Notch signaling is involved in human articular chondrocytes de-differentiation during osteoarthritis.

Context: During osteoarthritis (OA), chondrocytes undergo de-differentiation, resulting in the acquisition of a fibroblast-like morphology, decreased expression of collagen type II (colII) and aggrecan, and increased expression of collagen type I (colI), metalloproteinase 13 (MMP13) and nitric oxide synthase (eNOS). Notch signaling plays a crucial role during embryogenesis. Several studies showed that Notch is expressed in adulthood.

Viable osteoblastic potential of cortical reamings from intramedullary nailing.

To analyze the effect of intramedullary reaming on fracture healing, we investigated whether or not cortical reamings contain viable bone cells. There are several tissue components contained in medullary reamings including blood, bone marrow and cortical bone. This study is focused on the cortical reamings, which are produced during reaming of the medullary cavity.

Effect of (poly)-L-lactic acid on the proliferation and differentiation of primary bone cells in vitro.

A previous study has shown bone formation around poly-L-lactic acid (PLLA) wire in vivo. However, it is still unknown how bone cells are stimulated to form bone around PLLA wire. The effect of PLLA on primary bone cells in vitro is the subject of this study.

Opposite effects of osteogenic protein and transforming growth factor beta on chondrogenesis in cultured long bone rudiments.

Osteogenic protein-1 (OP-1, also called BMP-7) is a bone morphogenetic member of the TGF-beta superfamily. In the present study, we examined the effect of recombinant human OP-1 on cartilage and bone formation in organ cultures of metatarsal long bones of mouse embryos and compared the OP-1 effects with those of human TGF-beta 1 and porcine TGF-beta 1 and beta 2. Cartilage formation was determined by measurement of longitudinal growth of whole bone rudiments during culture and by the incorporation of 35SO4 into glycosaminoglycans.

Osteoclastic invasion and mineral resorption of fetal mouse long bone rudiments are inhibited by culture under intermittent compressive force.

To study the effect of low-magnitude mechanical stimuli on mineralized matrix metabolism, fetal mouse long bone rudiments were cultured for 5d in the absence or presence of intermittent (0.3 Hz) compressive force (ICF) of 132 g/cm2. ICF treatment stimulated mineralization of the diaphyseal bone collar as well as hypertrophic cartilage, but inhibited the release of 45Ca from prelabeled rudiments.