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Arnold G. Herman - One of the best experts on this subject based on the ideXlab platform.

  • Effects of storage temperature and Fetal Calf Serum on the endothelium of porcine aortic valves: Functional and microscopic evaluation
    Cardiac Valve Allografts, 1997
    Co-Authors: X.-j. Feng, Cor E. Van Hove, P. J. Walter, Luc Andries, Arnold G. Herman
    Abstract:

    Endothelial integrity and function may be an important determinant for long-term success of allograft heart valves. To determine the optimal storage temperatures for preserving long-term endothelial function of porcine aortic valves, different storage temperatures and different periods of time were investigated. Fresh valves were either a) stored at 4 °C with or without 10% Fetal Calf Serum (FCS) supplement, for 1, 2,4, 7, 14, 21, and 28 days. b) cryopreserved for 2, 4, and 8 weeks without FCS in either at − 80 °C or at − 170 °C. c) cryopreserved in long-term storage (as long as 1 year), with or without FCS, at − 170 °C. Viability of endothelial cells was assessed through measurement of the production of prostacyclin (PGI2) in basal and bradykinin (BK) stimulated conditions, during in vitro incubation of the valve cusps at 37 °C, using a radioimmunoassay for 6-oxo-prostaglandin F1α (PGF1α). Endothelial morphological variations in valves stored at 4 °C were evaluated by scanning electron microscopy (SEM), in valves cryopreserved at − 80 °C and − 170 °C were evaluated by confocal scanning laser microscopy (CSLM). Results: a) With storage at 4 °C, after 4 days the valves produced already significantly less (p < 0.05) PGI2 than fresh preparations in both basal (0.21 ± 0.04 vs 3.56 ± 0.03 ng/ml · cm2) and stimulated conditions (4.17 ± 0.36 vs 24.23 ± 1.83). Morphological changes could not yet be distinguished with SEM at that time. When the storage period was extended, the levels of PGI2 further diminished; after 14 days, PGI2 release could no longer be detected. b) In cryopreserved valves, PGI2 production was similar for as long as 2 weeks of storage either at − 80 °C or at − 170 °C in basal (2.69 ± 0.63 vs 2.93 ± 0.51) and stimulated (16.43 ± 3.19 vs 16.50 ± 2.57) conditions. After 8 weeks, no PGI2 release could be detected in valves stored at − 80 °C. c) After 6 months storage at − 170 °C, the PGI2 production was significantly (p < 0.05) reduced compared with fresh valves; it then remained constant for as long as 1 year. The valves stored with Fetal Calf Serum produced significantly (p < 0.05) less PGI2 than did those without FCS. CLSM showed that large areas of valve cusps retain intact endothelial cells after 1 year stored at − 170 °C. For longer cryopreserved banking, we recommend storing heart valves at − 170 °C instead of at − 80 °C for maintaining viability of endothelial cells. Fetal Calf Serum would harm endothelial viability during long-term cryopreservation.

  • Effects of storage temperature and Fetal Calf Serum on the endothelium of porcine aortic valves.
    The Journal of thoracic and cardiovascular surgery, 1996
    Co-Authors: X.-j. Feng, Cor E. Van Hove, P. J. Walter, Arnold G. Herman
    Abstract:

    Abstract Endothelial integrity and function may be an important determinant for long-term success of allograft heart valves. To determine the optimal storage temperatures for preservation of long-term endothelial function in porcine aortic valves, different storage temperatures and times were investigated. Fresh valves were either (1) stored at 4° C, with or without 10% Fetal Calf Serum supplement, for 1, 2, 4, 7, 14, 21, or 28 days; (2) cryopreserved for 2, 4, or 8 weeks at -80o C or -170° C; (3) cryopreserved in long-term storage (as long as 1 year), with or without Fetal Calf Serum, at -170° C. Viability of endothelial cells was assessed through measurement of the production of prostacyclin in basal and bradykinin-stimulated conditions, during in vitro incubation of the valve cusps at 37° C. Endothelial morphologic variations in valves stored at 4° C were evaluated by scanning electron microscopy. With storage at 4° C, after 4 days the valves already produced significantly less ( p -1 · cm -2 ) and stimulated conditions (4.17 ± 0.36 vs 24.23 ± 1.83). Morphologic changes could not yet be distinguished with scanning electron microscopy at that time. When the storage period was extended, the levels of prostacyclin further diminished; after 14 days, prostacyclin release could no longer be detected. In cryopreserved valves, prostacyclin production was similar for as long as 2 weeks of storage either at -80° C or at -170° C in basal (2.69 ± 0.63 vs 2.93 ± 0.51) and stimulated (16.43 ± 3.19 vs 16.50 ± 2.57, = 6) conditions. After 8 weeks, no prostacyclin release could be detected in valves stored at -80° C. After 6 months storage at -170° C, the prostacyclin production was significantly ( p p

Christopher Todd Brown - One of the best experts on this subject based on the ideXlab platform.

