| 1. |
- Bausch, Birke, et al.
(författare)
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Germline NF1 mutational spectra and loss-of-heterozygosity analyses in patients with pheochromocytoma and neurofibromatosis type 1.
- 2007
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Ingår i: Journal of Clinical Endocrinology and Metabolism. - : The Endocrine Society. - 0021-972X .- 1945-7197. ; 92:7, s. 2784-92
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Neurofibromatosis type 1 (NF1) is a pheochromocytoma-associated syndrome. Because of the low prevalence of pheochromocytoma in NF1, we ascertained subjects by pheochromocytoma that also had NF1 in the hope of describing the germline NF1 mutational spectra of NF1-related pheochromocytoma.MATERIALS AND METHODS: An international registry for NF1-pheochromocytomas was established. Mutation scanning was performed using denaturing HPLC for intragenic variation and quantitative PCR for large deletions. Loss-of-heterozygosity analysis using markers in and around NF1 was performed.RESULTS: There were 37 eligible subjects (ages 14-70 yr). Of 21 patients with corresponding tumor available, 67% showed somatic loss of the nonmutated allele at the NF1 locus vs. 0 of 12 sporadic tumors (P = 0.0002). Overall, 86% of the 37 patients had exonic or splice site mutations, 14% large deletions or duplications; 79% of the mutations are novel. The cysteine-serine rich domain (CSR) was affected in 35% but the RAS GTPase activating protein domain (RGD) in only 13%. There did not appear to be an association between any clinical features, particularly pheochromocytoma presentation and severity, and NF1 mutation genotype.CONCLUSIONS: The germline NF1 mutational spectra comprise intragenic mutations and deletions in individuals with pheochromocytoma and NF1. NF1 mutations tended to cluster in the CSR over the RAS-GAP domain, suggesting that CSR plays a more prominent role in individuals with NF1-pheochromocytoma than in NF1 individuals without this tumor. Loss-of-heterozygosity of NF1 markers in NF1-related pheochromocytoma was significantly more frequent than in sporadic pheochromocytoma, providing further molecular evidence that pheochromocytoma is a true component of NF1.
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| 2. |
- Brede, Jens, et al.
(författare)
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Dynamics of molecular self-ordering in tetraphenyl porphyrin monolayers on metallic substrates
- 2009
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Ingår i: NANOTECHNOLOGY. - : IOP Publishing. - 0957-4484 .- 1361-6528. ; 20:27, s. 275602-
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Tidskriftsartikel (refereegranskat)abstract
- A molecular model system of tetraphenyl porphyrins (TPP) adsorbed on metallic substrates is systematically investigated within a joint scanning tunnelling microscopy/molecular modelling approach. The molecular conformation of TPP molecules, their adsorption on a gold surface and the growth of highly ordered TPP islands are modelled with a combination of density functional theory and dynamic force field methods. The results indicate a subtle interplay between different contributions. The molecule-substrate interaction causes a bending of the porphyrin core which also determines the relative orientations of phenyl legs attached to the core. A major consequence of this is a characteristic (and energetically most favourable) arrangement of molecules within self-assembled molecular clusters; the phenyl legs of adjacent molecules are not aligned parallel to each other (often denoted as pi-pi stacking) but perpendicularly in a T-shaped arrangement. The results of the simulations are fully consistent with the scanning tunnelling microscopy observations, in terms of the symmetries of individual molecules, orientation and relative alignment of molecules in the self-assembled clusters.
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| 3. |
- Hoffmann, Markus, et al.
(författare)
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Enhanced pi conjugation around a porphyrin[6] nanoring
- 2008
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Ingår i: Angewandte Chemie - International Edition. - : Wiley. - 1433-7851 .- 1521-3773. ; 47:27, s. 4993-4996
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Tidskriftsartikel (refereegranskat)abstract
- (Figure Presented) Strong cycle: The cyclic hexamer-template complex 3 obtained through template-directed trimerization of a porphyrin dimer 2, using a hexapyridyl template 1, is extremely stable (K f =7×10 38 m -1 ), but the free macrocycle 4 can be liberated using amine ligands. Spectroscopic data and DFT calculations show that the cyclic hexamer is more conjugated than its linear analogue. © 2008 Wiley-VCH Verlag GmbH & Co. KGaA.
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| 4. |
- Hoffmann, Markus H., et al.
(författare)
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The rheumatoid arthritis-associated autoantigen hnRNP-A2 (RA33) is a major stimulator of autoimmunity in rats with pristane-induced arthritis
- 2007
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Ingår i: Journal of Immunology. - 1550-6606. ; 179:11, s. 7568-7576
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Tidskriftsartikel (refereegranskat)abstract
- A single intradermal injection of the mineral oil pristane in susceptible DA.1F rats induces erosive arthritis closely mimicking rheumatoid arthritis (RA). Pristane-induced arthritis (PIA) is driven by autoreactive T cells but no autoantigen has been identified to date. We therefore analyzed B and T cell responses to autoantigens potentially involved in the pathogenesis of RA, including IgG, citrullinated proteins, stress proteins, glucose-6-phosphate isomerase, and heterogeneous nuclear ribonucleoprotein (hnRNP)-A2 (RA33). IgG and lgM autoantibodies to hnRNP-A2 were detectable in sera of pristane-primed DA.1F rats already 1 wk before disease onset, reached maximum levels during the acute phase, and correlated with arthritis severity. Apart from rheumatoid factor, autoantibodies to other Ags were not observed. CD4(+) lymph node cells isolated 10 days after pristane injection produced IFN-gamma but not IL-4 in response to stimulation with hnRNP-A2, whereas none of the other candidate Ags elicited cytokine secretion. Surprisingly, hnRNP-A2 also stimulated lymph node cells of naive animals to produce inflammatory cytokines in a MyD88-dependent manner. Furthermore, hnRNP-A2 was highly overexpressed in the joints of rats injected with pristane. Overexpression coincided with the appearance of anti-RA33 Abs and preceded the onset of clinical symptoms of PIA by several days. Taken together, these data suggest hnRNP-A2 to be among the primary inducers of autoimmunity in PIA. Therefore, this Ag might play a pivotal role in the pathogenesis of PIA and possibly also human RA.
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| 5. |
- Kuimova, M. K., et al.
(författare)
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Determination of the triplet state energies of a series of conjugated porphyrin oligomers
- 2007
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Ingår i: Photochemical and Photobiological Sciences. - : Springer Science and Business Media LLC. - 1474-9092 .- 1474-905X. ; 6:6, s. 675-682
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Tidskriftsartikel (refereegranskat)abstract
- We report a systematic study of the photophysical parameters relevant to photodynamic therapy (PDT) by a new type of sensitizers, conjugated porphyrin oligomers. Due to the strong nonlinear properties of oligomers containing 2, 4 and 8 porphyrin units, these molecules are attractive candidates for PDT via multiphoton excitation. The triplet state energy levels for all molecules have been determined by the triplet quenching method, phosphorescence measurements and DFT calculations. We find that the triplet energies of all the oligomers are sufficient to generate singlet oxygen, > 94 kJ mol(-1). However, low singlet oxygen quantum yields are observed for the tetramer and the octamer, as compared to the conjugated dimer and monomeric porphyrin, reflecting the decrease in triplet yield. Thus the conjugated porphyrin dimer is the most promising core structure for PDT applications via multiphoton excitation.
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