| 1. |
- Lau, Joey, et al.
(författare)
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Beneficial role of pancreatic microenvironment for angiogenesis in transplanted pancreatic islets
- 2009
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Ingår i: Cell Transplantation. - : SAGE Publications. - 0963-6897 .- 1555-3892. ; 18:1, s. 23-30
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Tidskriftsartikel (refereegranskat)abstract
- Pancreatic islets implanted heterotopically (i.e., into the kidney, spleen, or liver) become poorly revascularized following transplantation. We hypothesized that islets implanted into the pancreas Would become better revascularized. Islets isolated from transgenic mice expressing enhanced yellow fluorescent protein (EYFP) in all somatic cells were Cultured before they were implanted into the pancreas or beneath the renal capsule of athymic mice. Vascular density was evaluated in histological sections 1 month posttransplantation. EYFP was used as reporter for the transgene to identify the transplanted islets. Islet endothelial cells were visualized by staining with the lectin Bandeiraea simplicifolia (BS-1). Capillary numbers in intrapancreatically implanted islets were only slightly lower than those counted in endogenous islets, whereas islets implanted beneath the renal capsule had a markedly lower vascular density. In order to determine if this high graft vascular density at the intrapancreatic site reflected expansion of remnant donor endothelial cells or increased ingrowth of blood vessels from the host. also islets from Tie2-green fluorescent protein (GFP) mice (i.e., islets with fluorescent endothelial cells) were transplanted into the pancreas or beneath the renal capsule of athymic mice. These islet grafts revealed that the new vascular structures formed in the islet grafts contained very few GFP-positive cells, and thus mainly were of recipient origin. The reason(s) for the much better ingrowth of blood vessels at the intrapancreatic site merits further studies, because this may help us form strategies to overcome the barrier for ingrowth of host vessels also into islets in heterotopic implantation sites.
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| 2. |
- Lau, Joey, et al.
(författare)
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Implantation site-dependent dysfunction of transplanted pancreatic islets
- 2007
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Ingår i: Diabetes. - : American Diabetes Association. - 0012-1797 .- 1939-327X. ; 56:6, s. 1544-1550
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVE—Clinical islet transplantations are performed through infusion of islets via the portal vein into the liver. This study aimed at characterizing the influence of the implantation microenvironment on islet graft metabolism and function. RESEARCH DESIGN AND METHODS—Islets were transplanted into their normal environment, i.e., the pancreas, or intraportally into the liver of mice. One month posttransplantation, the transplanted islets were retrieved and investigated for changes in function and gene expression. RESULTS—Insulin content, glucose-stimulated insulin release, (pro)insulin biosynthesis, and glucose oxidation rate were markedly decreased in islets retrieved from the liver, both when compared with islets transplanted into the pancreas and endogenous islets. Islets transplanted into the pancreas showed normal insulin content, (pro)insulin biosynthesis, and glucose oxidation rate but increased basal insulin secretion and impaired glucose stimulation index. Gene expression data for retrieved islets showed downregulation of pancreatic and duodenal homeobox gene-1, GLUT-2, glucokinase, mitochondrial glycerol-phosphate dehydrogenase, and pyruvate carboxylase, preferentially in intraportally transplanted islets. CONCLUSIONS—Islets transplanted into their normal microenvironment, i.e., the pancreas, display gene expression changes when compared with endogenous islets but only moderate changes in metabolic functions. In contrast, site-specific properties of the liver markedly impaired the metabolic functions of intraportally transplanted islets.
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| 3. |
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| 4. |
- Nyqvist, Johanna, et al.
