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Background: There has been a recent increase in the number of patients suffering from bone and joint diseases, as a consequence of corticosteroids administration. There are more patients treated with low dose of GCs under long-term conditions in clinical, such as effect of GCs on Rheumatoid arthritis, Crohn's disease and Asthma patients. Hence, it was difficult for doctor to determine which problem occur first - OP or ON; however, there was no clinical report previously in the literature, and there was no effective animal model of OP and ON about low dose GCs. This study was conducted to develop rabbit models of glucocorticoid (GC)-induced femoral head ON and OP and to investigate the temporal relationship between the occurrence of the two events following administration of glucocorticoids. Materials and Methods: Fifty six, 6 months old female rabbits were randomly divided into the GC group and control group (C). Rabbits received gluteal injections of methylprednisolone sodium succinate once a day for 4 weeks, while normal saline solution in the control group. Rabbits were sacrificed at 0, 2, 4, and 8 weeks. Hip magnetic resonance imaging was performed before the rabbits were sacrificed. Serum calcium (Ca), phosphorus (P), total cholesterol, and triglyceride levels were also measured. The bone mineral density (BMD) of femoral head and the femoral shaft were measured by dual-energy X-ray absorptiometry. The trabecular parameters of the femur and the 4th lumbar vertebrae (L4) were measured with a micro-computed tomography (µ-CT). Also, the femoral head was stained with hematoxylin-eosin staining. Results: At 4 weeks in the GC group, the BMD of the femur reduced 33% and 22% in the femoral head and shaft; there was irregular intermediate to high T2-weighted images signals; µ-CT showed microfractures and cystic changes in the femoral head and L4 at 4 weeks. At 8 weeks in the GC group, the classical "line-like sign" indicating ON of the femoral head was observed in 64.3% of the rabbits. Conclusion: A rabbit model of GC-induced OP and ON was developed by repetitive injection with small doses of GCs in the gluteal region. OP was observed at 4 weeks while ON developed at 8 weeks and followed a clear temporal pattern. [ABSTRACT FROM AUTHOR]

MicroRNAs are involved in different cancer-related processes. MicroRNA-21 (miR-21), as an oncomiR, is overexpressed in all kinds of tumors and the role of miR-21 in carcinogenesis is elucidated in many cancers gradually. However, the function of miR-21 in osteosarcoma is still unclear. In our study, we found that miR-21 was significantly overexpressed in osteosarcoma tissues. More importantly, we confirmed that knockdown of miR-21 greatly decreased cell invasion and migration of MG-63. Furthermore, we identified that RECK (reversion-inducing-cysteine-rich protein with kazal motifs), a tumor suppressor gene, was a direct target of miR-21. Finally, the expression of RECK protein negatively correlated with the expression of miR-21 in human osteosarcoma tissues, indicating the potential regulation of RECK by miR-21. Our results suggest that miR-21 expression has a key role in regulating cellular processes in osteosarcoma, likely through regulating RECK and may serve as a therapeutic target. [ABSTRACT FROM AUTHOR]

The objective was to evaluate the availability and efficacy of internal fixation with absorbable poly- D, L-lactic acid (PDLLA) pins for the treatment of late presenting irreducible Gartland type III supracondylar fracture of the humerus in children. Fifty-six cases of late presenting irreducible Gartland type III supracondylar fracture of the humerus in children were treated by open reduction and bioabsorbable PDLLA pin fixation from March 2005 to March 2008. The outcome of treatment was evaluated by the Mayo Elbow Performance Score (MEPS) and the criteria of Flynn. Fifty-six patients were followed up from 24 to 36 months (mean: 22 months). No displacement of bone fracture occurred, and all fractures healed within a normal time without wound infection; there were no cases of Volkmann's ischaemic contracture, myositis ossificans or iatrogenic injury of the ulnar nerve. No residual vascular deficits or iatrogenic nerve injury were noted; cubitus varus deformity occurred in one case. There were 49 excellent, four good and three fair results according to the MEPS; the rate of excellent and good outcome was 94.6%. All children but one had excellent cosmetic results according to the criteria of Flynn. All of the children and their parents stated that they would choose this treatment again. Treatment of late presenting irreducible Gartland type III supracondylar fracture of the humerus in children with bioabsorbable PDLLA pins provides sufficient stability and satisfactory efficacy. The absorbable implant has become popular for its avoidance of a second operation to remove the internal fixation, and the degree of patient satisfaction is high. [ABSTRACT FROM AUTHOR]

