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- Achen, M G, et al.
(författare)
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Monoclonal antibodies to vascular endothelial growth factor-D block its interactions with both VEGF receptor-2 and VEGF receptor-3.
- 2000
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Ingår i: European Journal of Biochemistry. - 0014-2956 .- 1432-1033. ; 267:9
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Tidskriftsartikel (refereegranskat)abstract
- Vascular endothelial growth factor-D (VEGF-D), the most recently discovered mammalian member of the VEGF family, is an angiogenic protein that activates VEGF receptor-2 (VEGFR-2/Flk1/KDR) and VEGFR-3 (Flt4). These receptor tyrosine kinases, localized on vascular and lymphatic endothelial cells, signal for angiogenesis and lymphangiogenesis. VEGF-D consists of a central receptor-binding VEGF homology domain (VHD) and N-terminal and C-terminal propeptides that are cleaved from the VHD to generate a mature, bioactive form consisting of dimers of the VHD. Here we report characterization of mAbs raised to the VHD of human VEGF-D in order to generate VEGF-D antagonists. The mAbs bind the fully processed VHD with high affinity and also bind unprocessed VEGF-D. We demonstrate, using bioassays for the binding and cross-linking of VEGFR-2 and VEGFR-3 and biosensor analysis with immobilized receptors, that one of the mAbs, designated VD1, is able to compete potently with mature VEGF-D for binding to both VEGFR-2 and VEGFR-3 for binding to mature VEGF-D. This indicates that the binding epitopes on VEGF-D for these two receptors may be in close proximity. Furthermore, VD1 blocks the mitogenic response of human microvascular endothelial cells to VEGF-D. The anti-(VEGF-D) mAbs raised to the bioactive region of this growth factor will be powerful tools for analysis of the biological functions of VEGF-D.
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2. |
- Bergström, Joakim, et al.
(författare)
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Two different types of amyloid deposits - apolipoprotein A-IV and transthyretin - in a patient with systemic amyloidosis
- 2004
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Ingår i: Lab. Invest.. ; 84, s. 981-988
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Tidskriftsartikel (refereegranskat)abstract
- Certain forms of systemic amyloidosis have been associated with the pathologic deposition as fibrils of three different apolipoprotein-related proteins--apolipoprotein A-I, apolipoprotein A-II, and serum amyloid A. We have previously reported (Bergstrom et al, Biochem Biophys Res Commun 2001;285:903-908) that amyloid fibrils extracted from the heart of an elderly male with senile systemic amyloidosis contained, in addition to wild-type transthyretin-related molecules, an N-terminal fragment of yet a fourth apolipoprotein--apolipoprotein A-IV (apoA-IV). We now provide the results of our studies that have established the complete amino-acid sequence of this approximately 70-residue component and, additionally, have shown this protein to be the product of an unmutated apoA-IV gene. Notably, the apoA-IV and transthyretin fibrils were not codeposited but, rather, had anatomically distinct patterns of distribution within the heart and other organs, as evidenced immunohistochemically, by variation in the ultra structural morphology and by differences in the intensity of Congo red birefringence. These findings provide the first conclusive evidence that two separate forms of amyloid, each derived from a wild-type amyloidogenic precursor protein, were present in a patient with systemic amyloidosis.
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3. |
- Holten-Andersen, MN, et al.
(författare)
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Measurement of the noncomplexed free fraction of tissue inhibitor of metalloproteinases I in plasma by immunoassay
- 2002
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Ingår i: Clinical Chemistry. - 0009-9147. ; 48:8, s. 1305-1313
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Tidskriftsartikel (refereegranskat)abstract
- Background: We previously found differences in total concentrations of tissue inhibitor of metalloproteinases 1 (TIMP-1) in plasma from donors and cancer patients. Because TIMP-1 can exist in more than one molecular form, a new immunoassay to specifically detect free TIMP-1 was developed and concentrations were determined in plasma from healthy donors and colorectal cancer (CRC) patients. Methods: We established and validated an immunoassay for the specific measurement of free TIMP-1 that uses a polyclonal anti-TIMP-1 antibody for capture and a monoclonal anti-TIMP-1 antibody that binds only free TIMP-1 for detection of antigen. Plasma samples from healthy donors and CRC patients were assayed for free TIMP-1. Total TIMP-1 was measured by our previously published assay. Results: The mean (SD) concentrations of free TIMP-1 were similar in citrate [55.5 (11.5) mug/L] and EDTA plasma [58.9 (13.3) mug/L] from 76 donors (r(2) = 0.82). In 154 donors, the ratio of free TIMP-1 [mean (SD), 64.5 (18.0) mug/L] to total TIMP-1 [83.8 (19.8) mug/L] in EDTA plasma was 0.77. Plasma concentrations of free and total TIMP-1 correlated significantly to age (free, r(2) = 0.19; total, r(2) = .0.27; P < 0.0001), increasing 50% over an age span of 45 years. Free and total TIMP-1 were significantly increased in CRC patients (P < 0.0001), whereas the ratio of free to total TIMP-1 (mean, 0.58) was significantly lower than in donors. Conclusions: Most of the TIMP-1 in donor plasma is present in its free form, and free TIMP-1 increases with age. Free and total TIMP-1 are increased in CRC patient plasma, but the ratio of free to total TIMP-1 is significantly lower in these patients than in donors. (C) 2002 American Association for Clinical Chemistry.
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4. |
- Lundmark, Katarzyna, et al.
(författare)
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Transmissibility of systemic amyloidosis by a prion-like mechanism
- 2002
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Ingår i: Proceedings of the National Academy of Sciences of the United States of America. - : Proceedings of the National Academy of Sciences. - 0027-8424 .- 1091-6490. ; 99:10, s. 6979-6984
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Tidskriftsartikel (refereegranskat)abstract
- The generation of amyloid fibrils from an amyloidogenic polypeptide occurs by a nucleation-dependent process initiated in vitro by seeding the protein solution with preformed fibrils. This phenomenon is evidenced in vivo by the fact that amyloid protein A (AA) amyloidosis in mice is markedly accelerated when the animals are given, in addition to an inflammatory stimulus, an i.v. injection of protein extracted from AA amyloid-laden mouse tissue. Heretofore, the chemical nature of this “amyloid enhancing factor” (AEF) has not been definitively identified. Here we report that the active principle of AEF extracted from the spleen of mice with silver nitrate-induced AA amyloidosis was identified unequivocally as the AA fibril itself. Further, we demonstrated that this material was extremely potent, being active in doses <1 ng, and that it retained its biologic activity over a considerable length of time. Notably, the AEF was also effective when administered orally. Our studies have provided evidence that AA and perhaps other forms of amyloidosis are transmissible diseases, akin to the prion-associated disorders.
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