0.05).[Conclusion]BMSCs could be successfully differentiated into endothelial cells in vitro,and the functional genes were stably expressed in BMSCs-derived endothelial cells.They are ideal donor cells of tissue engineering vascularization.

[Objective]To explore the expression of OPG/OPGL protein and its significance in rat model of trauma-induced osteonecrosis of the femoral head(ONFH). [Methods]Thirty-two SD rats about 6 months were divided randomly into experimental and control groups.The animal model of femoral head necrosis was established in 32 SD rats by removing round ligaments of femoral head.Animals were sacrificed at 1,2,4 and 6 weeks after operation,respectively.The specimens were examined through histological observation under light microscope.The other side with sham operation served as normal control group.The comparison of fat tissue with hematopoietic tissue in the cavity of bone marrow of femoral head were performed by CMIAS computer-assisted image and statistical analysis.The percentage of empty lacuna in the femoral heads was obtained.Immunohistochemistry was used to determine the expression of OPG/OPGL protein in ONFH.[Results]ONFH was confirmed in experimental group.The model in various stages was successfully duplicated.Compared with normal control group,the percentage of empty lacuna remarkable increase was found in experimental groups in different periods(P

0.05).[Conclusion]Allogeneic freeze-dried bone marrow stromal cells has better biocompatibility but no cytotoxicity.It provids experimental data for its clinical application.

Objective To explore new insight into the immunopathogenesis of ulcerative colitis.Methods Immunohistochemistry for the immunoglobulin(IgG)and complement(C 3c )was performed in biopsy specimens of the mucous membrane from 50 patients with ulcerative colitis(32 in active state and 18 in inactive state)and 5 controls.Results The immunoglobulin and activated complement were found in the epithelium mucosae and basement membrane of capillary walls in ulcerative colitis,with highest density in patients with active ulcerative colitis as compared with inactive ones.Conclusions The activation of immunoglobulin(IgG)and complement(C 3c )are closely related to active ulcerative colitis which plays an important role in the tissue damage of active ulcerative colits.Immunoglobulin(IgG)and complement(C 3c )are important components of immunoregulatory network of ulcerative colitis

Objective To investigate the expression and distribution of basic fibroblast growth factor (bFGF)and platelet-derived growth factor (PDGF)in the different phases of femoral neck fracture.Methods Immunohistochemical assays were used to determine the expression and distribution of bFGF and PDGF protein in 36 human specimen of femoral neck fracture.A was measured and analyzed by CMIAS color imaging analysis system for signals of bFGF protein were found high in the mesenchymal cells,monocyte and vascular endothelial cells at 1st week after fracture in 9 subjects,with A of (0.4076 ±0.0902).The weakly positive signals of PDGF protein were found in the mesenchymal cells,while strongly positive in the vascular endothelial cells with A of (0.2261 ±0.0636).At 2rd week,in 9 cases the expression of bFGF and PDGF was strongly expressed in fibroblasts,endothelial cells,cartilage cell and cartilage matrix,osteoblast,with A of[(0.6404±0.0920)and (0.7457±0.0756)]and significandy higher than that at 1st week (P＜0.05,P＜0.01).There was no significant difference between the 3rd and 3nd week with A of[(0.7168±0.1346)and (0.8033±0.0491),P＞0.05 ].The expression of bFGF and PDGF protein was reduced obviously at 4th week but was positive in young and cartilage tissue,with A of [(0.5374correlation between bFGF and PDGF protein in different phases (r1week=0.792,r2week=0.834,r3week=0.880,entiation of cartilage cell and osteoblast,and induce proliferation of vascular endothelial cells and new blood vessel.③ Both bFGF and PDGF are bone growth factors, cooperating in regulating proliferation and differentiation of cartilage cell and osteoblast for fracture healing.