To understand the molecular mechanisms underlying chloroplast development, we isolated and characterized the albino mutant emb1303-1 in Arabidopsis. The mutant displayed a severe dwarf phenotype with small albino rosette leaves and short roots on a synthetic medium containing sucrose. It is pigment-deficient and seedling lethal when grown in soil. Embryo development was delayed in the mutant, although seed germination was not significantly impaired. The plastids of emb1303-1 were arrested in early developmental stages without the classical stack of thylakoid membrane. Genetic and molecular analyses uncovered that the EMB1303 gene encodes a novel chloroplast-localized protein. Microarray and RT-PCR analyses revealed that a number of nuclear- and plastid-encoded genes involved in photosynthesis and chloroplast biogenesis were substantially downregulated in the mutant. Moreover, the accumulation of several major chloroplast proteins was severely compromised in emb1303-1. These results suggest that EMB1303 is essential for chloroplast development. [ABSTRACT FROM AUTHOR]

Abstract  Osteoclasts are formed from the monocyte-macrophage lineage in response to receptor activator of nuclear factor κB ligand (RANKL) expressed by osteoblasts. Bone is the most common site of breast cancer metastasis, and osteoclasts play roles in the metastasis. The taxane-derived compounds paclitaxel and docetaxel are used for the treatment of malignant diseases, including breast cancer. Here we explored the effects of docetaxel on osteoclastic bone resorption in mouse culture systems. Osteoclasts were formed within 6 days in cocultures of osteoblasts and bone marrow cells treated with 1,25-dihydroxyvitamin D3 plus prostaglandin E2. Docetaxel at 10−8 M inhibited osteoclast formation in the coculture when added for the entire culture period or for the first 3 days. Docetaxel, even at 10−6 M added for the final 3 days, failed to inhibit osteoclast formation. Osteoprotegerin, a decoy receptor of RANKL, completely inhibited osteoclast formation when added for the final 3 days. Docetaxel at 10−8 M inhibited the proliferation of osteoblasts and bone marrow cells. RANKL mRNA expression induced by 1,25-dihydroxyvitamin D3 plus prostaglandin E2 in osteoblasts was not affected by docetaxel even at 10−6 M. Docetaxel at 10−6 M, but not at 10−8 M, inhibited pit-forming activity of osteoclasts cultured on dentine. Actin ring formation and l-glutamate secretion by osteoclasts were also inhibited by docetaxel at 10−6 M. Thus, docetaxel inhibits bone resorption in two different manners: inhibition of osteoclast formation at 10−8 M and of osteoclast function at 10−6 M. These results suggest that taxanes have beneficial effects in the treatment of bone metastatic cancers. [ABSTRACT FROM AUTHOR]

