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To explore the roles of nano-hydroxyapatite/collagen/PLA (nHAC/PLA) plus endothelial progenitor cells (EPCs) in repairing segmental bone defects of rabbit radius and enhancing angiogenesis and new bone formation.EPCs isolated from New Zealand white rabbit bone marrow were cultured, identified and seeded into nHAC/PLA scaffolds. And the growth of EPCs in scaffolds was observed under scanning electron microscopy (SEM). Thirty-six were randomly divided into 3 groups to establish segmental bone defect models in radii. Two groups were implanted with EPCs/scaffolds constructs (group A, n = 16) and scaffolds alone (group B, n = 16) respectively. The remaining four rabbits were used as negative control (group C) and nothing was implanted. Animals were sacrificed at different timepoints and radii harvested to undergo radiological examination, histological examination and microvessle density test.These cells isolated from bone marrow were confirmed as EPCs. SEM showed that EPCs attached to the nHAC/PLA scaffolds, grew and proliferated well. Animal experiments revealed that radiological scores (5w: 2.25 ± 0.50 vs 1.00 ± 0.00; 10w: 2.75 ± 0.50 vs 1.75 ± 0.50; 15w: 4.25 ± 0.50 vs 3.0 ± 0.0; each P0.05), percentage of new bone formation area in bone defect regions (5w: 29.0% ± 3.5% vs 8.1% ± 0.8%; 10w: 63.4% ± 5.5% vs 16.6% ± 1.3%; 15w: 96.0% ± 4.3% vs 34.0% ± 6.6%; each P0.05) and microvessel density (2w: 13.5 ± 0.9 vs 4.3 ± 1.0; 5w:9.8 ± 0.7 vs 4.8 ± 0.3; 10w: 7.0 ± 0.4 vs 4.5 ± 0.4; each P0.05) in group A were significantly higher than those in group B. No new bone formation occurred in group C.The composite structure of EPCs-nHAC/PLA can enhance angiogenesis and new bone formation in segmental bone defects in rabbit radii. It may become a potential candidate of promoting revascularization of tissue engineering bone and repairing large bone defects.

To retrospectively explore the influences of minor back trauma on surgical outcomes in patients with thoracic ossification of ligamentum flavum (TOLF) and preliminarily detect its possible causes.A total of 94 TOLF patients were divided into two groups according to the absence or presence of minor back trauma: MT (minor trauma, n = 16) and NT (no trauma, n = 78). They were compared in terms of gender, age, duration of symptoms, levels of involvement, numbers of involved segments, ratio of intramedullary signal changes (IMSC), pre-post-operative JOA (Japanese Orthopedic Association) score, recovery rate (RR) at the final follow-up. Multiple regression analysis was employed to elucidate the causes related with the surgical outcomes. The MT group was further divided into two subgroups according to the intervals between trauma and surgery to clarify the influences of surgical timing on the efficacies.The JOA scores were 4.0 ± 1.4 and 8.4 ± 1.7 respectively in MT and NT groups at the final follow-up. The neurological status of patients improved in both groups (MT: P = 0.009, NT: P = 0.000). The patients were younger in MT groups (50 ± 11 years) than those in NT groups (58 ± 8 years) (P = 0.046). The ratio of IMSC was higher in MT groups (75.0%) than that in NT groups (25.6%) (P = 0.000). The pre-post-operative JOA scores were lower in MT groups than those in NT groups (both P = 0.000). Multiple regression analysis revealed that the postoperative JOA score at the final follow-up was positively related with the preoperative JOA score (r = 0.60, P = 0.000) and negatively with trauma and IMSC (r = -1.82 and r = -1.87, P = 0.000) while the final postoperative RR were negatively related with trauma and IMSC (r = -26.26 and r = -33.70, P = 0.000). The surgical timing after trauma did not influence the efficacies (P = 0.147).The TOLF patients with minor back trauma have a worse post-operative recovery. A minor trauma might be a risk factor of adverse surgical outcomes.

