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| 2. |
- Fondell, Elinor, et al.
(författare)
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Physical Activity, Stress, and Self-Reported Upper Respiratory Tract Infection
- 2011
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Ingår i: Medicine & Science in Sports & Exercise. - : LIPPINCOTT WILLIAMS & WILKINS. - 0195-9131 .- 1530-0315. ; 43:2, s. 272-279
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Tidskriftsartikel (refereegranskat)abstract
- Purpose: Upper respiratory tract infection (URTI) is the most common reason for seeking primary care in many countries. Still, little is known about potential strategies to reduce susceptibility. We investigated the relationships between physical activity level, perceived stress, and incidence of self-reported URTI. Methods: We conducted a population-based prospective cohort study of 1509 Swedish men and women aged 20-60 yr with a follow-up period of 4 months. We used a Web-based questionnaire to assess disease status and lifestyle factors at the start of the study. We assessed physical activity and inactivity as total MET-hours (MET task) per day and perceived stress by the 14-item Perceived Stress Scale. Participants were contacted every 3 wk via e-mail to assess incidence of URTI. They reported a total of 1181 occurrences of URTI. We used Poisson regression models to control for age, sex, and other potential confounding factors. Results: We found that high levels of physical activity (>= 55 MET.h.d(-1)) were associated with an 18% reduced risk (incidence rate ratio (IRR) = 0.82, 95% confidence interval (CI) = 0.69-0.98) of self-reporting URTI compared with low levels of physical activity (< 45 MET.h.d(-1)). This association was stronger among those reporting high levels of stress (IRR = 0.58, 95% CI = 0.43-0.78), especially among men (IRR = 0.37, 95% CI = 0.24-0.59), but absent in the group with low levels of stress. Conclusions: We found that high physical activity was associated with a lower risk of contracting URTI for both men and women. In addition, we found that highly stressed people, particularly men, appear to benefit more from physical activity than those with lower stress levels.
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| 3. |
- Garcia-Bennett, Alfonso E., et al.
(författare)
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Delivery of Differentiation Factors by Mesoporous Silica Particles Assists Advanced Differentiation of Transplanted Murine Embryonic Stem Cells
- 2013
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Ingår i: Stem Cells Translational Medicine. - : Oxford University Press (OUP). - 2157-6564 .- 2157-6580. ; 2:11, s. 906-915
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Tidskriftsartikel (refereegranskat)abstract
- Stem cell transplantation holds great hope for the replacement of damaged cells in the nervous system. However, poor long-term survival after transplantation and insufficiently robust differentiation of stem cells into specialized cell types in vivo remain major obstacles for clinical application. Here, we report the development of a novel technological approach for the local delivery of exogenous trophic factor mimetics to transplanted cells using specifically designed silica nanoporous particles. We demonstrated that delivering Cintrofin and Gliafin, established peptide mimetics of the ciliary neurotrophic factor and glial cell line-derived neurotrophic factor, respectively, with these particles enabled not only robust functional differentiation of motor neurons from transplanted embryonic stem cells but also their long-term survival in vivo. We propose that the delivery of growth factors by mesoporous nanoparticles is a potentially versatile and widely applicable strategy for efficient differentiation and functional integration of stem cell derivatives upon transplantation.
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| 4. |
- Garcia-Bennett, Alfonso E., et al.
(författare)
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In vitro generation of motor neuron precursors from mouse embryonic stem cells using mesoporous nanoparticles
- 2014
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Ingår i: Nanomedicine. - 1743-5889 .- 1748-6963. ; 9:16, s. 2457-2466
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Tidskriftsartikel (refereegranskat)abstract
- Aim: Stem cell-derived motor neurons (MNs) are utilized to develop replacement strategies for spinal cord disorders. Differentiation of embryonic stem cells into MN precursors involves factors and their repeated administration. We investigated if delivery of factors loaded into mesoporous nanoparticles could be effective for stem cell differentiation in vitro. Materials & methods: We used a mouse embryonic stem cell line expressing green fluorescent protein under the promoter for the MN-specific gene Hb9 to visualize the level of MN differentiation. The differentiation of stem cells was evaluated by expression of MN-specific transcription factors monitored by quantitative real-time PCR reactions and immunocytochemistry. Results: Mesoporous nanoparticles have strong affiliation to the embryoid bodies, penetrate inside the embryoid bodies and come in contact with differentiating cells. Conclusion: Repeated administration of soluble factors into a culture medium can be avoided due to a sustained release effect using mesoporous silica.
