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Rate of change in lumbar spine bone mineral density in women with distal forearm fracture
322
Abstracts
Bone September
groups. The controls lost bone from the LS at a rate of -0.59% per year (P
scan, biopsy with histology or at post mortem PTHrP was 5 2.6 pmol/L in 46 (Gp A) and < 2.6 pmol/L in 29 (Gp 8). Metastatic disease was present in 57 patients. (Gp A 42 (93%), Cp B 15 (50-%o). Bone m&stases were present in 25 of Gp A (54%) and 7 of Gp B (24%). Liver metastases were present in 20 of Gp A (43%) and 9 of Gp B (31%). All patients with breast Ca in Gp A (n=ll) and 2 patients with breast Ca in Gp B (n=4) had metastases in bone. Patients with malignancy of lung were more likely to have liver metastases (Gp A bone metastases 5/13, liver 7/14 and Gp B bone metastases 2/7, liver 4/7). Pyr and Dpyr are given in the table. Mean f SEM
CPA mets-ve 06.8f19.2 21.5f4.2 4.OztO.2
CPA IIwts
+ve
88.2k9.7 17.6i2.6 5.6f0.5
F’THrP secretion in HCM poorer survival, increased and Dpyr excretion.
GPB metr-ve 53.2k7.7 ll.Of3.1 5.4io.8
P8. The choice of algorithm for evaluating spine deformities from 6 point placements: use of DXA densitometw M Lund, T O’Neill, D Felsenberg, L Benevolen&ya, J Cannata, J Dequeker, C Dodenhof, J Falch, P Masaryk, H Pals, G Poor, D Reid, C Scheidt-Nave, K Weber, J Kanis, A Silman, J Reeve EPOS, Institure of Public Health, Cambridge CB2 2SR
Ref Range GPB mets+ve 92.7f15.9 7.4-34.9 21.2k3.5 1.3-15.8 4.7ko.8 1.73-3.45
patients is associated with relatively metastatic disease and elevated Pyr
Methods: Thirteen centres (Aberdeen, Berlin, Budapest Erfurt, Graz, Harrow, Heidelberg, Leuven, Moscow, Oslo, O&do, Pie&any and Rotterdam) contributed spine X-rays (T4-L4) to Berlin for blinded six-point quantitation and performed DXA of the hip and/or spine with cross-calibrated equipment (European Spine Phantom prototype). The Berlin data were evaluated in Manchester using 4 published algorithms, those of Melton and Eastell (grade 1+2 or grade 2 only, Black’s modified method with anterior adjustment and that of McCloskey and Kanisl. Results: Using logistic regression, all methods of X-ray quantitation showed statistically significant relationships (p-zO.05) between bone density and risk of deformity (any type: wedge, crush or biconcavity). For all methods, the prevalence was similar in males and females, at 21% for Melton grade 1+2, 7% for Melton grade 2 and 13% for both Black and McCloskey. In males, odds ratios per SD decrease in Bone Mineral Density (BMD) were similar for all sites, being lowest for Melton grade 1+2 (1.19-1.21 depending on site) and highest for McCloskey (1.46-1.662 In females, odds ratios were highest for trochanteric BMD, ranging from 1.46 (95% CI: 1.24, 1.72) for Melton I+2 to 1.92 (95% CI: 1.48. 2.50) for Melton 2 and 1.82 (Cl: 1.49, 2.23) for McCloskey. ’ Conclusion: On the twin criteria of high risk ratios, which give a measure of specificity, and the observed prevalences (reflecting sensitivity) ‘the M;Closkey-Kanis algdrithm showed clear advantages, suggesting that it makes better use of the inherent similarities in shape between unfractured, adjacent vertebral bodies to identify the characteristic disruption of pattern imposed by osteoporotic fracture.
