| 1. |
- Molin, Mikael, 1973, et al.
(författare)
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Protein kinase A controls yeast growth in visible light
- 2020
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Ingår i: BMC Biology. - : Springer Science and Business Media LLC. - 1741-7007. ; 18:1
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Tidskriftsartikel (refereegranskat)abstract
- Background: A wide variety of photosynthetic and non-photosynthetic species sense and respond to light, having developed protective mechanisms to adapt to damaging effects on DNA and proteins. While the biology of UV light-induced damage has been well studied, cellular responses to stress from visible light (400–700 nm) remain poorly understood despite being a regular part of the life cycle of many organisms. Here, we developed a high-throughput method for measuring growth under visible light stress and used it to screen for light sensitivity in the yeast gene deletion collection. Results: We found genes involved in HOG pathway signaling, RNA polymerase II transcription, translation, diphthamide modifications of the translational elongation factor eEF2, and the oxidative stress response to be required for light resistance. Reduced nuclear localization of the transcription factor Msn2 and lower glycogen accumulation indicated higher protein kinase A (cAMP-dependent protein kinase, PKA) activity in many light-sensitive gene deletion strains. We therefore used an ectopic fluorescent PKA reporter and mutants with constitutively altered PKA activity to show that repression of PKA is essential for resistance to visible light. Conclusion: We conclude that yeast photobiology is multifaceted and that protein kinase A plays a key role in the ability of cells to grow upon visible light exposure. We propose that visible light impacts on the biology and evolution of many non-photosynthetic organisms and have practical implications for how organisms are studied in the laboratory, with or without illumination.
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| 2. |
- Svensson, Mattias, 1982, et al.
(författare)
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Fms-like tyrosine kinase 3 ligand controls formation of regulatory T cells in autoimmune arthritis.
- 2013
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Ingår i: PloS one. - : Public Library of Science (PLoS). - 1932-6203. ; 8:1
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Tidskriftsartikel (refereegranskat)abstract
- Fms-like tyrosine kinase 3 ligand (Flt3L) is known as the primary differentiation and survival factor for dendritic cells (DCs). Furthermore, Flt3L is involved in the homeostatic feedback loop between DCs and regulatory T cell (Treg). We have previously shown that Flt3L accumulates in the synovial fluid in rheumatoid arthritis (RA) and that local exposure to Flt3L aggravates arthritis in mice, suggesting a possible involvement in RA pathogenesis. In the present study we investigated the role of Flt3L on DC populations, Tregs as well as inflammatory responses in experimental antigen-induced arthritis. Arthritis was induced in mBSA-immunized mice by local knee injection of mBSA and Flt3L was provided by daily intraperitoneal injections. Flow cytometry analysis of spleen and lymph nodes revealed an increased formation of DCs and subsequently Tregs in mice treated with Flt3L. Flt3L-treatment was also associated with a reduced production of mBSA specific antibodies and reduced levels of the pro-inflammatory cytokines IL-6 and TNF-α. Morphological evaluation of mBSA injected joints revealed reduced joint destruction in Flt3L treated mice. The role of DCs in mBSA arthritis was further challenged in an adoptive transfer experiment. Transfer of DCs in combination with T-cells from mBSA immunized mice, predisposed naïve recipients for arthritis and production of mBSA specific antibodies. We provide experimental evidence that Flt3L has potent immunoregulatory properties. Flt3L facilitates formation of Treg cells and by this mechanism reduces severity of antigen-induced arthritis in mice. We suggest that high systemic levels of Flt3L have potential to modulate autoreactivity and autoimmunity.
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| 3. |
- Arner, Peter, et al.
