[Effects of bone morphogenetic protein-2 gene therapy on the bone-implant interface: an experimental study with dogs].

Objective: To investigate the effects of bone morphogenetic protein-2 (BMP-2) gene therapy on the bone-implant interface in the reconstruction of periprosthetic bone defect.

Methods: Transverse defects were caused in the external condylae of both femurs of 14 adult Beagle dogs. Titanium alloy implants were inserted and a bone defect 3 mm wide around the titanium alloy implant was preserved.

[An immunological study on adenovirus mediated human bone morphogenetic protein 2 gene therapy].

Objective: To evaluate the host immune reaction against adenovirus mediated human bone morphogenetic protein 2 (Adv-hBMP-2) gene therapy in repair of tibial defects.

Methods: Twelve goats were made 2.1 cm segmental defects in the tibial diaphysis and divided into 2 groups.

Evaluation of different scaffolds for BMP-2 genetic orthopedic tissue engineering.

To better understand the effects of scaffold materials for bone morphogenetic protein 2 (BMP-2) genetic tissue engineering in vivo, several gels, including alginate, collagen, agarose, hyaluronate, fibrin, or Pluronic, were mixed with adenovirus-mediated human BMP-2 gene (Adv-hBMP-2) transduced bone marrow stromal cells (BMSCs) and injected into the muscles of athymic mice to evaluate the resulting osteogenesis and chondrogenesis. These gel and gene-transduced BMSC mixtures were also loaded onto beta-TCP/HAP biphasic calcined bone (BCB) and observed under scanning electron microscopy (SEM). In addition, these composite scaffolds were implanted into the subcutaneous site of athymic mice to construct tissue-engineered bone.

[Experimental study of immunological tolerance induced by cytotoxic T lymphocyte-associated antigen 4 immunoglobulin in fresh bone allografts].

Objective: To study the immunological tolerance induced by blocking the second signal of T cell with extrinsic cytotoxic T lymphocyte-associated antigen 4 immuno globulin (CTLA4-Ig).

Methods: Fifty-four BALB/C mice, inbred strains, were employed as recipients of bone allografts, using a model of heterotopic muscle pouch. The 54 mice were divided into 3 groups and 18 for each group.

[Experimental research on human insulin-like growth factor I gene transfect the cultured bone marrow mesenchymal stem cells].

Objective: To investigate the effectiveness of human insulin-like growth factor I (hIGF-I) gene transferred into the cultured goat bone marrow mesenchymal stem cells with liposome, and find a new method of cell-mediated gene therapy.

Methods: Bone marrow was extracted from adult goats and cultured in vitro by monolayer. Then the recombinant eukaryotic expression plasmid pIRES2-EGFP-hIGF was transfected into cells by FuGene 6.

Investigation of elemental content distribution in femoral head slice with osteoporosis by SRXRF microprobe.

A synchrotron radiation X-ray fluorescence microprobe analysis technique was used to scan a slice of the femoral head from its periphery to its center, via cartilage, compact, and spongy zones in order to determine the distribution and the way inorganic substances are lost in bone tissue. The sample preparation and experimental apparatus are described in detail. The quantitative computerized tomography of elemental distribution, such as Ca, P, K, Fe, Zn, Sr, and Pb in bone slice tissue, including cartilage, substantial compact, and substantial spongy, is investigated.

Ectopic bone formation of human bone morphogenetic protein-2 gene transfected goat bone marrow-derived mesenchymal stem cells in nude mice.

Objective: To evaluate the osteogenic potential of bone morphogenetic protein (BMP)-2 gene transfected goat bone marrow-derived mesenchymal stem cells (MSCs).

Methods: Goat bone marrow-derived MSCs were transfected by Adv-human bone morphogenetic protein (hBMP)-2 gene (Group 1), Adv-beta gal transfected MSCs (Group 2) and uninfected MSCs (Group 3). Western blot analysis, alkaline phosphatase staining, Von Kossa staining and transmission electron microscopy were adopted to determine the phenotype of MSCs.

[Preparation of a biphasic calcined bone of beta-TCP/HAP and its application in BMP-2 gene medicine].

In this study, we produced a biphasic absorbable calcined bone (CB) of beta-TCP/HAP, and evaluated its function as a carrier of bone marrow derived mesenchymal stem cells(BMSCs) in BMP-2 gene medicine. Biphasic CB was manufactured and its surface was coated by collagen. X-ray diffraction analysis, scanning electron microscopy and biomechanical measurement were performed on the product.

[The role of Smads and related transcription factors in the signal transduction of bone morphogenetic protein inducing bone formation].

Objective: To clarify the mechanisms of the signal transduction of bone morphogenetic proteins (BMPs) inducing bone formation and to provide theoretical basis for basic and applying research of BMPs.

Method: We looked up the literature of the role of Smads and related transcription factors in the signal transduction of BMPs inducing bone formation.

Results: The signal transduction processes of BMPs included: 1.

[BMP-2 gene modified tissue-engineered bone repairing segmental tibial bone defects in goats].

Objective: To evaluate the effectiveness of the tissue-engineered bone substitute loaded with adenovirus mediated human bone morphogenetic protein-2 gene (Adv-hBMP-2) transfected bone marrow derived mesenchymal stem cells (BMSC) in the repair of diaphyseal segmental bone defect of large animal.

Methods: The right tibial bone defects (2.6 cm) model of 26 goats were established and divided into 5 groups: I.

In vitro study of immune tolerance induced by CTLA4-Ig in bone transplantation: The effect on cell proliferation stimulated by lymphocytes and bone supernatant.

To clarify the effect of CTLA4-lg on immune rejection of bone grafts, we observed the effect of CTLA4-lg on lymphocyte proliferation of BALB/C mice stimulated by lymphocytes and bone supernatant of C57BL/6 mice. The splenic lymphocytes and bone supernatant of C57BL/6 mice, as the stimulator cells and stimulator antigens, were cultured in vitro with the splenic lymphocyte of BALB/C mice. At the same time, CTLA4-lg at a dose of 5,10 or 20 &mgr;g/ml and L6 (as control) at 20 &mgr;g/ml were added.

[Measurement and classification of geometric parameters in Chinese proximal femur].

This study sought to establish a set of hip prostheses for the Chinese population and improve the design guidelines for hip prostheses. 480 cadaveric adult femora were obtained for X-ray imaging. 21 geometric parameters of femora were sampled on the anteroposterior(AP) and mediolateral(ML) views of radiograph in conjunction with computer-aided image processing technology.

A biomechanical investigation on the incorporation of cortical allograft in rabbit ulna defects.

OBJECTIVE: To explore the changes of biomechanic al properties of cortical allograft in different mechanical environments. METHODS: Cortical allograft was transplanted to each side of th e midshaft diaphyseal ulna of each one of 40 rabbits. The left transplanted allo graft underwent normal physiological load, while the right one underwent lower l oad.