with 18F-fluorodeoxyglucose ([(18)F]FDG) and carefully mixed with unlabeled islets just prior to intraportal transplantation. The peak radioactivity concentration in the liver was found at 19 min after start of islet infusion and corresponded to only 75% of what was expected, indicating that islets are lost during the transplantation procedure. No accumulation of radioactivity was found in the lungs. A nonphysiological peak of C-peptide was found in plasma during and immediately after transplantation in all subjects. Distribution in the liver was heterogeneous with wide variations in location and concentration. Islets found in areas with concentrations of >400 IEQ/cc liver tissue varied between 1% and 32% of the graft in different subjects. No side effects attributed to the PET/CT procedure were found. Clinical outcome in all patients was comparable to that previously observed indicating that the [(18)F]FDG labeling procedure did not harm the islets. The technique has potential to be used to assess approaches to enhance islet survival and engraftment in clinical transplantation.
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| 24. |
- Eriksson, Olof, et al.
(författare)
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Preclinical evaluation of a 68Ga-labeled biotin analogue for applications in islet transplantation
- 2012
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Ingår i: Nuclear Medicine and Biology. - : Elsevier BV. - 0969-8051 .- 1872-9614. ; 39:3, s. 415-421
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Tidskriftsartikel (refereegranskat)abstract
- INTRODUCTION:Islet transplantation is a promising treatment for type 1 diabetes mellitus, but the fate of the cells after intraportal infusion is unclear. It is therefore imperative to develop novel techniques for noninvasive imaging and quantification of events following islet transplantation.METHODS:Small islet-like microbeads, avidin-covered agarose resins (AARs), were used as a model system for islet transplantation. Capability for specific [(68)Ga]Ga-DOTA-(PEG)(2)-biotin uptake and retention for either AARs or human islets conjugated with avidin by means of a heparin scaffold was studied in vitro. Biodistribution of the novel positron emission tomography (PET) tracer [(68)Ga]Ga-DOTA-(PEG)(2)-biotin was evaluated in mice treated by intraportal transplantation of AARs by μPET/computed tomography and ex vivo organ distribution and compared with control mice.RESULTS:AARs had high capability to bind [(68)Ga]Ga-DOTA-(PEG)(2)-biotin, close to 50% of administrated tracer/μl in vitro (>0.25 MBq/μl). Avidin-tagged human islets could bind on average 2.2% of administered tracer/μl. Specificity (>90%) and retention (>90% after 1 h) were high for both AARs and avidin-tagged islets. Hepatic tracer uptake and retention were increased in mice transplanted with AARs [standardized uptake value (SUV)=2.6] compared to the untreated group (SUV=1.4). In vivo uptake of tracer to AARs was blocked by preadministration of unlabeled biotin.CONCLUSIONS:Avidin-tagged islet-like objects can be tracked in hepatic volume after intraportal transplantation by using [(68)Ga]Ga-DOTA-(PEG)(2)-biotin and PET.
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| 25. |
- Eriksson, Olof, et al.
(författare)
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Quantitative Imaging of Serotonergic Biosynthesis and Degradation in the Endocrine Pancreas
- 2014
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Ingår i: Journal of Nuclear Medicine. - : Society of Nuclear Medicine. - 0161-5505 .- 1535-5667 .- 2159-662X. ; 55:3, s. 460-465
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Tidskriftsartikel (refereegranskat)abstract
- Serotonergic biosynthesis in the endocrine pancreas, of which the islets of Langerhans is the major constituent, has been implicated in insulin release and β cell proliferation. In this study, we investigated the feasibility of quantitative noninvasive imaging of the serotonergic metabolism in the pancreas using the PET tracer (11)C-5-hydroxy-l-tryptophan ((11)C-5-HTP).METHODS: Uptake of (11)C-5-HTP, and its specificity for key enzymes in the serotonergic metabolic pathway, was assessed in vitro (INS-1 and PANC1 cells and human islet and exocrine preparations) and in vivo (nonhuman primates and healthy and diabetic rats).RESULTS: In vitro tracer uptake in endocrine cells (INS-1 and human islets), but not PANC1 and exocrine cells, was mediated specifically by intracellular conversion into serotonin. Pancreatic uptake of (11)C-5-HTP in nonhuman primates was markedly decreased by inhibition of the enzyme dopa decarboxylase, which converts (11)C-5-HTP to (11)C-serotonin and increased after inhibition of monoamine oxidase-A, the main enzyme responsible for serotonin degradation. Uptake in the rat pancreas was similarly modulated by inhibition of monoamine oxidase-A and was reduced in animals with induced diabetes.CONCLUSION: The PET tracer (11)C-5-HTP can be used for quantitative imaging of the serotonergic system in the endocrine pancreas.
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