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1.4 MiB
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3 lines
1.4 MiB
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{"dateoftransformation":"2017-11-06T17:13:01.996Z","pid":[{"qualifier":{"classid":"doi","classname":"doi","schemename":"dnet:pid_types","schemeid":"dnet:pid_types"},"value":"10.1177/194760350900101S03"},{"qualifier":{"classid":"pmc","classname":"pmc","schemename":"dnet:pid_types","schemeid":"dnet:pid_types"},"value":"PMC4513500"}],"originalId":["oai:europepmc.org:3798670"],"oaiprovenance":{"originDescription":{"metadataNamespace":"","altered":true,"baseURL":"file:///mnt/downloaded_dumps/mdstore/od_______908_epmc/merged_epmc_pmc_all_24092017.xml.gz","datestamp":"2016-04-15","harvestDate":"2017-09-25T16:17:32.167Z","identifier":"oai:europepmc.org:3798670"}},"result":{"instance":[{"hostedby":{"value":"Europe PubMed Central","key":"10|opendoar____::8b6dd7db9af49e67306feb59a8bdc52c"},"url":["http://europepmc.org/articles/PMC4513500"],"dateofacceptance":{"value":"2009-01-01"},"collectedfrom":{"value":"Europe PubMed Central","key":"10|opendoar____::8b6dd7db9af49e67306feb59a8bdc52c"},"accessright":{"classid":"OPEN","classname":"Open Access","schemename":"dnet:access_modes","schemeid":"dnet:access_modes"},"instancetype":{"classid":"0001","classname":"Article","schemename":"dnet:publication_resource","schemeid":"dnet:publication_resource"}}],"metadata":{"publisher":{"value":"SAGE Publications"},"description":[{"value":"Introduction Articular cartilage of higher animals does not regenerate, but under some circumstances mesenchymal cells can be inducted to behave phenotypically as chondrocytes. Tissue engineering has produced only partial cartilage repair and inconsistent outcomes. This study reports full thickness articular cartilage regeneration induced by freeze-dried particulate cartilage. Methods and Materials Full thickness cartilage defects in the femoral condyles of 22 baboons were filled with freeze-dried cartilage particles. Defects in two animals were filled with frozen cartilage particles. Four animals served as controls. Experimental animals were sacrificed at 2 weeks (2), 6 weeks (6), 9 weeks (1) 12 weeks (3), 14?16 weeks (4) and at 7 and 14 months. The knees were photographed and x-rayed. The condyles were frozen, sectioned, photographed again, fixed, decalcified and processed for histology. To determine if cartilage preparations were osteogenic samples were implanted intramusculary in 16 athymic rats. The specimens were examined at 1,2,4 & 8 weeks. Cartilage particles were also implanted intraosseously into 2 baboons. Regenerating cartilage was graded in accordance with a modified Mankin's method. Results Cartilage regeneration proceeded from the edges of the defect. The 12 week and older defects were covered with smooth and glistening new cartilage. Control defects remained open or contained uneven patches of cartilage. Animals with frozen cartilage implants appeared identical to controls. Cartilage particles implanted into athymic rats remained inert and elicited neither osteogenesis nor chondrogenesis, as did cartilage placed intramedullary in baboons. Conclusions The data demonstrates induction of articular cartilage regeneration by freeze-dried hyaline cartilage particles implanted orthotopically."},{"value":"Introduction Long-term maintenance of cartilage allograft tissue is challenging. This study examines if dexamethasone, a synthetic adrenal corticosteroid, can play a role in maintaining the mechanical properties of cartilage explants in serum-free tissue culture. Methods and Materials In Study 1, middle zone explant disks were harvested from juvenile (4?6 month) bovine cartilage plugs. In Study 2, full-thickness osteochondral plugs were harvested from mature (1?2 year-old) bovine femoral condyles. Explants were cultured with continuous dexamethasone (0.1 microM) supplementation; with dexamethasone removed after 2 weeks of culture; or dexamethasone-free throughout 28 days of culture. Results In Study 1, Youngs modulus (Ey) of explants grown with continuous dexamethasone supplementation increased ?50% from initial values (reaching 2800 kPa) while dexamethasone-free explants decreased ?80% (down to 400 kPa).
