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  • Electronic Resource  (4)
  • Bone  (1)
  • HLA  (1)
  • Incidence  (1)
  • Key words:Bone mineral density – Osteoporosis – TGF-β  (1)
  • 1
    Electronic Resource
    Electronic Resource
    Springer
    Osteoporosis international 9 (1999), S. 398-404 
    ISSN: 1433-2965
    Keywords: Key words:Bone mineral density – Osteoporosis – TGF-β
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract: Osteoporosis is a major public health problem characterized by low bone mineral density (BMD) that presently has no biochemical test useful for its diagnosis. The cytokine TGF-β has been postulated to play a role in controlling bone density by regulating the fine balance between bone matrix deposition by osteoblasts and its resorption by osteoclasts. We explored whether measurement of serum levels of different TGF-β isoforms could be useful as a clinical tool in osteoporosis. We measured the concentration of TGF-β1 antigen using the BDA19 capture sandwich enzyme-linked immunosorbent assay (ELISA), TGF-β2 antigen concentration using a Quantikine sandwich ELISA kit and TGF-β3 antigen concentration using a modified version of the TGF-β1 Quantikine sandwich ELISA kit. Subjects were 41 women with osteoporosis (with nontraumatic vertebral fracture or lumbar spine BMD Z-score 〈−1.5 SD) and a total of 199 control women from different sources. Serum concentrations of TGF-β1 and TGF-β2 were similar in all groups. However, detectable levels of TGF-β3 (〉0.2 ng/ml) were found in 35 of 41 patients with osteoporosis (median 7.2 (5.2–8.9) ng/ml) compared with 11 of 36 controls or 24 of 89 healthy women of unknown bone density. Differences among the groups could not be accounted for by age, weight, medications, use of hormone replacement therapy or the presence of osteoarthritis. Using the optimal cut-off of ≥2 ng/ml, the test was able to detect an individual with low spine BMD (Z-score 〈−1.5) with a sensitivity of 84% and a specificity of 53%, with similar results for the femoral neck. The odds ratio for osteoporosis associated with a positive test at this level was 5.93 (95% CI 2.41–11.59), and 4.1 (95% CI 1.66–10.11) using the WHO cut-off of T-score 〈−2.5. Serum TGF-β3 concentration is raised in osteoporotic women and the test appears to have potential as a marker for osteoporosis. The underlying mechanisms and the relationships between TGF-β3 and bone turnover and fractures remain to be explored.
    Type of Medium: Electronic Resource
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  • 2
    ISSN: 1433-2965
    Keywords: Incidence ; Morphometry ; Prevalence ; Sensitivity ; Specificity ; Vertebral fracture
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract The absence of specific criteria for the definition of vertebral fracture has major implications for assessing the apparent prevalence and incidence of vertebral deformity. Also, little is known of the effect of using different criteria for new vertebral fractures in clinical studies. We therefore developed radiological criteria for vertebral fracture in women for assessing both the prevalence and the incidence of vertebral osteoporosis in population and in prospective studies and compared these with several other published methods. Normal ranges for vertebral shape were obtained from radiographs in 100 women aged 45–50 years. These included ranges for the ratios of anterior/posterior, central/posterior and posterior/predicted posterior vertebral heights from T4 to L5. The predicted posterior height was calculated from adjacent vertebrae. In contrast to other methods, our definition of fracture required the fulfilment of two criteria at each vertebral site, and was associated with a lower apparent prevalence of fracture in the control women due to a lower false positive rate. The prevalence and incidence of vertebral deformity using different criteria were then compared in a series of women with skeletal metastases from breast cancer in whom radiographs were obtained 6 months apart. The prevalence of vertebral deformity and the specificity for deformity varied markedly with differing criteria. Using a cut-off of 3 standard deviations the prevalence of vertebral deformity in the women with breast cancer was 46%. Using other methods, the prevalences of deformity ranged from 33% to 74%. Over a 6-month interval 25% of patients with breast cancer sustained 61 deformities using our method, of which only 8% resulted from errors in reproducibility. The number of patients sustaining new deformities was increased twofold when assessed by other methods (45%–53%), but errors of reproducibility may have accounted for 21% of the new deformities. The magnitude and distribution of these errors have important implications for the apparent therapeutic efficacy of agents in clinical trials of osteoporosis. The rapid semi-automated technique for assessing vertebral deformities on lateral spine radiographs that we have developed has a high specificity, and reduces the impact of errors of reproducibility on estimates of prevalence and incidence. The method should prove a value in assessing vertebral deformity both in population studies and in prospective clinical trials.
    Type of Medium: Electronic Resource
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  • 3
    ISSN: 1434-9949
    Keywords: Pyridinium Crosslinks ; Steroids ; Bone
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Bone loss is a feature of RA, but the exact mechanisms involved are not clear. The collagen crosslinks deoxypyridinoline (DPYR) and pyridinoline (PYR) are specific indices of ‘mature’ collagen breakdown and reflect increased bone turnover. The aims of the study were to examine crosslink levels in RA and their association with disease activity and the effect of steroids. Urinary crosslinks corrected for creatinine were measured on morning fasting samples by HPLC in 70 postmenopausal women with rheumatoid arthritis (RA) aged 45–65 and compared with 169 postmenopausal healthy age-matched controls from the population. Mean levels of PYR were significantly higher in RA cases than in controls (52.4 versus 37.5 nmols/mmolCr) although mean levels of DPYR did not differ significantly. A weak correlation was found with ESR and PYR (r=0.35) but not with other markers of disease activity. Thirteen of the RA cases were current steroid users and their levels of DPYR and PYR even with low doses, were significantly elevated above those of non-users, ex-users and controls. The finding of raised urinary PYR but not the bone specific DPYR in nonsteroid using RA cases suggests that the increased collagen breakdown does not primarily come from bone but from other sources such as cartilage and synovium. The large increases in collagen excretion in low dose steroid users, may reflect the higher risk of osteoporosis in this group.
    Type of Medium: Electronic Resource
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  • 4
    ISSN: 1434-9949
    Keywords: Rheumatoid Arthritis ; Ankylosing Spondylitis ; Testosterone ; HLA
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary A crosssectional study of testosterone levels in 276 males was undertaken. Of these 87 were RA patients, 48 males with AS and 141 were healthy controls. Free and serum testosterone levels were significantly lower in the RA males than in either the AS group or the healthy controls (p 〈 0.001). This difference was unaffected by age. No differences were seen in testosterone levels between DR1 or DR4 RA patients compared to those without these antigens. No evidence of hyperandrogenicity was seen in the AS group. The finding that males with RA have lower androgen levels than both normal controls and a disease group with inflammatory spondarthritis supports the hypothesis that male sex hormones may be a protective factor against the development of RA.
    Type of Medium: Electronic Resource
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