  • Characterization of Proteoglycans Synthesized by Cultured Corneal Fibroblasts in Response to Transforming Growth Factor β and Fetal Calf Serum
    The Journal of biological chemistry, 1999
    Co-Authors: Christopher Todd Brown, Matthew A. Nugent, Francis W. Lau, Vickery Trinkaus-randall
    Abstract:

    Abstract A culture system was developed to analyze the relationship between proteoglycans and growth factors during corneal injury. Specifically, the effects of transforming growth factor β-1 (TGF-β1) and Fetal Calf Serum on proteoglycan synthesis in corneal fibroblasts were examined. Glycosaminoglycan synthesis and sulfation were determined using selective polysaccharidases. Proteoglycan core proteins were analyzed using gel electrophoresis and Western blotting. Cells cultured in 10% dialyzed Fetal Calf Serum exhibited decreased synthesis of more highly sulfated chondroitin sulfate and heparan sulfate compared with cells cultured in 1% dialyzed Fetal Calf Serum. The amount and sulfation of the glycosaminoglycans was not significantly influenced by TGF-β1. The major proteoglycan species secreted into the media were decorin and perlecan. Decorin was glycanated with chondroitin sulfate. Perlecan was linked to either chondroitin sulfate, heparan sulfate, or both chondroitin sulfate and heparan sulfate. Decorin synthesis was reduced by either TGF-β1 or Serum. At early time points, both TGF-β1 and Serum induced substantial increases in perlecan bearing chondroitin sulfate and/or heparan sulfate chains. In contrast, after extended periods in culture, the amount of perlecan bearing heparan sulfate chains was unaffected by TGF-β1 and decreased by Serum. The levels of perlecan bearing chondroitin sulfate chains were elevated with TGF-β1 treatment and were decreased with Serum. Because both decorin and perlecan bind growth factors and are proposed to modulate their activity, changes in the expression of either of these proteoglycans could substantially affect the cellular response to injury.

  • characterization of proteoglycans synthesized by cultured corneal fibroblasts in response to transforming growth factor beta and Fetal Calf Serum
    Journal of Biological Chemistry, 1999
    Co-Authors: Christopher Todd Brown, Matthew A. Nugent, Francis W. Lau, Vickery Trinkausrandall
    Abstract:

    Abstract A culture system was developed to analyze the relationship between proteoglycans and growth factors during corneal injury. Specifically, the effects of transforming growth factor β-1 (TGF-β1) and Fetal Calf Serum on proteoglycan synthesis in corneal fibroblasts were examined. Glycosaminoglycan synthesis and sulfation were determined using selective polysaccharidases. Proteoglycan core proteins were analyzed using gel electrophoresis and Western blotting. Cells cultured in 10% dialyzed Fetal Calf Serum exhibited decreased synthesis of more highly sulfated chondroitin sulfate and heparan sulfate compared with cells cultured in 1% dialyzed Fetal Calf Serum. The amount and sulfation of the glycosaminoglycans was not significantly influenced by TGF-β1. The major proteoglycan species secreted into the media were decorin and perlecan. Decorin was glycanated with chondroitin sulfate. Perlecan was linked to either chondroitin sulfate, heparan sulfate, or both chondroitin sulfate and heparan sulfate. Decorin synthesis was reduced by either TGF-β1 or Serum. At early time points, both TGF-β1 and Serum induced substantial increases in perlecan bearing chondroitin sulfate and/or heparan sulfate chains. In contrast, after extended periods in culture, the amount of perlecan bearing heparan sulfate chains was unaffected by TGF-β1 and decreased by Serum. The levels of perlecan bearing chondroitin sulfate chains were elevated with TGF-β1 treatment and were decreased with Serum. Because both decorin and perlecan bind growth factors and are proposed to modulate their activity, changes in the expression of either of these proteoglycans could substantially affect the cellular response to injury.

X.-j. Feng - One of the best experts on this subject based on the ideXlab platform.