(författare)
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Differences in health related quality of life in the randomised ARTSCAN study; accelerated vs. conventional radiotherapy for head and neck cancer. A five year follow up
- 2016
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Ingår i: Radiotherapy and Oncology. - : Elsevier BV. - 0167-8140 .- 1879-0887. ; 118:2, s. 335-341
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Tidskriftsartikel (refereegranskat)abstract
- Background and purpose: Health related quality of life (HRQoL) was assessed in the randomised, prospective ARTSCAN study comparing conventional radiotherapy (CF) with accelerated radiotherapy (AF) for head and neck cancer. Material and methods: 750 patients with squamous cell carcinoma (of any grade and stage) in the oral cavity, oro-, or hypopharynx or larynx (except T1-2, NO glottic carcinoma) without distant metastases were randomised to either conventional fractionation (2 Gy/day, 5 days/week in 49 days, total dose 68 Gy) or accelerated fractionation (1.1 + 2.0 Gy/day, 5 days/week in 35 days, total dose 68 Gy). HRQoL was assessed with EORTC QLQ-C30, QLQ-H&N35 and HADS at baseline, at end of radiotherapy (eRT) and at 3 and 6 months and 1, 2 and 5 years after start of treatment. Results: The AF group reported HRQoL was significantly lower at eRT and at 3 months for most symptoms, scales and functions. Few significant differences were noted between the groups at 6 months and 5 years. Scores related to functional oral intake never reached baseline. Conclusion: In comparison to CF, AF has a stronger adverse effect on HRQoL in the acute phase.
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| 5. |
- von Seth, Erik, et al.
(författare)
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Distribution of intraportally implanted microspheres and fluorescent islets in mice
- 2007
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Ingår i: Cell Transplantation. - : SAGE Publications. - 0963-6897 .- 1555-3892. ; 16:6, s. 621-627
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Tidskriftsartikel (refereegranskat)abstract
- The aim of the study was to evaluate the distribution of intraportally transplanted islets in mice. We initially administered 2000 polystyrene microspheres with a diameter of 50 microm intraportally into normoglycemic C57BL/6 mice. In separate experiments other mice were injected similarly with 300 microspheres each with a diameter of 100 or 200 microm. One week later the animals were killed, and the lungs and livers were removed and divided into lobes. The number of microspheres in each individual liver lobe and in the lungs was counted using a stereomicroscope. In other experiments, athymic C57BL/6 mice were similarly implanted with 250 islets isolated from transgenic mice expressing the enhanced yellow fluorescent protein in the islet cells. The distribution of microspheres and islets was independent of size, and fairly homogenous within the liver, with the exception of the caudate lobe, which contained fewer microspheres and islets, respectively. Approximately one third of all microspheres and islets were present as aggregates. Eighty-five to 90% of the implanted microspheres were identified in the liver sections, whereas 60-65% of the implanted islets were recovered. Aggregates or single fluorescent cells were observed in the liver of islet-implanted mice. We conclude that islets and microspheres implanted into the liver distribute fairly homogenously and quite a few of them exist as aggregates or, with respect to islets, as fragments.
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| 6. |
- Andersson, Alf, et al.
(författare)
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Inline Process Control – a concept study of efficient in-line process control and process adjustment with respect to product geometry
- 2016
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Ingår i: Swedish Production Symposium 2016 SPS 2016. - Lund, Sweden.
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Konferensbidrag (refereegranskat)abstract
- All manufacturing processes have variation which may violate the fulfillment of assembly, functional, geometrical or esthetical requirements and difficulties to reach desired form in all areas. The cost for geometry defects rises downstream in the process chain. Therefore, it is vital to discover these defects as soon as they appear. Then adjustments can be done in the process without losing products or time. In order to find a solution for this, a project with the overall scope “development of an intelligent process control system” has been initiated. This project consists of five different work packages: Inline measurement, Process Evaluation, Corrective actions, Flexible tooling and demonstrator cell. These work packages address different areas which are necessary to fulfill the overall scope of the project. The system shall both be able to detect geometrical defects, propose adjustments and adjust simple process parameters. The results are demonstrated in a demo cell located at Chalmers University of Technology. In the demonstrator all the different areas have been verified in an industrial case study – assembly of GOR Volvo S80. Efficient offline programming for robot based measurement, efficient process evaluation based on case base reasoning (CBR) methodology, flexible fixtures and process adjustments based on corrective actions regarding in going part positioning.