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| 5. |
- Garcia-Bennett, Alfonso, et al.
(författare)
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In vitro generation of motor neuron precursors from mouse embryonic stem cells using mesoporous nanoparticles
- 2014
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Ingår i: Nanomedicine. - : Future Medicine Ltd. - 1743-5889 .- 1748-6963. ; 9:16, s. 2457-2466
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Tidskriftsartikel (refereegranskat)abstract
- Aim: Stem cell-derived motor neurons (MNs) are utilized to develop replacement strategies for spinal cord disorders. Differentiation of embryonic stem cells into MN precursors involves factors and their repeated administration. We investigated if delivery of factors loaded into mesoporous nanoparticles could be effective for stem cell differentiation in vitro.Materials & methods: We used a mouse embryonic stem cell line expressing green fluorescent protein under the promoter for the MN-specific gene Hb9 to visualize the level of MN differentiation. The differentiation of stem cells was evaluated by expression of MN-specific transcription factors monitored by quantitative real-time PCR reactions and immunocytochemistry.Results: Mesoporous nanoparticles have strong affiliation to the embryoid bodies, penetrate inside the embryoid bodies and come in contact with differentiating cells.Conclusion: Repeated administration of soluble factors into a culture medium can be avoided due to a sustained release effect using mesoporous silica.
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| 6. |
- Hoeber, Jan, 1986-, et al.
(författare)
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A Combinatorial Approach to Induce Sensory Axon Regeneration into the Dorsal Root Avulsed Spinal Cord
- 2017
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Ingår i: Stem Cells and Development. - : Mary Ann Liebert Inc. - 1547-3287 .- 1557-8534. ; 26:14, s. 1065-1077
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Tidskriftsartikel (refereegranskat)abstract
- Spinal root injuries result in newly formed glial scar formation, which prevents regeneration of sensory axons causing permanent sensory loss. Previous studies showed that delivery of trophic factors or implantation of human neural progenitor cells supports sensory axon regeneration and partly restores sensory functions. In this study, we elucidate mechanisms underlying stem cell-mediated ingrowth of sensory axons after dorsal root avulsion (DRA). We show that human spinal cord neural stem/progenitor cells (hscNSPC), and also, mesoporous silica particles loaded with growth factor mimetics (MesoMIM), supported sensory axon regeneration. However, when hscNSPC and MesoMIM were combined, sensory axon regeneration failed. Morphological and tracing analysis showed that sensory axons grow through the newly established glial scar along "bridges" formed by migrating stem cells. Coimplantation of MesoMIM prevented stem cell migration, "bridges" were not formed, and sensory axons failed to enter the spinal cord. MesoMIM applied alone supported sensory axons ingrowth, but without affecting glial scar formation. In vitro, the presence of MesoMIM significantly impaired migration of hscNSPC without affecting their level of differentiation. Our data show that (1) the ability of stem cells to migrate into the spinal cord and organize cellular "bridges" in the newly formed interface is crucial for successful sensory axon regeneration, (2) trophic factor mimetics delivered by mesoporous silica may be a convenient alternative way to induce sensory axon regeneration, and (3) a combinatorial approach of individually beneficial components is not necessarily additive, but can be counterproductive for axonal growth.
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| 7. |
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| 8. |
- Hoeber, Jan, et al.
