| 1. |
- Wenger, Anna, 1990, et al.
(författare)
-
Stem cell cultures derived from pediatric brain tumors accurately model the originating tumors.
- 2017
-
Ingår i: Oncotarget. - : Impact Journals, LLC. - 1949-2553. ; 8, s. 18626-18639
-
Tidskriftsartikel (refereegranskat)abstract
- Brain tumors are the leading cause of cancer-related death in children but high-grade gliomas in children and adolescents have remained a relatively under-investigated disease despite this. A better understanding of the cellular and molecular pathogenesis of the diseases is required in order to improve the outcome for these children. In vitro-cultured primary tumor cells from patients are indispensable tools for this purpose by enabling functional analyses and development of new therapies. However, relevant well-characterized in vitro cultures from pediatric gliomas cultured under serum-free conditions have been lacking. We have therefore established patient-derived in vitro cultures and performed thorough characterization of the cells using large-scale analyses of DNA methylation, copy-number alterations and investigated their stability during prolonged time in culture. We show that the cells were stable during prolonged culture in serum-free stem cell media without apparent alterations in morphology or growth rate. The cells were proliferative, positive for stem cell markers, able to respond to differentiation cues and initiated tumors in zebrafish and mice suggesting that the cells are cancer stem cells or progenitor cells. The cells accurately mirrored the tumor they were derived from in terms of methylation pattern, copy number alterations and DNA mutations. These unique primary in vitro cultures can thus be used as a relevant and robust model system for functional studies on pediatric brain tumors.
|
|
| 2. |
- Berglund, Anna, 1949-, et al.
(författare)
-
Våldsutsatta kvinnor- samhällets ansvar
- 2014. - 3
-
Ingår i: Lärobok, tredje upplagan, framtagen av Nationellt centrum för kvinnofrid, Uppsala universitet. - Uppsala : Studentlitteratur AB. - 9789144094441
-
Bokkapitel (övrigt vetenskapligt/konstnärligt)
|
|
| 3. |
- Byström, Emil, et al.
(författare)
-
Plasma brominated polymer particles as grafting substrate for thiol-terminated telomers
- 2010
-
Ingår i: Journal of Separation Science. - Weinheim : WILEY-VCH Verlag GmbH & Co. KGaA. - 1615-9306 .- 1615-9314. ; 33:11, s. 1563-70
-
Tidskriftsartikel (refereegranskat)abstract
- A combined surface activation and "grafting to" strategy was developed to convert divinylbenzene particles into weak cation exchangers suitable for protein separation. The initial activation step was based on plasma modification with bromoform, which rendered the particles amenable to further reaction with nucleophiles by introducing Br to a surface content of 11.2 atom-%, as determined by X-ray photoelectron spectroscopy. Grafting of thiol-terminated glydicyl methacrylate telomers to freshly plasma activated surfaces was accomplished without the use of added initiator, and the grafting was verified both by reduction in bromine content and the appearance of sulfur-carbon linkages, showing that the surface grafts were covalently bonded. Following grafting the attached glydicyl methacrylate telomer tentacles were further modified by a two-step procedure involving hydrolysis to 2,3-hydroxypropyl groups and conversion of hydroxyl groups to carboxylate functionality by succinic anhydride. The final material was capable of baseline separating four model proteins in 3 min by gradient cation exchange chromatography in a fully aqueous eluent.
|
|
| 4. |
- Danielsson, Anna, 1973, et al.
(författare)
-
MethPed: a DNA methylation classifier tool for the identification of pediatric brain tumor subtypes
- 2015
-
Ingår i: Clinical Epigenetics. - : Springer Science and Business Media LLC. - 1868-7083 .- 1868-7075. ; 7
-
Tidskriftsartikel (refereegranskat)abstract
- Background: Classification of pediatric tumors into biologically defined subtypes is challenging, and multifaceted approaches are needed. For this aim, we developed a diagnostic classifier based on DNA methylation profiles. Results: Methylation data generated by the Illumina Infinium HumanMethylation 450 BeadChip arrays were downloaded from the Gene Expression Omnibus (n = 472). Using the data, we built MethPed, which is a multiclass random forest algorithm, based on DNA methylation profiles from nine subgroups of pediatric brain tumors. DNA from 18 regional samples was used to validate MethPed. MethPed was additionally applied to a set of 28 publically available tumors with the heterogeneous diagnosis PNET. MethPed could successfully separate individual histology tumor types at a very high accuracy (kappa = 0.98). Analysis of a regional cohort demonstrated the clinical benefit of MethPed, as confirmation of diagnosis of tumors with clear histology but also identified possible differential diagnoses in tumors with complicated and mixed type morphology. Conclusions: We demonstrate the utility of methylation profiling of pediatric brain tumors and offer MethPed as an easy-to-use toolbox that allows researchers and clinical diagnosticians to test single samples as well as large cohorts for subclass prediction of pediatric brain tumors. This will immediately aid clinical practice and importantly increase our molecular knowledge of these tumors for further therapeutic development.
|
|
| 5. |
- Fragemann, Anna, et al.
(författare)
-
Frequency converters from visible to mid-infrared with periodically poled RbTiOPO4
- 2003
-
Ingår i: Applied Physics Letters. - : AIP Publishing. - 0003-6951 .- 1077-3118. ; 83:15, s. 3090-3092
-
Tidskriftsartikel (refereegranskat)abstract
- Electric-field poling has been used to fabricate quasi-phase-matched frequency converters in RbTiOPO4. A more accurate Sellmeier equation has been obtained for wavelengths between 0.43 and 3.4 mum. The dispersion of the thermo-optic coefficient for n(z) refractive index has been derived in the near- to mid-infrared spectral region. The nonlinear performance of periodically poled RbTiOPO4 obtained in the infrared optical parametric devices is comparable to that of periodically poled KTiOPO4.
|
|
| 6. |
- Hemström, Petrus, et al.
