Effect of bone marrow mesenchymal stem cell transplantation combined with lugua polypeptide injection on osteoarthritis in rabbit knee joint.

PURPOSE: This study aimed to elucidate the effect of bone marrow mesenchymal stem cell (BMSC) transplantation combined with the administration of Lugua polypeptide injection into the knee joint cavity to treat knee osteoarthritis (KOA) in rabbits. MATERIAL AND METHODS: Sixty white New Zealand rabbits were randomly divided into the blank, model, Lugua polypeptide, BMSC, and combined (Lugua polypeptide plus BMSC) groups, with 12 rabbits in each group. The mRNA and protein expression levels of cyclin D1, bcl-2, TIMP-1, p21, caspase-3, Bax, MMP-1, MMP-13, TLR-4, and NF-κB p65 in chondrocytes, and levels of IL-1, NO, TNF-α, and IL-6 in the synovial fluid were compared. RESULTS: The severity of cartilage damage in the combined group was significantly less (P <0.01). Compared to the MG, the mRNA and protein expression levels of cyclin D1, bcl-2 and TIMP-1 in chondrocytes of the three other groups were significantly increased, while those of p21, caspase-3, Bax, MMP-1, MMP-13, TLR-4, and NF-κB p65 in the chondrocytes and levels of IL-1, NO, TNF-α, and IL-6 in the synovial fluid of the three other groups were significantly reduced (P <0.05). The aforementioned indicators in the combined group were significantly better than those of the Lugua polypeptide and BMSCs groups (P <0.05). CONCLUSIONS: BMSC transplantation combined with Lugua polypeptide injection may improve KOA-related cartilage tissue damage in rabbits.

Patient-specific geometrical modeling of orthopedic structures with high efficiency and accuracy for finite element modeling and 3D printing.

We improved the geometrical modeling procedure for fast and accurate reconstruction of orthopedic structures. This procedure consists of medical image segmentation, three-dimensional geometrical reconstruction, and assignment of material properties. The patient-specific orthopedic structures reconstructed by this improved procedure can be used in the virtual surgical planning, 3D printing of real orthopedic structures and finite element analysis. A conventional modeling consists of: image segmentation, geometrical reconstruction, mesh generation, and assignment of material properties. The present study modified the conventional method to enhance software operating procedures. Patient's CT images of different bones were acquired and subsequently reconstructed to give models. The reconstruction procedures were three-dimensional image segmentation, modification of the edge length and quantity of meshes, and the assignment of material properties according to the intensity of gravy value. We compared the performance of our procedures to the conventional procedures modeling in terms of software operating time, success rate and mesh quality. Our proposed framework has the following improvements in the geometrical modeling: (1) processing time: (femur: 87.16 ± 5.90 %; pelvis: 80.16 ± 7.67 %; thoracic vertebra: 17.81 ± 4.36 %; P < 0.05); (2) least volume reduction (femur: 0.26 ± 0.06 %; pelvis: 0.70 ± 0.47, thoracic vertebra: 3.70 ± 1.75 %; P < 0.01) and (3) mesh quality in terms of aspect ratio (femur: 8.00 ± 7.38 %; pelvis: 17.70 ± 9.82 %; thoracic vertebra: 13.93 ± 9.79 %; P < 0.05) and maximum angle (femur: 4.90 ± 5.28 %; pelvis: 17.20 ± 19.29 %; thoracic vertebra: 3.86 ± 3.82 %; P < 0.05). Our proposed patient-specific geometrical modeling requires less operating time and workload, but the orthopedic structures were generated at a higher rate of success as compared with the conventional method. It is expected to benefit the surgical planning of orthopedic structures with less operating time and high accuracy of modeling.

Effects of tourism and topography on vegetation diversity in the subalpine meadows of the Dongling Mountains of Beijing, China.

Subalpine meadows in the Dongling Mountains (located at E115º26'-115º40', N40º00'-40º05') of Beijing, China are important for tourism and the provision of ecosystem services. However, because of poor management serious degradation has occurred on these subalpine meadows. The aim of this paper is to present a quantitative analysis of effects of tourism disturbance and topography on the status and diversity of montane meadow communities and to provide direction for improved management. Sixty quadrats of 2 × 2 m(2) along 10 transects were set up to collect data on site characteristics and vegetation status. The relationships between community composition and structure, species diversity, and tourism disturbance and topographic variables were analyzed by multivariate methods (TWINSPAN and CCA). The results showed that eight meadow communities were identified by TWINSPAN. Most of them were seriously degraded. The first CCA axis identified an elevation and tourism disturbance intensity gradient, which illustrated that tourism disturbance and elevation were most important factors influencing meadow types, composition and structure. Some resistant species and response species to tourism disturbance were identified and can be used as indicator species of tourism disturbance. Species richness, heterogeneity and evenness were closely related to tourism disturbance and elevation. It is concluded that tourism disturbance must be controlled to enable grassland rehabilitation to occur in the meadows. Measures of effective management of the meadows were discussed.