The regulatory effects of niacinamide (Nia) on intervertebral disc (IVD) aggrecan in vitro was investigated. Chiba's 10 ng/mL interleukin-1 (IL-1)-induced rabbit IVD degeneration model in vitro was established. 0. 5, 0. 25 and 0. 05 mg/mL Nia was added to normal and degenerated IVDs for intervention. On the first and second week after intervention, safranin O-fast green staining intensity and glycosaminoglycan (GS) content were measured. The expression of aggrecan core protein was detected by RT-PCR. The results showed: (1) After treatment with 0.5 mg/mL Nia for one week, the GS content in nucleus pulposus (NP) was increased by 44.8%, as compared with control group ( P<0.01); The GS content in IL-1 induction groups was increased with the increase of Nia concentrations: After treatment with 0.5 mg/mL for one week, the GS content in NP was increased by 68.3 % as compared with control group ( P<0.01). After two weeks, GS content in NP and fibrous rings was still higher than in control group at the same period ( P<0.01) and untreated group ( P<0.01). (2) Safranin O-fast green staining revealed that with the increase of Nia concentrations staining density in NP and fibrous rings was increased and histological structure damage to IVDs by IL-1β was alleviated. (3) RT-PCR showed that the expression of core protein gene in IL-1β-induced degenerated IVDS was increased with the increase of Nia concentrations. It was concluded that under conditions in vitro, Nia could up-regulate the expression of aggrecan in IVDs and protect IVDs from IL-1β-induced degeneration at least partially, which offers a potential choice for IVD degeneration clinical therapy. [ABSTRACT FROM AUTHOR]

To study the effect on regulation of cell cycle of osteosarcoma cell line MG63 tranceduced with exogenous p16ink4a and hRb1 genes, pIRES-p16ink4a-hRbl, PIRES-p16ink4a and pIRES-hRb1 plasmids were constructed by gene recombination technology. The recombinant plasmid was transferred into osteosarcoma cell line MG63 by metafectene, and the resistant clones were selected by G418 selective medium. mRNA and protein expression of osteosarcoma cell line were assayed by RT-PCR and Western-Blot respectively. Cell cycle and apoptosis were analyzed by subG1 flow cytometric. Cell proliferation was tested by MTT. In the genome of these transfected target cells, the expression of p16ink4a and hRb1 mRNA and protein were detected respectively in vitro. It was demonstrated with subG1 flow cytometric analysis and MTT method that p16ink4a and hRb1 genes cooperation more significantly inhibited cell growth and induced a more marked G1 arrest and apoptosis than p16ink4a/hRb1 alone ( P<0.01). Coexpression of exogenous p16ink4a with hRb1 broke the regulatory feedback loop of p16ink4a-cyclinD1/CDK-hRb1 and played a more significant role in inhibiting cell growth as well as inducing cell apoptosis than p16ink4a or hRb1 did alone in vitro. [ABSTRACT FROM AUTHOR]

The biocompatibility and osteogenic activity of allogenic decalcified bone matrix (DBM) used as a carrier for bone tissue engineering were studied. Following the method described by Urist, allogenic DBM was made. In vitro, DBM and bone marrow stromal cell (BMSC) from rabbits were co-cultured for 3–7 days and subjected to HE staining, and a series of histomorphological observations were performed under phase-contrast microscopy and scanning electron microscopy (SEM). In vivo the mixture of DBM/BMSC co-cultured for 3 days was planted into one side of muscules sacrospinalis of rabbits, and the DBM without BMSC was planted into other side as control. Specimens were collected at postoperative week 1, 2 and 4, and subjected to HE staining, and observed under SEM. The results showed during culture in vitro, the BMSCs adherent to the wall of DBM grew, proliferated and had secretive activity. The in vivo experiment revealed that BMSCs and undifferentiated mesenchymal cells in the perivascular region invaded gradually and proliferated together in DBM/BMSC group, and colony-forming units of chondrocytes were found. Osteoblasts, trabecular bone and medullary cavity appeared. The inflammatory reaction around muscles almost disappeared at the second weeks. In pure DBM group, the similar changes appeared from the surface of the DBM to center, and the volume of total regenerate bones was less than the DBM/BMSC group at the same time. The results indicated that the mixture of DBM and BMSC had good biocompatibility and ectopic induced osteogenic activity. [ABSTRACT FROM AUTHOR]