(författare)
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Variations in the size of the major omentum are primarily determined by fat cell number
- 2013
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Ingår i: Journal of Clinical Endocrinology and Metabolism. - : The Endocrine Society. - 0021-972X .- 1945-7197. ; 98:5, s. E897-E901
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVE: Accumulation of visceral adipose tissue (VAT) is strongly linked to insulin resistance. Variations in the size of any adipose depot are determined by alterations in adipocyte volume and/or number. The individual contribution of each of the latter factors was determined in the major omentum, a fully resectable VAT depot.SUBJECTS: Total removal of the major omentum (omentectomy) was performed in conjunction with bariatric surgery in 55 obese patients. Tissue weight as well as mean adipocyte size and number in the omentum were determined. In subgroups, total VAT was estimated by computerized tomography (n = 17) or dual-energy x-ray absorptiometry (n = 34).RESULTS: The weight of the major omentum (on average 0.6 kg) correlated significantly with total VAT mass estimated by computerized tomography or dual-energy x-ray absorptiometry (r = 0.48-0.7; P < .01). Omental weight in relation to total body fat correlated with several features of the metabolic syndrome and inversely with serum-leptin (P < .001). Mean adipocyte size and total adipocyte number correlated strongly with omental weight (r = 0.6-0.8; P < .0001), irrespective of body mass index and total body fat mass, and accounted almost in total for interindividual variations in omental size. However, stepwise regression analysis demonstrated that adipocyte number was significantly (P < .0001) more important (62%) than adipocyte size (35%).CONCLUSION: The size of the major omentum is representative for VAT mass and correlates with a pernicious metabolic profile. Variations in omental weight are primarily determined by adipocyte number and to a lesser degree by adipocyte size, suggesting that increased VAT mass in obesity is predominantly dependent on adipocyte proliferation.
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| 4. |
- Backlund, Per, 1964-, et al.
(författare)
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Enhancing Immersion with Contextualized Scenarios: Role-Playing in Prehospital Care Training
- 2015
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Ingår i: 2015 7th International Conference on Games and Virtual Worlds for Serious Applications (VS-Games). - Skövde : IEEE Computer Society. ; , s. 167-170
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Konferensbidrag (refereegranskat)abstract
- This paper reports on a field experiment with 12 paramedic teams (n=24) exploring how they perceive a novel training approach. The feeling of being engaged in training (i.e. being immersed) is often held forward as a major benefit of roleplaying exercises. Engagement is expected to raise the quality of training as well as improving learning and retention. However, much simulation-based training in prehospital care is decontextualized, meaning that medical care is trained without taking other characteristics of prehospital care into account. In this paper we investigate how a richer setting (contextualization), which includes more of the complicating aspects of prehospital care, affects the perceived immersion of the participants. The results show that contextualization has a significant positive impact on perceived immersion. These results are important for further studies on how to organize and design role-playing exercises.
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| 5. |
- Backlund, Per, 1964-, et al.
(författare)
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The S.A.R.E.K Simulation Environment : Technical description of a flexible training environment for prehospital care
- 2017
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- This report contains a technical description of the result of the S.A.R.E.K (Simulation – Ambulance – Research – Education - Kinship) collaboration project and the Sim2020 project. The projects are collaborations between researchers in healthcare and IT, and prehospital care practitioners, with the aim to design, develop and test a contextualized simulation environment for prehospital care. We built a simulation environment representing the full depth and width of a prehospital care process. Breadth refers to including all phases of a prehospital mission, from dispatch to handover; while depth refers to detailed representations and recreation of artefacts, information and context for each of these phases. This report outlines the details of the overall design, all equipment and practical solutions used to create this. Apart from the installation which is described in this report we have also developed methods and carried out a variety of tests and experiments which are reported elsewhere. The focus of this report is the system and its components.
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| 6. |
- Engström, Henrik, 1968-, et al.
