A biomimetic gradient porous cage with a micro-structure for enhancing mechanical properties and accelerating osseointegration in spinal fusion.

Objectives: Spinal fusion is a widely employed treatment of patients with degenerative disc disease, in which a cage is used to replace the disc for spinal fusion. But it often fails for insufficient mechanical strength and poor osseointegration. Here, we designed a polyether-ether-ketone (PEEK)/tantalum (Ta) composite cage with a biomimetic gradient porous micro-structure, simultaneously enhancing mechanical properties and accelerating osseointegration in spinal fusion. Materials and methods: In the study, based on the mechanical performances of PEEK and osteogenic potential of Ta, and the three-dimensional (3D) structures of cuttlebone and vertebra, the cages were respectively 3D printed by pure PEEK, PEEK with 5 wt% Ta (PEEK/Ta-5), PEEK with 10 wt% Ta (PEEK/Ta-10) and PEEK with 15 wt% Ta (PEEK/Ta-15), then verified in vitro and in sheep cervical fusion model systematically. Results: Vertebral Gyroid structure PEEK/Ta-15 cage exhibited superior mechanical properties than Cuttlebone-like structure PEEK/Ta-15 cage, closer to the cervical vertebra. Furthermore, PEEK/Ta-15 cage with higher Ta microparticles in PEEK provided a biomimetic gradient porous micro-structure with higher surface energy, guiding cell biological behavior, promoting new bone penetration, and accelerating osseointegration in vivo. Conclusion: In conclusion, the study designed a biomimetic gradient porous cage with a micro-structure for enhancing mechanical properties, accelerating osseointegration and forming an anatomical lock in the fusion segment through composites, mechanical efficiency, surface extension, and pores.

PPM1D exerts its oncogenic properties in human pancreatic cancer through multiple mechanisms.

Protein phosphatase, Mg(2+)/Mn(2+) dependent, 1D (PPM1D) is emerging as an oncogene by virtue of its negative control on several tumor suppressor pathways. However, the clinical significance of PPM1D in pancreatic cancer (PC) has not been defined. In this study, we determined PPM1D expression in human PC tissues and cell lines and their irrespective noncancerous controls. We subsequently investigated the functional role of PPM1D in the migration, invasion, and apoptosis of MIA PaCa-2 and PANC-1 PC cells in vitro and explored the signaling pathways involved. Furthermore, we examined the role of PPM1D in PC tumorigenesis in vivo. Our results showed that PPM1D is overexpressed in human PC tissues and cell lines and significantly correlated with tumor growth and metastasis. PPM1D promotes PC cell migration and invasion via potentiation of the Wnt/ß-catenin pathway through downregulation of apoptosis-stimulating of p53 protein 2 (ASPP2). In contrast to PPM1D, our results showed that ASPP2 is downregulated in PC tissues. Additionally, PPM1D suppresses PC cell apoptosis via inhibition of the p38 MAPK/p53 pathway through both dephosphorylation of p38 MAPK and downregulation of ASPP2. Furthermore, PPM1D promotes PC tumor growth in vivo. Our results demonstrated that PPM1D is an oncogene in PC.

New endoscopic thyroidectomy with the transareola single-site approach: a comparison with the bilateral areolar approach.

PURPOSE: We developed the transareola single-site approach (TASSA) for less invasive endoscopic thyroidectomy to avoid scars on exposed areas. Here, we report our experience with the TASSA technique in treatment of benign thyroid tumors and evaluate its feasibility through comparison with the bilateral areolar approach (BAA). METHODS: From September 2009 to December 2011, 129 patients with benign thyroid tumors were enrolled in the study. Of these patients, 51 patients underwent endoscopic thyroidectomy by TASSA and 78 patients by BAA. The TASSA technique was performed using one 10 mm trocar and one 5 mm trocar through circumareolar incisions using conventional endoscopic instruments. The BAA procedure was performed using one 10 mm trocar and two 5 mm trocars through bilateral circumareolar incisions. RESULTS: Comparing TASSA with BAA, there were significant differences in the mean operative time (141.96 ± 19.85 vs. 98.14 ± 14.15 min) for lobectomy (P<0.05) and in the subcutaneous dissection area (101.00 ± 6.33 vs. 132.51 ± 5.25 cm, P<0.05). However, there were no significant differences in the duration of hospitalization, amount of drainage, occurrence of postoperative complications, and postoperative pain. All the patients were satisfied with the cosmetic result in the 2 groups. CONCLUSIONS: Endoscopic thyroidectomy using the TASSA procedure is feasible and safe, and affords the advantages of minimal invasiveness and excellent cosmesis results compared with other approaches including BAA. The 2 procedures are technically more challenging procedures, which may become alternative procedures for treatment of patients with benign thyroid tumors, especially those with strong desire for cervical cosmesis.

Effect of a high-fat diet in development of colonic adenoma in an animal model.

AIM: To investigate the effect of a high-fat diet in the formation of the precursors of colorectal cancer using an animal model. METHODS: Wistar rats were divided into two groups that were fed either a high-fat diet (HFD) or a normal-fat diet (ND), and 1,2-dimethylhydrazine was administered at a dose of 40 mg/kg for 10 wk. The body weight/liver weight/epididymal fat weight were recorded after rats were sacrificed, and the formation of colonic adenoma was also observed. The levels of insulin, leptin, tumor necrosis factor (TNF)-α, insulin-like growth factor (IGF)-1 and triglycerides were determined by enzyme-linked immunosorbent assay in order to compare the altered levels of biochemical indices and inflammatory cytokines in the serum between rats fed an ND and HFD. Cell proliferation activity (Ki-67) was determined by immunohistochemical analysis. Western blot and immunofluorescence staining were used to examine the expression of proliferating cell nuclear antigen (PCNA), cyclooxygenase (COX)-2, cyclin D1, ß-catenin and nuclear factor (NF)-κB proteins in the adenoma and comparative control tissues. RESULTS: The number of colonic adenomas and the colonic epithelial Ki-67 were significantly higher in the HFD group than in the ND group. The HFD group also had increased body weight, liver weight and epididymal fat weight, which were associated with increased levels of serum insulin, leptin, TNF-α, IGF-1 and triglycerides. HFD induced upregulation of PCNA, COX-2, cyclin D1, ß-catenin and NF-κB proteins, as revealed by Western blot and immunofluorescence staining. CONCLUSION: HFD promotes the formation of colonic adenoma through inflammation, metabolic abnormalities, and increases cell cycle progression.