BACKGROUND:Conventjonally,the osteoinduction of bone substitute materials is detected in vivo,which is unsatisfactory regarding the reliability,chronergy and precision,especially for a large amount of substitute materials.OBJECTIVE:To search an in vitro assay for determining in vitro osteogenic activities of bone graft substitutes.DESIGN:Controlled cytological trials.TIME AND SETTING:The experiments were carried out in the Institute of Orthopaedics.Chinese PLA General Hospital(Beijing,China)from August 2006 to May 2007.MATERIALS:C2C 12 cells was offered by the Cell Center of Peking Union Medical College;Human decalcified bone matrix and bone protein were offered by the Institute of Orthopaedics in Chinese PLA General Hospital;Type Ⅰ collagen extracted from bovine tendon was purchased from Beijing Yierkang Bioengineering Development Center;Recombinant human bone morphogenetic protein 2 was purchased from Hangzhou Gene Technology of Huadong Medicine Group.METHODS:By means of dialysis,a composite material was prepared with the bone protein extracted from human,human decalcified bone matrix and type Ⅰ collagen of bovine tendon.The samples of decalcified bone matrix.composite material and recombinant human bone morphogenetic protein 2 were respectively co-incubated with C2C12cells for 72 hours.Negative control group comprised pure cells without materials.Then C2C 1 2 cells were lysed and the lysate were assayed for the absorbance of alkaline phosphatase(ALP)and total protein by chromatometry.ALP is (the specific mark of osteoblastic phenotype.The relative ratio of absorbance value between ALP and total protein could represent ALP activity in the unit quantitative C2C12 cells.MAIN OUTCOME MEASURES:The ratio of absorbance value between ALP and total protein.RESULTS:The ALP activity was the highest in the recombinant human bone morphogenetic protein 2 group,then in the decalcified bone matrix group and composite material group,and the lowest in the negative control group.There were significant differences in the ALP activity between the three trial groups and the negative control group(P＜0.05).CONCLUSION:The assay in vitro is effective to detect the ALP activity and it can be used to determine the osteoinduction of bone graft substitutes.

Object In pursuit of a clear cut view on the change of water molecules in the crystal lattice of montmorillonite, to provide a basis for the study of mechanism of action and its further development Methods The chemical structure of the mineral was studied by IR spectral analysis Results Information concerning the change of water in regard to its chemical structure were obtained Conclusion Montmori llonite is a mineral clay which can expand to exhibit its absorption properties, and can be used as an active absorbent excipient in drug formulation

Objective To observe the distribution of substance P in the accessory auditory pathway of pigeon. Methods Immunocytochemical staining by using specific antibody against substance P was used. Results Intensely stained SP-like immunoreactive (SP-ir) neurons and fibers were mainly observed in the nucleus intercollicularis (ICo), periphery area of nucleus ventralis leminisci lateralis(VLV), shell area of nucleus ovoidalis (Ov), nucleus periventricularis magnocellularis (PVM), nucleus ventromedialis hypothalami(VMN), periphery area of the nucleus taeniae (Tn) of posterior archistriatum, nucleus preopticus anterior(POA), and the tractus septomesencephalicus(TSM).Conclusion There are many SP-ir structures in the accessory auditory pathway and brain regions related to reproductive control of the pigeon. Our results suggest SP may play a functional role in the vocal and endocrine regulation.

GAP-43,netrin-1,collapsin-1,and neuropilin-1 have been regarded to play crucial roles in the formation of patterned neural connections.The cerebellum consists of five distinct concentric layers:white matter,internal granule layer (IGL),Purkinje cell layer (PCL),molecular layer (ML),and external granule layer (EGL) in young rodents.Cells in EGL are generated after birth.In contrast Purkinje neurons are born before birth,which receive main innervations of climbing fibers fi'om the inferior olivary nucleus and parallel fibers from the internal granule cells.These innervations are mostly established in the first three postnatal weeks,accompanying the sprouting and maturation of Purkinje cells.The potential roles of GAP-43,netrin-1,collapsin-1 and neuropilin-1 in the postnatal development of cerebellum remain unclear.To get insights into the above issue,the expression of GAP-43,netrin-1,collapsin-1,and neuropilin-1 mRNAs and proteins were examined in the cerebellum of mice at postnatal days (P) 5,P10,P20 and adulthood.The results showed that these four molecules were expressed in different temporal and spatial patterns in the postnatal cerebellum of mice,which was in match with axonal synaptogenesis,elongation and synapse formation during postnatal development and adulthood.By using double immunohistocbemistry,it was found that the Purkinje cells stained for GAP-43 were also positive for either netrin-1 or collapsin-1 at P10,and cells stained for collapsin-1 were also positive for netrin-1 or neuropilin-1.It was suggested that the four molecules are involved in the postnatal development of cerebellum.