| 1. |
- Etemadi, Leila, et al.
(författare)
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UVB irradiation induces contralateral changes in galanin, substance P and c-fos immunoreactivity in rat dorsal root ganglia, dorsal horn and lateral spinal nucleus
- 2021
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Ingår i: Peptides. - : Elsevier BV. - 0196-9781. ; 136
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Tidskriftsartikel (refereegranskat)abstract
- The selection of control group is crucial, as the use of an inadequate group may strongly affect the results. In this study we examine the effect on contralateral tissue protein levels, in a model of unilateral UVB irradiation, as the contralateral side is commonly used as a control. Previous studies have shown that UVB irradiation increases immunoreactivity for inflammatory regulated neuropeptides. Unilateral UVB irradiation of rat hind paw was performed and corresponding contralateral spinal cord and dorsal root ganglia (DRG) were collected 2–96 h after and investigated for changes in galanin, substance P and c-fos immunoreactivity. Control tissue was collected from naïve rats. Measurement of skin blood flow from contralateral heel hind paws (Doppler), revealed no change compared to naïve rats. However, UVB irradiation caused a significant reduction in the contralateral proportion of galanin immunopositive DRG neurons, at all-time points, as well as an increase in the contralateral spinal cord dorsal horn, around the central canal and in the lateral spinal nucleus (2–48 h). The contralateral proportion of SP positive DRG neurons and dorsal horn immunoreactivity was unchanged, whereas the lateral spinal nucleus area showed increased immunoreactivity (48 h). UVB irradiation also induced a slight contralateral upregulation of c-fos in the dorsal horn/central canal area (24 and 48 h). In summary, unilateral UVB irradiation induced contralateral changes in inflammatory/nociceptive neuropeptides in spinal cord and afferent pathways involved in pain signaling already within 24 h, a time point when also ipsilateral neurochemical/physiological changes have been reported for rats and humans.
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| 2. |
- Möller, Riitta, et al.
(författare)
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Portföljen synliggör lärandet och kompetensutvecklingen
- 2021
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Ingår i: Lakartidningen. - 0023-7205. ; 118
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Tidskriftsartikel (refereegranskat)abstract
- Portfolio used in education can be defined as a collection of documentation of performed learning activities, feedback, and progress. Currently, the documentation is electronic, hence the term e-portfolio is used. The portfolio must have a clear purpose and be aligned with the learning outcomes of the program. To be successfully implemented a portfolio must be an integral part of the education with defined tasks for both the students and the teachers. Students and teacher support in how to use the portfolio is essential especially in the beginning of the program. Learning analytics enables teachers to identify and develop support for students at risk of not achieving the outcomes.
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| 3. |
- Etemadi, Leila, et al.
(författare)
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UVB irradiation induces rapid changes in galanin, substance P and c-fos immunoreactivity in rat dorsal root ganglia and spinal cord
- 2017
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Ingår i: Peptides. - : Elsevier BV. - 0196-9781. ; 87, s. 71-83
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Tidskriftsartikel (refereegranskat)abstract
- Recent studies have shown that UVB irradiation induces primary and secondary hyperalgesia in rats and humans peaking about 24 h after UVB exposure. In the present study we investigated the changes in galanin, substance P and c-fos immunoreactivity in rat DRG and spinal cord at the L5 level 2–96 h after UVB irradiation. UVB irradiation of the heel area in rats almost increased the skin blood flow two-fold 24 h after irradiation as measured by laser Doppler technique. UVB irradiation induced a significant reduction of the proportion of galanin positive DRG neurons for all time points, except at 12 h. In the spinal cord, UVB irradiation induced increased immunoreactivity for galanin in the dorsal horn, the area around the central canal and interestingly also in the lateral spinal nucleus 12–96 h after exposure. For substance P the proportion of substance P positive neurons was unchanged but UVB irradiation induced increased substance P immunoreactivity in the dorsal part of the spinal cord 48 h after irradiation. UVB irradiation also induced c-fos immunoreactivity in the dorsal horn and the area around the central canal 24 and 48 h after exposure. This translational model of UVB irradiation will induce rapid changes of neuropeptides implicated in nociceptive signaling in areas known to be of importance for nociception in a time frame, about 24 h after exposure, where also neurophysiological alteration have been described in humans and rats.
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| 4. |
- Gällentoft, Lina, et al.
