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  • Bone remodeling  (3)
  • Broadband ultrasound attenuation  (3)
  • 1
    Electronic Resource
    Electronic Resource
    Ultrasound measurements on os calcis: Precision and age-related changes in a normal female population (1993)
    Springer
    Osteoporosis international 3 (1993), S. 249-254 
    Details
    ISSN: 1433-2965
    Keywords: Bone mineral density ; Broadband ultrasound attenuation ; Speed of sound ; Ultrasound References
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract We performed ultrasound measurements in the calcaneus of 512 healthy women. Broadband ultrasonic attenuation (BUA) and speed of sound (SOS) were obtained with a Lunar Achilles ultrasonic instrument. Subjects studied were one group of 67 women working in our hospital (group A) and two groups which are part of two large prospective cohort studies (groups B and C). Group B consisted of 244 women aged 31–79 years randomly selected from a large insurance company, and group C consisted of 201 women aged 74–91 years randomly selected from the electoral rolls. Dual-energy X-ray absorptiometry (DXA) measurements of femoral neck and total body were performed with a Hologic QDR 2000 for group B and with a Lunar DPX Plus for group C. The in vitro precision of the Achilles, estimated by measuring a phantom daily for 45 days, was 0.84% for BUA and 0.12% for SOS. We assessed the in vivo short-term precision in 20 healthy volunteers working at the hospital, measured three times each. The coefficients of variation were 0.93% (±0.21) for BUA and 0.15% (±0.03) for SOS. The precision error was compared with the true variation, to obtain a standardized coefficient of variation. We analysed the three groups pooled together (n=512) and found for BUA an average 20% decrease and for SOS a 5% decrease between the ages of 20 and 90 years. We also performed separate analyses of subjects younger than 50 and older than 50 years, and within each 10-year age group we found that BUA was stable or slightly increased from 20 to 50 years and then decreased after 50. In contrast, SOS did not increase but decreased from the age of 20. We compared DXA measurements of the femoral neck and the total body with ultrasound measurements in groups B and C. In both groups the correlations were better with total body DXA than with femoral neck and spine DXA.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01623828
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  • 2
    Electronic Resource
    Electronic Resource
    Fluoride-induced bone changes in lambs during and after exposure to sodium fluoride (1991)
    Springer
    Osteoporosis international 2 (1991), S. 26-33 
    Details
    ISSN: 1433-2965
    Keywords: Bone fluoride content ; Bone remodeling ; Fluoride ; Histomorphometry ; Lambs
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract The evolution of bone changes induced by fluoride after the end of exposure was investigated in lambs. Sodium fluoride (NaF) was given orally at a dose of 3.5 mg/kg per day to 14 animals for 120 days. A group of 7 control and 7 treated lambs was slaughtered at the end of NaF administration (T120) and another group 120 days after the end of NaF exposure (T240). At T120, the bone fluoride content (BFC) was very significantly increased in treated animals. The histomorphometric analysis confirmed that fluoride induces an increase in bone formation (the osteoid perimeter and area were 3-fold and 4.5-fold higher respectively in treated than in control animals). The number of osteoblasts was significantly augmented. Serum osteocalcin level was twice as high in treated animals compared with controls. The bone formation rate at the tissue level (BFR) doubled after treatment, but the apposition rate (Aj.AR) was half that in the control group. The mineralization lag time (Mlt) was 120 days in treated animals compared with 42 days in controls. At T240, BFC had decreased by 50% compared with the level at T120, but it was still significantly higher than in controls. The osteoid and osteoblastic parameters were 2 and 1.3 times higher than in control animals. BFR remained significantly increased in treated animals, but Aj.AR and Mlt were similar in control and treated animals. In conclusion, after 4 months of NaF exposure fluoride induced an increase in osteoblast natality and bone formation at the tissue level, associated with a toxic effect at the individual cell level. Four months after the end of NaF exposure, positive effects on bone formation were still present but the evidence of cellular toxicity had disappeared.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01627075