(författare)
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The impact of contextualization on immersion in healthcare simulation
- 2016
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Ingår i: Advances in Simulation. - : BioMed Central. - 2059-0628. ; 1
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Tidskriftsartikel (refereegranskat)abstract
- BackgroundThe aim of this paper is to explore how contextualization of a healthcare simulation scenarios impacts immersion, by using a novel objective instrument, the Immersion Score Rating Instrument. This instrument consists of 10 triggers that indicate reduced or enhanced immersion among participants in a simulation scenario. Triggers refer to events such as jumps in time or space (sign of reduced immersion) and natural interaction with the manikin (sign of enhanced immersion) and can be used to calculate an immersion score.MethodsAn experiment using a randomized controlled crossover design was conducted to compare immersion between two simulation training conditions for prehospital care: one basic and one contextualized. The Immersion Score Rating Instrument was used to compare the total immersion score for the whole scenario, the immersion score for individual mission phases, and to analyze differences in trigger occurrences. A paired t test was used to test for significance.ResultsThe comparison shows that the overall immersion score for the simulation was higher in the contextualized condition. The average immersion score was 2.17 (sd = 1.67) in the contextualized condition and −0.77 (sd = 2.01) in the basic condition (p < .001). The immersion score was significantly higher in the contextualized condition in five out of six mission phases. Events that might be disruptive for the simulation participants’ immersion, such as interventions of the instructor and illogical jumps in time or space, are present to a higher degree in the basic scenario condition; while events that signal enhanced immersion, such as natural interaction with the manikin, are more frequently observed in the contextualized condition.ConclusionsThe results suggest that contextualization of simulation training with respect to increased equipment and environmental fidelity as well as functional task alignment might affect immersion positively and thus contribute to an improved training experience.
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| 7. |
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| 8. |
- Baranowska Körberg, Izabella, et al.
(författare)
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A Simple Repeat Polymorphism in the MITF-M Promoter Is a Key Regulator of White Spotting in Dogs
- 2014
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Ingår i: PLOS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 9:8, s. e104363-
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Tidskriftsartikel (refereegranskat)abstract
- The white spotting locus (S) in dogs is colocalized with the MITF (microphtalmia-associated transcription factor) gene. The phenotypic effects of the four S alleles range from solid colour (S) to extreme white spotting (s(w)). We have investigated four candidate mutations associated with the s(w) allele, a SINE insertion, a SNP at a conserved site and a simple repeat polymorphism all associated with the MITF-M promoter as well as a 12 base pair deletion in exon 1B. The variants associated with white spotting at all four loci were also found among wolves and we conclude that none of these could be a sole causal mutation, at least not for extreme white spotting. We propose that the three canine white spotting alleles are not caused by three independent mutations but represent haplotype effects due to different combinations of causal polymorphisms. The simple repeat polymorphism showed extensive diversity both in dogs and wolves, and allele-sharing was common between wolves and white spotted dogs but was non-existent between solid and spotted dogs as well as between wolves and solid dogs. This finding was unexpected as Solid is assumed to be the wild-type allele. The data indicate that the simple repeat polymorphism has been a target for selection during dog domestication and breed formation. We also evaluated the significance of the three MITF-M associated polymorphisms with a Luciferase assay, and found conclusive evidence that the simple repeat polymorphism affects promoter activity. Three alleles associated with white spotting gave consistently lower promoter activity compared with the allele associated with solid colour. We propose that the simple repeat polymorphism affects cooperativity between transcription factors binding on either flanking sides of the repeat. Thus, both genetic and functional evidence show that the simple repeat polymorphism is a key regulator of white spotting in dogs.
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| 9. |
- Benson, Mikael, 1954, et al.
(författare)
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A network-based analysis of the late-phase reaction of the skin.