P6. Bisphosphonates induce apoptosis in murk macrophrgeIike cells KM Chilton, RGG Russell, MJ Rogers Department. of Human Metabolism, CIinicaJ Biochemistry, Medical School, Beech Hill Road, University of Sheffield Sheffield Bisphosphonates are a class of anti-resorptive drugs that are widely used to treat disorders of bone metabolism in which the overactivity of bone-resorbing osteoclasts is an important feature. Although the exact molecular mechanism by which bisphosphonates inhibit osteoclasts has not been established, there are numerous reports in the literature that these drugs cause morphological changes in osteoclasts in vitro, and in osteoclasts in yivo in bisphosphonate-treated animals. These changes often involve the appearance of condensed, pyknotic and degenerating nuclei, features which are characteristic of apoptotic, rather than necrotic, cell death. We have found that treatment of the murine macrophage-like cell lines J774.2 and RAW264 with l-IOOpM alendronate for 24 hours causes marked changes in the appearance of nuclei after staining with the fluorescent DNA label DAPI. Chromatin becomes condensed around the nuclear envelope and within discrete vacuolar structures, while fluorescence staining also appears within cytoplasmic vacuoles, an effect that was not observed in untreated cells. The proportion of cells that exhibited such morphological changes was dose-dependent. The changes in nuclear morphology observed after bisphosphonate treatment are indicative of apoptosis. Since macrophages, like bone-resorbing osteoclasts, appear to be particularly sensitive to the toxic effects of bisphosphonates in vitro, this supports the recent claim (Hunhes et al, TBMR 9 5347. 1994) that bi$hosphonates induce apopt&is in ost~e&lasts. P7. Rate of change in lumbar spine bone mineral density in women with distal forearm fracture NFA Peal, AG Smith, RA Hannon, R Eastell Department of Human Metabolism and Clinical Biochemistry, Clinical Sciences Centre, Northern General Hospital, Herries Road, Sheffield In a cross-sectional study of women with distal forearm fracture we found that lumbar spine bone mineral density (LSBMD) was decreased but that there appeared to be no further decrease with ageing (BMJ, 1994;308:1543). The aim of this prospective study was to determine the rate of bone loss from the LS in these women. 66 (69%) of the original cohort, ages SO to 80 years, with distal forearm fracture were studied. They were compared to 297 age-matched women from a population-based cohort. LSBMD was measured by DXA (Lunar DPX) at baseline and after 2 years. Baseline mean LSBMD 2 score fnormalised for age and weight) was decreased in the women with distal forearm fracture (-0.37 SD units, 95% Cl -0.58 to -0.16). Baseline LS-BMD decreased with age in the controls (r=-O.29, P~.ooOl) but not in the women with distal forearm fracture (r=0.08, NS). The slopes (P=O.O09) and intercepts (P=O.O031 of this relationship differed between the two
Vol. 17, No. 3 1995:319-331
P9. Characterisation of thyroid hormone (Tsl receptors (TSR) in primary cultures of rat calvarial osteoblrsts R Bland, RL Sammons*, MC Sheppard, GR Williams Department of Medicine and *The School of Dentistry, Universify of Birmingham, Birmingham 815 2TH
I
The sites and mechanisms of T? action in bone remain unknown and controversial despite-its requirement in skeletal development and maintenance of bone turnover. T3 action is mediated by several functionally distinct TSR isoforms that preferentially bind DNA as heterodimers with retinoid X receptors (RXRl to regulate target gene expression in response to T3 activation but,also interact with vitamin D3 receptors. We previously described functional T3R and RXRs in 3 rat osteosarcoma transformed cell lines that express distinct stages of the osteoblast phenotype and have now studied 3 separate populations of primary cultures derived from neonatal rat calvarial bone and periosteum The presence of osteoblasts in each population was confirmed by basal expression of mRNAs encoding collagen Ial and ~2, osteopontin and alkaline phosphatase whilst a lack of osteocalcin mRNA expression from all cultures indicated the absence of terminally differentiated osteoblasts. Each population expressed comparable levels of T3R al, a2 and p proteins as well as RXR in Western analyses of nuclear extracts. These data represent the first characterisation of T3R expression in osteoblasts and provide evidence of their direct responsiveness to T3. Co-expression of three T3R isoforms with RXR provides for complex T3 responses in bone and the potential for multiple interactions with both retinoid and vitamin & signalling.
