| 1. |
- Adams, Yvonne, et al.
(författare)
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3D blood-brain barrier-organoids as a model for Lyme neuroborreliosis highlighting genospecies dependent organotropism
- 2023
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Ingår i: ISCIENCE. - : CELL PRESS. - 2589-0042. ; 26:1
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Tidskriftsartikel (refereegranskat)abstract
- Lyme neuroborreliosis (LNB), a tick-borne infection caused by spirochetes within the Borrelia burgdorferi sensu lato (s.L.) complex, is among the most prevalent bacterial central nervous system (CNS) infections in Europe and the US. Here we have screened a panel of low- passage B. burgdorferi s.l. isolates using a novel, human-derived 3D blood-brain barrier (BBB)-organoid model. We show that human-derived BBB-organoids support the entry of Borrelia spirochetes, leading to swelling of the organoids and a loss of their structural integrity. The use of the BBB-organoid model highlights the organotropism between B. burgdorferi s.l. genospecies and their ability to cross the BBB contributing to CNS infection.
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| 2. |
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| 3. |
- Widestrand, Åsa, 1978, et al.
(författare)
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Increased neurogenesis and astrogenesis from neural progenitor cells grafted in the hippocampus of GFAP-/- Vim-/- mice.
- 2007
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Ingår i: Stem cells (Dayton, Ohio). - : Oxford University Press (OUP). - 1549-4918 .- 1066-5099. ; 25:10, s. 2619-27
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Tidskriftsartikel (refereegranskat)abstract
- After neurotrauma, ischemia, or neurodegenerative disease, astrocytes upregulate their expression of the intermediate filament proteins glial fibrillary acidic protein (GFAP), vimentin (Vim), and nestin. This response, reactive gliosis, is attenuated in GFAP(-/-)Vim(-/-) mice, resulting in the promotion of synaptic regeneration after neurotrauma and improved integration of retinal grafts. Here we assessed whether GFAP(-/-)Vim(-/-) astrocytes affect the differentiation of neural progenitor cells. In coculture with GFAP(-/-)Vim(-/-) astrocytes, neural progenitor cells increased neurogenesis by 65% and astrogenesis by 124%. At 35 days after transplantation of neural progenitor cells into the hippocampus, adult GFAP(-/-)Vim(-/-) mice had more transplant-derived neurons and astrocytes than wild-type controls, as well as increased branching of neurite-like processes on transplanted cells. Wnt3 immunoreactivity was readily detected in hippocampal astrocytes in wild-type but not in GFAP(-/-)Vim(-/-) mice. These findings suggest that GFAP(-/-)Vim(-/-) astrocytes allow more neural progenitor cell-derived neurons and astrocytes to survive weeks after transplantation. Thus, reactive gliosis may adversely affect the integration of transplanted neural progenitor cells in the brain. Disclosure of potential conflicts of interest is found at the end of this article.
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| 4. |
- Wilhelmsson, Peter, et al.
(författare)
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A prospective study on the incidence of Borrelia burgdorferi sensu lato infection after a tick bite in Sweden and On the Åland Islands, Finland (2008-2009)
- 2016
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Ingår i: Ticks and Tick-borne Diseases. - : Elsevier. - 1877-959X .- 1877-9603. ; 7:1, s. 71-79
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Tidskriftsartikel (refereegranskat)abstract
- Lyme borreliosis (LB) is a common and increasing tick-borne disease in Europe. The risk of acquiring a Borrelia infection after a tick bite is not fully known. Therefore, we investigated the incidence of Borrelia infection after a bite by a Borrelia-infected tick and if the Borrelia load and/or the duration of tick-feeding influenced the risk of infection. During 2008-2009, ticks and blood samples were collected from 1546 tick-bitten persons from Sweden and the Åland Islands, Finland. Follow-up blood samples were taken 3 months after the tick bite. The duration of tick feeding was microscopically estimated and Borrelia was detected and quantified in ticks by real-time PCR. Anti-Borrelia antibodies were detected in sera using ELISA tests and immunoblot. Five percent (78/1546) of the study participants developed Borrelia infection (LB diagnosis and/or seroconversion) after a tick bite (45% bitten by Borrelia-infected ticks and 55% bitten by uninfected ticks). Of these, 33 developed LB (whereof 9 also seroconverted) while 45 participants seroconverted only. Experience of non-specific symptoms was more frequently reported by Borrelia-infected participants compared to uninfected participants. All who seroconverted removed "their" ticks significantly later than those who did not. The Borrelia load in the ticks did not explain the risk of seroconversion. Regional and sex differences in the Borrelia seroprevalence were found. The risk of developing a Borrelia infection after a bite by a Borrelia-infected tick is small but increases with the duration of tick feeding.