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{"dateoftransformation":"2018-08-31T00:28:36.62Z","pid":[{"qualifier":{"classid":"doi","classname":"doi","schemename":"dnet:pid_types","schemeid":"dnet:pid_types"},"value":"10.1177/194760350900101S03"},{"qualifier":{"classid":"pmc","classname":"pmc","schemename":"dnet:pid_types","schemeid":"dnet:pid_types"},"value":"PMC4513500"}],"originalId":["oai:pubmedcentral.nih.gov:4513500"],"oaiprovenance":{"originDescription":{"metadataNamespace":"","altered":true,"baseURL":"https://www.ncbi.nlm.nih.gov/pmc/oai/oai.cgi","datestamp":"2016-04-13","harvestDate":"2018-06-12T10:20:13.714Z","identifier":"oai:pubmedcentral.nih.gov:4513500"}},"result":{"instance":[{"hostedby":{"value":"Europe PubMed Central","key":"10|opendoar____::8b6dd7db9af49e67306feb59a8bdc52c"},"url":["http://europepmc.org/articles/PMC4513500"],"dateofacceptance":{"value":"2009-01-01"},"collectedfrom":{"value":"PubMed Central","key":"10|opendoar____::eda80a3d5b344bc40f3bc04f65b7a357"},"accessright":{"classid":"OPEN","classname":"Open Access","schemename":"dnet:access_modes","schemeid":"dnet:access_modes"},"instancetype":{"classid":"0001","classname":"Article","schemename":"dnet:publication_resource","schemeid":"dnet:publication_resource"}}],"metadata":{"publisher":{"value":"SAGE Publications"},"description":[{"value":"Introduction Articular cartilage of higher animals does not regenerate, but under some circumstances mesenchymal cells can be inducted to behave phenotypically as chondrocytes. Tissue engineering has produced only partial cartilage repair and inconsistent outcomes. This study reports full thickness articular cartilage regeneration induced by freeze-dried particulate cartilage. Methods and Materials Full thickness cartilage defects in the femoral condyles of 22 baboons were filled with freeze-dried cartilage particles. Defects in two animals were filled with frozen cartilage particles. Four animals served as controls. Experimental animals were sacrificed at 2 weeks (2), 6 weeks (6), 9 weeks (1) 12 weeks (3), 14–16 weeks (4) and at 7 and 14 months. The knees were photographed and x-rayed. The condyles were frozen, sectioned, photographed again, fixed, decalcified and processed for histology. To determine if cartilage preparations were osteogenic samples were implanted intramusculary in 16 athymic rats. The specimens were examined at 1,2,4 & 8 weeks. Cartilage particles were also implanted intraosseously into 2 baboons. Regenerating cartilage was graded in accordance with a modified Mankin's method. Results Cartilage regeneration proceeded from the edges of the defect. The 12 week and older defects were covered with smooth and glistening new cartilage. Control defects remained open or contained uneven patches of cartilage. Animals with frozen cartilage implants appeared identical to controls. Cartilage particles implanted into athymic rats remained inert and elicited neither osteogenesis nor chondrogenesis, as did cartilage placed intramedullary in baboons. Conclusions The data demonstrates induction of articular cartilage regeneration by freeze-dried hyaline cartilage particles implanted orthotopically."},{"value":"Introduction Long-term maintenance of cartilage allograft tissue is challenging. This study examines if dexamethasone, a synthetic adrenal corticosteroid, can play a role in maintaining the mechanical properties of cartilage explants in serum-free tissue culture. Methods and Materials In Study 1, middle zone explant disks were harvested from juvenile (4∼6 month) bovine cartilage plugs. In Study 2, full-thickness osteochondral plugs were harvested from mature (1∼2 year-old) bovine femoral condyles. Explants were cultured with continuous dexamethasone (0.1 microM) supplementation; with dexamethasone removed after 2 weeks of culture; or dexamethasone-free throughout 28 days of culture. Results In Study 1, Youngs modulus (Ey) of explants grown with continuous dexamethasone supplementation increased ∼50% from initial values (reaching 2800 kPa) while dexamethasone-free explants decreased ∼80% (down to 400 kPa). Removal of dexamethasone aft
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