| 1. |
- Bourquin, V., et al.
(författare)
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Xyloglucan endotransglycosylases have a function during the formation of secondary cell walls of vascular tissues
- 2002
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Ingår i: The Plant Cell. - : Oxford University Press (OUP). - 1040-4651 .- 1532-298X. ; 14:12, s. 3073-3088
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Tidskriftsartikel (refereegranskat)abstract
- Xyloglucan transglycosylases (XETs) have been implicated in many aspects of cell wall biosynthesis, but their function in vascular tissues, in general, and in the formation of secondary walls, in particular, is less well understood. Using an in situ XET activity assay in poplar stems, we have demonstrated XET activity in xylem and phloem fibers at the stage of secondary wall formation. Immunolocalization of fucosylated xylogucan with CCRC-M1 antibodies showed that levels of this species increased at the border between the primary and secondary wall layers at the time of secondary wall deposition. Furthermore, one of the most abundant XET isoforms in secondary vascular tissues (PttXET16A) was cloned and immunolocalized to fibers at the stage of secondary wall formation. Together, these data strongly suggest that XET has a previously unreported role in restructuring primary walls at the time when secondary wall layers are deposited, probably creating and reinforcing the connections between the primary and secondary wall layers. We also observed that xylogucan is incorporated at a high level in the inner layer of nacreous walls of mature sieve tube elements.
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| 2. |
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| 3. |
- Kobayashi, T, et al.
(författare)
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Lack of antibody production against Hanganutziu-Deicher (H-D) antigens with N-glycolylneuraminic acid in patients with porcine exposure history.
- 2000
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Ingår i: Xenotransplantation. - : Wiley. - 0908-665X. ; 7:3, s. 177-80
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Tidskriftsartikel (refereegranskat)abstract
- The significance of non-alphagalactosyl antigens remains unclear in pig-to-primate xenotransplantation. Hanganutziu-Deicher (H-D) antigens with terminal N-glycolylneuraminic acid (NeuGc) are widely expressed on endothelial cells of mammalian species, with the exception of humans. As baboons and monkeys also express H-D antigens, a pig-to-non-human primate experimental model cannot resolve the question of whether H-D antigens can elicit a potent humoral response in human recipients. The purpose of this study was to elucidate the clinical significance of H-D antigens by examining the sera from patients who have been previously exposed to porcine tissue. After the digestion of porcine aortic endothelial cells (PAEC) by neuraminidase, NeuGc and N-acetylneuraminic acid (NeuAc) were quantitated by HPLC. IgG and IgM antibody levels against H-D antigens were measured by NeuGc-GM3-coated ELISA plates in the sera of patients who had undergone ex vivo kidney perfusion 1 to 3 weeks and 2 years previously (n=2) or had been injected with fetal porcine islets 2 months previously (n= 10). HPLC determined that 9.7x 10(7) NeuAc and 6.3x 10(7) NeuGc residues per cell were released from PAEC by neuraminidase, while 25.7x 10(7) NeuAc and an undetectable level of NeuGc were released from human aortic endothelial cells (HAEC). No significant elevation of IgG or IgM antibody levels against NeuGc-GM3 was observed in sera from patients with a history of porcine exposure. Considering the active production of antibody against the foreign galactosyl antigens after pig-to-human xenotransplantation, some production of antibodies against the equally foreign H-D antigens would be expected, because large amounts of NeuGc terminated saccharides are present in the pig endothelial cell surface. However, no production of antibodies directed to H-D antigens could be found in patients exposed to porcine tissue. Further studies are warranted to explain why H-D antigens do not elicit a significant antibody production.
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| 4. |
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| 5. |
- Petrykin, V., Kakihana, M., Tanaka,Y., Yasuoka, H., Abe, M. and Eriksson, S.
(författare)
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Ferromagnetic and superconducting properties of pure RuCe0.5Eu1.5Sr2Cu2O10 samples prepared by polymerizable complex method
- 2002
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Ingår i: Physica. ; C 378-381, s. 47-
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Tidskriftsartikel (refereegranskat)
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| 6. |
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| 7. |
- Yoshihara, S., et al.
(författare)
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Long-lasting smooth-muscle relaxation by a novel PACAP analogue in human bronchi
- 2004
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Ingår i: Regul Pept. ; 123:1-3
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Tidskriftsartikel (refereegranskat)abstract
- We compared the relaxant effect of original pituitary adenylate cyclase-activating peptide (PACAP)1-27 with that of a newly developed, synthetic PACAP1-27 analogue, [Arg(15,20,21) Leu(17)]-PACAP-Gly-Lys-Arg-NH(2), in human bronchi in vitro (n=4-5 in each group). Using precontraction by carbachol (0.1 muM), cumulative administration of PACAP1-27 and salbutamol caused concentration-dependent smooth muscle relaxation with similar potencies and maximum relaxant effects. Non-cumulative administration of the PACAP1-27 analogue and the original PACAP1-27 caused concentration-dependent relaxation with a similar maximum relaxant effect and potency as well. However, the onset and offset of action was markedly slower for the PACAP1-27 analogue than for the original PACAP1-27 (>90% versus <10% of peak relaxation remaining 5 h after administration). Peptidase inhibition by captopril (10 muM) and phosphoramidon (1 muM) significantly increased the maximum relaxant effect and duration of action of PACAP1-27 but not of the PACAP1-27 analogue, during the 3 h of observation in the human bronchi. We conclude that [Arg(15,20,21) Leu(17)]-PACAP-Gly-Lys-Arg-NH(2) produces significant concentration-dependent and sustained bronchial smooth muscle relaxation in vitro. The sustained relaxant effect is due, at least in part, to the synthetic PACAP1-27 analogue being less susceptible to cleavage by peptidases than the original peptide PACAP1-27.
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