(n.) One of the protoplasmic cells which occur in the osteogenetic layer of the periosteum, and from or around which the matrix of the bone is developed; an osteoplast.
Example Sentences:
(1) Blocking the heparin-binding domains of fibronectin inhibited osteoblast attachment by 40-45%, which is complementary to inhibition results previously obtained with the RGDS tetrapeptide.
(2) Human GH did not alter basal cyclic AMP levels in mouse osteoblasts.
(3) The detailed sequence of the expression of osteoblastic genes in situ has not been fully characterized.
(4) The present data indicate the osteoblast as a direct and specific target for ipriflavone and suggest that this compound may share intracellular transducing mechanisms with other antiosteoporotic hormones such as estrogen and calcitonin.
(5) The data suggest that after spaceflight there is a strong and rapid recovery mechanism for osteoblast differentiation that is not suppressed by physiological stress.
(6) The presence of alkaline phosphatase-positive cells forming woven bone in giant cell granulomas suggests that osteoblasts are present in the lesion.
(7) Marked declines in stainable bone-surface aluminum were associated with increases in bone formation rate and osteoblastic osteoid following deferoxamine.
(8) They were formed by budding off from the cytoplasmic projections of the osteoblastic tumor cells.
(9) In order to determine the specific action of cadmium on bone metabolism, the effect of cadmium on alkaline phosphatase activity, a marker enzyme of osteoblasts, was compared with that of other divalent heavy metal ions, i.e., zinc, manganese, lead, copper, nickel and mercury (10 microM each), using cloned osteoblast-like cells, MC3T3-E1.
(10) Osteoblast-like rat calvaria cells release specific insulin-like growth factor (IGF) carrier proteins (CPs).
(11) The osseous component consisted of immature woven bone trabeculae lined by abnormal osteoblasts with a fibroblastlike appearance.
(12) This heterogeneity of the osteoblast and odontoblast population suggests that the composition of the matrix produced by these cells also differs.
(13) ALP activity in PLF was stimulated but that of osteoblasts was inhibited under the hypoxic condition.
(14) WCM stimulated adenylate cyclase in osteoblast like cells, the dose-response curve paralleling that of hPTHrP(1-34).
(15) Sections of mitochondria from prenatal osteoblasts showed an average number of 10 granuales per mitochondrial section, whereas sections of mitochondria of postnatal osteoblasts showed only occasionally 1-2 granules per mitochondrial section.
(16) Zn was found in bone matrix, osteoblasts, osteocytes and hypertrophied chondrocytes.
(17) Gold(III) (Au(III)) up to 0.25 microM increased parathyroid hormone- and prostaglandin E2-sensitive chick osteoblast adenylate cyclase activity without affecting 5'-guanylylimidodiphosphate-stimulated enzyme activity.
(18) Biosynthesis of calcitroic acid has been demonstrated in two target cells of vitamin D, in the kidney and the osteoblastic cell line UMR-106.
(19) Cd-treated cells were well differentiated into osteoblasts morphologically, but the mineralization degree was lower than that of the controls.
(20) A monoclonal antibody (MBP 322), raised against a denatured form of a small collagenous bone protein, reacted strongly with osteoblastic cells but more moderately with alveolar bone.
Osteoclast
Definition:
(n.) A myeloplax.
(n.) An instrument for performing osteoclasis.
Example Sentences:
(1) A novel staining procedure for enumerating osteoclasts on neonatal mouse calvaria with the vital fluorescent dye acridine orange is described.
(2) Light microscopic autoradiography after labeling of the cultures with tritiated thymidine showed that both RA and 1,25-(OH)2D3 induced osteoclast differentiation from proliferating and postmitotic precursors.
(3) We have previously shown that multinucleated cells (MNC) with many features of the osteoclast phenotype form in long term human marrow cultures.
(4) Osteoclasts dissolve bone mineral by the vectorial secretion of hydrogen ion at their osseous attachment site.
(5) Superoxide dismutase (SOD) inhibited the accumulation of formazan by the isolated osteoclasts.
(6) Addition of extracellular Ca2+ (5 mM CaCl2), a potent osteoclast inhibitor, increased [Ca2+]i in all osteoclasts, but 10(-6) M salmon calcitonin (sCT) did so only in a subpopulation of osteoclasts.
(7) Osteoclasts were isolated from the long bones of neonatal rabbits and cultured on devitalized bovine bone slices for 8, 24, 48 and 72 h with and without prostaglandin E2 (PGE2) (10(-6) M).
(8) Marrow macrophages, at various stages of in vitro maturation, also possess lysozyme mRNA but in amounts approximately two to four times lower than osteoclasts.
(9) The use of diphosphonates (bisphosphonates), a group of potent osteoclast inhibitors, is discussed in some detail.
(10) Dimethylamiloride (100 microM) inhibited bone resorption by 80% and 65% when added at t = 0 or 1 hr after osteoclast adherence, but was without effect when added at t = 3 or 6 hr.
(11) These results provide strong evidence for the osteoclastic nature of the giant cells in this variant of the MFH.
(12) Since the osteoclast plays an important role in the resorption and remodeling of bone in these middle ear diseases, the source, physiology, and local control of these cells are of prime importance in investigating the pathophysiology of these diseases.
(13) The effects of interleukin-1 did not appear to be related to osteoclast precursor proliferation, since hydroxyurea (which inhibits DNA synthesis in these cultures) had no effect on the response of calvaria calavaria increases osteoclast to interleukin-1.
(14) These results indicate that CT activates PKC in osteoclasts and that this activation, like the activation of cAMP-dependent protein kinase, leads to an inhibition of bone resorption.
(15) Quantitative time-lapse videomicroscopy showed that the CT-induced retraction of osteoclasts also involved activation of the PKC pathway and could therefore be induced by phorbol esters.
(16) Thus, the resorption-antagonizing capacities of EHDP, Cl2MDP and APD reflect metabolic inhibition, with selectivity for the osteoclast resulting from high affinity binding to bone mineral.
(17) NBT staining was detected only in osteoclasts in cultures of resorbing bones.
(18) Band 5 represents the only tartrate-resistant form and is present in bone osteoclasts and in human alveolar macrophages (AMs).
(19) These results suggest that osteoclast resorbs bone by secreting protons through vacuolar H(+)-ATPase.
(20) Hypercalcemia in this model is mediated in part by the effects of PTH-rP to increase osteoclastic bone resorption.