- 2006
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Ingår i: The Journal of allergy and clinical immunology. - : Elsevier BV. - 0091-6749 .- 1097-6825. ; 118:1, s. 220-5
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: The late-phase reaction (LPR) of the skin is an in vivo model of allergic inflammation. OBJECTIVE: We sought to identify disease-associated pathways in the LPR using a network-based analysis. METHODS: The LPR was examined by means of DNA microarray analysis of skin biopsy specimens from 10 patients with allergic rhinitis and 10 healthy control subjects. The results were further analyzed in 2 different materials consisting of nasal fluids and allergen-challenged CD4(+) T cells from patients with allergic rhinitis. RESULTS: The DNA microarray analysis revealed several genes of known relevance to allergy. The eosinophil marker Charcot-Leyden crystal protein (CLC) that encodes Charcot-Leyden crystal protein differed most in expression. A network-based analysis showed upregulation of IL-4- and CCL4-dependent pathways and downregulation of a TGF-beta-induced pathway. CCL4 is expressed by CD4(+) T cells and chemotactic for eosinophils. We hypothesized that allergen induces release of CCL4 from T(H)2 cells and that this contributes to influx of eosinophils. Further analysis showed increase of CCL4 protein in nasal fluids from allergic patients during the season. Allergen challenge of PBMCs resulted in proliferation of T(H)2 cells and increased production of CCL4 in CD4(+) T cells from allergic patients. An analysis of the DNA microarray data revealed a significant correlation between CCL4 and the eosinophil marker CLC. CONCLUSION: A network-based analysis of the LPR showed increased activity of IL-4- and CCL4- dependent pathways and downregulation of the TGF-beta-induced pathway. Allergen-induced release of CCL4 from T(H)2 cells might contribute to influx of eosinophils during the LPR. CLINICAL IMPLICATIONS: Involvement of multiple interacting pathways indicates that it might be difficult to identify one single mediator as a biomarker or drug target in allergic inflammation.
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| 10. |
- Demidova, Marina M., et al.
(författare)
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Prognostic value of early sustained ventricular arrhythmias in ST-segment elevation myocardial infarction treated by primary percutaneous coronary intervention : A substudy of VALIDATE-SWEDEHEART trial
- 2023
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Ingår i: Heart rhythm O2. - : Elsevier. - 2666-5018. ; 4:3, s. 200-206
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Prognostic assessment of ventricular tachycardia (VT) or ventricular fibrillation (VF) in ST-segment elevation myocardial infarction (STEMI) is based mainly on distinguishing between early (<48 hours) and late arrhythmias, and does not take into account its time distribution with regard to reperfusion, or type of arrhythmia.OBJECTIVE: We analyzed the prognostic value of early ventricular arrhythmias (VAs) in STEMI with regard to their type and timing.METHODS: The prespecified analysis of the multicenter prospective Bivalirudin versus Heparin in ST-Segment and Non-ST-Segment Elevation Myocardial Infarctionin Patients on Modern Antiplatelet Therapy in the Swedish Web System for Enhancement and Development of Evidence-based Care in Heart Disease evaluated according to Recommended Therapies Registry Trial included 2886 STEMI patients undergoing primary percutaneous coronary intervention (PCI). VA episodes were characterized regarding their type and timing. Survival status at 180 days was assessed through the population registry.RESULTS: Nonmonomorphic VT or VF was observed in 97 (3.4%) and monomorphic VT in 16 (0.5%) patients. Only 3 (2.7%) early VA episodes occurred after 24 hours from symptom onset. VA was associated with higher risk of death (hazard ratio 3.59; 95% confidence interval [CI] 2.01-6.42) after adjustment for age, sex, and STEMI localization. VA after PCI was associated with an increased mortality compared with VA before PCI (hazard ratio 6.68; 95% CI 2.90-15.41). Early VA was associated with in-hospital mortality (odds ratio 7.39; 95% CI 3.68-14.83) but not with long-term prognosis in patients discharged alive. The type of VA was not associated with mortality.CONCLUSION: VA after PCI was associated with an increased mortality compared with VA before PCI. Long-term prognosis did not differ between patients with monomorphic VT and nonmonomorphic VT or VF, but events were few. VA incidence during 24 to 48 hours of STEMI is negligibly low, thus precluding assessment of its prognostic importance.
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