Objective:To investigate the expression of transforming growth factor ?1(TGF-?1) in dog mandibular distraction osteogenensis (DO). Methods: Mandibular DO model was established in 12 dogs and nonunion model in another 12 dogs, 4 dogs were used as the no-treatment control. Tissue samples were obtained 6 d,2 and 8 weeks after operation respectively.Immunohistochemistry and enzyme-linked immunosorbent assay (ELISA) were used to determine the expressions of TGF-?1 in the samples.Results: TGF-?1 (ng/g) in control group was 1394.3?20.1,6 d after operation that in DO and nonunion groups was 1928.5?33.5(vs control,P

Objective:To investigate hypoxia location in condylar cartilage in the early growth stage of rats.Methods:40 Sprague-Dawley rats were breastfed from 1 4 d to 21 d of age.1 0 rats were sacrificed at 1 2,24,48 and 96 h respectively after initiation of normal food at 21 d of age.The rats were administered pimonidazole hydrochloride (HP-1 )at a dose of 60 mg/kg by intraperitoneal injection 2 h before sacrifice.The expression of HP-1 in the whole condylar cartilage was detected by immunohistochemical staining.Results:HP-1 was mainly expressed in the chondrocytes of the fibrous and proliferative layer of cartilage,primarily concentrated in the weight-bearing area of joint-anterior aspect of the condyle and posterior aspect of the articular eminence at all time points.The highest expres-sion was observed at 24 h after initiation of normal food (P <0.01 ).Conclusion:In the early growth stage of rats,dietary loading may directly induce hypoxia in uper layer of condylar cartilage,the hyoxia level may change with time of dietary loading.