The feasibility of using gene therapy to treat full-thickness articular cartilage defects was investigated with respect to the transfection and expression of exogenous transforming growth factor (TGF)-β1 genes in bone marrow-derived mesenchymal stem cells (MSCs) in vitro. The full-length rat TGF-β1 cDNA was transfected to MSCs mediated by lipofectamine and then selected with G418, a synthetic neomycin analog. The transient and stable expression of TGF-β1 by MSCs was detected by using immunohistochemical staining. The lipofectamine-mediated gene therapy efficiently transfected MSCs in vitro with the TGF-β1 gene causing a marked up-regulation in TGF-β1 expression as compared with the vector-transfected control groups, and the increased expression persisted for at least 4 weeks after selected with G418. It was suggested that bone marrow-derived MSCs were susceptible to in vitro lipofectamine mediated TGF-β1 gene transfer and that transgene expression persisted for at least 4 weeks. Having successfully combined the existing techniques of tissue engineering with the novel possibilities offered by modern gene transfer technology, an innovative concept, i.e. molecular tissue engineering, are put forward for the first time. As a new branch of tissue engineering, it represents both a new area and an important trend in research. Using this technique, we have a new powerful tool with which: (1) to modify the functional biology of articular tissue repair along defined pathways of growth and differentiation and (2) to affect a better repair of full-thickness articular cartilage defects that occur as a result of injury and osteoarthritis. [ABSTRACT FROM AUTHOR]

An improved method of epiphyseal lengthening operation and subsequent outer fixation are presented on the basis of experience in 30 cases. The operative technique is described in detail, including the different options of separative traction and osteotomy at subtrochanteric, distal part of the upper femur and lower tibial levels. The physiological and histological research concerning this method is discussed. The authors believe that this procedure is better than the other methods. [ABSTRACT FROM AUTHOR]

RGD-containing peptide (K16-GRGDSPC), characterized as non-viral gene vectors, was fabricated to modify the surface of PLGA-[ASP-PEG] matrix, which offered the foundation for gene transfer with porous matrix of gene activated later. Peptide was synthesized and matrix was executed into chips A, B and chip C. Chip C was regarded as control. Chips A and B were reacted with cross-linker. Then chip A was reacted with peptide. MS and HPLC were used to detect the MW and purity of peptide. Sulphur, existing on the surface of biomaterials, was detected by XPS. The purity of un-reacted peptide in residual solution was detected by a spectrophotometer. HPLC shows that the peptide purity was 94%–95%, and MS shows that the MW was 2 741.3307. XPS reveals that the binding energy of sulphur was 164 eV and the ratio of carbon to sulphur (C/S) was 99.746:0.1014 in reacted chip A. The binding energy of sulphur in reacted chip B was 164 eV and 162 eV, C/S was 99.574:0.4255, and there was no sulphur in chip C. Peptide was manufactured and linked to the surface of biomimetic and 3-D matrix, which offered the possibilities for gene transfer and tissue engineering with this new kind of non-viral gene vector. [ABSTRACT FROM AUTHOR]

The necessity and superiority of the surgical operation on children with floating knee injury and the fracture union and complications were investigated. Twenty-eight children with floating knee injury were subjected to open reduction and internal fixation or external fixator. The patients were followed up for 18 months to 7 years. The curative effectiveness was scored by Karlstrom criteria. The results showed that no nonunion or deformity was found. The affected limb was 1.2 cm to 1.5 cm longer in 2 cases, 0.8 to 1.2 cm shorter in 3 cases than the contralateral. No severe dysfunction of knee joint occurred. The excellent-good rate was 92.8% and the curative rate 71.4% respectively. So for children whose age is older than 5 years, it's a good way to treat the fractures of femur and tibia with open reduction and internal fixation or external fixator. The method can be advantageous for the nursing care, early function recovery, shortening of the hospital stay and avoidance of severe complications. [ABSTRACT FROM AUTHOR]