(författare)
-
Polymer-based monolithic microcolumns for hydrophobic interaction chromatography of proteins.
- 2006
-
Ingår i: Journal of Separation Science. - : Wiley. - 1615-9306 .- 1615-9314. ; 29:1, s. 25-32
-
Tidskriftsartikel (refereegranskat)abstract
- Monolithic capillary columns for hydrophobic interaction chromatography (HIC) have been prepared by thermally initiated, single-step in situ polymerization of mixtures of monovinyl monomers including butyl methacrylate and/or 2-hydroxyethyl methacrylate, with a divinyl crosslinker glycerol dimethacrylate or 1,4-butanediol dimethacrylate using two different porogen systems. Two porogenic solvent mixtures were used; one "hydrophilic", consisting of water, butanediol, and propanol, and one "hydrophobic," comprising dodecanol and cyclohexanol. The porous structures of the monoliths were characterized and their performance was demonstrated with a separation of a mixture of myoglobin, ribonuclease A, and lysozyme under conditions typical of HIC.
|
|
| 7. |
- Nguyen, Anh Mai, et al.
(författare)
-
Thermally induced dissolution/precipitation : A simple approach for the preparation of Macroporous Monoliths from Linear Aliphatic Polyamides
- 2009
-
Ingår i: Journal of Separation Science. - : Wiley InterScience. - 1615-9306 .- 1615-9314. ; 32:15-16, s. 2619-2628
-
Tidskriftsartikel (refereegranskat)abstract
- A versatile way of preparing macroporous monolithic materials from linear aliphatic polyamides is presented. Simply, polyamide pellets were treated in benzyl alcohol (BA) at elevated temperature, causing dissolution by interchain hydrogen bond disruption. Subsequent cooling below the upper critical solution temperature (UCST) resulted in precipitation and partial restoration of the semicrystalline polymer, which is organized into network structures. The final steps were a solvent exchange of BA for methanol, followed by drying to form monolithic entities. A number of polyamides ranging from hydrophilic to hydrophobic were tested and under the experimental conditions, poly(1-aza-2-cycloheptanone (PA6) and (poly-[imino-1,6-hexanediylimino{1,10-dioxo-1,10-decanediyl}] (PA610) yielded entities with macroporous properties that were deemed useful for liquid chromatography. The morphological features and porous properties of the monoliths produced by this dissolution-precipitation procedure were studied by scanning electron microscopy, adsorption/desorption of N2(g) according to the Brunauer-Emmett-Teller (BET) principle, and mercury intrusion porosimetry. Degradation of the polymer backbone was noticeable when the dissolution time was extended and shortening of the polymer chains was confirmed by MALDI-MS, viscosity measurements, X-ray photoelectron spectroscopy (XPS), and potentiometric titration. When the heating was limited to the time it took to dissolve the polymers, mechanically stable monoliths could be obtained. The dissolution/heat treatment time further seemed to be useful for controlling the macroporous morphology.
|
|
| 8. |
- Nordborg, Anna, et al.
(författare)
-
A cation-exchange material for protein separations based on grafting of thiol-terminated sulfopropyl methacrylate telomers onto hydrophilized monodisperse divinylbenzene particles
- 2008
-
Ingår i: Journal of Separation Science. - : Wiley-VCH Verlagsgesellschaft. - 1615-9306 .- 1615-9314. ; 31:12, s. 2143-2150
-
Tidskriftsartikel (refereegranskat)abstract
- A strong cation-exchange separation material has been prepared from monodisperse divinylbenzene particles modified by a grafting to approach, utilizing as anchoring points epoxy groups introduced onto the surface of the particles via oxidation of residual vinyl groups. The grafted chains consisted of thiol-terminated telomers of sulfopropyl methacrylate prepared by iniferter mediated polymerization, and grafting was performed by reaction of the corresponding thiolate anion with the surface epoxy groups. Attachment through epoxy moieties that were subsequently converted into 2,3-propanediol groups increased the hydrophilicity of the polymeric particles and incubation experiments showed no signs of the proteins denaturing on the column during an extended contact time of 1 h at room temperature. The performance of the grafted material was demonstrated by the chromatographic separation of cytochrome C, lysozyme, myoglobin, and ribonuclease A, in a cation-exchange mode.
|
|
| 9. |
|
|
| 10. |
- Nordborg, Anna, et al.
(författare)
-
A Library of Thiol-Terminated Methacrylate Telomers Prepared by Photoinitiated Iniferter Mediated Polymerization for Use in Modifications of Chromatographic Surfaces by the "Grafting to" Approach
- 2010
-
Ingår i: Journal of Applied Polymer Science. - [Nordborg, Anna; Irgum, Knut] Umea Univ, Dept Chem, S-90187 Umea, Sweden. : Wiley. - 0021-8995 .- 1097-4628. ; 117:5, s. 2781-2789
-
Tidskriftsartikel (refereegranskat)abstract
- A library of thiol-terminated methacrylate telomers aimed for use in surface modifications of chromatographic support materials has been prepared by iniferter mediated polymerization, using isopropylxanthic disulfide as a photoiniferter. The telomers range from hydrophobic to hydrophilic and were prepared in different lengths, with the length being adjusted by the ratio of monomer to iniferter used in the polymerization mixture. The telomers were characterized by size-exclusion chromatography and MALDI-TOF-MS. In initial surface characterization experiments, the prepared telomers were attached to the inner surface of fused silica capillaries by radical initiated addition to vinyl groups, and the electro-osmotic flow (EOF) in the prepared capillaries was determined in a capillary electrophoresis set-up. The EOF measurements verified surface grafting.
|
|
