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- Ghosh, Fredrik, et al.
(författare)
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Selective Removal of Photoreceptor Cells In Vivo Using the Biodegradable Elastomer Poly(Glycerol Sebacate)
- 2009
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Ingår i: Tissue Engineering. Part A. - 1937-335X. ; 17:13-14, s. 1675-1682
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Tidskriftsartikel (refereegranskat)abstract
- Retinal transplantation experiments have advanced considerably during recent years, but remaining diseased photoreceptor cells in the host retina physically obstruct the development of graft-host neuronal contacts which are required for vision. We here report selective removal of photoreceptors using the biodegradable elastomer poly(glycerol sebacate) (PGS). A 1x3 mm PGS membrane was implanted in the subretinal space of normal rabbit eyes, and morphologic specimens were examined with hematoxylin and eosin staining and a panel of immunohistochemical markers. Seven days postoperatively, a patent separation of the neuroretina and retinal pigment epithelium was found as well as loss of several rows of photoreceptors in combination with massive TUNEL staining for apoptosis in the outer nuclear layer. After 28 days, the neuroretina was reattached, the PGS membrane had degraded, and photoreceptors were absent in the implantation area. Activated Müller cells were found in the entire retina in 7-day specimens, and in the implantation area after 28 days. AII amacrine and rod bipolar cell morphology was not affected, except for disrupted dendritic branching which was present in rod bipolar cells in 28-day specimens. We conclude that retinal detachment induced by the biodegradable PGS membrane creates a permissive environment in which graft-host neuronal connections may be facilitated in future retinal transplantation experiments.
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- Huth, Cornelia, et al.
(författare)
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IL6 gene promoter polymorphisms and type 2 diabetes - Joint analysis of individual participants' data from 21 studies
- 2006
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Ingår i: DIABETES. - : American Diabetes Association. - 0012-1797 .- 1939-327X. ; 55:10, s. 2915-2921
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Tidskriftsartikel (refereegranskat)abstract
- Several lines of evidence indicate a causal role of the cytokine interleukin (IL)-6 in the development of type 2 diabetes in humans. Two common polymorphisms in the promoter of the IL-6 encoding gene IL6, −174G>C (rs1800795) and −573G>C (rs1800796), have been investigated for association with type 2 diabetes in numerous studies but with results that have been largely equivocal. To clarify the relationship between the two IL6 variants and type 2 diabetes, we analyzed individual data on >20,000 participants from 21 published and unpublished studies. Collected data represent eight different countries, making this the largest association analysis for type 2 diabetes reported to date. The GC and CC genotypes of IL6 −174G>C were associated with a decreased risk of type 2 diabetes (odds ratio 0.91, P = 0.037), corresponding to a risk modification of nearly 9%. No evidence for association was found between IL6 −573G>C and type 2 diabetes. The observed association of the IL6 −174 C-allele with a reduced risk of type 2 diabetes provides further evidence for the hypothesis that immune mediators are causally related to type 2 diabetes; however, because the association is borderline significant, additional data are still needed to confirm this finding.
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- Nadvornik, Milan, et al.
(författare)
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Syntheses, X-ray, MSn, NMR and CD structure determination of nickel(II) complexes of Schiff bases of (S)-N-(2-benzoylphenyl)-1-benzylpyrrolidine-2-carboxamide and aromatic α-amino acids
- 2008
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Ingår i: Polyhedron. - : Elsevier BV. - 0277-5387. ; 27:17, s. 3477-3483
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Tidskriftsartikel (refereegranskat)abstract
- A preparative procedure for the synthesis of an important chiral synthon of side-chain protected tyrosine was developed and optimised for the minimisation of nickel salts waste. While preparing a similar side-chain protected tryptophan synthon, an unexpected low stability was found of the Boc-protective group of the tryptophan aromatic nitrogen during purification on silica gel. X-ray crystal structure determination, tandem mass spectrometry (MS/MS) and NMR were applied for the elucidation of the structures of the prepared complexes and by-products. Stereochemistry of products of α-methylation of the complexes was assessed using a model tyrosine-derived compound.
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- Popkov, Alexander, et al.
(författare)
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New Chiral Synthons of 13C- or 15N-labelled α-amino acids
- 2006
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Ingår i: Isotopes - 9th International Symposium. ; 9, s. 206-
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- Easily available chiral synthons of α-amino acids selectively labelled with 13C or 15N could significantly simplify preparation of enantiomerically pure selectively isotopically substituted α-amino acids for NMR and MS studies of biological systems. Based on previously described preparation of labelled synthons of nucleophilic and electrophilic glycine, different approaches to labelled quaternary α-amino acids were evaluated. In the case of α-(13C)methyl α-amino acids, two alternatives exists:1. preparation of an alanine synthon by introduction of the α-(13C)methyl group into a glycine synthon followed by anattachment of a side chain;2. usage of α-amino acids synthons carrying a side chain and introduction of the α-(13C)methyl group.The second approach was found to be better suited for the preparative applications. An optimisation was done in orderto increase yields and decrease release of by-products to waste water.
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