| 1. |
- Hladik, Daniela, et al.
(författare)
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Combined Treatment with Low-Dose Ionizing Radiation and Ketamine Induces Adverse Changes in CA1 Neuronal Structure in Male Murine Hippocampi
- 2019
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Ingår i: International Journal of Molecular Sciences. - : MDPI. - 1661-6596 .- 1422-0067. ; 20:23
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Tidskriftsartikel (refereegranskat)abstract
- In children, ketamine sedation is often used during radiological procedures. Combined exposure of ketamine and radiation at doses that alone did not affect learning and memory induced permanent cognitive impairment in mice. The aim of this study was to elucidate the mechanism behind this adverse outcome. Neonatal male NMRI mice were administered ketamine (7.5 mg kg(-1)) and irradiated (whole-body, 100 mGy or 200 mGy, Cs-137) one hour after ketamine exposure on postnatal day 10. The control mice were injected with saline and sham-irradiated. The hippocampi were analyzed using label-free proteomics, immunoblotting, and Golgi staining of CA1 neurons six months after treatment. Mice co-exposed to ketamine and low-dose radiation showed alterations in hippocampal proteins related to neuronal shaping and synaptic plasticity. The expression of brain-derived neurotrophic factor, activity-regulated cytoskeleton-associated protein, and postsynaptic density protein 95 were significantly altered only after the combined treatment (100 mGy or 200 mGy combined with ketamine, respectively). Increased numbers of basal dendrites and branching were observed only after the co-exposure, thereby constituting a possible reason for the displayed alterations in behavior. These data suggest that the risk of radiation-induced neurotoxic effects in the pediatric population may be underestimated if based only on the radiation dose.
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| 2. |
- Kilpeläinen, Tuomas O, et al.
(författare)
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Genome-wide meta-analysis uncovers novel loci influencing circulating leptin levels
- 2016
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Ingår i: Nature Communications. - : Springer Science and Business Media LLC. - 2041-1723. ; 7
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Tidskriftsartikel (refereegranskat)abstract
- Leptin is an adipocyte-secreted hormone, the circulating levels of which correlate closely with overall adiposity. Although rare mutations in the leptin (LEP) gene are well known to cause leptin deficiency and severe obesity, no common loci regulating circulating leptin levels have been uncovered. Therefore, we performed a genome-wide association study (GWAS) of circulating leptin levels from 32,161 individuals and followed up loci reaching P<10(-6) in 19,979 additional individuals. We identify five loci robustly associated (P<5 × 10(-8)) with leptin levels in/near LEP, SLC32A1, GCKR, CCNL1 and FTO. Although the association of the FTO obesity locus with leptin levels is abolished by adjustment for BMI, associations of the four other loci are independent of adiposity. The GCKR locus was found associated with multiple metabolic traits in previous GWAS and the CCNL1 locus with birth weight. Knockdown experiments in mouse adipose tissue explants show convincing evidence for adipogenin, a regulator of adipocyte differentiation, as the novel causal gene in the SLC32A1 locus influencing leptin levels. Our findings provide novel insights into the regulation of leptin production by adipose tissue and open new avenues for examining the influence of variation in leptin levels on adiposity and metabolic health.
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| 3. |
- Bakshi, Mayur V, et al.
(författare)
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Total body exposure to low-dose ionizing radiation induces long term alterations to the liver proteome of neonatally exposed mice
- 2015
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Ingår i: Journal of Proteome Research. - : American Chemical Society (ACS). - 1535-3893 .- 1535-3907. ; 14:1, s. 366-373
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Tidskriftsartikel (refereegranskat)abstract
- Tens of thousands of people are being exposed daily toenvironmental low-dose gamma radiation. Epidemiological data indicate thatsuch low radiation doses may negatively affect liver function and result in thedevelopment of liver disease. However, the biological mechanisms behindthese adverse effects are unknown. The aim of this study was to investigateradiation-induced damage in the liver after low radiation doses. Neonatal maleNMRI mice were exposed to total body irradiation on postnatal day 10 usingacute single doses ranging from 0.02 to 1.0 Gy. Early (1 day) and late (7months) changes in the liver proteome were tracked using isotope-codedprotein label technology and quantitative mass spectrometry. Our dataindicate that low and moderate radiation doses induce an immediateinhibition of the glycolysis pathway and pyruvate dehydrogenase availability inthe liver. Furthermore, they lead to significant long-term alterations in lipidmetabolism and increased liver inflammation accompanying inactivation of thetranscription factor peroxisome proliferator-activated receptor alpha. This study contributes to the understanding of the potentialrisk of liver damage in populations environmentally exposed to ionizing radiation.