  • Effects of storage temperature and Fetal Calf Serum on the endothelium of porcine aortic valves: Functional and microscopic evaluation
    Cardiac Valve Allografts, 1997
    Co-Authors: X.-j. Feng, Cor E. Van Hove, P. J. Walter, Luc Andries, Arnold G. Herman
    Abstract:

    Endothelial integrity and function may be an important determinant for long-term success of allograft heart valves. To determine the optimal storage temperatures for preserving long-term endothelial function of porcine aortic valves, different storage temperatures and different periods of time were investigated. Fresh valves were either a) stored at 4 °C with or without 10% Fetal Calf Serum (FCS) supplement, for 1, 2,4, 7, 14, 21, and 28 days. b) cryopreserved for 2, 4, and 8 weeks without FCS in either at − 80 °C or at − 170 °C. c) cryopreserved in long-term storage (as long as 1 year), with or without FCS, at − 170 °C. Viability of endothelial cells was assessed through measurement of the production of prostacyclin (PGI2) in basal and bradykinin (BK) stimulated conditions, during in vitro incubation of the valve cusps at 37 °C, using a radioimmunoassay for 6-oxo-prostaglandin F1α (PGF1α). Endothelial morphological variations in valves stored at 4 °C were evaluated by scanning electron microscopy (SEM), in valves cryopreserved at − 80 °C and − 170 °C were evaluated by confocal scanning laser microscopy (CSLM). Results: a) With storage at 4 °C, after 4 days the valves produced already significantly less (p < 0.05) PGI2 than fresh preparations in both basal (0.21 ± 0.04 vs 3.56 ± 0.03 ng/ml · cm2) and stimulated conditions (4.17 ± 0.36 vs 24.23 ± 1.83). Morphological changes could not yet be distinguished with SEM at that time. When the storage period was extended, the levels of PGI2 further diminished; after 14 days, PGI2 release could no longer be detected. b) In cryopreserved valves, PGI2 production was similar for as long as 2 weeks of storage either at − 80 °C or at − 170 °C in basal (2.69 ± 0.63 vs 2.93 ± 0.51) and stimulated (16.43 ± 3.19 vs 16.50 ± 2.57) conditions. After 8 weeks, no PGI2 release could be detected in valves stored at − 80 °C. c) After 6 months storage at − 170 °C, the PGI2 production was significantly (p < 0.05) reduced compared with fresh valves; it then remained constant for as long as 1 year. The valves stored with Fetal Calf Serum produced significantly (p < 0.05) less PGI2 than did those without FCS. CLSM showed that large areas of valve cusps retain intact endothelial cells after 1 year stored at − 170 °C. For longer cryopreserved banking, we recommend storing heart valves at − 170 °C instead of at − 80 °C for maintaining viability of endothelial cells. Fetal Calf Serum would harm endothelial viability during long-term cryopreservation.

  • Effects of storage temperature and Fetal Calf Serum on the endothelium of porcine aortic valves.
    The Journal of thoracic and cardiovascular surgery, 1996
    Co-Authors: X.-j. Feng, Cor E. Van Hove, P. J. Walter, Arnold G. Herman
    Abstract:

    Abstract Endothelial integrity and function may be an important determinant for long-term success of allograft heart valves. To determine the optimal storage temperatures for preservation of long-term endothelial function in porcine aortic valves, different storage temperatures and times were investigated. Fresh valves were either (1) stored at 4° C, with or without 10% Fetal Calf Serum supplement, for 1, 2, 4, 7, 14, 21, or 28 days; (2) cryopreserved for 2, 4, or 8 weeks at -80o C or -170° C; (3) cryopreserved in long-term storage (as long as 1 year), with or without Fetal Calf Serum, at -170° C. Viability of endothelial cells was assessed through measurement of the production of prostacyclin in basal and bradykinin-stimulated conditions, during in vitro incubation of the valve cusps at 37° C. Endothelial morphologic variations in valves stored at 4° C were evaluated by scanning electron microscopy. With storage at 4° C, after 4 days the valves already produced significantly less ( p -1 · cm -2 ) and stimulated conditions (4.17 ± 0.36 vs 24.23 ± 1.83). Morphologic changes could not yet be distinguished with scanning electron microscopy at that time. When the storage period was extended, the levels of prostacyclin further diminished; after 14 days, prostacyclin release could no longer be detected. In cryopreserved valves, prostacyclin production was similar for as long as 2 weeks of storage either at -80° C or at -170° C in basal (2.69 ± 0.63 vs 2.93 ± 0.51) and stimulated (16.43 ± 3.19 vs 16.50 ± 2.57, = 6) conditions. After 8 weeks, no prostacyclin release could be detected in valves stored at -80° C. After 6 months storage at -170° C, the prostacyclin production was significantly ( p p

Vickery Trinkaus-randall - One of the best experts on this subject based on the ideXlab platform.

