title: Luminescence imaging of regenerating free bone graft in rats.
abstract: BACKGROUND
  Bone transplantation is an important procedure often used for bone defect reconstruction after trauma and malignancies. However, the kinetics of free bone graft-derived cells remains unclarified. The authors examined the kinetics of graft-derived cells using transgenic rats systemically expressing firefly luciferase.
  
  
  METHODS
  Free iliac bone grafts (5 × 5 × 2 mm, n = 10) derived from luciferase transgenic rats were transplanted into the subcutaneous space of the back of wild-type Lewis rats, and the kinetics of graft-derived cells were evaluated over time by determining the level of luminescence emission.
  
  
  RESULTS
  Although the luminescence level emitted by luciferase decreased after transplantation, a substantial luminescence level (mean, 1.6 × 10(7) photons/second) was emitted from donor-derived cells even at 180 days after transplantation, suggesting a long-term survival of graft-derived cells. In a computed tomographic image analysis of bone grafts retrieved 180 days after transplantation, high-luminescence grafts with a sufficient number of viable graft-derived cells (mean, 2.6 × 10(7) photons/second; n = 4) showed significantly higher bone graft volume (3.1-fold) and polar moment of inertia of area (7.2-fold) than low-luminescence grafts (mean, 1.0 × 10(7) photons/second; n = 4), indicating that high-luminescence grafts maintain better conditions.
  
  
  CONCLUSIONS
  These results suggest that bone graft-derived cells can survive for a long time and that the presence of a sufficient number of viable graft-derived cells is essential for graft engraftment and remodeling.
authors.affiliation: Shimotsuke, Tochigi, Japan From the Division of Plastic Surgery, Department of Surgery, the Division of Bioimaging Sciences Center for Molecular Medicine, and the Center For Development of Advanced Medical Technology, Jichi Medical University.
authors.forename: Asako
authors.initials: A
authors.lastname: Yamaguchi
authors.forename: Takashi
authors.initials: T
authors.lastname: Murakami
authors.forename: Masafumi
authors.initials: M
authors.lastname: Takahashi
authors.forename: Eiji
authors.initials: E
authors.lastname: Kobayashi
authors.forename: Yasushi
authors.initials: Y
authors.lastname: Sugawara
mesh_terms: D000818:Animals; D016723:Bone Remodeling / Q000502:physiology; D016025:Bone Transplantation; D002470:Cell Survival / Q000502:physiology; D007700:Kinetics; D008156:Luciferases / Q000378:metabolism; D008163:Luminescent Measurements; D009929:Organ Size; D051381:Rats; D011917:Rats, Inbred Lew; D055647:Rats, Transgenic; D014057:Tomography, X-Ray Computed
chemical_list: D008156:Luciferases