ABSTRACT
BACKGROUND:Growth differentiation factor 5 (GDF5) has been shown to play a crucial role in the development of chondrocytes via different regulatory mechanisms. OBJECTIVE:To explore the effect of GDF5 on the chondrogenic differentiation of adipose-derived stem cel s (ADSCs). METHODS:ADSCs in passage 4 isolated from Japanese White rabbits were cultured in the medium containing 0 (blank control group), 10, 50, 100, 150 and 200μg/L, respectively. The morphological changes were observed, and the optimal concentration of GDF-5 was screened, and its round coverslips at 1, 2 and 3 weeks of culture were selected to undergo immunocytochemistry, toluidine blue staining and immunofluorescent staining. RESULTS AND CONCLUSION:The growth of ADSCs was stable in the medium containing 10 and 50μg/L GDF5, while apoptotic cel s appeared after induction with 200μg/L GDF5. In the medium containing 100 and 150μg/L GDF5, some spindle-shaped cel s changed into irregular shape, and became round or oval after 7-10 days of culture. The optimal concentration of GDF5 was 100μg/L. The cel s transfected by 100μg/L GDF5 were positive for type II col agen obviously and with blue-stained nucleus. The transfected cel s were positive for toluidine blue, and metachromatic granules were visible in the cytoplasm. The proteoglycan mRNA expression of the transfected cel s was significantly increased, and reached the highest at 3 weeks. These results suggest that GDF5 promotes the chondrocytic differentiation of ADSCs.
ABSTRACT
BACKGROUND:Traditional external fixation of tibial fractures exhibits obvious stress shielding that delays fracture healing. Polyetheretherketone (PEEK) material has a similar elastic modulus to the bone, and it wil be possible to address this clinical problem. OBJECTIVE:To compare the outcome of PEEK external fixator versus traditionaly external fixator in the treatment of tibial fractures. METHODS:Clinical data of 86 patients with tibial fractures, including 64 males and 22 females, aged 24-78 years (mean age of 56 years), were retrospectively reviewed. There were 30 cases of closed fractures and 56 cases of open fractures; 32 cases received flat-patient surgery and 54 cases underwent emergency surgery. Al the patients were divided into two groups according to different fixation methods: PEEK group and traditional external fixator group. After operation, patients were checked regularly and at the last folow-up, functional recovery was evaluated according to Johner-Wruhs criteria. RESULTS AND CONCLUSION:Al the patients were folowed up for 5-20 months. The mean fixator removal time of the PEEK group was 8.7 weeks and the mean duration of fracture healing was 4.2 months. The mean fixator removal time of the traditional external fixator group was 10.6 weeks and the mean duration of fracture healing was 6.1 months. At the last folow-up, in the PEEK group, 26 cases were assessed as excelent, 13 as good, 4 as poor; in the traditional external fixator group, 19 cases were assessed as excelent, 13 as good, 11 as poor. These findings indicate that PEEK external fixator for different types of tibial fractures can maintain the fracture stability, promote fracture healing and contribute to the functional recovery of the affected limbs.
ABSTRACT
The role of catecholamine (CA) in the pathogenesis and development of macular edema of central serous chorioretinopathy (CSC) was studied, and its relations with visual acuity were investigated. Plasma concentrations of epinephrine (E) and norepinephrine (NE) were determined in 30 consecutive eyes with CSC. Central macular thickness analysis was done by RTA and all the data were compared with normal eyes and analyzed with SAS software package. Plasma concentrations of E and NE were increased to (569 +/- 123) ng/L and (721 +/- 104) ng/L respectively in active CSC patients, significantly higher than those in normal subjects (P < 0.01), and decreased to normal in convalescent stage. RTA analysis revealed that the retinal thickness of CSC patients was increased at active and recovery stage as compared with normal subjects; and the plasma concentration of E was significantly correlated with central macular thickness (t = 2.173, P < 0.05). Also, central macular thickness measured by RTA was significantly correlated with the visual acuity (r = -0.8046, P < 0.001) in CSC eyes. RTA analysis might be useful to quantitatively detect and evaluate prognosis in CSC patients. The plasma concentration of E, which was highly correlated with macular edema, might play an important role in the early damage and the pathogenesis of CSC.