Fibroblast growth factor receptor 3 regulation and mechanism in callus formation / 中国组织工程研究

BACKGROUND: In clinical treatment, patients with traumatic nerve injury and fractures show accelerated fracturehealing and excessive osteophyte growth, and even heterotopic ossification in the muscle, all of which seriously affect the therapeutic efficacy on such fractures. The specific causes and mechanisms for the acceleration of fracture healing after denervation are currently unclear. OBJECTIVE: To investigate the role and expression of fibroblast growth factor receptors 3 (FGFR3) inhibitor in the process of fracture healing. METHODS: The study protocol was approved by the Animal Ethics Committee of Second Hospital of Lanzhou University. Sixty female Sprague-Dawley rats were used to make a transverse humeral fracture model of sciatic nerve injury. They were randomly divided into two groups, experimental group and control group. The experimental group received intraperitoneal injection of FGFR3 blocker; the control group received an equal dose of normal saline. The X-ray films were taken at 4, 7, 10, 14 and 21 days after surgery, and tibia specimens for six animals were subsequently taken at each time point, followed by histological observations using hematoxylin-eosin staining and Masson’s trichrome staining. Osteocyte density and trabecular bone density of the rat tibia were calculated; and the fiber rate of the tibia was determined. RESULTS AND CONCLUSION: There were no significant differences in the X-ray findings of the tibia between the two groups. The experimental group had better bone repair than the control group, shown by hematoxylin-eosin staining and Masson’s trichrome staining. Osteocyte density, trabecular bone density, and fiber rate of the rat tibia were significantly higher in the experimental group than the control group at 7-14 days after treatment. Inhibition of FGFR3 can accelerate fracture healing and promote the shaping of callus in the case of peripheral nerve denervation. FGFR3 is most active at 7-14 days after fracture.

Effect of Sodium ferulate on glucocorticoid-induced osteoporosis / 中国药理学通报

Aim To study the influence of Sodium fer-ulate ( SF) on bone metabolism in glucocorticoid–in-duced osteoporosis rats. Methods Thirty cases of fe-male Wistar Rats(3-month-old) were divided into con-trol group, model group and SF group ( low-dose group, middle-dose group, high-dose group ) by ran-domized block design. Double fluorochrome labeling with calcein was performed before necropsy. The left tibia was taken for bone histomorphometry. Results In static parameters, the proximal tibia cancellous bone trabecular thickness, trabecular quantity and area ratio were significantly reduced in model group compared with control group;while compared with model group, those were increased in middle and high-dose SF group. Trabecular separation degree was increased in model group compared with control group, while it was decreased in middle and high-dose SF group compared with model group. In dynamic parameters, the calcula-tion parameters of cancellous bone mark perimeter rate and the bone formation rate were increased in model group compared with control group, in middle and high-dose SF group the bone formation rate was in-creased compared with model group. In bone cells, os-teoclast number per mm, osteoblast number per mm, percent osteoblast surface perimeter and percent osteo-clast surface perimeter were increased in model group compared with control group. In growth-plate, the thickness of growth-plate was increased in model group compared with control group. In bone cells and growth-plate there was no statistical significance between treat-ment group and model group. Conclusion This study demonstrates that SF can increase bone mass and im-prove bone structure,which may be related to the im-provement of bone formation. SF is effective for GIOP in rats.

Comparison of the Proliferation pattern of Cultured Rat Calvaria Cell on the Resorbable Barrier Membrane / 대한치주과학회지

The purpose of this study is to evaluate the phenomenon of attachment and spreading of the cultured rat calvarial cell inoculated on their surface of different kinds of biodegradable membrane which had been used on tissue regeneration on periodontal defects by using scanning electron microscope. In this experiment 30 Sprague-Dawley male rats (mean BW 150gm) were used to harvest abundant number of cell in the short period. The rats were sacrificed by decapitatioan to obtain the calvaria for bone cell culture. Calvarial cells were cultured with Dulbecco's Modified Essential Medium contained with 10% Fetal Bovine Serum under the conventional conditions. Biodegradable barrier membrane were collected with collagen type, and were divided into 3 different kind of surface such as scattered, polarized and fine-net type as their surface texture. Microcover plate which usually used for cell cuture was used as control for smooth surface. All the membrane were seeded with cultured calvarial cell on their surface. The number of cell inoculated on the membrane were 1x106 Cells/ml. After the culture as designed time, all the membrane were washed with 0.1 M Phosphate Buffered saline and fixed with 2.5% Glutaraldehyde. And all specimen were treated with OsO4, and Tannic acid before drying the cell for coating the cell with gold. Scanning Electron Microscope was used to observation. The following results were obtained. 1. During the whole period of experiment, the phenomenon of cell attachment and spreading were revealed similar pattern to compare with smooth surface culture plate and ordinary culture dish. 2. The shape of cell attchment and spreading on the surface of barrier membrane were observed no remaked difference pattern between smooth surface culture plate and ordinary culture dish. 3. The cytoplasmic process of cultured calvaria cell extent to the deep portion of barrier membrane like as their own proper shape. 4. There were no remarkable relationships between the degree of cultured cell spreading and surface structure of barrier membrane. 5. Slight starified layer of cultured calvaria cell were observed on the scattered type of resorbable membrane. Conclusively, this study thus suggest that cultured bone cell inoculated onto the biodegradable barrier membrane may have an important role of carrier for many cell which could be used as new tissue regeneration, and those tissue engeering technique may become an new method in the approach to the repair of bone defects.

The effects of mechanical stress on cultured bone cell populations / 대한치과교정학회지

The movement of teeth during orthodontic treatment requires bone remodeling process of bone formation and bone resorption. To find out the changes occuring in the cell itself, mechanical stress was applied to the cell populations involved in the bone metabolism. Bone tissue cell populations were isolated from fetal rat calvaria and divided into OC and OB groups. Following results were obtained from measuring the changes in acid & alkaline phosphatease activity, cyclic AMP and PGE2 production in time lapse after the application of mechanical stress. 1. In case of the marker enzyme of specific bone tissue cell, acid phosphatase activity was high in OC group and alkaline phosphatase activity was high in OB group. 2. After the mechanical stress was applied, acid phosphatase activity was decreased in both OC and OB groups and alkaline phosphatase activity was increase in OB group. 3. When the mechanical stress was applied for 15, 30 and 60 minutes, the production of PGE2 increased in both OC and OB groups, as the time span increased. 4. When the mechanical stress was applied for 20 and 40 minutes, the production of PGE2 increased in both OC and OB groups, as the time span increased.