| dc.contributor.author | Bourque, William Timothy. | en_US |
| dc.date.accessioned | 2014-10-21T12:37:45Z | |
| dc.date.available | 1992 | |
| dc.date.issued | 1992 | en_US |
| dc.identifier.other | AAINN87446 | en_US |
| dc.identifier.uri | http://hdl.handle.net/10222/55355 | |
| dc.description | An animal model has been developed to study repair of a tibial fracture. The model provides both reproducible and quantifiable results. Using this model, the fracture repair process has been divided into four stages. The duration of each stage is consistently reproducible. Stage 1 termed "the inflammatory response stage", lasts from immediately post-fracture until day 2 post-fracture. Histologically, this stage was marked by the formation of a haematoma, and transformation of monocytes to macrophages. Stage 2, termed the "periosteal-fibrous callus stage", lasted from days 2 to 5 post-fracture. Histologically, this stage was marked by cellular activity in the cambial layer of the periosteum and the accumulation of fibroblast-like mesenchymal cells. Stage 3, termed the "chondrogenic stage", lasted from days 5 to 9 post-fracture. During this stage, the fibrous callus was transformed into cartilage. Stage 4, termed the "endochondral stage", lasted from days 9 to 21 post-fracture. During this stage, the cartilaginous callus was replaced by new bone. | en_US |
| dc.description | A new tissue processing method was devised which preserves tissue architecture and antigenic sites on growth factors during decalcification. Using this new method four growth factors were localized during the repair process. PDGF was visualized in macrophages in close proximity to the periosteum during stage 1. aFGF was visualized in cells of the expanding cambial layer and was associated with a rapid increase in the population of fibroblast-like mesenchymal cells during stage 2. IGF-I was visualized in young chondroblasts at the edge of the cartilage mass replacing the fibrous callus during stage 3. TGF-$\beta\sb1$ was visualized in calcified matrix producing chondrocytes at the edge of ossification fronts replacing the cartilage callus during stage 4. | en_US |
| dc.description | mRNA to aFGF was present in tissues harvested from the fracture site during the repair process. This supported the hypothesis that aFGF is produced in situ during fracture repair. A model was proposed to explain the relationship between the cellular activity in tissues (replication, matrix production) occurring during each stage of fracture repair, and the particular growth factor present at each stage. | en_US |
| dc.description | Thesis (Ph.D.)--Dalhousie University (Canada), 1992. | en_US |
| dc.language | eng | en_US |
| dc.publisher | Dalhousie University | en_US |
| dc.publisher | | en_US |
| dc.subject | Biology, Cell. | en_US |
| dc.title | The presence of several growth factors during the stages of fracture repair. | en_US |
| dc.type | text | en_US |
| dc.contributor.degree | Ph.D. | en_US |
