| 1. |
- Andersson, Irene, 1978, et al.
(författare)
-
Endothelial dysfunction in growth hormone transgenic mice
- 2006
-
Ingår i: Clinical Science. - 0143-5221 .- 1470-8736. ; 110:2, s. 217-25
-
Tidskriftsartikel (refereegranskat)abstract
- Acromegaly [overproduction of GH (growth hormone)] is associated with cardiovascular disease. Transgenic mice overexpressing bGH (bovine GH) develop hypertension and hypercholesterolaemia and could be a model for cardiovascular disease in acromegaly. The aims of the present study were to investigate the effects of excess GH on vascular function and to test whether oxidative stress affects endothelial function in bGH transgenic mice. We studied the ACh (acetylcholine)-induced relaxation response in aortic and carotid rings of young (9-11 weeks) and aged (22-24 weeks) female bGH transgenic mice and littermate control mice, without and with the addition of a free radical scavenger {MnTBAP [Mn(III)tetrakis(4-benzoic acid)porphyrin chloride]}. We also measured mRNA levels of eNOS (endothelial nitric oxide synthase) and EC-SOD (extracellular superoxide dismutase). Intracellular superoxide anion production in the vascular wall was estimated using a dihydroethidium probe. Carotid arteries from bGH transgenic mice had an impaired ACh-induced relaxation response (young, 46 +/- 7% compared with 69 +/- 8%; aged, 52 +/- 5% compared with 80 +/- 3%; P < 0.05), whereas endothelial function in aorta was intact in young but impaired in aged bGH transgenic mice. Endothelial dysfunction was corrected by addition of MnTBAP in carotid arteries from young mice and in aortas from aged mice; however, MnTBAP did not correct endothelial dysfunction in carotid arteries from aged bGH transgenic mice. There was no difference in intracellular superoxide anion production between bGH transgenic mice and control mice, whereas mRNA expression of EC-SOD and eNOS was increased in aortas from young bGH transgenic mice compared with control mice (P < 0.05). We interpret these data to suggest that bGH overexpression is associated with a time- and vessel-specific deterioration in endothelial function, initially caused by increased oxidative stress and later by other alterations in vascular function.
|
|
| 2. |
- de Peppo, Giuseppe Maria, 1981, et al.
(författare)
-
Osteogenic response of human mesenchymal stem cells to well-defined nanoscale topography in vitro
- 2014
-
Ingår i: International journal of nanomedicine. - : Informa UK Limited. - 1176-9114 .- 1178-2013. ; 9:1, s. 2499-2515
-
Tidskriftsartikel (refereegranskat)abstract
- Background: Patterning medical devices at the nanoscale level enables the manipulation of cell behavior and tissue regeneration, with topographic features recognized as playing a significant role in the osseointegration of implantable devices. Methods: In this study, we assessed the ability of titanium-coated hemisphere-like topographic nanostructures of different sizes (approximately 50, 100, and 200 nm) to influence the morphology, proliferation, and osteogenic differentiation of human mesenchymal stem cells (hMSCs). Results: We found that the proliferation and osteogenic differentiation of hMSCs was influenced by the size of the underlying structures, suggesting that size variations in topographic features at the nanoscale level, independently of chemistry, can be exploited to control hMSC behavior in a size-dependent fashion. Conclusion: Our studies demonstrate that colloidal lithography, in combination with coating technologies, can be exploited to investigate the cell response to well defined nanoscale topography and to develop next-generation surfaces that guide tissue regeneration and promote implant integration.
|
|
| 3. |
- Gustafsson, Håkan, 1976-, et al.
(författare)
-
Magnetic and Electron Spin Relaxation Properties of (GdxY1-x)2O3 (0 ≤ x ≤ 1) Nanoparticles Synthesized by the Combustion Method. Increased Electron Spin Relaxation Times with Increasing Yttrium Content
- 2011
-
Ingår i: The Journal of Physical Chemistry C. - United States : American Chemical Society. - 1932-7447 .- 1932-7455. ; 115:13, s. 5469-5477
-
Tidskriftsartikel (refereegranskat)abstract
- The performance of a magnetic resonance imaging contrast agent (CA) depends on several factors, including the relaxation times of the unpaired electrons in the CA. The electron spin relaxation time may be a key factor for the performance of new CAs, such as nanosized Gd2O3 particles. The aim of this work is, therefore, to study changes in the magnetic susceptibility and the electron spin relaxation time of paramagnetic Gd2O3 nanoparticles diluted with increasing amounts of diamagnetic Y2O3. Nanoparticles of (GdxY1-x)2O3 (0 e x e 1) were prepared by the combustion method and thoroughly characterized (by X-ray di.raction, transmission electron microscopy, thermogravimetry coupled with mass spectroscopy, photoelectron spectroscopy, Fourier transform infrared spectroscopy, and magnetic susceptibility measurements). Changes in the electron spin relaxation time were estimated by observations of the signal line width in electron paramagnetic resonance spectroscopy, and it was found that the line width was dependent on the concentration of yttrium, indicating that diamagnetic Y2O3 may increase the electron spin relaxation time of Gd2O3 nanoparticles.
|
|
| 4. |
- Gustafsson, Maria, 1976, et al.