Abstracts
Bone September
groups. The controls lost bone from the LS at a rate of -0.59% per year (P
scan, biopsy with histology or at post mortem PTHrP was 5 2.6 pmol/L in 46 (Gp A) and < 2.6 pmol/L in 29 (Gp 8). Metastatic disease was present in 57 patients. (Gp A 42 (93%), Cp B 15 (50-%o). Bone m&stases were present in 25 of Gp A (54%) and 7 of Gp B (24%). Liver metastases were present in 20 of Gp A (43%) and 9 of Gp B (31%). All patients with breast Ca in Gp A (n=ll) and 2 patients with breast Ca in Gp B (n=4) had metastases in bone. Patients with malignancy of lung were more likely to have liver metastases (Gp A bone metastases 5/13, liver 7/14 and Gp B bone metastases 2/7, liver 4/7). Pyr and Dpyr are given in the table. Mean f SEM
CPA mets-ve 06.8f19.2 21.5f4.2 4.OztO.2
CPA IIwts
+ve
88.2k9.7 17.6i2.6 5.6f0.5
F’THrP secretion in HCM poorer survival, increased and Dpyr excretion.
GPB metr-ve 53.2k7.7 ll.Of3.1 5.4io.8
P8. The choice of algorithm for evaluating spine deformities from 6 point placements: use of DXA densitometw M Lund, T O’Neill, D Felsenberg, L Benevolen&ya, J Cannata, J Dequeker, C Dodenhof, J Falch, P Masaryk, H Pals, G Poor, D Reid, C Scheidt-Nave, K Weber, J Kanis, A Silman, J Reeve EPOS, Institure of Public Health, Cambridge CB2 2SR
Ref Range GPB mets+ve 92.7f15.9 7.4-34.9 21.2k3.5 1.3-15.8 4.7ko.8 1.73-3.45
patients is associated with relatively metastatic disease and elevated Pyr
Methods: Thirteen centres (Aberdeen, Berlin, Budapest Erfurt, Graz, Harrow, Heidelberg, Leuven, Moscow, Oslo, O&do, Pie&any and Rotterdam) contributed spine X-rays (T4-L4) to Berlin for blinded six-point quantitation and performed DXA of the hip and/or spine with cross-calibrated equipment (European Spine Phantom prototype). The Berlin data were evaluated in Manchester using 4 published algorithms, those of Melton and Eastell (grade 1+2 or grade 2 only, Black’s modified method with anterior adjustment and that of McCloskey and Kanisl. Results: Using logistic regression, all methods of X-ray quantitation showed statistically significant relationships (p-zO.05) between bone density and risk of deformity (any type: wedge, crush or biconcavity). For all methods, the prevalence was similar in males and females, at 21% for Melton grade 1+2, 7% for Melton grade 2 and 13% for both Black and McCloskey. In males, odds ratios per SD decrease in Bone Mineral Density (BMD) were similar for all sites, being lowest for Melton grade 1+2 (1.19-1.21 depending on site) and highest for McCloskey (1.46-1.662 In females, odds ratios were highest for trochanteric BMD, ranging from 1.46 (95% CI: 1.24, 1.72) for Melton I+2 to 1.92 (95% CI: 1.48. 2.50) for Melton 2 and 1.82 (Cl: 1.49, 2.23) for McCloskey. ’ Conclusion: On the twin criteria of high risk ratios, which give a measure of specificity, and the observed prevalences (reflecting sensitivity) ‘the M;Closkey-Kanis algdrithm showed clear advantages, suggesting that it makes better use of the inherent similarities in shape between unfractured, adjacent vertebral bodies to identify the characteristic disruption of pattern imposed by osteoporotic fracture.
