In men aged less than 60, the association of serum and urinary levels of biochemical bone turnover markers (BTMs) and bone mineral density (BMD) is weak or not significant. After this age, higher BTM levels are correlated weakly, but significantly, with lower BMD and faster bone loss. Limited data from the cohort studies suggest that BTM measurement does not improve the prediction of fragility ...

Although hypercalcemia, osteoporosis, and increased bone turnover are associated with thyrotoxicosis, no direct effects of thyroid hormones on bone metabolism have been reported previously in organ culture. We have now demonstrated that prolonged treatment with thyroxine (T4) or triiodothyronine (T3) can directly increase bone resorption in cultured fetal rat long bones as measured by the relea...

Vitamin K2 is widely used for the treatment of osteoporosis in Japan. To understand the effects of vitamin K2 on bone mass and bone metabolism, we reviewed its effects on the development of osteopenia in rats, which characterizes models of osteoporosis. Vitamin K2 was found to attenuate the increase in bone resorption and/or maintain bone formation, reduce bone loss, protect against the loss of...

BACKGROUND Bone resorption is initiated by osteoclastic acidification of the resorption lacunae. This process is mediated by secretion of protons through the V-ATPase and chloride through the chloride antiporter ClC-7. To shed light on the intracellular signalling controlling extracellular acidification, we screened a protein kinase inhibitor library in human osteoclasts. METHODS Human osteoc...

In this paper we develop a lattice-based computational model focused on bone resorption by osteoclasts in a single cortical basic multicellular unit (BMU). Our model takes into account the interaction of osteoclasts with the bone matrix, the interaction of osteoclasts with each other, the generation of osteoclasts from a growing blood vessel, and the renewal of osteoclast nuclei by cell fusion....

Pathological bone resorption is a source of significant morbidity in diseases affecting the skeleton such as rheumatoid arthritis, periodontitis, and cancer metastasis to bone. Evidence indicates that elevated levels of inflammatory mediators such as IL-1, IL-6, and TNF-α play a role in this process by promoting the formation of bone-resorbing osteoclasts. Additionally, current studies have ide...

Bone plays a pivotal role in storing calcium and phosphate in vertebrates. This tissue is maintained by the balance of bone formation and bone resorption. Osteoblast-lineage cells, consisting of osteoblasts, osteocytes and bone lining cells, are engaged in bone formation. Bone resorption is mediated by osteoclasts. Recent research revealed that receptor activator of NF-κB (RANK)-RANK ligand (RA...

introduction: tooth avulsion is a real dental emergency. if immediate replantation is not performed, the avulsed tooth may be lost due to inflammatory or replacement resorption. this animal study aimed to evaluate the bone response to the titanium coating of the root surface as an artificial barrier, and prevention of resorption of avulsed teeth. methods and materials: this experimental study w...

Quantitative morphologic methods were used to measure the effects of feeding a low phosphorus diet to intact and thyroparathyroidectomized rats on several processes of bone mineralization and turnover. In severely hypophosphatemic animals, the matrix formation rate was decreased, the osteoid maturation rate was decreased, which indicated a delay in the onset of mineralization, the initial rate ...

In our study (Sun et al., 2006), we conclude that FSH has a direct role in causing bone loss in hypogonadal mice. Our study does not, however, imply that estrogen and testosterone are not critical regulators of bone mass. To the contrary, we assert that sex steroids regulate bone formation and bone resorption, whereas FSH directly stimulates bone resorption. Problems in interpretation can arise...