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| 5. |
- Wilhelmsson, Peter, et al.
(författare)
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A prospective study on the incidence of Borrelia infection after a tick bite in Sweden and on the Åland Islands, Finland (2008-2009)
- 2016
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Ingår i: Ticks and Tick-borne Diseases. - : Elsevier. - 1877-959X .- 1877-9603. ; 7:1, s. 71-79
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Tidskriftsartikel (refereegranskat)abstract
- Lyme borreliosis (LB) is a common and increasing tick-borne disease in Europe. The risk of acquiring a Borrelia infection after a tick bite is not fully known. Therefore, we investigated the incidence of Borrelia infection after a tick bite and if the Borrelia load and/or the duration of tick-feeding influenced the risk of infection. During 2008-2009, ticks and blood samples were collected from 1546 tick-bitten persons from Sweden and the Åland Islands, Finland. Follow-up blood samples were taken three months after the tick bite. The duration of tick feeding was microscopically estimated and Borrelia was detected and quantified in ticks by real-time PCR. Anti-Borrelia antibodies were detected in sera using ELISA assays and immunoblot.Even though 28 % of the participants were bitten by a Borrelia-positive tick, only 7.5% (32/428) of them developed a Borrelia infection, half of them LB. All who seroconverted removed “their” ticks significantly later than those who did not. The Borrelia load in the ticks did not explain the risk of seroconversion. Regional as well as gender differences in the Borrelia seroprevalence were found. The risk of developing a Borrelia infection after a bite by a Borrelia-infected tick is small but increases with the duration of tick feeding.
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| 6. |
- Aase, Audun, et al.
(författare)
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Validate or falsify: Lessons learned from a microscopy method claimed to be useful for detecting Borrelia and Babesia organisms in human blood
- 2016
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Ingår i: INFECTIOUS DISEASES. - : TAYLOR & FRANCIS LTD. - 2374-4235 .- 2374-4243. ; 48:6, s. 411-419
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Tidskriftsartikel (refereegranskat)abstract
- Background A modified microscopy protocol (the LM-method) was used to demonstrate what was interpreted as Borrelia spirochetes and later also Babesia sp., in peripheral blood from patients. The method gained much publicity, but was not validated prior to publication, which became the purpose of this study using appropriate scientific methodology, including a control group. Methods Blood from 21 patients previously interpreted as positive for Borrelia and/or Babesia infection by the LM-method and 41 healthy controls without known history of tick bite were collected, blinded and analysed for these pathogens by microscopy in two laboratories by the LM-method and conventional method, respectively, by PCR methods in five laboratories and by serology in one laboratory. Results Microscopy by the LM-method identified structures claimed to be Borrelia- and/or Babesia in 66% of the blood samples of the patient group and in 85% in the healthy control group. Microscopy by the conventional method for Babesia only did not identify Babesia in any samples. PCR analysis detected Borrelia DNA in one sample of the patient group and in eight samples of the control group; whereas Babesia DNA was not detected in any of the blood samples using molecular methods. Conclusions The structures interpreted as Borrelia and Babesia by the LM-method could not be verified by PCR. The method was, thus, falsified. This study underlines the importance of doing proper test validation before new or modified assays are introduced.
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| 7. |
- Aissaoui, Nesrine, 1983, et al.
(författare)
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FRET enhancement close to gold nanoparticles positioned in DNA origami constructs
- 2017
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Ingår i: Nanoscale. - Cambridge, United Kingdom : Royal Society of Chemistry (RSC). - 2040-3372 .- 2040-3364. ; 9:2, s. 673-683
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Tidskriftsartikel (refereegranskat)abstract
- Here we investigate the energy transfer rates of a Förster resonance energy transfer (FRET) pair positioned in close proximity to a 5 nm gold nanoparticle (AuNP) on a DNA origami construct. We study the distance dependence of the FRET rate by varying the location of the donor molecule, D, relative to the AuNP while maintaining a fixed location of the acceptor molecule, A. The presence of the AuNP induces an alteration in the spontaneous emission of the donor (including radiative and non-radiative rates) which is strongly dependent on the distance between the donor and AuNP surface. Simultaneously, the energy transfer rates are enhanced at shorter D-A (and D-AuNP) distances. Overall, in addition to the direct influence of the acceptor and AuNP on the donor decay there is also a significant increase in decay rate not explained by the sum of the two interactions. This leads to enhanced energy transfer between donor and acceptor in the presence of a 5 nm AuNP. We also demonstrate that the transfer rate in the three "particle" geometry (D + A + AuNP) depends approximately linearly on the transfer rate in the donor-AuNP system, suggesting the possibility to control FRET process with electric field induced by 5 nm AuNPs close to the donor fluorophore. It is concluded that DNA origami is a very versatile platform for studying interactions between molecules and plasmonic nanoparticles in general and FRET enhancement in particular.
