The clinical comparative study on high and low viscosity bone cement application in vertebroplasty.

OBJECTIVE: To investigate the clinical effect of high and low viscosity bone cement in vertebroplasty for treatment of osteoporotic vertebral compression fractures. METHODS: 40 cases of patients with osteoporotic thoracolumbar compression fractures admitted into department of orthopeadics in our hospital were reviewed. All patients were divided into high viscosity bone cement group (20 cases) and low viscosity bone cement group (20 cases). Visual Analog Score (VAS), Oswestry Dability Index (ODI), injured vertebral height restoration (Cobb Angle) and bone cement leakage rate, subsequent fracture rate of vertebrae body with or without surgical treatment were measured. RESULTS: Compared with the low viscosity bone cement group, the VAS score, ODI score and Cobb angle of high viscosity bone cement group had a statistical difference (P<0.05). The postoperative complications in high viscosity bone cement group were lower than those in low viscosity bone cement group (P<0.05). CONCLUSION: Compared with low viscosity bone cement, bone cement leakage rate reduced obviously in high viscosity bone cement with good clinical effect and prognosis in vertebroplasty for treatment of osteoporotic thoracolumbar compression fractures.

The study on biocompatibility of porous nHA/PLGA composite scaffolds for tissue engineering with rabbit chondrocytes in vitro.

OBJECTIVE: To examine the biocompatibility of a novel nanohydroxyapatite/poly[lactic-co-glycolic acid] (nHA/PLGA) composite and evaluate its feasibility as a scaffold for cartilage tissue engineering. METHODS: Chondrocytes of fetal rabbit were cultured with nHA/PLGA scaffold in vitro and the cell viability was assessed by MTT assay first. Cells adhering to nHA/PLGA scaffold were then observed by inverted microscope and scanning electron microscope (SEM). The cell cycle profile was analyzed by flow cytometry. RESULTS: The viability of the chondrocytes on the scaffold was not affected by nHA/PLGA comparing with the control group as it was shown by MTT assay. Cells on the surface and in the pores of the scaffold increased in a time-dependent manner. Results obtained from flow cytometry showed that there was no significant difference in cell cycle profiles between the coculture group and control (P > 0.05). CONCLUSION: The porous nHA/PLGA composite scaffold is a biocompatible and good kind of scaffold for cartilage tissue engineering.

Differentiation of human bone marrow precursor cells into neuronal-like cells after transplantation into canine spinal cord organotypic slice cultures.

BACKGROUND: Treatments to regenerate different tissue involving the transplantation of bone marrow derived mesenchymal precursor cells are anticipated. Using an alternative methods, in vitro organotypic slice culture method, would be useful to transplant cells and assessing the effects. This study was to determine the possibility of differentiating human bone marrow precursor cells into cells of the neuronal lineage by transplanting into canine spinal cord organotypic slice cultures. METHODS: Bone marrow aspirates were obtained from posterior superior iliac spine (PSIS) of patients that had undergone spinal fusion due to a degenerative spinal disorder. For cell imaging, mesenchymal precursor cells (MPCs) were pre-stained with PKH-26 just before transplantation to canine spinal cord slices. Canine spinal cord tissues were obtained from three adult beagle dogs. Spinal cords were cut into transverse slices of 1 mm using tissue chopper. Two slices were transferred into 6-well plate containing 3 ml DMEM with antibiotics. Prepared MPCs (1×10(4)) were transplanted into spinal cord slices. On days 0, 3, 7, 14, MPCs were observed for morphological changes and expression of neuronal markers through immunofluorescence and reverse transcription-polymerase chain reaction (RT-PCR). RESULTS: The morphological study showed: spherical cells in the control and experiment groups on day 0; and on day 3, cells in the control group had one or two thick, short processes and ones in the experiment group had three or four thin, long processes. On day 7, these variously-sized processes contacted each other in the experiment group, but showed typical spindle-shaped cells in the control group. Immunofluorescence showed that PKH-26(+) MPCs stained positive for NeuN(+) and GFAP(+) in experimental group only. Also RT-PCR showed weak expression of ß-tubulin III and GFAP. CONCLUSIONS: Human bone marrow mesenchymal precursor cells (hMPCs) have the potential to differentiate into the neuronal like cells in this canine spinal cord organotypic slice culture model. Furthermore, these findings suggested the possibility that these cells can be utilized to treat patients with spinal cord injuries.

Resveratrol inhibits interleukin 1ß-mediated inducible nitric oxide synthase expression in articular chondrocytes by activating SIRT1 and thereby suppressing nuclear factor-κB activity.

In chondrocytes, resveratrol, a natural SIRT1 activator, exerts an anti-inflammatory response via inhibition of nuclear factor kappaB (NF-κB). Given that SIRT1 inhibits the transactivation potential of NF-κB by deacetylating acetylated lysines in p65, the NF-κB subunit, we investigated the effects of resveratrol-activated SIRT1 on articular chondrocytes. We found that when chondrocytes were stimulated with interleukin 1ß (IL-1ß), the time- and dose-dependent expression of inducible nitric oxide synthase (iNOS) expression and nitric oxide (NO) production was suppressed by resveratrol. Resveratrol-activated SIRT1 mediated this suppression. SIRT1 suppressed not only the nuclear translocation of NF-κB but also the acetylation of p65. Furthermore, acetylated Lys310 in p65, which must be present for transactivation activity, was the immediate downstream target of SIRT1. Therefore, SIRT1 protects against the inflammatory response induced by IL-1ß in articular chondrocytes. Resveratrol, as an activator of SIRT1, merits consideration as a therapeutic agent in the treatment and prevention of osteoarthritis.

[Clinical study of nanometer calcium phosphate ceramic artificial bone].

OBJECTIVE: To study the clinical effects and security of nanometer ceramics artificial bone transplantation to treat the bone defect. METHODS: From March 2005 to November 2007, 32 patients (artificial bone group) with extremity bone defects applied nanometer ceramics artificial bone transplantations, included 19 males and 13 females, aged from 17 to 63 years old (averaged 31.4 years). The other 36 patients (internal fixation group) with extremity bone defects were treated by the internal fixation in the same period, included 21 males and 15 females, aged from 16 to 65 years old (averaged 32.6 years). Ca, P, B-ALP, IgG, IgA, IgM, CIC, C3, SL-2R and CD4+/CD8+ in the peripheral venous blood were measured in the 1st and 2th week and 1st, 3rd, 6th month after operation. All patients were followed up and the limb function was evaluated according to Enneking standard. RESULTS: The wounds of all patients smoothly healed after operation. Every immunological indicators had no significant difference between two groups. Serum calcium and phosphorus content did not significantly increased. Serum B-ALP of all patients were increased after operation, fell to normal levels in the internal fixation group, but remained at a relatively high level in the artificial bone group. All patients were followed-up for from 9 to 24 months (averaged 15 months). All patients get the excellent physical function. CONCLUSION: The artificial bone has no immunogenicity, no rejection,does not affect the blood calcium and phosphorus content, and has higher osteogenic activity. It is affirmed that nanometer ceramics artificial bone is used to treat the smaller bone defect on clinical.