Many techniques have been tested for their ability to restore cartilage defects, but several problems still remain in the complete healing of injured cartilage. In our previous study, we found that a carboxymethyl-chitin/beta-tricalcium phosphate (CM-chitin/beta-TCP) composite induced cartilage regeneration in the osteochondral defects of rabbits in vivo. We also found that CM-chitin stimulated peritoneal exudate cells (PEC) in mice and induced several kinds of inflammatory cytokines and transforming growth factor beta-1 (TGF-beta1). In this study, we examined whether CM-chitin is responsible for the induction of chondrogenesis via the production of TGF-beta1 in vitro. The murine pluripotent cell line C3H10T1/2 was maintained as a micromass culture in conditioned medium prepared from PEC stimulated with and without CM-chitin. CM-chitin-conditioned medium induced RNA expression of the chondrogenic-factor Sox9 and the matrix proteins aggrecan, Col2a1, and Comp. Their expression levels were decreased in the presence of anti-TGF-beta1 antibody. The micromass tissues cultured in CM-chitin conditioned medium at day 21 were clearly stained by Toluidine blue or Alcian blue (histological staining) and collagen II antibody (immunohistological staining), showing the expression of acidic glycosaminoglycan and type II collagen. Similar results were observed in micromass tissue stimulated with TGF-beta1 as a positive control. However, no chondrogenesis occurred when CM-chitin was added directly to a C3H10T1/2 cell culture. These results indicated that CM-chitin is a potent inducer of chondrogenesis via the induction of TGF-beta1 in immune cells.
Background & Aims: Various insoles have been developed, but little objective evaluation of their effectiveness has been conducted. We investigated the effect of insoles supporting the cuboid bone and anterior part of the calcaneus in healthy individuals. Methods: The subjects included 18 healthy males and females. They walked in standardized shoes with a flat insole (hereinafter, FI, a flat insole made of polyurethane without an arched shape on the surface) and a carbon fiber insole (hereinafter, CFI, made of carbon and supporting the cuboid and anterior part of the calcaneus). We used a three-dimensional motion analysis device and a force plate to analyze gait and quantitatively compared the effect of CFI. Results: The CFI reduced ankle power without reducing walking ability. In particular, with regard to the left-right difference in ankle joint sagittal plane power, we found that when the left-right difference was large, the use of CFI reduced the left-right difference in power.
Conclusion:The burden on the muscles of the lower limbs on one side is reduced, and sports performance, including walking, can be maintained.
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