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- Hertegard, S., et al.
(författare)
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Viscoelastic and histologic properties in scarred rabbit vocal folds after mesenchymal stem cell injection
- 2006
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Ingår i: The Laryngoscope. - : Wiley-Blackwell. - 0023-852X .- 1531-4995. ; 116:7, s. 1248-1254
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVE/HYPOTHESIS:The aim of this study was to analyze the short-term viscoelastic and histologic properties of scarred rabbit vocal folds after injection of human mesenchymal stem cells (MSC) as well as the degree of MSC survival. Because MSCs are antiinflammatory and regenerate mesenchymal tissues, can MSC injection reduce vocal fold scarring after injury?STUDY DESIGN:Twelve vocal folds from 10 New Zealand rabbits were scarred by a localized resection and injected with human MSC or saline. Eight vocal folds were left as controls.MATERIAL AND METHODS:After 4 weeks, 10 larynges were stained for histology and evaluation of the lamina propria thickness. Collagen type I content was analyzed from six rabbits. MSC survival was analyzed by fluorescent in situ hybridization staining from three rabbits. Viscoelasticity for 10 vocal folds was analyzed in a parallel-plate rheometer.RESULTS:The rheometry on fresh-frozen samples showed decreased dynamic viscosity and lower elastic modulus (P<.01) in the scarred samples injected with MSC as compared with the untreated scarred group. Normal controls had lower dynamic viscosity and elastic modulus as compared with the scarred untreated and treated vocal folds (P<.01). Histologic analysis showed a higher content of collagen type 1 in the scarred samples as compared with the normal vocal folds and with the scarred folds treated with MSC. MSCs remained in all samples analyzed.CONCLUSIONS:The treated scarred vocal folds showed persistent MSC. Injection of scarred rabbit vocal folds with MSC rendered improved viscoelastic parameters and less signs of scarring expressed as collagen content in comparison to the untreated scarred vocal folds.
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| 2. |
- De Sitter, K, et al.
(författare)
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Silica filled poly(1-trimethylsilyl-1-propyne) nanocomposite membranes: Relation between the transport of gases and structural characteristics
- 2006
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Ingår i: Journal of Membrane Science. - : Elsevier BV. - 0376-7388. ; 278:1-2, s. 83-91
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Tidskriftsartikel (refereegranskat)abstract
- The performance of poly(1-trimethylsilyl-1-propyne) (PTMSP)/silica nanocomposites was studied for membranes with a filler content between 0 and 50 wt%. An increase in permeability and a decrease in vapor selectivity was measured with increasing filler content. The free volume sizes and interstitial mesopore sizes of the composites were determined by use of positron annihilation lifetime spectroscopy (PALS). In addition to an increase in large free volume size with increasing filler content, interstitial mesopores were observed in all PTMSP/silica nanocomposites. The size of these interstitial cavities, located between the particles of a silica agglomerate, was increasing with increasing filler concentration. The presence of these agglomerates was visualized by TEM. The existence of the cavities was confirmed by nitrogen adsorption measurements. The hydrogen, nitrogen and propane permeability was clearly correlated with the size of the interstitial mesopores. (c) 2005 Elsevier B.V. All rights reserved.
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| 4. |
- Maurer, Matthew, et al.
(författare)
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3-Phosphoinositide-dependent kinase 1 potentiates upstream lesions on the phosphatidylinositol 3-kinase pathway in breast carcinoma
- 2009
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Ingår i: Cancer Research. - 1538-7445. ; 69:15, s. 306-6299
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Tidskriftsartikel (refereegranskat)abstract
- Lesions of ERBB2, PTEN, and PIK3CA activate the phosphatidylinositol 3-kinase (PI3K) pathway during cancer development by increasing levels of phosphatidylinositol-3,4,5-triphosphate (PIP(3)). 3-Phosphoinositide-dependent kinase 1 (PDK1) is the first node of the PI3K signal output and is required for activation of AKT. PIP(3) recruits PDK1 and AKT to the cell membrane through interactions with their pleckstrin homology domains, allowing PDK1 to activate AKT by phosphorylating it at residue threonine-308. We show that total PDK1 protein and mRNA were overexpressed in a majority of human breast cancers and that 21% of tumors had five or more copies of the gene encoding PDK1, PDPK1. We found that increased PDPK1 copy number was associated with upstream pathway lesions (ERBB2 amplification, PTEN loss, or PIK3CA mutation), as well as patient survival. Examination of an independent set of breast cancers and tumor cell lines derived from multiple forms of human cancers also found increased PDK1 protein levels associated with such upstream pathway lesions. In human mammary cells, PDK1 enhanced the ability of upstream lesions to signal to AKT, stimulate cell growth and migration, and rendered cells more resistant to PDK1 and PI3K inhibition. After orthotopic transplantation, PDK1 overexpression was not oncogenic but dramatically enhanced the ability of ERBB2 to form tumors. Our studies argue that PDK1 overexpression and increased PDPK1 copy number are common occurrences in cancer that potentiate the oncogenic effect of upstream lesions on the PI3K pathway. Therefore, we conclude that alteration of PDK1 is a critical component of oncogenic PI3K signaling in breast cancer.
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| 7. |
- Winberg, Petra, et al.
(författare)
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Free volume and interstitial mesopores in silica filled poly(I-trimethylsilyl-l-propyne) nanocomposites
- 2005
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Ingår i: Macromolecules. - : American Chemical Society (ACS). - 0024-9297 .- 1520-5835. ; 38:9, s. 3776-3782
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Tidskriftsartikel (refereegranskat)abstract
- The free volume sizes and interstitial mesopore sizes in poly(l-trimethylsilyl-l-propyne) (PTMSP)/silica nanocomposites and the correlation between nitrogen permeability and cavity sizes were studied with positron annihilation lifetime spectroscopy (PALS) at filler concentrations between 0 and 50 wt %. A bimodal free volume distribution was observed for PTMSP, and the size of the larger free volume cavities was significantly increased upon addition of hydrophobic fumed silica. Nanometer-sized interstitial cavities in filler agglomerates were observed in all PTMSP/fumed silica nanocomposites and in neat hydrophobic fumed silica. The radius of these interstitial mesopores in the nanocomposites decreased with decreasing filler concentration. A strong correlation between nitrogen permeability and the volume of the interstitial mesopores in the nanocomposite membranes was observed.
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