Estrogen Modulates Cartilage and Subchondral Bone Remodeling in an Ovariectomized Rat Model of Postmenopausal Osteoarthritis.

BACKGROUND Estrogen levels regulate changes in osteoarthritis (OA) by inhibiting degradation of the extracellular matrix. Recent in vitro studies have also shown the role of microRNA-140-5p (miR-140-5p). This study aimed to investigate the role of estrogen deficiency, selective modulation of expression of the estrogen receptor (ER), and expression of miR-140-5p in cartilage and subchondral bone remodeling in an ovariectomized rat model of postmenopausal OA.

Isolation and characterization of human mesenchymal stem cells derived from synovial fluid by magnetic-activated cell sorting (MACS).

Mesenchymal stem cells (MSCs) are the primary source of cells used for cell-based therapy in tissue engineering. MSCs are found in synovial fluid, a source that could be conveniently used for cartilage tissue engineering. However, the purification and characterization of SF-MSCs has been poorly documented in the literature.

Femoral footprint variation of the posterolateral bundle of the anterior cruciate ligament and double-bundle reconstruction.

Background: The study is aimed to observe the range of variation of the ACL PLB femoral footprint and investigate countermeasures for accurate femoral bone tunnel placement during double-bundle ACL reconstruction.

Methods: The femoral insertions of the anteromedial bundle (AMB) and PLB of the ACL were dissected in 30 male cadaveric knees. The ACL footprint on the lateral intercondylar wall (LIW) was observed, and the shape of the LIW, the resident ridge, the angle between the ACL long axis and femoral axis (AA), and the vertical distance from the center of the PLB to the lowest cartilage border of the LIW (PD) were measured.

In vitro study of nano-HA/PLLA composite scaffold for rabbit BMSC differentiation under TGF-β1 induction.

The aim of this study is to investigate the effects of differentiation of rabbit bone marrow mesenchymal stem cells (rBMSCs) into chondrocytes induced by transforming growth factor-beta1 (TCP-β1) composite poly-1actide-co-glycolic acid/nano-hydroxyapatite (PLLA/nano-HA) to the construction of biomimetic artificial cartilage in vitro. In the low-temperature extrusion preparation of PLLA/nano-HA composite porous scaffolds, rBMSCs were isolated and cultured to third generation in vitro, induced by TGF-β1-contained special inducing system into chondrocytes, 14 d later, identified by toluidine blue and type II collagen immunohistochemistry staining, and then the differential chondrocytes composite into the PLLA/nano-HA composite porous scaffolds, using scanning electron microscopy (SEM) to observe the growth conditions and cell attachment on the composite in the 7th,14th, and 21st day and to gather cells on composite in the 7th, 14th, and 21st day of cell. RT-PCR is used to detect the expression of aggrecan (Col2A1 in mRNA) and Western blot for detection of the expression of type II collagen of the attached cells.

Performance test of Nano-HA/PLLA composites for interface fixation.

Objective: By in situ polymerization of poly-L-lactic acid (PLLA) and nano-hydroxyapatite (Nano-HA), and finding the best proportion of composite, so as to get ideal interface fixation material.

Methods: According to a certain ratio (the mass fraction of Nano-HA, respectively, is 0%, 10%, 20%, 30% and 40%), composite PLLA and Nano-HA by in situ polymerization, and test the performance of this kind of new type of interface fixation such as, bending strength,compressive strength, elastic modulus, scanning electron microscopy (SEM) and degradation experiments in vitro. Then observe its mechanical properties, microstructure, the dispersion of Nano-HA in the PLLA and degradation rate of composite materials.

Arthroscopic findings in the recurrent anterior instability of the shoulder.

Background: A recurrent anterior shoulder dislocation consists of a variety of lesion types.

Objectives: To evaluate the pathological classification of recurrent anterior dislocation of the shoulder joint under arthroscopy.

Methods: Thirty-one patients with recurrent anterior shoulder dislocation were inspected by arthroscopy, including 23 males and 8 females, with a mean age of 35.

Application of a computerised navigation technique to assist arthroscopic anterior cruciate ligament reconstruction.

Purpose: Based on biomechanical cadaver studies, anatomical double-bundle reconstruction of the anterior cruciate ligament (ACL) was introduced to achieve better stability in the knee, particularly in respect of rotatory loads. Previously, the success of ACL reconstruction was believed to be mainly dependent on correct positioning of the graft, irrespective of the number of bundles for which computer-assisted surgery was developed to avoid malpositioning of the tunnel. The aim of this study was to compare rotational and translational stability after computer-navigated standard single-bundle and anatomical double-bundle ACL reconstruction.

An experimental study on the application of radionuclide imaging in repairing bone defects.

Objective: In order to study the ability of nano-hydroxyapatite artificial bone in repair of large segmental bone defect and to evaluate the value of radionuclide bone imaging in monitoring the bone's repairing in the bone defect.

Methods: The animal model of bone defect was made on the bilateral radius of 24 (New repaired with HA artificial bone) with 12 rabbits in each group. The ability of bone defect repair was evaluated by using radionuclide bone imaging at 2， 4， 8 and 12 weeks postoperatively.

Gene expression profile of the synovium and cartilage in a chronic arthritis rat model.

Background: Primary osteoarthritis (OA) is a polygenic disease. To investigate the gene expression profile of cartilage and synovium from osteoarthritis and healthy rats using cDNA microarray is beneficial to recognize the pathogenesis of osteoarthritis and provide evidence for gene therapy of osteoarthritis.

Objective: The present study aimed to investigate the gene expression profile of the cartilage and synovium of chronic arthritis and healthy rats through cDNA microarray assay, and identify the differentially expressed genes.

Experimental study of nano-hydroxyapatite/recombinant human bone morphogenetic protein-2 composite artificial bone.

Objective: To investigate the repairing ability of nano-hydroxyapatite/recombinant human bone morphogenetic protein-2 (Nano-HA/rhBMP-2) composite artificial bone for bone defect and to provide evidence for its application in clinical repair of bone defect.

Methods: The animal model of bone defect was made on unilateral radius of 90 New Zealand white rabbits, which were randomly divided into experimental group (group A, bone defect was repaired with Nano-HA/rhBMP-2 composite artificial bone), control group (group B, bone defect was repaired with Nano-HA artificial bone), and blank group (group C, bone defect was unrepaired). The repairing ability for bone defect was evaluated by gross observation, X-ray examination, scanning electron microscope, radionuclide bone imaging and biomechanical analysis at 4(th), 8(th), and 12th week postoperatively.