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  • Bone mineral density  (3)
  • Bone histomorphometry  (2)
  • 1
    Electronic Resource
    Electronic Resource
    Mean wall thickness of trabecular bone packets in the human iliac crest: Changes with age (1978)
    Springer
    Calcified tissue international 26 (1978), S. 13-17 
    Details
    ISSN: 1432-0827
    Keywords: Bone remodelling ; Bone histomorphometry ; Amount of bone ; Osteoporosis ; Osteopenia
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Summary The mean wall thickness (MWT) of packets of trabecular bone was measured in undecalcified iliac crest bone samples of 36 normal subjects (14 female and 22 male) under polarized light. The mean wall thickness was 49.7±8.7 μm at a mean age of 50.9 years. There existed a significant decrease of MWT with advancing age. With an appositional rate of 0.72 μm/day, the mean formation time of iliac trabecular bone packets is 69 days. The decrease of MWT with age corresponds to a decrease in bone formation at the basic multicellular unit (BMU) level with aging and can partly explain the physiological senile osteopenia.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02013227
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    Paper (German National Licenses)
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  • 2
    Electronic Resource
    Electronic Resource
    Dual-energy X-ray absorptiometry of the spine in anteroposterior and lateral projections (1994)
    Springer
    Osteoporosis international 4 (1994), S. 110-116 
    Details
    ISSN: 1433-2965
    Keywords: Bone mineral density ; Densitometry ; Dual-energy X-ray absorptiometry ; Osteoporosis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Dual-energy X-ray absorptiometry (DXA) of the lumbar spine provides an estimation of the bone mineral content (BMC) corrected by the projected area of the spine and expressed in g/cm2. This two-dimensional estimate of the bone mineral density (BMD) is influenced by the skeletal size, assessed by the subject's height. In order to obtain an estimate of the volumetric BMD, we measured BMC with a new DXA device (Sophos L-XRA) equipped with 24 detectors and a rotating arm, thus allowing scanning of the lumbar spine in both an anteroposterior (AP) projection and a lateral (LAT) projection with the patient in a supine position. Comparison between the results obtained on the third (L3) and fourth (L4) lumbar vertebrae with automatic or manual analysis showed that the best precision was obtained with the lateral measurement of L3 alone with an automatic soft tissue baseline determination. Results were expressed in g/cm2 and in g/cm3 (by dividing the g/cm2 value by the width (AP area divided by the height of the vertebra) of L3), and were compared with those obtained by conventional AP scanning of L2–4 (g/cm2). The in vivo precision error evaluated by triplicate measurements on 10 controls was 17 mg/cm2 (1.96%) and 5.2 mg/cm3 (2.31%) for LAT L3 as compared with 13 mg/cm2 (1.15%) for AP L2–4. Volumetric BMD (g/cm3) measurement, assessed in vitro on a calibrated hydroxyapatite phantom, and the absolute values obtained in normal women were similar to those obtained by quantitative computed tomography (QCT). In 39 healthy adults (27±4 years) BMD expressed in g/cm2 was correlated with height (r=0.36 for AP L2–4 andr=0.39 for LAT L3;p〈0.05 for both) but not with LAT L3 BMD expressed in g/cm3 (r=0.02; NS). The age-related bone loss between 30 and 80 years of age, derived from the normal values for 101 healthy women (age range 19–73 years) was 36% for AP L2–4, 52% for LAT L3 (g/cm2) and 60% for LAT L3 (g/cm3). In a group of 22 women with untreated postmenopausal vertebral osteoporosis (one or more non-traumatic vertebral crush fractures) the mean decrease in BMD, expressed as a percentage of the age-adjusted normal value, was more pronounced (p〈0.001) for LAT L3 BMD (−21% in g/cm2,Z-score −1.08; −22% in g/cm3,Z-score −0.94) than for AP L2–4 BMD (−9%,Z-score −0.66). We conclude that: 1) BMD measurement restricted to the vertebral body of L3 can be achieved with a low precision error with this new DXA device; 2) it allows an estimate of the volumetric density (g/cm3) which does not seem to be influenced by skeletal size; 3) lateral BMD appears to be more sensitive than conventional AP scanning for assessing age-related bone loss and should be useful in the investigation of trabecular osteoporosis.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01623234
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  • 3
    Electronic Resource
    Electronic Resource
    Gastrointestinal calcium absorption and dietary calcium load: Relationships with bone remodelling in vertebral osteoporosis (1995)
    Springer
    Osteoporosis international 5 (1995), S. 14-22 
    Details
    ISSN: 1433-2965
    Keywords: Bone histomorphometry ; Calcium-47 ; Calcium absorption ; Osteoporosis ; Vitamin D
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Patients with vertebral osteoporosis have a wide range of bone loss rates, bone remodelling rates and capacities for gastrointestinal (GI) calcium absorption. To test the hypothesis that variations in GI absorptive capacity determine rates of bone loss or remodelling, we have sought relationships betwen calcium absorption or vitamin D metabolite levels on the one hand and rates of cancellous and cortical bone loss (measured by serial quantiative computed tomography in the radius;n=25) or indices of bone remodelling in tetracycline-prelabelled transiliac biopsies (n=41) on the other, in a sequential untreated group. Calcium absorption (net and true) was measured in 18-day balances and by a two-isotope deconvolution method (fractional absorption and maximum absorption rate, MAR). There was no significant seasonal effect on any of these four measures of calcium absorption (variance ratio,F=0.52–1.61,p〉0.1) or on 1,25-dihydroxyvitamin D levels (F=0.13,p〉0.1; range 11–69 pg/ml), notwithstanding the expected seasonal effect on 25-hydroxyvitamin D levels (mean 18.7 ng/ml, zenith mid July, semi-amplitude 7.5 ng/ml;F=6.82,p〈0.01). Neither this metabolite nor 1,25-dihydroxyvitamin D correlated with any index of calcium absorption (p〉0.1). No measure of calcium absorption (or intake) had a significant relationship with radial cortical or cancellous bone loss (p all 〉0.1) but cancellous bone loss was associated with the rate of endogenous calcium excretion (r=0.50,p〈0.05). A positive relationship between 25-hydroxyvitamin D and unlabelled osteoid surface (a marker of reduced blast vigour) persisted after adjustment for season (Student'st=2.70,p〈0.01) but did not reflect 1,25-dihydroxyvitamin D levels. This study did not address the question of whether reduced GI calcium absorption has a uniform effect on bone remodelling in osteoporosis. However, variations in capacity for calcium absorption are unlikely to be responsible for the heterogeneity in bone loss and remodelling rates seen in vertebral osteoporosis.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01623653
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    Paper (German National Licenses)
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  • 4
    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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    Paper (German National Licenses)
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  • 5
    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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