Metastatic breast cancer causes destruction of significant amounts of bone, and, although bone is the most likely site of breast cancer metastasis, little is understood about interactions between tumor cells and bone-resorbing osteoclasts. We have investigated the paracrine factors produced by breast cancer cells that are involved in increasing osteoclast activity. We have determined by immunoa...

We studied the response of biochemical markers of bone metabolism to exercise intensity in horses. Four horses were walked on a mechanical walker for one week (pre-exercise). Then they performed low-speed exercise on a high-speed treadmill in the first week and medium-speed exercise in the second week and high-speed exercise in the third week of training. We measured two indices of bone resorpt...

Polymethoxyflavonoids (PMFs) are a family of the natural compounds that mainly compise nobiletin, tangeretin, heptamethoxyflavone (HMF), and tetramethoxyflavone (TMF) in citrus fruits. PMFs have shown various biological functions, including anti-oxidative effects. We previously showed that nobiletin, tangeretin, and HMF all inhibited interleukin (IL)-1-mediated osteoclast differentiation via th...

Activated T and B lymphocytes in periodontal disease lesions express receptor activator of NF-κB ligand (RANKL), which induces osteoclastic bone resorption. The objective of this study was to evaluate the effects of anti-RANKL antibody on periodontal bone resorption in vitro and in vivo. Aggregatibacter actinomycetemcomitans outer membrane protein 29 (Omp29) and A. actinomycetemcomitans lipopol...

Bone has the capacity to alter its mass and structure to its mechanical environment. Osteocytes are the predominant bone cells and it is generally accepted that the osteocytes are the professional mechanosensors of bone. A strain-derived fluid flow through the lacuno-canalicular porosity seems to mechanically activate them, resulting in the production of signalling molecules such as nitric oxid...

In order to study the effect of calcitonin on the bone collagen metabolism in osteolathyrism, male Wistar rats were placed on 0.1% aminoacetonitrile diet for 9 days. Porcine calcitonin dissolved in gelatin was concurrently administered in a dose of 0.1 MRC U/100g body weight for 8 days and on the 9th day 0.75 MRC U/100g body weight was given 3, 2 and 1hr respectively before sacrifice. Both bone...

The function of osteoclasts (OCs), multinucleated giant cells (MGCs) of the monocytic lineage, is bone resorption. To resorb bone, OCs form podosomes. These are actin-rich adhesive structures that pattern into rings that drive OC migration and into "sealing-zones" (SZs) that confine the resorption lacuna. Although changes in actin dynamics during podosome patterning have been documented, the me...

Bone remodeling, a coupled process involving bone resorption and formation, is initiated by mechanical signals and is controlled by local and systemic factors that regulate osteoblast and osteoclast differentiation and function. An excess of resorption over formation leads to the bone loss and increased propensity to fracture that is characteristic of osteoporosis. A newly described inhibitor o...

Bisphosphonates (BPs) are drugs that act primarily to inhibit osteoclast activity and bone resorption, used in many clinical conditions associated with excessive bone resorption. Aim of this review is to investigate the effects of BPs on orthodontic tooth movement. All selected studies showed that orthodontic tooth movement is reduced after BPs administration, with not clear effect on root reso...

When the rate of bone resorption exceeds that of bone formation, destruction of bone tissue occurs, resulting in a fragile skeleton. The clinical consequences, namely osteoporosis and fragility fractures, are common and costly problems. Treatments that normalize the balance of bone turnover by inhibiting bone resorption preserve bone mass and reduce fracture risk. The discovery of receptor acti...