Objective To investigate cytotoxicity,biocompatibility and new bone formation traced of Chinese porous tantalum,and provide experimental strategies for further clinical application.Methods The physical properties of the porous tantalum were observed by the SEM.The osteoblasts were isolated from rabbit embryo.The extract fluid from tantalum was made.The cytotoxicity and proliferation of osteoblasts compounded with porous tantalum in vitro were detected by the MTT assay.The osteoblasts were co-cultured with extract of tantalum in vitro and the morphological changes,proliferation and adhesion were observed under SEM.A total of 24 New Zealand rabbits were used to establish the model of femoral condyles with porous tantalum bars implanted.Among which 4 of them was injected with calcein and alizarin on the 5th day and the 19th day and sacrificed at 10 week postoperatively.The specimens were observed with LSCM at 488 nm and 543 nm wavelength respectively.The remained 20 animals were sacrificed successively at 2,4,8,12 weeks of implantation,then were examined by histological observation.Results The SEM showed that the pore of porous tantalum were three-dimensional connected morphology.MTT assay showed that the osteoblasts grew well in extract and no significant difference between experimental and control groups.The osteoblasts grew and spread extensively on porous tantalum.Early on co-culture,the osteoblasts attached to the surface and inner walls of material,in the later stage,the osteoblasts excreted bone matrix over the surface of porous tantalum.The animal model showed that porous tantalum was bonded closely with host bone.Hard slicing showed that new bone and capillary regenerated on tantalum-bone interface at 2,4 weeks postoperatively.The pores were full with bone tissue at 8,12 weeks.The LSCM indicated that the green and red fluorescence-labeled new bone was displayed on tantalum-bone interface,while the red zone located around the green zones.They appeared to be discontinuous at early stage,but connected with each other at the end.Conclusion The Chinese porous tantalum has good biocompatibility and no cytotoxicity.The contact osteogenesis and bone conduction exist in tantalum-bone interface,and in a time-dependent manner.

Objective:To study the influence of bone morphogenetic protein-7 ( BMP-7 ) on chondro-cyte secretion and expression of type Ⅱ collagen ( Col-Ⅱ) , aggrecan ( AGG ) and SRY-related high mobility group-box gene 9 ( Sox9 ) mRNA in porous tantalum-chondrocyte composites.Methods: The articular chondrocytes were isolated from 3-week-old New Zealand immature rabbits and identified.The 2nd generation of chondrocytes with 1 ×106/mL inoculate concentration was seeded in porous tantalum and divided into 4 groups, and control group ( tantalum/chondrocyte) , 50μg/L BMP-7 group (50μg/L BMP-7/tantalum/chondrocyte) , 100 μg/L BMP-7 group ( 100 μg/L BMP-7/tantalum/chondrocyte ) , and 200 μg/L BMP-7 group ( 200 μg/L BMP-7/tantalum/chondrocyte ) .The proliferation of chondro-cytes was measured by CCK-8 assay.The chondrocyte growth and morphology were observed by scanning electron microscopy ( SEM) .The synthesis of glycosaminoglycan ( GAG) in chondrocytes was tested by dimethyl methylene blue ( DMMB) colorimetric quantification method.Col-Ⅱ, AGG and Sox9 mRNA in chondrocytes were detected by real-time PCR.Results: The chondrocytes were spindle-shaped in 24 hours of primary cell culture and most cells became polygonal shaped in 4 days.The chondrocytes were affirmed by alcian blue, safranin O and Col-Ⅱimmunocytochemistry staining.The result of CCK-8 assay showed that the level of cell proliferation in 100 μg/L BMP-7 groups were higher than those in the other groups ( P<0 .05 ) .The chondrocytes implanted into porous tantalum scaffolds with BMP-7 had better functions, by which cytoplasmic processes developed and extended to the surface and inner of porous tan-talum by SEM observation.DMMB quantitative determination of GAG showed that GAG amount of chon-drocytes in 100 μg/L BMP-7 groups was significantly higher than those in the other groups ( P<0 .05 ) . The expressions of Col-Ⅱ, AGG and Sox9 mRNA in chondrocytes were up-regulated in the experimental groups, compared with the control group and the best effect appeared when concentration of BMP-7 was 200μg/L.(P<0.05).Conclusion:BMP-7/tantalum/chondrocytes composites enhanced in vitro chon-drocyte proliferation and extracellular matrix greatly, and can promote chondrogenic gene expression.

Objective To determine the maintenance and loss of Epstein-Barr virus (EBV) genome during the clonal expansion of the EBV-infected epithelial cells. Methods The epithelial tumor cell line, 293-EBV, in which the EBV genome was observed with green fluorescent protein (GFP) readout. After a dozen of passages, it contained cells with strong or weak GFP expression, and some with complete loss of EBV genome. The cell growth was then continuously observed under a confocal microscope. The cell dividing and GFP expression were also observed during the clonal expansion by being made into very low density. Results The cells moved around due to adherence and mobility, while the GFP expression remained unchanged in the undivided cells. The cells could form compact or loosen clones. The EBV genome easily persisted in those clones when cells were growing compactly. As the cell number increased, the GFP expression became weak or even died away at the sites of low density in the loosen clones. Conclusion EBV-positive epithelial cells are able to sustain the EBV genome during its clonal expansion. The cells maintain EBV genomes by passing them to the daughter cells after replication. When the cells unsuccessfully inherit the EBV genome, the daughter cells may lose them which is related to the low cell density as well as the epithelial environment.