(författare)
-
Retention of Low-Density Lipoprotein in Atherosclerotic Lesions of the Mouse. Evidence for a Role of Lipoprotein Lipase
- 2007
-
Ingår i: Circ Res. - 1524-4571. ; 101:8, s. 777-783
-
Tidskriftsartikel (refereegranskat)abstract
- Direct binding of apolipoprotein (apo)B-containing lipoproteins to proteoglycans is the initiating event in atherosclerosis, but the processes involved at later stages of development are unclear. Here, we investigated the importance of the apoB-proteoglycan interaction in the development of atherosclerosis over time and investigated the role of lipoprotein lipase (LPL) to facilitate low-density lipoprotein (LDL) retention at later stages of development. Atherosclerosis was analyzed in apoB transgenic mice expressing LDL with normal (control LDL) or reduced proteoglycan-binding (RK3359-3369SA LDL) activity after an atherogenic diet for 0 to 40 weeks. The initiation of atherosclerosis was delayed in mice expressing RK3359-3369SA LDL, but they eventually developed the same level of atherosclerosis as mice expressing control LDL. Retention studies in vivo showed that although higher levels of (131)I-tyramine cellobiose-labeled control LDL ((131)I-TC-LDL) were retained in nonatherosclerotic aortae compared with RK3359-3369SA (131)I-TC-LDL, the retention was significantly higher and there was no difference between the groups in atherosclerotic aortae. Lower levels of control (125)I-TC-LDL and RK3359-3369SA (125)I-TC-LDL were retained in atherosclerotic aortae from ldlr(-/-) mice transplanted with lpl(-/-) compared with lpl(+/+) bone marrow. Uptake of control LDL or RK3359-3369SA LDL into macrophages with specific expression of human catalytically active or inactive LPL was increased compared with control macrophages. Furthermore, transgenic mice expressing catalytically active or inactive LPL developed the same extent of atherosclerosis. Thus, retention of LDL in the artery wall is initiated by direct LDL-proteoglycan binding but shifts to indirect binding with bridging molecules such as LPL.
|
|
| 5. |
- Hedlund, Anna, et al.
(författare)
-
Gd2O3 nanoparticles in hematopoietic cells for MRI contrast enhancement
- 2011
-
Ingår i: International journal of nano medicine. - Manchester, UK : Dove Medical Press Ltd. - 1178-2013. ; 6, s. 3233-3240
-
Tidskriftsartikel (refereegranskat)abstract
- As the utility of magnetic resonance imaging (MRI) broadens, the importance of having specific and efficient contrast agents increases and in recent time there has been a huge development in the fields of molecular imaging and intracellular markers. Previous studies have shown that gadolinium oxide (Gd2O3) nanoparticles generate higher relaxivity than currently available Gd chelates: In addition, the Gd2O3 nanoparticles have promising properties for MRI cell tracking. The aim of the present work was to study cell labeling with Gd2O3 nanoparticles in hematopoietic cells and to improve techniques for monitoring hematopoietic stem cell migration by MRI. Particle uptake was studied in two cell lines: the hematopoietic progenitor cell line Ba/F3 and the monocytic cell line THP-1. Cells were incubated with Gd2O3 nanoparticles and it was investigated whether the transfection agent protamine sulfate increased the particle uptake. Treated cells were examined by electron microscopy and MRI, and analyzed for particle content by inductively coupled plasma sector field mass spectrometry. Results showed that particles were intracellular, however, sparsely in Ba/F3. The relaxation times were shortened with increasing particle concentration. Relaxivities, r1 and r2 at 1.5 T and 21°C, for Gd2O3 nanoparticles in different cell samples were 3.6–5.3 s-1 mM-1 and 9.6–17.2 s-1 mM-1, respectively. Protamine sulfate treatment increased the uptake in both Ba/F3 cells and THP-1 cells. However, the increased uptake did not increase the relaxation rate for THP-1 as for Ba/F3, probably due to aggregation and/or saturation effects. Viability of treated cells was not significantly decreased and thus, it was concluded that the use of Gd2O3 nanoparticles is suitable for this type of cell labeling by means of detecting and monitoring hematopoietic cells. In conclusion, Gd2O3 nanoparticles are a promising material to achieve positive intracellular MRI contrast; however, further particle development needs to be performed.
|
|
| 6. |
- Axaeus, Jennie, 1974-, et al.
