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  • 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
    Relationship between bone fluoride content and histological evidence of calcification defects in osteoporotic women treated long term with sodium fluoride (1993)
    Springer
    Osteoporosis international 3 (1993), S. 204-208 
    Details
    ISSN: 1433-2965
    Keywords: Bone ; Bone fluoride content ; Calcification defects ; Osteoporosis ; Sodium fluoride treatment
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Fluoride treatment is used to increase bone formation and cancellous bone mass in patients suffering from postmenopausal osteoporosis with vertebral fractures. Patients submitted to similar therapeutic protocols have shown various histological responses to the treatment, some developing calcification defects and others not. In fact, the bone histological response to fluoride salts depends on the cumulative uptake of fluoride by bone. To clarify the relationship between the presence of calcification defects (identified by the presence of mottled bone and linear formation defects) and the bone fluoride content, a retrospective study was performed on 29 women with type 1 osteoporosis and treated for several months (11–24) with sodium fluoride (50 mg/day), calcium and vitamin D. Bone fluoride content always significantly increased after treatment, but it was significantly higher in patients showing calcification defects than in those having no defects. These differences between the two groups of patients were not due to differences in clinical details (no significant differences concerning age, duration of treatment, total amount of fluoride ingested, renal function) or in their bone remodelling activity. Thus, it may be hypothesized that the high bone fluoride uptake is due to different individual responses from one patient to another concerning the bioavailability of the same dose of fluoride. This is difficult to predict, except by testing the individual bioavailability of the compound to be used in each patient before starting long-term treatment.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01623677
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    Paper (German National Licenses)
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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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  • 4
    Electronic Resource
    Electronic Resource
    Trabecular and endocortical bone remodeling in postmenopausal osteoporosis: Comparison with normal postmenopausal women (1990)
    Springer
    Osteoporosis international 1 (1990), S. 41-49 
    Details
    ISSN: 1433-2965
    Keywords: Bone ; Histomorphometry ; Osteoporosis ; Osteoblasts ; Osteocalcin
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract To assess the bone turnover abnormalities which characterize postmenopausal osteoporosis with vertebral fractures (PMOp), a transiliac bone biopsy was performed after double labeling of the mineralizing front with tetracycline in 50 untreated PMOp patients who were compared with 13 healthy age-matched volunteer females. The analysis of bone remodeling and structure parameters demonstrated that PMOp is a disease affecting both the cancellous and the endocortical envelopes and characterized by increased resorption and by a marked decrease in the osteoblastic apposition rate due to a reduced duration of bone formation. This induces a decrease in the width of both individual osteons and trabeculae. In PMOp, the wide spectrum of bone turnover as compared with the controls, associated with the typical bimodal distribution of cancellous osteoid perimeter, allowed us to identify two subsets, one with normal turnover (NT) and one with high turnover (HT) representing 30% of the cases. When compared to NT, HT was characterized by increased osteoclast number, lower bone volume, thinner osteons, increased formation at the tissue-level and markedly decreased duration of formation. In HT the marked decrease in the duration of activity of osteoblasts and the markedly increased number of osteoclasts induced a greater decrease in bone volume, despite the increase of bone formation at the tissue level. These subsets could not be distinguished by any clinical or biochemical parameter except for serum bone gla protein (osteocalcin) which was significantly higher (as a group) in HT than in NT. The underlying cause for these two subsets is unknown. We conclude that PMOp affects the cancellous and the endocortical bone. Bone loss results from a wide spectrum of bone turnover abnormalities, with two distinct subsets, one with normal turnover and one with high turnover.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01880415
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    Paper (German National Licenses)
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