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| 4. |
- Eriksson, Stefanie
(författare)
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Development of Novel Diffusion NMR Methods : Preclinical Applications in Colloidal Model Systems
- 2016
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- NMR is a powerful non-invasive technique utilizing radiofrequency and gradient pulses to manipulate the spinsof atomic nuclei. In particular, diffusion NMR uses strong magnetic field gradients to label the positions of spins allowing for the measurement of translational motion of molecules in liquids. The average displacement of water molecules can give information on the pore microstructure in various materials including biological cells and tissues.The interpretation of conventional diffusion NMR signal can be ambiguous, as it contains effects from microstructure, size and orientation. In this work, the underlying microscopic structures are exposed with novel diffusion NMR methods. q-MAS is a pulse sequence for isotropic diffusion encoding, which in combination with conventional diffusion NMR can be used to quantify the microscopic anisotropy. The shape of the microscopic diffusion tensor can be revealed by varying the anisotropy of the diffusion encoding. The methods are demonstrated in lyotropic liquid crystals and yeast cell suspensions.Diffusion NMR can be used to measure exchange between intra- and extracellular compartments. This can give information on the water transport across biological cell membranes. A method for measuring exchange in yeast cells with different intra- and extracelllular T2 values is presented.
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| 5. |
- ERIKSSON, STEFANIE, et al.
(författare)
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NMR diffusion-encoding with axial symmetry and variable anisotropy: Distinguishing between prolate and oblate microscopic diffusion tensors with unknown orientation distribution
- 2015
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Ingår i: Journal of Chemical Physics. - : American Institute of Physics (AIP). - 0021-9606 .- 1089-7690. ; 142:10, s. 104201-
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Tidskriftsartikel (refereegranskat)abstract
- We introduce a nuclear magnetic resonance method for quantifying the shape of axially symmetric microscopic diffusion tensors in terms of a new diffusion anisotropy metric, D-Delta, which has unique values for oblate, spherical, and prolate tensor shapes. The pulse sequence includes a series of equal-amplitude magnetic field gradient pulse pairs, the directions of which are tailored to give an axially symmetric diffusion-encoding tensor b with variable anisotropy b(Delta). Averaging of data acquired for a range of orientations of the symmetry axis of the tensor b renders the method insensitive to the orientation distribution function of the microscopic diffusion tensors. Proof-of-principle experiments are performed on water in polydomain lyotropic liquid crystals with geometries that give rise to microscopic diffusion tensors with oblate, spherical, and prolate shapes. The method could be useful for characterizing the geometry of fluid-filled compartments in porous solids, soft matter, and biological tissues. (C) 2015 Author(s).
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| 6. |
- Eriksson, Stefanie, et al.
(författare)
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NMR quantification of diffusional exchange in cell suspensions with relaxation rate differences between intra and extracellular compartments
- 2017
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Ingår i: PLoS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 12:5
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Tidskriftsartikel (refereegranskat)abstract
- Water transport across cell membranes can be measured non-invasively with diffusion NMR. We present a method to quantify the intracellular lifetime of water in cell suspensions with short transverse relaxation times, T2, and also circumvent the confounding effect of different T2 values in the intra- and extracellular compartments. Filter exchange spectroscopy (FEXSY) is specifically sensitive to exchange between compartments with different apparent diffusivities. Our investigation shows that FEXSY could yield significantly biased results if differences in T2 are not accounted for. To mitigate this problem, we propose combining FEXSY with diffusion-relaxation correlation experiment, which can quantify differences in T2 values in compartments with different diffusivities. Our analysis uses a joint constrained fitting of the two datasets and considers the effects of diffusion, relaxation and exchange in both experiments. The method is demonstrated on yeast cells with and without human aquaporins.
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| 7. |
- Ferrari, Stefano, et al.
(författare)
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EURO-B.O.S.S. : A European study on chemotherapy in bone-sarcoma patients aged over 40: Outcome in primary high-grade osteosarcoma
- 2018
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Ingår i: Tumori. - : SAGE Publications. - 0300-8916 .- 2038-2529. ; 104:1, s. 30-36
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Tidskriftsartikel (refereegranskat)abstract
- INTRODUCTION: The EUROpean Bone Over 40 Sarcoma Study (EURO-B.O.S.S.) was the first prospective international study for patients 41-65 years old with high-grade bone sarcoma treated with an intensive chemotherapy regimen derived from protocols for younger patients with high-grade skeletal osteosarcoma.METHODS: Chemotherapy based on doxorubicin, cisplatin, ifosfamide, and methotrexate was suggested, but patients treated with other regimens at the investigators' choice were also eligible for the study.RESULTS: The present report focuses on the subgroup of 218 patients with primary high-grade osteosarcoma. With a median follow-up of 47 months, the 5-year probability of overall survival (OS) was 66% in patients with localized disease and 22% in case of synchronous metastases. The 5-year OS in patients with localized disease was 29% in pelvic tumors, and 70% and 73% for extremity or craniofacial locations, respectively. In primary chemotherapy, tumor necrosis ≥90% was reported in 21% of the patients. There were no toxic deaths; however, hematological toxicity was considerable with 32% of patients experiencing 1 or more episodes of neutropenic fever. The incidence of nephrotoxicity and neurotoxicity (mainly peripheral) was 28% and 24%, respectively. After methotrexate, 23% of patients experienced delayed excretion, in 4 cases with nephrotoxicity.CONCLUSIONS: In patients over 40 years of age with primary high-grade osteosarcoma, an aggressive approach with chemotherapy and surgery can offer the probability of survival similar to that achieved in younger patients. Chemotherapy-related toxicity is significant and generally higher than that reported in younger cohorts of osteosarcoma patients treated with more intensive regimens.