To investigate therapeutic efficiency of Ad/CMV-hTGF-β1 gene for rabbit intervertebral dise degeneration model. 60 Japanese white rabbits were selected to form the L5-L6 Anterior-Lateral-Anulus-Fibrosus-Incision-Induced model in order to simulate human intervertebral dise degeneration. 36 rabbits, whose corresponding intervertebral discs were injected with 20 μl (10×106 pfu) of Ad CMV-hTGF-β1 gene, constituted the therapy group, 12 were injected with 20 μl (10×106 pfu) of Ad CMV-LacZ gene as comparison group, while 12 were only injected with equivalent capacity of saline for empty comparison group, 3 weeks after injection, examples were taken for investigation of HE staining, MRI. Western Blotting and immunohistochemical research TGF-β1. Wide distribution of TGF-β1 was detected by immunohistochemical research in the degenerated annulus fibrosus after injection. Western Blotting research showed significant increase of TGF-β1 content in intervertebral dises treated with TGF-β1 gene than comparison groups. MRI signal transformed from low to comparatively high and that intervertebral dise pathological degree improved. Ad CMV-hTGF-β1 gene transfection is a potential method to increase TGF-β1 content and reverse intervertebral dise degeneration. [ABSTRACT FROM AUTHOR]

To study the expression of mTERT gene in the testis of SD rats and its significance, in situ hybridization (ISH) techniques were used to detect the expression of telomerase gene mTERT mRNA in the testis of SD rats. The expression of mTERT was detectable in different-age male SD rats testis. There was a positive correlation between the expression of mTERT and the location of germ cells (spermatogonia, spermatocyte, spermatid). In Sertoli cells, leydig cell and spermatozoa, telomerase mTERT was not detected. Type A spermatogonia expressed the highest level of telomerase mTERT mRNA. Our results suggest that the expression of mTERT gene in the testis of SD rats is of lifetime and coincide with the telomerase activity. [ABSTRACT FROM AUTHOR]

To explore a new method for the therapy of the avascular necrosis of the femoral head, the recombinant plasmid pCD-hVEGF165 was mixed with collagen and was implanted in the necrotic femoral head. The expression of vascular endothelial growth factor (VEGF) was detected by RNA dot hybridization and immunohistochemical method. The repair of the femoral head was observed by histological method. The results showed that the expression of VEGF was detectable in the femoral head treated with VEGF gene. Angiogenesis in these femoral heads was more abundant than the control. Bone repairing was augmented in the femoral head treated with VEGF gene. The results suggest that angiogenesis in bone tissue could be augmented by gene transfection of VEGF and bone repairing would be accelerated accordingly. [ABSTRACT FROM AUTHOR]

To construct the antisense transforming growth factorβ1 (TGFβ1) gene and investigate the effect of TGFβ1 autocrine loop blockage on the proliferation of osteosarcoma cells. TGFβ1 cDNA was cloned by RT-PCR from human osteosarcoma cells (MG-63) and inserted into pcDNA3 to construct an antisense expression vector, which was dubbed pcDNA3-TGFβ1(−). MTT was used to detect the proliferation of osteosarcoma cells transfected by antisense TGFβ1 gene. Our results showed that the proliferation of the transfected osteosarcoma cells was suppressed markedly. It is concluded that TGFβ1 autocrine loop blockage in osteosarcoma cells could inhibit cell proliferation, which might be helpful for gene therapy of osteosarcoma. [ABSTRACT FROM AUTHOR]

To construct basic fibroblast growth factor (bFGF) eukaryotic expression vector and to evaluate the possibility of bFGF gene therapy in orthopedic disease, the pCD-rbFGF recombinant plasmid was constructed by cloning rat basic fibroblast growth factor (bFGF) cDNA into an eukaryotic expression vector, pcDNA3. Rat osteoblasts were transfected with pCD-rbFGF plasmid by lopofectin mediated gene transfer, the transient expression was detected by streptavidin-biotin-enzyme complex (SABC) method. It was observed that the expression of rat bFGF gene was detected 72 h after transfected distinctly. Basic fibroblast growth factor gene therapy is a method of potential for a wide array of orthopedic diseases. [ABSTRACT FROM AUTHOR]