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| 7. |
- Andrée, Maria, 1974-, et al.
(författare)
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Play with Science in Inquiry Based Science Education
- 2011
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Konferensbidrag (refereegranskat)abstract
- In science education students sometimes engage in imaginary science-oriented play where ideas about science and scientists are put to use. Through play, children interpret their experiences, dramatize, give life to and transform what they know into a lived narrative. In this paper we build on the work of Vygotsky on imagination and creativity. Previous research on play in primary and secondary school has focused on play as a method for formal instruction rather than students’ spontaneous informal play. Our aim is to explore students’ informal play as part of activity in lower secondary school science. The empirical study was conducted as part of a larger study on learning, narrative knowing and remembering in inquiry based science education in two Swedish compulsory schools. Data were collected during 10 weeks using video- and audiotape recordings. The results show that the studied classroom practices offer students a variety of resources that may be used to engage in spontaneous play with science. We discern two categories of play: role-playing and game-playing involving transformations of classroom tasks and opening up for different social positioning in relation to science. Implications for teaching science is that teachers, in order to promote students learning about science as a cultural endeavor and about themselves in relation to science and scientist communities may encourage students’ informal play.
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| 8. |
- Andrée, Maria, 1974-, et al.
(författare)
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Play with Science in Inquiry Based Science Education
- 2012
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Ingår i: Science learning and Citizenship. E-bok: http://lsg.ucy.ac.cy/esera/e_book/base/table-of-content.html..
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Konferensbidrag (refereegranskat)abstract
- In science education students sometimes engage in imaginary science-oriented play where ideas about science and scientists are put to use. Through play, children interpret their experiences, dramatize, give life to and transform what they know into a lived narrative. In this paper we build on the work of Vygotsky on imagination and creativity. Previous research on play in primary and secondary school has focused on play as a method for formal instruction rather than students’ spontaneous informal play. Our aim is to explore students’ informal play as part of activity in lower secondary school science. The empirical study was conducted as part of a larger study on learning, narrative knowing and remembering in inquiry based science education in two Swedish compulsory schools. Data were collected during 10 weeks using video- and audiotape recordings. Our analyses of play show that the students step in and out of play when engaging in task completion. Play offers opportunities for sense-making, opposition and exploration of ways of enacting science identities. Implications for teaching science are that teachers, in order to promote students’ learning about science as a cultural endeavor and students’ learning about themselves in relation to science and scientist communities, may encourage students’ informal play.
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| 9. |
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| 10. |
- Andrée, Maria, 1974-, et al.
(författare)
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Students' Ways of Using Prior Experience in Inquiry Based Science Education – the case of NTA
- 2010
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Konferensbidrag (refereegranskat)abstract
- Inquiry has been identified as a 'key-approach' and recommended as an important pedagogy to improve primary science education in Europe. Inquiry is also a key component in the US national science education standards. In Sweden, inquiry pedagogy in primary science has been introduced through a large curriculum program called NTA (Science and Technology for all). The aim of this paper is to shed light on what inquiry based science education (IBSE) practices are emerging in Swedish primary schools through the introduction of the NTA-program and what activities students are engaging in, in these practices. In particular we focus on ways of working with 'what is already known' which is held to be a central aspect to IBSE in e.g. the definition of inquiry in the US national science education standards. The research questions investigated are: In what actions do students engage in when working with ‘what is already known’ in IBSE practice? How is 'what is already known' acted with in practice? Data was collected, during a 10-week-period using video- and audiotape recordings of classroom work, in two 6th grade classes where teachers and students worked with an NTA-unit called 'the Chemistry of food'. Our analysis is conceptualized within a cultural-historical activity-theoretical perspective. Results show that students participate in three different actions: A) separation of tasks, B) playing the lottery and C) challenging test results with ‘what is already known’. These different actions involve different types of use of 'what is already known' , and the actions correspond to, and acquire meaning in relation to, different goals. Common to the different ways of working is that we can discern two different types of ‘what is already known’: (1) referring to facts, and (2) making use of ideas about science culture.
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