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| 8. |
- Andersson, Peter, et al.
(författare)
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Texter som inte räknas? : Om digitala läs- och skrivaktiviteter bland barn och unga
- 2010
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Ingår i: Utbildning och lärande. - Skövde : Avdelningen barns, ungas och vuxnas lärande vid Högskolan i Skövde. - 1653-0594. ; 4:1, s. 14-33
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Tidskriftsartikel (refereegranskat)abstract
- In the age of the Internet and a changing semiotic landscape, reading and writing become increasingly complex activities in school. ICT have to be considered as a partner in the daily pedagogies. Digital media and new forms of communication are of great interest for literacy researches, particularly within the area of research that has come to be called New literacies. This article presents the results of a survey in which we asked 320 pupils about their use of information technology as part of daily literacy activities in and outside school. The study is inspired by an American study among young adolescents in New York (Agee & Altarriba 2009), but based on a wider range of ages: between 10-16 years. Our results show some significant differences in the pupils’ literacy activities based on factors such as gender, age, and attitudes towards reading and writing. Of particular interest is one group that distinguishes itself by having a negative attitude to reading and writing even though spending much time on digital literacies in and outside school.
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| 9. |
- Aspelin, Peter, et al.
(författare)
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Ultrasound examination of soft tissue injury of the lower limb in athletes
- 1992
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Ingår i: The American journal of sports medicine. - : SAGE Publications. - 1552-3365 .- 0363-5465. ; 20:5, s. 601-603
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Tidskriftsartikel (refereegranskat)abstract
- We performed ultrasonography on 32 athletes complaining of intense pain in a swollen and tender thigh or calf after a contusion or stretching trauma. The ultrasonogram was used to visualize the presence and size of a suspected hematoma. The findings included the following: 7 patients with a circumscribed, anechoic lesion compatible with a liquefied hematoma; 10 patients with a circumscribed lesion of mixed echogenicity compatible with areas of liquefied hematoma, coagulated blood, and edema; and 15 patients with a diffuse change in echogenicity of the whole muscle. The circumscribed liquefied, and mixed hematoma were more common after contusion trauma, while the diffuse type was more common after injury caused by stretching. Ultrasonography is useful in localizing the hematoma and in characterizing the different types. Differentiation is important in diagnosis and choice of treatment.
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| 10. |
- Bijelovic, Stojanka, et al.
(författare)
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Wear-resistant magnetic thin film material based on a Ti1−xFexC1−y nanocomposite alloy
- 2010
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Ingår i: Physical Review B Condensed Matter. - : The American Physical Society. - 0163-1829 .- 1095-3795. ; 81:1, s. 014405-
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Tidskriftsartikel (refereegranskat)abstract
- In this study we report on the film growth and characterization of thin films deposited on amorphous quartz. The experimental studies have been complemented by first-principles density-functional theory metastable Ti-Fe-C film changes. With increasing annealing time, there is a depletion of iron close to the surface of the film, while regions enriched in iron are simultaneously formed deeper into the film. Both the magnetic ordering temperature and the saturation magnetization changes significantly upon annealing. The DFT calculations show that the critical temperature and the magnetic moment both increase with increasing Fe and C-vacancy concentration. The formation of the metastable iron-rich Ti-Fe-C compound is reflected in the strong increase in the magnetic ordering temperature. Eventually, after enough annealing time nanocrystalline -Fe starts to precipitate, the amount and size of which can be controlled by the annealing procedure; after 20 min of annealing, the experimental results indicate a nanocrystalline iron-film embedded in a wear-resistant TiC compound. This conclusion is further supported by transmission electron microscopy studies on epitaxial Ti-Fe-C films deposited on single-crystalline MgO substrates where, upon annealing, an iron film embedded in TiC is formed. Our results suggest that annealing of metastable Ti-Fe-C films can be used as an efficient way of creating a wear-resistant magnetic thin film material. approximately 50-nm-thick Ti-Fe-CDFT calculations. Upon annealing of as-prepared films, the composition of the10 min, nanocrystalline -Fe starts to precipitate, the amount and size of which can be controlled by the annealing procedure; after 20 min of annealing, the experimental results indicate a nanocrystalline iron-film embedded in a wear-resistant TiC compound. This conclusion is further supported by transmission electron microscopy studies on epitaxial Ti-Fe-C films deposited on single-crystalline MgO substrates where, upon annealing, an iron film embedded in TiC is formed. Our results suggest that annealing of metastable Ti-Fe-C films can be used as an efficient way of creating a wear-resistant magnetic thin film material.
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