(författare)
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Human Embryonic Stem Cell-Derived Progenitors Assist Functional Sensory Axon Regeneration after Dorsal Root Avulsion Injury
- 2015
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Ingår i: Scientific Reports. - : Springer Science and Business Media LLC. - 2045-2322. ; 5
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Tidskriftsartikel (refereegranskat)abstract
- Dorsal root avulsion results in permanent impairment of sensory functions due to disconnection between the peripheral and central nervous system. Improved strategies are therefore needed to reconnect injured sensory neurons with their spinal cord targets in order to achieve functional repair after brachial and lumbosacral plexus avulsion injuries. Here, we show that sensory functions can be restored in the adult mouse if avulsed sensory fibers are bridged with the spinal cord by human neural progenitor (hNP) transplants. Responses to peripheral mechanical sensory stimulation were significantly improved in transplanted animals. Transganglionic tracing showed host sensory axons only in the spinal cord dorsal horn of treated animals. Immunohistochemical analysis confirmed that sensory fibers had grown through the bridge and showed robust survival and differentiation of the transplants. Section of the repaired dorsal roots distal to the transplant completely abolished the behavioral improvement. This demonstrates that hNP transplants promote recovery of sensorimotor functions after dorsal root avulsion, and that these effects are mediated by spinal ingrowth of host sensory axons. These results provide a rationale for the development of novel stem cell-based strategies for functionally useful bridging of the peripheral and central nervous system.
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| 9. |
- Kosykh, Anastasiia, et al.
(författare)
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Neural crest stem cells from hair follicles and boundary cap have different effects on pancreatic islets in vitro
- 2015
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Ingår i: International Journal of Neuroscience. - London : Informa Healthcare. - 0020-7454 .- 1563-5279 .- 1543-5245. ; 125:7, s. 547-554
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Tidskriftsartikel (refereegranskat)abstract
- Purpose:Neural crest stem cells derived from the boundary cap (bNCSCs), markedly promote survival, proliferation and function of insulin producing β-cells in vitro and in vivo after coculture/transplantation with pancreatic islets [ 1, 2 ]. Recently, we have shown that beneficial effects on β-cells require cadherin contacts between bNCSCs and β-cells [ 3, 4 ]. Here we investigated whether hair follicle (HF) NCSCs, a potential source for human allogeneic transplantation, exert similar positive effects on β-cells.Materials and Methods:We established cocultures of HF-NCSCs or bNCSCs from mice expressing enhanced green fluorescent protein together with pancreatic islets from DxRed expressing mice or NMRI mice and compared their migration towards islet cells and effect on proliferation of β-cells as well as intracellular relations between NCSCs and islets using qRT-PCR analysis and immunohistochemistry.Results:Whereas both types of NCSCs migrated extensively in the presence of islets, only bNCSCs demonstrated directed migration toward islets, induced β-cell proliferation and increased the presence of cadherin at the junctions between bNCSCs and β-cells. Even in direct contact between β-cells and HF-NCSCs, no cadherin expression was detected.Conclusions:These observations indicate that HF-NCSCs do not confer the same positive effect on β-cells as demonstrated for bNCSCs. Furthermore, these data suggest that induction of cadherin expression by HF-NCSCs may be useful for their ability to support β-cells in coculture and after transplantation.
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| 10. |
- König, Niclas, et al.
(författare)
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Forced Runx1 expression in human neural stem/progenitor cells transplanted to the rat dorsal root ganglion cavity results in extensive axonal growth specifically from spinal cord-derived neurospheres
- 2011
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Ingår i: Stem Cells and Development. - : Mary Ann Liebert Inc. - 1547-3287 .- 1557-8534. ; 20:11, s. 1847-1857
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Tidskriftsartikel (refereegranskat)abstract
- Cell replacement therapy holds great promise for treating a wide range of human disorders. However, ensuring the predictable differentiation of transplanted stem cells, eliminating their risk of tumor formation, and generating fully functional cells after transplantation remain major challenges in regenerative medicine. Here, we explore the potential of human neural stem/progenitor cells isolated from the embryonic forebrain (hfNSPCs) or the spinal cord (hscNSPCs) to differentiate to projection neurons when transplanted into the dorsal root ganglion cavity of adult recipient rats. To stimulate axonal growth, we transfected hfNSPC- and hscNSPC-derived neurospheres, prior to their transplantation, with a Tet-Off Runx1-overexpressing plasmid to maintain Runx1 expression in vivo after transplantation. Although pronounced cell differentiation was found in the Runx1-expressing transplants from both cell sources, we observed extensive, long-distance growth of axons exclusively from hscNSPC-derived transplants. These axons ultimately reached the dorsal root transitional zone, the boundary separating peripheral and central nervous systems. Our data show that hscNSPCs have the potential to differentiate to projection neurons with long-distance axonal outgrowth and that Runx1 overexpression is a useful approach to induce such outgrowth in specific sources of NSPCs.
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