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Cortical Bone Thickness (cortical + bone_thickness)
Selected AbstractsOsteoblast-Specific Targeting of Soluble Colony-Stimulating Factor-1 Increases Cortical Bone Thickness in Mice,,JOURNAL OF BONE AND MINERAL RESEARCH, Issue 8 2003SL Abboud Abstract The soluble and membrane-bound forms of CSF-1 are synthesized by osteoblasts and stromal cells in the bone microenvironment. Transgenic mice, generated to selectively express sCSF-1 in bone, showed increased cortical thickness in the femoral diaphysis caused by new bone formation along the endosteal surface. The ability of sCSF-1 to enhance bone cell activity in vivo is potentially relevant for increasing cortical bone in a variety of disorders. Introduction: The soluble form of colony-stimulating factor-1 (sCSF-1) and the membrane-bound form of CSF-1 (mCSF-1) have been shown to support osteoclastogenesis in vitro; however, the effect of each peptide on bone remodeling in vivo is unclear. To determine the effect of sCSF-1, selectively expressed in bone, the skeletal phenotype of transgenic mice harboring the human sCSF-1 cDNA under the control of the osteocalcin promoter was assessed. Methods: At 5 and 14 weeks, mice were analyzed for CSF-1 protein levels, weighed, and X-rayed, and femurs were removed for peripheral quantitative computed tomography, histology, and histomorphometry. Results: High levels of human sCSF-1 were detected in bone extracts and, to a lesser extent, in plasma. Adult transgenic mice showed normal body weight and increased circulating monocytic cells. At 5 weeks, the femoral diaphysis was similar in CSF-1T and wt/wt littermates. However, by 14 weeks, the femoral diaphysis in CSF-1T mice showed increased cortical thickness and bone mineral density. In contrast to the diaphysis, the femoral metaphysis of CSF-1T mice showed normal cancellous bone comparable with wt/wt littermates at each time point. Histological sections demonstrated increased woven bone along the endosteal surface of the diaphysis and intracortical remodeling. Fluorochrome-labeling analysis confirmed endocortical bone formation in CSF-1T, with a 3.1-fold increase in the percentage of double-labeled surfaces and a 3.6-fold increase in the bone formation rate compared with wt/wt mice. Although remodeling resulted in a slightly porous cortex, sCSF-1 preferentially stimulated endocortical bone formation, leading to increased cortical thickness. Conclusions: These findings indicate that sCSF-1 is a key determinant of bone cell activity in the corticoendosteal envelope. [source] Recombinant Human Parathyroid Hormone (1,34) [Teriparatide] Improves Both Cortical and Cancellous Bone StructureJOURNAL OF BONE AND MINERAL RESEARCH, Issue 11 2003Yebin Jiang MD Abstract Histomorphometry and ,CT of 51 paired iliac crest biopsy specimens from women treated with teriparatide revealed significant increases in cancellous bone volume, cancellous bone connectivity density, cancellous bone plate-like structure, and cortical thickness, and a reduction in marrow star volume. Introduction: We studied the ability of teriparatide (rDNA origin) injection [rhPTH(1,34), TPTD] to improve both cancellous and cortical bone in a subset of women enrolled in the Fracture Prevention Trial of postmenopausal women with osteoporosis after a mean treatment time of 19 months. This is the first report of a biopsy study after treatment with teriparatide having a sufficient number of paired biopsy samples to provide quantitative structural data. Methods: Fifty-one paired iliac crest bone biopsy specimens (placebo [n = 19], 20 ,g teriparatide [n = 18], and 40 ,g teriparatide [n = 14]) were analyzed using both two-dimensional (2D) histomorphometry and three-dimensional (3D) microcomputed tomography (,CT). Data for both teriparatide treatment groups were pooled for analysis. Results and Conclusions: By 2D histomorphometric analyses, teriparatide significantly increased cancellous bone volume (median percent change: teriparatide, 14%; placebo, ,24%; p = 0.001) and reduced marrow star volume (teriparatide, ,16%; placebo, 112%; p = 0.004). Teriparatide administration was not associated with osteomalacia or woven bone, and there were no significant changes in mineral appositional rate or wall thickness. By 3D cancellous and cortical bone structural analyses, teriparatide significantly decreased the cancellous structure model index (teriparatide, ,12%; placebo, 7%; p = 0.025), increased cancellous connectivity density (teriparatide, 19%; placebo, ,14%; p = 0.034), and increased cortical thickness (teriparatide, 22%; placebo, 3%; p = 0.012). These data show that teriparatide treatment of postmenopausal women with osteoporosis significantly increased cancellous bone volume and connectivity, improved trabecular morphology with a shift toward a more plate-like structure, and increased cortical bone thickness. These changes in cancellous and cortical bone morphology should improve biomechanical competence and are consistent with the substantially reduced incidences of vertebral and nonvertebral fractures during administration of teriparatide. [source] Daidzein but not other phytoestrogens preserves bone architecture in ovariectomized female rats in vivoJOURNAL OF CELLULAR BIOCHEMISTRY, Issue 6 2008D. Somjen Abstract Ovariectomy of immature female rats, results in significant decrease of trabecular bone volume and in cortical bone thickness. Previously, we found that estradiol-17, (E2) restored bone structure of ovariectomized (Ovx) female rats to values obtained in intact sham-operated female rats. E2 also selectively stimulated creatine kinase (CK) specific activity a hormonal-genomic activity marker. In the present study, we compared the effects of E2 and the phytoestrogens: daidzein (D), biochainin A (BA), genistein (G), carboxy-derivative of BA (cBA), and the SERM raloxifene (Ral) in Ovx, on both histological changes of bones and CK, when administered in multiple daily injections for 2.5 months. Bone from Ovx rats, showed significant disrupted architecture of the growth plate, with fewer proliferative cells and less chondroblasts. The metaphysis underneath the growth plate, contained less trabeculae but a significant increased number of adipocytes in the bone marrow. D like E2 and Ral but not G, BA, or cBA, restored the morphology of the tibiae, similar to that of control sham-operated animals; the bony trabeculeae observed in the primary spongiosa was thicker, with almost no adipocytes in bone marrow. Ovariectomy resulted also in reduced CK, which in both epiphysis and diaphysis was stimulated by all estrogenic compounds tested. In summary, only D stimulated skeletal tissues growth and differentiation as effectively as E2 or Ral, suggesting that under our experimental conditions, D is more effective in reversing menopausal changes than any of the other isolated phytoestrogens which cannot be considered as one entity. J. Cell. Biochem. 103: 1826,1832, 2007. © 2007 Wiley-Liss, Inc. [source] Quantitative radiographic changes in the mandible and the tibia in systemically loaded rats fed a low-calcium dietORAL DISEASES, Issue 5 2000Y Morimoto The combined effect of the duration of loaded physical exercise and the percentage of calcium intake on the mandible and tibia were studied in developing male rats. For the loaded exercise, rats ran on a treadmill at a rate of 12 m per min for either 1 or 2 h per day. A total of 54 4-week-old male Wistar rats were randomly assigned to one of six groups. After 4 weeks of the diet and loaded exercise, the rats were killed and their mandibles and tibia were removed. Each individual bone was assessed by radiography and the radiographs were then used for measurements of cortical thickness, bone length and bone width. All radiographic images were analyzed using a computer-based scanner image analysis system. In addition, we measured the dry weight both of the tibia and mandible. The results demonstrated that significant differences in cortical thickness, bone length, bone width, and bone weight, both of the tibia and the mandible, were detectable between the normal diet group and the low-calcium diet group. Among the normal diet groups, significant differences were found in cortical thickness, bone length, bone width, and bone weight of the tibia, whereas no significant differences in either cortical bone thickness, bone length or bone weight of the mandible were detected. In contrast, among the low-calcium diet groups, no significant differences were detected in cortical thickness, bone length, bone width or bone weight for either the tibia or the mandible. Our results suggested that systemic exercise, such as running, promote the linear dimensions and the cortical thickness of the tibia in response to local stimuli. Furthermore, sufficient calcium intake appears to be necessary to allow the effect of systemic exercise on tibial bone growth to occur. In contrast, systemic loaded exercise does not promote either bone growth or development of the mandible even under conditions of sufficient calcium intake. [source] The effects of socioeconomic status on endochondral and appositional bone growth, and acquisition of cortical bone in children from 19th century Birmingham, EnglandAMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY, Issue 3 2009Simon Mays Abstract Endochondral growth, appositional growth, and acquisition of cortical bone thickness in the femur are investigated in subadult skeletons (N = 43, dental age range birth to 12 years) from the 19th -century AD burial site of St. Martin's churchyard, Birmingham, England. Endochondral growth is monitored using diaphyseal femoral length. Appositional growth is monitored using radiographic midshaft mediolateral width and acquisition of cortical bone using combined mediolateral cortical thickness measured at the midshaft from radiographs. The methodology involves plotting these variables against dental age. Growth is compared in children of differing socioeconomic status. Higher and lower status individuals are identified in the assemblage by their burial in brick vaults in the case of the former and in earth-cut graves in the case of the latter. The relationships between bone dimensions and dental age are described using a polynomial regression procedure, and analysis of regression residuals is used to evaluate differences in bone dimension-for-dental age between the two status groups. Results show that lower socioeconomic status individuals had lower cortical thickness-for-dental age than those of higher status. This was interpreted as likely reflecting poorer nutrition in the children of lower socioeconomic backgrounds. There was no patterning with respect to socioeconomic status in femur diaphyseal length or midshaft width. The results support the idea that, for skeletal populations, growth in cortical thickness may be a more sensitive indicator of adverse conditions in childhood than growth in bone length or width. Am J Phys Anthropol, 2009. © 2009 Wiley-Liss, Inc. [source] | |||||||||||||