  • Characterization of Proteoglycans Synthesized by Cultured Corneal Fibroblasts in Response to Transforming Growth Factor β and Fetal Calf Serum
    The Journal of biological chemistry, 1999
    Co-Authors: Christopher Todd Brown, Matthew A. Nugent, Francis W. Lau, Vickery Trinkaus-randall
    Abstract:

    Abstract A culture system was developed to analyze the relationship between proteoglycans and growth factors during corneal injury. Specifically, the effects of transforming growth factor β-1 (TGF-β1) and Fetal Calf Serum on proteoglycan synthesis in corneal fibroblasts were examined. Glycosaminoglycan synthesis and sulfation were determined using selective polysaccharidases. Proteoglycan core proteins were analyzed using gel electrophoresis and Western blotting. Cells cultured in 10% dialyzed Fetal Calf Serum exhibited decreased synthesis of more highly sulfated chondroitin sulfate and heparan sulfate compared with cells cultured in 1% dialyzed Fetal Calf Serum. The amount and sulfation of the glycosaminoglycans was not significantly influenced by TGF-β1. The major proteoglycan species secreted into the media were decorin and perlecan. Decorin was glycanated with chondroitin sulfate. Perlecan was linked to either chondroitin sulfate, heparan sulfate, or both chondroitin sulfate and heparan sulfate. Decorin synthesis was reduced by either TGF-β1 or Serum. At early time points, both TGF-β1 and Serum induced substantial increases in perlecan bearing chondroitin sulfate and/or heparan sulfate chains. In contrast, after extended periods in culture, the amount of perlecan bearing heparan sulfate chains was unaffected by TGF-β1 and decreased by Serum. The levels of perlecan bearing chondroitin sulfate chains were elevated with TGF-β1 treatment and were decreased with Serum. Because both decorin and perlecan bind growth factors and are proposed to modulate their activity, changes in the expression of either of these proteoglycans could substantially affect the cellular response to injury.

Vickery Trinkausrandall - One of the best experts on this subject based on the ideXlab platform.

  • characterization of proteoglycans synthesized by cultured corneal fibroblasts in response to transforming growth factor beta and Fetal Calf Serum
    Journal of Biological Chemistry, 1999
    Co-Authors: Christopher Todd Brown, Matthew A. Nugent, Francis W. Lau, Vickery Trinkausrandall
    Abstract:

    Abstract A culture system was developed to analyze the relationship between proteoglycans and growth factors during corneal injury. Specifically, the effects of transforming growth factor β-1 (TGF-β1) and Fetal Calf Serum on proteoglycan synthesis in corneal fibroblasts were examined. Glycosaminoglycan synthesis and sulfation were determined using selective polysaccharidases. Proteoglycan core proteins were analyzed using gel electrophoresis and Western blotting. Cells cultured in 10% dialyzed Fetal Calf Serum exhibited decreased synthesis of more highly sulfated chondroitin sulfate and heparan sulfate compared with cells cultured in 1% dialyzed Fetal Calf Serum. The amount and sulfation of the glycosaminoglycans was not significantly influenced by TGF-β1. The major proteoglycan species secreted into the media were decorin and perlecan. Decorin was glycanated with chondroitin sulfate. Perlecan was linked to either chondroitin sulfate, heparan sulfate, or both chondroitin sulfate and heparan sulfate. Decorin synthesis was reduced by either TGF-β1 or Serum. At early time points, both TGF-β1 and Serum induced substantial increases in perlecan bearing chondroitin sulfate and/or heparan sulfate chains. In contrast, after extended periods in culture, the amount of perlecan bearing heparan sulfate chains was unaffected by TGF-β1 and decreased by Serum. The levels of perlecan bearing chondroitin sulfate chains were elevated with TGF-β1 treatment and were decreased with Serum. Because both decorin and perlecan bind growth factors and are proposed to modulate their activity, changes in the expression of either of these proteoglycans could substantially affect the cellular response to injury.