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  • 3
    Electronic Resource
    Electronic Resource
    Age-related changes in os calcis ultrasonic indices: A 2-year prospective study (1995)
    Springer
    Osteoporosis international 5 (1995), S. 478-483 
    Details
    ISSN: 1433-2965
    Keywords: Aging ; Bone loss ; Bone mineral density ; Broadband ultrasound attenuation ; Speed of sound ; Stiffness index ; Ultrasound
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract We performed repeated ultrasound measurements approximately 2 years apart (average 23 months ±3 months) on the os calcis of 113 healthy postmeno-pausal women recruited from two large prospective cohort studies named OFELY and EPIDOS. Group A (from OFELY) consisted of 88 women aged 52–72 (63±5) years, randomly selected from a large insurance company, and group B (from EPIDOS) consisted of 25 women aged 75–88 (80±4) years, randomly selected from the voting lists. We obtained broadband ultrasonic attenuation (BUA) and speed of sound (SOS) measurements, as well as the Stiffness index, with a Lunar Achilles ultrasound machine. We performed dual energy X-ray absorptiometry (DXA) measurements of femoral neck bone mineral density (neck BMD) with a Hologic QDR 2000 for group A and with a Lunar DPX Plus for group B. The decrease that we observed over 2 years was on average ±1 SD: −1.01±4.6 dB/MHz (p=0.02) for BUA (which is approximately equal to the long-term precision error in vitro), −11.3±9.2 m/s (p=0.0001) for SOS (approximately 5 times the precision error), −3.8±4.2 %YA (p=0.0001) for Stiffness (2.5 times the precision error) and −0.01±0.03 g/cm2 (p=0.0001) for neck BMD (approximately equal to the precision error). In terms of percentage change this represents: −1.0%±4.3% for BUA, −0.8%±0.6% for SOS and −1.85%±4.4% for neck BMD. At the individual level, most SOS and Stiffness values were consistent with a decrease, whereas BUA and neck BMD values were spread out above and below the zero line of no change. The decreases in SOS and Stiffness were significantly larger in the early postmenopause (⩽20 years since menopause [YSM]) than in the late postmenopause (〉20 YSM). We observed a similar trend for BUA and BMD but this did not reach statistical significance. We found a weak but significant correlation between changes in ultrasound variables and changes in neck BMD. However, the 2-year changes observed in SOS were not significantly correlated with changes in BUA. This study suggests that the heel ultrasound measurements of SOS and Stiffness are valuable indices of postmenopausal bone loss, and could be used for follow-up in therapeutic trials.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01626612
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  • 4
    Electronic Resource
    Electronic Resource
    Mean wall thickness and formation periods of trabecular bone packets in corticosteroid-induced osteoporosis (1983)
    Springer
    Calcified tissue international 35 (1983), S. 410-417 
    Details
    ISSN: 1432-0827
    Keywords: Bone remodeling ; Histomorphometry ; Corticosteroid therapy ; Osteoporosis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Summary We have compared the mean wall thickness (MWT) and active formation periods (sigmaf(A)) of trabecular bone packets in iliac crest biopsies from 20 patients (7 male, 13 female) with corticosteroid-induced osteoporosis (CS-OP) and 20 age- and sex-matched controls. The trabecular bone volume (TBV) of the CS-OP patients (9.6%±2.2% [SD]) was significantly reduced compared to controls (19.3%±5.1%). The MWT of CS-OP patients (32.7±4.3 µm) was also significantly lower than the control value (48.0±6.2 µm). There was a positive correlation between MWT and TBV in both groups. The mineralization rate (M) of the CS-OP patients (0.54±0.25 µm/day) was within the normal range, and since there was no increase in osteoid seam thickness, so therefore was the osteoblastic appositional rate (OAR). The active formation period of trabecular bone packets (sigmaf(A)=MWT/M) was significantly lower in the CS-OP patients (55.9 ± 14.4 days) than in the control group (68.1 ± 9.4 days). MWT and sigmaf(A) both decreased with age in the control group, whereas in the CS-OP group they were independent of age. We conclude that corticosteroid therapy results in a reduction of the MWT of trabecular bone packets and, consequently, of TBV. In these patients, where the OAR was normal, the reduction in MWT was apparently caused by a shortening of the lifespan of the active osteoblastic population at the basic multicellular unit (BMU) level.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02405069
