Endochondral bone formation observed at the mandibular condyle is regulated by various growth factors including insulin-like growth factor-I (IGF-I). In this paper, we describe a method for the local administration of IGF-I to the bilateral mandibular articular cavities of 3- and 12-week-old rats, and the effects of IGF-I on endochondral bone formation by histomorphometric techniques. In 3-week...

Crude bovine BMP was implanted into the thigh muscle pouch of mice. Tetracycline was injected 1 week and calcein was injected 2 weeks after implant. At 3 weeks after implant, the mice were sacrificed and reviewed histologically. Coexistence of calcified bone and osteoid was observed in Villanueva Goldner stained sections. Toluidine blue staining demonstrated cartilaginous matrix and adjacent lo...

Hepatic biotransformation of bilirubin to the hydrophilic species bilirubin mono- (BMG) and diglucuronide (BDG) by microsomal bilirubin UDP-glucuronosyl-transferase (GT) is a prerequisite for its physiologic excretion into bile. The reaction mechanism of bilirubin-GT and the access of bilirubin and BMG (the intermediate substrate) to the active site of bilirubin-GT are undefined. Highly purifie...

The proprotein convertase site-1 protease (S1P) converts latent ER-membrane bound transcription factors SREBPs and ATF6 to their active forms. SREBPs are involved in cholesterol and fatty acid homeostasis whereas ATF6 is involved in unfolded protein response pathways (UPR). Cartilage-specific ablation of S1P in mice (S1Pcko) results in abnormal cartilage devoid of type II collagen protein (Col ...

The axial and appendicular skeleton of vertebrates develops by endochondral ossification, in which skeletogenic tissue is initially cartilaginous and the differentiation of chondrocytes via the hypertrophic pathway precedes the differentiation of osteoblasts and the deposition of a definitive bone matrix. Results from both loss-of-function and misexpression studies have implicated the related h...

Normal endochondral bone formation follows a temporal sequence: immature or resting chondrocytes move away from the resting zone, proliferate, flatten, become arranged into columns, and finally become hypertrophic, disintegrate, and are replaced by bone. The mechanisms that guide this process are incompletely understood, but they include programmed cell death, a stage important in development a...

UNLABELLED A bioinformatics-based analysis of endochondral bone formation model detected several genes upregulated in this process. Among these genes the dickkopf homolog 3 (Dkk3) was upregulated and further studies showed that its expression affects in vitro and in vivo osteogenesis. This study indicates a possible role of Dkk3 in regulating bone formation. INTRODUCTION Endochondral bone for...

Bone matrix is a repository of growth and differentiation factors as demonstrated by the induction of local cartilage and bone formation in rats. The bone inductive activity, termed osteogenin, can be dissociatively extracted, and it was isolated by heparin affinity, hydroxyapatite and molecular sieve chromatography. Osteogenin has been purified to homogeneity from bovine bone matrix and the se...

BACKGROUND Cyclo-oxygenase-2 (Cox-2) is an inflammatory mediator that is necessary for the tissue repair, including bone fracture healing. Although the application of Cox-2 gene therapy to a murine closed femoral fracture has accelerated bony union, but the beneficial effect was not observed until the endochondral stage of bone repair that is well after the inflammatory stage normally subsides....