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| 8. |
- Ishikawa, Kazuhiro, et al.
(författare)
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Microemulsions of Record Low Amphiphile Concentrations Are Affected by the Ambient Gravitational Field
- 2016
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Ingår i: The Journal of Physical Chemistry Part B. - : American Chemical Society (ACS). - 1520-6106 .- 1520-5207. ; 120:26, s. 6074-6079
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Tidskriftsartikel (refereegranskat)abstract
- It is shown that the ternary system heavy water-heptane-hexadecyl hexaethylene oxide (C16E6) has a stable bicontinuous microemulsion phase down to an exceptionally low concentration at the balanced temperature of 26.8 °C. It is further demonstrated that the ambient gravitational field has an influence on the observed phase equilibria for typical sample sizes (∼1 cm). Direct measurements using a nuclear magnetic resonance imaging technique demonstrate that sample compositions vary with the height in the vials. It is furthermore found that some samples show four phases at equilibrium in apparent violation of Gibbs' phase rule. It is pointed out that Gibbs' phase rule strictly applies only when effects of gravity are negligible. A further consequence of the ambient gravitational field is that, for the system studied, the microemulsion one-phase samples are not observed, when using standard size vials, that is, sample heights on the order of a centimeter. Quantitative determinations of concentration profiles can be used to determine parameters of the free-energy density for the system.
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| 9. |
- Law, Philip J., et al.
(författare)
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Association analyses identify 31 new risk loci for colorectal cancer susceptibility
- 2019
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Ingår i: Nature Communications. - : Springer Science and Business Media LLC. - 2041-1723. ; 10
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Tidskriftsartikel (refereegranskat)abstract
- Colorectal cancer (CRC) is a leading cause of cancer-related death worldwide, and has a strong heritable basis. We report a genome-wide association analysis of 34,627 CRC cases and 71,379 controls of European ancestry that identifies SNPs at 31 new CRC risk loci. We also identify eight independent risk SNPs at the new and previously reported European CRC loci, and a further nine CRC SNPs at loci previously only identified in Asian populations. We use in situ promoter capture Hi-C (CHi-C), gene expression, and in silico annotation methods to identify likely target genes of CRC SNPs. Whilst these new SNP associations implicate target genes that are enriched for known CRC pathways such as Wnt and BMP, they also highlight novel pathways with no prior links to colorectal tumourigenesis. These findings provide further insight into CRC susceptibility and enhance the prospects of applying genetic risk scores to personalised screening and prevention.
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| 10. |
- Palmgren, Madelene, et al.
(författare)
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Quantification of the Intracellular Life Time of Water Molecules to Measure Transport Rates of Human Aquaglyceroporins
- 2017
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Ingår i: Journal of Membrane Biology. - : Springer Science and Business Media LLC. - 0022-2631 .- 1432-1424. ; 250:6, s. 629-639
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Tidskriftsartikel (refereegranskat)abstract
- Orthodox aquaporins are transmembrane channel proteins that facilitate rapid diffusion of water, while aquaglyceroporins facilitate the diffusion of small uncharged molecules such as glycerol and arsenic trioxide. Aquaglyceroporins play important roles in human physiology, in particular for glycerol metabolism and arsenic detoxification. We have developed a unique system applying the strain of the yeast Pichia pastoris, where the endogenous aquaporins/aquaglyceroporins have been removed and human aquaglyceroporins AQP3, AQP7, and AQP9 are recombinantly expressed enabling comparative permeability measurements between the expressed proteins. Using a newly established Nuclear Magnetic Resonance approach based on measurement of the intracellular life time of water, we propose that human aquaglyceroporins are poor facilitators of water and that the water transport efficiency is similar to that of passive diffusion across native cell membranes. This is distinctly different from glycerol and arsenic trioxide, where high glycerol transport efficiency was recorded.
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