BACKGROUND:Bone morphogenetic protein 7 (BMP-7) can induce bone and cartilage formationin vivo, and induce chondrogenic and osteogenic differentiation of mesenchymal cels in muscles and around the vessels.
OBJECTIVE:To observe the structure of domestic tantalum-muscle interface fibrous capsule, growth of muscle and smal blood vessels into the porous tantalum and the ability of ectopic osteogenesis after implantation of porous tantalum loaded with BMP-7 into the erector spinae of rabbits.
METHODS: Porous tantalum slices loaded with BMP-7 (experimental group) and porous tantalum slices (control group) were implanted into the erector spinae muscle of New Zealand white rabbits. And the porous tantalum slices with surrounding muscle tissues about 0.5 cm thick were removed at 2, 4, 8 weeks after implantation, and observed under scanning electron microscope for hematoxylin eosin staining, Masson staining and hard tissue slice observation.
RESULTS AND CONCLUSION:(1) Hematoxylin-eosin staining: Fibrous capsule formation was observed around the materials in the two groups, and with the extension of time, the fibrous capsules were slightly dense, and thinned. There was no obvious inflammatory reaction in the interface between the material and the muscle. There was no significant difference between the two groups in the fibrous capsules thickness. (2) Scanning electron microscope: 2 weeks after the surgery, a smal amount of colagen and muscle fibers were formed in the porous tantalum pores in the two groups, and some of colagen fibers attached to the pore wals. At 8 weeks after the surgery, al the pores of porous tantalum were ful of muscle fibers that were combined with the pore wal closely. There was no significant difference between the two groups. (3) Hard tissue slices: 2 weeks after the surgery, a smal amount of fibroblast cels and muscle fibers grew into the pores of porous tantalum in the two groups and new capilaries grew into the pores of porous tantalum in the experimental group. At 8 weeks after the surgery, the porous tantalum and al the pores were ful of muscle fibers that were combined with the pore wal closely, the number of smal blood vessels and cels decreased, and the tantalum and the muscle were fused closely. (4) Masson staining: 8 weeks after the surgery, a large number of mesenchymal cels, ossein and cartilage matrix formed in the muscle gaps and a few cartilage bone tissues were formed in the experimental group, but no cartilage was found in the control group. The study showed that porous tantalum carrying BMP-7 has good biocompatibility and osteogenic induction ability. Subject headings: Tantalum; Bone Morphogenetic Protein 7; Tissue Engineering.

Objective To investegate the effect of ginsenoside Rg1 on the apoptosis related protein FLICE-inhibitory protein(FLIP),Fas-associated death domain protein (FADD)and Caspase-3 in the subatania nigra(SN)of 1-methyl-4-phenyl-1,2,3,6-tetrahyd-ropyridine (MPTP)-induced mouse models of Parkinson’s disease(PD), and to investigate the role of FADD and FLIP in the pathogenesis of PD and the protective effect of ginsenosides Rg1 on dopaminergic neurons.Methods 45 C57BL/6N mice were randomly divided into control group,model group and ginsenoside Rg1 group (n=15).The mice in model group were injected with MPTP by intraperitoneal,the mice in Rg1 group were injected with ginsenoside Rg1 before injecting MPTP,and the mice in control group were injected with normal saline by intraperitoneal. The behavioral changes of the mice in various groups were observed, and immunohistochemistry and Western blotting methods were used to observe the expressions of tyrosine hydroxylase (TH),FADD,FLIP and Caspase-3 in substantia nigra of the mice.Results Compared with control group,the mice in model group presented with typical symptoms of PD, the TH-positive neurons in the subatania nigra was significantly reduced (P<0.01 ), the number of FADD, FLIP and Caspase-3 positive cells was significantly increased(P<0.01),and the cytoplasm was deeply stained;the protein expression levels of FADD,FLIP and Caspase-3 were significantly increased (P<0.01).Compared with model group,the PD symptoms of the mice in ginsenoside Rg1 group reduced, the number of TH-positive neurons was significantly increased, the number of positive cells of FLIP,FADD and Caspase-3 were significantly reduced(P<0.01),and the cytoplasm was lightly stained;the protein expression levels of FADD, FLIP and Caspase-3 were significantly reduced (P<0.01 ). Nonlinear correlation analysis found that there was a positive relationship between the number of FADD and Caspase-3 positive cells (r=0.791,P<0.05).Conclusion Ginsenoside Rg1 may play a neural protective effect dopaminergic on neurons by modulating the FADD and FLIP expressions in SN of PD model mice.