To study the effects of siRNA-mediated beta-catenin down-regulation on Wnt/beta-catenin signal transduction pathway in lung adenocarcinoma A549 cells.A549 cell was divided into three groups: PGCsil-CTNNB1-siRNA group (transfection with beta-catenin interference plasmids), negative control group (transfection with negative control plasmids) and non-transfection group (blank control). For each group, real-time PCR was employed to detect the expression of beta-catenin and cyclin D1 (a target gene of Wnt/beta-catenin pathway). A MTT cell proliferation assay was performed to study the proliferating capacity. Flow cytometry was used for cell cycle analysis. Clone formation and Millicell chamber experiment were performed to evaluate the clone formation and migration capacities of cells.The expression of beta-catenin and cyclin D1 in PGCsil-CTNNB1-siRNA cell decreased at the mRNA level. It was lower than negative control (0.002+/-0.001 vs 0.023+/-0.002, P0.01; 0.005+/-0.002 vs 0.040+/-0.020, P0.05) and blank control groups (beta-catenin mRNA: 0.021+/-0.003, P0.01; cyclin D1 mRNA: 0.042+/-0.004, P0.05). Also the proliferating capacity at Days 5-7 was inhibited in comparison with negative control and blank control groups (P0.05, P0.01). The cell-doubling time (58.1 h) was markedly longer than those of negative control group (37.9 h, P0.05) and blank control group (34.2 h, P0.05). The number of cells in G0-G1 phrase increased in PGCsil-CTNNB1-siRNA group (86.4%+/-2.6%) in comparison with negative control (73.8%+/-0.9%, P0.01) and blank control groups (75.8%+/-1.5%, P0.01). In PGCsil-CTNNB1-siRNA group, the clone formation ratio (31.6%+/-7.7%) was lower than negative control (46.9%+/-7.3%, P0.05) and blank control groups (44.2%+/-2.5%, P0.05). And the number of cells (16.0+/-3.8) passing through the membrane of Millicell chamber was smaller than negative control (32.7+/-3.1, P0.01) and blank control groups (33.0+/-2.7, P0.01).Knocking down beta-catenin not only inhibits the Wnt/beta-catenin signal transduction pathway in lung adenocarcinoma A549 cells but also decreases cell proliferation, clone formation and migration capacity. Thus it may become a novel target for lung cancer therapy.

To evaluate the antitumor effects of the conjugates synthesized by coupling cytotoxic paclitaxel (PTX) to somatostatin analog octreotide (OCT) on human non small cell lung cancer (NSCLC).Two cytotoxic somatostatin analog, PTX-OCT and 2PTX-OCT, were developed in which PTX was linked to octreotide. Forty-five BALB/c nu/nu nude mice were injected with human NSCLC cells of the line A549 into the right armpit. The nude mice that were xenografted were randomly divided into 8 groups. (1) control group (n = 6), (2) PTX-OCT group (n = 5), injected intravenously with PTC-OCT 150 nmol/kg on days 1, 7, and 21, (3) 2PTX-OCT group (n = 6), injected intravenously with PTC-OCT 150 nmol/kg, (4) OP group (n = 6), injected with mixture of PTX and OCT 150 nmol/kg, (5) OCT group (n = 5) injected with OCT 150 nmol/kg (6) PTX group (n = 6), injected with PTX 150 nmol/kg, (7) 2PTX group, injected with PTX 300 nmol/kg, and (8) 2(PTX-OCT) injected with PTX-OCT 300 nmol/kg, The tumor volume and body weight (BW) were observed regularly. The tumor volume doubling time was calculated. White blood cells were counted by collecting peripheral blood sample. By the end of experiment the mice were killed with the tumors taken out. The expression of mRNA of subtypes1-5 of human somatostatin receptor (SSTR1-SSTR5) were investigated using RT-PCR. Histological apoptosis was detected by DNA ladder. Immunohistochemistry was used to examine the SSTR2 and SSTR5 expression and tumor microvessel density (MVD).The tumor volumes of 2PTX-OCT and 2(2PTX-OCT) groups were significantly smaller than those of other groups (all P0.01). The tumor doubling times of the 2PTX-OCT and 2 (2PTX-OCT) groups were significantly longer than those of the other groups too (all P0.01). The MVD levels of the 2PTX-OCT and 2 (2PTX-OCT) groups were significant lower than those of the other groups (all P0.01). The toxicity of the PTX group was more obvious. The WBC count levels of the PTX and 2PTX groups were significantly lower than those of the other groups (all P0.05). mRNA expression could be found for SSTR1, 2, 4, and 5 in the A549 xenografts. Immunohistochemistry showed that SSTR2 was mainly found in the tumor cell membrane, and SSTR5 was found in the tumor cell membrane and cytoplasm. More histological apoptosis bands were shown by DNA ladder method in the 2PTX-OCT and 2 (PTX-OCT) groups.The targeting conjugate 2PTX-OCT inhibits the proliferation of tumor cells, reduces microvessel, and decreases the toxicity in comparison with the cytotoxic radical PTX.