Bone remodeling, the fundamental process for bone renewal, is targeted by treatments of osteoporosis to correct the imbalance between bone resorption and bone formation and reduce the risk of fractures and associated clinical consequences. Currently available therapeutics affect bone resorption and bone formation in the same direction and either decrease (inhibitors of bone resorption) or incre...

The objective of this study was to investigate the role of the serine-threonine kinase mitogen-activated protein kinase 2 (MK2) in bone homeostasis. Primary bone cell cultures from MK2(+/+) and MK2(-/-) mice were assessed for osteoclast and osteoblast differentiation, bone resorption, and gene expression. Bone architecture of MK2(+/+) and MK2(-/-) mice was investigated by micro-computed tomogra...

A monocyte-derived factor with IL-1-like properties has recently been shown to cause resorption of bone in organ culture. We have investigated the action of IL-1 on disaggregated populations of osteoclasts, incubated alone or in the presence of osteoblastic cells, in an attempt to identify the target cell for IL-1 in bone, and to elucidate the mechanism by which IL-1 induces osteoclastic resorp...

Osteoclasts, the principal cells mediating bone resorption, are believed to increase their size, number, and resorbing activity in response to parathyroid hormone (PTH) through mechanisms dependent upon the fusion of specific mononuclear precursor cells into either new or existing multinucleated osteoclasts. To address the question of whether these actions of PTH are dependent on the replicatio...

OBJECTIVE Re-implantation of autologous skull bone has been known to be difficult because of its propensity for resorption. Moreover, the structural characteristics of the area of the defect cannot tolerate physiologic loading, which is an important factor for graft healing. This paper describes our experiences and results with cranioplasty following decompressive craniectomy using autologous b...

BACKGROUND Normal osteoclasts resorb bone by secretion of acid and proteases. Recent studies of patients with loss of function mutations affecting either of these processes have indicated a divergence in osteoclastic phenotypes. These difference in osteoclast phenotypes may directly or indirectly have secondary effects on bone remodeling, a process which is of importance for the pathogenesis of...

The humoral hypercalcemia of malignancy (HHM) is caused by tumor cells that release a circulating factor which stimulates osteoclastic bone resorption. Recently, it has been reported that tumors associated with HHM contain factors that stimulate renal and bone cell adenylate cyclase. The activity was inhibited by parathyroid hormone (PTH) antagonists, and this led to the hypothesis that hyperca...

Chronic arthritis typically leads to loss of periarticular bone, which results from an imbalance between bone formation and bone resorption. Recent research has focused on the role of osteoclastogenesis and bone resorption in arthritis. Bone resorption cannot be observed isolated, however, since it is closely linked to bone formation and altered bone formation may also affect inflammatory bone ...

Background Craniectomies and cranioplasty are common neurosurgical procedures performed after brain trauma, ischemia, tumor resection, or infection. Post-cranioplasty autologous bone flap resorption may occur in patients after delayed cranial reconstruction. The occurrence is usually low when bone flaps are stored in subcutaneous abdominal tissue. We report a unique case of post-cranioplasty cr...

OBJECTIVE Wear particle induced bone resorption is thought to be one of the mechanisms that contribute to implant loosening. It has previously been shown that macrophages, in response to polymethylmethacrylate (PMMA) particles, differentiate into bone resorbing osteoclasts, and that this process is inhibited by a bisphosphonate, etidronate (EHDP). The aim of this study was to determine whether ...