(författare)
-
Portar till språk och litteratur : CSL 2007
- 2007
-
Bok (övrigt vetenskapligt/konstnärligt)abstract
- Språk och litteratur öppnar portar till nya världar. Detta var temat för 2007 års CSL-dag. I denna bok har vi samlat fjorton av bidragen som presenterades på konferensen, skrivna av forskare och studenter vid Karlstads universitet.Håller engelskan på att förstöra svenskan? Är dagens elever sämre på att skriva än ungdomarna var för tjugo år sedan? Skall vi ha en litteraturkanon i skolan - och läser eleverna över huvud taget böcker nu för tiden? Detta är några av de frågor som ställs i artiklarna där svaren kanske kan överraska.Andra artiklar handlar om hur man stimulerar elever till att läsa och skriva, problematiken när det gäller att undervisa i svenska som andraspråk och varför elever väljer - eller inte väljer - att studera något annat främmande språk än engelska. Porten kanske finns där - men den är inte alltid helt lätt att öppna!
|
|
| 7. |
|
|
| 8. |
|
|
| 9. |
- Benrick, Anna, 1979, et al.
(författare)
-
A non-conservative polymorphism in the IL-6 signal transducer (IL6ST)/gp130 is associated with myocardial infarction in a hypertensive population.
- 2008
-
Ingår i: Regulatory peptides. - : Elsevier BV. - 0167-0115. ; 146:1-3, s. 189-96
-
Tidskriftsartikel (refereegranskat)abstract
- Inflammation is a key component in the development of atherosclerosis, and myocardial infarction (MI); therefore we investigated the association between an interleukin-6 signal transducer (IL6ST)/gp130 polymorphism, gp130 function and risk of MI. Structural modeling suggested that a non-conservative single nucleotide polymorphism in the gp130, Gly148Arg, can change the stability and functional properties of the molecule. In vitro studies were done with BAF/3 cells lacking endogenous gp130. Cells stably transfected with the gp130 148Arg variant proliferated less and showed slightly lower STAT-3 phosphorylation in response to gp130 stimulation as compared to cells transfected with gp130 148Gly. In a prospectively followed hypertensive cohort we identified 167 patients who suffered a MI during the study and compared them to matched controls (mean age 57 years, 73% males, n=482). Carriers of the 148Arg variant (f(Arg)=0.12) of the gp130 receptor had decreased odds ratio for MI in univariate analysis (0.56, 95% CI 0.34-0.91, p=0.02). In conclusion, a genetically determined structural variant of the IL-6 receptor subunit gp130 is, independently of other known risk factors, associated with decreased risk of MI. The variant is also associated with decreased IL-6 responsiveness and could lead to a configuration change in the gp130 receptor.
|
|
| 10. |
- Bjursell, Cecilia, 1970-, et al.
(författare)
-
Lifelong Learning Through Context Collapse : Higher education Teachers’ Narratives About Online education During The Pandemic
- 2022
-
Ingår i: Proceedings of INTED2022 Conference 7th-8th March 2022. - : IATED. - 9788409377589 ; , s. 2632-2641
-
Konferensbidrag (refereegranskat)abstract
- The COVID-19 pandemic has elicited a shift from campus classrooms to distance education in higher education worldwide, shaping not only students’ experiences, but also those of teachers, especially those who never have taught online. In addition, the pandemic created a meta-context that has positioned distance education as something different from previous efforts. This study aimed to investigate higher education teachers’ experiences during the transition from classroom to online teaching by using a collective auto-ethnography method based on 13 personal stories from Swedish faculty. For the abductive approach in the analysis, a framework that combines lifelong learning theory with the context collapse concept has been applied. The disjuncture that the pandemic has elicited created a situation in which teachers had to make sense of the fact that their previous experiences did not completely fit the new situation. Context collapse, a term used to describe encounters with many audiences in social media, has been introduced to highlight the clash between professional and private contexts in online educational platforms. Based on lifelong learning theories, we suggest that context collapse should be examined in terms of how it can help improve higher education, as it holds the potential to include the entire person – body and mind – in education.
|
|
