METHODS: The proximal tibia was resected as a single osteochondral unit during total knee replacement from patients (N = 10). The osteoarthritic chondrocytes were isolated from the osteochondral units, and characterized using reverse transcriptase-polymerase chain reaction. The isolated osteoarthritic chondrocytes were cultured and embedded in agarose, and then subjected to 10% and 20% uniaxial dynamic compression up to 8-days using a bioreactor. The morphological features and changes in the osteoarthritic chondrocytes upon compression were evaluated using scanning electron microscopy. Safranin O was used to detect the presence of cartilage matrix proteoglycan expression while quantitative analysis was conducted by measuring type VI collagen using an immunohistochemistry and fluorescence intensity assay.
FINDINGS: Gene expression analysis indicated that the isolated osteoarthritic chondrocytes expressed chondrocyte-specific markers, including BGN, CD90 and HSPG-2. Moreover, the compressed osteoarthritic chondrocytes showed a more intense and broader deposition of proteoglycan and type VI collagen than control. The expression of type VI collagen was directly proportional to the duration of compression in which 8-days compression was significantly higher than 4-days compression. The 20% compression showed significantly higher intensity compared to 10% compression in 4- and 8-days.
INTERPRETATION: The biosynthetic activity of human chondrocytes from osteoarthritic joints can be enhanced using selected compression regimes.
OBJECTIVES: The aims of this study is to investigate the capability of random walks as knee cartilage segmentation method.
METHODS: Experts would scribble on knee cartilage image to initialize random walks segmentation. Then, reproducibility of the method is assessed against manual segmentation by using Dice Similarity Index. The evaluation consists of normal cartilage and diseased cartilage sections which is divided into whole and single cartilage categories.
RESULTS: A total of 15 normal images and 10 osteoarthritic images were included. The results showed that random walks method has demonstrated high reproducibility in both normal cartilage (observer 1: 0.83±0.028 and observer 2: 0.82±0.026) and osteoarthritic cartilage (observer 1: 0.80±0.069 and observer 2: 0.83±0.029). Besides, results from both experts were found to be consistent with each other, suggesting the inter-observer variation is insignificant (Normal: P=0.21; Diseased: P=0.15).
CONCLUSION: The proposed segmentation model has overcame technical problems reported by existing semi-automated techniques and demonstrated highly reproducible and consistent results against manual segmentation method.
METHODS: 20-Plex proteins were quantified using Human Magnetic Luminex® assay (R&D Systems, USA) from plasma and SF of OA (n = 14) and non-OA (n = 14) patients. Ingenuity Pathway Analysis (IPA) software was used to predict the relationship and possible interaction of molecules pertaining to OA.
RESULTS: There were significant differences in plasma level for matrix metalloproteinase (MMP)-3, interleukin (IL)-27, IL-8, IL-4, tumour necrosis factor-alpha, MMP-1, IL-15, IL-21, IL-10, and IL-1 beta between the groups, as well as significant differences in SF level for IL-15, IL-8, vascular endothelial growth factor (VEGF), MMP-1, and IL-18. Our predictive OA model demonstrated that toll-like receptor (TLR) 2, macrophage migration inhibitory factor (MIF), TLR4 and IL-1 were the main regulators of IL-1B, IL-4, IL-8, IL-10, IL-15, IL-21, IL-27, MMP-1 and MMP-3 in the plasma system; whilst IL-1B, TLR4, IL-1, and basigin (BSG) were the regulators of IL-4, IL-8, IL-10, IL-15, IL-18, IL-21, IL-27, MMP-1, and MMP-3 in the SF system.
CONCLUSION: The elevated plasma IL-8 and SF IL-18 may be associated with the pathogenesis of OA via the activation of MMP-3.
METHODS: Osteoarthritis was induced at the right knee of sheep by complete resection of ACL and medial meniscus. Stem cells from sheep were induced to chondrogenic lineage. Test sheep received 5 mls single doses of 2 × 107 autologous PKH26-labelled ADSCs or BMSCs, while controls received basal medium. Functional recovery of the knees was evaluated via electromyography.
RESULTS: Induced ADSCs had 625, 255, 393, 908, 409, 157 and 1062 folds increases of collagen I, collagen II, aggrecan, SOX9, cartilage oligomeric protein, chondroadherin and fibromodullin compare to uninduced cells, while BMSCs had 702, 657, 321, 276, 337, 233 and 1163 respectively; p = .001. Immunocytochemistry was positive for these chondrogenic markers. 12 months post-treatment, controls scored 4 in most regions using ICRS, while the treated had 8; P = .001. Regenerated cartilages were positive to PKH26 and demonstrated the presence of condensing cartilages on haematoxylin and eosin; and Safranin O. OA degenerations caused significant amplitude shift from right to left hind limb. After treatments, controls persisted with significant decreases; while treated samples regained balance.
CONCLUSIONS: Both ADSCs and BMSCs had increased chondrogenic gene expressions using TGF-β3 and BMP-6. The treated knees had improved cartilage scores; PKH26 can provide elongated tracking, while EMG results revealed improved joint recoveries. These could be suitable therapies for osteoarthritis.