(författare)
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Impact of degradable nanowires on long-term brain tissue responses
- 2016
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Ingår i: Journal of Nanobiotechnology. - : Springer Science and Business Media LLC. - 1477-3155. ; 14:1
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Tidskriftsartikel (refereegranskat)abstract
- Background: A promising approach to improve the performance of neural implants consists of adding nanomaterials, such as nanowires, to the surface of the implant. Nanostructured interfaces could improve the integration and communication stability, partly through the reduction of the cell-to-electrode distance. However, the safety issues of implanted nanowires in the brain need to be evaluated and understood before nanowires can be used on the surface of implants for long periods of time. To this end we here investigate whether implanted degradable nanowires offer any advantage over non-degradable nanowires in a long-term in vivo study (1 year) with respect to brain tissue responses. Results: The tissue response after injection of degradable silicon oxide (SiOx)-coated gallium phosphide nanowires and biostable hafnium oxide-coated GaP nanowires into the rat striatum was compared. One year after nanowire injection, no significant difference in microglial or astrocytic response, as measured by staining for ED1 and glial fibrillary acidic protein, respectively, or in neuronal density, as measured by staining for NeuN, was found between degradable and biostable nanowires. Of the cells investigated, only microglia cells had engulfed the nanowires. The SiOx-coated nanowire residues were primarily seen in aggregated hypertrophic ED1-positive cells, possibly microglial cells that have fused to create multinucleated giant cells. Occasionally, degradable nanowires with an apparently intact shape were found inside single, small ED1-positive cells. The biostable nanowires were found intact in microglia cells of both phenotypes described. Conclusion: The present study shows that the degradable nanowires remain at least partly in the brain over long time periods, i.e. 1 year; however, no obvious bio-safety issues for this degradable nanomaterial could be detected.
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| 5. |
- Pettersson, Lina M E, et al.
(författare)
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Altered behavioural responses and functional recovery in rats following sciatic nerve compression and early vs late decompression
- 2016
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Ingår i: Journal of Plastic Surgery and Hand Surgery. - 2000-656X. ; 50:6, s. 321-330
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Tidskriftsartikel (refereegranskat)abstract
- Objective: The aim of the study was to examine sensory behaviour and functional recovery in rats during nerve compression and after decompression. Compression injury is a far more common condition than nerve transection. The condition is characterised by numbness and a tingling/burning sensation, and some patients experience pain and allodynia during compression or after decompression treatment. The aetiology is in many cases unknown. Thus, further studies are of great importance for the understanding of this condition. Methods: In the present study, behavioural responses to tactile stimulation, thermal pain, as well as functional sensorimotor behaviour were investigated in rats before, during severe compression, and after decompression. The sciatic nerve of the rats was experimentally compressed for 3 or 28 days, whereafter surgical release, i.e. decompression, of the nerve was performed and the rats were examined up to ∼9 weeks. Results: An altered behaviour was found in response to compression injury, which is mitigated after early decompression treatment. Conclusions: These findings indicate that early intervention during severe compression injuries is of great importance for recovery and restoration of nerve function and, thus, should have an impact on clinical routines regarding treatment of compression injuries.
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| 6. |
- Gällentoft, Lina, et al.
(författare)
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Size-dependent long-term tissue response to biostable nanowires in the brain.
- 2015
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Ingår i: Biomaterials. - : Elsevier BV. - 1878-5905 .- 0142-9612. ; 42, s. 172-183
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Tidskriftsartikel (refereegranskat)abstract
- Nanostructured neural interfaces, comprising nanotubes or nanowires, have the potential to overcome the present hurdles of achieving stable communication with neuronal networks for long periods of time. This would have a strong impact on brain research. However, little information is available on the brain response to implanted high-aspect-ratio nanoparticles, which share morphological similarities with asbestos fibres. Here, we investigated the glial response and neuronal loss in the rat brain after implantation of biostable and structurally controlled nanowires of different lengths for a period up to one year post-surgery. Our results show that, as for lung and abdominal tissue, the brain is subject to a sustained, local inflammation when biostable and high-aspect-ratio nanoparticles of 5 μm or longer are present in the brain tissue. In addition, a significant loss of neurons was observed adjacent to the 10 μm nanowires after one year. Notably, the inflammatory response was restricted to a narrow zone around the nanowires and did not escalate between 12 weeks and one year. Furthermore, 2 μm nanowires did not cause significant inflammatory response nor significant loss of neurons nearby. The present results provide key information for the design of future neural implants based on nanomaterials.
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| 7. |
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| 8. |
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| 9. |
- Lind, Gustav, et al.
(författare)
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Multiple implants do not aggravate the tissue reaction in rat brain.
- 2012
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Ingår i: PLoS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 7:10
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Tidskriftsartikel (refereegranskat)abstract
- Chronically implanted microelectrodes are an invaluable tool for neuroscientific research, allowing long term recordings in awake and behaving animals. It is known that all such electrodes will evoke a tissue reaction affected by its' size, shape, surface structure, fixation mode and implantation method. However, the possible correlation between tissue reactions and the number of implanted electrodes is not clear. We implanted multiple wire bundles into the brain of rats and studied the correlation between the astrocytic and microglial reaction and the positioning of the electrode in relation to surrounding electrodes. We found that an electrode implanted in the middle of a row of implants is surrounded by a significantly smaller astrocytic scar than single ones. This possible interaction was only seen between implants within the same hemisphere, no interaction with the contralateral hemisphere was found. More importantly, we found no aggravation of tissue reactions as a result of a larger number of implants. These results highlight the possibility of implanting multiple electrodes without aggravating the glial scar surrounding each implant.
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