Peripheral Quantitative Computed Tomography in Human Long Bones: Evaluation of In Vitro and In Vivo Precision

1998 ◽  
Vol 13 (5) ◽  
pp. 871-882 ◽  
Author(s):  
Harri Sievänen ◽  
Virpi Koskue ◽  
Anne Rauhio ◽  
Pekka Kannus ◽  
Ari Heinonen ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Quantitative Computed Tomography ◽  
Peripheral Quantitative Computed Tomography ◽  
Long Bones

Long term in vitro precision of single slice peripheral Quantitative Computed Tomography (pQCT): multicenter comparison

1997 ◽  
Vol 5 (5) ◽  
pp. 375-381 ◽  
Author(s):  
G. Guglielmi ◽  
M. Cammisa ◽  
A. De Serio ◽  
G.M. Giannatempo ◽  
B. Bagni ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Quantitative Computed Tomography ◽  
Peripheral Quantitative Computed Tomography ◽  
Single Slice

Targeted disruption of nuclear factor erythroid-derived 2-like 1 in osteoblasts reduces bone size and bone formation in mice

2010 ◽  
Vol 40 (2) ◽  
pp. 100-110 ◽  
Author(s):  
Jonghyun Kim ◽  
Weirong Xing ◽  
Jon Wergedal ◽  
Jefferson Y. Chan ◽  
Subburaman Mohan
Keyword(s):  
Ascorbic Acid ◽  
Bone Formation ◽  
Osteoblast Differentiation ◽  
Quantitative Computed Tomography ◽  
Antioxidant Response ◽  
Peripheral Quantitative Computed Tomography ◽  
Bone Size ◽  
Nuclear Factor

Previous in vitro studies found that nuclear factor erythroid-derived 2-like 1 (NFE2L1) was involved in mediating ascorbic acid-induced osterix expression and osteoblast differentiation via binding to the antioxidant response element of the osterix promoter. To test the role of NFE2L1 in regulating bone formation in vivo, we disrupted NFE2L1 specifically in osteoblasts. Mice expressing Cre under the control of Col1α2 promoter were crossed with NFE2L1 loxP mice to generate Cre+ knockout (KO) and Cre− wild-type (WT) mice. Skeletal measurements by DEXA revealed 8–10% and 9–11% reduction in total body BMC and bone area in the KO mice from 3 to 8 wk of age. Peripheral quantitative computed tomography analyses found both periosteal and endosteal circumferences were reduced by 6% at the middiaphysis of the femurs from 8 wk old KO mice. Histomorphometric analyses revealed reduced bone formation was a cause for reduced bone size in the KO mice. Microcomputed tomography analysis of the metaphysis of the femur revealed that trabecular bone volume/total volume, and trabecular numbers were decreased by 30 and 53% in the NFE2L1 KO mice. Expression of osterix was decreased by 57% in the bones of NFE2L1 KO mice. In vitro nodule assay demonstrated that mineralized nodule area was reduced by 68% in the cultures of bone marrow stromal cells from NFE2L1 KO mice. Treatment of primary osteoblasts with ascorbic acid increased osterix expression by fourfold, whereas loss of NFE2L1 in osteoblasts diminished ascorbic acid stimulation of osterix expression by 50%. Our data provide the first in vivo experimental evidence that NFE2L1 produced by osteoblasts is involved in regulating osterix expression, osteoblast differentiation, and bone formation.

Effect of sex steroids on peak bone density of growing rabbits

1988 ◽  
Vol 255 (4) ◽  
pp. E416-E421 ◽  
Author(s):  
V. Gilsanz ◽  
T. F. Roe ◽  
D. T. Gibbens ◽  
E. E. Schulz ◽  
M. E. Carlson ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Neutron Activation Analysis ◽  
Bone Density ◽  
Sex Steroids ◽  
Skeletal Maturity ◽  
Quantitative Computed Tomography ◽  
Peak Bone Density ◽  
New Zealand White Rabbits

To determine the effect of sex hormones on bone density (BD) during growth, longitudinal quantitative computed tomography (QCT) measurements were obtained in growing, castrated New Zealand White rabbits following administration of normal saline, testosterone, or estrogen from 6 wk of age until the time of skeletal maturity. Vertebral QCT densities increased during growth, were highest at the time of epiphyseal closure, and were significantly greater (P less than 0.001) in hormone-treated animals. In vivo QCT measurements in 12 vertebraes correlated strongly (r = 0.92) with percentage of calcium per weight assessed in vitro by neutron activation analysis.

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