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  • 5
    Electronic Resource
    Electronic Resource
    Ultrasound measurements on the os calcis in a prospective multicenter study (1994)
    Springer
    Calcified tissue international 55 (1994), S. 94-99 
    Details
    ISSN: 1432-0827
    Keywords: Broadband ultrasound attenuation ; Speed-of-sound ; Stiffness index ; Interunit precision
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Abstract Ultrasonic assessment is a new approach to assess both quality and density. Two ultrasonic parameters are measured on the os calcis: the attenuation or broadband ultrasound attenuation (BUA) and the velocity or speed of sound (SOS). The interunit variations in vitro and in vivo of an ultrasound instrument, the Lunar AchillesR system, used in a French multicenter study named EPIDOS, were calculated and the stability of these intruments over a 12-month period was evaluated. A third parameter called “stiffness index”, calculated from the SOS and BUA, was also used in this study. The average CV in vitro for the BUA and SOS was 0.92% and 0.12%, respectively, and the average CV in vivo for the BUA, the SOS, and the stiffness index was 1.83%, 0.23%, and 1.9%, respectively. The interunit (or inter-machines) variations were calculated by a one-way analysis of variance. We detected small but significant measurement differences among centers on a phantom for both SOS (maximum significant difference 0.4%) and stiffness (maximum significant difference 3.5%) but not for BUA. Similar diffrences were found in vivo. The precision over 12 months of the interunit variations in vitro was evaluated by measuring a single phantom traveling from one center to another several times. The range of the CV for the BUA (1.54–0.51%), for the SOS (0.25–0.14%), and for the stiffness index (2.26–1.10%) are explained in part by technical failures. The variation among the five Achilles was estimated by the combined CV which was 1.42% for the BUA, 0.32% for the SOS, and 2.33% for the stiffness index. In conclusion, our findings indicate that equipment from one manufacturer appears to be consistent between machines for the BUA, but not completely for the SOS. The results for this stiffness index are necessarily influenced by both SOS and BUA. The shortterm and long-term interunit precision is good, both in vitro and in vivo. Such results provide increased confidence in multicenter clinical trials where ultrasonic data are pooled.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00297182
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  • 6
    Electronic Resource
    Electronic Resource
    Mean wall thickness and formation periods of trabecular bone packets in idiopathic osteoporosis (1981)
    Springer
    Calcified tissue international 33 (1981), S. 199-204 
    Details
    ISSN: 1432-0827
    Keywords: Bone remodeling ; Histomorphometry ; Trabecular bone ; Osteoporosis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Summary The mean wall thickness (MWT) and duration of formation periods (sigmaf) of trabecular bone packets have been measured in iliac crest biopsies following double tetracycline labeling from 9 women having primary osteoporosis, with vertebral crush fractures and reduced trabecular bone volume (TBV), and 9 age- and sex-matched controls. The MWT of the osteoporotic biopsies was significantly less than that of the controls and was negatively correlated with age in the latter. There was also a positive correlation between MWT and TBV in the controls but not in the osteoporotics. Sigmaf, in days, showed a tendency to decline with age in the control biopsies and was further decreased in the osteoporotic patients. These results suggest that a major contribution to the negative skeletal balance existing in both primary osteoporosis and physiological osteopenia is a decrease in bone formation, caused by a reduction in the life span of the osteoblastic population at the basic multicellular unit (BMU) level.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02409438
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