P6. Bisphosphonates induce apoptosis in murk macrophrgeIike cells KM Chilton, RGG Russell, MJ Rogers Department. of Human Metabolism, CIinicaJ Biochemistry, Medical School, Beech Hill Road, University of Sheffield Sheffield Bisphosphonates are a class of anti-resorptive drugs that are widely used to treat disorders of bone metabolism in which the overactivity of bone-resorbing osteoclasts is an important feature. Although the exact molecular mechanism by which bisphosphonates inhibit osteoclasts has not been established, there are numerous reports in the literature that these drugs cause morphological changes in osteoclasts in vitro, and in osteoclasts in yivo in bisphosphonate-treated animals. These changes often involve the appearance of condensed, pyknotic and degenerating nuclei, features which are characteristic of apoptotic, rather than necrotic, cell death. We have found that treatment of the murine macrophage-like cell lines J774.2 and RAW264 with l-IOOpM alendronate for 24 hours causes marked changes in the appearance of nuclei after staining with the fluorescent DNA label DAPI. Chromatin becomes condensed around the nuclear envelope and within discrete vacuolar structures, while fluorescence staining also appears within cytoplasmic vacuoles, an effect that was not observed in untreated cells. The proportion of cells that exhibited such morphological changes was dose-dependent. The changes in nuclear morphology observed after bisphosphonate treatment are indicative of apoptosis. Since macrophages, like bone-resorbing osteoclasts, appear to be particularly sensitive to the toxic effects of bisphosphonates in vitro, this supports the recent claim (Hunhes et al, TBMR 9 5347. 1994) that bi$hosphonates induce apopt&is in ost~e&lasts. P7. Rate of change in lumbar spine bone mineral density in women with distal forearm fracture NFA Peal, AG Smith, RA Hannon, R Eastell Department of Human Metabolism and Clinical Biochemistry, Clinical Sciences Centre, Northern General Hospital, Herries Road, Sheffield In a cross-sectional study of women with distal forearm fracture we found that lumbar spine bone mineral density (LSBMD) was decreased but that there appeared to be no further decrease with ageing (BMJ, 1994;308:1543). The aim of this prospective study was to determine the rate of bone loss from the LS in these women. 66 (69%) of the original cohort, ages SO to 80 years, with distal forearm fracture were studied. They were compared to 297 age-matched women from a population-based cohort. LSBMD was measured by DXA (Lunar DPX) at baseline and after 2 years. Baseline mean LSBMD 2 score fnormalised for age and weight) was decreased in the women with distal forearm fracture (-0.37 SD units, 95% Cl -0.58 to -0.16). Baseline LS-BMD decreased with age in the controls (r=-O.29, P~.ooOl) but not in the women with distal forearm fracture (r=0.08, NS). The slopes (P=O.O09) and intercepts (P=O.O031 of this relationship differed between the two
Vol. 17, No. 3 1995:319-331
P9. Characterisation of thyroid hormone (Tsl receptors (TSR) in primary cultures of rat calvarial osteoblrsts R Bland, RL Sammons*, MC Sheppard, GR Williams Department of Medicine and *The School of Dentistry, Universify of Birmingham, Birmingham 815 2TH
I
The sites and mechanisms of T? action in bone remain unknown and controversial despite-its requirement in skeletal development and maintenance of bone turnover. T3 action is mediated by several functionally distinct TSR isoforms that preferentially bind DNA as heterodimers with retinoid X receptors (RXRl to regulate target gene expression in response to T3 activation but,also interact with vitamin D3 receptors. We previously described functional T3R and RXRs in 3 rat osteosarcoma transformed cell lines that express distinct stages of the osteoblast phenotype and have now studied 3 separate populations of primary cultures derived from neonatal rat calvarial bone and periosteum The presence of osteoblasts in each population was confirmed by basal expression of mRNAs encoding collagen Ial and ~2, osteopontin and alkaline phosphatase whilst a lack of osteocalcin mRNA expression from all cultures indicated the absence of terminally differentiated osteoblasts. Each population expressed comparable levels of T3R al, a2 and p proteins as well as RXR in Western analyses of nuclear extracts. These data represent the first characterisation of T3R expression in osteoblasts and provide evidence of their direct responsiveness to T3. Co-expression of three T3R isoforms with RXR provides for complex T3 responses in bone and the potential for multiple interactions with both retinoid and vitamin & signalling.